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Sample records for psig maximum leakage

  1. Releasable activity and maximum permissible leakage rate within a transport cask of Tehran Research Reactor fuel samples

    National Research Council Canada - National Science Library

    Rezaeian Mahdi; Kamali Jamshid; Roshanzamir Manoochehr; Moosakhani Alireza; Noori Elghar

    2015-01-01

    ... operators. Based on IAEA regulations, releasable activity and maximum permissible volumetric leakage rate within the cask containing fuel samples of Tehran Research Reactor enclosed in an irradiated capsule are calculated...

  2. Releasable activity and maximum permissible leakage rate within a transport cask of Tehran Research Reactor fuel samples

    OpenAIRE

    Rezaeian Mahdi; Kamali Jamshid; Roshanzamir Manoochehr; Moosakhani Alireza; Noori Elghar

    2015-01-01

    Containment of a transport cask during both normal and accident conditions is important to the health and safety of the public and of the operators. Based on IAEA regulations, releasable activity and maximum permissible volumetric leakage rate within the cask containing fuel samples of Tehran Research Reactor enclosed in an irradiated capsule are calculated. The contributions to the total activity from the four sources of gas, volatile, fines, and corrosion...

  3. Releasable activity and maximum permissible leakage rate within a transport cask of Tehran Research Reactor fuel samples

    Directory of Open Access Journals (Sweden)

    Rezaeian Mahdi

    2015-01-01

    Full Text Available Containment of a transport cask during both normal and accident conditions is important to the health and safety of the public and of the operators. Based on IAEA regulations, releasable activity and maximum permissible volumetric leakage rate within the cask containing fuel samples of Tehran Research Reactor enclosed in an irradiated capsule are calculated. The contributions to the total activity from the four sources of gas, volatile, fines, and corrosion products are treated separately. These calculations are necessary to identify an appropriate leak test that must be performed on the cask and the results can be utilized as the source term for dose evaluation in the safety assessment of the cask.

  4. The PSIG procedure to Persistent Scatterer Interferometry (PSI) using X-band and C-band Sentinel-1 data

    Science.gov (United States)

    Cuevas-González, María.; Devanthéry, Núria; Crosetto, Michele; Monserrat, Oriol; Crippa, Bruno

    2015-10-01

    A new approach to Persistent Scatterer Interferometry (PSI) data processing and analysis implemented in the PSI chain of the Geomatics (PSIG) Division of CTTC is used in this work. The flexibility of the PSIG procedure allowed evaluating two different processing chains of the PSIG procedure. A full PSIG procedure was implemented in the TerraSAR-X dataset while a reduced PSIG procedure was applied to the nine Sentinel-1 images available at the time of processing. The performance of the PSIG procedure is illustrated using X-band and C-band Sentinel-1 data and several examples of deformation maps covering different types of deformation phenomena are shown.

  5. The properties of the positively charged loop region in PSI-G are essential for its "spontaneous" insertion into thylakoids and rapid assembly into the photosystem I complex

    National Research Council Canada - National Science Library

    Zygadlo, Agnieszka; Robinson, Colin; Scheller, Henrik Vibe; Mant, Alexandra; Jensen, Poul Erik

    2006-01-01

    The PSI-G subunit of photosystem I (PSI) is an 11-kDa membrane protein that plays an important role in electron transport between plastocyanin and PSI and is involved in the stability of the PSI complex...

  6. Relative Roles of the fla/che PA, PD-3, and PsigD Promoters in Regulating Motility and sigD Expression in Bacillus subtilis

    Science.gov (United States)

    West, Joyce T.; Estacio, William; Márquez-Magaña, Leticia

    2000-01-01

    Three promoters have been identified as having potentially important regulatory roles in governing expression of the fla/che operon and of sigD, a gene that lies near the 3′ end of the operon. Two of these promoters, fla/che PA and PD-3, lie upstream of the >26-kb fla/che operon. The third promoter, PsigD, lies within the operon, immediately upstream of sigD. fla/che PA, transcribed by EςA, lies ≥24 kb upstream of sigD and appears to be largely responsible for sigD expression. PD-3, transcribed by EςD, has been proposed to participate in an autoregulatory positive feedback loop. PsigD, a minor ςA-dependent promoter, has been implicated as essential for normal expression of the fla/che operon. We tested the proposed functions of these promoters in experiments that utilized strains that bear chromosomal deletions of fla/che PA, PD-3, or PsigD. Our analysis of these strains indicates that fla/che PA is absolutely essential for motility, that PD-3 does not function in positive feedback regulation of sigD expression, and that PsigD is not essential for normal fla/che expression. Further, our results suggest that an additional promoter(s) contributes to sigD expression. PMID:10940026

  7. Accidental Bowel Leakage

    Science.gov (United States)

    ... I do to help treat accidental bowel leakage? Kegel exercises strengthen the muscles that surround the openings ... bowels that may cause cramping, diarrhea, or constipation. Kegel Exercises: Pelvic muscle exercises that assist in bladder ...

  8. Determination of leakage areas in nuclear piping

    Energy Technology Data Exchange (ETDEWEB)

    Keim, E. [Siemens/KWU, Erlangen (Germany)

    1997-04-01

    For the design and operation of nuclear power plants the Leak-Before-Break (LBB) behavior of a piping component has to be shown. This means that the length of a crack resulting in a leak is smaller than the critical crack length and that the leak is safely detectable by a suitable monitoring system. The LBB-concept of Siemens/KWU is based on computer codes for the evaluation of critical crack lengths, crack openings, leakage areas and leakage rates, developed by Siemens/KWU. In the experience with the leak rate program is described while this paper deals with the computation of crack openings and leakage areas of longitudinal and circumferential cracks by means of fracture mechanics. The leakage areas are determined by the integration of the crack openings along the crack front, considering plasticity and geometrical effects. They are evaluated with respect to minimum values for the design of leak detection systems, and maximum values for controlling jet and reaction forces. By means of fracture mechanics LBB for subcritical cracks has to be shown and the calculation of leakage areas is the basis for quantitatively determining the discharge rate of leaking subcritical through-wall cracks. The analytical approach and its validation will be presented for two examples of complex structures. The first one is a pipe branch containing a circumferential crack and the second one is a pipe bend with a longitudinal crack.

  9. Flowrate testing of the bag filter LANCS-BOP 6CPVC-1.5-2SPVC (LANCS Industries) at 1 psig

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Murray E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Currie, Karissa Lyn [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Berg, Charlotte Katherine [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-13

    The air flowrate through a flexible HEPA grade filter (Part LANCS-BOP 6CPVC-1.5-2SPVC www.lancsindustries.com) was measured at 48 ALPM for a differential pressure drop of 1.0 psig (28 inWC, 7.0 kPa). These filters are rated by the manufacturer to have a flowrate of 3 ALPM at a differential pressure drop of 1 inWC (0.25 kPa). The Los Alamos National Laboratory Aerosol Engineering Facility used one of their test rigs (originally developed to measure the pressure drop in capsule HEPA filters) to measure the airflow through the LANCS bag filter.

  10. Leakage resilient password systems

    CERN Document Server

    Li, Yingjiu; Deng, Robert H

    2015-01-01

    This book investigates tradeoff between security and usability in designing leakage resilient password systems (LRP) and introduces two practical LRP systems named Cover Pad and ShadowKey. It demonstrates that existing LRP systems are subject to both brute force attacks and statistical attacks and that these attacks cannot be effectively mitigated without sacrificing the usability of LRP systems. Quantitative analysis proves that a secure LRP system in practical settings imposes a considerable amount of cognitive workload unless certain secure channels are involved. The book introduces a secur

  11. Multifamily Envelope Leakage Model

    Energy Technology Data Exchange (ETDEWEB)

    Faakye, Omari [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Griffiths, Dianne [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2015-05-08

    “The cost for blower testing is high, because it is labor intensive, and it may disrupt occupants in multiple units. This high cost and disruption deter program participants, and dissuade them from pursuing energy improvements that would trigger air leakage testing, such as improvements to the building envelope.” This statement found in a 2012 report by Heschong Mahone Group for several California interests emphasizes the importance of reducing the cost and complexity of blower testing in multifamily buildings. Energy efficiency opportunities are being bypassed. The cost of single blower testing is on the order of $300. The cost for guarded blower door testing—the more appropriate test for assessing energy savings opportunities—could easily be six times that, and that’s only if you have the equipment and simultaneous access to multiple apartments. Thus, the proper test is simply not performed. This research seeks to provide an algorithm for predicting the guarded blower door test result based upon a single, total blower door test.

  12. Duct Leakage Repeatability Testing

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-01-01

    Duct leakage often needs to be measured to demonstrate compliance with requirements or to determine energy or Indoor Air Quality (IAQ) impacts. Testing is often done using standards such as ASTM E1554 (ASTM 2013) or California Title 24 (California Energy Commission 2013 & 2013b), but there are several choices of methods available within the accepted standards. Determining which method to use or not use requires an evaluation of those methods in the context of the particular needs. Three factors that are important considerations are the cost of the measurement, the accuracy of the measurement and the repeatability of the measurement. The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards.

  13. Duct Leakage Repeatability Testing

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-08-01

    The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques for duct leakage using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards. The three duct leak measurement methods assessed in this report are the two duct pressurization methods that are commonly used by many practitioners and the DeltaQ technique. These are methods B, C and A, respectively of the ASTM E1554 standard. Although it would be useful to evaluate other duct leak test methods, this study focused on those test methods that are commonly used and are required in various test standards, such as BPI (2010), RESNET (2014), ASHRAE 62.2 (2013), California Title 24 (CEC 2012), DOE Weatherization and many other energy efficiency programs.

  14. Carbon leakage and green growth

    NARCIS (Netherlands)

    Altaghlibi, M.

    2017-01-01

    This dissertation consists of four chapters. A general introduction to the problem of carbon leakage and the necessity of sustainable development is furnished in the first chapter. In chapter 2, we investigate the conditions under which a donor country is motivated to give unconditional mitigation

  15. Practical Leakage-Resilient Symmetric Cryptography

    DEFF Research Database (Denmark)

    Faust, Sebastian; Pietrzak, Krzysztof; Schipper, Joachim

    2012-01-01

    Leakage resilient cryptography attempts to incorporate side-channel leakage into the black-box security model and designs cryptographic schemes that are provably secure within it. Informally, a scheme is leakage-resilient if it remains secure even if an adversary learns a bounded amount of arbitr......Leakage resilient cryptography attempts to incorporate side-channel leakage into the black-box security model and designs cryptographic schemes that are provably secure within it. Informally, a scheme is leakage-resilient if it remains secure even if an adversary learns a bounded amount...

  16. Estimation of leakage power and delay in CMOS circuits using parametric variation

    Directory of Open Access Journals (Sweden)

    Preeti Verma

    2016-09-01

    Full Text Available With the advent of deep-submicron technologies, leakage power dissipation is a major concern for scaling down portable devices that have burst-mode type integrated circuits. In this paper leakage reduction technique HTLCT (High Threshold Leakage Control Transistor is discussed. Using high threshold transistors at the place of low threshold leakage control transistors, result in more leakage power reduction as compared to LCT (leakage control transistor technique but at the scarifies of area and delay. Further, analysis of effect of parametric variation on leakage current and propagation delay in CMOS circuits is performed. It is found that the leakage power dissipation increases with increasing temperature, supply voltage and aspect ratio. However, opposite pattern is noticed for the propagation delay. Leakage power dissipation for LCT NAND gate increases up to 14.32%, 6.43% and 36.21% and delay decreases by 22.5%, 42% and 9% for variation of temperature, supply voltage and aspect ratio. Maximum peak of equivalent output noise is obtained as 127.531 nV/Sqrt(Hz at 400 mHz.

  17. Issues behind Competitiveness and Carbon Leakage

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This report explores the vulnerability of heavy industry to carbon leakage and competitiveness loss. It reviews the existing literature on competitiveness and carbon leakage under uneven climate policies. It also suggests a statistical method to track carbon leakage, and applies this methodology to Phase I of the EU emissions trading scheme, for various industrial activities: iron and steel, cement, aluminium and refineries. Finally, it reviews measures to mitigate carbon leakage, as discussed in Australia, Canada, Europe, New Zealand and the US.

  18. 16 CFR 1507.5 - Pyrotechnic leakage.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Pyrotechnic leakage. 1507.5 Section 1507.5... FIREWORKS DEVICES § 1507.5 Pyrotechnic leakage. The pyrotechnic chamber in fireworks devices shall be sealed in a manner that prevents leakage of the pyrotechnic composition during shipping, handling, and...

  19. Heat exchanger leakage problem location

    Directory of Open Access Journals (Sweden)

    Jícha Miroslav

    2012-04-01

    Full Text Available Recent compact heat exchangers are very often assembled from numerous parts joined together to separate heat transfer fluids and to form the required heat exchanger arrangement. Therefore, the leak tightness is very important property of the compact heat exchangers. Although, the compact heat exchangers have been produced for many years, there are still technological problems associated with manufacturing of the ideal connection between the individual parts, mainly encountered with special purpose heat exchangers, e.g. gas turbine recuperators. This paper describes a procedure used to identify the leakage location inside the prime surface gas turbine recuperator. For this purpose, an analytical model of the leaky gas turbine recuperator was created to assess its performance. The results obtained are compared with the experimental data which were acquired during the recuperator thermal performance analysis. The differences between these two data sets are used to indicate possible leakage areas.

  20. Conversion efficiency of an energy harvester based on resonant tunneling through quantum dots with heat leakage.

    Science.gov (United States)

    Kano, Shinya; Fujii, Minoru

    2017-03-03

    We study the conversion efficiency of an energy harvester based on resonant tunneling through quantum dots with heat leakage. Heat leakage current from a hot electrode to a cold electrode is taken into account in the analysis of the harvester operation. Modeling of electrical output indicates that a maximum heat leakage current is not negligible because it is larger than that of the heat current harvested into electrical power. A reduction of heat leakage is required in this energy harvester in order to obtain efficient heat-to-electrical conversion. Multiple energy levels of a quantum dot can increase the output power of the harvester. Heavily doped colloidal semiconductor quantum dots are a possible candidate for a quantum-dot monolayer in the energy harvester to reduce heat leakage, scaling down device size, and increasing electrical output via multiple discrete energy levels.

  1. VISUAL INSPECTION OF WATER LEAKAGE FROM GROUND PENETRATING RADAR RADARGRAM

    Directory of Open Access Journals (Sweden)

    N. N. Halimshah

    2015-10-01

    Full Text Available Water loss in town and suburban is currently a significant issue which reflect the performance of water supply management in Malaysia. Consequently, water supply distribution system has to be maintained in order to prevent shortage of water supply in an area. Various techniques for detecting a mains water leaks are available but mostly are time-consuming, disruptive and expensive. In this paper, the potential of Ground Penetrating Radar (GPR as a non-destructive method to correctly and efficiently detect mains water leaks has been examined. Several experiments were designed and conducted to prove that GPR can be used as tool for water leakage detection. These include instrument validation test and soil compaction test to clarify the maximum dry density (MDD of soil and simulation studies on water leakage at a test bed consisting of PVC pipe burying in sand to a depth of 40 cm. Data from GPR detection are processed using the Reflex 2D software. Identification of water leakage was visually inspected from the anomalies in the radargram based on GPR reflection coefficients. The results have ascertained the capability and effectiveness of the GPR in detecting water leakage which could help avoiding difficulties with other leak detection methods.

  2. Leakage, entrepreneurship, and satisfaction in hospitality

    OpenAIRE

    Galdón Salvador, José Luis; Garrigós Simón, Fernando José; Gil Pechuán, Ignacio

    2013-01-01

    This is an Accepted Manuscript of an article published by Taylor & Francis in The Service Industries Journal on 2013, available online:http://www.tandfonline.com/10.1080/02642069.2013.740464 Tourism is a very important tool for economic development. However, its economic effects are mainly conditioned by the level of leakage. This work defines leakage, provides an original evaluation of the entrepreneurial environment in showing that it is the one with the lowest level of leakage, and crea...

  3. Improving stopping construction to minimize leakage.

    Science.gov (United States)

    Grau, Roy H; Mazzella, Andrew L; Martikainen, Anu L

    2012-07-01

    The proper sealing of stoppings is an important step in reducing leakage from the intake to the return airways. Leakage and the subsequent loss of ventilation resulting from improperly sealed stoppings can lead to unhealthy and unsafe working conditions. The research presented in this paper investigates the total leakage of a stopping, including air leakage through the stopping, at the stopping perimeter, and through the coalbed. The study also examines sealing considerations for stoppings that are constructed under roof control screen, the effects that wooden wedges had on inhibiting efficient application of polyurethane foam sealant, and airflow leakage through the surrounding coal. The work involved building a stopping in a dead end room of the NIOSH Safety Research Coal Mine and then pressurising the room using compressed air. Stopping leakage was evaluated by measuring air pressure loss in the enclosed room due to the air leakage. Part of the research utilises a diluted soap solution that was applied to the stopping and the surrounding coal to detect air leakage signified by bubble formations. The results show that stopping leakage can be minimised with proper sealing.

  4. Forest Carbon Leakage Quantification Methods and Their Suitability for Assessing Leakage in REDD

    Directory of Open Access Journals (Sweden)

    Sabine Henders

    2012-01-01

    Full Text Available This paper assesses quantification methods for carbon leakage from forestry activities for their suitability in leakage accounting in a future Reducing Emissions from Deforestation and Forest Degradation (REDD mechanism. To that end, we first conducted a literature review to identify specific pre-requisites for leakage assessment in REDD. We then analyzed a total of 34 quantification methods for leakage emissions from the Clean Development Mechanism (CDM, the Verified Carbon Standard (VCS, the Climate Action Reserve (CAR, the CarbonFix Standard (CFS, and from scientific literature sources. We screened these methods for the leakage aspects they address in terms of leakage type, tools used for quantification and the geographical scale covered. Results show that leakage methods can be grouped into nine main methodological approaches, six of which could fulfill the recommended REDD leakage requirements if approaches for primary and secondary leakage are combined. The majority of methods assessed, address either primary or secondary leakage; the former mostly on a local or regional and the latter on national scale. The VCS is found to be the only carbon accounting standard at present to fulfill all leakage quantification requisites in REDD. However, a lack of accounting methods was identified for international leakage, which was addressed by only two methods, both from scientific literature.

  5. Radiofrequency radiation leakage from microwave ovens.

    Science.gov (United States)

    Lahham, Adnan; Sharabati, Afifeh

    2013-12-01

    This work presents data on the amount of radiation leakage from 117 microwave ovens in domestic and restaurant use in the West Bank, Palestine. The study of leakage is based on the measurements of radiation emissions from the oven in real-life conditions by using a frequency selective field strength measuring system. The power density from individual ovens was measured at a distance of 1 m and at the height of centre of door screen. The tested ovens were of different types, models with operating powers between 1000 and 1600 W and ages ranging from 1 month to >20 y, including 16 ovens with unknown ages. The amount of radiation leakage at a distance of 1 m was found to vary from 0.43 to 16.4 μW cm(-2) with an average value equalling 3.64 μW cm(-2). Leakages from all tested microwave ovens except for seven ovens (∼6 % of the total) were below 10 μW cm(-2). The highest radiation leakage from any tested oven was ∼16.4 μW cm(-2), and found in two cases only. In no case did the leakage exceed the limit of 1 mW cm(-2) recommended by the ICNIRP for 2.45-GHz radiofrequency. This study confirms a linear correlation between the amount of leakage and both oven age and operating power, with a stronger dependence of leakage on age.

  6. Predicting Envelope Leakage in Attached Dwellings

    Energy Technology Data Exchange (ETDEWEB)

    Faakye, O.; Arena, L.; Griffiths, D.

    2013-07-01

    The most common method for measuring air leakage is to use a single blower door to pressurize and/or depressurize the test unit. In detached housing, the test unit is the entire home and the single blower door measures air leakage to the outside. In attached housing, this 'single unit', 'total', or 'solo' test method measures both the air leakage between adjacent units through common surfaces as well air leakage to the outside. Measuring and minimizing this total leakage is recommended to avoid indoor air quality issues between units, reduce energy losses to the outside, reduce pressure differentials between units, and control stack effect. However, two significant limitations of the total leakage measurement in attached housing are: for retrofit work, if total leakage is assumed to be all to the outside, the energy benefits of air sealing can be significantly over predicted; for new construction, the total leakage values may result in failing to meet an energy-based house tightness program criterion. The scope of this research is to investigate an approach for developing a viable simplified algorithm that can be used by contractors to assess energy efficiency program qualification and/or compliance based upon solo test results.

  7. Experimental evaluation of clinical colon anastomotic leakage

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian

    2014-01-01

    UNLABELLED: Colorectal anastomotic leakage remains a frequent and serious complication in gastrointestinal surgery. Patient and procedure related risk factors for anastomotic leakage have been identified. However, the responsible pathophysiological mechanisms are still unknown. Among these......, whereas the eight-suture control anastomoses had a 0% leakage rate. Furthermore, the use of absorbable suture together with voluntarily ingested Temgesic in chocolate spread as analgesic regimen were feasible. This model may be used to test the leakage reducing potential of coating materials. STUDY 3...... has been improved and is now thoroughly validated. If used by researchers worldwide, comparison of results is possible. Pure ischemia/anoxia may be too simple an approach to create a clinical leakage model. Thus, future models could focus on multiple risk factors. Conclusively, large-scale clinical...

  8. SU-F-J-144: Scatter and Leakage Survey of An Integrated MR-Linac System

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J; Bosco, G; Darenbourg, B; Ibbott, G [UT MD Anderson Cancer Center, Houston, TX (United States)

    2016-06-15

    Purpose: To assess the scatter and leakage radiation of an integrated 1.5T MRI-Linac system. Methods: A 150cc chamber (model 96020C, Inovision) was used in all the scatter and leakage measurements, after being recalibrated for MV energy by the Accredited Dosimetry Calibration Laboratory at MD Anderson. The scatter radiation was measured by placing a 25 cm stack of solid-water materials at iso-center on the patient couch to simulate patient scatter. Gantry angles were positioned at 0 degree (beam pointing downward) and 270 (beam pointing laterally). Scatter radiation was measured at selective locations inside the RF room. Beam stopper leakage was measured at the exterior panel of the gantry. The head leakage was measured at 1 meter away from the Linac head in the direction which was determined to be the area of maximum leakage by wrapped films test. All measurements were repeated with the 1.5T magnetic field turned off to study the effect of magnetic field. Results: When the magnet was on (B=1.5T), the maximum head leakage at 1 meter was 191.6mR/1000MU. The scatter radiation at 1 meter from the iso-center was 1.091R/1000MU when the radiation beam was pointing downward, 1.296R/1000MU when the beam pointed laterally. The beam stopper leakage was measured as 299.4 mR/1000MU at the exterior panel of the gantry. When magnet was off (B=0), the head leakage was measured as 198.6mR/1000MU. The scatter radiation at 1 meter was 1.153R/1000MU when beam pointed downward, 1.287R/1000MU when beam pointed laterally. The beam stopper leakage was measured as 309.4 mR/1000MU at the exterior panel of the gantry. Conclusion: The measurements indicate that the scatter and leakage radiation from the integrated MR-Linac system are in-line with the expected values. The beam stopper leakage is approximately 300 mR/1000MU. The leakage and scatter difference with the magnetic field ON and OFF was within 5%. The authors received a corporate sponsored grant from Elekta which is the vendor of

  9. RF leakage current in electrosurgical units: Influence of the layout in taking measurements

    Energy Technology Data Exchange (ETDEWEB)

    Gentile, L; Palacios, P [Cardiology and Cardiovascular Surgery Institute, Favaloro Foundation Biomedical Engineering Department, Av. Belgrano 1746. Bs. As. (Argentina)

    2007-11-15

    The RF leakage current in electrosurgical units is a critical parameter to measure, because it may cause accidental burns in patients. The particular standard for electrosurgical units IEC 60601-2-2 indicates the maximum RF leakage levels and defines the elements and their layout to do these measurements. On this paper we show the RF leakage current values of 6 electrosurgical units. We did these measurements in two different ways: in the first one we measured in normal conditions of use in the operating rooms and in the second we followed the mentioned Standard. The results shows differences between one group and the other, observing higher RF leakage current values in the measurements that we did without following the standard's layout.

  10. Climate Policy and Carbon Leakage

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This report explores the effects of the EU emissions trading scheme on the aluminium sector (i.e. competitiveness loss and carbon leakage). With its very high electricity intensity, primary aluminium stands out in the heavy industry picture: a sector whose emissions are not capped in the present EU ETS, European aluminium smelters still stand to lose profit margins and, possibly, market shares, as electricity prices increase following CO2 caps on generators' emissions - the famous pass-through of CO2 prices into electricity prices. The analysis includes a method of quantification of this issue, based on two indicators: profit margins and trade flows. As the EU is at the forefront of such policy, the paper provides policy messages to all countries on how trade exposed energy-intensive industries can be 'moved' by carbon constraint. This also is a contentious topic in Australia, Japan, New Zealand, and the US, where ambitious climate policies -- including cap-and-trade systems -- are currently debated.

  11. Leakage-Resilient Circuits without Computational Assumptions

    DEFF Research Database (Denmark)

    Dziembowski, Stefan; Faust, Sebastian

    2012-01-01

    into the model and to construct schemes that are provably secure within them. We design a general compiler that transforms any cryptographic scheme, e.g., a block-cipher, into a functionally equivalent scheme which is resilient to any continual leakage provided that the following three requirements are satisfied......: (i) in each observation the leakage is bounded, (ii) different parts of the computation leak independently, and (iii) the randomness that is used for certain operations comes from a simple (non-uniform) distribution. In contrast to earlier work on leakage resilient circuit compilers, which relied...

  12. Carbon leakage from a Nordic perspective

    Energy Technology Data Exchange (ETDEWEB)

    Naess-Schmidt, S.; Hansen, Martin Bo; Sand Kirk, J. [Copenhagen Economics, Copenhagen (Denmark)

    2012-02-15

    Carbon pricing is generally considered a highly effective tool in reducing carbon emissions. Putting a price on carbon provides incentives for users and producers of fossil fuels to reduce consumption and develop low carbon products and processes. However, pursuing an ambitious climate policy can lead to carbon leakage, which refers to a situation where unilateral or regional climate change policy drives the relocation of industry investments and installations, and associated emissions, to third countries. This report by Copenhagen Economics has been commissioned by the Nordic Council of Ministers to give an overview of the industries at risk of carbon leakage in the Nordic countries, and estimate the expected extent of carbon leakage from unilateral climate policies in the Nordic countries. The report also assesses available policy options that may reduce the risk of carbon leakage, such as exemptions from energy tax and exemptions from quota obligations under green certificate schemes. The key drivers of carbon leakage are identified, which include energy intensity, product differentiation, transportation costs and capital intensity. The analysis suggests that industries such as paper and pulp, iron and steel, aluminium, cement, pharmaceuticals, chemicals, and fertilizers are most at risk of carbon leakage in the Nordic manufacturing sector. (Author)

  13. Copper Ion as a New Leakage Tracer

    Science.gov (United States)

    Modaresi, J; Baharizade, M; Shareghi, A; Ahmadi, M; Daneshkazemi, A

    2013-01-01

    Statement of Problem: Most failures of root canal treatments are caused by bacteria. Studies showed that the most common cause of endodontic failures were the incomplete obturation of the root canal and the lack of adequate apical seal. Some in-vitro methods are used to estimate sealing quality, generally by measuring microleakage that allows the tracer agent to penetrate the filled canal. Purpose: Conventional methods of evaluating the seal of endodontically treated teeth are complicated and have some drawbacks. We used copper ion diffusion method to assess the leakage and the results were compared to dye penetration method. Materials and Method: The crowns of 21 extracted teeth were cut off at the CEJ level. After preparing the canals, the teeth were placed in tubes containing saline. They were divided randomly into 15 experimental cases; 3 positive and 3 negative controls. Positive controls were filled by single cone without sealer while the experimental and the negative control groups were filled by lateral technique. The coronal portion of gutta was removed and 9mm was left. The external surface of each tooth was coated with nail polish. Two millimeters of apical portion was immersed into 9ml of distilled water and 0.3ml of CuSO4 solution was injected into the coronal portion. After 2 days, copper sulfate was measured by an atomic absorption spectrophotometer. The teeth were then immersed in 2% methylene blue for 24 hours, sectioned and the extent of dye penetration was measured by a stereomicroscope. Results: The maximum and minimum recorded copper ion concentrations for the experimental group were 18.37 and 2.87ppm respectively. The maximum and minimum recorded dye penetrations for the experimental group were 8.5 and 3.5mm respectively. The statistical analysis, adopting paired samples test, showed poor correlation between average recorded results of two methods. Conclusion: Based on our results, there was no significant correlation between the dye

  14. Calculation of Leakage Inductance for High Frequency Transformers

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Jun, Zhang; Hurley, William Gerard

    2015-01-01

    Frequency dependent leakage inductance is often observed. High frequency eddy current effects cause a reduction in leakage inductance. The proximity effect between adjacent layers is responsible for the reduction of leakage inductance. This paper gives a detailed analysis of high frequency leakage...

  15. Maximum Autocorrelation Factorial Kriging

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg; Conradsen, Knut; Pedersen, John L.

    2000-01-01

    This paper describes maximum autocorrelation factor (MAF) analysis, maximum autocorrelation factorial kriging, and its application to irregularly sampled stream sediment geochemical data from South Greenland. Kriged MAF images are compared with kriged images of varimax rotated factors from...

  16. Quantifying Information Leakage of Randomized Protocols

    DEFF Research Database (Denmark)

    Biondi, Fabrizio; Wasowski, Andrzej; Legay, Axel

    2013-01-01

    The quantification of information leakage provides a quantitative evaluation of the security of a system. We propose the usage of Markovian processes to model and analyze the information leakage of deterministic and probabilistic systems. We show that this method generalizes the lattice...... of information approach and is a natural framework for modeling refined attackers capable to observe the internal behavior of the system. We also use our method to obtain an algorithm for the computation of channel capacity from our Markovian models. Finally, we show how to use the method to analyze timed...

  17. Quantifying information leakage of randomized protocols

    DEFF Research Database (Denmark)

    Biondi, Fabrizio; Legay, Axel; Malacaria, Pasquale

    2015-01-01

    The quantification of information leakage provides a quantitative evaluation of the security of a system. We propose the usage of Markovian processes to model deterministic and probabilistic systems. By using a methodology generalizing the lattice of information approach we model refined attackers...... capable to observe the internal behavior of the system, and quantify the information leakage of such systems. We also use our method to obtain an algorithm for the computation of channel capacity from our Markovian models. Finally, we show how to use the method to analyze timed and non-timed attacks...

  18. Leakage current measurement in transformerless PV inverters

    DEFF Research Database (Denmark)

    Kerekes, Tamas; Sera, Dezso; Mathe, Laszlo

    2012-01-01

    Photovoltaic (PV) installations have seen a huge increase during the last couple of years. Transformerless PV inverters are gaining more share of the total inverter market, due to their high conversion efficiency, small weight and size. Nevertheless safety should have an important role in case...... to be used in commercial PV inverters for the measurement of leakage and fault ground currents. The German VDE0126–1–1 standard gives the limit for fault and leakage ground currents and all grid connected PV inverters have to comply with these limits and disconnect from the grid in case of a fault....

  19. Intraoperative and postoperative risk factors for anastomotic leakage and pneumonia after esophagectomy for cancer.

    Science.gov (United States)

    Goense, L; van Rossum, P S N; Tromp, M; Joore, H C; van Dijk, D; Kroese, A C; Ruurda, J P; van Hillegersberg, R

    2017-01-01

    Morbidity and mortality after esophagectomy are often related to anastomotic leakage or pneumonia. This study aimed to assess the relationship of intraoperative and postoperative vital parameters with anastomotic leakage and pneumonia after esophagectomy. Consecutive patients who underwent transthoracic esophagectomy with cervical anastomosis for esophageal cancer from January 2012 to December 2013 were analyzed. Univariable and multivariable logistic regression analyses were used to determine potential associations of hemodynamic and respiratory parameters with anastomotic leakage or pneumonia. From a total of 82 included patients, 19 (23%) developed anastomotic leakage and 31 (38%) experienced pneumonia. The single independent factor associated with an increased risk of anastomotic leakage in multivariable analysis included a lower minimum intraoperative pH (OR 0.85, 95% CI 0.77-0.94). An increased risk of pneumonia was associated with a lower mean arterial pressure (MAP) in the first 12 hours after surgery (OR 0.93, 95% CI 0.86-0.99) and a higher maximum intraoperative pH (OR 1.14, 95% CI 1.02-1.27). Interestingly, no differences were noted for the MAP and inotrope requirement between patients with and without anastomotic leakage. A lower minimum intraoperative pH (below 7.25) is associated with an increased risk of anastomotic leakage after esophagectomy, whereas a lower postoperative average MAP (below 83 mmHg) and a higher intraoperative pH (above 7.34) increase the risk of postoperative pneumonia. These parameters indicate the importance of setting strict perioperative goals to be protected intensively. © International Society for Diseases of the Esophagus 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Leakage Resilient Secure Two-Party Computation

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Hazay, Carmit; Patra, Arpita

    2012-01-01

    Definitions.} We formalize the notion of secure two-party computation in the presence of leakage and introduce security definitions in the {\\em ideal/real framework}. Our formalization induces two types of adversarial attacks. We further study the feasibility of our definitions in the computational setting...

  1. Protection of window glass from acoustic leakage

    OpenAIRE

    Lych, Sergij; Rakobovchuk, Volodymyr

    2013-01-01

    In a survey was presented an analysis of the most common glass samples on the Ukrainian market on their protection level against leakage of acoustic information. The glass samples were studied by means of roentgen analysis, and the impact of elemental composition of glass according to a laser beam reflection factor was defined.

  2. Pressure Gauges Monitor Leakage Past Seals

    Science.gov (United States)

    Smith, Steven A.

    1990-01-01

    Method devised to measure leakage of gas past each of two sets of primary and secondary seals into common volume from which aggregate flow measured. Although method applicable only to specific combination of flow configuration and thermal conditions, it serves as example of more general approach involving use of statistical analysis to extract additional information from measurements.

  3. Analyze of Hydrophobic Characteristic of Surface Material Based on The Value of THD Leakage Current

    Directory of Open Access Journals (Sweden)

    Abdul Syakur

    2009-08-01

    Full Text Available Polymer material has been developed to replace the porcelain insulator material and glass. When it is used as outdoor insulator, environmental conditions have a significant influence to the value of surface discharge current, especially for the coastal area and industry. Salt, dust and chemicals contaminant are suspected as the causes of initial current of surface discharge and the insulator surface degradation which lead to a flashover. To analyze the performance of the insulator surface when the leakage current occurs, the Total Harmonic Distortion (THD is needed to be determined. The value of THD leakage current indicates the hydrophobic characteristic of surface material. This paper analyzes the results of leakage current measurement in laboratory-scale based on IEC 587:1986 with Inclined-Plane Tracking (IPT method to the High Density Polyethylene (HDPE polymer material which is provided in smooth and rough surface. The testing voltage is 50 Hz AC. Data of leakage current magnitude values cover its maximum average as a function of time and the result of FFT to the wave form of the leakage current. As the result, the value of percentage THD decrease as the function of time. The smooth surface material has THD value 43.42% and the rough surface has 15.89%.

  4. Minimum Leakage/Low Cost Duct Connections

    Energy Technology Data Exchange (ETDEWEB)

    John Proctor

    2003-08-01

    Leaky and disconnected joints in HVAC air distribution systems are extremely widespread. The average efficiency of duct systems in homes in the US is approximately 55% with approximately 60% of the loss due to duct leakage. Beyond the energy and emissions penalties caused by these leaks, leaky systems have detrimental comfort, health, and safety effects. The health and safety effects include the delivery of combustion products into the homes due to leakage induced depressurization. Current duct installation practice does not attempt to address the problem. This project developed a prototype Professionally Engineered Duct System that will virtually eliminate air leakage and that can be applied in new and replacement installations at the same labor cost as current designs. It uses snap-together duct fittings that will not come apart, can be applied to all types of duct systems, and cannot be separated without exceptional force. its use would require minimal changes to current installation practice. The research team developed the prototype through a multi-step process beginning with a functional analysis of duct connections. This was followed by identifying duct sealing and attachment methods offering potential to meet design objectives, evaluating the designs in terms of function and economic feasibility, and building and testing the most promising design option. Two versions of this design were developed through a test, revise, retest process. One application was to a rigid sheet metal duct, the other was to a helix core flex duct. The process produced a sheet metal application with 1/20th the leakage of a standard connection and a flex duct application with 1/10th the leakage of a standard connection. A patent search has found that the design will not infringe on existing patents and is patentable.

  5. Energetic ion leakage from foreshock transient cores

    Science.gov (United States)

    Liu, Terry Z.; Angelopoulos, Vassilis; Hietala, Heli

    2017-07-01

    Earth's foreshock is filled with backstreaming particles that can interact with the ambient solar wind and its discontinuities to form foreshock transients. Many foreshock transients have a core with low dynamic pressure that can significantly perturb the bow shock and the magnetosphere-ionosphere system. Foreshock transients have also been recently recognized as sites of particle acceleration, which may be important for seeding the parent shock with energetic particles. A relevant step of this seeding would be energetic ion leakage into the surrounding foreshock environment. On the other hand, such leakage would also suppress the energetic particle flux contrast across foreshock transients' boundaries masking their perceived contribution to ion energization. To further examine this hypothesis of ion leakage, we report on multipoint case studies of three foreshock transient events selected from a large database. The cases were selected to exemplify, in increasing complexity, the nature and consequences of energetic ion leakage. Ion energy dispersion, observed upstream and/or downstream of the foreshock transients, is explained with a simple, ballistic model of ions leaking from the foreshock transients. Larger energies are required for leaked ions to reach the spacecraft as the distance between the transient and spacecraft increases. Our model, which explains well the observed ion energy dispersion and velocity distributions, can also be used to reveal the shape of the foreshock transients in three dimensions. Our results suggest that ion leakage from foreshock transient cores needs to be accounted for both in statistical studies and in global models of ion acceleration under quasi-parallel foreshock conditions.

  6. A Labview Based Leakage Current Monitoring System For HV Insulators

    Directory of Open Access Journals (Sweden)

    N. Mavrikakis

    2015-10-01

    Full Text Available In this paper, a Labview based leakage current monitoring system for High Voltage insulators is described. The system uses a general purpose DAQ system with the addition of different current sensors. The DAQ system consists of a chassis and hot-swappable modules. Through the proper design of current sensors, low cost modules operating with a suitable input range can be employed. Fully customizable software can be developed using Labview, allowing on-demand changes and incorporation of upgrades. Such a system provides a low cost alternative to specially designed equipment with the added advantage of maximum flexibility. Further, it can be modified to satisfy the specifications (technical and economical set under different scenarios. In fact, the system described in this paper has already been installed in the HV Lab of the TEI of Crete whereas a variation of it is currently in use in TALOS High Voltage Test Station.

  7. Measurement Methods to Determine Air Leakage Between Adjacent Zones

    Energy Technology Data Exchange (ETDEWEB)

    Hult, Erin L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dickerhoff, Darryl J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Price, Phillip N. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-09-01

    Air leakage between adjacent zones of a building can lead to indoor air quality and energy efficiency concerns, however there is no existing standard for measuring inter-zonal leakage. In this study, synthesized data and field measurements are analyzed in order to explore the uncertainty associated with different methods for collecting and analyzing fan pressurization measurements to calculate interzone leakage.

  8. Techniques for Leakage Power Reduction in Nanoscale Circuits: A Survey

    DEFF Research Database (Denmark)

    Liu, Wei

    This report surveys progress in the field of designing low power especially low leakage CMOS circuits in deep submicron era. The leakage mechanism and various recently proposed run time leakage reduction techniques are presented. Two designs from Cadence and Sony respectively, which can represent...... current industrial application of these techniques, are also illustrated....

  9. 49 CFR 192.706 - Transmission lines: Leakage surveys.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Transmission lines: Leakage surveys. 192.706... Transmission lines: Leakage surveys. Leakage surveys of a transmission line must be conducted at intervals not exceeding 15 months, but at least once each calendar year. However, in the case of a transmission line which...

  10. 3DHZETRN: Neutron leakage in finite objects

    Science.gov (United States)

    Wilson, John W.; Slaba, Tony C.; Badavi, Francis F.; Reddell, Brandon D.; Bahadori, Amir A.

    2015-11-01

    The 3DHZETRN formalism was recently developed as an extension to HZETRN with an emphasis on 3D corrections for neutrons and light ions. Comparisons to Monte Carlo (MC) simulations were used to verify the 3DHZETRN methodology in slab and spherical geometry, and it was shown that 3DHZETRN agrees with MC codes to the degree that various MC codes agree among themselves. One limitation of such comparisons is that all of the codes (3DHZETRN and three MC codes) utilize different nuclear models/databases; additionally, using a common nuclear model is impractical due to the complexity of the software. It is therefore difficult to ascertain if observed discrepancies are caused by transport code approximations or nuclear model differences. In particular, an important simplification in the 3DHZETRN formalism assumes that neutron production cross sections can be represented as the sum of forward and isotropic components, where the forward component is subsequently solved within the straight-ahead approximation. In the present report, previous transport model results in specific geometries are combined with additional results in related geometries to study neutron leakage using the Webber 1956 solar particle event as a source boundary condition. A ratio is defined to quantify the fractional neutron leakage at a point in a finite object relative to a semi-infinite slab geometry. Using the leakage ratio removes some of the dependence on the magnitude of the neutron production and clarifies the effects of angular scattering and absorption with regard to differences between the models. Discussion is given regarding observed differences between the MC codes and conclusions drawn about the need for further code development. Although the current version of 3DHZETRN is reasonably accurate compared to MC simulations, this study shows that improved leakage estimates can be obtained by replacing the isotropic/straight-ahead approximation with more detailed descriptions.

  11. Control of Leakage in the Triaxial Test

    Science.gov (United States)

    1964-03-01

    ON MEMBRANES APPENDIX F DATA FOR OSMOSIS TSSTS ON NATURAL RUBBER MEMBRANES APPENDIX G DATA FOR BINDING LEAKAGE TESTS APPENDIX H DATA FOR...Fraction of Sucrose Required to Prevent Flow due to Hydraulic Pressure and/or Mole Fraction Differences. :• ’ ’ : XV Figures in Appendices A-l... osmosis . Osmosis or osmotic pressure differences are caused by differences in the mole fraction of ions or molecules across a barrier. (The

  12. Alopecia associated with unexpected leakage from electron cone

    Energy Technology Data Exchange (ETDEWEB)

    Wen, B.C.; Pennington, E.C.; Hussey, D.H.; Jani, S.K.

    1989-06-01

    Excessive irradiation due to unexpected leakage was found on a patient receiving electron beam therapy. The cause of this leakage was analyzed and the amount of leakage was measured for different electron beam energies. The highest leakage occurred with a 6 x 6 cm cone using a 12 MeV electron beam. The leakage dose measured along the side of the cone could be as great as 40%. Until the cones are modified or redesigned, it is advised that all patient setups be carefully reviewed to assure that no significant patient areas are in the side scatter region.

  13. SETI VIA LEAKAGE FROM LIGHT SAILS IN EXOPLANETARY SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Guillochon, James; Loeb, Abraham, E-mail: jguillochon@cfa.harvard.edu, E-mail: aloeb@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, The Institute for Theory and Computation, 60 Garden Street, Cambridge, MA 02138 (United States)

    2015-10-01

    The primary challenge of rocket propulsion is the burden of needing to accelerate the spacecraft’s own fuel, resulting in only a logarithmic gain in maximum speed as propellant is added to the spacecraft. Light sails offer an attractive alternative in which fuel is not carried by the spacecraft, with acceleration being provided by an external source of light. By artificially illuminating the spacecraft with beamed radiation, speeds are only limited by the area of the sail, heat resistance of its material, and power use of the accelerating apparatus. In this paper, we show that leakage from a light sail propulsion apparatus in operation around a solar system analogue would be detectable. To demonstrate this, we model the launch and arrival of a microwave beam-driven light sail constructed for transit between planets in orbit around a single star, and find an optimal beam frequency on the order of tens of GHz. Leakage from these beams yields transients with flux densities of Jy and durations of tens of seconds at 100 pc. Because most travel within a planetary system would be conducted between the habitable worlds within that system, multiply transiting exoplanetary systems offer the greatest chance of detection, especially when the planets are in projected conjunction as viewed from Earth. If interplanetary travel via beam-driven light sails is commonly employed in our galaxy, this activity could be revealed by radio follow-up of nearby transiting exoplanetary systems. The expected signal properties define a new strategy in the search for extraterrestrial intelligence (SETI)

  14. Comparing Natural Gas Leakage Detection Technologies Using an Open-Source "Virtual Gas Field" Simulator.

    Science.gov (United States)

    Kemp, Chandler E; Ravikumar, Arvind P; Brandt, Adam R

    2016-04-19

    We present a tool for modeling the performance of methane leak detection and repair programs that can be used to evaluate the effectiveness of detection technologies and proposed mitigation policies. The tool uses a two-state Markov model to simulate the evolution of methane leakage from an artificial natural gas field. Leaks are created stochastically, drawing from the current understanding of the frequency and size distributions at production facilities. Various leak detection and repair programs can be simulated to determine the rate at which each would identify and repair leaks. Integrating the methane leakage over time enables a meaningful comparison between technologies, using both economic and environmental metrics. We simulate four existing or proposed detection technologies: flame ionization detection, manual infrared camera, automated infrared drone, and distributed detectors. Comparing these four technologies, we found that over 80% of simulated leakage could be mitigated with a positive net present value, although the maximum benefit is realized by selectively targeting larger leaks. Our results show that low-cost leak detection programs can rely on high-cost technology, as long as it is applied in a way that allows for rapid detection of large leaks. Any strategy to reduce leakage should require a careful consideration of the differences between low-cost technologies and low-cost programs.

  15. Lyman Continuum Leakage in the Local Universe

    Science.gov (United States)

    Leitherer, Claus; Hernandez, Svea; Lee, Janice; Oey, Sally

    2015-08-01

    Star-forming galaxies are viable candidates for providing the ionizing photon supply accounting for the reionization of the early universe. However, direct determination of the fraction of ionizing photons that can escape the optically thick galaxy ISM is challenging. I will discuss Lyman continuum observations of a sample of massive young star clusters in local galaxies which take advantage of a new capability of HST's Cosmic Origins Spectrograph. The derived photon leakages are compared to values found at high redshift and discussed in the context of cosmological models.

  16. EVA Suit Microbial Leakage Investigation Project

    Science.gov (United States)

    Falker, Jay; Baker, Christopher; Clayton, Ronald; Rucker, Michelle

    2016-01-01

    The objective of this project is to collect microbial samples from various EVA suits to determine how much microbial contamination is typically released during simulated planetary exploration activities. Data will be released to the planetary protection and science communities, and advanced EVA system designers. In the best case scenario, we will discover that very little microbial contamination leaks from our current or prototype suit designs, in the worst case scenario, we will identify leak paths, learn more about what affects leakage--and we'll have a new, flight-certified swab tool for our EVA toolbox.

  17. Analysis of U.S. residential air leakage database

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Wanyu R.; Price, Phillip N.; Sohn, Michael D.; Gadgil, Ashok J.

    2003-07-01

    The air leakage of a building envelope can be determined from fan pressurization measurements with a blower door. More than 70,000 air leakage measurements have been compiled into a database. In addition to air leakage, the database includes other important characteristics of the dwellings tested, such as floor area, year built, and location. There are also data for some houses on the presence of heating ducts, and floor/basement construction type. The purpose of this work is to identify house characteristics that can be used to predict air leakage. We found that the distribution of leakage normalized with floor area of the house is roughly lognormal. Year built and floor area are the two most significant factors to consider when predicting air leakage: older and smaller houses tend to have higher normalized leakage areas compared to newer and larger ones. Results from multiple linear regression of normalized leakage with respect to these two factors are presented for three types of houses: low-income, energy-efficient, and conventional. We demonstrate a method of using the regression model in conjunction with housing characteristics published by the US Census Bureau to derive a distribution that describes the air leakage of the single-family detached housing stock. Comparison of our estimates with published datasets of air exchange rates suggests that the regression model generates accurate estimates of air leakage distribution.

  18. Maximum likely scale estimation

    DEFF Research Database (Denmark)

    Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo

    2005-01-01

    A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and...

  19. Maximum modular graphs

    NARCIS (Netherlands)

    Trajanovski, S.; Wang, H.; Van Mieghem, P.

    2012-01-01

    Modularity has been explored as an important quantitative metric for community and cluster detection in networks. Finding the maximum modularity of a given graph has been proven to be NPcomplete and therefore, several heuristic algorithms have been proposed. We investigate the problem of finding the

  20. Biomembrane Permeabilization: Statistics of Individual Leakage Events Harmonize the Interpretation of Vesicle Leakage

    Czech Academy of Sciences Publication Activity Database

    Braun, S.; Pokorná, Šárka; Šachl, Radek; Hof, Martin; Heerklotz, H.; Hoernke, M.

    2018-01-01

    Roč. 12, č. 1 (2018), s. 813-819 ISSN 1936-0851 R&D Projects: GA ČR GA17-03160S Institutional support: RVO:61388955 Keywords : leakage * dye release * pore Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 13.942, year: 2016

  1. Maximum Likelihood Fusion Model

    Science.gov (United States)

    2014-08-09

    Symposium of Robotics Re- search. Sienna, Italy: Springer, 2003. [12] D. Hall and J. Llinas, “An introduction to multisensor data fusion ,” Proceed- ings of...a data fusion approach for combining Gaussian metric models of an environment constructed by multiple agents that operate outside of a global... data fusion , hypothesis testing,maximum likelihood estimation, mobile robot navigation REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT

  2. Transformerless photovoltaic inverters with leakage current and pulsating power elimination

    DEFF Research Database (Denmark)

    Tang, Yi; Yao, Wenli; Wang, H.

    2015-01-01

    This paper presents a transformerless inverter topology, which is capable of simultaneously solving leakage current and pulsating power issues in grid-connected photovoltaic (PV) systems. Without adding any additional components to the system, the leakage current caused by the PV-to-ground parasi......This paper presents a transformerless inverter topology, which is capable of simultaneously solving leakage current and pulsating power issues in grid-connected photovoltaic (PV) systems. Without adding any additional components to the system, the leakage current caused by the PV...

  3. Agulhas leakage as a key process in the modes of Quaternary climate changes.

    Science.gov (United States)

    Caley, Thibaut; Giraudeau, Jacques; Malaizé, Bruno; Rossignol, Linda; Pierre, Catherine

    2012-05-01

    Heat and salt transfer from the Indian Ocean to the Atlantic Ocean (Agulhas leakage) has an important effect on the global thermohaline circulation and climate. The lack of long transfer record prevents elucidation of its role on climate changes throughout the Quaternary. Here, we present a 1,350-ka accumulation rate record of the planktic foraminiferal species Globorotalia menardii. We demonstrate that, according to previous assumptions, the presence and reseeding of this fauna in the subtropical southeast Atlantic was driven by interocean exchange south of Africa. The Agulhas transfer strengthened at glacial ice-volume maxima for every glacial-interglacial transition, with maximum reinforcements organized according to a 400-ka periodicity. The long-term dynamics of Agulhas leakage may have played a crucial role in regulating meridional overturning circulation and global climate changes during the Mid-Brunhes event and the Mid-Pleistocene transition, and could also play an important role in the near future.

  4. Development of leakage monitoring system using radioisotopes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. C.; Lee, D. S. [Seoil College, Seoul (Korea); Cho, Y. S. [Konyang University, Nonsan (Korea); Shin, S. K. [Sungkyunkwan Univ., Seoul (Korea)

    2000-04-01

    This study is to development the potable neutron back-scattering gauge for leakage and detecting liquid interface of an oil and liquid tank, using a radioisotopes. For this purpose, small sized, light weight potable gauge is to be designed as to develope neutron shielding mechanism, low power supply circuit, high voltage circuit, measurement circuit, and operating handle etc. The user will be able to set the duration of the time interval, the scale, the high voltage, the threshold, the channel window, the selection whether the data storage or not, the selection whether the scale, high voltage, threshold and window fix or not at any time. The counted pulse will be displayed with the numerical value and the line bar. The gauge will be able to connect to an IBM compatible PC via a serial port, power will be supplied by internal battery. 9 refs., 28 figs., 10 tabs. (Author)

  5. Markovian Processes for Quantitative Information Leakage

    DEFF Research Database (Denmark)

    Biondi, Fabrizio

    Quantification of information leakage is a successful approach for evaluating the security of a system. It models the system to be analyzed as a channel with the secret as the input and an output as observable by the attacker as the output, and applies information theory to quantify the amount...... of information transmitted through such channel, thus effectively quantifying how many bits of the secret can be inferred by the attacker by analyzing the system’s output. Channels are usually encoded as matrices of conditional probabilities, known as channel matrices. Such matrices grow exponentially...... in the size of the secret and observables, are cumbersome to compute and store, encode both the behavior of the system and assumptions about the attacker, and assume an input-output behavior of the system. For these reasons we propose to model the systemattacker scenario with Markovian models. We show...

  6. Fluid leakage near the percolation threshold

    Science.gov (United States)

    Dapp, Wolf B.; Müser, Martin H.

    2016-02-01

    Percolation is a concept widely used in many fields of research and refers to the propagation of substances through porous media (e.g., coffee filtering), or the behaviour of complex networks (e.g., spreading of diseases). Percolation theory asserts that most percolative processes are universal, that is, the emergent powerlaws only depend on the general, statistical features of the macroscopic system, but not on specific details of the random realisation. In contrast, our computer simulations of the leakage through a seal—applying common assumptions of elasticity, contact mechanics, and fluid dynamics—show that the critical behaviour (how the flow ceases near the sealing point) solely depends on the microscopic details of the last constriction. It appears fundamentally impossible to accurately predict from statistical properties of the surfaces alone how strongly we have to tighten a water tap to make it stop dripping and also how it starts dripping once we loosen it again.

  7. Maximum Entropy Fundamentals

    Directory of Open Access Journals (Sweden)

    F. Topsøe

    2001-09-01

    Full Text Available Abstract: In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over

  8. Maximum Entropy Fundamentals

    Science.gov (United States)

    Harremoeës, P.; Topsøe, F.

    2001-09-01

    In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over the development of natural

  9. An observed 20-year time series of Agulhas leakage

    NARCIS (Netherlands)

    Le Bars, D.; Durgadoo, J. V.; Dijkstra, H. A.; Biastoch, A.; De Ruijter, W. P M

    2014-01-01

    We provide a time series of Agulhas leakage anomalies over the last 20-years from satellite altimetry. Until now, measuring the interannual variability of Indo-Atlantic exchange has been the major barrier in the investigation of the dynamics and large scale impact of Agulhas leakage. We compute the

  10. Leakage-Resilient Cryptography from the Inner-Product Extractor

    DEFF Research Database (Denmark)

    Dziembowski, Stefan; Faust, Sebastian

    2011-01-01

    We present a generic method to secure various widely-used cryptosystems against arbitrary side-channel leakage, as long as the leakage adheres three restrictions: first, it is bounded per observation but in total can be arbitrary large. Second, memory parts leak independently, and, third, the ran...

  11. Contrast media for radiological examination in gastrointestinal tract leakage

    NARCIS (Netherlands)

    A.Z. Ginai (Abida)

    1987-01-01

    textabstractThe aim of this investigation has been to find a safe and suitable contrast medium for radiological evaluation of the gastrointestinal tract in cases where leakage outside the GIT can be suspected. Leakage outside the gastro-intestinal tract lumen can occur in many ways eg.,

  12. Macrophage migration inhibitory factor induces vascular leakage via autophagy

    Directory of Open Access Journals (Sweden)

    Hong-Ru Chen

    2015-01-01

    Full Text Available Vascular leakage is an important feature of acute inflammatory shock, which currently has no effective treatment. Macrophage migration inhibitory factor (MIF is a pro-inflammatory cytokine that can induce vascular leakage and plays an important role in the pathogenesis of shock. However, the mechanism of MIF-induced vascular leakage is still unclear. In this study, using recombinant MIF (rMIF, we demonstrated that MIF induced disorganization and degradation of junction proteins and increased the permeability of human endothelial cells in vitro. Western blotting analysis showed that rMIF treatment induced LC3 conversion and p62 degradation. Inhibition of autophagy with a PI3K inhibitor (3-MA, a ROS scavenger (NAC or autophagosomal-lysosomal fusion inhibitors (bafilomycin A1 and chloroquine rescued rMIF-induced vascular leakage, suggesting that autophagy mediates MIF-induced vascular leakage. The potential involvement of other signaling pathways was also studied using different inhibitors, and the results suggested that MIF-induced vascular leakage may occur through the ERK pathway. In conclusion, we showed that MIF triggered autophagic degradation of endothelial cells, resulting in vascular leakage. Inhibition of MIF-induced autophagy may provide therapeutic targets against vascular leakage in inflammatory shock.

  13. Late anastomotic leakage in colorectal surgery : a significant problem

    NARCIS (Netherlands)

    Morks, A. N.; Ploeg, R. J.; Hofker, H. Sijbrand; Wiggers, T.; Havenga, K.

    Aim Reported incidence rates of colorectal anastomotic leakage (AL) vary between 2.5 and 20%. There is little information on late anastomotic leakage (LAL). The aim of this study was to determine the incidence of LAL after colorectal resection. Method All patients undergoing colorectal resection

  14. Continuous leakage measurement during hyperthermic isolated limb perfusion

    NARCIS (Netherlands)

    Daryanani, D; Komdeur, R; Ter Veen, J; Nijhuis, PH; Piers, DA; Hoekstra, HJ

    Background: Continuous measurement of perfusate leakage into the systemic circulation is of the utmost importance and can be performed with the help of radioactive tracers. The purpose of this study was to assess changes in the perfusion leakage rate between two periods: 1977-1990 and 1991-2000, and

  15. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan

    2015-02-12

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  16. Insulator Contamination Forecasting Based on Fractal Analysis of Leakage Current

    Directory of Open Access Journals (Sweden)

    Bing Luo

    2012-07-01

    Full Text Available In this paper, an artificial pollution test is carried out to study the leakage current of porcelain insulators. Fractal theory is adopted to extract the characteristics hidden in leakage current waveforms. Fractal dimensions of the leakage current for the security, forecast and danger zones are analyzed under four types of degrees of contamination. The mean value and the standard deviation of the fractal dimension in the forecast zone are calculated to characterize the differences. The analysis reveals large differences in the fractal dimension of leakage current under different contamination discharge stages and degrees. The experimental and calculation results suggest that the fractal dimension of a leakage current waveform can be used as a new indicator of the discharge process and contamination degree of insulators. The results provide new methods and valid indicators for forecasting contamination flashovers.

  17. Study on Acoustic Catheter of Boiler Tube Leakage Monitoring Systems

    Science.gov (United States)

    Lv, Yongxing; Feng, Qiang

    Boiler tube leakage is the major reason of affecting the safe operation of the unit now, there are 3 methods of the "four tube" leakage detection: Traditional method, filtering method and acoustic spectrum analysis, acoustic spectrum analysis is the common method, but this method have low sensitivity and the sensor damage easily. Therewith, designed the special acoustic catheter with acoustic resonance cavity type, proved by experiments, the acoustic catheter with acoustic resonance cavity type can enhance leakage sound, can accurately extract leakage signals, has high sensitivity, and can avoid the effect of sensor by fire and hot-gas when the furnace is in positive pressure situation, reduce the installation and maintenance costs of the boiler tube leakage monitor system.

  18. Air leakage in refrigerated vans: report of confirmation tests conducted with the prototype air leakage test set

    Energy Technology Data Exchange (ETDEWEB)

    1978-10-01

    The objective of the work described was to evaluate the utility of the Prototype Air Leakage Test Set constructed for the United States Department of Energy under this contract, and to compare the air leakage data obtained by use of the Test Set to that obtained by use of three different, existing test equipments at three manufacturers of trailers and containers.

