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Sample records for solute leakage technique

  1. Calculation of transformers leakage reactance using electromagnetic energy technique

    International Nuclear Information System (INIS)

    Feiz, J.; Mohseni, H.; Sabet Marzooghi, S.; Naderian Jahromi, A.

    2004-01-01

    Determination of transformer leakage reactance using magnetic cores has long been an area of interest to engineers involved in the design of power and distribution transformers. This is required for predicting the performance of transformers before actual assembly of the transformers. In this paper a closed form solution technique applicable to the leakage reactance calculations for transformers is presented. An emphasis is on the development of a simple method to calculate the leakage reactance of the distribution transformers and smaller transformers. Energy technique procedure for computing the leakage reactances in distribution transformers is presented. This method is very efficient compared with the use of flux element and image technique and is also remarkably accurate. Examples of calculated leakage inductances and the short circuit impedance are given for illustration. For validation, the results are compared with the results obtained using test. This paper presents a novel technique for calculation of the leakage inductance in different parts of the transformer using the electromagnetic stored energy

  2. Time reversal technique for gas leakage detection.

    Science.gov (United States)

    Maksimov, A O; Polovinka, Yu A

    2015-04-01

    The acoustic remote sensing of subsea gas leakage traditionally uses sonars as active acoustic sensors and hydrophones picking up the sound generated by a leak as passive sensors. When gas leaks occur underwater, bubbles are produced and emit sound at frequencies intimately related to their sizes. The experimental implementation of an acoustic time-reversal mirror (TRM) is now well established in underwater acoustics. In the basic TRM experiment, a probe source emits a pulse that is received on an array of sensors, time reversed, and re-emitted. After time reversal, the resulting field focuses back at the probe position. In this study, a method for enhancing operation of the passive receiving system has been proposed by using it in the regime of TRM. Two factors, the local character of the acoustic emission signal caused by the leakage and a resonant nature of the bubble radiation at their birth, make particularly effective scattering with the conjugate wave (CW). Analytical calculations are performed for the scattering of CW wave on a single bubble when CW is formed by bubble birthing wail received on an array, time reversed, and re-emitted. The quality of leakage detection depends on the spatio-temporal distribution of ambient noise.

  3. PERFORMANCE OF LEAKAGE POWER MINIMIZATION TECHNIQUE FOR CMOS VLSI TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    T. Tharaneeswaran

    2012-06-01

    Full Text Available Leakage power of CMOS VLSI Technology is a great concern. To reduce leakage power in CMOS circuits, a Leakage Power Minimiza-tion Technique (LPMT is implemented in this paper. Leakage cur-rents are monitored and compared. The Comparator kicks the charge pump to give body voltage (Vbody. Simulations of these circuits are done using TSMC 0.35µm technology with various operating temper-atures. Current steering Digital-to-Analog Converter (CSDAC is used as test core to validate the idea. The Test core (eg.8-bit CSDAC had power consumption of 347.63 mW. LPMT circuit alone consumes power of 6.3405 mW. This technique results in reduction of leakage power of 8-bit CSDAC by 5.51mW and increases the reliability of test core. Mentor Graphics ELDO and EZ-wave are used for simulations.

  4. Developement of leakage localization technique by using acoustic signal

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y. H.; Jeon, J. H.; Seo, D. H.; Kim, K. W. [KAIST, Daejeon (Korea, Republic of)

    2010-07-15

    The objective of this research is to develop a leakage monitoring system for pipelines or valves in the secondary water system of a nuclear power plant. The system aims to detect the existence of leakage and to estimate the leak location, especially by utilizing the noise generated from the leak. It is safe, precise real-time alert system compared with the previous monitoring methods and tools such as the visual test and the thermal imaging camera. When there exists leakage in the pipeline or valves of nuclear power plant, the noise due to gas flow is radiated through leak region. That is, the secondary water system with leakage generates different noise from the system without leakage. This motivates us to measure and analyze the noise generated from the secondary water system, so as firstly to detect the existence of leakage, and secondly to estimate the leak location by using the noise source identification technique such as beamforming and acoustic holography. Especially the beamforming method models the signal from the noise source to estimate the location of source. Therefore, it is necessary to model the noise due to leakage which is dependent upon parameters. In the process of leak localization, the reflected wave due to interior walls and the measurement noise should be removed for the precise estimation. Therefore, we attempt to characterize the reflected wave and the measurement noise by modeling the interior sound field, thus to remove them and to localize the leak location with high precision

  5. 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.

  6. First principle leakage current reduction technique for CMOS devices

    CSIR Research Space (South Africa)

    Tsague, HD

    2015-12-01

    Full Text Available This paper presents a comprehensive study of leakage reduction techniques applicable to CMOS based devices. In the process, mathematical equations that model the power-performance trade-offs in CMOS logic circuits are presented. From those equations...

  7. The Technique to Prevent the Data Leakage using Covert Channels

    Directory of Open Access Journals (Sweden)

    Anna Vasilievna Arkhangelskaya

    2013-12-01

    Full Text Available The purpose of the article was to analyze technique to prevent information leakage using covert channels. The main steps are as follows: involving covert channels identification, data throughput estimation, its elimination or limitation, audit and detection. Three schemes of identification had been analyzed: shared resources methodology, covert flow tree method, message sequence diagram method. Ways of guarantee information delivery from systems with low security level to systems with high security level have been investigated.

  8. Air leakage test of reactor hall using tracer technique

    International Nuclear Information System (INIS)

    Yang Yanqiu; Yang Liang; Yang Tongzai

    2011-01-01

    The leakage ratios of three related reactor halls were tested by sulfur hexafluoride gaseous tracer technique. Moreover, the accumulation intensities of leak gas and its retention time in some important working rooms, the crossroads of corridors and anteroom of the building were detected. The results show that the air leakage ratios of the three reactor halls are (7.30±0.16) x 10 -4 , (1.88±0.12) x 10 -4 and (2.07±0.07) x 10 -4 h -1 . The leak gas accumulates in all the detected working rooms fast, and the retention time to various rooms is about 5 h. The heaviest intensities are in the clothes change rooms on the first floor. However, the retention time to the crossroads and the anteroom is about 10 h, and the accumulation intensities are much small. (authors)

  9. Leakage investigation in an underground cooling water pipeline at a thermal power station using radiotracer technique

    International Nuclear Information System (INIS)

    Khan, I.H.; Din, U.G.; Gul, S.; Farooq, M.; Qureshi, R.M.

    2004-05-01

    The objective of this study was to locate the leakage point(s) in an underground cooling water pipeline of a Thermal Power Station for pre-shutdown planning purposes. The internal diameter of the pipeline was 2240 mm with 12 mm with 12 (mild steel) wall thickness and it was buried under 1.0 meter reinforced concrete and 0.5-1.0 meter soil/sand cover. The volume flow rate of the pipeline was 29043 m/sup 3/hour at 2kg/cm/sup 2/ pressure. The linear speed of water flowing inside the pipeline was around 2 m/sec. This gave rise to a very high volume fast moving system. Radiotracer technique was used to investigate the problem under investigation. About 50 mCi of /sup 131/I radiotracer, in the form of NaI solution, was injected into the system and radiotracer evolution near suspected leakage point(s) was monitored using radiation detectors (NaI, 2 x 2 inch crystal size). Seven detectors were installed around three teeing off pipes (leakage area) inside the plant building and one at the injection point near the pump outlet. On line data acquisition system was used to acquire the radiotracer data. The leakage water was exiting from the floor just along the pipes carrying main flow of water. The time lag between the arrival, at detectors, of radiotracer flowing inside the pipeline and that present in the leakage water (outside the pipeline) was exploited to identify the position of leakage. The tracer test revealed that there was leakage at two points. The leakage at one point was small as compared at the other points. (author)

  10. 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 ...

  11. Leakage Reduction in Water Distribution Systems with Efficient Placement and Control of Pressure Reducing Valves Using Soft Computing Techniques

    Directory of Open Access Journals (Sweden)

    A. Gupta

    2017-04-01

    Full Text Available Reduction of leakages in a water distribution system (WDS is one of the major concerns of water industries. Leakages depend on pressure, hence installing pressure reducing valves (PRVs in the water network is a successful techniques for reducing leakages. Determining the number of valves, their locations, and optimal control setting are the challenges faced. This paper presents a new algorithm-based rule for determining the location of valves in a WDS having a variable demand pattern, which results in more favorable optimization of PRV localization than that caused by previous techniques. A multiobjective genetic algorithm (NSGA-II was used to determine the optimized control value of PRVs and to minimize the leakage rate in the WDS. Minimum required pressure was maintained at all nodes to avoid pressure deficiency at any node. Proposed methodology is applied in a benchmark WDS and after using PRVs, the average leakage rate was reduced by 6.05 l/s (20.64%, which is more favorable than the rate obtained with the existing techniques used for leakage control in the WDS. Compared with earlier studies, a lower number of PRVs was required for optimization, thus the proposed algorithm tends to provide a more cost-effective solution. In conclusion, the proposed algorithm leads to more favorable optimized localization and control of PRV with improved leakage reduction rate.

  12. Characterization of aqueous silver nitrate solutions for leakage tests

    Directory of Open Access Journals (Sweden)

    José Ferreira Costa

    2011-06-01

    Full Text Available OBJECTIVE: To determine the pH over a period of 168 h and the ionic silver content in various concentrations and post-preparation times of aqueous silver nitrate solutions. Also, the possible effects of these factors on microleakage test in adhesive/resin restorations in primary and permanent teeth were evaluated. MATERIAL AND METHODS: A digital pHmeter was used for measuring the pH of the solutions prepared with three types of water (purified, deionized or distilled and three brands of silver nitrate salt (Merck, Synth or Cennabras at 0, 1, 2, 24, 48, 72, 96 and 168 h after preparation, and storage in transparent or dark bottles. Ionic silver was assayed according to the post-preparation times (2, 24, 48, 72, 96, 168 h and concentrations (1, 5, 25, 50% of solutions by atomic emission spectrometry. For each sample of each condition, three readings were obtained for calculating the mean value. Class V cavities were prepared with enamel margins on primary and permanent teeth and restored with the adhesive systems OptiBond FL or OptiBond SOLO Plus SE and the composite resin Filtek Z-250. After nail polish coverage, the permanent teeth were immersed in 25% or 50% AgNO3 solution and the primary teeth in 5% or 50% AgNO3 solutions for microleakage evaluation. ANOVA and the Tukey's test were used for data analyses (α=5%. RESULTS: The mean pH of the solutions ranged from neutral to alkaline (7.9±2.2 to 11.8±0.9. Mean ionic silver content differed depending on the concentration of the solution (4.75±0.5 to 293±15.3 ppm. In the microleakage test, significant difference was only observed for the adhesive system factor (p=0.000. CONCLUSIONS: Under the tested experimental conditions and based on the obtained results, it may be concluded that the aqueous AgNO3 solutions: have neutral/alkaline pH and service life of up to 168 h; the level of ionic silver is proportional to the concentration of the solution; even at 5% concentration, the solutions were

  13. Detection of mechanical damage using the magnetic flux leakage technique

    International Nuclear Information System (INIS)

    Clapham, L.; Babbar, V.; Byrne, J.

    2007-01-01

    Since magnetism is strongly stress dependent, Magnetic Flux Leakage (MFL) inspection tools have the potential to locate and characterize mechanical damage in pipelines. However, MFL application to mechanical damage detection faces hurdles which make signal interpretation problematic: 1) the MFL signal is a superposition of geometrical and stress effects; 2) the stress distribution around a mechanically damaged region is very complex, consisting of plastic deformation and residual (elastic) stresses; 3) the effect of stress on magnetic behaviour is not well understood. This paper summarizes recent results of experimental and modeling studies of MFL signals resulting from mechanical damage. In experimental studies, mechanical damage was simulated using a tool and die press to produce dents of varying depths in plate samples. MFL measurements were made before and after selective stress-relieving heat treatments. These annealing treatments enabled the stress and geometry components of the MFL signal to be separated. In general, geometry effects scale with dent depth and tend to dominate in deep dents, while stress contribution to the MFL signals is relatively constant and is more significant for shallow dents. The influence of other parameters such as flux density and topside/bottomside inspection was also quantified. In the finite element analysis work, stress was incorporated by modifying the magnetic permeability in the residual stress regions of the modeled dent. Both stress and geometry contributions to the MFL signal were examined separately. Despite using a number of simplifying assumptions, the modeled results matched the experimental results very closely, and were used to aid in interpretation of the MFL signals. (author)

  14. Radiotracer technique for leakage detection under simulated conditions

    International Nuclear Information System (INIS)

    Yelgaonkar, V.N.; Sharma, V.K.; Tapase, A.S.

    2001-01-01

    Radiotracer techniques are often used to locate leaks in underground pipelines. An attempt was made to standardize radiotracer pulse migration in terms of minimum detectable limit. For this purpose a 6 inch diameter 1200 long steel pipe was used. Two leak rates viz. 10 litres per minute and 1 litre per minute with an accuracy of ± 10% were simulated. The experiments on this pipeline showed that this method could be used to locate a leak of the order of 1 litre per minute in a 6 inch diameter isolated underground pipeline. (author)

  15. Evaluation of inverse modeling techniques for pinpointing water leakages at building constructions

    NARCIS (Netherlands)

    Schijndel, van A.W.M.

    2015-01-01

    The location and nature of the moisture leakages are sometimes difficult to detect. Moreover, the relation between observed inside surface moisture patterns and where the moisture enters the construction is often not clear. The objective of this paper is to investigate inverse modeling techniques as

  16. 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

    2018-04-01

    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 anatomy should be considered.

  17. 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.

  18. A leakage-free resonance sparse decomposition technique for bearing fault detection in gearboxes

    Science.gov (United States)

    Osman, Shazali; Wang, Wilson

    2018-03-01

    Most of rotating machinery deficiencies are related to defects in rolling element bearings. Reliable bearing fault detection still remains a challenging task, especially for bearings in gearboxes as bearing-defect-related features are nonstationary and modulated by gear mesh vibration. A new leakage-free resonance sparse decomposition (LRSD) technique is proposed in this paper for early bearing fault detection of gearboxes. In the proposed LRSD technique, a leakage-free filter is suggested to remove strong gear mesh and shaft running signatures. A kurtosis and cosine distance measure is suggested to select appropriate redundancy r and quality factor Q. The signal residual is processed by signal sparse decomposition for highpass and lowpass resonance analysis to extract representative features for bearing fault detection. The effectiveness of the proposed technique is verified by a succession of experimental tests corresponding to different gearbox and bearing conditions.

  19. Totally percutaneous rendezvous techniques for the treatment of bile strictures and leakages.

    Science.gov (United States)

    De Robertis, Riccardo; Contro, Alberto; Zamboni, Giulia; Mansueto, Giancarlo

    2014-04-01

    Some challenging pathologic conditions of the biliary tract cannot be treated with endoscopy alone, and a combined approach with rendezvous techniques is frequently needed. Three different totally percutaneous rendezvous techniques were successfully applied in three cases. The rendezvous techniques were performed either with bilateral catheterization of bile ducts to treat a challenging type IV biliary stenosis and iatrogenic biliary damage or with biliary catheterization and percutaneous puncture of the anastomotic loop to treat a biliodigestive anastomosis failure with bile leakage. Copyright © 2014 SIR. Published by Elsevier Inc. All rights reserved.

  20. An Ice Block: A Novel Technique of Successful Prevention of Cement Leakage Using an Ice Ball

    Energy Technology Data Exchange (ETDEWEB)

    Uri, Ishaq Fahmi, E-mail: uri.isaac@gmail.com [The Royal National Orthopaedic Hospital (United Kingdom); Garnon, Julien, E-mail: juliengarnon@gmail.com; Tsoumakidou, Georgia, E-mail: georgia.tsoumakidou@chru-strasbourg.fr; Gangi, Afshin, E-mail: gangi@unistra.fr [Hôpital Universitaire de Strasbourg, Service d’Imagerie Interventionnelle (France)

    2015-04-15

    We report three cases of painful bone metastases with extraosseous invasion treated with cementoplasty and cryoablation. Due to significant cortical loss in all cases, the ice ball was used simultaneously during cementoplasty to deter potential cement leakage. This was achieved by direct application of the ice ball against the cortical surface, resulting in adequate consolidation and successful containment of the cement within the treated bones. To the authors’ knowledge, this is the first report to describe such a combined technique.

  1. A new circuit technique for reduced leakage current in Deep Submicron CMOS technologies

    Directory of Open Access Journals (Sweden)

    A. Schmitz

    2005-01-01

    Full Text Available Modern CMOS processes in the Deep Submicron regime are restricted to supply voltages below 2 volts and further to account for the transistors' field strength limitations and to reduce the power per logic gate. To maintain the high switching performance, the threshold voltage must be scaled according with the supply voltage. However, this leads to an increased subthreshold current of the transistors in standby mode (VGS=0. Another source of leakage is gate current, which becomes significant for gate oxides of 3nm and below. We propose a Self-Biasing Virtual Rails (SBVR - CMOS technique which acts like an adaptive local supply voltage in case of standby mode. Most important sources of leakage currents are reduced by this technique. Moreover, SBVR-CMOS is capable of conserving stored information in sleep mode, which is vital for memory circuits. Memories are exposed to radiation causing soft errors. This well-known problem becomes even worse in standby mode of typical SRAMs, that have low driving performance to withstand alpha particle hits. In this paper, a 16-transistor SRAM cell is proposed, which combines the advantage of extremely low leakage currents with a very high soft error stability.

  2. Percutaneous Extraction of Cement Leakage After Vertebroplasty Under CT and Fluoroscopy Guidance: A New Technique

    International Nuclear Information System (INIS)

    Amoretti, Nicolas; Huwart, Laurent

    2012-01-01

    Purpose: We report a new minimally invasive technique of extraction of cement leakage following percutaneous vertebroplasty in adults. Methods: Seven adult patients (five women, two men; mean age: 81 years) treated for vertebral compression fractures by percutaneous vertebroplasty had cement leakage into perivertebral soft tissues along the needle route. Immediately after vertebroplasty, the procedure of extraction was performed under computed tomography (CT) and fluoroscopy guidance: a Chiba needle was first inserted using the same route as the vertebroplasty until contact was obtained with the cement fragment. This needle was then used as a guide for an 11-gauge Trocar t’am (Thiebaud, France). After needle withdrawal, a 13-gauge endoscopy clamp was inserted through the cannula to extract the cement fragments. The whole procedure was performed under local anesthesia. Results: In each patient, all cement fragments were withdrawn within 10 min, without complication. Conclusions: This report suggests that this CT- and fluoroscopy-guided percutaneous technique of extraction could reduce the rate of cement leakage-related complications.

  3. Technology Solutions Case Study: Air Leakage and Air Transfer Between Garage and Living Space, Waldorf, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-11-01

    In this project, Building Science Corporation worked with production homebuilder K. Hovnanian to evaluate 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 multipoint fan pressurization tests and additional zone pressure diagnostic testing measured 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.

  4. "Rendezvous technique" for intraluminal vacuum therapy of anastomotic leakage of the jejunum.

    Science.gov (United States)

    Krajinovic, K; Reimer, S; Kudlich, T; Germer, C T; Wiegering, A

    2016-12-01

    Anastomotic leakage (AL) is one of the most common and serious complications following visceral surgery. In recent years, endoluminal vacuum therapy has dramatically changed therapeutic options for AL, but its use has been limited to areas easily accessible by endoscope. We describe the first use of endoluminal vacuum therapy in the small intestine employing a combined surgical and endoscopic "rendezvous technique" in which the surgeon assists the endoscopic placement of an endoluminal vacuum therapy sponge in the jejunum by means of a pullback string. This technique led to a completely closed AL after 27 days and 7 changes of the endosponge. The combined surgical and endoscopic rendezvous technique can be useful in cases of otherwise difficult endosponge placement.

  5. Evaluation of the Sealing Ability of Three Obturation Techniques Using a Glucose Leakage Test

    Directory of Open Access Journals (Sweden)

    Katarzyna Olczak

    2017-01-01

    Full Text Available The aim of this study was to evaluate the sealing ability of three different canal filling techniques. Sixty-four roots of extracted human maxillary anterior teeth were prepared using ProTaper® rotary instruments. The specimens were then randomly divided into 3 experimental groups (n=16 and 2 control groups (n=8. The root canals were filled using cold lateral compaction (CLC group, continuous wave condensation technique using the Elements Obturation Unit® (EOU group, and ProTaper obturators (PT group. For the negative control group, 8 roots were filled using lateral compaction as in the CLC group, and the teeth were covered twice with a layer of nail varnish (NCG group. Another 8 roots were filled using lateral compaction, but without sealer, and these were used as the positive control (PCG group. A glucose leakage model was used for quantitative evaluation of microleakage for 24 hours and 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12 weeks. No significant difference in the cumulative amount of leakage was found between the three experimental groups at all observation times. The lateral condensation of cold gutta-percha can guarantee a similar seal of canal fillings as can be achieved by using thermal methods, in the round canals.

  6. Performance of evaluation techniques for planning preventive repair of leakages on BWR vessel stub tubes

    International Nuclear Information System (INIS)

    Prat, J.P.

    1985-01-01

    Stub tubes have been installed on the control rod drive assemblies of the majority of boiling water reactor vessel bottoms. These stub tubes can undergo a slow process of cracking, producing no potential hazard but occasional plant unavailability due to leakage in excess of specification limits. In the case considered here, the development and application of remotely controlled equipment permitting access both from inside and outside the housing, and of crack evolution and location techniques, has made the progressive development, selection and planning of repairs a possibility, thus minimizing the risk of leakages appearing between refuelling outages. The example used here is of a Nuclear Power Plant in which a first leak appeared in 1981. Since that time extensive and progressive laboratory and field development work has been carried out. This paper presents the experience gained with customized, remote-control inspection equipment, and several developed or adapted techniques, as the basis for an in-service repair decision tree, the case in question being that of a BWR plant in which a cracking process, not affecting safety but potentially affecting availability, has given rise to leaks after ten years of operation

  7. Membrane damage and solute leakage from germinating pea seed under cadmium stress

    Energy Technology Data Exchange (ETDEWEB)

    Rahoui, Sondes, E-mail: rahoui.sondes@yahoo.fr [Bio-Physiologie Cellulaires, Departement des Sciences de la Vie, Faculte des Sciences de Bizerte, 7021 Zarzouna (Tunisia); Chaoui, Abdelilah, E-mail: cabdelilah1@yahoo.fr [Bio-Physiologie Cellulaires, Departement des Sciences de la Vie, Faculte des Sciences de Bizerte, 7021 Zarzouna (Tunisia); El Ferjani, Ezzeddine, E-mail: ezzferjani2002@yahoo.fr [Bio-Physiologie Cellulaires, Departement des Sciences de la Vie, Faculte des Sciences de Bizerte, 7021 Zarzouna (Tunisia)

    2010-06-15

    Seed germination represents a limiting stage of plant life cycle under heavy metal stress situation. Delay in germination can be associated with disorders in the event chain of germinative metabolism which is a highly complex multistage process, but one of underlying metabolic activities following imbibition of seed is the storage mobilization. The influence of cadmium on carbohydrates and aminoacids export from cotyledon to embryonic axis during germination of pea seed was investigated. Compared to the control, Cd caused a restriction in reserve mobilization as evidenced by the pronounced increase in cotyledon/embryo ratios of total soluble sugars, glucose, fructose and aminoacids. Moreover, the nutrient concentrations, as well as the electrical conductivity of germination medium were determined to quantify the extent of solute leakage. Such nutrients were lost into the imbibition medium at the expense of suitable mobilization to the growing embryonic axis. This was concomitant with an over-accumulation of lipid peroxidation products in Cd-poisoned embryonic tissues. However, the impairment of membrane integrity cannot be due to a stimulation in lipoxygenase activity, since the later was markedly inhibited after Cd exposure.

  8. Membrane damage and solute leakage from germinating pea seed under cadmium stress

    International Nuclear Information System (INIS)

    Rahoui, Sondes; Chaoui, Abdelilah; El Ferjani, Ezzeddine

    2010-01-01

    Seed germination represents a limiting stage of plant life cycle under heavy metal stress situation. Delay in germination can be associated with disorders in the event chain of germinative metabolism which is a highly complex multistage process, but one of underlying metabolic activities following imbibition of seed is the storage mobilization. The influence of cadmium on carbohydrates and aminoacids export from cotyledon to embryonic axis during germination of pea seed was investigated. Compared to the control, Cd caused a restriction in reserve mobilization as evidenced by the pronounced increase in cotyledon/embryo ratios of total soluble sugars, glucose, fructose and aminoacids. Moreover, the nutrient concentrations, as well as the electrical conductivity of germination medium were determined to quantify the extent of solute leakage. Such nutrients were lost into the imbibition medium at the expense of suitable mobilization to the growing embryonic axis. This was concomitant with an over-accumulation of lipid peroxidation products in Cd-poisoned embryonic tissues. However, the impairment of membrane integrity cannot be due to a stimulation in lipoxygenase activity, since the later was markedly inhibited after Cd exposure.

  9. In situ solution mining technique

    International Nuclear Information System (INIS)

    Learmont, R.P.

    1978-01-01

    A method of in situ solution mining is disclosed in which a primary leaching process employing an array of 5-spot leaching patterns of production and injection wells is converted to a different pattern by converting to injection wells all the production wells in alternate rows

  10. Space Vector Modulation Technique to Reduce Leakage Current of a Transformerless Three-Phase Four-Leg Photovoltaic System

    Directory of Open Access Journals (Sweden)

    F. Hasanzad

    2017-06-01

    Full Text Available Photovoltaic systems integrated to the grid have received considerable attention around the world. They can be connected to the electrical grid via galvanic isolation (transformer or without it (transformerless. Despite making galvanic isolation, low frequency transformer increases size, cost and losses. On the other hand, transformerless PV systems increase the leakage current (common-mode current, (CMC through the parasitic capacitors of the PV array. Inverter topology and switching technique are the most important parameters the leakage current depends on. As there is no need to extra hardware for switching scheme modification, it's an economical method for reducing leakage current. This paper evaluates the effect of different space vector modulation techniques on leakage current for a two-level three-phase four-leg inverter used in PV system. It proposes an efficient space vector modulation method which decreases the leakage current to below the quantity specified in VDE-0126-1-1 standard. furthermore, some other characteristics of the space vector modulation schemes that have not been significantly discussed for four-leg inverter, are considered, such as, modulation index, switching actions per period, common-mode voltage (CMV, and total harmonic distortion (THD. An extend software simulation using MATLAB/Simulink is performed to verify the effectiveness of the modulation technique.

  11. Motor current and leakage flux signature analysis technique for condition monitoring

    International Nuclear Information System (INIS)

    Pillai, M.V.; Moorthy, R.I.K.; Mahajan, S.C.

    1994-01-01

    Till recently analysis of vibration signals was the only means available to predict the state of health of plant equipment. Motor current and leakage magnetic flux signature analysis is acquiring importance as a technique for detection of incipient damages in the electrical machines and as a supplementary technique for diagnostics of driven equipment such as centrifugal and reciprocating pumps. The state of health of the driven equipment is assessed by analysing time signal, frequency spectrum and trend analysis. For example, the pump vane frequency, piston stroke frequency, gear frequency and bearing frequencies are indicated in the current and flux spectra. By maintaining a periodic record of the amplitudes of various frequency lines in the frequency spectra, it is possible to understand the trend of deterioration of parts and components of the pump. All problems arising out of inappropriate mechanical alignment of vertical pumps are easily identified by a combined analysis of current, flux and vibration signals. It is found that current signature analysis technique is a sufficient method in itself for the analysis of state of health of reciprocating pumps and compressors. (author). 10 refs., 4 figs

  12. 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

  13. Endoscopic endonasal skull base surgery: advantages, limitations, and our techniques to overcome cerebrospinal fluid leakage: technical note.

    Science.gov (United States)

    Ishii, Yudo; Tahara, Shigeyuki; Teramoto, Akira; Morita, Akio

    2014-01-01

    In recent years, resections of midline skull base tumors have been conducted using endoscopic endonasal skull base (EESB) approaches. Nevertheless, many surgeons reported that cerebrospinal fluid (CSF) leakage is still a major complication of these approaches. Here, we report the results of our 42 EESB surgeries and discuss the advantages and limits of this approach for resecting various types of tumors, and also report our technique to overcome CSF leakage. All 42 cases involved midline skull base tumors resected using the EESB technique. Dural incisions were closed using nasoseptal flaps and fascia patch inlay sutures. Total removal of the tumor was accomplished in seven pituitary adenomas (33.3%), five craniopharyngiomas (62.5%), five tuberculum sellae meningiomas (83.3%), three clival chordomas (100%), and one suprasellar ependymoma. Residual regions included the cavernous sinus, the outside of the intracranial part of the internal carotid artery, the lower lateral part of the posterior clivus, and the posterior pituitary stalk. Overall incidence of CSF leakage was 7.1%. Even though the versatility of the approach is limited, EESB surgery has many advantages compared to the transcranial approach for managing mid-line skull base lesions. To avoid CSF leakage, surgeons should have skills and techniques for complete closure, including use of the nasoseptal flap and fascia patch inlay techniques.

  14. Model-based monitoring techniques for leakage localization in distribution water networks

    OpenAIRE

    Meseguer Amela, Jordi; Mirats Tur, Josep Maria; Cembrano Gennari, Gabriela; Puig Cayuela, Vicenç

    2015-01-01

    This is an open access article under the CC BY-NC-ND license This paper describes an integrated model-based monitoring framework for leakage localization in district-metered areas (DMA) of water distribution networks, which takes advantage of the availability of a hydraulic model of the network. The leakage localization methodology is based on the use of flow and pressure sensors at the DMA inlets and a limited number of pressure sensors deployed inside the DMA. The placement of these sens...

  15. High Tc superconductors using solution techniques

    International Nuclear Information System (INIS)

    Barboux, P.; Valente, I.; Henry, M.; Morineau, R.; Tarascon, J.M.; Khan, S.; Shokoohi, F.; Bagley, B.G.

    1989-01-01

    The authors have investigated different solution techniques to synthesize the Cu-based superconductors in the thick film form. Thick films of YBa 2 Cu 3 O 7 have been produced using controlled precipitation techniques. Bi-based and Tl-based materials have been deposited by spraying of ionic solutions. The numerous difficulties encountered during each process are analyzed in order to propose new synthesis procedures such as a new method, based on the precipitation of hydroxides only, which is described as a prospective for lowering the synthesis temperature and shortening the reaction time

  16. clay nanocomposite by solution intercalation technique

    Indian Academy of Sciences (India)

    Polymer–clay nanocomposites of commercial polystyrene (PS) and clay laponite were prepared via solution intercalation technique. Laponite was modified suitably with the well known cationic surfactant cetyltrimethyl ammonium bromide by ion-exchange reaction to render laponite miscible with hydrophobic PS.

  17. Application of Electrical Resistivity Tomography Technique for Characterizing Leakage Problem in Abu Baara Earth Dam, Syria

    Directory of Open Access Journals (Sweden)

    Walid Al-Fares

    2014-01-01

    Full Text Available Electrical Resistivity Tomography (ERT survey was carried out at Abu Baara earth dam in northwestern Syria, in order to delineate potential pathways of leakage occurring through the subsurface structure close to the dam body. The survey was performed along two straight measuring profiles of 715 and 430 m length in up- and downstream sides of the dam’s embankment. The analysis of the inverted ERT sections revealed the presence of fractured and karstified limestone rocks which constitute the shallow bedrock of the dam reservoir. Several subsurface structural anomalies were identified within the fractured bedrock, most of which are associated with probable karstic cavities, voids, and discontinuity features developed within the carbonates rocks. Moreover, results also showed the occurrence of a distinguished subsiding structure coinciding with main valley course. Accordingly, it is believed that the bedrock and the other detected features are the main potential causes of water leakage from the dam’s reservoir.

  18. Data leakage quantification

    NARCIS (Netherlands)

    Vavilis, S.; Petkovic, M.; Zannone, N.; Atluri, V.; Pernul, G.

    2014-01-01

    The detection and handling of data leakages is becoming a critical issue for organizations. To this end, data leakage solutions are usually employed by organizations to monitor network traffic and the use of portable storage devices. These solutions often produce a large number of alerts, whose

  19. Rendezvous technique treatment for late-onset biliary leakage after major hepatectomy of a living donor: report of a case.

    Science.gov (United States)

    Kimura, Koichi; Ikegami, Toru; Yamashita, Yo-ichi; Saeki, Hiroshi; Oki, Eiji; Yoshizumi, Tomoharu; Uchiyama, Hideaki; Kawanaka, Hirofumi; Soejima, Yuji; Morita, Masaru; Shirabe, Ken; Ikeda, Tetsuo; Maehara, Yoshihiko

    2013-09-01

    Biliary leakage is a major complication after hepatectomy. We report the case of a living-donor liver transplantation (LDLT) donor with a late-onset bile leak from the trifurcation of the hepatic duct who was successfully treated using rendezvous technique. A 52-year-old man underwent extended left hepatectomy for donation and was discharged on postoperative day (PD) 13. However, he was rehospitalized on PD 26 with severe abdominal pain. Physical examination suggested panperitonitis, and abdominocentesis showed bilious ascites. Emergent laparotomy for biliary leakage and peritonitis was performed. There was bilious ascites in the peritoneal cavity. A biliary fistula was recognized at the trifurcation of B8a, B8b, and B5. Intraoperative transhepatic biliary drainage of each bile duct was performed. Endoscopic transpapillary drainage was performed on PD 24. Finally, external drains were removed and complete internal drainage established on PD 70. The bile leak was considered to be the result of injury from electrocautery device. Appropriate making choices of the electrocautery devices enable us to avoid over thermal injury of the liver surface. Rendezvous bidirectional drainage effectively treated late-onset bile leakage from the trifurcation of a hepatic bile duct.

  20. Solution chemistry techniques in SYNROC preparation

    International Nuclear Information System (INIS)

    Dosch, R.G.; Lynch, A.W.

    1981-07-01

    Investigations of titanate-based ceramic forms for radioactive waste immobilization are underway at Sandia National Laboratories (SNLA) and at Lawrence Livermore National Laboratory (LLNL). Although the waste forms differ as to overall product composition, the waste-containing phases in both ceramic products have similar crystalline structure types. These include metallic phases along with oxides with structure types of the mineral analogues perovskite, zirconolite, and hollandite. Significant differences also exist in the area of processing. More conventional ceramic processing methods are used at LLNL to produce SYNROC while solution chemistry techniques involving metal alkoxide chemistry and ion exchange have been developed at SNLA to prepare calcium titanate-based waste ceramics. The SNLA techniques were recently modified and applied to producing SYNROC (compositions C and D) as part of an interlaboratory information exchange between SNLA and LLNL. This report describes the methods used in preparing SYNROC including the solution interaction, and hot-pressing methods used to obtain fully dense SYNROC monoliths

  1. Cerebrospinal fluid leakage. Indications, technique and results of treatment with a blood patch

    International Nuclear Information System (INIS)

    Gottschalk, A.

    2015-01-01

    In most cases cerebrospinal fluid (CSF) leaks are iatrogenic and caused by medical interventions, such as lumbar puncture, peridural anesthesia and surgical interventions on the spine, However, spontaneous cerebral hypotension is currently detected more frequently due to improvements in diagnostic possibilities but often the cause cannot be clarified with certainty. There are various diagnostic tools for confirming the diagnosis and searching for the site of CSF leakage, such as postmyelography computed tomography (postmyelo-CT), indium 111 radioisotope cisternography and (myelo) magnetic resonance imaging (MRI), which show different sensitivities. In accordance with own experience native MRI with fat-saturated T2-weighted sequences is often sufficient for diagnosing CSF leakage and the site. For the remaining cases an additional postmyelo-CT or alternatively myelo-MRI is recommended. In some patients with spontaneous cranial hypotension multiple CSF leaks are found at different spinal levels. The main symptom in most cases is an orthostatic headache. While post-puncture syndrome is self-limiting in many cases, spontaneous CSF leakage usually requires blood patch therapy. A lumbar blood patch can be safely carried out under guidance by fluoroscopy. In the case of a cervical or dorsal blood patch, CT guidance is recommended, which ensures epidural application of the blood patch and minimizes the risk of damaging the spinal cord. Despite a high success rate at the first attempt with a blood patch of up to 85 %, some cases require repeating the blood patch. A targeted blood patch of a CSF leak should generally be favoured over a blindly placed blood patch; nevertheless, if a CSF leak cannot be localized by CT or MRI a therapeutic attempt with a lumbar blood patch can be carried out. After a successful blood patch intracranial hygromas and pachymeningeal enhancement in the head show fast regression; however, epidural hygromas of the spine can persist for a period of

  2. Effects of Repeated Screw Tightening on Implant Abutment Interfaces in Terms of Bacterial and Yeast Leakage in Vitro: One-Time Abutment Versus the Multiscrewing Technique.

    Science.gov (United States)

    Calcaterra, Roberta; Di Girolamo, Michele; Mirisola, Concetta; Baggi, Luigi

    2016-01-01

    Screw loosening can damage the interfaces of implant components, resulting in susceptibility to contamination of the internal parts by microorganisms. The aim of this study was to investigate the impact of abutment screw retightening on the leakage of two different types of bacteria, Streptococcus sanguinis and Fusobacterium nucleatum, and of the yeast Candida albicans. Two types of implant-abutment systems with tube-in-tube interfaces were tested. Groups A and B each used a different type of system that consisted of 20 different pieces that were assembled according to the manufacturer's torque recommendations; four samples in each group were closed just one time, four samples three times, four samples five times, four samples seven times, and four samples nine times. The implants of groups A and B were contaminated with 0.1 μL of microbial solution just before being assembled for the last time to minimize the possibility of contamination. Results showed a direct correlation between the number of colony-forming units grown in the plates and the closing/opening cycles of the implant-abutment systems. Within the limitations of this study, the results indicate the possibility that repeated closing/opening cycles of the implant-abutment unit may influence bacterial/yeast leakage, most likely as a consequence of decreased precision of the coupling between the abutment and the internal part of the dental implant. These findings suggest that a one-time abutment technique may avoid microbiologic leakage in cases of implant-abutment systems with tube-in-tube interfaces.

  3. Long-distance fiber optic sensing solutions for pipeline leakage, intrusion, and ground movement detection

    Science.gov (United States)

    Nikles, Marc

    2009-05-01

    An increasing number of pipelines are constructed in remote regions affected by harsh environmental conditions where pipeline routes often cross mountain areas which are characterized by unstable grounds and where soil texture changes between winter and summer increase the probability of hazards. Third party intentional interference or accidental intrusions are a major cause of pipeline failures leading to large leaks or even explosions. Due to the long distances to be monitored and the linear nature of pipelines, distributed fiber optic sensing techniques offer significant advantages and the capability to detect and localize pipeline disturbance with great precision. Furthermore pipeline owner/operators lay fiber optic cable parallel to transmission pipelines for telecommunication purposes and at minimum additional cost monitoring capabilities can be added to the communication system. The Brillouin-based Omnisens DITEST monitoring system has been used in several long distance pipeline projects. The technique is capable of measuring strain and temperature over 100's kilometers with meter spatial resolution. Dedicated fiber optic cables have been developed for continuous strain and temperature monitoring and their deployment along the pipeline has enabled permanent and continuous pipeline ground movement, intrusion and leak detection. This paper presents a description of the fiber optic Brillouin-based DITEST sensing technique, its measurement performance and limits, while addressing future perspectives for pipeline monitoring. The description is supported by case studies and illustrated by field data.

  4. Indocyanine green staining facilitates detection of bleb leakage during trabeculectomy.

    Science.gov (United States)

    Okazaki, Teruhiko; Kiuchi, Takahiro; Kawana, Keisuke; Oshika, Tetsuro

    2007-03-01

    To report a new technique to visualize bleb leakage using indocyanine green (ICG) staining during trabeculectomy. The ICG solution was widely applied over the filtering bleb including the conjunctival wound before completion of trabeculectomy. This procedure was performed in 48 eyes of 44 consecutive patients undergoing trabeculectomy between December 2004 and October 2005. Without staining, bleb leakage was not identified by the direct observation under the operating microscope. ICG staining clearly visualized aqueous leakage from the bleb in 5 eyes (10.4%). The bleb leakage in these eyes was easily repaired with 10-0 nylon sutures, and no eyes, including these 5 cases, showed bleb leakage after surgery. There were no intraoperative and postoperative complications related to ICG application. The application of ICG during trabeculectomy is a simple and useful technique to facilitate detection and repair of the bleb leakage.

  5. Quantification of Wellbore Leakage Risk Using Non-destructive Borehole Logging Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Duguid, Andrew; Butsch, Robert; Cary, J.; Celia, Michael; Chugunov, Nikita; Gasda, Sarah; Hovorka, Susan; Ramakrishnan, T. S.; Stamp, Vicki; Thingelstad, Rebecca; Wang, James

    2014-08-29

    Well integrity is important at all potential CCS locations and may play a crucial role establishing leakage risk in areas where there is a high density of existing wells that could be impacted by the storage operations including depleted petroleum fields where EOR or CCS will occur. To address a need for risk quantification methods that can be directly applied to individual wells using borehole logging tools a study was conducted using data from five wells in Wyoming. The objectives of the study were: Objective 1: Develop methods to establish the baseline flow parameters (porosity and permeability or mobility) from individual measurements of the material properties and defects in a well. Objective 2: Develop a correlation between field flow-property data and cement logs that can be used to establish the flow-properties of well materials and well features using cement mapping tools. Objective 3: Establish a method that uses the flow-property model (Objective 2) to analyze the statistical uncertainties associated with individual well leakage that can provide basis for uncertainty in risk calculations. The project objectives were met through the logging of five wells in Carbon and Natrona County Wyoming to collect data that was used to estimate individual and average well flow properties and model the results using ultrasonic data collected during the logging. Three of the five wells provided data on point and average flow properties for well annuli. Data from the other two wells were used to create models of cement permeability and test whether information collected in one well could be used to characterize another well. The results of the in-situ point measurements were confirmed by the lab measurements sidewall cores collected near the same depths Objective 1 was met using the data collected through logging, testing, and sampling. The methods were developed that can establish baseline flow parameters of wells by both point and average test methods. The methods to

  6. Preoperative, intraoperative and postoperative risk factors for anastomotic leakage after laparoscopic low anterior resection with double stapling technique anastomosis.

    Science.gov (United States)

    Kawada, Kenji; Sakai, Yoshiharu

    2016-07-07

    Anastomotic leakage (AL) is one of the most devastating complications after rectal cancer surgery. The double stapling technique has greatly facilitated intestinal reconstruction especially for anastomosis after low anterior resection (LAR). Risk factor analyses for AL after open LAR have been widely reported. However, a few studies have analyzed the risk factors for AL after laparoscopic LAR. Laparoscopic rectal surgery provides an excellent operative field in a narrow pelvic space, and enables total mesorectal excision surgery and preservation of the autonomic nervous system with greater precision. However, rectal transection using a laparoscopic linear stapler is relatively difficult compared with open surgery because of the width and limited performance of the linear stapler. Moreover, laparoscopic LAR exhibits a different postoperative course compared with open LAR, which suggests that the risk factors for AL after laparoscopic LAR may also differ from those after open LAR. In this review, we will discuss the risk factors for AL after laparoscopic LAR.

  7. Theoretical investigation of metal magnetic memory testing technique for detection of magnetic flux leakage signals from buried defect

    Science.gov (United States)

    Xu, Kunshan; Qiu, Xingqi; Tian, Xiaoshuai

    2018-01-01

    The metal magnetic memory testing (MMMT) technique has been extensively applied in various fields because of its unique advantages of easy operation, low cost and high efficiency. However, very limited theoretical research has been conducted on application of MMMT to buried defects. To promote study in this area, the equivalent magnetic charge method is employed to establish a self-magnetic flux leakage (SMFL) model of a buried defect. Theoretical results based on the established model successfully capture basic characteristics of the SMFL signals of buried defects, as confirmed via experiment. In particular, the newly developed model can calculate the buried depth of a defect based on the SMFL signals obtained via testing. The results show that the new model can successfully assess the characteristics of buried defects, which is valuable in the application of MMMT in non-destructive testing.

  8. Detection of concrete dam leakage using an integrated geophysical technique based on flow-field fitting method

    Science.gov (United States)

    Dai, Qianwei; Lin, Fangpeng; Wang, Xiaoping; Feng, Deshan; Bayless, Richard C.

    2017-05-01

    An integrated geophysical investigation was performed at S dam located at Dadu basin in China to assess the condition of the dam curtain. The key methodology of the integrated technique used was flow-field fitting method, which allowed identification of the hydraulic connections between the dam foundation and surface water sources (upstream and downstream), and location of the anomalous leakage outlets in the dam foundation. Limitations of the flow-field fitting method were complemented with resistivity logging to identify the internal erosion which had not yet developed into seepage pathways. The results of the flow-field fitting method and resistivity logging were consistent when compared with data provided by seismic tomography, borehole television, water injection test, and rock quality designation.

  9. Use of isotopes and geophysical techniques in studying dam leakage-case of the Afamia dams Syria

    International Nuclear Information System (INIS)

    Kattan, Z.; Naser, R.; Al-Fares, W.; Kadkoy, N.; Sbenati, M.R.; Al-Hilal, M.; Sleman, I.; Al-Ali, A.

    2011-08-01

    Different techniques such as: hydrochemistry, environmental isotopes, radon and geophysical surveys have been applied all together in investigating the water leakages from the Afamia (A, B and C) dams during the period 2006-2008. Groundwater movement in this area shows the existence of two major discharge cones or sinks in the vicinity of B and C reservoirs. This movement suggests a probable vertical leaking and interconnection between the shallow Neogene aquifer and the deeper Karstified water bearing system of the Upper Cretaceous. Spatial distribution patterns of major ions in the groundwater provided comprehensive arguments for the existence of an active dissolution zone of calcareous rocks at a depth of about 45 m below the land surface, facilitating hence the vertical penetration of stored surface water towards the Cretaceous aquifer. The remarkable contrasts in stable isotope compositions between the depleted and highly enriched waters nearby the B reservoir provide another support for water leaks by vertical penetration beneath or very close to the B dam body. The high radon values in the soils, linearly distributed along some tectonic lineaments, may indicate the usefulness of radon method for tracing and mapping unknown faults. Application of some selected geophysical methods (electromagnetic survey, vertical geoelectric sounding and tomography plates) revealed the presence of alternating lithological heterogeneity between permeable and impermeable layers, which may lead to subhorizontal infiltration through the geological formations of the basin. Vertical leakage which could take place in certain locations via existing faults and karst and fractures that hit the main valley may pass through the dam lake. This structure is most likely causing hydraulic connections between the superficial Neogene deposits and the underlying Cretaceous fractured and permeable carbonates rocks. The presence of clayey and silty zones, mostly of high electrical conductivity

  10. Leakage current minimisation and power reduction techniques using sub-threshold design

    CSIR Research Space (South Africa)

    Tsague, HD

    2015-11-01

    Full Text Available Low power IC solutions are in great demand with the rapid advancement of handheld devices, wearables, smart cards and radio frequency identification bringing a massive amount of new products to market that all have the same primary need: Powering...

  11. Feasibility of a tracer gas technique for containment leakage characterization at Bruce NGS

    International Nuclear Information System (INIS)

    Singh, V.P.

    1985-11-01

    Methods for tracer gas test have been conceived and are proposed for use in conjunction with other techniques used during off-power pressurization tests. During pressurization tests is appears possible to quantify leaks through containment boundaries which make up one of the walls in adjacent rooms but quantification of leaks to open areas will require further development. Several gases may be used as tracers during pressurization tests but the preferred tracer gas is sulphur hexafluoride (SF 6 ) at an in-vault concentration of 100 μL/L if open area sampling is to be carried out of 10 μL/L if only closed room sampling is to be performed. Large values of the ratio (tracer gas concentration in containment/lower detection limit) are necessary for identification of leak sites in open areas having significant ventilation flow. It is recommended that in-station trials be carried out to test the validity of this technique. In addition, a tracer gas technique for use during on-power operation is also proposed but leak site identification and quantification during on-power tests is only possible for containment boundaries which make up the wall(s) of adjacent rooms. The use of SF 6 is required for tests conducted during on-power operation. The recommended in-vault concentration is 10 μL/L. Recommendations are made for future work, including leak tests during on-power operation

  12. In-vitro comparison of micro-leakage between nanocomposite and microhybrid composite in class v cavities treated with the self-etch technique

    International Nuclear Information System (INIS)

    Mahvish, S.; Khan, F.R.

    2016-01-01

    Background: When a light cure composite resin is used to restore a class V lesion, certain stresses are generated at the tooth-restoration interface. If these stresses exceed the bond strength of the restorative material, microscopic gaps are formed which eventually cause micro-leakage at the tooth-restoration interface. The objective of the present study was to compare the micro-leakage values at the tooth-restoration interface using dye penetration method between a Nano filled and a Micro hybrid light cured composite resin in class V cavities using the self-etch technique. Methods: Sixty class V cavities were made coronal to the cemento-enamel junction in the extracted premolars. These were then randomly divided into two study groups. Group A: Self-etch; filled with P-60 (micro-hybrid) n=30. Group B: Self-etch; filled with Z-350 (nano-filled) n=30. Specimens were subjected to thermo-cycling at 5-55 degree C ± 2 degree C with a 30 seconds dwell time. After which they were stained with 2% methylene blue. Later, sectioned bucco-lingually and examined using a stereo microscope (magnification X4) at the occlusal, axial and gingival surfaces. Micro-leakage around the tooth-restoration interface was assessed by using the degree of dye penetration in millimetres. Results: There was 100% micro leakage seen at both the occlusal and gingival surfaces when using the P-60 composite. With the Z-350 composite 84% occlusal and 88% of the gingival surfaces exhibited micro-leakage. Conclusions: With respect to micro-leakage in class V cavities, Z-350 was found to be a superior restorative material compared to P-60 on the occlusal surface. Overall, there is no statistically significant difference in the micro-leakage exhibited by the two restorative materials in class V preparations subjected to self-etch protocol. (author)

  13. Study of leakages at dam sites in fractured rocks with the aid of the borehole dilution technique

    International Nuclear Information System (INIS)

    Ozbek, E.

    1978-02-01

    The connection between springs which occurred after the impoundment of Keban Lake and the lake was proved by tritium measurements. By additional application of single borehole techniques using radioisotopes as tracers it was possible to localize solution channels in the karstic aquifer as preferential paths for the water movement

  14. Integration of geotechnical and geophysical techniques for the characterization of a small earth-filled canal dyke and the localization of water leakage

    Science.gov (United States)

    Bièvre, Grégory; Lacroix, Pascal; Oxarango, Laurent; Goutaland, David; Monnot, Guy; Fargier, Yannick

    2017-04-01

    This paper investigates the combined use of extensive geotechnical, hydrogeological and geophysical techniques to assess a small earth dyke with a permanent hydraulic head, namely a canal embankment. The experimental site was chosen because of known issues regarding internal erosion and piping phenomena. Two leakages were visually located following the emptying of the canal prior to remediation works. The results showed a good agreement between the geophysical imaging techniques (Electrical Resistivity Tomography, P- and SH-waves Tomography) and the geotechnical data to detect the depth to the bedrock and its lateral variations. It appeared that surface waves might not be fully adapted for dyke investigation because of the particular geometry of the studied dyke, non-respectful of the 1D assumption, and which induced depth and velocity discrepancies retrieved from Rayleigh and Love waves inversion. The use of these classical prospecting techniques however did not allow to directly locate the two leakages within the studied earth dyke. The analysis of ambient vibration time series with a modified beam-forming algorithm allowed to localize the most energetic water flow prior to remediation works. It was not possible to detect the leakage after remediation works, suggesting that they efficiently contributed to significantly reduce the water flow. The second leakage was not detected probably because of a non-turbulent water flow, generating few energetic vibrations.

  15. Evaluation of the Repeatability of the Delta Q Duct Leakage Testing TechniqueIncluding Investigation of Robust Analysis Techniques and Estimates of Weather Induced Uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Dickerhoff, Darryl; Walker, Iain

    2008-08-01

    The DeltaQ test is a method of estimating the air leakage from forced air duct systems. Developed primarily for residential and small commercial applications it uses the changes in blower door test results due to forced air system operation. Previous studies established the principles behind DeltaQ testing, but raised issues of precision of the test, particularly for leaky homes on windy days. Details of the measurement technique are available in an ASTM Standard (ASTM E1554-2007). In order to ease adoption of the test method, this study answers questions regarding the uncertainty due to changing weather during the test (particularly changes in wind speed) and the applicability to low leakage systems. The first question arises because the building envelope air flows and pressures used in the DeltaQ test are influenced by weather induced pressures. Variability in wind induced pressures rather than temperature difference induced pressures dominates this effect because the wind pressures change rapidly over the time period of a test. The second question needs to answered so that DeltaQ testing can be used in programs requiring or giving credit for tight ducts (e.g., California's Building Energy Code (CEC 2005)). DeltaQ modeling biases have been previously investigated in laboratory studies where there was no weather induced changes in envelope flows and pressures. Laboratory work by Andrews (2002) and Walker et al. (2004) found biases of about 0.5% of forced air system blower flow and individual test uncertainty of about 2% of forced air system blower flow. The laboratory tests were repeated by Walker and Dickerhoff (2006 and 2008) using a new ramping technique that continuously varied envelope pressures and air flows rather than taking data at pre-selected pressure stations (as used in ASTM E1554-2003 and other previous studies). The biases and individual test uncertainties for ramping were found to be very close (less than 0.5% of air handler flow) to those

  16. Innovative health solutions using nuclear techniques

    International Nuclear Information System (INIS)

    Bailey, Dale

    2013-01-01

    Australian nuclear medicine is currently amongst the highest standard of anywhere in the world. Its origins here are firmly entrenched in Internal Medicine, with its emphasis on physiology and function, unlike many other countries such as the USA where a Radiology orientation dominates. In addition, Australia has been well served by extremely competent and innovative physical scientists working in universities, government research facilities (e.g., AAEC, ANSTO) and tertiary referral hospitals who have established their main affiliations as being within the highly multidisciplinary nuclear medicine community. Nuclear medicine in the past 10-15 years has experienced a massive shift towards 'hybrid' imaging - where two (or more) complementary imaging modalities, such as X-ray CT and a Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) scanner, are combined into a functionally single device which provides high resolution spatial anatomical (form, or structure) and radionuclide distribution (function) images. In addition, the nuclear imaging techniques maintain their quantitative characteristics and thus combined structure-function imaging results in a significant improvement in diagnostic capability - looking beyond simple forms to quantifying degree of disease, e.g., malignancy of a cancer. Recently, PET scanners have been combined with NMR Imaging (MRI) and these will provide new areas of application, especially in magnetic resonance spectroscopy and radionuclide imaging. The techniques are extremely valuable in monitoring response to treatment, allowing treatments to be changed if proving ineffective. In addition, new techniques are emerging using radionuclides for therapy, combined with the improvements in imaging. This permits exquisite targeting and optimal patient selection. This talk will highlight a number of these achievements and ask the question as to what is holding back developments in Australia at present.

  17. Pickering unit 1 containment leakage characterization

    International Nuclear Information System (INIS)

    Zakaib, G.D.

