WorldWideScience

Sample records for large volume fractions

  1. Non-equilibrium Inertial Separation Array for High-throughput, Large-volume Blood Fractionation.

    Science.gov (United States)

    Mutlu, Baris R; Smith, Kyle C; Edd, Jon F; Nadar, Priyanka; Dlamini, Mcolisi; Kapur, Ravi; Toner, Mehmet

    2017-08-30

    Microfluidic blood processing is used in a range of applications from cancer therapeutics to infectious disease diagnostics. As these applications are being translated to clinical use, processing larger volumes of blood in shorter timescales with high-reliability and robustness is becoming a pressing need. In this work, we report a scaled, label-free cell separation mechanism called non-equilibrium inertial separation array (NISA). The NISA mechanism consists of an array of islands that exert a passive inertial lift force on proximate cells, thus enabling gentler manipulation of the cells without the need of physical contact. As the cells follow their size-based, deterministic path to their equilibrium positions, a preset fraction of the flow is siphoned to separate the smaller cells from the main flow. The NISA device was used to fractionate 400 mL of whole blood in less than 3 hours, and produce an ultrapure buffy coat (96.6% white blood cell yield, 0.0059% red blood cell carryover) by processing whole blood at 3 mL/min, or ∼300 million cells/second. This device presents a feasible alternative for fractionating blood for transfusion, cellular therapy and blood-based diagnostics, and could significantly improve the sensitivity of rare cell isolation devices by increasing the processed whole blood volume.

  2. Immunoglobulin G levels during collection of large volume plasma for fractionation.

    Science.gov (United States)

    Burkhardt, Thomas; Rothe, Remo; Moog, Rainer

    2017-06-01

    There is a need of comprehensive work dealing with the quality of plasma for fractionation with respect to the IgG content as today most plasma derivates are used to treat patients with immunodeficiencies and autoimmune disorders. Therefore, a prospective study was carried out to analyse IgG levels before plasmapheresis and every 200ml collected plasma. Fifty-four experienced plasmapheresis donors were recruited for subsequent 850ml plasmapheresis using the Aurora Plasmapheresis System. Donorś peripheral blood counts were analysed before and after plasmapheresis using an electronic counter. Total protein, IgG and citrate were measured turbidometrically before, during and after apheresis as well as in the plasma product. Furthermore, platelets, red and white blood cells were analysed as parameters of product quality. An average of 2751±247ml blood was processed in 47±6min. The collected plasma volume was 850±1mL and citrate consumption was 177±15mL. A continuous drop of donors' IgG level was observed during plasmapheresis. The drop was 13% of the IgG baseline value at 800mL collected plasma. Total protein, IgG and cell counts of the plasma product met current guidelines of plasma for fractionation. Donors' IgG levels during apheresis showed a steady decrease without compromising the quality of plasma product. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Determination of average fission fraction produced by 14 MeV neutrons in assemblies with large volume of depleted uranium

    International Nuclear Information System (INIS)

    Wang Dalun; Li Benci; Wang Xiuchun; Li Yijun; Zhang Shaohua; He Yongwu

    1991-07-01

    The average fission fraction of 238 U caused by 14 MeV neutrons in assemblies with large volume depleted uranium has been determined. The measured value of p f 238U (R ∞ depleted ) 14 was 0.897 ± 0.036. Measurements were also completed for neutron flux distribution and average fission fraction of 235 U isotope in depleted uranium sphere. Values of p f 238U (R depleted ) have been obtained by using a series of uranium spheres. For a sphere with Φ 600 the p f 23 '8 U (R 300 depleted ) is 0.823 ± 0.041, the density of depleted uranium assembly is 18.8g/cm 3 and total weight of assembly is about 2.8t

  4. SU-E-T-480: Radiobiological Dose Comparison of Single Fraction SRS, Multi-Fraction SRT and Multi-Stage SRS of Large Target Volumes Using the Linear-Quadratic Formula

    International Nuclear Information System (INIS)

    Ding, C; Hrycushko, B; Jiang, S; Meyer, J; Timmerman, R

    2014-01-01

    Purpose: To compare the radiobiological effect on large tumors and surrounding normal tissues from single fraction SRS, multi-fractionated SRT, and multi-staged SRS treatment. Methods: An anthropomorphic head phantom with a centrally located large volume target (18.2 cm 3 ) was scanned using a 16 slice large bore CT simulator. Scans were imported to the Multiplan treatment planning system where a total prescription dose of 20Gy was used for a single, three staged and three fractionated treatment. Cyber Knife treatment plans were inversely optimized for the target volume to achieve at least 95% coverage of the prescription dose. For the multistage plan, the target was segmented into three subtargets having similar volume and shape. Staged plans for individual subtargets were generated based on a planning technique where the beam MUs of the original plan on the total target volume are changed by weighting the MUs based on projected beam lengths within each subtarget. Dose matrices for each plan were export in DICOM format and used to calculate equivalent dose distributions in 2Gy fractions using an alpha beta ratio of 10 for the target and 3 for normal tissue. Results: Singe fraction SRS, multi-stage plan and multi-fractionated SRT plans had an average 2Gy dose equivalent to the target of 62.89Gy, 37.91Gy and 33.68Gy, respectively. The normal tissue within 12Gy physical dose region had an average 2Gy dose equivalent of 29.55Gy, 16.08Gy and 13.93Gy, respectively. Conclusion: The single fraction SRS plan had the largest predicted biological effect for the target and the surrounding normal tissue. The multi-stage treatment provided for a more potent biologically effect on target compared to the multi-fraction SRT treatments with less biological normal tissue than single-fraction SRS treatment

  5. Large volume TENAX {sup registered} extraction of the bioaccessible fraction of sediment-associated organic compounds for a subsequent effect-directed analysis

    Energy Technology Data Exchange (ETDEWEB)

    Schwab, K.; Brack, W. [UFZ - Helmholtz Centre or Environmental Research, Leipzig (Germany). Dept. of Effect-Directed Analysis

    2007-06-15

    Background, Aim and Scope: Effect-directed analysis (EDA) is a powerful tool for the identification of key toxicants in complex environmental samples. In most cases, EDA is based on total extraction of organic contaminants leading to an erroneous prioritization with regard to hazard and risk. Bioaccessibility-directed extraction aims to discriminate between contaminants that take part in partitioning between sediment and biota in a relevant time frame and those that are enclosed in structures, that do not allow rapid desorption. Standard protocols of targeted extraction of rapidly desorbing, and thus bioaccessible fraction using TENAX {sup registered} are based only on small amounts of sediment. In order to get sufficient amounts of extracts for subsequent biotesting, fractionation, and structure elucidation a large volume extraction technique needs to be developed applying one selected extraction time and excluding toxic procedural blanks. Materials and Methods: Desorption behaviour of sediment contaminants was determined by a consecutive solid-solid extraction of sediment using TENAX {sup registered} fitting a tri-compartment model on experimental data. Time needed to remove the rapidly desorbing fraction trap was calculated to select a fixed extraction time for single extraction procedures. Up-scaling by about a factor of 100 provided a large volume extraction technique for EDA. Reproducibility and comparability to small volume approach were proved. Blanks of respective TENAX {sup registered} mass were investigated using Scenedesmus vacuolatus and Artemia salina as test organisms. Results: Desorption kinetics showed that 12 to 30 % of sediment associated pollutants are available for rapid desorption. t{sub r}ap is compound dependent and covers a range of 2 to 18 h. On that basis a fixed extraction time of 24 h was selected. Validation of large volume approach was done by the means of comparison to small method and reproducibility. The large volume showed a good

  6. Dose fractionated gamma knife radiosurgery for large arteriovenous malformations on daily or alternate day schedule outside the linear quadratic model: Proof of concept and early results. A substitute to volume fractionation.

    Science.gov (United States)

    Mukherjee, Kanchan Kumar; Kumar, Narendra; Tripathi, Manjul; Oinam, Arun S; Ahuja, Chirag K; Dhandapani, Sivashanmugam; Kapoor, Rakesh; Ghoshal, Sushmita; Kaur, Rupinder; Bhatt, Sandeep

    2017-01-01

    To evaluate the feasibility, safety and efficacy of dose fractionated gamma knife radiosurgery (DFGKRS) on a daily schedule beyond the linear quadratic (LQ) model, for large volume arteriovenous malformations (AVMs). Between 2012-16, 14 patients of large AVMs (median volume 26.5 cc) unsuitable for surgery or embolization were treated in 2-3 of DFGKRS sessions. The Leksell G frame was kept in situ during the whole procedure. 86% (n = 12) patients had radiologic evidence of bleed, and 43% (n = 6) had presented with a history of seizures. 57% (n = 8) patients received a daily treatment for 3 days and 43% (n = 6) were on an alternate day (2 fractions) regimen. The marginal dose was split into 2 or 3 fractions of the ideal prescription dose of a single fraction of 23-25 Gy. The median follow up period was 35.6 months (8-57 months). In the three-fraction scheme, the marginal dose ranged from 8.9-11.5 Gy, while in the two-fraction scheme, the marginal dose ranged from 11.3-15 Gy at 50% per fraction. Headache (43%, n = 6) was the most common early postoperative complication, which was controlled with short course steroids. Follow up evaluation of at least three years was achieved in seven patients, who have shown complete nidus obliteration in 43% patients while the obliteration has been in the range of 50-99% in rest of the patients. Overall, there was a 67.8% reduction in the AVM volume at 3 years. Nidus obliteration at 3 years showed a significant rank order correlation with the cumulative prescription dose (p 0.95, P value 0.01), with attainment of near-total (more than 95%) obliteration rates beyond 29 Gy of the cumulative prescription dose. No patient receiving a cumulative prescription dose of less than 31 Gy had any severe adverse reaction. In co-variate adjusted ordinal regression, only the cumulative prescription dose had a significant correlation with common terminology criteria for adverse events (CTCAE) severity (P value 0.04), independent of age, AVM volume

  7. Spatiotemporal Fractionation Schemes for Irradiating Large Cerebral Arteriovenous Malformations

    Energy Technology Data Exchange (ETDEWEB)

    Unkelbach, Jan, E-mail: junkelbach@mgh.harvard.edu [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Bussière, Marc R. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Chapman, Paul H. [Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts (United States); Loeffler, Jay S.; Shih, Helen A. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2016-07-01

    Purpose: To optimally exploit fractionation effects in the context of radiosurgery treatments of large cerebral arteriovenous malformations (AVMs). In current practice, fractionated treatments divide the dose evenly into several fractions, which generally leads to low obliteration rates. In this work, we investigate the potential benefit of delivering distinct dose distributions in different fractions. Methods and Materials: Five patients with large cerebral AVMs were reviewed and replanned for intensity modulated arc therapy delivered with conventional photon beams. Treatment plans allowing for different dose distributions in all fractions were obtained by performing treatment plan optimization based on the cumulative biologically effective dose delivered at the end of treatment. Results: We show that distinct treatment plans can be designed for different fractions, such that high single-fraction doses are delivered to complementary parts of the AVM. All plans create a similar dose bath in the surrounding normal brain and thereby exploit the fractionation effect. This partial hypofractionation in the AVM along with fractionation in normal brain achieves a net improvement of the therapeutic ratio. We show that a biological dose reduction of approximately 10% in the healthy brain can be achieved compared with reference treatment schedules that deliver the same dose distribution in all fractions. Conclusions: Boosting complementary parts of the target volume in different fractions may provide a therapeutic advantage in fractionated radiosurgery treatments of large cerebral AVMs. The strategy allows for a mean dose reduction in normal brain that may be valuable for a patient population with an otherwise normal life expectancy.

  8. Cerebral blood volume alterations during fractional pneumoencephalography

    International Nuclear Information System (INIS)

    Voigt, K.; Greitz, T.

    1976-01-01

    Simultaneous and continuous measurements of the cerebral blood volume (CBV), cerebrospinal fluid (CSF) and blood pressure were carried out in six patients during fractional pneumoencephalography in order to examine intracranial volumetric interactions. Three patients (Group A) showed normal encephalographic findings, and in three patients (Group B) communicating hydrocephalus with convexity block was found encephalographically. In all patients the injection of air was followed by an immediate increase of CSF pressure and blood pressure and a concomitant decrease of CBV. The initial CSF pressure was invariably re-established within 3 to 3.5 min. During this time interval the CBV of the patients of Group B decreased significantly and 30 percent more than that of Group A. Furthermore, after restoration of the original CSF pressure, CBV returned to its initial level in all patients of Group A, whereas it remained unchanged or showed a further decrease in the patients of Group B. Removal of an amount of CSF corresponding to half of the amount of injected air was followed by a significant reactive hyperemic response in two normal patients. The intracranial volumetric alterations during fractional pneumoencephalography are discussed in detail with respect to the underlying physiologic mechanisms and are suggested as a model for acute and low pressure hydrocephalus

  9. Large volume cryogenic silicon detectors

    International Nuclear Information System (INIS)

    Braggio, C.; Boscardin, M.; Bressi, G.; Carugno, G.; Corti, D.; Galeazzi, G.; Zorzi, N.

    2009-01-01

    We present preliminary measurements for the development of a large volume silicon detector to detect low energy and low rate energy depositions. The tested detector is a one cm-thick silicon PIN diode with an active volume of 31 cm 3 , cooled to the liquid helium temperature to obtain depletion from thermally-generated free carriers. A thorough study has been done to show that effects of charge trapping during drift disappears at a bias field value of the order of 100V/cm.

  10. Large volume cryogenic silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Braggio, C. [Dipartimento di Fisica, Universita di Padova, via Marzolo 8, 35131 Padova (Italy); Boscardin, M. [Fondazione Bruno Kessler (FBK), via Sommarive 18, I-38100 Povo (Italy); Bressi, G. [INFN sez. di Pavia, via Bassi 6, 27100 Pavia (Italy); Carugno, G.; Corti, D. [INFN sez. di Padova, via Marzolo 8, 35131 Padova (Italy); Galeazzi, G. [INFN lab. naz. Legnaro, viale dell' Universita 2, 35020 Legnaro (Italy); Zorzi, N. [Fondazione Bruno Kessler (FBK), via Sommarive 18, I-38100 Povo (Italy)

    2009-12-15

    We present preliminary measurements for the development of a large volume silicon detector to detect low energy and low rate energy depositions. The tested detector is a one cm-thick silicon PIN diode with an active volume of 31 cm{sup 3}, cooled to the liquid helium temperature to obtain depletion from thermally-generated free carriers. A thorough study has been done to show that effects of charge trapping during drift disappears at a bias field value of the order of 100V/cm.

  11. Bidisperse and polydisperse suspension rheology at large solid fraction

    Energy Technology Data Exchange (ETDEWEB)

    Pednekar, Sidhant [Benjamin Levich Institute and Department of Chemical Engineering, The City College of New York, New York, New York 10031; Chun, Jaehun [Pacific Northwest National Laboratory, Richland, Washington 99352; Morris, Jeffrey F. [Benjamin Levich Institute and Department of Chemical Engineering, The City College of New York, New York, New York 10031

    2018-03-01

    At the same solid volume fraction, bidisperse and polydisperse suspensions display lower viscosities, and weaker normal stress response, compared to monodisperse suspensions. The reduction of viscosity associated with size distribution can be explained by an increase of the maximum flowable, or jamming, solid fraction. In this work, concentrated or "dense" suspensions are simulated under strong shearing, where thermal motion and repulsive forces are negligible, but we allow for particle contact with a mild frictional interaction with interparticle friction coefficient of 0.2. Aspects of bidisperse suspension rheology are first revisited to establish that the approach reproduces established trends; the study of bidisperse suspensions at size ratios of large to small particle radii (2 to 4) shows that a minimum in the viscosity occurs for zeta slightly above 0.5, where zeta=phi_{large}/phi is the fraction of the total solid volume occupied by the large particles. The simple shear flows of polydisperse suspensions with truncated normal and log normal size distributions, and bidisperse suspensions which are statistically equivalent with these polydisperse cases up to third moment of the size distribution, are simulated and the rheologies are extracted. Prior work shows that such distributions with equivalent low-order moments have similar phi_{m}, and the rheological behaviors of normal, log normal and bidisperse cases are shown to be in close agreement for a wide range of standard deviation in particle size, with standard correlations which are functionally dependent on phi/phi_{m} providing excellent agreement with the rheology found in simulation. The close agreement of both viscosity and normal stress response between bi- and polydisperse suspensions demonstrates the controlling in influence of the maximum packing fraction in noncolloidal suspensions. Microstructural investigations and the stress distribution according to particle size are also presented.

  12. Accuracy of cancellous bone volume fraction measured by micro-CT scanning

    DEFF Research Database (Denmark)

    Ding, Ming; Odgaard, A; Hvid, I

    1999-01-01

    Volume fraction, the single most important parameter in describing trabecular microstructure, can easily be calculated from three-dimensional reconstructions of micro-CT images. This study sought to quantify the accuracy of this measurement. One hundred and sixty human cancellous bone specimens...... which covered a large range of volume fraction (9.8-39.8%) were produced. The specimens were micro-CT scanned, and the volume fraction based on Archimedes' principle was determined as a reference. After scanning, all micro-CT data were segmented using individual thresholds determined by the scanner...

  13. Lamb Wave Assessment of Fiber Volume Fraction in Composites

    Science.gov (United States)

    Seale, Michael D.; Smith, Barry T.; Prosser, W. H.; Zalameda, Joseph N.

    1998-01-01

    Among the various techniques available, ultrasonic Lamb waves offer a convenient method of examining composite materials. Since the Lamb wave velocity depends on the elastic properties of a material, an effective tool exists to evaluate composites by measuring the velocity of these waves. Lamb waves can propagate over long distances and are sensitive to the desired in-plane elastic properties of the material. This paper discusses a study in which Lamb waves were used to examine fiber volume fraction variations of approximately 0.40-0.70 in composites. The Lamb wave measurements were compared to fiber volume fractions obtained from acid digestion tests. Additionally, a model to predict the fiber volume fraction from Lamb wave velocity values was evaluated.

  14. Performance enhancement of direct ethanol fuel cell using Nafion composites with high volume fraction of titania

    Science.gov (United States)

    Matos, B. R.; Isidoro, R. A.; Santiago, E. I.; Fonseca, F. C.

    2014-12-01

    The present study reports on the performance enhancement of direct ethanol fuel cell (DEFC) at 130 °C with Nafion-titania composite electrolytes prepared by sol-gel technique and containing high volume fractions of the ceramic phase. It is found that for high volume fractions of titania (>10 vol%) the ethanol uptake of composites is largely reduced while the proton conductivity at high-temperatures is weakly dependent on the titania content. Such tradeoff between alcohol uptake and conductivity resulted in a boost of DEFC performance at high temperatures using Nafion-titania composites with high fraction of the inorganic phase.

  15. Local progression and pseudo progression after single fraction or fractionated stereotactic radiotherapy for large brain metastases. A single centre study

    Energy Technology Data Exchange (ETDEWEB)

    Wiggenraad, R.; Verbeek-de Kanter, A.; Mast, M. [Radiotherapy Centre West, The Hague (Netherlands); Molenaar, R. [Diaconessenhuis, Leiden (Netherlands). Dept. of Neurology; Lycklama a Nijeholt, G. [Medical Centre Haagladen, The Hague (Netherlands). Dept. of Radiology; Vecht, C. [Medical Centre Haagladen, The Hague (Netherlands). Dept. of Neurology; Struikmans, H. [Radiotherapy Centre West, The Hague (Netherlands); Leiden Univ. Medical Centre (Netherlands). Dept. of Radiotherapy; Kal, H.B.

    2012-08-15

    Purpose: The 1-year local control rates after single-fraction stereotactic radiotherapy (SRT) for brain metastases > 3 cm diameter are less than 70%, but with fractionated SRT (FSRT) higher local control rates have been reported. The purpose of this study was to compare our treatment results with SRT and FSRT for large brain metastases. Materials and methods: In two consecutive periods, 41 patients with 46 brain metastases received SRT with 1 fraction of 15 Gy, while 51 patients with 65 brain metastases received FSRT with 3 fractions of 8 Gy. We included patients with brain metastases with a planning target volume of > 13 cm{sup 3} or metastases in the brainstem. Results: The minimum follow-up of patients still alive was 22 months. Comparing 1 fraction of 15 Gy with 3 fractions of 8 Gy, the 1-year rates of freedom from any local progression (54% and 61%, p = 0.93) and pseudo progression (85% and 75%, p = 0.25) were not significantly different. Overall survival rates were also not different. Conclusion: The 1-year local progression and pseudo progression rates after 1 fraction of 15 Gy or 3 fractions of 8 Gy for large brain metastases and metastases in the brainstem are similar. For better local control rates, FSRT schemes with a higher biological equivalent dose may be necessary. (orig.)

  16. Local progression and pseudo progression after single fraction or fractionated stereotactic radiotherapy for large brain metastases. A single centre study

    International Nuclear Information System (INIS)

    Wiggenraad, R.; Verbeek-de Kanter, A.; Mast, M.; Molenaar, R.; Lycklama a Nijeholt, G.; Vecht, C.; Struikmans, H.; Leiden Univ. Medical Centre; Kal, H.B.

    2012-01-01

    Purpose: The 1-year local control rates after single-fraction stereotactic radiotherapy (SRT) for brain metastases > 3 cm diameter are less than 70%, but with fractionated SRT (FSRT) higher local control rates have been reported. The purpose of this study was to compare our treatment results with SRT and FSRT for large brain metastases. Materials and methods: In two consecutive periods, 41 patients with 46 brain metastases received SRT with 1 fraction of 15 Gy, while 51 patients with 65 brain metastases received FSRT with 3 fractions of 8 Gy. We included patients with brain metastases with a planning target volume of > 13 cm 3 or metastases in the brainstem. Results: The minimum follow-up of patients still alive was 22 months. Comparing 1 fraction of 15 Gy with 3 fractions of 8 Gy, the 1-year rates of freedom from any local progression (54% and 61%, p = 0.93) and pseudo progression (85% and 75%, p = 0.25) were not significantly different. Overall survival rates were also not different. Conclusion: The 1-year local progression and pseudo progression rates after 1 fraction of 15 Gy or 3 fractions of 8 Gy for large brain metastases and metastases in the brainstem are similar. For better local control rates, FSRT schemes with a higher biological equivalent dose may be necessary. (orig.)

  17. Effect of reinforcement volume fraction on the density & elastic ...

    African Journals Online (AJOL)

    Effect of reinforcement volume fraction on the density & elastic parameters of BMG's matrix composites. Wahiba Metiri 1, Fatiha Hadjoub1, 2 and Leila Touati Tliba 1. 1 Laboratoire des Semi-Conducteurs, Département de Physique, Faculté des Sciences, Université Badji-. Mokhtar, BP 12, Annaba -23000, Algeria.

  18. Effective moduli of high volume fraction particulate composites

    International Nuclear Information System (INIS)

    Kwon, P.; Dharan, C.K.H.

    1995-01-01

    Predictions using current micromechanics theories for the effective moduli of particulate-reinforced composites tend to break down at high volume fractions of the reinforcing phase. The predictions are usually well below experimentally measured values of the Young's modulus for volume fractions exceeding about 0.6. In this paper, the concept of contiguity, which is a measure of phase continuity, is applied to Mori-Tanaka micromechanics theory. It is shown that contiguity of the second phase increases with volume fraction, leading eventually to a reversal in the roles of the inclusion and matrix. In powder metallurgy practice, it is well known that at high volume fractions, sintering and consolidation of the reinforcement make it increasingly continuous and more like the matrix phase, while the former matrix tends to become more like the inclusion phase. The concept of contiguity applied to micromechanics theory results in very good agreement between the predicted Young's modulus and experimental data on tungsten carbide particulate-reinforced cobalt

  19. Large deflection of viscoelastic beams using fractional derivative model

    International Nuclear Information System (INIS)

    Bahranini, Seyed Masoud Sotoodeh; Eghtesad, Mohammad; Ghavanloo, Esmaeal; Farid, Mehrdad

    2013-01-01

    This paper deals with large deflection of viscoelastic beams using a fractional derivative model. For this purpose, a nonlinear finite element formulation of viscoelastic beams in conjunction with the fractional derivative constitutive equations has been developed. The four-parameter fractional derivative model has been used to describe the constitutive equations. The deflected configuration for a uniform beam with different boundary conditions and loads is presented. The effect of the order of fractional derivative on the large deflection of the cantilever viscoelastic beam, is investigated after 10, 100, and 1000 hours. The main contribution of this paper is finite element implementation for nonlinear analysis of viscoelastic fractional model using the storage of both strain and stress histories. The validity of the present analysis is confirmed by comparing the results with those found in the literature.

  20. Method and apparatus for probing relative volume fractions

    Science.gov (United States)

    Jandrasits, Walter G.; Kikta, Thomas J.

    1998-01-01

    A relative volume fraction probe particularly for use in a multiphase fluid system includes two parallel conductive paths defining therebetween a sample zone within the system. A generating unit generates time varying electrical signals which are inserted into one of the two parallel conductive paths. A time domain reflectometer receives the time varying electrical signals returned by the second of the two parallel conductive paths and, responsive thereto, outputs a curve of impedance versus distance. An analysis unit then calculates the area under the curve, subtracts the calculated area from an area produced when the sample zone consists entirely of material of a first fluid phase, and divides this calculated difference by the difference between an area produced when the sample zone consists entirely of material of the first fluid phase and an area produced when the sample zone consists entirely of material of a second fluid phase. The result is the volume fraction.

  1. Laser-induced incandescence: Towards quantitative soot volume fraction measurements

    Energy Technology Data Exchange (ETDEWEB)

    Tzannis, A P; Wienbeucker, F; Beaud, P; Frey, H -M; Gerber, T; Mischler, B; Radi, P P [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Laser-Induced Incandescence has recently emerged as a versatile tool for measuring soot volume fraction in a wide range of combustion systems. In this work we investigate the essential features of the method. LII is based on the acquisition of the incandescence of soot when heated through a high power laser pulse. Initial experiments have been performed on a model laboratory flame. The behaviour of the LII signal is studied experimentally. By applying numerical calculations we investigate the possibility to obtain two-dimensional soot volume fraction distributions. For this purpose a combination of LII with other techniques is required. This part is discussed in some extent and the future work is outlined. (author) 4 figs., 3 refs.