  19. Isolated limb perfusion with cytostatic drug leakage.

    Science.gov (United States)

    Zarazua, M; Paredes, P; Gahete-Santiago, F; Rull, R; Blasi, A; Balust, J

    2017-07-25

    Isolated limb perfusion is the treatment of stage III melanoma with in-transit metastasis. This technique allows the administration of cytostatics at an effective concentration and temperature, which could not be administered systemically because of their toxicity. The toxicity due to leakage of the chemotherapy agent from the limb into the systemic circulation is the most serious short-term complication, and is manifested by a systemic inflammatory response syndrome in the immediate post-intervention period. Early detection of this complication and its peri-operative management requires a multidisciplinary approach, in which the anaesthesiologist plays a key role. A case of isolated lower limb perfusion is reported in which the procedure had to be interrupted due to the passage of tumour necrosis factor into the systemic circulation, with severe intra-operative haemodynamic repercussions. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Quantum Speed Limits for Leakage and Decoherence.

    Science.gov (United States)

    Marvian, Iman; Lidar, Daniel A

    2015-11-20

    We introduce state-independent, nonperturbative Hamiltonian quantum speed limits for population leakage and fidelity loss, for a gapped open system interacting with a reservoir. These results hold in the presence of initial correlations between the system and the reservoir, under the sole assumption that their interaction and its commutator with the reservoir Hamiltonian are norm bounded. The reservoir need not be thermal and can be time dependent. We study the significance of energy mismatch between the system and the local degrees of freedom of the reservoir that directly interact with the system. We demonstrate that, in general, by increasing the system gap we may reduce this energy mismatch, and, consequently, drive the system and the reservoir into resonance; this can accelerate fidelity loss, irrespective of the thermal properties or state of the reservoir. This implies that quantum error suppression strategies based on increasing the gap are not uniformly beneficial. Our speed limits also yield an elementary lower bound on the relaxation time of spin systems.

  1. Insulin Antagonizes Thrombin-Induced Microvessel Leakage.

    Science.gov (United States)

    Liu, Yan; Chen, Xue Lian; Wang, Lei; Martins-Green, Manuela

    2017-01-01

    Sustained increase in microvessel permeability results in cell and tissue damage. To date, it has not been possible to safely and specifically block increased microvessel permeability in vivo. We showed that insulin stimulates angiogenesis and that the new microvessels are associated with more αSMA-producing cells, suggesting greater stability. In this study, we show that local injection of insulin under the skin of mice significantly inhibits thrombin-induced microvessel permeability and that insulin improves the barrier function of primary human endothelial cells under conditions that mimic endothelium in vivo. These findings indicate that insulin antagonizes thrombin-induced microvessel permeability. At the cell and molecular levels, we show that insulin interferes with thrombin-induced VE-cadherin signaling by decreasing the ability of thrombin to induce VE-cadherin translocation to the cytoskeleton/nuclear compartment, leading to microvessel leakage. Simultaneously, the rapid activation of Src by insulin followed by the activation of Rac1, a small GTPase involved in cytoskeletal reorganization, leads to the maintenance of endothelial barrier, short-circuiting the slower thrombin-induced Src-RhoA signaling that leads to endothelial permeability. This novel mechanism by which insulin inhibits thrombin-induced permeability provides support for the use of insulin treatment in pathological conditions that involve blood-barrier dysfunction, especially as resuscitation treatment methods for extensive burns, sepsis, and other severe pathological conditions. © 2017 S. Karger AG, Basel.

  2. Modeling colorant leakage techniques: application to endodontics.

    Science.gov (United States)

    Romieu, Olivier J; Zimányi, László; Warszyński, Piotr; Levallois, Bernard; Cuisinier, Frédéric J; de Périère, Dominique Deville; Jacquot, Bruno

    2010-09-01

    Our aim was to improve the comprehension of in vitro tracer leakage studies and to determine in which conditions such studies can be reliable. We aimed to develop different theoretical models to describe either an initially dry or a wet interface (slit) between sealer and dentin. Equations based on physical laws were derived to model theoretically in vitro tracer penetration. For the dry interfaces, atmospheric, hydrostatic, tracer gravimetric, capillary and internal air pressures were considered as the underlying forces that control tracer penetration. For wet interfaces, the laws of diffusion were used to model colorant penetration. In both cases penetration is influenced by the width of the interface and by the size of the colorant. Calculations for dry conditions have shown that penetration is quick, mainly driven by the capillary pressure, and the penetration increases as the width of the interface diminishes. Dentinal tubules and the extent of their interconnection modify the penetration depth. For wet conditions, tracer size is the main factor controlling the penetration length and speed (the bigger the tracer, the slower the penetration). Our model calculations demonstrate that tracer penetration studies have to be performed under strict experimental conditions. Dry and wet interfaces are two extreme cases with very different tracer penetration modes. In vitro colorant penetration tests should be performed in both of these conditions avoiding cases where the slit contains both air and water. Theses models can be adapted to other dental situations as well. Copyright 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  3. Thermal image analysis for detecting facemask leakage

    Science.gov (United States)

    Dowdall, Jonathan B.; Pavlidis, Ioannis T.; Levine, James

    2005-03-01

    Due to the modern advent of near ubiquitous accessibility to rapid international transportation the epidemiologic trends of highly communicable diseases can be devastating. With the recent emergence of diseases matching this pattern, such as Severe Acute Respiratory Syndrome (SARS), an area of overt concern has been the transmission of infection through respiratory droplets. Approved facemasks are typically effective physical barriers for preventing the spread of viruses through droplets, but breaches in a mask"s integrity can lead to an elevated risk of exposure and subsequent infection. Quality control mechanisms in place during the manufacturing process insure that masks are defect free when leaving the factory, but there remains little to detect damage caused by transportation or during usage. A system that could monitor masks in real-time while they were in use would facilitate a more secure environment for treatment and screening. To fulfill this necessity, we have devised a touchless method to detect mask breaches in real-time by utilizing the emissive properties of the mask in the thermal infrared spectrum. Specifically, we use a specialized thermal imaging system to detect minute air leakage in masks based on the principles of heat transfer and thermodynamics. The advantage of this passive modality is that thermal imaging does not require contact with the subject and can provide instant visualization and analysis. These capabilities can prove invaluable for protecting personnel in scenarios with elevated levels of transmission risk such as hospital clinics, border check points, and airports.

  4. Satellite assisted aerosol correlation in a sequestered CO2 leakage controlled site

    Science.gov (United States)

    Landulfo, Eduardo; da Silva Lopes, Fábio J.; Nakaema, Walter M.; de Medeiros, José A. G.; Moreira, Andrea

    2014-10-01

    Currently one of the main challenges in CO2 storage research is to grant the development, testing and validation of accurate and efficient Measuring, Monitoring and Verification (MMV) techniques to be deployed at the final storage site, targeting maximum storage efficiency at the minimal leakage risk levels. For such task a mimetic sequestration site has been deployed in Florianopolis, Brazil, in order to verify the performance of monitoring plataforms to detect and quantify leakages of ground injected CO2, namely a Cavity Ring Down System (CRDS) - Los Gatos Research - an Eddy Covariance System (Campbell Scientific and Irgason) and meteorological tower for wind, humidity, precipitation and temperature monitoring onsite. The measurement strategy for detecting CO2 leakages can be very challenging since environmental and phytogenic influence can be very severe and play a role on determining if the values measured are unambiguous or not. One external factor to be considered is the amount of incoming solar radiation which will be the driving force for the whole experimental setup and following this reasoning the amount of aerosols in the atmospheric column can be a determinant factor influencing the experimental results. Thus the investigation of measured fluxes CO2 and its concentration with the aforementioned experimental instruments and their correlation with the aerosol data should be taken into account by means of satellite borne systems dedicated to measure aerosol vertical distribution and its optical properties, in this study we have selected CALIPSO and MODIS instrumentation to help on deriving the aerosol properties and CO2 measurements.

  5. Junction leakage measurements with micro four-point probes

    DEFF Research Database (Denmark)

    Lin, Rong; Petersen, Dirch Hjorth; Wang, Fei

    2012-01-01

    We present a new, preparation-free method for measuring the leakage current density on ultra-shallow junctions. The junction leakage is found by making a series of four-point sheet resistance measurements on blanket wafers with variable electrode spacings. The leakage current density is calculated...... using a fit of the measured four-point resistances to an analytical two-sheet model. The validity of the approximation involved in the two-sheet model is verified by a comparison to finite element model calculations....

  6. In-vitro evaluation of coronal microbial leakage after post space tooth preparation.

    Science.gov (United States)

    Saberi, Eshaghali; Akbari, Narjes; Ebrahimipour, Sediqe; Jalilpour, Heybatollah

    2016-06-01

    The aim of this in-vitro study was to determine the occurrence of coronal microbial leakage in endodontically treated teeth that have been prepared for post space, and also determine the minimum and maximum time required for the permanent restoration of the teeth after post space preparation. This experimental study was conducted using a simple random sampling. Fifty extracted single-root teeth with approximately the same length were selected for this study. In order to assimilate the samples length, the crowns of all teeth were cut perpendicular to the long axis of the teeth at a distance of 15 mm from the apex. The canals of 40 teeth were filled with gutta-percha and sealer and prepared for post placement. The teeth were divided randomly into two equal groups of 20 each. In one group, temporary dressing (Cavisol) was used while in the other group, no dressing was used. Five of the teeth were considered as a positive and 5 as a negative control group. For evaluation of microbial leakage, "two-chamber setup" was used. The solution of Proteus mirabilis with fresh culture was injected in the upper chamber and incubated. If the bacteria pass through the dressing and obturation, the trypticase soy broth (TSB) media become turbid. TSB medium in the lower chamber (apex) were investigated every day in terms of occurrence of turbidity and the duration of occurrence of coronal leakage was recorded. The data were analyzed using independent t-test. The leakage time in the group without temporary filling was within 7-21 days and it was within 28-47 days in group with temporary filling (PRCT in the shortest possible time, to reduce the need for retreatment.

  7. Characterization of subretinal fluid leakage in central serous chorioretinopathy

    DEFF Research Database (Denmark)

    Pryds, Anders; Sander, Birgit; Larsen, Michael

    2010-01-01

    The purpose of the study was to determine which category of hydrodynamic phenomena the smokestack in central serous chorioretinopathy (CSC) most likely belongs to: leakage by diffusion or bulk flow....

  8. Low-leakage modular regenerators for gas-turbine engines

    Energy Technology Data Exchange (ETDEWEB)

    Kluka, J.A. [Pratt and Whitney, Middletown, CT (United States); Wilson, D.G. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Mechanical Engineering

    1998-04-01

    One of the significant problems plaguing regenerator designs is seal leakage resulting in a reduction of thermal efficiency. This paper describes the preliminary design and analysis of a new regenerative heat-exchanger concept, called a modular regenerator, that promises to provide improved seal-leakage performance. The modular regenerator concept consists of a ceramic-honeycomb matrix discretized into rectangular blocks, called modules. Separating the matrix into modules substantially reduces the transverse sealing lengths and substantially increases the longitudinal sealing lengths as compared with typical rotary designs. Potential applications can range from small gas-turbine engines for automotive applications to large stationary gas turbines for industrial power generation. Descriptions of two types of modular regenerators are presented including sealing concepts. Results of seal leakage analysis for typical modular regenerators sized for a small gas-turbine engine (120 kW) predict leakage rates under one percent for most seal-clearance heights.

  9. Understanding instrumental Stokes leakage in Murchison Widefield Array polarimetry

    National Research Council Canada - National Science Library

    Sutinjo, A; O'Sullivan, J; Lenc, E; Wayth, R. B; Padhi, S; Hall, P; Tingay, S. J

    2015-01-01

    ...” with the Murchison Widefield Array (MWA) as an example. A long‐standing issue that has been seen here is significant instrumental Stokes leakage after calibration, particularly in Stokes Q at high frequencies...

  10. An Investigation of Leakage Current and Partial Discharge For

    Directory of Open Access Journals (Sweden)

    Arkan A. Hussain

    2013-05-01

    Full Text Available High voltage insulators used in various overhead forms are exposed to leakage current and partial discharge.This work deals with different structure forms of insulator, such as (pin post, clamp top and tie top. These structures are applied in different tests, as covered and stripped states. The leakage current for these forms were measured by raising the insulator voltage to (5.25, 6.35, 7.57 kV for covered and stripped state. Partial discharges were determined in covered and stripped state of these insulator forms using (straight and balanced detection method.Pin post insulators have a leakage current and electric field larger than both clamp top and tie top. The clamp top and tie top insulator show almost the same value of leakage current measurements.The stripped conductors always produce large partial discharge than covered conductor.

  11. Low-frequency measurement of leakage in enclosures

    Science.gov (United States)

    Sherman, Max; Modera, Mark

    1986-07-01

    A wide variety of enclosed structures either require or cannot entirely prevent leakage from their interior space to the outside. Existing methods for measuring such leakage have important disadvantages. We have developed a device and technique that permits leakage areas to be measured from within or without the enclosure without causing unacceptable disturbance. The apparatus uses low-frequency (1 Hz) acoustic monopoles to generate an internal pressure signal which is then analyzed synchronously to provide a measurement of leakage area. We have successfully applied this technique to measuring air tightness in residential houses, and believe it can be easily adapted for use in field, laboratory, or classroom applications. We are currently evaluating why the values we obtained were, on average, 14% lower than those obtained through conventional methods and we are investigating the apparent inability of the device, as presently designed, to measure large leaks.

  12. Leakage Flow Influence on SHF pump model performances

    National Research Council Canada - National Science Library

    Dupont, Patrick; Bayeul-Lainé, Annie-Claude; Dazin, Antoine; Bois, Gérard; Roussette, Olivier; Si, Qiaorui

    2015-01-01

    This paper deals with the influence of leakage flow existing in SHF pump model on the analysis of internal flow behaviour inside the vane diffuser of the pump model performance using both experiments and calculations...

  13. Leakage Flow Influence on SHF pump model performances

    National Research Council Canada - National Science Library

    Dupont, Patrick; Bayeul-Lainé, Annie-Claude; Dazin, Antoine; Bois, Gérard; Roussette, Olivier; Si, Qiaorui

    2015-01-01

    This paper deals with the influence of leakage flow existing in SHF pump model on the analysis of internal flow behaviour inside the vane diffuser of the pump model performance using both experiments and calculations...

  14. Automating the Classification of Field Leakage Current Waveforms

    OpenAIRE

    D. Pylarinos; K. Siderakis; Pyrgioti, E.; E. Thalassinakis; I. Vitellas

    2011-01-01

    Leakage current monitoring is widely employed to investigate the performance of high voltage insulators and the development of surface activity. Field measurements offer an exact view of experienced activity and insulators’ performance, which are strongly correlated to local conditions. The required long term monitoring however, results to the accumulation of vast amounts of data. Therefore, an identification system for the classification of field leakage current waveforms rises as a ne...

  15. Expedient methods of respiratory protection. II. Leakage tests. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, D.W.; Hinds, W.C.; Price, J.M.; Weker, R.; Yee, H.S.

    1983-07-01

    The following readily-available materials were tested on a manikin connected to a breathing simulator to determine the fraction of an approximately 2-..mu..m-diameter aerosol that would leak around the seal of the materials to the manikin's face: cotton/polyester shirt material, cotton handkerchief material, toweling (a wash cloth), a surgical mask (Johnson and Johnson Co., model HRI 8137), and a NIOSH-approved disposable face mask (3M, model number 8710). The leakage tests were performed to supplement the measurements of penetration through the materials, conducted as the first phase of this investigation. The leakage tests were performed with the materials held on to the face by three methods, leakage fractions being determined from comparisons with the penetration of the same aerosol for the materials fully taped to the face. At a breathing rate of 37 liters per minute, mean leakages ranged from 0.0 percent to 63 percent. Mean penetrations exclusive of leakage ranged from 0.6 percent to 39 percent. Use of nylon hosiery material (panty hose) to hold the handkerchief material or the disposable face mask to the face was found to be very effective in preventing leakage. Such a combination could be expected to reduce leakage around the handkerchief to about ten percent or less in practice, and around the mask to less than one percent, offering substantial protection from accidentally generated aerosols. The reduction in leakage around the mask provided by the hosiery material suggests the adaptation and use of such an approach in regular industrial hygiene practice. The third and final phase of this investigation is underway, in which the penetration of the materials by particles with diameters between 0.05 and 0.5 ..mu..m is being measured and the effectiveness of the methods for dose reduction in the presence of radioactive aerosols is being modeled.

  16. Energy Efficient High-Pressure Turbine Leakage Technology Report

    Science.gov (United States)

    Gardner, W. B.

    1980-01-01

    The leakage test program was one of such supporting technology programs structured to provide guidance to the Energy Efficient Engine High Pressure Turbine Component Design Effort. Leakage reduction techniques were identified and evaluated. Test models were used to simulate component leak paths and to evaluate leakage reduction techniques. These models simulated the blade/disk attachment, the vane inner platform attachment, and the vane outer platform attachment combined with the blade outer airseal. Disk blade attachment testing indicated that leakage in this area could be reduced to very low levels by paying careful attention to the tolerances along the contact surface between the blade vibration damper and the blade platform contact surface. The aim of feather seal testing was to achieve a goal for an effective leakage gap of one mil (.001 inch) per inch of feather seal length. Results indicated that effective gaps even below the goal level were achievable by (1) maintaining close tolerances between feather seals and their slots to minimize end gaps and limit seal rotation, (2) avoiding feather seal overlap, and (3) minimizing feather seal intersections. W seals were shown to be effective leakage control devices. Wire rope, in its present state of development, was shown not to be an effective sealing concept for application to the component design.

  17. [Conservative therapy in the treatment of cervical chylous leakage].

    Science.gov (United States)

    Wu, Gao-song; Huang, Li-li; Tu, Shun-gui; Liu, Yan-yan; Liu, Jie; Yan, Qun; Yi, Ji-lin; Zou, Sheng-quan

    2009-05-01

    To explore and evaluate the combined conservative managements in the treatment of cervical chylous leakage. Thirty nine cases of cervical chylous leakage from June 1992 to June 2008 were retrospectively analyzed in this hospital. All of the 39 cases were cured by treating with conservative individualized therapy, including the applying of diet with high calorie, high protein and low fat and fatty food should only contains medium-chain triglycerides, total parenteral nutrition, keep the balance of hydrogen and electrolyte and correct hypoproteinemia, local pressure dressing, high persistent vacuum drainage (-50 approximately -80 kPa) and/or somatostatin analogue. All the cases of chylous leakage happened 2nd to 5th days after the operation. Among the 39 cases, 7 were high flow (drainage>or=500 ml/d) chylous leakage, the amount of drainage reached as high as 1440 ml per day. The time of chylous leakage closure was 3 approximately 12 days, and the mean time was 7 days. No one experienced re-operation, wound hydrops or wound infection. The conservative individualized therapy may play a key role in the treatment of cervical chylous leakage.

  18. International Market Leakage from China’s Forestry Policies

    Directory of Open Access Journals (Sweden)

    Xin Hu

    2014-11-01

    Full Text Available Carbon leakage can be a problem when seeking to reduce carbon emissions through forest policy. International market leakage is mainly caused by supply and demand imbalances in the timber market. This paper selects China, which is implementing forestry policy changes, as the research object. We begin by offering a brief analysis of China’s forestry policy changes, such as the logging quota and Six Key Forestry Programs to determine whether those policies affect timber supply. Second, through the use of three shock variables, carbon leakage is simulated under different scenarios by the Global Trade Analysis Project (GTAP model. The results reveal that the magnitude of leakage caused by implementing China’s forestry policies is between 79.7% and 88.8% with carbon leakage mainly displaced to Russia, Southeast Asia, and the EU. Two effective scenarios for reducing market leakage are presented: forest tenure reform and fast growing forest projects to improve domestic timber production, and raising tariffs on timber imports to reduce imports.

  19. Acute alcohol intoxication-induced microvascular leakage.

    Science.gov (United States)

    Doggett, Travis M; Breslin, Jerome W

    2014-09-01

    Alcohol intoxication can increase inflammation and worsen injury, yet the mechanisms involved are not clear. We investigated whether acute alcohol intoxication increases microvascular permeability and investigated potential signaling mechanisms in endothelial cells that may be involved. Conscious rats received a 2.5 g/kg alcohol bolus via gastric catheters to produce acute intoxication. Microvascular leakage of intravenously administered fluorescein isothiocyanate (FITC)-conjugated albumin (FITC-albumin) from the mesenteric microcirculation was assessed by intravital microscopy. Endothelial-specific mechanisms were studied using cultured endothelial cell monolayers. Transendothelial electrical resistance (TER) served as an index of barrier function, before and after treatment with alcohol or its metabolite acetaldehyde. Pharmacologic agents were used to test the roles of alcohol metabolism, oxidative stress, p38 mitogen-activated protein kinase (MAPK), myosin light-chain kinase (MLCK), rho kinase (ROCK), and exchange protein activated by cAMP (Epac). VE-cadherin localization was investigated to assess junctional integrity. Rac1 and RhoA activation was assessed by ELISA assays. Alcohol significantly increased FITC-albumin extravasation from the mesenteric microcirculation. Alcohol also significantly decreased TER and disrupted VE-cadherin organization at junctions. Acetaldehyde significantly decreased TER, but inhibition of alcohol dehydrogenase or application of a superoxide dismutase mimetic failed to prevent alcohol-induced decreases in TER. Inhibition of p38 MAPK, but not MLCK or ROCK, significantly attenuated the alcohol-induced barrier dysfunction. Alcohol rapidly decreased GTP-bound Rac1 but not RhoA during the drop in TER. Activation of Epac increased TER, but did not prevent alcohol from decreasing TER. However, activation of Epac after initiation of alcohol-induced barrier dysfunction quickly resolved TER to baseline levels. Our results suggest that

  20. Effects of in vitro ozone exposure on peroxidative damage, membrane leakage, and taurine content of rat alveolar macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Banks, M.A.; Porter, D.W.; Martin, W.G.; Castranova, V. (National Institute for Occupational Safety and Health, Morgantown, WV (USA))

    1990-08-01

    Rat alveolar macrophages (AM) were isolated by pulmonary lavage, allowed to adhere to a tissue culture flask, and then exposed to 0.45 +/- 0.05 ppm ozone. After exposures ranging from 0 to 60 min, the medium was decanted and cells were harvested. Cells were assayed for oxidant damage and media analyzed for leakage of intracellular components. Increasing length of exposure to ozone resulted in a decreased number of adherent AM and decreased cell viability. Resting and zymosan-stimulated chemiluminescence increased immediately after ozone exposure and reached a maximum at 15-30 min, then declined to initial levels after 60 min of ozone exposure. Lipid peroxidation and leakage of protein and K+ ions increased with increasing length of exposure to ozone, while leakage of reduced and oxidized glutathione increased through 30 min, then declined (reduced) or leveled off (oxidized). Activity of the Na+/K+ ATPase decreased with time while intracellular taurine concentration exhibited an initial rise, peaked at 30 min, and then returned to the untreated level. Leakage of taurine into the medium increased with time of exposure, suggesting that exposure of AM to ozone results in a shift from bound to free intracellular taurine. These data indicate that in vitro exposure of AM to ozone results in a time-dependent alteration of cell function, membrane integrity, and viability.

  1. Magnetotelluric Detection Thresholds as a Function of Leakage Plume Depth, TDS and Volume

    Energy Technology Data Exchange (ETDEWEB)

    Yang, X. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Buscheck, T. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mansoor, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Carroll, S. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-04-21

    We conducted a synthetic magnetotelluric (MT) data analysis to establish a set of specific thresholds of plume depth, TDS concentration and volume for detection of brine and CO2 leakage from legacy wells into shallow aquifers in support of Strategic Monitoring Subtask 4.1 of the US DOE National Risk Assessment Partnership (NRAP Phase II), which is to develop geophysical forward modeling tools. 900 synthetic MT data sets span 9 plume depths, 10 TDS concentrations and 10 plume volumes. The monitoring protocol consisted of 10 MT stations in a 2×5 grid laid out along the flow direction. We model the MT response in the audio frequency range of 1 Hz to 10 kHz with a 50 Ωm baseline resistivity and the maximum depth up to 2000 m. Scatter plots show the MT detection thresholds for a trio of plume depth, TDS concentration and volume. Plumes with a large volume and high TDS located at a shallow depth produce a strong MT signal. We demonstrate that the MT method with surface based sensors can detect a brine and CO2 plume so long as the plume depth, TDS concentration and volume are above the thresholds. However, it is unlikely to detect a plume at a depth larger than 1000 m with the change of TDS concentration smaller than 10%. Simulated aquifer impact data based on the Kimberlina site provides a more realistic view of the leakage plume distribution than rectangular synthetic plumes in this sensitivity study, and it will be used to estimate MT responses over simulated brine and CO2 plumes and to evaluate the leakage detectability. Integration of the simulated aquifer impact data and the MT method into the NRAP DREAM tool may provide an optimized MT survey configuration for MT data collection. This study presents a viable approach for sensitivity study of geophysical monitoring methods for leakage detection. The results come in handy for rapid assessment of leakage detectability.

  2. Percutaneous Management of Postoperative Duodenal Stump Leakage with Foley Catheter

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Jung Suk, E-mail: oj-cumc@daum.net; Lee, Hae Giu, E-mail: hgleehfh@catholic.ac.kr; Chun, Ho Jong; Choi, Byung Gil [Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Department of Radiology (Korea, Republic of); Lee, Sang Hoon; Hahn, Seong Tai [Yeouido St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Department of Radiology (Korea, Republic of); Ohm, Joon Young [Bucheon St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Department of Radiology (Korea, Republic of)

    2013-10-15

    Purpose: This study was designed to evaluate retrospectively the safety and efficacy of the percutaneous management of duodenal stump leakage with a Foley catheter after subtotal gastrectomy. Methods: Ten consecutive patients (M:F = 9:1, median age: 64 years) were included in this retrospective study. The duodenal stump leakages were diagnosed in all the patients within a median of 10 days (range, 6-20). At first, the patients underwent percutaneous drainage on the day of or the day after confirmation of the presence of duodenal stump leakage, and then the Foley catheters were replaced at a median of 9 days (range, 6-38) after the percutaneous drainage. Results: Foley catheters were placed successfully in the duodenal lumen of all the patients under a fluoroscopic guide. No complication was observed during and after the procedures in all the patients. All of the patients started a regular diet 1 day after the Foley catheter placement. The patients were discharged at a median of 7 days (range, 5-14) after the Foley catheter placement. The catheters were removed in an outpatient clinic 10-58 days (median, 28) after the Foley catheter placement. Conclusions: Fluoroscopy-guided percutaneous Foley catheter placement may be a safe and effective treatment option for postoperative duodenal stump leakage and may allow for shorter hospital stays, earlier oral intake, and more effective control of leakage sites.

  3. Suppression and control of leakage field in electromagnetic helical microwiggler

    Energy Technology Data Exchange (ETDEWEB)

    Ohigashi, N. [Kansai Univ., Osaka (Japan); Tsunawaki, Y. [Osaka Sangyo Univ. (Japan); Imasaki, K. [Institute for Laser Technology, Osaka (Japan)] [and others

    1995-12-31

    Shortening the period of electromagnetic wiggler introduces both the radical increase of the leakage field and the decrease of the field in the gap region. The leakage field is severer problem in planar electromagnetic wiggler than in helical wiggler. Hence, in order to develop a short period electromagnetic wiggler, we have adopted {open_quotes}three poles per period{close_quotes} type electromagnetic helical microwiggler. In this work, we inserted the permanent magnet (PM) blocks with specific magnetized directions in the space between magnetic poles, for suppressing the leakage field flowing out from a pole face to the neighboring pole face. These PM-blocks must have higher intrinsic coersive force than saturation field of pole material. The gap field due to each pole is adjustable by controlling the leakage fields, that is, controlling the position of each iron screw set in each retainer fixing the PM-blocks. At present time, a test wiggler with period 7.8mm, periodical number 10 and gap length 4.6mm has been manufactured. Because the ratio of PM-block aperture to gap length is important parameter to suppress the leakage field, the parameter has been surveyed experimentally for PM-blocks with several dimensions of aperture. The field strength of 3-5kG (K=0.2-0.4) would be expected in the wiggler.

  4. Leakage magnetic field of BLDCM based on Comsol multiphysics

    Science.gov (United States)

    Zhang, Xiaojun; Wen, Jiabao; Wang, Wen; Sun, Jinghua

    2017-04-01

    The measurement of geomagnetic field conducted by underwater robot is widely used during cruise, however, it is often influenced by the strong electromagnetic interference of the other large-scale electronic equipment on the robot itself. The leakage magnetic field of high-power brushless DC motor (BLDCM) has been identified as one of the main interference source. To obtain accurate geomagnetic data, it is necessary to analyze the magnetic field characteristics of the leakage field of BLDCM. In this paper, we build a two-dimensional BLDCM model. In addition, we present the rotor's leakage magnetic field when the BLDCM is static, dynamic leakage magnetic field of the stator and rotor when BLDCM is working and the near-field characteristic of BLDCM's leakage magnetic field. Finally, this paper studies the relationship between the frequency of the magnetic field change and the speed of the BLDCM, which can be used to eliminate the AC interference magnetic field. Therefore the measuring accuracy of the geomagnetic field can be improved.

  5. Gas-path leakage seal for a gas turbine

    Science.gov (United States)

    Wolfe, Christopher E.; Dinc, Osman S.; Bagepalli, Bharat S.; Correia, Victor H.; Aksit, Mahmut F.

    1996-01-01

    A gas-path leakage seal for generally sealing a gas-path leakage-gap between spaced-apart first and second members of a gas turbine (such as combustor casing segments). The seal includes a generally imperforate foil-layer assemblage which is generally impervious to gas and is located in the leakage-gap. The seal also includes a cloth-layer assemblage generally enclosingly contacting the foil-layer assemblage. In one seal, the first edge of the foil-layer assemblage is left exposed, and the foil-layer assemblage resiliently contacts the first member near the first edge to reduce leakage in the "plane" of the cloth-layer assemblage under conditions which include differential thermal growth of the two members. In another seal, such leakage is reduced by having a first weld-bead which permeates the cloth-layer assemblage, is attached to the metal-foil-layer assemblage near the first edge, and unattachedly contacts the first member.

  6. Air-steam leakage through cracks in concrete walls

    Energy Technology Data Exchange (ETDEWEB)

    Simon, H. [CEA Saclay, DM2S/SFME, Laboratoire d' Etudes des Transferts et de Mecanique des Fluides, F-91 191 Gif sur Yvette Cedex (France)]. E-mail: helene.simon@cea.fr; Nahas, G. [IRSN, DSR/SAMS, Bureau d' Analyse du Genie Civil et des Structures, F-92 265 Fontenay-aux-Roses Cedex (France); Coulon, N. [CEA Saclay, DM2S/SFME, Laboratoire d' Etudes des Transferts et de Mecanique des Fluides, F-91 191 Gif sur Yvette Cedex (France)

    2007-09-15

    In the context of a severe accident in a PWR nuclear plant, the evaluation of the leakage through the containment wall remains a key point of the safety analysis. Here we calculate the leakage of an air steam mixture through a traversing crack taking into account condensation. A 40 h test has been performed on a representative concrete slab with measurements of crack openings and flow rates. The CAST3M code enables us to simulate this test by making thermo-mechanical calculations and calculation of the leakage flow rate. Thermo-mechanical calculations provide data needed by the leakage calculations which are not measurable in the experiment. These are the internal crack profiles (variation of the opening with the curvilinear coordinate of the crack inside the concrete slab). Thermo-mechanical calculations are difficult to perform because boundary conditions of the test are complicated. Leakage calculations are performed with various hypotheses for the internal cracks profiles. A coefficient is applied on the friction factor to take into account additional complexity of the crack geometry.

  7. Low dark leakage current in organic planar heterojunction photodiodes

    Science.gov (United States)

    Shekhar, Himanshu; Solomeshch, Olga; Liraz, Dan; Tessler, Nir

    2017-11-01

    It is often suggested that the dark leakage current of organic photodiodes is due to extrinsic leakage paths that do not involve the electronic junction. By studying a series of devices, where the acceptor is kept constant (C70) and the donor material is varied, we find a direct correlation between the strength of the sub-gap signature of the charge-transfer states and the leakage current. Attributing the differences in the sub-gap absorption to the donor's sub-gap states suggests that the donor's side of the junction should be made longer, to push the Fermi level at V = 0 towards the acceptor's LUMO, and thus, an optimized value of 800 Pacm-2 at V = -1 V is reported.

  8. Air Leakage Rates in Typical Air Barrier Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Hun, Diana E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Atchley, Jerald Allen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Childs, Phillip W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-11-01

    Estimates for 2010 indicate that infiltration in residential buildings was responsible for 2.85 quads of energy (DOE 2014), which is about 3% of the total energy consumed in the US. One of the mechanisms being implemented to reduce this energy penalty is the use of air barriers as part of the building envelope. These technologies decrease airflow through major leakage sites such as oriented strand board (OSB) joints, and gaps around penetrations (e.g., windows, doors, pipes, electrical outlets) as indicated by Hun et al. (2014). However, most air barrier materials do not properly address leakage spots such as wall-to-roof joints and wall-to-foundation joints because these are difficult to seal, and because air barrier manufacturers usually do not provide adequate instructions for these locations. The present study focuses on characterizing typical air leakage sites in wall assemblies with air barrier materials.

  9. Reducing water leakage into underground coal mines by aquifer dewatering

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, J. P.

    1978-01-01

    Based on stratigraphic, structural, hydrogeologic, and mining data collected during a study in central Pennsylvania, a two-dimensional, finite-difference computer model was used to simulate groundwater flow in a sandstone unit (0.3 to 11 m thick) overlying an underground mine, and to evaluate the responses of the flow system and leakage rate into the mine when hypothetical dewatering wells are introduced into the system. Simulation of well dewatering, using 25 wells, showed that negligible reduction in leakage would occur if sandstone permeability was less than 0.30 m/day. When sandstone permeability equalled 3.0 m/day, 25 wells reduced leakage by 2.4 percent.

  10. Identifying and Managing Gas Leakage from Subsurface Sources

    Science.gov (United States)

    Benson, S. M.

    2015-12-01

    Subsurface gas accumulations exist from both natural sources such as hydrocarbon reservoirs, as well as, man-made sources such as natural gas storage, gas pipelines, CO2 storage, or even H2 storage. Both natural and manmade sources of subsurface gases have the potential to leak to the surface. Leakage can cause safety hazards and detrimental impacts associated with the release of greenhouse gases into the atmosphere. Leak management, which involves identifying, characterizing, assessing, and remediating leakage requires a coordinated and systematic approach to effectively deal with these occurrences. Here an overall workflow for leak management is presented, along with technological options and challenges for successful implementation. Many tools and approaches for leak management are available and in use today. However, the increased attention to leakage from a larger variety of sources, particularly associated with legacy facilities and infrastructure, raises new issues and challenges that are highlighted here.

  11. Air Leakage of U.S. Homes: Model Prediction

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max H.; McWilliams, Jennifer A.

    2007-01-01

    Air tightness is an important property of building envelopes. It is a key factor in determining infiltration and related wall-performance properties such as indoor air quality, maintainability and moisture balance. Air leakage in U.S. houses consumes roughly 1/3 of the HVAC energy but provides most of the ventilation used to control IAQ. The Lawrence Berkeley National Laboratory has been gathering residential air leakage data from many sources and now has a database of more than 100,000 raw measurements. This paper uses a model developed from that database in conjunction with US Census Bureau data for estimating air leakage as a function of location throughout the US.

  12. Wet-aerosol leakage through simulated containment leak paths

    Energy Technology Data Exchange (ETDEWEB)

    Sutradhar, S.C. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2007-07-01

    Some types of postulated accidents in a nuclear reactor can result in the formation of radioactive wet aerosols in containment and their subsequent release into the environment. Wet-aerosol leakage was investigated using simulated leak paths for isolation damper valves and airlock door seals. Leakage was calculated from measured uranine concentrations deposited on high-quality filters positioned downstream of the simulated leak paths. Test results indicated that a small fraction of wet aerosols leaked through the simulated isolation damper valves, whereas a large fraction leaked through the simulated airlock door seals. Data on wet-aerosol leakage through containment leak paths are needed to develop and validate models in safety analysis codes. (author)

  13. Functions and requirements for single-shell tank leakage mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Cruse, J.M.

    1994-09-22

    This document provides the initial functions and requirements for the leakage mitigation mission applicable to past and potential future leakage from the Hanford Site`s 149 single-shell high-level waste tanks. This mission is a part of the overall mission of the Westinghouse Hanford Company Tank Waste Remediation System division to remediate the tank waste in a safe and acceptable manner. Systems engineering principles are being applied to this effort. A Mission Analysis has been completed, this document reflects the next step in the systems engineering approach to decompose the mission into primary functions and requirements. The functions and requirements in this document apply to mitigative actions to be taken regarding below ground leaks from SST containment boundaries and the resulting soil contamination. Leakage mitigation is invoked in the TWRS Program in three fourth level functions: (1) Store Waste, (2) Retrieve Waste, and (3) Disposition Excess Facilities.

  14. On camera-based smoke and gas leakage detection

    Energy Technology Data Exchange (ETDEWEB)

    Nyboe, Hans Olav

    1999-07-01

    Gas detectors are found in almost every part of industry and in many homes as well. An offshore oil or gas platform may host several hundred gas detectors. The ability of the common point and open path gas detectors to detect leakages depends on their location relative to the location of a gas cloud. This thesis describes the development of a passive volume gas detector, that is, one than will detect a leakage anywhere in the area monitored. After the consideration of several detection techniques it was decided to use an ordinary monochrome camera as sensor. Because a gas leakage may perturb the index of refraction, parts of the background appear to be displaced from their true positions, and it is necessary to develop algorithms that can deal with small differences between images. The thesis develops two such algorithms. Many image regions can be defined and several feature values can be computed for each region. The value of the features depends on the pattern in the image regions. The classes studied in this work are: reference, gas, smoke and human activity. Test show that observation belonging to these classes can be classified fairly high accuracy. The features in the feature set were chosen and developed for this particular application. Basically, the features measure the magnitude of pixel differences, size of detected phenomena and image distortion. Interesting results from many experiments are presented. Most important, the experiments show that apparent motion caused by a gas leakage or heat convection can be detected by means of a monochrome camera. Small leakages of methane can be detected at a range of about four metres. Other gases, such as butane, where the densities differ more from the density of air than the density of methane does, can be detected further from the camera. Gas leakages large enough to cause condensation have been detected at a camera distance of 20 metres. 59 refs., 42 figs., 13 tabs.

  15. Investigation of Flyback Transformer Flux Leakage Reduction Ways

    Directory of Open Access Journals (Sweden)

    Edvardas Bielskis

    2017-07-01

    Full Text Available Results of experimental investigation and design optimization of flyback transformer are presented. Aim of the work is to investigate experimentally the impact of the flyback transformer design on the flux leakage and maximal output power. It is difficult to evaluate the effect of the leakage flux mathematically because it depends on various factors: the position of the windings relative to each other; the position of the windings in the transformer; the distance between the winding. A multi-winding flyback transformer was used for experiments. Using the results of the experiments optimal design of the investigated flyback transformer was defined.

  16. Leakage Inductance Calculation for Planar Transformers with a Magnetic Shunt

    DEFF Research Database (Denmark)

    Jun, Zhang; Ouyang, Ziwei; Duffy, M. C.

    2013-01-01

    with a magnetic shunt by means of the stored magnetic energy in the primary and secondary sides of the transformer using the magnetomotive force (MMF) variation method, as well as the stored energy in the shunt based on the reluctance model. The detailed calculation method is described. Both the FEA simulation......The magnetic shunt is generally inserted in a planar transformer to increase the leakage inductance which can be utilized as the series inductor in resonant circuits such as the LLC resonant converter. This paper presents a calculation methodology for the leakage inductance of the transformer...

  17. Leakage Inductance Calculation for Planar Transformers with a Magnetic Shunt

    DEFF Research Database (Denmark)

    Zhang, Jun; Ouyang, Ziwei; Duffy, Maeve C.

    2014-01-01

    with a magnetic shunt by means of the stored magnetic energy in the primary and secondary sides of the transformer using the magnetomotive force (MMF) variation method, as well as the stored energy in the shunt based on the reluctance model. The detailed calculation method is described. Both the FEA simulation......The magnetic shunt is generally inserted in a planar transformer to increase the leakage inductance which can be utilized as the series inductor in resonant circuits such as the LLC resonant converter. This paper presents a calculation methodology for the leakage inductance of the transformer...

  18. Single ion heat engine with maximum efficiency at maximum power

    OpenAIRE

    Abah, Obinna; Rossnagel, Johannes; Jacob, Georg; Deffner, Sebastian; Schmidt-Kaler, Ferdinand; Singer, Kilian; Lutz, Eric

    2012-01-01

    We propose an experimental scheme to realize a nano heat engine with a single ion. An Otto cycle may be implemented by confining the ion in a linear Paul trap with tapered geometry and coupling it to engineered laser reservoirs. The quantum efficiency at maximum power is analytically determined in various regimes. Moreover, Monte Carlo simulations of the engine are performed that demonstrate its feasibility and its ability to operate at maximum efficiency of 30% under realistic conditions.

  19. Development of references of anomalies detection on P91 material using Self-Magnetic Leakage Field (SMLF) technique

    Science.gov (United States)

    Husin, Shuib; Afiq Pauzi, Ahmad; Yunus, Salmi Mohd; Ghafar, Mohd Hafiz Abdul; Adilin Sekari, Saiful

    2017-10-01

    This technical paper demonstrates the successful of the application of self-magnetic leakage field (SMLF) technique in detecting anomalies in weldment of a thick P91 materials joint (1 inch thickness). Boiler components such as boiler tubes, stub boiler at penthouse and energy piping such as hot reheat pipe (HRP) and H-balance energy piping to turbine are made of P91 material. P91 is ferromagnetic material, therefore the technique of self-magnetic leakage field (SMLF) is applicable for P91 in detecting anomalies within material (internal defects). The technique is categorized under non-destructive technique (NDT). It is the second passive method after acoustic emission (AE), at which the information on structures radiation (magnetic field and energy waves) is used. The measured magnetic leakage field of a product or component is a magnetic leakage field occurring on the component’s surface in the zone of dislocation stable slipbands under the influence of operational (in-service) or residual stresses or in zones of maximum inhomogeneity of metal structure in new products or components. Inter-granular and trans-granular cracks, inclusion, void, cavity and corrosion are considered types of inhomogeneity and discontinuity in material where obviously the output of magnetic leakage field will be shown when using this technique. The technique does not required surface preparation for the component to be inspected. This technique is contact-type inspection, which means the sensor has to touch or in-contact to the component’s surface during inspection. The results of application of SMLF technique on the developed P91 reference blocks have demonstrated that the technique is practical to be used for anomaly inspection and detection as well as identification of anomalies’ location. The evaluation of this passive self-magnetic leakage field (SMLF) technique has been verified by other conventional non-destructive tests (NDTs) on the reference blocks where simulated

  20. Principles of maximum entropy and maximum caliber in statistical physics

    Science.gov (United States)

    Pressé, Steve; Ghosh, Kingshuk; Lee, Julian; Dill, Ken A.

    2013-07-01

    The variational principles called maximum entropy (MaxEnt) and maximum caliber (MaxCal) are reviewed. MaxEnt originated in the statistical physics of Boltzmann and Gibbs, as a theoretical tool for predicting the equilibrium states of thermal systems. Later, entropy maximization was also applied to matters of information, signal transmission, and image reconstruction. Recently, since the work of Shore and Johnson, MaxEnt has been regarded as a principle that is broader than either physics or information alone. MaxEnt is a procedure that ensures that inferences drawn from stochastic data satisfy basic self-consistency requirements. The different historical justifications for the entropy S=-∑ipilog⁡pi and its corresponding variational principles are reviewed. As an illustration of the broadening purview of maximum entropy principles, maximum caliber, which is path entropy maximization applied to the trajectories of dynamical systems, is also reviewed. Examples are given in which maximum caliber is used to interpret dynamical fluctuations in biology and on the nanoscale, in single-molecule and few-particle systems such as molecular motors, chemical reactions, biological feedback circuits, and diffusion in microfluidics devices.

  1. Benchmarking leakage from water reticulation systems in South Africa

    African Journals Online (AJOL)

    driniev

    The model is used to assist water utilities to evaluate the levels of leakage and non- revenue water in their water distribution systems. A project was previously initiated by the Water Research ... the BENCHLEAK model and the results carefully screened for ... The length of mains is the total length of the bulk and distribution.

  2. 77 Post Oesophagectomy Leakage at Kenyatta National Hospital ...

    African Journals Online (AJOL)

    user

    2005-12-02

    Dec 2, 2005 ... Two thirds (67.1%) of the anastomoses were fashioned within the thoracic cavity while the rest were fashioned within the cervical area. A total 16.4% of anastomoses leaked. The in-hospital mortality rate for all oesophagectomies was 28.9%. The in-hospital mortality for the post anastomotic leakage patients ...

  3. Blower-door techniques for measuring interzonal leakage

    Energy Technology Data Exchange (ETDEWEB)

    Hult, Erin L.; Sherman, Max H.; Walker, Iain

    2013-01-01

    Abstract The standard blower door test methods, such as ASTM E779, describe how to use a single blower door to determine the total leakage of a single-zone structure such as a detached single-family home. There are no standard test methods for measuring interzonal leakage in a two-zone or multi-zone building envelope such as might be encountered in with an attached garage or in a multifamily building. Some practitioners have been using techniques that involve making multiple measurements with a single blower door as well as combined measurements using multiple blower doors. Even for just two zones there are dozens of combinations of one-door and two-door test protocols that could conceivably be used to determine the interzonal air tightness. We examined many of these two-zone configurations using both simulation and measured data to estimate the accuracy and precision of each technique for realistic measurement scenarios. We also considered the impact of taking measurements at a single pressure versus over multiple pressures. We compared the various techniques and evaluated them for specific uses. Some techniques work better in one leakage regime; some are more sensitive to wind and other noise; some are more suited to determining only a subset of the leakage values. This paper makes recommendations on which techniques to use or not use for various cases and provides data that could be used to develop future test methods.

  4. Incidence and management of bile leakage after partial liver resection

    NARCIS (Netherlands)

    Erdogan, D.; Busch, O. R. C.; van Delden, O. M.; Rauws, E. A. J.; Gouma, D. J.; van Gulik, T. M.

    2008-01-01

    Background/Aims: Bile leakage after partial liver resection still is a common complication and is associated with substantial morbidity and even mortality. Methods: A total of 234 consecutive liver resections without biliary reconstruction, performed between January 1992 and December 2004, were

  5. Leakage Currents and Gas Generation in Advanced Wet Tantalum Capacitors

    Science.gov (United States)

    Teverovsky, Alexander

    2015-01-01

    Currently, military grade, established reliability wet tantalum capacitors are among the most reliable parts used for space applications. This has been achieved over the years by extensive testing and improvements in design and materials. However, a rapid insertion of new types of advanced, high volumetric efficiency capacitors in space systems without proper testing and analysis of degradation mechanisms might increase risks of failures. The specifics of leakage currents in wet electrolytic capacitors is that the conduction process is associated with electrolysis of electrolyte and gas generation resulting in building up of internal gas pressure in the parts. The risk associated with excessive leakage currents and increased pressure is greater for high value advanced wet tantalum capacitors, but it has not been properly evaluated yet. In this work, in Part I, leakages currents in various types of tantalum capacitors have been analyzed in a wide range of voltages, temperatures, and time under bias. Gas generation and the level of internal pressure have been calculated in Part II for different case sizes and different hermeticity leak rates to assess maximal allowable leakage currents. Effects related to electrolyte penetration to the glass seal area have been studied and the possibility of failures analyzed in Part III. Recommendations for screening and qualification to reduce risks of failures have been suggested.

  6. Vented piston seal prevents fluid leakage between two chambers

    Science.gov (United States)

    Mac Glashan, W. F.; Morrison, R.

    1964-01-01

    To prevent fluid leakage around piston seals separating two fluids under differential pressure, a venting system has been devised. Two methods may be used for venting seals through internal passages to an external low-pressure area, O-ring or split-ring seals.

  7. Incidence and management of biliary leakage after hepaticojejunostomy

    NARCIS (Netherlands)

    de Castro, Steve M. M.; Kuhlmann, Koert F. D.; Busch, Olivier R. C.; van Delden, Otto M.; Laméris, Johan S.; van Gulik, Thomas M.; Obertop, Hugo; Gouma, Dirk J.

    2005-01-01

    This study analyzes the change in the management of biliary leakage after hepaticojejunostomy. Between 1993 and 2003 all patients (n = 1033) were studied with a hepaticojejunostomv as part of a pancreatoduodenectomy (n = 486), proximal bile duct resection (without liver resection) (n = 35), and

  8. Exploitation of Unintentional Information Leakage from Integrated Circuits

    Science.gov (United States)

    Cobb, William E.

    2011-01-01

    The information leakage of electronic devices, especially those used in cryptographic or other vital applications, represents a serious practical threat to secure systems. While physical implementation attacks have evolved rapidly over the last decade, relatively little work has been done to allow system designers to effectively counter the…

  9. Theory and Practice of a Leakage Resilient Masking Scheme

    DEFF Research Database (Denmark)

    Balasch, Josep; Faust, Sebastian; Gierlichs, Benedikt

    2012-01-01

    model, most of them are unfortunately rather inefficient and come without practical security evaluations nor implementation attempts. In this work, we take a further step towards closing the gap between theoretical leakage resilient cryptography and more practice-oriented research. In particular, we...... implementation of the AES for an 8-bit processor...

  10. Effect of Surface Treatments on Leakage of Zirconium Oxide Ceramics

    Directory of Open Access Journals (Sweden)

    Göknil Alkan Demetoğlu

    2016-08-01

    Full Text Available Objective: The aim of this pilot study was to compare the effects of pretreatments on leakage of zirconia ceramics. Materials and Methods: The speciments divided into 6 groups that were subsequently treated as follows: group 1, no treatment (control; group 2, the ceramic surfaces were airborne-particle abraded with 110 μm aluminum-oxide (Al2O3 particles; group 3, after abrasion of the surfaces with 110 μm Al2O3 particles, silica coating using 30 μm (Al2O3 particles modified by silica (rocatec system and application of the silane coupling agent (espe-sil; group 4, ceramic surfaces irritated with neodymium-doped yttrium aluminium garnet (Nd:YAG laser [fidelis plus 3 foton (Ljubljana, Slovenia] at 20 hz, 100 mj, 2 w, 100 μs; group 5, ceramic surfaces irritated with Nd:YAG laser at fidelis plus 3 fotona (Ljubljana, Slovenia at 20 hz, 100 mj, 2 w, 100 μs; group 6; application of a zirconia primer (z-prime plus bisco, IL, USA agent. And all ceramics tested for leakage. Results: For marginal leakage, score 0 was found in all groups. Conclusion: No significant differences were found in marginal leakage under all conditions.

  11. Variation in ion leakage parameters of two wheat genotypes with ...

    Indian Academy of Sciences (India)

    The reaction to soil drying was evaluated in two Triticum aestivum near-isogenic lines carrying different alleles of the height-reducing gene Rht-B1 based on an improved method for assessment of electrolyte leakage. The two lines were previously shown to differ in their physiological responses to induced water deficit ...

  12. Osmotic Stressing, Membrane Leakage, and Fluorescence: An Introductory Biochemistry Demonstration

    Science.gov (United States)

    Seu, Kalani J.

    2015-01-01

    A fluorescence demonstration is described that incorporates several fundamental aspects of an introductory biochemistry course. A variation of a known leakage assay is utilized to prepare vesicles containing a quenched fluorophore. The vesicles are exposed to several osmotic environments ranging from isotonic to hypotonic. The degree of vesicle…

  13. Chylous leakage after thoracolumbar fracture may cause paraplegia.

    Science.gov (United States)

    von Knoch, Marius; Michiels, Ivo; Mueller, Stefan; Siahkamary, Leila

    2004-01-15

    Retrospective case report. This case demonstrates that paraplegia can develop due to chylous leakage into the spinal canal without obvious retroperitoneal or intrathoracic involvement. This clinical presentation of chylous leakage has not been reported previously. RESULTS A 61-year-old female with osteoporosis suffered a pathologic fracture of the vertebral bodies T12 and L1 and developed partial paraplegia two weeks later. Imaging showed expansive pooling of intraspinal fluid without intrathoracic or retroperitoneal involvement. A blood-tinged fluid was aspirated from dorsal. Repeated surgery by a posterior approach with drainage of the fluid did not improve the patient's condition, so she was finally transferred to our hospital. Under the suspected diagnosis of lymphatic leakage a scintiscan with 123I-iodinephenylpentadekanacid-marked cream verified the presumption of a lymph fistula at the level of T12/L1, originating from the thoracic duct. By permanent draining of the posterior fistula without suction and strict intravenous alimentation the fluid production decreased continuously and finally ceased completely. Simultaneously, the neurologic state improved gradually without returning to normal completely. This case demonstrates that paraplegia can develop due to chylous leakage into the spinal canal without obvious retroperitoneal or intrathoracic involvement. This differential diagnosis should be kept in mind when treating patients with abundant fluid drainage into or from the spinal canal.

  14. Cysteamine prevents vascular leakage through inhibiting transglutaminase in diabetic retina.

    Science.gov (United States)

    Lee, Yeon-Ju; Jung, Se-Hui; Hwang, JongYun; Jeon, Sohee; Han, Eun-Taek; Park, Won Sun; Hong, Seok-Ho; Kim, Young-Myeong; Ha, Kwon-Soo

    2017-10-01

    Cysteamine (an aminothiol), which is derived from coenzyme A degradation and metabolized into taurine, has beneficial effects against cystinosis and neurodegenerative diseases; however, its role in diabetic complications is unknown. Thus, we sought to determine the preventive effect of cysteamine against hyperglycemia-induced vascular leakage in the retinas of diabetic mice. Cysteamine and ethanolamine, the sulfhydryl group-free cysteamine analogue, inhibited vascular endothelial growth factor (VEGF)-induced stress fiber formation and vascular endothelial (VE)-cadherin disruption in endothelial cells, which play a critical role in modulating endothelial permeability. Intravitreal injection of the amine compounds prevented hyperglycemia-induced vascular leakage in the retinas of streptozotocin-induced diabetic mice. We then investigated the potential roles of reactive oxygen species (ROS) and transglutaminase (TGase) in the cysteamine prevention of VEGF-induced vascular leakage. Cysteamine, but not ethanolamine, inhibited VEGF-induced ROS generation in endothelial cells and diabetic retinas. In contrast, VEGF-induced TGase activation was prevented by both cysteamine and ethanolamine. Our findings suggest that cysteamine protects against vascular leakage through inhibiting VEGF-induced TGase activation rather than ROS generation in diabetic retinas. © 2017 Society for Endocrinology.

  15. Detection of tissue expander leakage by methylene blue instillation ...

    African Journals Online (AJOL)

    Background: Tissue expansion is an important and widely used technique of soft tissue reconstruction. Leakage of the expanders is one of the complications and it might at times be difficult to detect. Method and Conclusion: We used methylene blue stained saline for inflation of tissue expanders in 42 cases and found it to ...

  16. Impact of the Indonesian throughflow on Agulhas leakage

    NARCIS (Netherlands)

    le Bars, D.L.B.|info:eu-repo/dai/nl/326165150; Dijkstra, H.A.|info:eu-repo/dai/nl/073504467; de Ruijter, W.P.M.|info:eu-repo/dai/nl/068476760

    2013-01-01

    Using ocean models of different complexity we show that opening the Indonesian Passage between the Pacific and the Indian Ocean increases the input of Indian Ocean water into the South Atlantic via the Agulhas leakage. In a strongly eddying global 5 ocean model this response results from an

  17. Characterization of CO2 leakage into the freshwater body

    DEFF Research Database (Denmark)

    Singh, Ashok; Delfs, Jens Olaf; Shao, H.

    2013-01-01

    , the leakage into a multi-layered fractured saline aquifer is modelled with a numerical model regarding its pressure build-up process. The investigation is performed with the non-isothermal compositional fluid flow module implemented by authors in the OpenGeoSys (OGS) software for geotechnical applications....

  18. Leakage Testing for Different Adhesive Systems and Composites to ...

    African Journals Online (AJOL)

    shrinkage is one of the most important causes of failures. Departments of Pedodontics ... Kılınç G. Leakage testing for different adhesive systems and composites to permanent teeth. Niger J Clin Pract 2017;20:787-91. Date of Acceptance: 16-Nov-2015 .... practiced to the cavity, by brushing the adhesive over the entire ...

  19. Pre-stretch induced leakage current in VHB electroactive polymers

    Science.gov (United States)

    Hammami, S.; Jean-Mistral, C.; Jomni, F.; Sylvestre, A.

    2016-04-01

    Dielectric elastomers generators (DEGs) constitute promising systems due to their high energy density. This latter is influenced by viscoelasticity and the leakage current. An understanding of this leakage current and how it can be influenced by the stretch state of material is required to predict or optimize DEGs. In this context, our work consisted in studying the evolution of the leakage current in commercial electroactive polymer (3 M VHB4910) using silver grease as electrodes. This analysis has been performed in order to evaluate the influence of three different factors: the biaxial prestretch (λ2 = 4, 9 and 16), the temperature (from 20°C to 80°C) and the high electric field (from 1MVm-1 to 20MVm-1). Main results are (i) the increase in the leakage current at higher pre-stretch due to the increase of the electric field, (ii) a predominant Schottky conduction mechanism (iii) a lower current at room temperature for asymmetric pre-stretch compared to an equivalent area surface ratio with symmetric pre-stretch, (iv) the point iii fails when the material works at temperatures higher than room temperature. Probable changes in the molecular chains with strain explain these results.

  20. On the Connection between Leakage Tolerance and Adaptive Security

    DEFF Research Database (Denmark)

    Nielsen, Jesper Buus; Venturi, Daniele; Zottarel, Angela

    2013-01-01

    We revisit the context of leakage-tolerant interactive protocols as defined by Bitanski, Canetti and Halevi (TCC 2012). Our contributions can be summarized as follows: For the purpose of secure message transmission, any encryption protocol with message space M and secret key space SK tolerating...

  1. Carbon Leakage Revisited : Unilateral Climate Policy with Directed Technical Change

    NARCIS (Netherlands)

    Di Maria, C.; van der Werf, E.H.

    2005-01-01

    The increase in carbondioxide emissions by some countries in reaction to an emission reduction by countries with climate policy (carbon leakage) is seen as a serious threat to unilateral climate policy.Using a two-country model where only one of the countries enforces an exogenous cap on emissions,

  2. Large Epiphrenic Diverticulum with Perforation and Leakage below the Diaphragm

    DEFF Research Database (Denmark)

    Brønserud, Majken Munk; Brenøe, Anne-Sofie; Eckardt, Jens

    2015-01-01

    We present a rare case of an epiphrenic esophageal diverticulum, complicated by perforation and leakage below the diaphragm in a 57-year-old male patient. The patient was referred to the emergency department with suspected aspiration pneumonia. A thoracoabdominal computed tomography with oral...

  3. Factors related to ostomy leakage in the community setting.

    Science.gov (United States)

    Ratliff, Catherine R

    2014-01-01

    The purpose of this study was to describe demographic and clinical variables related to ostomy pouch leakage from those discharged from a major medical center during a 2-year period. A convenience sample of 198 persons with an ostomy was obtained using the ICD-9 (International Classification of Diseases, Ninth Revision) codes for colostomy, ileostomy, and ileal conduit for patients who were discharged from the medical center within the time frame of July 2009 to July 2011. One hundred seven participants (55%) returned a completed survey. Respondents included 57 men (53%) and 50 women (47%). The mean age was 60 years with age range from 23 to 91 years. Fecal ostomies made up the majority of the stomas representing 71 patients (66%). A descriptive, cross-sectional research design was used to describe clinical variables related to ostomy pouch leakage for those discharged from a major academic medical center over a 2-year period of time. Participants were mailed an introductory letter from the principal investigator, a self-administered questionnaire, and a prepaid return envelope. Ninety-three patients (87%) reported leakage; however, 48 patients (45%) stated that they did not leak often. A logistic regression was estimated to determine which variables were significant predictors of the dependent variable of leaking status (no/seldom leaking vs more frequent leaking). Two variables were individually significant predictors, sex (P = .021) and 2-piece pouch (P = .015). Women were 4 times more likely to be in the more frequent leaking group than were men. Those who were wearing 2-piece pouches were 78% less likely to be in the more frequent leaking group. Participants with ileostomies or urostomies were more likely to be in the more frequent leaking group and those with peristomal skin irritation were more likely to be in the more frequent leaking group. Findings from this study reveal that women were more likely to experience leakage than men and that wearing a 2-piece

  4. Understanding and managing leakage in forest-based greenhouse-gas-mitigation projects.

    Science.gov (United States)

    Schwarze, Reimund; Niles, John O; Olander, Jacob

    2002-08-15

    A major concern about land use, land-use change and forestry (LULUCF) projects under the Clean Development Mechanism (CDM) is the potential for leakage. Leakage refers to a net increase of greenhouse-gas emissions in an area outside the project resulting from the CDM activity. This paper provides an overview of leakage, its definitions and its causes. It describes ways that LULUCF projects may suffer from leakage and attempts to assess the magnitude of leakage risks for different LULUCF project types. It also summarizes some of the approaches, both in terms of policies and project development, to address LULUCF leakage.