    1994-01-01

    Results of the design pressure test carried out on Pickering Reactor Building number 1 during late 1992 showed that the leakage rate of the building was close to the safety analysis value of 2.7% contained mass per hour at the design pressure of 41.4 kPa(g) and was significantly higher than that reported after the previous test conducted in the spring of 1987. This unexpected finding initiated the longest and the most comprehensive containment leakage investigation ever undertaken by Ontario Hydro. A thorough investigation of leakage behaviour by repeated testing, inspections, leak search and analysis was launched. The extensive leak search effort included items such as: leak source detection by soap solution application, use of ultrasonic detectors, fogging and tracer gas techniques, systematic systems isolation, thermal imaging of the exterior, and quantification of leak sites by flowmeter and bagging. Using a specially designed volumetric technique, the root cause of the problem was finally confirmed as being due to 'pressure dependent laminar leakage' through the hairline cracks in the dome concrete. Structural analysis indicated that the thermal gradients and pressure loading combined to cause the cracking early in the structure's operating history and that overall structural integrity has not been compromised. Leakage rate analysis using a new fluid mechanics model augmented by the effect of thermal strains indicated that the leakage could be significantly less under certain transient temperature gradient conditions. Several options for repairing the dome were considered by a multidisciplinary team and it was finally decided to apply a specially engineered multilayer elastomeric coating to the exterior concrete surface. When the unit was re-tested in October 1993, a dramatic ten-fold improvement in leakage rate (down to 0.25%/h at design pressure) was observed. This is lower than even the commissioning results and comparable to the performance of newer units

  18. A PD-SOI based DTI-LOCOS combined cross isolation technique for minimizing TID radiation induced leakage in high density memory

    International Nuclear Information System (INIS)

    Qiao Fengying; Pan Liyang; Wu Dong; Liu Lifang; Xu Jun

    2014-01-01

    In order to minimize leakage current increase under total ionizing dose (TID) radiation in high density memory circuits, a new isolation technique, combining deep trench isolation (DTI) between the wells, local oxidation of silicon (LOCOS) isolation between the devices within the well, and a P-diffused area in order to limit leakage at the isolation edge is implemented in partly-depleted silicon-on-insulator (PD-SOI) technology. This radiation hardening technique can minimize the layout area by more than 60%, and allows flexible placement of the body contact. Radiation hardened transistors and 256 Kb flash memory chips are designed and fabricated in a 0.6 μm PD-SOI process. Experiments show that no obvious increase in leakage current is observed for single transistors under 1 Mrad(Si) radiation, and that the 256 Kb memory chip still functions well after a TID of 100 krad(Si), with only 50% increase of the active power consumption in read mode. (semiconductor devices)

  19. An improved technique for oral administration of solutions of test ...

    African Journals Online (AJOL)

    Medicut intravenous cannula as an improvised oral cannula to administer solutions of drugs and test substances to experimental rats. Techniques of handling and manipulating the rat with the goal of having the eosophagus as straight as possible ...

  20. Stress-induced leakage current characteristics of PMOS fabricated by a new multi-deposition multi-annealing technique with full gate last process

    International Nuclear Information System (INIS)

    Wang Yanrong; Yang Hong; Xu Hao; Luo Weichun; Qi Luwei; Zhang Shuxiang; Wang Wenwu; Zhu Huilong; Zhao Chao; Chen Dapeng; Ye Tianchun; Yan Jiang

    2017-01-01

    In the process of high- k films fabrication, a novel multi deposition multi annealing (MDMA) technique is introduced to replace simple post deposition annealing. The leakage current decreases with the increase of the post deposition annealing (PDA) times. The equivalent oxide thickness (EOT) decreases when the annealing time(s) change from 1 to 2. Furthermore, the characteristics of SILC (stress-induced leakage current) for an ultra-thin SiO 2 /HfO 2 gate dielectric stack are studied systematically. The increase of the PDA time(s) from 1 to 2 can decrease the defect and defect generation rate in the HK layer. However, increasing the PDA times to 4 and 7 may introduce too much oxygen, therefore the type of oxygen vacancy changes. (paper)

  1. Effect of gamma radiation on the leakage of substances from lymphocytes. In vitro study using immuno-precipitation techniques in gel medium

    International Nuclear Information System (INIS)

    Dubos, M.; Nguyen, T.-L.; Drouet, J.; Goujon, P.

    In vitro effect of a 5000 R irradiation on rat blood lymphocytes was studied during several days in surviving cell suspensions, at various incubation temperature. Immunochemical analysis in agarose gel, using the simple diffusion technique, exhibited the leakage of two groups of antigenic compounds, from lymphocytes. The first group compounds seemed to be periodical renewal products of surface cell membrane elements, common to lymphocytes and erythrocytes; irradiation increased their release. A correlation was established between the second group compounds and cell metabolism and these compounds seemed to be enzymes of cytolitic origin [fr

  2. Comparison of CT characteristics of extravertebral cement leakages after vertebroplasty performed by different navigation and injection techniques

    International Nuclear Information System (INIS)

    Kaso, G.; Horvath, Z.; Doczi, T.; Szenohradszky, K.; Sandor, J.

    2008-01-01

    This study was intended to assess the results of post-operative CT scans in three groups of patients following percutaneous vertebroplasty (VP) using different navigation and injection methods, in an attempt to explain the radiological characteristics of extravertebral cement leakage with relation to needle placement and focused on the ventral epidural accumulation of bone cement. Furthermore, we have suggested a morphological (and functional) classification of the types of cement leakage. Between July 2001 and February 2005, 123 percutaneous VP procedures were performed during 75 sessions in 65 patients for treatment of painful osteoporotic vertebral body compression fractures. These included: group 1: 28 patients, 33 sessions; 50 right sided unilateral VP under fluoroscopic control with central position of the tip of the needle within the bone marrow. Group 2: 27 patients, 28 sessions; 50 bilateral VP under fluoroscopic control with separate cement injections into both 'hemivertebrae'. Group 3: 14 patients, 14 sessions; 23 bilateral VP navigated by frameless stereotaxy (neuronavigation). Needles were positioned strictly into the lateral thirds of the vertebral bodies. Leakages were classified as epidural, foraminal, intradiscal, venous paravertebral, compact extravertebral on the post-operative CT scans, and their frequency was compared in relation to the navigation method and the position of the tip of the needle. Group 1: extravertebral cement was detected in 23 patients (82 %), and in 35 (70 %) of the 50 vertebrae treated (ventral epidural: 23 vertebrae = 46 %; intradiscal: 12 vertebrae = 24 %; venous paravertebral: 8 vertebrae = 16 %; intraforaminal: 7 vertebrae = 14 %; and compact extravertebral: 3 vertebrae = 6 %). Group 2: extravertebral cement was detected in 20 patients (74 %), and in 38 (76 %) of the 50 vertebrae treated (ventral epidural: 12 vertebrae = 24 %; intradiscal: 12 vertebrae = 24 %; venous paravertebral: 9 vertebrae = 18 %; and foraminal: 1

  3. Solution-Processed Small-Molecule Bulk Heterojunctions: Leakage Currents and the Dewetting Issue for Inverted Solar Cells.

    Science.gov (United States)

    Destouesse, Elodie; Chambon, Sylvain; Courtel, Stéphanie; Hirsch, Lionel; Wantz, Guillaume

    2015-11-11

    In organic photovoltaic (PV) devices based on solution-processed small molecules, we report here that the physicochemical properties of the substrate are critical for achieving high-performances organic solar cells. Three different substrates were tested: ITO coated with PSS, ZnO sol-gel, and ZnO nanoparticles. PV performances are found to be low when the ZnO nanoparticles layer is used. This performance loss is attributed to the formation of many dewetting points in the active layer, because of a relatively high roughness of the ZnO nanoparticles layer, compared to the other layers. We successfully circumvented this phenomenon by adding a small quantity of polystyrene (PS) in the active layer. The introduction of PS improves the quality of film forming and reduces the dark currents of solar cells. Using this method, high-efficiency devices were achieved, even in the case of substrates with higher roughness.

  4. On Probability Leakage

    OpenAIRE

    Briggs, William M.

    2012-01-01

    The probability leakage of model M with respect to evidence E is defined. Probability leakage is a kind of model error. It occurs when M implies that events $y$, which are impossible given E, have positive probability. Leakage does not imply model falsification. Models with probability leakage cannot be calibrated empirically. Regression models, which are ubiquitous in statistical practice, often evince probability leakage.

  5. Leakage radiation interference microscopy.

    Science.gov (United States)

    Descrovi, Emiliano; Barakat, Elsie; Angelini, Angelo; Munzert, Peter; De Leo, Natascia; Boarino, Luca; Giorgis, Fabrizio; Herzig, Hans Peter

    2013-09-01

    We present a proof of principle for a new imaging technique combining leakage radiation microscopy with high-resolution interference microscopy. By using oil immersion optics it is demonstrated that amplitude and phase can be retrieved from optical fields, which are evanescent in air. This technique is illustratively applied for mapping a surface mode propagating onto a planar dielectric multilayer on a thin glass substrate. The surface mode propagation constant estimated after Fourier transformation of the measured complex field is well matched with an independent measurement based on back focal plane imaging.

  6. Photometric estimation of plutonium in product solutions and acid waste solutions using flow injection analysis technique

    International Nuclear Information System (INIS)

    Dhas, A.J.A.; Dharmapurikar, G.R.; Kumaraguru, K.; Vijayan, K.; Kapoor, S.C.; Ramanujam, A.

    1995-01-01

    Flow injection analysis technique is employed for the measurement of plutonium concentrations in product nitrate solutions by measuring the absorbance of Pu(III) at 565 nm and of Pu(IV) at 470 nm, using a Metrohm 662 photometer, with a pyrex glass tube of 2 nm (ID) inserted in the light path of the detector serving as a flow cell. The photometer detector never comes in contact with radioactive solution. In the case of acid waste solutions Pu is first purified by extraction chromatography with 2-ethyl hexyl hydrogen 2 ethyl hexyl phosphonate (KSM 17)- chromosorb and the Pu in the eluate in complexed with Arsenazo III followed by the measured of absorbance at 665 nm. Absorbance of reference solutions in the desired concentration ranges are measured to calibrate the system. The results obtained agree with the reference values within ±2.0%. (author). 3 refs., 1 tab

  7. Usefulness of the 'Rendezvous' Technique in Living Related Right Liver Donors with Postoperative Biliary Leakage from Bile Duct Anastomosis

    International Nuclear Information System (INIS)

    Miraglia, R.; Traina, M.; Maruzzelli, L.; Caruso, S.; Di Pisa, M.; Gruttadauria, S.; Luca, A.; Gridelli, B.

    2008-01-01

    This is a report on two cases of large bile leak following right hepatectomy performed for living related liver transplantation, originating from the stump of the ligated right bile duct, and treated with the placement of large percutaneous biliary catheters through a combined percutaneous transhepatic and endoscopic approach (rendezvous technique).

  8. Pneumoperitoneum Caused by Air Leakage Through the Percutaneous Puncture Tract as a Complication of Rendezvous Technique: A Case Report

    Directory of Open Access Journals (Sweden)

    Chiao-Hsiung Chuang

    2008-11-01

    Full Text Available The rendezvous technique, combining percutaneous and endoscopic procedures, is a safe and effective method to achieve biliary cannulation if an endoscopic approach fails. The two procedures in this technique can be carried out simultaneously or in stages. A simultaneous approach is reported to be associated with fewer complications, and patients undergoing this approach can recover and be discharged more rapidly. Here, we report a complication of pneumoperitoneum in a patient who underwent percutaneous and endoscopic procedures simultaneously for the removal of a common bile duct stone. It was supposed that prolonged air insufflation during endoscopy forced intestinal air to track into the peritoneal cavity through the bile ducts and the puncture tract. Accordingly, a short wait before removing the percutaneous catheter to deflate the intestinal air will be helpful to avoid such a complication.

  9. Marginal Leakage of Class V Composite Resin Restorations

    Directory of Open Access Journals (Sweden)

    Maryam Khoroushi

    2018-01-01

    Full Text Available >Introduction: Marginal leakage is one of the significant causes of restoration failure. This in-vitro study was conducted to compare cone beam computed tomography (CBCT and dye-penetration methods for determining marginal leakage at gingival surface of class V resin composite restorations.Materials and Methods: Class V cavities were prepared on the buccal surfaces of nineteen caries-free extracted human molar teeth. Cavities were conditioned and filled. The teeth were immersed in a 50% w/w aqueous silver nitrate solution for 24 h and were taken out and rinsed with distilled water. Then, they were put into a developing solution. Whole specimens were first viewed with CBCT and were then sectioned and evaluated by stereomicroscope.Results: Measurement of agreement between CBCT and stereomicroscope revealed that 15 (78.9% teeth had score 0, 1 (5.3% tooth had score 1, and 1 (5.3% tooth had score 2 in both techniques. Measurement of agreement between CBCT and stereomicroscope techniques, in the detection of marginal leakage, was 89.5% (Kappa coefficient = 0.627, P = 0.00. The Wilcoxon paired rank test revealed no significant difference between the results of CBCT and stereomicroscope in measuring the leakage at gingival margin (P = 0.157.Conclusion: Considering the limitations of the study, there was no significant difference between the results of CBCT and stereomicroscope in measuring the leakage at gingival margin of class V composite restorations. CBCT can be used noninvasively to detect the marginal leakage of gingival wall of class V composite restorations using aqueous silver nitrate solution as a tracer.

  10. Obesity prevention: Comparison of techniques and potential solution

    Science.gov (United States)

    Zulkepli, Jafri; Abidin, Norhaslinda Zainal; Zaibidi, Nerda Zura

    2014-12-01

    Over the years, obesity prevention has been a broadly studied subject by both academicians and practitioners. It is one of the most serious public health issue as it can cause numerous chronic health and psychosocial problems. Research is needed to suggest a population-based strategy for obesity prevention. In the academic environment, the importance of obesity prevention has triggered various problem solving approaches. A good obesity prevention model, should comprehend and cater all complex and dynamics issues. Hence, the main purpose of this paper is to discuss the qualitative and quantitative approaches on obesity prevention study and to provide an extensive literature review on various recent modelling techniques for obesity prevention. Based on these literatures, the comparison of both quantitative and qualitative approahes are highlighted and the justification on the used of system dynamics technique to solve the population of obesity is discussed. Lastly, a potential framework solution based on system dynamics modelling is proposed.

  11. HPAT: A nondestructive analysis technique for plutonium and uranium solutions

    International Nuclear Information System (INIS)

    Aparo, M.; Mattia, B.; Zeppa, P.; Pagliai, V.; Frazzoli, F.V.

    1989-03-01

    Two experimental approaches for the nondestructive characterization of mixed solutions of plutonium and uranium, developed at BNEA - C.R.E. Casaccia, with the goal of measuring low plutonium concentration (<50 g/l) even in presence of high uranium content, are described in the following. Both methods are referred to as HPAT (Hybrid Passive-Active Technique) since they rely on the measurement of plutonium spontaneous emission in the LX-rays energy region as well as the transmission of KX photons from the fluorescence induced by a radioisotopic source on a suitable target. Experimental campaigns for the characterization of both techniques have been carried out at EUREX Plant Laboratories (C.R.E. Saluggia) and at Plutonium Plant Laboratories (C.R.E. Casaccia). Experimental results and theoretical value of the errors are reported. (author)

  12. Nanoscale Ferroelectric Switchable Polarization and Leakage Current Behavior in (Ba0.50Sr0.50(Ti0.80Sn0.20O3 Thin Films Prepared Using Chemical Solution Deposition

    Directory of Open Access Journals (Sweden)

    Venkata Sreenivas Puli

    2015-01-01

    Full Text Available Nanoscale switchable ferroelectric (Ba0.50Sr0.50(Ti0.80Sn0.20O3-BSTS polycrystalline thin films with a perovskite structure were prepared on Pt/TiOx/SiO2/Si substrate by chemical solution deposition. X-ray diffraction (XRD spectra indicate that a cubic perovskite crystalline structure and Raman spectra revealed that a tetragonal perovskite crystalline structure is present in the thin films. Sr2+ and Sn4+ cosubstituted film exhibited the lowest leakage current density. Piezoresponse Force Microscopy (PFM technique has been employed to acquire out-of-plane (OPP piezoresponse images and local piezoelectric hysteresis loop in polycrystalline BSTS films. PFM phase and amplitude images reveal nanoscale ferroelectric switching behavior at room temperature. Square patterns with dark and bright contrasts were written by local poling and reversible nature of the piezoresponse behavior was established. Local piezoelectric butterfly amplitude and phase hysteresis loops display ferroelectric nature at nanoscale level. The significance of this paper is to present ferroelectric/piezoelectric nature in present BSTS films at nanoscale level and corroborating ferroelectric behavior by utilizing Raman spectroscopy. Thus, further optimizing physical and electrical properties, BSTS films might be useful for practical applications which include nonvolatile ferroelectric memories, data-storage media, piezoelectric actuators, and electric energy storage capacitors.

  13. Inner volume leakage during integrated leakage rate testing

    International Nuclear Information System (INIS)

    Glover, J.P.

    1987-01-01

    During an integrated leak rate test (ILRT), the containment structure is maintained at test pressure with most penetrations isolated. Since penetrations typically employ dual isolation, the possibility exists for the inner isolation to leak while the outer holds. In this case, the ILRT instrumentation system would indicate containment out-leakage when, in fact, only the inner volume between closures is being pressurized. The problem is compounded because this false leakage is not readily observable outside of containment by standard leak inspection techniques. The inner volume leakage eventually subsides after the affected volumes reach test pressure. Depending on the magnitude of leakage and the size of the volumes, equalization could occur prior to the end of the pretest stabilization period, or significant false leakages may persist throughout the entire test. Two simple analyses were performed to quantify the effects of inside volume leakages. First, a lower bound for the equalization time was found. A second analysis was performed to find an approximate upper bound for the stabilization time. The results of both analyses are shown

  14. Solution of the fully fuzzy linear systems using iterative techniques

    International Nuclear Information System (INIS)

    Dehghan, Mehdi; Hashemi, Behnam; Ghatee, Mehdi

    2007-01-01

    This paper mainly intends to discuss the iterative solution of fully fuzzy linear systems which we call FFLS. We employ Dubois and Prade's approximate arithmetic operators on LR fuzzy numbers for finding a positive fuzzy vector x-tilde which satisfies A-tildex-tilde=b, where A-tilde and b-tilde are a fuzzy matrix and a fuzzy vector, respectively. Please note that the positivity assumption is not so restrictive in applied problems. We transform FFLS and propose iterative techniques such as Richardson, Jacobi, Jacobi overrelaxation (JOR), Gauss-Seidel, successive overrelaxation (SOR), accelerated overrelaxation (AOR), symmetric and unsymmetric SOR (SSOR and USSOR) and extrapolated modified Aitken (EMA) for solving FFLS. In addition, the methods of Newton, quasi-Newton and conjugate gradient are proposed from nonlinear programming for solving a fully fuzzy linear system. Various numerical examples are also given to show the efficiency of the proposed schemes

  15. Improved parallel solution techniques for the integral transport matrix method

    Energy Technology Data Exchange (ETDEWEB)

    Zerr, R. Joseph, E-mail: rjz116@psu.edu [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA (United States); Azmy, Yousry Y., E-mail: yyazmy@ncsu.edu [Department of Nuclear Engineering, North Carolina State University, Burlington Engineering Laboratories, Raleigh, NC (United States)

    2011-07-01

    Alternative solution strategies to the parallel block Jacobi (PBJ) method for the solution of the global problem with the integral transport matrix method operators have been designed and tested. The most straightforward improvement to the Jacobi iterative method is the Gauss-Seidel alternative. The parallel red-black Gauss-Seidel (PGS) algorithm can improve on the number of iterations and reduce work per iteration by applying an alternating red-black color-set to the subdomains and assigning multiple sub-domains per processor. A parallel GMRES(m) method was implemented as an alternative to stationary iterations. Computational results show that the PGS method can improve on the PBJ method execution time by up to 10´ when eight sub-domains per processor are used. However, compared to traditional source iterations with diffusion synthetic acceleration, it is still approximately an order of magnitude slower. The best-performing cases are optically thick because sub-domains decouple, yielding faster convergence. Further tests revealed that 64 sub-domains per processor was the best performing level of sub-domain division. An acceleration technique that improves the convergence rate would greatly improve the ITMM. The GMRES(m) method with a diagonal block pre conditioner consumes approximately the same time as the PBJ solver but could be improved by an as yet undeveloped, more efficient pre conditioner. (author)

  16. Improved parallel solution techniques for the integral transport matrix method

    International Nuclear Information System (INIS)

    Zerr, R. Joseph; Azmy, Yousry Y.

    2011-01-01

    Alternative solution strategies to the parallel block Jacobi (PBJ) method for the solution of the global problem with the integral transport matrix method operators have been designed and tested. The most straightforward improvement to the Jacobi iterative method is the Gauss-Seidel alternative. The parallel red-black Gauss-Seidel (PGS) algorithm can improve on the number of iterations and reduce work per iteration by applying an alternating red-black color-set to the subdomains and assigning multiple sub-domains per processor. A parallel GMRES(m) method was implemented as an alternative to stationary iterations. Computational results show that the PGS method can improve on the PBJ method execution time by up to 10´ when eight sub-domains per processor are used. However, compared to traditional source iterations with diffusion synthetic acceleration, it is still approximately an order of magnitude slower. The best-performing cases are optically thick because sub-domains decouple, yielding faster convergence. Further tests revealed that 64 sub-domains per processor was the best performing level of sub-domain division. An acceleration technique that improves the convergence rate would greatly improve the ITMM. The GMRES(m) method with a diagonal block pre conditioner consumes approximately the same time as the PBJ solver but could be improved by an as yet undeveloped, more efficient pre conditioner. (author)

  17. A Study on the Leakage Characteristic Evaluation of High Temperature and Pressure Pipeline at Nuclear Power Plants Using the Acoustic Emission Technique

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Hoon; Kim, Jin Hyun; Song, Bong Min; Lee, Joon Hyun; Cho, Youn Ho [Pusan National University, Busan (Korea, Republic of)

    2009-10-15

    An acoustic leak monitoring system(ALMS) using acoustic emission(AE) technique was applied for leakage detection of nuclear power plant's pipeline which is operated in high temperature and pressure condition. Since this system only monitors the existence of leak using the root mean square(RMS) value of raw signal from AE sensor, the difficulty occurs when the characteristics of leak size and shape need to be evaluated. In this study, dual monitoring system using AE sensor and accelerometer was introduced in order to solve this problem. In addition, artificial neural network(ANN) with Levenberg Marquardt(LM) training algorithm was also applied due to rapid training rate and gave the reliable classification performance. The input parameters of this ANN were extracted from varying signal received from experimental conditions such as the fluid pressure inside pipe, the shape and size of the leak area. Additional experiments were also carried out and with different objective which is to study the generation and characteristic of lamb and surface wave according to the pipe thickness

  18. A Study on the Leakage Characteristic Evaluation of High Temperature and Pressure Pipeline at Nuclear Power Plants Using the Acoustic Emission Technique

    International Nuclear Information System (INIS)

    Kim, Young Hoon; Kim, Jin Hyun; Song, Bong Min; Lee, Joon Hyun; Cho, Youn Ho

    2009-01-01

    An acoustic leak monitoring system(ALMS) using acoustic emission(AE) technique was applied for leakage detection of nuclear power plant's pipeline which is operated in high temperature and pressure condition. Since this system only monitors the existence of leak using the root mean square(RMS) value of raw signal from AE sensor, the difficulty occurs when the characteristics of leak size and shape need to be evaluated. In this study, dual monitoring system using AE sensor and accelerometer was introduced in order to solve this problem. In addition, artificial neural network(ANN) with Levenberg Marquardt(LM) training algorithm was also applied due to rapid training rate and gave the reliable classification performance. The input parameters of this ANN were extracted from varying signal received from experimental conditions such as the fluid pressure inside pipe, the shape and size of the leak area. Additional experiments were also carried out and with different objective which is to study the generation and characteristic of lamb and surface wave according to the pipe thickness

  19. Solidification of radioactive waste solutions by pelletization technique

    International Nuclear Information System (INIS)

    Akbar, A.H.; Koester, R.; Rudolph, G.

    1980-04-01

    A possible way of performing the cement fixation of radioactive wastes is the incorporation into cement pellets on a pan pelletizer, followed by embedding the pellets into an inactive cement matrix. This procedure is suitable for various types of waste, particularly for medium level liquid wastes, and can be used both at drum disposal and at in-situ solidification. This report describes some initial studies on the pelletization technique using a laboratory pelletizer. Formation and size of the pellets have been found to be determined by speed, angle, and load of the pan, ratio and mode of addition of the liquid and solid components, ect. Pellets in various compositions have been produced from cement and water or simulated waste solution, in some cases with the addition of bentonite for improving cesium retention. Some mechanical properties of the pellets such as fall height of fresh pellets, development of hardness (crush test), impact and abrasion resistance, have been determined. Some preliminary experiments were done on backfilling the void space between the pellets - about 40 per cent of the bulk volume - with cement grouts of appropriate compositions. (orig.) [de

  20. The Leakage Current Improvement of a Ni-Silicided SiGe/Si Junction Using a Si Cap Layer and the PAI Technique

    International Nuclear Information System (INIS)

    Chang Jian-Guang; Wu Chun-Bo; Ji Xiao-Li; Ma Hao-Wen; Yan Feng; Shi Yi; Zhang Rong

    2012-01-01

    We investigate the leakage current of ultra-shallow Ni-silicided SiGe/Si junctions for 45 nm CMOS technology using a Si cap layer and the pre-amorphization implantation (PAI) process. It is found that with the conventional Ni silicide method, the leakage current of a p + (SiGe)—n(Si) junction is large and attributed to band-to-band tunneling and the generation-recombination process. The two leakage contributors can be suppressed quite effectively when a Si cap layer is added in the Ni silicide method. The leakage reduction is about one order of magnitude and could be associated with the suppression of the agglomeration of the Ni germano-silicide film. In addition, the PAI process after the application of a Si cap layer has little effect on improving the junction leakage but reduces the sheet resistance of the silicide film. As a result, the novel Ni silicide method using a Si cap combined with PAI is a promising choice for SiGe junctions in advanced technology. (cross-disciplinary physics and related areas of science and technology)

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

    International Nuclear Information System (INIS)

    Veselov, D. A.; 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.

    2016-01-01

    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. 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).

  3. Signal attenuation due to cavity leakage

    International Nuclear Information System (INIS)

    Sherman, M.H.; Modera, M.P.

    1988-01-01

    The propagation of sound waves in fluids requires information about three properties of the system: capacitance (compressibility), resistance (friction), and inductance (inertia). Acoustical design techniques to date have tended to ignore the frictional effects associated with airflow across the envelope of the acoustic cavity (e.g., resistive vents). Since such leakage through the cavity envelope is best expressed with a power law dependence on the pressure, standard Fourier techniques that rely on linearity cannot be used. In this article, the theory relevant to nonlinear leakage is developed and equations presented. Potential applications of the theory to techniques for quantifying the leakage of buildings are presented. Experimental results from pressure decays in a full-scale test structure are presented and the leakage so measured is compared with independent measurements to demonstrate the technique

  4. Novel precipitation technique for uranium recovery from carbonate leach solutions

    International Nuclear Information System (INIS)

    Sujoy Biswas; Rupawate, V.H.; Hareendran, K.N.; Roy, S.B.; Chakravartty, J.K.

    2015-01-01

    The recovery of uranium from carbonate ore leach solution was studied using novel precipitation method. The uranium from leach liquor was recovered as magnesium diuranate with NaOH in presence of trace amount of Mg 2+ . Effects of various parameters such as addition of H 2 SO 4 , MgO, MgSO 4 as well as NaOH were investigated for maximum uranium recovery. Overall uranium recovery of the process was 97 % with improved particle size (∼57 µm). Based on the experimental findings, a process flow-sheet was developed for uranium recovery from carbonate ore leach solution with a uranium concentration of <1 g/L. (author)

  5. Chemical solution deposition techniques for epitaxial growth of complex oxides

    NARCIS (Netherlands)

    ten Elshof, Johan E.; Koster, G.; Huijben, Mark; Rijnders, G.

    2015-01-01

    The chemical solution deposition (CSD) process is a wet-chemical process that is employed to fabricate a wide variety of amorphous and crystalline oxide thin films. This chapter describes the typical steps in a CSD process and their influence on the final microstructure and properties of films, and

  6. Land-use Leakage

    Energy Technology Data Exchange (ETDEWEB)

    Calvin, Katherine V.; Edmonds, James A.; Clarke, Leon E.; Bond-Lamberty, Benjamin; Kim, Son H.; Wise, Marshall A.; Thomson, Allison M.; Kyle, G. Page

    2009-12-01

    Leakage occurs whenever actions to mitigate greenhouse gas emissions in one part of the world unleash countervailing forces elsewhere in the world so that reductions in global emissions are less than emissions mitigation in the mitigating region. While many researchers have examined the concept of industrial leakage, land-use policies can also result in leakage. We show that land-use leakage is potentially as large as or larger than industrial leakage. We identify two potential land-use leakage drivers, land-use policies and bioenergy. We distinguish between these two pathways and run numerical experiments for each. We also show that the land-use policy environment exerts a powerful influence on leakage and that under some policy designs leakage can be negative. International “offsets” are a potential mechanism to communicate emissions mitigation beyond the borders of emissions mitigating regions, but in a stabilization regime designed to limit radiative forcing to 3.7 2/m2, this also implies greater emissions mitigation commitments on the part of mitigating regions.

  7. Modeling valve leakage

    International Nuclear Information System (INIS)

    Bell, S.R.; Rohrscheib, R.

    1994-01-01

    The American Society of Mechanical Engineers (ASME) Code requires individual valve leakage testing for Category A valves. Although the U.S. Nuclear Regulatory Commission (USNRC) has recognized that it is more appropriate to test containment isolation valves in groups, as allowed by 10 CFR 50, Appendix J, a utility seeking relief from these Code requirements must provide technical justification for the relief and establish a conservative alternate acceptance criteria. In order to provide technical justification for group testing of containment isolation valves, Illinois Power developed a calculation (model) for determining the size of a leakage pathway in a valve disc or seat for a given leakage rate. The model was verified experimentally by machining leakage pathways of known size and then measuring the leakage and comparing this value to the calculated value. For the range of values typical of leakage rate testing, the correlation between the experimental values and calculated values was quote good. Based upon these results, Illinois Power established a conservative acceptance criteria for all valves in the inservice testing (IST) program and was granted relief by the USNRC from the individual leakage testing requirements of the ASME Code. This paper presents the results of Illinois Power's work in the area of valve leakage rate testing

  8. ATR confinement leakage determination

    International Nuclear Information System (INIS)

    Kuan, P.; Buescher, B.J.

    1998-01-01

    The air leakage rate from the Advanced Test Reactor (ATR) confinement is an important parameter in estimating hypothesized accidental releases of radiation to the environment. The leakage rate must be determined periodically to assure that the confinement has not degraded with time and such determination is one of the technical safety requirements of ATR operation. This paper reviews the methods of confinement leakage determination and presents an analysis of leakage determination under windy conditions, which can complicate the interpretation of the determined leakage rates. The paper also presents results of analyses of building air exchange under windy conditions. High wind can enhance air exchange and this could increase the release rates of radioisotopes following an accident

  9. Radioactivity leakage monitoring system

    International Nuclear Information System (INIS)

    Nakajima, Takuichiro; Noguchi, Noboru.

    1982-01-01

    Purpose: To obtain a device for detecting the leakage ratio of a primary coolant by utilizing the variation in the radioactivity concentration in a reactor container when the coolant is leaked. Constitution: A measurement signal is produced from a radioactivity measuring instrument, and is continuously input to a malfunction discriminator. The discriminator inputs a measurement signal to a concentration variation discriminator when the malfunction is recognized and simultaneously inputs a measurement starting time from the inputting time to a concentration measuring instrument. On the other hand, reactor water radioactivity concentration data obtained by sampling the primary coolant is input to a concentration variation computing device. A comparator obtains the ratio of the measurement signal from the measuring instrument and the computed data signal from the computing device at the same time and hence the leakage rate, indicates the average leakage rate by averaging the leakage rate signals and also indicates the total leakage amount. (Yoshihara, H.)

  10. Model for Electromagnetic Information Leakage

    OpenAIRE

    Mao Jian; Li Yongmei; Zhang Jiemin; Liu Jinming

    2013-01-01

    Electromagnetic leakage will happen in working information equipments; it could lead to information leakage. In order to discover the nature of information in electromagnetic leakage, this paper combined electromagnetic theory with information theory as an innovative research method. It outlines a systematic model of electromagnetic information leakage, which theoretically describes the process of information leakage, intercept and reproduction based on electromagnetic radiation, and ana...

  11. The White test: a new dye test for intraoperative detection of bile leakage during major liver resection.

    Science.gov (United States)

    Nadalin, Silvio; Li, Jun; Lang, Hauke; Sotiropoulos, Georgios C; Schaffer, Randolph; Radtke, Arnold; Saner, Fuat; Broelsch, Christoph E; Malagó, Massimo

    2008-04-01

    To describe a new intraoperative bile leakage test in patients undergoing a major liver resection aimed to combine the advantages of each of the other standard bile leakage tests (accurate visualization of leaks, reproducibility, and ease of use) without their disadvantages. At the end of the major hepatic resection, 10 to 30 mL of sterile fat emulsion, 5%, is injected via an olive-tip cannula through the cystic duct while manually occluding the distal common bile duct. As the biliary tree fills with fat emulsion solution, leakage of the white fluid is visualized on the raw surface of the liver resection margin. The detected leakages are closed by means of single stitches. Afterwards, the residual fat emulsion on the resection surface is washed off with saline and the White test is repeated to detect and/or exclude additional bile leakages. At the end, residual fat emulsion is washed out from the biliary tract by a low-pressure infusion of saline solution. Intraoperatively, additional potential bile leakages (not seen using a conventional saline bile leakage test) were identified in 74% of our patients. Postoperative bile leakages (within 30 days) occurred in only 5.1% of patients when the White test was used. No adverse effects related to this technique were observed. The White test has clear advantages in comparison with other bile leakage tests: it precisely detects bile leakages, regardless of size; it does not stain the resection surface, allowing it to be washed off and repeated ad infinitum; and it is safe, quick, and inexpensive.

  12. Complicated problem solution techniques in optimal parameter searching

    International Nuclear Information System (INIS)

    Gergel', V.P.; Grishagin, V.A.; Rogatneva, E.A.; Strongin, R.G.; Vysotskaya, I.N.; Kukhtin, V.V.

    1992-01-01

    An algorithm is presented of a global search for numerical solution of multidimentional multiextremal multicriteria optimization problems with complicated constraints. A boundedness of object characteristic changes is assumed at restricted changes of its parameters (Lipschitz condition). The algorithm was realized as a computer code. The algorithm was realized as a computer code. The programme was used to solve in practice the different applied optimization problems. 10 refs.; 3 figs

  13. Soil solution extraction techniques for microbial ecotoxicity testing: a comparative evaluation.

    Science.gov (United States)

    Tiensing, T; Preston, S; Strachan, N; Paton, G I

    2001-02-01

    The suitability of two different techniques (centrifugation and Rhizon sampler) for obtaining the interstitial pore water of soil (soil solution), integral to the ecotoxicity assessment of metal contaminated soil, were investigated by combining chemical analyses and a luminescence-based microbial biosensor. Two different techniques, centrifugation and Rhizon sampler, were used to extract the soil solution from Insch (a loamy sand) and Boyndie (a sandy loam) soils, which had been amended with different concentrations of Zn and Cd. The concentrations of dissolved organic carbon (DOC), major anions (F- , CI-, NO3, SO4(2-)) and major cations (K+, Mg2+, Ca2+) in the soil solutions varied depending on the extraction technique used. Overall, the concentrations of Zn and Cd were significantly higher in the soil solution extracted using the centrifugation technique compared with that extracted using the Rhizon sampler technique. Furthermore, the differences observed between the two extraction techniques depended on the type of soil from which the solution was being extracted. The luminescence-based biosensor Escherichia coli HB101 pUCD607 was shown to respond to the free metal concentrations in the soil solutions and showed that different toxicities were associated with each soil, depending on the technique used to extract the soil solution. This study highlights the need to characterise the type of extraction technique used to obtain the soil solution for ecotoxicity testing in order that a representative ecotoxicity assessment can be carried out.

  14. Existence of solutions for Hamiltonian field theories by the Hamilton-Jacobi technique

    International Nuclear Information System (INIS)

    Bruno, Danilo

    2011-01-01

    The paper is devoted to prove the existence of a local solution of the Hamilton-Jacobi equation in field theory, whence the general solution of the field equations can be obtained. The solution is adapted to the choice of the submanifold where the initial data of the field equations are assigned. Finally, a technique to obtain the general solution of the field equations, starting from the given initial manifold, is deduced.

  15. Universal leakage elimination

    International Nuclear Information System (INIS)

    Byrd, Mark S.; Lidar, Daniel A.; Wu, L.-A.; Zanardi, Paolo

    2005-01-01

    'Leakage' errors are particularly serious errors which couple states within a code subspace to states outside of that subspace, thus destroying the error protection benefit afforded by an encoded state. We generalize an earlier method for producing leakage elimination decoupling operations and examine the effects of the leakage eliminating operations on decoherence-free or noiseless subsystems which encode one logical, or protected qubit into three or four qubits. We find that by eliminating a large class of leakage errors, under some circumstances, we can create the conditions for a decoherence-free evolution. In other cases we identify a combined decoherence-free and quantum error correcting code which could eliminate errors in solid-state qubits with anisotropic exchange interaction Hamiltonians and enable universal quantum computing with only these interactions

  16. Uranium solution mining cost estimating technique: means for rapid comparative analysis of deposits

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    Twelve graphs provide a technique for determining relative cost ranges for uranium solution mining projects. The use of the technique can provide a consistent framework for rapid comparative analysis of various properties of mining situations. The technique is also useful to determine the sensitivities of cost figures to incremental changes in mining factors or deposit characteristics

  17. Coolant leakage detecting device

    International Nuclear Information System (INIS)

    Yamauchi, Kiyoshi; Kawai, Katsunori; Ishihara, Yoshinao.

    1995-01-01

    The device of the present invention judges an amount of leakage of primary coolants of a PWR power plant at high speed. Namely, a mass of coolants contained in a pressurizer, a volume controlling tank and loop regions is obtained based on a preset relational formula and signals of each of process amount, summed up to determine the total mass of coolants for every period of time. The amount of leakage for every period of time is calculated by a formula of Karman's filter based on the total mass of the primary coolants for every predetermined period of time, and displays it on CRT. The Karman's filter is formed on every formula for several kinds of states formed based on the preset amount of the leakage, to calculate forecasting values for every mass of coolants. An adaptable probability for every preset leakage amount is determined based on the difference between the forecast value and the observed value and the scattering thereof. The adaptable probability is compared with a predetermined threshold value, which is displayed on the CRT. This device enables earlier detection of leakage and identification of minute leakage amount as compared with the prior device. (I.S.)

  18. Comparison of multiple support excitation solution techniques for piping systems

    International Nuclear Information System (INIS)

    Sterkel, H.P.; Leimbach, K.R.

    1980-01-01

    Design and analysis of nuclear power plant piping systems exposed to a variety of dynamic loads often require multiple support excitation analysis by modal or direct time integration methods. Both methods have recently been implemented in the computer program KWUROHR for static and dynamic analysis of piping systems, following the previous implementation of the multiple support excitation response spectrum method (see papers K 6/15 and K 6/15a of the SMiRT-4 Conference). The results of multiple support excitation response spectrum analyses can be examined by carrying out the equivalent time history analyses which do not distort the time phase relationship between the excitations at different support points. A frequent point of discussion is multiple versus single support excitation. A single support excitation analysis is computationally straightforward and tends to be on the conservative side, as the numerical results show. A multiple support excitation analysis, however, does not incur much more additional computer cost than the expenditure for an initial static solution involving three times the number, L, of excitation levels, i.e. 3L static load cases. The results are more realistic than those from a single support excitation analysis. A number of typical nuclear plant piping systems have been analyzed using single and multiple support excitation algorithms for: (1) the response spectrum method, (2) the modal time history method via the Wilson, Newmark and Goldberg integration operators and (3) the direct time history method via the Wilson integration operator. Characteristic results are presented to compare the computational quality of all three methods. (orig.)

  19. Experimental evaluation of clinical colon anastomotic leakage.

    Science.gov (United States)

    Pommergaard, Hans-Christian

    2014-03-01

    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, ischemia and insufficient surgical technique have been suggested to play a central role. Animal models are valuable means to evaluate pathophysiological mechanisms and may be used to test preventive measures aiming at reducing the risk of anastomotic leakage, such as external anastomotic coating. The aim of this thesis was to: Clarify the best suited animal to model clinical anastomotic leakage in humans; Create animal models mimicking anastomotic leakage in humans induced by insufficient surgical technique and tissue ischemia; Determine the best suited coating materials to prevent anastomotic leakage. This study is a systematic review using the databases MEDLINE and Rex. MEDLINE was searched up to October 2010 to identify studies on experimental animal models of clinical colon anastomotic leakage. From the Rex database, textbooks on surgical aspects as well as gastrointestinal physiology and anatomy of experimental animals were identified. The results indicated that the mouse and the pig are the best suited animals to evaluate clinical anastomotic leakage. However, the pig model is less validated and more costly to use compared with the mouse. Most frequently, rats are used as models. However, extreme interventions are needed to create clinical leakage in these animals. The knowledge from this study formed the basis for selecting the animal species most suited for the models in the next studies. STUDY 2: In this experimental study, technically insufficient colonic anastomoses were performed in 110 C57BL/6 mice. The number of sutures in the intervention group was reduced to produce a suitable leakage rate. Moreover, the analgesia and suture material were changed in order to optimize the

  20. Solution of the diffusion equation in the GPT theory by the Laplace transform technique

    International Nuclear Information System (INIS)

    Lemos, R.S.M.; Vilhena, M.T.; Segatto, C.F.; Silva, M.T.

    2003-01-01

    In this work we present a analytical solution to the auxiliary and importance functions attained from the solution of a multigroup diffusion problem in a multilayered slab by the Laplace Transform technique. We also obtain the the transcendental equation for the effective multiplication factor, resulting from the application of the boundary and interface conditions. (author)

  1. Coolant leakage detection device

    International Nuclear Information System (INIS)

    Ito, Takao.

    1983-01-01

    Purpose: To surely detect the coolant leakage at a time when the leakage amount is still low in the intra-reactor inlet pipeway of FBR type reactor. Constitution: Outside of the intra-reactor inlet piping for introducing coolants at low temperature into a reactor core, an outer closure pipe is furnished. The upper end of the outer closure pipe opens above the liquid level of the coolants in the reactor, and a thermocouple is inserted to the opening of the upper end. In such a structure, if the coolants in the in-reactor piping should leak to the outer closure pipe, coolants over-flows from the opening thereof, at which the thermocouple detects the temperature of the coolants at a low temperature, thereby enabling to detect the leakage of the coolants at a time when it is still low. (Kamimura, M.)

  2. Channel follower leakage restrictor

    International Nuclear Information System (INIS)

    Williamson, H.E.; Smith, B.A.

    1977-01-01

    An improved means is provided to control coolant leakage between the flow channel and the lower tie plate of a nuclear fuel assembly. The means includes an opening in the lower tie plate and a movable element adjacent thereto. The coolant pressure within the tie plate biases the movable means toward the inner surface of the surrounding flow channel to compensate for any movement of the flow channel away from the lower tie plate to thereby control the leakage of coolant flow from the fuel assemblies to the spaces among the fuel assemblies of the core. 9 figures

  3. A Framework to Implement IoT Network Performance Modelling Techniques for Network Solution Selection

    Directory of Open Access Journals (Sweden)

    Declan T. Delaney

    2016-12-01

    Full Text Available No single network solution for Internet of Things (IoT networks can provide the required level of Quality of Service (QoS for all applications in all environments. This leads to an increasing number of solutions created to fit particular scenarios. Given the increasing number and complexity of solutions available, it becomes difficult for an application developer to choose the solution which is best suited for an application. This article introduces a framework which autonomously chooses the best solution for the application given the current deployed environment. The framework utilises a performance model to predict the expected performance of a particular solution in a given environment. The framework can then choose an apt solution for the application from a set of available solutions. This article presents the framework with a set of models built using data collected from simulation. The modelling technique can determine with up to 85% accuracy the solution which performs the best for a particular performance metric given a set of solutions. The article highlights the fractured and disjointed practice currently in place for examining and comparing communication solutions and aims to open a discussion on harmonising testing procedures so that different solutions can be directly compared and offers a framework to achieve this within IoT networks.

  4. A Framework to Implement IoT Network Performance Modelling Techniques for Network Solution Selection.

    Science.gov (United States)

    Delaney, Declan T; O'Hare, Gregory M P

    2016-12-01

    No single network solution for Internet of Things (IoT) networks can provide the required level of Quality of Service (QoS) for all applications in all environments. This leads to an increasing number of solutions created to fit particular scenarios. Given the increasing number and complexity of solutions available, it becomes difficult for an application developer to choose the solution which is best suited for an application. This article introduces a framework which autonomously chooses the best solution for the application given the current deployed environment. The framework utilises a performance model to predict the expected performance of a particular solution in a given environment. The framework can then choose an apt solution for the application from a set of available solutions. This article presents the framework with a set of models built using data collected from simulation. The modelling technique can determine with up to 85% accuracy the solution which performs the best for a particular performance metric given a set of solutions. The article highlights the fractured and disjointed practice currently in place for examining and comparing communication solutions and aims to open a discussion on harmonising testing procedures so that different solutions can be directly compared and offers a framework to achieve this within IoT networks.

  5. Solving the problem of valve stem leakage

    International Nuclear Information System (INIS)

    Dixon, D.F.

    1976-01-01

    Engineering solutions to valve stem leakage, in systems carrying expensive heavy water under pressure, have progressed from changing packing brands (failure) to leak collection (partial success) to elimination of small packed valves and an improved valve packing strategy involving stable packing materials, live Belleville spring-loading of packing, and issuance of a detailed stuffing box specification (success). (E.C.B.)

  6. Zero leakage quantization scheme for biometric verification

    NARCIS (Netherlands)

    Groot, de J.A.; Linnartz, J.P.M.G.

    2011-01-01

    Biometrics gain increasing interest as a solution for many security issues, but privacy risks exist in case we do not protect the stored templates well. This paper presents a new verification scheme, which protects the secrets of the enrolled users. We will show that zero leakage is achieved if

  7. Multiple Solutions of Nonlinear Boundary Value Problems of Fractional Order: A New Analytic Iterative Technique

    Directory of Open Access Journals (Sweden)

    Omar Abu Arqub

    2014-01-01

    Full Text Available The purpose of this paper is to present a new kind of analytical method, the so-called residual power series, to predict and represent the multiplicity of solutions to nonlinear boundary value problems of fractional order. The present method is capable of calculating all branches of solutions simultaneously, even if these multiple solutions are very close and thus rather difficult to distinguish even by numerical techniques. To verify the computational efficiency of the designed proposed technique, two nonlinear models are performed, one of them arises in mixed convection flows and the other one arises in heat transfer, which both admit multiple solutions. The results reveal that the method is very effective, straightforward, and powerful for formulating these multiple solutions.

  8. Assessing Agulhas leakage

    NARCIS (Netherlands)

    van Sebille, E.

    2009-01-01

    Agulhas leakage, the water that flows from the Indian Ocean to the Atlantic Ocean, plays an important role in the circulation of the Atlantic Ocean. The magnitude of this flux of warm and saline Indian Ocean water into the much colder and fresher Atlantic Ocean can be related to the strength of the

  9. Roxby Downs water leakage

    International Nuclear Information System (INIS)

    1996-01-01

    The Environment, Resource and development Committee has been asked by Parliament to examine 'a massive leakage of water at Roxby Downs' and to make recommendations 'as to further action'. It has also been specifically asked to comment on 'the desirability of the Department of Mines and Energy having prime responsibility for environmental matters in relation to mining operations'. This report begins with a description of the Olympic Dam operations near Roxby Downs and with a brief overview of the regulations controlling those operations. The site of the leakage the Olympic Dam tailings retention system is then described in greater detail. Part 3 describes how the system was originally designed, modified and approved. It ends with a series of findings about the adequacy of the original design (including the monitoring systems built into it) and of the approvals process. Recommendations are then made about how future approvals should be handled. Part 4 of the report outlines how the tailings retention system was built and operated and how the massive leakage from it was detected and reported. Findings about the adequacy of the management of the system and about the initial reactions to the leakage are then made, together with recommendations designed to improve future management of the system. 25 refs., 15 figs

  10. Evaluation of the White Test for the Intraoperative Detection of Bile Leakage

    OpenAIRE

    Leelawat, Kawin; Chaiyabutr, Kittipong; Subwongcharoen, Somboon; Treepongkaruna, Sa-ad

    2012-01-01

    We assess whether the White test is better than the conventional bile leakage test for the intraoperative detection of bile leakage in hepatectomized patients. This study included 30 patients who received elective liver resection. Both the conventional bile leakage test (injecting an isotonic sodium chloride solution through the cystic duct) and the White test (injecting a fat emulsion solution through the cystic duct) were carried out in the same patients. The detection of bile leakage was c...

  11. Colorectal Anastomotic Leakage: New perspectives

    NARCIS (Netherlands)

    F. Daams (Freek)

    2014-01-01

    markdownabstract__Abstract__ This thesis provides new perspectives on colorectal anastomotic leakages. In both experimental and clinical studies, aspects of prevention, early identification, treatment and consequences of anastomotic leakage are discussed.

  12. A numerical technique for enhanced efficiency and stability for the solution of the nuclear reactor equation

    International Nuclear Information System (INIS)

    Khotylev, V.A.; Hoogenboom, J.E.

    1996-01-01

    The paper presents new techniques for the solution of the nuclear reactor equation in diffusion approximation, that has enhanced efficiency and stability. The code system based on the new technique solves a number of steady-state and/or transient problems with coupled thermal hydraulics in one-, two-, or three dimensional geometry with reduced CPU time as compared to similar code systems of previous generations if well-posed neutronics problems are considered. Automated detection of ill-posed problem and selection of the appropriate numerical method makes the new code system capable of yielding a correct solution for wider range of problems without user intervention. (author)

  13. A numerical technique for enhanced efficiency and stability for the solution of the nuclear reactor equation

    Energy Technology Data Exchange (ETDEWEB)

    Khotylev, V.A.; Hoogenboom, J.E. [Delft Univ. of Technology, Interfaculty Reactor Inst., Delft (Netherlands)

    1996-07-01

    The paper presents new techniques for the solution of the nuclear reactor equation in diffusion approximation, that has enhanced efficiency and stability. The code system based on the new technique solves a number of steady-state and/or transient problems with coupled thermal hydraulics in one-, two-, or three dimensional geometry with reduced CPU time as compared to similar code systems of previous generations if well-posed neutronics problems are considered. Automated detection of ill-posed problem and selection of the appropriate numerical method makes the new code system capable of yielding a correct solution for wider range of problems without user intervention. (author)

  14. Investigation of Different Colloidal Porous Silicon Solutions and Their Composite Solid Matrix Rods by Optical Techniques

    Science.gov (United States)

    Khan, M. Naziruddin; Aldalbahi, Ali; Almohammedi, Abdullah

    2018-03-01

    Colloidal porous silicon (PSi) in different solvents was synthesized by simple chemical etching. Colloidal solutions were then prepared using different quantities of silicon wafer pieces (Pcs) and chloroplatinic (Pt) acid in catalyst solution. The effect on the properties of the colloidal solutions and composite rods were investigated using various optical characterization techniques. Absorption and photoluminescence (PL) intensity of the colloidal PSi solutions are observed to depend on the quantity of wafer Pcs, the Pt-solution, and the porosity formation on the wafer surface. The morphological structure of the PSi in a solvent and the solid-rod environments were studied using field-emission scanning electron microscopy (FE-SEM) and were observed to have different structures. A mono-oriented structure of PSi exists in tetrahydrofuran, which has stereo orientation in dioxane and dimethylsulfoxide (approximately 5-8 nm as confirmed using high resolution transmission electron microscopy). Subsequently, some colloidal PSi solutions were directly embedded in three types of sol-gel-based matrices, silica, ormosils (or organically modified silica) and polymer, which easily generated solid rods. Spontaneous emission (SE) of the PSi solutions and their composite rods were examined using a high power picosecond 355 nm laser source. The emitted PL and SE signals of the colloidal PSi solutions were dependent on the Pt volume, nature of the solvent, quantity of Si wafer piece, and pumping energy. The response of SE signals from the PSi composites rods is an interesting phenomenon, and such nanocomposites may be used for future research on light amplification.

  15. On an asymptotic technique of solution of the inverse problem of helioseismology

    International Nuclear Information System (INIS)

    Brodskij, M.A.; Vorontsov, S.V.

    1987-01-01

    The technique for the solution of the universe problem for the solar 5-min. oscillations is proposed, which provides an independent determination of the second speed as a function of depth in solar interior and the frequency dependence of the effective phase shift for the reflection of the trapped acoustic waves from the outer layers. The preliminary numerical results are presented

  16. The solution of linear and nonlinear systems of Volterra functional equations using Adomian-Pade technique

    International Nuclear Information System (INIS)

    Dehghan, Mehdi; Shakourifar, Mohammad; Hamidi, Asgar

    2009-01-01

    The purpose of this study is to implement Adomian-Pade (Modified Adomian-Pade) technique, which is a combination of Adomian decomposition method (Modified Adomian decomposition method) and Pade approximation, for solving linear and nonlinear systems of Volterra functional equations. The results obtained by using Adomian-Pade (Modified Adomian-Pade) technique, are compared to those obtained by using Adomian decomposition method (Modified Adomian decomposition method) alone. The numerical results, demonstrate that ADM-PADE (MADM-PADE) technique, gives the approximate solution with faster convergence rate and higher accuracy than using the standard ADM (MADM).

  17. Higher-order Solution of Stochastic Diffusion equation with Nonlinear Losses Using WHEP technique

    KAUST Repository

    El-Beltagy, Mohamed A.; Al-Mulla, Noah

    2014-01-01

    Using Wiener-Hermite expansion with perturbation (WHEP) technique in the solution of the stochastic partial differential equations (SPDEs) has the advantage of converting the problem to a system of deterministic equations that can be solved efficiently using the standard deterministic numerical methods [1]. The Wiener-Hermite expansion is the only known expansion that handles the white/colored noise exactly. The main statistics, such as the mean, covariance, and higher order statistical moments, can be calculated by simple formulae involving only the deterministic Wiener-Hermite coefficients. In this poster, the WHEP technique is used to solve the 2D diffusion equation with nonlinear losses and excited with white noise. The solution will be obtained numerically and will be validated and compared with the analytical solution that can be obtained from any symbolic mathematics package such as Mathematica.

  18. Higher-order Solution of Stochastic Diffusion equation with Nonlinear Losses Using WHEP technique

    KAUST Repository

    El-Beltagy, Mohamed A.

    2014-01-06

    Using Wiener-Hermite expansion with perturbation (WHEP) technique in the solution of the stochastic partial differential equations (SPDEs) has the advantage of converting the problem to a system of deterministic equations that can be solved efficiently using the standard deterministic numerical methods [1]. The Wiener-Hermite expansion is the only known expansion that handles the white/colored noise exactly. The main statistics, such as the mean, covariance, and higher order statistical moments, can be calculated by simple formulae involving only the deterministic Wiener-Hermite coefficients. In this poster, the WHEP technique is used to solve the 2D diffusion equation with nonlinear losses and excited with white noise. The solution will be obtained numerically and will be validated and compared with the analytical solution that can be obtained from any symbolic mathematics package such as Mathematica.

  19. Determination of the uranium concentration in soil solutions by the fission track registration technique

    International Nuclear Information System (INIS)

    Fernandes, G.P.

    1980-02-01

    The fission tracks registration technique was used to determine the uranium concentration in soil solutions. The Makrofol KG, a synthetic plastic manufactured by Bayer, was used as a detector and the wet method was applied. From the calibration curves obtained, it was possible to determine uranium concentrations in soil solutions, from 90 to 320 μg U/l, with an error between 9.4% and 4.0%, respectively. The method was applied to a few soil samples from Pocos de Caldas, Minas Gerais in Brazil. The uranium concentrations in the sample and residues were also determined by other methods to compare the results obtained; only one sample showed deviation from the results obtained by the fission tracks method. And this discrepancy was explained in a reasonable way. It was shown that the fission tracks technique can be used with sucess for application in soil solutions. (Author) [pt

  20. Comparing the Titrations of Mixed-Acid Solutions Using Dropwise and Constant-Flow Techniques

    Science.gov (United States)

    Charlesworth, Paul; Seguin, Matthew J.; Chesney, David J.

    2003-11-01

    A mixed-acid solution containing hydrochloric and phosphoric acids was used to determine the error associated with performing a real-time titration. The results were compared against those obtained by performing the titration in a more traditional dropwise addition of titrant near the equivalence points. It was found that the real-time techniques resulted in significantly decreased analysis times while maintaining a low experimental error. The constant-flow techniques were implemented into two different levels of chemistry. It was found that students could successfully utilize the modified experiments. Problems associated with the techniques, major sources of error, and their solutions are discussed. In both cases, the use of the constant-flow setup has increased student recollection of key concepts, such as pKa determination, proper indicator choice, and recognizing the shape of specific titration curves by increasing student interest in the experiment.