  2. Gamma ray densitometry techniques for measuring of volume fractions

    Energy Technology Data Exchange (ETDEWEB)

    Affonso, Renato Raoni Werneck; Silva, Ademir Xavier da; Salgado, Cesar Marques, E-mail: raoniwa@yahoo.com.br, E-mail: ademir@nuclear.ufrj.br, E-mail: otero@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    Knowledge of the volume fraction in a multiphase flow is of key importance in predicting the performance of many systems and processes. It is therefore an important parameter to characterize such flows. In the context of nuclear techniques, the gamma ray densitometry is promising and this is due to its non-invasive characteristics and very reliable results. It is used in several applications for multiphase flows (water-oil-air), which are employed tools such as: computational fluid dynamics, artificial neural networks and statistical methods of radiation transport, such as the Monte Carlo method. Based on the gamma radiation techniques for measurements of volume fractions, the aim of this paper is to present several techniques developed for this purpose. (author)

  3. Gamma ray densitometry techniques for measuring of volume fractions

    International Nuclear Information System (INIS)

    Affonso, Renato Raoni Werneck; Silva, Ademir Xavier da; Salgado, Cesar Marques

    2015-01-01

    Knowledge of the volume fraction in a multiphase flow is of key importance in predicting the performance of many systems and processes. It is therefore an important parameter to characterize such flows. In the context of nuclear techniques, the gamma ray densitometry is promising and this is due to its non-invasive characteristics and very reliable results. It is used in several applications for multiphase flows (water-oil-air), which are employed tools such as: computational fluid dynamics, artificial neural networks and statistical methods of radiation transport, such as the Monte Carlo method. Based on the gamma radiation techniques for measurements of volume fractions, the aim of this paper is to present several techniques developed for this purpose. (author)

  4. Absorbed fractions for alpha particles in ellipsoidal volumes

    International Nuclear Information System (INIS)

    Amato, Ernesto; Baldari, Sergio; Italiano, Antonio

    2013-01-01

    Internal dosimetry of alpha particles is gaining attention due to the increasing applications in cancer treatment and also for the assessment of environmental contamination from radionuclides. We developed a Monte Carlo simulation in GEANT4 in order to calculate the absorbed fractions for monoenergetic alpha particles in the energy interval between 0.1 and 10 MeV, uniformly distributed in ellipsoids made of soft tissue. For each volume, we simulated a spherical shape, three oblate and three prolate ellipsoids, and one scalene shape. For each energy and for every geometrical configuration, an analytical relationship between the absorbed fraction and a ‘generalized radius’ was found; and the dependence of the fit parameters on the alpha energy is discussed and fitted by parametric functions. With the proposed formulation, the absorbed fraction for alpha particles in the energy range explored can be calculated for volumes and for ellipsoidal shapes of practical interest. This method can be applied to the evaluation of absorbed fraction from alpha-emitting radionuclides. The contribution to the deposited energy coming from electron and photon emissions can be accounted for exploiting the specific formulations previously introduced. As an example of application, the dosimetry of 213 Bi and its decay chain in ellipsoids is reported. (paper)

  5. Calculation of Steam Volume Fraction in Subcooled Boiling

    Energy Technology Data Exchange (ETDEWEB)

    Rouhani, S Z

    1967-06-15

    An analysis of subcooled boiling is presented. It is assumed that heat is removed by vapor generation, heating of the liquid that replaces the detached bubbles, and to some extent by single phase heat transfer. Two regions of subcooled boiling are considered and a criterion is provided for obtaining the limiting value of subcooling between the two regions. Condensation of vapor in the subcooled liquid is analysed and the relative velocity of vapor with respect to the liquid is neglected in these regions. The theoretical arguments result in some equations for the calculation of steam volume fraction and true liquid subcooling.

  6. Large volume axionic Swiss cheese inflation

    Science.gov (United States)

    Misra, Aalok; Shukla, Pramod

    2008-09-01

    Continuing with the ideas of (Section 4 of) [A. Misra, P. Shukla, Moduli stabilization, large-volume dS minimum without anti-D3-branes, (non-)supersymmetric black hole attractors and two-parameter Swiss cheese Calabi Yau's, arXiv: 0707.0105 [hep-th], Nucl. Phys. B, in press], after inclusion of perturbative and non-perturbative α corrections to the Kähler potential and (D1- and D3-) instanton generated superpotential, we show the possibility of slow roll axionic inflation in the large volume limit of Swiss cheese Calabi Yau orientifold compactifications of type IIB string theory. We also include one- and two-loop corrections to the Kähler potential but find the same to be subdominant to the (perturbative and non-perturbative) α corrections. The NS NS axions provide a flat direction for slow roll inflation to proceed from a saddle point to the nearest dS minimum.

  7. Large volume axionic Swiss cheese inflation

    International Nuclear Information System (INIS)

    Misra, Aalok; Shukla, Pramod

    2008-01-01

    Continuing with the ideas of (Section 4 of) [A. Misra, P. Shukla, Moduli stabilization, large-volume dS minimum without anti-D3-branes, (non-)supersymmetric black hole attractors and two-parameter Swiss cheese Calabi-Yau's, (arXiv: 0707.0105 [hep-th]), Nucl. Phys. B, in press], after inclusion of perturbative and non-perturbative α ' corrections to the Kaehler potential and (D1- and D3-) instanton generated superpotential, we show the possibility of slow roll axionic inflation in the large volume limit of Swiss cheese Calabi-Yau orientifold compactifications of type IIB string theory. We also include one- and two-loop corrections to the Kaehler potential but find the same to be subdominant to the (perturbative and non-perturbative) α ' corrections. The NS-NS axions provide a flat direction for slow roll inflation to proceed from a saddle point to the nearest dS minimum

  8. Influence of bress laminate volume fraction on electromechanical properties of externally laminated coated conductor tapes

    Energy Technology Data Exchange (ETDEWEB)

    Bautista, Zhierwinjay M.; Shin, Hyung Seop [Dept. of Mechanical Design Engineering, Andong National University, Andong (Korea, Republic of); Lee, Jae Hun; Lee, Hun Ju; Moon, Seung Hyun [SuNAM Co Ltd., Anseong (Korea, Republic of)

    2016-09-15

    The enhancement of mechanical properties of coated conductor (CC) tapes in practical application are usually achieved by reinforcing through lamination or electroplating metal layers on either sides of the CC tape. Mechanical or electromechanical properties of the CC tapes have been largely affected by the lamination structure under various loading modes such as tension, bending or even cyclic. In this study, the influence of brass laminate volume fraction on electromechanical properties of RCE-DR processed Gadolinium-barium-copper-oxide (GdBCO) CC tapes was investigated. The samples used were composed of single-side and both-side laminate of brass layer to the Cu-stabilized CC tape and their Ic behaviors were compared to those of the Cu-stabilized CC tape without external lamination. The stress/strain dependences of Ic in laminated CC tapes under uniaxial tension were analyzed and the irreversible stress/strain limits were determined. As a result, the increase of brass laminate volume fraction initially increased the irreversible strain limit and became gradual. The corresponding irreversible stress limit, however, showed no difference even though the brass laminate volume fraction increased to 3.4. But the irreversible load limit linearly increased with the brass laminate volume fraction.

  9. Study of volume fractions on biphasic stratified regime using gamma ray

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, William L.; Brandão, Luis E.B., E-mail: william.otero@hotmail.com, E-mail: brandao@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    In the oil industries, interconnected pipelines are used to carry large quantities of petroleum and its byproducts. This modal has an advantage because they are more economical, eliminate a need for stocks and, in addition, great safety in operation minimizing a possibility of loss or theft when transported another way. In many cases, especially in the petrochemical industry, the same pipeline is used to carry more than one type of product. They are called poliduct. In the operation of a poliduct there is a sequence of products to be transported and during the exchange of the product, there are still fractions of the previous product and this generates contamination. It is therefore important to identify precisely this region in order to reduce the costs of reprocessing and treatment of discarded products. In this way, this work presents a methodology to evaluate the sensitivity of the gamma densitometry technique in a study of the calculation of volume fractions in biphasic systems, submitted to the stratified flow regime. Using computational simulations using the Monte Carlo Method with the MCNPX code measurement geometry was proposed that presented a higher sensitivity for the calculation of volume fractions. The relevant technical data to perform a simulation of the scintillator detectors were based on information obtained from the gammagraphy technique. The study had a theoretical validation through analytical equations, and the results show that it is possible to identify volume fractions equivalent to 3%. (author)

  10. Study of volume fractions on biphasic stratified regime using gamma ray

    International Nuclear Information System (INIS)

    Salgado, William L.; Brandão, Luis E.B.

    2017-01-01

    In the oil industries, interconnected pipelines are used to carry large quantities of petroleum and its byproducts. This modal has an advantage because they are more economical, eliminate a need for stocks and, in addition, great safety in operation minimizing a possibility of loss or theft when transported another way. In many cases, especially in the petrochemical industry, the same pipeline is used to carry more than one type of product. They are called poliduct. In the operation of a poliduct there is a sequence of products to be transported and during the exchange of the product, there are still fractions of the previous product and this generates contamination. It is therefore important to identify precisely this region in order to reduce the costs of reprocessing and treatment of discarded products. In this way, this work presents a methodology to evaluate the sensitivity of the gamma densitometry technique in a study of the calculation of volume fractions in biphasic systems, submitted to the stratified flow regime. Using computational simulations using the Monte Carlo Method with the MCNPX code measurement geometry was proposed that presented a higher sensitivity for the calculation of volume fractions. The relevant technical data to perform a simulation of the scintillator detectors were based on information obtained from the gammagraphy technique. The study had a theoretical validation through analytical equations, and the results show that it is possible to identify volume fractions equivalent to 3%. (author)

  11. Microstrain evolution during creep of a high volume fraction superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Ma, S. [Materials Department, New Mexico Tech, Socorro, NM 87801 (United States); Brown, D. [Los Alamos National Laboratory, Los Alamos, NM (United States); Bourke, M.A.M. [Los Alamos National Laboratory, Los Alamos, NM (United States); Daymond, M.R. [Rutherford Appleton Laboratory, ISIS Facility, Chilton, Didcot, Oxon OX11 0QX (United Kingdom); Majumdar, B.S. [Materials Department, New Mexico Tech, Socorro, NM 87801 (United States)]. E-mail: majumdar@nmt.edu

    2005-06-15

    The creep of superalloys containing a high volume fraction of {gamma}' phase is significantly influenced by initial misfit and by the evolution of internal stresses. An in situ neutron diffraction technique was used to monitor elastic microstrains in a polycrystalline superalloy, CM247 LC. The misfit was nearly zero at room temperature and it increased to -0.17% at 900 deg. C. These values are rationalized in terms of thermal mismatch using an eigenstrain formulation and a simple formula is derived to relate the thermal mismatch to the misfit strain. During creep at 425 MPa at 900 deg. C, the material exhibited primarily tertiary behavior. For grains with [0 0 1] axis close to the loading direction, the elastic microstrain in the loading direction increased with creep time for the {gamma}' phase, whereas the opposite occurred for the {gamma} phase. These results are explained in terms of constrained deformation in the narrow {gamma} channels and by an interface dislocation buildup. TEM analysis of the crept microstructure provides evidence of the interface dislocation network.

  12. Modeling the Effect of Glass Microballoon (GMB) Volume Fraction on Behavior of Sylgard/GMB Composites.

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Judith Alice [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Long, Kevin Nicholas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-05-01

    This work was done to support customer questions about whether a Sylgard/Glass Microballoon (GMB) potting material in current use could be replaced with pure Sylgard and if this would significantly change stresses imparted to internal components under thermal cycling conditions. To address these questions, we provide micromechanics analysis of Sylgard/GMB materials using both analytic composite theory and finite element simulations to better understand the role of the GMB volume fraction in determining thermal expansion coefficient, elastic constants, and behavior in both confined and unconfined compression boundary value problems. A key finding is that damage accumulation in the material from breakage of GMBs significantly limits the global stress magnitude and results in a plateau stress behavior over large ranges of compressive strain. The magnitude of this plateau stress is reduced with higher volume fractions of GMBs. This effect is particularly pronounced in confined compression, which we estimate bears the most similarity to the application of interest. This stress-limiting damage mechanism is not present in pure Sylgard, however, and the result is much higher stresses under confined compression. Thus, we recommend that some volume fraction greater than 10% GMBs be used for confined deformation applications.

  13. The parallel volume at large distances

    DEFF Research Database (Denmark)

    Kampf, Jürgen

    In this paper we examine the asymptotic behavior of the parallel volume of planar non-convex bodies as the distance tends to infinity. We show that the difference between the parallel volume of the convex hull of a body and the parallel volume of the body itself tends to . This yields a new proof...... for the fact that a planar body can only have polynomial parallel volume, if it is convex. Extensions to Minkowski spaces and random sets are also discussed....

  14. The parallel volume at large distances

    DEFF Research Database (Denmark)

    Kampf, Jürgen

    In this paper we examine the asymptotic behavior of the parallel volume of planar non-convex bodies as the distance tends to infinity. We show that the difference between the parallel volume of the convex hull of a body and the parallel volume of the body itself tends to 0. This yields a new proof...... for the fact that a planar body can only have polynomial parallel volume, if it is convex. Extensions to Minkowski spaces and random sets are also discussed....

  15. Extracting and analyzing ejection fraction values from electronic echocardiography reports in a large health maintenance organization.

    Science.gov (United States)

    Xie, Fagen; Zheng, Chengyi; Yuh-Jer Shen, Albert; Chen, Wansu

    2017-12-01

    The left ventricular ejection fraction value is an important prognostic indicator of cardiovascular outcomes including morbidity and mortality and is often used clinically to indicate severity of heart disease. However, it is usually reported in free-text echocardiography reports. We developed and validated a computerized algorithm to extract ejection fraction values from echocardiography reports and applied the algorithm to a large volume of unstructured echocardiography reports between 1995 and 2011 in a large health maintenance organization. A total of 621,856 echocardiography reports with a description of ejection fraction values or systolic functions were identified, of which 70 percent contained numeric ejection fraction values and the rest (30%) were text descriptions explicitly indicating the systolic left ventricular function. The 12.1 percent (16.0% for male and 8.4% for female) of these extracted ejection fraction values are <45 percent. Validation conducted based on a random sample of 200 reports yielded 95.0 percent sensitivity and 96.9 percent positive predictive value.

  16. Large volumes and spectroscopy of walking theories

    CERN Document Server

    Del Debbio, L; Patella, A; Pica, C; Rago, A

    2016-01-01

    A detailed investigation of finite size effects is performed for SU(2) gauge theory with two fermions in the adjoint representation, which previous lattice studies have shown to be inside the conformal window. The system is investigated with different spatial and temporal boundary conditions on lattices of various spatial and temporal extensions, for two values of the bare fermion mass representing a {\\em heavy} and {\\em light} fermion regime. Our study shows that the infinite volume limit of masses and decay constants in the mesonic sector is reached only when the mass of the pseudoscalar particle $M_\\mathrm{PS}$ and the spatial lattice size $L$ satisfy the relation $L M_\\mathrm{PS} \\ge 15$. This bound, which is at least a factor of three higher than what observed in QCD, is a likely consequence of the different spectral signatures of the two theories, with the scalar isosinglet ($0^{++}$ glueball) being the lightest particle in our model. In addition to stressing the importance of simulating large lattice s...

  17. Airborne release fractions/rates and respirable fractions for nonreactor nuclear facilities. Volume 2, Appendices

    International Nuclear Information System (INIS)

    1994-12-01

    This document contains compiled data from the DOE Handbook on Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear facilities. Source data and example facilities utilized, such as the Plutonium Recovery Facility, are included

  18. Adsorption of transuranic elements from large volume sea water

    International Nuclear Information System (INIS)

    Holm, E.; Ballestra, S.

    1976-01-01

    Some years ago a sampler for concentrating radionuclides from large volumes of sea water was developed by Silker et al. of the Battelle Northwest Laboratories. They used pure A1 2 O 3 as the adsorbent. The device has been applied successfully to the determination of 238 Pu and 239 Pu in several sea water samples. Our experience on the application of an identical system for the determination of transuranics in Mediterranean sea water was not quite as satisfactory as we had hoped. The chemistry involved in leaching up to 1 kg Al 2 O 3 . with acid, followed by removal of dissolved aluminium from the transuranic fraction, is rather tedious and time-consuming for routine use. The adsorption efficiency of transuranics, checked by dual-bed adsorption did not give consistent results. However, since the principle of the device is attractive enough for handling large volume water samples, it was felt that it was worthwhile to test other types of adsorbents which are easier to handle than Al 2 O 3 . For this purpose, chitosan and manganese dioxide were chosen and series of experiments were conducted in order to examine the suitability of these materials as an adsorbent in the system

  19. Real-time particle volume fraction measurement in centrifuges by wireless electrical resistance detector

    International Nuclear Information System (INIS)

    Nagae, Fumiya; Okawa, Kazuya; Matsuno, Shinsuke; Takei, Masahiro; Zhao Tong; Ichijo, Noriaki

    2015-01-01

    In this study, wireless electrical resistance detector is developed as first step in order to develop electrical resistance tomography (ERT) that are attached wireless communication, and miniaturized. And the particle volume fraction measurement results appropriateness is qualitatively examined. The real-time particle volume fraction measurement is essential for centrifuges, because rotational velocity and supply should be controlled based on the results in order to obtain the effective separation, shorten process time and save energy. However, a technique for the particle volume fraction measurement in centrifuges has not existed yet. In other words, the real-time particle volume fraction measurement in centrifuges becomes innovative technologies. The experiment device reproduces centrifugation in two-phase using particle and salt solution as measuring object. The particle concentration is measured changing rotational velocity, supply and measurement section position. The measured concentration changes coincide with anticipated tendency of concentration changes. Therefore the particle volume fraction measurement results appropriateness are qualitatively indicated. (author)

  20. SU-E-T-429: Uncertainties of Cell Surviving Fractions Derived From Tumor-Volume Variation Curves

    International Nuclear Information System (INIS)

    Chvetsov, A

    2014-01-01

    Purpose: To evaluate uncertainties of cell surviving fraction reconstructed from tumor-volume variation curves during radiation therapy using sensitivity analysis based on linear perturbation theory. Methods: The time dependent tumor-volume functions V(t) have been calculated using a twolevel cell population model which is based on the separation of entire tumor cell population in two subpopulations: oxygenated viable and lethally damaged cells. The sensitivity function is defined as S(t)=[δV(t)/V(t)]/[δx/x] where δV(t)/V(t) is the time dependent relative variation of the volume V(t) and δx/x is the relative variation of the radiobiological parameter x. The sensitivity analysis was performed using direct perturbation method where the radiobiological parameter x was changed by a certain error and the tumor-volume was recalculated to evaluate the corresponding tumor-volume variation. Tumor volume variation curves and sensitivity functions have been computed for different values of cell surviving fractions from the practically important interval S 2 =0.1-0.7 using the two-level cell population model. Results: The sensitivity functions of tumor-volume to cell surviving fractions achieved a relatively large value of 2.7 for S 2 =0.7 and then approached zero as S 2 is approaching zero Assuming a systematic error of 3-4% we obtain that the relative error in S 2 is less that 20% in the range S2=0.4-0.7. This Resultis important because the large values of S 2 are associated with poor treatment outcome should be measured with relatively small uncertainties. For the very small values of S2<0.3, the relative error can be larger than 20%; however, the absolute error does not increase significantly. Conclusion: Tumor-volume curves measured during radiotherapy can be used for evaluation of cell surviving fractions usually observed in radiation therapy with conventional fractionation

  1. Volume independence in large Nc QCD-like gauge theories

    International Nuclear Information System (INIS)

    Kovtun, Pavel; Uensal, Mithat; Yaffe, Laurence G.

    2007-01-01

    Volume independence in large N c gauge theories may be viewed as a generalized orbifold equivalence. The reduction to zero volume (or Eguchi-Kawai reduction) is a special case of this equivalence. So is temperature independence in confining phases. A natural generalization concerns volume independence in 'theory space' of quiver gauge theories. In pure Yang-Mills theory, the failure of volume independence for sufficiently small volumes (at weak coupling) due to spontaneous breaking of center symmetry, together with its validity above a critical size, nicely illustrate the symmetry realization conditions which are both necessary and sufficient for large N c orbifold equivalence. The existence of a minimal size below which volume independence fails also applies to Yang-Mills theory with antisymmetric representation fermions [QCD(AS)]. However, in Yang-Mills theory with adjoint representation fermions [QCD(Adj)], endowed with periodic boundary conditions, volume independence remains valid down to arbitrarily small size. In sufficiently large volumes, QCD(Adj) and QCD(AS) have a large N c ''orientifold'' equivalence, provided charge conjugation symmetry is unbroken in the latter theory. Therefore, via a combined orbifold-orientifold mapping, a well-defined large N c equivalence exists between QCD(AS) in large, or infinite, volume and QCD(Adj) in arbitrarily small volume. Since asymptotically free gauge theories, such as QCD(Adj), are much easier to study (analytically or numerically) in small volume, this equivalence should allow greater understanding of large N c QCD in infinite volume

  2. Large sulfur isotope fractionations in Martian sediments at Gale crater

    Science.gov (United States)

    Franz, H. B.; McAdam, A. C.; Ming, D. W.; Freissinet, C.; Mahaffy, P. R.; Eldridge, D. L.; Fischer, W. W.; Grotzinger, J. P.; House, C. H.; Hurowitz, J. A.; McLennan, S. M.; Schwenzer, S. P.; Vaniman, D. T.; Archer, P. D., Jr.; Atreya, S. K.; Conrad, P. G.; Dottin, J. W., III; Eigenbrode, J. L.; Farley, K. A.; Glavin, D. P.; Johnson, S. S.; Knudson, C. A.; Morris, R. V.; Navarro-González, R.; Pavlov, A. A.; Plummer, R.; Rampe, E. B.; Stern, J. C.; Steele, A.; Summons, R. E.; Sutter, B.

    2017-09-01

    Variability in the sulfur isotopic composition in sediments can reflect atmospheric, geologic and biological processes. Evidence for ancient fluvio-lacustrine environments at Gale crater on Mars and a lack of efficient crustal recycling mechanisms on the planet suggests a surface environment that was once warm enough to allow the presence of liquid water, at least for discrete periods of time, and implies a greenhouse effect that may have been influenced by sulfur-bearing volcanic gases. Here we report in situ analyses of the sulfur isotopic compositions of SO2 volatilized from ten sediment samples acquired by NASA’s Curiosity rover along a 13 km traverse of Gale crater. We find large variations in sulfur isotopic composition that exceed those measured for Martian meteorites and show both depletion and enrichment in 34S. Measured values of δ34S range from -47 +/- 14‰ to 28 +/- 7‰, similar to the range typical of terrestrial environments. Although limited geochronological constraints on the stratigraphy traversed by Curiosity are available, we propose that the observed sulfur isotopic signatures at Gale crater can be explained by equilibrium fractionation between sulfate and sulfide in an impact-driven hydrothermal system and atmospheric processing of sulfur-bearing gases during transient warm periods.

  3. Nondestructive Determination of Reinforcement Volume Fractions in Particulate Composites : Ultrasonic Method

    International Nuclear Information System (INIS)

    Jeong, Hyun Jo

    1998-01-01

    A nondestructive ultrasonic technique is presented for estimating the reinforcement volume fractions of particulate composites. The proposed technique employs a theoretical model which accounts for composite microstructures, together with a measurement of ultrasonic velocity to determine the reinforcement volume fractions. The approach is used for a wide range of SiC particulate reinforced Al matrix (SiC p /AI) composites. The method is considered to be reliable in determining the reinforcement volume fractions. The technique could be adopted in a production unit for the quality assessment of the metal matrix particulate composite extrusions

  4. Energy Performance and Pressure Fluctuation of a Multiphase Pump with Different Gas Volume Fractions

    Directory of Open Access Journals (Sweden)

    Jinsong Zhang

    2018-05-01

    Full Text Available Large petroleum resources in deep sea, and huge market demands for petroleum need advanced petroleum extraction technology. The multiphase pump, which can simultaneously transport oil and gas with considerable efficiency, has been a crucial technology in petroleum extraction. A numerical approach with mesh generation and a Navier-Stokes equation solution is employed to evaluate the effects of gas volume fraction on energy performance and pressure fluctuations of a multiphase pump. Good agreement of experimental and calculation results indicates that the numerical approach can accurately simulate the multiphase flow in pumps. The pressure rise of a pump decreases with the increasing of flow rate, and the pump efficiency decreases with the increasing of GVF (the ratio of the gas volume to the whole volume. Results show that the dominant frequencies of pressure fluctuation in the impeller and diffuser are eleven and three times those of the impeller rotational frequency, respectively. Due to the larger density of water and centrifugal forces, the water aggregates to the shroud and the gas gathers to the hub, which renders the distribution of GVF in the pump uneven. A vortex develops at the blade suction side, near the leading edge, induced by the leakage flow, and further affects the pressure fluctuation in the impeller. The obvious vortex in the diffuser indicates that the design of the divergence angle of the diffuser is not optimal, which induces flow separation due to large diffusion ratio. A uniform flow pattern in the impeller indicates good hydraulic performance of the pump.

  5. Determination of bone mineral volume fraction using impedance analysis and Bruggeman model

    Energy Technology Data Exchange (ETDEWEB)

    Ciuchi, Ioana Veronica; Olariu, Cristina Stefania, E-mail: oocristina@yahoo.com; Mitoseriu, Liliana, E-mail: lmtsr@uaic.ro

    2013-11-20

    Highlights: • Mineral volume fraction of a bone sample was determined. • Dielectric properties for bone sample and for the collagen type I were determined by impedance spectroscopy. • Bruggeman effective medium approximation was applied in order to evaluate mineral volume fraction of the sample. • The computed values were compared with ones derived from a histogram test performed on SEM micrographs. -- Abstract: Measurements by impedance spectroscopy and Bruggeman effective medium approximation model were employed in order to determine the mineral volume fraction of dry bone. This approach assumes that two or more phases are present into the composite: the matrix (environment) and the other ones are inclusion phases. A fragment of femur diaphysis dense bone from a young pig was investigated in its dehydrated state. Measuring the dielectric properties of bone and its main components (hydroxyapatite and collagen) and using the Bruggeman approach, the mineral volume filling factor was determined. The computed volume fraction of the mineral volume fraction was confirmed by a histogram test analysis based on the SEM microstructures. In spite of its simplicity, the method provides a good approximation for the bone mineral volume fraction. The method which uses impedance spectroscopy and EMA modeling can be further developed by considering the conductive components of the bone tissue as a non-invasive in situ impedance technique for bone composition evaluation and monitoring.

  6. Determination of bone mineral volume fraction using impedance analysis and Bruggeman model

    International Nuclear Information System (INIS)

    Ciuchi, Ioana Veronica; Olariu, Cristina Stefania; Mitoseriu, Liliana

    2013-01-01

    Highlights: • Mineral volume fraction of a bone sample was determined. • Dielectric properties for bone sample and for the collagen type I were determined by impedance spectroscopy. • Bruggeman effective medium approximation was applied in order to evaluate mineral volume fraction of the sample. • The computed values were compared with ones derived from a histogram test performed on SEM micrographs. -- Abstract: Measurements by impedance spectroscopy and Bruggeman effective medium approximation model were employed in order to determine the mineral volume fraction of dry bone. This approach assumes that two or more phases are present into the composite: the matrix (environment) and the other ones are inclusion phases. A fragment of femur diaphysis dense bone from a young pig was investigated in its dehydrated state. Measuring the dielectric properties of bone and its main components (hydroxyapatite and collagen) and using the Bruggeman approach, the mineral volume filling factor was determined. The computed volume fraction of the mineral volume fraction was confirmed by a histogram test analysis based on the SEM microstructures. In spite of its simplicity, the method provides a good approximation for the bone mineral volume fraction. The method which uses impedance spectroscopy and EMA modeling can be further developed by considering the conductive components of the bone tissue as a non-invasive in situ impedance technique for bone composition evaluation and monitoring

  7. Effects of uncertainty in model predictions of individual tree volume on large area volume estimates

    Science.gov (United States)

    Ronald E. McRoberts; James A. Westfall

    2014-01-01

    Forest inventory estimates of tree volume for large areas are typically calculated by adding model predictions of volumes for individual trees. However, the uncertainty in the model predictions is generally ignored with the result that the precision of the large area volume estimates is overestimated. The primary study objective was to estimate the effects of model...