  5. Leakage of colon anastomoses: development of an experimental model in pigs

    DEFF Research Database (Denmark)

    Nordentoft, Tyge; Sørensen, Michael

    2007-01-01

    Background: In order to investigate anastomotic leakage, a number of experimental animal studies have been previously carried out. Due to the low frequency of spontaneous anastomotic leakages, there have been studies on gastrointestinal anastomoses with iatrogenically produced leakages. A leakage...... model has only been developed in one gastric bypass study. The aim of the present study was to develop a leakage model of pig colon anastomoses. This type of study has never been performed before. Materials and Methods: Anastomosis was performed in 22 pigs. In all anastomoses a standardized rupture......: A model of anastomotic leakage on pig colon is developed with creation of a 21-mm rupture in the anastomotic line....

  6. A Location Method Using Sensor Arrays for Continuous Gas Leakage in Integrally Stiffened Plates Based on the Acoustic Characteristics of the Stiffener

    Directory of Open Access Journals (Sweden)

    Xu Bian

    2015-09-01

    Full Text Available This paper proposes a continuous leakage location method based on the ultrasonic array sensor, which is specific to continuous gas leakage in a pressure container with an integral stiffener. This method collects the ultrasonic signals generated from the leakage hole through the piezoelectric ultrasonic sensor array, and analyzes the space-time correlation of every collected signal in the array. Meanwhile, it combines with the method of frequency compensation and superposition in time domain (SITD, based on the acoustic characteristics of the stiffener, to obtain a high-accuracy location result on the stiffener wall. According to the experimental results, the method successfully solves the orientation problem concerning continuous ultrasonic signals generated from leakage sources, and acquires high accuracy location information on the leakage source using a combination of multiple sets of orienting results. The mean value of location absolute error is 13.51 mm on the one-square-meter plate with an integral stiffener (4 mm width; 20 mm height; 197 mm spacing, and the maximum location absolute error is generally within a ±25 mm interval.

  7. Effects of La Incorporation in Hf Based Dielectric on Leakage Conduction and Carrier Scattering Mechanisms.

    Science.gov (United States)

    You, Seung-Won; Lee, Dong Hwi; Nguyen, Manh Cuong; Jeon, Yoon Seok; Tong, Duc-Tai; Bang, Hyun Joon; Jeong, Jae Kyoung; Choi, Rino

    2015-10-01

    Metal-oxide-semiconductor field effect transistors (MOSFETs) with various doses of La-incorporated in Hafnium-based dielectrics were characterized to evaluate the effect of La on dielectric and device properties. It is found that the Poole-Frenkel emission model could explain our experimental leakage current conduction mechanism reasonably and barrier heights of localized Poole-Frenkel trap sites increase gradually with increasing La incorporation. Cryogenic measurement (from 100 K to 300 K) of MOSFETs reveals that, as the content of La incorporation in the dielectric increases, the more increase of maximum effective mobility has been found at low temperature. It is mainly attributed to the more reduction of phonon scattering due to higher content of La atoms at the interface of dielectric and channel. Though it is relatively small, the existence of La in dielectric reduces coulomb scattering rate as well.

  8. Extremum seeking x-ray position feedback using power line harmonic leakage as the perturbation

    Energy Technology Data Exchange (ETDEWEB)

    Zohar, S.; Kissick, D. J.; Venugopalan, N.; Ogata, C. M.; Makarov, O.; Stepanov, S.; Fischetti, R. F.

    2016-09-01

    Small x-ray beam sizes necessary for probing nanoscale phenomena require exquisite stability to prevent data corruption by noise. One source of instability at synchrotron radiation x-ray beamlines is the slow detuning of x-ray optics to marginal alignment where the onset of clipping increases the beam's susceptibility to higher frequency position oscillations. In this article, we show that a 1 mu m amplitude horizontal x-ray beam oscillation driven by power line harmonic leakage into the electron storage ring can be used as perturbation for horizontal position extremum seeking feedback. Feedback performance is characterized by convergence to 1.5% away from maximum intensity at optimal alignment.

  9. Extremum seeking x-ray position feedback using power line harmonic leakage as the perturbation

    Energy Technology Data Exchange (ETDEWEB)

    Zohar, S.; Kissick, D. J.; Venugopalan, N.; Ogata, C. M.; Makarov, O.; Stepanov, S.; Fischetti, R. F.

    2016-09-01

    Small X-ray beam sizes necessary for probing nanoscale phenomena require exquisite stability to prevent data corruption by noise. One source of instability at synchrotron radiation X-ray beamlines is the slow detuning of X-ray optics to marginal alignment where the onset of clipping increases the beam’s susceptibility to higher frequency position oscillations. In this article, we show that a 1 µm amplitude horizontal X-ray beam oscillation driven by power line harmonic leakage into the electron storage ring can be used as perturbation for horizontal position extremum seeking feedback. Feedback performance is characterized by convergence to 1.5% away from maximum intensity at optimal alignment.

  10. Extremum seeking x-ray position feedback using power line harmonic leakage as the perturbation

    Directory of Open Access Journals (Sweden)

    S. Zohar

    2016-09-01

    Full Text Available Small x-ray beam sizes necessary for probing nanoscale phenomena require exquisite stability to prevent data corruption by noise. One source of instability at synchrotron radiation x-ray beamlines is the slow detuning of x-ray optics to marginal alignment where the onset of clipping increases the beam’s susceptibility to higher frequency position oscillations. In this article, we show that a 1  μm amplitude horizontal x-ray beam oscillation driven by power line harmonic leakage into the electron storage ring can be used as perturbation for horizontal position extremum seeking feedback. Feedback performance is characterized by convergence to 1.5% away from maximum intensity at optimal alignment.

  11. Rarity of late anastomotic leakage after low anterior resection of the rectum.

    Science.gov (United States)

    Maeda, Hiromichi; Okamoto, Ken; Namikawa, Tsutomu; Akimori, Toyokazu; Kamioka, Norihito; Shiga, Mai; Dabanaka, Ken; Hanazaki, Kazuhiro; Kobayashi, Michiya

    2015-06-01

    Late anastomotic leakage is reported to account for half of all anastomotic leakages after low anterior resection of the rectum. An important clinical question is whether late and early anastomotic leakages are different entities. We retrospectively reviewed the medical records of patients who experienced anastomotic leakage after low anterior resection in two Japanese hospitals. The clinical characteristics were extracted and analyzed. During the study period, 179 patients underwent low anterior resection. A pelvic drainage tube was routinely utilized in all cases and was generally removed 4 to 6 days after the operation. Twenty-six patients had anastomotic leakage; the diagnosis was based on fecal contamination of the drainage in 24 cases. The median interval between operation and detection of anastomotic leakage was 3.5 days. Anastomotic leakage was diagnosed within 7 days of the operation in 25 cases and on postoperative day 20 (after hospital discharge) in one case. There was no instance of anastomotic leakage diagnosed more than 30 days after the operation. There was no relationship between clinical variables and days of leakage diagnosis. The rarity of late anastomotic leakage in our study, compared with previous studies, may relate to the relatively extended period of pelvic drainage tube usage in our institutes, which likely shortens the interval before leakage diagnosis. Our results suggest that late anastomotic leakage is a delayed symptom of subtle early anastomotic leakage rather than a separate entity.

  12. Perioperative Statin Therapy Is Not Associated With Reduced Risk of Anastomotic Leakage After Colorectal Resection

    DEFF Research Database (Denmark)

    Bisgård, Anne Sofie; Noack, Morten Westergaard; Klein, Mads

    2013-01-01

    Anastomotic leakage is a serious complication of colorectal surgery. Several studies have demonstrated the beneficial pleiotropic effects of statins, and preliminary studies have suggested that perioperative statin treatment may be associated with reduced risk of anastomotic leakage....

  13. Injection Technique and Pen Needle Design Affect Leakage From Skin After Subcutaneous Injections

    DEFF Research Database (Denmark)

    Præstmark, Kezia Ann; Stallknecht, Bente; Jensen, Morten Lind

    2016-01-01

    BACKGROUND: After a subcutaneous injection fluid might leak out of the skin, commonly referred to as leakage or backflow. The objective was to examine the influence of needle design and injection technique on leakage after injections in the subcutaneous tissue of humans and pigs. METHOD: Leakage...... data were obtained from a post hoc analysis of clinical trial data and from a pig study. Data from the clinical study were used to determine leakage as a function of injection volume, speed and region. Data from the pig study were used to determine leakage as a function of needle wall thickness, needle...... taper, injection angle, and wait time from end of injection to withdrawal of needle from skin. RESULTS: Leakage volume was positively related to injection volume. Injections in the abdomen caused less leakage than thigh injections. A 32G needle caused less leakage than a 31G and a 32G tip (tapered...

  14. ENUGU USING MAXIMUM TEMPERATURE DATA

    African Journals Online (AJOL)

    2008-01-28

    Jan 28, 2008 ... daily global solar radiation on a horizontal surface for some towns in Nigeria. For example, Sanusi and Aliyu (2005) used maximum temperature data to predict for. Sokoto. lheonu (2001) did the same for lbadan. Badmus and Momoh(2005) did likewise for Birnin Kebbi. So did Awachie and Okeke(1 990) for ...

  15. Maximum stellar iron core mass

    Indian Academy of Sciences (India)

    Abstract. An analytical method of estimating the mass of a stellar iron core, just prior to core collapse, is .... approximately as an ideal gas, the mean kinetic energies of the free electrons and atomic nuclei will be equal. .... whose density varies from a maximum at the core's center to a minimum at its 'surface'. The dimensional ...

  16. Abolishing the maximum tension principle

    Directory of Open Access Journals (Sweden)

    Mariusz P. Da̧browski

    2015-09-01

    Full Text Available We find the series of example theories for which the relativistic limit of maximum tension Fmax=c4/4G represented by the entropic force can be abolished. Among them the varying constants theories, some generalized entropy models applied both for cosmological and black hole horizons as well as some generalized uncertainty principle models.

  17. maXImum medical aid

    African Journals Online (AJOL)

    1990-08-04

    Aug 4, 1990 ... the passage of time. S Afr Med J 1990; 78: 147-151. Medicine prices have increased significantly in recent years. Over the past 5 years, the medicines price .... Maximum. "- dispensed. No. in. Approved price before. Product list name. Strength. Form. Pack prof. fee (R) examples. Allopurinol. 100 mg. Tablets.

  18. 40 CFR 86.166-12 - Method for calculating emissions due to air conditioning leakage.

    Science.gov (United States)

    2010-07-01

    ... to air conditioning leakage. 86.166-12 Section 86.166-12 Protection of Environment ENVIRONMENTAL... for calculating emissions due to air conditioning leakage. This section describes procedures used to determine a refrigerant leakage rate in grams per year from vehicle-based air conditioning units. The...

  19. Gas-path leakage seal for a turbine

    Science.gov (United States)

    Bagepalli, Bharat Sampathkumaran; Aksit, Mahmut Faruk; Farrell, Thomas Raymond

    1999-01-01

    A gas-path leakage seal for generally sealing a gas-path leakage-gap between spaced-apart first and second members of a turbine (such as combustor casing segments of a gas turbine). The seal includes a flexible and generally imperforate metal sheet assemblage having opposing first and second surfaces and two opposing raised edges extending a generally identical distance above and below the surfaces. A first cloth layer assemblage has a thickness generally equal to the previously-defined identical distance and is superimposed on the first surface between the raised edges. A second cloth layer assemblage is generally identical to the first cloth layer assemblage and is superimposed on the second surface between the raised edges.

  20. The Impact of Statistical Leakage Models on Design Yield Estimation

    Directory of Open Access Journals (Sweden)

    Rouwaida Kanj

    2011-01-01

    Full Text Available Device mismatch and process variation models play a key role in determining the functionality and yield of sub-100 nm design. Average characteristics are often of interest, such as the average leakage current or the average read delay. However, detecting rare functional fails is critical for memory design and designers often seek techniques that enable accurately modeling such events. Extremely leaky devices can inflict functionality fails. The plurality of leaky devices on a bitline increase the dimensionality of the yield estimation problem. Simplified models are possible by adopting approximations to the underlying sum of lognormals. The implications of such approximations on tail probabilities may in turn bias the yield estimate. We review different closed form approximations and compare against the CDF matching method, which is shown to be most effective method for accurate statistical leakage modeling.

  1. Impact of the Indonesian Throughflow on Agulhas leakage

    Directory of Open Access Journals (Sweden)

    D. Le Bars

    2013-09-01

    Full Text Available Using ocean models of different complexity we show that opening the Indonesian Passage between the Pacific and the Indian oceans increases the input of Indian Ocean water into the South Atlantic via the Agulhas leakage. In a strongly eddying global ocean model this response results from an increased Agulhas Current transport and a constant proportion of Agulhas retroflection south of Africa. The leakage increases through an increased frequency of ring shedding events. In an idealized two-layer and flat-bottom eddy resolving model, the proportion of the Agulhas Current transport that retroflects is (for a wide range of wind stress forcing not affected by an opening of the Indonesian Passage. Using a comparison with a linear model and previous work on the retroflection problem, the result is explained as a balance between two mechanisms: decrease retroflection due to large-scale momentum balance and increase due to local barotropic/baroclinic instabilities.

  2. Support calculations for management of PRISE leakage accidents

    Energy Technology Data Exchange (ETDEWEB)

    Matejovic, P.; Vranka, L. [Nuclear Power Plants Research Inst. Vuje, Trnava (Slovakia)

    1997-12-31

    Accidents involving primary-to-secondary leakage (PRISE) caused by rupture of one or a few tubes are well known design basis events in both, western and VVER NPPs. Operating experience and in-service inspections of VVER-440 units have demonstrated also the potential for large PRISE leaks in the case of the steam generator (SG) primary collector cover lift-up (Rovno NPP). Without performing any countermeasure for limitation of SG collector cover lift-up, a full opening results in PRISE leak with an equivalent diameter 107 mm. Although this accident was not considered in the original design, this event is usually analysed as DBA too. Different means are available for detection and mitigation of PRISE leakage in NPPs currently in operation (J.Bohunice V-1 and V-2) or under construction (Mochovce) in Slovakia. 8 refs.

  3. Distributed public key schemes secure against continual leakage

    DEFF Research Database (Denmark)

    Akavia, Adi; Goldwasser, Shafi; Hazay, Carmit

    2012-01-01

    In this work we study distributed public key schemes secure against continual memory leakage. The secret key will be shared among two computing devices communicating over a public channel, and the decryption operation will be computed by a simple 2-party protocol between the devices. Similarly...... the value of the respective function on the internal state of the respective device (namely, on its secret share, internal randomness, and results of intermediate computations). We present distributed public key encryption (DPKE) and distributed identity based encryption (DIBE) schemes that are secure......-secure against continual memory leakage. Our DPKE scheme also implies a secure storage system on leaky devices, where a value s can be secretely stored on devices that continually leak information about their internal state to an external attacker. The devices go through a periodic refresh protocol...

  4. Mission analysis report for single-shell tank leakage mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Cruse, J.M.

    1994-09-01

    This document provides an analysis of the leakage mitigation mission applicable to past and potential future leakage from the Hanford Site`s 149 single-shell high-level waste tanks. This mission is a part of the overall missions of the Westinghouse Hanford Company Tank Waste Remediation System division to remediate the tank waste in a safe and acceptable manner. Systems engineers principles are being applied to this effort. Mission analysis supports early decision making by clearly defining program objectives. This documents identifies the initial conditions and acceptable final conditions, defines the programmatic and physical interfaces and constraints, estimates the resources to carry out the mission, and establishes measures of success. The results of the mission analysis provide a consistent basis for subsequent systems engineering work.

  5. Binding and Leakage of Barium in Alginate Microbeads

    Science.gov (United States)

    Mørch, Yrr A.; Qi, Meirigeng; Gundersen, Per Ole M.; Formo, Kjetil; Lacik, Igor; Skjåk-Bræk, Gudmund; Oberholzer, Jose; Strand, Berit L.

    2013-01-01

    Microbeads of alginate cross-linked with Ca2+ and/or Ba2+ are popular matrices in cell-based therapy. The aim of this study was to quantify the binding of barium in alginate microbeads and its leakage under in vitro and accumulation under in vivo conditions. Low concentrations of barium (1 mM) in combination with calcium (50 mM) and high concentrations of barium (20 mM) in gelling solutions were used for preparation of microbeads made of high-G and high-M alginates. High-G microbeads accumulated barium from gelling solution and contained higher concentrations of divalent ions for both low- and high-Ba exposure compared to high-G microbeads exposed to calcium solely and to high-M microbeads for all gelling conditions. Although most of the unbound divalent ions were removed during the wash and culture steps, leakage of barium was still detected during storage. Barium accumulation in blood and femur bone of mice implanted with high-G beads was found to be dose-dependent. Estimated barium leakage relevant to transplantation to diabetic patients with islets in alginate microbeads showed that the leakage was 2.5 times lower than the tolerable intake value given by WHO for high-G microbeads made using low barium concentration. The similar estimate gave 1.5 times higher than is the tolerable intake value for the high-G microbeads made using high barium concentration. In order to reduce the risk of barium accumulation that may be of safety concern, the microbeads made of high-G alginate gelled with a combination of calcium and low concentration of barium ions is recommended for islet transplantation. PMID:22700168

  6. A Labview Based Leakage Current Monitoring System For HV Insulators

    OpenAIRE

    N. Mavrikakis; I. Androulidakis; D. Pylarinos; K. Siderakis

    2015-01-01

    In this paper, a Labview based leakage current monitoring system for High Voltage insulators is described. The system uses a general purpose DAQ system with the addition of different current sensors. The DAQ system consists of a chassis and hot-swappable modules. Through the proper design of current sensors, low cost modules operating with a suitable input range can be employed. Fully customizable software can be developed using Labview, allowing on-demand changes and incorporatio...

  7. Thermogenic Wet Gas in Immature Caprock Sections: Leakage or Generation.

    Science.gov (United States)

    Abrakasa, Selegha; Beka, Francis; Ndukauba, Egesi

    2017-04-01

    Gas geochemistry, an aspect of Petroleum Geoscience is a growing science, various concepts has been used to evaluation potential source rock for shale gas while in conventional petroleum exploration similar concepts have been used to determine potential productive formation for liquid hydrocarbons. Prior to the present times, headspace gas data had been used to recognize by pass pays, serve as indicators of petroleum accumulations, evaluate maturity and productive capacity of corresponding formations, evaluate the maturity and source of gas accumulations. Integrating studies in bid to achieve high degree of accuracy, data on direct hydrocarbon indicators (DHIs) such as oil stains, oil shows and seeps have been employed. Currently popular among professionals is the use of gas clouds on seismic cross sections. In contemporary times, advancement in gas geochemistry has witnessed the application of concepts on headspace gas to expound the efficiency of petroleum caprocks whose major role is to foster accumulation and preservation. This enables extricating potential leakage mechanism via caprock reservoir interface and unravel its corresponding migrational pathways. In this study thermogenic wet gas has been used as a dependable tool for delineating caprock leakage by discriminating migrant from indigenous hydrocarbons in caprock rock sections overlying the reservoirs. The thermogenic gas profile in corroboration with the thermogenic signature and maturity data were used. Summary statistics indicates that 60% of the 50 wells studied has wet gas up to 500m above the reservoir-caprock interface and 10% of the leaking wells are fracture prone leakage.The amount of wet gas ranges of up to 200,000 ppm in the caprock sections, this indicates pervasive leakage. Log view plots were modelled using Schlumbergers' Techlog, while descriptive lithologies were modeled using Zetawares' genesis.

  8. Pore formation by T3SS translocators: liposome leakage assay.

    Science.gov (United States)

    Faudry, Eric; Perdu, Caroline; Attrée, Ina

    2013-01-01

    Gram-negative bacteria utilize a dedicated membrane-embedded apparatus, the type III secretion system (T3SS), to inject proteins into host cells. The passage of the proteins across the target membrane is accomplished by a proteinaceous pore-the translocon-formed within the host-cell cytoplasmic membrane. Translocators bound to their chaperones can be expressed in Escherichia coli and subsequently dissociated from the chaperone by guanidine treatment. The pore formation properties of the translocators can then be studied by an in-vitro liposome leakage assay. Sulforhodamine-B is encapsulated within lipid vesicles during liposome preparation. At high concentration, this fluorochrome exhibits self-quenching limiting fluorescence emission. Upon pore formation, liposome leakage leads to the dilution of Sulforhodamine-B in the medium and fluorescence emission increases. Alternatively, fluorochromes coupled to large dextran molecules can be encapsulated in order to estimate pore dimensions. Here we describe protein expression and purification, dye-liposome preparation, and leakage assay conditions.

  9. Indoor-Outdoor Air Leakage of Apartments and Commercial Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Price, P.N.; Shehabi, A.; Chan, R.W.; Gadgil, A.J.

    2006-06-01

    We compiled and analyzed available data concerning indoor-outdoor air leakage rates and building leakiness parameters for commercial buildings and apartments. We analyzed the data, and reviewed the related literature, to determine the current state of knowledge of the statistical distribution of air exchange rates and related parameters for California buildings, and to identify significant gaps in the current knowledge and data. Very few data were found from California buildings, so we compiled data from other states and some other countries. Even when data from other developed countries were included, data were sparse and few conclusive statements were possible. Little systematic variation in building leakage with construction type, building activity type, height, size, or location within the u.s. was observed. Commercial buildings and apartments seem to be about twice as leaky as single-family houses, per unit of building envelope area. Although further work collecting and analyzing leakage data might be useful, we suggest that a more important issue may be the transport of pollutants between units in apartments and mixed-use buildings, an under-studied phenomenon that may expose occupants to high levels of pollutants such as tobacco smoke or dry cleaning fumes.

  10. Subsurface Barrier Formation as a CO2 Leakage Mitigation Technology

    Science.gov (United States)

    Castaneda Herrera, C. A.; Stevens, G.; Haese, R. R.

    2015-12-01

    Long-term CO2 containment in a geological storage reservoir is a key criterion for successfully implementing carbon capture and storage (CCS), however, CO2 leakage through different pathways cannot be completely ruled out in some instances. In this study we investigate the conditions for reactive barrier formation as a technology to mitigate and remediate CO2 leakage. We propose to inject a liquid reagent consistent of an alkaline sodium-silicate solution on top of the storage caprock, which will lead to silica mineral precipitation when in contact with an acidic, CO2-enriched fluid. This reaction will create a barrier that seals the leakage by reducing the permeability. Preliminary modelling has shown that the density, viscosity and alkalinity of the reagent fluid are critical for a successful seal formation, whereas differences in formation water composition and in the rock mineral composition are less important. In order to study the reaction through experiments, different reagent solutions were prepared and characterised in terms of silica concentration, density, viscosity and buffer capacity. In a static, diffusion-controlled batch experiment we observed silica mineral precipitation in the outer layer of the piece of rock inhibiting further mixing of the two fluids and slowing down the initial reaction rate. Core-flood experiments will be carried out to simulate barrier formation under fluid flow conditions. Here, the sealing efficiency of the reaction will be continuously measured in terms of a change in permeability.

  11. Air Leakage and Air Transfer Between Garage and Living Space

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, Armin [Building Science Corporation, Westford, MA (United States)

    2014-09-01

    This research project focused on evaluation of air transfer between the garage and living space in a single-family detached home constructed by a production homebuilder in compliance with the 2009 International Residential Code and the 2009 International Energy Conservation Code. The project gathered important information about the performance of whole-building ventilation systems and garage ventilation systems as they relate to minimizing flow of contaminated air from garage to living space. A series of 25 multi-point fan pressurization tests and additional zone pressure diagnostic testing characterized the garage and house air leakage, the garage-to-house air leakage, and garage and house pressure relationships to each other and to outdoors using automated fan pressurization and pressure monitoring techniques. While the relative characteristics of this house may not represent the entire population of new construction configurations and air tightness levels (house and garage) throughout the country, the technical approach was conservative and should reasonably extend the usefulness of the results to a large spectrum of house configurations from this set of parametric tests in this one house. Based on the results of this testing, the two-step garage-to-house air leakage test protocol described above is recommended where whole-house exhaust ventilation is employed.

  12. A Minimum Leakage Quasi-Static RAM Bitcell

    Directory of Open Access Journals (Sweden)

    Adam Teman

    2011-05-01

    Full Text Available As SRAMs continue to grow and comprise larger percentages of the area and power consumption in advanced systems, the need to minimize static currents becomes essential. This brief presents a novel 9T Quasi-Static RAM Bitcell that provides aggressive leakage reduction and high write margins. The quasi-static operation method of this cell, based on internal feedback and leakage ratios, minimizes static power while maintaining sufficient, albeit depleted, noise margins. This paper presents the concept of the novel cell, and discusses the stability of the cell under hold, read and write operations. The cell was implemented in a low-power 40 nm TSMC process, showing as much as a 12× reduction in leakage current at typical conditions, as compared to a standard 6T or 8T bitcell at the same supply voltage. The implemented cell showed full functionality under global and local process variations at nominal and low voltages, as low as 300 mV.

  13. 10 CFR Appendix J to Part 50 - Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors

    Science.gov (United States)

    2010-01-01

    ...-Cooled Power Reactors J Appendix J to Part 50 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Pt. 50, App. J Appendix J to Part 50—Primary Reactor Containment... basis accident and specified either in the technical specification or associated bases. J. Pt (p.s.i.g...

  14. Maximum Entropy Discrimination Markov Networks

    OpenAIRE

    Zhu, Jun; Xing, Eric P.

    2009-01-01

    In this paper, we present a novel and general framework called {\\it Maximum Entropy Discrimination Markov Networks} (MaxEnDNet), which integrates the max-margin structured learning and Bayesian-style estimation and combines and extends their merits. Major innovations of this model include: 1) It generalizes the extant Markov network prediction rule based on a point estimator of weights to a Bayesian-style estimator that integrates over a learned distribution of the weights. 2) It extends the ...

  15. Scintigraphic localization of lymphatic leakage site after oral administration of iodine-123-IPPA.

    Science.gov (United States)

    Kettner, B I; Aurisch, R; Rückert, J C; Sandrock, D; Munz, D L

    1998-12-01

    Chylothorax can occur secondary to traumatic lesions of the thoracic duct caused by chest injuries, surgical procedures involving the pleural space, neoplasms or malformations of the lymphatics. Lymphatic leakage sites were localized by scintigraphy after oral administration of the 123I-labeled long-chain fatty acid derivative iodophenyl pentadecanoic acid (IPPA). We report on three patients with different lymphatic leakage sites and on one normal control subject. IPPA scintigraphy localized the lymphatic leakage site correctly in all three patients. In two of them, the method even guided the successful surgical treatment of the leakage. This approach is suitable for detecting lymphatic leakages of intestinal origin.

  16. [Detection of marginal leakage of Class V restorations in vitro by micro-CT].

    Science.gov (United States)

    Gu, Lin-juan; Zhao, Xin-yi; Li, Shi-bao

    2012-09-01

    To evaluate the reliability and superiority of micro-CT in marginal leakage assessment of Class V restorations. Class V preparations with gingival margins in dentin and occlusal in enamel were made in sixteen extracted non-carious human molars and restored with dental bonding agents and composite resin. All teeth were then immersed in 50% ammonia-silver nitrate solution for 12 hours, followed by developing solution for 8 hours. Each restoration was scanned by a micro-CT and silver leakage was measured and three-dimensional image of the silver leakage alone cavity wall were reconstructed. Afterward, all restorations were sectioned and examined for leakage depth using a microscope. The silver leakage depth of each restoration obtained by micro-CT and microscope were compared for equivalency. The silver leakage depths in gingival wall obtained with micro-CT (0.78 mm) and microscope (0.74 mm) showed no significant difference (P > 0.05), while the judgment of leakage depths in occlusal wall in micro-CT image (0.40 mm) was affected by adjacent enamel structure, giving less leakage depths compared to microscope (0.72 mm)(P Class V restorations were multiform and some leakages showed channels on their way to spreading. Micro-CT can detect precisely the silver leakage in the dentin wall of a restoration and display its three-dimensional shape fully. Enamel structure affects the detection of the silver leakage next to it.

  17. Short-term effects of CO2 leakage on the soil bacterial community in a simulated gas leakage scenario

    Directory of Open Access Journals (Sweden)

    Jing Ma

    2017-11-01

    Full Text Available The technology of carbon dioxide (CO2 capture and storage (CCS has provided a new option for mitigating global anthropogenic emissions with unique advantages. However, the potential risk of gas leakage from CO2 sequestration and utilization processes has attracted considerable attention. Moreover, leakage might threaten soil ecosystems and thus cannot be ignored. In this study, a simulation experiment of leakage from CO2 geological storage was designed to investigate the short-term effects of different CO2 leakage concentration (from 400 g m−2 day−1 to 2,000 g m−2 day−1 on soil bacterial communities. A shunt device and adjustable flow meter were used to control the amount of CO2 injected into the soil. Comparisons were made between soil physicochemical properties, soil enzyme activities, and microbial community diversity before and after injecting different CO2 concentrations. Increasing CO2 concentration decreased the soil pH, and the largest variation ranged from 8.15 to 7.29 (p < 0.05. Nitrate nitrogen content varied from 1.01 to 4.03 mg/Kg, while Olsen-phosphorus and total phosphorus demonstrated less regular downtrends. The fluorescein diacetate (FDA hydrolytic enzyme activity was inhibited by the increasing CO2 flux, with the average content varying from 22.69 to 11.25 mg/(Kg h (p < 0.05. However, the increasing activity amplitude of the polyphenol oxidase enzyme approached 230%, while the urease activity presented a similar rising trend. Alpha diversity results showed that the Shannon index decreased from 7.66 ± 0.13 to 5.23 ± 0.35 as the soil CO2 concentration increased. The dominant phylum in the soil samples was Proteobacteria, whose proportion rose rapidly from 28.85% to 67.93%. In addition, the proportion of Acidobacteria decreased from 19.64% to 9.29% (p < 0.01. Moreover, the abundances of genera Methylophilus, Methylobacillus, and Methylovorus increased, while GP4, GP6 and GP7 decreased. Canonical correlation analysis

  18. Decomposition using Maximum Autocorrelation Factors

    DEFF Research Database (Denmark)

    Larsen, Rasmus

    2002-01-01

    are organised in a two-dimensional grid. Another example is biological shape analysis. Here each observation (e.g. human bone, cerebral ventricle) is represented by a number of landmarks the coordinates of which are the variables. Here we do not have an ordering of the observations (individuals). However......, normally we have an ordering of landmarks (variables) along the contour of the objects. For the case with observation ordering the maximum autocorrelation factor (MAF) transform was proposed for multivariate imagery in\\verb+~+\\$\\backslash\\$cite{switzer85}. This corresponds to a R-mode analyse of the data...

  19. Generic maximum likely scale selection

    DEFF Research Database (Denmark)

    Pedersen, Kim Steenstrup; Loog, Marco; Markussen, Bo

    2007-01-01

    in this work is on applying this selection principle under a Brownian image model. This image model provides a simple scale invariant prior for natural images and we provide illustrative examples of the behavior of our scale estimation on such images. In these illustrative examples, estimation is based......The fundamental problem of local scale selection is addressed by means of a novel principle, which is based on maximum likelihood estimation. The principle is generally applicable to a broad variety of image models and descriptors, and provides a generic scale estimation methodology. The focus...

  20. Carbon Equivalent and Maximum Hardness

    OpenAIRE

    Haruyoshi, Suzuki; Head Office, Nippon Steel Corporation

    1984-01-01

    The accuracy of formulae for estimating the maximum hardness values of the HAZ from chemical composition and cooling time for welds in high strength steel is discussed and a new formula. NSC-S, is proposed which uses only C%, Pcm% and cooling time for the purpose of satisfactory accuracy. IIW CE and Ito-Bessyo Pcm carbon equivalent alone are not satisfactory in establishing Hmax values. The former is good only for slow cooling, t8/5 longer than 10 seconds, while the latter is good only for fa...

  1. CCS Site Optimization by Applying a Multi-objective Evolutionary Algorithm to Semi-Analytical Leakage Models

    Science.gov (United States)

    Cody, B. M.; Gonzalez-Nicolas, A.; Bau, D. A.

    2011-12-01

    Carbon capture and storage (CCS) has been proposed as a method of reducing global carbon dioxide (CO2) emissions. Although CCS has the potential to greatly retard greenhouse gas loading to the atmosphere while cleaner, more sustainable energy solutions are developed, there is a possibility that sequestered CO2 may leak and intrude into and adversely affect groundwater resources. It has been reported [1] that, while CO2 intrusion typically does not directly threaten underground drinking water resources, it may cause secondary effects, such as the mobilization of hazardous inorganic constituents present in aquifer minerals and changes in pH values. These risks must be fully understood and minimized before CCS project implementation. Combined management of project resources and leakage risk is crucial for the implementation of CCS. In this work, we present a method of: (a) minimizing the total CCS cost, the summation of major project costs with the cost associated with CO2 leakage; and (b) maximizing the mass of injected CO2, for a given proposed sequestration site. Optimization decision variables include the number of CO2 injection wells, injection rates, and injection well locations. The capital and operational costs of injection wells are directly related to injection well depth, location, injection flow rate, and injection duration. The cost of leakage is directly related to the mass of CO2 leaked through weak areas, such as abandoned oil wells, in the cap rock layers overlying the injected formation. Additional constraints on fluid overpressure caused by CO2 injection are imposed to maintain predefined effective stress levels that prevent cap rock fracturing. Here, both mass leakage and fluid overpressure are estimated using two semi-analytical models based upon work by [2,3]. A multi-objective evolutionary algorithm coupled with these semi-analytical leakage flow models is used to determine Pareto-optimal trade-off sets giving minimum total cost vs. maximum mass

  2. Simulations of hydraulic fracturing and leakage in sedimentary basins

    Energy Technology Data Exchange (ETDEWEB)

    Lothe, Ane Elisabeth

    2004-01-01

    Hydraulic fracturing and leakage of water through the caprock is described from sedimentary basin over geological time scale. Abnormal pressure accumulations reduce the effective stresses in the underground and trigger the initiation of hydraulic fractures. The major faults in the basin define these pressure compartments. In this Thesis, basin simulations of hydraulic fracturing and leakage have been carried out. A simulator (Pressim) is used to calculate pressure generation and dissipitation between the compartments. The flux between the compartments and not the flow within the compartments is modelled. The Griffith-Coulomb failure criterion determines initial failure at the top structures of overpressured compartments, whereas the frictional sliding criterion is used for reactivation along the same fractures. The minimum horizontal stress is determined from different formulas, and an empirical one seems to give good results compared to measured pressures and minimum horizontal stresses. Simulations have been carried out on two datasets; one covering the Halten Terrace area and one the Tune Field area in the northern North Sea. The timing of hydraulic fracturing and amount of leakage has been quantified in the studies from the Halten Terrace area. This is mainly controlled by the lateral fluid flow and the permeability of the major faults in the basin. Low fault permeability gives early failure, while high fault permeabilities results in no or late hydraulic fracturing and leakage from overpressured parts of the basin. In addition to varying the transmissibility of all faults in a basin, the transmissibility across individual faults can be varied. Increasing the transmissibility across faults is of major importance in overpressured to intermediately pressured areas. However, to obtain change in the flow, a certain pressure difference has to be the situation between the different compartments. The coefficient of internal friction and the coefficient of frictional

  3. Assessment of different dyes used in leakage studies.

    Science.gov (United States)

    Mente, Johannes; Ferk, Stephan; Dreyhaupt, Jens; Deckert, Andreas; Legner, Milos; Staehle, Hans Joerg

    2010-06-01

    The goal of this in vitro study was to identify the most suitable dye for endodontic dye leakage studies, which could be a further step towards standardisation. The root canals of 70 extracted, single-rooted human adult teeth were enlarged to apical size 50 using hand instruments. The teeth were divided into seven groups (n = 10 each), and all root canals were completely filled by injection with one of the following dyes: methylene blue 0.5% and 5%, blue ink, black ink, eosin 5%, basic fuchsin 0.5% and drawing ink. Transverse root sections from the coronal, middle and apical part of the roots were examined, and the percentage of the dentine penetrated by dye was evaluated by software-supported light microscopy. In addition, the range of particle size of drawing ink particles was evaluated. There were conspicuous differences in the relative dye penetration into the root dentine and the penetration behaviour in the different root sections (two-way ANOVA, both p < 0.0001). One dye (drawing ink) penetrated less into the root dentine compared with all the others (p <0.0001). The particle size of this agent (0.1-2 microm) corresponds best with the size range of a representative selection of 21 species of pathogenic endodontic bacteria. Compared to the other dyes tested, drawing ink appears to be superior for use in endodontic dye leakage studies. The penetration behaviour into the root dentine of all the other dyes tested might be one factor that limits the applicability of these dyes in dye leakage studies.

  4. An iterative method for airway segmentation using multiscale leakage detection

    Science.gov (United States)

    Nadeem, Syed Ahmed; Jin, Dakai; Hoffman, Eric A.; Saha, Punam K.

    2017-02-01

    There are growing applications of quantitative computed tomography for assessment of pulmonary diseases by characterizing lung parenchyma as well as the bronchial tree. Many large multi-center studies incorporating lung imaging as a study component are interested in phenotypes relating airway branching patterns, wall-thickness, and other morphological measures. To our knowledge, there are no fully automated airway tree segmentation methods, free of the need for user review. Even when there are failures in a small fraction of segmentation results, the airway tree masks must be manually reviewed for all results which is laborious considering that several thousands of image data sets are evaluated in large studies. In this paper, we present a CT-based novel airway tree segmentation algorithm using iterative multi-scale leakage detection, freezing, and active seed detection. The method is fully automated requiring no manual inputs or post-segmentation editing. It uses simple intensity based connectivity and a new leakage detection algorithm to iteratively grow an airway tree starting from an initial seed inside the trachea. It begins with a conservative threshold and then, iteratively shifts toward generous values. The method was applied on chest CT scans of ten non-smoking subjects at total lung capacity and ten at functional residual capacity. Airway segmentation results were compared to an expert's manually edited segmentations. Branch level accuracy of the new segmentation method was examined along five standardized segmental airway paths (RB1, RB4, RB10, LB1, LB10) and two generations beyond these branches. The method successfully detected all branches up to two generations beyond these segmental bronchi with no visual leakages.

  5. Air Leakage and Air Transfer Between Garage and Living Space

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, A.

    2014-09-01

    This research project focused on evaluation of air transfer between the garage and living space in a single-family detached home constructed by a production homebuilder in compliance with the 2009 International Residential Code and the 2009 International Energy Conservation Code. The project gathered important information about the performance of whole-building ventilation systems and garage ventilation systems as they relate to minimizing flow of contaminated air from garage to living space. A series of 25 multi-point fan pressurization tests and additional zone pressure diagnostic testing characterized the garage and house air leakage, the garage-to-house air leakage, and garage and house pressure relationships to each other and to outdoors using automated fan pressurization and pressure monitoring techniques. While the relative characteristics of this house may not represent the entire population of new construction configurations and air tightness levels (house and garage) throughout the country, the technical approach was conservative and should reasonably extend the usefulness of the results to a large spectrum of house configurations from this set of parametric tests in this one house. Based on the results of this testing, the two-step garage-to-house air leakage test protocol described above is recommended where whole-house exhaust ventilation is employed. For houses employing whole-house supply ventilation (positive pressure) or balanced ventilation (same pressure effect as the Baseline condition), adherence to the EPA Indoor airPLUS house-to-garage air sealing requirements should be sufficient to expect little to no garage-to-house air transfer.

  6. Lightweight space radiator with leakage control by internal electrostatic fields

    Science.gov (United States)

    Kim, Hyo; Bankoff, S. G.; Miksis, Michael J.

    1991-01-01

    An electrostatic liquid film space radiator is proposed. This will employ an internal electrostatic field to prevent leakage of the liquid-metal coolant out of a puncture. This overcomes the major disadvantage of membrane radiators, which is their vulnerability to micrometeorite impacts. Calculations show that leaks of liquid lithium at 700° K can easily be stopped from punctures which are several mm in diameter, with very large safety factors. The basic idea lends itself to a variety of radiator concepts, both rotating and non-rotating. Some typical film thickness and pressure calculations in the presence of an electric field are shown.

  7. Threats of Password Pattern Leakage Using Smartwatch Motion Recognition Sensors

    Directory of Open Access Journals (Sweden)

    Jihun Kim

    2017-06-01

    Full Text Available Thanks to the development of Internet of Things (IoT technologies, wearable markets have been growing rapidly. Smartwatches can be said to be the most representative product in wearable markets, and involve various hardware technologies in order to overcome the limitations of small hardware. Motion recognition sensors are a representative example of those hardware technologies. However, smartwatches and motion recognition sensors that can be worn by users may pose security threats of password pattern leakage. In the present paper, passwords are inferred through experiments to obtain password patterns inputted by users using motion recognition sensors, and verification of the results and the accuracy of the results is shown.

  8. Low Leakage Turbine Shaft Seals for Advanced Combined Cycle Systems.

    Science.gov (United States)

    1984-11-01

    leakage causes virtually all of the makeup feedwater requirements and consequent requirements for evaporators, storage tanks, DI bottle sizes, and...conservative approach and thereby maximizing reliability potential. The face seal configuration features a (rotating) runner which is virtually ...STANDARD, 196 A -I--~ ~ FD In~IU1 ~ - - - K ’ ,t ~N _i.SA 4 0 0 0 di- AULAS -w - W-6 4. . 0I - I 0 i C- A L; u V) c, 3>. _ I IL’C a rx i.- V

  9. Pharmacological effects of various venoms on cutaneous capillary leakage.

    Science.gov (United States)

    Burnett, J W; Calton, G J

    1986-01-01

    Studies to counteract the cutaneous vasopermeability actions of a wasp (Vespa orientalis), an anemone (Bolocera tuediae) and three jellyfish (Chironex fleckeri, Chrysaora quinquecirrha and Physalia physalis) venoms were conducted by using various pharmacological antagonists. Piripost (a leukotriene inhibitor) reduced vasopermeability if administered 5 min prior to challenge with the jellyfish venoms. Methysergide counteracted the vasopermeability of three of four coelenterate venoms, whereas indomethacin was effective against capillary leakage induced by Chironex venom. These studies indicate that anti-dermonecrotic therapy against various venoms will have to be species-specific.

  10. Current leakage for low altitude satellites. [to surrounding plasma sheath

    Science.gov (United States)

    Mccoy, J. E.; Konradi, A.; Garriott, O. K.

    1979-01-01

    Ionospheric plasma densities exceeding 1,000,000 per cu cm exist around satellites in low earth orbit. Operation of large solar arrays at high voltage may drive substantial leakage currents through this surrounding plasma. Power losses exceeding solar cell output have been observed for small arrays biased above +2,000 V. Estimates of these effects for very large power systems are developed. Recent large scale (10 meter) lab tests are reported. Estimates based on calculations of space charge limited sheath dimensions are identified as a good working model, leading to projected power losses for large arrays increasing much more slowly than for small arrays.

  11. Design of Earth Leakage Circuit Breaker on Sensitivity 20 MA

    Directory of Open Access Journals (Sweden)

    Pandung Sarungallo

    2008-08-01

    Full Text Available Electrics current can flow out to the ground by using a human body. This electric current will be dangerous to the human when it exceed 20mA. A very sensitive earth leakage circuit breaker (ELCB is needed to anticipate the leaky current but most of ELCB can only be found in the market with sensitivitas 30mA or bigger. This research is succees to design an ELCB with sensitivity 20mA. Characteristic of an ELCB is very influenced by the current transformer characteristic and the relay which are used.

  12. Decreased Leakage Rate of Colonic Anastomoses by Tachosil Coating

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian; Achiam, Michael Patrick; Burcharth, Jakob

    2014-01-01

    Colorectal anastomotic coating has been proposed as a means to lower the leakage rate. Prior to clinical testing, coating materials need thorough experimental evaluation to ensure safety and efficacy. The aim of this study was to evaluate Tachosil as an anastomotic coating agent. Technically...... coating (10/40 versus 20/40 in controls; P=0.037). However, more cases of large bowel obstruction were found in the Tachosil group (12/40 versus 0/40 in controls; P... studies are needed to clarify the efficacy of Tachosil anastomotic coating....

  13. Comparative evaluation of marginal leakage of provisional crowns cemented with different temporary luting cements: In vitro study

    Science.gov (United States)

    Arora, Sheen Juneja; Arora, Aman; Upadhyaya, Viram; Jain, Shilpi

    2016-01-01

    Background or Statement of Problem: As, the longevity of provisional restorations is related to, a perfect adaptation and a strong, long-term union between restoration and teeth structures, therefore, evaluation of marginal leakage of provisional restorative materials luted with cements using the standardized procedures is essential. Aims and Objectives: To compare the marginal leakage of the provisional crowns fabricated from Autopolymerizing acrylic resin crowns and bisphenol A-glycidyl dimethacrylate (BIS-GMA) resin crowns. To compare the marginal leakage of the provisional crowns fabricated from autopolymerizing acrylic resin crowns and BIS-GMA resin crowns cemented with different temporary luting cements. To compare the marginal leakage of the provisional crowns fabricated from autopolymerizing acrylic resin (SC-10) crowns cemented with different temporary luting cements. To compare the marginal leakage of the provisional crowns fabricated from BIS-GMA resin crowns (Protemp 4) cemented with different temporary luting cements. Methodology: Freshly extracted 60 maxillary premolars of approximately similar dimensions were mounted in dental plaster. Tooth reduction with shoulder margin was planned to use a customized handpiece-holding jig. Provisional crowns were prepared using the wax pattern fabricated from computer aided designing/computer aided manufacturing milling machine following the tooth preparation. Sixty provisional crowns were made, thirty each of SC-10 and Protemp 4 and were then cemented with three different luting cements. Specimens were thermocycled, submerged in a 2% methylene blue solution, then sectioned and observed under a stereomicroscope for the evaluation of marginal microleakage. A five-level scale was used to score dye penetration in the tooth/cement interface and the results of this study was analyzed using the Chi-square test, Mann–Whitney U-test, Kruskal–Wallis H-test and the results were statistically significant P crowns

  14. Last Glacial Maximum in Poland

    Science.gov (United States)

    Marks, Leszek

    2002-01-01

    The Last Glacial Maximum (LGM) in Poland is represented by the Leszno Phase and occurred after 21 ka radiocarbon years. In turn the deglacial Poznań Phase is estimated at 18.4 ka, the Pomeranian Phase at 15.2 ka, the Gardno Phase at about 14.0-13.8 ka, the Słupsk Bank Phase at 13.5-13.2 ka and the Southern Middle Bank Phase at 12.7-12.5 ka BP. The ice sheet limit at LGM was not synchronous everywhere in Poland but occurred as several major and minor ice lobes that reflected a stream-like structure of the ice body that radiated southwards from the Baltic Basin. Meltwater runoff during the LGM created a complex system of sandur trains and ice-marginal spillways, with numerous intervening proglacial lakes.

  15. Objects of maximum electromagnetic chirality

    CERN Document Server

    Fernandez-Corbaton, Ivan

    2015-01-01

    We introduce a definition of the electromagnetic chirality of an object and show that it has an upper bound. The upper bound is attained if and only if the object is transparent for fields of one handedness (helicity). Additionally, electromagnetic duality symmetry, i.e. helicity preservation upon scattering, turns out to be a necessary condition for reciprocal scatterers to attain the upper bound. We use these results to provide requirements for the design of such extremal scatterers. The requirements can be formulated as constraints on the polarizability tensors for dipolar scatterers or as material constitutive relations. We also outline two applications for objects of maximum electromagnetic chirality: A twofold resonantly enhanced and background free circular dichroism measurement setup, and angle independent helicity filtering glasses.

  16. Maximum mutual information regularized classification

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-09-07

    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  17. System for Memorizing Maximum Values

    Science.gov (United States)

    Bozeman, Richard J., Jr. (Inventor)

    1996-01-01

    The invention discloses a system capable of memorizing maximum sensed values. The system includes conditioning circuitry which receives the analog output signal from a sensor transducer. The conditioning circuitry rectifies and filters the analog signal and provides an input signal to a digital driver, which may be either liner or logarithmic. The driver converts the analog signal to discrete digital values, which in turn triggers an output signal on one of a plurality of driver output lines n. The particular output lines selected is dependent on the converted digital value. A microfuse memory device connects across the driver output lines, with n segments. Each segment is associated with one driver output line, and includes a microfuse that is blown when a signal appears on the associated driver output line.

  18. Application Of The Climafor Baseline To Determine Leakage: TheCase Of Scolel Te.

    Energy Technology Data Exchange (ETDEWEB)

    De Jong, B.H.J.; Bazan, E. Esquivel; Quechulpa Montalvo, S.

    2007-06-01

    The acceptance of forestry-based project activities tomitigate greenhouse gases emissions has been subjected to a number ofmethodological questions to be answered, of which the most challengingare baseline establishment and identification of and measuring leakage.Here we pose hypotheses for and quantify leakage of the Scolel Te projectin Chiapas, Mexico. In this project small-scale farmers are implementingforestry, agroforestry, and forest conservation activities, with carbonsequestration as one of the goals. The main leakage monitoring domain isdefined as the area owned by the participating farmers or communitiesoutside the area where the specific project activities take place. Thenull-hypothesis (no leakage) is that non-project land owned by the farmeror community will experience the same carbon stock changes as predictedby the regional baseline, specifically developed for the project. Firstwe assessed the most likely causes and sources of leakage that may occurin the project. From this analysis, one type of leakage seems to beimportant, i.e., activity shifting. Second we estimated the leakage of asample of participating farmers and communities. Actual land use was thencompared with expected land use derived from the baseline. The Plan Vivoof each participant, complemented with readily available tools toidentify the main sources and drivers of leakage are used to developsimple leakage assessment procedures, as demonstrated in this paper.Negative leakage was estimated to be negligible in this study.Incorporating these procedures already in the project planning stage willreduce the uncertainties related to the actual carbon mitigationpotential of any forestry project.

  19. Studies of axial-leakage simulations for homogeneous and heterogeneous EBR-II core configurations

    Energy Technology Data Exchange (ETDEWEB)

    Grimm, K.N.; Meneghetti, D.

    1985-08-01

    When calculations of flux are done in less than three dimensions, leakage-absorption cross sections are normally used to model leakages (flows) in the dimensions for which the flux is not calculated. Since the neutron flux is axially dependent, the leakages, and hence the leakage-absorption cross sections, are also axially dependent. Therefore, to obtain axial flux profiles (or reaction rates) for individual subassemblies, an XY-geometry calculation delineating each subassembly has to be done at several axial heights with space- and energy-dependent leakage-absorption cross sections that are appropriate for each height. This report discusses homogeneous and heterogeneous XY-geometry calculations at various axial locations and using several differing assumptions for the calculation of the leakage-absorption cross section. The positive (outward) leakage-absorption cross sections are modeled as actual leakage absorptions, but the negative (inward) leakage-absorption cross sections are modeled as either negative leakage absorptions (+-B/sup 2/ method) or positive downscatter cross sections (the ..sigma../sub s/(1 ..-->.. g) method). 3 refs., 52 figs., 10 tabs.

  20. Credibility Assessments as 'Normative Leakage': Asylum Applications, Gender and Class

    Directory of Open Access Journals (Sweden)

    Hanna Wikström

    2013-10-01

    Full Text Available Based on the assumption that credibility assessments function as 'normative leakage' within the asylum process, we analyse how narratives of gender and class are articulated, rendered meaningful, or silenced in credibility assessments. Two cases concerning male applicants are selected in order to illustrate these processes. In relation to the existing concepts of internal/external credibility, we wish to introduce the concept of social credibility, which focuses on how the assessors read different socio-cultural narratives. While previous research has shown that the postcolonial will to protect women favours women as victims of patriarchal cultures, we wish to point out the continuity of this line of argumentation in relation to male and female applicants by adopting a theoretical generalization: male applicants instead become situated at the other end of the spectrum of postcolonial notions of modernity as non-victims, victims of other circumstances or perpetrators. We argue that these processes are accentuated in relation to credibility assessments. In order to prevent processes of social exclusion and to enhance inclusive practice, authorities need to acknowledge the 'normative leakage' associated with the assessment process.

  1. Secure Mobile Agent from Leakage-Resilient Proxy Signatures

    Directory of Open Access Journals (Sweden)

    Fei Tang

    2015-01-01

    Full Text Available A mobile agent can sign a message in a remote server on behalf of a customer without exposing its secret key; it can be used not only to search for special products or services, but also to make a contract with a remote server. Hence a mobile agent system can be used for electronic commerce as an important key technology. In order to realize such a system, Lee et al. showed that a secure mobile agent can be constructed using proxy signatures. Intuitively, a proxy signature permits an entity (delegator to delegate its signing right to another entity (proxy to sign some specified messages on behalf of the delegator. However, the proxy signatures are often used in scenarios where the signing is done in an insecure environment, for example, the remote server of a mobile agent system. In such setting, an adversary could launch side-channel attacks to exploit some leakage information about the proxy key or even other secret states. The proxy signatures which are secure in the traditional security models obviously cannot provide such security. Based on this consideration, in this paper, we design a leakage-resilient proxy signature scheme for the secure mobile agent systems.

  2. Detection and quantification of methane leakage from landfills

    Energy Technology Data Exchange (ETDEWEB)

    Ljungberg, Sven-Aake; Maartensson, Stig-Goeran (Univ. of Gaevle, Gaevle (Sweden)); Meijer, Jan-Erik; Rosqvist, Haakan (NSR AB, Helsingborg (Sweden))

    2009-03-15

    The purpose of this project was to detect gas leakage and to measure and quantify methane emission from landfills using modern remote sensing techniques. In this project, a handheld laser instrument and an IR camera were used. The overall objective was to develop cost-effective methods for detecting and quantifying methane emissions from landfills. There are many methods available for measuring the methane concentration in air, both from close-up and from long distances. Combined with the use of a tracer gas, the methane emission from entire landfills can be measured relatively accurately. A number of methods are used to detect leakage from parts of landfill surfaces, but there are few methods for quantifying leakage from sub-zones. Field measurements with the laser instrument and the IR camera were carried out at seven Swedish landfills and two landfills in France. The investigated surfaces at the Swedish landfills were divided into different zones, such as top surface, slope, crest and toe of slope. The field measurements in France were taken over entire landfills. The methane emission varied between the different landfills in the project, and also between the different landfill zones. The results from repeated field measurements indicated that a landfill with a final cap and a successful gas recovery system produces barely measurable emissions. The weak points at a landfill are generally slopes, including crests and toes of slopes. Where the covering of the waste is inadequate, leakage often occurs at lift joints and in areas where waste protrudes through the cover. Other weak points are deficiencies in the gas recovery system. Leachate systems can lead landfill gas and thereby cause methane leakage. Along with wind velocity and variations in atmospheric pressure, moisture content in the ground is an important factor that affects methane emissions from landfill surfaces. Results from field measurements of the same feature/surface at different points in time and

  3. Low standby leakage 12T SRAM cell characterisation

    Science.gov (United States)

    Yadav, Arjun; Nakhate, Sangeeta

    2016-09-01

    In this work, a low power and variability-aware static random access memory (SRAM) architecture based on a twelve-transistor (12T) cell is proposed. This cell obtains low static power dissipation due to a parallel global latch (G-latch) and storage latch (S-latch), along with a global wordline (GWL), which offer a high cell ratio and pull-up ratio for reliable read and write operations and a low cell ratio and pull-up ratio during idle mode to reduce the standby power dissipation. In the idle state, only the S-latch stores bits, while the G-latch is isolated from the S-latch and the GWL is deactivated. The leakage power consumption of the proposed SRAM cell is thereby reduced by 38.7% compared to that of the conventional six-transistor (6T) SRAM cell. This paper evaluates the impact of the chip supply voltage and surrounding temperature variations on the standby leakage power and observes considerable improvement in the power dissipation. The read/write access delay, read static noise margin (SNM) and write SNM were evaluated, and the results were compared with those of the standard 6T SRAM cell. The proposed cell, when compared with the existing cell using the Monte Carlo method, shows an appreciable improvement in the standby power dissipation and layout area.

  4. Heparin Leakage in Central Venous Catheters by Hemodynamic Transport

    Science.gov (United States)

    Barbour, Michael; McGah, Patrick; Gow, Kenneth; Aliseda, Alberto

    2014-11-01

    Central venous catheters (CVCs), placed in the superior vena cava for hemodialysis, are routinely filled with heparin, an anticoagulant, while not in use to maintain patency and prevent thrombus formation at the catheter tip. However, the heparin-lock procedure places the patient at risk for systemic bleeding incidences, as heparin is known to leak into the blood stream. We propose that the driving mechanism behind heparin leakage is advective-diffusive transport due to the pulsatile blood flow surrounding the catheter tip. This novel hypothesis is based on Planar Laser Induced Fluorescence (PLIF) measurements of heparin transport from a CVC placed inside an in vitro pulsatile flow loop and validated with CFD simulations. The results show an initial, fast (catheter lumen, where concentration is still high, that is insufficient at replenishing the lost heparin at the tip. These results, which estimate leakage rates consistent with published in vivo data, predict that the concentration of heparin at the catheter tip is effectively zero for the majority of the interdialytic phase, rendering the heparin lock ineffective.

  5. AN ADVANCED LEAKAGE SCHEME FOR NEUTRINO TREATMENT IN ASTROPHYSICAL SIMULATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Perego, A. [Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstraße 2, D-64289 Darmstadt (Germany); Cabezón, R. M. [Physics Department, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Käppeli, R., E-mail: albino.perego@physik.tu-darmstadt.de [Seminar for Applied Mathematics, ETH Zürich, Rämistrasse 101, 8092 Zürich (Switzerland)

    2016-04-15

    We present an Advanced Spectral Leakage (ASL) scheme to model neutrinos in the context of core-collapse supernovae (CCSNe) and compact binary mergers. Based on previous gray leakage schemes, the ASL scheme computes the neutrino cooling rates by interpolating local production and diffusion rates (relevant in optically thin and thick regimes, respectively) separately for discretized values of the neutrino energy. Neutrino trapped components are also modeled, based on equilibrium and timescale arguments. The better accuracy achieved by the spectral treatment allows a more reliable computation of neutrino heating rates in optically thin conditions. The scheme has been calibrated and tested against Boltzmann transport in the context of Newtonian spherically symmetric models of CCSNe. ASL shows a very good qualitative and a partial quantitative agreement for key quantities from collapse to a few hundreds of milliseconds after core bounce. We have proved the adaptability and flexibility of our ASL scheme, coupling it to an axisymmetric Eulerian and to a three-dimensional smoothed particle hydrodynamics code to simulate core collapse. Therefore, the neutrino treatment presented here is ideal for large parameter-space explorations, parametric studies, high-resolution tests, code developments, and long-term modeling of asymmetric configurations, where more detailed neutrino treatments are not available or are currently computationally too expensive.

  6. The impact of added insulation on air leakage

    Energy Technology Data Exchange (ETDEWEB)

    Anon

    2002-01-01

    It is relatively easy to calculate the impact on energy consumption when thermal insulation is added to the building envelope. However, other effects such as air leakage through the exterior wall assembly, and the potential for water condensation also have to be considered. By adding insulation to the exterior wall assembly, the temperature gradient of the wall is changed and the risk of condensation is increased, especially if warm, moist indoor air can flow through the wall. The study by Dominique Derome, Paul Fazio and Guylaine Desmarais for the CMHC Research Division, of which this paper is a summary, examined three types of air leakage paths, i.e. long air exfiltration path; concentrated air exfiltration path; and distributed exfiltration path. Experiments involved placing 38 mm rigid extruded polystyrene insulation on the interior side of three wood studs and fiberglass batt insulation wall assemblies, while four other samples had the same 38 mm rigid extruded polystyrene insulation added on the exterior of the assembly over the fiberboard sheathing. Both, warm and cold side additions of rigid foam insulation to the existing assemblies increased thermal performance by 55 per cent. When blown cellulose fibre was used as insulation instead of fibreglass batting, the increase in thermal performance was 66 per cent. Addition of the rigid foam insulation on the warm side tended to increase the effectiveness. For example, moisture content generally did not rise above 25 per cent, whereas it could climb up to 70 per cent when the insulation was added on the cold side.