  1. 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

  2. Finding p-Hub Median Locations: An Empirical Study on Problems and Solution Techniques

    Directory of Open Access Journals (Sweden)

    Xiaoqian Sun

    2017-01-01

    Full Text Available Hub location problems have been studied by many researchers for almost 30 years, and, accordingly, various solution methods have been proposed. In this paper, we implement and evaluate several widely used methods for solving five standard hub location problems. To assess the scalability and solution qualities of these methods, three well-known datasets are used as case studies: Turkish Postal System, Australia Post, and Civil Aeronautics Board. Classical problems in small networks can be solved efficiently using CPLEX because of their low complexity. Genetic algorithms perform well for solving three types of single allocation problems, since the problem formulations can be neatly encoded with chromosomes of reasonable size. Lagrangian relaxation is the only technique that solves reliable multiple allocation problems in large networks. We believe that our work helps other researchers to get an overview on the best solution techniques for the problems investigated in our study and also stipulates further interest on cross-comparing solution techniques for more expressive problem formulations.

  3. Polyaniline (PANI) modified bentonite by plasma technique for U(VI) removal from aqueous solution

    International Nuclear Information System (INIS)

    Liu, Xinghao; Cheng, Cheng; Xiao, Chengjian; Shao, Dadong; Xu, Zimu; Wang, Jiaquan; Hu, Shuheng; Li, Xiaolong; Wang, Weijuan

    2017-01-01

    Highlights: • PANI/bentonie can be synthesized by simple plasma technique. • PANI/bentonie has an excellent adsorption capacity for trace uranium in solution. • U(VI) adsorption on PANI/bentonite is a spontaneous and endothermic process. - Abstract: Polyaniline (PANI) modified bentonite (PANI/bentonie) was synthesized by plasma induced polymerization of aniline on bentonite surface, and applied to uptake of uranium(VI) ions from aqueous solution. The as-synthesized PANI/bentonie was characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), thermal gravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). Batch adsorption technique was utilized to investigate the adsorption of U(VI) on bentonite and PANI/bentonite. The adsorption of U(VI) (10 mg/L) on PANI/bentonite surface is fairly depend on solution pH, ionic strength, and temperature in solution. The modified PANI on PANI/bentonite surface significantly enhances its adsorption capability for U(VI). The presence of humic acid (HA) can sound enhance U(VI) adsorption on PANI/bentonite at pH 6.5. According to the thermodynamic parameters, the adsorption of U(VI) on PANI/bentonite surface is a spontaneous and endothermic process. The results highlight the application of PANI/bentonite composites as candidate material for the uptake of trace U(VI) from aqueous solution.

  4. Polyaniline (PANI) modified bentonite by plasma technique for U(VI) removal from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xinghao [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900 (China); Intelligent Manufacturing Technology Research Institute, Hefei University of Technology, Hefei 230088 (China); Cheng, Cheng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Xiao, Chengjian, E-mail: xiaocj@caep.cn [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900 (China); Shao, Dadong, E-mail: shaodadong@126.com [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Xu, Zimu, E-mail: xzm@mail.ustc.edu.cn [Intelligent Manufacturing Technology Research Institute, Hefei University of Technology, Hefei 230088 (China); Wang, Jiaquan; Hu, Shuheng [Intelligent Manufacturing Technology Research Institute, Hefei University of Technology, Hefei 230088 (China); Li, Xiaolong; Wang, Weijuan [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900 (China)

    2017-07-31

    Highlights: • PANI/bentonie can be synthesized by simple plasma technique. • PANI/bentonie has an excellent adsorption capacity for trace uranium in solution. • U(VI) adsorption on PANI/bentonite is a spontaneous and endothermic process. - Abstract: Polyaniline (PANI) modified bentonite (PANI/bentonie) was synthesized by plasma induced polymerization of aniline on bentonite surface, and applied to uptake of uranium(VI) ions from aqueous solution. The as-synthesized PANI/bentonie was characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), thermal gravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). Batch adsorption technique was utilized to investigate the adsorption of U(VI) on bentonite and PANI/bentonite. The adsorption of U(VI) (10 mg/L) on PANI/bentonite surface is fairly depend on solution pH, ionic strength, and temperature in solution. The modified PANI on PANI/bentonite surface significantly enhances its adsorption capability for U(VI). The presence of humic acid (HA) can sound enhance U(VI) adsorption on PANI/bentonite at pH < 6.5 because of the strong complexation, and inhibits U(VI) adsorption at pH > 6.5. According to the thermodynamic parameters, the adsorption of U(VI) on PANI/bentonite surface is a spontaneous and endothermic process. The results highlight the application of PANI/bentonite composites as candidate material for the uptake of trace U(VI) from aqueous solution.

  5. Simultaneous PIV and pulsed shadow technique in slug flow: a solution for optical problems

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, S. [Karman Institute for Fluid Dynamics, Chaussee de Waterloo 72, B-1640, Rhode Saint Genese (Belgium); Centro de Estudos de Fenomenos de Transporte, Departamento de Eng. Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465, Porto (Portugal); Sousa, R.G.; Pinto, A.M.F.R.; Campos, J.B.L.M. [Centro de Estudos de Fenomenos de Transporte, Departamento de Eng. Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465, Porto (Portugal); Riethmuller, M.L. [Karman Institute for Fluid Dynamics, Chaussee de Waterloo 72, B-1640, Rhode Saint Genese (Belgium)

    2003-12-01

    A recent technique of simultaneous particle image velocimetry (PIV) and pulsed shadow technique (PST) measurements, using only one black and white CCD camera, is successfully applied to the study of slug flow. The experimental facility and the operating principle are described. The technique is applied to study the liquid flow pattern around individual Taylor bubbles rising in an aqueous solution of glycerol with a dynamic viscosity of 113 x 10{sup -3} Pa s. With this technique the optical perturbations found in PIV measurements at the bubble interface are completely solved in the nose and in annular liquid film regions as well as in the rear of the bubble for cases in which the bottom is flat. However, for Taylor bubbles with concave oblate bottoms, some optical distortions appear and are discussed. The measurements achieved a spatial resolution of 0.0022 tube diameters. The results reported show high precision and are in agreement with theoretical and experimental published data. (orig.)

  6. ''FIXBOX'' - a new technique for the reliable conditioning of plutonium waste solutions

    International Nuclear Information System (INIS)

    Bruchertseifer, H.; Sommer, E.; Steinemann, M.; Bart, G.

    1994-01-01

    ''FIXBOX'' - A new technique and facility for the conditioning of plutonium waste solutions has been developed and brought into operation in the Hot-laboratory at PSI, for the solidification of the waste from the research programmes. The facility is situated in glove-boxes for handling alpha activity and gamma-shielded for conditioning of fission product-containing waste. This report gives a brief description of the FIXBOX facility, the procedure and the first results of the cementation of plutonium waste solutions. As a result of this solidification, the actinide waste is homogeneous and strongly bound in the cement. The presence of gluconic acid and other complexing agents in the waste solution will not disturb this process. (author) figs., tabs., refs

  7. Solution of the finite Milne problem in stochastic media with RVT Technique

    Science.gov (United States)

    Slama, Howida; El-Bedwhey, Nabila A.; El-Depsy, Alia; Selim, Mustafa M.

    2017-12-01

    This paper presents the solution to the Milne problem in the steady state with isotropic scattering phase function. The properties of the medium are considered as stochastic ones with Gaussian or exponential distributions and hence the problem treated as a stochastic integro-differential equation. To get an explicit form for the radiant energy density, the linear extrapolation distance, reflectivity and transmissivity in the deterministic case the problem is solved using the Pomraning-Eddington method. The obtained solution is found to be dependent on the optical space variable and thickness of the medium which are considered as random variables. The random variable transformation (RVT) technique is used to find the first probability density function (1-PDF) of the solution process. Then the stochastic linear extrapolation distance, reflectivity and transmissivity are calculated. For illustration, numerical results with conclusions are provided.

  8. Dynamical scaling in polymer solutions investigated by the neutron spin echo technique

    International Nuclear Information System (INIS)

    Richter, D.; Ewen, B.

    1979-01-01

    Chain dynamics in polymer solutions was investigated by means of the recently developed neutron spin echo spectroscopy. - By this technique, it was possible for the first time to verify unambiguously the scaling predictions of the Zimm model in the case of single chain behaviour and to observe the cross over to many chain behaviour. The segmental diffusion of single chains exhibits deviations from a simple exponential law, indicating the importance of memory effects. (orig.) [de

  9. Selective separation of Cu, Zn, and As from solution by flotation techniques

    International Nuclear Information System (INIS)

    Stalidis, G.A.; Matis, K.A.; Lazaridis, N.K.

    1989-01-01

    The selective precipitation and flotation of copper, zinc, and arsenic ions from dilute aqueous solutions were investigated. Phase separation was accomplished effectively by the dissolved-air technique for the production of fine gas bubbles, and a short-chain xanthate was applied as the collector for copper ions, dialkyl-dithiocarbamate for zinc, and ferric sulfate for the pentavalent arsenic. The procedures followed were ion flotation for copper and zinc, and adsorbing colloid flotation for arsenic (without a surfactant)

  10. Accès à l'eau : des solutions techniques et sociales aident des ...

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

    Grâce à la modélisation par ordinateur faisant appel à des techniques de pointe et à la consultation des collectivités, l'organisme bolivien Agua Sustentable a trouvé des solutions politiques à des conflits qui auraient pu s'avérer désastreux au sujet de l'accès à l'eau. Cet organisme de recherche subventionné par le CRDI a ...

  11. Numerical solution of large nonlinear boundary value problems by quadratic minimization techniques

    International Nuclear Information System (INIS)

    Glowinski, R.; Le Tallec, P.

    1984-01-01

    The objective of this paper is to describe the numerical treatment of large highly nonlinear two or three dimensional boundary value problems by quadratic minimization techniques. In all the different situations where these techniques were applied, the methodology remains the same and is organized as follows: 1) derive a variational formulation of the original boundary value problem, and approximate it by Galerkin methods; 2) transform this variational formulation into a quadratic minimization problem (least squares methods) or into a sequence of quadratic minimization problems (augmented lagrangian decomposition); 3) solve each quadratic minimization problem by a conjugate gradient method with preconditioning, the preconditioning matrix being sparse, positive definite, and fixed once for all in the iterative process. This paper will illustrate the methodology above on two different examples: the description of least squares solution methods and their application to the solution of the unsteady Navier-Stokes equations for incompressible viscous fluids; the description of augmented lagrangian decomposition techniques and their application to the solution of equilibrium problems in finite elasticity

  12. Quantitative single-vesicle analysis of antimicrobial peptide-induced leakage

    DEFF Research Database (Denmark)

    Kristensen, Kasper; Ehrlich, Nicky; Henriksen, Jonas Rosager

    2013-01-01

    Although the research field of antimicrobial peptides has attracted considerable scientific attention in the past decades, the microbicidal mechanisms of antimicrobial peptides still remain elusive. One of the keys to a more profound comprehension of the function of these peptides is a deeper...... was combined with fluorescence correlation spectroscopy to quantify leakage from a bulk collection of lipid vesicles in aqueous solution. Quantitative correlation between the two techniques was achieved through a detailed experimental protocol. The potential of combining the two techniques was tested using...

  13. Corrosion behaviour of the UO2 pellet in corrosive solutions using electrochemical Technique

    International Nuclear Information System (INIS)

    Taftanzani, A.; Sucipto; Lahagu, F.; Irianto, B.

    1996-01-01

    The UO 2 electrodes has been made from the local product of UO 2 pellets. The corrosion behaviour of the UO 2 pellets is affected by solution, by pH value and by concentration of salt solution. Investigation into corrosion behaviour of UO 2 electrodes have been carried out in saturated salt solutions using electrochemical technique. The saturated solutions have been made from salts NaCl, Na 2 CO 3 , Na 2 SO 4 and Na 3 PO 4 . The pH value have been done over range 1 pH 10 and the salt concentration (C) over range 0,001 mol/l C 1,0 mol/l, Na 2 CO 3 solution produced the lowest corrosion rates of UO 2 pellets. Those rates were relative constant in the range of pH = 4 - 8. The results indicate an influence of the Na 2 CO 3 concentrations on the corrosions on the corrosion rate, and the lowest rates occur in 0,10 mol/l Na 2 CO 3 . The lowest corrosion rate was 0.3388 mil/year in 0.10 mol/l Na 2 CO 3 by pH = 4. (author)

  14. Flow shop scheduling decisions through Techniques for Order Preference by Similarity to an Ideal Solution (TOPSIS

    Directory of Open Access Journals (Sweden)

    Arun Gupta

    2016-07-01

    Full Text Available The flow-shop scheduling problem (FSP has been widely studied in the literature and having a very active research area. Over the last few decades, a number of heuristic/meta-heuristic solution techniques have been developed. Some of these techniques offer excellent effectiveness and efficiency at the expense of substantial implementation efforts and being extremely complicated. This paper brings out the application of a Multi-Criteria Decision Making (MCDM method known as techniques for order preference by similarity to an ideal solution (TOPSIS using different weighting schemes in flow-shop environment. The objective function is identification of a job sequence which in turn would have minimum makespan (total job completion time. The application of the proposed method to flow shop scheduling is presented and explained with a numerical example. The results of the proposed TOPSIS based technique of FSP are also compared on the basis of some benchmark problems and found compatible with the results obtained from other standard procedures.

  15. Determination of Unidentified Leakage Using a Kalman Smoother

    International Nuclear Information System (INIS)

    Jang, Soek Bo; Heo, Gyunyoung; Ra, Insik; Han, Jeonghyun; Lee, Seon Woo

    2008-01-01

    Since the safety significance of leaks from the RCS can widely vary depending on the source of the leak as well as the leak rate, the detection of the leakage is an important issue. The leakage is classified into 1) identified leakage which is defined as leakage into closed systems such as pump seal or valve packing leaks that can be captured, and 2) unidentified leakage which is all other leakage. The unidentified leakage is typically determined by the RCS inventory balance method which is based on NUREG-1107. Since the accuracy of leak rate calculation is dependent of the plant operating condition, the change in the RCS temperature, inventory, and the transient operating condition should be avoided during the measurement period. Nevertheless, the operation of the makeup of the borated water into the RCS and the diversion of the inventory to the outside of the RCS boundary makes it difficult to maintain the plant stable over an hour. Due to the large fluctuation of the calculated leak rate, it is sometimes hard to know the trend of the leakage as well as the instantaneous leak rate. Any fluctuation of operating conditions can results in unreliable leak rate. This study proposes a new way of determining the unidentified leak rate using a Kalman filter and smoother technique. The proposed algorithm enhances the accuracy of the leak rate calculation not only for the steady state operations but also for transients in a well timed manner

  16. Management of cerebrospinal fluid leakage after anterior decompression for ossification of posterior longitudinal ligament in the thoracic spine: the utilization of a volume-controlled pseudomeningocele.

    Science.gov (United States)

    Cho, Ji Young; Chan, Chee Keong; Lee, Sang-Ho; Choi, Won-Chul; Maeng, Dae Hyeon; Lee, Ho-Yeon

    2012-06-01

    Retrospective review To determine the efficacy of management of cerebrospinal fluid (CSF) leakage after the anterior thoracic approach. CSF leakage after incidental durotomy commonly occurs after anterior thoracic ossification of posterior longitudinal ligament (OPLL) surgery. Pseudomeningocele will invariably form under such circumstances. Among them, uncontrolled CSF leakage with a fistulous condition is problematic. As a solution, we have managed these durotomies with chest drains alone without any CSF drainage by the concept of a "volume-controlled pseudomeningocele." Between 2001 and 2009, CSF leakage occurred in 26 patients (37.7%) of the total 69 patients who underwent anterior decompression for thoracic OPLL. In the initial 11 cases, subarachnoid drainage was utilized as an augmentive measure in combination with chest tube drainage in the postoperative period (group A). In the subsequent 15 cases, the durotomy was managed in a similar manner but in the absence of any subarachnoid drainage (group B). Various parameters such as the duration of postoperative hospital stay, clinical outcome score, drainage output, resolution of CSF leakage, complications, and additional surgery performed were analyzed and compared between the 2 groups. A resolution of the CSF leakage grading system was also proposed for the residual pseudomeningocele that formed in each group. There were statistically no significant differences in the outcome parameters between the 2 groups and also in patients with grade I or grade II residual pseudomeningocele of the new grading system. Two complications occurred in group A. No reexploration for persistent CSF leakage was required in both groups. CSF leakage managed with controlled chest tube drainage can produce a comparable result with those with additional subarachnoid drainage when watertight dural repair is impossible. The concept of controlled pseudomeningocele may be a useful and practical technique for the treatment of CSF leakage

  17. Leakage of caesium braquitherapy sources

    International Nuclear Information System (INIS)

    Lozada, J.A.

    1998-01-01

    In several Venezuelan public hospitals where cervix uteri tumours are treated by intracavitary radiotherapy, that use manual after loading Fletcher method, with Caesium 137 sources, the use of improper source holders, locally manufactured from pieces of drainage plastic tubing, which deteriorated and created a corrosive environment all around the sources, omission of manufacturer's recommendations regarding corrosion information, source storage, inspection and testing, violation of International Atomic Energy Agency Radiation Protection Procedures, and lack of proper regulatory control, resulted integrity damage to about sixty special form sources (ISO2919 C 63322), leakage of Cs-137 from a supposed insoluble refractory active content (caesium silicoaluminate), and contamination of applicators, floors and bedding. When the situation was detected by means removal contamination tests, after routine inspections, the sources were removed from the hospitals, decontaminated by means of immersion in 3% EDTA solution in ultrasonic bath, subjected to leaking assessment tests, and the ones that passed were placed in low cost stainless steel source holders, designed and built by the instituto Venezolano de Investigaciones Cientificas (IVIC) returned to the hospitals. The leaking sources were removed from use and considered radioactive waste. In order to avoid the occurrence of similar situations, all the importers of such sources are now required to send them to IVIC for testing and placement in proper source holders, before they are shipped to the hospitals. (author)

  18. Lung protein leakage in feline septic shock.

    Science.gov (United States)

    Schützer, K M; Larsson, A; Risberg, B; Falk, A

    1993-06-01

    The aim of the present study was to explore lung microvascular leakage of protein and water in a feline model of septic shock, using a double isotope technique with external gamma camera detection and gravimetric lung water measurements. The experiments were performed on artificially ventilated cats. One group of cats (n = 8) was given an infusion of live Escherichia coli bacteria, and another group (n = 5) served as a control group receiving saline. Plasma transferrin was radiolabeled in vivo with indium-113m-chloride, and erythrocytes were labeled with technetium-99m. The distribution of these isotopes in the lungs was continuously measured with a gamma camera. A normalized slope index (NSI) was calculated, indicative of the transferrin accumulation corrected for changes in local blood volume that reflect protein leakage. In the septic group there was a protein leakage after bacterial infusion, with a NSI of 39 x 10(-4) +/- 5 x 10(-4) min-1 (mean +/- SEM), and the PaO2 diminished from 21 +/- 1 to 9.5 +/- 1 kPa. In control cats a slight protein leakage with a NSI of 9 +/- 10(-4) +/- 2 x 10(-4) min-1 was detected, probably caused by the operative procedure, but PaO2 did not change. Wet-to-dry-weight ratios of postmortem lungs were not significantly different between the groups. It was concluded that an intravenous infusion of live E. coli bacteria induces a lung capillary protein leakage without increased lung water and a concomitantly disturbed gas exchange.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Bridge flap technique as a single-step solution to mucogingival problems: A case series

    Directory of Open Access Journals (Sweden)

    Vivek Gupta

    2011-01-01

    Full Text Available Shallow vestibule, gingival recession, inadequate width of attached gingiva (AG and aberrant frenum pull are an array of mucogingival problems for which several independent and effective surgical solutions are reported in the literature. This case series reports the effectiveness of the bridge flap technique as a single-step surgical entity for increasing the depth of the vestibule, root coverage, increasing the width of the AG and solving the problem of abnormal frenum pull. Eight patients with 18 teeth altogether having Millers class I, II or III recession along with problems of shallow vestibule, inadequate width of AG and with or without frenum pull underwent this surgical procedure and were followed-up till 9 months post-operatively. The mean root coverage obtained was 55% and the mean average gain in width of the AG was 3.5 mm. The mean percentage gain in clinical attachment level was 41%. The bridge flap technique can be an effective single-step solution for the aforementioned mucogingival problems if present simultaneously in any case, and offers considerable advantages over other mucogingival surgical techniques in terms of simplicity, limited chair-time for the patient and the operator, single surgical intervention for manifold mucogingival problems and low morbidity because of the absence of palatal donor tissue.

  20. Gold nanoparticles prepared by electro-exploding wire technique in aqueous solutions

    Science.gov (United States)

    Kumar, Lalit; Kapoor, Akanksha; Meghwal, Mayank; Annapoorni, S.

    2016-05-01

    This article presents an effective approach for the synthesis of Au nanoparticles via an environmentally benevolent electro-exploding wire (EEW) technique. In this process, Au nanoparticles evolve through the plasma generated from the parent Au metal. Compared to other typical chemical methods, electro-exploding wire technique is a simple and economical technique which normally operates in water or organic liquids under ambient conditions. Efficient size control was achieved using different aqueous medium like (1mM) NaCl, deionized water and aqueous solution of sodium hydroxide (NaOH, pH 9.5) using identical electro-exploding conditions. The gold nanoparticles exhibited the UV-vis absorption spectrum with a maximum absorption band at 530 nm, similar to that of gold nanoparticles chemically prepared in a solution. The mechanism of size variation of Au nanoparticles is also proposed. The results obtained help to develop methodologies for the control of EEW based nanoparticle growth and the functionalization of nanoparticle surfaces by specific interactions.

  1. Study of micelle formation in solutions of alkylammonium carboxylates in apolar solvents by positron annihilation techniques

    International Nuclear Information System (INIS)

    Fucugauchi, L.A.; Djermouni, B.; Handel, E.D.; Ache, H.J.

    1979-01-01

    The positron annihilation technique was applied to the study of the self-association process in solutions of alkylammonium carboxylates in apolar solvents, such as cyclohexane and benzene. The results indicate that the positronium formation probability responds very sensitively to changes in the microenvironment in these solutions. A distinct cooperative effect of the solution resulting in abrupt changes in the number of thermal ortho-positronium atoms formed was observed and studied as a function of the length and structure of the hydrocarbon chain in the cationic and anionic parts of the surfactant molecules. While the chain length in the cationic portion of the surfactant seems to have little effect on the positronium formation probability, distinct differences can be observed when the structure of the carboxylate is changed. Furthermore, a profound effect in the physical property of the solutions was recognized when cyclohexane was replaced by benzene as a solvent. The results are discussed in terms of the existing models for self-association. 4 figures

  2. Polyaniline (PANI) modified bentonite by plasma technique for U(VI) removal from aqueous solution

    Science.gov (United States)

    Liu, Xinghao; Cheng, Cheng; Xiao, Chengjian; Shao, Dadong; Xu, Zimu; Wang, Jiaquan; Hu, Shuheng; Li, Xiaolong; Wang, Weijuan

    2017-07-01

    Polyaniline (PANI) modified bentonite (PANI/bentonie) was synthesized by plasma induced polymerization of aniline on bentonite surface, and applied to uptake of uranium(VI) ions from aqueous solution. The as-synthesized PANI/bentonie was characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), thermal gravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). Batch adsorption technique was utilized to investigate the adsorption of U(VI) on bentonite and PANI/bentonite. The adsorption of U(VI) (10 mg/L) on PANI/bentonite surface is fairly depend on solution pH, ionic strength, and temperature in solution. The modified PANI on PANI/bentonite surface significantly enhances its adsorption capability for U(VI). The presence of humic acid (HA) can sound enhance U(VI) adsorption on PANI/bentonite at pH 6.5. According to the thermodynamic parameters, the adsorption of U(VI) on PANI/bentonite surface is a spontaneous and endothermic process. The results highlight the application of PANI/bentonite composites as candidate material for the uptake of trace U(VI) from aqueous solution.

  3. Theory and Application of Magnetic Flux Leakage Pipeline Detection.

    Science.gov (United States)

    Shi, Yan; Zhang, Chao; Li, Rui; Cai, Maolin; Jia, Guanwei

    2015-12-10

    Magnetic flux leakage (MFL) detection is one of the most popular methods of pipeline inspection. It is a nondestructive testing technique which uses magnetic sensitive sensors to detect the magnetic leakage field of defects on both the internal and external surfaces of pipelines. This paper introduces the main principles, measurement and processing of MFL data. As the key point of a quantitative analysis of MFL detection, the identification of the leakage magnetic signal is also discussed. In addition, the advantages and disadvantages of different identification methods are analyzed. Then the paper briefly introduces the expert systems used. At the end of this paper, future developments in pipeline MFL detection are predicted.

  4. Copper ion as a new leakage tracer.

    Science.gov (United States)

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

    2013-12-01

    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. 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. 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. 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. Based on our results, there was no significant correlation between the dye penetration and the copper ion diffusion methods.

  5. Leakage monitoring device and method

    International Nuclear Information System (INIS)

    Yamada, Izumi; Matsui, Yuji; Fujimori, Haruo.

    1995-01-01

    In a water leakage monitor for a steam generator, output signals from an acoustic sensor disposed in the vicinity of a region to be monitored is subjected to phasing calculation (beam forming calculation) to determine the distribution of a sound source intensity distribution. A peak is retrieved based on the distribution of the sound source intensity distribution. A correction coefficient depending on the position of the peak is multiplied to the sound source intensity. The presence or absence of leakage is determined based on the degree of the sound source intensity after the completion of correction. Namely, a relative value of sound source intensity for each of the portions in the region to be monitored is determined, and the point of the greatest sound source intensity is assumed as a leaking point, to determine the position of the leakage. An absolute value of the sound source intensity at the leaking point is determined by such a constitution that a correction coefficient depending on the position is multiplied to the intensity of the position of the peak in the distribution of the sound intensity. A threshold value for the determination of the presence or absence of the leakage can be set if a relation between an amount of the leakage previously determined experimentally and the intensity of the sound source. Then, a countermeasure can easily be taken after the detection of the leakage and a restoring operation can be carried out rapidly after the occurrence of leakage while avoiding unnecessary shutdown. (N.H.)

  6. An accurate technique for the solution of the nonlinear point kinetics equations

    International Nuclear Information System (INIS)

    Picca, Paolo; Ganapol, Barry D.; Furfaro, Roberto

    2011-01-01

    A novel methodology for the solution of non-linear point kinetic (PK) equations is proposed. The technique is based on a piecewise constant approximation of PK system of ODEs and explicitly accounts for reactivity feedback effects, through an iterative cycle. High accuracy is reached by introducing a sub-mesh for the numerical evaluation of integrals involved and by correcting the source term to include the non-linear effect on a finer time scale. The use of extrapolation techniques for convergence acceleration is also explored. Results for adiabatic feedback model are reported and compared with other benchmarks in literature. The convergence trend makes the algorithm particularly attractive for applications, including in multi-point kinetics and quasi-static frameworks. (author)

  7. A severity-based quantification of data leakages in database systems

    NARCIS (Netherlands)

    Vavilis, S.; Petkovic, M.; Zannone, N.

    2016-01-01

    The detection and handling of data leakages is becoming a critical issue for organizations. To this end, data leakage solutions are usually employed by organizations to monitor network traffic and the use of portable storage devices. However, these solutions often produce a large number of alerts,

  8. [Rapid measurement of trace mercury in aqueous solutions with optical-electrical dual pulse LIBS technique].

    Science.gov (United States)

    Zhang, Qian; Xiong, Wei; Chen, Yu-Qi; Li, Run-Hua

    2011-02-01

    A wood slice was used as absorber to transfer liquid sample to solid sample in order to solve the problems existing in directly analyzing aqueous solutions with laser-induced breakdown spectroscopy (LIBS). An optical-electrical dual pulse LIBS (OEDP-LIBS) technique was first used to enhance atomic emission of mercury in laser-induced plasma. The calibration curves of mercury were obtained by typical single pulse LIBS and OEDP-LIBS techniques. The limit of detection (LOD) of mercury in these two techniques reaches 2.4 and 0.3 mg x L(-1), respectively. Under current experimental conditions, the time-integrated a tomic emission of mercury at 253.65 nm was enhanced 50 times and the LOD of mercury was improved by one order, if comparing OEDP-LIBS to single pulse LIBS. The required time for a whole analysis process is less than 5 minutes. As the atomic emission of mercury decays slowly while increasing the delay time between electrical pulse and laser pulse, increasing the electrical pulse width can further enhance the time integrated intensity of mercury emission and improve the detection sensitivity of mercury by OEDP-LIBS technique.

  9. [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 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.

  10. A new technique in constructing closed-form solutions for nonlinear PDEs appearing in fluid mechanics and gas dynamics

    Directory of Open Access Journals (Sweden)

    Panayotounakos D. E.

    1996-01-01

    Full Text Available We develop a new unique technique in constructing closed-form solutions for several nonlinear partial differential systems appearing in fluid mechanics and gas dynamics. The obtained solutions include fewer arbitrary functions than needed for general solutions, fact that permits us to specify them according to the initial state, or the geometry, of each specific problem under consideration. In order to apply the before mentioned technique we construct closed-form solutions concerning the gas-dynamic equations with constant pressure, the dynamic equations of an ideal gas in isentropic flow, and the two-dimensional incompressible boundary layer flow.

  11. A safeguards verification technique for solution homogeneity and volume measurements in process tanks

    International Nuclear Information System (INIS)

    Suda, S.; Franssen, F.

    1987-01-01

    A safeguards verification technique is being developed for determining whether process-liquid homogeneity has been achieved in process tanks and for authenticating volume-measurement algorithms involving temperature corrections. It is proposed that, in new designs for bulk-handling plants employing automated process lines, bubbler probes and thermocouples be installed at several heights in key accountability tanks. High-accuracy measurements of density using an electromanometer can now be made which match or even exceed analytical-laboratory accuracies. Together with regional determination of tank temperatures, these measurements provide density, liquid-column weight and temperature gradients over the fill range of the tank that can be used to ascertain when the tank solution has reached equilibrium. Temperature-correction algorithms can be authenticated by comparing the volumes obtained from the several bubbler-probe liquid-height measurements, each based on different amounts of liquid above and below the probe. The verification technique is based on the automated electromanometer system developed by Brookhaven National Laboratory (BNL). The IAEA has recently approved the purchase of a stainless-steel tank equipped with multiple bubbler and thermocouple probes for installation in its Bulk Calibration Laboratory at IAEA Headquarters, Vienna. The verification technique is scheduled for preliminary trials in late 1987

  12. On the use of the Lie group technique for differential equations with a small parameter: Approximate solutions and integrable equations

    International Nuclear Information System (INIS)

    Burde, G.I.

    2002-01-01

    A new approach to the use of the Lie group technique for partial and ordinary differential equations dependent on a small parameter is developed. In addition to determining approximate solutions to the perturbed equation, the approach allows constructing integrable equations that have solutions with (partially) prescribed features. Examples of application of the approach to partial differential equations are given

  13. Applying Lean Techniques to Reduce Intravenous Waste Through Premixed Solutions and Increasing Production Frequency.

    Science.gov (United States)

    Lin, Alex C; Penm, Jonathan; Ivey, Marianne F; Deng, Yihong; Commins, Monica

    This study aims to use lean techniques and evaluate the impact of increasing the use of premixed IV solutions and increased IV production frequency on IV waste. Study was conducted at a tertiary hospital pharmacy department in three phases. Phase I included evaluation of IV waste when IV production occurred three times a day and eight premixed IV products were used. Phase II increased the number of premixed IV products to 16. Phase III then increased IV production to five times a day. During Phase I, an estimate of 2,673 IV doses were wasted monthly, accounting for 6.14% of overall IV doses. This accounted for 688 L that cost $60,135. During Phase II, the average monthly IV wastage reduced significantly to 1,069 doses (2.84%), accounting for 447 L and $34,003. During Phase III, the average monthly IV wastage was further decreased to 675 doses (1.69%), accounting for 78 L and $3,431. Hence, a potential annual saving of $449,208 could result from these changes. IV waste was reduced through the increased use of premixed solutions and increasing IV production frequency.

  14. Solution Procedure for Transport Modeling in Effluent Recharge Based on Operator-Splitting Techniques

    Directory of Open Access Journals (Sweden)

    Shutang Zhu

    2008-01-01

    Full Text Available The coupling of groundwater movement and reactive transport during groundwater recharge with wastewater leads to a complicated mathematical model, involving terms to describe convection-dispersion, adsorption/desorption and/or biodegradation, and so forth. It has been found very difficult to solve such a coupled model either analytically or numerically. The present study adopts operator-splitting techniques to decompose the coupled model into two submodels with different intrinsic characteristics. By applying an upwind finite difference scheme to the finite volume integral of the convection flux term, an implicit solution procedure is derived to solve the convection-dominant equation. The dispersion term is discretized in a standard central-difference scheme while the dispersion-dominant equation is solved using either the preconditioned Jacobi conjugate gradient (PJCG method or Thomas method based on local-one-dimensional scheme. The solution method proposed in this study is applied to the demonstration project of groundwater recharge with secondary effluent at Gaobeidian sewage treatment plant (STP successfully.

  15. Radionuclide diagnosis of pulmonary capillary protein leakage

    International Nuclear Information System (INIS)

    Creutzig, H.; Sturm, J.A.; Schober, O.; Nerlich, M.L.; Kant, C.J.; Medizinische Hochschule Hannover

    1984-01-01

    Pulmonary extravascular albumin extra-vasation in patients with adult respiratory distress syndrome can be quantified with radionuclide techniques. While imaging procedures with a computerized gamma camera will allow reproducible ROIs, this will be the main limitation in nonimaging measurements with small scintillation probes. Repeated positioning by one operator results in a mean spatial variation of position of about 2 cm and a variation in count rate of 25%. For the estimation of PCPL the small probes must be positioned under scintigraphic control. Under these conditions the results of both techniques are identical. The upper limit of normal was estimated to be 1 x E-5/sec. The standard deviation abnormal measurements was about 10%. The pulmonary capillary protein leakage can be quantified by radionuclide techniques with good accuracy, using the combination of imaging and nonimaging techniques. (orig.) [de

  16. Colorectal anastomotic leakage: Aspects of prevention, detection and treatment

    NARCIS (Netherlands)

    F. Daams (Freek); M. Luyer (Misha); J.F. Lange (Johan)

    2013-01-01

    textabstractAll colorectal surgeons are faced from time to time with anastomotic leakage after colorectal surgery. This complication has been studied extensively without a significant reduction of incidence over the last 30 years. New techniques of prevention, by innovative anastomotic techniques

  17. Inhaled corticosteroid metered-dose inhalers: how do variations in technique for solutions versus suspensions affect drug distribution?

    Science.gov (United States)

    Robinson, Christie A; Tsourounis, Candy

    2013-03-01

    To assess the literature that evaluates how variations in metered-dose inhaler (MDI) technique affect lung distribution for inhaled corticosteroids (ICSs) formulated as MDI suspensions and solutions. PubMed (up to November 2012) and Cochrane Library (up to November 2012) were searched using the terms metered-dose inhalers, HFA 134a, Asthma/*drug therapy, and inhaled corticosteroids. In addition, reference citations from publications identified were reviewed. All articles in English from the data sources that assessed MDI technique comparing total lung distribution (TLD) of MDI solutions or suspensions formulated with ICSs were included in the review. Five relevant studies were identified. Five controlled studies compared how variations in MDI technique affect TLD for ICS MDI solutions with suspensions. MDI solutions resulted in greater TLD compared with larger particle MDI suspensions. Delayed or early inspiration upon device actuation of MDI solutions resulted in less TLD than coordinated actuation, but with a 3- to 4-times greater TLD than MDI suspensions inhaled using a standard technique. A sixth study evaluated inspiratory flow rates (IFR) for small, medium, and large particles. Rapid and slow IFRs resulted in similar TLD for small particles, while far fewer particles reached the airways with medium and large particles at rapid, rather than slow, IFRs. Based on the literature evaluated, standard MDI technique should be used for ICS suspensions. ICS MDI solutions can provide a higher average TLD than larger-particle ICS suspensions using standard technique, discoordinated inspiration and medication actuation timing, or rapid and slow IFRs. ICS MDI solutions allow for a more forgiving technique, which makes them uniquely suitable options for patients with asthma who have difficultly with MDI technique.

  18. Determination of boron in aqueous solutions by solid state nuclear track detectors technique, using a filtered neutron beam

    International Nuclear Information System (INIS)

    Moraes, M.A.P.V. de; Pugliesi, R.; Khouri, M.T.F.C.

    1985-11-01

    The solid state nuclear track detectors technique has been used for determination of boron in aqueous solutions, using a filtered neutron beam. The particles tracks from the 10 B(n,α)Li 7 reaction were registered in the CR-39 film, chemically etched in a (30%) KOH solution 70 0 C during 90 minutes. The obtained results showed the usefulness of this technique for boron determination in the ppm range. The inferior detectable limit was 9 ppm. The combined track registration efficiency factor K has been evaluated in the solutions, for the CR-39 detector and its values is K= (4,60 - + 0,06). 10 -4 cm. (Author) [pt

  19. A solution for future designs using techniques from vernacular architecture in southern Iran

    Science.gov (United States)

    Mirahmadi, Fatima; Altan, Hasim

    2018-02-01

    Nowadays in modern life, every technology and technique for comfortable life is available. People with low income, in other words, with low levels of economic power, can also have those facilities to stay warm in winter and stay cool in summer. Many years back when there were no advanced systems for human needs, passive strategies played a big role in peoples' lives. This paper concentrates on a small city in Iran that had used special strategies to solve peoples' environmental issues. The city is called Evaz, which is located in the Fars region of Iran with distance around 20 km from Gerash city and 370 km from south east of Shiraz. Evaz receives minimum rainfall, which is the reason why water is limited in this area and therefore, cisterns (water storage) had been used for many years that is studied in more detail in this paper. In summers, the climate is hot and dry, sometimes the external temperatures reaching around 46 °C during the day. Although the winters are typically cold and likewise dry, moderate climate is available in Evaz during autumn and spring. This study identifies some of the past strategies and describes them in detail with analysis for transformation and connections with the modern and traditional fundamentals. Furthermore, the study develops some solutions utilizing a combination of both modern and traditional techniques in design to suggest better and more effective ways to save energy, and at the same time to remain sustainable for the future.

  20. Solution of the mathematical adjoint equations for an interface current nodal formulation

    International Nuclear Information System (INIS)

    Yang, W.S.; Taiwo, T.A.; Khalil, H.

    1994-01-01

    Two techniques for solving the mathematical adjoint equations of an interface current nodal method are described. These techniques are the ''similarity transformation'' procedure and a direct solution scheme. A theoretical basis is provided for the similarity transformation procedure originally proposed by Lawrence. It is shown that the matrices associated with the mathematical and physical adjoint equations are similar to each other for the flat transverse leakage approximation but not for the quadratic leakage approximation. It is also shown that a good approximate solution of the mathematical adjoint for the quadratic transverse leakage approximation is obtained by applying the similarity transformation for the flat transverse leakage approximation to the physical adjoint solution. The direct solution scheme, which was developed as an alternative to the similarity transformation procedure, yields the correct mathematical adjoint solution for both flat and quadratic transverse leakage approximations. In this scheme, adjoint nodal equations are cast in a form very similar to that of the forward equations by employing a linear transformation of the adjoint partial currents. This enables the use of the forward solution algorithm with only minor modifications for solving the mathematical adjoint equations. By using the direct solution scheme as a reference method, it is shown that while the results computed with the similarity transformation procedure are approximate, they are sufficiently accurate for calculations of global and local reactivity changes resulting from coolant voiding in a liquid-metal reactor

  1. A TOTAL MANUFACTURING SOLUTIONS TECHNIQUE TO SELECT APPROPRIATE IMPROVEMENT STRATEGY: CASE STUDY OF A FOOTWEAR FACTORY

    Directory of Open Access Journals (Sweden)

    Gezahegn Tesfaye

    2014-09-01

    Full Text Available The Government of Ethiopia is promoting the manufacturing sector to join the global market in a large scale. Due to its comparative advantages, the Ethiopian leather and leather products industry have been given due attention. To fully utilize such advantages, the country shifted its export items from hides/skins to footwear products. Nevertheless, the performance of the leather sector in general and footwear sub-sector in particular is far below the desired standards. The improvement strategies applied hitherto were mainly to tackle a small portion of their total problems. If the Ethiopian footwear companies have to become globally competitive, their entire business spectrum has to be assessed and appropriate improvement strategies must be selected. In this research, we used a Total manufacturing solutions (TMS technique to identify areas of improvement and improvement strategy of one of Ethiopian footwear companies. For this purpose, we conducted two surveys using structured questionnaire. The first survey was to test the TMS technique against the context of footwear industry. The result proved that the original TMS model can be used to measure the performance of footwear companies. The second survey was done to identify company's total problems, map its current position and select appropriate improvement strategy. The result revealed that the company has company-wide problems and its current position is a plodder. For plodders which have company-wide problems, the improvement strategy must include aggressive application of BPR; and the implementation of best practices to develop workers skills that encourages networking and promotion, a market-led manufacturing strategy, employee involvement and team work cultures. According to the findings of this research, we suggested that a BPR technique followed by a continuous improvement programme could be an appropriate improvement strategy for this company. The company requires long-term improvement

  2. ANOVA-HDMR structure of the higher order nodal diffusion solution

    International Nuclear Information System (INIS)

    Bokov, P. M.; Prinsloo, R. H.; Tomasevic, D. I.

    2013-01-01

    Nodal diffusion methods still represent a standard in global reactor calculations, but employ some ad-hoc approximations (such as the quadratic leakage approximation) which limit their accuracy in cases where reference quality solutions are sought. In this work we solve the nodal diffusion equations utilizing the so-called higher-order nodal methods to generate reference quality solutions and to decompose the obtained solutions via a technique known as High Dimensional Model Representation (HDMR). This representation and associated decomposition of the solution provides a new formulation of the transverse leakage term. The HDMR structure is investigated via the technique of Analysis of Variance (ANOVA), which indicates why the existing class of transversely-integrated nodal methods prove to be so successful. Furthermore, the analysis leads to a potential solution method for generating reference quality solutions at a much reduced calculational cost, by applying the ANOVA technique to the full higher order solution. (authors)

  3. Facepiece leakage and fitting of respirators

    International Nuclear Information System (INIS)

    White, J.M.

    1978-05-01

    The ways in which airborne contaminants can penetrate respirators and the factors which affect the fit of respirators are discussed. The fit of the respirator to the face is shown to be the most critical factor affecting the protection achieved by the user. Qualitative and quantitative fit testing techniques are described and their application to industrial respirator programs is examined. Quantitative measurement of the leakage of a respirator while worn can be used to numerically indicate the protection achieved. These numbers, often referred to as protection factors, are sometimes used as the basis for selecting suitable respirators and this practice is reviewed. (author)

  4. Detecting the leakage source of a reservoir using isotopes.

    Science.gov (United States)

    Yi, Peng; Yang, Jing; Wang, Yongdong; Mugwanezal, Vincent de Paul; Chen, Li; Aldahan, Ala

    2018-07-01

    A good monitoring method is vital for understanding the sources of a water reservoir leakage and planning for effective restoring. Here we present a combination of several tracers ( 222 Rn, oxygen and hydrogen isotopes, anions and temperature) for identification of water leakage sources in the Pushihe pumped storage power station which is in the Liaoning province, China. The results show an average 222 Rn activity of 6843 Bq/m 3 in the leakage water, 3034 Bq/m 3 in the reservoir water, and 41,759 Bq/m 3 in the groundwater. Considering that 222 Rn activity in surface water is typically less than 5000 Bq/m 3 , the low level average 222 Rn activity in the leakage water suggests the reservoir water as the main source of water. Results of the oxygen and hydrogen isotopes show comparable ranges and values in the reservoir and the leakage water samples. However, important contribution of the groundwater (up to 36%) was present in some samples from the bottom and upper parts of the underground powerhouse, while the leakage water from some other parts indicate the reservoir water as the dominant source. The isotopic finding suggests that the reservoir water is the main source of the leakage water which is confirmed by the analysis of anions (nitrate, sulfate, and chloride) in the water samples. The combination of these tracer methods for studying dam water leakage improves the accuracy of identifying the source of leaks and provide a scientific reference for engineering solutions to ensure the dam safety. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Containment leakage rate testing requirements

    International Nuclear Information System (INIS)

    Arndt, E.G.

    1992-01-01

    This report presents the status of several documents under revision or development that provide requirements and guidance for testing nuclear power plant containment systems for leakage rates. These documents include the general revision to 10 CFR Part 50, Appendix J; the regulatory guide affiliated with the revision to Appendix J; the national standard that the regulatory guide endorses, ANSI/ANS-56.8, 'Containment System Leakage Rate Testing Requirements'; and the draft industry Licensing Topical Report, 'Standardized Program for Primary Containment Integrity Testing'. The actual or potential relationships between these documents are also explored

  6. A Visualization Technique for Accessing Solution Pool in Interactive Methods of Multiobjective Optimization

    OpenAIRE

    Filatovas, Ernestas; Podkopaev, Dmitry; Kurasova, Olga

    2015-01-01

    Interactive methods of multiobjective optimization repetitively derive Pareto optimal solutions based on decision maker’s preference information and present the obtained solutions for his/her consideration. Some interactive methods save the obtained solutions into a solution pool and, at each iteration, allow the decision maker considering any of solutions obtained earlier. This feature contributes to the flexibility of exploring the Pareto optimal set and learning about the op...

  7. Management and prevention of chylous leakage after laparoscopic lymphadenectomy.

    Science.gov (United States)

    Han, L-P; Zhang, H-M; Abha, H-D; Liu, T; Zhang, X-P

    2014-01-01

    To investigate the development and management of chylous leakage after laparoscopic retroperitoneal lymphadenectomy. From July 2006 to September 2013, 13 cases of chylous leakage after the laparoscopic lymphadenectomy (6 cases of renal cell carcinoma, 4 cases of gastric cancer, 2 cases of ovarian cancer, 1 case of endometrial cancer) were studied to analyze the occurrence, development and management of chylous leakage. In 3 cases (2 cases of renal cell carcinoma, 1 case of gastric cancer) massive amount of milky fluid drainage was be seen after the first two days post operation. Dietary intervention, TPN (total parenteral nutrition), somatostatin therapy, maintenance of continuous drainage helped to successfully manage the condition in about 1 month duration. In the remaining 10 cases, chylous leakage appeared after restoring normal diet. Managed with changes in diet and maintenance of unobstructed drainage, they were cured in about 2 weeks after treatment. There was significant reduction in drain output, ultrasonography did not reveal presence of free fluid collection in abdomen, and the patients were in good condition without signs and symptoms of infections. Chylous leakage is a rare complication of retroperitoneal lymph node dissection. Surgeons should be familiar with laparoscopic techniques, relevant anatomy and be aware of the fact that the effect of CO2 pressure and use of ultrasonic knife to occlude the lymphatic vessel can transiently block the leakage making the surgeon overlook them. Routine placement of indwelling drainage tube, immediate diagnosis, dietary modification, TPN, somatostatin and drainage are the modalities of conservative management.

  8. Superconducting coil configurations, with low flux leakage, for energy storage

    International Nuclear Information System (INIS)

    Vincent-Viry, O.; Mailfert, A.; Trassart, D.

    2001-01-01

    This paper presents two original types of SMES structures for energy storage. These two groups of SMES structures proceeded from an ideal structure: the full toroid, are modeled by the use of purely surface current densities. Their main advantage is to present no flux leakage, they give then satisfactory solution to the problem of energy storage. (orig.)

  9. A white-box anomaly-based framework for database leakage detection

    NARCIS (Netherlands)

    Costante, E.; den Hartog, J.; Petkovic, M.; Etalle, S.; Pechenizkiy, M.

    2017-01-01

    Data leakage is at the heart most of the privacy breaches worldwide. In this paper we present a white-box approach to detect potential data leakage by spotting anomalies in database transactions. We refer to our solution as white-box because it builds self explanatory profiles that are easy to

  10. Incompressible Navier-Stokes and parabolized Navier-Stokes solution procedures and computational techniques

    Science.gov (United States)

    Rubin, S. G.

    1982-01-01

    Recent developments with finite-difference techniques are emphasized. The quotation marks reflect the fact that any finite discretization procedure can be included in this category. Many so-called finite element collocation and galerkin methods can be reproduced by appropriate forms of the differential equations and discretization formulas. Many of the difficulties encountered in early Navier-Stokes calculations were inherent not only in the choice of the different equations (accuracy), but also in the method of solution or choice of algorithm (convergence and stability, in the manner in which the dependent variables or discretized equations are related (coupling), in the manner that boundary conditions are applied, in the manner that the coordinate mesh is specified (grid generation), and finally, in recognizing that for many high Reynolds number flows not all contributions to the Navier-Stokes equations are necessarily of equal importance (parabolization, preferred direction, pressure interaction, asymptotic and mathematical character). It is these elements that are reviewed. Several Navier-Stokes and parabolized Navier-Stokes formulations are also presented.

  11. Watermarking Techniques Using Least Significant Bit Algorithm for Digital Image Security Standard Solution- Based Android

    Directory of Open Access Journals (Sweden)

    Ari Muzakir

    2017-05-01

    Full Text Available Ease of deployment of digital image through the internet has positive and negative sides, especially for owners of the original digital image. The positive side of the ease of rapid deployment is the owner of that image deploys digital image files to various sites in the world address. While the downside is that if there is no copyright that serves as protector of the image it will be very easily recognized ownership by other parties. Watermarking is one solution to protect the copyright and know the results of the digital image. With Digital Image Watermarking, copyright resulting digital image will be protected through the insertion of additional information such as owner information and the authenticity of the digital image. The least significant bit (LSB is one of the algorithm is simple and easy to understand. The results of the simulations carried out using android smartphone shows that the LSB watermarking technique is not able to be seen by naked human eye, meaning there is no significant difference in the image of the original files with images that have been inserted watermarking. The resulting image has dimensions of 640x480 with a bit depth of 32 bits. In addition, to determine the function of the ability of the device (smartphone in processing the image using this application used black box testing. 

  12. Studies of implicit and explicit solution techniques in transient thermal analysis of structures

    International Nuclear Information System (INIS)

    Adelman, H.M.; Haftka, R.T.; Robinson, J.C.

    1982-08-01

    Studies aimed at an increase in the efficiency of calculating transient temperature fields in complex aerospace vehicle structures are reported. The advantages and disadvantages of explicit and implicit algorithms are discussed and a promising set of implicit algorithms with variable time steps, known as GEARIB, is described. Test problems, used for evaluating and comparing various algorithms, are discussed and finite element models of the configurations are described. These problems include a coarse model of the Space Shuttle wing, an insulated frame test article, a metallic panel for a thermal protection system, and detailed models of sections of the Space Shuttle wing. Results generally indicate a preference for implicit over explicit algorithms for transient structural heat transfer problems when the governing equations are stiff (typical of many practical problems such as insulated metal structures). The effects on algorithm performance of different models of an insulated cylinder are demonstrated. The stiffness of the problem is highly sensitive to modeling details and careful modeling can reduce the stiffness of the equations to the extent that explicit methods may become the best choice. Preliminary applications of a mixed implicit-explicit algorithm and operator splitting techniques for speeding up the solution of the algebraic equations are also described

  13. Studies of implicit and explicit solution techniques in transient thermal analysis of structures

    Science.gov (United States)

    Adelman, H. M.; Haftka, R. T.; Robinson, J. C.

    1982-01-01

    Studies aimed at an increase in the efficiency of calculating transient temperature fields in complex aerospace vehicle structures are reported. The advantages and disadvantages of explicit and implicit algorithms are discussed and a promising set of implicit algorithms with variable time steps, known as GEARIB, is described. Test problems, used for evaluating and comparing various algorithms, are discussed and finite element models of the configurations are described. These problems include a coarse model of the Space Shuttle wing, an insulated frame tst article, a metallic panel for a thermal protection system, and detailed models of sections of the Space Shuttle wing. Results generally indicate a preference for implicit over explicit algorithms for transient structural heat transfer problems when the governing equations are stiff (typical of many practical problems such as insulated metal structures). The effects on algorithm performance of different models of an insulated cylinder are demonstrated. The stiffness of the problem is highly sensitive to modeling details and careful modeling can reduce the stiffness of the equations to the extent that explicit methods may become the best choice. Preliminary applications of a mixed implicit-explicit algorithm and operator splitting techniques for speeding up the solution of the algebraic equations are also described.

  14. Techniques to limit gaseous releases in case of reactor accident. Choice criteria - present solutions

    International Nuclear Information System (INIS)

    Billard, Francois; Lavie, Jean-Marie

    1964-10-01

    Within the frame of the study of radiological risks associated with a reactor accident in order to define the required responses, this study comprises, on the one hand, an analysis of the different accident types in order to select typical accidents, and on the other hand, a site-based analysis to define the maximum admissible radioactivity release for a given site. The determination of minimum required coefficient of risk reduction results from a compromise between the choice of reactor configuration type and the efficiency of purification devices, while taking into account minimum characteristics of the enclosure mechanical strength, local release conditions, and nature of gaseous effluents to be processed. After a review of available containment techniques, the author applies this analysis method to the different French reactor types. He gives a brief description of adopted solutions for the most typical French reactors in terms of characteristics of venting and filtration devices. As data quality is a crucial requirement, the author outlines the need for further studies regarding fission product emission and transfer, the purification of gaseous effluents and their diffusion in the atmosphere [fr

  15. Feasibility of Locating Leakages in Sewage Pressure Pipes Using the Distributed Temperature Sensing Technology

    OpenAIRE

    Apperl, Benjamin; Pressl, Alexander; Schulz, Karsten

    2017-01-01

    The cost effective maintenance of underwater pressure pipes for sewage disposal in Austria requires the detection and localization of leakages. Extrusion of wastewater in lakes can heavily influence the water and bathing quality of surrounding waters. The Distributed Temperature Sensing (DTS) technology is a widely used technique for oil and gas pipeline leakage detection. While in pipeline leakage detection, fiber optic cables are installed permanently at the outside or within the protective...

  16. 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...

  17. [Bile leakage after liver resection: A retrospective cohort study].

    Science.gov (United States)

    Menclová, K; Bělina, F; Pudil, J; Langer, D; Ryska, M

    2015-12-01

    Many previous reports have focused on bile leakage after liver resection. Despite the improvements in surgical techniques and perioperative care the incidence of this complication rather keeps increasing. A number of predictive factors have been analyzed. There is still no consensus regarding their influence on the formation of bile leakage. The objective of our analysis was to evaluate the incidence of bile leakage, its impact on mortality and duration of hospitalization at our department. At the same time, we conducted an analysis of known predictive factors. The authors present a retrospective review of the set of 146 patients who underwent liver resection at the Department of Surgery of the 2nd Faculty of Medicine of the Charles University and Central Military Hospital Prague, performed between 20102013. We used the current ISGLS (International Study Group of Liver Surgery) classification to evaluate the bile leakage. The severity of this complication was determined according to the Clavien-Dindo classification system. Statistical significance of the predictive factors was determined using Fishers exact test and Students t-test. The incidence of bile leakage was 21%. According to ISGLS classification the A, B, and C rates were 6.5%, 61.2%, and 32.3%, respectively. The severity of bile leakage according to the Clavien-Dindo classification system - I-II, IIIa, IIIb, IV and V rates were 19.3%, 42%, 9.7%, 9.7%, and 19.3%, respectively. We determined the following predictive factors as statistically significant: surgery for malignancy (pBile leakage significantly prolonged hospitalization time (pbile leakage the perioperative mortality was 23 times higher (pBile leakage is one of the most serious complications of liver surgery. Most of the risk factors are not easily controllable and there is no clear consensus on their influence. Intraoperative leak tests could probably reduce the incidence of bile leakage. In the future, further studies will be required to improve

  18. A note on the solution of general Falkner-Skan problem by two novel semi-analytical techniques

    Directory of Open Access Journals (Sweden)

    Ahmed Khidir

    2015-12-01

    Full Text Available The aim of this paper is to give a presentation of two new iterative methods for solving non-linear differential equations, they are successive linearisation method and spectral homotopy perturbation method. We applied these techniques on the non-linear boundary value problems of Falkner-Skan type. The methods used to find a recursive former for higher order equations that are solved using the Chebyshev spectral method to find solutions that are accurate and converge rapidly to the full numerical solution. The methods are illustrated by progressively applying the technique to the Blasius boundary layer equation, the Falkner-Skan equation and finally, the magnetohydrodynamic (MHD Falkner-Skan equation. The solutions are compared to other methods in the literature such as the homotopy analysis method and the spectral-homotopy analysis method with focus on the accuracy and convergence of this new techniques.