  8. SU-E-T-427: Cell Surviving Fractions Derived From Tumor-Volume Variation During Radiotherapy for Non-Small Cell Lung Cancer: Comparison with Predictive Assays

    International Nuclear Information System (INIS)

    Chvetsov, A; Schwartz, J; Mayr, N; Yartsev, S

    2014-01-01

    Purpose: To show that a distribution of cell surviving fractions S 2 in a heterogeneous group of patients can be derived from tumor-volume variation curves during radiotherapy for non-small cell lung cancer. Methods: Our analysis was based on two data sets of tumor-volume variation curves for heterogeneous groups of 17 patients treated for nonsmall cell lung cancer with conventional dose fractionation. The data sets were obtained previously at two independent institutions by using megavoltage (MV) computed tomography (CT). Statistical distributions of cell surviving fractions S 2 and cell clearance half-lives of lethally damaged cells T1/2 have been reconstructed in each patient group by using a version of the two-level cell population tumor response model and a simulated annealing algorithm. The reconstructed statistical distributions of the cell surviving fractions have been compared to the distributions measured using predictive assays in vitro. Results: Non-small cell lung cancer presents certain difficulties for modeling surviving fractions using tumor-volume variation curves because of relatively large fractional hypoxic volume, low gradient of tumor-volume response, and possible uncertainties due to breathing motion. Despite these difficulties, cell surviving fractions S 2 for non-small cell lung cancer derived from tumor-volume variation measured at different institutions have similar probability density functions (PDFs) with mean values of 0.30 and 0.43 and standard deviations of 0.13 and 0.18, respectively. The PDFs for cell surviving fractions S 2 reconstructed from tumor volume variation agree with the PDF measured in vitro. Comparison of the reconstructed cell surviving fractions with patient survival data shows that the patient survival time decreases as the cell surviving fraction increases. Conclusion: The data obtained in this work suggests that the cell surviving fractions S 2 can be reconstructed from the tumor volume variation curves measured

  9. Preface to the volume Large Rivers

    Science.gov (United States)

    Latrubesse, Edgardo M.; Abad, Jorge D.

    2018-02-01

    The study and knowledge of the geomorphology of large rivers increased significantly during the last years and the factors that triggered these advances are multiple. On one hand, modern technologies became more accessible and their disseminated usage allowed the collection of data from large rivers as never seen before. The generalized use of high tech data collection with geophysics equipment such as acoustic Doppler current profilers-ADCPs, multibeam echosounders, plus the availability of geospatial and computational tools for morphodynamics, hydrological and hydrosedimentological modeling, have accelerated the scientific production on the geomorphology of large rivers at a global scale. Despite the advances, there is yet a lot of work ahead. Good parts of the large rivers are in the tropics and many are still unexplored. The tropics also hold crucial fluvial basins that concentrate good part of the gross domestic product of large countries like the Parana River in Argentina and Brazil, the Ganges-Brahmaputra in India, the Indus River in Pakistan, and the Mekong River in several countries of South East Asia. The environmental importance of tropical rivers is also outstanding. They hold the highest biodiversity of fluvial fauna and alluvial vegetation and many of them, particularly those in Southeast Asia, are among the most hazardous systems for floods in the entire world. Tropical rivers draining mountain chains such as the Himalaya, the Andes and insular Southeast Asia are also among the most heavily sediment loaded rivers and play a key role in both the storage of sediment at continental scale and the transference of sediments from the continent to the Ocean at planetary scale (Andermann et al., 2012; Latrubesse and Restrepo, 2014; Milliman and Syvitski, 1992; Milliman and Farsnworth, 2011; Sinha and Friend, 1994).

  10. The coupled effect of fiber volume fraction and void fraction on hydraulic fluid absorption of quartz/BMI laminates

    Science.gov (United States)

    Hurdelbrink, Keith R.; Anderson, Jacob P.; Siddique, Zahed; Altan, M. Cengiz

    2016-03-01

    Bismaleimide (BMI) resin with quartz (AQ581) fiber reinforcement is a composite material frequently used in aerospace applications, such as engine cowlings and radomes. Various composite components used in aircrafts are exposed to different types of hydraulic fluids, which may lead to anomalous absorption behavior over the service life of the composite. Accurate predictive models for absorption of liquid penetrants are particularly important as the composite components are often exposed to long-term degradation due to absorbed moisture, hydraulic fluids, or similar liquid penetrants. Microstructural features such as fiber volume fraction and void fraction can have a significant effect on the absorption behavior of fiber-reinforced composites. In this paper, hydraulic fluid absorption characteristics of quartz/BMI laminates fabricated from prepregs preconditioned at different relative humidity and subsequently cured at different pressures are presented. The composite samples are immersed into hydraulic fluid at room temperature, and were not subjected to any prior degradation. To generate process-induced microvoids, prepregs were conditioned in an environmental chamber at 2% or 99% relative humidity at room temperature for a period of 24 hours prior to laminate fabrication. To alter the fiber volume fraction, the laminates were fabricated at cure pressures of 68.9 kPa (10 psi) or 482.6 kPa (70 psi) via a hot-press. The laminates are shown to have different levels of microvoids and fiber volume fractions, which were observed to affect the absorption dynamics considerably and exhibited clear non-Fickian behavior. A one-dimensional hindered diffusion model (HDM) was shown to be successful in predicting the hydraulic fluid absorption. Model prediction indicates that as the fabrication pressure increased from 68.9 kPa to 482.6 kPa, the maximum fluid content (M∞) decreased from 8.0% wt. to 1.0% wt. The degree of non-Fickian behavior, measured by hindrance coefficient (

  11. New large volume Calabi-Yau threefolds

    Science.gov (United States)

    Altman, Ross; He, Yang-Hui; Jejjala, Vishnu; Nelson, Brent D.

    2018-02-01

    In previous work, we have commenced the task of unpacking the 473 800 776 reflexive polyhedra by Kreuzer and Skarke into a database of Calabi-Yau threefolds [R. Altman et al. J. High Energy Phys. 02 (2015) 158., 10.1007/JHEP02(2015)158] (see www.rossealtman.com). In this paper, following a pedagogical introduction, we present a new algorithm to isolate Swiss cheese solutions characterized by "holes," or small 4-cycles, descending from the toric divisors inherent to the original four dimensional reflexive polyhedra. Implementing these methods, we find 2268 explicit Swiss cheese manifolds, over half of which have h1 ,1=6 . Many of our solutions have multiple large cycles. Such Swiss cheese geometries facilitate moduli stabilization in string compactifications and provide flat directions for cosmological inflation.

  12. Large volumes and spectroscopy of walking theories

    DEFF Research Database (Denmark)

    Del Debbio, L.; Lucini, B.; Patella, A.

    2016-01-01

    A detailed investigation of finite-size effects is performed for SU(2) gauge theory with two fermions in the adjoint representation, which previous lattice studies have shown to be inside the conformal window. The system is investigated with different spatial and temporal boundary conditions...... and the spatial lattice size L satisfy the relation LMPS≥15. This bound, which is at least a factor of three higher than what is observed in QCD, is a likely consequence of the different spectral signatures of the two theories, with the scalar isosinglet (0++ glueball) being the lightest particle in our model....... In addition to stressing the importance of simulating large lattice sizes, our analysis emphasizes the need to understand quantitatively the full spectrum of the theory rather than just the spectrum in the mesonic isotriplet sector. While for the lightest fermion measuring masses from gluonic operators proves...

  13. Volume measurement study for large scale input accountancy tank

    International Nuclear Information System (INIS)

    Uchikoshi, Seiji; Watanabe, Yuichi; Tsujino, Takeshi

    1999-01-01

    Large Scale Tank Calibration (LASTAC) facility, including an experimental tank which has the same volume and structure as the input accountancy tank of Rokkasho Reprocessing Plant (RRP) was constructed in Nuclear Material Control Center of Japan. Demonstration experiments have been carried out to evaluate a precision of solution volume measurement and to establish the procedure of highly accurate pressure measurement for a large scale tank with dip-tube bubbler probe system to be applied to the input accountancy tank of RRP. Solution volume in a tank is determined from substitution the solution level for the calibration function obtained in advance, which express a relation between the solution level and its volume in the tank. Therefore, precise solution volume measurement needs a precise calibration function that is determined carefully. The LASTAC calibration experiments using pure water showed good result in reproducibility. (J.P.N.)

  14. High Volume Fraction Carbon Nanotube Composites for Aerospace Applications

    Science.gov (United States)

    Siochi, E. J.; Kim, J.-W.; Sauti, G.; Cano, R. J.; Wincheski, R. A.; Ratcliffe, J. G.; Czabaj, M.

    2016-01-01

    Reported mechanical properties of carbon nanotubes (CNTs) at the nanoscale suggest their potential to enable significantly lighter structures of interest for space applications. However, their utility depends on the retention of these properties in bulk material formats that permit practical fabrication of large structures. This presentation summarizes recent progress made to produce carbon nanotube composites with specific tensile properties that begin to rival those of carbon fiber reinforced polymer composites. CNT content in these nanocomposites was greater than 70% by weight. Tested nanocomposite specimens were fabricated from kilometers or tens of square meters of CNT, depending on the starting material format. Processing methods to yield these results, and characterization and testing to evaluate the performance of these composites will be discussed. The final objective is the demonstration of a CNT composite overwrapped pressure vessel to be flight tested in the Fall of 2016.

  15. Influence of titanium volume fraction on the mechanical properties of Mg-Ti composites

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Pablo; Garces, Gerardo; Adeva, Paloma [Centro Nacional de Investigaciones Metalurgicas (CENIM, CSIC), Madrid (Spain). Dept. de Metalurgia Fisica

    2009-03-15

    The influence of titanium volume fraction on the mechanical properties of Mg-Ti composites prepared through a powder metallurgy route has been evaluated. Titanium was added as particles smaller than 25 {mu}m and volume fractions ranging from 5 to 15%. The increase in the volume fraction of titanium particles results in a slight decrease in the maximum strength. In contrast to this, the ductility of all composites was significantly enhanced by titanium additions. The mechanical properties can be explained on the basis of texture changes induced by the presence of titanium particles. The decrease in the basal texture along the extrusion direction as the amount of titanium is progressively increased accounts for the decrease in the maximum strength. (orig.)

  16. Soot volume fraction fields in unsteady axis-symmetric flames by continuous laser extinction technique.

    Science.gov (United States)

    Kashif, Muhammad; Bonnety, Jérôme; Guibert, Philippe; Morin, Céline; Legros, Guillaume

    2012-12-17

    A Laser Extinction Method has been set up to provide two-dimensional soot volume fraction field time history at a tunable frequency up to 70 Hz inside an axis-symmetric diffusion flame experiencing slow unsteady phenomena preserving the symmetry. The use of a continuous wave laser as the light source enables this repetition rate, which is an incremental advance in the laser extinction technique. The technique is shown to allow a fine description of the soot volume fraction field in a flickering flame exhibiting a 12.6 Hz flickering phenomenon. Within this range of repetition rate, the technique and its subsequent post-processing require neither any method for time-domain reconstruction nor any correction for energy intrusion. Possibly complemented by such a reconstruction method, the technique should support further soot volume fraction database in oscillating flames that exhibit characteristic times relevant to the current efforts in the validation of soot processes modeling.

  17. Dosimetric impact of prostate volume change between CT-based HDR brachytherapy fractions

    International Nuclear Information System (INIS)

    Kim, Yongbok; Hsu, I-C.; Lessard, Etienne; Vujic, Jasmina; Pouliot, Jean

    2004-01-01

    Purpose: The objective is to evaluate the prostate volume change and its dosimetric consequences after the insertion of catheters for high-dose-rate brachytherapy. Methods and Materials: For 13 consecutive patients, a spiral CT scan was acquired before each of the 2 fractions, separated on average by 20 hours. The coordinates of the catheters were obtained on 3 axial CT slices corresponding to apex, mid portion, and base portion of the prostate. A mathematical expansion model was used to evaluate the change of prostate volumes between the 2 fractions. It is based on the difference in the cube of the average distance between the centroid and catheter positions. The variation of implant dose-volume histograms between fractions was computed for plans produced by either inverse planning based on simulated annealing or geometric optimization. Results: The average magnitude of either increase or reduction in prostate volume was 7.8% (range, 2-17%). This volume change corresponds to an average prostate radius change of only 2.5% (range, 0.7-5.4%). For 5 patients, the prostate volume increased on average by 9% (range, 2-17%), whereas a reduction was observed for 8 patients by an average of 7% (range, 2-13%). More variation was observed at the prostate base than at mid or apex gland. The comparison of implant dose-volume histograms showed a small reduction of V100 receiving the prescription dose, with an average of 3.5% (range, 0.5-12%) and 2.2% (range, 1-6%) for inverse planning based on our simulated annealing and geometric optimization plans, respectively. Conclusion: Small volume change was observed between treatment fractions. This translates into small changes in dose delivered to the prostate volume

  18. Effect of Fiber Volume Fraction and Water Absorption toward Bending Strength of Coconut Filters/ Polyester Composite

    Directory of Open Access Journals (Sweden)

    I Putu Lokantara

    2012-11-01

    Full Text Available The variation of fibre volume and the duration of water soaking take influence on the mechanical properties of composite. This research aim is to know the influence of fraction volume fibre and soaking duration on the mineral watertoward the tensile strength and flexural of polyester-coconut-tapis composite. This research used coconut-tapis fibre which is cut 1 cm in length with 0%, 5%, 7,5%, and 10% fiber volume fraction, unsaturated-polyester (UPRs matrix resin type Yucalac 157 BQTN-EX, and MEKPO hardener. The flexure specimen are made by press hand lay-up method and cut according ASTM D790-03 for the flexure test. The result of flexure test shows that the duration of soaking and the fiber volume fraction give a significant effect on the flexural strength of composite. The highest strength are reached by composite with 10% fibre volume on 48 hour soaking time equal to 41.994 MPa. The flexure modulus happenend shows increasing until 24 hour soaking time. The highest modulus are reached by composite with 10% fibre volume equal to 7.114 GPa while the lowest are reached by composite with 0% fibre volume equal to 3,023 GPa.

  19. Development of large-volume rhyolitic ignibrites (LRI'S): The Chalupas Caldera, an example from Ecuador

    International Nuclear Information System (INIS)

    Hammersley, L.; DePaolo, D.J; Beate, B

    2001-01-01

    The mechanisms responsible for the generation of large volumes of silicic magma and the eruption of large-volume rhyolitic ignimbrites (LRI's) remain poorly understood. Of particular interest are the relative roles of crustal assimilation, fractional crystallization and magma supply and the processes by which large volumes of magma accumulate in crustal chambers rather than erupt in smaller batches. Isotope geochemistry, combined with study of major and trace element variations of lavas, can be used to infer the relative contribution of crustal material and continued magmatic supply. Timescales for the accumulation of magma can be estimated using detailed geochronology. Magma supply rates can be estimated from eruption rates of nearby volcanoes. In this study we investigate the evolution of the Chalupas LRI, a caldera system in the Ecuadorian Andes where LRI's are rare in comparison to the Southern Volcanic Zone (SVZ) of South America (au)

  20. Volume fraction calculation in multiphase system such as oil-water-gas using neutron

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Robson; Brandao, Luis E.B.; Salgado, Cesar Marques; Pereira, Claudio M.N.A. [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)]. E-mails: robson@ien.gov.br; brandao@ien.gov.br; otero@ien.gov.br; cmnap@ien.gov.br; Schirru, Roberto; Silva, Ademir Xavier da [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear]. E-mails: schirru@lmp.ufrj.br; ademir@con.ufrj.br

    2007-07-01

    Multi-phase flows are common in diverse industrial sectors and the attainment of the volume fraction of each element that composes the flow system presents difficulties for the engineering process, therefore, to determine them is very important. In this work is presented methodology for determination of volume fractions in annular three-phase flow systems, such as oil-water-gas, based on the use of nuclear techniques and artificial intelligence. Using the principle of the fast-neutron transmission/scattering, come from an isotopic {sup 241}Am-Be source, and two point detectors, is gotten measured that they are influenced by the variations of the volume fractions of each phase present in the flow. An artificial neural network is trained to correlate such measures with the respective volume fractions. In order to get the data for training of the artificial neural network without necessity to carry through experiments, MCNP-X code is used, that simulates computational of the neutrons transport. The methodology is sufficiently advantageous, therefore, allows to develop a measurement system capable to determine the fractions of the phases (oil-water-gas), with proper requirements of each petroliferous installation and with national technology contributing, possibly, with reduction of costs and increase of productivity. (author)

  1. Volume fraction calculation in multiphase system such as oil-water-gas using neutron

    International Nuclear Information System (INIS)

    Ramos, Robson; Brandao, Luis E.B.; Salgado, Cesar Marques; Pereira, Claudio M.N.A.; Schirru, Roberto; Silva, Ademir Xavier da

    2007-01-01

    Multi-phase flows are common in diverse industrial sectors and the attainment of the volume fraction of each element that composes the flow system presents difficulties for the engineering process, therefore, to determine them is very important. In this work is presented methodology for determination of volume fractions in annular three-phase flow systems, such as oil-water-gas, based on the use of nuclear techniques and artificial intelligence. Using the principle of the fast-neutron transmission/scattering, come from an isotopic 241 Am-Be source, and two point detectors, is gotten measured that they are influenced by the variations of the volume fractions of each phase present in the flow. An artificial neural network is trained to correlate such measures with the respective volume fractions. In order to get the data for training of the artificial neural network without necessity to carry through experiments, MCNP-X code is used, that simulates computational of the neutrons transport. The methodology is sufficiently advantageous, therefore, allows to develop a measurement system capable to determine the fractions of the phases (oil-water-gas), with proper requirements of each petroliferous installation and with national technology contributing, possibly, with reduction of costs and increase of productivity. (author)

  2. Pancreas volume and fat fraction in children with Type 1 diabetes.

    Science.gov (United States)

    Regnell, S E; Peterson, P; Trinh, L; Broberg, P; Leander, P; Lernmark, Å; Månsson, S; Elding Larsson, H

    2016-10-01

    People with Type 1 diabetes have smaller pancreases than healthy individuals. Several diseases causing pancreatic atrophy are associated with pancreatic steatosis, but pancreatic fat in Type 1 diabetes has not been measured. This cross-sectional study aimed to compare pancreas size and fat fraction in children with Type 1 diabetes and controls. The volume and fat fraction of the pancreases of 22 children with Type 1 diabetes and 29 controls were determined using magnetic resonance imaging. Pancreas volume was 27% smaller in children with diabetes (median 34.9 cm(3) ) than in controls (47.8 cm(3) ; P Pancreas volume correlated positively with age in controls (P = 0.033), but not in children with diabetes (P = 0.649). Pancreas volume did not correlate with diabetes duration, but it did correlate positively with units of insulin/kg body weight/day (P = 0.048). A linear model of pancreas volume as influenced by age, body surface area and insulin units/kg body weight/day found that insulin dosage correlated with pancreas volume after controlling for both age and body surface area (P = 0.009). Pancreatic fat fraction was not significantly different between the two groups (1.34% vs. 1.57%; P = 0.891). Our findings do not indicate that pancreatic atrophy in Type 1 diabetes is associated with an increased pancreatic fat fraction, unlike some other diseases featuring reduced pancreatic volume. We speculate that our results may support the hypotheses that much of pancreatic atrophy in Type 1 diabetes occurs before the clinical onset of the disease and that exogenous insulin administration decelerates pancreatic atrophy after diabetes onset. © 2016 Diabetes UK.

  3. Thermosetting resins with high fractions of free volume and inherently low dielectric constants.

    Science.gov (United States)

    Lin, Liang-Kai; Hu, Chien-Chieh; Su, Wen-Chiung; Liu, Ying-Ling

    2015-08-18

    This work demonstrates a new class of thermosetting resins, based on Meldrum's acid (MA) derivatives, which have high fractions of free volume and inherently low k values of about 2.0 at 1 MHz. Thermal decomposition of the MA groups evolves CO2 and acetone to create air-trapped cavities so as to reduce the dielectric constants.

  4. Volume fraction dependence and reorganization in cluster-cluster aggregation processes

    NARCIS (Netherlands)

    Garderen, van H.F.; Dokter, W.H.; Beelen, T.P.M.; Santen, van R.A.; Pantos, E.; Michels, M.A.J.; Hilbers, P.A.J.

    1995-01-01

    Off-lattice diffusion limited cluster aggregation simulations in two dimensions have been performed in a wide volume fraction range between 0.001 and 0.60. Starting from a system of 10 000 monomers with radius 0.5, that follow Brownian trajectories, larger aggregates are generated by bond formation

  5. Planar measurements of soot volume fraction and OH in a JP-8 pool fire

    Energy Technology Data Exchange (ETDEWEB)

    Henriksen, Tara L.; Ring, Terry A.; Eddings, Eric G. [Department of Chemical Engineering, University of Utah, Salt Lake City, UT 84112 (United States); Nathan, Graham J. [School of Mechanical Engineering, University of Adelaide, SA 5005 (Australia); Alwahabi, Zeyad T.; Qamar, Nader [School of Chemical Engineering, University of Adelaide, SA 5005 (Australia)

    2009-07-15

    The simultaneous measurement of soot volume fraction by laser induced incandescence (LII) and qualitative imaging of OH by laser induced fluorescence (LIF) was performed in a JP-8 pool fire contained in a 152 mm diameter pan. Line of sight extinction was used to calibrate the LII system in a laminar flame, and to provide an independent method of measuring average soot volume fraction in the turbulent flame. The presence of soot in the turbulent flame was found to be approximately 50% probable, resulting in high levels of optical extinction, which increased slightly through the flame from approximately 30% near the base, to approximately 50% at the tip. This high soot loading pushes both techniques toward their detection limit. Nevertheless, useful accuracy was obtained, with the LII measurement of apparent extinction in the turbulent flame being approximately 21% lower than a direct measurement, consistent with the influence of signal trapping. The axial and radial distributions of soot volume fraction are presented, along with PDFs of volume fraction, and new insight into the behavior of soot sheets in pool fires are sought from the simultaneous measurements of OH and LII. (author)

  6. Higgs, moduli problem, baryogenesis and large volume compactifications

    International Nuclear Information System (INIS)

    Higaki, Tetsutaro; Takahashi, Fuminobu

    2012-07-01

    We consider the cosmological moduli problem in the context of high-scale supersymmetry breaking suggested by the recent discovery of the standard-model like Higgs boson. In order to solve the notorious moduli-induced gravitino problem, we focus on the LARGE volume scenario, in which the modulus decay into gravitinos can be kinematically forbidden. We then consider the Affleck-Dine mechanism with or without an enhanced coupling with the inflaton, taking account of possible Q-ball formation. We show that the baryon asymmetry of the present Universe can be generated by the Affleck-Dine mechanism in LARGE volume scenario, solving the moduli and gravitino problems.

  7. Higgs, moduli problem, baryogenesis and large volume compactifications

    Energy Technology Data Exchange (ETDEWEB)

    Higaki, Tetsutaro [RIKEN Nishina Center, Saitama (Japan). Mathematical Physics Lab.; Kamada, Kohei [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Takahashi, Fuminobu [Tohoku Univ., Sendai (Japan). Dept. of Physics

    2012-07-15

    We consider the cosmological moduli problem in the context of high-scale supersymmetry breaking suggested by the recent discovery of the standard-model like Higgs boson. In order to solve the notorious moduli-induced gravitino problem, we focus on the LARGE volume scenario, in which the modulus decay into gravitinos can be kinematically forbidden. We then consider the Affleck-Dine mechanism with or without an enhanced coupling with the inflaton, taking account of possible Q-ball formation. We show that the baryon asymmetry of the present Universe can be generated by the Affleck-Dine mechanism in LARGE volume scenario, solving the moduli and gravitino problems.

  8. Fractionation in normal tissues: the (α/β)eff concept can account for dose heterogeneity and volume effects.

    Science.gov (United States)

    Hoffmann, Aswin L; Nahum, Alan E

    2013-10-07

    The simple Linear-Quadratic (LQ)-based Withers iso-effect formula (WIF) is widely used in external-beam radiotherapy to derive a new tumour dose prescription such that there is normal-tissue (NT) iso-effect when changing the fraction size and/or number. However, as conventionally applied, the WIF is invalid unless the normal-tissue response is solely determined by the tumour dose. We propose a generalized WIF (gWIF) which retains the tumour prescription dose, but replaces the intrinsic fractionation sensitivity measure (α/β) by a new concept, the normal-tissue effective fractionation sensitivity, [Formula: see text], which takes into account both the dose heterogeneity in, and the volume effect of, the late-responding normal-tissue in question. Closed-form analytical expressions for [Formula: see text] ensuring exact normal-tissue iso-effect are derived for: (i) uniform dose, and (ii) arbitrary dose distributions with volume-effect parameter n = 1 from the normal-tissue dose-volume histogram. For arbitrary dose distributions and arbitrary n, a numerical solution for [Formula: see text] exhibits a weak dependence on the number of fractions. As n is increased, [Formula: see text] increases from its intrinsic value at n = 0 (100% serial normal-tissue) to values close to or even exceeding the tumour (α/β) at n = 1 (100% parallel normal-tissue), with the highest values of [Formula: see text] corresponding to the most conformal dose distributions. Applications of this new concept to inverse planning and to highly conformal modalities are discussed, as is the effect of possible deviations from LQ behaviour at large fraction sizes.

  9. Fractional filling with the microdepot technique as an alternative to bolus hyaluronic acid injections in facial volume restoration.

    Science.gov (United States)

    Lim, Adrian C; Lowe, Patricia M

    2011-05-01

    For volume restoration of the face, hyaluronic acid is conventionally injected through long, large-bore, 18-gauge needles because of the higher viscosity subtypes required. These hyaluronic acids are either more highly cross-linked or larger in particle size than the less-viscous subtypes. The microdepot injection technique involves using the 31-gauge BD insulin syringe (Becton-Dickinson, North Ryde, NSW Australia) to deposit small amounts of filler (0.05-0.1 mL) throughout the area of volume loss. The procedure is extremely well tolerated, requiring only topical and ice anaesthesia. Using this method, volume restoration can be achieved naturally and progressively over a period of time. Fractional filling every 3-4 months is continued until the desired level of volume correction is attained. Patients undergoing fractional filling followed over a 12-month period did not indicate any observable compromise in filler longevity, even when highly viscous hyaluronic acid fillers were injected through small-bore, 31-gauge insulin syringes. © 2011 The Authors. Australasian Journal of Dermatology © 2011 The Australasian College of Dermatologists.