  7. Stereomicroscopic Dye Leakage Measurement of Six Different Root Canal Sealers.

    Science.gov (United States)

    Ballullaya, Srinidhi V; Vinay, Vusurumarthi; Thumu, Jayaprakash; Devalla, Srihari; Bollu, Indira Priyadarshini; Balla, Sagarika

    2017-06-01

    Hermetic sealing of the root canal is the most desirable outcome of any root canal treatment, but almost always the filling of the root canal is defective, which is a multifactorial outcome. One such factor majorly influencing the obturation is the root canal sealer used. The present study was done for evaluating microleakage in different root canal sealers. Sixty extracted human single rooted teeeth were used in this in-vitro study. Sealers tested for microleakage in this study were zinc oxide eugenol based sealer, Sealapex, AH Plus, MTA Plus, EndoRez, Endosequence BC. All the specimens were examined under stereomicroscope for microleakage and the obtained data were statistically analysed using One-way ANOVA test and Tukey's multiple comparision tests using the software GraphPad Prism 7.02. The Endosequence BC group showed the least dye leakage and the highest leakage was seen in Zinc oxide Eugenol based sealer. Bio ceramic salers being hydrophilic show better sealing ability compared to resin based and eugenol based sealers.

  8. ANALYSIS OF MEASUREMENT UNCERTAINTIES IN THE NULLING TEST FOR AIR LEAKAGE FROM RESIDENTIAL DUCTS.

    Energy Technology Data Exchange (ETDEWEB)

    ANDREWS,J.W.

    2001-04-01

    An analysis of measurement uncertainties in a recently proposed method of measuring air leakage in residential duct systems has been carried out. The uncertainties in supply and return leakage rates are expressed in terms of the value of the envelope leakage flow coefficient and the uncertainties in measured pressures and air flow rates. Results of the analysis are compared with data published by two research groups.

  9. Investigation of Leakage Current Waveforms Recorded in a Coastal High Voltage Substation

    OpenAIRE

    E. Thalassinakis; Pyrgioti, E.; K. Siderakis; D. Pylarinos; I. Vitellas

    2011-01-01

    Leakage current monitoring is a widely employed technique to monitor the performance of outdoor insulation. The evaluation of leakage current waveforms recorded in the field, offers significant information since insulation’s performance is strongly linked with local conditions, and the waveforms’ shape correlate to different types of surface activity. In this paper, an investigation of leakage current waveforms recorded in a 150 kV coastal Substations suffering which suffers inten...

  10. Vestige: Maximum likelihood phylogenetic footprinting

    Directory of Open Access Journals (Sweden)

    Maxwell Peter

    2005-05-01

    Full Text Available Abstract Background Phylogenetic footprinting is the identification of functional regions of DNA by their evolutionary conservation. This is achieved by comparing orthologous regions from multiple species and identifying the DNA regions that have diverged less than neutral DNA. Vestige is a phylogenetic footprinting package built on the PyEvolve toolkit that uses probabilistic molecular evolutionary modelling to represent aspects of sequence evolution, including the conventional divergence measure employed by other footprinting approaches. In addition to measuring the divergence, Vestige allows the expansion of the definition of a phylogenetic footprint to include variation in the distribution of any molecular evolutionary processes. This is achieved by displaying the distribution of model parameters that represent partitions of molecular evolutionary substitutions. Examination of the spatial incidence of these effects across regions of the genome can identify DNA segments that differ in the nature of the evolutionary process. Results Vestige was applied to a reference dataset of the SCL locus from four species and provided clear identification of the known conserved regions in this dataset. To demonstrate the flexibility to use diverse models of molecular evolution and dissect the nature of the evolutionary process Vestige was used to footprint the Ka/Ks ratio in primate BRCA1 with a codon model of evolution. Two regions of putative adaptive evolution were identified illustrating the ability of Vestige to represent the spatial distribution of distinct molecular evolutionary processes. Conclusion Vestige provides a flexible, open platform for phylogenetic footprinting. Underpinned by the PyEvolve toolkit, Vestige provides a framework for visualising the signatures of evolutionary processes across the genome of numerous organisms simultaneously. By exploiting the maximum-likelihood statistical framework, the complex interplay between mutational

  11. Vestige: maximum likelihood phylogenetic footprinting.

    Science.gov (United States)

    Wakefield, Matthew J; Maxwell, Peter; Huttley, Gavin A

    2005-05-29

    Phylogenetic footprinting is the identification of functional regions of DNA by their evolutionary conservation. This is achieved by comparing orthologous regions from multiple species and identifying the DNA regions that have diverged less than neutral DNA. Vestige is a phylogenetic footprinting package built on the PyEvolve toolkit that uses probabilistic molecular evolutionary modelling to represent aspects of sequence evolution, including the conventional divergence measure employed by other footprinting approaches. In addition to measuring the divergence, Vestige allows the expansion of the definition of a phylogenetic footprint to include variation in the distribution of any molecular evolutionary processes. This is achieved by displaying the distribution of model parameters that represent partitions of molecular evolutionary substitutions. Examination of the spatial incidence of these effects across regions of the genome can identify DNA segments that differ in the nature of the evolutionary process. Vestige was applied to a reference dataset of the SCL locus from four species and provided clear identification of the known conserved regions in this dataset. To demonstrate the flexibility to use diverse models of molecular evolution and dissect the nature of the evolutionary process Vestige was used to footprint the Ka/Ks ratio in primate BRCA1 with a codon model of evolution. Two regions of putative adaptive evolution were identified illustrating the ability of Vestige to represent the spatial distribution of distinct molecular evolutionary processes. Vestige provides a flexible, open platform for phylogenetic footprinting. Underpinned by the PyEvolve toolkit, Vestige provides a framework for visualising the signatures of evolutionary processes across the genome of numerous organisms simultaneously. By exploiting the maximum-likelihood statistical framework, the complex interplay between mutational processes, DNA repair and selection can be evaluated both

  12. Single phase cascaded H5 inverter with leakage current elimination for transformerless photovoltaic system

    DEFF Research Database (Denmark)

    Guo, Xiaoqiang; Jia, X.; Lu, Z.

    2016-01-01

    inverter fails to reduce the leakage current is clarified. In order to solve the problem, a new cascaded H5 inverter is proposed to solve the leakage current issue. Finally, the experimental results are presented to verify the effectiveness of the proposed topology with the leakage current reduction......Leakage current reduction is one of the important issues for the transformelress PV systems. In this paper, the transformerless single-phase cascaded H-bridge PV inverter is investigated. The common mode model for the cascaded H4 inverter is analyzed. And the reason why the conventional cascade H4...

  13. The Analysis and Comparison of Leakage Inductance in Different Winding Arrangements for Planar Transformer

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Thomsen, Ole Cornelius; Andersen, Michael Andreas E.

    2009-01-01

    to reduce leakage inductance further. Some important issues are presented to acquire desired leakage inductance. The design and modeling of 1 kW planar transformer is presented. In order to verify the analytical method for leakage inductance in this paper, finite element analysis (FEA) and measurement...... (MMF) and energy distribution in planar transformer and correct the formula of leakage inductance proposed by previous publications. The investigation of different winding arrangements shows significant advantages of interleaving structure. In this work, a novel half turn structure is proposed...

  14. Behavior of AC High Voltage Polyamide Insulators: Evolution of Leakage Current in Different Surface Conditions

    OpenAIRE

    Mohammed El Amine Slama; Abderrahmane Beroual

    2015-01-01

    This paper is aimed at a systematic study of the leakage current of high voltage polyamide insulator string under different conditions of pollution for possible application in the electric locomotive systems. It is shown that in the case of clean/dry and clean/wetted insulators, the leakage current and applied voltage are linear. While in the case of pollution with saline spray, the leakage current and the applied voltage are not linear; the leakage current changes from a linear regime to a n...

  15. Behavior of AC High Voltage Polyamide Insulators: Evolution of Leakage Current in Different Surface Conditions

    Directory of Open Access Journals (Sweden)

    Mohammed El Amine Slama

    2015-01-01

    Full Text Available This paper is aimed at a systematic study of the leakage current of high voltage polyamide insulator string under different conditions of pollution for possible application in the electric locomotive systems. It is shown that in the case of clean/dry and clean/wetted insulators, the leakage current and applied voltage are linear. While in the case of pollution with saline spray, the leakage current and the applied voltage are not linear; the leakage current changes from a linear regime to a nonlinear regime up to total flashover of the insulators sting. Traces of erosion and tracking of insulators resulting of partial discharges are observed.

  16. Method of detecting leakage from geologic formations used to sequester CO.sub.2

    Science.gov (United States)

    White, Curt [Pittsburgh, PA; Wells, Arthur [Bridgeville, PA; Diehl, J Rodney [Pittsburgh, PA; Strazisar, Brian [Venetia, PA

    2010-04-27

    The invention provides methods for the measurement of carbon dioxide leakage from sequestration reservoirs. Tracer moieties are injected along with carbon dioxide into geological formations. Leakage is monitored by gas chromatographic analyses of absorbents. The invention also provides a process for the early leak detection of possible carbon dioxide leakage from sequestration reservoirs by measuring methane (CH.sub.4), ethane (C.sub.2H.sub.6), propane (C.sub.3H.sub.8), and/or radon (Rn) leakage rates from the reservoirs. The invention further provides a method for branding sequestered carbon dioxide using perfluorcarbon tracers (PFTs) to show ownership.

  17. Detection of marginal leakage of Class V restorations in vitro by micro-computed tomography.

    Science.gov (United States)

    Zhao, X Y; Li, S B; Gu, L J; Li, Y

    2014-01-01

    This in vitro study evaluated the efficacy of micro-computed tomography (CT) in marginal leakage detection of Class V restorations. Standardized Class V preparations with cervical margins in dentin and occlusal margins in enamel were made in 20 extracted human molars and restored with dental bonding agents and resin composite. All teeth were then immersed in 50% ammoniacal silver nitrate solution for 12 hours, followed by a developing solution for eight hours. Each restoration was scanned by micro-CT, the depth of marginal silver leakage in the central scanning section was measured, and the three-dimensional images of the silver leakage around each restoration were reconstructed. Afterward, all restorations were cut through the center and examined for leakage depth using a microscope. The silver leakage depth of each restoration obtained by the micro-CT and the microscope were compared for equivalency. The silver leakage depth in cervical walls observed by micro-CT and microscope showed no significant difference; however, in certain cases the judgment of leakage depth in the occlusal wall in micro-CT image was affected by adjacent enamel structure, providing less leakage depth than was observed with the microscope (pClass V restorations with clear borders only in the dentin region. It can be concluded that micro-CT can detect nondestructively the leakage around a resin composite restoration in two and three dimensions, with accuracy comparable to that of the conventional microscope method in the dentin region but with inferior accuracy in the enamel region.

  18. Reanastomosis with Stapler in Duodenojejunal Junction Anastomosis Leakage: A Case Report

    Directory of Open Access Journals (Sweden)

    Ahmet Seker

    2013-04-01

    Full Text Available After anastomosis leakages, treatment of patient gets more difficult and mortality rates increase. At lower level gastrointestinal anastomosis leakages, because of always there is an ostomy alternative, digestion problems are seen lesser. But at upper level gastrointestinal system anastomosis leakages, when it is taken account of nutrient condition of patient, requirement of making anastomos increases. So moratlity rates increase. At this article we aimed to present a different technique that we administered on management of a patient who had duodenojejunal junction anastomosis leakage.

  19. Modeling of leakage currents in high-k dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Jegert, Gunther Christian

    2012-03-15

    Leakage currents are one of the major bottlenecks impeding the downscaling efforts of the semiconductor industry. Two core devices of integrated circuits, the transistor and, especially, the DRAM storage capacitor, suffer from the increasing loss currents. In this perspective a fundamental understanding of the physical origin of these leakage currents is highly desirable. However, the complexity of the involved transport phenomena so far has prevented the development of microscopic models. Instead, the analysis of transport through the ultra-thin layers of high-permittivity (high-k) dielectrics, which are employed as insulating layers, was carried out at an empirical level using simple compact models. Unfortunately, these offer only limited insight into the physics involved on the microscale. In this context the present work was initialized in order to establish a framework of microscopic physical models that allow a fundamental description of the transport processes relevant in high-k thin films. A simulation tool that makes use of kinetic Monte Carlo techniques was developed for this purpose embedding the above models in an environment that allows qualitative and quantitative analyses of the electronic transport in such films. Existing continuum approaches, which tend to conceal the important physics behind phenomenological fitting parameters, were replaced by three-dimensional transport simulations at the level of single charge carriers. Spatially localized phenomena, such as percolation of charge carriers across pointlike defects, being subject to structural relaxation processes, or electrode roughness effects, could be investigated in this simulation scheme. Stepwise a self-consistent, closed transport model for the TiN/ZrO{sub 2} material system, which is of outmost importance for the semiconductor industry, was developed. Based on this model viable strategies for the optimization of TiN/ZrO{sub 2}/TiN capacitor structures were suggested and problem areas

  20. Passive electrical monitoring and localization of fluid leakages from wells

    Science.gov (United States)

    Revil, A.; Mao, D.; Haas, A. K.; Karaoulis, M.; Frash, L.

    2015-02-01

    Electrokinetic phenomena are a class of cross-coupling phenomena involving the relative displacement between the pore water (together with the electrical diffuse layer) with respect to the solid phase of a porous material. We demonstrate that electrical fields of electrokinetic nature can be associated with fluid leakages from wells. These leakages can be remotely monitored and the resulting signals used to localize their causative source distribution both in the laboratory and in field conditions. The first laboratory experiment (Experiment #1) shows how these electrical fields can be recorded at the surface of a cement block during the leakage of a brine from a well. The measurements were performed with a research-grade medical electroencephalograph and were inverted using a genetic algorithm to localize the causative source of electrical current and therefore, localize the leak in the block. Two snapshots of electrical signals were used to show how the leak evolved over time. The second experiment (Experiment #2) was performed to see if we could localize a pulse water injection from a shallow well in field conditions in the case of a heterogeneous subsurface. We used the same equipment as in Experiment #1 and processed the data with a trend removal algorithm, picking the amplitude from 24 receiver channels just after the water injection. The amplitude of the electric signals changed from the background level indicating that a volume of water was indeed flowing inside the well into the surrounding soil and then along the well. We used a least-square inversion algorithm to invert a snapshot of the electrical potential data at the injection time to localize the source of the self-potential signals. The inversion results show positive potential anomalies in the vicinity of the well. For both experiments, forward numerical simulations of the problem using a finite element package were performed in order to assess the underlying physics of the causative source of the

  1. On the problem of internal optical loss and current leakage in laser heterostructures based on AlGaInAs/InP solid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Veselov, D. A., E-mail: dmitriy90@list.ru; Shashkin, I. S.; Bakhvalov, K. V.; Lyutetskiy, A. V.; Pikhtin, N. A.; Rastegaeva, M. G.; Slipchenko, S. O.; Bechvay, E. A.; Strelets, V. A.; Shamakhov, V. V.; Tarasov, I. S. [Russian Academy of Sciences, Ioffe Physical–Technical Institute (Russian Federation)

    2016-09-15

    Semiconductor lasers based on MOCVD-grown AlGaInAs/InP separate-confinement heterostructures are studied. It is shown that raising only the energy-gap width of AlGaInAs-waveguides without the introduction of additional barriers results in more pronounced current leakage into the cladding layers. It is found that the introduction of additional barrier layers at the waveguide–cladding-layer interface blocks current leakage into the cladding layers, but results in an increase in the internal optical loss with increasing pump current. It is experimentally demonstrated that the introduction of blocking layers makes it possible to obtain maximum values of the internal quantum efficiency of stimulated emission (92%) and continuouswave output optical power (3.2 W) in semiconductor lasers in the eye-safe wavelength range (1400–1600 nm).

  2. Revisited approach for the characterization of Gate Induced Drain Leakage

    Science.gov (United States)

    Rafhay, Quentin; Xu, Cuiqin; Batude, Perrine; Mouis, Mireille; Vinet, Maud; Ghibaudo, Gérard

    2012-05-01

    This work presents a critical review and a re-investigation of the electrical characterization of Gate Induced Drain Leakage (GIDL) [1,2]. The underlying assumptions of the previously proposed extraction methods are exposed and their ability to capture Band-to-Trap mechanisms is discussed. A new approach is introduced to overcome some of the limiting assumptions made by the previous extraction methods. This new approach is benchmarked against the previously proposed ones. The results show that it enables a better extraction of the GIDL parameters compared to the conventional methods, by using the voltage dependency of the activation energy to gain insight in the electric field responsible for Band-to-Band Tunneling in the device. Finally, the experimental application of this new approach is carried out on cold process FDSOI MOSFET and confirms the ability of this new method to quantify the impact of trap assisted tunneling on GIDL.

  3. Moisture Risk in Unvented Attics Due to Air Leakage Paths

    Energy Technology Data Exchange (ETDEWEB)

    Prahl, D.; Shaffer, M.

    2014-11-01

    IBACOS completed an initial analysis of moisture damage potential in an unvented attic insulated with closed-cell spray polyurethane foam. To complete this analysis, the research team collected field data, used computational fluid dynamics to quantify the airflow rates through individual airflow (crack) paths, simulated hourly flow rates through the leakage paths with CONTAM software, correlated the CONTAM flow rates with indoor humidity ratios from Building Energy Optimization software, and used Warme und Feuchte instationar Pro two-dimensional modeling to determine the moisture content of the building materials surrounding the cracks. Given the number of simplifying assumptions and numerical models associated with this analysis, the results indicate that localized damage due to high moisture content of the roof sheathing is possible under very low airflow rates. Reducing the number of assumptions and approximations through field studies and laboratory experiments would be valuable to understand the real-world moisture damage potential in unvented attics.

  4. Moisture Risk in Unvented Attics Due to Air Leakage Paths

    Energy Technology Data Exchange (ETDEWEB)

    Prahl, D. [IBACOS, Inc., Pittsburgh, PA (United States); Shaffer, M. [IBACOS, Inc., Pittsburgh, PA (United States)

    2014-11-01

    IBACOS completed an initial analysis of moisture damage potential in an unvented attic insulated with closed-cell spray polyurethane foam. To complete this analysis, the research team collected field data, used computational fluid dynamics to quantify the airflow rates through individual airflow (crack) paths, simulated hourly flow rates through the leakage paths with CONTAM software, correlated the CONTAM flow rates with indoor humidity ratios from Building Energy Optimization software, and used Wärme und Feuchte instationär Pro two-dimensional modeling to determine the moisture content of the building materials surrounding the cracks. Given the number of simplifying assumptions and numerical models associated with this analysis, the results indicate that localized damage due to high moisture content of the roof sheathing is possible under very low airflow rates. Reducing the number of assumptions and approximations through field studies and laboratory experiments would be valuable to understand the real-world moisture damage potential in unvented attics.

  5. Quench tank in-leakage diagnosis at St. Lucie

    Energy Technology Data Exchange (ETDEWEB)

    Price, J.E.; Au-Yang, M.K.; Beckner, D.A.; Vickery, A.N.

    1996-12-01

    In February 1995, leakage into the quench tank of the St. Lucie Nuclear Station Unit 1 was becoming an operational concern. This internal leak resulted in measurable increases in both the temperature and level of the quench tank water, and was so severe that, if the trend continued, plant shut down would be necessary. Preliminary diagnosis based on in-plant instrumentation indicated that any one of 11 valves might be leaking into the quench tank. This paper describes the joint effort by two teams of engineers--one from Florida Power & Light, the other from Framatome Technologies--to identify the sources of the leak, using the latest technology developed for valve diagnosis.

  6. An Estimate of P-Mode Damping by Wave Leakage

    Science.gov (United States)

    De Moortel, I.; Rosner, R.

    2007-11-01

    High-cadence TRACE observations show that outward-propagating intensity disturbances are a common feature in large, quiescent coronal loops. Analysis of the frequency distribution of these modes shows peaks at both three- and five-minute periods, indicating that they may be driven by the solar surface oscillations ( p modes). The energy flux contained within the coronal intensity disturbances is of the order of (1.1±0.4)×103 ergs cm-2 s-1. A simple order-of-magnitude estimate of the damping rate of the relevant p modes allows us to put an observational constraint on the damping of p modes and shows that leakage into the overlying coronal atmosphere might be able to account for a significant fraction of p-mode damping.

  7. Structural and leakage integrity of tubes affected by circumferential cracking

    Energy Technology Data Exchange (ETDEWEB)

    Hernalsteen, P. [TRACTEBEL, Brussels (Belgium)

    1997-02-01

    In this paper the author deals with the notion that circumferential cracks are generally considered unacceptable. He argues for the need to differentiate two facets of such cracks: the issue of the size and growth rate of a crack; and the issue of the structural strength and leakage potential of the tube in the presence of the crack. In this paper the author tries to show that the second point is not a major concern for such cracks. The paper presents data on the structural strength or burst pressure characteristics of steam generator tubes derived from models and data bases of experimental work. He also presents a leak rate model, and compares the performance of circumferential and axial cracks as far as burst strength and leak rate. The final conclusion is that subject to improvement in NDE capabilities (sizing, detection, growth), that Steam Generator Defect Specific Management can be used to allow circumferentially degraded tubes to remain in service.

  8. A Study of Neutron Leakage in Finite Objects

    Science.gov (United States)

    Wilson, John W.; Slaba, Tony C.; Badavi, Francis F.; Reddell, Brandon D.; Bahadori, Amir A.

    2015-01-01

    A computationally efficient 3DHZETRN code capable of simulating High charge (Z) and Energy (HZE) and light ions (including neutrons) under space-like boundary conditions with enhanced neutron and light ion propagation was recently developed for simple shielded objects. Monte Carlo (MC) benchmarks were used to verify the 3DHZETRN methodology in slab and spherical geometry, and it was shown that 3DHZETRN agrees with MC codes to the degree that various MC codes agree among themselves. One limitation in the verification process is that all of the codes (3DHZETRN and three MC codes) utilize different nuclear models/databases. In the present report, the new algorithm, with well-defined convergence criteria, is used to quantify the neutron leakage from simple geometries to provide means of verifying 3D effects and to provide guidance for further code development.

  9. A nationwide study on anastomotic leakage after colonic cancer surgery

    DEFF Research Database (Denmark)

    Krarup, Peter-Martin; Jorgensen, L N; Andreasen, A H

    2012-01-01

    : AL occurred in 593 (6.4%) of 9333 patients. Laparoscopic surgery (odds ratio [OR], 1.34; 95% confidence interval [CI], 1.05-1.70; P = 0.03); left hemicolectomy (OR, 2.02; 95% CI, 1.50-2.72) or sigmoid colectomy (OR, 1.69; 95% CI, 1.32-2.17; P = 0.01); intraoperative blood loss (OR, 1.04; 95% CI, 1......Aim: Anastomotic leakage (AL) is a major challenge in colorectal cancer surgery due to increased morbidity and mortality. Possible risk factors should be investigated differentially, distinguishing between rectal and colonic surgery in large-scale studies to avoid selection bias and confounding....... Method: The incidence and risk factors associated with AL were analysed in an unselected nation-wide prospective cohort of patient subjected to curative colonic cancer surgery with primary anastomosis and entered into The Danish Colorectal Cancer Group database between May 2001 and December 2008. Results...

  10. Program for stator winding leakage inductance determination by FEA

    Directory of Open Access Journals (Sweden)

    Olivian Chiver

    2009-05-01

    Full Text Available This paper presents a program designed by the author in order to determine the stator winding parameters. The program is realized in Visual Basic and, in fact, it is for computer aided design of AC machines. Starting from the design data, based on the classical analytical formulas, geometrical parameters of the stator and the parameters of the stator winding are computed. This program works with a finite elements analysis (FEA software (the one used by the author is MagNet, a product of Infolytica company and according to data obtained after the design calculation, or according to data specified by user (in case of an existing machine, the stator and stator winding are built 3D (three-dimensional. For the same stator, different types of winding can be chosen. After realizing numerical model, by 3D FEA, leakage inductance is determined.

  11. Leakage radiation spectroscopy of organic/dielectric/metal systems

    DEFF Research Database (Denmark)

    Fiutowski, Jacek; Kawalec, Tomasz; Kostiučenko, Oksana

    2014-01-01

    excitons and surface plasmon polaritons (SPPs) of the metal/dielectric boundary. The presence of the SiO2 layer considerably changes the dispersion curve in comparison to the one of the Ag/p-6P/air system. However, the Ag/SiO2/p-6P/air stack forms a stable structure allowing construction of organic......Leakage radiation spectroscopy of organic para-Hexaphenylene (p-6P) molecules has been performed in the spectral range 420-675 nm which overlaps with the p-6P photoluminescence band. The p-6P was deposited on 40 nm silver (Ag) films on BK7 glass, covered with SiO2 layers. The SiO2 layer thickness...

  12. Remote sensing of CO2 leakage from geologic sequestration projects

    Science.gov (United States)

    Verkerke, Joshua L.; Williams, David J.; Thoma, Eben

    2014-09-01

    Monitoring for leak hazards is an important consideration in the deployment of carbon dioxide geologic sequestration. Failure to detect and correct leaks may invalidate any potential emissions benefits intended by such projects. Presented is a review of remote sensing methods primed to serve a central role in any monitoring program due to their minimally invasive nature and potential for large area coverage in a limited timeframe or in real-time as a continuous monitoring program. Methods investigated were divided into those capable of indirect detection of carbon dioxide leakage, such as monitoring for vegetative stress and ground surface deformation, and those that directly detect gaseous and atmospheric compounds, by means of such tools as Open-Path Fourier Transform Infrared or Tunable Diode Lasers. Both direct and indirect methods present viable means of detecting a leak event, though ultimately, a robust approach will incorporate multiple monitoring tools that may include both direct and indirect remote sensing methods.

  13. An objective comparison of leakage between commonly used earplugs.

    Science.gov (United States)

    Alt, Jeremiah A; Collins, William O

    2012-01-01

    We sought to determine the efficacy of commonly used earplugs using an anatomically correct ear model. The total volume and rate of water that leaked past the earplug and subsequent defect in the tympanic membrane over separately measured 30, 60, 120, and 180-second intervals were recorded. Scenarios tested included a control with no earplug, custom molded earplug (Precision Laboratories, Orlando, FL), Mack's plug (Warren, MI), Doc's plug (Santa Cruz, CA), and cotton balls coated with petroleum jelly. All plugs tested resulted in less leakage at all time points when compared with no plug (P earplugs. If the clinician feels that middle ear and external canal water exposure should be minimized, then use of earplugs, particularly the moldable variety, merits further consideration. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. Spatial and Temporal Monitoring Resolutions for CO2 Leakage Detection at Carbon Storage Sites

    Science.gov (United States)

    Yang, Y. M.; Dilmore, R. M.; Daley, T. M.; Carroll, S.; Mansoor, K.; Gasperikova, E.; Harbert, W.; Wang, Z.; Bromhal, G. S.; Small, M.

    2016-12-01

    Different leakage monitoring techniques offer different strengths in detection sensitivity, coverage, feedback time, cost, and technology availability, such that they may complement each other when applied together. This research focuses on quantifying the spatial coverage and temporal resolution of detection response for several geophysical remote monitoring and direct groundwater monitoring techniques for an optimal monitoring plan for CO2 leakage detection. Various monitoring techniques with different monitoring depths are selected: 3D time-lapse seismic survey, wellbore pressure, groundwater chemistry and soil gas. The spatial resolution in terms of leakage detectability is quantified through the effective detection distance between two adjacent monitors, given the magnitude of leakage and specified detection probability. The effective detection distances are obtained either from leakage simulations with various monitoring densities or from information garnered from field test data. These spatial leakage detection resolutions are affected by physically feasible monitoring design and detection limits. Similarly, the temporal resolution, in terms of leakage detectability, is quantified through the effective time to positive detection of a given size of leak and a specified detection probability, again obtained either from representative leakage simulations with various monitoring densities or from field test data. The effective time to positive detection is also affected by operational feedback time (associated with sampling, sample analysis and data interpretation), with values obtained mainly through expert interviews and literature review. In additional to the spatial and temporal resolutions of these monitoring techniques, the impact of CO2 plume migration speed and leakage detection sensitivity of each monitoring technique are also discussed with consideration of how much monitoring is necessary for effective leakage detection and how these monitoring

  15. Numerical studies on the performance of an aerosol respirator with faceseal leakage

    Science.gov (United States)

    Zaripov, S. K.; Mukhametzanov, I. T.; Grinshpun, S. A.

    2016-11-01

    We studied the efficiency of a facepiece filtering respirator (FFR) in presence of a measurable faceseal leakage using the previously developed model of a spherical sampler with porous layer. In our earlier study, the model was validated for a specific filter permeability value. In this follow-up study, we investigated the effect of permeability on the overall respirator performance accounting for the faceseal leakage. The Total Inward Leakage (TIL) was calculated as a function of the leakage-to-filter surface ratio and the particle diameter. A good correlation was found between the theoretical and experimental TIL values. The TIL value was shown to increase and the effect of particle size on TIL to decrease as the leakage-to- filter surface ratio grows. The model confirmed that within the most penetrating particle size range (∼50 nm) and at relatively low leakage-to-filter surface ratios, an FFR performs better (TIL is lower) when the filter has a lower permeability which should be anticipated as long as the flow through the filter represents the dominant particle penetration pathway. An increase in leak size causes the TIL to rise; furthermore, under certain leakage-to-filter surface ratios, TIL for ultrafine particles becomes essentially independent on the filter properties due to a greater contribution of the aerosol flow through the faceseal leakage. In contrast to the ultrafine fraction, the larger particles (e.g., 800 nm) entering a typical high- or medium-quality respirator filter are almost fully collected by the filter medium regardless of its permeability; at the same time, the fraction penetrated through the leakage appears to be permeability- dependent: higher permeability generally results in a lower pressure drop through the filter which increases the air flow through the filter at the expense of the leakage flow. The latter reduces the leakage effect thus improving the overall respiratory protection level. The findings of this study provide

  16. Study on unsteady tip leakage vortex cavitation in an axial-flow pump using an improved filter-based model

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Desheng; Shi, Lei; Zhao, Ruijie; Shi, Weidong; Pan, Qiang [Jiangsu University, Zhenjiang (China); Esch, B. P. [Eindhoven University of Technology, Eindhoven (Netherlands)

    2017-02-15

    The aim of the present investigation is to simulate and analyze the tip leakage flow structure and instantaneous evolution of tip vortex cavitation in a scaled axial-flow pump model. The improved filter-based turbulence model based on the density correction and a homogeneous cavitation model were used for implementing this work. The results show that when entering into the tip clearance, the backward flow separates from the blade tip near the pressure side, resulting in the generation of a corner vortex with high magnitude of turbulence kinetic energy. Then, at the exit of the tip clearance, the leakage jets would re-attach on the blade tip wall. Moreover, the maximum swirling strength method was employed in identifying the TLV core and a counter-rotating induced vortex near the end-wall successfully. The three dimensional cavitation patterns and in-plain cavitation structures obtained by the improved numerical method agree well with the experimental results. At the sheet cavitation trailing edge in the tip region, the perpendicular cavitation cloud induced by TLV sheds and migrates toward the pressure side of the neighboring blade. During its migration, it breaks down abruptly and generates a large number of smallscale cavities, leading to severe degradation of the pump performance, which is similar with the phenomenon observed by Tan et al.

  17. Non-Pulse-Leakage 100-kHz Level, High Beam Quality Industrial Grade Nd:YVO4 Picosecond Amplifier

    Directory of Open Access Journals (Sweden)

    Zhenao Bai

    2017-06-01

    Full Text Available A non-pulse-leakage optical fiber pumped 100-kHz level high beam quality Nd:YVO4 picosecond amplifier has been developed. An 80 MHz, 11.5 ps mode-locked picosecond laser is used as the seed with single pulse energy of 1 nJ. By harnessing the double β-BaB2O4 (BBO crystal Pockels cells in both the pulse picker and regenerative amplifier, the seed pulse leakage of the output is suppressed effectively with an adjustable repetition rate from 200 to 500 kHz. Through one stage traveling-wave amplifier, a maximum output power of 24.5 W is generated corresponding to the injected regenerative amplified power of 9.73 W at 500 kHz. The output pulse duration is 16.9 ps, and the beam quality factor M2 is measured to be 1.25 with near-field roundness higher than 99% at the full output power.

  18. Leakage Characteristics of Dual-Cannula Fenestrated Tracheostomy Tubes during Positive Pressure Ventilation: A Bench Study

    Directory of Open Access Journals (Sweden)

    Thomas Berlet

    2016-01-01

    Full Text Available This study compared the leakage characteristics of different types of dual-cannula fenestrated tracheostomy tubes during positive pressure ventilation. Fenestrated Portex® Blue Line Ultra®, TRACOE® twist, or Rüsch® Traceofix® tracheostomy tubes equipped with nonfenestrated inner cannulas were tested in a tracheostomy-lung simulator. Transfenestration pressures and transfenestration leakage rates were measured during positive pressure ventilation. The impact of different ventilation modes, airway pressures, temperatures, and simulated static lung compliance settings on leakage characteristics was assessed. We observed substantial differences in transfenestration pressures and transfenestration leakage rates. The leakage rates of the best performing tubes were <3.5% of the delivered minute volume. At body temperature, the leakage rates of these tracheostomy tubes were <1%. The tracheal tube design was the main factor that determined the leakage characteristics. Careful tracheostomy tube selection permits the use of fenestrated tracheostomy tubes in patients receiving positive pressure ventilation immediately after stoma formation and minimises the risk of complications caused by transfenestration gas leakage, for example, subcutaneous emphysema.

  19. Leakage Characteristics of Dual-Cannula Fenestrated Tracheostomy Tubes during Positive Pressure Ventilation: A Bench Study.

    Science.gov (United States)

    Berlet, Thomas; Marchon, Mathias

    2016-01-01

    This study compared the leakage characteristics of different types of dual-cannula fenestrated tracheostomy tubes during positive pressure ventilation. Fenestrated Portex® Blue Line Ultra®, TRACOE® twist, or Rüsch® Traceofix® tracheostomy tubes equipped with nonfenestrated inner cannulas were tested in a tracheostomy-lung simulator. Transfenestration pressures and transfenestration leakage rates were measured during positive pressure ventilation. The impact of different ventilation modes, airway pressures, temperatures, and simulated static lung compliance settings on leakage characteristics was assessed. We observed substantial differences in transfenestration pressures and transfenestration leakage rates. The leakage rates of the best performing tubes were <3.5% of the delivered minute volume. At body temperature, the leakage rates of these tracheostomy tubes were <1%. The tracheal tube design was the main factor that determined the leakage characteristics. Careful tracheostomy tube selection permits the use of fenestrated tracheostomy tubes in patients receiving positive pressure ventilation immediately after stoma formation and minimises the risk of complications caused by transfenestration gas leakage, for example, subcutaneous emphysema.

  20. Effects of Chemistry Parameters of Primary Water affecting Leakage of Steam Generator Tube Cracks

    Energy Technology Data Exchange (ETDEWEB)

    Shin, D. M.; Cho, N. C.; Kang, Y. S.; Lee, K. H. [KHNP CRI, Daejeon (Korea, Republic of)

    2016-10-15

    Degradation of steam generator (SG) tubes can affect pressure boundary tightness. As a defense-in-depth measure, primary to secondary leak monitoring program for steam generators is implemented, and operation is allowed under leakage limits in nuclear power plants. Chemistry parameters that affect steam generator tube leakage due to primary water stress corrosion cracking (PWSCC) are investigated in this study. Tube sleeves were installed to inhibit leakage and improve tube integrity as a part of maintenance methods. Steam generators occurred small leak during operation have been replaced with new steam generators according to plant maintenance strategies. The correlations between steam generator leakage and chemistry parameters are presented. Effects of primary water chemistry parameters on leakage from tube cracks were investigated for the steam generators experiencing small leak. Unit A experienced small leakage from steam generator tubes in the end of operation cycle. It was concluded that increased solubility of oxides due to high pHT could make leakage paths, and low boron concentration lead to less blockage in cracks. Increased dissolved hydrogen may retard crack propagations, but it did not reduce leak rate of the leaking steam generator. In order to inhibit and reduce leakage, pH{sub T} was controlled by servicing cation bed operation. The test results of decreasing pHT indicate low pHT can reduce leak rate of PWSCC cracks in the end of cycle.

  1. Outdoor leakage current monitoring of silicone composite insulators in coastal service conditions

    Energy Technology Data Exchange (ETDEWEB)

    Vlastos, A.E. [Chalmers Univ. of Technology, Gothenburg (Sweden); Orbeck, T. [Sediver Inc., York, SC (United States)

    1996-04-01

    The behavior of the polymeric insulators under salt-storm conditions is crucial for their design. In this paper the leakage currents monitored on silicone composite insulators during two severe salt-storms on the Swedish West Coast are analyzed. The results show that reduction of the leakage distance on silicone rubber units causes considerable dry-band arc activity.

  2. Quantification of leakage from large unilamellar lipid vesicles by fluorescence correlation spectroscopy

    DEFF Research Database (Denmark)

    Kristensen, Kasper; Henriksen, Jonas Rosager; Andresen, Thomas Lars

    2014-01-01

    that mastoparan X forms transient transmembrane pores in POPC/POPG (3:1) vesicles, resulting in size-dependent leakage of molecules from the vesicles. We conclude the paper by discussing some of the advantages and limitations of FCS as compared to other existing methods to measure leakage from large unilamellar...

  3. The extent of on-site leakage in selected suburbs of Johannesburg ...

    African Journals Online (AJOL)

    This study investigated on-site leakage on 182 properties with relatively new municipal water meters in well-established suburbs of Johannesburg. A methodology was developed to estimate the on-site leakage rate from readings taken from these municipal water meters, which was then adjusted to account for metering ...

  4. Blood-brain barrier leakage after status epilepticus in rapamycin-treated rats II : Potential mechanisms

    NARCIS (Netherlands)

    van Vliet, Erwin A; Otte, Wim M; Wadman, Wytse J; Aronica, Eleonora; Kooij, Gijs; de Vries, Helga E; Dijkhuizen, Rick M; Gorter, Jan A

    OBJECTIVE: Blood-brain barrier (BBB) leakage may play a pro-epileptogenic role after status epilepticus. In the accompanying contrast-enhanced magnetic resonance imaging (CE-MRI) study we showed that the mammalian target of rapamycin (mTOR) inhibitor rapamycin reduced BBB leakage and seizure

  5. Prevention through policy : Urban macroplastic leakages to the marine environment during extreme rainfall events

    NARCIS (Netherlands)

    Axelsson, Charles; van Sebille, Erik

    2017-01-01

    The leakage of large plastic litter (macroplastics) into the ocean is a major environmental problem. A significant fraction of this leakage originates from coastal cities, particularly during extreme rainfall events. As coastal cities continue to grow, finding ways to reduce this macroplastic

  6. Systemic inflammatory response syndrome as a predictor of anastomotic leakage after esophagectomy.

    Science.gov (United States)

    Tsujimoto, Hironori; Ono, Satoshi; Takahata, Risa; Hiraki, Shuichi; Yaguchi, Yoshihisa; Kumano, Isao; Matsumoto, Yusuke; Yoshida, Kazumichi; Aiko, Satoshi; Ichikura, Takashi; Yamamoto, Junji; Hase, Kazuo

    2012-01-01

    Esophageal anastomotic leakage is still a major cause of morbidity and mortality after esophagectomy. We conducted this study to elucidate how anastomotic leakage affects the systemic inflammatory response syndrome (SIRS) criteria. The subjects of this retrospective study were 61 patients who underwent esophagectomy. We evaluated their preoperative status, the surgical procedures, and postoperative systemic response, including white blood cell count, heart rate, respiratory rate, body temperature, and laboratory data up to postoperative day (POD) 4. Anastomotic leakage developed in nine patients (14.8%) and was found on POD 7 on average. These patients had a significantly longer hospital stay than those without leakage. Although no difference was observed in postoperative changes of any of the SIRS criteria, the postoperative incidence of SIRS was significantly higher in the patients with anastomotic leakage on POD 4. The number of positive criteria for SIRS was also significantly higher in patients with anastomotic leakage than in those without leakage on PODs 3 and 4. The SIRS scoring system is valuable for evaluating the severity of systemic inflammatory response caused by anastomosis leakage, and may serve as an indicator for prompt management.

  7. The Dutch multicenter experience of the Endo-Sponge treatment for anastomotic leakage after colorectal surgery

    NARCIS (Netherlands)

    van Koperen, P.J.; van Berge Henegouwen, M.I.; Rosman, C.; Bakker, C.M.; Heres, P.; Slors, J.F.M.; Bemelman, W.A.

    2009-01-01

    Anastomotic leakage is a feared complication following colorectal surgery and is associated with early and long-term morbidity and mortality. The presacral cavity as the result of leakage can be treated with an endo-sponge (B-Braun Medical). The aim of this study was to assess the effectiveness of

  8. 47 CFR 76.611 - Cable television basic signal leakage performance criteria.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Cable television basic signal leakage...) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Technical Standards § 76.611 Cable television basic signal leakage performance criteria. (a) No cable television system shall commence or...

  9. Leakage Current Elimination of Four-Leg Inverter for Transformerless Three-Phase PV Systems

    DEFF Research Database (Denmark)

    Guo, Xiaoqiang; He, Ran; Jian, Jiamin

    2016-01-01

    Eliminating the leakage current is one of the most important issues for transformerless three phase photovoltaic (PV) systems. In this paper, the leakage current elimination of a three-phase four-leg PV inverter is investigated. With the common mode loop model established, the generation mechanism...

  10. Hyperspectral indices for detecting changes in canopy reflectance as a result of underground natural gas leakage

    NARCIS (Netherlands)

    Noomen, M.F.; Smith, K.L.; Colls, J.J.; Steven, M.D.; Skidmore, A.K.; Meer, van der F.D.

    2008-01-01

    Natural gas leakage from underground pipelines is known to affect vegetation adversely, probably by displacement of the soil oxygen needed for respiration. This causes changes in plant and canopy reflectance, which may serve as indicators of gas leakage. In this study, a covariance analysis was

  11. REDD+ and international leakage via food and timber markets: a CGE analysis

    NARCIS (Netherlands)

    Kuik, O.J.

    2014-01-01

    This paper studies the effect of international trade in food and timber on land use and potential carbon leakage in the context of actions to reduce emissions from deforestation and forest degradation (REDD+). First a simple analytical model of international leakage is presented that focuses on

  12. Compressibility effects on rotor forces in the leakage path between a shrouded pump impeller and its housing

    Science.gov (United States)

    Cao, Nhai The

    1993-01-01

    A modified approach to Childs' previous work on fluid-structure interaction forces in the leakage path between an impeller shroud and its housing is presented in this paper. Three governing equations consisting of continuity, path-momentum, and circumferential-momentum equations were developed to describe the leakage path inside a pump impeller. Radial displacement perturbations were used to solve for radial and circumferential force coefficients. In addition, impeller-discharge pressure disturbances were used to obtain pressure oscillation responses due to precessing impeller pressure wave pattern. Childs' model was modified from an incompressible model to a compressible barotropic-fluid model (the density of the working fluid is a function of the pressure and a constant temperature only). Results obtained from this model yielded interaction forces for radial and circumferential force coefficients. Radial and circumferential forces define reaction forces within the impeller leakage path. An acoustic model for the same leakage path was also developed. The convective, Coriolis, and centrifugal acceleration terms are removed from the compressible model to obtain the acoustics model. A solution due to impeller discharge pressure disturbances model was also developed for the compressible and acoustics models. The results from these modifications are used to determine what effects additional perturbation terms in the compressible model have on the acoustic model. The results show that the additional fluid mechanics terms in the compressible model cause resonances (peaks) in the force coefficient response curves. However, these peaks only occurred at high values of inlet circumferential velocity ratios greater than 0.7. The peak pressure oscillation was shown to occur at the wearing ring seal. Introduction of impeller discharge disturbances with n = 11 diametral nodes showed that maximum peak pressure oscillations occurred at nondimensional precession frequencies of f

  13. Work output and efficiency at maximum power of linear irreversible heat engines operating with a finite-sized heat source.

    Science.gov (United States)

    Izumida, Yuki; Okuda, Koji

    2014-05-09

    We formulate the work output and efficiency for linear irreversible heat engines working between a finite-sized hot heat source and an infinite-sized cold heat reservoir until the total system reaches the final thermal equilibrium state with a uniform temperature. We prove that when the heat engines operate at the maximum power under the tight-coupling condition without heat leakage the work output is just half of the exergy, which is known as the maximum available work extracted from a heat source. As a consequence, the corresponding efficiency is also half of its quasistatic counterpart.

  14. Occupational Exposure due to RF leakages within GSM Base ...

    African Journals Online (AJOL)

    The maximum instantaneous electric field strength obtained from GSM 1800 radio was 3.72 V/m, 16.56 V/m for GSM 900 radio and 11.29 V/m for the Tx cables. The maximum instantaneous indoor and out power density were 35.47 mW/m2 and 6.64 mW/m2 respectively. Also, the average values of the obtained electric field ...

  15. Leakage current analysis of single-phase transformer-less grid-connected PV inverters

    DEFF Research Database (Denmark)

    Ma, Lin; Kerekes, Tamas; Teodorescu, Remus

    2015-01-01

    Transformer-less string PV inverter is getting more and more widely utilized due to its higher efficiency, smaller volume and weight. However, without the galvanic isolation, the leakage current limitation and operation safety became the key issues of transformer-less inverters. This paper...... simplifies the leakage current generation circuit model and presents a leakage current estimation method both in real time and frequency domain. It shows that the leakage current is related to the circuit stray parameters, output filter and common mode voltage. Furthermore, with the proposed analysis method......, the leakage current generation of H-bridge with different modulation methods and HERIC inverter are discussed individually. At last, the presented method has been verified via simulation....

  16. FORUM: Indirect leakage leads to a failure of avoided loss biodiversity offsetting.

    Science.gov (United States)

    Moilanen, Atte; Laitila, Jussi

    2016-02-01

    Biodiversity offsetting has quickly gained political support all around the world. Avoided loss (averted risk) offsetting means compensation for ecological damage via averted loss of anticipated impacts through the removal of threatening processes in compensation areas.Leakage means the phenomenon of environmentally damaging activity relocating elsewhere after being stopped locally by avoided loss offsetting. Indirect leakage means that locally avoided losses displace to other administrative areas or spread around diffusely via market effects. Synthesis and applications . Indirect leakage can lead to high net biodiversity loss. It is difficult to measure or prevent, raising doubts about the value of avoided loss offsetting. Market demand for commodities is on the rise, following increasing human population size and per capita consumption, implying that indirect leakage will be a rule rather than an exception. Leakage should be accounted for when determining offset multipliers (ratios) even if multipliers become extremely high.

  17. Study on detecting leachate leakage of municipal solid waste landfill site.

    Science.gov (United States)

    Liu, Jiangang; Cao, Xianxian; Ai, Yingbo; Zhou, Dongdong; Han, Qiting

    2015-06-01

    The article studies the detection of the leakage passage of leachate in a waste landfill dam. The leachate of waste landfill has its own features, like high conductivity, high chroma and an increasing temperature, also, the horizontal flow velocity of groundwater on the leakage site increases. This article proposes a comprehensive tracing method to identify the leakage site of an impermeable membrane by using these features. This method has been applied to determine two leakage sites of the Yahu municipal solid waste landfill site in Pingshan District, Shenzhen, China, which shows that there are two leachate leakage passages in the waste landfill dam A between NZK-2 and NZK-3, and between NZK-6 and NZK-7. © The Author(s) 2015.

  18. Leakage current and deep levels in CoSi{sub 2} silicided junctions

    Energy Technology Data Exchange (ETDEWEB)

    Codegoni, D. [ST Microelectronics Via Olivetti 2, 20041 Agrate Brianza, Milan (Italy); Carnevale, G.P. [ST Microelectronics Via Olivetti 2, 20041 Agrate Brianza, Milan (Italy); De Marco, C. [ST Microelectronics Via Olivetti 2, 20041 Agrate Brianza, Milan (Italy); Mica, I. [ST Microelectronics Via Olivetti 2, 20041 Agrate Brianza, Milan (Italy); Polignano, M.L. [ST Microelectronics Via Olivetti 2, 20041 Agrate Brianza, Milan (Italy)]. E-mail: marialuisa.polignano@st.com

    2005-12-05

    In this work the leakage current of junctions with a self-aligned cobalt silicide is studied. It is shown that junctions with a self-aligned CoSi{sub 2} layer show a leakage current excess which is strongly reduced by increasing the PAI energy. This indicates that the observed leakage current excess is related to the CoSi{sub 2} formation conditions. The mechanism responsible for the leakage of CoSi{sub 2} junctions is investigated by current versus temperature measurements and by deep level transient spectroscopy. In addition, the role of the mechanical stress is investigated by comparing different isolation structures and by numerical stress calculations. It is concluded that the shallow trench isolation (STI) induced stress and the cobalt silicide formation concur to produce a junction leakage current increase by creating a deep level in silicon located close to midgap. This level can possibly identified with a level ascribed to a point defect excess.

  19. Development of a Pipeline Leakage Location Instrument Based on Acoustic Waves

    Science.gov (United States)

    Shen, Gongtian; Liu, Shifeng; Hu, Zhenlong

    A pipeline leakage location instrument based on acoustic method and correlation location of continuous signals was developed. This instrument uses a lot of advanced electronic techniques such as low-frequency acoustic emission sensor, high-speed acquisition of waveform of leakage signals, wireless data communication based on Internet, data high-speed communication-based USB, and time control based on GPS positioning. The real-time leakage location test and remote wireless leakage location test are realized for different kinds of pipelines with different medium leak. The testing result proves that this instrument can detect the leakage of 1 mm hole far from 50 m and 2 mm hole far from 100 m for steel pipeline under 0.4 MPa compressed air.

  20. Characterization of CO2 leakage into the freshwater body

    Science.gov (United States)

    Singh, Ashok; Delfs, Jens-Olaf; Shao, Habing; Kolditz, Olaf

    2013-04-01

    Current research into Carbon dioxide Capture and Storage (CCS) is dominated by improving the CO2 storage capacity. However, potential leakage of CO2 can cause environmental problems, particularly if freshwater resources are nearby. In this regards, it is important to understand the chemistry of CO2 and the water system. CO2 leakage across the fluid interface (CO2 and water) is controlled by the difference in the partial pressure of CO2 in the storage and in the freshwater body. Once the CO2 is in solution, it equilibrates with the bicarbonate and carbonate ions. According to Millero (1994)such a system can be characterized by two parameters out of the four: total alkalinity (TA), total carbonate (TCO2), fugacity of CO2(fCO2) and pH. In the present modeling study, we are interested in the (i) CO2 leakage into a freshwater body (while injecting CO2 for storage) through an inclined fracture and (ii) characterization of the system by measuring fugacity of CO2 and pH. According to work presented by Singh et al. (2012), about 31% of injected CO2 leaks into the freshwater body. Solubility of CO2 in water follows Henry's law, while the Henry constant, K0 is calculated by an empirical relation developed by Murray and Riley (1971), which is a function of salinity and temperature. According to our results, pH and fugacity both appear to be a linear function of temperature. To simulate the discussed problem, a corresponding numerical module has been developed for multi-component fluid flow coupled with heat and mass transport processes. Governing equations and Volume Translated Peng-Robinson equations of state are implemented within the object-oriented finite element code OpenGeoSys (Kolditz et al., 2012; www.opengeosys.org). Primary variables are pressure, temperature and salinity which are obtained by solving the governing equations in a monolithic way The governing equations are discretized spatially within the context of a Galerkin approach, whereas the temporal

  1. Early prediction of anastomotic leakage after free jejunal flap reconstruction of circumferential pharyngeal defects.

    Science.gov (United States)

    Chan, Jimmy Yu Wai; Liu, Lawrence Hin Lun; Wei, William Ignace

    2013-03-01

    Anastomotic leakage from the free jejunal flap, if diagnosed late, can result in catastrophes. Our study aims to look for clinical parameters that allow early identification of leakage so that appropriate interventions can be taken. Between 1980 and 2011, consecutive patients with free jejunal flap reconstruction of circumferential pharyngeal defects were included. A retrospective chart review was then performed comparing the clinical parameters (body temperature, heart rate, serum albumin, haemoglobin and white cell count) between patients with no leakage and those with clinical and radiological leakage. 4. Ninety-six patients were included in the study. The median age was 62 years. Majority (69.8%) of the defects were created after resection of tumours in the hypopharynx. Five (5.2%) patients had clinical leakage and 12 (12.5%) had radiological leakage. There was no significant difference in body temperature, heart rate, incidence of atrial fibrillation and haemoglobin level between those with and without leakage. The serum white cell count was higher in the patients who leaked, but it became statistically significant only after day 7 postoperatively. The serum albumin level was significantly lower in patients with anastomotic leakage starting as early as day 3 after surgery, and the difference persisted until the leak was controlled. However, there was no significant difference in the plasma albumin level between those with clinical or radiological leak. Both serum albumin level and white cell count identified the presence of anastomotic leakage from the free jejunal flap. Serum albumin allows early prediction of leakage so that early interventions can be taken to avoid the damage resulting from the delay in diagnosis. Copyright © 2012 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  2. Clinical manifestations and risk factors of anastomotic leakage after low anterior resection for rectal cancer.

    Science.gov (United States)

    Yun, Jung-A; Cho, Yong Beom; Park, Yoon Ah; Huh, Jung Wook; Yun, Seong Hyeon; Kim, Hee Cheol; Lee, Woo Yong; Chun, Ho-Kyung

    2017-11-01

    Anastomotic leakage is a common complication that can be associated with catastrophic consequences. However, the risk factors and incidence of anastomotic leakage vary considerably among clinical studies because of the lack of a standardized definition, clinical course and appropriate treatment options. The aim of this study was to identify and classify the clinical manifestations and treatment of anastomotic leakage and analyse the possible risk factors after low anterior resection. From January 2009 to June 2010, 632 patients underwent low anterior resection for primary colorectal cancer at Samsung Medical Center. Patients with only one colorectal anastomosis were included from this prospectively collected medical database. The overall leakage rate was 6.0% (n = 38). In cases of generalized leakage, the patients that selected surgical management, regardless of having protective enterostomy and time of occurrence, had better outcomes. Protective enterostomy did not have a preventive effect and was not associated with a lower rate of anastomotic leakage. However, protective enterostomy confined the inflammation to only the pelvic cavity (P = 0.045) and no surgical intervention was initially needed. Male gender (P = 0.021, relative risk (RR) = 2.680, 95% confidence interval (CI) = 1.164-6.171) and side-to-end/J pouch-to-end anastomosis (P = 0.012, RR = 2.696, 95% CI = 1.249-5.818) were significant risk factors that affected anastomotic leakage. Surgical management is the best choice for generalized leakage. A protective enterostomy diminished the occurrence of generalized leakage and consequent surgical management; therefore, fragile patients at high risk for anastomotic leakage are recommended to undergo protective enterostomy. © 2015 Royal Australasian College of Surgeons.

  3. Correlating antimicrobial activity and model membrane leakage induced by nylon-3 polymers and detergents.

    Science.gov (United States)

    Hovakeemian, Sara G; Liu, Runhui; Gellman, Samuel H; Heerklotz, Heiko

    2015-09-14

    Most antimicrobial peptides act upon target microorganisms by permeabilizing their membranes. The mode of action is often assessed by vesicle leakage experiments that use model membranes, with the assumption that biological activity correlates with the permeabilization of the lipid bilayer. The current work aims to extend the interpretation of vesicle leakage results and examine the correlation between vesicle leakage and antimicrobial activity. To this end, we used a lifetime-based leakage assay with calcein-loaded vesicles to study the membrane permeabilizing properties of a novel antifungal polymer poly-NM, two of its analogs, and a series of detergents. In conjunction, the biological activities of these compounds against Candida albicans were assessed and correlated with data from vesicle leakage. Poly-NM induces all-or-none leakage in polar yeast lipid vesicles at the polymer's MIC, 3 μg mL(-1). At this and higher concentrations, complete leakage after an initial lag time was observed. Concerted activity tests imply that this polymer acts independently of the detergent octyl glucoside (OG) for both vesicle leakage and activity against C. albicans spheroplasts. In addition, poly-NM was found to have negligible activity against zwitterionic vesicles and red blood cells. Our results provide a consistent, detailed picture of the mode of action of poly-NM: this polymer induces membrane leakage by electrostatic lipid clustering. In contrast, poly-MM:CO, a nylon-3 polymer comprised of both cationic and hydrophobic segments, seems to act by a different mechanism that involves membrane asymmetry stress. Vesicle leakage for this polymer is transient (limited to nylon-3 polymers we examined act via similar mechanisms; it is surprising that their mechanisms are so distinct. Some, but not all mechanisms of vesicle permeabilization allow for antimicrobial activity.

  4. Calcium Dobesilate Prevents Neurodegeneration and Vascular Leakage in Experimental Diabetes.

    Science.gov (United States)

    Solà-Adell, Cristina; Bogdanov, Patricia; Hernández, Cristina; Sampedro, Joel; Valeri, Marta; Garcia-Ramirez, Marta; Pasquali, Christian; Simó, Rafael

    2017-09-01

    The mechanisms involved in the reported beneficial effects of Calcium dobesilate monohydrate (CaD) for the treatment of diabetic retinopathy (DR) remain to be elucidated. The main aim of the present study is to examine whether CaD prevents early events in the pathogenesis of DR such as neurodegeneration and vascular leakage. In addition, putative mediators of both neurodegeneration (glutamate/GLAST, ET-1/ETB receptor) and early microvascular impairment (ET-1/ETA receptor, oxidative stress, VEGF, and the PKC-delta-p38 MAPK pathway) have been examined. Diabetic (db/db) mice were randomly assigned to daily oral treatment with CaD (200 mg/Kg/day) (n = 12) or vehicle (n = 12) for 14 days. In addition, 12 non-diabetic (db/+) mice matched by age were used as the control group. Functional abnormalities were assessed by electroretinography. Neurodegeneration and microvascular abnormalities were evaluated by immunohistochemistry and Western blot. Glutamate was determined by HPLC. CaD significantly decreased glial activation and apoptosis and produced a significant improvement in the electroretinogram parameters. Mechanistically, CaD prevented the diabetes-induced up-regulation of ET-1 and its cognate receptors (ETA-R and ETB-R), which are involved in microvascular impairment and neurodegeneration, respectively. In addition, treatment with CaD downregulated GLAST, the main glutamate transporter, and accordingly prevented the increase in glutamate. Finally, CaD prevented oxidative stress, and the upregulation of VEGF and PKC delta-p38 MAPK pathway induced by diabetes, thus resulting in a significant reduction in vascular leakage. Our findings demonstrate for the first time that CaD exerts neuroprotection in an experimental model of DR. In addition, we provide first evidence that CaD prevents the overexpression of ET-1 and its receptors in the diabetic retina. These beneficial effects on the neurovascular unit could pave the way for clinical trials addressed to confirm the

  5. Maximum Power from a Solar Panel

    Directory of Open Access Journals (Sweden)

    Michael Miller

    2010-01-01

    Full Text Available Solar energy has become a promising alternative to conventional fossil fuel sources. Solar panels are used to collect solar radiation and convert it into electricity. One of the techniques used to maximize the effectiveness of this energy alternative is to maximize the power output of the solar collector. In this project the maximum power is calculated by determining the voltage and the current of maximum power. These quantities are determined by finding the maximum value for the equation for power using differentiation. After the maximum values are found for each time of day, each individual quantity, voltage of maximum power, current of maximum power, and maximum power is plotted as a function of the time of day.