  19. 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 (pleakage around the Class 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.

  20. Effects of radical scavengers on aqueous solutions exposed to heavy-ion irradiation using the liquid microjet technique

    Science.gov (United States)

    Nomura, Shinji; Tsuchida, Hidetsugu; Furuya, Ryousuke; Miyahara, Kento; Majima, Takuya; Itoh, Akio

    2015-12-01

    The effects of the radical scavenger ascorbic acid on water radiolysis are studied by fast heavy-ion irradiation of aqueous solutions of ascorbic acid, using the liquid microjet technique under vacuum. To understand the reaction mechanisms of hydroxyl radicals in aqueous solutions, we directly measure secondary ions emitted from solutions with different ascorbic acid concentrations. The yield of hydronium secondary ions is strongly influenced by the reaction between ascorbic acid and hydroxyl radicals. From analysis using a simple model considering chemical equilibria, we determine that the upper concentration limit of ascorbic acid with a radical scavenger effect is approximately 70 μM.

  1. Effects of radical scavengers on aqueous solutions exposed to heavy-ion irradiation using the liquid microjet technique

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, Shinji [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Tsuchida, Hidetsugu, E-mail: tsuchida@nucleng.kyoto-u.ac.jp [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Quantum Science and Engineering Center, Kyoto University, Uji 611-0011 (Japan); Furuya, Ryousuke; Miyahara, Kento [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Majima, Takuya; Itoh, Akio [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Quantum Science and Engineering Center, Kyoto University, Uji 611-0011 (Japan)

    2015-12-15

    The effects of the radical scavenger ascorbic acid on water radiolysis are studied by fast heavy-ion irradiation of aqueous solutions of ascorbic acid, using the liquid microjet technique under vacuum. To understand the reaction mechanisms of hydroxyl radicals in aqueous solutions, we directly measure secondary ions emitted from solutions with different ascorbic acid concentrations. The yield of hydronium secondary ions is strongly influenced by the reaction between ascorbic acid and hydroxyl radicals. From analysis using a simple model considering chemical equilibria, we determine that the upper concentration limit of ascorbic acid with a radical scavenger effect is approximately 70 μM.

  2. Effects of radical scavengers on aqueous solutions exposed to heavy-ion irradiation using the liquid microjet technique

    International Nuclear Information System (INIS)

    Nomura, Shinji; Tsuchida, Hidetsugu; Furuya, Ryousuke; Miyahara, Kento; Majima, Takuya; Itoh, Akio

    2015-01-01

    The effects of the radical scavenger ascorbic acid on water radiolysis are studied by fast heavy-ion irradiation of aqueous solutions of ascorbic acid, using the liquid microjet technique under vacuum. To understand the reaction mechanisms of hydroxyl radicals in aqueous solutions, we directly measure secondary ions emitted from solutions with different ascorbic acid concentrations. The yield of hydronium secondary ions is strongly influenced by the reaction between ascorbic acid and hydroxyl radicals. From analysis using a simple model considering chemical equilibria, we determine that the upper concentration limit of ascorbic acid with a radical scavenger effect is approximately 70 μM.

  3. Multigrid techniques for nonlinear eigenvalue probems: Solutions of a nonlinear Schroedinger eigenvalue problem in 2D and 3D

    Science.gov (United States)

    Costiner, Sorin; Taasan, Shlomo

    1994-01-01

    This paper presents multigrid (MG) techniques for nonlinear eigenvalue problems (EP) and emphasizes an MG algorithm for a nonlinear Schrodinger EP. The algorithm overcomes the mentioned difficulties combining the following techniques: an MG projection coupled with backrotations for separation of solutions and treatment of difficulties related to clusters of close and equal eigenvalues; MG subspace continuation techniques for treatment of the nonlinearity; an MG simultaneous treatment of the eigenvectors at the same time with the nonlinearity and with the global constraints. The simultaneous MG techniques reduce the large number of self consistent iterations to only a few or one MG simultaneous iteration and keep the solutions in a right neighborhood where the algorithm converges fast.

  4. Automation of unit for leakage test

    OpenAIRE

    LYCHKOVSKAYA V.S.; TSYGANKOV A.S.; GRINBERG G.M.; STANOVOVA O.A.

    2015-01-01

    Federal state educational standard requirements for training of university students have been considered. Leakage test procedures for components of aerospace vehicles have been described. Automation procedures of existing laboratory leakage test units have been outlined.

  5. 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.

  6. Subsea Hydraulic Leakage Detection and Diagnosis

    OpenAIRE

    Stavenes, Thomas

    2010-01-01

    The motivation for this thesis is reduction of hydraulic emissions, minimizing of process emergency shutdowns, exploitation of intervention capacity, and reduction of costs. Today, monitoring of hydraulic leakages is scarce and the main way to detect leakage is the constant need for filling of hydraulic fluid to the Hydraulic Power Unit (HPU). Leakage detection and diagnosis has potential, which would be adressed in this thesis. A strategy towards leakage detection and diagnosis is given....

  7. Simulation of leakage through mechanical sealing device

    Science.gov (United States)

    Tikhomorov, V. P.; Gorlenko, O. A.; Izmerov, M. A.

    2018-03-01

    The procedure of mathematical modeling of leakage through the mechanical seal taking into account waviness and roughness is considered. The percolation process is represented as the sum of leakages through a gap between wavy surfaces and percolation through gaps formed by fractal roughness, i.e. the total leakage is determined by the slot model and filtration leakage. Dependences of leaks on the contact pressure of corrugated and rough surfaces of the mechanical seal elements are presented.

  8. 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.

  9. 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.

  10. Measurement of resistance to solute transport across surfactant-laden interfaces using a Fluorescence Recovery After Photobleaching (FRAP) technique

    Science.gov (United States)

    Browne, Edward P.; Nivaggioli, Thierry; Hatton, T. Alan

    1994-01-01

    A noninvasive fluorescence recovery after photobleaching (FRAP) technique is under development to measure interfacial transport in two phase systems without disturbing the interface. The concentration profiles of a probe solute are measured in both sides of the interface by argon-ion laser, and the system relaxation is then monitored by a microscope-mounted CCD camera.

  11. The Identification of Reasons, Solutions, and Techniques Informing a Theory-Based Intervention Targeting Recreational Sports Participation

    Science.gov (United States)

    St Quinton, Tom; Brunton, Julie A.

    2018-01-01

    Purpose: This study is the 3rd piece of formative research utilizing the theory of planned behavior to inform the development of a behavior change intervention. Focus groups were used to identify reasons for and solutions to previously identified key beliefs in addition to potentially effective behavior change techniques. Method: A purposive…

  12. Determination of the free ion concentration of trace metals in soil solution using a soil column Donnan membrane technique

    NARCIS (Netherlands)

    Weng, L.; Temminghoff, E.J.M.; Riemsdijk, van W.H.

    2001-01-01

    Accurate measurement of the free metal ion is difficult, especially for trace metals present in very small concentrations (less than micromolar) in natural systems. The recently developed Donnan membrane technique can measure the concentrations in solution in the presence of inorganic and organic

  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

    The coupling of the windings can be easily increased by using multiply stacked planar windings connection. Interleaving is a well-known technique used to reduce leakage inductance and minimize high-frequency winding losses. The paper aims to analyze leakage inductance based on magneto motive force...

  14. 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.

  15. Extending the Constant Coefficient Solution Technique to Variable Coefficient Ordinary Differential Equations

    Science.gov (United States)

    Mohammed, Ahmed; Zeleke, Aklilu

    2015-01-01

    We introduce a class of second-order ordinary differential equations (ODEs) with variable coefficients whose closed-form solutions can be obtained by the same method used to solve ODEs with constant coefficients. General solutions for the homogeneous case are discussed.

  16. Leakage of pressurized gases through unlined concrete containment structures

    International Nuclear Information System (INIS)

    Rizkalla, S.H.; Simmonds, S.H.

    1983-01-01

    Eight reinforced concrete specimens were fabricated and subjected to tensile membrane forces and air pressure to study the air leakage characteristics in cracked reinforced concrete members. A mathematical expression for the rate of pressurized air flowing through an idealized crack is presented. The mathematical expression is refined by using the experimental data to describe the air flow rate through any given crack pattern. Graphical charts are also presented for the calculation of the air leakage rate through concrete cracks. The concept of equivalent crack width for a given crack pattern is introduced. The mathematical expression and graphical charts are modified to include this equivalent crack width concept. The proposed technique is applicable for the prediction of the leakage from concrete containment structures or any similar structures due to high internal pressure sufficient to initiate cracking. (orig.)

  17. Patterning titania with the conventional and modified micromolding in capillaries technique from sol–gel and dispersion solutions

    Directory of Open Access Journals (Sweden)

    Sajid Ullah Khan and Johan E ten Elshof

    2012-01-01

    Full Text Available We report TiO2 patterns obtained by a soft-lithographic technique called 'micromolding in capillaries' using sol–gel and dispersion solutions. A comparison between patterning with a sol–gel and dispersion solutions has been performed. The patterns obtained from sol–gel solutions showed good adhesion to the substrate and uniform shapes, but large shrinkage, whereas those obtained from dispersion solution had high solid content, but exhibited poor adhesion and non-uniform shapes. A fabrication method of a layer-by-layer structured pattern is also demonstrated. This type of pattern may find application in sensors, waveguides and other photonics elements. The occurrence of an undesirable residue layer, which hinders the fabrication of isolated patterns, is highlighted and a method of prevention is suggested.

  18. Evaluation of the white test for the intraoperative detection of bile leakage.

    Science.gov (United States)

    Leelawat, Kawin; Chaiyabutr, Kittipong; Subwongcharoen, Somboon; Treepongkaruna, Sa-Ad

    2012-01-01

    We assess whether the White test is better than the conventional bile leakage test for the intraoperative detection of bile leakage in hepatectomized patients. This study included 30 patients who received elective liver resection. Both the conventional bile leakage test (injecting an isotonic sodium chloride solution through the cystic duct) and the White test (injecting a fat emulsion solution through the cystic duct) were carried out in the same patients. The detection of bile leakage was compared between the conventional method and the White test. A bile leak was demonstrated in 8 patients (26.7%) by the conventional method and in 19 patients (63.3%) by the White test. In addition, the White test detected a significantly higher number of bile leakage sites compared with the conventional method (Wilcoxon signed-rank test; P detection of bile leakage. Based on our study, we recommend that surgeons investigating bile leakage sites during liver resections should use the White test instead of the conventional bile leakage test.

  19. Measurement of the thermal diffusivity and speed of sound of hydrothermal solutions via the laser-induced grating technique

    International Nuclear Information System (INIS)

    Butenhoff, T.J.

    1994-01-01

    Hydrothermal processing is being developed as a method for organic destruction for the Hanford Site in Washington. Hydrothermal processing refers to the redox reactions of chemical compounds in supercritical or near-supercritical aqueous solutions. In order to design reactors for the hydrothermal treatment of complicated mixtures found in the Hanford wastes, engineers need to know the thermophysical properties of the solutions under hydrothermal conditions. The author used the laser-induced grating technique to measure the thermal diffusivity and speed of sound of hydrothermal solutions. In this non-invasive optical technique, a transient grating is produced in the hydrothermal solution by optical absorption from two crossed time-coincident nanosecond laser pulses. The grating is probed by measuring the diffraction efficiency of a third laser beam. The grating relaxes via thermal diffusion, and the thermal diffusivity can be determined by measuring the decay of the grating diffraction efficiency as a function of the pump-probe delay time. In addition, intense pump pulses produce counterpropagating acoustic waves that appear as large undulations in the transient grating decay spectrum. The speed of sound in the sample is simply the grating fringe spacing divided by the undulation period. The cell is made from a commercial high pressure fitting and is equipped with two diamond windows for optical access. Results are presented for dilute dye/water solutions with T = 400 C and pressures between 20 and 70 MPa

  20. Insulation Resistance and Leakage Currents in Low-Voltage Ceramic Capacitors with Cracks

    Science.gov (United States)

    Teverovsky, Alexander A.

    2016-01-01

    Measurement of insulation resistance (IR) in multilayer ceramic capacitors (MLCCs) is considered a screening technique that ensures the dielectric is defect-free. This work analyzes the effectiveness of this technique for revealing cracks in ceramic capacitors. It is shown that absorption currents prevail over the intrinsic leakage currents during standard IR measurements at room temperature. Absorption currents, and consequently IR, have a weak temperature dependence, increase linearly with voltage (before saturation), and are not sensitive to the presence of mechanical defects. In contrary, intrinsic leakage currents increase super-linearly with voltage and exponentially with temperature (activation energy is in the range from 0.6 eV to 1.1 eV). Leakage currents associated with the presence of cracks have a weaker dependence on temperature and voltage compared to the intrinsic leakage currents. For this reason, intrinsic leakage currents prevail at high temperatures and voltages, thus masking the presence of defects.

  1. Feasibility of Locating Leakages in Sewage Pressure Pipes Using the Distributed Temperature Sensing Technology.

    Science.gov (United States)

    Apperl, Benjamin; Pressl, Alexander; Schulz, Karsten

    2017-01-01

    The cost effective maintenance of underwater pressure pipes for sewage disposal in Austria requires the detection and localization of leakages. Extrusion of wastewater in lakes can heavily influence the water and bathing quality of surrounding waters. The Distributed Temperature Sensing (DTS) technology is a widely used technique for oil and gas pipeline leakage detection. While in pipeline leakage detection, fiber optic cables are installed permanently at the outside or within the protective sheathing of the pipe; this paper aims at testing the feasibility of detecting leakages with temporary introduced fiber optic cable inside the pipe. The detection and localization were tested in a laboratory experiment. The intrusion of water from leakages into the pipe, producing a local temperature drop, served as indicator for leakages. Measurements were taken under varying measurement conditions, including the number of leakages as well as the positioning of the fiber optic cable. Experiments showed that leakages could be detected accurately with the proposed methodology, when measuring resolution, temperature gradient and measurement time were properly selected. Despite the successful application of DTS for leakage detection in this lab environment, challenges in real system applications may arise from temperature gradients within the pipe system over longer distances and the placement of the cable into the real pipe system.

  2. Development of numerical solution techniques in the KIKO3D code

    International Nuclear Information System (INIS)

    Panka, Istvan; Kereszturi, Andras; Hegedus, Csaba

    2005-01-01

    The paper describes the numerical methods applied in KIKO3D three-dimensional reactor dynamics code and present a new, more effective method (Bi-CGSTAB) for accelerating the large sparse matrix equation solution. The convergence characteristics were investigated in a given macro time step of a Control Rod Ejection transient. The results obtained by the old GMRES and new Bi-CGSTAB methods are compared. It is concluded that the real relative errors of the solutions obtained by GMRES or Bi - CGSTAB algorithms are in fact closer together than the estimated relative errors. The KIKO3D-Bi-CGSTAB method converges safely and it is 7-12 % faster than the old KIKO3D-GMRES solution (Authors)

  3. Separation and Concentration of Succinic Adic from Multicomponent Aqueous Solutions by Nanofiltration Technique

    Directory of Open Access Journals (Sweden)

    Antczak Jerzy

    2014-06-01

    Full Text Available This paper applies the determined suitability of nanofiltration (NF membrane separation for selective isolation and concentration of succinic acid from aqueous solutions which are post-fermentation multicomponent fluids. The study analyzed the influence of concentration and the pH of the separated solutions on the efficiency and selectivity of NF process that runs in a module equipped with a ceramic membrane. Moreover, the effect of applied trans-membrane pressure on the retention of succinic acid and sodium succinate has been studied. The investigations have shown that in the used NF module the retention of succinic acid salt is equal almost 50% in the case of a three-component model solution, although the degree of retention depends on both the transmembrane pressure and the initial concentration of separated salt.

  4. Comparison of in situ polymerization and solution-dispersion techniques in the preparation of Polyimide/Montmorillonite (MMT) Nanocomposites.

    Science.gov (United States)

    Ahmad, Mansor Bin; Gharayebi, Yadollah; Salit, Mohd Sapuan; Hussein, Mohd Zobir; Shameli, Kamyar

    2011-01-01

    In this paper, Polyimide/Montmorillonite Nanocomposites (PI/MMT NCs), based on aromatic diamine (4-Aminophenyl sulfone) (APS) and aromatic dianhydride (3,3',4,4'-benzophenonetetracarboxylic dianhydride) (BTDA) were prepared using in situ polymerization and solution-dispersion techniques. The prepared PI/MMT NCs films were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The XRD results showed that at the content of 1.0 wt % Organo Montmorillonite (OMMT) for two techniques and 3.0 wt % OMMT for the in situ polymerization technique, the OMMT was well-intercalated, exfoliated and dispersed into polyimide matrix. The OMMT agglomerated when its amount exceeded 10 wt % and 3.0 wt % for solution-dispersion and in situ polymerization techniques respectively. These results were confirmed by the TEM images of the prepared PI/MMT NCs. The TGA thermograms indicated that thermal stability of prepared PI/MMT NCs were increased with the increase of loading that, the effect is higher for the samples prepared by in situ polymerization technique.

  5. On the solution of two-point linear differential eigenvalue problems. [numerical technique with application to Orr-Sommerfeld equation

    Science.gov (United States)

    Antar, B. N.

    1976-01-01

    A numerical technique is presented for locating the eigenvalues of two point linear differential eigenvalue problems. The technique is designed to search for complex eigenvalues belonging to complex operators. With this method, any domain of the complex eigenvalue plane could be scanned and the eigenvalues within it, if any, located. For an application of the method, the eigenvalues of the Orr-Sommerfeld equation of the plane Poiseuille flow are determined within a specified portion of the c-plane. The eigenvalues for alpha = 1 and R = 10,000 are tabulated and compared for accuracy with existing solutions.

  6. removal of hazardous pollutants from industrial waste solutions using membrane techniques

    International Nuclear Information System (INIS)

    Selim, Y.T.M.

    2001-01-01

    the removal of hazardous pollutants from industrial waste solutions is of essential demand field for both scientific and industrial work. the present work includes detailed studies on the possible use of membrane technology especially liquid emulsion membrane for the removal of hazardous pollutants such as; cadmium , cobalt , lead, copper and uranium from different industrial waste solution . this research can be applied for mixed waste problems. the work carried out in this thesis is presented in three main chapters, namely introduction, experimental and results and discussion

  7. A new multi-step technique with differential transform method for analytical solution of some nonlinear variable delay differential equations.

    Science.gov (United States)

    Benhammouda, Brahim; Vazquez-Leal, Hector

    2016-01-01

    This work presents an analytical solution of some nonlinear delay differential equations (DDEs) with variable delays. Such DDEs are difficult to treat numerically and cannot be solved by existing general purpose codes. A new method of steps combined with the differential transform method (DTM) is proposed as a powerful tool to solve these DDEs. This method reduces the DDEs to ordinary differential equations that are then solved by the DTM. Furthermore, we show that the solutions can be improved by Laplace-Padé resummation method. Two examples are presented to show the efficiency of the proposed technique. The main advantage of this technique is that it possesses a simple procedure based on a few straight forward steps and can be combined with any analytical method, other than the DTM, like the homotopy perturbation method.

  8. Demonstration of a Solution Film Leak Test Technique and Equipment for the S00645 Canister Closure

    International Nuclear Information System (INIS)

    Cannell, G.R.

    1999-01-01

    The purpose of this effort was to demonstrate that the SFT technique, when adapted to a DWPF canister nozzle, is capable of detecting leaks not meeting the Waste Acceptance Product Specifications (WAPS) acceptance criterion

  9. 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.

  10. A new structural technique for examining ion-neutral association in aqueous solution

    Czech Academy of Sciences Publication Activity Database

    Mason, Philip E.; Neilson, G. W.; Price, D. L.; Saboungi, M. L.; Brady, J. W.

    2013-01-01

    Roč. 160, 07 January (2013), s. 161-170 ISSN 1359-6640 Grant - others:NIH(US) GM63018 Institutional support: RVO:61388963 Keywords : aqueous solutions * neutron diffraction * molecular dynamics Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.194, year: 2013

  11. Evaluations of cellulose accessibilities of lignocelluloses by solute exclusion and protein adsorption techniques

    Science.gov (United States)

    Q.Q. Wang; Z. He; Z. Zhu; Y.-H.P. Zhang; Y. Ni; X.L. Luo; J.Y. Zhu

    2012-01-01

    Cellulose accessibilities of a set of hornified lignocellulosic substrates derived by drying the never dried pretreated sample and a set of differently pretreated lodgepople pine substrates, were evaluated using solute exclusion and protein adsorption methods. Direct measurements of cellulase adsorption onto cellulose surface of the set of pretreated substrates were...

  12. Comparison of three Stark problem solution techniques for the bounded case

    Science.gov (United States)

    Hatten, Noble; Russell, Ryan P.

    2015-01-01

    Three methods of obtaining solutions to the Stark problem—one developed by Lantoine and Russell using Jacobi elliptic and related functions, one developed by Biscani and Izzo using Weierstrass elliptic and related functions, and one developed by Pellegrini, Russell, and Vittaldev using and Taylor series extended to the Stark problem—are compared qualitatively and quantitatively for the bounded motion case. For consistency with existing available code for the series solution, Fortran routines of the Lantoine method and Biscani method are newly implemented and made available. For these implementations, the Lantoine formulation is found to be more efficient than the Biscani formulation in the propagation of a single trajectory segment. However, for applications for which acceptable accuracy may be achieved by orders up to 16, the Pellegrini series solution is shown to be more efficient than either analytical method. The three methods are also compared in the propagation of sequentially connected trajectory segments in a low-thrust orbital transfer maneuver. Separate tests are conducted for discretizations between 8 and 96 segments per orbit. For the series solution, the interaction between order and step size leads to computation times that are nearly invariable to discretization for a given truncation error tolerance over the tested range of discretizations. This finding makes the series solution particularly attractive for mission design applications where problems may require both coarse and fine discretizations. Example applications include the modeling of low-thrust propulsion and time-varying perturbations—problems for which the efficient propagation of relatively short Stark segments is paramount because the disturbing acceleration generally varies continuously.

  13. Cerebrospinal fluid leakage. Indications, technique and results of treatment with a blood patch; Liquorverlustsyndrom. Indikation, Technik und Ergebnisse der Behandlung mit ''blood patch''

    Energy Technology Data Exchange (ETDEWEB)

    Gottschalk, A. [Krankenhaus Nordwest, Abteilung Neuroradiologie, Frankfurt am Main (Germany)

    2015-06-15

    In most cases cerebrospinal fluid (CSF) leaks are iatrogenic and caused by medical interventions, such as lumbar puncture, peridural anesthesia and surgical interventions on the spine, However, spontaneous cerebral hypotension is currently detected more frequently due to improvements in diagnostic possibilities but often the cause cannot be clarified with certainty. There are various diagnostic tools for confirming the diagnosis and searching for the site of CSF leakage, such as postmyelography computed tomography (postmyelo-CT), indium{sup 111} radioisotope cisternography and (myelo) magnetic resonance imaging (MRI), which show different sensitivities. In accordance with own experience native MRI with fat-saturated T2-weighted sequences is often sufficient for diagnosing CSF leakage and the site. For the remaining cases an additional postmyelo-CT or alternatively myelo-MRI is recommended. In some patients with spontaneous cranial hypotension multiple CSF leaks are found at different spinal levels. The main symptom in most cases is an orthostatic headache. While post-puncture syndrome is self-limiting in many cases, spontaneous CSF leakage usually requires blood patch therapy. A lumbar blood patch can be safely carried out under guidance by fluoroscopy. In the case of a cervical or dorsal blood patch, CT guidance is recommended, which ensures epidural application of the blood patch and minimizes the risk of damaging the spinal cord. Despite a high success rate at the first attempt with a blood patch of up to 85 %, some cases require repeating the blood patch. A targeted blood patch of a CSF leak should generally be favoured over a blindly placed blood patch; nevertheless, if a CSF leak cannot be localized by CT or MRI a therapeutic attempt with a lumbar blood patch can be carried out. After a successful blood patch intracranial hygromas and pachymeningeal enhancement in the head show fast regression; however, epidural hygromas of the spine can persist for a period

  14. Development of a technique for the on line determination of uranium in solution by gamma ray spectroscopy

    International Nuclear Information System (INIS)

    Singh, Sarabjit; Ramaswami, A.; Gill, Jatinder Singh

    2005-02-01

    A technique based on gamma ray spectrometry has been developed for the continuous monitoring of uranium in the solution form. Simulated container and support system was designed and fabricated for the development of an efficiency calibration curve and to find the detection limit for the estimation of uranium using 185.7 keV ( 235 U) gamma ray. The system was calibrated for its counting efficiency using HPGe detector system, in a standard source mount to detector geometry. The sensitivity of the detection system and counting time for low-level estimation of uranium has also been established. The detection limit of the monitor is ∼10 mg of uranium per litre of the solution. In order to correct for the density variation of the solution experiment was carried to study the variation of count rate of 185.7 ke V gamma ray of 235 U as a function of the density of the solution. This report gives the details of the development of a continuous monitor for the determination of uranium in the solution streams. (author)

  15. Application of natural dyes in textile industry and the treatment of dye solutions using electrolytic techniques

    OpenAIRE

    Abouamer, Karima Massaud

    2008-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 25/02/2008. Anodic oxidation of a commercial dye, methylene blue (MB), from aqueous solutions using an electrochemical cell is reported. Data are provided on the effects of eight different types of supporting electrolytes, concentration of electrolytes, initial dye concentration, current and electrolytic time on the percentage removal of methylene blue. Anodic oxidation was found to be effect...

  16. Why the CDM can reduce carbon leakage

    International Nuclear Information System (INIS)

    Kallbekken, S.

    2006-04-01

    Carbon leakage is an important concern because it can reduce the environmental effectiveness of the Kyoto Protocol. The Clean Development Mechanism, one of the flexibility mechanisms allowed under the protocol, has the potential to reduce carbon leakage significantly because it reduces the relative competitive disadvantage to Annex B countries of restricting greenhouse gas emissions. The economic intuition behind this mechanism is explored in a theoretical analysis. It is then analyzed numerically using a CGE model. The results indicate that, assuming appropriate accounting for leakage and under realistic assumptions on CDM activity, the CDM has the potential to reduce the magnitude of carbon leakage by around three fifths

  17. The numerical solution of thawing process in phase change slab using variable space grid technique

    Directory of Open Access Journals (Sweden)

    Serttikul, C.

    2007-09-01

    Full Text Available This paper focuses on the numerical analysis of melting process in phase change material which considers the moving boundary as the main parameter. In this study, pure ice slab and saturated porous packed bed are considered as the phase change material. The formulation of partial differential equations is performed consisting heat conduction equations in each phase and moving boundary equation (Stefan equation. The variable space grid method is then applied to these equations. The transient heat conduction equations and the Stefan condition are solved by using the finite difference method. A one-dimensional melting model is then validated against the available analytical solution. The effect of constant temperature heat source on melting rate and location of melting front at various times is studied in detail.It is found that the nonlinearity of melting rate occurs for a short time. The successful comparison with numerical solution and analytical solution should give confidence in the proposed mathematical treatment, and encourage the acceptance of this method as useful tool for exploring practical problems such as forming materials process, ice melting process, food preservation process and tissue preservation process.

  18. Study of iodine-iodate isotopic exchange reaction in neutral aqueous solutions by radiotracer technique

    International Nuclear Information System (INIS)

    Tripathi, R.; Ram, K.D.

    1993-01-01

    The isotopic exchange of iodine atoms in neutral aqueous solutions of iodate ions and iodine (in KI) is found to obey the rate law R = k [IO 3 - ] 0.4 [I 2 ] 1.2 at 175 o C. The addition of neutral ionic salts, e.g. KCl and KNO 3 , in the reaction mixture showed a slight catalytic effect on the exchange rate. Further, the kinetic salt effect indicated the involvement of at least one neutral species on the rate-determining step. The activation energy in neutral aqueous solutions of iodate ions and iodine is found to be 86 ± 3 kJ mol -1 , which decreases in the presence of KCl (79 ± 3 kJ mol -1 and KNO 3 (82 + 3 kJ mol -1 ). The activation parameters, viz. free energy of activation, enthalpy of activation and entropy of activation, were also calculated. Based on these results, an association-dissociation type of reaction mechanism is proposed for this exchange reaction in neutral aqueous medium, similar to that proposed earlier for iodide-iodate isotopic exchange reaction in neutral aqueous solutions, nitrate eutectic melts and iodide-iodate melts. (author)

  19. Analytical vs. Simulation Solution Techniques for Pulse Problems in Non-linear Stochastic Dynamics

    DEFF Research Database (Denmark)

    Iwankiewicz, R.; Nielsen, Søren R. K.

    Advantages and disadvantages of available analytical and simulation techniques for pulse problems in non-linear stochastic dynamics are discussed. First, random pulse problems, both those which do and do not lead to Markov theory, are presented. Next, the analytical and analytically-numerical tec......Advantages and disadvantages of available analytical and simulation techniques for pulse problems in non-linear stochastic dynamics are discussed. First, random pulse problems, both those which do and do not lead to Markov theory, are presented. Next, the analytical and analytically...

  20. Determination of the diffusion coefficient of oxygen in sodium chloride solutions with a transient pulse technique

    NARCIS (Netherlands)

    van Stroe, A.J.; Janssen, L.J.J.

    1993-01-01

    An accurate and rapid method for detg. the diffusion coeffs. of electrochem. active gases in electrolytes is described. The technique is based on chronoamperometry where transient currents are measured and interpreted with a Cottrell-related equation. The diffusion coeffs. of oxygen were detd. for

  1. A technique for accurate measurements of temperature variations in solution calorimetry and osmometry of actinide complexes

    International Nuclear Information System (INIS)

    Ponkshe, M.R.; Samuel, J.K.

    1982-01-01

    The temperature variations of the order of 10 3- to 10 -4 C are measured by means of matched pair of thermistors and constant current techniques. The factors deciding the sensitivity and accuracy are fully discussed. Also the factors which put restrictions on the practical detection limits are also described. (author)

  2. On solutions of stochastic oscillatory quadratic nonlinear equations using different techniques, a comparison study

    International Nuclear Information System (INIS)

    El-Tawil, M A; Al-Jihany, A S

    2008-01-01

    In this paper, nonlinear oscillators under quadratic nonlinearity with stochastic inputs are considered. Different methods are used to obtain first order approximations, namely, the WHEP technique, the perturbation method, the Pickard approximations, the Adomian decompositions and the homotopy perturbation method (HPM). Some statistical moments are computed for the different methods using mathematica 5. Comparisons are illustrated through figures for different case-studies

  3. Valve packing leakage monitoring device

    International Nuclear Information System (INIS)

    Ezekoye, L.I.

    1985-01-01

    A device for monitoring leakage of fluid across a seal in a component connected to a pressurized fluid system including a housing having a chamber with an inlet for receiving fluid leaking across the seal and an outlet. A positioning means is connected to an orifice plug so as to move the plug for permitting the fluid to be discharged through the orifice at the same rate at which it enters the first chamber and means for detecting the movement of the plug is provided to produce and output signal corresponding to the distance moved by the plug and thereby indicate flow rate. The positioning means compromise a piston attached to the plug by a hollow tube and springs, which at low flow rates locate the piston. When flow increases sufficiently pressure increases and urges the piston upwards. A magnetic portion of tube actuates a succession of proximity switches to indicate flow rate. (author)

  4. Comparison of soil solution sampling techniques to assess metal fluxes from contaminated soil to groundwater.

    Science.gov (United States)

    Coutelot, F; Sappin-Didier, V; Keller, C; Atteia, O

    2014-12-01

    The unsaturated zone plays a major role in elemental fluxes in terrestrial ecosystems. A representative chemical analysis of soil pore water is required for the interpretation of soil chemical phenomena and particularly to assess Trace Elements (TEs) mobility. This requires an optimal sampling system to avoid modification of the extracted soil water chemistry and allow for an accurate estimation of solute fluxes. In this paper, the chemical composition of soil solutions sampled by Rhizon® samplers connected to a standard syringe was compared to two other types of suction probes (Rhizon® + vacuum tube and Rhizon® + diverted flow system). We investigated the effects of different vacuum application procedures on concentrations of spiked elements (Cr, As, Zn) mixed as powder into the first 20 cm of 100-cm columns and non-spiked elements (Ca, Na, Mg) concentrations in two types of columns (SiO2 sand and a mixture of kaolinite + SiO2 sand substrates). Rhizon® was installed at different depths. The metals concentrations showed that (i) in sand, peak concentrations cannot be correctly sampled, thus the flux cannot be estimated, and the errors can easily reach a factor 2; (ii) in sand + clay columns, peak concentrations were larger, indicating that they could be sampled but, due to sorption on clay, it was not possible to compare fluxes at different depths. The different samplers tested were not able to reflect the elemental flux to groundwater and, although the Rhizon® + syringe device was more accurate, the best solution remains to be the use of a lysimeter, whose bottom is kept continuously at a suction close to the one existing in the soil.

  5. 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...... investigates the modeling of one of the major spatial artifacts produced by local dimming: leakage. Leakage appears in dark areas when the backlight level is too high for LC cells to block sufficiently and the final displayed brightness is higher than it should. A subjective quality experiment was run...... 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...

  6. On substructuring algorithms and solution techniques for the numerical approximation of partial differential equations

    Science.gov (United States)

    Gunzburger, M. D.; Nicolaides, R. A.

    1986-01-01

    Substructuring methods are in common use in mechanics problems where typically the associated linear systems of algebraic equations are positive definite. Here these methods are extended to problems which lead to nonpositive definite, nonsymmetric matrices. The extension is based on an algorithm which carries out the block Gauss elimination procedure without the need for interchanges even when a pivot matrix is singular. Examples are provided wherein the method is used in connection with finite element solutions of the stationary Stokes equations and the Helmholtz equation, and dual methods for second-order elliptic equations.

  7. Visual Inspection of Water Leakage from Ground Penetrating Radar Radargram

    Science.gov (United States)

    Halimshah, N. N.; Yusup, A.; Mat Amin, Z.; Ghazalli, M. D.

    2015-10-01

    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.

  8. Leakage detection in underground gas mains with radioaktive argon

    International Nuclear Information System (INIS)

    Schmitz, J.

    1975-01-01

    In the field of gas supply, radionuclide techniques are suitable for the routine monitoring of transport mains by means of highly active tracer clouds and a measuring scraper as well as for exact leakage detection in local gas distribution systems. Very good results are obtained in the case of mains lying lower than 1.5 m if the length and alignment of the pipe section allow a towing probe to be pulled through. This was investigated systematically on a model stretch under practical conditions. The attempts to detect leakages were made with the aid of the radioactive isotope 41 Ar. Under conditions close to practice concerning pipe bedding, branching, pre-pressure, and leakage diameter, a leak with leakage rates as small as approx. 1 l/min could be measured with the aid of a towing probe with a precision of +-0.5 m. This accuracy is another advantage of this method. Branching and fittings with a big dead volume do not interfere with the evaluation. The investment for this method can be compared to other physical/technical investigations on mains, e.g. weld seam tests. (orig./LN) [de

  9. 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.

  10. Measurement of the temperature of density maximum of water solutions using a convective flow technique

    OpenAIRE

    Cawley, M.F.; McGlynn, D.; Mooney, P.A.

    2006-01-01

    A technique is described which yields an accurate measurement of the temperature of density maximum of fluids which exhibit such anomalous behaviour. The method relies on the detection of changes in convective flow in a rectangular cavity containing the test fluid.The normal single-cell convection which occurs in the presence of a horizontal temperature gradient changes to a double cell configuration in the vicinity of the density maximum, and this transition manifests itself in changes in th...

  11. A Structured Grid Based Solution-Adaptive Technique for Complex Separated Flows

    Science.gov (United States)

    Thornburg, Hugh; Soni, Bharat K.; Kishore, Boyalakuntla; Yu, Robert

    1996-01-01

    The objective of this work was to enhance the predictive capability of widely used computational fluid dynamic (CFD) codes through the use of solution adaptive gridding. Most problems of engineering interest involve multi-block grids and widely disparate length scales. Hence, it is desirable that the adaptive grid feature detection algorithm be developed to recognize flow structures of different type as well as differing intensity, and adequately address scaling and normalization across blocks. In order to study the accuracy and efficiency improvements due to the grid adaptation, it is necessary to quantify grid size and distribution requirements as well as computational times of non-adapted solutions. Flow fields about launch vehicles of practical interest often involve supersonic freestream conditions at angle of attack exhibiting large scale separate vortical flow, vortex-vortex and vortex-surface interactions, separated shear layers and multiple shocks of different intensity. In this work, a weight function and an associated mesh redistribution procedure is presented which detects and resolves these features without user intervention. Particular emphasis has been placed upon accurate resolution of expansion regions and boundary layers. Flow past a wedge at Mach=2.0 is used to illustrate the enhanced detection capabilities of this newly developed weight function.

  12. Modeling drain current of indium zinc oxide thin film transistors prepared by solution deposition technique

    Science.gov (United States)

    Qiang, Lei; Liang, Xiaoci; Cai, Guangshuo; Pei, Yanli; Yao, Ruohe; Wang, Gang

    2018-06-01

    Indium zinc oxide (IZO) thin film transistor (TFT) deposited by solution method is of considerable technological interest as it is a key component for the fabrication of flexible and cheap transparent electronic devices. To obtain a principal understanding of physical properties of solution-processed IZO TFT, a new drain current model that account for the charge transport is proposed. The formulation is developed by incorporating the effect of gate voltage on mobility and threshold voltage with the carrier charges. It is demonstrated that in IZO TFTs the below threshold regime should be divided into two sections: EC - EF > 3kT and EC - EF ≤ 3kT, where kT is the thermal energy, EF and EC represent the Fermi level and the conduction band edge, respectively. Additionally, in order to describe conduction mechanisms more accurately, the extended mobility edge model is conjoined, which can also get rid of the complicated and lengthy computations. The good agreement between measured and calculated results confirms the efficiency of this model for the design of integrated large-area thin film circuits.

  13. Optimization of the indirect at neutron activation technique for the determination of boron in aqueous solutions

    International Nuclear Information System (INIS)

    Luz, L.C.Q.P. da.

    1984-01-01

    The purpose of this work was the development of an instrumental method for the optimization of the indirect neutron activation analysis of boron in aqueous solutions. The optimization took into account the analytical parameters under laboratory conditions: activation carried out with a 241 Am/Be neutron source and detection of the activity induced in vanadium with two NaI(Tl) gamma spectrometers. A calibration curve was thus obtained for a concentration range of 0 to 5000 ppm B. Later on, experimental models were built in order to study the feasibility of automation. The analysis of boron was finally performed, under the previously established conditions, with an automated system comprising the operations of transport, irradiation and counting. An improvement in the quality of the analysis was observed, with boron concentrations as low as 5 ppm being determined with a precision level better than 0.4%. The experimental model features all basic design elements for an automated device for the analysis of boron in agueous solutions wherever this is required, as in the operation of nuclear reactors. (Author) [pt

  14. Correlation between ICDAS and histology: Differences between stereomicroscopy and microradiography with contrast solution as histological techniques.

    Directory of Open Access Journals (Sweden)

    Samara de Azevedo Gomes Campos

    Full Text Available Detection of occlusal caries with visual examination using ICDAS correlates strongly with histology under stereomicroscopy (SM, but dentin aspects under SM are ambiguous regarding mineral content. Thus, our aim was to test two null hypotheses: SM and microradiography result in similar correlations between ICDAS and histology; SM and microradiography result in similar positive (PPV and negative predictive values (NPV of ICDAS cut-off 1-2 (scores 0-2 as sound with histological threshold D3 (demineralization in the inner third of dentin. Occlusal surfaces of extracted permanent teeth (n = 115 were scored using ICDAS. Undemineralized ground sections were histologically scored using both SM without contrast solution and microradiography after immersion in Thoulet's solution 1.47 for 24 h (MRC. Correlation between ICDAS and histology differed from SM (0.782 to MRC (0.511 (p = 0.0002, with a large effect size "q" of 0.49 (95% CI: 0.638/0.338. For ICDAS cut-off 1-2 and D3, PPV from MRC (0.56 was higher than that from SM (0.28 (p< 0.00001; effect size h = 0.81, and NPV from MRC (0.72 was lower than that from SM (1,00 (p < 0.00001; effect size h = 1.58. In conclusion, SM overestimated the correlation between ICDAS and lesion depth, and underestimated the number of occlusal surfaces with ICDAS cut-off 1-2 and deep dentin demineralization.

  15. Pulse sequences for suppressing leakage in single-qubit gate operations

    Science.gov (United States)

    Ghosh, Joydip; Coppersmith, S. N.; Friesen, Mark

    2017-06-01

    Many realizations of solid-state qubits involve couplings to leakage states lying outside the computational subspace, posing a threat to high-fidelity quantum gate operations. Mitigating leakage errors is especially challenging when the coupling strength is unknown, e.g., when it is caused by noise. Here we show that simple pulse sequences can be used to strongly suppress leakage errors for a qubit embedded in a three-level system. As an example, we apply our scheme to the recently proposed charge quadrupole (CQ) qubit for quantum dots. These results provide a solution to a key challenge for fault-tolerant quantum computing with solid-state elements.

  16. 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.

  17. Growth and characterization of yttrium iron garnet films on Si substrates by Chemical Solution Deposition (CSD) technique

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xin; Chen, Ying; Wang, Genshui [Key Laboratory of Inorganic Function Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 1295 Dingxi Rd., Shanghai 200050 (China); Zhang, Yuanyuan [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, 500 Dongchuan Rd., Shanghai 200241 (China); Ge, Jun [Key Laboratory of Inorganic Function Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 1295 Dingxi Rd., Shanghai 200050 (China); Tang, Xiaodong [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, 500 Dongchuan Rd., Shanghai 200241 (China); Ponchel, Freddy; Rémiens, Denis [Institute of Electronics, Microelectronics and Nanotechnology (IEMN)–DOAE, UMR CNRS 8520, Université des Sciences et Technologies de Lille, 59652 Villeneuve d’Ascq Cedex (France); Dong, Xianlin, E-mail: xldong@mail.sic.ac.cn [Key Laboratory of Inorganic Function Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 1295 Dingxi Rd., Shanghai 200050 (China)

    2016-06-25

    Yttrium Iron Garnet (YIG) films were prepared on Si substrates by Chemical Solution Deposition (CSD) technique using acetic acid and deionized water as solvents. Well-crystallized and crack-free YIG films were obtained when annealed at 750 °C and 850 °C respectively, showing a low surface roughness of several nanometers. When annealed at 750 °C for 30 min, the saturated magnetization (Ms) and coercive field (Hc) of YIG films were 0.121 emu/mm{sup 3} (4πMs = 1.52 kGs) and 7 Oe respectively, which were similar to that prepared by PLD technique. The peak-to-peak linewidth of ferromagnetic resonance (FMR) was 220 Oe at 9.10 GHz. The results demonstrated that CSD was an excellent technique to prepare high quality yttrium iron garnet (YIG) films on silicon, which could provide a lower-cost way for large-scale production on Si-based integrated devices. - Highlights: • The preparation of YIG films by Chemical Solution Deposition are demonstrated. • Well-crystallized and crack-free YIG films can be obtained on Si substrate by CSD. • YIG films can be crystallized in 750 °C with good magnetic performances. • It's beneficial to large-scale production of YIG films on Si integrated devices.

  18. Toward Understanding Tip Leakage Flows in Small Compressor Cores Including Stator Leakage Flow

    Science.gov (United States)

    Berdanier, Reid A.; Key, Nicole L.

    2017-01-01

    The focus of this work was to provide additional data to supplement the work reported in NASA/CR-2015-218868 (Berdanier and Key, 2015b). The aim of that project was to characterize the fundamental flow physics and the overall performance effects due to increased rotor tip clearance heights in axial compressors. Data have been collected in the three-stage axial research compressor at Purdue University with a specific focus on analyzing the multistage effects resulting from the tip leakage flow. Three separate rotor tip clearances were studied with nominal tip clearance gaps of 1.5 percent, 3.0 percent, and 4.0 percent based on a constant annulus height. Overall compressor performance was previously investigated at four corrected speedlines (100 percent, 90 percent, 80 percent, and 68 percent) for each of the three tip clearance configurations. This study extends the previously published results to include detailed steady and time-resolved pressure data at two loading conditions, nominal loading (NL) and high loading (HL), on the 100 percent corrected speedline for the intermediate clearance level (3.0 percent). Steady detailed radial traverses of total pressure at the exit of each stator row are supported by flow visualization techniques to identify regions of flow recirculation and separation. Furthermore, detailed radial traverses of time-resolved total pressures at the exit of each rotor row have been measured with a fast-response pressure probe. These data were combined with existing three-component velocity measurements to identify a novel technique for calculating blockage in a multistage compressor. Time-resolved static pressure measurements have been collected over the rotor tips for all rotors with each of the three tip clearance configurations for up to five loading conditions along the 100 percent corrected speedline using fast-response piezoresistive pressure sensors. These time-resolved static pressure measurements reveal new knowledge about the

  19. Microvascular dysfunction with increased vascular leakage response in mice systemically exposed to arsenic.

    Science.gov (United States)

    Chen, Shih-Chieh; Huang, Shin-Yin; Lu, Chi-Yu; Hsu, Ya-Hung; Wang, Dean-Chuan

    2014-09-01

    The mechanisms underlying cardiovascular disease induced by arsenic exposure are not completely understood. The objectives of this study were to investigate whether arsenic-fed mice have an increased vascular leakage response to vasoactive agents and whether enhanced type-2 protein phosphatase (PP2A) activity is involved in mustard oil-induced leakage. ICR mice were fed water or sodium arsenite (20 mg/kg) for 4 or 8 weeks. The leakage response to vasoactive agents was quantified using the Evans blue (EB) technique or vascular labeling with carbon particles. Increased EB leakage and high density of carbon-labeled microvessels were detected in arsenic-fed mice treated with mustard oil. Histamine induced significantly higher vascular leakage in arsenic-fed mice than in water-fed mice. Pretreatment with the PP2A inhibitor okadaic acid or the neurokinin 1 receptor (NK1R) blocker RP67580 significantly reduced mustard oil-induced vascular leakage in arsenic-fed mice. The protein levels of PP2Ac and NK1R were similar in both groups. PP2A activity was significantly higher in the arsenic-fed mice compared with the control group. These findings indicate that microvessels generally respond to vasoactive agents, and that the increased PP2A activity is involved in mustard oil-induced vascular leakage in arsenic-fed mice. Arsenic may initiate endothelial dysfunction, resulting in vascular leakage in response to vasoactive agents.

  20. Intelligent Pressure Management to Reduce Leakage in Urban Water Supply Networks, A Case Study of Sarafrazan District, Mashhad

    OpenAIRE

    Mohammad Soltani Asl; Mahmoud Faghfour Maghrebi

    2009-01-01

    Water losses are inevitable in urban water distribution systems. The two approaches adopted nowadays to combat this problem include management of hydraulic parameters such as pressure and leakage detection in the network. Intellitgent pressure management is a suitable technique for controlling leakage and reducing damages due to high operating pressures in a network. This paper aims to investigate the effects of pressure reduction on leakage. The EPANET 2.10 software is used to simulate the w...

  1. Radiofrequency radiation leakage from microwave ovens

    International Nuclear Information System (INIS)

    Lahham, A.; Sharabati, A.

    2013-01-01

    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 -1 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 μWcm -1 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. (authors)

  2. Leakage-resilient cryptography from minimal assumptions

    DEFF Research Database (Denmark)

    Hazay, Carmit; López-Alt, Adriana; Wee, Hoeteck

    2013-01-01

    We present new constructions of leakage-resilient cryptosystems, which remain provably secure even if the attacker learns some arbitrary partial information about their internal secret key. For any polynomial ℓ, we can instantiate these schemes so as to tolerate up to ℓ bits of leakage. While the...

  3. Predicting Envelope Leakage in Attached Dwellings

    Energy Technology Data Exchange (ETDEWEB)

    Faakye, O. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Arena, L. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Griffiths, D. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    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.

  4. Hybrid vapor phase-solution phase growth techniques for improved CZT(S,Se) photovoltaic device performance

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Liang-Yi; Gershon, Talia S.; Haight, Richard A.; Lee, Yun Seog

    2016-12-27

    A hybrid vapor phase-solution phase CZT(S,Se) growth technique is provided. In one aspect, a method of forming a kesterite absorber material on a substrate includes the steps of: depositing a layer of a first kesterite material on the substrate using a vapor phase deposition process, wherein the first kesterite material includes Cu, Zn, Sn, and at least one of S and Se; annealing the first kesterite material to crystallize the first kesterite material; and depositing a layer of a second kesterite material on a side of the first kesterite material opposite the substrate using a solution phase deposition process, wherein the second kesterite material includes Cu, Zn, Sn, and at least one of S and Se, wherein the first kesterite material and the second kesterite material form a multi-layer stack of the absorber material on the substrate. A photovoltaic device and method of formation thereof are also provided.

  5. 'Ab initio' structure solution from electron diffraction data obtained by a combination of automated diffraction tomography and precession technique

    International Nuclear Information System (INIS)

    Mugnaioli, E.; Gorelik, T.; Kolb, U.

    2009-01-01

    Using a combination of our recently developed automated diffraction tomography (ADT) module with precession electron technique (PED), quasi-kinematical 3D diffraction data sets of an inorganic salt (BaSO 4 ) were collected. The lattice cell parameters and their orientation within the data sets were found automatically. The extracted intensities were used for 'ab initio' structure analysis by direct methods. The data set covered almost the complete set of possible symmetrically equivalent reflections for an orthorhombic structure. The structure solution in one step delivered all heavy (Ba, S) as well as light atoms (O). Results of the structure solution using direct methods, charge flipping and maximum entropy algorithms as well as structure refinement for three different 3D electron diffraction data sets were presented.

  6. Determination of boron in water solution by an indirect neutron activation technique from a 241Am/Be source

    International Nuclear Information System (INIS)

    Sales, H.B.

    1981-08-01

    Boron content in water solutions has been analysed by Indirect Activation Technique a twin 241 Am/Be neutron source with a source strength of 9x10 6 n/seg. The boron concentration was inferred from the measurement of the activity induced in a vanadium flux monitor. The vanadium rod was located inside the boron solution in a standart geometrical set up with respect to the neutron source. Boron concentrations in the range of 100 to 1000 ppm were determined with an overall accuracy of about 2% during a total analysis time of about 20 minutes. Eventhough the analysis is not selective for boron yet due the rapid, simple and precise nature, it is proposed for the analysis of boron in the primary coolant circuit of Nuclear Power Plants of PWR type. (Author) [pt

  7. Analysis and design of machine learning techniques evolutionary solutions for regression, prediction, and control problems

    CERN Document Server

    Stalph, Patrick

    2014-01-01

    Manipulating or grasping objects seems like a trivial task for humans, as these are motor skills of everyday life. Nevertheless, motor skills are not easy to learn for humans and this is also an active research topic in robotics. However, most solutions are optimized for industrial applications and, thus, few are plausible explanations for human learning. The fundamental challenge, that motivates Patrick Stalph, originates from the cognitive science: How do humans learn their motor skills? The author makes a connection between robotics and cognitive sciences by analyzing motor skill learning using implementations that could be found in the human brain – at least to some extent. Therefore three suitable machine learning algorithms are selected – algorithms that are plausible from a cognitive viewpoint and feasible for the roboticist. The power and scalability of those algorithms is evaluated in theoretical simulations and more realistic scenarios with the iCub humanoid robot. Convincing results confirm the...

  8. Evaluation of sorptive flotation technique for enhanced removal of radioactive Eu(III) from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ezzat, Amir; Saad, Ebtissam A. [Ain Shams Univ., Cairo (Egypt). Chemistry Dept.; Mahmoud, Mamdoh R. [Atomic Energy Authority, Cairo (Egypt). Nuclear Chemistry Dept.; Soliman, Mohamed A. [Atomic Energy Authority, Cairo (Egypt). Egypt Second Research Reactor; Kandil, Abdelhakim [Helwan Univ., Cairo (Egypt). Chemistry Dept.

    2017-06-01

    The present study aims at the removal of Eu(III) from aqueous solutions by sorptive flotation process. This process involves adsorption of Eu(III) onto bentonite and kaolinite clays followed by floatation using sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) collectors. The effect of adsorption parameters (pH, contact time, clay weight, Eu(III) concentration, ionic strength) as well as flotation parameters (collector and frother concentrations, bubbling time, concentrations of foreign cations and anions) on the removal efficiency of Eu(III) were studied. The obtained results show that Eu(III) ions are removed efficiently (R% ∝ 95%) at pH=4 after 1 h shaking with clay and 15 min floatation. The adsorption kinetics of Eu(III) onto the employed clays followed the pseudo-second-order model and the equilibrium data fitted well to the Freundlich isotherm model.

  9. Application of Buckmaster Electrolyte Ion Leakage Test to Woody Biofuel Feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Broderick, Thomas F [Forest Concepts, LLC; Dooley, James H [Forest Concepts, LLC

    2014-08-28

    In an earlier ASABE paper, Buckmaster reported that ion conductivity of biomass leachate in aqueous solution was directly correlated with activity access to plant nutrients within the biomass materials for subsequent biological or chemical processing. The Buckmaster test involves placing a sample of the particles in a beaker of constant-temperature deionized water and monitoring the change in electrical conductivity over time. We adapted the Buckmaster method to a range of woody biomass and other cellulosic bioenergy feedstocks. Our experimental results suggest differences of electrolyte leakage between differently processed woody biomass particles may be an indicator of their utility for conversion in bioenergy processes. This simple assay appears to be particularly useful to compare different biomass comminution techniques and particle sizes for biochemical preprocessing.

  10. Lyophilization monophase solution technique for improvement of the solubility and dissolution of piroxicam.

    Science.gov (United States)

    Dixit, M; Kulkarni, P K

    2012-01-01

    Piroxicam (PX), an anti-inflammatory drug, exhibits poor water solubility, dissolution and flow properties. Thus, the aim of the present study was to improve the solubility and dissolution rate of PX by freeze drying technique using dimethylformamide (DMF), chloroform and water as co-solvent system. The prepared crystals containing PX were evaluated for DMF and chloroform solvent residual by gas chromatography and solubility and in vitro dissolution. The prepared formulations were characterized by scanning electron microscopy, differential scanning calorimeter; X-ray diffraction and fourier transform infrared spectroscopy. Dissolution profile of the freeze dried crystals was compared with its recrystallized and pure samples. The samples were stored in stability chamber to investigate their physical stability. Solvent residual of DMF and chloroform was found to be within the toxic level. Freeze dried crystals exhibited decreased crystallinity and the solubility and dissolution of the PX crystals were significantly improved compared to its recrystallized and pure samples. In stability test, the release profile of the freeze dried crystals was almost unchanged as compared with the freshly prepared freeze dried crystals stored at 40°C and 75% relative humidity for 90 days. Hence, this technique can be used for formulation of PX tablets by direct compression with directly compressible tablet excipients.

  11. Acceptable solutions obtained by unfolding noisy data with a conjugate gradient technique

    International Nuclear Information System (INIS)

    Lang, D.W.

    1976-01-01

    A linear resolution function in a physical measurement leads to data values and standard deviations at, say, N points. It is noted that the associated resolution functions may require that a number n of particular linear combinations of the data values be each not significantly different from zero. One is left with at most N-n parameters to evaluate. If the resolution functions are reasonably behaved, one can show that one sensible way to describe the underlying spectrum treats it as a linear combination of the given resolution functions and includes all the significant information from the data. An iterative search for the best component available to minimize the chi-square of the next fit to the data leads to a conjugate gradient technique. Programs based on the technique have been successfully used to obtain neutron spectra as a function of energy; in raw data from a pulse height analysis of proton recoils in a proportional counter, and where the raw data are time of flight spectra from a time dependent pulse of known form. It is planned to incorporate these, together with working programs respectively for photonuclear analysis and to explore the impurity concentration profile in a surface, into a single ''work-bench'' type program. A suitably difficult model unfolding problem has been developed and used to show the strengths and weaknesses of a number of other methods that have been used for unfolding

  12. Periodic solutions of the Hamilton-Jacobi equation by the shooting method: A technique for beam dynamics

    International Nuclear Information System (INIS)

    Gabella, W.E.; Ruth, R.D.; Warnock, R.L.