  10. SU-E-T-427: Cell Surviving Fractions Derived From Tumor-Volume Variation During Radiotherapy for Non-Small Cell Lung Cancer: Comparison with Predictive Assays

    Energy Technology Data Exchange (ETDEWEB)

    Chvetsov, A; Schwartz, J; Mayr, N [University of Washington, Seattle, WA (United States); Yartsev, S [London Health Sciences Centre, London, Ontario (Canada)

    2014-06-01

    Purpose: To show that a distribution of cell surviving fractions S{sub 2} in a heterogeneous group of patients can be derived from tumor-volume variation curves during radiotherapy for non-small cell lung cancer. Methods: Our analysis was based on two data sets of tumor-volume variation curves for heterogeneous groups of 17 patients treated for nonsmall cell lung cancer with conventional dose fractionation. The data sets were obtained previously at two independent institutions by using megavoltage (MV) computed tomography (CT). Statistical distributions of cell surviving fractions S{sup 2} and cell clearance half-lives of lethally damaged cells T1/2 have been reconstructed in each patient group by using a version of the two-level cell population tumor response model and a simulated annealing algorithm. The reconstructed statistical distributions of the cell surviving fractions have been compared to the distributions measured using predictive assays in vitro. Results: Non-small cell lung cancer presents certain difficulties for modeling surviving fractions using tumor-volume variation curves because of relatively large fractional hypoxic volume, low gradient of tumor-volume response, and possible uncertainties due to breathing motion. Despite these difficulties, cell surviving fractions S{sub 2} for non-small cell lung cancer derived from tumor-volume variation measured at different institutions have similar probability density functions (PDFs) with mean values of 0.30 and 0.43 and standard deviations of 0.13 and 0.18, respectively. The PDFs for cell surviving fractions S{sup 2} reconstructed from tumor volume variation agree with the PDF measured in vitro. Comparison of the reconstructed cell surviving fractions with patient survival data shows that the patient survival time decreases as the cell surviving fraction increases. Conclusion: The data obtained in this work suggests that the cell surviving fractions S{sub 2} can be reconstructed from the tumor volume

  11. Crystallization of sheared hard spheres at 64.5% volume fraction

    Science.gov (United States)

    Swinney, H. L.; Rietz, F.; Schroeter, M.; Radin, C.

    2017-11-01

    A classic experiment by G.D. Scott Nature 188, 908, 1960) showed that pouring balls into a rigid container filled the volume to an upper limit of 64% of the container volume, which is well below the 74% volume fraction filled by spheres in a hexagonal close packed (HCP) or face center cubic (FCC) lattice. Subsequent experiments have confirmed a ``random closed packed'' (RCP) fraction of about 64%. However, the physics of the RCP limit has remained a mystery. Our experiment on a cubical box filled with 49400 weakly sheared glass spheres reveals a first order phase transition from a disordered to an ordered state at a volume fraction of 64.5%. The ordered state consists of crystallites of mixed FCC and HCP symmetry that coexist with the amorphous bulk. The transition is initiated by homogeneous nucleation: in the shearing process small crystallites with about ten or fewer spheres dissolve, while larger crystallites grow. A movie illustrates the crystallization process. German Academic Exchange Service (DAAD), German Research Foundation (DFG), NSF DMS, and R.A. Welch Foundation.

  12. Models for high cell density bioreactors must consider biomass volume fraction: Cell recycle example.

    Science.gov (United States)

    Monbouquette, H G

    1987-06-01

    Intrinsic models, which take into account biomass volume fraction, must be formulated for adequate simulation of high-biomass-density fermentations with cell recycle. Through comparison of corresponding intrinsic and non-intrinsic models in dimensionless form, constraints for non-intrinsic model usage in terms of biokinetic and fermenter operating parameters can be identified a priori. Analysis of a simple product-inhibition model indicates that the non-intrinsic approach is suitable only when the attainable biomass volume fraction in the fermentation broth is less than about 0.10. Inappropriate application of a non-intrinsic model can lead to gross errors in calculated substrate and product concentrations, substrate conversion, and volumetric productivity.

  13. Models for high cell density bioreactors must consider biomass volume fraction: cell recycle example

    Energy Technology Data Exchange (ETDEWEB)

    Monbouquette, H.G.

    1987-06-01

    Intrinsic models, which take into account biomass volume fraction, must be formulated for adequate simulation of high-biomass-density fermentations with cell recycle. Through comparison of corresponding intrinsic and non-intrinsic models in dimensionless form, constraints for non-intrinsic model usage in terms of biokinetic and fermenter operating parameters can be identified a priori. Analysis of a simple product-inhibition model indicates that the non-intrinsic approach is suitable only when the attainable biomass volume fraction in the fermentation broth is less than about 0.10. Inappropriate application of a non-intrinsic model can lead to gross errors in calculated substrate and product concentrations, substrate conversion, and volumetric productivity. (Refs. 14).

  14. Damping behavior of polymer composites with high volume fraction of NiMnGa powders

    Science.gov (United States)

    Sun, Xiaogang; Song, Jie; Jiang, Hong; Zhang, Xiaoning; Xie, Chaoying

    2011-03-01

    Polymer composites inserted with high volume fraction (up to 70 Vol%) of NiMnGa powders were fabricated and their damping behavior was investigated by dynamic mechanical analysis. It is found that the polymer matrix has little influence on the transformation temperatures of NiMnGa powders. A damping peak appears for NiMnGa/epoxy resin (EP) composites accompanying with the martensitic transformation or reverse martensitic transformation of NiMnGa powders during cooling or heating. The damping capacity for NiMnGa/EP composites increases linearly with the increase of volume fraction of NiMnGa powders and, decreases dramatically as the test frequency increases. The fracture strain of NiMnGa/EP composites decrease with the increase of NiMnGa powders.

  15. Atomic force microscopy imaging to measure precipitate volume fraction in nickel-based superalloys

    International Nuclear Information System (INIS)

    Bourhettar, A.; Troyon, M.; Hazotte, A.

    1995-01-01

    In nickel-based superalloys, quantitative analysis of scanning electron microscopy images fails in providing accurate microstructural data, whereas more efficient techniques are very time-consuming. As an alternative approach, the authors propose to perform quantitative analysis of atomic force microscopy images of polished/etched surfaces (quantitative microprofilometry). This permits the measurement of microstructural parameters and the depth of etching, which is the main source of measurement bias. Thus, nonbiased estimations can be obtained by extrapolation of the measurements up to zero etching depth. In this article, the authors used this approach to estimate the volume fraction of γ' precipitates in a nickel-based superalloy single crystal. Atomic force microscopy images of samples etched for different times show definition, homogeneity, and contrast high enough to perform image analysis. The result after extrapolation is in very good agreement with volume fraction values available from published reports

  16. Volume Fraction Dependent Thermal Performance of UAlx-Al Dispersion Target

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Eui Hyun; Tahk, Young Wook; Kim, Hyun Jung; Oh, Jae Yong; Yim, Jeong Sik [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    Unlike U-Al alloys, properties of UAl{sub x}-Al dispersion target can be highly sensitive to volume fraction of UAlx in a target meat due to the interface resistance between target particles and matrix. The interface resistance effects on properties of the target meat including thermal conductivity, thermal expansion coefficient, specific heat, elastic modulus and so on. Thermal performances of a dispersion target meat were theoretically evaluated under normal operation condition of KJRR (Kijang Research Reactor) during short effective full power days (EFPD) of 7 days, based on reported measured thermal conductivities of UAl{sub x}-Al dispersion fuels. Effective thermal conductivity determines maximum temperature of dispersion target plate. And for that volume fraction of UAlx in target meat has to be determined considering manufacturing of target plate without degradation of physical and mechanical characteristics.

  17. Effects of morphology and wavelength on the measurement accuracy of soot volume fraction by laser extinction

    Science.gov (United States)

    Wang, Ya-fei; Huang, Qun-xing; Wang, Fei; Chi, Yong; Yan, Jian-hua

    2018-01-01

    A novel method to evaluate the quantitative effects of soot morphology and incident wavelength on the measurement accuracy of soot volume fraction, by the laser extinction (LE) technique is proposed in this paper. The results indicate that the traditional LE technique would overestimate soot volume fraction if the effects of morphology and wavelength are not considered. Before the agglomeration of isolated soot primary particles, the overestimation of the LE technique is in the range of 2-20%, and rises with increasing primary particle diameter and with decreasing incident wavelength. When isolated primary particles are agglomerated into fractal soot aggregates, the overestimation would exceed 30%, and rise with increasing primary particle number per soot aggregate, fractal dimension and fractal prefactor and with decreasing incident wavelength to a maximum value of 55%. Finally, based on these results above, the existing formula of the LE technique gets modified, and the modification factor is 0.65-0.77.

  18. The equivalent electrical permittivity of gas-solid mixtures at intermediate solid volume fractions.

    Energy Technology Data Exchange (ETDEWEB)

    Torczynski, John Robert; Ceccio, Steven Louis; Tortora, Paul Richard

    2005-07-01

    Several mixture models are evaluated for their suitability in predicting the equivalent permittivity of dielectric particles in a dielectric medium for intermediate solid volume fractions (0.4 to 0.6). Predictions of the Maxwell, Rayleigh, Bottcher and Bruggeman models are compared to computational simulations of several arrangements of solid particles in a gas and to the experimentally determined permittivity of a static particle bed. The experiment uses spherical glass beads in air, so air and glass permittivity values (1 and 7, respectively) are used with all of the models and simulations. The experimental system used to measure the permittivity of the static particle bed and its calibration are described. The Rayleigh model is found to be suitable for predicting permittivity over the entire range of solid volume fractions (0-0.6).

  19. Thermal Diffusivity and Thermal Conductivity of Dispersed Glass Sphere Composites Over a Range of Volume Fractions

    Science.gov (United States)

    Carson, James K.

    2018-06-01

    Glass spheres are often used as filler materials for composites. Comparatively few articles in the literature have been devoted to the measurement or modelling of thermal properties of composites containing glass spheres, and there does not appear to be any reported data on the measurement of thermal diffusivities over a range of filler volume fractions. In this study, the thermal diffusivities of guar-gel/glass sphere composites were measured using a transient comparative method. The addition of the glass beads to the gel increased the thermal diffusivity of the composite, more than doubling the thermal diffusivity of the composite relative to the diffusivity of the gel at the maximum glass volume fraction of approximately 0.57. Thermal conductivities of the composites were derived from the thermal diffusivity measurements, measured densities and estimated specific heat capacities of the composites. Two approaches to modelling the effective thermal diffusivity were considered.

  20. Volume fraction dependence of transient absorption signal and nonlinearities in metal nanocolloids

    International Nuclear Information System (INIS)

    Jayabalan, J; Singh, Asha; Khan, Salahuddin; Chari, Rama

    2013-01-01

    Electron–lattice thermalization dynamics in metal nanoparticles or in bulk metal is usually estimated by measuring the decay time of the change in transmission following an optical excitation. Such measurements can be performed in transient absorption geometry using a femtosecond laser. We find that for silver nanoplatelet/water colloids, the decay time of the transient absorption depends on the volume fraction of silver in water. By estimating the volume fraction dependence of nonlinearities in the same samples, we show that the variation in the measured decay time is due to pump-depletion effects present in the sample. The correct correction factor for taking into account pump-depletion effects in fifth- and higher-order nonlinearities is also presented. (paper)

  1. Effect, Feasibility, and Clinical Relevance of Cell Enrichment in Large Volume Fat Grafting

    DEFF Research Database (Denmark)

    Rasmussen, Bo Sonnich; Lykke Sørensen, Celine; Vester-Glowinski, Peter Viktor

    2017-01-01

    Large volume fat grafting is limited by unpredictable volume loss; therefore, methods of improving graft retention have been developed. Fat graft enrichment with either stromal vascular fraction (SVF) cells or adipose tissue-derived stem/stromal cells (ASCs) has been investigated in several animal...... and human studies, and significantly improved graft retention has been reported. Improvement of graft retention and the feasibility of these techniques are equally important in evaluating the clinical relevance of cell enrichment. We conducted a systematic search of PubMed to identify studies on fat graft...... enrichment that used either SVF cells or ASCs, and only studies reporting volume assessment were included. A total of 38 articles (15 human and 23 animal) were included to investigate the effects of cell enrichment on graft retention as well as the feasibility and clinical relevance of cell-enriched fat...

  2. Volume fraction prediction in biphasic flow using nuclear technique and artificial neural network

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, Cesar M.; Brandao, Luis E.B., E-mail: otero@ien.gov.br, E-mail: brandao@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The volume fraction is one of the most important parameters used to characterize air-liquid two-phase flows. It is a physical value to determine other parameters, such as the phase's densities and to determine the flow rate of each phase. These parameters are important to predict the flow pattern and to determine a mathematical model for the system. To study, for example, heat transfer and pressure drop. This work presents a methodology for volume fractions prediction in water-gas stratified flow regime using the nuclear technique and artificial intelligence. The volume fractions calculate in biphasic flow systems is complex and the analysis by means of analytical equations becomes very difficult. The approach is based on gamma-ray pulse height distributions pattern recognition by means of the artificial neural network. The detection system uses appropriate broad beam geometry, comprised of a ({sup 137}Cs) energy gamma-ray source and a NaI(Tl) scintillation detector in order measure transmitted beam whose the counts rates are influenced by the phases composition. These distributions are directly used by the network without any parameterization of the measured signal. The ideal and static theoretical models for stratified regime have been developed using MCNP-X code, which was used to provide training, test and validation data for the network. The detector also was modeled with this code and the results were compared to experimental photopeak efficiency measurements of radiation sources. The proposed network could obtain with satisfactory prediction of the volume fraction in water-gas system, demonstrating to be a promising approach for this purpose. (author)

  3. Volume fraction prediction in biphasic flow using nuclear technique and artificial neural network

    International Nuclear Information System (INIS)

    Salgado, Cesar M.; Brandao, Luis E.B.

    2015-01-01

    The volume fraction is one of the most important parameters used to characterize air-liquid two-phase flows. It is a physical value to determine other parameters, such as the phase's densities and to determine the flow rate of each phase. These parameters are important to predict the flow pattern and to determine a mathematical model for the system. To study, for example, heat transfer and pressure drop. This work presents a methodology for volume fractions prediction in water-gas stratified flow regime using the nuclear technique and artificial intelligence. The volume fractions calculate in biphasic flow systems is complex and the analysis by means of analytical equations becomes very difficult. The approach is based on gamma-ray pulse height distributions pattern recognition by means of the artificial neural network. The detection system uses appropriate broad beam geometry, comprised of a ( 137 Cs) energy gamma-ray source and a NaI(Tl) scintillation detector in order measure transmitted beam whose the counts rates are influenced by the phases composition. These distributions are directly used by the network without any parameterization of the measured signal. The ideal and static theoretical models for stratified regime have been developed using MCNP-X code, which was used to provide training, test and validation data for the network. The detector also was modeled with this code and the results were compared to experimental photopeak efficiency measurements of radiation sources. The proposed network could obtain with satisfactory prediction of the volume fraction in water-gas system, demonstrating to be a promising approach for this purpose. (author)

  4. Left ventricular ejection fraction and volumes as measured by 3D echocardiography and ultrafast computed tomography

    International Nuclear Information System (INIS)

    Vieira, Marcelo Luiz Campos; Nomura, Cesar H.; Tranchesi Junior, Bernardino; Oliveira, Wercules A. de; Naccarato, Gustavo; Serpa, Bruna S.; Passos, Rodrigo B.D.; Funari, Marcelo B. G.; Fischer, Claudio H.; Morhy, Samira S.

    2009-01-01

    Background: Real-time three-dimensional echocardiography (RT-3D-Echo) and ultrafast computed tomography (CT) are two novel methods for the analysis of LV ejection fraction and volumes. Objective: To compare LVEF and volume measurements as obtained using RT-3D-Echo and ultrafast CT. Methods: Thirty nine consecutive patients (27 men, mean age of 57+- 12 years) were studied using RT-3D-Echo and 64-slice ultrafast CT. LVEF and LV volumes were analyzed. Statistical analysis: coefficient of correlation (r: Pearson), Bland-Altman analysis, linear regression analysis, 95% CI, p 5 .58)%; end-diastolic volume ranged from 49.6 to 178.2 (87+-27.8) ml; end-systolic volume ranged from 11.4 to 78 (33.1+-13.6) ml. CT scan measurements: LVEF ranged from 53 to 86% (67.8+-7.78); end-diastolic volume ranged from 51 to 186 (106.5+-30.3) ml; end-systolic volume ranged from 7 to 72 (35.5+-13.4)ml. Correlations between RT-3D-Echo and CT were: LVEF (r: 0.7888, p<0.0001, 95% CI 0.6301 to 0.8843); end-diastolic volume (r: 0.7695, p<0.0001, 95% CI 0.5995 to 0.8730); end-systolic volume (r: 0.8119, p<0.0001, 95% CI 0.6673 to 0.8975). Conclusion: Good correlation between LVEF and ventricular volume parameters as measured by RT-3D-Echo and 64-slice ultrafast CT was found in the present case series. (author)

  5. Controlling thermal deformation by using composite materials having variable fiber volume fraction

    International Nuclear Information System (INIS)

    Bouremana, M.; Tounsi, A.; Kaci, A.; Mechab, I.

    2009-01-01

    In application, many thin structural components such as beams, plates and shells experience a through-thickness temperature variation. This temperature variation can produce both an in-plane expansion and an out-of-plane (bending) curvature. Given that these thin components interact with or connect to other components, we often wish to minimize the thermal deformation or match the thermal deformation of another component. This is accomplished by using a composite whose fibers have a negative axial thermal expansion coefficient. By varying the fiber volume fraction within a symmetric laminated beam to create a functionally graded material (FGM), certain thermal deformations can be controlled or tailored. Specifically, a beam can be designed which does not curve under a steady-state through-thickness temperature variation. Continuous gradation of the fiber volume fraction in the FGM layer is modelled in the form of a mth power polynomial of the coordinate axis in thickness direction of the beam. The beam results are independent of the actual temperature values, within the limitations of steady-state heat transfer and constant material properties. The influence of volume fiber fraction distributions are studied to match or eliminate an in-plane expansion coefficient, or to match a desired axial stiffness. Combining two fiber types to create a hybrid FGM can offer desirable increase in axial and bending stiffness while still retaining the useful thermal deformation behavior.

  6. A framework to measure myocardial extracellular volume fraction using dual-phase low dose CT images

    International Nuclear Information System (INIS)

    Liu, Yixun; Summers, Ronald M.; Yao, Jianhua; Liu, Songtao; Sibley, Christopher T.; Bluemke, David A.; Nacif, Marcelo S.

    2013-01-01

    Purpose: Myocardial extracellular volume fraction (ECVF) is a surrogate imaging biomarker of diffuse myocardial fibrosis, a hallmark of pathologic ventricular remodeling. Low dose cardiac CT is emerging as a promising modality to detect diffuse interstitial myocardial fibrosis due to its fast acquisition and low radiation; however, the insufficient contrast in the low dose CT images poses great challenge to measure ECVF from the image. Methods: To deal with this difficulty, the authors present a complete ECVF measurement framework including a point-guided myocardial modeling, a deformable model-based myocardium segmentation, nonrigid registration of pre- and post-CT, and ECVF calculation. Results: The proposed method was evaluated on 20 patients by two observers. Compared to the manually delineated reference segmentations, the accuracy of our segmentation in terms of true positive volume fraction (TPVF), false positive volume fraction (FPVF), and average surface distance (ASD), were 92.18% ± 3.52%, 0.31% ± 0.10%, 0.69 ± 0.14 mm, respectively. The interobserver variability measured by concordance correlation coefficient regarding TPVF, FPVF, and ASD were 0.95, 0.90, 0.94, respectively, demonstrating excellent agreement. Bland-Altman method showed 95% limits of agreement between ECVF at CT and ECVF at MR. Conclusions: The proposed framework demonstrates its efficiency, accuracy, and noninvasiveness in ECVF measurement and dramatically advances the ECVF at cardiac CT toward its clinical use

  7. Salinity independent volume fraction prediction in water-gas-oil multiphase flows using artificial neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, C.M.; Pereira, Claudio M.N.A.; Brandao, Luis E.B., E-mail: otero@ien.gov.b, E-mail: cmnap@ien.gov.b, E-mail: brandao@ien.gov.b [Instituto de Engenharia Nuclear (DIRA/IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Div. de Radiofarmacos

    2011-07-01

    This work investigates the response of a volume fraction prediction system for water-gas-oil multiphase flows considering variations on water salinity. The approach is based on gamma-ray pulse height distributions pattern recognition by means the artificial neural networks (ANNs). The detection system uses appropriate fan beam geometry, comprised of a dual-energy gamma-ray source and two NaI(Tl) detectors adequately positioned outside the pipe in order measure transmitted and scattered beams. An ideal and static theoretical model for annular flow regime have been developed using MCNP-X code, which was used to provide training, test and validation data for the ANN. More than 500 simulations have been done, in which water salinity have been ranged from 0 to 16% in order to cover a most practical situations. Validation tests have included values of volume fractions and water salinity different from those used in ANN training phase. The results presented here show that the proposed approach may be successfully applied to material volume fraction prediction on watergas- oil multiphase flows considering practical (real) levels of variations in water salinity. (author)

  8. Salinity independent volume fraction prediction in water-gas-oil multiphase flows using artificial neural networks

    International Nuclear Information System (INIS)

    Salgado, C.M.; Pereira, Claudio M.N.A.; Brandao, Luis E.B.

    2011-01-01

    This work investigates the response of a volume fraction prediction system for water-gas-oil multiphase flows considering variations on water salinity. The approach is based on gamma-ray pulse height distributions pattern recognition by means the artificial neural networks (ANNs). The detection system uses appropriate fan beam geometry, comprised of a dual-energy gamma-ray source and two NaI(Tl) detectors adequately positioned outside the pipe in order measure transmitted and scattered beams. An ideal and static theoretical model for annular flow regime have been developed using MCNP-X code, which was used to provide training, test and validation data for the ANN. More than 500 simulations have been done, in which water salinity have been ranged from 0 to 16% in order to cover a most practical situations. Validation tests have included values of volume fractions and water salinity different from those used in ANN training phase. The results presented here show that the proposed approach may be successfully applied to material volume fraction prediction on watergas- oil multiphase flows considering practical (real) levels of variations in water salinity. (author)

  9. A framework to measure myocardial extracellular volume fraction using dual-phase low dose CT images

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yixun; Summers, Ronald M.; Yao, Jianhua, E-mail: JYao@cc.nih.gov [Clinical Image Processing Service, Radiology and Imaging Sciences, NIH Clinical Center, Bethesda, Maryland 20892 (United States); Liu, Songtao; Sibley, Christopher T.; Bluemke, David A. [Radiology and Imaging Sciences, NIH Clinical Center, Bethesda, Maryland 20892-1182 and Molecular Biomedical Imaging Laboratory, National Institute of Biomedical Imaging and Bioengineering, NIH Clinical Center, Bethesda, Maryland 20892 (United States); Nacif, Marcelo S. [Radiology and Imaging Sciences, NIH Clinical Center, Bethesda, Maryland 20892-1182 (United States)

    2013-10-15

    Purpose: Myocardial extracellular volume fraction (ECVF) is a surrogate imaging biomarker of diffuse myocardial fibrosis, a hallmark of pathologic ventricular remodeling. Low dose cardiac CT is emerging as a promising modality to detect diffuse interstitial myocardial fibrosis due to its fast acquisition and low radiation; however, the insufficient contrast in the low dose CT images poses great challenge to measure ECVF from the image. Methods: To deal with this difficulty, the authors present a complete ECVF measurement framework including a point-guided myocardial modeling, a deformable model-based myocardium segmentation, nonrigid registration of pre- and post-CT, and ECVF calculation. Results: The proposed method was evaluated on 20 patients by two observers. Compared to the manually delineated reference segmentations, the accuracy of our segmentation in terms of true positive volume fraction (TPVF), false positive volume fraction (FPVF), and average surface distance (ASD), were 92.18% ± 3.52%, 0.31% ± 0.10%, 0.69 ± 0.14 mm, respectively. The interobserver variability measured by concordance correlation coefficient regarding TPVF, FPVF, and ASD were 0.95, 0.90, 0.94, respectively, demonstrating excellent agreement. Bland-Altman method showed 95% limits of agreement between ECVF at CT and ECVF at MR. Conclusions: The proposed framework demonstrates its efficiency, accuracy, and noninvasiveness in ECVF measurement and dramatically advances the ECVF at cardiac CT toward its clinical use.

  10. Soot volume fraction in a piloted turbulent jet non-premixed flame of natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Qamar, N.H.; Alwahabi, Z.T.; King, K.D. [Fluid Mechanics, Energy and Combustion Group, University of Adelaide, Adelaide, SA 5005 (Australia); School of Chemical Engineering, University of Adelaide, Adelaide, SA 5005 (Australia); Chan, Q.N. [Fluid Mechanics, Energy and Combustion Group, University of Adelaide, Adelaide, SA 5005 (Australia); School of Chemical Engineering, University of Adelaide, Adelaide, SA 5005 (Australia); School of Mechanical Engineering, University of Adelaide, Adelaide, SA 5005 (Australia); Nathan, G.J. [Fluid Mechanics, Energy and Combustion Group, University of Adelaide, Adelaide, SA 5005 (Australia); School of Mechanical Engineering, University of Adelaide, Adelaide, SA 5005 (Australia); Roekaerts, D. [Department of Multi-Scale Physics, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg, 1, NL-2628 CJ Delft (Netherlands)

    2009-07-15

    Planar laser-induced incandescence (LII) has been used to measure soot volume fraction in a well-characterised, piloted, turbulent non-premixed flame known as the ''Delft Flame III''. Simulated Dutch natural gas was used as the fuel to produce a flame closely matching those in which a wide range of previous investigations, both experimental and modelling, have been performed. The LII method was calibrated using a Santoro-style burner with ethylene as the fuel. Instantaneous and time-averaged data of the axial and radial soot volume fraction distributions of the flame are presented here along with the Probability Density Functions (PDFs) and intermittency. The PDFs were found to be well-characterised by a single exponential distribution function. The distribution of soot was found to be highly intermittent, with intermittency typically exceeding 97%, which increases measurement uncertainty. The instantaneous values of volume fraction are everywhere less than the values in strained laminar flames. This is consistent with the soot being found locally in strained flame sheets that are convected and distorted by the flow. (author)

  11. Physical aging and structural recovery in a colloidal glass subjected to volume-fraction jump conditions

    Science.gov (United States)

    Peng, Xiaoguang; McKenna, Gregory B.