  6. Degradation of Leakage Currents and Reliability Prediction for Tantalum Capacitors

    Science.gov (United States)

    Teverovsky, Alexander

    2016-01-01

    Two types of failures in solid tantalum capacitors, catastrophic and parametric, and their mechanisms are described. Analysis of voltage and temperature reliability acceleration factors reported in literature shows a wide spread of results and requires more investigation. In this work, leakage currents in two types of chip tantalum capacitors were monitored during highly accelerated life testing (HALT) at different temperatures and voltages. Distributions of degradation rates were approximated using a general log-linear Weibull model and yielded voltage acceleration constants B = 9.8 +/- 0.5 and 5.5. The activation energies were Ea = 1.65 eV and 1.42 eV. The model allows for conservative estimations of times to failure and was validated by long-term life test data. Parametric degradation and failures are reversible and can be annealed at high temperatures. The process is attributed to migration of charged oxygen vacancies that reduce the barrier height at the MnO2/Ta2O5 interface and increase injection of electrons from the MnO2 cathode. Analysis showed that the activation energy of the vacancies' migration is 1.1 eV.

  7. Data Leakage Prevention: E-Mail Protection via Gateway

    Science.gov (United States)

    Kaur, Kamaljeet; Gupta, Ishu; Singh, Ashutosh Kumar

    2018-01-01

    Protection of digital assets and intellectual property is becoming a challenge for most of the companies. Due to increasing availability of database services on internet, data may be insecure after passing through precarious networks. To protect intellectual property (IP) is a major concern for today's organizations, because a leakage that compromises IP means, sensitive information of a company is in the hands of biggest competitors. Electronic information processing and communication is replacing paper in many applications increasingly. Instead of paper, an email is being used for communication at workplace and from social media logins to bank accounts. Nowadays an email is becoming a mainstream business tool. An email can be misused to leave company’s sensitive data open to compromise. So, it may be of little surprise that attacks on emails are common. So, here we need an email protection system (EPS) that will protect information to leave organization via mail. In this paper, we developed an algorithm that will offer email protection via gateway during data transfer. This algorithm matches the patterns with the keywords stored in the database and then takes the actions accordingly to protect the data. This paper describes why email protection is important? How companies can protect their confidential information from being leaked by insiders.

  8. Feasibility study of tank leakage mitigation using subsurface barriers

    Energy Technology Data Exchange (ETDEWEB)

    Treat, R.L.; Peters, B.B.; Cameron, R.J.; McCormak, W.D.; Trenkler, T.; Walters, M.F. [Ensearch Environmental, Inc. (United States); Rouse, J.K.; McLaughlin, T.J. [Bovay Northwest, Inc., Richland, WA (United States); Cruse, J.M. [Westinghouse Hanford Co., Richland, WA (United States)

    1994-09-21

    The US Department of Energy (DOE) has established the Tank Waste Remediation System (TWRS) to satisfy manage and dispose of the waste currently stored in the underground storage tanks. The retrieval element of TWRS includes a work scope to develop subsurface impermeable barriers beneath SSTs. The barriers could serve as a means to contain leakage that may result from waste retrieval operations and could also support site closure activities by facilitating cleanup. Three types of subsurface barrier systems have emerged for further consideration: (1) chemical grout, (2) freeze walls, and (3) desiccant, represented in this feasibility study as a circulating air barrier. This report contains analyses of the costs and relative risks associated with combinations retrieval technologies and barrier technologies that from 14 alternatives. Eight of the alternatives include the use of subsurface barriers; the remaining six nonbarrier alternative are included in order to compare the costs, relative risks and other values of retrieval with subsurface barriers. Each alternative includes various combinations of technologies that can impact the risks associated with future contamination of the groundwater beneath the Hanford Site to varying degrees. Other potential risks associated with these alternatives, such as those related to accidents and airborne contamination resulting from retrieval and barrier emplacement operations, are not quantitatively evaluated in this report.

  9. The surface leakage currents of CdZnTe wafers

    Energy Technology Data Exchange (ETDEWEB)

    Zha Gangqiang [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi' an 710072 (China)]. E-mail: zha_gq@hotmail.com; Jie Wanqi [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi' an 710072 (China); Tan Tingting [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi' an 710072 (China); Li Peisen [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi' an 710072 (China)

    2007-01-30

    The surface leakage currents (SLCs) and surface sheet resistances (SSRs) of CdZnTe (1 1 0) (1 1 1) A and (1 1 1) B surfaces after etching with Br-MeOH solution, chemo-mechanical polishing (CMP) and passivation were measured in the parallel stripe model, respectively. Meanwhile the surface compositions were determined by X-ray photoelectron spectroscopy (XPS). Te enrichment introduced by etching with Br-MeOH resulted in the increase of the SLCs of CdZnTe wafers. After chemo-mechanical polishing, Te enrichment was removed, and SLCs decreased. CdZnTe (1 1 1) B without Te enrichment possesses higher SLC than that of (1 1 1) A, and (1 1 0) surface has the lowest SLC, which should be attributed to the lower surface dangling bonds. Passivation treatment with NH{sub 4}F + H{sub 2}O{sub 2} is an effective method to decrease SLCs of CdZnTe, by which the SLC was decreased two orders.

  10. Routine endoscopy to detect anastomotic leakage after esophagectomy.

    Science.gov (United States)

    Page, Richard D; Asmat, Atasha; McShane, James; Russell, Glenn N; Pennefather, Stephen H

    2013-01-01

    This study evaluated the safety and efficacy of endoscopy in diagnosing anastomotic leaks after esophagectomy. One hundred consecutive postesophagectomy patients, all having reconstruction using the stomach, underwent endoscopy in the first week after operation. The anastomosis and gastric mucosa were examined for evidence of ischemia, necrosis, and leak. There was no evidence that the procedure caused damage to the anastomosis or gastric conduit. The results of 79 examinations were normal, 15 showed gastric ischemia, 2 showed a leak, and 4 showed ischemia plus leakage. The 15 patients with ischemia alone were monitored with a repeat endoscopy after a further week: a late leak developed in 1 patient that was diagnosed at the second examination. No further leaks developed subsequently, making endoscopy 100% accurate in the diagnosis of leaks after esophagectomy. Esophagoscopy within 1 week of esophagectomy is a safe and highly accurate method of diagnosing leaks and provides unique information on the condition of the stomach. We believe it allows a more targeted approach to patient care in the context of anastomotic healing and in the treatment of leaks. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  11. Structural and leakage integrity assessment of WWER steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Splichal, K.; Otruba, J. [Nuclear Research Inst., Rez (Switzerland)

    1997-12-31

    The integrity of heat exchange tubes may influence the life-time of WWER steam generators and appears to be an important criterion for the evaluation of their safety and operational reliability. The basic requirement is to assure a very low probability of radioactive water leakage, preventing unstable crack growth and sudden tube rupture. These requirements led to development of permissible limits for primary to secondary leak evolution and heat exchange tubes plugging based on eddy current test inspection. The stress corrosion cracking and pitting are the main corrosion damage of WWER heat exchange tubes and are initiated from the outer surface. They are influenced by water chemistry, temperature and tube wall stress level. They take place under crevice corrosion condition and are indicated especially (1) under the tube support plates, where up to 90-95 % of defects detected by the ECT method occur, and (2) on free spans under tube deposit layers. Both the initiation and crack growth cause thinning of the tube wall and lead to part thickness cracks and through-wall cracks, oriented above all in the axial direction. 10 refs.

  12. Specifics of Building Envelope Air Leakage Problems and Airtightness Measurements

    Directory of Open Access Journals (Sweden)

    Borodinecs Anatolijs

    2016-01-01

    Full Text Available In addition to transmission heat loses the infiltration of outdoor air can cause significant heat losses. The external building envelope should be airtight in order to prevent uncontrolled cold air infiltration. The article analysis modern building materials and structures influence on airtightness. The practical measurements of renovated buildings’ airtightness are presented and compared to non-renovated buildings. In addition paper presents data on airtightness measurements of whole multi apartment building and single apartment in analyzed building taking inco accout properties of building materials. The airtightness of single apartment was evaluated with support pressure in neighbor apartments. The results show that the airtightness measurements of multi apartment building can be evaluated by measuring single apartment on last floor with support pressure in neighbor apartments. The practical measurement of renovated buildings had shown the air leakage rate q50 of typical Latvian construction after renovation is between 2.5 and 2.9 m3/(m2·h. Since the building envelope has to minimize the heat loses (transmission and infiltration and ventilation system either mechanical or natural has to provide necessary air exchange, the building envelope airtightness shouldn’t be dependent on type of ventilation systems.

  13. Anastomotic leakage after colorectal surgery: diagnostic accuracy of CT

    Energy Technology Data Exchange (ETDEWEB)

    Kauv, Paul; Benadjaoud, Samir; Boulay-Coletta, Isabelle; Zins, Marc [Fondation Hopital Saint-Joseph, Department of Radiology, Paris (France); Curis, Emmanuel [Universite Paris Descartes, Laboratoire de biomathematiques, Faculte de pharmacie, Paris (France); Loriau, Jerome [Fondation Hopital Saint-Joseph, Department of Digestive Surgery, Paris (France)

    2015-12-15

    To evaluate the diagnostic accuracy of CT in postoperative colorectal anastomotic leakage (AL). Two independent blinded radiologists reviewed 153 CTs performed for suspected AL within 60 days after surgery in 131 consecutive patients, with (n = 58) or without (n = 95) retrograde contrast enema (RCE). Results were compared to original interpretations. The reference standard was reoperation or consensus (a radiologist and a surgeon) regarding clinical, laboratory, radiological, and follow-up data after medical treatment. AL was confirmed in 34/131 patients. For the two reviewers and original interpretation, sensitivity of CT was 82 %, 87 %, and 71 %, respectively; specificity was 84 %, 84 %, and 92 %. RCE significantly increased the positive predictive value (from 40 % to 88 %, P = 0.0009; 41 % to 92 %, P = 0.0016; and 40 % to 100 %, P = 0.0006). Contrast extravasation was the most sensitive (reviewers, 83 % and 83 %) and specific (97 % and 97 %) sign and was significantly associated with AL by univariate analysis (P < 0.0001 and P < 0.0001). By multivariate analysis with recursive partitioning, CT with RCE was accurate to confirm or rule out AL with contrast extravasation. CT with RCE is accurate for diagnosing postoperative colorectal AL. Contrast extravasation is the most reliable sign. RCE should be performed during CT for suspected AL. (orig.)

  14. The Dangers of Rooting: Data Leakage Detection in Android Applications

    Directory of Open Access Journals (Sweden)

    Luca Casati

    2018-01-01

    Full Text Available Mobile devices are widely spread all over the world, and Android is the most popular operative system in use. According to Kaspersky Lab’s threat statistic (June 2017, many users are tempted to root their mobile devices to get an unrestricted access to the file system, to install different versions of the operating system, to improve performance, and so on. The result is that unintended data leakage flaws may exist. In this paper, we (i analyze the security issues of several applications considered relevant in terms of handling user sensitive information, for example, financial, social, and communication applications, showing that 51.6% of the tested applications suffer at least of an issue and (ii show how an attacker might retrieve a user access token stored inside the device thus exposing users to a possible identity violation. Notice that such a token, and a number of other sensitive information, can be stolen by malicious users through a man-in-the-middle (MITM attack.

  15. Modeling and analysis of sub-surface leakage current in nano-MOSFET under cutoff regime

    Science.gov (United States)

    Swami, Yashu; Rai, Sanjeev

    2017-02-01

    The high leakage current in nano-meter regimes is becoming a significant portion of power dissipation in nano-MOSFET circuits as threshold voltage, channel length, and gate oxide thickness are scaled down to nano-meter range. Precise leakage current valuation and meticulous modeling of the same at nano-meter technology scale is an increasingly a critical work in designing the low power nano-MOSFET circuits. We present a specific compact model for sub-threshold regime leakage current in bulk driven nano-MOSFETs. The proposed logical model is instigated and executed into the latest updated PTM bulk nano-MOSFET model and is found to be in decent accord with technology-CAD simulation data. This paper also reviews various transistor intrinsic leakage mechanisms for nano-MOSFET exclusively in weak inversion, like drain-induced barricade lowering (DIBL), gate-induced drain leakage (GIDL), gate oxide tunneling (GOT) leakage etc. The root cause of the sub-surface leakage current is mainly due to the nano-scale short channel length causing source-drain coupling even in sub-threshold domain. Consequences leading to carriers triumphing the barricade between the source and drain. The enhanced model effectively considers the following parameter dependence in the account for better-quality value-added results like drain-to-source bias (VDS), gate-to-source bias (VGS), channel length (LG), source/drain junction depth (Xj), bulk doping concentration (NBULK), and operating temperature (Top).

  16. Risk Factors for Anastomotic Leakage of Esophagojejunostomy after Laparoscopy-Assisted Total Gastrectomy for Gastric Cancer.

    Science.gov (United States)

    Oshi, Masanori; Kunisaki, Chikara; Miyamoto, Hiroshi; Kosaka, Takashi; Akiyama, Hirotoshi; Endo, Itaru

    2017-04-26

    The study aimed to clarify the risk factors for anastomotic leakage after laparoscopy-assisted total gastrectomy (LATG) for gastric cancer. In this study, we enrolled 131 patients with preoperatively diagnosed early gastric cancer who underwent LATG by a single surgeon between June 2006 and February 2014 at the Department of Surgery, Gastroenterological Center, Yokohama City University. Risk factors for anastomotic leakage (esophagojejunostomy) after LATG were retrospectively evaluated by univariate and multivariate analyses. Anastomotic leakage of the esophagojejunostomy was observed in 13 (9.9%) of 131 patients. Univariate analysis of risk factors for anastomotic leakage revealed that the prognostic nutritional index (PNI) is a risk factor for anastomotic leakage (<55, 11 of 63 vs. ≥55, 2 of 55; p = 0.039). Multivariate analysis revealed that PNI is an independent risk factor for anastomotic leakage (OR 0.208; 95% CI 0.044-0.981; p = 0.047). Gastric cancer patients with a low PNI have a higher risk for anastomotic leakage after LATG. The results of this study must be confirmed by a study with a large cohort of patients receiving LATG reconstructed using the same method by experienced surgeons in multiple institutions. © 2017 S. Karger AG, Basel.

  17. Impact of leakage delay on bifurcation in high-order fractional BAM neural networks.

    Science.gov (United States)

    Huang, Chengdai; Cao, Jinde

    2018-02-01

    The effects of leakage delay on the dynamics of neural networks with integer-order have lately been received considerable attention. It has been confirmed that fractional neural networks more appropriately uncover the dynamical properties of neural networks, but the results of fractional neural networks with leakage delay are relatively few. This paper primarily concentrates on the issue of bifurcation for high-order fractional bidirectional associative memory(BAM) neural networks involving leakage delay. The first attempt is made to tackle the stability and bifurcation of high-order fractional BAM neural networks with time delay in leakage terms in this paper. The conditions for the appearance of bifurcation for the proposed systems with leakage delay are firstly established by adopting time delay as a bifurcation parameter. Then, the bifurcation criteria of such system without leakage delay are successfully acquired. Comparative analysis wondrously detects that the stability performance of the proposed high-order fractional neural networks is critically weakened by leakage delay, they cannot be overlooked. Numerical examples are ultimately exhibited to attest the efficiency of the theoretical results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. CT evaluation of local leakage of bone cement after percutaneous kyphoplasty and vertebroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Lee, In Jae; Choi, A. Lam; Yie, Mi-Yeon; Yoon, Ji Young; Jeon, Eui Yong; Koh, Sung Hye; Yoon, Dae Young; Lim, Kyung Ja (Dept. of Radiology, Hallym Univ. Sacred Heart Hospital, Seoul (Korea)), e-mail: ijlee2003@medimail.co.kr; Im, Hyoung June (Dept. of Occupational Medicine, Hallym Univ. College of Medicine, Seoul (Korea))

    2010-07-15

    Background: Percutaneous injection of bone cement (acrylic cement) during percutaneous kyphoplasty and vertebroplasty can cause symptomatic or asymptomatic complications due to leakage, extravasation or vascular migration of cement. Purpose: To investigate and to compare the incidence and site of local leakage or complications of bone cement after percutaneous kyphoplasty and vertebroplasty using bone cement. Material and Methods: We retrospectively reviewed 473 cases of percutaneous kyphoplasty or vertebroplasty performed under fluoroscopic guidance. Of the 473 cases, follow-up CT scans that covered the treated bones were available for 83 cases (59 kyphoplasty and 24 vertebroplasty). Results: The rate of local leakage of bone cement was 87.5% (21/24) for percutaneous vertebroplasty and 49.2% (29/59) for kyphoplasty. The most common site of local leakage was perivertebral soft tissue (n=8, 38.1%) for vertebroplasty. The most common site of local leakage was a perivertebral vein (n=7, 24.1%) for kyphoplasty. Two cases of pulmonary cement embolism developed: one case after kyphoplasty and one case after vertebroplasty. Conclusion: Local leakage of bone cement was more common for percutaneous vertebroplasty compared with kyphoplasty (P<0.005). The most common sites of local leakage were perivertebral soft tissue and perivertebral vein.

  19. Leakage diagnostics, sealant longevity, sizing and technology transfer in residential thermal distribution systems

    Energy Technology Data Exchange (ETDEWEB)

    Walker, I.; Sherman, M.; Modera, M.; Siegel, J.

    1998-01-01

    This field study concentrated on measurement of duct leakage to outside the conditioned space because this is most useful in energy calculations. For room by room load/comfort requirements, the total duct leakage (including leaks to conditioned space) is more appropriate, particularly for additional comfort considerations. The objective of this field study is to help to identify major sources of uncertainty and to quantify the trade offs between different test methods. The identification of the areas requiring significant improvement will aid in future development of duct leakage test methods. For example, during the course of this study a new method for correcting house pressure tests to account for the presence of duct leakage in measured envelope leakage was developed. Each of the measurement techniques investigated has resulted from a different set of priorities and hence compromises. Thus each one of them is measuring a different physical quantity, although they all report the same parameter; duct leakage to outside at operating conditions. Given that real houses do not meet all of the simplifying assumptions that must be made to achieve similarity, the same numbers from each test method are not expected. Potentially these differences can be quite large and one of the benefits of field measurement is that the differences in the measurements helps put a realistic bound on how different some of these leakage diagnostics may be.

  20. Evaluation of the effects of enameloplasty and air abrasion on sealant micro-leakage.

    Science.gov (United States)

    Soleymani, Aliasghar; Bahrololoomi, Zahra; Javadinejadi, Shahrzad; Salehi, Parisa

    2014-11-01

    Micro-leakage, one of the major reasons for recurrent decays, may lead to uncontrollable flow of liquids, pulp inflammation and peri-apical pathology. The purpose of this in vitro study was to evaluate micro-leakage of pit and fissure sealants after using three different pit and fissure preparation techniques: 1) acid etching, 2) fissure enameloplasty and acid etching, and 3) air abrasion and acid etching. Sixty-nine extracted sound molars and premolars were randomly divided into three groups (23 samples in each group). Teeth were prepared using one of three occlusal surface treatments. Then the sealant was applied on the occlusal fissures of all teeth. The teeth were thermocycled and stored in normal saline. All teeth were sealed apically and coated with nail varnish and then were immersed in a 2% solution of methylen blue. Two buccolingual sections were made. The surfaces were scored 0 to 3 for the extent of micro-leakage using a stereomicroscope. Data were analyzed by Kruskal- wallis and Dunn procedure. Enameloplasty and acid etching were significantly different regarding micro-leakage (P= 0.016), but no significant difference in micro-leakage was observed between air abrasion and the other methods. Enameloplasty followed by acid etching produced significantly less micro-leakage than the acid etching technique. Air abrasion acid etching was better than the acid etching technique in reducing micro-leakage too.

  1. Evaluation of the effects of enameloplasty and air abrasion on sealant micro-leakage.

    Directory of Open Access Journals (Sweden)

    Aliasghar Soleymani

    2014-12-01

    Full Text Available Micro-leakage, one of the major reasons for recurrent decays, may lead to uncontrollable flow of liquids, pulp inflammation and peri-apical pathology. The purpose of this in vitro study was to evaluate micro-leakage of pit and fissure sealants after using three different pit and fissure preparation techniques: 1 acid etching, 2 fissure enameloplasty and acid etching, and 3 air abrasion and acid etching.Sixty-nine extracted sound molars and premolars were randomly divided into three groups (23 samples in each group. Teeth were prepared using one of three occlusal surface treatments. Then the sealant was applied on the occlusal fissures of all teeth. The teeth were thermocycled and stored in normal saline. All teeth were sealed apically and coated with nail varnish and then were immersed in a 2% solution of methylen blue. Two buccolingual sections were made. The surfaces were scored 0 to 3 for the extent of micro-leakage using a stereomicroscope. Data were analyzed by Kruskal- wallis and Dunn procedure.Enameloplasty and acid etching were significantly different regarding micro-leakage (P= 0.016, but no significant difference in micro-leakage was observed between air abrasion and the other methods.Enameloplasty followed by acid etching produced significantly less micro-leakage than the acid etching technique. Air abrasion acid etching was better than the acid etching technique in reducing micro-leakage too.

  2. Gate Leakage Reduction by Clocked Power Supply of Adiabatic Logic Circuits

    Directory of Open Access Journals (Sweden)

    Ph. Teichmann

    2005-01-01

    Full Text Available Losses due to gate-leakage-currents become more dominant in new technologies as gate leakage currents increase exponentially with decreasing gate oxide thickness. The most promising Adiabatic Logic (AL families use a clocked power supply with four states. Hence, the full VDD voltage drops over an AL gate only for a quarter of the clock cycle, causing a full gate leakage only for a quarter of the clock period. The rising and falling ramps of the clocked power supply lead to an additional energy consumption by gate leakage. This energy is smaller than the fraction caused by the constant VDD drop, because the gate leakage exponentially depends on the voltage across the oxide. To obtain smaller energy consumption, Improved Adiabatic Logic (IAL has been introduced. IAL swaps all n- and p-channel transistors. The logic blocks are built of p-channel devices which show gate tunneling currents significantly smaller than in n-channel devices. Using IAL instead of conventional AL allows an additional reduction of the energy consumption caused by gate leakage. Simulations based on a 90nm CMOS process show a lowering in gate leakage energy consumption for AL by a factor of 1.5 compared to static CMOS. For IAL the factor is up to 4. The achievable reduction varies depending on the considered AL family and the complexity of the gate.

  3. Numerical studies of CO2 and brine leakage into a shallow aquifer through an open wellbore

    Science.gov (United States)

    Wang, Jingrui; Hu, Litang; Pan, Lehua; Zhang, Keni

    2017-11-01

    Industrial-scale geological storage of CO2 in saline aquifers may cause CO2 and brine leakage from abandoned wells into shallow fresh aquifers. This leakage problem involves the flow dynamics in both the wellbore and the storage reservoir. T2Well/ECO2N, a coupled wellbore-reservoir flow simulator, was used to analyze CO2 and brine leakage under different conditions with a hypothetical simulation model in water-CO2-brine systems. Parametric studies on CO2 and brine leakage, including the salinity, excess pore pressure (EPP) and initially dissolved CO2 mass fraction, are conducted to understand the mechanism of CO2 migration. The results show that brine leakage rates increase proportionally with EPP and inversely with the salinity when EPP varies from 0.5 to 1.5 MPa; however, there is no CO2 leakage into the shallow freshwater aquifer if EPP is less than 0.5 MPa. The dissolved CO2 mass fraction shows an important influence on the CO2 plume, as part of the dissolved CO2 becomes a free phase. Scenario simulation shows that the gas lifting effect will significantly increase the brine leakage rate into the shallow freshwater aquifer under the scenario of 3.89% dissolved CO2 mass fraction. The equivalent porous media (EPM) approach used to model the wellbore flow has been evaluated and results show that the EPM approach could either under- or over-estimate brine leakage rates under most scenarios. The discrepancies become more significant if a free CO2 phase evolves. Therefore, a model that can correctly describe the complex flow dynamics in the wellbore is necessary for investigating the leakage problems.

  4. Postprocedural CT for perivertebral cement leakage in percutaneous vertebroplasty is not necessary - results from VERTOS II

    Energy Technology Data Exchange (ETDEWEB)

    Venmans, Alexander; Klazen, Caroline A.; Rooij, Willem Jan van; Lohle, Paul N. [St. Elisabeth Ziekenhuis Tilburg, Department of Radiology, Tilburg (Netherlands); Vries, Jolanda de [St. Elisabeth Ziekenhuis Tilburg, Department of Medical Psychology, Tilburg (Netherlands); Mali, Willem P. [University Medical Centre Utrecht, Department of Radiology, Utrecht (Netherlands)

    2011-01-15

    During percutaneous vertebroplasty (PV), perivertebral cement leakage frequently occurs. There is some concern that cement deposits may migrate towards the lungs via the veins during follow-up. We used baseline and follow-up computed tomography (CT) to assess the incidence and extend of late cement migration in a large consecutive patient cohort. VERTOS II is a prospective multicenter randomized controlled trial comparing PV with conservative therapy for osteoporotic vertebral compression fractures (OVCFs). Patients assigned to PV had baseline postprocedural CT scans of the treated vertebral bodies. After a mean follow-up of 22 months, 54 of 78 patients (69%) had follow-up CT. CT scans were analyzed and compared for perivertebral venous, discal, and soft tissue leakage. Perivertebral cement leakage occurred in 64 of 80 treated vertebrae (80%; 95% CI, 70% to 87%). All patients remained asymptomatic. Perivertebral venous leakage was present in 56 vertebrae (88%), mostly in the anterior external venous plexus (46 of 56, 82%). Discal leakage occurred in 22 of 64 vertebrae (34%) and soft tissue leakage in two of 64 (4%). Mean injected cement volume in vertebrae with leakage was higher (4.5 versus 3.7 cm{sup 3}, p = 0.04). Follow-up CT scan showed unchanged perivertebral cement leakages without late cement migration. Perivertebral cement leaks during PV for OVCFs occurred frequently in the VERTOS II trial. Cement leakage occurred more frequently with higher injected volumes. However, all patients remained asymptomatic, and late cement migration during follow-up did not occur. Standard postprocedural CT of the treated vertebral body in PV is not necessary. (orig.)

  5. Dosimetry and evaluating the effect of treatment parameters on the leakage of multi leaf collimators in ONCOR linear accelerators

    Directory of Open Access Journals (Sweden)

    Keyvan Jabbari

    2016-01-01

    Conclusions: The amount of leakage was more for 18 MV compare to 6 MV The percentage of the leakage for both energies is less than the 5% value which is recommended by protocols. The fluctuation of the MLC leakage reduced by increasing the field size and depth.

  6. The Diagnosis of Internal Leakage of Control Valve Based on the Grey Correlation Analysis Method

    Directory of Open Access Journals (Sweden)

    Zheng DING

    2014-07-01

    Full Text Available The valve plays an important part in the industrial automation system. Whether it operates normally or not relates with the quality of the products directly while its faults are relatively common because of bad working conditions. And the internal leakage is one of the common faults. Consequently, this paper sets up the experimental platform to make the valve in different working condition and collect relevant data online. Then, diagnose the internal leakage of the valve by using the grey correlation analysis method. The results show that this method can not only diagnose the internal leakage of valve accurately, but also distinguish fault degree quantitatively.

  7. Modeling the leakage of LCD displays with local backlight for quality assessment

    DEFF Research Database (Denmark)

    Mantel, Claire; Korhonen, Jari; Pedersen, Jesper M.

    2014-01-01

    The recent technique of local backlight dimming has a significant impact on the quality of images displayed with a LCD screen with LED local dimming. Therefore it represents a necessary step in the quality assessment chain, independently from the other processes applied to images. This paper...... on videos displayed on LCD TV with local backlight dimming viewed from a 0° and 15° angles. The subjective results are then compared objective data using different leakage models: constant over the whole display or horizontally varying and three leakage factor (no leakage, measured at 0° and 15...

  8. Research on Multi-level Electromagnetic Leakage Protection Strategy of Industrial Control System

    Science.gov (United States)

    Li, Yang; Li, Feng; Wang, Xu; Guo, Qingrui

    2017-10-01

    The structure of industrial control system (ICS) is different from computer architecture, electromagnetic leakage protection of computer system is no longer suitable for industrial control system. In this paper, a method of electromagnetic leakage multi-level protection for industrial control system is presented, which combines software development, system overhaul and repair management as well as maintainers management. Through the application of the comprehensive and multi-level protection structure, the electromagnetic leakage of the industrial control system is effectively reduced. The defects of traditional protection which focus on local structure and lack of overall protection, are improved.

  9. ERROR REDUCTION IN DUCT LEAKAGE TESTING THROUGH DATA CROSS-CHECKS

    Energy Technology Data Exchange (ETDEWEB)

    ANDREWS, J.W.

    1998-12-31

    One way to reduce uncertainty in scientific measurement is to devise a protocol in which more quantities are measured than are absolutely required, so that the result is over constrained. This report develops a method for so combining data from two different tests for air leakage in residential duct systems. An algorithm, which depends on the uncertainty estimates for the measured quantities, optimizes the use of the excess data. In many cases it can significantly reduce the error bar on at least one of the two measured duct leakage rates (supply or return), and it provides a rational method of reconciling any conflicting results from the two leakage tests.

  10. Cumulative Impacts of Energy and Climate Change Policies on Carbon Leakage

    Energy Technology Data Exchange (ETDEWEB)

    Varma, A.; Milnes, R.; Miller, K.; Williams, E. [AEA Technology plc, London (United Kingdom); De Bruyn, S.; Brinke, L. [CE Delft, Delft (Netherlands)

    2012-02-15

    Carbon leakage occurs when climate change policy aimed at reducing carbon dioxide emissions in one country leads to an increase in carbon dioxide emissions in a country that is not bound by these policies. Given that climate change is a global issue, carbon leakage impacts upon the effectiveness of climate change policies. This independent study examines the cumulative impact of climate change policies on carbon leakage. The report brings together findings and analysis from a wide range of primary literature in this area and where possible, conclusions relevant to the UK are drawn.

  11. 50 CFR 259.34 - Minimum and maximum deposits; maximum time to deposit.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Minimum and maximum deposits; maximum time to deposit. 259.34 Section 259.34 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL... Capital Construction Fund Agreement § 259.34 Minimum and maximum deposits; maximum time to deposit. (a...

  12. Simulating Remediation of CO2 Leakage from Geological Storage Sites

    Science.gov (United States)

    Zhang, Y.; Oldenburg, C. M.; Benson, S. M.

    2003-12-01

    One strategy to reduce net greenhouse gas emissions is to inject carbon dioxide (CO2) deep into subsurface formations where presumably it would be stored indefinitely. Although geologic storage formations will be carefully selected, CO2 injected into a target formation may unexpectedly migrate upwards and ultimately seep out at the ground surface, creating a potential hazard to human beings and ecosystems. In this case, CO2 that has leaked from the geologic storage site is considered a contaminant, and remediation strategies such as passive venting and active pumping are needed. The purpose of this study is to investigate remediation strategies for CO2 leakage from geologic storage sites. We use the integral finite-difference code TOUGH2 to simulate the remediation of CO2 in subsurface systems. We consider the components of water, CO2 and air, and model flow and transport in aqueous and gas phases subject to a variety of initial and boundary conditions including passive venting and active pumping. We have investigated the time it takes for a gas plume of CO2 to be removed from the vadose zone both by natural attenuation processes and by active extraction wells. The time for removal is parameterized in terms of a CO2 plume half-life, defined as the time required for one-half of the CO2 mass to be removed. Initial simulations show that barometric pressure fluctuations enhance the removal of CO2 from the vadose zone, but that CO2 trapped near the water table is difficult to remove by either passive or active remediation approaches. This work was supported by a Cooperative Research and Development Agreement (CRADA) between BP Corporation North America, as part of the CO2 Capture Project (CCP), and the U.S. Department of Energy (DOE) through the National Energy Technologies Laboratory (NETL), and by the U.S. Department of Energy under contract DE-AC03-76SF00098.

  13. Maximum daily rainfall in South Korea

    Indian Academy of Sciences (India)

    sponding datasets are described in section 2. The data used are the annual maximum daily rainfall from 1961 to 2001. The models and the fitting procedures are described in section 3. We use the method of maximum likelihood for estimation and the profile likelihood method for the corresponding confidence intervals.

  14. Location specific forecasting of maximum and minimum ...

    Indian Academy of Sciences (India)

    But, accurate forecasting of surface param- eters, particularly maximum and minimum tem- peratures over India, is a difficult task due to. Keywords. Statistical bias correction; location specific forecast; DMO; Numerical Weather Prediction; maximum and minimum temperature forecast. J. Earth Syst. Sci. 123, No. 5, July 2014 ...

  15. 24 CFR 200.15 - Maximum mortgage.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Maximum mortgage. 200.15 Section... Generally Applicable to Multifamily and Health Care Facility Mortgage Insurance Programs; and Continuing Eligibility Requirements for Existing Projects Eligible Mortgage § 200.15 Maximum mortgage. Mortgages must not...

  16. Modelling maximum canopy conductance and transpiration in ...

    African Journals Online (AJOL)

    There is much current interest in predicting the maximum amount of water that can be transpired by Eucalyptus trees. It is possible that industrial waste water may be applied as irrigation water to eucalypts and it is important to predict the maximum transpiration rates of these plantations in an attempt to dispose of this ...

  17. Duality of Maximum Entropy and Minimum Divergence

    Directory of Open Access Journals (Sweden)

    Shinto Eguchi

    2014-06-01

    Full Text Available We discuss a special class of generalized divergence measures by the use of generator functions. Any divergence measure in the class is separated into the difference between cross and diagonal entropy. The diagonal entropy measure in the class associates with a model of maximum entropy distributions; the divergence measure leads to statistical estimation via minimization, for arbitrarily giving a statistical model. The dualistic relationship between the maximum entropy model and the minimum divergence estimation is explored in the framework of information geometry. The model of maximum entropy distributions is characterized to be totally geodesic with respect to the linear connection associated with the divergence. A natural extension for the classical theory for the maximum likelihood method under the maximum entropy model in terms of the Boltzmann-Gibbs-Shannon entropy is given. We discuss the duality in detail for Tsallis entropy as a typical example.

  18. Leakage Characteristics of Dual-Cannula Fenestrated Tracheostomy Tubes during Positive Pressure Ventilation: A Bench Study

    National Research Council Canada - National Science Library

    Berlet, Thomas; Marchon, Mathias

    2016-01-01

    This study compared the leakage characteristics of different types of dual-cannula fenestrated tracheostomy tubes during positive pressure ventilation. Fenestrated Portex® Blue Line Ultra®, TRACOE® twist, or Rüsch® Traceofix...

  19. Humidity-induced charge leakage and field attenuation in electric field microsensors

    National Research Council Canada - National Science Library

    Zhang, Haiyan; Fang, Dongming; Yang, Pengfei; Peng, Chunrong; Wen, Xiaolong; Xia, Shanhong

    2012-01-01

    The steady-state zero output of static electric field measuring systems often fluctuates, which is caused mainly by the finite leakage resistance of the water film on the surface of the electric field...

  20. Signal-based Gas Leakage Detection for Fluid Power Accumulators in Wind Turbines

    DEFF Research Database (Denmark)

    Liniger, Jesper; Sepehri, Nariman; N. Soltani, Mohsen

    2017-01-01

    This paper describes the development and application of a signal-based fault detection method for identifying gas leakage in hydraulic accumulators used in wind turbines. The method uses Multiresolution Signal Decomposition (MSD) based on wavelets for feature extraction from a~single fluid pressure...... on an experimental setup allowing for the replication of the conditions for accumulators in wind turbines. Robustness is tested in a multi-fault environment where gas and external fluid leakage occurs simultaneously. In total, 24 experiments are performed, which show that the method is sensitive to gas leakage...... in the desired range and can be isolated from external fluid leakage. Additionally, the robustness to other operating conditions, such as wind speeds between rated and cut-off, turbulence intensity and ambient temperature is evaluated via simulations of a pitch system in a wind turbine using the Fatigue...

  1. Leakage current transport mechanisms of La0. 67Sr0. 33MnO3 ...

    Indian Academy of Sciences (India)

    limited current mechanism under forward bias while thermionic emission model under reverse bias. Analysis indicates that a modulating Schottky barrier exists at the LSMO/BTO interface, which dominates the leakage current transport properties ...

  2. Peritoneal microdialysis. Early diagnosis of anastomotic leakage after low anterior resection for rectosigmoid cancer

    DEFF Research Database (Denmark)

    Pedersen, Mark Ellebæk; Qvist, N; Bisgaard, C

    2009-01-01

    BACKGROUND: The aim of the present study was to evaluate the efficacy and safety of intraperitoneal microdialysis in early detection of anastomotic leakage after low anterior resection for rectosigmoid cancer. METHODS: In a series of 116 consecutive patients scheduled for low anterior resection......-252) hours. Samples were collected every 4-hours, and the concentration of glucose, lactate, pyruvate and glycerol was measured. RESULTS: Four patients developed symptomatic anastomotic leakage. Two patients developed non-abdominal sepsis. In 38 patients the postoperative course was uncomplicated...... anastomotic leakage it coincided with the development of clinical symptoms. In the two patients with non-abdominal sepsis the values were within normal range. CONCLUSION: Peritoneal microdialysis is a safe and promising tool in early diagnosis of anastomotic leakage after low anterior resection...

  3. Holding the World Bank accountable for leakage of funds from Africa's health sector.

    Science.gov (United States)

    Marouf, Fatma E

    2010-06-15

    This article explores the accountability of international financial institutions (IFIs), such as the World Bank, for human rights violations related to the massive leakage of funds from sub-Saharan Africa's health sector. The article begins by summarizing the quantitative results of Public Expenditure Tracking Surveys performed in six African countries, all showing disturbingly high levels of leakage in the health sector. It then addresses the inadequacy of good governance and anticorruption programs in remedying this problem. After explaining how the World Bank's Inspection Panel may serve as an accountability mechanism for addressing the leakage of funds, discussing violations of specific Bank policies and procedures that would support a claim related to leakage and examining the relevance of human rights concerns to such as claim, the article explores some of the Panel's limitations and the positive steps taken to address these concerns.

  4. Ray-leakage-free discal solar concentrators of a novel design

    Science.gov (United States)

    Yin, Peng; Xu, Xiping; Jiang, Zhaoguo; Hai, Yina

    2017-12-01

    For high concentration ratio of the planar concentrator which is mainly used for photovoltaic or solar-thermal applications, the ray-leakage must be prevented during rays propagated in the lightguide. In this paper, the design of a ray-leakage-free discal solar concentrator is proposed which provides a high concentration ratio while acquiring a high optical efficiency. The design structure of the coupling structure is a straightforward hemisphere instead of complicated structure in other concentrators because the emergent rays from the hybrid collectors have any tilt angle, which prompts the ray-leakage-free propagating length can be raised greatly. A mathematical model between geometrical concentration ratio, reflection times and the corresponding parameters is established, where the corresponding parameters include the parabola coefficient, outermost collector width, collector height, the expanding angle and the collector quantity. Numerical simulation results show that more than 1200x geometrical concentration ratio of the proposed concentrator is achieved without any leakage from the lightguide.

  5. Prevention of leakage of low-melting-point metals from styrofoam molds.

    Science.gov (United States)

    Herman, M W; Robinson, A; Small, R C

    1975-10-01

    Leakage of low-melting-point metals from the underside of polystyrene molds can be prevented by applying a silicone caulking material to the bottom of the mold and pressing the mold on a metal plate before pouring.

  6. Compilation of current literature on seals, closures, and leakage for radioactive material packagings

    Energy Technology Data Exchange (ETDEWEB)

    Warrant, M.M.; Ottinger, C.A.

    1989-01-01

    This report presents an overview of the features that affect the sealing capability of radioactive material packagings currently certified by the US Nuclear Regulatory Commission. The report is based on a review of current literature on seals, closures, and leakage for radioactive material packagings. Federal regulations that relate to the sealing capability of radioactive material packagings, as well as basic equations for leakage calculations and some of the available leakage test procedures are presented. The factors which affect the sealing capability of a closure, including the properties of the sealing surfaces, the gasket material, the closure method and the contents are discussed in qualitative terms. Information on the general properties of both elastomer and metal gasket materials and some specific designs are presented. A summary of the seal material, closure method, and leakage tests for currently certified packagings with large diameter seals is provided. 18 figs., 9 tabs.

  7. Leakage current and commutation losses reduction in electric drives for Hybrid Electric Vehicle

    Science.gov (United States)

    Miliani, El Hadj

    2014-06-01

    Nowadays, leakage current and inverter losses, produced by adjustable-speed AC drive systems become one of the main interested subject for researchers on Electric Vehicle (EV) and Hybrid Electric Vehicle (HEV) technology. The continuous advancements in solid state device engineering have considerably minimized the switching transients for power switches but the high dv/dt and high switching frequency have caused many adverse effects such as shaft voltage, bearing current, leakage current and electromagnetic interference (EMI). The major objective of this paper is to investigate and suppress of the adverse effects of a PWM inverter feeding AC motor in EV and HEV. A technique to simultaneously reduce the leakage current and the switching losses is presented in this paper. Based on a discontinuous space vector pulse width modulation (DSVPWM) and a modular switches gate resistance, inverter losses and leakage current are reduced. Algorithms are presented and implemented on a DSP controller and experimental results are presented.

  8. Spatio-temporal characteristics of Agulhas leakage: a model inter-comparison study

    CSIR Research Space (South Africa)

    Holton, L

    2016-05-01

    Full Text Available Investigating the variability of Agulhas leakage, the volume transport of water from the Indian Ocean to the South Atlantic Ocean, is highly relevant due to its potential contribution to the Atlantic Meridional Overturning Circulation as well...

  9. The effect of gap width on viscous stresses within the leakage across a bileaflet valve pivot

    DEFF Research Database (Denmark)

    Travis, Brandon R; Andersen, Morten E; Fründ, Ernst Torben

    2008-01-01

    BACKGROUND AND AIM OF THE STUDY: Stresses of leakage flow may contribute to the increased tendency for thromboembolic complications in patients with mechanical valves. In bileaflet valves, leakage occurs primarily in the pivots, and the width of the pivot gap influences viscous stress magnitudes....... The present study was conducted to investigate the effects of gap width on viscous stresses within the pivots of a bileaflet mitral valve during the leakage phase. METHODS: A computational model of a bileaflet valve was created and inserted between models of the left atrium and ventricle. Three simulations...... reported within the pivots in previous studies. Velocities measured experimentally were even larger than those estimated computationally. CONCLUSION: These experiments suggest that viscous stresses in leakage flow across a bileaflet mitral valve increase with gap width, and may contribute more to blood...

  10. Computing Optimal Mixed Strategies for Terrorist Plot Detection Games with the Consideration of Information Leakage

    Directory of Open Access Journals (Sweden)

    Li MingChu

    2017-01-01

    Full Text Available The terrorist’s coordinated attack is becoming an increasing threat to western countries. By monitoring potential terrorists, security agencies are able to detect and destroy terrorist plots at their planning stage. Therefore, an optimal monitoring strategy for the domestic security agency becomes necessary. However, previous study about monitoring strategy generation fails to consider the information leakage, due to hackers and insider threat. Such leakage events may lead to failure of watching potential terrorists and destroying the plot, and cause a huge risk to public security. This paper makes two major contributions. Firstly, we develop a new Stackelberg game model for the security agency to generate optimal monitoring strategy with the consideration of information leakage. Secondly, we provide a double-oracle framework DO-TPDIL for calculation effectively. The experimental result shows that our approach can obtain robust strategies against information leakage with high feasibility and efficiency.

  11. A method to investigate inter-aquifer leakage using hydraulics and multiple environmental tracers

    Science.gov (United States)

    Priestley, Stacey; Love, Andrew; Wohling, Daniel; Post, Vincent; Shand, Paul; Kipfer, Rolf; Tyroller, Lina

    2016-04-01

    Informed aquifer management decisions regarding sustainable yields or potential exploitation require an understanding of the groundwater system (Alley et al. 2002, Cherry and Parker 2004). Recently, the increase in coal seam gas (CSG) or shale gas production has highlighted the need for a better understanding of inter-aquifer leakage and contaminant migration. In most groundwater systems, the quantity or location of inter-aquifer leakage is unknown. Not taking into account leakage rates in the analysis of large scale flow systems can also lead to significant errors in the estimates of groundwater flow rates in aquifers (Love et al. 1993, Toth 2009). There is an urgent need for robust methods to investigate inter-aquifer leakage at a regional scale. This study builds on previous groundwater flow and inter-aquifer leakage studies to provide a methodology to investigate inter-aquifer leakage in a regional sedimentary basin using hydraulics and a multi-tracer approach. The methodology incorporates geological, hydrogeological and hydrochemical information in the basin to determine the likelihood and location of inter-aquifer leakage. Of particular benefit is the analysis of hydraulic heads and environmental tracers at nested piezometers, or where these are unavailable bore couplets comprising bores above and below the aquitard of interest within a localised geographical area. The proposed methodology has been successful in investigating inter-aquifer leakage in the Arckaringa Basin, South Australia. The suite of environmental tracers and isotopes used to analyse inter-aquifer leakage included the stable isotopes of water, radiocarbon, chloride-36, 87Sr/86Sr and helium isotopes. There is evidence for inter-aquifer leakage in the centre of the basin ~40 km along the regional flow path. This inter-aquifer leakage has been identified by a slight draw-down in the upper aquifer during pumping in the lower aquifer, overlap in Sr isotopes, δ2H, δ18O and chloride

  12. Leakage Characteristics of Dual-Cannula Fenestrated Tracheostomy Tubes during Positive Pressure Ventilation: A Bench Study

    OpenAIRE

    Thomas Berlet; Mathias Marchon

    2016-01-01

    This study compared the leakage characteristics of different types of dual-cannula fenestrated tracheostomy tubes during positive pressure ventilation. Fenestrated Portex? Blue Line Ultra?, TRACOE? twist, or R?sch? Traceofix? tracheostomy tubes equipped with nonfenestrated inner cannulas were tested in a tracheostomy-lung simulator. Transfenestration pressures and transfenestration leakage rates were measured during positive pressure ventilation. The impact of different ventilation modes, air...

  13. Embolization for Thoracic Duct Collateral Leakage in High-Output Chylothorax After Thoracic Surgery

    Energy Technology Data Exchange (ETDEWEB)

    Kariya, Shuji, E-mail: kariyas@hirakata.kmu.ac.jp; Nakatani, Miyuki, E-mail: nakatanm@hirakata.kmu.ac.jp; Yoshida, Rie, E-mail: yagir@hirakata.kmu.ac.jp; Ueno, Yutaka, E-mail: uenoyut@hirakata.kmu.ac.jp; Komemushi, Atsushi, E-mail: komemush@takii.kmu.ac.jp; Tanigawa, Noboru, E-mail: tanigano@hirakata.kmu.ac.jp [Kansai Medical University, Department of Radiology (Japan)

    2017-01-15

    PurposeThis study was designed to investigate thoracic duct collateral leakage and the supply route of lymphatic fluid by lymphangiography and transcatheter thoracic ductography and to evaluate the results of embolization for thoracic duct collateral leakage performed to cut off this supply route.MethodsData were retrospectively collected from five patients who underwent embolization for thoracic duct collateral leakage in persistent high-output chylothorax after thoracic surgery. Extravasation of lipiodol at the ruptured thoracic duct collaterals was confirmed in all patients on lymphangiography. Transcatheter thoracic ductography was used to identify extravasation of iodinated contrast agent and to identify communication between the thoracic duct and leakage site. Thoracic duct embolization (TDE) was performed using the percutaneous transabdominal approach to cut off the supply route using N-butyl cyanoacrylate (NBCA) mixed with lipiodol (1:5–1:20).ResultsClinical success (drainage volume ≤10 mL/kg/day within 7 days after TDE) was achieved in all patients. The collateral routes developed as consequence of surgical thoracic duct ligation. In three patients, NBCA-Lipiodol reached the leakage site through direct communication between the thoracic duct and the ruptured lymphatic duct. In the other two patients, direct communication and extravasation was not detected on thoracic ductography, and NBCA-Lipiodol did not reach the leakage site. However, NBCA-Lipiodol did reach the cisterna chyli, lumbar trunks, and some collateral routes via the cisterna chyli or lumbar lymphatics. As a result, leakage was stopped.ConclusionsTDE was effective for the management of leakage of the collaterals in high-output chylothorax after thoracic surgery.

  14. Potential for the Use of Wireless Sensor Networks for Monitoring of CO2 Leakage Risks

    Science.gov (United States)

    Pawar, R.; Illangasekare, T. H.; Han, Q.; Jayasumana, A.

    2015-12-01

    Storage of supercritical CO2 in deep saline geologic formation is under study as a means to mitigate potential global climate change from green house gas loading to the atmosphere. Leakage of CO2 from these formations poses risk to the storage permanence goal of 99% of injected CO2 remaining sequestered from the atmosphere,. Leaked CO2 that migrates into overlying groundwater aquifers may cause changes in groundwater quality that pose risks to environmental and human health. For these reasons, technologies for monitoring, measuring and accounting of injected CO2 are necessary for permitting of CO2 sequestration projects under EPA's class VI CO2 injection well regulations. While the probability of leakage related to CO2 injection is thought to be small at characterized and permitted sites, it is still very important to protect the groundwater resources and develop methods that can efficiently and accurately detect CO2 leakage. Methods that have been proposed for leakage detection include remote sensing, soil gas monitoring, geophysical techniques, pressure monitoring, vegetation stress and eddy covariance measurements. We have demonstrated the use of wireless sensor networks (WSN) for monitoring of subsurface contaminant plumes. The adaptability of this technology for leakage monitoring of CO2 through geochemical changes in the shallow subsurface is explored. For this technology to be viable, it is necessary to identify geochemical indicators such as pH or electrical conductivity that have high potential for significant change in groundwater in the event of CO2 leakage. This talk presents a conceptual approach to use WSNs for CO2 leakage monitoring. Based on our past work on the use of WSN for subsurface monitoring, some of the challenges that need to be over come for this technology to be viable for leakage detection will be discussed.

  15. Clinical Relevance of Cement Leakage after Radiofrequency Kyphoplasty vs. Balloon Kyphoplasty: A Prospective Randomised Study.

    Science.gov (United States)

    Riesner, H-J; Kiupel, K; Lang, P; Stuby, F; Friemert, B; Palm, H-G

    2016-08-01

    Cement leakage is regarded as a typical complication of cement-based augmentation of vertebral fractures. The gold standard is balloon kyphoplasty (BK). Recent methods, such as radiofrequency kyphoplasty (RFK), must be compared with BK in terms of therapeutic success and complication rates. It is unclear whether the cement leakage rate in RFK is lower than with BK and whether this has any clinical relevance. Therefore, the aim of our prospective clinical study was to compare RFK with BK with respect to cement leakage rates and associated clinical complications. After prospective randomisation, 100 patients (76 women and 24 men with an average age of 78.5 years) or 162 vertebral bodies were treated by BK (n = 79) or RFK (n = 83). We evaluated the parameters "localisation of cement leakage" (epidural, intradiscal, extracorporal, intravascular) and "clinical relevance". More cement is used in BK (5.2 ml) than in RFK (4.0 ml, p = 0.001). Cement leakage was found in 48/79 patients (60.8 %) with BK and 53/83 patients (63.9 %) with RFK (p = 0.420). Even subanalysis by location showed no significant difference between the two methods. Despite the high leakage rates, we experienced only two cases (1× BK, 1× RFK) with intravascular leakage in the inferior vena cava, with interventional endovascular salvage. The two examined kyphoplasty methods (BK vs. RFK) have the same high rates of cement leakage, but are rarely associated with clinically manifest complications. Clinically relevant differences between the two compared kyphoplasty methods could not be found. Georg Thieme Verlag KG Stuttgart · New York.

  16. An Automatic System to Detect Thermal Leakages and Damages on Building Facade Using Thermal Images

    OpenAIRE

    Sirmacek, Beril; Hoegner, Ludwig; Stilla, Uwe

    2011-01-01

    In recent years, very high energy consumption is the major problem of the big cities. Most of the energy of the cities are disbursed to warm and cool buildings. Thus, detecting heat leakages on building walls is a new research problem. In this study, we propose a novel system to detect thermal leakages automatically from thermal camera images. To this end, we use sequential thermal images of buildings. First, we start with fusing thermal image sequences to obtain rectified building facade wit...

  17. Design and Development of Gas Leakage Monitoring System Using Arduino and ZigBee

    OpenAIRE

    Yan, Huan Hui; Rahayu, Yusnita

    2014-01-01

    Gas leakage in industrial area causes many health issues. Thus, to prevent such disasters happen, the atmosphere of a workplace should be regularly monitored and controlled, in order to maintain the clean air environment. However, efforts in industrial air quality control have been impeded by the lack of science-based approaches to identify and assess atmosphere air quality and level of dangerous gas. Therefore, a monitoring system for gas leakage detection needs to be developed. For the deve...

  18. CO2 Leakage, Storage and Injection Monitoring by Using Experimental, Numerical and Analytical Methods

    Directory of Open Access Journals (Sweden)

    A. Namdar

    2014-09-01

    Full Text Available The maintaining environment is priority to any plan in human life. It is planned for monitoring CO2 injection, storage and leakage by using geophysical, numerical and analytical methods in seismic zone. In this regard the mineralogy, chemical composite, lithology, seismic wave propagation, small earthquake, accelerating natural earthquake, thermal stress-strain modeling, ground movement level and fault activation will be consider. It is expected to better understand CO2 leakage, storage and injection process and problems.

  19. Dengue Virus Nonstructural Protein 1 Induces Vascular Leakage through Macrophage Migration Inhibitory Factor and Autophagy.

    Directory of Open Access Journals (Sweden)

    Hong-Ru Chen

    2016-07-01

    Full Text Available Dengue virus (DENV is the most common mosquito-borne flavivirus; it can either cause mild dengue fever or the more severe dengue hemorrhagic fever (DHF and dengue shock syndrome (DSS. One of the characteristic features of DHF/DSS is vascular leakage; although DENV nonstructural protein 1 (NS1 has been proved to induce vascular leakage after binding to Toll-like receptor 4, the down-stream mechanism has not yet been fully understood. In the sera of DENV-infected patients, the concentrations of DENV NS1 and inflammatory cytokine macrophage migration inhibitory factor (MIF are positively correlated with disease severity, but whether DENV NS1 induces vascular leakage through MIF secretion remains unknown. We demonstrated that recombinant NS1 induced vascular leakage and MIF secretion both in human endothelial cell line HMEC-1 and in mice. Furthermore, these phenomena were inhibited in the presence of anti-NS1 antibodies both in vitro and in vivo. DENV NS1 also induced LC3-I to LC3-II conversion and p62 degradation in endothelial cell line, which indicated the formation of autophagy. To clarify whether MIF or autophagy mediated DENV NS1-induced vascular leakage, various inhibitors were applied. The results showed that DENV NS1-induced vascular leakage and VE-cadherin disarray were blocked in the presence of MIF inhibitors, anti-MIF-antibodies or autophagy inhibitors. An Atg5 knockdown clone further confirmed that autophagy formation of endothelial cells was required in NS1-induced vascular leakage. Furthermore, DENV NS1-induced LC3 puncta were also decreased in the presence of MIF inhibitors, indicating that MIF mediated DENV NS1-induced autophagy. Taken together, the results suggest a potential mechanism of DENV-induced vascular leakage and provide possible therapeutic targets against DHF/DSS.

  20. Calculation of surface leakage currents on high voltage insulators by ant colony algorithm-supported FEM

    OpenAIRE

    ÖZTÜRK, DURSUN; CEBECİ, MEHMET

    2015-01-01

    The weakness of the outer insulation at high voltages is the reduction of the surface resistance as a result of the environmental pollution yielding formation of flashover due to the surface leakage currents. In this study, it was shown how to calculate the surface leakage currents resulting in flashover in polluted insulators and therefore power cuts by means of the ant colony algorithm (ACA). For this purpose, first, field distribution on the sample insulator surface in question was defined...

  1. Comparison of leakage rates of methyl bromide and sulfuryl fluoride during structural fumigations

    OpenAIRE

    Maier. D. E.; Subramanyam, B.; Chayaprasert, W.

    2010-01-01

    In structural fumigations, half-loss time (HLT) is the most frequently used indicator for comparing fumigant leakage rates. In practical situations where gas leakage rates during structural fumigations are compared, environmental conditions generally are not analyzed in detail and sealing quality is assumed to be constant or fixed. This gives a false impression that a certain gas fumigant might be contained in a structure better than another fumigant. During commercial structural fumigations ...

  2. Leakage Risk Assessment for a Potential CO2 Storage Project in Saskatchewan, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Houseworth, J.E.; Oldenburg, C.M.; Mazzoldi, A.; Gupta, A.K.; Nicot, J.-P.; Bryant, S.L.

    2011-05-01

    A CO{sub 2} sequestration project is being considered to (1) capture CO{sub 2} emissions from the Consumers Cooperative Refineries Limited at Regina, Saskatchewan and (2) geologically sequester the captured CO{sub 2} locally in a deep saline aquifer. This project is a collaboration of several industrial and governmental organizations, including the Petroleum Technology Research Centre (PTRC), Sustainable Development Technology Canada (SDTC), SaskEnvironment Go Green Fund, SaskPower, CCRL, Schlumberger Carbon Services, and Enbridge. The project objective is to sequester 600 tonnes CO{sub 2}/day. Injection is planned to start in 2012 or 2013 for a period of 25 years for a total storage of approximately 5.5 million tonnes CO{sub 2}. This report presents an assessment of the leakage risk of the proposed project using a methodology known as the Certification Framework (CF). The CF is used for evaluating CO{sub 2} leakage risk associated with geologic carbon sequestration (GCS), as well as brine leakage risk owing to displacement and pressurization of brine by the injected CO{sub 2}. We follow the CF methodology by defining the entities (so-called Compartments) that could be impacted by CO{sub 2} leakage, the CO{sub 2} storage region, the potential for leakage along well and fault pathways, and the consequences of such leakage. An understanding of the likelihood and consequences of leakage forms the basis for understanding CO{sub 2} leakage risk, and forms the basis for recommendations of additional data collection and analysis to increase confidence in the risk assessment.

  3. Multigas Leakage Correction in Static Environmental Chambers Using Sulfur Hexafluoride and Raman Spectroscopy.

    Science.gov (United States)

    Jochum, Tobias; von Fischer, Joseph C; Trumbore, Susan; Popp, Jürgen; Frosch, Torsten

    2015-11-03

    In static environmental chamber experiments, the precision of gas flux measurements can be significantly improved by a thorough gas leakage correction to avoid under- or overestimation of biological activity such as respiration or photosynthesis. Especially in the case of small biological net gas exchange rates or gas accumulation phases during long environmental monitoring experiments, gas leakage fluxes could distort the analysis of the biogenic gas kinetics. Here we propose and demonstrate a general protocol for online correction of diffusion-driven gas leakage in plant chambers by simultaneous quantification of the inert tracer sulfur hexafluoride (SF6) and the investigated biogenic gases using enhanced Raman spectroscopy. By quantifying the leakage rates of carbon dioxide (CO2), methane (CH4), and hydrogen (H2) simultaneously with SF6 in the test chamber, their effective diffusivity ratios of approximately 1.60, 1.96, and 5.65 were determined, each related to SF6. Because our experiments suggest that the effective diffusivity ratios are reproducible for an individual static environmental chamber, even under varying concentration gradients and slight changes of the chamber sealing, an experimental method to quantify gas leakage fluxes by using effective diffusivity ratios and SF6 leakage fluxes is proposed. The method is demonstrated by quantifying the CO2 net exchange rate of a plant-soil ecosystem (Mirabilis jalapa). By knowing the effective chamber diffusivity ratio CO2/SF6 and the measured SF6 leakage rate during the experiment, the leakage contribution to the total CO2 exchange rate could be calculated and the biological net CO2 concentration change within the chamber atmosphere determined.