    1988-05-01

    Periodic solutions of the Hamilton-Jacobi equation determine invariant tori in phase space. The Fourier spectrum of a torus with respect to angular coordinates gives useful information about nonlinear resonances and their potential for causing instabilities. We describe a method to solve the Hamilton-Jacobi equation for an arbitrary accelerator lattice. The method works with Fourier modes of the generating functions, and imposes periodicity in the machine azimuth by a shooting method. We give examples leading to three-dimensional plots in a surface of section. It is expected that the technique will be useful in lattice optimization. 14 refs., 6 figs., 1 tab

  13. Flexible body stability analysis of Space Shuttle ascent flight control system by using lambda matrix solution techniques

    Science.gov (United States)

    Bown, R. L.; Christofferson, A.; Lardas, M.; Flanders, H.

    1980-01-01

    A lambda matrix solution technique is being developed to perform an open loop frequency analysis of a high order dynamic system. The procedure evaluates the right and left latent vectors corresponding to the respective latent roots. The latent vectors are used to evaluate the partial fraction expansion formulation required to compute the flexible body open loop feedback gains for the Space Shuttle Digital Ascent Flight Control System. The algorithm is in the final stages of development and will be used to insure that the feedback gains meet the design specification.

  14. A combination between Laplace transformation technique and numerical approximations to the Fokker-Planck equation solutions

    International Nuclear Information System (INIS)

    Monticelli, Cintia O.; Wortmann, Sergio; Segatto, Cynthia F.

    2005-01-01

    In this work is obtained a hybrid solution to the Fokker-Planck equation with energy dependency, very used in ion implantation problems. The main idea relies on the application of Laplace transform in the energy variable, and finite-difference in the spatial variable and in the angular variable. This procedure leads to a symbolic matrix problem for the transformed energy. To solve this system, is needed to do the Laplace inverse of the (sI+A) matrix, where s is a complex parameter, I is the identity matrix and A is a square matrix that was proceeded from the finite-difference in the spatial variable and in the angular variable. The matrix A is not defective, then is taken decomposition of A in a sum of two others matrices, where one is defective. It leads a iterative inversion method, similar the source fixed method combined with the diagonalization method, then is obtained the values to the angular flux. Hereafter we can to determine the energy deposited into the electronic system and in the nuclear system of the target. To comprove the results obtained, the simulation of implantation of B into Si at energies ranging from 1 KeV to 50 MeV was carried out and compared with the results by software SRIM2003. (author)

  15. 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.

  16. 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-Braek, Gudmund; Oberholzer, Jose; Strand, Berit L

    2012-11-01

    Microbeads of alginate crosslinked with Ca(2+) and/or Ba(2+) 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 with 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. 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. Copyright © 2012 Wiley Periodicals, Inc.

  17. Acoustic emission monitoring of leakage through seal-plug in PHWR systems

    Energy Technology Data Exchange (ETDEWEB)

    Jha, S K; Badgujar, B P; Goswami, G L [Bhabha Atomic Research Centre, Bombay (India). Atomic Fuels Div.; Patel, R J; Bhattacharya, S; Agrawal, R G [Bhabha Atomic Research Centre, Mumbai (India). Refuelling Technology Division

    1994-12-31

    Acoustic Emission (AE) technique is being developed as an in-service inspection tool for monitoring the leakage through seal-plugs in Pressurised Heavy Water Reactors (PHWRs). Time as well as frequency domain analysis have been utilised during the experiment carried out at Bhabha Atomic Research Centre (BARC) using test set up simulating the pressure and temperature conditions. The work involved were to determine the temperature profile on end-fitting, effect of pressure and temperature on leakage etc. This paper discusses various relationships like signal-level vs. pressure, frequency spectrum of signal, signal-level vs. leakage based on the above experimental work. (author). 4 refs., 6 figs.

  18. Surface CO2 leakage during the first shallow subsurface CO2 release experiment

    OpenAIRE

    Lewicki, J.L.; Oldenburg, C.; Dobeck, L.; Spangler, L.

    2008-01-01

    A new field facility was used to study CO2 migration processes and test techniques to detect and quantify potential CO2 leakage from geologic storage sites. For 10 days starting 9 July 2007, and for seven days starting 5 August 2007, 0.1 and 0.3 t CO2 d-1, respectively, were released from a ~;100-m long, sub-water table (~;2.5-m depth) horizontal well. The spatio-temporal evolution of leakage was mapped through repeated grid measurements of soil CO2 flux (FCO2). The surface leakage onset...

  19. Effect of Instrumentation Techniques, Irrigant Solutions and Artificial accelerated Aging on Fiberglass Post Bond Strength to Intraradicular Dentin.

    Science.gov (United States)

    Santana, Fernanda Ribeiro; Soares, Carlos José; Silva, Júlio Almeida; Alencar, Ana Helena Gonçalves; Renovato, Sara Rodrigues; Lopes, Lawrence Gonzaga; Estrela, Carlos

    2015-07-01

    To evaluate the effect of instrumentation techniques, irrigant solutions and specimen aging on fiberglass posts bond strength to intraradicular dentine. A total of 120 bovine teeth were prepared and randomized into control and experimental groups resulting from three study factors (instrumentation techniques, irrigant solutions, specimen aging). Posts were cemented with RelyX U100. Samples were submitted to push-out test and failure mode was evaluated under a confocal microscope. In specimens submitted to water artificial aging, nickel-titanium rotary instruments group presented higher bond strength values in apical third irrigated with NaOCl or chlorhexi-dine. Irrigation with NaOCl resulted in higher bond strength than ozonated water. Artificial aging resulted in significant bond strength increase. Adhesive cement-dentin failure was prevalent in all the groups. Root canal preparation with NiTi instruments associated with NaOCl irrigation and ethylenediaminetetra acetic acid (EDTA) increased bond strength of fiberglass posts cemented with self-adhesive resin cement to intraradicular dentine. Water artificial aging significantly increased post-Clinical significance: The understanding of factors that may influence the optimal bond between post-cement and cement-dentin are essential to the success of endodontically treated tooth restoration.

  20. Fabrication of assembled ZnO/TiO2 heterojunction thin film transistors using solution processing technique

    Science.gov (United States)

    Liau, Leo Chau-Kuang; Lin, Yun-Guo

    2015-01-01

    Ceramic-based metal-oxide-semiconductor (MOS) field-effect thin film transistors (TFTs), which were assembled by ZnO and TiO2 heterojunction films coated using solution processing technique, were fabricated and characterized. The fabrication of the device began with the preparation of ZnO and TiO2 films by spin coating. The ZnO and TiO2 films that were stacked together and annealed at 450 °C were characterized as a p-n junction diode. Two types of the devices, p-channel and n-channel TFTs, were produced using different assemblies of ZnO and TiO2 films. Results show that the p-channel TFTs (p-TFTs) and n-channel TFTs (n-TFTs) using the assemblies of ZnO and TiO2 films were demonstrated by source-drain current vs. drain voltage (IDS-VDS) measurements. Several electronic properties of the p- and n- TFTs, such as threshold voltage (Vth), on-off ratio, channel mobility, and subthreshold swing (SS), were determined by current-voltage (I-V) data analysis. The ZnO/TiO2-based TFTs can be produced using solution processing technique and an assembly approach.

  1. A New Approach and Solution Technique to Solve Time Fractional Nonlinear Reaction-Diffusion Equations

    Directory of Open Access Journals (Sweden)

    Inci Cilingir Sungu

    2015-01-01

    Full Text Available A new application of the hybrid generalized differential transform and finite difference method is proposed by solving time fractional nonlinear reaction-diffusion equations. This method is a combination of the multi-time-stepping temporal generalized differential transform and the spatial finite difference methods. The procedure first converts the time-evolutionary equations into Poisson equations which are then solved using the central difference method. The temporal differential transform method as used in the paper takes care of stability and the finite difference method on the resulting equation results in a system of diagonally dominant linear algebraic equations. The Gauss-Seidel iterative procedure then used to solve the linear system thus has assured convergence. To have optimized convergence rate, numerical experiments were done by using a combination of factors involving multi-time-stepping, spatial step size, and degree of the polynomial fit in time. It is shown that the hybrid technique is reliable, accurate, and easy to apply.

  2. Relationships between the group-theoretic and soliton-theoretic techniques for generating stationary axisymmetric gravitational solutions

    International Nuclear Information System (INIS)

    Cosgrove, C.M.

    1980-01-01

    We investigate the precise interrelationships between several recently developed solution-generating techniques capable of generating asymptotically flat gravitational solutions with arbitrary multipole parameters. The transformations we study in detail here are the Lie groups Q and Q of Cosgrove, the Hoenselaers--Kinnersley--Xanthopoulos (HKX) transformations and their SL(2) tensor generalizations, the Neugebauer--Kramer discrete mapping, the Neugebauer Baecklund transformations I 1 and I 2 , the Harrison Baecklund transformation, and the Belinsky--Zakharov (BZ) one- and two-soliton transformations. Two particular results, among many reported here, are that the BZ soliton transformations are essentially equivalent to Harrison transformations and that the generalized HKX transformation may be deduced as a confluent double soliton transformation. Explicit algebraic expressions are given for the transforms of the Kinnersley--Chitre generating functions under all of the above transformations. In less detail, we also study the Kinnersley--Chitre β transformations, the non-null HKX transformations, and the Hilbert problems proposed independently by Belinsky and Zakharov, and Hauser and Ernst. In conclusion, we describe the nature of the exact solutions constructible in a finite number of steps with the available methods

  3. An implicit scheme with memory reduction technique for steady state solutions of DVBE in all flow regimes

    Science.gov (United States)

    Yang, L. M.; Shu, C.; Yang, W. M.; Wu, J.

    2018-04-01

    High consumption of memory and computational effort is the major barrier to prevent the widespread use of the discrete velocity method (DVM) in the simulation of flows in all flow regimes. To overcome this drawback, an implicit DVM with a memory reduction technique for solving a steady discrete velocity Boltzmann equation (DVBE) is presented in this work. In the method, the distribution functions in the whole discrete velocity space do not need to be stored, and they are calculated from the macroscopic flow variables. As a result, its memory requirement is in the same order as the conventional Euler/Navier-Stokes solver. In the meantime, it is more efficient than the explicit DVM for the simulation of various flows. To make the method efficient for solving flow problems in all flow regimes, a prediction step is introduced to estimate the local equilibrium state of the DVBE. In the prediction step, the distribution function at the cell interface is calculated by the local solution of DVBE. For the flow simulation, when the cell size is less than the mean free path, the prediction step has almost no effect on the solution. However, when the cell size is much larger than the mean free path, the prediction step dominates the solution so as to provide reasonable results in such a flow regime. In addition, to further improve the computational efficiency of the developed scheme in the continuum flow regime, the implicit technique is also introduced into the prediction step. Numerical results showed that the proposed implicit scheme can provide reasonable results in all flow regimes and increase significantly the computational efficiency in the continuum flow regime as compared with the existing DVM solvers.

  4. Leakage Resilient Secure Two-Party Computation

    DEFF Research Database (Denmark)

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

    2012-01-01

    we initiate the study of {\\em secure two-party computation in the presence of leakage}, where on top of corrupting one of the parties the adversary obtains leakage from the content of the secret memory of the honest party. Our study involves the following contributions: \\BE \\item {\\em Security...... and returns its result. Almost independently of secure computation, the area of {\\em leakage resilient cryptography} has recently been evolving intensively, studying the question of designing cryptographic primitives that remain secure even when some information about the secret key is leaked. In this paper...

  5. Method to detect steam generator tube leakage

    International Nuclear Information System (INIS)

    Watabe, Kiyomi

    1994-01-01

    It is important for plant operation to detect minor leakages from the steam generator tube at an early stage, thus, leakage detection has been performed using a condenser air ejector gas monitor and a steam generator blow down monitor, etc. In this study highly-sensitive main steam line monitors have been developed in order to identify leakages in the steam generator more quickly and accurately. The performance of the monitors was verified and the demonstration test at the actual plant was conducted for their intended application to the plants. (author)

  6. Comparison between two meshless methods based on collocation technique for the numerical solution of four-species tumor growth model

    Science.gov (United States)

    Dehghan, Mehdi; Mohammadi, Vahid

    2017-03-01

    As is said in [27], the tumor-growth model is the incorporation of nutrient within the mixture as opposed to being modeled with an auxiliary reaction-diffusion equation. The formulation involves systems of highly nonlinear partial differential equations of surface effects through diffuse-interface models [27]. Simulations of this practical model using numerical methods can be applied for evaluating it. The present paper investigates the solution of the tumor growth model with meshless techniques. Meshless methods are applied based on the collocation technique which employ multiquadrics (MQ) radial basis function (RBFs) and generalized moving least squares (GMLS) procedures. The main advantages of these choices come back to the natural behavior of meshless approaches. As well as, a method based on meshless approach can be applied easily for finding the solution of partial differential equations in high-dimension using any distributions of points on regular and irregular domains. The present paper involves a time-dependent system of partial differential equations that describes four-species tumor growth model. To overcome the time variable, two procedures will be used. One of them is a semi-implicit finite difference method based on Crank-Nicolson scheme and another one is based on explicit Runge-Kutta time integration. The first case gives a linear system of algebraic equations which will be solved at each time-step. The second case will be efficient but conditionally stable. The obtained numerical results are reported to confirm the ability of these techniques for solving the two and three-dimensional tumor-growth equations.

  7. Phosphate dosing of mains water : novel approaches to water loss reduction through leakage detection and policy [abstract

    OpenAIRE

    Ascott, M.J.; Gooddy, D.C.; Lapworth, D.J.; Stuart, M.E.

    2016-01-01

    Detection and t racing of leakage in the environment are essential component s of water loss reduction strategies. Industry standard techniques for tracing leaks include analysis of chlorine and trihalomethane concentrations, but levels of these determinands can fall belo w detection limits due to their volatile nature 1 . Consequently additional tools to trace leakage in the environment are a useful step ...

  8. 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.

  9. A Fluorescence Recovery After Photobleaching (FRAP) Technique for the Measurement of Solute Transport Across Surfactant-Laden Interfaces

    Science.gov (United States)

    Browne, Edward P.; Hatton, T. Alan

    1996-01-01

    The technique of Fluorescence Recovery After Photobleaching (FRAP) has been applied to the measurement of interfacial transport in two-phase systems. FRAP exploits the loss of fluorescence exhibited by certain fluorophores when over-stimulated (photobleached), so that a two-phase system, originally at equilibrium, can be perturbed without disturbing the interface by strong light from an argon-ion laser and its recovery monitored by a microscope-mounted CCD camera as it relaxes to a new equilibrium. During this relaxation, the concentration profiles of the probe solute are measured on both sides of the interface as a function of time, yielding information about the transport characteristics of the system. To minimize the size of the meniscus between the two phases, a photolithography technique is used to selectively treat the glass walls of the cell in which the phases are contained. This allows concentration measurements to be made very close to the interface and increases the sensitivity of the FRAP technique.

  10. Effect of condenser water in-leakage on steam generator water chemistry

    International Nuclear Information System (INIS)

    Balakrishnan, P.V.

    1978-01-01

    Corrosive environments may be generated within steam genrators from condenser cooling water in-leakage. Theoretical as well as experimental evaluation of the aggressiveness of such environments is being carried out for the condenser-cooling waters used at CANDU-PHW nuclear power stations. Calculations have shown that highly concentrated chloride solutions - acidic in the case of sea-water in-leakage, and alkaline in the rest of the cases considered - would be produced within the steam generator. Experiments in a model boiler showed that sea-water in-leakage caused rapid corrosion of carbon steel components when only AVT (all volatile treatment) was used for water chemistry control. Use of a non-volatile reagent, as in the congruent phosphate treatment, avoided the rapid corrosion of carbon steel. On the basis of our studies, congruent phosphate treatment during sea water in-leakage appears desirable. (author)

  11. Apparatus for detecting leakage of liquid sodium

    Science.gov (United States)

    Himeno, Yoshiaki

    1978-01-01

    An apparatus for detecting the leakage of liquid sodium includes a cable-like sensor adapted to be secured to a wall of piping or other equipment having sodium on the opposite side of the wall, and the sensor includes a core wire electrically connected to the wall through a leak current detector and a power source. An accidental leakage of the liquid sodium causes the corrosion of a metallic layer and an insulative layer of the sensor by products resulted from a reaction of sodium with water or oxygen in the atmospheric air so as to decrease the resistance between the core wire and the wall. Thus, the leakage is detected as an increase in the leaking electrical current. The apparatus is especially adapted for use in detecting the leakage of liquid sodium from sodium-conveying pipes or equipment in a fast breeder reactor.

  12. Electroplating eliminates gas leakage in brazed areas

    Science.gov (United States)

    Leigh, J. D.

    1966-01-01

    Electroplating method seals brazed or welded joints against gas leakage under high pressure. Any conventional electroplating process with many different metal anodes can be used, as well as the build up of layers of different metals to any required thickness.

  13. Analysis of ONKALO water leakage mapping results

    International Nuclear Information System (INIS)

    Ahokas, H.; Nummela, J; Turku, J.

    2014-04-01

    As part of the programme for the final disposal of spent nuclear fuel, an analysis has been compiled of water leakage mapping performed in ONKALO. Leakage mapping is part of the Olkiluoto Monitoring Programme (OMO) and the field work has been carried out by Posiva Oy. The main objective of the study is to analyse differences detected between mapping campaigns carried out typically twice a year in 2005-2012. Differences were estimated to be caused by the differences in groundwater conditions caused by seasonal effects or by differences between the years. The effect of technical changes like shotcreting, postgrouting, ventilation etc. on the results was also studied. The development of the visualisation of mapping results was also an objective of this work. Leakage mapping results have been reported yearly in the monitoring reports of Hydrology with some brief comments on the detected differences. In this study, the development of the total area and the number of different leakages as well as the correlation of changes with shotcreting and grouting operations were studied. In addition, traces of fractures on tunnel surfaces, and the location of rock bolts and drain pipes were illustrated together with leakage mapping. In water leakage mapping, the tunnel surfaces are visually mapped to five categories: dry, damp, wet, dripping and flowing. Major changes were detected in the total area of damp leakages. It is likely that the increase has been caused by the condensation of warm ventilation air on the tunnel surfaces and the corresponding decrease by the evaporation of moisture into the dry ventilation air. Shotcreting deep in ONKALO may also have decreased the total area of damp leakages. Changes in the total area and number of wet leakages correlate at least near the surface with differences in yearly precipitation. It is possible that strong rains have also caused a temporary increase in wet leakages. Dripping and wet leakages have been observed on average more

  14. Analysis of ONKALO water leakage mapping results

    Energy Technology Data Exchange (ETDEWEB)

    Ahokas, H.; Nummela, J; Turku, J. [Poeyry Finland Oy, Vantaa (Finland)

    2014-04-15

    As part of the programme for the final disposal of spent nuclear fuel, an analysis has been compiled of water leakage mapping performed in ONKALO. Leakage mapping is part of the Olkiluoto Monitoring Programme (OMO) and the field work has been carried out by Posiva Oy. The main objective of the study is to analyse differences detected between mapping campaigns carried out typically twice a year in 2005-2012. Differences were estimated to be caused by the differences in groundwater conditions caused by seasonal effects or by differences between the years. The effect of technical changes like shotcreting, postgrouting, ventilation etc. on the results was also studied. The development of the visualisation of mapping results was also an objective of this work. Leakage mapping results have been reported yearly in the monitoring reports of Hydrology with some brief comments on the detected differences. In this study, the development of the total area and the number of different leakages as well as the correlation of changes with shotcreting and grouting operations were studied. In addition, traces of fractures on tunnel surfaces, and the location of rock bolts and drain pipes were illustrated together with leakage mapping. In water leakage mapping, the tunnel surfaces are visually mapped to five categories: dry, damp, wet, dripping and flowing. Major changes were detected in the total area of damp leakages. It is likely that the increase has been caused by the condensation of warm ventilation air on the tunnel surfaces and the corresponding decrease by the evaporation of moisture into the dry ventilation air. Shotcreting deep in ONKALO may also have decreased the total area of damp leakages. Changes in the total area and number of wet leakages correlate at least near the surface with differences in yearly precipitation. It is possible that strong rains have also caused a temporary increase in wet leakages. Dripping and wet leakages have been observed on average more

  15. Technology evaluation for space station atmospheric leakage

    Energy Technology Data Exchange (ETDEWEB)

    Lemon, D.K.; Friesel, M.A.; Griffin, J.W.; Skorpik, J.R.; Shepard, C.L.; Antoniak, Z.I.; Kurtz, R.J.

    1990-02-01

    A concern in operation of a space station is leakage of atmosphere through seal points and through the walls as a result of damage from particle (space debris and micrometeoroid) impacts. This report describes a concept for a monitoring system to detect atmosphere leakage and locate the leak point. The concept is based on analysis and testing of two basic methods selected from an initial technology survey of potential approaches. 18 refs., 58 figs., 5 tabs.

  16. Enhanced ground bounce noise reduction in a low-leakage CMOS multiplier

    Science.gov (United States)

    Verma, Bipin Kumar; Akashe, Shyam; Sharma, Sanjay

    2015-09-01

    In this paper, various parameters are used to reduce leakage power, leakage current and noise margin of circuits to enhance their performance. A multiplier is proposed with low-leakage current and low ground bounce noise for the microprocessor, digital signal processors (DSP) and graphics engines. The ground bounce noise problem appears when a conventional power-gating circuit transits from sleep-to-active mode. This paper discusses a reduction in leakage current in the stacking power-gating technique by three modes - sleep, active and sleep-to-active. The simulation results are performed on a 4 × 4 carry-save multiplier for leakage current, active power, leakage power and ground bounce noise, and comparison made for different nanoscales. Ground bounce noise is limited to 90%. The leakage current of the circuit is decimated up to 80% and the active power is reduced to 31%. We performed simulations using cadence virtuoso 180 and 45 nm at room temperature at various supply voltages.

  17. 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)

  18. The leakage problem in vacuum system. Realization of a mass spectrometer detecting leaks; Le probleme des fuites en technique du vide. Realisation d'un spectrometre de masse detecteur de fuite

    Energy Technology Data Exchange (ETDEWEB)

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

    1954-11-15

    In the first part of this paper we consider the problem of leaks in vacuum systems, and their detection. We consider in particular the method of detection by means of a helium spectrometer. The second part deals with the experimental set p. The analyser and the ion source have been studied in great detail, and we have also discussed the technological and mechanical aspects of the apparatus and its performances. (author) [French] Dans la premiere partie de ce travail, nous traitons le probleme des fuites en technique du vide et leur detection en general. La methode de detection par spectrometre a helium y est envisagee plus particulierement. La deuxieme partie de l'article est consacree a la realisation du spectrometre. Le tube analyseur et la source d'ions y sont etudies en detail. Nous exposons de meme les conceptions technologiques et mecaniques de l'appareil ainsi que ses performances. (auteur)

  19. Analytical solution of the multigroup neutron diffusion kinetic equation in one-dimensional cartesian geometry by the integral transform technique

    International Nuclear Information System (INIS)

    Ceolin, Celina

    2010-01-01

    The objective of this work is to obtain an analytical solution of the neutron diffusion kinetic equation in one-dimensional cartesian geometry, to monoenergetic and multigroup problems. These equations are of the type stiff, due to large differences in the orders of magnitude of the time scales of the physical phenomena involved, which make them difficult to solve. The basic idea of the proposed method is applying the spectral expansion in the scalar flux and in the precursor concentration, taking moments and solving the resulting matrix problem by the Laplace transform technique. Bearing in mind that the equation for the precursor concentration is a first order linear differential equation in the time variable, to enable the application of the spectral method we introduce a fictitious diffusion term multiplied by a positive value which tends to zero. This procedure opened the possibility to find an analytical solution to the problem studied. We report numerical simulations and analysis of the results obtained with the precision controlled by the truncation order of the series. (author)

  20. Analysis of the validity of the asymptotic techniques in the lower hybrid wave equation solution for reactor applications

    International Nuclear Information System (INIS)

    Cardinali, A.; Morini, L.; Castaldo, C.; Cesario, R.; Zonca, F.

    2007-01-01

    Knowing that the lower hybrid (LH) wave propagation in tokamak plasmas can be correctly described with a full wave approach only, based on fully numerical techniques or on semianalytical approaches, in this paper, the LH wave equation is asymptotically solved via the Wentzel-Kramers-Brillouin (WKB) method for the first two orders of the expansion parameter, obtaining governing equations for the phase at the lowest and for the amplitude at the next order. The nonlinear partial differential equation (PDE) for the phase is solved in a pseudotoroidal geometry (circular and concentric magnetic surfaces) by the method of characteristics. The associated system of ordinary differential equations for the position and the wavenumber is obtained and analytically solved by choosing an appropriate expansion parameter. The quasilinear PDE for the WKB amplitude is also solved analytically, allowing us to reconstruct the wave electric field inside the plasma. The solution is also obtained numerically and compared with the analytical solution. A discussion of the validity limits of the WKB method is also given on the basis of the obtained results

  1. Accurate characterization of organic thin film transistors in the presence of gate leakage current

    Directory of Open Access Journals (Sweden)

    Vinay K. Singh

    2011-12-01

    Full Text Available The presence of gate leakage through polymer dielectric in organic thin film transistors (OTFT prevents accurate estimation of transistor characteristics especially in subthreshold regime. To mitigate the impact of gate leakage on transfer characteristics and allow accurate estimation of mobility, subthreshold slope and on/off current ratio, a measurement technique involving simultaneous sweep of both gate and drain voltages is proposed. Two dimensional numerical device simulation is used to illustrate the validity of the proposed technique. Experimental results obtained with Pentacene/PMMA OTFT with significant gate leakage show a low on/off current ratio of ∼ 102 and subthreshold is 10 V/decade obtained using conventional measurement technique. The proposed technique reveals that channel on/off current ratio is more than two orders of magnitude higher at ∼104 and subthreshold slope is 4.5 V/decade.

  2. Growth, structural, optical and electrical study of ZnS thin films deposited by solution growth technique (SGT)

    International Nuclear Information System (INIS)

    Sadekar, H.K.; Deshpande, N.G.; Gudage, Y.G.; Ghosh, A.; Chavhan, S.D.; Gosavi, S.R.; Sharma, Ramphal

    2008-01-01

    ZnS thin films have been deposited onto glass substrates at temperature 90 deg. C by solution growth technique (SGT). The deposition parameters were optimized. Triethanolamine (TEA) was used as a complexing agent for uniform deposition of the thin films. The elemental composition of the film was confirmed by energy dispersive analysis by X-ray (EDAX) technique. Structure and surface morphology of as-deposited films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), atomic force microscopy (AFM), respectively. XRD patterns reveal that as-deposited thin films were amorphous in nature; while the obtained precipitate powder was polycrystalline in nature. SEM results revealed that deposited ZnS material has ∼120 ± 20 nm average grain size and the spherical grains are distributed over the entire glass substrate. Low surface roughness was found to be 2.7 nm from AFM studies. Transmission spectra indicate a high transmission coefficient (∼75%) with direct band gap energy equal to 3.72 eV while indirect band gap was found to be 3.45 eV. A photoluminescence (PL) study of the ZnS at room temperature (300 K) indicates a strong luminescence band at energy 2.02 eV

  3. Growth, structural, optical and electrical study of ZnS thin films deposited by solution growth technique (SGT)

    Energy Technology Data Exchange (ETDEWEB)

    Sadekar, H K [Arts, Commerce and Science college, Sonai 414105 (M.S.) (India); Thin film and Nanotechnology Laboratory, Department of Physics, Dr. B.A.M. University, Aurangabad 431004 (M.S.) (India); Deshpande, N G; Gudage, Y G; Ghosh, A; Chavhan, S D; Gosavi, S R [Thin film and Nanotechnology Laboratory, Department of Physics, Dr. B.A.M. University, Aurangabad 431004 (M.S.) (India); Sharma, Ramphal [Thin film and Nanotechnology Laboratory, Department of Physics, Dr. B.A.M. University, Aurangabad 431004 (M.S.) (India)

    2008-04-03

    ZnS thin films have been deposited onto glass substrates at temperature 90 deg. C by solution growth technique (SGT). The deposition parameters were optimized. Triethanolamine (TEA) was used as a complexing agent for uniform deposition of the thin films. The elemental composition of the film was confirmed by energy dispersive analysis by X-ray (EDAX) technique. Structure and surface morphology of as-deposited films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), atomic force microscopy (AFM), respectively. XRD patterns reveal that as-deposited thin films were amorphous in nature; while the obtained precipitate powder was polycrystalline in nature. SEM results revealed that deposited ZnS material has {approx}120 {+-} 20 nm average grain size and the spherical grains are distributed over the entire glass substrate. Low surface roughness was found to be 2.7 nm from AFM studies. Transmission spectra indicate a high transmission coefficient ({approx}75%) with direct band gap energy equal to 3.72 eV while indirect band gap was found to be 3.45 eV. A photoluminescence (PL) study of the ZnS at room temperature (300 K) indicates a strong luminescence band at energy 2.02 eV.

  4. 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.

  5. Detection Test for Leakage of CO2 into Sodium Loop

    International Nuclear Information System (INIS)

    Park, Sun Hee; Wi, Myung-Hwan; Min, Jae Hong

    2015-01-01

    This report is about the facility for the detection test for leakage of CO 2 into sodium loop. The facility for the detection test for leakage of CO 2 into sodium loop was introduced. The test will be carried out. Our experimental results are going to be expected to be used for approach methods to detect CO 2 leaking into sodium in heat exchangers. A sodium-and-carbon dioxide (Na-CO 2 ) heat exchanger is one of the key components for the supercritical CO 2 Brayton cycle power conversion system of sodium-cooled fast reactors (SFRs). A printed circuit heat exchanger (PCHE) is considered for the Na-CO 2 heat exchanger, which is known to have potential for reducing the volume occupied by the exchangers compared to traditional shell-and-tube heat exchangers. Among various issues about the Na- CO 2 exchanger, detection of CO 2 leaking into sodium in the heat exchanger is most important thing for its safe operation. It is known that reaction products from sodium and CO 2 such as sodium carbonate (Na 2 CO 3 ) and amorphous carbon are hardly soluble in sodium, which cause plug sodium channels. Detection technique for Na 2 CO 3 in sodium loop has not been developed yet. Therefore, detection of CO 2 and CO from reaction of sodium and CO 2 are proper to detect CO 2 leakage into sodium loop

  6. Geologic Carbon Sequestration Leakage Detection: A Physics-Guided Machine Learning Approach

    Science.gov (United States)

    Lin, Y.; Harp, D. R.; Chen, B.; Pawar, R.

    2017-12-01

    One of the risks of large-scale geologic carbon sequestration is the potential migration of fluids out of the storage formations. Accurate and fast detection of this fluids migration is not only important but also challenging, due to the large subsurface uncertainty and complex governing physics. Traditional leakage detection and monitoring techniques rely on geophysical observations including pressure. However, the resulting accuracy of these methods is limited because of indirect information they provide requiring expert interpretation, therefore yielding in-accurate estimates of leakage rates and locations. In this work, we develop a novel machine-learning technique based on support vector regression to effectively and efficiently predict the leakage locations and leakage rates based on limited number of pressure observations. Compared to the conventional data-driven approaches, which can be usually seem as a "black box" procedure, we develop a physics-guided machine learning method to incorporate the governing physics into the learning procedure. To validate the performance of our proposed leakage detection method, we employ our method to both 2D and 3D synthetic subsurface models. Our novel CO2 leakage detection method has shown high detection accuracy in the example problems.

  7. Use Residual Correction Method and Monotone Iterative Technique to Calculate the Upper and Lower Approximate Solutions of Singularly Perturbed Non-linear Boundary Value Problems

    Directory of Open Access Journals (Sweden)

    Chi-Chang Wang

    2013-09-01

    Full Text Available This paper seeks to use the proposed residual correction method in coordination with the monotone iterative technique to obtain upper and lower approximate solutions of singularly perturbed non-linear boundary value problems. First, the monotonicity of a non-linear differential equation is reinforced using the monotone iterative technique, then the cubic-spline method is applied to discretize and convert the differential equation into the mathematical programming problems of an inequation, and finally based on the residual correction concept, complex constraint solution problems are transformed into simpler questions of equational iteration. As verified by the four examples given in this paper, the method proposed hereof can be utilized to fast obtain the upper and lower solutions of questions of this kind, and to easily identify the error range between mean approximate solutions and exact solutions.

  8. How to attribute market leakage to CDM projects

    NARCIS (Netherlands)

    Vöhringer, F.; Kuosmanen, T.K.; Dellink, R.B.

    2006-01-01

    Economic studies suggest that market leakage rates of greenhouse gas abatement can reach the two-digit percentage range. Although the Marrakesh Accords require Clean Development Mechanism (CDM) projects to account for leakage, most projects neglect market leakage. Insufficient leakage accounting is

  9. 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 leakag...

  10. [Nuclear medicine diagnosis of pulmonary capillary protein leakage].

    Science.gov (United States)

    Creutzig, H; Sturm, J A; Schober, O; Nerlich, M L; Kant, C J

    1984-10-01

    Pulmonary extravascular albumin extravasation in patients with adult respiratory distress syndrome can be quantified with radionuclide techniques. While imaging procedures with a computerized gamma camera will allow reproducible ROIs, this will be the main limitation in nonimaging measurements with small scintillation probes. Repeated positioning by one operator results in a mean spatial variation of position of about 2 cm and a variation in count rate of 25%. For the estimation of PCPL the small probes must be positioned under scintigraphic control. Under these conditions the results of both techniques are identical. The upper limit of normal was estimated to be 1 x E-5/sec. The standard deviation of abnormal measurements was about 10%. The pulmonary capillary protein leakage can be quantified by radionuclide techniques with good accuracy, using the combination of imaging and nonimaging techniques.

  11. 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

    Fluorescence correlation spectroscopy (FCS) is a powerful experimental technique that in recent years has found numerous applications for studying biological phenomena. In this article, we scrutinize one of these applications, namely, FCS as a technique for studying leakage of fluorescent molecul...

  12. Determination of leakage areas in nuclear piping

    International Nuclear Information System (INIS)

    Keim, E.

    1997-01-01

    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

  13. Sustainable management of leakage from wastewater pipelines.

    Science.gov (United States)

    DeSilva, D; Burn, S; Tjandraatmadja, G; Moglia, M; Davis, P; Wolf, L; Held, I; Vollertsen, J; Williams, W; Hafskjold, L

    2005-01-01

    Wastewater pipeline leakage is an emerging concern in Europe, especially with regards to the potential effect of leaking effluent on groundwater contamination and the effects infiltration has on the management of sewer reticulation systems. This paper describes efforts by Australia, in association with several European partners, towards the development of decision support tools to prioritize proactive rehabilitation of wastewater pipe networks to account for leakage. In the fundamental models for the decision support system, leakage is viewed as a function of pipeline system deterioration. The models rely on soil type identification across the service area to determine the aggressiveness of the pipe environment and for division of the area into zones based on pipe properties and operational conditions. By understanding the interaction between pipe materials, operating conditions, and the pipe environment in the mechanisms leading to pipe deterioration, the models allow the prediction of leakage rates in different zones across a network. The decision support system utilizes these models to predict the condition of pipes in individual zones, and to optimize the utilization of rehabilitation resources by targeting the areas with the highest leakage rates.

  14. 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.

  15. Regulatory concerns for leakage testing of packagings with three O-ring closure seals

    International Nuclear Information System (INIS)

    Oras, J.J.; Towell, R.H.; Wangler, M.E.

    1997-01-01

    The American National Standard for Radioactive Materials--Leakage Tests on Packages for Shipment (ANSI N14.5) provides guidance for leakage rate testing to show that a particular packaging complies with regulatory requirements and also provides guidance in determining appropriate acceptance criteria. Recent radioactive packagings designs have incorporated three O-ring closure seals, the middle O-ring being the containment seal. These designs have the potential for false positive results of leakage rate tests. The volume between the containment O-ring and the inner O-ring is used for the helium gas required for the leakage rate tests to reduce both the amount of helium used and the time required to conduct the tests. A leak detector samples the evacuated volume between the outer O-ring and the containment O-ring. False positive results can be caused in two ways, a large leakage in the containment seal or leakage in the inner seal. This paper will describe the problem together with possible solutions/areas that need to be addressed in a Safety Analysis Report for Packagings before a particular packaging design can be certified for transport

  16. Space Shuttle Orbital Maneuvering Subsystem (OMS) Engine Propellant Leakage Ball-Valve Shaft Seals

    Science.gov (United States)

    Lueders, Kathy; Buntain, Nick; Fries, Joseph (Technical Monitor)

    1999-01-01

    Evidence of propellant leakage across ball-valve shaft seals has been noted during the disassembly of five flight engines and one test engine at the NASA Lyndon B. Johnson Space Center, White Sands Test Facility. Based on data collected during the disassembly of these five engines, the consequences of propellant leakage across the ball-valve shaft seals can be divided into four primary areas of concern: Damage to the ball-valve pinion shafts, damage to sleeved bearings inside the ball-valve and actuator assemblies, degradation of the synthetic rubber o-rings used in the actuator assemblies, and corrosion and degradation to the interior of the actuator assemblies. The exact time at which leakage across the ball-valve shaft seals occurs has not been determined, however, the leakage most likely occurs during engine firings when, depending on the specification used, ball-valve cavity pressures range as high as 453 to 550 psia. This potential pressure range for the ball-valve cavities greatly exceeds the acceptance leakage test pressure of 332 psia. Since redesign and replacement of the ball-valve shaft seals is unlikely, the near term solution to prevent damage that occurs from shaft-seal leakage is to implement a routine overhaul and maintenance program for engines in the fleet. Recommended repair, verification, and possible preventative maintenance measures are discussed in the paper.

  17. Analyses on the measurement of leakage currents in CdZnTe radiation detectors

    International Nuclear Information System (INIS)

    Mescher, M.J.; Hoburg, J.F.; Schlesinger, T.E.; James, R.B.

    1999-01-01

    Models that place design constraints on devices which are used to measure the leakage currents in high-resistivity semiconductor materials are presented. If these design constraints are met, these models can then be used to quantitatively predict the surface sheet resistance of devices which are dominated by surface leakage currents. As a result, a means is provided to directly compare passivation techniques which are developed to decrease surface leakage currents. Furthermore, these models illustrate the necessity for inclusion of relevant geometrical data on sample size and shape and electrode configuration when reporting results of surface passivation techniques. These models specifically examine the case where a dc potential is applied across two electrodes on the surface of a semiconductor substrate which has a surface layer with lower resistivity than the bulk material. The authors describe several of the more common configurations used in analyzing passivation techniques for compounds of Cd 1-x Zn x Te (CZT) used for room-temperature radiation detection

  18. 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

  19. [Endoscopic endonasal detection of cerebrospinal fluid leakage with topical fluorescein].

    Science.gov (United States)

    Sato, Taku; Kishida, Yugo; Watanabe, Tadashi; Tani, Akiko; Tada, Yasuhiro; Tamura, Takamitsu; Ichikawa, Masahiro; Sakuma, Jun; Omori, Koichi; Saito, Kiyoshi

    2013-08-01

    We evaluated the effectiveness of intraoperative topical application of fluorescein to detect the leakage point of cerebrospinal fluid(CSF)rhinorrhea. Three patients with CSF rhinorrhea were treated with an endoscopic endonasal technique. Ten percent fluorescein was topically used for intraoperative localization of the leak site. A change of the fluorescein color from brown to green due to dilation of CSF were recognized as evidence of CSF rhinorrhea. We repeated the procedure to detect any small defects. All CSF rhinorrheas were successfully repaired by this endoscopic endonasal approach. Topical application of fluorescein is simple and sensitive for identifying intraoperative CSF rhinorrhea.

  20. Clear corneal incision leakage after phacoemulsification--detection using povidone iodine 5%.

    Science.gov (United States)

    Chee, Soon-Phaik

    2005-01-01

    The purpose of this work was to study the incidence of clear corneal wound leakage at the conclusion of standard co-axial phacoemulsification in a prospective observational series of 100 consecutive cataract cases in a single surgeon's institutional practice. At the conclusion of standard co-axial phacoemulsification using a 2.75 mm temporal single plane clear corneal incision with a 1 mm clear corneal side-port incision, the wounds were hydrated and checked for water-tightness. Povidone iodine 5% (P-I) was then evenly dripped over the cornea and the wounds were inspected visually. Any leakage of aqueous observed was recorded. The amount of leakage was graded as small or large from each wound. Leaky wounds were further hydrated and retested with P-I until sealed. Wound integrity was reassessed on the first postoperative day by use of fluorescein. Of the 100 cases, wound leakage was observed for 31 eyes (31%)-ten main incisions, nineteen side-port incisions, and both incisions in two cases. Wound leakage was easily detected as a ribbon of clear fluid streaming from the incision amid a pool of brown solution. Povidone iodine was not observed within the tract in any incision. All wound leakage was small except for one from the main incision and two from the side-port incision. None of the eyes developed wound leakage the day after surgery and none developed endophthalmitis. In conclusion, leakage from clear corneal incisions at the conclusion of phacoemulsification occurs in almost a third of cases, predominantly from the side incision. It is easily detected by use of the P-I test.

  1. 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.

  2. Component external leakage and rupture frequency estimates

    International Nuclear Information System (INIS)

    Eide, S.A.; Khericha, S.T.; Calley, M.B.; Johnson, D.A.; Marteeny, M.L.

    1991-11-01

    In order to perform detailed internal flooding risk analyses of nuclear power plants, external leakage and rupture frequencies are needed for various types of components - piping, valves, pumps, flanges, and others. However, there appears to be no up-to-date, comprehensive source for such frequency estimates. This report attempts to fill that void. Based on a comprehensive search of Licensee Event Reports (LERs) contained in Nuclear Power Experience (NPE), and estimates of component populations and exposure times, component external leakage and rupture frequencies were generated. The remainder of this report covers the specifies of the NPE search for external leakage and rupture events, analysis of the data, a comparison with frequency estimates from other sources, and a discussion of the results

  3. Leakage-Resilient Circuits without Computational Assumptions

    DEFF Research Database (Denmark)

    Dziembowski, Stefan; Faust, Sebastian

    2012-01-01

    Physical cryptographic devices inadvertently leak information through numerous side-channels. Such leakage is exploited by so-called side-channel attacks, which often allow for a complete security breache. A recent trend in cryptography is to propose formal models to incorporate leakage...... on computational assumptions, our results are purely information-theoretic. In particular, we do not make use of public key encryption, which was required in all previous works...... 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...

  4. 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...... and randomized processes with Markovian models and to compute their information leakage for a very general model of attacker. We present the QUAIL tool that automates such analysis and is able to compute the information leakage of an imperative WHILE language. Finally, we show how to use QUAIL to analyze some...... 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...

  5. Reactor coolant pressure boundary leakage detection system

    International Nuclear Information System (INIS)

    Dissing, E.; Svansson, L.

    1980-01-01

    This study deals with a system for monitoring the leakage of reactor coolant. This system is based primarily on the detection of the 13 N content in the containment atmosphere. 13 N is produced from the oxygen of the reactor water via the recoil proton nuclear process Hl+016/yields/ 13 N+ 4 He. The generation is therefore independent of fuel element leakage and of the corrosion product content in the water. It is solely related to the neutron flux level in the reactor core. Typical figures for the equilibrium 13 N concentration in the containment atmosphere following a 4 kg/minute coolant leakage are 5 kBq m/sup -3/ and 7 kBq m/sup -3/ for BWR and PWR respectively. These levels are readily measured with a 10 liter Ge(Li) flow detector assembly operated at elevated pressure. 8 refs

  6. Reactor coolant pressure boundary leakage detection system

    International Nuclear Information System (INIS)

    Dissing, E.; Svansson, L.

    1980-01-01

    This study deals with a system for monitoring the leakage of reactor coolant. This system is based primarily on the detection of the N13 content in the containment atmosphere. N13 is produced from the oxygen of the reactor water via the recoil proton nuclear process Hl+016/yields/Nl3+He4. The generation is therefore independent of fuel element leakage and of the corrosion product content in the water. It is solely related to the neutron flux level in the reactor core. Typical figures for the equilibrium N13 concentration in the containment atmosphere following a 4 kg/minute coolant leakage are 5 kBq m/sup -3/ and 7 kBq m/sup -3/ for BWR and PWR respectively. These levels are readily measured with a 10 liter Ge(Li) flow detector assembly operated at elevated pressure. 8 refs

  7. Reactor coolant pressure boundary leakage detection system

    International Nuclear Information System (INIS)

    Dissing, E.; Svansson, L.

    1979-08-01

    The present paper deals with a system for monitoring the leakage of reactor coolant. This system is based primarily on the detection of the N13 content in the containment atmosphere. N13 is produced from the oxygen of the reactor water via the recoil proton nuclear process H1+016 → N13+He4. The generation is therefore independent of fuel element leakage and of the corrosion product content in the water. It is solely related to the neutron flux level in the reactor core. Typical figures for the equilibrium N13 concentration in the containment atmosphere following a 4 kg/minute coolant leakage are 5 kBq m -3 and 7 kBq m -3 for BWR and PWR respectively. These levels are readily measured with a 10 liter Ge (Li) flow detector assembly operated at elevated pressure. (Auth.)

  8. Minimum Leakage Condenser Test Program

    International Nuclear Information System (INIS)

    1978-05-01

    This report presents the results and analysis of tests performed on four critical areas of large surface condensers: the tubes, tubesheets, tube/tubesheet joints and the water chambers. Significant changes in operation, service duty and the reliability considerations require that certain existing design criteria be verified and that improved design features be developed. The four critical areas were treated analytically and experimentally. The ANSYS finite element computer program was the basic analytical method and strain gages were used for obtaining experimental data. The results of test and analytical data are compared and recommendations made regarding potential improvement in condenser design features and analytical techniques

  9. 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...

  10. 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...

  11. Experimental evaluation of clinical colon anastomotic leakage

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian

    2014-01-01

    , 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...... experimental, in which designs were not comparable and many results were contradictory. In a clinical study, a non-significant benefit of fibrin sealant was found. Based on the available clinical and experimental data it was concluded that the fibrin-based sealants, such as Tisseel and Tachosil...

  12. The Leakage determination on corrosion fretting machine

    International Nuclear Information System (INIS)

    Sriyono; Satmoko, Ari; Hafid, Abdul; Febrianto; Prasetio, Joko; Abtokhi; Sumarno, Edy; Handoyo, Ismu; Hidayati, Nur Rahmah; Histori

    1998-01-01

    Fretting machine is an experimental loop to learn fretting corrosion phenomena wich is caused by loading and vibration. On the steam generator, one of the corrosion process that's occurred, it can be caused by vibration between tubes and bending material. Because of high flow rate inside the tube, the high frequency vibration will appeared so it can make the corrosion on bending material more faster. This process can be simulate by fretting machine. This machine has already damage because of leakage. So it will be repaired by dismantling, radiography testing and redrawing. from the result of radiography, the leakage is caused by cracking on bellows seals of the dynamic main support

  13. Design and fabrication of ZnO/TiO2-based thin-film inverter circuits using solution processing techniques

    International Nuclear Information System (INIS)

    Liau, Leo Chau-Kuang; Kuo, Juo-Wei; Chiang, Hsin-Ni

    2012-01-01

    Novel and cost-effective ceramic-based thin-film inverter circuits, based on two layers of TiO 2 and ZnO films to construct junction field-effect transistors (FETs), were designed and fabricated by solution coating techniques. The double layers of the sol–gel ZnO and TiO 2 films were coated and characterized as a diode according to the current–voltage performance. Two types of FETs, the p-channel (p-FET) and the n-channel (n-FET) devices, were produced using different coating sequences of ZnO and TiO 2 layers. Both of the transistor performances were evaluated by analyzing the source–drain current versus voltage (I ds –V ds ) data with the control of the gate voltage (V g ). The ZnO/TiO 2 -based inverter circuits, such as the complementary-FET device, were further fabricated using the integration of the p-FET and the n-FET. The voltage transfer characteristics of the inverters were estimated by the tests of the input voltage (V in ) versus the output voltage (V out ) for the thin-film inverter circuits. (paper)

  14. Influence of solution deposition rate on properties of V_2O_5 thin films deposited by spray pyrolysis technique

    International Nuclear Information System (INIS)

    Abd–Alghafour, N. M.; Ahmed, Naser M.; Hassan, Zai; Mohammad, Sabah M.

    2016-01-01

    Vanadium oxide (V_2O_5) thin films were deposited on glass substrates by using a cost-efficient spray pyrolysis technique. The films were grown at 350° through thermal decomposition of VCl_3 in deionized water with different solution spray rates. The high resolution X-ray diffraction results revealed the formation of nanocrystalline films having orthorhombic structures with preferential orientation along (101) direction. The spray rate influenced the surface morphology and crystallite size of the films. The crystallite size was found to increase whereas the micro-strain was decreased by increasing the spray deposition rates. The increase in crystallite size and decrease in the macrostrain resulted in an improvement in the films’ crystallinity. The UV-Visible spectroscopy analysis indicated that the average transmittance of all films lies in the range 75-80 %. The band gap of V_2O_5 film was decreased from 2.65 to 2.46 eV with increase of the spray deposition rate from 5 ml/min to 10 ml/min. first, second, and third level headings (first level heading).

  15. Behaviour of zirconium oxidation and is oxide films in alkali halide solutions as studied by electrochemical techniques

    International Nuclear Information System (INIS)

    Saleh, H.E.M.

    1996-01-01

    Study of the properties of Zr electrode and the oxide films that cover the metal surface is of extreme importance due to their wide applications in chemical and nuclear industry. In this thesis the electrochemical behaviour of Zr electrode in alkali halide solutions and with various surface conditions was studied, Also the galvanostatic oxidation of the metal in addition to the open circuit and impedance measurements were employed. Chapter I is a literature survey of the electrochemistry of Zr metal with particular emphasis on the stability and growth process of Zr in different media. Chapter II contains the experimental part, including details of the electrochemical techniques used in the measurements. The electrode impedance was always balanced as a series capacitance Cs and resistance Rs.Chapter III includes the experimental results and discussion. It is divide into sections, A and B. Section A includes the results of some experimental parameters which affect the reactivity of the oxide growth process on the zirconium surface, such as surface pre - treatment, electrolyte composition, the effect of different alkali halide anions, as well as the triiodide ion. 9 tabs.,26 figs.,67 refs

  16. 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...... calculated. Their performances of electrochemical impedance spectroscopy (EIS) were compared and distribution function of relaxation times (DRT) technique was also used to find the clue of gas leakage. Finally, thinning and penetrating holes were observed in electrolyte layer, which confirmed the occurrence...

  17. The Impact of Gas Turbine Component Leakage Fault on GPA Performance Diagnostics

    Directory of Open Access Journals (Sweden)

    E. L. Ntantis

    2016-01-01

    Full Text Available The leakage analysis is a key factor in determining energy loss from a gas turbine. Once the components assembly fails, air leakage through the opening increases resulting in a performance loss. Therefore, the performance efficiency of the engine cannot be reliably determined, without good estimates and analysis of leakage faults. Consequently, the implementation of a leakage fault within a gas turbine engine model is necessary for any performance diagnostic technique that can expand its diagnostics capabilities for more accurate predictions. This paper explores the impact of gas turbine component leakage fault on GPA (Gas Path Analysis Performance Diagnostics. The analysis is demonstrated with a test case where gas turbine performance simulation and diagnostics code TURBOMATCH is used to build a performance model of a model engine similar to Rolls-Royce Trent 500 turbofan engine, and carry out the diagnostic analysis with the presence of different component fault cases. Conclusively, to improve the reliability of the diagnostic results, a leakage fault analysis of the implemented faults is made. The diagnostic tool used to deal with the analysis of the gas turbine component implemented faults is a model-based method utilizing a non-linear GPA.

  18. Numerical and experimental study of the leakage flow in guide vanes with different hydrofoils

    Directory of Open Access Journals (Sweden)

    Sailesh Chitrakar

    2017-07-01

    Full Text Available Clearance gaps between guide vanes and cover plates of Francis turbines tend to increase in size due to simultaneous effect of secondary flow and erosion in sediment affected hydropower plants. The pressure difference between the two sides of the guide vane induces leakage flow through the gap. This flow enters into the suction side with high acceleration, disturbing the primary flow and causing more erosion and losses in downstream turbine components. A cascade rig containing a single guide vane passage has been built to study the effect of the clearance gap using pressure sensors and PIV (Particle Image Velocimetry technique. This study focuses on developing a numerical model of the test rig, validating the results with experiments and investigating the behavior of leakage flow numerically. It was observed from both CFD and experiment that the leakage flow forms a passage vortex, which shifts away from the wall while travelling downstream. The streamlines contributing to the formation of this vortex have been discussed. Furthermore, the reference guide vane with symmetrical hydrofoil has been compared with four cambered profiles, in terms of the guide vane loading and the consequent effect on the leakage flow. A dimensionless term called Leakage Flow Factor (Lff has been introduced to compare the performances of hydrofoils. It is shown that the leakage flow and its effect on increasing losses and erosion can be minimized by changing the pressure distribution over the guide vane.

  19. Neutron leakage measurements from a medical linear accelerator

    International Nuclear Information System (INIS)

    Palta, J.R.; Hogstrom, K.R.; Tannanonta, C.

    1984-01-01

    The McCall method has been used to measure neutron leakage from the Mevatron 77, 18- and 15-MV photon beams. Gold foil activation has been used employing a beta counting technique for the 18-MV beam and a gamma counting technique for both the 18- and 15-MV beam. The two counting techniques were used to evaluate their relative merit. The measurements were made at various locations in the patient-treatment plane for different field sizes. The results show that the thermal-neutron dose equivalent contributes only about 1%--2% of the total neutron dose equivalent. At 100 cm, the neutron dose equivalent for the 18-MV beam is approximately six times that of the 15-MV beam, slightly exceeding the 0.1% of the useful beam criteria used by some of the regulatory agencies. In light of the uncertainty in fluence to dose equivalent conversion factors, the increased dose equivalent above 0.1% is insignificant

  20. Advanced Detection Technology of Trace-level Borate for SG Leakage Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seban; Kang, Dukwon; Kim, Seungil; Kim, Hyunki; Heo, Jun; Sung, Jinhyun [Radiation Eng. Center, Shihung (Korea, Republic of); Lee, Dongbum [Academic Support Dept., Seoul (Korea, Republic of)

    2013-05-15

    Many studies have been reported for monitoring technology of steam generator, however, all of these methods have their own limitations. The leakage monitoring technology of steam generator of PWR has also got a limit due to the adoption of specific radionuclides (N-16, Ar-41, H-3, Xe, etc.) generated by nuclear fission, which are available only when reactor output is 20% or more. Most of domestic NPPs apply the N-16 technique for monitoring tube leakage but it has some problem that it is difficult to calculate the leakage rate because neutron flux are not completely formed during low power operation. For example, tube leakage of steam generator occurred in the Uljin nuclear power plant in 2002 during coast down operation for periodic plant maintenance. This plant could not prevent a rupture accident in advance because N-16 method is not possible the leak monitoring less than 20% reactor power. The development of excellent alternative monitoring technology that can monitor the real-time leakage is required under a variety of operating conditions like start-up and abnormal conditions of NPPs. This study was performed to lay a foundation in monitoring the leakage of steam generator coping with the lower output and low power operational condition using trace level of boron which is non-radioactive nuclide to inject control neutron injection. In this study, non-radioactive nuclide boron ion, which existed in the secondary system water, as leakage monitoring indicator was investigated for the separation of complex cation and anion phase. Borate was detected by using borate concentrator column coupled with the ion-exclusion column analytical column, revealing the problem of overlapped peak between fluoride and boron ions. Meanwhile, ion-exchange column could confirm the possibility as a leakage monitoring indicator of steam generator, despite the peak of glycolic acid salts was slightly overlapped. It will be needed for further research regarding the selectivity of the

  1. Advanced Detection Technology of Trace-level Borate for SG Leakage Monitoring

    International Nuclear Information System (INIS)

    Lee, Seban; Kang, Dukwon; Kim, Seungil; Kim, Hyunki; Heo, Jun; Sung, Jinhyun; Lee, Dongbum

    2013-01-01

    Many studies have been reported for monitoring technology of steam generator, however, all of these methods have their own limitations. The leakage monitoring technology of steam generator of PWR has also got a limit due to the adoption of specific radionuclides (N-16, Ar-41, H-3, Xe, etc.) generated by nuclear fission, which are available only when reactor output is 20% or more. Most of domestic NPPs apply the N-16 technique for monitoring tube leakage but it has some problem that it is difficult to calculate the leakage rate because neutron flux are not completely formed during low power operation. For example, tube leakage of steam generator occurred in the Uljin nuclear power plant in 2002 during coast down operation for periodic plant maintenance. This plant could not prevent a rupture accident in advance because N-16 method is not possible the leak monitoring less than 20% reactor power. The development of excellent alternative monitoring technology that can monitor the real-time leakage is required under a variety of operating conditions like start-up and abnormal conditions of NPPs. This study was performed to lay a foundation in monitoring the leakage of steam generator coping with the lower output and low power operational condition using trace level of boron which is non-radioactive nuclide to inject control neutron injection. In this study, non-radioactive nuclide boron ion, which existed in the secondary system water, as leakage monitoring indicator was investigated for the separation of complex cation and anion phase. Borate was detected by using borate concentrator column coupled with the ion-exclusion column analytical column, revealing the problem of overlapped peak between fluoride and boron ions. Meanwhile, ion-exchange column could confirm the possibility as a leakage monitoring indicator of steam generator, despite the peak of glycolic acid salts was slightly overlapped. It will be needed for further research regarding the selectivity of the

  2. Integral leakage rate tests of containments

    International Nuclear Information System (INIS)

    Engel, M.; Siefart, E.; Walter, R.