    2016-04-01

    Three important kinetic phenomena have been cataloged by Kovacs in the investigation of molecular glasses during structural recovery or physical aging. These are responses to temperature-jump histories referred to as intrinsic isotherms, asymmetry of approach, and memory effect. Here we use a thermosensitive polystyrene-poly (N -isopropylacrylamide)-poly (acrylic acid) core-shell particle-based dispersion as a colloidal model and by working at a constant number concentration of particles we use temperature changes to create volume-fraction changes. This imposes conditions similar to those defined by Kovacs on the colloidal system. We use creep experiments to probe the physical aging and structural recovery behavior of colloidal glasses in the Kovacs-type histories and compare the results with those seen in molecular glasses. We find that there are similarities in aging dynamics between molecular glasses and colloidal glasses, but differences also persist. For the intrinsic isotherms, the times teq needed for relaxing or evolving into the equilibrium (or stationary) state are relatively insensitive to the volume fraction and the values of teq are longer than the α -relaxation time τα at the same volume fraction. On the other hand, both of these times grow at least exponentially with decreasing temperature in molecular glasses. For the asymmetry of approach, similar nonlinear behavior is observed for both colloidal and molecular glasses. However, the equilibration time teq is the same for both volume-fraction up-jump and down-jump experiments, different from the finding in molecular glasses that it takes longer for the structure to evolve into equilibrium for the temperature up-jump condition than for the temperature down-jump condition. For the two-step volume-fraction jumps, a memory response is observed that is different from observations of structural recovery in two-step temperature histories in molecular glasses. The concentration dependence of the dynamics

  12. Validity of automated measurement of left ventricular ejection fraction and volume using the Philips EPIQ system.

    Science.gov (United States)

    Hovnanians, Ninel; Win, Theresa; Makkiya, Mohammed; Zheng, Qi; Taub, Cynthia

    2017-11-01

    To assess the efficiency and reproducibility of automated measurements of left ventricular (LV) volumes and LV ejection fraction (LVEF) in comparison to manually traced biplane Simpson's method. This is a single-center prospective study. Apical four- and two-chamber views were acquired in patients in sinus rhythm. Two operators independently measured LV volumes and LVEF using biplane Simpson's method. In addition, the image analysis software a2DQ on the Philips EPIQ system was applied to automatically assess the LV volumes and LVEF. Time spent on each analysis, using both methods, was documented. Concordance of echocardiographic measures was evaluated using intraclass correlation (ICC) and Bland-Altman analysis. Manual tracing and automated measurement of LV volumes and LVEF were performed in 184 patients with a mean age of 67.3 ± 17.3 years and BMI 28.0 ± 6.8 kg/m 2 . ICC and Bland-Altman analysis showed good agreements between manual and automated methods measuring LVEF, end-systolic, and end-diastolic volumes. The average analysis time was significantly less using the automated method than manual tracing (116 vs 217 seconds/patient, P Automated measurement using the novel image analysis software a2DQ on the Philips EPIQ system produced accurate, efficient, and reproducible assessment of LV volumes and LVEF compared with manual measurement. © 2017, Wiley Periodicals, Inc.

  13. Quantitative gated SPECT: the effect of reconstruction filter on calculated left ventricular ejection fractions and volumes

    International Nuclear Information System (INIS)

    Wright, Graham A.; McDade, Mark; Martin, William; Hutton, William

    2002-01-01

    Gated SPECT (GSPECT) offers the possibility of obtaining additional functional information from perfusion studies, including calculation of left ventricular ejection fraction (LVEF). The calculation of LVEF relies upon the identification of the endocardial surface, which will be affected by the spatial resolution and statistical noise in the reconstructed images. The aim of this study was to compare LVEFs and ventricular volumes calculated from GSPECT using six reconstruction filters. GSPECT and radionuclide ventriculography (RNVG) were performed on 40 patients; filtered back projection was used to reconstruct the datasets with each filter. LVEFs and volumes were calculated using the Cedars-Sinai QGS package. The correlation coefficient between RNVG and GSPECT ranged from 0.81 to 0.86 with higher correlations for smoother filters. The narrowest prediction interval was 11±2%. There was a trend towards higher LVEF values with smoother filters, the ramp filter yielding LVEFs 2.55±3.10% (p<0.001) lower than the Hann filter. There was an overall fall in ventricular volumes with smoother filters with a mean difference of 13.98±10.15 ml (p<0.001) in EDV between the Butterworth-0.5 and Butterworth-0.3 filters. In conclusion, smoother reconstruction filters lead to lower volumes and higher ejection fractions with the QGS algorithm, with the Butterworth-0.4 filter giving the highest correlation with LVEFs from RNVG. Even if the optimal filter is chosen the uncertainty in the measured ejection fractions is still too great to be clinically acceptable. (author)

  14. Study of volume fractions for stratified and annular regime in multiphase flows using gamma-rays and artificial neural network

    International Nuclear Information System (INIS)

    Salgado, Cesar M.; Brandao, Luis Eduardo; Pereira, Claudio M.N.A.; Ramos, Robson; Schirru, Roberto; Silva, Ademir X.

    2007-01-01

    This work presents methodology based on the use of nuclear technique and artificial intelligence for attainment of volume fractions in stratified and annular multiphase flow regime, oil-water-gas, very frequent in the offshore industry petroliferous. Using the principles of absorption and scattering of gamma-rays and an adequate geometry scheme of detection with two detectors and two energies measurement are gotten and they vary as changes in the volume fractions of flow regime occur. The MCNP-X code was used in order to provide the data training for artificial neural network that matched such information with the respective actual volume fractions of each material. (author)

  15. Study of volume fractions for stratified and annular regime in multiphase flows using gamma-rays and artificial neural network

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, Cesar M.; Brandao, Luis Eduardo; Pereira, Claudio M.N.A.; Ramos, Robson [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)]. E-mail: otero@ien.gov.br; brandao@ien.gov.br; cmnap@ien.gov.br; robson@ien.gov.br; Schirru, Roberto; Silva, Ademir X. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE). Programa de Energia Nuclear (PEN)]. E-mails: ademir@con.ufrj.br; schirru@lmp.ufrj.br

    2007-07-01

    This work presents methodology based on the use of nuclear technique and artificial intelligence for attainment of volume fractions in stratified and annular multiphase flow regime, oil-water-gas, very frequent in the offshore industry petroliferous. Using the principles of absorption and scattering of gamma-rays and an adequate geometry scheme of detection with two detectors and two energies measurement are gotten and they vary as changes in the volume fractions of flow regime occur. The MCNP-X code was used in order to provide the data training for artificial neural network that matched such information with the respective actual volume fractions of each material. (author)

  16. Beam Attenuators and the Risk of Unrecognized Large-Fraction Irradiation of Critical Tissues

    International Nuclear Information System (INIS)

    Luka, S.; Marks, J.E.

    2015-01-01

    The use of radiation beam attenuators led to radiation injury of the spinal cord in one patient and of the peripheral nerve in another due to unsuspected large-fraction irradiation. The anatomic distribution of radiation dose was reconstructed in the sagittal plane for the patient who developed radiation myelopathy and in the axial plane for the patient who developed peripheral neuropathy. The actual dose delivered to the injured structure in each patient was taken from the dose distribution and recorded along with the time, number of fractions, and dose per fraction. The patient who developed radiation myelopathy received a total of 46.5 Gy in twenty-three 2.1 Gy fractions in 31 days to the upper cervical spinal cord where the thickness of the neck was less than the central axis thickness due to cervical lordosis and absence of a posterior compensating filter. The patient who developed peripheral neuropathy received 55 Gy in twenty-five 2.2 Gy fractions in 50 days to the femoral nerve using bolus over the groins and an anterior one-half value layer Cerrobend pelvic block to bias the dose anteriorly. Compensating filters and other beam attenuators should be used with caution because they may result in unsuspected large-fraction irradiation and total doses of radiation that exceed the tolerance of critical structures.

  17. Beam Attenuators and the Risk of Unrecognized Large-Fraction Irradiation of Critical Tissues

    Energy Technology Data Exchange (ETDEWEB)

    Luka, S.; Marks, J.E.

    2015-01-15

    The use of radiation beam attenuators led to radiation injury of the spinal cord in one patient and of the peripheral nerve in another due to unsuspected large-fraction irradiation. The anatomic distribution of radiation dose was reconstructed in the sagittal plane for the patient who developed radiation myelopathy and in the axial plane for the patient who developed peripheral neuropathy. The actual dose delivered to the injured structure in each patient was taken from the dose distribution and recorded along with the time, number of fractions, and dose per fraction. The patient who developed radiation myelopathy received a total of 46.5 Gy in twenty-three 2.1 Gy fractions in 31 days to the upper cervical spinal cord where the thickness of the neck was less than the central axis thickness due to cervical lordosis and absence of a posterior compensating filter. The patient who developed peripheral neuropathy received 55 Gy in twenty-five 2.2 Gy fractions in 50 days to the femoral nerve using bolus over the groins and an anterior one-half value layer Cerrobend pelvic block to bias the dose anteriorly. Compensating filters and other beam attenuators should be used with caution because they may result in unsuspected large-fraction irradiation and total doses of radiation that exceed the tolerance of critical structures.

  18. Coupling of RF antennas to large volume helicon plasma

    Directory of Open Access Journals (Sweden)

    Lei Chang

    2018-04-01

    Full Text Available Large volume helicon plasma sources are of particular interest for large scale semiconductor processing, high power plasma propulsion and recently plasma-material interaction under fusion conditions. This work is devoted to studying the coupling of four typical RF antennas to helicon plasma with infinite length and diameter of 0.5 m, and exploring its frequency dependence in the range of 13.56-70 MHz for coupling optimization. It is found that loop antenna is more efficient than half helix, Boswell and Nagoya III antennas for power absorption; radially parabolic density profile overwhelms Gaussian density profile in terms of antenna coupling for low-density plasma, but the superiority reverses for high-density plasma. Increasing the driving frequency results in power absorption more near plasma edge, but the overall power absorption increases with frequency. Perpendicular stream plots of wave magnetic field, wave electric field and perturbed current are also presented. This work can serve as an important reference for the experimental design of large volume helicon plasma source with high RF power.

  19. Birth weight and neonatal adiposity prediction using fractional limb volume obtained with 3D ultrasound.

    Science.gov (United States)

    O'Connor, Clare; O'Higgins, Amy; Doolan, Anne; Segurado, Ricardo; Stuart, Bernard; Turner, Michael J; Kennelly, Máireád M

    2014-01-01

    The objective of this investigation was to study fetal thigh volume throughout gestation and explore its correlation with birth weight and neonatal body composition. This novel technique may improve birth weight prediction and lead to improved detection rates for fetal growth restriction. Fractional thigh volume (TVol) using 3D ultrasound, fetal biometry and soft tissue thickness were studied longitudinally in 42 mother-infant pairs. The percentages of neonatal body fat, fat mass and fat-free mass were determined using air displacement plethysmography. Correlation and linear regression analyses were performed. Linear regression analysis showed an association between TVol and birth weight. TVol at 33 weeks was also associated with neonatal fat-free mass. There was no correlation between TVol and neonatal fat mass. Abdominal circumference, estimated fetal weight (EFW) and EFW centile showed consistent correlations with birth weight. Thigh volume demonstrated an additional independent contribution to birth weight prediction when added to the EFW centile from the 38-week scan (p = 0.03). Fractional TVol performed at 33 weeks gestation is correlated with birth weight and neonatal lean body mass. This screening test may highlight those at risk of fetal growth restriction or macrosomia.

  20. An investigation of the relation between the 30 meter running time and the femoral volume fraction in the thigh

    Directory of Open Access Journals (Sweden)

    MY Tasmektepligil

    2009-12-01

    Full Text Available Leg components are thought to be a related to speed. Only a limited number of studies have, however, examined the interaction between speed and bone size. In this study, we examined the relationship between the time taken by football players to run thirty meters and the fraction which the femur forms compared to the entire thigh region. Data collected from thirty male football players of average age 17.3 (between 16-19 years old were analyzed. First we detected the thirty meter running times and then we estimated the volume fraction of the femur to the entire thigh region using stereological methods on magnetic resonance images. Our data showed that there was a highly negative relationship between the 30 meter running times and the volume fraction of the bone to the thigh region. Thus, 30 meter running time decreases as the fraction of the bone to the thigh region increases. In other words, speed increases as the fraction of bone volume increases. Our data indicate that selecting sportsman whose femoral volume fractions are high will provide a significant benefit to enhancing performance in those branches of sports which require speed. Moreover, we concluded that training which can increase the bone volume fraction should be practiced when an increase in speed is desired and that the changes in the fraction of thigh region components should be monitored during these trainings.

  1. A digital gain stabilizer for large volume organic scintillation detectors

    International Nuclear Information System (INIS)

    Braunsfurth, J.; Geske, K.

    1976-01-01

    A digital gain stabilizer is described, optimized for use with photomultipliers mounted on large volume organic scintillators, or other radiation detectors, which exhibit no prominent peaks in their amplitude spectra. As applications of this kind usually involve many phototubes or detectors, circuit simplicity, production reproduceability, and the possibility of computer controlled operation were major design criteria. Two versions were built, the first one using standard TTL-SSI and MSI circuitry, the second one - to reduce power requirements - using a mixture of TTL- and CMOS-LSI circuits. (Auth.)

  2. Removal of rare gases from large volume airstreams

    International Nuclear Information System (INIS)

    Hopke, P.K.; Leong, K.H.; Stukel, J.J.; Lewis, C.; Jebackumar, R.; Illinois Univ., Urbana; Illinois Univ., Urbana

    1986-01-01

    The cost-effective removal of low levels of rare gases and particularly radon from large volume air flows is a difficult problem. The use of various scrubbing systems using non-conventional fluids has been studied. The parameters for both a packed tower absorber and a gas scrubber have been calculated for a system using perfluorobenzene as the fluid. Based on these parameters, a packed bed tower of conventional proportions is feasible for the removal of >95% of 37 Bq/m 3 of radon from a flow of 4.7 m 3 /second. (author)

  3. Naturally light hidden photons in LARGE volume string compactifications

    International Nuclear Information System (INIS)

    Goodsell, M.; Jaeckel, J.; Redondo, J.; Ringwald, A.

    2009-09-01

    Extra ''hidden'' U(1) gauge factors are a generic feature of string theory that is of particular phenomenological interest. They can kinetically mix with the Standard Model photon and are thereby accessible to a wide variety of astrophysical and cosmological observations and laboratory experiments. In this paper we investigate the masses and the kinetic mixing of hidden U(1)s in LARGE volume compactifications of string theory. We find that in these scenarios the hidden photons can be naturally light and that their kinetic mixing with the ordinary electromagnetic photon can be of a size interesting for near future experiments and observations. (orig.)

  4. Entropy of level-cut random Gaussian structures at different volume fractions.

    Science.gov (United States)

    Marčelja, Stjepan

    2017-10-01

    Cutting random Gaussian fields at a given level can create a variety of morphologically different two- or several-phase structures that have often been used to describe physical systems. The entropy of such structures depends on the covariance function of the generating Gaussian random field, which in turn depends on its spectral density. But the entropy of level-cut structures also depends on the volume fractions of different phases, which is determined by the selection of the cutting level. This dependence has been neglected in earlier work. We evaluate the entropy of several lattice models to show that, even in the cases of strongly coupled systems, the dependence of the entropy of level-cut structures on molar fractions of the constituents scales with the simple ideal noninteracting system formula. In the last section, we discuss the application of the results to binary or ternary fluids and microemulsions.

  5. Entropy of level-cut random Gaussian structures at different volume fractions

    Science.gov (United States)

    Marčelja, Stjepan

    2017-10-01

    Cutting random Gaussian fields at a given level can create a variety of morphologically different two- or several-phase structures that have often been used to describe physical systems. The entropy of such structures depends on the covariance function of the generating Gaussian random field, which in turn depends on its spectral density. But the entropy of level-cut structures also depends on the volume fractions of different phases, which is determined by the selection of the cutting level. This dependence has been neglected in earlier work. We evaluate the entropy of several lattice models to show that, even in the cases of strongly coupled systems, the dependence of the entropy of level-cut structures on molar fractions of the constituents scales with the simple ideal noninteracting system formula. In the last section, we discuss the application of the results to binary or ternary fluids and microemulsions.

  6. Large volume syringe pump extruder for desktop 3D printers

    Directory of Open Access Journals (Sweden)

    Kira Pusch

    2018-04-01

    Full Text Available Syringe pump extruders are required for a wide range of 3D printing applications, including bioprinting, embedded printing, and food printing. However, the mass of the syringe becomes a major challenge for most printing platforms, requiring compromises in speed, resolution and/or volume. To address these issues, we have designed a syringe pump large volume extruder (LVE that is compatible with low-cost, open source 3D printers, and herein demonstrate its performance on a PrintrBot Simple Metal. Key aspects of the LVE include: (1 it is open source and compatible with open source hardware and software, making it inexpensive and widely accessible to the 3D printing community, (2 it utilizes a standard 60 mL syringe as its ink reservoir, effectively increasing print volume of the average bioprinter, (3 it is capable of retraction and high speed movements, and (4 it can print fluids using nozzle diameters as small as 100 μm, enabling the printing of complex shapes/objects when used in conjunction with the freeform reversible embedding of suspended hydrogels (FRESH 3D printing method. Printing performance of the LVE is demonstrated by utilizing alginate as a model biomaterial ink to fabricate parametric CAD models and standard calibration objects. Keywords: Additive manufacturing, 3D bioprinting, Embedded printing, FRESH, Soft materials extrusion

  7. Stratification of mixtures in evaporating liquid films occurs only for a range of volume fractions of the smaller component

    Science.gov (United States)

    Sear, Richard P.

    2018-04-01

    I model the drying of a liquid film containing small and big colloid particles. Fortini et al. [Phys. Rev. Lett. 116, 118301 (2016)] studied these films with both computer simulation and experiment. They found that at the end of drying, the mixture had stratified with a layer of the smaller particles on top of the big particles. I develop a simple model for this process. The model has two ingredients: arrest of the diffusion of the particles at high density and diffusiophoretic motion of the big particles due to gradients in the volume fraction of the small particles. The model predicts that stratification only occurs over a range of initial volume fractions of the smaller colloidal species. Above and below this range, the downward diffusiophoretic motion of the big particles is too slow to remove the big particles from the top of the film, and so there is no stratification. In agreement with earlier work, the model also predicts that large Péclet numbers for drying are needed to see stratification.

  8. SOLA-VOF, 2-D Transient Hydrodynamic Using Fractional Volume of Fluid Method

    International Nuclear Information System (INIS)

    Nichols, B.D.; Hirt, C.W.; Hotchkiss, R.S.

    1991-01-01

    1 - Description of problem or function: SOLA-VOF is a program for the solution of two-dimensional transient fluid flow with free boundaries, based on the concept of a fractional volume of fluid (VOF). Its basic mode of operation is for single fluid calculations having multiple free surfaces. However, SOLA-VOF can also be used for calculations involving two fluids separated by a sharp interface. In either case, the fluids may be treated as incompressible or as having limited compressibility. Surface tension forces with wall adhesion are permitted in both cases. Internal obstacles may be defined by blocking out any desired combination of cells in the mesh, which is composed of rectangular cells of variable size. 2 - Method of solution: The basis of the SOLA-VOF method is the fractional volume of fluid scheme for tracking free boundaries. In this technique, a function F(x,y,t) is defined whose value is unity at any point occupied by fluid and zero elsewhere. When averaged over the cells of a computational mesh, the average value of F in a cell is equal to the fractional volume of the cell occupied by fluid. In particular, a unit value of F corresponds to a cell full of fluid, whereas a zero value indicates that the cell contains no fluid. Cells with F values between zero and one contain a free surface. SOLA-VOF uses an Eulerian mesh of rectangular cells having variable sizes. The fluid equations solved are the finite difference approximations of the Navier-Stokes equations. 3 - Restrictions on the complexity of the problem: The setting of array dimensions is controlled through PARAMETER statements

  9. APPHi: Automated Photometry Pipeline for High Cadence Large Volume Data

    Science.gov (United States)

    Sánchez, E.; Castro, J.; Silva, J.; Hernández, J.; Reyes, M.; Hernández, B.; Alvarez, F.; García T.

    2018-04-01

    APPHi (Automated Photometry Pipeline) carries out aperture and differential photometry of TAOS-II project data. It is computationally efficient and can be used also with other astronomical wide-field image data. APPHi works with large volumes of data and handles both FITS and HDF5 formats. Due the large number of stars that the software has to handle in an enormous number of frames, it is optimized to automatically find the best value for parameters to carry out the photometry, such as mask size for aperture, size of window for extraction of a single star, and the number of counts for the threshold for detecting a faint star. Although intended to work with TAOS-II data, APPHi can analyze any set of astronomical images and is a robust and versatile tool to performing stellar aperture and differential photometry.

  10. A randomized trial comparing bladder volume consistency during fractionated prostate radiation therapy

    LENUS (Irish Health Repository)

    Mullaney, L.

    2014-01-10

    Organ motion is a contributory factor to the variation in location of the prostate and organs at risk during a course of fractionated prostate radiation therapy (RT). A prospective randomized controlled trial was designed with the primary endpoint to provide evidence-based bladder-filling instructions to achieve a consistent bladder volume (BV) and thus reduce the bladder-related organ motion. The secondary endpoints were to assess the incidence of acute and late genitourinary (GU) and gastrointestinal (GI) toxicity for patients and patients’ satisfaction with the bladder-filling instructions.

  11. Structuring polymer blends with bicontinuous phase morphology. Part II. Tailoring blends with ultralow critical volume fraction

    DEFF Research Database (Denmark)

    Lyngaae-Jørgensen, Jørgen; Utracki, Leszek

    2003-01-01

    A hypothesis providing a guideline for the development of immiscible polymer blends with co-continuous phase structure at very low critical volume fraction of one component is. postulated and experimentally verified. Based on a number of simplifying assumptions the following relation was derived......: phi(cr) = k(lambdagamma)(1-z)/(theta(b)(*))(z) where lambdagamma is a Deborah number and theta(b)(*) is a dimensionless break-up time. The equation parameters, k and z are constant that depend on the flow field hence on the blending equipment. For the studies an internal mixer with Walzenkneter...

  12. System modeling and identification in indicator dilution method for assessment of ejection fraction and pulmonary blood volume

    NARCIS (Netherlands)

    Bharath, H.N.; Prabhu, K.M.M.; Korsten, H.H.M.; Mischi, M.

    2012-01-01

    Clinically relevant cardiovascular parameters, such as pulmonary blood volume (PBV) and ejection fraction (EF), can be assessed through indicator dilution techniques. Among these techniques, which are typically invasive due to the need for central catheterization, contrast ultrasonography provides a

  13. Effects of diluents on soot surface temperature and volume fraction in diluted ethylene diffusion flames at pressure

    KAUST Repository

    Kailasanathan, Ranjith Kumar Abhinavam; Zhang, Ji; Fang, Tiegang; Roberts, William L.

    2014-01-01

    Soot surface temperature and volume fraction are measured in ethylene/air coflowing laminar diffusion flames at high pressures, diluted with one of four diluents (argon, helium, nitrogen, and carbon dioxide) using a two-color technique. Both

  14. Effect of large volume paracentesis on plasma volume--a cause of hypovolemia

    International Nuclear Information System (INIS)

    Kao, H.W.; Rakov, N.E.; Savage, E.; Reynolds, T.B.

    1985-01-01

    Large volume paracentesis, while effectively relieving symptoms in patients with tense ascites, has been generally avoided due to reports of complications attributed to an acute reduction in intravascular volume. Measurements of plasma volume in these subjects have been by indirect methods and have not uniformly confirmed hypovolemia. We have prospectively evaluated 18 patients (20 paracenteses) with tense ascites and peripheral edema due to chronic liver disease undergoing 5 liter paracentesis for relief of symptoms. Plasma volume pre- and postparacentesis was assessed by a 125 I-labeled human serum albumin dilution technique as well as by the change in hematocrit and postural blood pressure difference. No significant change in serum sodium, urea nitrogen, hematocrit or postural systolic blood pressure difference was noted at 24 or 48 hr after paracentesis. Serum creatinine at 24 hr after paracentesis was unchanged but a small but statistically significant increase in serum creatinine was noted at 48 hr postparacentesis. Plasma volume changed -2.7% (n = 6, not statistically significant) during the first 24 hr and -2.8% (n = 12, not statistically significant) during the 0- to 48-hr period. No complications from paracentesis were noted. These results suggest that 5 liter paracentesis for relief of symptoms is safe in patients with tense ascites and peripheral edema from chronic liver disease

  15. Self Absorbed Fraction for Electrons and Beta Particles in Small Spherical Volumes

    International Nuclear Information System (INIS)

    Grosev, D.