  4. Leakage Detection and Estimation Algorithm for Loss Reduction in Water Piping Networks

    Directory of Open Access Journals (Sweden)

    Kazeem B. Adedeji

    2017-10-01

    Full Text Available Water loss through leaking pipes constitutes a major challenge to the operational service of water utilities. In recent years, increasing concern about the financial loss and environmental pollution caused by leaking pipes has been driving the development of efficient algorithms for detecting leakage in water piping networks. Water distribution networks (WDNs are disperse in nature with numerous number of nodes and branches. Consequently, identifying the segment(s of the network and the exact leaking pipelines connected to this segment(s where higher background leakage outflow occurs is a challenging task. Background leakage concerns the outflow from small cracks or deteriorated joints. In addition, because they are diffuse flow, they are not characterised by quick pressure drop and are not detectable by measuring instruments. Consequently, they go unreported for a long period of time posing a threat to water loss volume. Most of the existing research focuses on the detection and localisation of burst type leakages which are characterised by a sudden pressure drop. In this work, an algorithm for detecting and estimating background leakage in water distribution networks is presented. The algorithm integrates a leakage model into a classical WDN hydraulic model for solving the network leakage flows. The applicability of the developed algorithm is demonstrated on two different water networks. The results of the tested networks are discussed and the solutions obtained show the benefits of the proposed algorithm. A noteworthy evidence is that the algorithm permits the detection of critical segments or pipes of the network experiencing higher leakage outflow and indicates the probable pipes of the network where pressure control can be performed. However, the possible position of pressure control elements along such critical pipes will be addressed in future work.

  5. How Much Leakage Renders the Greenhouse Gas Footprint of Natural Gas Equivalent to Coal?

    Science.gov (United States)

    Sanchez, N., II; Mays, D. C.

    2015-12-01

    Under ideal circumstances, generating electricity from natural gas releases approximately half the carbon dioxide-equivalent emissions of coal. However, because the primary component of natural gas (i.e., methane) is a potent greenhouse gas, accounting for leakage is crucial when considering natural gas as a bridge fuel. This presentation answers the question: How much leakage renders the greenhouse gas (GHG) footprint of natural gas equivalent to coal? To answer this question, we present a simple model that assumes the GHG footprint for each fuel is the sum of emissions from (1) electricity generation and (2) natural gas leakage. Emissions resulting from electricity generation are taken from published life-cycle assessments (LCAs). Emissions from natural gas leakage are estimated assuming that natural gas is 80% methane, which is converted to carbon dioxide-equivalent emissions using the Intergovernmental Panel on Climate Change's (IPCC's) global warming potential (GWP). One complication in using the GWP is its dependence on time horizon, where shorter time horizons penalize methane emissions more, and longer time horizons less. Specifically, the IPCC considers time horizons of 20, 100 and 500 years for comparison between the differing greenhouse gases. To explicitly account for the effect of time horizon, the results presented here are shown on a straightforward plot of GHG footprint versus time horizon for natural gas leakage rates of 0, 1, 2, 4, and 8%. This plot shows that natural gas leakage of 2.0% or 4.8% eliminates half of natural gas's GHG footprint advantage over coal at 20- or 100-year time horizons, respectively. Leakage of 3.9% or 9.1% completely eliminates the GHG footprint advantage over coal at 20- and 100-year time horizons, respectively. Results indicate that leakage control is essential for the electricity generated from the combustion of natural gas to create a smaller GHG footprint than the electricity generated from the combustion of coal.

  6. Effect of Post-HALT Annealing on Leakage Currents in Solid Tantalum Capacitors

    Science.gov (United States)

    Teverovsky, Alexander

    2010-01-01

    Degradation of leakage currents is often observed during life testing of tantalum capacitors and is sometimes attributed to the field-induced crystallization in amorphous anodic tantalum pentoxide dielectrics. However, degradation of leakage currents and the possibility of annealing of degraded capacitors have not been investigated yet. In this work the effect of annealing after highly accelerated life testing (HALT) on leakage currents in various types of solid tantalum capacitors was analyzed. Variations of leakage currents with time during annealing at temperatures from 125 oC to 180 oC, thermally stimulated depolarization (TSD) currents, and I-V characteristics were measured to understand the conduction mechanism and the reason for current degradation. Annealing resulted in a gradual decrease of leakage currents and restored their initial values. Repeat HALT after annealing resulted in reproducible degradation of leakage currents. The observed results are explained based on ionic charge instability (drift/diffusion of oxygen vacancies) in the tantalum pentoxide dielectrics using a modified Schottky conduction mechanism.

  7. Simulation and experimental research of heat leakage of cryogenic transfer lines

    Science.gov (United States)

    Deng, B. C.; Xie, X. J.; Pan, W.; Jiang, R. X.; Li, J.; Yang, S. Q.; Li, Q.

    2017-12-01

    The heat leakage of cryogenic transfer lines directly influences the performance of large-scale helium refrigerator. In this paper, a thermal model of cryogenic transfer line considering numerical simulation of support coupled with MLI was established. To validate the model, test platform of cryogenic transfer lines with the merits of disassembly outer pipe and changeable easily multi-layer insulation has been built. The experimental results of heat leakage through overall length of cryogenic transfer lines, support and multi-layer insulation were obtained. The heat leakages of multi-layer insulation, a support and the overall leakage are 1.02 W/m, 0.44 W and 1.46 W/m from experimental data, respectively. The difference of heat leakage of MLI between experiment and simulation were less than 5%. The temperature distribution of support and MLI obtained in presented model in good agreement with experimental data. It is expected to reduce the overall heat leakage of cryogenic transfer lines further by optimizing structure of support based on the above thermal model and test platform in this paper.

  8. Assessment Of Carbon Leakage In Multiple Carbon-Sink Projects: ACase Study In Jambi Province, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Boer, Rizaldi; Wasrin, Upik R.; Hendri, Perdinan; Dasanto,Bambang D.; Makundi, Willy; Hero, Julius; Ridwan, M.; Masripatin, Nur

    2007-06-01

    Rehabilitation of degraded forest land throughimplementation of carbon sink projects can increase terrestrial carbonstock. However, carbon emissions outside the project boundary, which iscommonly referred to as leakage, may reduce or negate the sequestrationbenefits. This study assessed leakage from carbon sink projects thatcould potentially be implemented in the study area comprised of elevensub-districts in the Batanghari District, Jambi Province, Sumatra,Indonesia. The study estimates the probability of a given land use/coverbeing converted into other uses/cover, by applying a logit model. Thepredictor variables were: proximity to the center of the land use area,distance to transportation channel (road or river), area of agriculturalland, unemployment (number of job seekers), job opportunities, populationdensity and income. Leakage was estimated by analyzing with and withoutcarbon sink projects scenarios. Most of the predictors were estimated asbeing significant in their contribution to land use cover change. Theresults of the analysis show that leakage in the study area can be largeenough to more than offset the project's carbon sequestration benefitsduring the period 2002-2012. However, leakage results are very sensitiveto changes of carbon density of the land uses in the study area. Byreducing C-density of lowland and hill forest by about 10 percent for thebaseline scenario, the leakage becomes positive. Further data collectionand refinement is therefore required. Nevertheless, this study hasdemonstrated that regional analysis is a useful approach to assessleakage.

  9. Ray-leakage-free planar solar concentrator featuring achromatic hybrid collectors and innovative secondary optical elements

    Science.gov (United States)

    Yin, Peng; Xu, Xiping; Jiang, Zhaoguo

    2017-11-01

    For high concentration ratio of the planar concentrator which is mainly used for photovoltaic or solar-thermal applications, the ray-leakage must be prevented during rays propagated in the lightguide. In this paper, the design of a ray-leakage-free planar solar concentrator is introduced with achromatic hybrid collectors and innovative secondary optical elements. The distance between two columns of dimple structures is larger because the collector width is irrelevant to the collector length, which prompts the ray-leakage-free propagating length can be raised greatly. Put differently, the proposed concentrator can obtain a high geometrical concentration ratio while achieving a high optical efficiency. To increase the ray-leakage-free propagating distance, a mathematical model between ray-leakage-free propagating length and the corresponding parameters is established, where the corresponding parameters include the parabola coefficient, the width of collector, the concentrator height and the small expanding angle of the dimple structure. Numerical results display that more than 5000x geometrical concentration ratio of the proposed concentrator is achieved without any leakage from the lightguide.

  10. Leakage of CO2 from geologic storage: Role of secondaryaccumulation at shallow depth

    Energy Technology Data Exchange (ETDEWEB)

    Pruess, K.

    2007-05-31

    Geologic storage of CO2 can be a viable technology forreducing atmospheric emissions of greenhouse gases only if it can bedemonstrated that leakage from proposed storage reservoirs and associatedhazards are small or can be mitigated. Risk assessment must evaluatepotential leakage scenarios and develop a rational, mechanisticunderstanding of CO2 behavior during leakage. Flow of CO2 may be subjectto positive feedbacks that could amplify leakage risks and hazards,placing a premium on identifying and avoiding adverse conditions andmechanisms. A scenario that is unfavorable in terms of leakage behavioris formation of a secondary CO2 accumulation at shallow depth. This paperdevelops a detailed numerical simulation model to investigate CO2discharge from a secondary accumulation, and evaluates the role ofdifferent thermodynamic and hydrogeologic conditions. Our simulationsdemonstrate self-enhancing as well as self-limiting feedbacks.Condensation of gaseous CO2, 3-phase flow of aqueous phase -- liquid CO2-- gaseous CO2, and cooling from Joule-Thomson expansion and boiling ofliquid CO2 are found to play important roles in the behavior of a CO2leakage system. We find no evidence that a subsurface accumulation of CO2at ambient temperatures could give rise to a high-energy discharge, aso-called "pneumatic eruption."

  11. Evaluation of marginal leakage of different temporary restorative materials in Endodontics

    Directory of Open Access Journals (Sweden)

    Pedro Henrique Duarte França de Castro

    2013-01-01

    Full Text Available Aim: The aim of this study is to assess the coronal marginal leakage of three temporary restorative materials used for root canal sealing after endodontic treatment. Materials and Methods: A total of 88 single-rooted teeth were submitted to biomechanical preparation and filled by lateral condensation technique. After obturation process, the teeth were randomly separated into four groups, being two teeth of each group used as positive and negative control. Temporary sealing was performed as follows: GI - Clip F (VOCO; GII - Bioplic (Biodinβmica; GIII - Vitremer (3M ESPE and GIV - Ketak N100 (3M ESPE. Next, the specimens were immersed into Indian ink for 30 and 60- days, being 10 specimens for each time interval and then submitted to diaphanization to verify the amount of coronal leakage using a measuring microscope. Results : Leakage mean values within the 30-day period were as follows: Vitremer (0.3 mm, Ketak N100 and Clip F (0.6 mm and Bioplic (1.7 mm. Within the 60-day period, leakage means were 1.1 mm, 1.5 mm, 2.2 mm and 2.6 mm, respectively. Conclusions: None of the materials was capable of preventing marginal leakage within the 30- and 60-day period. In both time intervals, Bioplic presented the highest mean of leakage and Vitremer the lowest.

  12. Preoperative risk factors for anastomotic leakage after resection for colorectal cancer

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian; Gessler, B; Burcharth, Jakob

    2014-01-01

    AIM: Colorectal anastomotic leakage is a serious complication. Despite extensive research, no consensus on the most important preoperative risk factors exists. The aim of this systematic review and meta-analysis was to evaluate risk factors for anastomotic leakage in patients operated with colore......AIM: Colorectal anastomotic leakage is a serious complication. Despite extensive research, no consensus on the most important preoperative risk factors exists. The aim of this systematic review and meta-analysis was to evaluate risk factors for anastomotic leakage in patients operated...... with colorectal resection. METHOD: The databases MEDLINE, Embase and CINAHL were searched for prospective observational studies on preoperative risk factors for anastomotic leakage. Meta-analyses were performed on outcomes based on odds ratios (OR) from multivariate regression analyses. The Newcastle-Ottawa scale...... for cancer. The meta-analyses found that a low rectal anastomosis [OR = 3.26 (95% CI: 2.31-4.62)], male gender [OR = 1.48 (95% CI: 1.37-1.60)] and preoperative radiotherapy [OR = 1.65 (95% CI: 1.06-2.56)] may be risk factors for anastomotic leakage. Primarily as a result of observational design, the quality...

  13. Long-term monitoring of marine gas leakage

    Science.gov (United States)

    Spickenbom, Kai; Faber, Eckhard; Poggenburg, Jürgen; Seeger, Christian; Furche, Markus

    2010-05-01

    The sequestration of CO2 in sub-seabed geological formations is one of the Carbon Capture and Storage (CCS) strategies currently under study. Although offshore operations are significantly more expensive than comparable onshore operations, the growing public resistance against onshore CCS projects makes sub-seabed storage a promising option. Even after a thorough review of the geological setting, there is always the possibility of leakage from the reservoir. As part of the EU-financed project CO2ReMoVe (Research, Monitoring, Verification), which aims to develop innovative research and technologies for monitoring and verification of carbon dioxide geological storage, we are working on the development of submarine long-term gas flow monitoring systems. The basic design of the monitoring system builds on our experience in volcano monitoring. Early prototypes were composed of a raft floating on the surface of a mud volcano, carrying sensors for CO2 flux and concentration, data storage and transmission, and power supply by battery-buffered solar panels. The system was modified for installation in open sea by using a buoy instead of a raft and a funnel on the seafloor to collect the gas, connected by a flexible tube. This setup provides a cost-effective solution for shallow waters. However, a buoy interferes with ship traffic, and it is also difficult to adapt this design to greater water depths. These requirements can best be complied by a completely submersed system. A system for unattended long-term monitoring in a marine environment has to be extremely durable. Therefore, we focussed on developing a mechanically and electrically as simple setup as possible, which has the additional advantage of low cost. The system consists of a funnel-shaped gas collector, a sensor head and pressure housings for electronics and power supply. Since this setup is inexpensive, it can be deployed in numbers to cover larger areas. By addition of multi-channel data loggers, data

  14. Retinal-image quality and maximum disparity

    Science.gov (United States)

    Castro, José J.; Jiménez, J. R.; Ortiz, Carolina; Alarcón, Aixa

    2010-01-01

    The aim of this paper is to evaluate the role of interocular differences in retinal-image quality in stereoscopic depth perception. To characterize retinal-image quality, we took the Strehl ratio from a double-pass device. Stereopsis was quantified through maximum disparity using random-dot stereograms (RDS). Data were taken for 25 observers with ages ranging from 21 to 61 years. The results show a significant correlation between maximum disparity and interocular differences in the Strehl ratio: the lower interocular differences, the higher maximum disparity. No significant dependence with age was found.

  15. 5 CFR 1600.22 - Maximum contributions.

    Science.gov (United States)

    2010-01-01

    ... 1600.22 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD EMPLOYEE CONTRIBUTION ELECTIONS AND CONTRIBUTION ALLOCATIONS Program of Contributions § 1600.22 Maximum contributions. (a) Regular employee contributions. A participant's regular TSP contributions are subject the following limitations: (1...

  16. Recursive utility using the stochastic maximum principle

    National Research Council Canada - National Science Library

    Aase, Knut K

    2016-01-01

    .... We use the stochastic maximum principle to analyze the model. This method uses forward/backward stochastic differential equations, and works when the economy is not Markovian, which can be the case with recursive utility...

  17. Maximum phytoplankton concentrations in the sea

    DEFF Research Database (Denmark)

    Jackson, G.A.; Kiørboe, Thomas

    2008-01-01

    A simplification of plankton dynamics using coagulation theory provides predictions of the maximum algal concentration sustainable in aquatic systems. These predictions have previously been tested successfully against results from iron fertilization experiments. We extend the test to data collect...

  18. The maximum flow in dynamic networks

    Directory of Open Access Journals (Sweden)

    Maria A. Fonoberova

    2005-01-01

    Full Text Available The dynamic maximum flow problem that generalizes the static maximum flow problem is formulated and studied. We consider the problem on a network with capacities depending on time, fixed transit times on the arcs, and a given time horizon. The corresponding algorithm to solve this problem is proposed and some details concerning its complexity are discussed. Mathematics Subject Classification 2000: 90B10, 90C35, 90C27.

  19. Maximum Entropy Approaches to Living Neural Networks

    Directory of Open Access Journals (Sweden)

    John M. Beggs

    2010-01-01

    Full Text Available Understanding how ensembles of neurons collectively interact will be a key step in developing a mechanistic theory of cognitive processes. Recent progress in multineuron recording and analysis techniques has generated tremendous excitement over the physiology of living neural networks. One of the key developments driving this interest is a new class of models based on the principle of maximum entropy. Maximum entropy models have been reported to account for spatial correlation structure in ensembles of neurons recorded from several different types of data. Importantly, these models require only information about the firing rates of individual neurons and their pairwise correlations. If this approach is generally applicable, it would drastically simplify the problem of understanding how neural networks behave. Given the interest in this method, several groups now have worked to extend maximum entropy models to account for temporal correlations. Here, we review how maximum entropy models have been applied to neuronal ensemble data to account for spatial and temporal correlations. We also discuss criticisms of the maximum entropy approach that argue that it is not generally applicable to larger ensembles of neurons. We conclude that future maximum entropy models will need to address three issues: temporal correlations, higher-order correlations, and larger ensemble sizes. Finally, we provide a brief list of topics for future research.

  20. Updated hydrogeological statistics in ONKALO area and revised estimation of leakage water inflow into ONKALO tunnels

    Energy Technology Data Exchange (ETDEWEB)

    Sievaenen, U.; Tasapuro, V. [JP-Suoraplan Oy, Vantaa (Finland); Ahokas, H.; Hellae, P.; Vaittinen, T.; Nummela, J.; Tammisto, E. [JP-Fintact Oy, Porvoo (Finland)

    2006-03-15

    The prognosis of leakage water inflow into ONKALO tunnels was updated for this report. For this purpose the bedrock model 2003/1 was revised based on new investigation holes and the pumping test made in OL-KR24. The calculation was based on the current layout of ONKALO. The water inflow without grouting and after assumed grouting was calculated analytically. Also the need for grouting was evaluated. The bedrock was divided into major structures, local structures and averagely fractured rock. The hydraulic features of major structures were gathered and analysed for calculation. The local structures and the averagely fractured rock were divided according to the depth and then their respective data of hydraulic properties was statistically treated. When the averages of measured transmissivities of major structures were used, the total inflow into ONKALO without grouting was calculated to be 1560-2250 1/min. The total inflow into 1-3 shafts would be about 300-370 1/min. The water inflow from RH19A would be about 201/min/intersection, from RH 19B about 701/min/intersection, from RH20A about 200 1/min/intersection and from RH2OB about 801/min/intersection without grouting. When the maximums of measured transmissivities of major structures were used, the total inflow without grouting was calculated to be 2690-3480 1/min, out of which 760-930 1/min was estimated to flow into 1-3 shafts. The water inflow from RH19A would be about 70-1201/min/intersection, from RH19B about 1701/min/intersection, from RH2OA about 330-3 70 1/min/intersection and from RH2OB about 110- 120 1/min/intersection without grouting. After grouting the inflow into the access tunnel and the characterisation loop would be 90 1/min. After grouting, the inflow from RH19A and B would be about 1 1/min/intersection, from RH2CA and B about 2 1/min/intersection. The inflow into each shaft would be about 30 1/min, assuming a moderate grouting result. If assuming a good grouting result in shafts, th3 total inflow

  1. Leakage test evaluation used for qualification of iodine-125 seeds sealing

    Energy Technology Data Exchange (ETDEWEB)

    Feher, Anselmo; Rostelato, Maria E.C.M.; Zeituni, Carlos A.; Calvo, Wilson A.P.; Somessari, Samir L.; Moura, Joao A.; Moura, Eduardo S.; Souza, Carla D.; Rela, Paulo R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: afeher@ipen.br, e-mail: elisaros@ipen.br, e-mail: czeituni@pobox.com, e-mail: wapcalco@ipen.br, e-mail: somessar@ipen.br, e-mail: jmoura31@yahoo.com.br, e-mail: esmoura@ipen.br, e-mail: cdsouza@ipen.br, e-mail: prela@ipen.br

    2009-07-01

    The prostate cancer is a problem of public health in Brazil, and the second cause of cancer deaths in men, exceeded only by lung cancer. Among the possible treatments available for prostate cancer is brachytherapy, in which small seeds containing Iodine-125 radioisotope are implanted in the prostate. The seed consists of a sealed titanium tube measuring 0.8 mm external diameter and 4.5 mm in length, containing a central silver wire with adsorbed Iodine-125. The tube sealing is made with titanium at the ends, using electric arc welding or laser process. This sealing must be leakage-resistant and free of cracks, therefore avoiding the Iodine-125 to deposit in the silver wire to escape and spread into the human body. To ensure this problem does not occur, rigorous leakage tests, in accordance with the standard Radiation protection - Sealed Radioactive Sources - leakage Test Methods - ISO 9978, should be applied. The aim of this study is to determine, implement and evaluate the leakage test to be used in the Iodine-125 seeds production, in order to qualify the sealing procedure. The standard ISO 9978 presents a list of tests to be carried out according to the type of source. The preferential methods for brachytherapy sources are soaking and helium. To assess the seeds leakage, the method of immersion test at room temperature was applied. The seeds are considered leakage-free if the detected activity does not exceed the 185 Bq (5 nCi). An Iodine standard was prepared and its value determined in a sodium iodide detector. A liquid scintillation counter was calibrated with the standard for seeds leakage tests. Forty-eight seeds were welded for these tests. (author)

  2. Comparison of fluid filtration and bacterial leakage techniques for evaluation of microleakage in endodontics

    Directory of Open Access Journals (Sweden)

    Saeed Moradi

    2015-01-01

    Full Text Available Background: Apical leakage assessment is a way to compare the efficiency of a filling material to seal the apical region of the tooth. Many microleakage testing techniques have been introduced through the years, but there has been no agreement as to which technique gives the most accurate results. The aim of this study was to compare the accuracy of fluid filtration and bacterial leakage techniques in the assessment of the apical sealing ability of mineral trioxide aggregate (MTA and calcium enriched mixture (CEM. Materials and Methods: A sample of 34 extracted single-rooted human teeth were selected and prepared. The samples were divided in to 2 experimental groups. The apical 3 mm of each root was resected at 90° to its long axis and root end preparation was done with ultrasonic tips to a depth of 3 mm and filled with MTA and CEM, respectively. Assessment of apical sealing ability was done with fluid filtration technique and bacterial leakage technique along 90 days with Enterococcus faecalis bacteria. Mann-Whitney U-test and Chi-square test were used to analyze the data using SPSS (SPSS Inc., Chicago, IL, USA. P less than 0.05 was considered as significant. Results: There was no significant difference in apical sealing ability between MTA and CEM in bacterial leakage and fluid filtration techniques. Samples which had bacterial leakage showed higher leakage values by fluid filtration technique. Conclusion: Both techniques showed same results and there was no significant difference between fluid filtration and bacterial leakage techniques in assessment of apical microleakage.

  3. Prevalence of extravertebral cement leakage after vertebroplasty: procedural documentation versus CT detection

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Douglas J. [Coll. of Medicine, Mayo Clinic, Rochester (United States); Rad, Arash Ehteshami [Dept. of Radiology, Mayo Clinic, Rochester, (United States); Kallmes, David F. [Coll. of Medicine, Mayo Clinic, Rochester (United States); Dept. of Radiology, Mayo Clinic, Rochester (United States)], e-mail: kallmes.david@mayo.edu

    2012-06-15

    Background: Reported incidence of extravertebral cement leakage after vertebroplasty varies widely across studies. Purpose: To retrospectively compare the relative detection rates of extravertebral leakage noted under intra-procedural fluoroscopic surveillance, post procedure plain radiographs, and post procedure computed tomography (CT) in a cohort of patients undergoing vertebroplasty. Material and Methods: With IRB approval, we retrospectively identified 181 patients with 277 levels treated with percutaneous vertebroplasty among a total of 1255 patients undergoing vertebroplasty between 1999 and 2010 who had subsequently undergone a CT examination that included the treated level(s). Categories of leakage were paravertebral, end plate, epidural, and pre vertebral venous leakage. CT-detected leak rates were then compared to those noted on the vertebroplasty procedure reports and the archived fluoroscopic images for this same cohort using Pearson's {chi}{sup 2} test. Results: One hundred and forty-nine (82%, 95% CI 76-87%) of 181 patients demonstrated evidence of some type of leakage on CT at one or more treated levels. Sixty-two (34 %, 95 % CI 28-42 %) and seventy-seven (50%, 95% CI 43-57%) of 149 CT-detected leaks were reported in the procedural dictation or detected on plain radiography (P 0.01 and 0.006, respectively). The most common type of leakage noted on CT was end plate (n = 81, 45%, 95% CI 38-52%), followed by paravertebral (n 64, 35%, 95% CI 29-43%), epidural (n = 36, 20%, 95% CI 15-26%), and pre vertebral venous (n = 32, 18%, 95% CI 13-24%). Conclusion: Cement leakage after vertebroplasty is common and is often not reported by operators in procedural dictations. CT detects substantially more leaks than plain radiography.

  4. Numerical Modeling of Methane Leakage from a Faulty Natural Gas Well into Fractured Tight Formations.

    Science.gov (United States)

    Moortgat, Joachim; Schwartz, Franklin W; Darrah, Thomas H

    2018-01-23

    Horizontal drilling and hydraulic fracturing have enabled hydrocarbon recovery from unconventional reservoirs, but led to natural gas contamination of shallow groundwaters. We describe and apply numerical models of gas-phase migration associated with leaking natural gas wells. Three leakage scenarios are simulated: (1) high-pressure natural gas pulse released into a fractured aquifer; (2) continuous slow leakage into a tilted fractured formation; and (3) continuous slow leakage into an unfractured aquifer with fluvial channels, to facilitate a generalized evaluation of natural gas transport from faulty natural gas wells. High-pressure pulses of gas leakage into sparsely fractured media are needed to produce the extensive and rapid lateral spreading of free gas previously observed in field studies. Transport in fractures explains how methane can travel vastly different distances and directions laterally away from a leaking well, which leads to variable levels of methane contamination in nearby groundwater wells. Lower rates of methane leakage (≤1 Mcf/day) produce shorter length scales of gas transport than determined by the high-pressure scenario or field studies, unless aquifers have low vertical permeabilities (≤1 millidarcy) and fractures and bedding planes have sufficient tilt (∼10°) to allow a lateral buoyancy component. Similarly, in fractured rock aquifers or where permeability is controlled by channelized fluvial deposits, lateral flow is not sufficiently developed to explain fast-developing gas contamination (0-3 months) or large length scales (∼1 km) documented in field studies. Thus, current efforts to evaluate the frequency, mechanism, and impacts of natural gas leakage from faulty natural gas wells likely underestimate contributions from small-volume, low-pressure leakage events. © 2018, National Ground Water Association.

  5. Spatio-temporal characteristics of Agulhas leakage: a model inter-comparison study

    Science.gov (United States)

    Holton, L.; Deshayes, J.; Backeberg, B. C.; Loveday, B. R.; Hermes, J. C.; Reason, C. J. C.

    2017-04-01

    Investigating the variability of Agulhas leakage, the volume transport of water from the Indian Ocean to the South Atlantic Ocean, is highly relevant due to its potential contribution to the Atlantic Meridional Overturning Circulation as well as the global circulation of heat and salt and hence global climate. Quantifying Agulhas leakage is challenging due to the non-linear nature of this process; current observations are insufficient to estimate its variability and ocean models all have biases in this region, even at high resolution . An Eulerian threshold integration method is developed to examine the mechanisms of Agulhas leakage variability in six ocean model simulations of varying resolution. This intercomparison, based on the circulation and thermohaline structure at the Good Hope line, a transect to the south west of the southern tip of Africa , is used to identify features that are robust regardless of the model used and takes into account the thermohaline biases of each model. When determined by a passive tracer method, 60 % of the magnitude of Agulhas leakage is captured and more than 80 % of its temporal fluctuations, suggesting that the method is appropriate for investigating the variability of Agulhas leakage. In all simulations but one, the major driver of variability is associated with mesoscale features passing through the section. High resolution ({<} 1/10°) hindcast models agree on the temporal (2-4 cycles per year) and spatial (300-500 km) scales of these features corresponding to observed Agulhas Rings. Coarser resolution models ({<} 1/4°) reproduce similar time scale of variability of Agulhas leakage in spite of their difficulties in representing the Agulhas rings properties. A coarser resolution climate model (2°) does not resolve the spatio-temporal mechanism of variability of Agulhas leakage. Hence it is expected to underestimate the contribution of Agulhas Current System to climate variability.

  6. MR predictors of bone cement leakage in patients receiving percutaneous vertebroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Young Hwan; Han, Dae Hee; Choi, Young Ho; Cha, Joo Hee [Boramae Hospital, Incheon (Korea, Republic of); Jun, Deuk Soo; Jin, Wook; Kim, Hyung Sik [Gachon Medicine School, Gachon (Korea, Republic of)

    2005-07-15

    To identify MR predictors of bone cement leakage in patients receiving percutaneous vertebroplasty. Percutaneous vertebroplasties were performed in 45 vertebras (T7; one, T8; two, T10; two, T11; two, T12; eight, L1; fifteen, L2; eight, L3; five, L4; two) in 35 patients (age 52-83). The procedure was performed using an 11 G Jamshidi needle, which was inserted into the target by the bipedicular approach. Kyphoplasty, unilateral pedicular approach and extrapedicular approach cases were excluded. Shortly after the procedure, all patients underwent a noncontrast CT covering the vertebroplasty sites. A retrospective study was performed to determine whether cement leakage is related to any of following MR findings: presence of cortical disruption of the vertebral body, severity of body compression (proportion of abnormal to normal vertebral body volumes), bone cement amount, bone cement amount/severity of body compression ratio, proportion of low-signal area in a vertebral body on T1 weighted image, presence of either vacuum or cystic portion below a linear dark signal in a fractured vertebra, and the location of dark signal intensity line in a vertebral body. Logisgic discrimination model stepwise method was used in the statistical analysis. On post-vertebroplasty CT scan, bone cement leakage was detected in or around 29 vertebrae (64%), including 11 vertebrae (24%) where leakage was found in the epidural space or radial vein. No patient displayed any neurological symptoms or signs. The most frequent site of bone cement leakage was the anterior external vertebral venous plexus (49%). Endplate cortical bone disruption was related to an increased risk of intervertebral bone cement leakage ({rho} < 0.05). Bone cement leakage tended to occur less frequently when there is a vacuum or cystic change below the dark linear signal intensity in a fractured vertebra ({rho} < 0.05). No other MR findings showed a statistically significant correlation with bone cement leakage. On pre

  7. Determination of secondhand smoke leakage from the smoking room of an Internet café.

    Science.gov (United States)

    Kim, Hyejin; Lee, Kiyoung; An, Jaehoon; Won, Sungho

    2017-10-01

    Although Internet cafes have been designated as nonsmoking areas in Korea, smoke-free legislation has allowed the installation of indoor smoking rooms. The purposes of this study were to determine secondhand smoke (SHS) leakage from an Internet café smoking room and to identify factors associated with SHS leakage. PM2.5 (particulate matter with an aerodynamic diameter ≤2.5 μm) mass concentrations were measured simultaneously both inside and outside the door to the smoking room. During each measurement, a field technician observed how long the smoking room door was opened and closed, the direction of door opening, and the number of smokers. A multivariate linear regression model was used to identify the causality of SHS leakage from the smoking room. A time series of PM2.5 concentrations both inside and outside the door to the smoking room showed a similar trend. SHS leakage was significantly increased because of factors associated with the direction of the smoking room door being opened, the duration of how long the smoking room door was opened until it was closed, and the average PM2.5 concentration inside the smoking room when the door was opened. SHS leakage from inside the smoking room to outside the smoking room was evident especially when the smoking room door was opened. Since the smoking room is not effective in preventing SHS exposure, the smoking room should be removed from the facilities to protect citizens from SHS exposure through revision of the current legislation, which permits installation of a smoking room. This paper concerns secondhand smoke (SHS) leakage from indoor smoking room. Unlike previous studies, the authors statistically analyzed the causality of PM2.5 concentration leakage from a smoking room using time-series analysis. Since the authors selected the most common smoking room, the outcomes could be generalized. The study demonstrated that SHS leakage from smoking room and SHS leakage were clearly associated with door opening. The

  8. Parametrization of the radiation induced leakage current increase of NMOS transistors

    Science.gov (United States)

    Backhaus, M.

    2017-01-01

    The increase of the leakage current of NMOS transistors during exposure to ionizing radiation is known and well studied. Radiation hardness by design techniques have been developed to mitigate this effect and have been successfully used. More recent developments in smaller feature size technologies do not make use of these techniques due to their drawbacks in terms of logic density and requirement of dedicated libraries. During operation the resulting increase of the supply current is a serious challenge and needs to be considered during the system design. A simple parametrization of the leakage current of NMOS transistors as a function of total ionizing dose is presented. The parametrization uses a transistor transfer characteristics of the parasitic transistor along the shallow trench isolation to describe the leakage current of the nominal transistor. Together with a parametrization of the number of positive charges trapped in the silicon dioxide and number of activated interface traps in the silicon to silicon dioxide interface the leakage current results as a function of the exposure time to ionizing radiation. This function is fitted to data of the leakage current of single transistors as well as to data of the supply current of full ASICs.

  9. A Low Leakage Autonomous Data Retention Flip-Flop with Power Gating Technique

    Directory of Open Access Journals (Sweden)

    Xiaohui Fan

    2014-01-01

    Full Text Available With the scaling of technology process, leakage power becomes an increasing portion of total power. Power gating technology is an effective method to suppress the leakage power in VLSI design. When the power gating technique is applied in sequential circuits, such as flip-flops and latches, the data retention is necessary to store the circuit states. A low leakage autonomous data retention flip-flop (ADR-FF is proposed in this paper. Two high-Vth transistors are utilized to reduce the leakage power consumption in the sleep mode. The data retention cell is composed of a pair of always powered cross-coupled inverters in the slave latch. No extra control signals and complex operations are needed for controlling the data retention and restoration. The data retention flip-flops are simulated with NCSU 45 nm technology. The postlayout simulation results show that the leakage power of the ADR-FF reduces 51.39% compared with the Mutoh-FF. The active power of the ADR-FF is almost equal to other data retention flip-flops. The average state mode transition time of ADR-FF decreases 55.98%, 51.35%, and 21.07% as compared with Mutoh-FF, Balloon-FF, and Memory-TG-FF, respectively. Furthermore, the area overhead of ADR-FF is smaller than other data retention flip-flops.

  10. [Nursing Experience With a Patient With Gastrostomy Leakage Resulting in Moisture-Associated Skin Damage].

    Science.gov (United States)

    Hsu, Mei-Yu; Hsu, Hsiao-Hui; Lyu, Ji-Yan

    2016-10-01

    Leakage is a common complication of gastrostomy. Exposure of the skin surrounding the gastrostomy tube to moisture or chemical irritants may cause moisture-associated skin damage (MASD) and seriously affect the patient's quality of life. This case study describes a nursing experience with gastrostomy leakage that resulted in MASD. An assessment conducted from July 29, 2015 to August 20, 2015 revealed that heavy gastronomy leakage had caused extensive skin erosion, ulceration, hyperplasia, and superficial infection. Simultaneously, the patient was required to conduct complex stoma care, which resulted in physical and psychological exhaustion. Changes in traditional tube and wound care were discussed on multiple occasions with an interdisciplinary healthcare team. Based on the evidence-based literature, we provide gastrostomy and MASD management strategies. Through team collaboration, we prevented gastric contents from contacting the patient's skin directly, improved patient comfort, controlled effluent and skin infections, maintained fluid and electrolyte balances, and acce-lerated the healing of the damaged skin. We recommend that healthcare professionals caring for patients with gastrostomy leakage be provided with early skin protection programs to learn the standard methods for identifying and correcting leakage factors, containing effluent, and adequately stabilizing the gastrostomy tube in order to reduce the impact on the patient's quality of life. In addition, patient education on tube and skin care should be provided to prevent the reoccurrence of complications.

  11. Influence of the internal anatomy on the leakage of root canals filled with thermoplastic technique.

    Science.gov (United States)

    Al-Jadaa, Anas; Attin, T; Peltomäki, T; Heumann, C; Schmidlin, P R; Paquè, F

    2017-10-11

    The aim of this paper is to evaluate the influence of the internal anatomy on the leakage of root canals filled with the thermoplastic technique. The upper central incisors (UCI) and mesial roots of the lower molars (MRLM) (n = 12 each) were tested regarding leakage using the gas-enhanced permeation test (GEPT) after root filling. The quality of the root fillings was assessed using micro-computed tomography (μCT) by superimposing scans before and after treatment to calculate unfilled volume. The calculated void volume was compared between the groups and correlated to the measured leakage values. Data were analyzed using t test and Pearson's correlation tests (p UCI and MRLM (13.7 ± 6.2% vs. 14.2 ± 6.8%, respectively). However, significantly more leakage was evident in the MRLM (p UCI (R 2 = 0.467, p = 0.126). MRLM showed higher leakage values, which correlated to the void volume in the root canal fillings. Care should always be taken while doing root canal treatments, but attention to teeth with known/expected complex root canal anatomy should be considered.

  12. Simulation of leakage current measurement on medical devices using helmholtz coil configuration with different current flow

    Science.gov (United States)

    Sutanto, E.; Chandra, F.; Dinata, R.

    2017-05-01

    Leakage current measurement which can follow IEC standard for medical device is one of many challenges to be answered. The IEC 60601-1 has defined that the limit for a leakage current for Medical Device can be as low as 10 µA and as high as 500 µA, depending on which type of contact (applied part) connected to the patient. Most people are using ELCB (Earth-leakage circuit breaker) for safety purpose as this is the most common and available safety device in market. One type of ELCB devices is RCD (Residual Current Device) and this RCD type can measure the leakage current directly. This work will show the possibility on how Helmholtz Coil Configuration can be made to be like the RCD. The possibility is explored by comparing the magnetic field formula from each device, then it proceeds with a simulation using software EJS (Easy Java Simulation). The simulation will make sure the concept of magnetic field current cancellation follows the RCD concept. Finally, the possibility of increasing the measurement’s sensitivity is also analyzed. The sensitivity is needed to see the possibility on reaching the minimum leakage current limit defined by IEC, 0.01mA.

  13. Statistical imprints of CMB B-type polarization leakage in an incomplete sky survey analysis

    Science.gov (United States)

    Santos, Larissa; Wang, Kai; Hu, Yangrui; Fang, Wenjuan; Zhao, Wen

    2017-01-01

    One of the main goals of modern cosmology is to search for primordial gravitational waves by looking on their imprints in the B-type polarization in the cosmic microwave background radiation. However, this signal is contaminated by various sources, including cosmic weak lensing, foreground radiations, instrumental noises, as well as the E-to-B leakage caused by the partial sky surveys, which should be well understood to avoid the misinterpretation of the observed data. In this paper, we adopt the E/B decomposition method suggested by Smith in 2006, and study the imprints of E-to-B leakage residuals in the constructed B-type polarization maps, Script B(hat n), by employing various statistical tools. We find that the effects of E-to-B leakage are negligible for the Script B-mode power spectrum, as well as the skewness and kurtosis analyses of Script B-maps. However, if employing the morphological statistical tools, including Minkowski functionals and/or Betti numbers, we find the effect of leakage can be detected at very high confidence level, which shows that in the morphological analysis, the leakage can play a significant role as a contaminant for measuring the primordial B-mode signal and must be taken into account for a correct explanation of the data.

  14. Dinosaur Tail Sign: A Useful Spinal MRI Finding Indicative of Cerebrospinal Fluid Leakage.

    Science.gov (United States)

    Sakurai, Keita; Kanoto, Masafumi; Nakagawa, Motoo; Shimohira, Masashi; Tokumaru, Aya M; Kameyama, Masashi; Shimoji, Keigo; Morimoto, Satoru; Matsukawa, Noriyuki; Nishio, Minoru; Shibamoto, Yuta

    2017-06-01

    To evaluate the imaging characteristics and diagnostic utility of the "Dinosaur tail sign" in the diagnosis of cerebrospinal fluid (CSF) leakage. The authors propose the "Dinosaur tail sign," defined as a combination of the dorsal epidural hyperintensities, fat tissue, spinal cord, and cauda equine on lumbosacral sagittal fat-suppressed T2-weighted image (FST2WI), as a sensitive indicator for diagnosing CSF leakage. Imaging characteristics of the "Dinosaur tail sign" was evaluated in seven spontaneous intracranial hypotension (SIH) and 23 iatrogenic CSF leakage (ICSFL) patients. Additionally, the diagnostic index was compared between the "Dinosaur tail sign" and other previously reported useful magnetic resonance imaging (MRI) and magnetic resonance myelography (MRM) findings. In contrast to other imaging findings including the epidural expansion, floating dural sac sign, and distension of the spinal epidural veins on MRI, and paraspinal fluid collections (PFC) on MRM, the "Dinosaur tail sign" was found equally in both SIH and ICSFL patients (6 SIH and 19 ICSFL; 83% of all patients with CSF leakage). The "Dinosaur tail sign" showed sufficient diagnostic utility (sensitivity 83%, specificity 94%, accuracy 89%) that was comparable to that of PFC. The "Dinosaur tail sign" is a useful imaging finding suggestive of CSF leakage. Evaluation of subtle interspinous arched hyperintensities on spinal MRI is mandatory for the diagnosis of SIH and ICSFL. © 2017 American Headache Society.

  15. Local antibiotic decontamination to prevent anastomotic leakage short-term outcome in rectal cancer surgery.

    Science.gov (United States)

    Wirth, Ulrich; Rogers, Susanne; Haubensak, Kristina; Schopf, Stefan; von Ahnen, Thomas; Schardey, Hans Martin

    2017-11-08

    Anastomotic leakage still presents an issue in rectal cancer surgery with rates of about 11%. As bacteria play a critical role, there is the concept of perioperative local decontamination to prevent anastomotic leakage. To ascertain the effectiveness of this treatment, we performed a retrospective analysis on 206 rectal resections with primary anastomosis and routine use of a selective decontamination of the digestive tract (SDD) regimen for local decontamination. SDD medication was administered every 8 h from the day before surgery to the seventh postoperative day. All patients were treated according to the fast-track protocol without mechanical bowel preparation; instead, a laxative was used. Overall morbidity was 30%, overall mortality 0.5%. In our data, overall rate of anastomotic leakage (AL) was 5.8%, with 3.9% in anterior rectal resection and 6.5% in low anterior rectal resection group. In 75% of cases, anastomotic leakage was grade "C" and needed re-laparotomy. Surgical site infection rate was 19.9%. No serious adverse events were related to decontamination. Local antibiotic decontamination appears to be safe and effective to decrease the rate of anastomotic leakage in rectal cancer surgery. Further focus should be on perioperative management including bowel preparation and choice of antimicrobial agents for local decontamination.

  16. Marginal leakage in direct and indirect composite resin restorations in primary teeth: an in vitro study.

    Science.gov (United States)

    Ferreira, M C; Vieira, R S

    2008-05-01

    The aim of this study was to evaluate the marginal leakage in class II preparations, with margins in enamel, restored with composite resin indirect and direct restorations. Twenty extracted primary molars were chosen and divided at random into two groups: G1 (n=10) restored by a direct technique and G2 (n=10) restored by an indirect technique. The composite resin Filtek Z250 (3M) and the Adper Single Bond adhesive (3M) were used in both groups. Teeth were stored in a humid environment at 37 degrees C for 1 week, thermo cycled (500 cycles, 5 degrees C and 55 degrees C), sealed and immersed in a 0.5% basic fuchsine dye for 24h. Teeth were longitudinally sectioned, in a mesio-distal direction and leakage was assessed. No leakage in the specimens from G2 and leakage in four specimens from G1, but the Mann-Whitney test showed that there was no statistically significant difference between the groups, either for occlusal box (p=0.317) and proximal box (p=0.067). This study demonstrated that direct and indirect class II composite resin restorations with cervical margins in enamel show similar results regarding marginal leakage.

  17. Entropy generation: Minimum inside and maximum outside

    Science.gov (United States)

    Lucia, Umberto

    2014-02-01

    The extremum of entropy generation is evaluated for both maximum and minimum cases using a thermodynamic approach which is usually applied in engineering to design energy transduction systems. A new result in the thermodynamic analysis of the entropy generation extremum theorem is proved by the engineering approach. It follows from the proof that the entropy generation results as a maximum when it is evaluated by the exterior surroundings of the system and a minimum when it is evaluated within the system. The Bernoulli equation is analyzed as an example in order to evaluate the internal and external dissipations, in accordance with the theoretical results obtained.

  18. New times of maximum of CY Aquarii

    Science.gov (United States)

    Tuvikene, T.; Sterken, C.; Brogt, E.; Cont, D.; Henden, A.; Papadaki, C.; Volkov, I.; Wiedemair, C.

    2010-04-01

    We present a collection of 102 new times of maximum of the SX Phoenicis star CY Aquarii. These times, together with 20 times of maximum taken from the literature, lead to a new local linear ephemeris for 2003--2009 with a formally slightly shorter period than the one for 1996--2002. It will require at least another half decade of additional monitoring before any significant update to any model can be considered. Such monitoring should preferably occur at regular intervals, be done in a consistent photometric band, and at high time resolution.

  19. Maximum Entropy Learning with Deep Belief Networks

    Directory of Open Access Journals (Sweden)

    Payton Lin

    2016-07-01

    Full Text Available Conventionally, the maximum likelihood (ML criterion is applied to train a deep belief network (DBN. We present a maximum entropy (ME learning algorithm for DBNs, designed specifically to handle limited training data. Maximizing only the entropy of parameters in the DBN allows more effective generalization capability, less bias towards data distributions, and robustness to over-fitting compared to ML learning. Results of text classification and object recognition tasks demonstrate ME-trained DBN outperforms ML-trained DBN when training data is limited.

  20. Density estimation by maximum quantum entropy

    Energy Technology Data Exchange (ETDEWEB)

    Silver, R.N.; Wallstrom, T.; Martz, H.F.

    1993-11-01

    A new Bayesian method for non-parametric density estimation is proposed, based on a mathematical analogy to quantum statistical physics. The mathematical procedure is related to maximum entropy methods for inverse problems and image reconstruction. The information divergence enforces global smoothing toward default models, convexity, positivity, extensivity and normalization. The novel feature is the replacement of classical entropy by quantum entropy, so that local smoothing is enforced by constraints on differential operators. The linear response of the estimate is proportional to the covariance. The hyperparameters are estimated by type-II maximum likelihood (evidence). The method is demonstrated on textbook data sets.

  1. Revealing the Maximum Strength in Nanotwinned Copper

    DEFF Research Database (Denmark)

    Lu, L.; Chen, X.; Huang, Xiaoxu

    2009-01-01

    The strength of polycrystalline materials increases with decreasing grain size. Below a critical size, smaller grains might lead to softening, as suggested by atomistic simulations. The strongest size should arise at a transition in deformation mechanism from lattice dislocation activities to grain...... boundary–related processes. We investigated the maximum strength of nanotwinned copper samples with different twin thicknesses. We found that the strength increases with decreasing twin thickness, reaching a maximum at 15 nanometers, followed by a softening at smaller values that is accompanied by enhanced...

  2. Maximum entropy analysis of EGRET data

    DEFF Research Database (Denmark)

    Pohl, M.; Strong, A.W.

    1997-01-01

    EGRET data are usually analysed on the basis of the Maximum-Likelihood method \\cite{ma96} in a search for point sources in excess to a model for the background radiation (e.g. \\cite{hu97}). This method depends strongly on the quality of the background model, and thus may have high systematic...... uncertainties in region of strong and uncertain background like the Galactic Center region. Here we show images of such regions obtained by the quantified Maximum-Entropy method. We also discuss a possible further use of MEM in the analysis of problematic regions of the sky....

  3. Behavioral responses of Arctica islandica (Bivalvia: Arcticidae) to simulated leakages of carbon dioxide from sub-sea geological storage

    Energy Technology Data Exchange (ETDEWEB)

    Bamber, Shaw D., E-mail: shaw.bamber@iris.no; Westerlund, Stig, E-mail: sw@iris.no

    2016-11-15

    Highlights: • Valve pumping activity in A. islandica significantly increased at pH 6.2 seawater. • Changes in valve movements were not related to attempted burrowing activities. • Valve activity returned to control levels after 5 days of continuous exposure. • A. islandica tolerate pH reductions likely to follow leakage of sub-sea stored CO{sub 2}. - Abstract: Sub-sea geological storage of carbon dioxide (CO{sub 2}) provides a viable option for the Carbon Capture and Storage (CCS) approach for reducing atmospheric emissions of this greenhouse gas. Although generally considered to offer a low risk of major leakage, it remains relevant to establish the possible consequences for marine organisms that live in or on sediments overlying these storage areas if such an event may occur. The present study has used a series of laboratory exposures and behavioral bioassays to establish the sensitivity of Arctica islandica to simulated leakages of CO{sub 2}. This long-lived bivalve mollusc is widely distributed throughout the North Sea, an area where geological storage is currently taking place and where there are plans to expand this operation significantly. A recently published model has predicted a maximum drop of 1.9 pH units in seawater at the point source of a substantial escape of CO{sub 2} from sub-sea geological storage in this region. Valve movements of A. islandica exposed to reduced pH seawater were recorded continuously using Hall effect proximity sensors. Valve movement regulation is important for optimising the flow of water over the gills, which supplies food and facilitates respiration. A stepwise reduction in seawater pH showed an initial increase in both the rate and extent of valve movements in the majority of individuals tested when pH fell to 6.2 units. Exposing A. islandica to pH 6.2 seawater continuously for seven days resulted in a clear increase in valve movements during the first 40 h of exposure, followed by a gradual reduction in activity

  4. Connection between maximum-work and maximum-power thermal cycles.

    Science.gov (United States)

    Gonzalez-Ayala, Julian; Arias-Hernandez, L A; Angulo-Brown, F

    2013-11-01

    A new connection between maximum-power Curzon-Ahlborn thermal cycles and maximum-work reversible cycles is proposed. This linkage is built through a mapping between the exponents of a class of heat transfer laws and the exponents of a family of heat capacities depending on temperature. This connection leads to the recovery of known results and to a wide and interesting set of results for a class of thermal cycles. Among other results it was found that it is possible to use analytically closed expressions for maximum-work efficiencies to calculate good approaches to maximum-power efficiencies. Behind the proposed connection is an interpretation of endoreversibility hypothesis. Additionally, we suggest that certain reversible maximum-work cycles depending on working substance can be used as reversible landmarks for FTT maximum-power cycles, which also depend on working substance properties.

  5. Parametrization of the radiation induced leakage current increase of NMOS transistors

    CERN Document Server

    Backhaus, Malte

    2017-01-01

    The increase of the leakage current of NMOS transistors during exposure to ionizing radiation is known and well studied. Radiation hardness by design techniques have been developed to mitigate this effect and have been successfully used. More recent developments in smaller feature size technologies do not make use of these techniques due to their drawbacks in terms of logic density and requirement of dedicated libraries. During operation the resulting increase of the supply current is a serious challenge and needs to be considered during the system design. A simple parametrization of the leakage current of NMOS transistors as a function of total ionizing dose is presented. The parametrization uses a transistor transfer characteristics of the parasitic transistor along the shallow trench isolation to describe the leakage current of the nominal transistor. Together with a parametrization of the number of positive charges trapped in the silicon dioxide and number of activated interface traps in the silicon to si...

  6. Prediction of leakage and rotordynamic coefficients for the circumferential-groove pump seal using CFD analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Ho; Ha, Tae Woong [Gachon University, Seongnam (Korea, Republic of)

    2016-05-15

    The circumferential-groove seal is commonly used in various turbopumps to reduce leakage. The main goal of this paper is to develop the method of three-dimensional CFD analysis for determining leakage and rotordynamic coefficients of the circumferential-groovepump seal. A relative coordinate system was defined for steady-state simulation to calculate the velocity and pressure distributions of the seal clearance at each rotor whirl speed. Instead of setting the inlet and outlet pressures as the boundary conditions in the three dimensional CFD analysis, as it is more commonly done, we used the inlet velocity and outlet pressure obtained from a preliminary two dimensional CFD analysis. For prediction leakage, the presented analysis shows improvement from the bulk-flow model analysis. For the prediction of rotordynamic coefficients of K, k and C, the presented analysis provides results in closer agreement with the experimental values than those of the bulk-flow model analysis at several rotor speeds.

  7. Type of incision does not predict abdominal wall outcome after emergency surgery for colonic anastomotic leakage

    DEFF Research Database (Denmark)

    Jensen, Kristian Kiim; Oma, Erling; Harling, Henrik

    2017-01-01

    PURPOSE: Most literature on abdominal incision is based on patients undergoing elective surgery. In a cohort of patients with anastomotic leakage after colonic cancer resection, we analyzed the association between type of incision, fascial dehiscence, and incisional hernia. METHODS: Data were...... extracted from the Danish Colorectal Cancer Group database and merged with information from the Danish National Patient Register. All patients with anastomotic leakage after colonic resection in Denmark from 2001 until 2008 were included and surgical records on re-operations were retrieved. The primary...... for anastomotic leakage were included with a median follow-up of 5.4 years. Incisional hernia occurred in 41 of 227 (15.3%) patients undergoing midline incision compared with 14 of 81 (14.7%) following transverse incision, P = 1.00. After adjusting for confounders, there was no association between the type...

  8. Gate leakage current partitioning in nanoscale double gate MOSFETs, using compact analytical model

    Science.gov (United States)

    Darbandy, Ghader; Lime, François; Cerdeira, Antonio; Estrada, Magali; Garduño, Salvador Ivan; Iñiguez, Benjamin

    2012-09-01

    This paper presents a compact gate leakage current partitioning model for nanoscale Double Gate (DG) MOSFETs, using analytical models of the direct tunneling gate leakage current. Gate leakage current becomes important and an essential aspect of MOSFET modeling as the gate oxide thickness is scaled down to 1 nm and below in advanced CMOS processes. We considered an ideal interface (ideal case without an interfacial layer) and two layers high k dielectric materials as gate insulators. In the case of two layers, a thin layer of SiO2 as an interfacial layer is considered. The results of the gate current partitioning components into drain and source show good agreement with 2D TCAD numerical device simulation (Silvaco Atlas).

  9. [Dynamic simulation of ammonia- and nitrate N leakage from paddy field under different N supply].

    Science.gov (United States)

    Li, Jin-Wen; Zhong, Sheng; Wang, Mi; Yang, Jing-Ping; Xu, Wei

    2009-06-01

    By using self-designed lysimeters, the dynamic changes of ammonia- and nitrate N leakage from the plowpan of paddy field under different N supply were studied, aimed to understand the N leakage loss from paddy field during rice growth period. A dynamic model was built to simulate the N translocation and transformation in rice plant, soil, and water by Vensim software. The data from the field experiment with N fertilization rates of 0, 75, 150, 225, 300, and 375 kg x hm(-2) in Yuhang district, Hangzhou City in 2003 were used for calibrating the model, and the data from the field experiment in 2007 were utilized for validating the model. The simulated N concentrations in the leakage fitted well with the observed data, suggesting that the simulated results were reliable and the model was applicable.

  10. Highly Reliable Transformerless Photovoltaic Inverters With Leakage Current and Pulsating Power Elimination

    DEFF Research Database (Denmark)

    Tang, Yi; Yao, Wenli; Loh, Poh Chiang

    2016-01-01

    power that is inherent in single-phase PV systems. By properly injecting CM voltages to the output filter capacitors, the pulsating power can be decoupled from the dc-link. Therefore, it is possible to use long-lifetime film capacitors instead of electrolytic capacitors to improve the reliability......This paper presents a transformerless inverter topology, which is capable of simultaneously solving leakage current and pulsating power issues in grid-connected photovoltaic (PV) systems. Without adding any additional components to the system, the leakage current caused by the PV...... of the PV system. The mechanism of leakage current suppression and the closed-loop control of pulsating power decoupling are discussed in this paper in detail. A 500-W prototype was also built and tested in the laboratory, and both simulation and experimental results are finally presented to show...

  11. Leakage effects in n-GaAs MESFET with n-GaAs buffer layer

    Science.gov (United States)

    Wang, Y. C.; Bahrami, M.

    1983-01-01

    Whereas improvement of the interface between the active layer and the buffer layer has been demonstrated, the leakage effects can be important if the buffer layer resistivity is not sufficiently high and/or the buffer layer thickness is not sufficiently small. It was found that two buffer leakage currents exist from the channel under the gate to the source and from drain to the channel in addition to the buffer leakage resistance between drain and source. It is shown that for a 1 micron gate-length n-GaAs MESFET, if the buffer layer resistivity is 12 OHM-CM and the buffer layer thickness h is 2 microns, the performance of the device degrades drastically. It is suggested that h should be below 2 microns.

  12. Measurements and interpretations concerning leakage currents on polluted high voltage insulators

    Science.gov (United States)

    Thalassinakis, E.; Karagiannopoulos, C. G.

    2003-04-01

    This paper presents data that may aid physical interpretation of leakage currents on insulators suffering pollution under real physical conditions. The measurements were performed on the power distribution system on the island of Crete. An on-line recording system has been installed on the insulators of the 150 kV network, in order to monitor the leakage currents on the polluted insulators and investigate the various parameters of the phenomena. It is convincingly shown that in the timeframe of one period of 50 Hz, above a threshold voltage value (smaller than the peak voltage) a non-linear i-v relationship may develop, leading to bistability and non-linear conductance phenomena. The well-established theory regarding leakage currents on high voltage insulators, as well as that concerning dielectrics in strong electric fields, provide the required theoretical basis for the interpretation of the experimental results obtained.

  13. dc leakage behavior in vanadium-doped bismuth titanate thin films

    Science.gov (United States)

    Chaudhuri, Ayan Roy; Krupanidhi, S. B.

    2005-11-01

    The dc leakage current behavior and its thickness dependence in vanadium-doped bismuth titanate thin films have been investigated over a wide range of temperatures. The leakage current behavior was explained on the basis of space-charge-limited conduction theory. The current density, calculated from the I-V characteristics, was found to be 2.01×10-9 A/cm2 at an applied field of 2.9 KV/cm at room temperature. Three distinct regions were observed in the I-V plot which were attributed to the Ohmic region, trap-filled limit, and Child's law. The influence of the film thickness on the dc leakage current conduction was found to be matching with that predicted by Lampert's theory [Phys. Rev. 103, 1648 (1956)] of space-charge-limited conduction.

  14. Engine panel seals for hypersonic engine applications: High temperature leakage assessments and flow modelling

    Science.gov (United States)

    Steinetz, Bruce M.; Mutharasan, Rajakkannu; Du, Guang-Wu; Miller, Jeffrey H.; Ko, Frank

    1992-01-01

    A critical mechanical system in advanced hypersonic engines is the panel-edge seal system that seals gaps between the articulating horizontal engine panels and the adjacent engine splitter walls. Significant advancements in seal technology are required to meet the extreme demands placed on the seals, including the simultaneous requirements of low leakage, conformable, high temperature, high pressure, sliding operation. In this investigation, the seal concept design and development of two new seal classes that show promise of meeting these demands will be presented. These seals include the ceramic wafer seal and the braided ceramic rope seal. Presented are key elements of leakage flow models for each of these seal types. Flow models such as these help designers to predict performance-robbing parasitic losses past the seals, and estimate purge coolant flow rates. Comparisons are made between measured and predicted leakage rates over a wide range of engine simulated temperatures and pressures, showing good agreement.

  15. Intrathoracic anastomotic leakage after gastroesophageal cancer resection is associated with increased risk of recurrence

    DEFF Research Database (Denmark)

    Kofoed, Steen C; Calatayud, Dan; Jensen, Lone S

    2015-01-01

    OBJECTIVE: Intrathoracic anastomotic leakage after intended curative resection for cancer in the esophagus or gastroesophageal junction has a negative impact on long-term survival. The aim of this study was to investigate whether an anastomotic leakage was associated with an increased recurrence...... rate. METHODS: This nationwide study included consecutively collected data on patients undergoing curative surgical resection with intrathoracic anastomosis, alive 8 weeks postoperatively, between 2003 and 2011. Patients with incomplete resection, or metastatic disease intraoperatively, were excluded....... Only biopsy-proven recurrences were accepted. RESULTS: In total, 1085 patients were included. The frequency of anastomotic leakage was 8.6%. The median follow-up time was 29 months (interquartile range [IQR]: 13-58 months). Overall, 369 (34%) patients had disease recurrence, of which 346 patients died...