    1978-01-01

    A method is presented for the integral leakage rate tests of containments. This method, used in conjunction with statistical methods, provides reliable information on the tightness of the containment. This method forms the basis of DIN 25436/KTA 3405. (orig.) [de

  3. Poloidal field leakage optimization in ETE

    Energy Technology Data Exchange (ETDEWEB)

    Shibata, Carlos Shinya; Montes, Antonio

    1996-12-01

    A very simple but efficient numerical algorithm is used to minimize the Ohmic coil field leakage into the plasma region of the tokamak ETE. After few interactions the code provides the positions and the current required for two pairs of compensation coils. Resulting optimum field intensity distribution is presented and commented. (author). 5 refs., 4 figs., 2 tabs.

  4. The concept of leakage in threat assessment.

    Science.gov (United States)

    Meloy, J Reid; O'Toole, Mary Ellen

    2011-01-01

    Leakage in the context of threat assessment is the communication to a third party of an intent to do harm to a target. Third parties are usually other people, but the means of communication vary, and include letters, diaries, journals, blogs, videos on the internet, emails, voice mails, and other social media forms of transmission. Leakage is a type of warning behavior that typically infers a preoccupation with the target, and may signal the research, planning, and implementation of an attack. Nomothetic data suggest that leakage occurs in a majority of cases of attacks on and assassinations of public figures, adult mass murders, adolescent mass murders, and school or campus shootings: very low-frequency, but catastrophic acts of intended and targeted violence. Idiographic or case data illustrate the various permutations of leakage. We discuss the operational importance of the concept, place it in the context of other warning behaviors, emphasize the need for further research, and outline risk management strategies for the mitigation of such acts of violence in both law enforcement and clinical mental health settings. Copyright © 2011 John Wiley & Sons, Ltd.

  5. Secret rate - Privacy leakage in biometric systems

    NARCIS (Netherlands)

    Ignatenko, T.; Willems, F.M.J.

    2009-01-01

    Ahlswede and Csiszár [1993] introduced the concept of secret sharing. In their source model two terminals observe two correlated sequences. It is the objective of the terminals to form a common secret by interchanging a public message (helper data) in such a way that the secrecy leakage is

  6. Radiation leakage in nuclear ship 'MUTSU'

    International Nuclear Information System (INIS)

    Ando, Yoshio; Miyasaka, Shun-ichi; Takeuchi, Kiyoshi.

    1975-01-01

    Associated with the radiation leakage in MUTSU occurred in September 1974, this report reviews the shielding design for MUTSU, radiation measurement and inspection activities by a survey group, and 2 dimensional analysis on the behavior of fast neutrons to shielding based on Ssub(N) codes. In the first part, the purpose and the structure of the primary and the secondary shields of MUTSU are briefly illustrated. In the second part, the progress of the series of affairs is explained, starting from zero power criticality experiment, through discovery of radiation leakage in output-increasing test, sending of a survey group for various measurement and inspection, and finally to the conclusion drawn by the survey group. In the third part, various numerical analyses performed to investigate into the leakage are illustrated with their results. The transport codes used were ANISN, TWOTRAN, SPAN, and PALLAS-2DCY. As a result of those inspection and calculation, it was found that the radiation leakage was due to fast neutrons coming through the gap between the reactor vessel and the primary shield. (Aoki, K.)

  7. Poloidal field leakage optimization in ETE

    International Nuclear Information System (INIS)

    Shibata, Carlos Shinya; Montes, Antonio.

    1996-01-01

    A very simple but efficient numerical algorithm is used to minimize the Ohmic coil field leakage into the plasma region of the tokamak ETE. After few interactions the code provides the positions and the current required for two pairs of compensation coils. Resulting optimum field intensity distribution is presented and commented. (author). 5 refs., 4 figs., 2 tabs

  8. Acoustic control of sodium leakage in valve gates of NPP

    International Nuclear Information System (INIS)

    Trykov, E.L.; Kovtun, S.N.; Anan'ev, A.A.; Yugov, S.I.

    2014-01-01

    Short description of sodium bench and acoustic investigation results on leakage monitoring of valves DN10 and DN40 are given. It is shown that acoustic method can be used successfully to control the leakages of sodium valves. Leakages on both type of valves increase the acoustic signal dispersion by 2-3 orders. For each type of valve acoustic system of leakage determination allows to conduct the preliminary graduation of signal dispersion on the sodium discharge rate. It make possible not only to record the leakage presence but also to determine the sodium discharge rate through the valve during the leakage [ru

  9. High Resolution Spatio Temporal Moments Analysis of Solute Migration Captured using Pre-clinical Medical Imaging Techniques

    Science.gov (United States)

    Dogan, M.; Moysey, S. M.; Powell, B. A.; DeVol, T. A.

    2016-12-01

    Advances in medical imaging technologies are continuously expanding the range of applications enabled within the earth sciences. While computed x-ray tomography (CT) scans have traditionally been used for investigating the structure of geologic materials, it is now possible to perform 3D time-lapse imaging of dynamic processes, such as monitoring the infiltration of water into a soil, with sub-millimeter resolution. Likewise, single photon emission computed tomography (SPECT) can provide information on the evolution of solute transport with spatial resolution on the order of a millimeter by tracking the migration of gamma-ray emitting isotopes like 99mTc and 111In. While these imaging techniques are revolutionizing our ability to look within porous media, techniques for the analysis of such rich and large data sets are limited. The spatial and temporal moments of a plume have long been used to provide quantitative measures to describe plume movement in a wide range of settings from the lab to field. Moment analysis can also be used to estimate the hydrologic properties of the porous media. In this research, we investigate the use of moments for analyzing a high resolution 4D SPECT data set collected during a 99mTc transport experiment performed in a heterogeneous column. The 4D nature of the data set makes it amenable to the use of data mining and pattern recognition methods, such as cluster analysis, to identify regions or zones within the data that exhibit abnormal or unexpected behaviors. We then compare anomalous features within the SPECT data to similar features identified within the CT image to relate the flow behavior to pore-scale structures, such as porosity differences and macropores. Such comparisons help to identify whether these features are good predictors of preferential transport. Likewise, we evaluate whether local analysis of moments can be used to infer apparent parameters governing non-conservative transport in a heterogeneous porous media, such

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

    CERN Document Server

    Backhaus, Malte

    2017-01-13

    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...

  11. Global exponential convergence of neutral-type Hopfield neural networks with multi-proportional delays and leakage delays

    International Nuclear Information System (INIS)

    Xu, Changjin; Li, Peiluan

    2017-01-01

    This paper is concerned with a class of neutral-type Hopfield neural networks with multi-proportional delays and leakage delays. Using the differential inequality theory, a set of sufficient conditions which guarantee that all solutions of neutral-type Hopfield neural networks with multi-proportional delays and leakage delays converge exponentially to zero vector are derived. Computer simulations are carried out to verify our theoretical findings. The obtained results of this paper are new and complement some previous studies.

  12. Reactor coolant pump seal leakage monitoring

    International Nuclear Information System (INIS)

    Stevens, D.M.; Spencer, J.W.; Morris, D.J.; James, W.; Shugars, H.G.

    1986-01-01

    Problems with reactor coolant pump seals have historically accounted for a large percentage of unscheduled outages. Studies performed for the Electric Power Research Institute (EPRI) have shown that the replacement of coolant pump seals has been one of the leading causes of nuclear plant unavailability over the last ten years. Failures of coolant pump seals can lead to primary coolant leakage rates of 200-500 gallons per minute into the reactor building. Airborne activity and high surface contamination levels following these failures require a major cleanup effort and increases the time and personnel exposure required to refurbish the pump seals. One of the problems in assessing seal integrity is the inability to accurately measure seal leakage. Because seal leakage flow is normally very small, it cannot be sensed directly with normal flow instrumentation, but must be inferred from several other temperature and flow measurements. In operating plants the leakage rate has been quantified with a tipping-bucket gauge, a device which indicates when one quart of water has been accumulated. The tipping-bucket gauge has been used for most rainfall-intensity monitoring. The need for a more accurate and less expensive gauge has been addressed. They have developed a drop-counter precipitation sensor has been developed and optimized. The applicability of the drop-counter device to the problem of measuring seal leakage is being investigated. If a review of system specification and known drop-counter performance indicates that this method is feasible for measuring seal leak rates, a drop-counter gauge will be fabricated and tested in the laboratory. If laboratory tests are successful the gauge will be demonstrated in a pump test loop at Ontario Hydro and evaluated under simulated plant conditions. 3 references, 2 figures

  13. Investigation of sorption of Hg(II) ions onto coconut husk from aqueous solution using radiotracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Hasany, S.M.; Ahmad, R.; Chaudhary, M.H. [Nuclear Chemistry Div., Pakistan Inst. of Nuclear Science and Technology, Islamabad (Pakistan)

    2003-07-01

    The sorption of Hg(II) ions onto coconut (Cocos nucifera) husk has been studied using radiotracer technique. Maximum sorption (96%) of Hg(II) ions (7.39 x 10{sup -6} M) onto sorbent surface is achieved from 10{sup -3} M HNO{sub 3} solution in 30 min agitation time using 100 mg of coconut husk. The sorption data follow the Freundlich and Dubinin-Radushkevich (D-R) isotherms. Sorption capacity (6.84{+-}0.45 mmol g{sup -1}) and sorption energy (10.6{+-}0.13 kJ mol{sup -1}) have been evaluated using these isotherms. Among the ions tested to monitor their influence on the sorption, Ba(II), fluoride and tartarate increased the sorption, while thiosulfate, bromide and thiocyanate reduced (< 63 > 26%) the sorption. The cations K(I), Ce(III), Cr(III), Fe(III) and Zr(IV) partially suppressed the sorption. The variation of sorption with temperature yields thermodynamic parameters {delta}H = -37.4{+-}2 kJ mol{sup -1} {delta}S = -105{+-}7 J mol{sup -1} K{sup -1} and {delta}G = -2.58{+-}0.05 kJ mol{sup -1} at 298 K. The negative values of enthalpy and free energy reflect the spontaneous and exothermic nature of sorption, respectively. The selectivity studies of sorbent show that the coconut husk column can be used to separate Hg(II) ions from Se(IV), Zn(II), I(I) and Tc (VII). The sorbent has a potential in radiochemistry to separate gamma energies of {sup 203}Hg (279 keV) from {sup 75}Se (265 and 280 keV). (orig.)

  14. Investigation of sorption of Hg(II) ions onto coconut husk from aqueous solution using radiotracer technique

    International Nuclear Information System (INIS)

    Hasany, S.M.; Ahmad, R.; Chaudhary, M.H.

    2003-01-01

    The sorption of Hg(II) ions onto coconut (Cocos nucifera) husk has been studied using radiotracer technique. Maximum sorption (96%) of Hg(II) ions (7.39 x 10 -6 M) onto sorbent surface is achieved from 10 -3 M HNO 3 solution in 30 min agitation time using 100 mg of coconut husk. The sorption data follow the Freundlich and Dubinin-Radushkevich (D-R) isotherms. Sorption capacity (6.84±0.45 mmol g -1 ) and sorption energy (10.6±0.13 kJ mol -1 ) have been evaluated using these isotherms. Among the ions tested to monitor their influence on the sorption, Ba(II), fluoride and tartarate increased the sorption, while thiosulfate, bromide and thiocyanate reduced ( 26%) the sorption. The cations K(I), Ce(III), Cr(III), Fe(III) and Zr(IV) partially suppressed the sorption. The variation of sorption with temperature yields thermodynamic parameters ΔH = -37.4±2 kJ mol -1 ΔS = -105±7 J mol -1 K -1 and ΔG = -2.58±0.05 kJ mol -1 at 298 K. The negative values of enthalpy and free energy reflect the spontaneous and exothermic nature of sorption, respectively. The selectivity studies of sorbent show that the coconut husk column can be used to separate Hg(II) ions from Se(IV), Zn(II), I(I) and Tc (VII). The sorbent has a potential in radiochemistry to separate gamma energies of 203 Hg (279 keV) from 75 Se (265 and 280 keV). (orig.)

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

    International Nuclear Information System (INIS)

    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.

  16. Applications of exact traveling wave solutions of Modified Liouville and the Symmetric Regularized Long Wave equations via two new techniques

    Science.gov (United States)

    Lu, Dianchen; Seadawy, Aly R.; Ali, Asghar

    2018-06-01

    In this current work, we employ novel methods to find the exact travelling wave solutions of Modified Liouville equation and the Symmetric Regularized Long Wave equation, which are called extended simple equation and exp(-Ψ(ξ))-expansion methods. By assigning the different values to the parameters, different types of the solitary wave solutions are derived from the exact traveling wave solutions, which shows the efficiency and precision of our methods. Some solutions have been represented by graphical. The obtained results have several applications in physical science.

  17. Pancreatic anastomosis leakage management following pancreaticoduodenectomy how could be manage the anastomosis leakage after pancreaticoduodenectomy?

    Directory of Open Access Journals (Sweden)

    Seyed Abbas Tabatabei

    2015-01-01

    Full Text Available Background: Pancreatic anastomosis leakage and fistula formation following pancreaticoduodenectomy (Whipple′s procedure is a common complication. Delay in timely diagnosis and proper management is associated with high morbidity and mortality. To report our experience with management of pancreatic fistula following Whipple′s procedure. Materials and Methods: In this retrospective study, medical records of 90 patients who underwent Whipple′s procedure from 2009 to 2013 at our medical center were reviewed for documents about pancreatic anastomosis leakage and fistula formation. Results: There were 15 patients who developed pancreatico-jejunal anastomosis leakage. In 6 patients (3 males and 3 females the leakage was mild (conservative therapy was administered, but in 9 patients (6 males and 3 females, there was severe leakage. For the latter group, surgical intervention was done (2 cases underwent re-anastomosis and for 7 cases pancreatico-jejunal stump ligation was done along with drainage of the location. Conclusion: In severe pancreatic anastomotic leakage, it is better to intervene surgically as soon as possible by debridement of the distal part of the pancreas and ligation of the stump with nonabsorbable suture. Furthermore, debridement of the jejunum should be done, and the stump should be ligated thoroughly along with drainage.

  18. Model for CO2 leakage including multiple geological layers and multiple leaky wells.

    Science.gov (United States)

    Nordbotten, Jan M; Kavetski, Dmitri; Celia, Michael A; Bachu, Stefan

    2009-02-01

    Geological storage of carbon dioxide (CO2) is likely to be an integral component of any realistic plan to reduce anthropogenic greenhouse gas emissions. In conjunction with large-scale deployment of carbon storage as a technology, there is an urgent need for tools which provide reliable and quick assessments of aquifer storage performance. Previously, abandoned wells from over a century of oil and gas exploration and production have been identified as critical potential leakage paths. The practical importance of abandoned wells is emphasized by the correlation of heavy CO2 emitters (typically associated with industrialized areas) to oil and gas producing regions in North America. Herein, we describe a novel framework for predicting the leakage from large numbers of abandoned wells, forming leakage paths connecting multiple subsurface permeable formations. The framework is designed to exploit analytical solutions to various components of the problem and, ultimately, leads to a grid-free approximation to CO2 and brine leakage rates, as well as fluid distributions. We apply our model in a comparison to an established numerical solverforthe underlying governing equations. Thereafter, we demonstrate the capabilities of the model on typical field data taken from the vicinity of Edmonton, Alberta. This data set consists of over 500 wells and 7 permeable formations. Results show the flexibility and utility of the solution methods, and highlight the role that analytical and semianalytical solutions can play in this important problem.

  19. 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.

  20. Colorectal anastomotic leakage: aspects of prevention, detection and treatment.

    Science.gov (United States)

    Daams, Freek; Luyer, Misha; Lange, Johan F

    2013-04-21

    All colorectal surgeons are faced from time to time with anastomotic leakage after colorectal surgery. This complication has been studied extensively without a significant reduction of incidence over the last 30 years. New techniques of prevention, by innovative anastomotic techniques should improve results in the future, but standardization and "teachability" should be guaranteed. Risk scoring enables intra-operative decision-making whether to restore continuity or deviate. Early detection can lead to reduction in delay of diagnosis as long as a standard system is used. For treatment options, no firm evidence is available, but future studies could focus on repair and saving of the anastomosis on the one hand or anastomotical breakdown and definitive colostomy on the other hand.

  1. Incidence and management of pancreatic leakage after pancreatoduodenectomy

    NARCIS (Netherlands)

    de Castro, S. M. M.; Busch, O. R. C.; van Gulik, T. M.; Obertop, H.; Gouma, D. J.

    2005-01-01

    Background: Optimal management of severe pancreatic leakage after pancreatoduodenectomy can reduce morbidity and mortality. Completion pancreatectomy may be adequate but leads to endocrine insufficiency. This study evaluated an alternative management strategy for pancreatic leakage. Methods: Outcome

  2. Multiple leakage localization and leak size estimation in water networks

    NARCIS (Netherlands)

    Abbasi, N.; Habibi, H.; Hurkens, C.A.J.; Klabbers, M.D.; Tijsseling, A.S.; Eijndhoven, van S.J.L.

    2012-01-01

    Water distribution networks experience considerable losses due to leakage, often at multiple locations simultaneously. Leakage detection and localization based on sensor placement and online pressure monitoring could be fast and economical. Using the difference between estimated and measured

  3. Methods for constructing exact solutions of partial differential equations mathematical and analytical techniques with applications to engineering

    CERN Document Server

    Meleshko, Sergey V

    2005-01-01

    Differential equations, especially nonlinear, present the most effective way for describing complex physical processes. Methods for constructing exact solutions of differential equations play an important role in applied mathematics and mechanics. This book aims to provide scientists, engineers and students with an easy-to-follow, but comprehensive, description of the methods for constructing exact solutions of differential equations.

  4. Investigation of noise in Lightwave Synthesized Frequency Sweeper seeded LIDAR anemometers from leakage through the Acousto Optic Modulators

    DEFF Research Database (Denmark)

    Pedersen, Anders Tegtmeier; Lindelöw, Per Jonas Petter

    2009-01-01

    Train (FSPT) modulated lidars the leakage will give rise to rapidly growing noise in the bins which corresponds to the signal from low radial wind velocities. It is likely that noise canceling techniques similar to those used for RIN removal has to be deployed for measurements of low wind velocities.......Lightwave Synthesized Frequency Sweepers (LSFS) have potential use as lightsources in lidar anemometers. In this paper noise due to leakage in the acousto optic modulators in an LSFS is investigated. Theoretical expressions describing the build-up of noise in the LSFS due to leakage are derived...

  5. Nature Inspired Computational Technique for the Numerical Solution of Nonlinear Singular Boundary Value Problems Arising in Physiology

    Directory of Open Access Journals (Sweden)

    Suheel Abdullah Malik

    2014-01-01

    Full Text Available We present a hybrid heuristic computing method for the numerical solution of nonlinear singular boundary value problems arising in physiology. The approximate solution is deduced as a linear combination of some log sigmoid basis functions. A fitness function representing the sum of the mean square error of the given nonlinear ordinary differential equation (ODE and its boundary conditions is formulated. The optimization of the unknown adjustable parameters contained in the fitness function is performed by the hybrid heuristic computation algorithm based on genetic algorithm (GA, interior point algorithm (IPA, and active set algorithm (ASA. The efficiency and the viability of the proposed method are confirmed by solving three examples from physiology. The obtained approximate solutions are found in excellent agreement with the exact solutions as well as some conventional numerical solutions.

  6. Detection method of internal leakage from valve using acoustic method

    International Nuclear Information System (INIS)

    Kumagai, Hiromichi; Kitajima, Akira; Suzuki, Akio.

    1990-01-01

    The objective of this study is to estimate the feasibility of the acoustic method for the internal leakage from the valves in power plants. From the experimental results, it was suggested that the acoustic method for the monitoring of leakage was feasible. When the background levels are higher than the acoustic signals from leakage, we can detect the leakage analyzing the spectrum of the remainders which take the background noise from the acoustic signals. (author)

  7. Improving off-state leakage characteristics for high voltage AlGaN/GaN-HFETs on Si substrates

    Science.gov (United States)

    Moon, Sung-Woon; Twynam, John; Lee, Jongsub; Seo, Deokwon; Jung, Sungdal; Choi, Hong Goo; Shim, Heejae; Yim, Jeong Soon; Roh, Sungwon D.

    2014-06-01

    We present a reliable process and design technique for realizing high voltage AlGaN/GaN hetero-junction field effect transistors (HFETs) on Si substrates with very low and stable off-state leakage current characteristics. In this work, we have investigated the effects of the surface passivation layer, prepared by low pressure chemical vapor deposition (LPCVD) of silicon nitride (SiNx), and gate bus isolation design on the off-state leakage characteristics of metal-oxide-semiconductor (MOS) gate structure-based GaN HFETs. The surface passivated devices with gate bus isolation fully surrounding the source and drain regions showed extremely low off-state leakage currents of less than 20 nA/mm at 600 V, with very small variation. These techniques were successfully applied to high-current devices with 80-mm gate width, yielding excellent off-state leakage characteristics within a drain voltage range 0-700 V.

  8. Performance-based containment leakage testing

    International Nuclear Information System (INIS)

    Cybulskis, P.

    1995-01-01

    The U.S. Nuclear Regulatory Commission (NRC) is reviewing regulatory requirements in an effort to revise those that are marginal to safety but impose significant burdens on licensees. Identification of requirements marginal to safety and development and evaluation of alternatives utilize the NRC safety goals and insights from probabilistic risk assessments (PRAs). Since earlier studies found design-basis containment leakage to be a minor contributor to reactor accident risk, containment leakage testing has been selected as a candidate for change in regulations. This paper summarizes the technical analyses supporting the NRC proposal to amend Appendix J of 10 CFR Part 50 as its first effort to decrease unnecessary regulatory burdens on licensees

  9. Methane leakage in natural gas operations

    International Nuclear Information System (INIS)

    Jennervik, A.

    1992-01-01

    The world gas industry is efficient in conservation of natural gas within its systems. As the influence of methane as an infra-red absorbent gas has been more widely recognized, the considerations of methane's greenhouse effect has become vitally important to gas companies around the world. The industry is universally environmentally conscious. natural gas transmission and distribution companies want to maintain their image as suppliers of clean fuel. Further reductions in methane leakage --- particularly in older distribution systems --- can, should and will be pursued. Unfortunately, there has been little exchange of views on methane leakages between commentators on environmental matters and gas companies and organizations. There is absolutely no need for the industry to avoid the issue of greenhouse gases. Without industry involvement, the environmental debate concerning fossil fuels could lead to selective interpretation of scientific views and available evidence. Companies and authorities would be presented with confusing, contradictory evidence on which to base policy approaches and regulations

  10. 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.

  11. Numerical investigation of tip leakage vortex

    OpenAIRE

    Fredriksen, Vegard

    2017-01-01

    The Kaplan turbine has a small clearance gap between the blade tip and casing to allow the blades to rotate freely. This clearance gap is the cause of an undesirable Tip Leakage Vortex (TLV). A TLV might reduce the turbine efficiency, erode the turbine blades or cause instabilities for the power output. A literature study indicated that the tip clearance gap was a critical parameter affecting the behavior of the TLV. A research gap was observed for an operating Kaplan turbine where the ...

  12. Use of coliform bacteria for the detection of on-line leakage in drinking water

    International Nuclear Information System (INIS)

    Bibi, S.; Karim, H.M.A.; Mashiatullah, A.; Sajjad, I.

    1996-01-01

    In this method, rupture or leakage in under ground water pipes is detected simply by taking the water samples from the main supply lines of the houses and incubating them at 40 deg. C for sixteen hours, colonies (developed with yellow colour) are counted with colony counter. Thirteen samples (in triplicate) collected from different houses in the congested localities during repair work of the major supply line and all of them after test showed heavy rate of pollution. The experiment was repeated for the same locality and sampling sites after completion of repair work. This time the rate of pollution decreases very much showing drastically low growth of microorganisms except for two points. For two further investigation of the nearly leakages at these points, 13 samples (in triplicate) were again collected in serial wise number of houses. Two points of the leakage were identified where the growth rate of the microorganisms was abruptly high between two consecutive houses or opposite houses depending upon the supply of water pipe lines showing the leakage of houses. Two points of the leakage were identified where the growth rate of the microorganisms was abruptly high between two consecutive houses or opposite houses depending upon the supply of water pipe lines showing the leakage of he pipes. This method is useful and causes no health hazard to the population and gives best results where the water supply is on intermittent basis. The technique is specially useful in the remote areas of the country where research facilities are not available and the Pacqualab is a field instrument. So it is handy and rapid method for the detection of leakage in underground water supplies in the remote areas of the country. (author)

  13. Leakage current of amorphous silicon p-i-n diodes made by ion shower doping

    International Nuclear Information System (INIS)

    Kim, Hee Joon; Cho, Gyuseong; Choi, Joonhoo; Jung, Kwan-Wook

    2002-01-01

    In this letter, we report the leakage current of amorphous silicon (a-Si:H) p-i-n photodiodes, of which the p layer is formed by ion shower doping. The ion shower doping technique has an advantage over plasma-enhanced chemical vapor deposition (PECVD) in the fabrication of a large-area amorphous silicon flat-panel detector. The leakage current of the ion shower diodes shows a better uniformity within a 30 cmx40 cm substrate than that of the PECVD diodes. However, it shows a higher leakage current of 2-3 pA/mm 2 at -5 V. This high current originates from the high injection current at the p-i junction

  14. Optimization of path length stretching in Monte Carlo calculations for non-leakage problems

    Energy Technology Data Exchange (ETDEWEB)

    Hoogenboom, J.E. [Delft Univ. of Technology (Netherlands)

    2005-07-01

    Path length stretching (or exponential biasing) is a well known variance reduction technique in Monte Carlo calculations. It can especially be useful in shielding problems where particles have to penetrate a lot of material before being tallied. Several authors sought for optimization of the path length stretching parameter for detection of the leakage of neutrons from a slab. Here the adjoint function behaves as a single exponential function and can well be used to determine the stretching parameter. In this paper optimization is sought for a detector embedded in the system, which changes the adjoint function in the detector drastically. From literature it is known that the combination of path length stretching and angular biasing can result in appreciable variance reduction. However, angular biasing is not generally available in general purpose Monte Carlo codes and therefore we want to restrict ourselves to the application of pure path length stretching and finding optimum parameters for that. Nonetheless, the starting point for our research is the zero-variance scheme. In order to study the solution in detail the simplified monoenergetic two-direction model is adopted, which allows analytical solutions and can still be used in a Monte Carlo simulation. Knowing the zero-variance solution analytically, it is shown how optimum path length stretching parameters can be derived from it. It results in path length shrinking in the detector. Results for the variance in the detector response are shown in comparison with other patterns for the stretching parameter. The effect of anisotropic scattering on the path length stretching parameter is taken into account. (author)

  15. 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.

  16. Radiation induced leakage current and stress induced leakage current in ultra-thin gate oxides

    International Nuclear Information System (INIS)

    Ceschia, M.; Paccagnella, A.; Cester, A.; Scarpa, A.

    1998-01-01

    Low-field leakage current has been measured in thin oxides after exposure to ionizing radiation. This Radiation Induced Leakage Current (RILC) can be described as an inelastic tunneling process mediated by neutral traps in the oxide, with an energy loss of about 1 eV. The neutral trap distribution is influenced by the oxide field applied during irradiation, thus indicating that the precursors of the neutral defects are charged, likely being defects associated to trapped holes. The maximum leakage current is found under zero-field condition during irradiation, and it rapidly decreases as the field is enhanced, due to a displacement of the defect distribution across the oxide towards the cathodic interface. The RILC kinetics are linear with the cumulative dose, in contrast with the power law found on electrically stressed devices

  17. Optimization of core reload design for low leakage fuel management in pressurized water reactors

    International Nuclear Information System (INIS)

    Kim, Y.J.

    1986-01-01

    A new method was developed to optimize pressurized water reactor core reload design for low leakage fuel management, a strategy recently adopted by most utilities to extend cycle length and mitigate pressurized thermal shock concerns. The method consists of a two-stage optimization process which provides the maximum cycle length for a given fresh fuel loading subject to power peaking constraints. In the first stage, a best fuel arrangement is determined at the end of cycle in the absence of burnable poisons. A direct search method is employed in conjunction with a constant power, Haling depletion. In the second stage, the core control poison requirements are determined using a linear programming technique. The solution provides the fresh fuel burnable poison loading required to meet core power peaking constraints. An accurate method of explicitly modeling burnable absorbers was developed for this purpose. The design method developed here was implemented in a currently recognized fuel licensing code, SIMULATE, that was adapted to the CYBER-205 computer. This methodology was applied to core reload design of cycles 9 and 10 for the Commonwealth Edison Zion, Unit-1 Reactor. The results showed that the optimum loading pattern for cycle 9 yielded almost a 9% increase in the cycle length while reducing core vessel fluence by 30% compared with the reference design used by Commonwealth Edison

  18. Optimal sensor placement for leakage detection and isolation in water distribution networks

    OpenAIRE

    Rosich Oliva, Albert; Sarrate Estruch, Ramon; Nejjari Akhi-Elarab, Fatiha

    2012-01-01

    In this paper, the problem of leakage detection and isolation in water distribution networks is addressed applying an optimal sensor placement methodology. The chosen technique is based on structural models and thus it is suitable to handle non-linear and large scale systems. A drawback of this technique arises when costs are assigned uniformly. A main contribution of this paper is the proposal of an iterative methodology that focuses on identifying essential sensors which ultimately leads to...

  19. Solution of the advection-diffusion equation for a nonhomogeneous and nonstationary Planetary Boundary Layer by GILTT (Generalized Integral Laplace Transform Technique)

    International Nuclear Information System (INIS)

    Mello, Kelen Berra de

    2005-02-01

    In this work is shown the solution of the advection-diffusion equation to simulate a pollutant dispersion in the Planetary Boundary Layer. The solution is obtained through of the GILTT (Generalized Integral Laplace Transform Technique) analytic method and of the numerical inversion Gauss Quadrature. The validity of the solution is proved using concentration obtained from the model with concentration obtained for Copenhagen experiment. In this comparison was utilized potential and logarithmic wind profile and eddy diffusivity derived by Degrazia et al (1997) [17] and (2002) [19]. The best results was using the potential wind profile and the eddy diffusivity derived by Degrazia et al (1997). The vertical velocity influence is shown in the plume behavior of the pollutant concentration. Moreover, the vertical and longitudinal velocity provided by Large Eddy Simulation (LES) was stood in the model to simulate the turbulent boundary layer more realistic, the result was satisfactory when compared with contained in the literature. (author)

  20. Preliminary Study of Magnetic Flux Leakage on Tube Inspection

    International Nuclear Information System (INIS)

    Noorhazleena Azaman; Ilham Mukriz Zainal Abidin; Nurul Ain Ahmad Latif

    2015-01-01

    Magnetic Flux Leakage (MFL) is an advanced NDT technique which has the inspection capability in wall loss detection and measurement of sharp defects such as pitting, grooving and circumferential cracks in ferromagnetic samples. The working principle of MFL involves the induction of magnetic field in the part to be tested and the response or signal produced is analysed to determine the presence and characteristics of defects. In this paper, simulation and experimental work on wall loss detection in steel tube using MFL were carried out. The simulation was performed using Comsol software and followed by experimental work using MFL system for validation. The results from the simulation and experiment indicates that variation of the groove defect affect the magnetisation and the output of the MFL signal is related to change of flux caused by the detection of wall loss. (author)

  1. 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...... of these tranformerless systems, due to the missing galvanic isolation. Leakage and fault current measurement is a key issue for these inverter topologies to be able to comply with the required safety standards. This article presents the test results of two different current measurement sensors that were suggested...

  2. Leakage warning system for flexible underwater pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, E; Bernstein, L

    1985-08-01

    Underwater pipelines for unloading oil tankers, e.g. in 30 km distance from the harbour site, are required to be flexible and require supervision. This is done by implementation of oil sensitive sensors between the inner rubber tube and the following impregnated textile layer. The generated sensor signals, influenced by leak oil, have to be wireless transmitted from 150 meters under water to the supervisory station at the coast. Sensor configurations are described, to derive the point of the leakage from the topologized warning signals.

  3. Valve leakage inspection testing and maintenance process

    International Nuclear Information System (INIS)

    Aikin, J.A.; Reinwald, J.W.; Kittmer, C.A.

    1991-01-01

    In valve maintenance, packing rings that prevent leakage along the valve stem must periodically be replaced, either during routine maintenance or to correct a leak or valve malfunction. Tools and procedures currently in use for valve packing removal and inspection are generally of limited value due to various access and application problems. A process has been developed by AECL Research that addresses these problems. The process, using incompressible fluid pressure, quickly and efficiently confirms the integrity of the valve backseat, extracts hard-to-remove valve packing sets, and verifies the leak tightness of the repacked valve

  4. Unusual dialysate leakage complicating peritoneal dialysis

    International Nuclear Information System (INIS)

    Chiu, Jainn-Shiun; Yu, Fu-Chiu; Chen, Chiou-An; Wang, Yuh-Feng

    2006-01-01

    A 16-year-old female who had end-stage renal disease on 2-month continuous ambulatory peritoneal dialysis (CAPD) presented with perineal pain 4 days before admission. The physical examination revealed bilateral labial edema. Peritoneal scintigraphy was requested after infusing 2 L peritoneal dialysate with direct administration of 370 MBq (10mCi) technetium-99m diethylenetriamine pentra-acetic acid into peritoneal cavity via Tenckhoff catheter. Radioactive uptake from right inguinal to labial region was clearly demonstrated, and this indicated the site of peritoneal leakage. After surgical intervention unilaterally, she continued CAPD without any recurrence (au)

  5. A Three-Component Model for Magnetization Transfer. Solution by Projection-Operator Technique, and Application to Cartilage

    Science.gov (United States)

    Adler, Ronald S.; Swanson, Scott D.; Yeung, Hong N.

    1996-01-01

    A projection-operator technique is applied to a general three-component model for magnetization transfer, extending our previous two-component model [R. S. Adler and H. N. Yeung,J. Magn. Reson. A104,321 (1993), and H. N. Yeung, R. S. Adler, and S. D. Swanson,J. Magn. Reson. A106,37 (1994)]. The PO technique provides an elegant means of deriving a simple, effective rate equation in which there is natural separation of relaxation and source terms and allows incorporation of Redfield-Provotorov theory without any additional assumptions or restrictive conditions. The PO technique is extended to incorporate more general, multicomponent models. The three-component model is used to fit experimental data from samples of human hyaline cartilage and fibrocartilage. The fits of the three-component model are compared to the fits of the two-component model.

  6. Demonstration of an instrumental technique in the measurement of solution weight in the accountability vessels of a fuel reprocessing plant

    International Nuclear Information System (INIS)

    Nakajima, K.

    1977-04-01

    Load cells were installed on the input accountability vessel of a commercial reactor fuel reprocessing facility to determine if this proven principle of mass measurement is in fact applicable in such a severe radiation environment over a long period of time. Two other locations selected were the plutonium product nitrate solution accountability vessel and the plutonium product nitrate solution storage vessel. The latter two environments, while not severely radio-active, require a high degree of contamination control. All three vessels are of different geometrical configuration and capacity. Each vessel was carefully calibrated for volume measurements by adding controlled pre-measured increments of water. Measurements were made using the conventional dip-tube manometer system and the load cell - digital voltmeter. Standard deviation of the measurements on the input vessel and the plutonium storage vessel were in both cases 0.3%; for the plutonium accountability vessel 1.9%. Measurements taken of the input vessel during the ''cold run'' over a six-month period using solutions of unirradiated uranium showed a standard deviation of 0.4% and a bias of 0.8% in the summer months and 0.7% and 0.6% respectively in the winter months FINAL STOP CODE

  7. Retention of barium and europium radionuclides from aqueous solutions on ash-based sorbents by application of radiochemical techniques.

    Science.gov (United States)

    Noli, Fotini; Kapnisti, Maria; Buema, Gabriela; Harja, Maria

    2016-10-01

    New materials were synthesized for application in sorption of radionuclides from aqueous solutions. The elaboration was performed by conversion of power plant ash using the hydrothermal method under optimum experimental conditions. Sodalite, Na-Y, and analcime were formed from ash precursor during the treatment, exhibiting thermal stability as revealed by the characterization by X-ray diffraction (XRD) and thermogravimetric differential thermal analysis (TG-DTA). The Brunauer-Emmett-Teller (BET) surface area and pore volume were determined and they presented higher values than plant ash. The ability of the new products to retain Ba and Eu radionuclides was studied in aqueous solutions using (133)Ba and (152)Eu as tracers and γ-ray spectroscopy under batch experiments. The experimental data were modeled by the Langmuir and Freundlich equations, whereas sorption kinetics measurements were performed at 293, 308, and 323K and thermodynamic parameters were calculated. The release of the sorbed ions into the environment was also tested by leaching experiments. The results of these tests indicated that the synthesized materials are very efficient in removing the aforementioned metals from aqueous solutions and can be considered as potential low-cost sorbents in nuclear waste management. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Improvement of Physico-mechanical Properties of Partially Amorphous Acetaminophen Developed from Hydroalcoholic Solution Using Spray Drying Technique

    Science.gov (United States)

    Sadeghi, Fatemeh; Torab, Mansour; Khattab, Mostafa; Homayouni, Alireza; Afrasiabi Garekani, Hadi

    2013-01-01

    Objective(s): This study was performed aiming to investigate the effect of particle engineering via spray drying of hydroalcoholic solution on solid states and physico-mechanical properties of acetaminophen. Materials and Methods: Spray drying of hydroalcoholic solution (25% v/v ethanol/water) of acetaminophen (5% w/v) in the presence of small amounts of polyninylpyrrolidone K30 (PVP) (0, 1.25, 2.5 and 5% w/w based on acetaminophen weight) was carried out. The properties of spray dried particles namely morphology, surface characteristics, particle size, crystallinity, dissolution rate and compactibility were evaluated. Results: Spray drying process significantly changed the morphology of acetaminophen crystals from acicular (rod shape) to spherical microparticle. Differential scanning calorimetery (DSC) and x-ray powder diffraction (XRPD) studies ruled out any polymorphism in spray dried samples, however, a major reduction in crystallinity up to 65%, especially for those containing 5% w/w PVP was observed. Spray dried acetaminophen particles especially those obtained in the presence of PVP exhibited an obvious improvement of the dissolution and compaction properties. Tablets produced from spray dried samples exhibited excellent crushing strengths and no tendency to cap. Conclusions: The findings of this study revealed that spray drying of acetaminophen from hydroalcoholic solution in the presence of small amount of PVP produced partially amorphous particles with improved dissolution and excellent compaction properties. PMID:24379968

  9. 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

  10. 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 OBOR OECD: Physical chemistry Impact factor: 13.942, year: 2016

  11. Leakage in the Juelich research reactor

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    On August 17, 1978, a leakage occurred in the DIDO research reactor. Early in the afternoon of this day, the valves of the coolant loop had been checked with the reactor shut off. When the mechanics wanted to oil a tight valve and drilled a hole in the valve cover for this, heavy water started to leak (leakage in the valve membrane). The mechanics left the shielded valve space at once; directly after having a shower, they underwent a radiation protection examination. It was found that none of the mechanics had been exposed to an excessive dose. When other mechanics in protective suits had closed the leak in the valve, a total of 150 liters had leaked into the sump pump at the valve entrance. They were pumped back into the cooling system. About 5 liters of water were evaporated and, via the stack, escaped into the environment. The activity released was about 40 curie; this is less than the permissible amount of 60 curie per week during normal operation. Neither the KFA personnel nor the inhabitants of Juelich and its surroundings were in danger at any moment. Calculations so far yield a maximum radiation exposure below 1mrem at the point of maximum exposure. The cooling circuit could be entered again only one day after the incident. The present shut-off phase of the reactor is not unduly prolonged by this accident. (orig./HP) [de

  12. Leakage detection device for weld portion

    International Nuclear Information System (INIS)

    Shinkawa, Toshio; Setokuchi, Sadayuki.

    1994-01-01

    The present invention concerns leakage detection device for weld portions, for example, in a nuclear reactor cavity, which can rapidly detect by remote control. That is, a detection device capable of self running and stopping on a guide rail along a weld line is disposed. The detection device comprises a coating mechanism for automatically coating soap water to the weld portion, a vacuum box capable of evacuating the coated surface and a camera for detecting the presence or absence of the soap bubbles generated under the evacuation. Such a device can conduct, by remote control, self running/stopping along with the weld line, coating of the soap water, settling of the vacuum box and confirmation and recording of foaming by using a television monitor. Accordingly, leakage in the weld portion in the reactor cavity or the like can be inspected. As a result, it greatly contributes to improvement of danger upon worker's operation at high place, detection accuracy and reliability of detection and shortening of operation period. (I.S.)

  13. Leakage detection system in nuclear reactor container

    International Nuclear Information System (INIS)

    Kurosawa, Masahiko.

    1993-01-01

    The present invention comprises an injection means for adding radioactive materials to coolants in a container cooler, a gamma ray amplitude analyzer connected to coolant pipelines and a means for recording/transferring the data of the result of the measurement, a gamma ray amplitude analyzer connected to a drain water sump and a means for recording/transferring the data of the result of the measurement, a gamma ray amplitude analyzer connected to various kinds of pipelines and a means for recording/transferring the data of the result of the measurement, and a data processing means for comparing and analyzing the measured data of each of the gamma ray amplitude analyzers inputted from each of date recording/transferring means. The gamma ray amplitude analysis for each of the pipelines and drain water sump are conducted at an appropriate frequency, and the measured data are compared and analyzed, to improve the detection accuracy for a trace amount of leakage from each of the pressure pipelines and the container cooler coolant pipelines, thereby enabling to specify the pipeline having leakage. Maintenance efficiency is improved, and severe rupture accident in each of pressure pipelines is prevented previously. (N.H.)

  14. [Effect of carbamide peroxide bleaching agents on micro-leakage of composite resin interface in vitro].

    Science.gov (United States)

    Wang, Xiao-ling; Xu, Juan; Zhao, Xin-yi; He, Hui-ming

    2011-01-01

    To evaluate the effect of carbamide peroxide (CP) bleaching agents at different concentrations and with different carriers on the micro-leakage of composite resin interface. Class V cavity (2 mm in diameter and 2 mm in depth) preparations were made at the enamelo-cemental junction on the buccal and lingual surfaces of 35 extracted human premolars. The cavities were filled with hybrid composite resin. The teeth were stored for 24 h in distilled water at 37 degrees celsius; before thermocyling for 500 times between 5 and 55 degrees celsius;. The teeth were then randomly assigned into 7 groups, and in groups 1-6, the bleaching gels containing 10% or 20% of CP were applied on the buccal and lingual surface of the teeth for two weeks (6-8 h/day, 37 degrees celsius;, 100% relative humidity) using Carbopol, PVP or Poloxamer as the thickening carriers, respectively. The seventh group served as the control without bleaching treatment. Nail polish was applied to the surface of the tooth, and all the teeth were immersed in ammoniacal silver nitrate solution followed by developing solution. The teeth were finally sectioned through the midline of the restoration and observed under stereomicroscope. SEM micrographs were also made to observe the interface. With the same bleaching agent, the micro-leakage in the gingival wall was slightly greater than in the occlusive wall, but the difference was not significant. Only 20% CP with Poloxamer as the thickening agent significantly increased the leakage of dentine-resin composite interface, and 10% and 20% CP with Carbopol or PVP as the thickening agents and 10% CP with Poloxamer produced minimal effects on filling the micro-leakage. Thickening carriers and the concentration of CP (20% or below) have no significant effect on micro-leakage of composite resin.

  15. Nuclear techniques in the study of pollutant transport in the environment. Interaction of solutes with geological media (methodological aspects)

    International Nuclear Information System (INIS)

    1993-07-01

    This volume includes a summary of the 5-year co-ordinated research programme to use nuclear techniques for the study of the transport of pollutants (both radioactive and non-radioactive) in the environment as well as twelve individual reports of the different activities performed under the programme. These have been indexed separately. Refs, figs and tabs

  16. Simultaneous multigrid techniques for nonlinear eigenvalue problems: Solutions of the nonlinear Schrödinger-Poisson eigenvalue problem in two and three dimensions

    Science.gov (United States)

    Costiner, Sorin; Ta'asan, Shlomo

    1995-07-01

    Algorithms for nonlinear eigenvalue problems (EP's) often require solving self-consistently a large number of EP's. Convergence difficulties may occur if the solution is not sought in an appropriate region, if global constraints have to be satisfied, or if close or equal eigenvalues are present. Multigrid (MG) algorithms for nonlinear problems and for EP's obtained from discretizations of partial differential EP have often been shown to be more efficient than single level algorithms. This paper presents MG techniques and a MG algorithm for nonlinear Schrödinger Poisson EP's. The algorithm overcomes the above mentioned difficulties combining the following techniques: a MG simultaneous treatment of the eigenvectors and nonlinearity, and with the global constrains; MG stable subspace continuation techniques for the treatment of nonlinearity; and a MG projection coupled with backrotations for separation of solutions. These techniques keep the solutions in an appropriate region, where the algorithm converges fast, and reduce the large number of self-consistent iterations to only a few or one MG simultaneous iteration. The MG projection makes it possible to efficiently overcome difficulties related to clusters of close and equal eigenvalues. Computational examples for the nonlinear Schrödinger-Poisson EP in two and three dimensions, presenting special computational difficulties that are due to the nonlinearity and to the equal and closely clustered eigenvalues are demonstrated. For these cases, the algorithm requires O(qN) operations for the calculation of q eigenvectors of size N and for the corresponding eigenvalues. One MG simultaneous cycle per fine level was performed. The total computational cost is equivalent to only a few Gauss-Seidel relaxations per eigenvector. An asymptotic convergence rate of 0.15 per MG cycle is attained.

  17. Device for preventing leakage of coolant in nuclear fuel assembly

    International Nuclear Information System (INIS)

    Kobayashi, Yukio; Sekiguchi, Mamoru; Yoshida, Hideo.

    1975-01-01

    Object: To prevent leakage of coolant from between lower tie plate and channel box without causing deformation of the channel box and also without the possibility of disturbing the installation and removal of the box by the provision of a thin plate provided with leakage holes for the lower tie plate. Structure: Static water pressure within the lower tie plate is adapted to act upon the bear side of a flat plate for leakage prevention through leakage holes formed in the tie plate, thus urging the flat plate against the channel box inner surface. Meanwhile, static water pressure having been led through the leakage holes in the flat plate is adapted to press the flat plate in the vertical direction, thus urging the flat plate against the channel box inner surface and thereby preventing leakage of the coolant through a gap between the channel box and lower tie plate. (Yoshino, Y.)

  18. Determination of dextrose in peritoneal dialysis solution by localized surface plasmon resonance technique based on silver nanoparticles formation

    Science.gov (United States)

    Masrournia, Mahboube; Montazarolmahdi, Maliheh; Sani, Faramarz Aliasghari

    2017-07-01

    Determination of dextrose in peritoneal dialysis with a method based on silver nanoparticles (AgNPs) formation was investigated. In a green chemistry method, silver nanoparticles (AgNPs) were synthesized in the natural polymeric matrix of gelatin. The nanoparticles were characterized with UV-Vis spectroscopy and transmission electron microscopy (TEM). Absorbance signal of AgNPs could be applied to determine the various concentrations of dextrose solutions. Drop wise and ultrasonic methods were used and compared with each other. The dynamic range of methods with limit of detection and relative standard deviations were obtained. Results for real sample (peritoneal dialysis) were satisfied.

  19. Modeling of leakage currents in high-k dielectrics

    International Nuclear Information System (INIS)

    Jegert, Gunther Christian

    2012-01-01

    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 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 2 /TiN capacitor structures were suggested and problem areas that may

  20. 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

  1. Electrically conductive nanostructured silver doped zinc oxide (Ag:ZnO) prepared by solution-immersion technique

    International Nuclear Information System (INIS)

    Afaah, A. N.; Asib, N. A. M.; Aadila, A.; Khusaimi, Z.; Mohamed, R.; Rusop, M.

    2016-01-01

    p-type ZnO films have been fabricated on ZnO-seeded glass substrate, using AgNO_3 as a source of silver dopant by facile solution-immersion. Cleaned glass substrate were seeded with ZnO by mist-atomisation, and next the seeded substrates were immersed in Ag:ZnO solution. The effects of Ag doping concentration on the Ag-doped ZnO have been investigated. The substrates were immersed in different concentrations of Ag dopant with variation of 0, 1, 3, 5 and 7 at. %. The surface morphology of the films was characterized by field emission scanning electron microscope (FESEM). In order to investigate the electrical properties, the films were characterized by Current-Voltage (I-V) measurement. FESEM micrographs showed uniform distribution of nanostructured ZnO and Ag:ZnO. Besides, the electrical properties of Ag-doped ZnO were also dependent on the doping concentration. The I-V measurement result indicated the electrical properties of 1 at. % Ag:ZnO thin film owned highest electrical conductivity.

  2. Evaporation-Driven Deposition of ITO Thin Films from Aqueous Solutions with Low-Speed Dip-Coating Technique.

    Science.gov (United States)

    Ito, Takashi; Uchiyama, Hiroaki; Kozuka, Hiromitsu

    2017-05-30

    We suggest a novel wet coating process for preparing indium tin oxide (ITO) films from simple solutions containing only metal salts and water via evaporation-driven film deposition during low-speed dip coating. Homogeneous ITO precursor films were deposited on silica glass substrates from the aqueous solutions containing In(NO 3 ) 3 ·3H 2 O and SnCl 4 ·5H 2 O by dip coating at substrate withdrawal speeds of 0.20-0.50 cm min -1 and then crystallized by the heat treatment at 500-800 °C for 10-60 min under N 2 gas flow of 0.5 L min -1 . The ITO films heated at 600 °C for 30 min had a high optical transparency in the visible range and a good electrical conductivity. Multiple-coating ITO films obtained with five-times dip coating exhibited the lowest sheet (ρ S ) and volume (ρ V ) resistivities of 188 Ω sq -1 and 4.23 × 10 -3 Ω cm, respectively.

  3. An enhanced security solution for electronic medical records based on AES hybrid technique with SOAP/XML and SHA-1.

    Science.gov (United States)

    Kiah, M L Mat; Nabi, Mohamed S; Zaidan, B B; Zaidan, A A

    2013-10-01

    This study aims to provide security solutions for implementing electronic medical records (EMRs). E-Health organizations could utilize the proposed method and implement recommended solutions in medical/health systems. Majority of the required security features of EMRs were noted. The methods used were tested against each of these security features. In implementing the system, the combination that satisfied all of the security features of EMRs was selected. Secure implementation and management of EMRs facilitate the safeguarding of the confidentiality, integrity, and availability of e-health organization systems. Health practitioners, patients, and visitors can use the information system facilities safely and with confidence anytime and anywhere. After critically reviewing security and data transmission methods, a new hybrid method was proposed to be implemented on EMR systems. This method will enhance the robustness, security, and integration of EMR systems. The hybrid of simple object access protocol/extensible markup language (XML) with advanced encryption standard and secure hash algorithm version 1 has achieved the security requirements of an EMR system with the capability of integrating with other systems through the design of XML messages.

  4. Radiologic assessment of spinal CSF leakage in spontaneous intracranial hypotension

    International Nuclear Information System (INIS)

    Han, Chang Jin; Kim, Ji Hyung; Kim, Jang Sung; Kim, Sun Yong; Suh, Jung Ho

    1999-01-01

    To assess the usefulness of imaging modalities in the detection of spinal CSF leakage in spontaneous intracranial hypotension. Fifteen patients who complained of postural headache without any preceding cause showed typical brain MR findings of intracranial hypotension, including radiologically confirmed CSF leakage. All fifteen underwent brain MRI and radionuclide cisternography. CT myelography was performed in eight patients and spinal MRI in six. Medical records, imaging findings and the incidence of spinal CSF leakage during each modality were retrospectively reviewed. CSF leakage was most common at the cervicothoracic junction, where in seven of 15 cases it was seen on radionuclide cisternography as increased focal paraspinal activity. Leakage was noted at the mid-tho-racic level in three patients, at the upper thoracic level in two, and at the cervical and lumbar levels in the remaining two. In two patients multiple CSF leaks were noted, and in all, early radioactive accumulation in the bladder was visualized. CT myelography revealed extrathecal and paraspinal contrast leakage in three of eight patients, and among those who underwent spinal MRI, dural enhancement was observed at the site of CSF leakage in all six, abnormal CSF signal in the neural foramen in one, and epidural CSF collection in one. Radionuclide cisternography is a useful method for the detection of CSF leakage in spontaneous intracranial hypotension. CT myelography and spinal MRI help determine the precise location of leakage

  5. Particle and radiation leakage importance: definition, analysis, and interpretation

    International Nuclear Information System (INIS)

    Cacuci, D.G.; Wagschal, J.J.; Yaari, A.

    1982-01-01

    The concept of leakage importance function has been introduced and analyzed for physical systems governed by the Boltzmann transport equation. This leakage importance function represents a measure of the relative importance of source particles located at every point in phase space in contributing to the leakage and provides insight regarding the specific physical process that leads to leakage. The equation satisfied by the leakage importance function has been derived by using adjoint operators. It has been shown that procedures that are customarily used to derive an equation obeyed by an importance function suitable for an integral parameter such as a detector response or an eigenvalue lead to difficulties when directly applied to derive an equation obeyed by the leakage importance function. This is because, although leakage is also an integral parameter (i.e., a functional of the forward flux density), leakage is expressed in terms of a surface integral rather than in terms of volume integrals such as those appearing in expressions of detector responses or eigenvalues. Therefore, a procedure that departs from the customary course has been devised to derive the equation satisfied by the leakage importance function

  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. Anomaly detection using magnetic flux leakage technology

    Energy Technology Data Exchange (ETDEWEB)

    Rempel, Raymond G. [BJ Pipeline Inspection Services, Alberta (Canada)

    2005-07-01

    There are many aspects to properly assessing the integrity of a pipeline. In-line-Inspection (ILI) tools, in particular those that employ the advanced use of Magnetic Flux Leakage (MFL) technology, provide a valuable means of achieving required up-to-date knowledge of a pipeline. More prevalent use of High Resolution MFL In-Line-Inspection tools is growing the knowledge base that leads to more reliable and accurate identification of anomalies in a pipeline, thus, minimizing the need for expensive verification excavations. Accurate assessment of pipeline anomalies can improve the decision making process within an Integrity Management Program and excavation programs can then focus on required repairs instead of calibration or exploratory digs. Utilizing the information from an MFL ILI inspection is not only cost effective but, as well, can also prove to be an extremely valuable building block of a Pipeline Integrity Management Program. (author)

  8. Leakages and pressure relation: an experimental research

    Directory of Open Access Journals (Sweden)

    F. De Paola

    2012-11-01

    Full Text Available Leaks in water systems are presently a frequent and increasing event that involves cost increase and poor service, not compliant to quality standards and modern management criteria. The most recent data available in Italy, resumed into the report issued by Control Committee for Water Resources Use (CONVIRI, shows leakages with an average value of 37%. It is therefore important, for maintenance perspective, to investigate occurrence and evolution of water leaks and the analytical link between leaks Qp and network pressure P, for a reliable calibration of water networks quali-quantitative simulation models. The present work reports the first results of an experimental campaign started at Laboratory of Hydraulics of Department of Hydraulics, Geotechnical and Environmental Engineering of University of Naples Federico II in order to analyze the features of Qp(P relation, which are compared with other results issued in literature.