    2003-01-01

    Absorbed fraction and target organ mass are important parameters of internal dosimetry calculations that define the geometry of the system. Standard MIRD (Medical Internal Radiation Dosimetry) formalism assumes that the absorbed fraction for non-penetrating radiations (e.g., electrons, beta particles) is 1. This may not be correct in cases where dimensions of organs/tissues are comparable with the ranges of electrons/beta particles. Such is the case for example in radiodine ablation of thyroid remnant tissue. In this work the self-absorbed fraction (source and target volumes are the same) for monoenergetic electrons and beta particles is calculated for small spherical volumes of various sizes and unit density. Absorbed fraction can be expressed as an integral of the product of two quantities: (a) Scaled beta dose point kernel (mean absorbed dose rate per activity of the point source in infinite homogenous medium), F β ; (b) special geometrical reduction factor (GRF). F β is calculated using EGS4 Monte Carlo (MC) code for transport of electrons and photons. MC source code calculates the deposition of energy inside concentric spherical shells around the isotropic point source of electrons/beta particles in infinite medium (water). Shell thickness was δr=0.02·X 90 , where X 90 represents the radius of the sphere inside which 90% of the source energy is absorbed. Number of concentric spherical shells was 100, 10000 electron histories were started in each program run, and 10 runs were repeated for statistical reason. Numerical integration of the product of F β , calculated by MC program, and GRF for sphere was done using Simpson method. Absorbed fractions were calculated for spheres with mass from 0.01-20 g (r = 0.13 - 1.68 cm). Results are given for monoenergetic electrons with kinetic energy T=0.2, 0.4, 1.0 MeV, and for three beta emitters 1 31I , 3 2P , 9 0Y . For quantitative dosimetric protocols in radioiodine ablation therapy, results for 1 31I are of

  16. Doping the 1 kton Large Volume Detector with Gd

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, Gianmarco [University of L' Aquila, Via Vetoio snc, 67100 Coppito (AQ) Italy (Italy); Fulgione, Walter; Porta, Amanda [Istituto di Fisica dello Spazio Interplanetario, INAF, Corso Fiume 4, Torino (Italy); Machado, Ana Amelia Bergamini [Laboratori Nazionali del Gran Sasso, INFN, s.s. 17bis Km 18-10, Assergi (AQ) (Italy); Mal' gin, Alexei [Institute for Nuclear Research, Russian Academy of Sciences, pr. Shestidesyatiletiya Oktyabrya 7a, Moscow, 117312 (Russian Federation); Molinario, Andrea; Vigorito, Carlo, E-mail: bruno@to.infn.it, E-mail: fulgione@to.infn.it, E-mail: ana.machado@lngs.infn.it, E-mail: malgin@lngs.infn.it, E-mail: amolinar@to.infn.it, E-mail: Amanda.Porta@subatech.in2p3.fr, E-mail: vigorito@to.infn.it [INFN, Via Pietro Giuria 1, Torino (Italy)

    2011-06-01

    The Large Volume Detector (LVD) in the INFN Gran Sasso National Laboratory (LNGS), Italy, is a ν observatory which has been monitoring the Galaxy since June 1992 to study neutrinos from core collapse supernovae. The experiment in the present configuration is made by 840 scintillator detectors, for a total active mass of 1000 tons. The detector sensitivity to neutrino bursts due to a core collapse supernova has been already discussed in term of maximum detectable distance. In this paper we evaluate the improvements that LVD could obtain if all its active scintillator mass was doped with a small amount (0.14% in weight) of Gadolinium. We simulated neutron captures following ν-bar {sub e} inverse beta decay reactions in one LVD counter (1.2 ton) with Gd doped liquid scintillator obtaining an efficiency for the detection of this process of η{sub n}|{sub Gd} = 80% and a mean capture time τ = 25μs, in good agreement with the results obtained by the measures. This implies a gain of a factor ∼ 20 in the signal to noise ratio for neutron capture detection with respect to the undoped liquid scintillator. We discuss how the captures of neutrons from rock radioactivity on Gd modify the background conditions of the detector and we calculate the curves expressing the sensitivity to a ν-bar {sub e} burst from core collapse supernovae depending on the distance of the collapsing star. It results that doping the 1 kton Large Volume Detector with Gd would assure a 90% detection efficiency at the distance of the Large Magellanic Cloud (50 kpc), an achievement which is equivalent to that obtained by doubling the number of counters in LVD.

  17. Doping the 1 kton Large Volume Detector with Gd

    International Nuclear Information System (INIS)

    Bruno, Gianmarco; Fulgione, Walter; Porta, Amanda; Machado, Ana Amelia Bergamini; Mal'gin, Alexei; Molinario, Andrea; Vigorito, Carlo

    2011-01-01

    The Large Volume Detector (LVD) in the INFN Gran Sasso National Laboratory (LNGS), Italy, is a ν observatory which has been monitoring the Galaxy since June 1992 to study neutrinos from core collapse supernovae. The experiment in the present configuration is made by 840 scintillator detectors, for a total active mass of 1000 tons. The detector sensitivity to neutrino bursts due to a core collapse supernova has been already discussed in term of maximum detectable distance. In this paper we evaluate the improvements that LVD could obtain if all its active scintillator mass was doped with a small amount (0.14% in weight) of Gadolinium. We simulated neutron captures following ν-bar e inverse beta decay reactions in one LVD counter (1.2 ton) with Gd doped liquid scintillator obtaining an efficiency for the detection of this process of η n | Gd = 80% and a mean capture time τ = 25μs, in good agreement with the results obtained by the measures. This implies a gain of a factor ∼ 20 in the signal to noise ratio for neutron capture detection with respect to the undoped liquid scintillator. We discuss how the captures of neutrons from rock radioactivity on Gd modify the background conditions of the detector and we calculate the curves expressing the sensitivity to a ν-bar e burst from core collapse supernovae depending on the distance of the collapsing star. It results that doping the 1 kton Large Volume Detector with Gd would assure a 90% detection efficiency at the distance of the Large Magellanic Cloud (50 kpc), an achievement which is equivalent to that obtained by doubling the number of counters in LVD

  18. A large deviation principle in H\\"older norm for multiple fractional integrals

    OpenAIRE

    Sanz-Solé, Marta; Torrecilla-Tarantino, Iván

    2007-01-01

    For a fractional Brownian motion $B^H$ with Hurst parameter $H\\in]{1/4},{1/2}[\\cup]{1/2},1[$, multiple indefinite integrals on a simplex are constructed and the regularity of their sample paths are studied. Then, it is proved that the family of probability laws of the processes obtained by replacing $B^H$ by $\\epsilon^{{1/2}} B^H$ satisfies a large deviation principle in H\\"older norm. The definition of the multiple integrals relies upon a representation of the fractional Brownian motion in t...

  19. Inter fraction variations in rectum and bladder volumes and dose distributions during high dose rate brachytherapy treatment of the uterine cervix investigated by repetitive CT-examinations

    International Nuclear Information System (INIS)

    Hellebust, Taran Paulsen; Dale, Einar; Skjoensberg, Ane; Olsen, Dag Rune

    2001-01-01

    Purpose: To evaluate variation of dose to organs at risk for patients receiving fractionated high dose rate gynaecological brachytherapy by using CT-based 3D treatment planning and dose-volume histograms (DVH). Materials and methods: Fourteen patients with cancer of the uterine cervix underwent three to six CT examinations (mean 4.9) during their course of high-dose-rate brachytherapy using radiographically compatible applicators. The rectal and bladder walls were delineated and DVHs were calculated. Results: Inter fraction variation of the bladder volume (CV mean =44.1%) was significantly larger than the inter fraction variation of the mean dose (CV mean =19.9%, P=0.005) and the maximum dose (CV mean =17.5%, P=0.003) of the bladder wall. The same trend was seen for rectum, although the figures were not significantly different. Performing CT examinations at four of seven brachytherapy fractions reduced the uncertainty to 4 and 7% for the bladder and rectal doses, respectively. A linear regression analysis showed a significant, negative relationship between time after treatment start and the whole bladder volume (P=0.018), whereas no correlation was found for the rectum. For both rectum and bladder a linear regression analysis revealed a significant, negative relationship between the whole volume and median dose (P<0.05). Conclusion: Preferably a CT examination should be provided at every fraction. However, this is logistically unfeasible in most institutions. To obtain reliable DVHs the patients will in the future undergo 3-4 CT examinations during the course of brachytherapy at our institution. Since this study showed an association between large bladder volumes and dose reductions, the patients will be treated with a standardized bladder volume

  20. Effects of local single and fractionated X-ray doses on rat bone marrow blood flow and red blood cell volume

    International Nuclear Information System (INIS)

    Pitkaenen, M.A.; Hopewell, J.W.

    1985-01-01

    Time and dose dependent changes in blood flow and red blood cell volume were studied in the locally irradiated bone marrow of the rat femur after single and fractionated doses of X-rays. With the single dose of 10 Gy the bone marrow blood flow although initially reduced returned to the control levels by seven months after irradiation. With doses >=15 Gy the blood flow was still significantly reduced at seven months. The total dose levels predicted by the nominal standard dose equation for treatments in three, six or nine fractions produced approximately the same degree of reduction in the bone marrow blood flow seven months after the irradiation. However, the fall in the red blood cell volume was from 23 to 37% greater in the three fractions groups compared with that in the nine fractions groups. Using the red blood cell volume as a parameter the nominal standard dose formula underestimated the severity of radiation damage in rat bone marrow at seven months for irradiation with small numbers of large dose fractions. (orig.) [de

  1. ESB application for effective synchronization of large volume measurements data

    CERN Document Server

    Wyszkowski, Przemysław Michał

    2011-01-01

    The TOTEM experiment at CERN aims at measurement of total cross section, elastic scattering and diffractive processes of colliding protons in the Large Hadron Collider. In order for the research to be possible, it is necessary to process huge amounts of data coming from variety of sources: TOTEM detectors, CMS detectors, measurement devices around the Large Hadron Collider tunnel and many other external systems. Preparing final results involves also calculating plenty of intermediate figures, which also need to be stored. In order for the work of the scientist to be effective and convenient it is crucial to provide central point for the data storage, where all raw and intermediate figures will be stored. This thesis aims at presenting the usage of Enterprise Service Bus concept in building software infrastructure for transferring large volume of measurements data. Topics discussed here include technologies and mechanisms realizing the concept of integration bus, model of data transferring system based on ...

  2. SUSY’s Ladder: reframing sequestering at Large Volume

    Energy Technology Data Exchange (ETDEWEB)

    Reece, Matthew [Department of Physics, Harvard University,Cambridge, MA 02138 (United States); Xue, Wei [Center for Theoretical Physics, Massachusetts Institute of Technology,Cambridge, MA 02139 (United States)

    2016-04-07

    Theories with approximate no-scale structure, such as the Large Volume Scenario, have a distinctive hierarchy of multiple mass scales in between TeV gaugino masses and the Planck scale, which we call SUSY’s Ladder. This is a particular realization of Split Supersymmetry in which the same small parameter suppresses gaugino masses relative to scalar soft masses, scalar soft masses relative to the gravitino mass, and the UV cutoff or string scale relative to the Planck scale. This scenario has many phenomenologically interesting properties, and can avoid dangers including the gravitino problem, flavor problems, and the moduli-induced LSP problem that plague other supersymmetric theories. We study SUSY’s Ladder using a superspace formalism that makes the mysterious cancelations in previous computations manifest. This opens the possibility of a consistent effective field theory understanding of the phenomenology of these scenarios, based on power-counting in the small ratio of string to Planck scales. We also show that four-dimensional theories with approximate no-scale structure enforced by a single volume modulus arise only from two special higher-dimensional theories: five-dimensional supergravity and ten-dimensional type IIB supergravity. This gives a phenomenological argument in favor of ten dimensional ultraviolet physics which is different from standard arguments based on the consistency of superstring theory.

  3. An annular BF3 counter of large sensitive volume

    International Nuclear Information System (INIS)

    Janardhanan, S.; Swaminathan, N.

    1975-01-01

    An annular neutron counter having a large sensitive volume with inner and outer diameter 31 cms with multiple electrode system fabricated especially to measure the neutron output from fissile region of standard fast reactor fuel of length nearly equivalent to 500 cms is described. The counter efficiency is nearly 0.3% for neutron and sensitivity 0.0018 counts/neutron for (alpha, neutron) and spontaneous fission source. Its other potential applications which are indicated are : (1) quality control of fast reactor fuel pins (2) fuel inventory (3) assessing radioactivity of solid waste packets containing PuO 2 (4) uniformity of fuel loading of a reactor and (5) neutron monitoring in a fuel plant. (M.G.B.)

  4. Investigation of a large volume negative hydrogen ion source

    International Nuclear Information System (INIS)

    Courteille, C.; Bruneteau, A.M.; Bacal, M.

    1995-01-01

    The electron and negative ion densities and temperatures are reported for a large volume hybrid multicusp negative ion source. Based on the scaling laws an analysis is made of the plasma formation and loss processes. It is shown that the positive ions are predominantly lost to the walls, although the observed scaling law is n + ∝I 0.57 d . However, the total plasma loss scales linearly with the discharge current, in agreement with the theoretical model. The negative ion formation and loss is also discussed. It is shown that at low pressure (1 mTorr) the negative ion wall loss becomes a significant part of the total loss. The dependence of n - /n e versus the electron temperature is reported. When the negative ion wall loss is negligible, all the data on n - /n e versus the electron temperatures fit a single curve. copyright 1995 American Institute of Physics

  5. Dilute scintillators for large-volume tracking detectors

    Energy Technology Data Exchange (ETDEWEB)

    Reeder, R.A. (University of New Mexico, Albuquerque, NM (United States)); Dieterle, B.D. (University of New Mexico, Albuquerque, NM (United States)); Gregory, C. (University of New Mexico, Albuquerque, NM (United States)); Schaefer, F. (University of New Mexico, Albuquerque, NM (United States)); Schum, K. (University of New Mexico, Albuquerque, NM (United States)); Strossman, W. (University of California, Riverside, CA (United States)); Smith, D. (Embry-Riddle Aeronautical Univ., Prescott, AZ (United States)); Christofek, L. (Los Alamos National Lab., NM (United States)); Johnston, K. (Los Alamos National Lab., NM (United States)); Louis, W.C. (Los Alamos National Lab., NM (United States)); Schillaci, M. (Los Alamos National Lab., NM (United States)); Volta, M. (Los Alamos National Lab., NM (United States)); White, D.H. (Los Alamos National Lab., NM (United States)); Whitehouse, D. (Los Alamos National Lab., NM (United States)); Albert, M. (University of Pennsylvania, Phi

    1993-10-01

    Dilute scintillation mixtures emit isotropic light for both fast and slow particles, but retain the Cherenkov light cone from fast particles. Large volume detectors using photomultipliers to reconstruct relativistic tracks will also be sensitive to slow particles if they are filled with these mixtures. Our data show that 0.03 g/l of b-PBD in mineral oil has a 2.4:1 ratio (in the first 12 ns) of isotropic light to Cherenkov light for positron tracks. The light attenuation length is greater than 15 m for wavelength above 400 nm, and the scintillation decay time is about 2 ns for the fast component. There is also a slow isotropic light component that is larger (relative to the fast component) for protons than for electrons. This effect allows particle identification by a technique similar to pulse shape discrimination. These features will be utilized in LSND, a neutrino detector at LAMPF. (orig.)

  6. Fractional Modeling of the AC Large-Signal Frequency Response in Magnetoresistive Current Sensors

    Directory of Open Access Journals (Sweden)

    Sergio Iván Ravelo Arias

    2013-12-01

    Full Text Available Fractional calculus is considered when derivatives and integrals of non-integer order are applied over a specific function. In the electrical and electronic domain, the transfer function dependence of a fractional filter not only by the filter order n, but additionally, of the fractional order α is an example of a great number of systems where its input-output behavior could be more exactly modeled by a fractional behavior. Following this aim, the present work shows the experimental ac large-signal frequency response of a family of electrical current sensors based in different spintronic conduction mechanisms. Using an ac characterization set-up the sensor transimpedance function  is obtained considering it as the relationship between sensor output voltage and input sensing current,[PLEASE CHECK FORMULA IN THE PDF]. The study has been extended to various magnetoresistance sensors based in different technologies like anisotropic magnetoresistance (AMR, giant magnetoresistance (GMR, spin-valve (GMR-SV and tunnel magnetoresistance (TMR. The resulting modeling shows two predominant behaviors, the low-pass and the inverse low-pass with fractional index different from the classical integer response. The TMR technology with internal magnetization offers the best dynamic and sensitivity properties opening the way to develop actual industrial applications.

  7. SU-F-T-538: CyberKnife with MLC for Treatment of Large Volume Tumors: A Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Bichay, T; Mayville, A [Mercy Health, Saint Mary’s, Grand Rapids, MI (United States)

    2016-06-15

    Purpose: CyberKnife is a well-documented modality for SRS and SBRT treatments. Typical tumors are small and 1–5 fractions are usually used. We determined the feasibility of using CyberKnife, with an InCise multileaf collimator option, for larger tumors undergoing standard dose and fractionation. The intent was to understand the limitation of using this modality for other external beam radiation treatments. Methods: Five tumors from different anatomical sites with volumes from 127.8 cc to 1,320.5 cc were contoured and planned on a Multiplan V5.1 workstation. The target average diameter ranged from 7 cm to 13 cm. The dose fractionation was 1.8–2.0 Gy/fraction and 25–45 fractions for total doses of 45–81 Gy. The sites planned were: pancreas, head and neck, prostate, anal, and esophagus. The plans were optimized to meet conventional dose constraints based on various RTOG protocols for conventional fractionation. Results: The Multiplan treatment planning system successfully generated clinically acceptable plans for all sites studied. The resulting dose distributions achieved reasonable target coverage, all greater than 95%, and satisfactory normal tissue sparing. Treatment times ranged from 9 minutes to 38 minutes, the longest being a head and neck plan with dual targets receiving different doses and with multiple adjacent critical structures. Conclusion: CyberKnife, with the InCise multileaf collimation option, can achieve acceptable dose distributions in large volume tumors treated with conventional dose and fractionation. Although treatment times are greater than conventional accelerator time; target coverage and dose to critical structures can be kept within a clinically acceptable range. While time limitations exist, when necessary CyberKnife can provide an alternative to traditional treatment modalities for large volume tumors.

  8. Stationary high confinement plasmas with large bootstrap current fraction in JT-60U

    International Nuclear Information System (INIS)

    Sakamoto, Y.; Fujita, T.; Ide, S.; Isayama, A.; Takechi, M.; Suzuki, T.; Takenaga, H.; Oyama, N.; Kamada, Y.

    2005-01-01

    This paper reports the results of the progress in stationary discharges with a large bootstrap current fraction in JT-60U towards steady-state tokamak operation. In the weak shear plasma regime, high-β p ELMy H-mode discharges have been optimized under nearly full non-inductive current drive conditions by the large bootstrap current fraction (f BS ∼ 45%) and the beam driven current fraction (f BD ∼ 50%), which was sustained for 5.8 s in the stationary condition. This duration corresponds to ∼26τ E and ∼2.8τ R , which was limited by the pulse length of negative-ion-based neutral beams. The high confinement enhancement factor H 89 ∼ 2.2 (HH 98y2 ∼ 1.0) was obtained and the profiles of current and pressure reached the stationary condition. In the reversed shear plasma regime, a large bootstrap current fraction (f BS ∼ 75%) has been sustained for 7.4 s under nearly full non-inductive current drive conditions. This duration corresponds to ∼16τ E and ∼2.7τ R . The high confinement enhancement factor H 89 ∼ 3.0 (HH 98y2 ∼ 1.7) was also sustained, and the profiles of current and pressure reached the stationary condition. The large bootstrap current and the off-axis beam driven current sustained this reversed q profile. This duration was limited only by the duration of the neutral beam injection

  9. Characterization of segmented large volume, high purity germanium detectors

    Energy Technology Data Exchange (ETDEWEB)

    Bruyneel, B. [Koeln Univ. (Germany). Inst. fuer Kernphysik

    2006-07-01

    {gamma}-ray tracking in future HPGe arrays like AGATA will rely on pulse shape analysis (PSA) of multiple {gamma}-interactions. For this purpose, a simple and fast procedure was developed which enabled the first full characterization of a segmented large volume HPGe detector. An analytical model for the hole mobility in a Ge crystal lattice was developed to describe the hole drift anisotropy with experimental velocity values along the crystal axis as parameters. The new model is based on the drifted Maxwellian hole distribution in Ge. It is verified by reproducing successfully experimental longitudinal hole anisotropy data. A comparison between electron and hole mobility shows large differences for the longitudinal and tangential velocity anisotropy as a function of the electrical field orientation. Measurements on a 12 fold segmented, n-type, large volume, irregular shaped HPGe detector were performed in order to determine the parameters of anisotropic mobility for electrons and holes as charge carriers created by {gamma}-ray interactions. To characterize the electron mobility the complete outer detector surface was scanned in small steps employing photopeak interactions at 60 keV. A precise measurement of the hole drift anisotropy was performed with 356 keV rays. The drift velocity anisotropy and crystal geometry cause considerable rise time differences in pulse shapes depending on the position of the spatial charge carrier creation. Pulse shapes of direct and transient signals are reproduced by weighting potential calculations with high precision. The measured angular dependence of rise times is caused by the anisotropic mobility, crystal geometry, changing field strength and space charge effects. Preamplified signals were processed employing digital spectroscopy electronics. Response functions, crosstalk contributions and averaging procedures were taken into account implying novel methods due to the segmentation of the Ge-crystal and the digital electronics

  10. Characterization of segmented large volume, high purity germanium detectors

    International Nuclear Information System (INIS)

    Bruyneel, B.

    2006-01-01

    γ-ray tracking in future HPGe arrays like AGATA will rely on pulse shape analysis (PSA) of multiple γ-interactions. For this purpose, a simple and fast procedure was developed which enabled the first full characterization of a segmented large volume HPGe detector. An analytical model for the hole mobility in a Ge crystal lattice was developed to describe the hole drift anisotropy with experimental velocity values along the crystal axis as parameters. The new model is based on the drifted Maxwellian hole distribution in Ge. It is verified by reproducing successfully experimental longitudinal hole anisotropy data. A comparison between electron and hole mobility shows large differences for the longitudinal and tangential velocity anisotropy as a function of the electrical field orientation. Measurements on a 12 fold segmented, n-type, large volume, irregular shaped HPGe detector were performed in order to determine the parameters of anisotropic mobility for electrons and holes as charge carriers created by γ-ray interactions. To characterize the electron mobility the complete outer detector surface was scanned in small steps employing photopeak interactions at 60 keV. A precise measurement of the hole drift anisotropy was performed with 356 keV rays. The drift velocity anisotropy and crystal geometry cause considerable rise time differences in pulse shapes depending on the position of the spatial charge carrier creation. Pulse shapes of direct and transient signals are reproduced by weighting potential calculations with high precision. The measured angular dependence of rise times is caused by the anisotropic mobility, crystal geometry, changing field strength and space charge effects. Preamplified signals were processed employing digital spectroscopy electronics. Response functions, crosstalk contributions and averaging procedures were taken into account implying novel methods due to the segmentation of the Ge-crystal and the digital electronics. The results are

  11. A technique of using gated-CT images to determine internal target volume (ITV) for fractionated stereotactic lung radiotherapy

    International Nuclear Information System (INIS)

    Jin Jianyue; Ajlouni, Munther; Chen Qing; Yin, Fang-Fang; Movsas, Benjamin

    2006-01-01

    Background and purpose: To develop and evaluate a technique and procedure of using gated-CT images in combination with PET image to determine the internal target volume (ITV), which could reduce the planning target volume (PTV) with adequate target coverage. Patients and methods: A skin marker-based gating system connected to a regular single slice CT scanner was used for this study. A motion phantom with adjustable motion amplitude was used to evaluate the CT gating system. Specifically, objects of various sizes/shapes, considered as virtual tumors, were placed on the phantom to evaluate the number of phases of gated images required to determine the ITV while taking into account tumor size, shape and motion. A procedure of using gated-CT and PET images to define ITV for patients was developed and was tested in patients enrolled in an IRB approved protocol. Results: The CT gating system was capable of removing motion artifacts for target motion as large as 3-cm when it was gated at optimal phases. A phantom study showed that two gated-CT scans at the end of expiration and the end of inspiration would be sufficient to determine the ITV for tumor motion less than 1-cm, and another mid-phase scan would be required for tumors with 2-cm motion, especially for small tumors. For patients, the ITV encompassing visible tumors in all sets of gated-CT and regular spiral CT images seemed to be consistent with the target volume determined from PET images. PTV expanded from the ITV with a setup uncertainty margin had less volume than PTVs from spiral CT images with a 10-mm generalized margin or an individualized margin determined at fluoroscopy. Conclusions: A technique of determining the ITV using gated-CT images was developed and was clinically implemented successfully for fractionated stereotactic lung radiotherapy

  12. Dark Radiation predictions from general Large Volume Scenarios

    Science.gov (United States)

    Hebecker, Arthur; Mangat, Patrick; Rompineve, Fabrizio; Witkowski, Lukas T.

    2014-09-01

    Recent observations constrain the amount of Dark Radiation (Δ N eff ) and may even hint towards a non-zero value of Δ N eff . It is by now well-known that this puts stringent constraints on the sequestered Large Volume Scenario (LVS), i.e. on LVS realisations with the Standard Model at a singularity. We go beyond this setting by considering LVS models where SM fields are realised on 7-branes in the geometric regime. As we argue, this naturally goes together with high-scale supersymmetry. The abundance of Dark Radiation is determined by the competition between the decay of the lightest modulus to axions, to the SM Higgs and to gauge fields, and leads to strict constraints on these models. Nevertheless, these constructions can in principle meet current DR bounds due to decays into gauge bosons alone. Further, a rather robust prediction for a substantial amount of Dark Radiation can be made. This applies both to cases where the SM 4-cycles are stabilised by D-terms and are small `by accident', i.e. tuning, as well as to fibred models with the small cycles stabilised by loops. In these constructions the DR axion and the QCD axion are the same field and we require a tuning of the initial misalignment to avoid Dark Matter overproduction. Furthermore, we analyse a closely related setting where the SM lives at a singularity but couples to the volume modulus through flavour branes. We conclude that some of the most natural LVS settings with natural values of model parameters lead to Dark Radiation predictions just below the present observational limits. Barring a discovery, rather modest improvements of present Dark Radiation bounds can rule out many of these most simple and generic variants of the LVS.

  13. Scaling relations between trabecular bone volume fraction and microstructure at different skeletal sites.

    Science.gov (United States)

    Räth, Christoph; Baum, Thomas; Monetti, Roberto; Sidorenko, Irina; Wolf, Petra; Eckstein, Felix; Matsuura, Maiko; Lochmüller, Eva-Maria; Zysset, Philippe K; Rummeny, Ernst J; Link, Thomas M; Bauer, Jan S

    2013-12-01

    In this study, we investigated the scaling relations between trabecular bone volume fraction (BV/TV) and parameters of the trabecular microstructure at different skeletal sites. Cylindrical bone samples with a diameter of 8mm were harvested from different skeletal sites of 154 human donors in vitro: 87 from the distal radius, 59/69 from the thoracic/lumbar spine, 51 from the femoral neck, and 83 from the greater trochanter. μCT images were obtained with an isotropic spatial resolution of 26μm. BV/TV and trabecular microstructure parameters (TbN, TbTh, TbSp, scaling indices ( and σ of α and αz), and Minkowski Functionals (Surface, Curvature, Euler)) were computed for each sample. The regression coefficient β was determined for each skeletal site as the slope of a linear fit in the double-logarithmic representations of the correlations of BV/TV versus the respective microstructure parameter. Statistically significant correlation coefficients ranging from r=0.36 to r=0.97 were observed for BV/TV versus microstructure parameters, except for Curvature and Euler. The regression coefficients β were 0.19 to 0.23 (TbN), 0.21 to 0.30 (TbTh), -0.28 to -0.24 (TbSp), 0.58 to 0.71 (Surface) and 0.12 to 0.16 (), 0.07 to 0.11 (), -0.44 to -0.30 (σ(α)), and -0.39 to -0.14 (σ(αz)) at the different skeletal sites. The 95% confidence intervals of β overlapped for almost all microstructure parameters at the different skeletal sites. The scaling relations were independent of vertebral fracture status and similar for subjects aged 60-69, 70-79, and >79years. In conclusion, the bone volume fraction-microstructure scaling relations showed a rather universal character. © 2013.