  16. Investigation of Leakage Current Waveforms Recorded in a Coastal High Voltage Substation

    Directory of Open Access Journals (Sweden)

    E. Thalassinakis

    2011-06-01

    Full Text Available Leakage current monitoring is a widely employed technique to monitor the performance of outdoor insulation. The evaluation of leakage current waveforms recorded in the field, offers significant information since insulation’s performance is strongly linked with local conditions, and the waveforms’ shape correlate to different types of surface activity. In this paper, an investigation of leakage current waveforms recorded in a 150 kV coastal Substations suffering which suffers intense marine pollution is presented. Investigation of the recorded waveforms verified the basic waveform shapes described in the literature. Further, several variations of the basic types and complex waveforms, as well as field related waveforms, are presented. The need for added categorization criteria in the case of field measurements is discussed.

  17. Ability of various plant species to prevent leakage of N, P, and metals from sewage sludge.

    Science.gov (United States)

    Neuschütz, Clara; Greger, Maria

    2010-01-01

    The preventive effect of vegetation on nutrient and metal leakage from sewage sludge (SS) used in treatment of mine waste was investigated. In a 10-week greenhouse study, the release of ammonium, nitrate, phosphate, Cd, Cu, and Zn from SS was analyzed in the absence (control) and presence of basket willow, fireweed, reed Canary grass (RCG), and Scots pine. Plants significantly decreased the leakage by reducing the amount of leachate, and lowered the concentrations of phosphate (to 0.1 mg L(-1)), Cu (0.8 mg L(-1)), and Zn (2.2 mg L(-1)); and plants increased the pH in the leachate towards the end of the experiment. The most efficient plant was RCG that significantly decreased the total leakage of all pollutants. However, plants could not counteract high initial concentrations of ammonium and nitrate (additives are needed to prevent an initial decrease in pH.

  18. Leakage current and induced electrical energy dissipation in nonlinear oscillation of dielectric elastomer actuators

    Science.gov (United States)

    Zhang, Junshi; Chen, Hualing; Li, Dichen

    2017-09-01

    Subject to a high voltage, leakage current and induced electrical energy dissipation inevitably occur during the actuation of dielectric elastomers (DEs). In this article, a theoretical model is developed to investigate the dissipative performance of DEs in dynamic actuation. Effects of three different actuation conditions, including DE materials’ viscoelasticity intensity, amplitude of applied voltage, and mechanical tensile force, are considered. Numerical calculations are employed to detect the dynamic dissipative performance of DEs including leakage current, electrical power density, and electrical energy density in certain vibrational periods. Leakage current and induced electrical energy dissipation are enhanced with the enlargement of amplitude of applied voltage and mechanical force, and are suppressed as the intensity of DEs’ viscoelastic creep increases. The electrical energy for dissipation and actuation is also analyzed and compared.

  19. The occurrence of Enterococcus faecium and faecalis is significantly associated with anastomotic leakage after pancreaticoduodenectomy

    DEFF Research Database (Denmark)

    Belmouhand, M; Krohn, P S; Svendsen, L B

    2018-01-01

    BACKGROUND AND AIMS: Enterococcus has emerged as a virulent species; Enterococcus faecium especially has arisen as a source of nosocomial infections. Furthermore, specific Enterococcus faecalis species are significantly associated with anastomotic leakage in rodent studies. The objective of this ......BACKGROUND AND AIMS: Enterococcus has emerged as a virulent species; Enterococcus faecium especially has arisen as a source of nosocomial infections. Furthermore, specific Enterococcus faecalis species are significantly associated with anastomotic leakage in rodent studies. The objective...... of this study was to investigate whether the occurrence of Enterococci ( E. faecium and E. faecalis) obtained from drain samples was associated with leakage in humans undergoing pancreaticoduodenectomy. MATERIALS AND METHODS: All patients undergoing pancreaticoduodenectomy had a peritoneal drain sample sent...

  20. Formula Expression of Airgap Leakage flux Coefficient of Axial-Flux Permanent Magnet Motor

    Directory of Open Access Journals (Sweden)

    Yanliang Xu

    2013-07-01

    Full Text Available Airgap leakage flux coefficient is one of the main parameters which must be given ahead of time when performing initial designs or getting performance results by magnetic circuit analysis for any kinds of electrical machines. Three -dimensional finite element method (3D-FEM is the most reliable one to obtain the accurate leakage flux coefficient for axial flux permanent magnet (AFPM motor which definitely takes a much long time and is not advantageous to the motor’s initial and optimal design. By constituting the accurate lumped-parameter magnetic circuit (LPMC model and computing the resultant magnetic reluctances, the analytical formula of the leakage flux coefficient of AFPM is given which is verified by 3D-FEM and the prototyped AFPM experiment.

  1. Maximum potential preventive effect of hip protectors

    NARCIS (Netherlands)

    van Schoor, N.M.; Smit, J.H.; Bouter, L.M.; Veenings, B.; Asma, G.B.; Lips, P.T.A.M.

    2007-01-01

    OBJECTIVES: To estimate the maximum potential preventive effect of hip protectors in older persons living in the community or homes for the elderly. DESIGN: Observational cohort study. SETTING: Emergency departments in the Netherlands. PARTICIPANTS: Hip fracture patients aged 70 and older who

  2. 7 CFR 1778.11 - Maximum grants.

    Science.gov (United States)

    2010-01-01

    ... quantity of potable water, or an anticipated acute shortage or significant decline, cannot exceed $150,000... (CONTINUED) EMERGENCY AND IMMINENT COMMUNITY WATER ASSISTANCE GRANTS § 1778.11 Maximum grants. (a) Grants not to exceed $500,000 may be made to alleviate a significant decline in quantity or quality of water...

  3. Hard graphs for the maximum clique problem

    NARCIS (Netherlands)

    Hoede, C.

    1988-01-01

    The maximum clique problem is one of the NP-complete problems. There are graphs for which a reduction technique exists that transforms the problem for these graphs into one for graphs with specific properties in polynomial time. The resulting graphs do not grow exponentially in order and number.

  4. Maximum gain of Yagi-Uda arrays

    DEFF Research Database (Denmark)

    Bojsen, J.H.; Schjær-Jacobsen, Hans; Nilsson, E.

    1971-01-01

    Numerical optimisation techniques have been used to find the maximum gain of some specific parasitic arrays. The gain of an array of infinitely thin, equispaced dipoles loaded with arbitrary reactances has been optimised. The results show that standard travelling-wave design methods are not optimum....... Yagi–Uda arrays with equal and unequal spacing have also been optimised with experimental verification....

  5. Efficient Algorithms for the Maximum Sum Problems

    Directory of Open Access Journals (Sweden)

    Sung Eun Bae

    2017-01-01

    Full Text Available We present efficient sequential and parallel algorithms for the maximum sum (MS problem, which is to maximize the sum of some shape in the data array. We deal with two MS problems; the maximum subarray (MSA problem and the maximum convex sum (MCS problem. In the MSA problem, we find a rectangular part within the given data array that maximizes the sum in it. The MCS problem is to find a convex shape rather than a rectangular shape that maximizes the sum. Thus, MCS is a generalization of MSA. For the MSA problem, O ( n time parallel algorithms are already known on an ( n , n 2D array of processors. We improve the communication steps from 2 n − 1 to n, which is optimal. For the MCS problem, we achieve the asymptotic time bound of O ( n on an ( n , n 2D array of processors. We provide rigorous proofs for the correctness of our parallel algorithm based on Hoare logic and also provide some experimental results of our algorithm that are gathered from the Blue Gene/P super computer. Furthermore, we briefly describe how to compute the actual shape of the maximum convex sum.

  6. Global characterization of the Holocene Thermal Maximum

    NARCIS (Netherlands)

    Renssen, H.; Seppä, H.; Crosta, X.; Goosse, H.; Roche, D.M.V.A.P.

    2012-01-01

    We analyze the global variations in the timing and magnitude of the Holocene Thermal Maximum (HTM) and their dependence on various forcings in transient simulations covering the last 9000 years (9 ka), performed with a global atmosphere-ocean-vegetation model. In these experiments, we consider the

  7. Multi-Channel Maximum Likelihood Pitch Estimation

    DEFF Research Database (Denmark)

    Christensen, Mads Græsbøll

    2012-01-01

    In this paper, a method for multi-channel pitch estimation is proposed. The method is a maximum likelihood estimator and is based on a parametric model where the signals in the various channels share the same fundamental frequency but can have different amplitudes, phases, and noise characteristi...

  8. Neonatal Maximum Thigh Circumference Tape: An Alternative ...

    African Journals Online (AJOL)

    Conclusion: Using the cut-off values obtained, the neonates were categorized into three risk groups (“high risk”, “moderate risk”, and “low risk”), and a tricoloured MTC Tape was subsequently designed, using these inferences. Key words: Maximum thigh circumference, low birth weight, indicator. Nigerian Journal of ...

  9. Comparing maximum pressures in internal combustion engines

    Science.gov (United States)

    Sparrow, Stanwood W; Lee, Stephen M

    1922-01-01

    Thin metal diaphragms form a satisfactory means for comparing maximum pressures in internal combustion engines. The diaphragm is clamped between two metal washers in a spark plug shell and its thickness is chosen such that, when subjected to explosion pressure, the exposed portion will be sheared from the rim in a short time.

  10. 5 CFR 9701.312 - Maximum rates.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Maximum rates. 9701.312 Section 9701.312 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF HOMELAND SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES...

  11. Location specific forecasting of maximum and minimum ...

    Indian Academy of Sciences (India)

    Statistical bias correction; location specific forecast; DMO; Numerical Weather Prediction; maximum and minimum temperature forecast. Abstract. The output from Global Forecasting System (GFS) T574L64 operational at India Meteorological Department (IMD), New Delhi is used for obtaining location specific quantitative ...

  12. PARTICLE SWARM OPTIMIZATION BASED OF THE MAXIMUM ...

    African Journals Online (AJOL)

    2010-06-30

    Jun 30, 2010 ... systems from one hand and because of the instantaneous change of both insulation and temperature ... dealing accurately with these optimization problems and to overcome the incapacities of the traditional ... Series resistance RS, which gives a more accurate shape between the maximum power point ...

  13. Climate Change Impacts on Probable Maximum Precipitation

    Science.gov (United States)

    Kunkel, K.; Easterling, D. R.

    2011-12-01

    The estimation of the potential impacts of anthropogenic forcing of the climate system on extreme weather events relies heavily on the direct output of global and regional climate models, combined perhaps with extreme value statistical techniques. In this study, we use these tools along with physical and theoretical considerations to examine the potential impacts on Probable Maximum Precipitation estimates. Probable Maximum Precipitation (PMP) is the theoretically greatest depth of precipitation for a given duration that is physically possible over a particular drainage basin at a particular time of year. PMP values are used in the design of long-lived structures with lifetimes of many decades, such as dams. Climate change is an unavoidable consideration on those time scales. Many studies have documented an upward temporal trend in the frequency and intensity of extreme precipitation events. As the globe warms in response to increasing greenhouse gas concentrations, there is the potential for further changes in precipitation extremes. There are reasons why warming could lead to increased PMP values. One, the Clausius-Clapeyron relationship indicates that the saturation water vapor pressure increases with temperature; thus, precipitation-producing systems could have more "fuel" to precipitate. Two, warming may lead to an increase in the length of the convective season, when most of the extreme precipitation events occur. The methodology for estimation of PMP values has changed little over the last 30-40 years. The basic approach is to consider the factors that contribute to heavy precipitation and then consider the potential precipitation rates if all of those factors were simultaneously maximized. Convergence and vertical motion is one factor. Past work has assumed that there no empirical or satisfactory theoretical basis for assigning maximum values to this factor. The approach has been to use observed rainfall in notable storms as an indirect measure of maximum

  14. Should we fear cement leakage during kyphoplasty in percutaneous traumatic spine surgery? A single experience with 76 consecutive cases.

    Science.gov (United States)

    Capel, C; Fichten, A; Nicot, B; Lefranc, M; Toussaint, P; Desenclos, C; Deramond, H; Le Gars, D; Peltier, J

    2014-12-01

    Although kyphoplasty is widely used to repair osteoporotic and pathologic vertebral fractures, balloon kyphoplasty and vertebral body stenting are new treatment options in cases of traumatic spinal injury. To our knowledge, there are no literature data on the incidence of cement leakage whereas these two percutaneous techniques are commonly used to repair non-pathologic fractures. The aim of this study was to evaluate and compare the clinical characteristics and the incidence of cement leakage associated with balloon kyphoplasty and vertebral body stenting in the percutaneous treatment of traumatic spinal injury. A series of 76 consecutive kyphoplasties (50 with vertebral body stenting and 26 balloon kyphoplasties) were retrospectively reviewed. Preoperative and postoperative computed tomography scans were analyzed in order to detect cement leakage and grade it as minor, moderate or major. The overall leakage rate was 50%. None of the leakages gave rise to clinical symptoms. Although balloon kyphoplasty and vertebral body stenting did not differ in terms of the leakage rate, the latter technique was associated with a lower leakage volume. The Magerl type, fracture level and use of concomitant osteosynthesis did not appear to significantly influence the leakage rate. Vertebral body stenting can reduce the amount of cement leakage due to a better cohesion of the bone fragments after kyphosis correction and maintenance. Copyright © 2014. Published by Elsevier Masson SAS.

  15. [Experimental study of water leakage in duraplasty using ePTFE sheet as an artificial dura mater].

    Science.gov (United States)

    Yamamura, K; Sakata, K; Yamamoto, I

    1999-09-01

    The authors have evaluated the preventive effect of water leakage from the suture holes of expanded polytetrafluoroethylene (ePTFE) sheet. Six currently available suture materials (4-0 SURGILON, 4 types of Gore-tex suture, DuraClose) were compared. The water leakage was 0.05 cc/min when using Gore-tex suture (CV-6, needle/thread ratio = 1.0), 0.025 cc/min when using DuraClose. With each two material, the water leakage was significantly less (p water leakage from the suture holes of ePTFE sheet in duraplasty.

  16. Assessment of leakage at the implant-abutment connection using a new gas flow method.

    Science.gov (United States)

    Fauroux, Marie-Alix; Levallois, Bernard; Yachouh, Jacques; Torres, Jacques-Henri

    2012-01-01

    The aim of this study was to evaluate, with a new gas flow technique, leakage at the implant/abutment junction in systems with four different connections. Five Branemark System, five One Morse, five Intra-lock System, and five Ankylos Plus implants and abutments were used. A hole was drilled in the apex of each implant to allow gas to flow through the connection from negative to atmospheric pressure. The gas flow was calculated (slope of pressure decrease, in hPa.s-1). Each connection was tested after both manual and key tightening. Statistical analysis was performed on a generalized linear model with repeated measurements. The significance level was set at α=.05. A global significant difference was observed between the various systems (P=.0001). After manual tightening, gas leakage was (Ln[hPa.s-1], means±standard deviations): One Morse: 0.20 (±1.70); Branemark System: -4.56 (±2.61); Intra-lock: -4.31 (±4.17); Ankylos Plus; -7.59 (±0.76). After key tightening, mean values were: One Morse: -2.51 (±2.72); Branemark System: -7.23 (±1.01); Intra-lock: -7.76 (±0.50); Ankylos Plus; -7.73 (±0.62). This study confirms that gas flow is an appropriate method to assess connection leakage. Ankylos Plus connection leakage was very low when the assembly was tightened manually. Among conical connection systems, low (Ankylos Plus) and high (One Morse) leakage was observed. This gas flow study suggests, therefore, that connection design is not the most important parameter for implant/abutment connection leakage.

  17. Effects of freezing stress on electrolyte leakage of Persian shallot (Allium altissimum Regel. under controlled condition

    Directory of Open Access Journals (Sweden)

    Shahram Rezvan beydokhti

    2016-05-01

    Full Text Available In order to evaluate the effect of freezing stress on electrolyte leakage of three Mooseers’ (Allium altissimum Regel. ecotypes (Shirvan, Kalat and Tandoureh, a factorial experiment based on completely randomized design with three replications was carried out under the controlled conditions in the Faculty of Agricultural, Ferdowsi University of Mashhad, Iran, during 2009. Plants were grown in natural conditions to acclimate with the growth condition, and then at two growth stages of emergence and seedling were transferred to the thermogradiant freezer with the six freezing temperatures (0,-4, -8,-12, -16 and -20 oC. Cell membrane integrity was measured by electrolyte leakage (EL index and the lethal temperature 50% (LT50 of samples were determined based on this index. The results showed that electrolyte leakage percentage and LT50el were significantly affected by experimental treatments. As the temperature decreased, EL (% of leaf, bulb and root of all ecotypes was significantly increased. In the all freezing temperatures, the highest and the lowest electrolyte leakage was observed in the root and leaf in the emergence stage. Shirvan ecotype at two growth stage (emergence and seedling showed the highest root electrolyte leakage and hence showed the lowest freezing tolerance in comparison with Kalat and Tandoreh ecotypes. The lowest and highest LT50el due to freezing were observed in Kalat, Tandoureh ecotype and Shirvan ecotype, respectively. At seedling stage, Shirvan ecotype’s root showed the highest LT50el which was more sensitive to freezing temperatures in comparison with leaf and bulb. Among all ecotypes, Kalat and Tandoreh ecotypes showed the lowest electrolyte leakage percentage, the lowest LT50el and the most tolerance to the freezing stress.

  18. Hypertonic saline reduces vascular leakage in a mouse model of severe dengue.

    Science.gov (United States)

    Tan, Grace Kai Xin; Ng, Jowin Kai Wei; Tan, Kar Wai; Angeli, Veronique; Moochhala, Shabbir; Ooi, Eng Eong; Alonso, Sylvie

    2013-01-01

    Dengue (DEN) is a mosquito-borne viral disease and represents a serious public health threat and an economical burden throughout the tropics. Dengue clinical manifestations range from mild acute febrile illness to severe DEN hemorrhagic fever/DEN shock syndrome (DHF/DSS). Currently, resuscitation with large volumes of isotonic fluid remains the gold standard of care for DEN patients who develop vascular leakage and shock. Here, we investigated the ability of small volume of hypertonic saline (HTS) suspensions to control vascular permeability in a mouse model of severe DEN associated with vascular leakage. Several HTS treatment regimens were considered and our results indicated that a single bolus of 7.5% NaCl at 4 mL per kg of body weight administered at the onset of detectable vascular leakage rapidly and significantly reduced vascular leak for several days after injection. This transient reduction of vascular leakage correlated with reduced intestine and liver damage with restoration of the hepatic functions, and resulted in delayed death of the infected animals. Mechanistically, we showed that HTS did not directly impact on the viral titers but resulted in lower immune cells counts and decreased systemic levels of soluble mediators involved in vascular permeability. In addition, we demonstrated that neutrophils do not play a critical role in DEN-associated vascular leakage and that the therapeutic effect of HTS is not mediated by its impact on the neutrophil counts. Together our data indicate that HTS treatment can transiently but rapidly reduce dengue-associated vascular leakage, and support the findings of a recent clinical trial which evaluated the efficacy of a hypertonic suspension to impact on vascular permeability in DSS children.

  19. Promising results after endoscopic vacuum treatment of anastomotic leakage following resection of rectal cancer with ileostomy

    DEFF Research Database (Denmark)

    Nerup, Nikolaj; Johansen, John Lykkegaard; Alkhefagie, Ghalib Ali Abod

    2013-01-01

    INTRODUCTION: In colorectal surgery, the most feared complication is anastomotic leakage (AL), which is associated with a high morbidity and mortality. In this study, we focus on treatment of perianastomotic abscess following AL after low anterior resection (LAR) of rectal cancer. In the literature...... period. Patients who initiated treatment more than one month after the leakage were excluded. All patients had primary ileostomy. RESULTS: A total of 13 patients were included. All patients had successful closure of the perianastomotic abscess for a median of 18 (3-40) days in a median of eight (1...

  20. The study on the results of hydrogen pipeline leakage accident of different factors

    Science.gov (United States)

    Chen, Haonan; Mao, Zhanli

    2017-05-01

    Pipeline is frequently used in long-distance hydrogen transport, while pipes can be disturbed in some conditions, prone to leakage accident, causing severe combustion or explosion. This paper analyzed the influences of different factors on the consequences of hydrogen pipeline leakage through the simulation software ALOHA. The results show that wind speed, ground roughness, tube pressure and gap area have a great impact on the consequences of the accident; wind speed and ground roughness have negative correlation to danger distance; tube pressure and gap area have positive correlation to danger distance. These results are due to the release amount and release rate influenced by the four factors.

  1. Domino logic designs for high-performance and leakage-tolerant applications

    DEFF Research Database (Denmark)

    Moradi, Farshad; Vu Cao, Tuan; Vatajelu, Elena Ioana

    2013-01-01

    by utilizing proposed techniques. According to the simulations in TSMC 65 nm CMOS process, the proposed circuits increase noise immunity for wide OR gates by at least 3.5X and shows performance improvement of up to 20% compared to conventional domino logic circuits. For FinFET simulation TCAD tools have been......Robustness of high fan-in domino circuits is degraded by technology scaling due to exponential increase in leakage. In this paper, we propose several domino logic circuit techniques to improve the robustness and performance along with leakage power. Lower total power consumption is achieved...

  2. A simple method for removing leakage of metal pipes, like district heating and NG pipes

    Energy Technology Data Exchange (ETDEWEB)

    Tabatabaeeghomi, Mohammad; Mahmoudi, Jafar (Maelardalen Univ., Vaesteraas (Sweden)). E-mail: Jafar.Mahmoudi@mdh.se; Liaghat, Gholamhossien (Tarbiat Modaress Univ., Tehran (Iran))

    2009-07-01

    Explosive welding occur under high velocity oblique impact, though it is possible to use explosive energy to form a usual cold pressure weld. One of the advantages of this method is welding kind of materials with different shapes together. The ability of explosive welding can be used to maintenance of pipes and vessels, preventing pipe leakage especially under water in oil and gas industries. This research suggests a simple explosive welding method for removing the leakage of metal pipes that is very economy and easy for repairing pipes and vessels full of water or liquid

  3. Influence of Chemical, Mechanical, and Transport Processes on Wellbore Leakage from Geologic CO2Storage Reservoirs.

    Science.gov (United States)

    Carroll, Susan A; Iyer, Jaisree; Walsh, Stuart D C

    2017-08-15

    Wells are considered to be high-risk pathways for fluid leakage from geologic CO 2 storage reservoirs, because breaches in this engineered system have the potential to connect the reservoir to groundwater resources and the atmosphere. Given these concerns, a few studies have assessed leakage risk by evaluating regulatory records, often self-reported, documenting leakage in gas fields. Leakage is thought to be governed largely by initial well-construction quality and the method of well abandonment. The geologic carbon storage community has raised further concerns because acidic fluids in the CO 2 storage reservoir, alkaline cement meant to isolate the reservoir fluids from the overlying strata, and steel casings in wells are inherently reactive systems. This is of particular concern for storage of CO 2 in depleted oil and gas reservoirs with numerous legacy wells engineered to variable standards. Research suggests that leakage risks are not as great as initially perceived because chemical and mechanical alteration of cement has the capacity to seal damaged zones. Our work centers on defining the coupled chemical and mechanical processes governing flow in damaged zones in wells. We have developed process-based models, constrained by experiments, to better understand and forecast leakage risk. Leakage pathways can be sealed by precipitation of carbonate minerals in the fractures and deformation of the reacted cement. High reactivity of cement hydroxides releases excess calcium that can precipitate as carbonate solids in the fracture network under low brine flow rates. If the flow is fast, then the brine remains undersaturated with respect to the solubility of calcium carbonate minerals, and zones depleted in calcium hydroxides, enriched in calcium carbonate precipitates, and made of amorphous silicates leached of original cement minerals are formed. Under confining pressure, the reacted cement is compressed, which reduces permeability and lowers leakage risks. The

  4. Pareto versus lognormal: a maximum entropy test.

    Science.gov (United States)

    Bee, Marco; Riccaboni, Massimo; Schiavo, Stefano

    2011-08-01

    It is commonly found that distributions that seem to be lognormal over a broad range change to a power-law (Pareto) distribution for the last few percentiles. The distributions of many physical, natural, and social events (earthquake size, species abundance, income and wealth, as well as file, city, and firm sizes) display this structure. We present a test for the occurrence of power-law tails in statistical distributions based on maximum entropy. This methodology allows one to identify the true data-generating processes even in the case when it is neither lognormal nor Pareto. The maximum entropy approach is then compared with other widely used methods and applied to different levels of aggregation of complex systems. Our results provide support for the theory that distributions with lognormal body and Pareto tail can be generated as mixtures of lognormally distributed units.

  5. Maximum Variance Hashing via Column Generation

    Directory of Open Access Journals (Sweden)

    Lei Luo

    2013-01-01

    item search. Recently, a number of data-dependent methods have been developed, reflecting the great potential of learning for hashing. Inspired by the classic nonlinear dimensionality reduction algorithm—maximum variance unfolding, we propose a novel unsupervised hashing method, named maximum variance hashing, in this work. The idea is to maximize the total variance of the hash codes while preserving the local structure of the training data. To solve the derived optimization problem, we propose a column generation algorithm, which directly learns the binary-valued hash functions. We then extend it using anchor graphs to reduce the computational cost. Experiments on large-scale image datasets demonstrate that the proposed method outperforms state-of-the-art hashing methods in many cases.

  6. Solar Maximum Mission - A systems overview

    Science.gov (United States)

    Guha, A. K.

    1981-01-01

    The Solar Maximum Mission (SMM), or the central effort of the Solar Maximum Year research endeavor is discussed. The mission's attempt to exploit the synergistic advantages of correlated data to obtain a complete picture of solar phenomena is stressed, as is the coordination provided by a world-wide network of ground-based observations. The prominent features of the SMM observatory, including the payload module and the solar-array system, are shown diagramatically and the science instruments (coronagraph/polarimeter, ultraviolet spectrometer/polarimeter, soft X-ray polychromater) are discussed. Descriptions of the spacecraft's electrical power system, attitude determination and control systems and communications systems are also included. The Experiment Operations Facility, which provides quick response to rapidly changing solar conditions and permits coordination with a multitude of ground observatories and coordinated experiments, is described.

  7. Model fit after pairwise maximum likelihood

    Directory of Open Access Journals (Sweden)

    M. T. eBarendse

    2016-04-01

    Full Text Available Maximum likelihood factor analysis of discrete data within the structural equation modeling framework rests on the assumption that the observed discrete responses are manifestations of underlying continuous scores that are normally distributed. As maximizing the likelihood of multivariate response patterns is computationally very intensive, the sum of the log--likelihoods of the bivariate response patterns is maximized instead. Little is yet known about how to assess model fit when the analysis is based on such a pairwise maximum likelihood (PML of two--way contingency tables. We propose new fit criteria for the PML method and conduct a simulation study to evaluate their performance in model selection. With large sample sizes (500 or more, PML performs as well the robust weighted least squares analysis of polychoric correlations.

  8. A Maximum Radius for Habitable Planets.

    Science.gov (United States)

    Alibert, Yann

    2015-09-01

    We compute the maximum radius a planet can have in order to fulfill two constraints that are likely necessary conditions for habitability: 1- surface temperature and pressure compatible with the existence of liquid water, and 2- no ice layer at the bottom of a putative global ocean, that would prevent the operation of the geologic carbon cycle to operate. We demonstrate that, above a given radius, these two constraints cannot be met: in the Super-Earth mass range (1-12 Mearth), the overall maximum that a planet can have varies between 1.8 and 2.3 Rearth. This radius is reduced when considering planets with higher Fe/Si ratios, and taking into account irradiation effects on the structure of the gas envelope.

  9. Zipf's law, power laws and maximum entropy

    Science.gov (United States)

    Visser, Matt

    2013-04-01

    Zipf's law, and power laws in general, have attracted and continue to attract considerable attention in a wide variety of disciplines—from astronomy to demographics to software structure to economics to linguistics to zoology, and even warfare. A recent model of random group formation (RGF) attempts a general explanation of such phenomena based on Jaynes' notion of maximum entropy applied to a particular choice of cost function. In the present paper I argue that the specific cost function used in the RGF model is in fact unnecessarily complicated, and that power laws can be obtained in a much simpler way by applying maximum entropy ideas directly to the Shannon entropy subject only to a single constraint: that the average of the logarithm of the observable quantity is specified.

  10. Maximum likelihood estimation of fractionally cointegrated systems

    DEFF Research Database (Denmark)

    Lasak, Katarzyna

    In this paper we consider a fractionally cointegrated error correction model and investigate asymptotic properties of the maximum likelihood (ML) estimators of the matrix of the cointe- gration relations, the degree of fractional cointegration, the matrix of the speed of adjustment to the equilib......In this paper we consider a fractionally cointegrated error correction model and investigate asymptotic properties of the maximum likelihood (ML) estimators of the matrix of the cointe- gration relations, the degree of fractional cointegration, the matrix of the speed of adjustment...... to the equilibrium parameters and the variance-covariance matrix of the error term. We show that using ML principles to estimate jointly all parameters of the fractionally cointegrated system we obtain consistent estimates and provide their asymptotic distributions. The cointegration matrix is asymptotically mixed...

  11. Mammographic image restoration using maximum entropy deconvolution

    OpenAIRE

    Jannetta, Adrian; Jackson, John; Birch, Ian; Kotre, John; Robson, Kevin; Padgett, Rod

    2004-01-01

    An image restoration approach based on a Bayesian maximum entropy method (MEM) has been applied to a radiological image deconvolution problem, that of reduction of geometric blurring in magnification mammography. The aim of the work is to demonstrate an improvement in image spatial resolution in realistic noisy radiological images with no associated penalty in terms of reduction in the signal-to-noise ratio perceived by the observer. Images of the TORMAM mammographic image quality phantom wer...

  12. Maximum Entropy Moment Systems and Galilean Invariance

    OpenAIRE

    Junk, Michael; Unterreiter, Andreas

    2001-01-01

    In this article, we investigate the maximum entropy moment closure in gas dynamics. We show that the usual choice of polynomial weight functions may lead to hyperbolic systems with an unpleasant state space: equilibrium states are boundary points with possibly singular fluxes. In order to avoid singularities, the necessary arises to find weight functions which growing sub-quadratically at infinity. Unfortunately, this requirement leads to a conflict with Galilean invariance of the moment syst...

  13. Maximum Metric Spanning Tree made Byzantine Tolerant

    OpenAIRE

    Dubois, Swan; Masuzawa, Toshimitsu; Tixeuil, Sébastien

    2011-01-01

    Self-stabilization is a versatile approach to fault-tolerance since it permits a distributed system to recover from any transient fault that arbitrarily corrupts the contents of all memories in the system. Byzantine tolerance is an attractive feature of distributed systems that permits to cope with arbitrary malicious behaviors. This paper focus on systems that are both self-stabilizing and Byzantine tolerant. We consider the well known problem of constructing a maximum metric tree in this co...

  14. Shape Modelling Using Maximum Autocorrelation Factors

    DEFF Research Database (Denmark)

    Larsen, Rasmus

    2001-01-01

    of Active Shape Models by Timothy Cootes and Christopher Taylor by building new information into the model. This new information consists of two types of prior knowledge. First, in many situation we will be given an ordering of the shapes of the training set. This situation occurs when the shapes....... Both these types of knowledge may be used to defined Shape Maximum Autocorrelation Factors. The resulting point distribution models are compared to ordinary principal components analysis using leave-one-out validation....

  15. [Maximum entropy principle and population genetic equilibrium].

    Science.gov (United States)

    Wang, Xiao-Long; Yuan, Zhi-Fa; Guo, Man-Cai; Song, Shi-De; Zhang, Quan-Qi; Bao, Zhen-Min

    2002-06-01

    A general mathematic model of population genetic equilibrium was constructed based on the maximum entropy principle. We proved that the maximum entropy probability distribution was equivalent to the Hardy-Weinberg equilibrium law. A population reached genetic equilibrium when the genotype entropy of the population reached the maximal possible value. In information theory, the entropy or the information content is used to measure the uncertainty of a system. In population genetics, we can use entropy to measure the uncertainty of the genotype of a population. The agreement of the maximum entropy principle and the hardy-Weinberg equilibrium law indicated that random crossing is an irreversible process, which increases the genotype entropy of the population, while inbreeding and selection decrease the genotype entropy of the population. In animal or plant breeding, we often use selection and/or inbreeding to decrease the entropy of a population, and use intercrossing to increase the entropy of the population. In this point of view, breeding is actually regulating the entropy of population. By applying the basic principle of informatics in population genetics, we revealed the biological significance of the genotype entropy and demonstrated that we can work over population genetic problems with the principles and methods of informatics and cybernetics.

  16. A Maximum Resonant Set of Polyomino Graphs

    Directory of Open Access Journals (Sweden)

    Zhang Heping

    2016-05-01

    Full Text Available A polyomino graph P is a connected finite subgraph of the infinite plane grid such that each finite face is surrounded by a regular square of side length one and each edge belongs to at least one square. A dimer covering of P corresponds to a perfect matching. Different dimer coverings can interact via an alternating cycle (or square with respect to them. A set of disjoint squares of P is a resonant set if P has a perfect matching M so that each one of those squares is M-alternating. In this paper, we show that if K is a maximum resonant set of P, then P − K has a unique perfect matching. We further prove that the maximum forcing number of a polyomino graph is equal to the cardinality of a maximum resonant set. This confirms a conjecture of Xu et al. [26]. We also show that if K is a maximal alternating set of P, then P − K has a unique perfect matching.

  17. Continuity of the Maximum-Entropy Inference

    Science.gov (United States)

    Stephan, Weis

    2014-09-01

    We study the inverse problem of inferring the state of a finite-level quantum system from expected values of a fixed set of observables, by maximizing a continuous ranking function. We have proved earlier that the maximum-entropy inference can be a discontinuous map from the convex set of expected values to the convex set of states because the image contains states of reduced support, while this map restricts to a smooth parametrization of a Gibbsian family of fully supported states. Here we prove for arbitrary ranking functions that the inference is continuous up to boundary points. This follows from a continuity condition in terms of the openness of the restricted linear map from states to their expected values. The openness condition shows also that ranking functions with a discontinuous inference are typical. Moreover it shows that the inference is continuous in the restriction to any polytope which implies that a discontinuity belongs to the quantum domain of non-commutative observables and that a geodesic closure of a Gibbsian family equals the set of maximum-entropy states. We discuss eight descriptions of the set of maximum-entropy states with proofs of accuracy and an analysis of deviations.

  18. The maximum rate of mammal evolution

    Science.gov (United States)

    Evans, Alistair R.; Jones, David; Boyer, Alison G.; Brown, James H.; Costa, Daniel P.; Ernest, S. K. Morgan; Fitzgerald, Erich M. G.; Fortelius, Mikael; Gittleman, John L.; Hamilton, Marcus J.; Harding, Larisa E.; Lintulaakso, Kari; Lyons, S. Kathleen; Okie, Jordan G.; Saarinen, Juha J.; Sibly, Richard M.; Smith, Felisa A.; Stephens, Patrick R.; Theodor, Jessica M.; Uhen, Mark D.

    2012-03-01

    How fast can a mammal evolve from the size of a mouse to the size of an elephant? Achieving such a large transformation calls for major biological reorganization. Thus, the speed at which this occurs has important implications for extensive faunal changes, including adaptive radiations and recovery from mass extinctions. To quantify the pace of large-scale evolution we developed a metric, clade maximum rate, which represents the maximum evolutionary rate of a trait within a clade. We applied this metric to body mass evolution in mammals over the last 70 million years, during which multiple large evolutionary transitions occurred in oceans and on continents and islands. Our computations suggest that it took a minimum of 1.6, 5.1, and 10 million generations for terrestrial mammal mass to increase 100-, and 1,000-, and 5,000-fold, respectively. Values for whales were down to half the length (i.e., 1.1, 3, and 5 million generations), perhaps due to the reduced mechanical constraints of living in an aquatic environment. When differences in generation time are considered, we find an exponential increase in maximum mammal body mass during the 35 million years following the Cretaceous-Paleogene (K-Pg) extinction event. Our results also indicate a basic asymmetry in macroevolution: very large decreases (such as extreme insular dwarfism) can happen at more than 10 times the rate of increases. Our findings allow more rigorous comparisons of microevolutionary and macroevolutionary patterns and processes.

  19. A modelling study of the multiphase leakage flow from pressurised CO2 pipeline.

    Science.gov (United States)

    Zhou, Xuejin; Li, Kang; Tu, Ran; Yi, Jianxin; Xie, Qiyuan; Jiang, Xi

    2016-04-05

    The accidental leakage is one of the main risks during the pipeline transportation of high pressure CO2. The decompression process of high pressure CO2 involves complex phase transition and large variations of the pressure and temperature fields. A mathematical method based on the homogeneous equilibrium mixture assumption is presented for simulating the leakage flow through a nozzle in a pressurised CO2 pipeline. The decompression process is represented by two sub-models: the flow in the pipe is represented by the blowdown model, while the leakage flow through the nozzle is calculated with the capillary tube assumption. In the simulation, two kinds of real gas equations of state were employed in this model instead of the ideal gas equation of state. Moreover, results of the flow through the nozzle and measurement data obtained from laboratory experiments of pressurised CO2 pipeline leakage were compared for the purpose of validation. The thermodynamic processes of the fluid both in the pipeline and the nozzle were described and analysed. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Change regularity of water quality parameters in leakage flow conditions and their relationship with iron release.

    Science.gov (United States)

    Liu, Jingqing; Shentu, Huabin; Chen, Huanyu; Ye, Ping; Xu, Bing; Zhang, Yifu; Bastani, Hamid; Peng, Hongxi; Chen, Lei; Zhang, Tuqiao

    2017-11-01

    The long-term stagnation in metal water supply pipes, usually caused by intermittent consumption patterns, will cause significant iron release and water quality deterioration, especially at the terminus of pipelines. Another common phenomenon at the terminus of pipelines is leakage, which is considered helpful by allowing seepage of low-quality drinking water resulting from long-term stagnation. In this study, the effect of laminar flow on alleviating water quality deterioration under different leakage conditions was investigated, and the potential thresholds of the flow rate, which can affect the iron release process, were discussed. Based on a galvanized pipe and ductile cast iron pipe pilot platform, which was established at the terminus of pipelines, this research was carried out by setting a series of leakage rate gradients to analyze the influence of different leakage flow rates on iron release, as well as the relationship with chemical and biological parameters. The results showed that the water quality parameters were obviously influenced by the change in flow velocity. Water quality was gradually improved with an increase in flow velocity, but its change regularity reflected a diversity under different flow rates (p water distribution system, when the bulk water was at the critical laminar flow velocity, the concentration of total iron, the quantity and rate of total iron release remain relatively in an ideal and safe situation. Copyright © 2017. Published by Elsevier Ltd.

  1. On the leakage problem of MIM capacitors due to improper etching of titanium nitride

    NARCIS (Netherlands)

    Groenland, A.W.; Wolters, Robertus A.M.; Kovalgin, Alexeij Y.; Schmitz, Jurriaan

    2010-01-01

    In this work, Metal-insulator-metal (MIM) capacitor structures are fabricated in a technology using TiN as electrode material. The electrical characterization revealed devices with small and large leakage currents. Scanning Electron Microscopy (SEM) inspection showed a correlation between high

  2. Reduction of retinal albumin leakage by the antioxidant calcium dobesilate in streptozotocin-diabetic rats.

    Science.gov (United States)

    Rota, Rossella; Chiavaroli, Carlo; Garay, Ricardo P; Hannaert, Patrick

    2004-07-14

    Calcium dobesilate stabilizes blood-retinal barrier in patients with diabetic retinopathy and possesses antioxidant properties in the retinas of rats with streptozotocin-induced diabetes, exposed ex vivo to ischemia-reperfusion. Here we investigated the action of calcium dobesilate on retinal albumin leakage in streptozotocin-diabetic rats, together with relevant in vivo retinal antioxidant and permeability markers, i.e., carboxymethyl-lysine-advanced glycation end product (CML-AGE) formation and vascular endothelial cell growth factor (VEGF) overexpression. Twenty days after streptozotocin administration, diabetic rats were treated for 10 days with calcium dobesilate (100 mg/kg/day per os) or vehicle. Retinal albumin leakage, CML-AGE formation, and VEGF overexpression were evaluated by immunohistochemistry of frozen eye sections. Diabetic rats exhibited dramatic increases in: (i) retinal albumin leakage (31% of positive vessels vs. 0.2% in nondiabetic rats, Pdobesilate significantly reduced: (i) retinal albumin leakage (by 70%, Pdobesilate orally given to diabetic rats markedly reduced retinal hyperpermeability, CML-AGE contents, and VEGF overexpression. These results strongly suggest that calcium dobesilate stabilizes blood-retinal barrier in diabetic retinopathy via an in situ antioxidant action. Further studies in patients are required to confirm such view.

  3. Marginal Leakage of Class V Composite Restorations Assessed Using Microcomputed Tomography and Scanning Electron Microscope.

    Science.gov (United States)

    Rengo, C; Goracci, C; Ametrano, G; Chieffi, N; Spagnuolo, G; Rengo, S; Ferrari, M

    2015-01-01

    The aim of the study was to compare in Class V composite restorations marginal leakage measurements obtained with microcomputed tomography (micro-CT) and scanning electron microscopy (SEM) observations. Class V cavities were prepared on 10 human molars and restored using Optibond FL (Kerr, Orange, CA, USA) and Premise Flowable (Kerr). Sealing ability was evaluated by assessing silver-nitrate penetration depth along enamel and dentin margins. Leakage was quantified using a scoring system. Micro-CT analysis provided 502 cross-sectional images for each tooth. Microleakage evaluation was performed first on three cross-sections corresponding to the sections examined by SEM, then on all 502 of the obtained micro-CT images. SEM observations were performed first at 20× magnification, then, if showing a zero score, at 80× magnification. Enamel and dentin microleakage scores assigned to corresponding sections through micro-CT and SEM (20×) were compared (Wilcoxon signed-rank test, α=0.05). No statistically significant difference in leakage scores emerged between micro-CT and 20×-magnification SEM. Eight tooth sections that were given a zero score under SEM at 20× magnification showed to be infiltrated at the higher magnification (80×). For five teeth a higher score was assigned following scanning of 502 cross-sections than based on the observation of three sections. Micro-CT presents as a valid, nondestructive in vitro method to quantitatively evaluate marginal leakage of adhesive restorations.

  4. Marginal leakage of two newer glass-ionomer-based sealant materials assessed using micro-CT.

    NARCIS (Netherlands)

    Chen, X.; Cuijpers, V.M.J.I.; Fan, M.; Frencken, J.E.F.M.

    2010-01-01

    OBJECTIVES: To test newer glass-ionomer-based materials as sealant materials. One glass-ionomer sealant was light-cured to obtain an early setting reaction. The null-hypothesis tested was: there is no difference in marginal leakage of sealants produced with high-viscosity glass-ionomer, with and

  5. Water balance evaluation, leakage rate and total water loss of Koka ...

    African Journals Online (AJOL)

    Water balance evaluation of Koka Reservoir was attempted by different authors, and different leakage rates were estimated. However, the water balance equation that the previous authors used does not take into account ground water inflow into the reservoir. Koka Reservoir is known to receive groundwater inflow from the ...

  6. Risk Factors for Cement Leakage After Vertebroplasty or Kyphoplasty: A Meta-Analysis of Published Evidence.

    Science.gov (United States)

    Zhan, Yi; Jiang, Jianzhong; Liao, Haifen; Tan, Haitao; Yang, Keqin

    2017-05-01

    Cement leakage is the most common complication of vertebroplasty and kyphoplasty. So far, the reported risk factors remain conflicting because of limited data and lack of uniform measurement and evaluation. Here, we performed a systematic review and meta-analysis of potential risk factors for cement leakage after vertebroplasty or kyphoplasty. Relevant literature was retrieved using PubMed, EMBASE, Cochrane Controlled Trial Register, and MEDLINE with no language restriction, supplemented by a hand search of the reference lists of selected articles. A fixed-effects model was used if homogeneity existed among included studies; otherwise, a random-effects model was used. The results were presented with weighted mean difference for continuous outcomes and odds ratio (OR) for dichotomous outcomes with a 95% confidence interval (CI). Twenty-two studies consisting of 2872 patients with 4187 vertebrae were included in the meta-analysis. The incidences of cement leakage for percutaneous vertebroplasty and percutaneous balloon kyphoplasty were 54.7% and 18.4%, respectively. The significant risk factors for new vertebral compression fractures were intravertebral cleft (OR, 1.40; 95% CI, 1.09-1.78; P kyphoplasty. Rigorous patient selection and individual therapeutic strategy irrespective of age, sex and fracture type, operation level, and surgical approach may reduce the occurrence of cement leakage. Given the inherent limitation of the meta-analysis, more large sample-sized randomized controlled trials are needed to further validate the present findings. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Bacterial leakage through temporary fillings in core buildup composite material - an in vitro study.

    Science.gov (United States)

    Rechenberg, Dan-Krister; Schriber, Martina; Attin, Thomas

    2012-08-01

    To evaluate the ability of the provisional filling material Cavit-W alone or in combination with different restorative materials to prevent bacterial leakage through simulated access cavities in a resin buildup material. LuxaCore resin cylinders were subdivided into 4 experimental groups (n = 30), plus a positive (n = 5) and a negative (n = 30) control group. One bore hole was drilled through each cylinder, except those in the negative control group (G1). The holes were filled with Cavit-W (G2), Cavit-W and Ketac-Molar (glassionomer cement, G3), Cavit-W and LuxaCore bonded with LuxaBond (G4), Cavit-W and LuxaCore (G5), or left empty (G6). Specimens were mounted in a two-chamber leakage setup. The upper chamber was inoculated with E. faecalis. An enterococci-selective broth was used in the lower chamber. Leakage was assessed for 60 days and compared using Fisher's exact test (α Cavit-W alone or combined with a glass-ionomer cement did not prevent bacterial leakage through a resin buildup material for two months. In contrast, covering Cavit-W with a bonded resin material resulted in a bacteria-tight seal for two months.

  8. Novel Wearable Device for Blood Leakage Detection during Hemodialysis Using an Array Sensing Patch

    Directory of Open Access Journals (Sweden)

    Yi-Chun Du

    2016-06-01

    Full Text Available Hemodialysis (HD is a clinical treatment that requires the puncturing of the body surface. However, needle dislodgement can cause a high risk of blood leakage and can be fatal to patients. Previous studies proposed several devices for blood leakage detection using optical or electrical techniques. Nonetheless, these methods used single-point detection and the design was not suitable for multi-bed monitoring. This study proposed a novel wearable device for blood leakage monitoring during HD using an array sensing patch. The array sensing patch combined with a mapping circuit and a wireless module could measure and transmit risk levels. The different risk levels could improve the working process of healthcare workers, and enhance their work efficiency and reduce inconvenience due to false alarms. Experimental results showed that each point of the sensing array could detect up to 0.1 mL of blood leakage and the array sensing patch supports a risk level monitoring system up to 8 h to alert healthcare personnel of pertinent danger to the patients.

  9. Novel Wearable Device for Blood Leakage Detection during Hemodialysis Using an Array Sensing Patch.

    Science.gov (United States)

    Du, Yi-Chun; Lim, Bee-Yen; Ciou, Wei-Siang; Wu, Ming-Jui

    2016-06-09

    Hemodialysis (HD) is a clinical treatment that requires the puncturing of the body surface. However, needle dislodgement can cause a high risk of blood leakage and can be fatal to patients. Previous studies proposed several devices for blood leakage detection using optical or electrical techniques. Nonetheless, these methods used single-point detection and the design was not suitable for multi-bed monitoring. This study proposed a novel wearable device for blood leakage monitoring during HD using an array sensing patch. The array sensing patch combined with a mapping circuit and a wireless module could measure and transmit risk levels. The different risk levels could improve the working process of healthcare workers, and enhance their work efficiency and reduce inconvenience due to false alarms. Experimental results showed that each point of the sensing array could detect up to 0.1 mL of blood leakage and the array sensing patch supports a risk level monitoring system up to 8 h to alert healthcare personnel of pertinent danger to the patients.

  10. Optimized assessment of intestinal perfusion may reduce the risk of anastomotic leakage in the gastrointestinal tract

    DEFF Research Database (Denmark)

    Andersen, Helene Schou; Gögenur, Ismail

    2014-01-01

    The risk of anastomotic leakage is still high. Evaluation of blood perfusion intraoperatively may give the surgeon the possibility of changing strategy during the operation when needed. A review of the literature shows three different methods, none of which have been implemented in the surgical...

  11. 42 CFR 84.1150 - Exhalation valve leakage test; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Exhalation valve leakage test; minimum requirements. 84.1150 Section 84.1150 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust...

  12. Leakage mechanism of cation -modified BiFeO3 thin film

    National Research Council Canada - National Science Library

    Wu, Jiagang; Wang, John; Xiao, Dingquan; Zhu, Jianguo

    2011-01-01

    ... and BiFe0.95Mn0.05O3 thin films in a low electric field region, respectively, while an interface-limited Fowler-Nordheim tunneling is involved in their leakage behavior in a high electric field region...

  13. Evidence for paternal leakage in hybrid periodical cicadas (Hemiptera: Magicicada spp..

    Directory of Open Access Journals (Sweden)

    Kathryn M Fontaine

    Full Text Available Mitochondrial inheritance is generally assumed to be maternal. However, there is increasing evidence of exceptions to this rule, especially in hybrid crosses. In these cases, mitochondria are also inherited paternally, so "paternal leakage" of mitochondria occurs. It is important to understand these exceptions better, since they potentially complicate or invalidate studies that make use of mitochondrial markers. We surveyed F1 offspring of experimental hybrid crosses of the 17-year periodical cicadas Magicicada septendecim, M. septendecula, and M. cassini for the presence of paternal mitochondrial markers at various times during development (1-day eggs; 3-, 6-, 9-week eggs; 16-month old 1st and 2nd instar nymphs. We found evidence of paternal leakage in both reciprocal hybrid crosses in all of these samples. The relative difficulty of detecting paternal mtDNA in the youngest eggs and ease of detecting leakage in older eggs and in nymphs suggests that paternal mitochondria proliferate as the eggs develop. Our data support recent theoretical predictions that paternal leakage may be more common than previously estimated.

  14. Buoyancy-driven leakage of oil from a ruptured submarine pipeline

    NARCIS (Netherlands)

    Kranenburg, C.

    1983-01-01

    The rupture of a submarine oil pipeline starts various mechanisms leading to an oil spill. Among these mechanisms the leakage of oil driven by the difference in specific gravities of oil and sea-water is difficult to estimate. A simple mathematical model has been developed and laboratory experiments

  15. Apical Leakage of Epiphany Root Canal Sealer Combined with Different Master Cones

    Science.gov (United States)

    Kocak, Mustafa Murat; Er, Ozgur; Saglam, Baran Can; Yaman, Sis

    2008-01-01

    Objectives The aim of this study was to assess the apical sealing ability of different core materials used with EpiphanyTM sealer and to evaluate the effect of Resilon/EpiphanyTM system on creating an apical mono-block seal. Methods Fifty-five extracted human teeth were used. Forty-five were selected and randomly divided into three groups and ten teeth were used as positive and negative control groups. In Group 1, roots were obturated using Resilon™ and Epiphany™, In Group 2, roots were obturated using tapered single-cone gutta-percha and Epiphany™ and in Group 3, roots were obturated using Thermafil obturators and Epiphany™ sealer. The apical leakage was measured using the dye penetration methodology. The teeth were cleared, and the linear extent of dye penetration was measured with a stereomicroscope. Data were analyzed by the one-way ANOVA and Tukey HSD tests. Results The teeth filled with Thermafil obturators and Epiphany™ sealer displayed the most apical leakage. The least apical leakage was shown with Resilon™ and Epiphany™. Groups 1 and 2 had significantly leaked less than Group 3. Conclusions Based on the data of this study, although Resilon and Epiphany sealer showed the least apical leakage, statistical analysis showed no difference between gutta-percha and Epiphany™. PMID:19212517

  16. Intraoperative assessment of microperfusion with visible light spectroscopy for prediction of anastomotic leakage in colorectal anastomoses

    NARCIS (Netherlands)

    Karliczek, A.; Benaron, D. A.; Baas, P. C.; Zeebregts, C. J.; Wiggers, T.; van Dam, G. M.

    2010-01-01

    Purpose Anastomotic leakage is associated with increased morbidity and mortality. However, there is no accurate tool to predict its occurrence. We evaluated the predictive value of visible light spectroscopy (VLS), a novel method to measure tissue oxygenation [saturated O(2) (StO(2))], for

  17. Intestinal microbiota and anastomotic leakage of stapled colorectal anastomoses : a pilot study

    NARCIS (Netherlands)

    van Praagh, Jasper B.; de Goffau, Marcus C.; Bakker, Ilsalien S.; Harmsen, Hermie J. M.; Olinga, Peter; Havenga, Klaas

    Background Anastomotic leakage (AL) after colorectal surgery is a severe complication, resulting in morbidity, reinterventions, prolonged hospital stay and, in some cases, death. Some technical and patient-related aetiological factors of AL are well established. In many cases, however, none of these

  18. Reduction of leakage currents in ferroelectric thin films by flexoelectricity: a phase field study

    Science.gov (United States)

    Xu, Xiaofei; Jiang, Limei; Zhou, Yichun

    2017-11-01

    With the development of integrated circuit technology and the decreasing size of devices, ferroelectric films used in nano ferroelectric devices must become thinner and thinner. Along with the downscaling of the ferroelectric film is the increasing serious leakage current which has seriously hindered the broad application of ferroelectric devices. Here we tuned the leakage currents in Pb(Zr0.1Ti0.9)O3 ferroelectric thin films through flexoelectricity by means of the phase field method with diffusion equations for the electron/hole. It is shown that the strain gradient generated by the local compressive force can raise the hole current but reduce the electron current in ferroelectric film. Pure mechanical force can therefore be used to diminish the leakage current. With the further study of the effects of different flexoelectric coupling types on leakage current, we demonstrate that the flexocoupling type described by the longitudinal flexoelectric coefficient promotes the increase of the hole current but has a side-effect on the increase of the electron current. In contrast, the role of the flexocoupling type described by the transverse flexoelectric coefficient is just the opposite.

  19. Fuzzy Bayesian Network-Bow-Tie Analysis of Gas Leakage during Biomass Gasification

    Science.gov (United States)

    Yan, Fang; Xu, Kaili; Yao, Xiwen; Li, Yang

    2016-01-01

    Biomass gasification technology has been rapidly developed recently. But fire and poisoning accidents caused by gas leakage restrict the development and promotion of biomass gasification. Therefore, probabilistic safety assessment (PSA) is necessary for biomass gasification system. Subsequently, Bayesian network-bow-tie (BN-bow-tie) analysis was proposed by mapping bow-tie analysis into Bayesian network (BN). Causes of gas leakage and the accidents triggered by gas leakage can be obtained by bow-tie analysis, and BN was used to confirm the critical nodes of accidents by introducing corresponding three importance measures. Meanwhile, certain occurrence probability of failure was needed in PSA. In view of the insufficient failure data of biomass gasification, the occurrence probability of failure which cannot be obtained from standard reliability data sources was confirmed by fuzzy methods based on expert judgment. An improved approach considered expert weighting to aggregate fuzzy numbers included triangular and trapezoidal numbers was proposed, and the occurrence probability of failure was obtained. Finally, safety measures were indicated based on the obtained critical nodes. The theoretical occurrence probabilities in one year of gas leakage and the accidents caused by it were reduced to 1/10.3 of the original values by these safety measures. PMID:27463975

  20. Fuzzy Bayesian Network-Bow-Tie Analysis of Gas Leakage during Biomass Gasification.

    Directory of Open Access Journals (Sweden)

    Fang Yan

    Full Text Available Biomass gasification technology has been rapidly developed recently. But fire and poisoning accidents caused by gas leakage restrict the development and promotion of biomass gasification. Therefore, probabilistic safety assessment (PSA is necessary for biomass gasification system. Subsequently, Bayesian network-bow-tie (BN-bow-tie analysis was proposed by mapping bow-tie analysis into Bayesian network (BN. Causes of gas leakage and the accidents triggered by gas leakage can be obtained by bow-tie analysis, and BN was used to confirm the critical nodes of accidents by introducing corresponding three importance measures. Meanwhile, certain occurrence probability of failure was needed in PSA. In view of the insufficient failure data of biomass gasification, the occurrence probability of failure which cannot be obtained from standard reliability data sources was confirmed by fuzzy methods based on expert judgment. An improved approach considered expert weighting to aggregate fuzzy numbers included triangular and trapezoidal numbers was proposed, and the occurrence probability of failure was obtained. Finally, safety measures were indicated based on the obtained critical nodes. The theoretical occurrence probabilities in one year of gas leakage and the accidents caused by it were reduced to 1/10.3 of the original values by these safety measures.

  1. Fuzzy Bayesian Network-Bow-Tie Analysis of Gas Leakage during Biomass Gasification.

    Science.gov (United States)

    Yan, Fang; Xu, Kaili; Yao, Xiwen; Li, Yang

    2016-01-01

    Biomass gasification technology has been rapidly developed recently. But fire and poisoning accidents caused by gas leakage restrict the development and promotion of biomass gasification. Therefore, probabilistic safety assessment (PSA) is necessary for biomass gasification system. Subsequently, Bayesian network-bow-tie (BN-bow-tie) analysis was proposed by mapping bow-tie analysis into Bayesian network (BN). Causes of gas leakage and the accidents triggered by gas leakage can be obtained by bow-tie analysis, and BN was used to confirm the critical nodes of accidents by introducing corresponding three importance measures. Meanwhile, certain occurrence probability of failure was needed in PSA. In view of the insufficient failure data of biomass gasification, the occurrence probability of failure which cannot be obtained from standard reliability data sources was confirmed by fuzzy methods based on expert judgment. An improved approach considered expert weighting to aggregate fuzzy numbers included triangular and trapezoidal numbers was proposed, and the occurrence probability of failure was obtained. Finally, safety measures were indicated based on the obtained critical nodes. The theoretical occurrence probabilities in one year of gas leakage and the accidents caused by it were reduced to 1/10.3 of the original values by these safety measures.

  2. Alcohol Drinking does not Affect Postoperative Surgical Site Infection or Anastomotic Leakage

    DEFF Research Database (Denmark)

    Shabanzadeh, Daniel Mønsted; Sørensen, Lars Tue

    2014-01-01

    Alcohol abuse appears to increase postoperative complications, but clinical trials have reported conflicting results. The objective of this systematic review and meta-analysis is to clarify how alcohol drinking affects postoperative surgical site infection and anastomotic leakage and to determine...... the impact of perioperative alcohol intervention....

  3. An investigation into the signals leakage from a smartcard based on different runtime code

    CSIR Research Space (South Africa)

    Frieslaar, I

    2015-09-01

    Full Text Available This paper investigates the power leakage of a smartcard. It is intended to answer two vital questions: what information is leaked out when different characters are used as output; and does the length of the output affect the amount...

  4. Treatment with corticosteroids and the risk of anastomotic leakage following lower gastrointestinal surgery

    DEFF Research Database (Denmark)

    Eriksen, Tina Fransgård; Lassen, Cecilie Brandt; Gögenur, Ismail

    2014-01-01

    Anastomotic leakage is a serious complication in colorectal surgery. Treatment with corticosteroids is known to impair wound healing but their influence on the healing of a colorectal anastomosis remains unclear, and studies have reported conflicting results. The aim of this study was to evaluate...

  5. Analysis of Gas Leakage and Current Loss of Solid Oxide Fuel Cells by Screen Printing

    DEFF Research Database (Denmark)

    Jia, Chuan; Han, Minfang; Chen, Ming

    2017-01-01

    Two types of anode supported solid oxide fuel cell (SOFC) NiO-YSZ/YSZ/GDC/LSCF with the same structure and different manufacturing process were tested. Gas leakage was suspected for cells manufactured with screen printing technique. Effective leak current densities for both types of cells were...

  6. Comparison of apical leakage between immediate versus delayed post space preparation using two resin sealers

    Directory of Open Access Journals (Sweden)

    Priyanka Kaushal Kalra

    2009-01-01

    Full Text Available Post & Core Procedures have became an integral part of a dentist′s arsenal. This study was carried out in order to assess the microleakage when immediate and delayed post space preparations were done using resin sealers. Immediate post space preparations showed lesser apical leakage as opposed to delayed post space preparation.