  9. Potential gonadal dose from leakage radiation?

    International Nuclear Information System (INIS)

    Nicholson, R.A.

    1995-01-01

    The author draws attention to the potential dangers of leakage radiation from mobile image intensifier units, and points out that during interventional urological procedures, radiation from below the urologist's knees may irradiate male gonads without being intercepted by protective aprons. Results are presented for a Shimatzu WHA mobile II, phantom doses being measured with an ionization chamber. Dose rates measured in the male gonad position were compared with rates at waist level behind a 0.35 mm lead equivalent shielding and dose rates at collar level outside the lead apron. Results are also presented of a study on the effect on gonad dose of a) adding 0.7 mm lead shielding to the tube housing and b) adding 0.7 mm lead and removing the spacer cone to reduce scatter. Results show that it is possible for gonad doses to be comparable with those assumed for the eyes, rather than the body. (Author)

  10. Acoustic emission generated by fluid leakage

    International Nuclear Information System (INIS)

    Kim, H.C.

    1987-01-01

    The noise generated by the leaking saturated steam and subcooled water form various sizes of hole has been measured as function of leak rate and stagnation pressure. Acoustic emission (proportinal to root mean sguare voltage) is shown to be proportional to the leak rate and stagnation pressure. A transition of acoustic emission power is observed at the stagnation pressure 0.185 MPa associated with the transition to the critical flow state. Substantially higher acoustic emission power generated by the subcooled water leakage is attributed to the flashing source involving the phase transformation and volume expansion. The relative amplitude of noise spectrum becomes more spiky as the leak rate and stagnation pressure increased. (Author)

  11. Study of influence of fuel on dielectric and ferroelectric properties of bismuth titanate ceramics synthesized using solution based combustion technique

    International Nuclear Information System (INIS)

    Subohi, Oroosa; Malik, M M; Kurchania, Rajnish; Kumar, G S

    2015-01-01

    The effect of fuel characteristics on the processing and properties of bismuth titanate (BIT) ceramics obtained by solution combustion route using different fuels are reported in this paper. Dextrose, urea and glycine were used as fuel in this study. The obtained bismuth titanate ceramics were characterized by using XRD, SEM at different stages of sample preparation. It was observed that BIT obtained by using dextrose as fuel shows higher dielectric constant and higher remnant polarization due to smaller grain size and lesser c-axis growth as compared to the samples with urea and glycine as fuel. The electrical behavior of the samples with respect to temperature and frequency was also investigated to understand relaxation phenomenon. (paper)

  12. Systematic review of methods to predict and detect anastomotic leakage in colorectal surgery.

    Science.gov (United States)

    Hirst, N A; Tiernan, J P; Millner, P A; Jayne, D G

    2014-02-01

    Anastomotic leakage is a serious complication of gastrointestinal surgery resulting in increased morbidity and mortality, poor function and predisposing to cancer recurrence. Earlier diagnosis and intervention can minimize systemic complications but is hindered by current diagnostic methods that are non-specific and often uninformative. The purpose of this paper is to review current developments in the field and to identify strategies for early detection and treatment of anastomotic leakage. A systematic literature search was performed using the MEDLINE, Embase, PubMed and Cochrane Library databases. Search terms included 'anastomosis' and 'leak' and 'diagnosis' or 'detection' and 'gastrointestinal' or 'colorectal'. Papers concentrating on the diagnosis of gastrointestinal anastomotic leak were identified and further searches were performed by cross-referencing. Computerized tomography CT scanning and water-soluble contrast studies are the current preferred techniques for diagnosing anastomotic leakage but suffer from variable sensitivity and specificity, have logistical constraints and may delay timely intervention. Intra-operative endoscopy and imaging may offer certain advantages, but the ability to predict anastomotic leakage is unproven. Newer techniques involve measurement of biomarkers for anastomotic leakage and have the potential advantage of providing cheap real-time monitoring for postoperative complications. Current diagnostic tests often fail to diagnose anastomotic leak at an early stage that enables timely intervention and minimizes serious morbidity and mortality. Emerging technologies, based on detection of local biomarkers, have achieved proof of concept status but require further evaluation to determine whether they translate into improved patient outcomes. Further research is needed to address this important, yet relatively unrecognized, area of unmet clinical need. Colorectal Disease © 2013 The Association of Coloproctology of Great Britain

  13. Advantages of gadobenate dimeglumine-enhanced MR cholangiography in the diagnosis of post-liver transplant bile leakage.

    Science.gov (United States)

    Fontarensky, M; Montoriol, P-F; Buc, E; Poincloux, L; Petitcolin, V; Da Ines, D

    2013-04-01

    To assess the value of magnetic resonance cholangiography with gadobenate dimeglumine (Gd-BOPTA) where there is a suspicion of bile leakage in the post-liver transplant patient. Eight patients who had undergone a liver transplant underwent 14 MR cholangiograms, five of whom presented bile leakage while the other three had no biliary system complications. The results were compared to conventional bile duct opacification (by endoscopy or t-tube cholangiogram). The analysis covered whether there was opacification of the common bile duct and intrahepatic bile ducts on T1-weighted sequences after an injection of Gd-BOPTA on delayed biliary excretion phase sequences that were carried out on average 74 min after the injection. Enhancing perihepatic collections were also taken into account. Opacification of the bile ducts on delayed-phase MR cholangiogram sequences was always seen in the absence of bile leakage, and was never found when leakage was present. Enhancing perihepatic collections pointed to bile leakage every time. Gd-BOPTA-enhanced MR cholangiography is a simple and non-invasive technique for detecting bile leakage in the post-liver transplant patient. Copyright © 2013 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  14. Intelligent Pressure Management to Reduce Leakage in Urban Water Supply Networks, A Case Study of Sarafrazan District, Mashhad

    Directory of Open Access Journals (Sweden)

    Mohammad Soltani Asl

    2009-09-01

    Full Text Available Water losses are inevitable in urban water distribution systems. The two approaches adopted nowadays to combat this problem include management of hydraulic parameters such as pressure and leakage detection in the network. Intellitgent pressure management is a suitable technique for controlling leakage and reducing damages due to high operating pressures in a network. This paper aims to investigate the effects of pressure reduction on leakage. The EPANET 2.10 software is used to simulate the water distribution network in the Sarafrazan District,Mashhad, assuming leakage from network nodes. The results are then used to develop a pressure variation program based on the patterns obtained from the simulation, which is applied to the pressure reducing valve. The results show that pressure management can reduce nightly leakage by up to 35% while maintaining a more uniform pressure distribution. Implementation of the time-dependent pressure pattern by applying programmable pressure reducing valves in a real urban water distribution network is feasible and plays a key role in reducing water losses to leakage.

  15. Pre-Saturation Technique of the Recycled Aggregates: Solution to the Water Absorption Drawback in the Recycled Concrete Manufacture.

    Science.gov (United States)

    García-González, Julia; Rodríguez-Robles, Desirée; Juan-Valdés, Andrés; Morán-Del Pozo, Julia Mª; Guerra-Romero, M Ignacio

    2014-09-01

    The replacement of natural aggregates by recycled aggregates in the concrete manufacturing has been spreading worldwide as a recycling method to counteract the large amount of construction and demolition waste. Although legislation in this field is still not well developed, many investigations demonstrate the possibilities of success of this trend given that concrete with satisfactory mechanical and durability properties could be achieved. However, recycled aggregates present a low quality compared to natural aggregates, the water absorption being their main drawback. When used untreated in concrete mix, the recycled aggregate absorb part of the water initially calculated for the cement hydration, which will adversely affect some characteristics of the recycled concrete. This article seeks to demonstrate that the technique of pre-saturation is able to solve the aforementioned problem. In order to do so, the water absorption of the aggregates was tested to determine the necessary period of soaking to bring the recycled aggregates into a state of suitable humidity for their incorporation into the mixture. Moreover, several concrete mixes were made with different replacement percentages of natural aggregate and various periods of pre-saturation. The consistency and compressive strength of the concrete mixes were tested to verify the feasibility of the proposed technique.

  16. Pre-Saturation Technique of the Recycled Aggregates: Solution to the Water Absorption Drawback in the Recycled Concrete Manufacture †

    Science.gov (United States)

    García-González, Julia; Rodríguez-Robles, Desirée; Juan-Valdés, Andrés; Morán-del Pozo, Julia Mª; Guerra-Romero, M. Ignacio

    2014-01-01

    The replacement of natural aggregates by recycled aggregates in the concrete manufacturing has been spreading worldwide as a recycling method to counteract the large amount of construction and demolition waste. Although legislation in this field is still not well developed, many investigations demonstrate the possibilities of success of this trend given that concrete with satisfactory mechanical and durability properties could be achieved. However, recycled aggregates present a low quality compared to natural aggregates, the water absorption being their main drawback. When used untreated in concrete mix, the recycled aggregate absorb part of the water initially calculated for the cement hydration, which will adversely affect some characteristics of the recycled concrete. This article seeks to demonstrate that the technique of pre-saturation is able to solve the aforementioned problem. In order to do so, the water absorption of the aggregates was tested to determine the necessary period of soaking to bring the recycled aggregates into a state of suitable humidity for their incorporation into the mixture. Moreover, several concrete mixes were made with different replacement percentages of natural aggregate and various periods of pre-saturation. The consistency and compressive strength of the concrete mixes were tested to verify the feasibility of the proposed technique. PMID:28788188

  17. The Use of Low-frequency Active Channel Signals in an Information Leakage Detection and Prevention Systems

    Directory of Open Access Journals (Sweden)

    A. V. Mamaev

    2011-06-01

    Full Text Available This article describes a solution for the protection of the temporary lifting of control over the target machine, while using information leakage detection and prevention systems. It is proposed to use a specially designed channel for alert’s signals through the computer’s power supply.

  18. 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.

  19. 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.

  20. Botulinum neurotoxin for management of intractable central leakage through a voice prosthesis in surgical voice restoration.

    Science.gov (United States)

    Mullan, G P J; Lee, M T; Clarke, P M

    2006-09-01

    Rehabilitation of voice and speech after total laryngectomy has become established practice in recent years. A voice prosthesis is placed within a surgically produced fistula between the trachea and upper oesophagus and acts as a one way valve, allowing passage of pulmonary air from the trachea into the oesophagus and preventing aspiration of food and fluid from the oesophagus into the trachea. Persistent leakage through or around these prostheses is a recognized complication, the aetiology of which can vary widely, from mechanical issues with the prostheses themselves to anatomical and physiological issues associated with the reconstructed pharynx. We report a new technique of using Dysport in the management of intractable central leakage due to premature and forceful closure of the upper oesophageal sphincter during swallowing. This resulted in the pooling of fluids around the posterior flange of the prosthesis. This, along with the increased pressure from the muscle contraction, led to central leakage, as identified on videofluoroscopy. An injection of Dysport paralysed the upper oesophageal sphincter, preventing pooling of fluids around the prosthesis and the forcing open of the valve. The effect was to eliminate the leakage, and the patient did not require further injections over the following 22 months.

  1. Thermoluminescence properties of Li2B4O7:Cu, B phosphor synthesized using solution combustion technique

    International Nuclear Information System (INIS)

    Ozdemir, A.; Altunal, V.; Kurt, K.; Depci, T.; Yu, Y.; Lawrence, Y.; Nur, N.; Guckan, V.; Yegingil, Z.

    2017-01-01

    To determine the effects of various concentrations of the activators copper (Cu) and boron (B) on the thermoluminescence (TL) properties of lithium tetraborate, the phosphor was first synthesized and doped with five different concentrations of copper (0.1–0.005 wt%) using solution combustion method. 0.01 wt% Cu was the concentration which showed the most significant increase in the sensitivity of the phosphor. The second sort of Li 2 B 4 O 7 :Cu material was prepared by adding B (0.001–0.03 wt%) to it. The newly developed copper-boron activated lithium tetraborate (Li 2 B 4 O 7 :Cu, B) material with 0.01 wt% Cu and 0.001 wt% B impurity concentrations was shown to have promise as a TL phosphor. The material formation was examined using powder x-Ray Diffraction (XRD) analysis and Scanning Electron Microscope (SEM) imaging. Fourier Transform Infrared (FT-IR) spectrum of the synthesized polycrystalline powder sample was also recorded. The TL glow curves were analyzed to determine various dosimetric characteristics of the synthesized luminophosphors. The dose response increased in a “linear” way with the beta-ray exposure between 0.1–20 Gy, a dose range being interested in medical dosimetry. The response with changing photon and electron energy was studied. The rate of decay of the TL signal was investigated both for dark storage and under direct sunlight. Li 2 B 4 O 7 :Cu, B showed no individual variation of response in 9 recycling measurements. The fluorescence spectrum was determined. The kinetic parameters were estimated by different methods and the results discussed. The studied properties of synthesized Li 2 B 4 O 7 :Cu, B were found all favorable for dosimetric purposes. - Highlights: • Li 2 B 4 O 7 :Cu, B synthesis using solution combustion method with various concentrations. • Structure analysis of Li 2 B 4 O 7 :Cu, B using XRD, SEM and FTIR methods. • Investigation of thermoluminescent properties of Li 2 B 4 O 7 :Cu, B. • Relatively good

  2. Fabrication of a Textile-Based Wearable Blood Leakage Sensor Using Screen-Offset Printing

    Directory of Open Access Journals (Sweden)

    Ken-ichi Nomura

    2018-01-01

    Full Text Available We fabricate a wearable blood leakage sensor on a cotton textile by combining two newly developed techniques. First, we employ a screen-offset printing technique that avoids blurring, short circuiting between adjacent conductive patterns, and electrode fracturing to form an interdigitated electrode structure for the sensor on a textile. Furthermore, we develop a scheme to distinguish blood from other substances by utilizing the specific dielectric dispersion of blood observed in the sub-megahertz frequency range. The sensor can detect blood volumes as low as 15 μL, which is significantly lower than those of commercially available products (which can detect approximately 1 mL of blood and comparable to a recently reported value of approximately 10 μL. In this study, we merge two technologies to develop a more practical skin-friendly sensor that can be applied for safe, stress-free blood leakage monitoring during hemodialysis.

  3. A single-cell technique for the measurement of membrane potential, membrane conductance, and the efflux of rapidly penetrating solutes in Amphiuma erythrocytes.

    Science.gov (United States)

    Stoner, L C; Kregenow, F M

    1980-10-01

    We describe a single-cell technique for measuring membrane potential, membrane resistance, and the efflux of rapidly penetrating solutes such as Cl and H2O. Erythrocytes from Amphiuma means were aspirated into a Sylgard (Dow Corning Corp.)-coated capillary. The aspirated cell separated a solution within the capillary from a solution in the bath. Each of these two solutions was contiguous with approximately 5% of the total membrane surface. Microelectrodes placed concentrically within the capillary permit the measurement of intracellular voltage, specific membrane resistance, and the electrical seal between the two solutions. The intracellular voltage averaged -17.7 mV (pH 7.6) and changed as either intra- or extracellular chloride was varied. The average specific membrane resistance measured by passing current across the exposed membrane surface was 110 ohm-cm2. 36Cl and tritiated H2O fluxes (0.84 +/- 0.05 x 10(-6) M . cm-2 . min-1 and 6.4 +/- 1.5 x 10(-3) M . cm-2 . min-1, respectively) were determined by noting the rate at which isotope leaves the cell and crosses the membrane exposed to the bath. Our measured values for the flux of 36Cl and tritiated H2O approximate reported values for free-floating cells. 36Cl efflux, in addition, is inhibited by 4-acetamido-4'-isothiocyano-stilbene 2,2'-disulfonic acid (SITS) and furosemide, known inhibitors of the anion exchange mechanism responsible for the rapid anion fluxes of red blood cells. One can also demonstrate directly that > 89% of 36Cl efflux is "electrically silent" by analyzing the flux in the presence of an imposed transcellular voltage.

  4. Analytical techniques for in-line/on-line monitoring of uranium and plutonium in process solutions : a brief literature survey

    International Nuclear Information System (INIS)

    Marathe, S.G.; Sood, D.D.

    1991-01-01

    In-line/on-line monitoring of various parameters such as uranium-plutonium-fission product concentration, acidity, density etc. plays an important role in quickly understanding the efficiency of processes in a reprocessing plant. Efforts in studying and installation of such analytical instruments are going on since more than three decades with adaptation of newer methods and technologies. A review on the developement of in-line analytical instrumentation was carried out in this laboratory about two decades ago. This report presents a very short literature survey of the work in the last two decades. The report includes an outline of principles of the main techniques employed in the in-line/on-line monitoring. (author). 77 refs., 6 tabs

  5. X-ray fluorescence determination of Sn, Sb, Pb in lead-based bearing alloys using a solution technique

    Science.gov (United States)

    Tian, Lunfu; Wang, Lili; Gao, Wei; Weng, Xiaodong; Liu, Jianhui; Zou, Deshuang; Dai, Yichun; Huang, Shuke

    2018-03-01

    For the quantitative analysis of the principal elements in lead-antimony-tin alloys, directly X-ray fluorescence (XRF) method using solid metal disks introduces considerable errors due to the microstructure inhomogeneity. To solve this problem, an aqueous solution XRF method is proposed for determining major amounts of Sb, Sn, Pb in lead-based bearing alloys. The alloy samples were dissolved by a mixture of nitric acid and tartaric acid to eliminated the effects of microstructure of these alloys on the XRF analysis. Rh Compton scattering was used as internal standard for Sb and Sn, and Bi was added as internal standard for Pb, to correct for matrix effects, instrumental and operational variations. High-purity lead, antimony and tin were used to prepare synthetic standards. Using these standards, calibration curves were constructed for the three elements after optimizing the spectrometer parameters. The method has been successfully applied to the analysis of lead-based bearing alloys and is more rapid than classical titration methods normally used. The determination results are consistent with certified values or those obtained by titrations.

  6. Comprehensive Peptide Ion Structure Studies Using Ion Mobility Techniques: Part 3. Relating Solution-Phase to Gas-Phase Structures.

    Science.gov (United States)

    Kondalaji, Samaneh Ghassabi; Khakinejad, Mahdiar; Valentine, Stephen J

    2018-06-01

    Molecular dynamics (MD) simulations have been utilized to study peptide ion conformer establishment during the electrospray process. An explicit water model is used for nanodroplets containing a model peptide and hydronium ions. Simulations are conducted at 300 K for two different peptide ion charge configurations and for droplets containing varying numbers of hydronium ions. For all conditions, modeling has been performed until production of the gas-phase ions and the resultant conformers have been compared to proposed gas-phase structures. The latter species were obtained from previous studies in which in silico candidate structures were filtered according to ion mobility and hydrogen-deuterium exchange (HDX) reactivity matches. Results from the present study present three key findings namely (1) the evidence from ion production modeling supports previous structure refinement studies based on mobility and HDX reactivity matching, (2) the modeling of the electrospray process is significantly improved by utilizing initial droplets existing below but close to the calculated Rayleigh limit, and (3) peptide ions in the nanodroplets sample significantly different conformers than those in the bulk solution due to altered physicochemical properties of the solvent. Graphical Abstract ᅟ.

  7. SU-E-T-774: Use of a Scintillator-Mirror-Camera System for the Measurement of MLC Leakage Radiation with the CyberKnife M6 System

    Energy Technology Data Exchange (ETDEWEB)

    Goggin, L; Kilby, W; Noll, M; Maurer, C [Accuray Inc, Sunnyvale, CA (United States)

    2015-06-15

    Purpose: A technique using a scintillator-mirror-camera system to measure MLC leakage was developed to provide an efficient alternative to film dosimetry while maintaining high spatial resolution. This work describes the technique together with measurement uncertainties. Methods: Leakage measurements were made for the InCise™ MLC using the Logos XRV-2020A device. For each measurement approximately 170 leakage and background images were acquired using optimized camera settings. Average background was subtracted from each leakage frame before filtering the integrated leakage image to replace anomalous pixels. Pixel value to dose conversion was performed using a calibration image. Mean leakage was calculated within an ROI corresponding to the primary beam, and maximum leakage was determined by binning the image into overlapping 1mm x 1mm ROIs. 48 measurements were performed using 3 cameras and multiple MLC-linac combinations in varying beam orientations, with each compared to film dosimetry. Optical and environmental influences were also investigated. Results: Measurement time with the XRV-2020A was 8 minutes vs. 50 minutes using radiochromic film, and results were available immediately. Camera radiation exposure degraded measurement accuracy. With a relatively undamaged camera, mean leakage agreed with film measurement to ≤0.02% in 92% cases, ≤0.03% in 100% (for maximum leakage the values were 88% and 96%) relative to reference open field dose. The estimated camera lifetime over which this agreement is maintained is at least 150 measurements, and can be monitored using reference field exposures. A dependency on camera temperature was identified and a reduction in sensitivity with distance from image center due to optical distortion was characterized. Conclusion: With periodic monitoring of the degree of camera radiation damage, the XRV-2020A system can be used to measure MLC leakage. This represents a significant time saving when compared to the traditional

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

    Science.gov (United States)

    Braun, Stefan; Pokorná, Šárka; Šachl, Radek; Hof, Martin; Heerklotz, Heiko; Hoernke, Maria

    2018-01-23

    The mode of action of membrane-active molecules, such as antimicrobial, anticancer, cell penetrating, and fusion peptides and their synthetic mimics, transfection agents, drug permeation enhancers, and biological signaling molecules (e.g., quorum sensing), involves either the general or local destabilization of the target membrane or the formation of defined, rather stable pores. Some effects aim at killing the cell, while others need to be limited in space and time to avoid serious damage. Biological tests reveal translocation of compounds and cell death but do not provide a detailed, mechanistic, and quantitative understanding of the modes of action and their molecular basis. Model membrane studies of membrane leakage have been used for decades to tackle this issue, but their interpretation in terms of biology has remained challenging and often quite limited. Here we compare two recent, powerful protocols to study model membrane leakage: the microscopic detection of dye influx into giant liposomes and time-correlated single photon counting experiments to characterize dye efflux from large unilamellar vesicles. A statistical treatment of both data sets does not only harmonize apparent discrepancies but also makes us aware of principal issues that have been confusing the interpretation of model membrane leakage data so far. Moreover, our study reveals a fundamental difference between nano- and microscale systems that needs to be taken into account when conclusions about microscale objects, such as cells, are drawn from nanoscale models.

  9. A harmonic pulse testing method for leakage detection in deep subsurface storage formations

    Science.gov (United States)

    Sun, Alexander Y.; Lu, Jiemin; Hovorka, Susan

    2015-06-01

    Detection of leakage in deep geologic storage formations (e.g., carbon sequestration sites) is a challenging problem. This study investigates an easy-to-implement frequency domain leakage detection technology based on harmonic pulse testing (HPT). Unlike conventional constant-rate pressure interference tests, HPT stimulates a reservoir using periodic injection rates. The fundamental principle underlying HPT-based leakage detection is that leakage modifies a storage system's frequency response function, thus providing clues of system malfunction. During operations, routine HPTs can be conducted at multiple pulsing frequencies to obtain experimental frequency response functions, using which the possible time-lapse changes are examined. In this work, a set of analytical frequency response solutions is derived for predicting system responses with and without leaks for single-phase flow systems. Sensitivity studies show that HPT can effectively reveal the presence of leaks. A search procedure is then prescribed for locating the actual leaks using amplitude and phase information obtained from HPT, and the resulting optimization problem is solved using the genetic algorithm. For multiphase flows, the applicability of HPT-based leakage detection procedure is exemplified numerically using a carbon sequestration problem. Results show that the detection procedure is applicable if the average reservoir conditions in the testing zone stay relatively constant during the tests, which is a working assumption under many other interpretation methods for pressure interference tests. HPT is a cost-effective tool that only requires periodic modification of the nominal injection rate. Thus it can be incorporated into existing monitoring plans with little additional investment.

  10. Potential acidification impacts on zooplankton in CCS leakage scenarios

    International Nuclear Information System (INIS)

    Halsband, Claudia; Kurihara, Haruko

    2013-01-01

    Highlights: • Effects of CCS techniques and ocean acidification on zooplankton are under-studied. • Vulnerable zooplankton are meso-, bathypelagic and vertically migrating species. • Impacts include impaired calcification, reproduction, development and survival. • Need for modelling studies combining physico-chemical with ecological impacts. -- Abstract: Carbon capture and storage (CCS) technologies involve localized acidification of significant volumes of seawater, inhabited mainly by planktonic species. Knowledge on potential impacts of these techniques on the survival and physiology of zooplankton, and subsequent consequences for ecosystem health in targeted areas, is scarce. The recent literature has a focus on anthropogenic greenhouse gas emissions into the atmosphere, leading to enhanced absorption of CO 2 by the oceans and a lowered seawater pH, termed ocean acidification. These studies explore the effects of changes in seawater chemistry, as predicted by climate models for the end of this century, on marine biota. Early studies have used unrealistically severe CO 2 /pH values in this context, but are relevant for CCS leakage scenarios. Little studied meso- and bathypelagic species of the deep sea may be especially vulnerable, as well as vertically migrating zooplankton, which require significant residence times at great depths as part of their life cycle

  11. Modeling PWR systems for monitoring primary-to-secondary leakage using tritium tracer

    International Nuclear Information System (INIS)

    Peiffer, D.G.

    1992-01-01

    This paper discusses several techniques available for monitoring primary to secondary leakage, focusing on the advantages and disadvantages of each. A mathematical model of Millstone 2 describes the behavior of tritium activity in the secondary plant water when a leak exists. Real data from Millstone 2 illustrate the accuracy and reliability of the model and use of the model to measure the mass of water in the secondary system

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    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...

  13. 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.

  14. Theory and Practice of a Leakage Resilient Masking Scheme

    DEFF Research Database (Denmark)

    Balasch, Josep; Faust, Sebastian; Gierlichs, Benedikt

    2012-01-01

    A recent trend in cryptography is to formally prove the leakage resilience of cryptographic implementations – that is, one formally shows that a scheme remains provably secure even in the presence of side channel leakage. Although many of the proposed schemes are secure in a surprisingly strong m...

  15. 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.,

  16. 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...

  17. Anastomotic leakage after anterior resection for rectal cancer

    DEFF Research Database (Denmark)

    Bulow, S.

    2008-01-01

    On the basis of the literature about anastomotic leakage after anterior resection for rectal cancer a review is presented of the frequency, potential risk factors and consequences of leakage. The risk factors are evaluated according to the level of scientific evidence of the individual background...

  18. On the scaling of gas leakage from static seals

    International Nuclear Information System (INIS)

    Chivers, T.C.; Hunt, R.P.

    1977-01-01

    The interaction between gas leakage from static seals and eight potential variables is discussed. From a consideration of the interaction of these various parameters and the mechanical design of the seal system the importance of correctly interpreting leakage data is demonstrated. Given a situation where model experiments are necessary, this document forms a basis for the definition and interpretation of a test programme. (author)

  19. A review on leakage rate tests for containment isolation systems

    International Nuclear Information System (INIS)

    Kim, In Goo; Kim, Hho Jung

    1992-01-01

    Wide experiences in operating containment isolation systems have been accumulated in Korea since 1978. Hence, it becomes necessary to review the operating data in order to confirm the integrity of containments with about 50 reactor-years of experience and to establish the future direction to the containment test program. The objectives of present work are to collect, consolidate and assess the leakage rate data, and then to find out dominant leakage paths and factors affecting integrated leakage rate test. General trends of overall leakage show that more careful surveillance during pre-operational test can reduce the containment leakage. Dominant leakage paths are found to be through air locks and large-sized valves, such as butterfly valves of purge lines, so that weighted surveillance and inspection on these dominant leakage paths can considerably reduce the containment leakage. The atmosphere stabilization are found to be the most important to obtain the reliable result. In order to get well stabilized atmosphere, temperature and flow rate of compressed air should be kept constant and it is preferable not to operate fan cooler during pressurizing the containment for test

  20. Hunting the unknown: White-box database leakage detection

    NARCIS (Netherlands)

    Costante, E.; Hartog, den J.I.; Petkovic, M.; Etalle, S.; Pechenizkiy, M.; Atluri, V.; Pernul, G.

    2014-01-01

    Data leakage causes significant losses and privacy breaches worldwide. In this paper we present a white-box data leakage detection system to spot anomalies in database transactions. We argue that our approach represents a major leap forward w.r.t. previous work because: i) it significantly decreases

  1. Thermoluminescence properties of Li2B4O7:Cu, B phosphor synthesized using solution combustion technique

    Science.gov (United States)

    Ozdemir, A.; Altunal, V.; Kurt, K.; Depci, T.; Yu, Y.; Lawrence, Y.; Nur, N.; Guckan, V.; Yegingil, Z.

    2017-12-01

    To determine the effects of various concentrations of the activators copper (Cu) and boron (B) on the thermoluminescence (TL) properties of lithium tetraborate, the phosphor was first synthesized and doped with five different concentrations of copper (0.1-0.005 wt%) using solution combustion method. 0.01 wt% Cu was the concentration which showed the most significant increase in the sensitivity of the phosphor. The second sort of Li2B4O7:Cu material was prepared by adding B (0.001-0.03 wt%) to it. The newly developed copper-boron activated lithium tetraborate (Li2B4O7:Cu, B) material with 0.01 wt% Cu and 0.001 wt% B impurity concentrations was shown to have promise as a TL phosphor. The material formation was examined using powder x-Ray Diffraction (XRD) analysis and Scanning Electron Microscope (SEM) imaging. Fourier Transform Infrared (FT-IR) spectrum of the synthesized polycrystalline powder sample was also recorded. The TL glow curves were analyzed to determine various dosimetric characteristics of the synthesized luminophosphors. The dose response increased in a ;linear; way with the beta-ray exposure between 0.1-20 Gy, a dose range being interested in medical dosimetry. The response with changing photon and electron energy was studied. The rate of decay of the TL signal was investigated both for dark storage and under direct sunlight. Li2B4O7:Cu, B showed no individual variation of response in 9 recycling measurements. The fluorescence spectrum was determined. The kinetic parameters were estimated by different methods and the results discussed. The studied properties of synthesized Li2B4O7:Cu, B were found all favorable for dosimetric purposes.

  2. Ex vivo evaluation of coronal and apical microbial leakage of root canal - Filled with gutta-percha or Resilon/Epiphany root canal filling material

    Directory of Open Access Journals (Sweden)

    de Almeida-Gomes Fabio

    2010-01-01

    Full Text Available Objective: This ex vivo study compared coronal and apical microleakage of root canals filled with Resilon/Epiphany (RE or gutta-percha/Grossman sealer (GP, using either lateral condensation (LC or System B (SB technique. Materials and Methods: Specimens in eight experimental groups were obturated using the following materials and techniques: Groups 1 and 3 - GP and LC; groups 2 and 4 - GP and SB; groups 5 and 7 - RE and LC; groups 6 and 8 - RE and SB. Apical and coronal leakages were tested using bacterial methods. For coronal analysis, the number of days required for complete contamination of the root canals was recorded according to observation of the brain heart infusion broth turbidity for 15 weeks. For apical analysis, the teeth were cleaved and the leakage was measured at 30 days. Data were collected for each sample and analyzed statistically with the Chi-square and ANOVA tests. Results: Leakage was found in all groups. The difference between filling materials, obturation techniques, and median time of leakage was not statistically significant for coronal ( P=0.847 and apical ( P=0.5789 leakages. Conclusion: There were no differences between the different filling materials (gutta-percha/Grossman sealer and Resilon/Epiphany and obturation techniques (lateral condensation and system B technique in coronal or apical leakages.

  3. Failure analysis of leakage current in plastic encapsulated packages

    International Nuclear Information System (INIS)

    Hu, S.J.; Cheang, F.T.

    1989-12-01

    Plastic encapsulated packages exhibit high leakage current after a few hundred hours steam pressure pot test. The present study investigates two possible sources of leakage current, the mold compound and the lead frame tape used for taping the lead frame fingers. The results of the study indicate that the leakage current is independent of the frame and is not caused by the mold compound. The data further indicates that it is the ionic contents and acrylic-based adhesive layer of the lead frame tapes which cause the leakage current. To eliminate the leakage current, lead frame tape with low ionic contents and non acrylic-based adhesive should be used. (author). 1 fig., 2 tabs, 3 graphs

  4. 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 leakage when compared with the cotton ball coated with petroleum jelly (P leakage compared with the customized plug (P leakage than the cotton plug (P leakage rate (f(4,45) = 94 [P water exposure should be minimized, then use of earplugs, particularly the moldable variety, merits further consideration. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Leakage current characteristics of the multiple metal alloy nanodot memory

    International Nuclear Information System (INIS)

    Lee, Gae Hun; Lee, Jung Min; Yang, Hyung Jun; Song, Yun Heub; Bea, Ji Chel; Tanaka, Tetsu

    2010-01-01

    The leakage current characteristics of a multiple metal alloy nanodot device for a nonvolatile random access memory using FePt materials are investigated. Several annealing conditions are evaluated and optimized to suppress the leakage current and to better the memory characterisctics. This work confirmed that the annealing condition of 700 .deg. C in a high vacuum ambience (under 1 x 10 -5 Pa) simultaneously provided good cell characteristics from a high dot density of over 1 x 10 13 /cm 2 and a low leakage current. In addition, a smaller nanodot diameter was found to give a lower leakage current for the multiple nanodot memory. Finally, for the proposed annealing condition, the quadruple FePt multiple nanodot memory with a 2-nm dot diameter provided good leakage current characteristics, showing a threshold voltage shift of under 5% at an initial retention stage of 1000 sec.

  6. 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.

  7. Ship cabin leakage alarm based on ARM SCM

    Science.gov (United States)

    Qu, Liyan

    2018-03-01

    If there is a leakage in the cabin of a sailing ship, it is a major accident that threatens the personnel and property of the ship. If we can’t take timely measures, there will be a devastating disaster. In order to judge the leakage of the cabin, it is necessary to set up a leakage alarm system, so as to achieve the purpose of detecting and alarming the leakage of the cabin, and avoid the occurrence of accidents. This paper discusses the design of ship cabin leakage alarm system based on ARM SCM. In order to ensure the stability and precision of the product, the hardware design of the alarm system is carried out, such as circuit design, software design, the programming of SCM, the software programming of upper computer, etc. It is hoped that it can be of reference value to interested readers.

  8. Distributed public key schemes secure against continual leakage

    DEFF Research Database (Denmark)

    Akavia, Adi; Goldwasser, Shafi; Hazay, Carmit

    2012-01-01

    -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......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...... against continual memory leakage, under the Bilinear Decisional Diffie-Hellman and $2$-linear assumptions. Our schemes have the following properties: 1. Our DPKE and DIBE schemes tolerate leakage at all times, including during refresh. During refresh the tolerated leakage is a (1/2-o (1),1)-fraction...

  9. Physicochemical, bioactive, and sensory properties of persimmon-based ice cream: technique for order preference by similarity to ideal solution to determine optimum concentration.

    Science.gov (United States)

    Karaman, Safa; Toker, Ömer Said; Yüksel, Ferhat; Çam, Mustafa; Kayacier, Ahmed; Dogan, Mahmut

    2014-01-01

    In the present study, persimmon puree was incorporated into the ice cream mix at different concentrations (8, 16, 24, 32, and 40%) and some physicochemical (dry matter, ash, protein, pH, sugar, fat, mineral, color, and viscosity), textural (hardness, stickiness, and work of penetration), bioactive (antiradical activity and total phenolic content), and sensory properties of samples were investigated. The technique for order preference by similarity to ideal solution approach was used for the determination of optimum persimmon puree concentration based on the sensory and bioactive characteristics of final products. Increase in persimmon puree resulted in a decrease in the dry matter, ash, fat, protein contents, and viscosity of ice cream mix. Glucose, fructose, sucrose, and lactose were determined to be major sugars in the ice cream samples including persimmon and increase in persimmon puree concentration increased the fructose and glucose content. Better melting properties and textural characteristics were observed for the samples with the addition of persimmon. Magnesium, K, and Ca were determined to be major minerals in the samples and only K concentration increased with the increase in persimmon content. Bioactive properties of ice cream samples improved and, in general, acetone-water extracts showed higher bioactivity compared with ones obtained using methanol-water extracts. The technique for order preference by similarity to ideal solution approach showed that the most preferred sample was the ice cream containing 24% persimmon puree. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  10. Recovery and reuse of hexavalent chromium from aqueous solutions by a hybrid technique of electrodialysis and ion exchange

    Energy Technology Data Exchange (ETDEWEB)

    Gayathri, R. [Sengunthar Engineering College, Tiruchengode (India). Dept. of Civil Engineering], e-mail: gay3civil@gmail.com; Senthil Kumar, P. [SSN College of Engineering, Chennai (India). Dept. of Chemical Engineering], E-mail: senthilkumarp@ssn.edu.in

    2010-01-15

    The chrome plating industry is one of the highly polluting industries whose effluent mainly consists of chromium(VI). This compound is highly toxic to aquatic life and human health. The rinse water constituents reflect the chrome plating bath characteristics; generally dead tank wash water contains about 1% of the plating bath concentration. Other metals and metal compounds usually considered as toxic can be precipitated out by suitably adjusting the pH of the wastewaters. However, Cr(VI) is soluble in almost all pH ranges and therefore an efficient treatment is required for the removal and recovery of chromium, and also for the reuse of wastewaters. The present study aims to recover the chromium by a hybrid technique of electrodialysis and ion exchange for the removal and concentration of chromate ions from the effluent. The different modes of operation like batch recirculation process, batch recirculation process with continuous dipping and continuous process were carried out to remove and recover the chromium from the effluent and the percentage reductions of chromium were found to be 98.69%, 99.18% and 100%, respectively. (author)

  11. Recovery and reuse of hexavalent chromium from aqueous solutions by a hybrid technique of electrodialysis and ion exchange

    International Nuclear Information System (INIS)

    Gayathri, R.; Senthil Kumar, P.

    2010-01-01

    The chrome plating industry is one of the highly polluting industries whose effluent mainly consists of chromium(VI). This compound is highly toxic to aquatic life and human health. The rinse water constituents reflect the chrome plating bath characteristics; generally dead tank wash water contains about 1% of the plating bath concentration. Other metals and metal compounds usually considered as toxic can be precipitated out by suitably adjusting the pH of the wastewaters. However, Cr(VI) is soluble in almost all pH ranges and therefore an efficient treatment is required for the removal and recovery of chromium, and also for the reuse of wastewaters. The present study aims to recover the chromium by a hybrid technique of electrodialysis and ion exchange for the removal and concentration of chromate ions from the effluent. The different modes of operation like batch recirculation process, batch recirculation process with continuous dipping and continuous process were carried out to remove and recover the chromium from the effluent and the percentage reductions of chromium were found to be 98.69%, 99.18% and 100%, respectively. (author)

  12. Recovery and reuse of hexavalent chromium from aqueous solutions by a hybrid technique of electrodialysis and ion exchange

    Directory of Open Access Journals (Sweden)

    R. Gayathri

    2010-03-01

    Full Text Available The chrome plating industry is one of the highly polluting industries whose effluent mainly consists of chromium(VI. This compound is highly toxic to aquatic life and human health. The rinse water constituents reflect the chrome plating bath characteristics; generally dead tank wash water contains about 1% of the plating bath concentration. Other metals and metal compounds usually considered as toxic can be precipitated out by suitably adjusting the pH of the wastewaters. However, Cr(VI is soluble in almost all pH ranges and therefore an efficient treatment is required for the removal and recovery of chromium, and also for the reuse of wastewaters. The present study aims to recover the chromium by a hybrid technique of electrodialysis and ion exchange for the removal and concentration of chromate ions from the effluent. The different modes of operation like batch recirculation process, batch recirculation process with continuous dipping and continuous process were carried out to remove and recover the chromium from the effluent and the percentage reductions of chromium were found to be 98.69%, 99.18% and 100%, respectively.

  13. Highly efficient removal of perfluorooctanoic acid from aqueous solution by H2O2-enhanced electrocoagulation-electroflotation technique

    Directory of Open Access Journals (Sweden)

    Bo Yang

    2016-03-01

    Full Text Available Electrocoagulation (EC technique was used to investigate the removal performance of aqueous perfluorooctanoic acid (PFOA with relatively high concentration as simulating the wastewater from organic fluorine industry. A comparison was done with the similar amount of coagulant between EC and chemical coagulation process. PFOA removal obtained was higher with EC process, especially for Fe anode. Several factors were studied to optimize the EC process. At the optimal operating parameters including 37.5 mA/cm2 of current density, initial pH 3.77, and 180 rpm of mixing speed, 93% of PFOA could be removed with 100 mg/L of initial concentration after 90-min electrolysis. Furthermore, the remove efficiency could be obviously improved by H2O2 intermittent addition, which removed more than 99% of PFOA within 40-min EC. It could be attributed to that H2O2 facilitated the oxidative transformation from ferrous to ferric ion. In addition, the adsorptive removal of aqueous PFOA on Fe flocs during EC was also verified by fourier transform infrared spectra.

  14. Angular Multigrid Preconditioner for Krylov-Based Solution Techniques Applied to the Sn Equations with Highly Forward-Peaked Scattering

    Science.gov (United States)

    Turcksin, Bruno; Ragusa, Jean C.; Morel, Jim E.

    2012-01-01

    It is well known that the diffusion synthetic acceleration (DSA) methods for the Sn equations become ineffective in the Fokker-Planck forward-peaked scattering limit. In response to this deficiency, Morel and Manteuffel (1991) developed an angular multigrid method for the 1-D Sn equations. This method is very effective, costing roughly twice as much as DSA per source iteration, and yielding a maximum spectral radius of approximately 0.6 in the Fokker-Planck limit. Pautz, Adams, and Morel (PAM) (1999) later generalized the angular multigrid to 2-D, but it was found that the method was unstable with sufficiently forward-peaked mappings between the angular grids. The method was stabilized via a filtering technique based on diffusion operators, but this filtering also degraded the effectiveness of the overall scheme. The spectral radius was not bounded away from unity in the Fokker-Planck limit, although the method remained more effective than DSA. The purpose of this article is to recast the multidimensional PAM angular multigrid method without the filtering as an Sn preconditioner and use it in conjunction with the Generalized Minimal RESidual (GMRES) Krylov method. The approach ensures stability and our computational results demonstrate that it is also significantly more efficient than an analogous DSA-preconditioned Krylov method.

  15. Combination of acoustic levitation with small angle scattering techniques and synchrotron radiation circular dichroism. Application to the study of protein solutions.

    Science.gov (United States)

    Cristiglio, Viviana; Grillo, Isabelle; Fomina, Margarita; Wien, Frank; Shalaev, Evgenyi; Novikov, Alexey; Brassamin, Séverine; Réfrégiers, Matthieu; Pérez, Javier; Hennet, Louis

    2017-01-01

    The acoustic levitation technique is a useful sample handling method for small solid and liquids samples, suspended in air by means of an ultrasonic field. This method was previously used at synchrotron sources for studying pharmaceutical liquids and protein solutions using x-ray diffraction and small angle x-ray scattering (SAXS). In this work we combined for the first time this containerless method with small angle neutron scattering (SANS) and synchrotron radiation circular dichroism (SRCD) to study the structural behavior of proteins in solutions during the water evaporation. SANS results are also compared with SAXS experiments. The aggregation behavior of 45μl droplets of lysozyme protein diluted in water was followed during the continuous increase of the sample concentration by evaporating the solvent. The evaporation kinetics was followed at different drying stage by SANS and SAXS with a good data quality. In a prospective work using SRCD, we also studied the evolution of the secondary structure of the myoglobin protein in water solution in the same evaporation conditions. Acoustic levitation was applied for the first time with SANS and the high performances of the used neutron instruments made it possible to monitor fast container-less reactions in situ. A preliminary work using SRCD shows the potentiality of its combination with acoustic levitation for studying the evolution of the protein structure with time. This multi-techniques approach could give novel insights into crystallization and self-assembly phenomena of biological compound with promising potential applications in pharmaceutical, food and cosmetics industry. This article is part of a Special Issue entitled "Science for Life" Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazù and Dr. Federica Migliardo. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Procedure to carry out leakage test in beta radiation sealed sources emitters of 90Sr/90Y

    International Nuclear Information System (INIS)

    Alvarez R, J. T.

    2010-09-01

    In the alpha-beta room of the Secondary Laboratory of Dosimetric Calibration of the Metrology Department of Ionizing Radiations ophthalmic applicators are calibrated in absorbed dose terms in water D w ; these applicators, basically are emitter sealed sources of pure beta radiation of 90 Sr / 90 Y. Concretely, the laboratory quality system indicates to use the established procedure for the calibration of these sources, which establishes the requirement of to carry out a leakage test, before to calibrate the source. However, in the Laboratory leakage test certificates sent by specialized companies in radiological protection services have been received, in which are used gamma spectrometry equipment s for beta radiation leakage tests, since it is not reliable to detect pure beta radiation with a scintillating detector with NaI crystal, (because it could detect the braking radiation produced in the detector). Therefore the Laboratory has had to verify the results of the tests with a correct technique, with the purpose of determining the presence of sources with their altered integrity and radioactive material leakage. The objective of this work is to describe a technique for beta activity measurement - of the standard ISO 7503, part 1 (1988) - and its application with a detector Gm plane (type pankage) in the realization of leakage tests in emitter sources of pure beta radiation, inside the mark of quality assurance indicated by the report ICRU 76. (Author)

  17. Transcytosis Involvement in Transport System and Endothelial Permeability of Vascular Leakage during Dengue Virus Infection

    Directory of Open Access Journals (Sweden)

    Chanettee Chanthick

    2018-02-01

    Full Text Available The major role of endothelial cells is to maintain homeostasis of vascular permeability and to preserve the integrity of vascular vessels to prevent fluid leakage. Properly functioning endothelial cells promote physiological balance and stability for blood circulation and fluid components. A monolayer of endothelial cells has the ability to regulate paracellular and transcellular pathways for transport proteins, solutes, and fluid. In addition to the paracellular pathway, the transcellular pathway is another route of endothelial permeability that mediates vascular permeability under physiologic conditions. The transcellular pathway was found to be associated with an assortment of disease pathogeneses. The clinical manifestation of severe dengue infection in humans is vascular leakage and hemorrhagic diatheses. This review explores and describes the transcellular pathway, which is an alternate route of vascular permeability during dengue infection that corresponds with the pathologic finding of intact tight junction. This pathway may be the route of albumin transport that causes endothelial dysfunction during dengue virus infection.

  18. A new technique to preserve raw materials of ancient monuments against the humidity and its test using 22Na labeled solutions

    International Nuclear Information System (INIS)

    Martinez, G.L.; Navarrete, J.M.

    2007-01-01

    Erosion caused by external factors such as wind, rain, sunlight and temperature changes is considerable in raw materials used to build pre-hispanic monuments. However, there does exist an internal destruction factor even stronger: the humidity coming from the soil, which goes up by capillarity, depositing soluble salts on the walls surface. Therefore, one way to find some figure related to the specific capillarity or porosity shown by each raw material, is to obtain small prism-shaped pieces cut out from the large debris fallen down spontaneously from ancient walls due to internal humidity. Once these small samples are placed in contact with a 22 Na labeled solution during a given time, at the same geometrical conditions, dried overnight, conditioned either in test tubes or wrapped into polyethylene and detected in a well type 3' x 3' scintillation detector, the counts accumulated per time and weight units are a measure of the relative porosity shown by each material. In order to pull down this porosity, the samples are impregnated with a gelatin solution (50 g/l) at 60-80 deg C plus food preservatives such as potassium sorbate (2.5%) and sodium benzoate (2.5%). When gelatin begins to be formed 3 hours later and the samples look humid and brilliant, they are impregnated with formaldehyde solution (38%), and their absorption rate is dramatically reduced overnight (75-100%), which can be proven when samples are tested by making use of the 22 Na labeled solution. This technique has been applied at real scale in some pre-hispanic monuments. Ancient raw materials seems to be much more compact and well preserved during one limited period of time (10 to 13 months). Treatment is unnoticeable and reversible, and it may be applied periodically. (author)

  19. Leakage current-induced effects in the silicon microstrip and gas electron multiplier readout chain and their compensation method

    Science.gov (United States)

    Zubrzycka, W.; Kasinski, K.

    2018-04-01

    Leakage current flowing into the charge sensitive amplifier (CSA) is a common issue in many radiation detection systems as it can increase overall system noise, shift a DC baseline or even lead a recording channel to instability. The commonly known leakage current contributor is a detector, however other system components like wires or an input protection circuit may become a serious problem. Compensation of the leakage current resulting from the electrostatic discharge (ESD) protection circuit by properly sizing its components is possible only for a narrow temperature range. Moreover, the leakage current from external sources can be significantly larger. Many applications, especially High Energy Physics (HEP) experiments, require a fast baseline restoration for high input hit rates by applying either a low-value feedback resistor or a high feedback resistance combined with a pulsed reset circuit. Leakage current flowing in the feedback in conjunction with a large feedback resistance supplied with a pulsed reset results in a significant voltage offset between the CSA input and output which can cause problems (e.g. fake hits or instability). This paper shows an issue referred to the leakage current of the ESD protection circuit flowing into the input amplifier. The following analysis and proposed solution is a result of the time and energy readout ASIC project realization for the Compressed Baryonic Matter (CBM) experiment at FAIR (Facility for Antiproton and Ion Research) in Darmstadt, Germany. This chip is purposed to work with microstrip and gaseous detectors, with high average input pulses frequencies (250 kHit/s per channel) and the possibility to process input charge of both polarities. We present measurements of the test structure fabricated in UMC 180 nm technology and propose a solution addressing leakage current related issues. This work combines the leakage current compensation capabilities at the CSA level with high, controllable value of the amplifier

  20. Leakage experiences with 1 MW steam generator

    International Nuclear Information System (INIS)

    Kanamori, A.; Kawara, M.; Sano, A.

    1975-01-01

    An 1 MW steam generator was tested from October, 1971 and completed with the first series of experiments by May, 1972 after 3600 hours of operation. During these tests, unextraordinary heat absorption was experienced in the downcomer region, which led to shortage of heat transfer area to attain the rated steam temperature and to one of the reasons of flow instabilities. The steam generator was disassembled to get test pieces for structure as well as material examinations and then it was reassembled to proceed the second series of tests. Before it was done, a modification was provided to insulate the downcomer region by putting a gas space around the downcomer tube. The gas space was provided by a dual tube and spacers were welded on the inner tube and an end plate was welded on upper parts between the two to seal the gap by means of fillet welding. After the modified steam generator was put into operation, water happened to leak into a sodium side two times through these additional welding spots for the gas insulation. This paper presents operating conditions and behaviors of monitors at the time of the leakages, identifications of leaked spots, an evaluation of causes and a treatment or a precaution for them

  1. Radiation leakage from linac electron applicator assembly

    International Nuclear Information System (INIS)

    Keys, R.A.; Purdy, J.A.

    1984-01-01

    The electron beam applicator system currently in use on the linear accelerator is constructed of light-weight fiberglass and aluminum. With an applicator in place on the accelerator, the photon collimator jaws are automatically set several centimeters greater than the electron field size projected at the patient's surface. To ensure that no regions of high dose levels exist outside the useful beam, ionization and film measurements were made to quantitate the amount of leakage radiation through the 10 cm x 10 cm and 25 cm x 25 cm applicators. In most regions, the ionization levels at the patient's surface were below 5% of the central axis dose. In one area for the 25 cm applicator, the percentage ionization was 8.5%, which could be reduced by the addition of a small piece of 1/8 inch thick lead. However, ionization levels on the outside surface of the applicator were found to be considerably higher at certain locations for the 25 cm applicator. Results for 6, 9, 12 and 20 MeV electrons are reported here

  2. Effect of membrane and through-wall bending stresses on fatigue crack growth behavior and coolant leakage velocity

    International Nuclear Information System (INIS)

    Yoo, Yeon-Sik

    2003-11-01

    This study clarified the effect of a membrane and a through-wall bending stresses on fatigue crack growth behavior and coolant leakage velocity due to irregularity of crack surface. Each stress component relates to fatigue crack growth behavior directly in general and thus the wild-used K I solutions are anticipated to give good evaluation results on it. Meanwhile, it is necessary to notify that surface irregularity for coolant leakage assessment is made by stress history in nature. Surface irregularity is known to be largely classified into the following two aspects: surface roughness due to continuous crack opening and closure behavior and surface turnover due to cyclic bending stress dominance. Therefore, the deterministic parameters on resistance of coolant leakage by surface irregularity are considered to be not only stress history but crack opening behavior. (author)

  3. Detection of defect states responsible for leakage current in ultrathin tantalum pentoxide (Ta2O5) films by zero-bias thermally stimulated current spectroscopy

    International Nuclear Information System (INIS)

    Lau, W.S.; Zhong, L.; Lee, A.; See, C.H.; Han, T.; Sandler, N.P.; Chong, T.C.

    1997-01-01

    Defect states responsible for leakage current in ultrathin (physical thickness 2 O 5 ) films were measured with a novel zero-bias thermally stimulated current technique. It was found that defect states A, whose activation energy was estimated to be about 0.2 eV, can be more efficiently suppressed by using N 2 O rapid thermal annealing (RTA) instead of using O 2 RTA for postdeposition annealing. The leakage current was also smaller for samples with N 2 O RTA than those with O 2 RTA for postdeposition annealing. Hence, defect states A are quite likely to be important in causing leakage current. copyright 1997 American Institute of Physics

  4. Leakage pattern of linear accelerator treatment heads from multiple vendors

    International Nuclear Information System (INIS)

    Lonski, P.R.; Taylor, M.L.; Franich, R.D.; Harty, P.; Clements, N.; Kron, T.

    2011-01-01

    Full text: Patient life expectancy post-radiotherapy is becoming longer. Therefore, secondary cancers caused by radiotherapy treatment have more time to develop. Increasing attention is being given to out-of-field dose resulting from scatter and accelerator head leakage. Dose leakage from equivalent positions on Varian600C, Varian21-X, Siemens Primus and Elekta Synergy-II linacs were measured with TLD 1 00 H dosimeter chips and compared. Treatment parameters such as field size and beam energy were altered. Leakage doses are presented as a percentage of the dose to isocentre (5 Gy). Results illustrate significant variations in leakage dose between linac models where no model emits consistently lower amounts of radiation leakage for all treatment parameters. Results are shown below. Leakage through the collimator assembly in different units is varying as a function of location and unit design by more than a factor of 10. Differences are more pronounced in comparing Varian or Elekta models, which are fitted with an additional collimator separate from the MLC leaves, to the Siemens model, which uses MLC leaves as its only secondary collimator. Further measurements are currently being taken at the patient plane with a directional detector system to determine the spatial distribution of high leakage sources.

  5. Leakage characterization of a piloted power operated relief valve

    International Nuclear Information System (INIS)

    Ezekoye, L.I.; Hess, M.D.

    1995-01-01

    In Westinghouse Pressurized Water Reactors (PWRs), power operated relief valves (PORVs) are used to provide overpressure protection of the Pressurizer. The valves are fail closed globe valves which means that power is required to open the valves and, on loss of power, the valves close. There are two ways to operate the PORVs. The more common way is to directly couple the disc to an actuator via a disc-stem assembly. The type of design is not the object of this paper. The other and less common way of operating a PORV is by piloting the main valve such that the opening or closing of a pilot valve opens and closes the main valve. This is the design of interest. In most plants, the PORVs are installed with a water loop seal while in some plants no water loop seals are used. It is generally accepted that loop seal installation minimizes valve seat leakage. In non-loop seal installation, the valve seat is exposed to steam which increases the potential for seat leakage. This paper describes the results of some tests performed with nitrogen and steam to characterize the leakage potential of a pilot operated PORV. The test results were compared with seat leakage tests of check valves to provide insight on the leakage testing of pilot operated valves and check valves. The paper also compares the test data with leakage estimates using the ASME/ANSI OM Code guidance on valve leakage

  6. Detection device for pipeway water leakage in building

    International Nuclear Information System (INIS)

    Hanawa, Jun.

    1988-01-01

    Purpose: To rapidly detect pipeway leakage at predetermined areas over a wide range in a building. Constitution: If flooding should occur in a power plant building and left as it is, emergency core cooling system, as well as auxiliary equipments and electrical equipments of the system are flooded to make the safety shutdown of the plant impossible. The present invention copes with such a risk. That is, an inlet flow meter and as exit flow meter are disposed to the inlet and the exit of pipeways disposed in a predetermined region in the building and a flow rate difference detector between them is disposed. In this way, pipeway leakage is detected by detecting the flow rate difference between the inlet flow rate and the exit flow rate of the pipeway in the predetermined region. According to the present invention, if a pipeway in a predetermined region is raptured to cause water leakage, the pipeway leakage can rapidly be detected depending on the flow rate difference between the inlet flow rate and the exit flow rate. Further, the water leakage over the entire the predetermined region can be detected rapidly as compared with the conventional case of detecting the leakage at a restricted portion where the leakage detector is disposed. (Kamimura, M.)