  14. Airborne release fractions/rates and respirable fractions for nonreactor nuclear facilities. Volume 1, Analysis of experimental data

    International Nuclear Information System (INIS)

    1994-12-01

    This handbook contains (1) a systematic compilation of airborne release and respirable fraction experimental data for nonreactor nuclear facilities, (2) assessments of the data, and (3) values derived from assessing the data that may be used in safety analyses when the data are applicable. To assist in consistent and effective use of this information, the handbook provides: identification of a consequence determination methodology in which the information can be used; discussion of the applicability of the information and its general technical limits; identification of specific accident phenomena of interest for which the information is applicable; and examples of use of the consequence determination methodology and airborne release and respirable fraction information

  15. The large N limit of N=2 super Yang-Mills, fractional instantons and infrared divergences

    International Nuclear Information System (INIS)

    Ferrari, Frank

    2001-01-01

    We investigate the large N limit of pure N=2 supersymmetric gauge theory with gauge group SU(N) by using the exact low energy effective action. Typical one-complex dimensional sections of the moduli space parametrized by a global complex mass scale v display three qualitatively different regions depending on the ratio between vertical bar v vertical bar and the dynamically generated scale Λ. At large vertical bar v vertical bar/Λ, instantons are exponentially suppressed as N→∞. When vertical bar v vertical bar ∼Λ, singularities due to massless dyons occur. They are densely distributed in rings of calculable thicknesses in the v-plane. At small vertical bar v vertical bar/Λ, instantons disintegrate into fractional instantons of charge 1/(2N). These fractional instantons give non-trivial contributions to all orders of 1/N, unlike a planar diagrams expansion which generates a series in 1/N 2 , implying the presence of open strings. We have explicitly calculated the fractional instantons series in two representative examples, including the 1/N and 1/N 2 corrections. Our most interesting finding is that the 1/N expansion breaks down at singularities on the moduli space due to severe infrared divergencies, a fact that has remarkable consequences

  16. Study on water boiling noises in a large volume

    International Nuclear Information System (INIS)

    Masagutov, R.F.; Krivtsov, V.A.

    1977-01-01

    Presented are the results of measurement of the noise spectra during boiling of water in a large volume at the pressure of 1 at. Boiling of the distilled water has been accomplished with the use of the heaters made of the Kh18N10T steel, 50 mm in length, 2 mm in the outside diameter, with the wall thickness of 0.1 mm. The degree of water under heating changed during the experiments from 0 to 80 deg C, and the magnitude of the specific heat flux varied from o to 0.7 - 0.9 qsup(x), where qsup(x) was the specific heat flux of the tube burn-out. The noise spectrum of the boiling water was analyzed at frequencies of 0.5 to 200 kHz. The submerge-type pressure-electric transmitters were used for measurements. At underheating boiling during the experiment the standing waves have formed which determine the structure of the measured spectra. During saturated boiling of water no standing waves were revealed. At underheating over 15 - 20 deg C the water boiling process is accompanied by the noises within the ultrasonic frequency range. The maximum upper boundary of the noise in the experiments amounts to 90 - 100 kHz

  17. Prospects for accelerator neutron sources for large volume minerals analysis

    International Nuclear Information System (INIS)

    Clayton, C.G.; Spackman, R.

    1988-01-01

    The electron Linac can be regarded as a practical source of thermal neutrons for activation analysis of large volume mineral samples. With a suitable target and moderator, a neutron flux of about 10 10 n/cm/s over 2-3 kg of rock can be generated. The proton Linac gives the possibility of a high neutron yield (> 10 12 n/s) of fast neutrons at selected energies. For the electron Linac, targets of W-U and W-Be are discussed. The advantages and limitations of the system are demonstrated for the analysis of gold in rocks and ores and for platinum in chromitite. These elements were selected as they are most likely to justify an accelerator installation at the present time. Errors due to self shielding in gold particles for thermal neutrons are discussed. The proton Linac is considered for neutrons generated from a lithium target through the 7 Li(p, n) 7 Be reaction. The analysis of gold by fast neutron activation is considered. This approach avoids particle self-absorption and, by appropriate proton energy selection, avoids potentially dominating interfering reactions. The analysis of 235 U in the presence of 238 U and 232 Th is also considered. (author)

  18. Characterization of large volume HPGe detectors. Part II: Experimental results

    International Nuclear Information System (INIS)

    Bruyneel, Bart; Reiter, Peter; Pascovici, Gheorghe

    2006-01-01

    Measurements on a 12-fold segmented, n-type, large volume, irregular shaped HPGe detector were performed in order to determine the parameters of anisotropic mobility for electrons and holes as charge carriers created by γ-ray interactions. To characterize the electron mobility the complete outer detector surface was scanned in small steps employing photopeak interactions at 60keV. A precise measurement of the hole drift anisotropy was performed with 356keV γ-rays. The drift velocity anisotropy and crystal geometry cause considerable rise time differences in pulse shapes depending on the position of the spatial charge carrier creation. Pulse shapes of direct and transient signals are reproduced by weighting potential calculations with high precision. The measured angular dependence of rise times is caused by the anisotropic mobility, crystal geometry, changing field strength and space charge effects. Preamplified signals were processed employing digital spectroscopy electronics. Response functions, crosstalk contributions and averaging procedures were taken into account implying novel methods due to the segmentation of the Ge-crystal and digital signal processing electronics

  19. Elastic modulus of Al-Si/SiC metal matrix composites as a function of volume fraction

    Energy Technology Data Exchange (ETDEWEB)

    Santhosh Kumar, S; Rajasekharan, T [Powder Metallurgy Group, Defence Metallurgical Research Laboratory, Kanchanbagh PO, Hyderabad-500 058 (India); Seshu Bai, V [School of Physics, University of Hyderabad, Central University PO, Hyderabad-500 046 (India); Rajkumar, K V; Sharma, G K; Jayakumar, T, E-mail: dearsanthosh@gmail.co [Non-Destructive Evaluation Division, Indira Gandhi Center for Atomic Research, Kalpakkam, Chennai-603 102 (India)

    2009-09-07

    Aluminum alloy matrix composites have emerged as candidate materials for electronic packaging applications in the field of aerospace semiconductor electronics. Composites prepared by the pressureless infiltration technique with high volume fractions in the range 0.41-0.70 were studied using ultrasonic velocity measurements. For different volume fractions of SiC, the longitudinal velocity and shear velocity were found to be in the range of 7600-9300 m s{sup -1} and 4400-5500 m s{sup -1}, respectively. The elastic moduli of the composites were determined from ultrasonic velocities and were analysed as a function of the volume fraction of the reinforcement. The observed variation is discussed in the context of existing theoretical models for the effective elastic moduli of two-phase systems.

  20. An unstructured finite volume solver for two phase water/vapour flows based on an elliptic oriented fractional step method

    International Nuclear Information System (INIS)

    Mechitoua, N.; Boucker, M.; Lavieville, J.; Pigny, S.; Serre, G.

    2003-01-01

    Based on experience gained at EDF and Cea, a more general and robust 3-dimensional (3D) multiphase flow solver has been being currently developed for over three years. This solver, based on an elliptic oriented fractional step approach, is able to simulate multicomponent/multiphase flows. Discretization follows a 3D full unstructured finite volume approach, with a collocated arrangement of all variables. The non linear behaviour between pressure and volume fractions and a symmetric treatment of all fields are taken into account in the iterative procedure, within the time step. It greatly enforces the realizability of volume fractions (i.e 0 < α < 1), without artificial numerical needs. Applications to widespread test cases as static sedimentation, water hammer and phase separation are shown to assess the accuracy and the robustness of the flow solver in different flow conditions, encountered in nuclear reactors pipes. (authors)

  1. Volume fractions of DCE-MRI parameter as early predictor of histologic response in soft tissue sarcoma: A feasibility study.

    Science.gov (United States)

    Xia, Wei; Yan, Zhuangzhi; Gao, Xin

    2017-10-01

    To find early predictors of histologic response in soft tissue sarcoma through volume transfer constant (K trans ) analysis based on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). 11 Patients with soft tissue sarcoma of the lower extremity that underwent preoperative chemoradiotherapy followed by limb salvage surgery were included in this retrospective study. For each patient, DCE-MRI data sets were collected before and two weeks after therapy initiation, and histologic tumor cell necrosis rate (TCNR) was reported at surgery. The DCE-MRI volumes were aligned by registration. Then, the aligned volumes were used to obtain the K trans variation map. Accordingly, three sub-volumes (with increased, decreased or unchanged K trans ) were defined and identified, and fractions of the sub-volumes, denoted as F + , F - and F 0 , respectively, were calculated. The predictive ability of volume fractions was determined by using area under a receiver operating characteristic curve (AUC). Linear regression analysis was performed to investigate the relationship between TCNR and volume fractions. In addition, the K trans values of the sub-volumes were compared. The AUC for F - (0.896) and F 0 (0.833) were larger than that for change of tumor longest diameter ΔD (0.625) and the change of mean K trans ΔK trans ¯ (0.792). Moreover, the regression results indicated that TCNR was directly proportional to F 0 (R 2 =0.75, P=0.0003), while it was inversely proportional to F - (R 2 =0.77, P=0.0002). However, TCNR had relatively weak linear relationship with ΔK trans ¯ (R 2 =0.64, P=0.0018). Additionally, TCNR did not have linear relationship with DD (R 2 =0.16, P=0.1246). The volume fraction F - and F 0 have potential as early predictors of soft tissue sarcoma histologic response. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Topologically-based visualization of large-scale volume data

    International Nuclear Information System (INIS)

    Takeshima, Y.; Tokunaga, M.; Fujishiro, I.; Takahashi, S.

    2004-01-01

    Due to the recent progress in the performance of computing/measurement environments and the advent of ITBL environments, volume datasets have become larger and more complicated. Although computer visualization is one of the tools to analyze such datasets effectively, it is almost impossible to adjust the visualization parameter value by trial and error without taking the feature of a given volume dataset into consideration. In this article, we introduce a scheme of topologically-based volume visualization, which is intended to choose appropriate visualization parameter values automatically through topological volume skeletonization. (author)

  3. Myocardial T1 and extracellular volume fraction mapping at 3 tesla

    Directory of Open Access Journals (Sweden)

    Lee Jason J

    2011-11-01

    Full Text Available Abstract Background To compare 11 heartbeat (HB and 17 HB modified lock locker inversion recovery (MOLLI pulse sequence at 3T and to establish preliminary reference values for myocardial T1 and the extracellular volume fraction (ECV. Methods Both phantoms and normal volunteers were scanned at 3T using 11 HB and 17 HB MOLLI sequence with the following parameters: spatial resolution = 1.75 × 1.75 × 10 mm on a 256 × 180 matrix, TI initial = 110 ms, TI increment = 80 ms, flip angle = 35°, TR/TE = 1.9/1.0 ms. All volunteers were administered Gadolinium-DTPA (Magnevist, 0.15 mmol/kg, and multiple post-contrast MOLLI scans were performed at the same pre-contrast position from 3.5-23.5 minutes after a bolus contrast injection. Late gadolinium enhancement (LGE images were also acquired 12-30 minutes after the gadolinium bolus. Results T1 values of 11 HB and 17 HB MOLLI displayed good agreement in both phantom and volunteers. The average pre-contrast myocardial and blood T1 was 1315 ± 39 ms and 2020 ± 129 ms, respectively. ECV was stable between 8.5 to 23.5 minutes post contrast with an average of 26.7 ± 1.0%. Conclusion The 11 HB MOLLI is a faster method for high-resolution myocardial T1 mapping at 3T. ECV fractions are stable over a wide time range after contrast administration.

  4. Artificial neural network and neutron application in a volume fraction calculation in annular and stratified multiphase system

    International Nuclear Information System (INIS)

    Ramos, Robson; Brandao, Luis E.B.; Pereira, Claudio M.N.A.; Schirru, Roberto; Silva, Ademir Xavier da

    2009-01-01

    Multiphase flows, type oil-water-gas are very common among different industrial activities, such as chemical industries and petroleum extraction, and its measurements show some difficulties to be taken. Precisely determining the volume fraction of each one of the elements that composes a multiphase flow is very important in chemical plants and petroleum industries. This work presents a methodology able to determine volume fraction on Annular and Stratified multiphase flow system with the use of neutrons and artificial intelligence, using the principles of transmission/scattering of fast neutrons from a 241 Am-Be source and measurements of point flow that are influenced by variations of volume fractions. The proposed geometries used on the mathematical model was used to obtain a data set where the thicknesses referred of each material had been changed in order to obtain volume fraction of each phase providing 119 compositions that were used in the simulation with MCNP-X -computer code based on Monte Carlo Method that simulates the radiation transport. An artificial neural network (ANN) was trained with data obtained using the MCNP-X, and used to correlate such measurements with the respective real fractions. The ANN was able to correlate the data obtained on the simulation with MCNP-X with the volume fractions of the multiphase flows (oil-water-gas), both in the pattern of annular flow as stratified, resulting in a average relative error (%) for each production set of: annular (air = 3.85; water = 4.31; oil=1.08); stratified (air = 3.10, water 2.01, oil = 1.45). The method demonstrated good efficiency in the determination of each material that composes the phases, thus demonstrating the feasibility of the technique. (author)

  5. Artificial neural network and neutron application in a volume fraction calculation in annular and stratified multiphase system

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Robson; Brandao, Luis E.B.; Pereira, Claudio M.N.A., E-mail: robson@ien.gov.b, E-mail: brandao@ien.gov.b, E-mail: cmnap@ien.gov.b [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Div. de Radiofarmacos; Schirru, Roberto; Silva, Ademir Xavier da, E-mail: schirru@lmp.ufrj.b, E-mail: ademir@con.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Nuclear Engineering Dept.

    2009-07-01

    Multiphase flows, type oil-water-gas are very common among different industrial activities, such as chemical industries and petroleum extraction, and its measurements show some difficulties to be taken. Precisely determining the volume fraction of each one of the elements that composes a multiphase flow is very important in chemical plants and petroleum industries. This work presents a methodology able to determine volume fraction on Annular and Stratified multiphase flow system with the use of neutrons and artificial intelligence, using the principles of transmission/scattering of fast neutrons from a {sup 241}Am-Be source and measurements of point flow that are influenced by variations of volume fractions. The proposed geometries used on the mathematical model was used to obtain a data set where the thicknesses referred of each material had been changed in order to obtain volume fraction of each phase providing 119 compositions that were used in the simulation with MCNP-X -computer code based on Monte Carlo Method that simulates the radiation transport. An artificial neural network (ANN) was trained with data obtained using the MCNP-X, and used to correlate such measurements with the respective real fractions. The ANN was able to correlate the data obtained on the simulation with MCNP-X with the volume fractions of the multiphase flows (oil-water-gas), both in the pattern of annular flow as stratified, resulting in a average relative error (%) for each production set of: annular (air = 3.85; water = 4.31; oil=1.08); stratified (air = 3.10, water 2.01, oil = 1.45). The method demonstrated good efficiency in the determination of each material that composes the phases, thus demonstrating the feasibility of the technique. (author)

  6. Enlarged thalamic volumes and increased fractional anisotropy in the thalamic radiations in Veterans with suicide behaviors

    Directory of Open Access Journals (Sweden)

    Melissa eLopez-Larson

    2013-08-01

    Full Text Available Post-mortem studies have suggested a link between the thalamus, psychiatric disorders, and suicide. We evaluated the thalamus and anterior thalamic radiations (ATR in a group of Veterans with and without a history of suicidal behavior (SB to determine if thalamic abnormalities were associated with an increased risk of SB. Forty Veterans with mild traumatic brain injury (TBI and no SB (TBI-SB, 19 Veterans with mild TBI and a history of SB (TB+SB and 15 healthy controls (HC underwent MRI scanning including a structural and diffusion tensor imaging scan. Suicidal behaviors were evaluated utilizing the Columbia Suicide Rating Scale and impulsivity was measured using the Barratt Impulsiveness Scale (BIS. Differences in thalamic volumes and ATR fractional anisotropy (FA were examined between 1 TBI+SB versus HC and 2 TBI+SB versus combined HC and TBI-SB and 2 between TBI+SB and TBI-SB. Left and right thalamic volumes were significantly increased in those with TBI+SB compared to the HC, TBI-SB and the combined group. Veterans with TBI+SB had increased FA bilaterally compared to the HC, HC and TBI-SB group, and the TBI-SB only group. Significant positive associations were found for bilateral ATR and BIS in the TBI+SB group. Our findings of thalamic enlargement and increased FA in individuals with TBI+SB suggest that this region may be a biomarker for suicide risk. Our findings are consistent with previous evidence indicating that suicide may be associated with behavioral disinhibition and frontal-thalamic-limbic dysfunction and suggest a neurobiologic mechanism that may increase vulnerability to suicide.

  7. Calculation of Void Volume Fraction in the Subcooled and Quality Boiling Regions

    Energy Technology Data Exchange (ETDEWEB)

    Rouhani, S Z; Axelsson, E

    1968-10-15

    The complex problem of void calculation in the different regions of flow boiling is divided in two parts. The first part includes only the description of the mechanisms and the calculation of the rates of heat transfer for vapour and liquid. It is assumed that heat is removed by vapour generation, heating of the liquid that replaces the detached bubbles, and in some parts, by single phase heat transfer. By considering the rate of vapour condensation in liquid, an equation for the differential changes in the true steam quality throughout the boiling regions is obtained. Integration of this equation yields the vapour weight fraction at any position. The second part of the problem concerns the determination of the void fractions corresponding to the calculated steam qualities. For this purpose we use the derivations of Zuber and Findlay. This model is compared with data from different geometries including small rectangular channels and large rod bundles. The data covered pressures from 19 to 138 bars, heat fluxes from 18 to 120 W/cm{sup 2} with many different subcoolings and mass velocities. The agreement is generally very good.

  8. Calculation of Void Volume Fraction in the Subcooled and Quality Boiling Regions

    International Nuclear Information System (INIS)

    Rouhani, S.Z.; Axelsson, E.

    1968-10-01

    The complex problem of void calculation in the different regions of flow boiling is divided in two parts. The first part includes only the description of the mechanisms and the calculation of the rates of heat transfer for vapour and liquid. It is assumed that heat is removed by vapour generation, heating of the liquid that replaces the detached bubbles, and in some parts, by single phase heat transfer. By considering the rate of vapour condensation in liquid, an equation for the differential changes in the true steam quality throughout the boiling regions is obtained. Integration of this equation yields the vapour weight fraction at any position. The second part of the problem concerns the determination of the void fractions corresponding to the calculated steam qualities. For this purpose we use the derivations of Zuber and Findlay. This model is compared with data from different geometries including small rectangular channels and large rod bundles. The data covered pressures from 19 to 138 bars, heat fluxes from 18 to 120 W/cm 2 with many different subcoolings and mass velocities. The agreement is generally very good

  9. The effect of strain path change on subgrain volume fraction determined from in situ X-ray measurements

    DEFF Research Database (Denmark)

    Wejdemann, Christian; Poulsen, Henning Friis; Lienert, U.

    2009-01-01

    to additional 5% strain is performed in situ while mapping a selected X-ray reflection from one particular bulk grain with high angular resolution. The reciprocal space maps are analyzed with a recently developed fitting method, and a correlation is found between the evolution of the subgrain volume fraction...

  10. CMR reference values for left ventricular volumes, mass, and ejection fraction using computer-aided analysis : The Framingham Heart Study

    NARCIS (Netherlands)

    Chuang, Michael L.; Gona, Philimon; Hautvast, Gilion L.T.F.; Salton, Carol J.; Breeuwer, Marcel; O'Donnell, Christopher J.; Manning, Warren J.

    Purpose To determine sex-specific reference values for left ventricular (LV) volumes, mass, and ejection fraction (EF) in healthy adults using computer-aided analysis and to examine the effect of age on LV parameters. Materials and Methods We examined data from 1494 members of the Framingham Heart

  11. An experimental study on the excitation of large volume airguns in a small volume body of water

    International Nuclear Information System (INIS)

    Wang, Baoshan; Yang, Wei; Yuan, Songyong; Ge, Hongkui; Chen, Yong; Guo, Shijun; Xu, Ping

    2010-01-01

    A large volume airgun array is effective in generating seismic waves, which is extensively used in large volume bodies of water such as oceans, lakes and reservoirs. So far, the application of large volume airguns is subject to the distribution of large volume bodies of water. This paper reports an attempt to utilize large volume airguns in a small body of water as a seismic source for seismotectonic studies. We carried out a field experiment in Mapaoquan pond, Fangshan district, Beijing, during the period 25–30 May 2009. Bolt LL1500 airguns, each with volumes of 2000 in 3 , the largest commercial airguns available today, were used in this experiment. We tested the excitation of the airgun array with one or two guns. The airgun array was placed 7–11 m below the water's surface. The near- and far-field seismic motions induced by the airgun source were recorded by a 100 km long seismic profile composed of 16 portable seismometers and a 100 m long strong motion seismograph profile, respectively. The following conclusions can be drawn from this experiment. First, it is feasible to excite large volume airguns in a small volume body of water. Second, seismic signals from a single shot of one airgun can be recognized at the offset up to 15 km. Taking advantage of high source repeatability, we stacked records from 128 shots to enhance the signal-to-noise ratio, and direct P-waves can be easily identified at the offset ∼50 km in stacked records. Third, no detectable damage to fish or near-field constructions was caused by the airgun shots. Those results suggest that large volume airguns excited in small bodies of water can be used as a routinely operated seismic source for mid-scale (tens of kilometres) subsurface explorations and monitoring under various running conditions

  12. ECG-gated blood pool tomography in the determination of left ventricular volume, ejection fraction, and wall motion

    International Nuclear Information System (INIS)

    Underwood, S.R.; Ell, P.J.; Jarritt, P.H.; Emanuel, R.W.; Swanton, R.H.

    1984-01-01

    ECG-gated blood pool tomography promises to provide a ''gold standard'' for noninvasive measurement of left ventricular volume, ejection fraction, and wall motion. This study compares these measurements with those from planar radionuclide imaging and contrast ventriculography. End diastolic and end systolic blood pool images were acquired tomographically using an IGE400A rotating gamma camera and Star computer, and slices were reconstructed orthogonal to the long axis of the heart. Left ventricular volume was determined by summing the areas of the slices, and wall motion was determined by comparison of end diastolic and end systolic contours. In phantom experiments this provided an accurate measurement of volume (r=0.98). In 32 subjects who were either normal or who had coronary artery disease left ventricular volume (r=0.83) and ejection fraction (r=0.89) correlated well with those using a counts based planar technique. In 16 of 18 subjects who underwent right anterior oblique X-ray contrast ventriculography, tomographic wall motion agreed for anterior, apical, and inferior walls, but abnormal septal motion which was not apparent by contrast ventriculography, was seen in 12 subjects tomographically. All 12 had disease of the left anterior descending coronary artery and might have been expected to have abnormal septal motion. ECG-gated blood pool tomography can thus determine left ventricular volume and ejection fraction accurately, and provides a global description of wall motion in a way that is not possible from any single planar image

  13. Effects of diluents on soot surface temperature and volume fraction in diluted ethylene diffusion flames at pressure

    KAUST Repository

    Kailasanathan, Ranjith Kumar Abhinavam

    2014-05-20

    Soot surface temperature and volume fraction are measured in ethylene/air coflowing laminar diffusion flames at high pressures, diluted with one of four diluents (argon, helium, nitrogen, and carbon dioxide) using a two-color technique. Both temperature and soot measurements presented are line-of-sight averages. The results aid in understanding the kinetic and thermodynamic behavior of the soot formation and oxidation chemistry with changes in diluents, ultimately leading to possible methods of reducing soot emission from practical combustion hardware. The diluted fuel and coflow exit velocities (top-hat profiles) were matched at all pressures to minimize shear effects. In addition to the velocity-matched flow rates, the mass fluxes were held constant for all pressures. Addition of a diluent has a pronounced effect on both the soot surface temperature and volume fraction, with the helium diluted flame yielding the maximum and carbon dioxide diluted flame yielding minimum soot surface temperature and volume fraction. At low pressures, peak soot volume fraction exists at the tip of the flame, and with an increase in pressure, the location shifts lower to the wings of the flame. Due to the very high diffusivity of helium, significantly higher temperature and volume fraction are measured and explained. Carbon dioxide has the most dramatic soot suppression effect. By comparing the soot yield with previously measured soot precursor concentrations in the same flame, it is clear that the lower soot yield is a result of enhanced oxidation rates rather than a reduction in precursor formation. Copyright © 2014 Taylor & Francis Group, LLC.

  14. Outpatient management of patients with large multinodular goitres treated with fractionated radioiodine

    International Nuclear Information System (INIS)

    Howarth, D.M.; Thomas, P.A.; Allen, L.W.; Akerman, R.; Lan, L.; Epstein, M.T.

    1997-01-01

    The efficacy of fractionated out-patient radioiodine therapy in 38 patients with compressive symptoms due to long-standing large multinodular goitres was assessed. The diagnosis was established by clinical assessment in addition to technetium-99m pertechnetate thyroid scan or computed tomography scan of the thyroid and mediastinum. Oral iodine-131 therapy was administered as a 2.22 GBq (60 mCi) cumulative dose over 4 months (555 MBq per month). All patients were monitored with serum thyroid-stimulating hormone and free thyroxine (± free tri-iodothyronine) assays before the treatment and after each dose fraction. Clinical and biochemical follow-up was performed on all patients and ranged from 6 to 45 months after therapy. The patients consisted of 35 female and three male patients with a median age of 59 years (range 37-87 years). Prior to treatment 20 patients were biochemically hyperthyroid and 18 were euthyroid. Overall, 71% of patients reported a subjective improvement in compressive symptoms and 29% reported no change. Clinically assessed reduction in goitre size occurred in 92% of patients while there was no change in 8%. At 3 months of follow-up, 31% of patients had become hypothyroid and at 18 months 66% were hypothyroid. Seven hyperthyroid patients (35%) became euthyroid and 13 hyperthyroid patients (65%) became hypothyroid. Three patients who became hypothyroid experienced neck soreness (transient in one patient, persistent in two patients). There were no differences in outcome between patients who were hyperthyroid and those who were euthyroid prior to treatment. Fractionated out-patient radioiodine therapy showed excellent short- and medium-term safety, was very well tolerated and offered a satisfactory alternative treatment to surgery. (orig.)