  7. Sistem Proteksi Arus Bocor Menggunakan Earth Leakage Circuit Breaker Berbasis Arduino

    Directory of Open Access Journals (Sweden)

    Syukriyadin Syukriyadin

    2017-02-01

    Full Text Available Touching a live part of electrical equipment either intentionally or unintentionally can cause an electric shock. The touch can occur directly or indirectly and results in the flow of electric current through the human body to the ground. This electric current is known as the leakage current and can have fatal effects on the human body such as burns, cramps, faint and death. This paper aims to design a prototype protection model of the earth leakage circuit breaker device based on Arduino (ELCBA to protect the human body from the electrical hazards. The performance of the ELCBA is investigated by detecting the earth leakage current to the grounding system (TN.  The prototype is designed and simulated by using Proteus software. Based on the response test carried out on the prototype, it can be concluded that the ELCBA can operate properly to disconnect the electric circuit if the leakage current is detected greater than or equal to 30 mA with a time delay of 15 ms and to reclose the circuit again after 5 minutes.

  8. Postoperative non-steroidal anti-inflammatory drugs and colorectal anastomotic leakage

    DEFF Research Database (Denmark)

    Klein, Mads; Gögenur, Ismail; Rosenberg, Jacob

    2012-01-01

    Anastomotic leakage (AL) is the most important and one of the most serious complications after colorectal resections with primary anastomosis. Any factors that contribute to increase the risk of AL should be identified and - if possible - eliminated. Non-steroidal anti-inflammatory drugs (NSAIDs...

  9. Sealing ability of three single-cone obturation systems: An in-vitro glucose leakage study

    National Research Council Canada - National Science Library

    El Sayed, Mohamed Abdel Aziz Mohamed; Taleb, Ahmed Abdel Aziz; Balbahaith, Mohammed Sulaiman Mubarak

    2013-01-01

    ...; Group 3, single-cone Gutta-percha/and GuttaFlow2; Group 4, single-cone Resilon/RealSeal SE after 7 days, the sealing ability of root canal fillings was tested at different time intervals using glucose leakage model...

  10. Developments since 2005 in understanding potential environmental impacts of CO2 leakage from geological storage

    NARCIS (Netherlands)

    Jones, D.G.; Beaubien, S.E.; Blackford, J.C.; Foekema, E.M.; Lions, J.; Vittor, de C.; West, J.M.; Widdicombe, S.; Hauton, C.; Queiros, A.M.

    2015-01-01

    This paper reviews research into the potential environmental impacts of leakage from geological storage of CO2 since the publication of the IPCC Special Report on Carbon Dioxide Capture and Storage in 2005. Possible impacts are considered on onshore (including drinking water aquifers) and offshore

  11. Intra- and intergrader reliability of semiautomatic measurements of fundus fluorescein angiography leakage in proliferative diabetic retinopathy

    DEFF Research Database (Denmark)

    Torp, Thomas Lee; Frydkjær-Olsen, Ulrik; Hansen, Rasmus Søgaard

    2015-01-01

    Design of study: Cross-sectional image grading study. Purpose: Panretinal photocoagulation (PRP) is the gold-standard treatment for proliferative diabetic retinopathy (PDR). Fundus fluorescein angiography leakage (FFAL) is often used as a marker of disease activity, but evaluation of the difference...

  12. Cerebrospinal fluid leakage as complication of treatment with cabergoline for macroprolactinomas.

    NARCIS (Netherlands)

    Netea-Maier, R.T.; Lindert, E.J. van; Timmers, H.J.L.M.; Schakenraad, E.L.; Grotenhuis, J.A.; Hermus, A.R.M.M.

    2006-01-01

    Treatment of patients with prolactinomas consists primarily of dopamine agonists (DA). Cerebrospinal fluid (CSF) leakage has sporadically been reported in patients with macroprolactinomas treated with short-acting DA such as bromocriptine. Little is known on the incidence of this complication in

  13. Key Factors for Determining Risk of Groundwater Impacts Due to Leakage from Geologic Carbon Sequestration Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, Susan [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Keating, Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mansoor, Kayyum [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dai, Zhenue [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sun, Yunwei [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Trainor-Guitton, Whitney [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brown, Chris [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bacon, Diana [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-01-06

    The National Risk Assessment Partnership (NRAP) is developing a science-based toolset for the analysis of potential impacts to groundwater chemistry from CO2 injection (www.netldoe.gov/nrap). The toolset adopts a stochastic approach in which predictions address uncertainties in shallow underwater and leakage scenarios. It is derived from detailed physics and chemistry simulation results that are used to train more computationally efficient models,l referred to here as reduced-order models (ROMs), for each component system. In particular, these tools can be used to help regulators and operators understand the expected sizes and longevity of plumes in pH, TDS, and dissolved metals that could result from a leakage of brine and/or CO2 from a storage reservoir into aquifers. This information can inform, for example, decisions on monitoring strategies that are both effective and efficient. We have used this approach to develop predictive reduced-order models for two common types of reservoirs, but the approach could be used to develop a model for a specific aquifer or other common types of aquifers. In this paper we describe potential impacts to groundwater quality due to CO2 and brine leakage, discuss an approach to calculate thresholds under which "no impact" to groundwater occurs, describe the time scale for impact on groundwater, and discuss the probability of detecting a groundwater plume should leakage occur.

  14. Vacuum-assisted closure therapy in ureteroileal anastomotic leakage after surgical therapy of bladder cancer

    Directory of Open Access Journals (Sweden)

    Kessler Sigurd

    2007-04-01

    Full Text Available Abstract Background Vacuum-assisted closure (VAC is an acknowledged method of treating wound healing disorders, but has been viewed as a contraindication in therapy of intraabdominal fistulas. Case presentation We present the case of an 83-year old patient with ureteroileal anastomotic insufficiency following cystectomy and urinary diversion by Bricker ileal conduit due to urothelial bladder cancer. After developing an open abdomen on the 16th postoperative day a leakage of the ureteroileal anastomosis appeared that cannot be managed by surgical means. To stopp the continued leakage we tried a modified VAC therapy with a silicon covered polyurethane foam under a suction of 125 mmHg. After 32 days with regularly changes of the VAC foam under general anesthesia the fistula resolved without further problems of ureteroileal leakage. Conclusion We present the first report of VAC therapy successfully performed in urinary tract leakage after surgical treatment of bladder cancer. VAC therapy of such disorders requires greater care than of superficial application to avoid mechanical alterations of internal organs but opens new opportunities in cases without surgical alternatives.

  15. Potential errors and misuse of statistics in studies on leakage in endodontics.

    Science.gov (United States)

    Lucena, C; Lopez, J M; Pulgar, R; Abalos, C; Valderrama, M J

    2013-04-01

    To assess the quality of the statistical methodology used in studies of leakage in Endodontics, and to compare the results found using appropriate versus inappropriate inferential statistical methods. The search strategy used the descriptors 'root filling' 'microleakage', 'dye penetration', 'dye leakage', 'polymicrobial leakage' and 'fluid filtration' for the time interval 2001-2010 in journals within the categories 'Dentistry, Oral Surgery and Medicine' and 'Materials Science, Biomaterials' of the Journal Citation Report. All retrieved articles were reviewed to find potential pitfalls in statistical methodology that may be encountered during study design, data management or data analysis. The database included 209 papers. In all the studies reviewed, the statistical methods used were appropriate for the category attributed to the outcome variable, but in 41% of the cases, the chi-square test or parametric methods were inappropriately selected subsequently. In 2% of the papers, no statistical test was used. In 99% of cases, a statistically 'significant' or 'not significant' effect was reported as a main finding, whilst only 1% also presented an estimation of the magnitude of the effect. When the appropriate statistical methods were applied in the studies with originally inappropriate data analysis, the conclusions changed in 19% of the cases. Statistical deficiencies in leakage studies may affect their results and interpretation and might be one of the reasons for the poor agreement amongst the reported findings. Therefore, more effort should be made to standardize statistical methodology. © 2012 International Endodontic Journal.

  16. Leakage Current Suppression with A Novel Six-Switch Photovoltaic Grid-Connected Inverter

    DEFF Research Database (Denmark)

    Wei, Baoze; Guo, Xiaoqiang; Guerrero, Josep M.

    2015-01-01

    of unmatched inductances. And the stray capacitor voltage of the non-isolated photovoltaic system is free of high frequency ripples. Theoretical analysis and simulation are carried out to verify the proposed topology and its control strategy. Results indicate that the leakage current suppression can...

  17. Ketorolac and Other NSAIDs Increase the Risk of Anastomotic Leakage After Surgery for GEJ Cancers

    DEFF Research Database (Denmark)

    Fjederholt, Kaare Terp; Okholm, Cecilie; Svendsen, Lars Bo

    2018-01-01

    OBJECTIVE: The objective of this study is to investigate the impact of ketorolac and other nonsteroidal anti-inflammatory drugs on anastomotic leakage after surgery for gastro-esophageal-junction cancer. Within the last two decades, the incidence of gastro-esophageal-junction cancer has increased...

  18. Vascular leakage induced by exposure to arsenic via increased production of NO, hydroxyl radical and peroxynitrite.

    Science.gov (United States)

    Chen, Shih-Chieh; Chen, Wei-Chi

    2008-04-01

    Previous studies have shown that in situ exposure to arsenic induced increased vascular leakage. However, the underlying mechanism remains unclear. Reactive nitrogen and oxygen species such as nitric oxide (NO) and hydroxyl radical (OH(-)) are known to affect vascular permeability. Therefore, the goal of our present studies is to investigate the functional impact of the generation of NO or OH(-) on arsenic-induced vascular leakage. Vascular permeability changes were evaluated by means of Evans blue (EB) assay. Rats were anesthetized and intravenously injected with EB. Permeability changes were induced in back skin by intradermal injections of sodium arsenite mixed with NOS inhibitor: N(omega)-Nitro-L-arginine methyl ester (L-NAME) or aminoguanidine (AG) and OH(-) scavenger: 1,3 Dimethyl-2 thiourea (DMTU). Experiments were also performed to determine whether DMTU mixed with L-NAME would further inhibit arsenic-induced vascular leakage as compared with attenuation effects by either DMTU or L-NAME. One hour after administration, EB accumulated in the skin was extracted and quantified. Both L-NAME (0.02, 0.1 and 0.5 micromol/site) and DMTU (0.05, 0.2 and 1.2 micromol/site) inhibited the increase in vascular leakage induced by arsenite. However, only high dose (1 micromol/site) of AG significantly attenuated arsenite-induced vascular leakage. In contrast, neither D-NAME (0.02, 0.1 and 0.5 micromol/site) nor AG (0.04 and 0.2 micromol/site) attenuated increased vascular leakage by arsenic. DMTU mixed with L-NAME caused no further inhibition of arsenic-induced vascular leakage by either DMTU or L-NAME. The techniques of India ink and immunostaining were used to demonstrate both vascular labeling and nitrotyrosine staining in tissue treated with arsenic. L-NAME apparently reduced the density of leaky vessels and the levels of peroxynitrite staining induced by arsenite. These results suggest that NO, OH(-) and peroxynitrite play a role in increased vascular permeability

  19. An Improved Strategy to Detect Carbon Dioxide Leakage for Verification of Geologic Carbon Sequestration

    Science.gov (United States)

    Lewicki, J. L.; Hilley, G. E.; Oldenburg, C. M.

    2005-12-01

    One strategy to mitigate potential climate change associated with elevated atmospheric CO2 concentrations is the sequestration or storage of anthropogenic CO2 in deep geologic formations. While the purpose of geologic carbon sequestration is to trap CO2 underground, the potential exists for CO2 to migrate away from the intended storage site along permeable pathways such as well bores or faults and pass from the subsurface to the atmosphere. Therefore, to ensure the success of geologic carbon sequestration projects, the long-term storage of CO2 must be verified. Although numerous technologies are available to measure near-surface CO2 concentrations and fluxes, storage verification may be challenging due to the large variation in natural background CO2 fluxes and concentrations, within which a potentially small CO2 anomaly will have to be detected. To detect and quantify subtle CO2 leakage signals, we present a strategy that integrates near-surface measurements of CO2 fluxes or concentrations with an algorithm that enhances temporally- and spatially-correlated leakage signals while suppressing random background noise. The algorithm consists of a filter that highlights spatial coherence, and temporal stacking (averaging) that reduces noise from temporally uncorrelated background fluxes. We assess the performance of our strategy using synthetic data sets in which the surface leakage signal is either specified directly or calculated using flow and transport simulations of a variety of leakage source geometries one might expect to be present at sequestration sites. These simulations provide a means of estimating the number of measurements required to detect a potential CO2 leakage signal of given magnitude and area. Our results show that given a rigorous and well-planned field sampling program, subtle CO2 leakage may be detected using the statistical algorithm; however, leakage of very limited spatial extent or exceedingly small magnitude may be difficult to detect with

  20. Differences in Ostomy Pouch Seal Leakage Occurrences Between North American and European Residents.

    Science.gov (United States)

    Fellows, Jane; Forest Lalande, Louise; Martins, Lina; Steen, Anne; Størling, Zenia M

    The purpose of this study was to compare experiences and concerns about pouch seal leakage between persons with ostomies residing in North America (Canada and the United States) and Europe (United Kingdom, Netherlands, Sweden, Germany, Belgium, France, and Italy). Differences in reported pouch wear time and accessories used between the 2 groups were also examined. Secondary analysis of data from a cross-sectional study (Ostomy Life Study). Responses from persons residing in European countries (n = 1939) were compared with responses of 1387 individuals residing in North American countries. Persons with an ostomy completed a questionnaire that focused on 4 topics related to the daily use of an ostomy pouching system (pouch seal leakage, ballooning, appearance of pouching system such as color and size of the pouch and whether it is discrete under clothing, and coupling failure of 2-piece pouching systems). Pouch seal leakage was defined as stomal effluent seeping between the skin and the wafer of the ostomy pouching system. Statistical analysis was performed using a proportional odds model including various variable effects. Special attention was given to frequency of pouch seal leakage occurrences. All tests were 2-sided; P values ≤.05 were deemed statistically significant. Participants living in the North American countries indicated they were more likely to experience leakage from the ostomy (odds ratio = 2.610, 95% CI 2.187-3.115; P < .0001). Findings also indicated they were more likely to worry about pouch seal leakage than those in the European countries' data set (odds ratio = 2.722, 95% CI 2.283-3.246; P < .0001). Participants residing in the North American countries had significantly longer wear times than those participants in the European countries (P < .0001, χ test). The use of accessories was associated with a longer pouching system wear time. Study results suggest that participants from the North American countries indicated significantly more

  1. Defunctioning Stoma Reduces Symptomatic Anastomotic Leakage After Low Anterior Resection of the Rectum for Cancer

    Science.gov (United States)

    Matthiessen, Peter; Hallböök, Olof; Rutegård, Jörgen; Simert, Göran; Sjödahl, Rune

    2007-01-01

    Objective: The aim of this randomized multicenter trial was to assess the rate of symptomatic anastomotic leakage in patients operated on with low anterior resection for rectal cancer and who were intraoperatively randomized to a defunctioning stoma or not. Summary Background Data: The introduction of total mesorectal excision surgery as the surgical technique of choice for carcinoma in the lower and mid rectum has led to decreased local recurrence and improved oncological results. Despite these advances, perioperative morbidity remains a major issue, and the most feared complication is symptomatic anastomotic leakage. The role of the defunctioning stoma in regard to anastomotic leakage is controversial and has not been assessed in any randomized trial of sufficient size. Methods: From December 1999 to June 2005, a total of 234 patients were randomized to a defunctioning loop stoma or no loop stoma. Loop ileostomy or loop transverse colostomy was at the choice of the surgeon. Inclusion criteria for randomization were expected survival >6 months, informed consent, anastomosis ≤7 cm above the anal verge, negative air leakage test, intact anastomotic rings, and absence of major intraoperative adverse events. Results: The overall rate of symptomatic leakage was 19.2% (45 of 234). Patients randomized to a defunctioning stoma (n = 116) had leakage in 10.3% (12 of 116) and those without stoma (n = 118) in 28.0% (33 of 118) (odds ratio = 3.4; 95% confidence interval, 1.6–6.9; P stoma and 25.4% (30 of 118) in those without (P stoma of any kind, compared with 16.9% (20 of 118) those not defunctioned (not significant). The 30-day mortality after anterior resection was 0.4% (1 of 234) and after elective reversal a defunctioning stoma 0.9% (1 of 111). Median age was 68 years (range, 32–86 years), 45.3% (106 of 234) were females, 79.1% (185 of 234) had preoperative radiotherapy, the level of anastomosis was median 5 cm, and intraoperative blood loss 550 mL, without

  2. Diffusive leakage of brine from aquifers during CO2 geological storage

    Science.gov (United States)

    Dejam, Morteza; Hassanzadeh, Hassan

    2018-01-01

    The area of investigation in this study is designed around an improved understanding of fundamentals of the diffusive leakage of brine from a storage aquifer into overlying and underlying low permeability layers during geosequestration of carbon dioxide (CO2) through development of a theoretical model. Here, we consider a two-dimensional domain in cylindrical coordinates, comprised of an aquifer and an overburden, where the interaction between the two media is handled by imposing the continuities of pressures and fluid fluxes at the aquifer-overburden interface. This coupled problem is solved by successive implementation of the Laplace and finite Hankel transforms. The developed solutions can be used to analyze diffusive leakage of brine from the aquifer into overburden and generate type curves for average pressures in the aquifer and overburden during injection and post injection periods. The results show that the leakage rate at early times is scaled with t1/2 while it remains constant at late times. It is also shown that the average pressure in the aquifer is scaled with t for short and long times. Moreover, the average pressure in the overburden is scaled with t at late times while it is scaled with t3/2 at early times. In addition, the results reveal that factors affecting diffusive leakage rate through intact overburden during CO2 storage are, in decreasing order of significance, thickness of overburden, thickness of aquifer, aquifer to overburden permeability ratio, and aquifer to overburden porosity ratio. However, thickness of aquifer has minimal effect on diffusive leakage of brine within post injection period. To evaluate the theoretical model, case studies for two potential sites in United Kingdom, one in Lincolnshire and the other one in the Firth of Forth, are conducted. The field studies show that the diffusive leakage from the aquifer into the overburden diminishes ∼40 years after the injection has ceased for Lincolnshire while it stops after

  3. Microbial leakage of MTA, Portland cement, Sealapex and zinc oxide-eugenol as root-end filling materials.

    Science.gov (United States)

    Estrela, Carlos; Estrada-Bernabé, Pedro-Felício; de Almeida-Decurcio, Daniel; Almeida-Silva, Julio; Rodrigues-Araújo-Estrela, Cyntia; Poli-Figueiredo, José-Antonio

    2011-05-01

    The aim of this study was to compare the microbial leakage of mineral trioxide aggregate (MTA), Portland cement (PC), Sealapex and zinc oxide-eugenol (ZOE) as root-end filling materials. An in vitro microbial leakage test (MLT) with a split chamber was used in this study. A mixture of facultative bacteria and one yeast (S. aureus+E. faecalis+P. aeruginosa+B. subtilis+C. albicans) was placed in the upper chamber and it could only reach the lower chamber containing Brain Heart Infusion broth by way of leakage through the root-end filling. Microbial leakage was observed daily for 60 days. Sixty maxillary anterior human teeth were randomly assigned to different groups--MTA and PC (gray and white), Sealapex+zinc oxide and ZOE, control groups and subgroups to evaluate the influence of EDTA for smear layer removal. These materials were further evaluated by an agar diffusion test (ADT) to verify their antimicrobial efficacy. Data were analyzed statistically by Kruskal-Wallis and Mann-Whitney test. In the MLT, Sealapex+zinc oxide and ZOE did not show evidence of microbial leakage over the 60-day experimental period. The other materials showed leakage from the 15th day. The presence of smear layer influenced microbial leakage. Microbial inhibition zones were not observed in all samples tested by ADT. Sealapex+zinc oxide and ZOE did not show microbial leakage over the experimental period, whereas it was verified within 15 to 45 days in MTA and Portland cement.

  4. Analysis of leakage in IRGA's leaf chambers of open gas exchange systems: quantification and its effects in photosynthesis parameterization

    National Research Council Canada - National Science Library

    J. Flexas; A. Díaz-Espejo; J. A. Berry; J. Cifre; J. Galmés; R. Kaldenhoff; H. Medrano; M. Ribas-Carbó

    2007-01-01

    ... Ci. A quantitative analysis of CO2 leakage in the chamber of a portable open gas exchange system (Li-6400, LI-COR Inc., NE, USA) was performed. In an empty chamber, the measured CO2 leakage was similar to that calculated using the manufacturer's equations...

  5. Managing persistent wound leakage after total knee and hip arthroplasty. Results of a nationwide survey among Dutch orthopaedic surgeons

    NARCIS (Netherlands)

    Wagenaar, Frank-Christiaan; Löwik, Claudia A M; Stevens, Martin; Bulstra, Sjoerd K; Pronk, Yvette; van den Akker-Scheek, Inge; Wouthuyzen-Bakker, Marjan; Nelissen, Rob G H H; Poolman, Rudolf W; van der Weegen, Walter; Jutte, Paul C

    2017-01-01

    Background: Persistent wound leakage after joint arthroplasty is a scantily investigated topic, despite the claimed relation with a higher risk of periprosthetic joint infection. This results in a lack of evidence-based clinical guidelines for the diagnosis and treatment of persistent wound leakage

  6. Specific interaction of central nervous system myelin basic protein with lipids effects of basic protein on glucose leakage from liposomes

    NARCIS (Netherlands)

    Gould, R.M.; London, Y.

    1972-01-01

    The leakage from liposomes preloaded with glucose was continuously monitored in a Perkin-Elmer Model 356 dual beam spectrophotometer using an enzyme-linked assay system. The central nervous system myelin basic protein (A1 protein) caused a 3–4-fold increase in the rate of leakage from liposomes

  7. Decreased plasma levels of the endothelial protective sphingosine-1-phosphate are associated with dengue-induced plasma leakage

    NARCIS (Netherlands)

    Michels, M.; Japtok, L.; Alisjahbana, B.; Wisaksana, R.; Sumardi, U.; Puspita, M.; Kleuser, B.; Mast, Q. de; Ven, A.J.A.M. van der

    2015-01-01

    BACKGROUND: A transient endothelial hyperpermeability is a hallmark of severe dengue infections. Sphingosine-1-phosphate (S1P) maintains vascular integrity and protects against plasma leakage. We related plasma S1P levels to dengue-induced plasma leakage and studied mechanisms that may underlie the

  8. Management and outcome of cervical versus intrathoracic manifestation of cervical anastomotic leakage after transthoracic esophagectomy for cancer.

    Science.gov (United States)

    van Rossum, Peter S N; Haverkamp, Leonie; Carvello, Michele; Ruurda, Jelle P; van Hillegersberg, Richard

    2017-01-01

    The aim of this study was to evaluate management strategies and related outcomes for cervical versus intrathoracic manifestation of cervical anastomotic leakage after transthoracic esophagectomy for cancer with gastric conduit reconstruction. Patients with esophageal cancer undergoing transthoracic esophagectomy with cervical anastomosis from October 2003 to December 2014 were identified from a prospectively acquired database. Management strategies and related outcomes among patients with anastomotic leakage confined to the neck were compared to patients with intrathoracic manifestation of anastomotic leakage. From a total of 286 patients, leakage of the cervical anastomosis occurred in 60 patients (21%) at a median time of 7 days after esophagectomy. Leakage was confined to the neck in 23 of 60 patients (38%), whereas 37 of 60 patients (62%) presented with intrathoracic spread. Leakages with intrathoracic manifestation were more frequently accompanied by a positive SIRS score compared to leakages confined to the neck (73% vs. 35%, respectively; P = 0.004). Drainage of the anastomotic leakage through the neck wound was effective in all of 23 patients (100%) with cervical manifestation. In patients with intrathoracic manifestation, mediastinal drainage through the neck was successful in 15 of 37 patients (41%), whereas 22 patients (59%) required an intervention through the thoracic cavity. Compared to patients with leakage confined to the neck, patients with intrathoracic manifestation showed prolonged intensive care unit (ICU) stay (median 6 vs. 2 days, respectively; P = 0.001), hospital stay (median 34 vs. 19 days, respectively; P manifestation of cervical anastomotic leakage occurs in more than half of patients with anastomotic leakage after transthoracic esophagectomy for cancer. A SIRS reaction should raise the suspicion of intrathoracic spread of leakage. Intrathoracic manifestation can be managed effectively by mediastinal drainage through the

  9. Uncertainty quantification and risk analyses of CO2 leakage in heterogeneous geological formations

    Science.gov (United States)

    Hou, Z.; Murray, C. J.; Rockhold, M. L.

    2012-12-01

    A stochastic sensitivity analysis framework is adopted to evaluate the impact of spatial heterogeneity in permeability on CO2 leakage risk. The leakage is defined as the total mass of CO2 moving into the overburden through the caprock-overburden interface, in both gaseous and liquid (dissolved) phases. The entropy-based framework has the ability to quantify the uncertainty associated with the input parameters in the form of prior pdfs (probability density functions). Effective sampling of the prior pdfs enables us to fully explore the parameter space and systematically evaluate the individual and combined effects of the parameters of interest on CO2 leakage risk. The parameters that are considered in the study include: mean, variance, and horizontal to vertical spatial anisotropy ratio for caprock permeability, and those same parameters for reservoir permeability. Given the sampled spatial variogram parameters, multiple realizations of permeability fields were generated using GSLIB subroutines. For each permeability field, a numerical simulator, STOMP, (in the water-salt-CO2-energy operational mode) is used to simulate the CO2 migration within the reservoir and caprock up to 50 years after injection. Due to intensive computational demand, we run both a scalable version simulator eSTOMP and serial STOMP on various supercomputers. We then perform statistical analyses and summarize the relationships between the parameters of interest (mean/variance/anisotropy ratio of caprock and reservoir permeability) and CO2 leakage ratio. We also present the effects of those parameters on CO2 plume radius and reservoir injectivity. The statistical analysis provides a reduced order model that can be used to estimate the impact of heterogeneity on caprock leakage.

  10. Microbial leakage through the implant-abutment interface of Morse taper implants in vitro.

    Science.gov (United States)

    Aloise, João Pedro; Curcio, Ricardo; Laporta, Marcia Zorello; Rossi, Liliane; da Silva, Adriana Madeira Alvares; Rapoport, Abrão

    2010-03-01

    The aim of this study was to determine and compare the frequency of bacterial leakage of Streptococcus sanguinis biotype II along the implant-abutment interface between two systems of morse taper dental implants. Different methods of activation of the taper abutments were used: tapped-in (Bicon) and screwed-in (Ankylos). Twenty sterile assemblies were used and attached, 10 Bicon and 10 Ankylos implants, according to manufacturers' specifications. They were then totally immersed within 20 test tubes containing a sterile nutrient solution brain-heart infusion (BHI). The internal part of the 20 implants was previously inoculated with 0.1 microl of S. sanguinis II (ATCC 10557) and then connected to the respective abutments. The assemblies were incubated under anaerobic conditions for 14 days in an autoclave at 37 degrees C. They were monitored daily for solution cloudiness resultant from microbial leakage on the interface of the assemblies. For statistical analysis, the Fisher test was applied and significance was assigned at the 5% level. There was solution cloudiness, indicating the finding of bacterial growth inside two Bicon assemblies and two Ankylos assemblies 48 h after incubation. Microbial leakage was further substantiated by testing the suspension for the presence of Streptococcus sp. None of the sterility controls were contaminated. The frequency of bacterial leakage along the implant-abutment interface, with the two different morse taper implant systems, was 20% of the assemblies of each system. There were no statistical differences between them. Irrespective of which of the two morse taper implant connection systems of activation was analyzed, tapped-in (Bicon) or screwed-in (Ankylos), this in vitro experiment showed bacterial leakage along the implant-abutment interface.

  11. The Effect of the Z-Track Technique on Pain and Drug Leakage in Intramuscular Injections.

    Science.gov (United States)

    Yilmaz, Dilek; Khorshid, Leyla; Dedeoğlu, Yasemin

    The aim of this study was to investigate the effects of the Z-track technique in the administration of intramuscular diclofenac, a nonsteroidal anti-inflammatory drug, on pain and drug leakage. This is a semiexperimental and randomized controlled study. It was felt necessary to conduct this study to compare the effects on pain and drug leakage of the standard intramuscular injection method and the "Z-track technique," which is claimed to be helpful in this regard. The study was conducted in a government hospital in the Marmara region of Turkey. The research sample consisted of 60 patients, 26 female and 34 male, whose ages varied from 18 to 65 years. Sixty patients were randomly divided into 2 equal groups-the experimental group and the control group. The Z-track technique was used for intramuscular injection with the experimental group, whereas, with the control group, the standard technique of intramuscular injection was used. The patients of both groups were injected with 3-mL diclofenac sodium as prescribed by their doctor. Immediately after the procedure was finished and the needle was withdrawn, a different researcher used a 7 × 7-cm pre-prepared and sterilized standard drying paper to press on the needle entry point. The diameter of leakage was measured with a millimetric ruler and recorded on a data collection form. During this procedure, another nurse who was blind to the injection technique assessed the pain felt during the injection by means of the Visual Analog Scale. In the experimental group, mean pain severity was found to be 28.30 ± 23.0, and mean drug leakage was 6.93 ± 4.62 mm, whereas, in the control group, these values were 36.40 ± 28.40 and 10.03 ± 3.69 mm, respectively. Drug leakage was reduced when administering intramuscular diclofenac sodium by the Z technique, but pain severity was not significantly reduced.

  12. Comparison of Apical Sealing Ability of Two Phases of Gutta–Percha: A Bacterial Leakage Model

    Directory of Open Access Journals (Sweden)

    Raheleh Emami

    2016-08-01

    Full Text Available Objectives: The aim of this study was to compare apical sealing ability of alpha and beta phases of gutta-percha by means of bacterial leakage model.Materials and Methods: Fifty single-rooted human premolars were selected. The root canals were prepared with Mtwo rotary instruments up to apical #35.04. Forty teeth were randomly divided into two groups (n= 20. The root canals were obturated by alpha phase (G1 and beta phase (G2 of gutta-percha and AH26 sealer, respectively, with warm vertical compaction technique. Ten teeth served as positive (n=8 and negative (n=2 control groups. Then, the specimens were sterilized with ethylene oxide gas. Bacterial suspension of Enterococcus faecalis (E. faecalis in 0.5 McFarland concentration was prepared. All teeth were mounted in plastic vial caps containing Muller Hinton broth and then exposed to bacterial suspension of E. faecalis every three days up to 31 days. The number of days required for the contamination of the entire root canals was recorded. The data were analyzed using Mann Whitney U test.Results: There were no significant differences in bacterial leakage between the G1 and G2 groups (P>0.05. Negative controls revealed no microbial leakage; whereas positive controls showed gross microbial leakage.Conclusion: Despite better thermal conduction and adaptability of alpha phase of gutta-percha, our study revealed no significant difference in bacterial leakage between alpha and beta phases of gutta-percha in warm vertical compaction.

  13. A novel, intelligent, pressure-sensing colostomy plug for reducing fecal leakage.

    Science.gov (United States)

    Chen, Fei; Li, Zhi-Chao; Li, Qiang; Liang, Fei-Xue; Guo, Xiong-Bo; Huang, Zong-Hai

    2015-06-01

    This study aims to describe and report the effectiveness of a novel, pressure-sensing colostomy plug for reducing fecal leakage. Nine miniature Tibetan pigs, aged 6-8 months, were given colostomies and divided into three groups (n = 3 each group). A novel pressure-sensing colostomy plug was placed in each pig and set to indicate when intestinal pressures of either 5, 10, or 15 mm Hg, respectively, were reached. When the pressure thresholds were reached, the animals' bowels were examined for the presence of stool and/or stomal leakage, and the data were recorded at weeks 1, 4, and 8 after surgery. The colostomy plug calibrated to 15 mm Hg pressure demonstrated the greatest accuracy in predicting the presence of stool in the bowels of study animals, averaging >90% sensitivity. In general, the sensitivity for predicting the presence of stool did not vary significantly over time, though there was a slight increase in accuracy in the 5 mm Hg group at later time-points. The sensitivity for predicting stool in the bowel did not change significantly over time in any of the three groups. Stomal leakage was found to be inversely proportional to the pressure-sensor setting, in that the 15 mm Hg group exhibited the greatest amount of leakage. This difference, however, was found to be significant only at week 1 postsurgery. The intelligent, pressure-sensing colostomy plug was able to accurately predict the presence of stool in the bowel and maintain continence, allowing negligible leakage. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  14. Cryotherapy for massive vulvar lymphatic leakage complicated with lymphangiomas following gynecological cancer treatment.

    Science.gov (United States)

    Yanazume, Shintaro; Douzono, Haruhiko; Kubo, Hidemichi; Nagata, Tomomi; Douchi, Tsutomu; Kobayashi, Hiroaki

    2014-11-01

    Vulvar lymphatic leakage is a severe complication associated with gynecological cancer treatments. However, standard treatment strategies have not yet been determined. We encountered a rare case of a 76-year-old multiparous woman suffering from massive lymphatic fluid leakage from the entire vulva, and papules developed and were identified as lymphangiomas. A large amount of straw-colored discharge continued from all vulvar papules, which extended over the mons pubis. Nine years ago, the patient had undergone a radical hysterectomy with concurrent chemoradiation for uterine cervical cancer treatment. Her serum albumin level was 1.9 mg/dl, which was attributed to the loss of a large amount of lymph fluid due to leakage from the vulva. Her quality of life gradually decreased because of general fatigue and the need for frequent diaper exchanges every 2 h. The patient received a less-invasive treatment with cryotherapy using liquid nitrogen. She also received a multimodality treatment consisting of the intravenous administration of albumin, massage of the lower limbs and intensive rehabilitation. Cryotherapy was administered once a week for 3 months. Her discharge almost stopped and vulvar lymphangiomas decreased without any major complications. To the best of our knowledge, this is the first case report of massive lymphatic leakage complicated with vulvar lymphangiomas. Additionally, this case may represent the first successful treatment of vulva lymph leakage by cryotherapy without recurrence. Cryotherapy may have the potential to improve the quality of life as a less-invasive treatment for gynecological cancer survivors without serious complications. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Successful treatment of cervical esophageal leakage by endoscopic-vacuum assisted closure therapy.

    Science.gov (United States)

    Lenzen, Henrike; Negm, Ahmed A; Erichsen, Thomas J; Manns, Michael P; Wedemeyer, Jochen; Lankisch, Tim O

    2013-07-16

    To evaluate the efficacy and safety of endoscopic-vacuum assisted closure (E-VAC) therapy in the treatment of cervical esophageal leakage. Between May and November 2012, three male patients who developed post-operative cervical esophageal leakage were treated with E-VAC therapy. One patient had undergone surgical excision of a pharyngo-cervical liposarcoma with partial esophageal resection, and the other two patients had received surgical treatment for symptomatic Zenker's diverticulum. Following endoscopic verification of the leakage, a trimmed polyurethane sponge was fixed to the distal end of a nasogastric silicone tube and endoscopically positioned into the wound cavity, and with decreasing cavity size the sponge was positioned intraluminally to cover the leak. Continuous suction was applied, and the vacuum drainage system was changed twice a week. The initial E-VAC placement was technically successful for all three patients, and complete closure of the esophageal leak was achieved without any procedure-related complications. In all three patients, the insufficiencies were located either above or slightly below the upper esophageal sphincter. The median duration of the E-VAC drainage was 29 d (range: 19-49 d), with a median of seven sponge exchanges (range: 5-12 sponge exchanges). In addition, the E-VAC therapy reduced inflammatory markers to within normal range for all three patients. Two of the patients were immediately fitted with a percutaneous enteral gastric feeding tube with jejunal extension, and the third patient received parenteral feeding. All three patients showed normal swallow function and no evidence of stricture after completion of the E-VAC therapy. E-VAC therapy for cervical esophageal leakage was well tolerated by patients. This safe and effective procedure may significantly reduce morbidity and mortality following cervical esophageal leakage.

  16. Maximum caliber inference of nonequilibrium processes

    Science.gov (United States)

    Otten, Moritz; Stock, Gerhard

    2010-07-01

    Thirty years ago, Jaynes suggested a general theoretical approach to nonequilibrium statistical mechanics, called maximum caliber (MaxCal) [Annu. Rev. Phys. Chem. 31, 579 (1980)]. MaxCal is a variational principle for dynamics in the same spirit that maximum entropy is a variational principle for equilibrium statistical mechanics. Motivated by the success of maximum entropy inference methods for equilibrium problems, in this work the MaxCal formulation is applied to the inference of nonequilibrium processes. That is, given some time-dependent observables of a dynamical process, one constructs a model that reproduces these input data and moreover, predicts the underlying dynamics of the system. For example, the observables could be some time-resolved measurements of the folding of a protein, which are described by a few-state model of the free energy landscape of the system. MaxCal then calculates the probabilities of an ensemble of trajectories such that on average the data are reproduced. From this probability distribution, any dynamical quantity of the system can be calculated, including population probabilities, fluxes, or waiting time distributions. After briefly reviewing the formalism, the practical numerical implementation of MaxCal in the case of an inference problem is discussed. Adopting various few-state models of increasing complexity, it is demonstrated that the MaxCal principle indeed works as a practical method of inference: The scheme is fairly robust and yields correct results as long as the input data are sufficient. As the method is unbiased and general, it can deal with any kind of time dependency such as oscillatory transients and multitime decays.

  17. Maximum entropy and Bayesian methods. Proceedings.

    Science.gov (United States)

    Fougère, P. F.

    Bayesian probability theory and maximum entropy are the twin foundations of consistent inductive reasoning about the physical world. This volume contains thirty-two papers which are devoted to both foundations and applications and combine tutorial presentations and more research oriented contributions. Together these provide a state of the art account of latest developments in such diverse areas as coherent imaging, regression analysis, tomography, neural networks, plasma theory, quantum mechanics, and others. The methods described will be of great interest to mathematicians, physicists, astronomers, crystallographers, engineers and those involved in all aspects of signal processing.

  18. Conductivity maximum in a charged colloidal suspension

    Energy Technology Data Exchange (ETDEWEB)

    Bastea, S

    2009-01-27

    Molecular dynamics simulations of a charged colloidal suspension in the salt-free regime show that the system exhibits an electrical conductivity maximum as a function of colloid charge. We attribute this behavior to two main competing effects: colloid effective charge saturation due to counterion 'condensation' and diffusion slowdown due to the relaxation effect. In agreement with previous observations, we also find that the effective transported charge is larger than the one determined by the Stern layer and suggest that it corresponds to the boundary fluid layer at the surface of the colloidal particles.

  19. Maximum Probability Domains for Hubbard Models

    CERN Document Server

    Acke, Guillaume; Claeys, Pieter W; Van Raemdonck, Mario; Poelmans, Ward; Van Neck, Dimitri; Bultinck, Patrick

    2015-01-01

    The theory of Maximum Probability Domains (MPDs) is formulated for the Hubbard model in terms of projection operators and generating functions for both exact eigenstates as well as Slater determinants. A fast MPD analysis procedure is proposed, which is subsequently used to analyse numerical results for the Hubbard model. It is shown that the essential physics behind the considered Hubbard models can be exposed using MPDs. Furthermore, the MPDs appear to be in line with what is expected from Valence Bond Theory-based knowledge.

  20. Maximum power operation of interacting molecular motors

    DEFF Research Database (Denmark)

    Golubeva, Natalia; Imparato, Alberto

    2013-01-01

    , as compared to the non-interacting system, in a wide range of biologically compatible scenarios. We furthermore consider the case where the motor-motor interaction directly affects the internal chemical cycle and investigate the effect on the system dynamics and thermodynamics.......We study the mechanical and thermodynamic properties of different traffic models for kinesin which are relevant in biological and experimental contexts. We find that motor-motor interactions play a fundamental role by enhancing the thermodynamic efficiency at maximum power of the motors...

  1. On the maximum drawdown during speculative bubbles

    Science.gov (United States)

    Rotundo, Giulia; Navarra, Mauro

    2007-08-01

    A taxonomy of large financial crashes proposed in the literature locates the burst of speculative bubbles due to endogenous causes in the framework of extreme stock market crashes, defined as falls of market prices that are outlier with respect to the bulk of drawdown price movement distribution. This paper goes on deeper in the analysis providing a further characterization of the rising part of such selected bubbles through the examination of drawdown and maximum drawdown movement of indices prices. The analysis of drawdown duration is also performed and it is the core of the risk measure estimated here.

  2. The Maximum Resource Bin Packing Problem

    DEFF Research Database (Denmark)

    Boyar, J.; Epstein, L.; Favrholdt, L.M.

    2006-01-01

    Usually, for bin packing problems, we try to minimize the number of bins used or in the case of the dual bin packing problem, maximize the number or total size of accepted items. This paper presents results for the opposite problems, where we would like to maximize the number of bins used...... or minimize the number or total size of accepted items. We consider off-line and on-line variants of the problems. For the off-line variant, we require that there be an ordering of the bins, so that no item in a later bin fits in an earlier bin. We find the approximation ratios of two natural approximation...... algorithms, First-Fit-Increasing and First-Fit-Decreasing for the maximum resource variant of classical bin packing. For the on-line variant, we define maximum resource variants of classical and dual bin packing. For dual bin packing, no on-line algorithm is competitive. For classical bin packing, we find...

  3. Maximum Likelihood Analysis in the PEN Experiment

    Science.gov (United States)

    Lehman, Martin

    2013-10-01

    The experimental determination of the π+ -->e+ ν (γ) decay branching ratio currently provides the most accurate test of lepton universality. The PEN experiment at PSI, Switzerland, aims to improve the present world average experimental precision of 3 . 3 ×10-3 to 5 ×10-4 using a stopped beam approach. During runs in 2008-10, PEN has acquired over 2 ×107 πe 2 events. The experiment includes active beam detectors (degrader, mini TPC, target), central MWPC tracking with plastic scintillator hodoscopes, and a spherical pure CsI electromagnetic shower calorimeter. The final branching ratio will be calculated using a maximum likelihood analysis. This analysis assigns each event a probability for 5 processes (π+ -->e+ ν , π+ -->μ+ ν , decay-in-flight, pile-up, and hadronic events) using Monte Carlo verified probability distribution functions of our observables (energies, times, etc). A progress report on the PEN maximum likelihood analysis will be presented. Work supported by NSF grant PHY-0970013.

  4. Efficient heuristics for maximum common substructure search.

    Science.gov (United States)

    Englert, Péter; Kovács, Péter

    2015-05-26

    Maximum common substructure search is a computationally hard optimization problem with diverse applications in the field of cheminformatics, including similarity search, lead optimization, molecule alignment, and clustering. Most of these applications have strict constraints on running time, so heuristic methods are often preferred. However, the development of an algorithm that is both fast enough and accurate enough for most practical purposes is still a challenge. Moreover, in some applications, the quality of a common substructure depends not only on its size but also on various topological features of the one-to-one atom correspondence it defines. Two state-of-the-art heuristic algorithms for finding maximum common substructures have been implemented at ChemAxon Ltd., and effective heuristics have been developed to improve both their efficiency and the relevance of the atom mappings they provide. The implementations have been thoroughly evaluated and compared with existing solutions (KCOMBU and Indigo). The heuristics have been found to greatly improve the performance and applicability of the algorithms. The purpose of this paper is to introduce the applied methods and present the experimental results.

  5. Thermodynamic hardness and the maximum hardness principle

    Science.gov (United States)

    Franco-Pérez, Marco; Gázquez, José L.; Ayers, Paul W.; Vela, Alberto

    2017-08-01

    An alternative definition of hardness (called the thermodynamic hardness) within the grand canonical ensemble formalism is proposed in terms of the partial derivative of the electronic chemical potential with respect to the thermodynamic chemical potential of the reservoir, keeping the temperature and the external potential constant. This temperature dependent definition may be interpreted as a measure of the propensity of a system to go through a charge transfer process when it interacts with other species, and thus it keeps the philosophy of the original definition. When the derivative is expressed in terms of the three-state ensemble model, in the regime of low temperatures and up to temperatures of chemical interest, one finds that for zero fractional charge, the thermodynamic hardness is proportional to T-1(I -A ) , where I is the first ionization potential, A is the electron affinity, and T is the temperature. However, the thermodynamic hardness is nearly zero when the fractional charge is different from zero. Thus, through the present definition, one avoids the presence of the Dirac delta function. We show that the chemical hardness defined in this way provides meaningful and discernible information about the hardness properties of a chemical species exhibiting integer or a fractional average number of electrons, and this analysis allowed us to establish a link between the maximum possible value of the hardness here defined, with the minimum softness principle, showing that both principles are related to minimum fractional charge and maximum stability conditions.

  6. Maximum height and minimum time vertical jumping.

    Science.gov (United States)

    Domire, Zachary J; Challis, John H

    2015-08-20

    The performance criterion in maximum vertical jumping has typically been assumed to simply raise the center of mass as high as possible. In many sporting activities minimizing movement time during the jump is likely also critical to successful performance. The purpose of this study was to examine maximum height jumps performed while minimizing jump time. A direct dynamics model was used to examine squat jump performance, with dual performance criteria: maximize jump height and minimize jump time. The muscle model had activation dynamics, force-length, force-velocity properties, and a series of elastic component representing the tendon. The simulations were run in two modes. In Mode 1 the model was placed in a fixed initial position. In Mode 2 the simulation model selected the initial squat configuration as well as the sequence of muscle activations. The inclusion of time as a factor in Mode 1 simulations resulted in a small decrease in jump height and moderate time savings. The improvement in time was mostly accomplished by taking off from a less extended position. In Mode 2 simulations, more substantial time savings could be achieved by beginning the jump in a more upright posture. However, when time was weighted more heavily in these simulations, there was a more substantial reduction in jump height. Future work is needed to examine the implications for countermovement jumping and to examine the possibility of minimizing movement time as part of the control scheme even when the task is to jump maximally. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Maximum preheating in the liquid phase

    Energy Technology Data Exchange (ETDEWEB)

    1944-03-31

    This report dealt with the formation of hydrocarbons from CO or CO/sub 2/ to solve the problem of maximum preheating. Kroenig's old idea of operations with CO in the hydrogen was being tested to achieve increased temperatures in the converters. Dr. Kroenig tried to reduce the hydrogen consumption in the liquid phase when operating with oxygen-rich coals by the addition of a few percent CO to the fresh gas. This CO was supposed to compete with hydrogen for the oxygen of the coal, becoming converted to CO/sub 2/, which was stable at the relatively low temperatures of the converters. These experiments were discontinued. However, the idea of using the heat of reaction of the reaction of oxygen products with hydrogen to raise the temperature of the heater in the liquid phase was considered. It was known that the presence of even a few percent of CO in the fresh gas raised the converter temperature in the vapor phase dangerously, while the increase in the temperature of the preheater and the liquid phase converters amounted to but a few tenths of a millivolt. The reduction of CO with hydrogen was relatively slow but could be affected by catalysts. The heats of reactions for the various systems which could be utilized for heating were given. It was determined that from a standpoint of heat technology the formation of hydrocarbons from CO or CO/sub 2/ could be adapted to solve the problem of maximum preheating.

  8. Lake Basin Fetch and Maximum Length/Width

    Data.gov (United States)

    Minnesota Department of Natural Resources — Linear features representing the Fetch, Maximum Length and Maximum Width of a lake basin. Fetch, maximum length and average width are calcuated from the lake polygon...

  9. Social cost of carbon pricing of power sector CO2: accounting for leakage and other social implications from subnational policies

    Science.gov (United States)

    Bistline, John E.; Rose, Steven K.

    2018-01-01

    In environments where climate policy has partial coverage or unequal participation, carbon dioxide (CO2) emissions or economic activity may shift to locations and sectors where emissions are unregulated. This is referred to as leakage. Leakage can offset or augment emissions reductions associated with a policy, which has important environmental and economic implications. Although leakage has been studied at national levels, analysis of leakage for subnational policies is limited. This is despite greater market integration and many existing state and regional environmental regulations in the US. This study explores leakage potential, net emissions changes, and other social implications in the US energy system with regionally differentiated pricing of power sector CO2 emissions. We undertake an economic analysis using EPRI’s US-REGEN model, where power sector CO2 emissions are priced in individual US regions with a range of social cost of carbon (SCC) values. SCC estimates are being considered by policy-makers for valuing potential societal damages from CO2 emissions. In this study, we evaluate the emissions implications within the SCC pricing region, within the power sector outside the SCC region, and outside the power sector (i.e. in the rest of the energy system). Results indicate that CO2 leakage is possible within and outside the electric sector, ranging from negative 70% to over 80% in our scenarios, with primarily positive leakage outcomes. Typically ignored in policy analysis, leakage would affect CO2 reduction benefits. We also observe other potential societal effects within and across regions, such as higher electricity prices, changes in power sector investments, and overall consumption losses. Efforts to reduce leakage, such as constraining power imports into the SCC pricing region likely reduce leakage, but could also result in lower net emissions reductions, as well as larger price increases. Thus, it is important to look beyond leakage and consider a

  10. Hydraulic Limits on Maximum Plant Transpiration

    Science.gov (United States)

    Manzoni, S.; Vico, G.; Katul, G. G.; Palmroth, S.; Jackson, R. B.; Porporato, A. M.

    2011-12-01

    Photosynthesis occurs at the expense of water losses through transpiration. As a consequence of this basic carbon-water interaction at the leaf level, plant growth and ecosystem carbon exchanges are tightly coupled to transpiration. In this contribution, the hydraulic constraints that limit transpiration rates under well-watered conditions are examined across plant functional types and climates. The potential water flow through plants is proportional to both xylem hydraulic conductivity (which depends on plant carbon economy) and the difference in water potential between the soil and the atmosphere (the driving force that pulls water from the soil). Differently from previous works, we study how this potential flux changes with the amplitude of the driving force (i.e., we focus on xylem properties and not on stomatal regulation). Xylem hydraulic conductivity decreases as the driving force increases due to cavitation of the tissues. As a result of this negative feedback, more negative leaf (and xylem) water potentials would provide a stronger driving force for water transport, while at the same time limiting xylem hydraulic conductivity due to cavitation. Here, the leaf water potential value that allows an optimum balance between driving force and xylem conductivity is quantified, thus defining the maximum transpiration rate that can be sustained by the soil-to-leaf hydraulic system. To apply the proposed framework at the global scale, a novel database of xylem conductivity and cavitation vulnerability across plant types and biomes is developed. Conductivity and water potential at 50% cavitation are shown to be complementary (in particular between angiosperms and conifers), suggesting a tradeoff between transport efficiency and hydraulic safety. Plants from warmer and drier biomes tend to achieve larger maximum transpiration than plants growing in environments with lower atmospheric water demand. The predicted maximum transpiration and the corresponding leaf water

  11. Geochemical monitoring for detection of CO_{2} leakage from subsea storage sites

    Science.gov (United States)

    García-Ibáñez, Maribel I.; Omar, Abdirahman M.; Johannessen, Truls

    2017-04-01

    Carbon Capture and Storage (CCS) in subsea geological formations is a promising large-scale technology for mitigating the increases of carbon dioxide (CO2) in the atmosphere. However, detection and quantification of potential leakage of the stored CO2 remains as one of the main challenges of this technology. Geochemical monitoring of the water column is specially demanding because the leakage CO2 once in the seawater may be rapidly dispersed by dissolution, dilution and currents. In situ sensors capture CO2 leakage signal if they are deployed very close to the leakage point. For regions with vigorous mixing and/or deep water column, and for areas far away from the leakage point, a highly sensitive carbon tracer (Cseep tracer) was developed based on the back-calculation techniques used to estimate anthropogenic CO2 in the water column. Originally, the Cseep tracer was computed using accurate discrete measurements of total dissolved inorganic carbon (DIC) and total alkalinity (AT) in the Norwegian Sea to isolate the effect of natural submarine vents in the water column. In this work we assess the effect of measurement variables on the performance of the method by computing the Cseep tracer twice: first using DIC and AT, and second using partial pressure of CO2 (pCO2) and pH. The assessment was performed through the calculation of the signal to noise ratios (STNR). We found that the use of the Cseep tracer increases the STNR ten times compared to the raw measurement data, regardless of the variables used. Thus, while traditionally the pH-pCO2 pair generates the greatest uncertainties in the oceanic CO2 system, it seems that the Cseep technique is insensitive to that issue. On the contrary, the use of the pCO2-pH pair has the highest CO2 leakage detection and localization potential due to the fact that both pCO2 and pH can currently be measured at high frequency and in an autonomous mode.

  12. Maximum Profit Configurations of Commercial Engines

    Directory of Open Access Journals (Sweden)

    Yiran Chen

    2011-06-01

    Full Text Available An investigation of commercial engines with finite capacity low- and high-price economic subsystems and a generalized commodity transfer law [n ∝ Δ (P m] in commodity flow processes, in which effects of the price elasticities of supply and demand are introduced, is presented in this paper. Optimal cycle configurations of commercial engines for maximum profit are obtained by applying optimal control theory. In some special cases, the eventual state—market equilibrium—is solely determined by the initial conditions and the inherent characteristics of two subsystems; while the different ways of transfer affect the model in respects of the specific forms of the paths of prices and the instantaneous commodity flow, i.e., the optimal configuration.

  13. Co-Clustering under the Maximum Norm

    Directory of Open Access Journals (Sweden)

    Laurent Bulteau

    2016-02-01

    Full Text Available Co-clustering, that is partitioning a numerical matrix into “homogeneous” submatrices, has many applications ranging from bioinformatics to election analysis. Many interesting variants of co-clustering are NP-hard. We focus on the basic variant of co-clustering where the homogeneity of a submatrix is defined in terms of minimizing the maximum distance between two entries. In this context, we spot several NP-hard, as well as a number of relevant polynomial-time solvable special cases, thus charting the border of tractability for this challenging data clustering problem. For instance, we provide polynomial-time solvability when having to partition the rows and columns into two subsets each (meaning that one obtains four submatrices. When partitioning rows and columns into three subsets each, however, we encounter NP-hardness, even for input matrices containing only values from {0, 1, 2}.

  14. Maximum Spectral Luminous Efficacy of White Light

    CERN Document Server

    Murphy, T W

    2013-01-01

    As lighting efficiency improves, it is useful to understand the theoretical limits to luminous efficacy for light that we perceive as white. Independent of the efficiency with which photons are generated, there exists a spectrally-imposed limit to the luminous efficacy of any source of photons. We find that, depending on the acceptable bandpass and---to a lesser extent---the color temperature of the light, the ideal white light source achieves a spectral luminous efficacy of 250--370 lm/W. This is consistent with previous calculations, but here we explore the maximum luminous efficacy as a function of photopic sensitivity threshold, color temperature, and color rendering index; deriving peak performance as a function of all three parameters. We also present example experimental spectra from a variety of light sources, quantifying the intrinsic efficacy of their spectral distributions.

  15. Maximum spectral luminous efficacy of white light

    Science.gov (United States)

    Murphy, Thomas W.

    2012-05-01

    As lighting efficiency improves, it is useful to understand the theoretical limits to luminous efficacy for light that we perceive as white. Independent of the efficiency with which photons are generated, there exists a spectrally imposed limit to the luminous efficacy of any source of photons. We find that, depending on the acceptable bandpass and—to a lesser extent—the color temperature of the light, the ideal white light source achieves a spectral luminous efficacy of 250-370 lm/W. This is consistent with previous calculations, but here we explore the maximum luminous efficacy as a function of photopic sensitivity threshold, color temperature, and color rendering index; deriving peak performance as a function of all three parameters. We also present example experimental spectra from a variety of light sources, quantifying the intrinsic efficacy of their spectral distributions.

  16. Maximum screening fields of superconducting multilayer structures

    Science.gov (United States)

    Gurevich, Alex

    2015-01-01

    It is shown that a multilayer comprised of alternating thin superconducting and insulating layers on a thick substrate can fully screen the applied magnetic field exceeding the superheating fields Hs of both the superconducting layers and the substrate, the maximum Meissner field is achieved at an optimum multilayer thickness. For instance, a dirty layer of thickness ˜0.1 μm at the Nb surface could increase Hs ≃ 240 mT of a clean Nb up to Hs ≃ 290 mT. Optimized multilayers of Nb3Sn, NbN, some of the iron pnictides, or alloyed Nb deposited onto the surface of the Nb resonator cavities could potentially double the rf breakdown field, pushing the peak accelerating electric fields above 100 MV/m while protecting the cavity from dendritic thermomagnetic avalanches caused by local penetration of vortices.

  17. MLDS: Maximum Likelihood Difference Scaling in R

    Directory of Open Access Journals (Sweden)

    Kenneth Knoblauch

    2008-01-01

    Full Text Available The MLDS package in the R programming language can be used to estimate perceptual scales based on the results of psychophysical experiments using the method of difference scaling. In a difference scaling experiment, observers compare two supra-threshold differences (a,b and (c,d on each trial. The approach is based on a stochastic model of how the observer decides which perceptual difference (or interval (a,b or (c,d is greater, and the parameters of the model are estimated using a maximum likelihood criterion. We also propose a method to test the model by evaluating the self-consistency of the estimated scale. The package includes an example in which an observer judges the differences in correlation between scatterplots. The example may be readily adapted to estimate perceptual scales for arbitrary physical continua.

  18. Emitter frequency refinement based on maximum likelihood

    Science.gov (United States)

    Xu, Xin; Wang, Huijuan

    2015-07-01

    Frequency estimation via signal sorting is widely recognized as one of the most practical technologies in signal processing. However, the estimated frequencies via signal sorting may be inaccurate and biased due to signal fluctuation under different emitter working modes, problems of transmitter circuit, environmental noises or certain unknown interference sources. Therefore, it has become an important issue to further analyze and refine signal frequencies after signal sorting. To address the above problem, we have brought forward an iterative frequency refinement method based on maximum likelihood. Iteratively, the initial estimated signal frequency values are refined. Experimental results indicate that the refined signal frequencies are more informative than the initial ones. As another advantage of our method, noises and interference sources could be filtered out simultaneously. The efficiency and flexibility enables our method to apply in a wide application area, i.e., communication, electronic reconnaissance and radar intelligence analysis.

  19. The Federal Administrative Maximum Penitentiary, Florence, Colorado.

    Science.gov (United States)

    Coid, J W

    2001-10-01

    Policies for the control of dangerous and disruptive prisoners in European penal institutions depend upon social regimes managed by prison staff. These contrast with certain US regimes where there is increasing use of the incapacitation approach. This paper describes an incapacitation regime developed in the US Federal Administrative Maximum Penitentiary (ADX), Florence, Colorado which is complemented by an architectural design minimizing contact between prisoners and staff. This is reported to have been highly effective in controlling violent and predatory behaviour, escapes, drug-taking, and the influence of members of criminal gangs and notorious prisoners transferred to the ADX. Despite a shift of policy from therapeutic intervention towards deterrence of problem behaviour in prisons in some European countries, such as the UK, it is unlikely that such a regime would be acceptable in Europe.

  20. Spacecraft Maximum Allowable Concentrations for Airborne Contaminants

    Science.gov (United States)

    James, John T.

    2008-01-01

    The enclosed table lists official spacecraft maximum allowable concentrations (SMACs), which are guideline values set by the NASA/JSC Toxicology Group in cooperation with the National Research Council Committee on Toxicology (NRCCOT). These values should not be used for situations other than human space flight without careful consideration of the criteria used to set each value. The SMACs take into account a number of unique factors such as the effect of space-flight stress on human physiology, the uniform good health of the astronauts, and the absence of pregnant or very young individuals. Documentation of the values is given in a 5 volume series of books entitled "Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants" published by the National Academy Press, Washington, D.C. These books can be viewed electronically at http://books.nap.edu/openbook.php?record_id=9786&page=3. Short-term (1 and 24 hour) SMACs are set to manage accidental releases aboard a spacecraft and permit risk of minor, reversible effects such as mild mucosal irritation. In contrast, the long-term SMACs are set to fully protect healthy crewmembers from adverse effects resulting from continuous exposure to specific air pollutants for up to 1000 days. Crewmembers with allergies or unusual sensitivity to trace pollutants may not be afforded complete protection, even when long-term SMACs are not exceeded. Crewmember exposures involve a mixture of contaminants, each at a specific concentration (C(sub n)). These contaminants could interact to elicit symptoms of toxicity even though individual contaminants do not exceed their respective SMACs. The air quality is considered acceptable when the toxicity index (T(sub grp)) for each toxicological group of compounds is less than 1, where T(sub grp), is calculated as follows: T(sub grp) = C(sub 1)/SMAC(sub 1) + C(sub 2/SMAC(sub 2) + ...+C(sub n)/SMAC(sub n).