  7. 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....

  8. 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.

  9. Pulsed magnetic flux leakage method for hairline crack detection and characterization

    Science.gov (United States)

    Okolo, Chukwunonso K.; Meydan, Turgut

    2018-04-01

    The Magnetic Flux leakage (MFL) method is a well-established branch of electromagnetic Non-Destructive Testing (NDT), extensively used for evaluating defects both on the surface and far-surface of pipeline structures. However the conventional techniques are not capable of estimating their approximate size, location and orientation, hence an additional transducer is required to provide the extra information needed. This research is aimed at solving the inevitable problem of granular bond separation which occurs during manufacturing, leaving pipeline structures with miniature cracks. It reports on a quantitative approach based on the Pulsed Magnetic Flux Leakage (PMFL) method, for the detection and characterization of the signals produced by tangentially oriented rectangular surface and far-surface hairline cracks. This was achieved through visualization and 3D imaging of the leakage field. The investigation compared finite element numerical simulation with experimental data. Experiments were carried out using a 10mm thick low carbon steel plate containing artificial hairline cracks with various depth sizes, and different features were extracted from the transient signal. The influence of sensor lift-off and pulse width variation on the magnetic field distribution which affects the detection capability of various hairline cracks located at different depths in the specimen is explored. The findings show that the proposed technique can be used to classify both surface and far-surface hairline cracks and can form the basis for an enhanced hairline crack detection and characterization for pipeline health monitoring.

  10. Potential acidification impacts on zooplankton in CCS leakage scenarios.

    Science.gov (United States)

    Halsband, Claudia; Kurihara, Haruko

    2013-08-30

    Carbon capture and storage (CCS) technologies involve localized acidification of significant volumes of seawater, inhabited mainly by planktonic species. Knowledge on potential impacts of these techniques on the survival and physiology of zooplankton, and subsequent consequences for ecosystem health in targeted areas, is scarce. The recent literature has a focus on anthropogenic greenhouse gas emissions into the atmosphere, leading to enhanced absorption of CO2 by the oceans and a lowered seawater pH, termed ocean acidification. These studies explore the effects of changes in seawater chemistry, as predicted by climate models for the end of this century, on marine biota. Early studies have used unrealistically severe CO2/pH values in this context, but are relevant for CCS leakage scenarios. Little studied meso- and bathypelagic species of the deep sea may be especially vulnerable, as well as vertically migrating zooplankton, which require significant residence times at great depths as part of their life cycle. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Detection of infusate leakage in the brain using real-time imaging of convection-enhanced delivery.

    Science.gov (United States)

    Varenika, Vanja; Dickinson, Peter; Bringas, John; LeCouteur, Richard; Higgins, Robert; Park, John; Fiandaca, Massimo; Berger, Mitchel; Sampson, John; Bankiewicz, Krystof

    2008-11-01

    The authors have shown that convection-enhanced delivery (CED) of gadoteridol-loaded liposomes (GDLs) into different regions of normal monkey brain results in predictable, widespread distribution of this tracking agent as detected by real-time MR imaging. They also have found that this tracking technique allows monitoring of the distribution of similar nanosized agents such as therapeutic liposomes and viral vectors. A limitation of this procedure is the unexpected leakage of liposomes out of targeted parenchyma or malignancies into sulci and ventricles. The aim of the present study was to evaluate the efficacy of CED after the onset of these types of leakage. The authors documented this phenomenon in a study of 5 nonhuman primates and 7 canines, comprising 54 CED infusion sessions. Approximately 20% of these infusions resulted in leakage into cerebral ventricles or sulci. All of the infusions and leakage events were monitored with real-time MR imaging. The authors created volume-distributed versus volume-infused graphs for each infusion session. These graphs revealed the rate of distribution of GDL over the course of each infusion and allowed the authors to evaluate the progress of CED before and after leakage. The distribution of therapeutics within the target structure ceased to increase or resulted in significant attenuation after the onset of leakage. An analysis of the cases in this study revealed that leakage undermines the efficacy of CED. These findings reiterate the importance of real-time MR imaging visualization during CED to ensure an accurate, robust distribution of therapeutic agents.

  12. Optical and Thermal Behaviors of Polyamide-Layered Silicate Nanocomposites Based on 4,4'-Azodibenzoic Acid by Solution Intercalation Technique

    Science.gov (United States)

    Faghihi, Khalil; Shabanian, Meisam

    2011-04-01

    Two new samples of polyamide-montmorillonite reinforced nanocomposites based on 4,4'-azodibenzoic acid were prepared by a convenient solution intercalation technique. Polyamide (PA) 4 as a source of polymer matrix was synthesized by the direct polycondensation reaction of 4,4'-azodibenzoic acid 2 with 4,4'-diamino diphenyl sulfone 3 in the presence of triphenyl phosphate (TPP), CaCl2, pyridine and N-methyl-2-pyrrolidone (NMP). Morphology and structure of the resulting PA-nanocomposite films 4a and 4b with 10 and 20% silicate particles were characterized by FTIR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of clay dispersion and the interaction between clay and polymeric chains on the properties of nanocomposite films were investigated by using Uv-vis spectroscopy, thermogravimetric analysis (TGA) and water uptake measurements.

  13. Apollo management: A key to the solution of the social-economical dilemma - The transferability of space-travel managerial techniques to the civil sector

    Science.gov (United States)

    Puttkamer, J. V.

    1973-01-01

    An analysis has been conducted to find out whether the management techniques developed in connection with the Apollo project could be used for dealing with such urgent problems of modern society as the crisis of the cities, the increasing environmental pollution, and the steadily growing traffic. Basic concepts and definitions of program and system management are discussed together with details regarding the employment of these concepts in connection with the solution of the problems of the Apollo program. Principles and significance of a systems approach are considered, giving attention to planning, system analysis, system integration, and project management. An application of the methods of project management to the problems of the civil sector is possible if the special characteristics of each particular case are taken into account.

  14. Physical, optical and electrical properties of copper selenide (CuSe) thin films deposited by solution growth technique at room temperature

    International Nuclear Information System (INIS)

    Gosavi, S.R.; Deshpande, N.G.; Gudage, Y.G.; Sharma, Ramphal

    2008-01-01

    Copper selenide (CuSe) thin films are grown onto amorphous glass substrate from an aqueous alkaline medium using solution growth technique (SGT) at room temperature. The preparative parameters were optimized to obtain good quality of thin films. The as-deposited films were characterized for physical, optical and electrical properties. X-ray diffraction (XRD) pattern reveals that the films are polycrystalline in nature. Energy dispersive analysis by X-ray (EDAX) shows formation of stoichiometric CuSe compound. Uniform deposition of CuSe thin films on glass substrate was observed from scanning electron microscopy (SEM) and atomic force microscopy (AFM) micrographs. Average grain size was determined to 144.53 ± 10 nm using atomic force microscopy. The band gap was found to be 2.03 eV with direct band-to-band transition. Semi-conducting behaviour was observed from resistivity measurements. Ohmic behaviour was seen from I-V curve with good electrical conductivity

  15. Evaluation of Information Leakage from Cryptographic Hardware via Common-Mode Current

    Science.gov (United States)

    Hayashi, Yu-Ichi; Homma, Naofumi; Mizuki, Takaaki; Sugawara, Takeshi; Kayano, Yoshiki; Aoki, Takafumi; Minegishi, Shigeki; Satoh, Akashi; Sone, Hideaki; Inoue, Hiroshi

    This paper presents a possibility of Electromagnetic (EM) analysis against cryptographic modules outside their security boundaries. The mechanism behind the information leakage is explained from the view point of Electromagnetic Compatibility: electric fluctuation released from cryptographic modules can conduct to peripheral circuits based on ground bounce, resulting in radiation. We demonstrate the consequence of the mechanism through experiments where the ISO/IEC standard block cipher AES (Advanced Encryption Standard) is implemented on an FPGA board and EM radiations from power and communication cables are measured. Correlation Electromagnetic Analysis (CEMA) is conducted in order to evaluate the information leakage. The experimental results show that secret keys are revealed even though there are various disturbing factors such as voltage regulators and AC/DC converters between the target module and the measurement points. We also discuss information-suppression techniques as electrical-level countermeasures against such CEMAs.

  16. Estimation of Radiofrequency Power Leakage from Microwave Ovens for Dosimetric Assessment at Nonionizing Radiation Exposure Levels

    Directory of Open Access Journals (Sweden)

    Peio Lopez-Iturri

    2015-01-01

    Full Text Available The electromagnetic field leakage levels of nonionizing radiation from a microwave oven have been estimated within a complex indoor scenario. By employing a hybrid simulation technique, based on coupling full wave simulation with an in-house developed deterministic 3D ray launching code, estimations of the observed electric field values can be obtained for the complete indoor scenario. The microwave oven can be modeled as a time- and frequency-dependent radiating source, in which leakage, basically from the microwave oven door, is propagated along the complete indoor scenario interacting with all of the elements present in it. This method can be of aid in order to assess the impact of such devices on expected exposure levels, allowing adequate minimization strategies such as optimal location to be applied.

  17. Synchronization of nonidentical chaotic neural networks with leakage delay and mixed time-varying delays

    Directory of Open Access Journals (Sweden)

    Cao Jinde

    2011-01-01

    Full Text Available Abstract In this paper, an integral sliding mode control approach is presented to investigate synchronization of nonidentical chaotic neural networks with discrete and distributed time-varying delays as well as leakage delay. By considering a proper sliding surface and constructing Lyapunov-Krasovskii functional, as well as employing a combination of the free-weighting matrix method, Newton-Leibniz formulation and inequality technique, a sliding mode controller is designed to achieve the asymptotical synchronization of the addressed nonidentical neural networks. Moreover, a sliding mode control law is also synthesized to guarantee the reachability of the specified sliding surface. The provided conditions are expressed in terms of linear matrix inequalities, and are dependent on the discrete and distributed time delays as well as leakage delay. A simulation example is given to verify the theoretical results.

  18. Prevention of Information Leakage by Photo-Coupling in Smart Card

    Science.gov (United States)

    Shen, Sung-Shiou; Chiu, Jung-Hui

    Advances in smart card technology encourages smart card use in more sensitive applications, such as storing important information and securing application. Smart cards are however vulnerable to side channel attacks. Power consumption and electromagnetic radiation of the smart card can leak information about the secret data protected by the smart card. Our paper describes two possible hardware countermeasures that protect against side channel information leakage. We show that power analysis can be prevented by adopting photo-coupling techniques. This method involves the use of LED with photovoltaic cells and photo-couplers on the power, reset, I/O and clock lines of the smart card. This method reduces the risk of internal data bus leakage on the external data lines. Moreover, we also discuss the effectiveness of reducing electromagnetic radiation by using embedded metal plates.

  19. The detection of leakages in open reservoirs by the radioisotope sorption method

    International Nuclear Information System (INIS)

    Owczarczyk, A.; Wierzchnicki, R.; Urbanski, T.; Chmielewski, A.G.; Szpilowski, S.

    1992-01-01

    Location of leakages in large hydro-engineering plants and industrial water reservoirs is of great importance from view-point of both safety and economy of their exploitation. Large variety of water reservoirs encountered in hydro-engineering and industry calls for adaptation of investigation methods to their specific features. In the paper a number of methodological variants of known radiotracer technique developed at the INCT is presented. They are intended to detect and locate leakages in hydro-engineering reservoirs and dams as well as large open industrial tanks. The radioisotopes Au-198 and In-133 m being used for that purpose show excellent sorption characteristic on typical construction materials users to build such objects. (author). 8 refs, 8 figs

  20. Three-dimensional electron diffraction as a complementary technique to powder X-ray diffraction for phase identification and structure solution of powders.

    Science.gov (United States)

    Yun, Yifeng; Zou, Xiaodong; Hovmöller, Sven; Wan, Wei

    2015-03-01

    Phase identification and structure determination are important and widely used techniques in chemistry, physics and materials science. Recently, two methods for automated three-dimensional electron diffraction (ED) data collection, namely automated diffraction tomography (ADT) and rotation electron diffraction (RED), have been developed. Compared with X-ray diffraction (XRD) and two-dimensional zonal ED, three-dimensional ED methods have many advantages in identifying phases and determining unknown structures. Almost complete three-dimensional ED data can be collected using the ADT and RED methods. Since each ED pattern is usually measured off the zone axes by three-dimensional ED methods, dynamic effects are much reduced compared with zonal ED patterns. Data collection is easy and fast, and can start at any arbitrary orientation of the crystal, which facilitates automation. Three-dimensional ED is a powerful technique for structure identification and structure solution from individual nano- or micron-sized particles, while powder X-ray diffraction (PXRD) provides information from all phases present in a sample. ED suffers from dynamic scattering, while PXRD data are kinematic. Three-dimensional ED methods and PXRD are complementary and their combinations are promising for studying multiphase samples and complicated crystal structures. Here, two three-dimensional ED methods, ADT and RED, are described. Examples are given of combinations of three-dimensional ED methods and PXRD for phase identification and structure determination over a large number of different materials, from Ni-Se-O-Cl crystals, zeolites, germanates, metal-organic frameworks and organic compounds to intermetallics with modulated structures. It is shown that three-dimensional ED is now as feasible as X-ray diffraction for phase identification and structure solution, but still needs further development in order to be as accurate as X-ray diffraction. It is expected that three-dimensional ED methods

  1. Three-dimensional electron diffraction as a complementary technique to powder X-ray diffraction for phase identification and structure solution of powders

    Directory of Open Access Journals (Sweden)

    Yifeng Yun

    2015-03-01

    Full Text Available Phase identification and structure determination are important and widely used techniques in chemistry, physics and materials science. Recently, two methods for automated three-dimensional electron diffraction (ED data collection, namely automated diffraction tomography (ADT and rotation electron diffraction (RED, have been developed. Compared with X-ray diffraction (XRD and two-dimensional zonal ED, three-dimensional ED methods have many advantages in identifying phases and determining unknown structures. Almost complete three-dimensional ED data can be collected using the ADT and RED methods. Since each ED pattern is usually measured off the zone axes by three-dimensional ED methods, dynamic effects are much reduced compared with zonal ED patterns. Data collection is easy and fast, and can start at any arbitrary orientation of the crystal, which facilitates automation. Three-dimensional ED is a powerful technique for structure identification and structure solution from individual nano- or micron-sized particles, while powder X-ray diffraction (PXRD provides information from all phases present in a sample. ED suffers from dynamic scattering, while PXRD data are kinematic. Three-dimensional ED methods and PXRD are complementary and their combinations are promising for studying multiphase samples and complicated crystal structures. Here, two three-dimensional ED methods, ADT and RED, are described. Examples are given of combinations of three-dimensional ED methods and PXRD for phase identification and structure determination over a large number of different materials, from Ni–Se–O–Cl crystals, zeolites, germanates, metal–organic frameworks and organic compounds to intermetallics with modulated structures. It is shown that three-dimensional ED is now as feasible as X-ray diffraction for phase identification and structure solution, but still needs further development in order to be as accurate as X-ray diffraction. It is expected that three

  2. Effect of various de-anodizing techniques on the surface stability of non-colored and colored nanoporous AAO films in acidic solution

    Energy Technology Data Exchange (ETDEWEB)

    Awad, Ahmed M. [Chemical Engineering & Pilot Plant Department, National Research Centre, Dokki, Giza (Egypt); Shehata, Omnia S. [Physical Chemistry Department, National Research Centre, Dokki, Giza (Egypt); Heakal, Fakiha El-Taib, E-mail: fakihaheakal@yahoo.com [Chemistry Department, Faculty of Science, Cairo University, Giza 12613 (Egypt)

    2015-12-30

    Highlights: • Three de-anodization methods were used during two-step fabrication of nanoporous AAO. • Electrolytic etching (EE), chemical etching with H{sub 3}PO{sub 4} (PE) or NaOH (HE) were adopted. • After the second anodizing step, HE film was the thinnest as compared to EE and HE. • Stability order of nanoporous AAO films in 0.5 M HCl solution was: PE > EE > HE. • For the colored films by electrodeposited Cu atoms, the order was: HE > EE > PE. - Abstract: Anodic aluminum oxide (AAO) is well known as an important nanostructured material, and a useful template in the fabrication of nanostructures. Nanoporous anodic alumina (PAA) with high open porosity was prepared by adopting three de-anodizing regimes following the first anodizing step and preceding the second one. The de-anodizing methods include electrolytic etching (EE) and chemical etching using either phosphoric acid (PE) or sodium hydroxide (HE) solutions. Three of the obtained AAO samples were black colored by electrodeposition of copper nanoparticles in their pores. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques were used to characterize the electrochemical performance of the two sets of the prepared samples. In general, the data obtained in aggressive aerated 0.5 M HCl solution demonstrated dissimilar behavior for the three prepared samples despite that the second anodizing step was the same for all of them. The data indicated that the resistance and thickness of the inner barrier part of nano-PAA film, are the main controlling factors determining its stability. On the other hand, coloring the film decreased its stability due to the galvanic effect. The difference in the electrochemical behavior of the three colored samples was discussed based on the difference in both the pore size and thickness of the outer porous part of PAA film as supported by SEM, TEM and cross-sectional micrographs. These results can thus contribute for better engineering

  3. Effect of various de-anodizing techniques on the surface stability of non-colored and colored nanoporous AAO films in acidic solution

    Science.gov (United States)

    Awad, Ahmed M.; Shehata, Omnia S.; Heakal, Fakiha El-Taib

    2015-12-01

    Anodic aluminum oxide (AAO) is well known as an important nanostructured material, and a useful template in the fabrication of nanostructures. Nanoporous anodic alumina (PAA) with high open porosity was prepared by adopting three de-anodizing regimes following the first anodizing step and preceding the second one. The de-anodizing methods include electrolytic etching (EE) and chemical etching using either phosphoric acid (PE) or sodium hydroxide (HE) solutions. Three of the obtained AAO samples were black colored by electrodeposition of copper nanoparticles in their pores. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques were used to characterize the electrochemical performance of the two sets of the prepared samples. In general, the data obtained in aggressive aerated 0.5 M HCl solution demonstrated dissimilar behavior for the three prepared samples despite that the second anodizing step was the same for all of them. The data indicated that the resistance and thickness of the inner barrier part of nano-PAA film, are the main controlling factors determining its stability. On the other hand, coloring the film decreased its stability due to the galvanic effect. The difference in the electrochemical behavior of the three colored samples was discussed based on the difference in both the pore size and thickness of the outer porous part of PAA film as supported by SEM, TEM and cross-sectional micrographs. These results can thus contribute for better engineering applications of nanoporous AAO.

  4. [Bath Plug Closure Method for Cerebrospinal Fluid Leakage by Endoscopic Endonasal Approach:Cooperative Treatment by Neurosurgeons and Otolaryngologists].

    Science.gov (United States)

    Kawaguchi, Tomohiro; Arakawa, Kazuya; Nomura, Kazuhiro; Ogawa, Yoshikazu; Katori, Yukio; Tominaga, Teiji

    2017-12-01

    Endoscopic endonasal surgery, an innovative surgical technique, is used to approach sinus lesions, lesions of the skull base, and intradural tumors. The cooperation of experienced otolaryngologists and neurosurgeons is important to achieve safe and reliable surgical results. The bath plug closure method is a treatment option for patients with cerebrospinal fluid(CSF)leakage. Although it includes dural and/or intradural procedures, surgery tends to be performed by otolaryngologists because its indications, detailed maneuvers, and pitfalls are not well recognized by neurosurgeons. We reviewed the cases of patients with CSF leakage treated by using the bath plug closure method with an endoscopic endonasal approach at our institution. Three patients were treated using the bath plug closure method. CSF leakage was caused by a meningocele in two cases and trauma in one case. No postoperative intracranial complications or recurrence of CSF leakage were observed. The bath plug closure method is an effective treatment strategy and allows neurosurgeons to gain in-depth knowledge of the treatment options for CSF leakage by using an endoscopic endonasal approach.

  5. [Research on the spectral feature and identification of the surface vegetation stressed by stored CO2 underground leakage].

    Science.gov (United States)

    Chen, Yun-Hao; Jiang, Jin-Bao; Steven, Michael D; Gong, A-Du; Li, Yi-Fan

    2012-07-01

    With the global climate warming, reducing greenhouse gas emissions becomes a focused problem for the world. The carbon capture and storage (CCS) techniques could mitigate CO2 into atmosphere, but there is a risk in case that the CO2 leaks from underground. The objective of this paper is to study the chlorophyll contents (SPAD value), relative water contents (RWC) and leaf spectra changing features of beetroot under CO2 leakage stress through field experiment. The result shows that the chlorophyll contents and RWC of beetroot under CO2 leakage stress become lower than the control beetroot', and the leaf reflectance increases in the 550 nm region and decreases in the 680nm region. A new vegetation index (R550/R680) was designed for identifying beetroot under CO2 leakage stress, and the result indicates that the vegetation index R550/R680 could identify the beetroots after CO2 leakage for 7 days. The index has strong sensitivity, stability and identification for monitoring the beetroots under CO2 stress. The result of this paper has very important meaning and application values for selecting spots of CCS project, monitoring and evaluating land-surface ecology under CO2 stress and monitoring the leakage spots by using remote sensing.

  6. Leakage potential through mechanical penetrations in a severe accident environment

    International Nuclear Information System (INIS)

    Koenig, L.N.

    1986-01-01

    This paper reviews the findings of an ongoing program, Integrity of Containment Penetrations Under Severe Accident Loads. The program is concerned with the leakage modes as well as the magnitude of leakage through mechanical penetrations in a containment building subject to a severe accident. Seal and gasket tests are used to evaluate the effect of radiation aging, thermal aging, seal geometry, and seal squeeze on seals and gaskets subjected to a hypothesized severe accident. The effects on leakage of the structural response of equipment hatches, personnel airlocks, and drywell heads subjected to severe accident pressures are studied by experiments and analyses. The data gathered during this program will be used to develop methodologies for predicting leakage

  7. N13 - based reactor coolant pressure boundary leakage system

    International Nuclear Information System (INIS)

    Dissing, E.; Marbaeck, L.; Sandell, S.; Svansson, L.

    1980-05-01

    A system for the monitoring of leakage of coolant from the reactor coolant pressure boundary and auxiliary systems to the reactor containment, based on the detection of the N13 content in the atmosphere, has been tested. N13 is produced from the oxyegen of the reactor water via the recoil photon nuclear process H1 + 016 + He4. The generation of N13 is therefore independent of fuel element leakage and of the corrosion product content in the water. In the US AEC regulatory guide 1.45 has a leakage increase of 4 liter/ min been suggested as the response limit. The experiments carried out in Ringhals indicate, that with the accomplishment of minor improvements in the installation, a 4 liter/min leakage to the containment will give rise to a signal with a random error range of +- 0.25 liter/min, 99.7 % confidence level. (author)

  8. 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 parasitic capacitance can be bypassed by introducing a common mode (CM) conducting path to the inverter. The resulting ground leakage current is therefore well controlled to be below the regulation limit. Moreover, the proposed inverter can also eliminate the well-known double line frequency pulsating power....... The mechanism of leakage current suppression and the closed-loop control of pulsating power decoupling are discussed in the paper in details. A 500 W prototype was also built and tested in the laboratory, and both simulation and experimental results are finally presented to show the excellent performance...

  9. Competitiveness and carbon leakages in industry under asymmetric climate policy

    International Nuclear Information System (INIS)

    Demailly, D.

    2008-02-01

    This research aims at studying how to predict competitiveness loss for an industry submitted to an asymmetric carbon constraint, and carbon leakages, whether high losses and important leakages might be feared, and which policies can be used to mitigate these losses and escapes. The author analyses and comments the content of four articles dealing with: the impact on competitiveness, revenue distribution and economic efficiency of a change in the allocation rules for EU greenhouse gas allowances; the relationship between allocation of CO 2 allowances and competitiveness in the case of the European iron and steel industry; CO 2 abatement, competitiveness and leakage in the European cement industry under EU ETS; and leakage from climate policies and border tax adjustment (lessons from a geographic model of the cement industry). Then, the author combines several approaches to study the cement and steel industries

  10. Fractal modeling of fluidic leakage through metal sealing surfaces

    Science.gov (United States)

    Zhang, Qiang; Chen, Xiaoqian; Huang, Yiyong; Chen, Yong

    2018-04-01

    This paper investigates the fluidic leak rate through metal sealing surfaces by developing fractal models for the contact process and leakage process. An improved model is established to describe the seal-contact interface of two metal rough surface. The contact model divides the deformed regions by classifying the asperities of different characteristic lengths into the elastic, elastic-plastic and plastic regimes. Using the improved contact model, the leakage channel under the contact surface is mathematically modeled based on the fractal theory. The leakage model obtains the leak rate using the fluid transport theory in porous media, considering that the pores-forming percolation channels can be treated as a combination of filled tortuous capillaries. The effects of fractal structure, surface material and gasket size on the contact process and leakage process are analyzed through numerical simulations for sealed ring gaskets.

  11. Transanal stent in anterior resection does not prevent anastomotic leakage

    DEFF Research Database (Denmark)

    Bülow, Steffen; Bulut, O; Christensen, Ib Jarle

    2006-01-01

    OBJECTIVE: A defunctioning transanal stent may theoretically reduce the leakage rate after anterior rectal resection. We present a randomized open study with the aim of comparing the leakage rate after anterior resection with a loop ileostomy, a transanal stent, both or neither. PATIENTS...... completion of the operation the patients were randomized in two groups with and without a transanal stent. RESULTS: A clinically significant leakage was diagnosed in 25 patients (13%). No significant difference was found 17 of 98 patients with a stent and 8 of 96 without (P = 0.09), or in 9 of 44 ileostomy...... patients with a stent and in 3 of 45 without (P = 0.07). Several leaks over a short time led to an interim analysis after inclusion of 194 of 448 planned patients. The analysis showed no significant protective effect of the stent, and more leakages in the stent group, although not statistically significant...

  12. Prediction of leakage in the fixed mechanical seal

    Directory of Open Access Journals (Sweden)

    Asheichik Anatoly A.

    2017-01-01

    Full Text Available The questions of influence of the shape of contact surfaces on leakages through rubber seals in fixed connection of subassemblies are considered in the article. It is known from practice of operation of seals of various designs that the shape of contact surfaces and consequently also the shape of diagram of stresses in a contact zone considerably influences on value of leaks Linking leakage magnitude and distribution of contact stresses enables, firstly, more precisely calculate the amount of leakage for existing seals, and, secondly, to optimize the shape of the seals in their design in each case. As the result of experimental studies on the introduction of the rubber gasket ring fixed indenters different profiles found that by optimizing the shape of the indenter magnitude of leakage can be reduced by 10 times.

  13. Magnetic leakage shield of septum magnet for SPring-8 synchrotron

    International Nuclear Information System (INIS)

    Abe, Hiroshi; Aoki, Tsuyoshi; Fukami, Kenji

    1997-01-01

    This paper describes magnetic field measurements of the prototype septum magnet and countermeasure for reducing the leakage magnetic fields in the incidence and the extraction parts of the SPring-8 synchrotron. We studied and developed 'leakage magnetic shield' on the basis of the tests data got in these measurements. Consequentially, it succeeded in reducing effects of the leakage field to about 50% by installing the shield board in the magnet main body. Then, it was possible to manufacture the magnet which sufficiently held the effect of the leakage field for the electron and positron beam. In this examination, we confirmed the reproduction with the magnetic field distribution of the magnet measured in the manufacturer. We developed and produced of the septum magnets which were carried out determination of the shapes of the magnetic shielding. (author)

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

    African Journals Online (AJOL)

    2015-11-16

    Nov 16, 2015 ... resin composite, the fifth group – two‑stage SE adhesive applied and cavities filled with ... KEYWORDS: Adhesives, composite, evaluation, leakage ... the glass ionomers. ... systems are realized in one or two clinical step(s).[5].

  15. Effect of Graphene Oxide on the Reaction Kinetics of Methyl Methacrylate In Situ Radical Polymerization via the Bulk or Solution Technique

    Directory of Open Access Journals (Sweden)

    Ioannis S. Tsagkalias

    2017-09-01

    Full Text Available The synthesis of nanocomposite materials based on poly(methyl methacrylate and graphene oxide (GO is presented using the in situ polymerization technique, starting from methyl methacrylate, graphite oxide, and an initiator, and carried out either with (solution or without (bulk in the presence of a suitable solvent. Reaction kinetics was followed gravimetrically and the appropriate characterization of the products took place using several experimental techniques. X-ray diffraction (XRD data showed that graphite oxide had been transformed to graphene oxide during polymerization, whereas FTIR spectra revealed no significant interactions between the polymer matrix and GO. It appears that during polymerization, the initiator efficiency was reduced by the presence of GO, resulting in a reduction of the reaction rate and a slight increase in the average molecular weight of the polymer formed, measured by gel permeation chromatography (GPC, along with an increase in the glass transition temperature obtained from differential scanning calorimetry (DSC. The presence of the solvent results in the suppression of the gel-effect in the reaction rate curves, the synthesis of polymers with lower average molecular weights and polydispersities of the Molecular Weight Distribution, and lower glass transition temperatures. Finally, from thermogravimetric analysis (TG, it was verified that the presence of GO slightly enhances the thermal stability of the nano-hybrids formed.

  16. A new technique for the determination of coronal magnetic fields: A fixed mesh solution to Laplace's equation using line-of-sight boundary conditions

    International Nuclear Information System (INIS)

    Adams, J.; Pneuman, G.W.

    1976-01-01

    A new method for computing potential magnetic field configurations in the solar atmosphere is described. A discrete approximation to Laplace's equation is solved in the domain R(Sun) 1 , 0 1 being an arbitrary radial distance from the solar center). The method utilizes the measured line-of-sight magnetic fields directly as the boundary condition at the solar surface and constrains the field to become radial at the outer boundary, R 1 . First the differential equation and boundary conditions are reduced to a set of two-dimensional equations in r, theta by Fourier transforming out the periodic phi dependence. Next each transformed boundary condition is converted to a Dirichlet surface condition. Then each two-dimensional equation with standard Dirichlet-Dirichlet boundary conditions is solved for the Fourier coefficient it determines. Finally, the solution of the original three dimensional equation is obtained through inverse Fourier transformation. The primary numerical tools in this technique are the use of a finite fast Fourier transform technique and also a generalized cyclic reduction algorithm developed at NCAR. Any extraneous monopole component present in the data can be removed if so desired. (Auth.)

  17. Quantifying the benefit of wellbore leakage potential estimates for prioritizing long-term MVA well sampling at a CO2 storage site.

    Science.gov (United States)

    Azzolina, Nicholas A; Small, Mitchell J; Nakles, David V; Glazewski, Kyle A; Peck, Wesley D; Gorecki, Charles D; Bromhal, Grant S; Dilmore, Robert M

    2015-01-20

    This work uses probabilistic methods to simulate a hypothetical geologic CO2 storage site in a depleted oil and gas field, where the large number of legacy wells would make it cost-prohibitive to sample all wells for all measurements as part of the postinjection site care. Deep well leakage potential scores were assigned to the wells using a random subsample of 100 wells from a detailed study of 826 legacy wells that penetrate the basal Cambrian formation on the U.S. side of the U.S./Canadian border. Analytical solutions and Monte Carlo simulations were used to quantify the statistical power of selecting a leaking well. Power curves were developed as a function of (1) the number of leaking wells within the Area of Review; (2) the sampling design (random or judgmental, choosing first the wells with the highest deep leakage potential scores); (3) the number of wells included in the monitoring sampling plan; and (4) the relationship between a well’s leakage potential score and its relative probability of leakage. Cases where the deep well leakage potential scores are fully or partially informative of the relative leakage probability are compared to a noninformative base case in which leakage is equiprobable across all wells in the Area of Review. The results show that accurate prior knowledge about the probability of well leakage adds measurable value to the ability to detect a leaking well during the monitoring program, and that the loss in detection ability due to imperfect knowledge of the leakage probability can be quantified. This work underscores the importance of a data-driven, risk-based monitoring program that incorporates uncertainty quantification into long-term monitoring sampling plans at geologic CO2 storage sites.

  18. Analysis of reverse gate leakage mechanism of AlGaN/GaN HEMTs with N2 plasma surface treatment

    Science.gov (United States)

    Liu, Hui; Zhang, Zongjing; Luo, Weijun

    2018-06-01

    The mechanism of reverse gate leakage current of AlGaN/GaN HEMTs with two different surface treatment methods are studied by using C-V, temperature dependent I-V and theoretical analysis. At the lower reverse bias region (VR >- 3.5 V), the dominant leakage current mechanism of the device with N2 plasma surface treatment is the Poole-Frenkel emission current (PF), and Trap-Assisted Tunneling current (TAT) is the principal leakage current of the device which treated by HCl:H2O solution. At the higher reverse bias region (VR current of the device with N2 plasma surface treatment is one order of magnitude smaller than the device which treated by HCl:H2O solution. This is due to the recovery of Ga-N bond in N2 plasma surface treatment together with the reduction of the shallow traps in post-gate annealing (PGA) process. The measured results agree well with the theoretical calculations and demonstrate N2 plasma surface treatment can reduce the reverse leakage current of the AlGaN/GaN HEMTs.

  19. Method of detecting leakage in nuclear reactor containment vessel

    International Nuclear Information System (INIS)

    Koba, Akitoshi; Goto, Seiichiro.

    1974-01-01

    Object: To permit accurate and prompt detection of leakage of a radioactive substance. Structure: The rate of change of such factors as radiation dose, temperature and pressure in the containment vessel, and each detected rate of change is compared with a reference value. The running cycle of the condensed drain exhausting pump in a drain collecting tank within a predetermined period is detected, and it is also compared with a reference value. These comparisons determine the absence or presence of leakage. (Kamimura, M.)

  20. LMFBR technology. FFTF cover-gas leakage calculation

    International Nuclear Information System (INIS)

    Deboi, H.

    1974-01-01

    The FFTF LMFBR is intended to have a near zero release of radioactive gases during normal reactor operation with 1% failed fuel. This report presents calculations which provide an approximation of these cover gas leakages. Data from ongoing static and dynamic seal leak tests at AI are utilized. Leakage through both elastomeric and metallic seals in all sub-assemblies and penetrations comprising the reactor cover gas containment during reactor operation system are included

  1. An alternative treatment for anastomotic leakage after oesophageal resection

    DEFF Research Database (Denmark)

    Damm, P; Hoffmann, J.

    1988-01-01

    An alternative non-operative method for treatment for anastomotic leakage after oesophageal resection is presented. A mediastinal abscess cavity was drained by an ordinary nasogastric tube introduced via the nose through the anastomotic defect and into the cavity.......An alternative non-operative method for treatment for anastomotic leakage after oesophageal resection is presented. A mediastinal abscess cavity was drained by an ordinary nasogastric tube introduced via the nose through the anastomotic defect and into the cavity....

  2. Field size dependent mapping of medical linear accelerator radiation leakage

    International Nuclear Information System (INIS)

    Vu Bezin, Jérémi; De Vathaire, Florent; Diallo, Ibrahima; Veres, Attila; Lefkopoulos, Dimitri; Chavaudra, Jean; Deutsch, Eric

    2015-01-01

    The purpose of this study was to investigate the suitability of a graphics library based model for the assessment of linear accelerator radiation leakage. Transmission through the shielding elements was evaluated using the build-up factor corrected exponential attenuation law and the contribution from the electron guide was estimated using the approximation of a linear isotropic radioactive source. Model parameters were estimated by a fitting series of thermoluminescent dosimeter leakage measurements, achieved up to 100 cm from the beam central axis along three directions. The distribution of leakage data at the patient plane reflected the architecture of the shielding elements. Thus, the maximum leakage dose was found under the collimator when only one jaw shielded the primary beam and was about 0.08% of the dose at isocentre. Overall, we observe that the main contributor to leakage dose according to our model was the electron beam guide. Concerning the discrepancies between the measurements used to calibrate the model and the calculations from the model, the average difference was about 7%. Finally, graphics library modelling is a readily and suitable way to estimate leakage dose distribution on a personal computer. Such data could be useful for dosimetric evaluations in late effect studies. (paper)

  3. 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.

  4. Leakage localization with an acoustic array that covers a wide area for pipeline leakage monitoring in a closed space

    Energy Technology Data Exchange (ETDEWEB)

    Park, Choon Su [Center for Safety Measurements, Division of Metrology for Quality of Life, Korea Research institute of Standards and Science, Daejeon (Korea, Republic of); Jeon, Jong Hoon [Hyundai Heavy Industry Co.,Ltd., Ulsan (Korea, Republic of); Park, Jin Ho [Korea Atomiv Energy Institute, Daejeon (Korea, Republic of)

    2013-10-15

    It is of great importance to localize leakages in complex pipelines for assuring their safety. A sensor array that can detect where leakages occur enables us to monitor a wide area with a relatively low cost. Beam forming is a fast and efficient algorithm to estimate where sources are, but it is generally made use of in free field condition. In practice, however, many pipelines are placed in a closed space for the purpose of safety and maintenance. This leads us to take reflected waves into account to the beam forming for interior leakage localization. Beam power distribution of reflected waves in a closed space is formulated, and spatial average is introduced to suppress the effect of reflected waves. Computer simulations and experiments ensure how the proposed method is effective to localize leakage in a closed space for structural health monitoring.

  5. Excessive leakage measurement using pressure decay method in containment building local leakage rate test at nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Kyu; Kim, Chang Soo; Kim, Wang Bae [KHNP, Central Research Institute, Daejeon (Korea, Republic of)

    2016-06-15

    There are two methods for conducting the containment local leakage rate test (LLRT) in nuclear power plants: the make-up flow rate method and the pressure decay method. The make-up flow rate method is applied first in most power plants. In this method, the leakage rate is measured by checking the flow rate of the make-up flow. However, when it is difficult to maintain the test pressure because of excessive leakage, the pressure decay method can be used as a complementary method, as the leakage rates at pressures lower than normal can be measured using this method. We studied the method of measuring over leakage using the pressure decay method for conducting the LLRT for the containment building at a nuclear power plant. We performed experiments under conditions similar to those during an LLRT conducted on-site. We measured the characteristics of the leakage rate under varies pressure decay conditions, and calculated the compensation ratio based on these data.

  6. An Experimental Characterization of Tip Leakage Flows and Corresponding Effects on Multistage Compressor Performance

    Science.gov (United States)

    Berdanier, Reid Adam

    measurements collected at these part-speed and off-design conditions provides a unique data set for calibrating computational models and predictive algorithms. Further investigations with detailed steady total pressure traverses provide additional insight to tip leakage flow effects on stator performance. A series of data on the 100% corrected speedline further characterize the tip leakage flow using time-resolved measurements from a combination of instrumentation techniques. An array of high-frequency-response piezoresistive pressure transducers installed over the rotors allows quantification of tip leakage flow trajectories. These data, along with measurements from a fast-response total pressure probe downstream of the rotors, evaluate the development of tip leakage flows and assess the corresponding effects of upstream stator wakes. Finally, thermal anemometry measurements collected using the single slanted hot-wire technique evaluate three-dimensional velocity components throughout the compressor. These data facilitate calculations of several flow metrics, including a blockage parameter and phase-locked streamwise vorticity.

  7. Simulating CO₂ leakages from CCS to determine Zn toxicity using the marine microalgae Pleurochrysis roscoffensis.

    Science.gov (United States)

    Bautista-Chamizo, Esther; De Orte, Manoela Romanó; DelValls, Tomás Ángel; Riba, Inmaculada

    2016-02-01

    Due to the current climate change and ocean acidification, a new technology for CO2 mitigation has been proposed, the Carbon dioxide Capture and Storage (CCS). However, there is an ecological risk associated with potential CO2 leakages from the sub-seabed storages sites. To evaluate the effects related to CO2 leakages, laboratory-scales experiments were performed using the marine microalgae Pleurochrysis roscoffensis. Five Zn concentrations were tested at different pHs to study Zn toxicity under acidified conditions. Seawater was collected and submitted to acidification by means of CO2 injection and by HCl addition. Results showed differences between both acidification techniques: while microalgae growth was enhanced by CO2 supply, reaching the optimal growth at pH 6.5 and full inhibition at pH 5.5, HCl acidification growth was inhibited at pH 6.5. Although small concentrations of Zn were positive for P. roscoffensis growth, Zn toxicity increased at lower pHs, and more severely on samples acidified with HCl. The conclusions obtained in this work are useful to address the potential effects on the marine ecosystem related to changes in metal bioavailability during CO2 leakages scenarios. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. 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.

  9. A new approach for simple radioisotope cisternography examination in cerebrospinal fluid leakage detection.

    Science.gov (United States)

    Hoshino, Hiromitsu; Higuchi, Tetsuya; Achmad, Arifudin; Taketomi-Takahashi, Ayako; Fujimaki, Hiroya; Tsushima, Yoshito

    2016-01-01

    We developed a new quantitative interpretation technique of radioisotope cisternography (RIC) for the diagnosis of spontaneous cerebrospinal fluid hypovolemia (SCH). RIC studies performed for suspected SCH were evaluated. (111)In-DTPA RIC images were taken at 0, 1, 3, 6, and 24-h after radioisotope injection following the current protocol. Regions of interest (ROI) were selected on 3-h images to include brain, spine, bladder or the whole body. The accumulative radioactivity counts were calculated for quantitative analysis. Final diagnoses of SCH were established based on the diagnostic criteria recently proposed by Schievink and colleagues. Thirty-five patients were focused on. Twenty-one (60.0%) patients were diagnosed as having SCH according to the Schievink criteria. On the 3-h images, direct cerebrospinal fluid leakage sign was detected in nine of 21 SCH patients (42.9%), as well as three patients with suspected iatrogenic leakage. Compared to non-SCH patients, SCH patients showed higher bladder accumulation at 3-h images (P = 0.0002), and higher brain clearance between the 6- and 24-h images (P leakage was not observed. 1- and 6-h images did not provide any additional information in any patients. A new simple ROI setting method, in which only the 3-h whole body and 24-h brain images were necessary, was sufficient to diagnose SCH.

  10. Internal Leakage Fault Detection and Tolerant Control of Single-Rod Hydraulic Actuators

    Directory of Open Access Journals (Sweden)

    Jianyong Yao

    2014-01-01

    Full Text Available The integration of internal leakage fault detection and tolerant control for single-rod hydraulic actuators is present in this paper. Fault detection is a potential technique to provide efficient condition monitoring and/or preventive maintenance, and fault tolerant control is a critical method to improve the safety and reliability of hydraulic servo systems. Based on quadratic Lyapunov functions, a performance-oriented fault detection method is proposed, which has a simple structure and is prone to implement in practice. The main feature is that, when a prescribed performance index is satisfied (even a slight fault has occurred, there is no fault alarmed; otherwise (i.e., a severe fault has occurred, the fault is detected and then a fault tolerant controller is activated. The proposed tolerant controller, which is based on the parameter adaptive methodology, is also prone to realize, and the learning mechanism is simple since only the internal leakage is considered in parameter adaptation and thus the persistent exciting (PE condition is easily satisfied. After the activation of the fault tolerant controller, the control performance is gradually recovered. Simulation results on a hydraulic servo system with both abrupt and incipient internal leakage fault demonstrate the effectiveness of the proposed fault detection and tolerant control method.

  11. A direct-conversion WLAN transceiver baseband with DC offset compensation and carrier leakage reduction

    Energy Technology Data Exchange (ETDEWEB)

    Yuan Fang; Yan Jun; Ma Heping; Shi Yin [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Foster, Dai Fa, E-mail: fyuan@sci-inc.com.c [Department of Electrical and Computer Engineering, Auburn University, Auburn, AL 36849-5201 (United States)

    2010-10-15

    A dual-band direct-conversion WLAN transceiver baseband compliant with the IEEE 802.11a/b/g standards is described. Several critical techniques for receiver DC offset compensation and transmitter carrier leakage rejection calibration are presented that enable the direct-conversion architecture to meet all WLAN specifications. The receiver baseband VGA provides 62 dB gain range with steps of 2 dB and a DC offset cancellation circuit is introduced to remove the offset from layout and self-mixing. The calibration loop achieves constant high-pass pole when gain changes; and a fast response time by programming the pole to 1 MHz during preamble and to 30 kHz during receiving data. The transmitter baseband employs an auto-calibration loop with on-chip AD and DA to suppress the carrier leakage, and AD can be powered down after calibration to save power consumption. The chip consumes 17.52 mA for RX baseband VGA and DCOC, and 8.3 mA for TX carrier leakage calibration (5.88 mA after calibration) from 2.85 V supply. Implemented in a 0.35 {mu}m SiGe technology, they occupy 0.68 mm{sup 2} and 0.18 mm{sup 2} die size respectively. (semiconductor integrated circuits)

  12. Influence of process parameters on threshold voltage and leakage current in 18nm NMOS device

    Science.gov (United States)

    Atan, Norani Binti; Ahmad, Ibrahim Bin; Majlis, Burhanuddin Bin Yeop; Fauzi, Izzati Binti Ahmad

    2015-04-01

    The process parameters are very crucial factor in the development of transistors. There are many process parameters that influenced in the development of the transistors. In this research, we investigate the effects of the process parameters variation on response characteristics such as threshold voltage (VTH) and sub-threshold leakage current (IOFF) in 18nm NMOS device. The technique to identify semiconductor process parameters whose variability would impact most on the device characteristic is realized through the process by using Taguchi robust design method. This paper presents the process parameters that influenced in threshold voltage (VTH) and sub-threshold leakage current (IOFF) which includes the Halo Implantation, Compensation Implantation, Adjustment Threshold voltage Implantation and Source/Drain Implantation. The design, fabrication and characterization of 18nm HfO2/TiSi2 NMOS device is simulated and performed via a tool called Virtual Wafer Fabrication (VWF) Silvaco TCAD Tool known as ATHENA and ATLAS simulators. These two simulators were combined with Taguchi L9 Orthogonal method to aid in the design and the optimization of the process parameters to achieve the optimum average of threshold voltage (VTH) and sub-threshold leakage current, (IOFF) in 18nm device. Results from this research were obtained; where Halo Implantation dose was identified as one of the process parameter that has the strongest effect on the response characteristics. Whereby the Compensation Implantation dose was identified as an adjustment factor to get the nominal values of threshold voltage VTH, and sub-threshold leakage current, IOFF for 18nm NMOS devices equal to 0.302849 volts and 1.9123×10-16 A/μm respectively. The design values are referred to ITRS 2011 prediction.

  13. 4D ERT Monitoring of Subsurface Water Pipe Leakage During a Controlled Field Experiment

    Science.gov (United States)

    Inauen, C.; Chambers, J. E.; Wilkinson, P. B.; Meldrum, P.; Swift, R. T.; Uhlemann, S.; Gunn, D.; Dashwood, B.; Taxil, J.; Curioni, G.

    2016-12-01

    Locating and delineating leakage from subsurface pipelines is an important task for civil engineers. 4D Electrical Resistivity Tomography (ERT) allows changes in subsurface resistivity to be imaged at a high spatial and temporal resolution in a minimally invasive manner. It is therefore a promising tool to supplement conventional point-sensing techniques to monitor subsurface flow processes. To assess the efficacy of ERT for pipe leakage monitoring several controlled leak experiments were carried out at a test site in Blagdon, Bristol, UK. To simulate the leak, a plastic pipe with a hole was buried below a flat, grassed area at a depth of 0.7 m, representing a standard UK mains water pipe installation. The water table at the site lies well below the surface meaning that the experiment took entirely place in the vadose zone, where changes in resistivity are primarily sensitive to water content variations. The ERT array covered an area of 6.5m x 6.5m around the leak location. Data acquisition was carried out with the BGS PRIME (Proactive Infrastructure Monitoring and Evaluation) system, which facilitates remote scheduling and autonomous ERT data collection and transmission. To obtain the resistivity changes of the subsurface a 4D inversion was carried out using a Gauss-Newton approach with spatial and temporal smoothness constraints. We were able to reliably observe the onset, spread and cessation of the leakage. Measurements from in-situ soil sensors at several depths above and below the leak complemented the ERT data and allowed us to assess their reliability and directly relate them to hydrogeological processes. Moreover, through experimental tests with soil samples from the test area, a Waxman-Smits relation was obtained to directly convert the changes in electrical resistivity to gravimetric soil moisture content. With future experiments on the test site more work is planned towards survey optimization, automated processing and tracking of leakage plumes.

  14. Neopterin, kynurenine and tryptophan as new biomarkers for early detection of rectal anastomotic leakage.

    Science.gov (United States)

    Dusek, Tomas; Orhalmi, Julius; Sotona, Otakar; Krcmova, Lenka Kujovska; Javorska, Lenka; Dolejs, Josef; Paral, Jiri

    2018-03-01

    At present, there are no strong predictors, nor a useful scoring system, that clearly identifies patients at risk for anastomotic leakage. This study aimed to investigate a new method that assesses this risk by monitoring levels of neopterin, tryptophan, and kynurenine, in bodily fluids. This prospective study included patients who underwent elective rectal resection for carcinoma. The basic condition for inclusion was rectal anastomosis using the double-stapling technique. Preoperative levels of neopterin, tryptophan, kynurenine, and their ratios, were assessed with blood and urine samples. These levels were then monitored for 6 postoperative days in venous blood, urine, and abdominal drainage fluid. A total of 42 patients were enrolled in the study. Thirty-six patients underwent a laparoscopic resection and 6 patients had an open procedure. No differences were found among neopterin, tryptophan, and kynurenine serum levels. However, the groups were observed to have significant differences in the urinary neopterin/creatinine ratio: the preoperative neopterin/creatinine ratio was 139.5 μmol/mol in the group with leakage, vs 114.8 μmol/mol in the group without complications, p = 0.037. The same results were observed during the postoperative period, p = 0.012. Additionally, the group with complications had a higher mean value of neopterin in drainage fluid, p = 0.048. Our study demonstrated that high preoperative levels of urinary neopterin could be interpreted as a risk for anastomotic leakage. Moreover, pathological levels of neopterin in urine and abdominal drainage fluid could be useful for early identification of anastomotic leakage during the postoperative period prior to its clinical development.

  15. Hydrogeochemical impact of CO{sub 2} leakage from geological sequestration on shallow potable aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Cahill, A.G.

    2013-09-15

    with more than 770 water samples taken. In addition pre- and post-injection sediment cores were studied in order to assess sediment alteration and aid identification of controlling geochemical processes. Results show a significant lowering of pH and increase in electrical conductivity, but except for Al concentrations reaching up to 75 {mu}mol/L, the detrimental effects on groundwater quality were limited. Groundwater chemistry evolves spatially and temporally during leakage, thus risks posed and the best methods for detection will also vary. In addition, 2 main phases of leakage were identified; a pulse phase of elevated ions moving with advective flow succeeded by increasing persistent acidification caused by buffering exhaustion (i.e. depletion of reactive minerals). Aqueous element concentrations were delineated into 4 generalized behaviors; 1. advective pulse (Ca, Mg, Na, Si, Ba and Sr,), 2. pH sensitive abundance dependent (Al and Zn), 3. complete removal (Mn and Fe) and 4. unaffected (K). Concentration behaviors were characterized by; 1. a maximal front moving with advective flow, 2. continual increase in close proximity to the injection horizon, 3. removal from solution to zero concentration and 4. no significant change. Paper IV describes geochemical modeling conducted in support of field and laboratory activities and proposes that gibbsite derived Al{sup 3+} driven cation exchange can explain the majority of the water chemistry evolution at Vroegum. In addition buffering exhaustion/sediment depletion is corroborated explaining increasing acidification observed. Results infer risks associated with and how best to detect leakage will change with time and also increase with depth. Consequently water quality may become more deleterious as a leak matures and will vary with depth. (Author)

  16. Leakage evaluation in the PCV (Primary Containment Vessel) using chemical and radiochemical data

    International Nuclear Information System (INIS)

    Maeda, Katsuji; Nagasawa, Katsumi

    1998-01-01

    Keeping the reliability of nuclear power plant operation, the primary coolant leakage in the PCV is strictly restricted by the Technical Specifications. It is very important to detect an indication of leakage and estimate the source of leakage to provide countermeasures. Usually the indication of leakage will be detected by increase of drain flow in the PCV sump. There are some possibilities of leakage sources in the PCV, such as reactor water, main steam, condensate, feedwater and closed cooling water. The leakage source contain different chemical and radiochemical species. This means that the leakage source can be presumed and detected by using chemical information from the PCV atmosphere and sump water. To detect the leakage indication and the source quickly and exactly, the PCV Leakage Detection Expert System has been developed. This paper describes how to evaluate the leakage indication and source in the PCV by using chemical and radiochemical data. (author)

  17. Benchmarking whole-building energy performance with multi-criteria technique for order preference by similarity to ideal solution using a selective objective-weighting approach

    International Nuclear Information System (INIS)

    Wang, Endong

    2015-01-01

    Highlights: • A TOPSIS based multi-criteria whole-building energy benchmarking is developed. • A selective objective-weighting procedure is used for a cost-accuracy tradeoff. • Results from a real case validated the benefits of the presented approach. - Abstract: This paper develops a robust multi-criteria Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) based building energy efficiency benchmarking approach. The approach is explicitly selective to address multicollinearity trap due to the subjectivity in selecting energy variables by considering cost-accuracy trade-off. It objectively weights the relative importance of individual pertinent efficiency measuring criteria using either multiple linear regression or principal component analysis contingent on meta data quality. Through this approach, building energy performance is comprehensively evaluated and optimized. Simultaneously, the significant challenges associated with conventional single-criterion benchmarking models can be avoided. Together with a clustering algorithm on a three-year panel dataset, the benchmarking case of 324 single-family dwellings demonstrated an improved robustness of the presented multi-criteria benchmarking approach over the conventional single-criterion ones

  18. Influence of solution deposition rate on properties of V{sub 2}O{sub 5} thin films deposited by spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Abd–Alghafour, N. M., E-mail: na2013bil@gmail.com [Iraqi Ministry of Education, Anbar (Iraq); Ahmed, Naser M.; Hassan, Zai; Mohammad, Sabah M. [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, University Sains Malaysia,11800 Penang (Malaysia)

    2016-07-19

    Vanadium oxide (V{sub 2}O{sub 5}) thin films were deposited on glass substrates by using a cost-efficient spray pyrolysis technique. The films were grown at 350° through thermal decomposition of VCl{sub 3} in deionized water with different solution spray rates. The high resolution X-ray diffraction results revealed the formation of nanocrystalline films having orthorhombic structures with preferential orientation along (101) direction. The spray rate influenced the surface morphology and crystallite size of the films. The crystallite size was found to increase whereas the micro-strain was decreased by increasing the spray deposition rates. The increase in crystallite size and decrease in the macrostrain resulted in an improvement in the films’ crystallinity. The UV-Visible spectroscopy analysis indicated that the average transmittance of all films lies in the range 75-80 %. The band gap of V{sub 2}O{sub 5} film was decreased from 2.65 to 2.46 eV with increase of the spray deposition rate from 5 ml/min to 10 ml/min. first, second, and third level headings (first level heading).

  19. Optimal platform design using non-dominated sorting genetic algorithm II and technique for order of preference by similarity to ideal solution; application to automotive suspension system

    Science.gov (United States)

    Shojaeefard, Mohammad Hassan; Khalkhali, Abolfazl; Faghihian, Hamed; Dahmardeh, Masoud

    2018-03-01

    Unlike conventional approaches where optimization is performed on a unique component of a specific product, optimum design of a set of components for employing in a product family can cause significant reduction in costs. Increasing commonality and performance of the product platform simultaneously is a multi-objective optimization problem (MOP). Several optimization methods are reported to solve these MOPs. However, what is less discussed is how to find the trade-off points among the obtained non-dominated optimum points. This article investigates the optimal design of a product family using non-dominated sorting genetic algorithm II (NSGA-II) and proposes the employment of technique for order of preference by similarity to ideal solution (TOPSIS) method to find the trade-off points among the obtained non-dominated results while compromising all objective functions together. A case study for a family of suspension systems is presented, considering performance and commonality. The results indicate the effectiveness of the proposed method to obtain the trade-off points with the best possible performance while maximizing the common parts.

  20. 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.