  15. Outpatient management of patients with large multinodular goitres treated with fractionated radioiodine

    Energy Technology Data Exchange (ETDEWEB)

    Howarth, D.M.; Thomas, P.A.; Allen, L.W.; Akerman, R.; Lan, L. [Department of Nuclear Medicine, John Hunter Hospital, Newcastle, NSW (Australia); Epstein, M.T. [Department of Endocrinology, John Hunter Hospital, Newcastle, NSW (Australia)

    1997-12-01

    The efficacy of fractionated out-patient radioiodine therapy in 38 patients with compressive symptoms due to long-standing large multinodular goitres was assessed. The diagnosis was established by clinical assessment in addition to technetium-99m pertechnetate thyroid scan or computed tomography scan of the thyroid and mediastinum. Oral iodine-131 therapy was administered as a 2.22 GBq (60 mCi) cumulative dose over 4 months (555 MBq per month). All patients were monitored with serum thyroid-stimulating hormone and free thyroxine ({+-} free tri-iodothyronine) assays before the treatment and after each dose fraction. Clinical and biochemical follow-up was performed on all patients and ranged from 6 to 45 months after therapy. The patients consisted of 35 female and three male patients with a median age of 59 years (range 37-87 years). Prior to treatment 20 patients were biochemically hyperthyroid and 18 were euthyroid. Overall, 71% of patients reported a subjective improvement in compressive symptoms and 29% reported no change. Clinically assessed reduction in goitre size occurred in 92% of patients while there was no change in 8%. At 3 months of follow-up, 31% of patients had become hypothyroid and at 18 months 66% were hypothyroid. Seven hyperthyroid patients (35%) became euthyroid and 13 hyperthyroid patients (65%) became hypothyroid. Three patients who became hypothyroid experienced neck soreness (transient in one patient, persistent in two patients). There were no differences in outcome between patients who were hyperthyroid and those who were euthyroid prior to treatment. Fractionated out-patient radioiodine therapy showed excellent short- and medium-term safety, was very well tolerated and offered a satisfactory alternative treatment to surgery. (orig.) With 1 fig., 3 tabs., 23 refs.

  16. Efficacy and safety of 10,600-nm carbon dioxide fractional laser on facial skin with previous volume injections

    Directory of Open Access Journals (Sweden)

    Josiane Hélou

    2013-01-01

    Full Text Available Background: Fractionated carbon dioxide (CO 2 lasers are a new treatment modality for skin resurfacing. The cosmetic rejuvenation market abounds with various injectable devices (poly-L-lactic acid, polymethyl-methacrylate, collagens, hyaluronic acids, silicone. The objective of this study is to examine the efficacy and safety of 10,600-nm CO 2 fractional laser on facial skin with previous volume injections. Materials and Methods: This is a retrospective study including 14 patients treated with fractional CO 2 laser and who have had previous facial volume restoration. The indication for the laser therapy, the age of the patients, previous facial volume restoration, and side effects were all recorded from their medical files. Objective assessments were made through clinical physician global assessment records and improvement scores records. Patients′ satisfaction rates were also recorded. Results: Review of medical records of the 14 patients show that five patients had polylactic acid injection prior to the laser session. Eight patients had hyaluronic acid injection prior to the laser session. Two patients had fat injection, two had silicone injection and one patient had facial thread lift. Side effects included pain during the laser treatment, post-treatment scaling, post-treatment erythema, hyperpigmentation which spontaneously resolved within a month. Concerning the previous facial volume restoration, no granulomatous reactions were noted, no facial shape deformation and no asymmetry were encountered whatever the facial volume product was. Conclusion: CO 2 fractional laser treatments do not seem to affect facial skin which had previous facial volume restoration with polylactic acid for more than 6 years, hyaluronic acid for more than 0.5 year, silicone for more than 6 years, or fat for more than 1.4 year. Prospective larger studies focusing on many other variables (skin phototype, injected device type are required to achieve better

  17. EFFECTS OF OXYGEN AND AIR MIXING ON VOID FRACTIONS IN A LARGE SCALE SYSTEM

    International Nuclear Information System (INIS)

    Leishear, R; Hector Guerrero, H; Michael Restivo, M

    2008-01-01

    Oxygen and air mixing with spargers was performed in a 30 foot tall by 30 inch diameter column, to investigate mass transfer as air sparged up through the column and removed saturated oxygen from solution. The mixing techniques required to support this research are the focus of this paper. The fluids tested included water, water with an antifoam agent (AFA), and a high, solids content, Bingham plastic, nuclear waste simulant with AFA, referred to as AZ01 simulant, which is non-radioactive. Mixing of fluids in the column was performed using a recirculation system and an air sparger. The re-circulation system consisted of the column, a re-circulating pump, and associated piping. The air sparger was fabricated from a two inch diameter pipe concentrically installed in the column and open near the bottom of the column. The column contents were slowly re-circulated while fluids were mixed with the air sparger. Samples were rheologically tested to ensure effective mixing, as required. Once the fluids were adequately mixed, oxygen was homogeneously added through the re-circulation loop using a sintered metal oxygen sparger followed by a static mixer. Then the air sparger was re-actuated to remove oxygen from solution as air bubbled up through solution. To monitor mixing effectiveness several variables were monitored, which included flow rates, oxygen concentration, differential pressures along the column height, fluid levels, and void fractions, which are defined as the percent of dissolved gas divided by the total volume of gas and liquid. Research showed that mixing was uniform for water and water with AFA, but mixing for the AZ101 fluid was far more complex. Although mixing of AZ101 was uniform throughout most of the column, gas entrapment and settling of solids significantly affected test results. The detailed test results presented here provide some insight into the complexities of mixing and void fractions for different fluids and how the mixing process itself

  18. EFFECTS OF OXYGEN AND AIR MIXING ON VOID FRACTIONS IN A LARGE SCALE SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Leishear, R; Hector Guerrero, H; Michael Restivo, M

    2008-09-11

    Oxygen and air mixing with spargers was performed in a 30 foot tall by 30 inch diameter column, to investigate mass transfer as air sparged up through the column and removed saturated oxygen from solution. The mixing techniques required to support this research are the focus of this paper. The fluids tested included water, water with an antifoam agent (AFA), and a high, solids content, Bingham plastic, nuclear waste simulant with AFA, referred to as AZ01 simulant, which is non-radioactive. Mixing of fluids in the column was performed using a recirculation system and an air sparger. The re-circulation system consisted of the column, a re-circulating pump, and associated piping. The air sparger was fabricated from a two inch diameter pipe concentrically installed in the column and open near the bottom of the column. The column contents were slowly re-circulated while fluids were mixed with the air sparger. Samples were rheologically tested to ensure effective mixing, as required. Once the fluids were adequately mixed, oxygen was homogeneously added through the re-circulation loop using a sintered metal oxygen sparger followed by a static mixer. Then the air sparger was re-actuated to remove oxygen from solution as air bubbled up through solution. To monitor mixing effectiveness several variables were monitored, which included flow rates, oxygen concentration, differential pressures along the column height, fluid levels, and void fractions, which are defined as the percent of dissolved gas divided by the total volume of gas and liquid. Research showed that mixing was uniform for water and water with AFA, but mixing for the AZ101 fluid was far more complex. Although mixing of AZ101 was uniform throughout most of the column, gas entrapment and settling of solids significantly affected test results. The detailed test results presented here provide some insight into the complexities of mixing and void fractions for different fluids and how the mixing process itself

  19. A large neutral fraction of cosmic hydrogen a billion years after the Big Bang.

    Science.gov (United States)

    Wyithe, J Stuart B; Loeb, Abraham

    2004-02-26

    The fraction of ionized hydrogen left over from the Big Bang provides evidence for the time of formation of the first stars and quasar black holes in the early Universe; such objects provide the high-energy photons necessary to ionize hydrogen. Spectra of the two most distant known quasars show nearly complete absorption of photons with wavelengths shorter than the Lyman alpha transition of neutral hydrogen, indicating that hydrogen in the intergalactic medium (IGM) had not been completely ionized at a redshift of z approximately 6.3, about one billion years after the Big Bang. Here we show that the IGM surrounding these quasars had a neutral hydrogen fraction of tens of per cent before the quasar activity started, much higher than the previous lower limits of approximately 0.1 per cent. Our results, when combined with the recent inference of a large cumulative optical depth to electron scattering after cosmological recombination therefore suggest the presence of a second peak in the mean ionization history of the Universe.

  20. Performance of large electron energy filter in large volume plasma device

    International Nuclear Information System (INIS)

    Singh, S. K.; Srivastava, P. K.; Awasthi, L. M.; Mattoo, S. K.; Sanyasi, A. K.; Kaw, P. K.; Singh, R.

    2014-01-01

    This paper describes an in-house designed large Electron Energy Filter (EEF) utilized in the Large Volume Plasma Device (LVPD) [S. K. Mattoo, V. P. Anita, L. M. Awasthi, and G. Ravi, Rev. Sci. Instrum. 72, 3864 (2001)] to secure objectives of (a) removing the presence of remnant primary ionizing energetic electrons and the non-thermal electrons, (b) introducing a radial gradient in plasma electron temperature without greatly affecting the radial profile of plasma density, and (c) providing a control on the scale length of gradient in electron temperature. A set of 19 independent coils of EEF make a variable aspect ratio, rectangular solenoid producing a magnetic field (B x ) of 100 G along its axis and transverse to the ambient axial field (B z ∼ 6.2 G) of LVPD, when all its coils are used. Outside the EEF, magnetic field reduces rapidly to 1 G at a distance of 20 cm from the center of the solenoid on either side of target and source plasma. The EEF divides LVPD plasma into three distinct regions of source, EEF and target plasma. We report that the target plasma (n e ∼ 2 × 10 11  cm −3 and T e ∼ 2 eV) has no detectable energetic electrons and the radial gradients in its electron temperature can be established with scale length between 50 and 600 cm by controlling EEF magnetic field. Our observations reveal that the role of the EEF magnetic field is manifested by the energy dependence of transverse electron transport and enhanced transport caused by the plasma turbulence in the EEF plasma

  1. Effect, Feasibility, and Clinical Relevance of Cell Enrichment in Large Volume Fat Grafting: A Systematic Review.

    Science.gov (United States)

    Rasmussen, Bo Sonnich; Lykke Sørensen, Celine; Vester-Glowinski, Peter Viktor; Herly, Mikkel; Trojahn Kølle, Stig-Frederik; Fischer-Nielsen, Anne; Drzewiecki, Krzysztof Tadeusz

    2017-07-01

    Large volume fat grafting is limited by unpredictable volume loss; therefore, methods of improving graft retention have been developed. Fat graft enrichment with either stromal vascular fraction (SVF) cells or adipose tissue-derived stem/stromal cells (ASCs) has been investigated in several animal and human studies, and significantly improved graft retention has been reported. Improvement of graft retention and the feasibility of these techniques are equally important in evaluating the clinical relevance of cell enrichment. We conducted a systematic search of PubMed to identify studies on fat graft enrichment that used either SVF cells or ASCs, and only studies reporting volume assessment were included. A total of 38 articles (15 human and 23 animal) were included to investigate the effects of cell enrichment on graft retention as well as the feasibility and clinical relevance of cell-enriched fat grafting. Improvements in graft retention, the SVF to fat (SVF:fat) ratio, and the ASC concentration used for enrichment were emphasized. We proposed an increased retention rate greater than 1.5-fold relative to nonenriched grafts and a maximum SVF:fat ratio of 1:1 as the thresholds for clinical relevance and feasibility, respectively. Nine studies fulfilled these criteria, whereof 6 used ASCs for enrichment. We found no convincing evidence of a clinically relevant effect of SVF enrichment in humans. ASC enrichment has shown promising results in enhancing graft retention, but additional clinical trials are needed to substantiate this claim and also determine the optimal concentration of SVF cells/ASCs for enrichment. 4. © 2017 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

  2. Measurement of Soot Volume Fraction and Temperature for Oxygen-Enriched Ethylene Combustion Based on Flame Image Processing

    Directory of Open Access Journals (Sweden)

    Weijie Yan

    2017-05-01

    Full Text Available A method for simultaneously visualizing the two-dimensional distributions of temperature and soot volume fraction in an ethylene flame was presented. A single-color charge-coupled device (CCD camera was used to capture the flame image in the visible spectrum considering the broad-response spectrum of the R and G bands of the camera. The directional emissive power of the R and G bands were calibrated and used for measurement. Slightly increased temperatures and reduced soot concentration were predicted in the central flame without self-absorption effects considered, an iterative algorithm was used for eliminating the effect of self-absorption. Nine different cases were presented in the experiment to demonstrate the effects of fuel mass flow rate and oxygen concentration on temperature and soot concentration in three different atmospheres. For ethylene combustion in pure-air atmosphere, as the fuel mass flow rate increased, the maximum temperature slightly decreased, and the maximum soot volume fraction slightly increased. For oxygen fractions of 30%, 40%, and 50% combustion in O2/N2 oxygen-enhanced atmospheres, the maximum flame temperatures were 2276, 2451, and 2678 K, whereas combustion in O2/CO2 atmospheres were 1916, 2322, and 2535 K. The maximum soot volume fractions were 4.5, 7.0, and 9.5 ppm in oxygen-enriched O2/N2 atmosphere and 13.6, 15.3, and 14.8 ppm in oxygen-enriched O2/CO2 atmosphere. Compared with the O2/CO2 atmosphere, combustion in the oxygen-enriched O2/N2 atmosphere produced higher flame temperature and larger soot volume fraction. Preliminary results indicated that this technique is reliable and can be used for combustion diagnosis.

  3. 40 CFR 63.2854 - How do I determine the weighted average volume fraction of HAP in the actual solvent loss?

    Science.gov (United States)

    2010-07-01

    ... volume fraction of HAP in the actual solvent loss? 63.2854 Section 63.2854 Protection of Environment... AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Hazardous Air Pollutants: Solvent... average volume fraction of HAP in the actual solvent loss? (a) This section describes the information and...

  4. Large-volume injection in gas chromatographic trace analysis using temperature-programmable (PTV) injectors

    NARCIS (Netherlands)

    Mol, J.G.J.; Janssen, J.G.M.; Cramers, C.A.M.G.; Brinkman, U.A.T.

    1996-01-01

    The use of programmed-temperature vaporising (PTV) injectors for large-volume injection in capillary gas chromatography is briefly reviewed. The principles and optimisation of large-volume PTV injection are discussed. Guidelines are given for selection of the PTV conditions and injection mode for

  5. Calibration of a large volume argon-41 gas-effluent monitor

    International Nuclear Information System (INIS)

    Wilson, William E.; Lovas, Thomas A.

    1976-01-01

    In September of 1975, a large volume Argon-41 sampler was calibrated using a series connected calibration chamber of known sensitivity and a constant flow of activated Argon gas. The calibration included analysis of the effects of flow rate through the large volume sampler and yielded a calibration constant of 2.34 x 10 -8 μc/cm 3 /CPM. (author)

  6. Systematic Investigation of Magnetostriction in Composite Magnetorheological Elastomers: the Effect of Particle Shape, Alignment, and Volume Fraction

    Science.gov (United States)

    Kassner, Christopher; Rieger, William; von Lockette, Paris; Lofland, Samuel

    2013-03-01

    We have completed a study of the magnetoelastic properties of several types of magnetorheological elastomers (MREs), composites consisting of magnetic particles cured in an elastic matrix. We have made a number of samples with different particle arrangements (pseudo-random and aligned), volume fraction, and particle shape (rods, spheres, and disks) and measured the field dependent strain in order to determine the magnetostriction. We found that the magnetostriction in these samples is highly dependent on the sample particle shape (aspect ratio) and volume fraction and ordering to a lesser extent. While much of the past work has focused on spherical particles, our results indicate that both rods and disks can yield enhanced results. We discuss our findings in terms of magnetic energy of the particles and elastic energy of the matrix. We then consider the issue of optimization. This work was supported in part by NSF Grant CMMI - 0927326.

  7. Influence of Fiber Volume Fraction on the Tensile Properties and Dynamic Characteristics of Coconut Fiber Reinforced Composite

    OpenAIRE

    Izzuddin Zaman; Al Emran Ismail; Muhamad Khairudin Awang

    2011-01-01

    The utilization of coconut fibers as reinforcement in polymer composites has been increased significantly due to their low cost and high specific mechanical properties. In this paper, the mechanical properties and dynamic characteristics of a proposed combined polymer composite which consist of a polyester matrix and coconut fibers are determined. The influence of fibers volume fraction (%) is also evaluated and composites with volumetric amounts of coconut fiber up to 15% are fabricated. In ...

  8. Non-invasive measurement of stroke volume and left ventricular ejection fraction. Radionuclide cardiography compared with left ventricular cardioangiography

    DEFF Research Database (Denmark)

    Kelbaek, H; Svendsen, J H; Aldershvile, J

    1988-01-01

    The stroke volume (SV) was determined by first passage radionuclide cardiography and the left ventricular ejection fraction (LVEF) by multigated radionuclide cardiography in 20 patients with ischemic heart disease. The results were evaluated against those obtained by the invasive dye dilution or ...... are reliable. The discrepancy between the non-invasive and invasive LVEF values raises the question, whether LVEF is overestimated by cardioangiography or underestimated by radionuclide cardiography....

  9. Critical Void Volume Fraction fc at Void Coalescence for S235JR Steel at Low Initial Stress Triaxiality

    Science.gov (United States)

    Grzegorz Kossakowski, Paweł; Wciślik, Wiktor

    2017-10-01

    The paper is concerned with the nucleation, growth and coalescence of microdefects in the form of voids in S235JR steel. The material is known to be one of the basic steel grades commonly used in the construction industry. The theory and methods of damage mechanics were applied to determine and describe the failure mechanisms that occur when the material undergoes deformation. Until now, engineers have generally employed the Gurson-Tvergaard- Needleman model. This material model based on damage mechanics is well suited to define and analyze failure processes taking place in the microstructure of S235JR steel. It is particularly important to determine the critical void volume fraction fc , which is one of the basic parameters of the Gurson-Tvergaard-Needleman material model. As the critical void volume fraction fc refers to the failure stage, it is determined from the data collected for the void coalescence phase. A case of multi-axial stresses is considered taking into account the effects of spatial stress state. In this study, the parameter of stress triaxiality η was used to describe the failure phenomena. Cylindrical tensile specimens with a circumferential notch were analysed to obtain low values of initial stress triaxiality (η = 0.556 of the range) in order to determine the critical void volume fraction fc . It is essential to emphasize how unique the method applied is and how different it is from the other more common methods involving parameter calibration, i.e. curve-fitting methods. The critical void volume fraction fc at void coalescence was established through digital image analysis of surfaces of S235JR steel, which involved studying real, physical results obtained directly from the material tested.

  10. Transporting large volumes of residual radioactive material: FUSRAP solutions

    International Nuclear Information System (INIS)

    Pressnell, T.; McDaniel, P.; Darby, J.

    1997-01-01

    During the 1940s, 1950s and 1960s, many sites in the United States were used by the Manhattan Engineer District and the Atomic Energy Commission for processing and storing uranium and thorium ores and metals. Some of the sites were owned by the federal government; others were owned by universities or other institutions; and still others, such as chemical plants, were privately owned. The Formerly Utilized Sites Remedial Action Program (FUSRAP) is one of several U.S. Department of Energy programs created to address radioactive contamination in excess of guidelines at these sites. FUSRAP currently includes 46 sites in 14 states. This article includes the following topics in describing FUSRAP work: Logistics challenges; engineering challenges (package inspection, equipment compatability, moisture content requirements, waste volume estimation); Traffic management

  11. Effects of retained austenite volume fraction, morphology, and carbon content on strength and ductility of nanostructured TRIP-assisted steels

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Y.F., E-mail: shenyf@smm.neu.edu.cn [Key Laboratory for Anisotropy and Texture of Materials (MOE), Northeastern University, 3 Wenhua Road, Shenyang 110004 (China); Qiu, L.N. [Key Laboratory for Anisotropy and Texture of Materials (MOE), Northeastern University, 3 Wenhua Road, Shenyang 110004 (China); Sun, X. [Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352 (United States); Zuo, L. [Key Laboratory for Anisotropy and Texture of Materials (MOE), Northeastern University, 3 Wenhua Road, Shenyang 110004 (China); Liaw, P.K. [Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996 (United States); Raabe, D. [Max-Planck-Institut fuer Eisenforschung, Max-Planck-Str. 1, 8, 40237 Düsseldorf (Germany)

    2015-06-11

    With a suite of multi-modal and multi-scale characterization techniques, the present study unambiguously proves that a substantially-improved combination of ultrahigh strength and good ductility can be achieved by tailoring the volume fraction, morphology, and carbon content of the retained austenite (RA) in a transformation-induced-plasticity (TRIP) steel with the nominal chemical composition of 0.19C–0.30Si–1.76Mn–1.52Al (weight percent, wt%). After intercritical annealing and bainitic holding, a combination of ultimate tensile strength (UTS) of 1100 MPa and true strain of 50% has been obtained, as a result of the ultrafine RA lamellae, which are alternately arranged in the bainitic ferrite around junction regions of ferrite grains. For reference, specimens with a blocky RA, prepared without the bainitic holding, yield a low ductility (35%) and a low UTS (800 MPa). The volume fraction, morphology, and carbon content of RA have been characterized using various techniques, including the magnetic probing, scanning electron microscopy (SEM), electron-backscatter-diffraction (EBSD), and transmission electron microscopy (TEM). Interrupted tensile tests, mapped using EBSD in conjunction with the kernel average misorientation (KAM) analysis, reveal that the lamellar RA is the governing microstructure component responsible for the higher mechanical stability, compared to the blocky one. By coupling these various techniques, we quantitatively demonstrate that in addition to the RA volume fraction, its morphology and carbon content are equally important in optimizing the strength and ductility of TRIP-assisted steels.

  12. The Effect of Fiber Strength Stochastics and Local Fiber Volume Fraction on Multiscale Progressive Failure of Composites

    Science.gov (United States)

    Ricks, Trenton M.; Lacy, Jr., Thomas E.; Bednarcyk, Brett A.; Arnold, Steven M.

    2013-01-01

    Continuous fiber unidirectional polymer matrix composites (PMCs) can exhibit significant local variations in fiber volume fraction as a result of processing conditions that can lead to further local differences in material properties and failure behavior. In this work, the coupled effects of both local variations in fiber volume fraction and the empirically-based statistical distribution of fiber strengths on the predicted longitudinal modulus and local tensile strength of a unidirectional AS4 carbon fiber/ Hercules 3502 epoxy composite were investigated using the special purpose NASA Micromechanics Analysis Code with Generalized Method of Cells (MAC/GMC); local effective composite properties were obtained by homogenizing the material behavior over repeating units cells (RUCs). The predicted effective longitudinal modulus was relatively insensitive to small (8%) variations in local fiber volume fraction. The composite tensile strength, however, was highly dependent on the local distribution in fiber strengths. The RUC-averaged constitutive response can be used to characterize lower length scale material behavior within a multiscale analysis framework that couples the NASA code FEAMAC and the ABAQUS finite element solver. Such an approach can be effectively used to analyze the progressive failure of PMC structures whose failure initiates at the RUC level. Consideration of the effect of local variations in constituent properties and morphologies on progressive failure of PMCs is a central aspect of the application of Integrated Computational Materials Engineering (ICME) principles for composite materials.

  13. Multi-hadron spectroscopy in a large physical volume

    DEFF Research Database (Denmark)

    Bulava, John; Hörz, Ben; Morningstar, Colin

    2018-01-01

    We demonstrate the effcacy of the stochastic LapH method to treat all-toall quark propagation on a Nf = 2 + 1 CLS ensemble with large linear spatial extent L = 5:5 fm, allowing us to obtain the benchmark elastic isovector p-wave pion-pion scattering amplitude to good precision already on a relati...

  14. Content of DNA in cancerous tumours of the breast before and after large-fractionated irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Shiukashvili, N N

    1976-07-01

    The article presents the results of microspectrophotometric investigation of DNA in different cancerous tumors of the breast gland before and after large-fractionated irradiation. The study of quantitative content of DNA in the non-irradiated tumors of the breast of different histological structure showed that parenchymatous cells are characterized by a definite variety in the DNA content with a different level of their polyploidy. This points to the fact that different histological forms of the breast cancer are distinguished by the character of the components differentiation. The comparative assessment of the ploidity of the cancerous cells of irradiated and non-irradiated tumors revealed that under the changed conditions of co-existence in all histological forms of cancer new modal classes of the cells develop and general quantity of the DNA content decreases. This testifies to the fact that the histological forms of the breast cancer are not equal sensitive tumors. A microspectrophotometric study of the breast tumors makes it possible to reveal the injury of the malignant tumor cells in the initial period of irradiation, when it is difficult to discover clear-cut dystrophical changes during histological investigation.

  15. Usefulness of acoustic quantification method in left ventricular volume and ejection fraction. Compared with ventriculography and scintigraphy

    International Nuclear Information System (INIS)

    Shibata, Takahiro; Honda, Youichi; Kashiwagi, Hidehiko

    1996-01-01

    Acoustic quantification method (AQ: on-line automated boundary detection system) has proved to have a good correlation with left ventriculography (LVG) and scintigraphy (SG) in patients with normal left ventricular (LV) function. The aim of this study is to determine whether AQ is also useful in patients with abnormal LV function. We examined 54 patients with LV asynergy. End-diastolic volumes with AQ, LVG and SG were 77, 135, 118 ml. A good correlation was found between AQ and LVG and SG (LVG; r=0.81, SG; r=0.68). End-systolic volumes with AQ, LVG and SG were 38, 64 and 57 ml. Left ventricular volumes obtained from AQ had a good correlation with LVG and SG, but were underestimated. LV ejection fraction obtained from AQ had good correlation with those with LVG and SG (LVG; r=0.84. SG; r=0.77). On-line AQ appears to be a useful noninvasive method for evaluation of the left ventricular ejection fraction, but care must be exercised when estimations of left ventricular volumes are made. (author)

  16. Multi-slice Fractional Ventilation Imaging in Large Animals with Hyperpolarized Gas MRI

    Science.gov (United States)

    Emami, Kiarash; Xu, Yinan; Hamedani, Hooman; Xin, Yi; Profka, Harrilla; Rajaei, Jennia; Kadlecek, Stephen; Ishii, Masaru; Rizi, Rahim R.

    2012-01-01

    Noninvasive assessment of regional lung ventilation is of critical importance in quantifying the severity of disease and evaluating response to therapy in many pulmonary diseases. This work presents for the first time the implementation of a hyperpolarized (HP) gas MRI technique for measuring whole-lung regional fractional ventilation (r) in Yorkshire pigs (n = 5) through the use of a gas mixing and delivery device in supine position. The proposed technique utilizes a series of back-to-back HP gas breaths with images acquired during short end-inspiratory breath-holds. In order to decouple the RF pulse decay effect from ventilatory signal build-up in the airways, regional distribution of flip angle (α) was estimated in the imaged slices by acquiring a series of back-to-back images with no inter-scan time delay during a breath-hold at the tail-end of the ventilation sequence. Analysis was performed to assess the multi-slice ventilation model sensitivity to noise, oxygen and number of flip angle images. The optimal α value was determined based on minimizing the error in r estimation; αopt = 5–6° for the set of acquisition parameters in pigs. The mean r values for the group of pigs were 0.27±0.09, 0.35±0.06, 0.40±0.04 for ventral, middle and dorsal slices, respectively, (excluding conductive airways r > 0.9). A positive gravitational (ventral-dorsal) ventilation gradient effect was present in all animals. The trachea and major conductive airways showed a uniform near-unity r value, with progressively smaller values corresponding to smaller diameter airways, and ultimately leading to lung parenchyma. Results demonstrate the feasibility of measurements of fractional ventilation in large species, and provides a platform to address technical challenges associated with long breathing time scales through the optimization of acquisition parameters in species with a pulmonary physiology very similar to that of human beings. PMID:22290603

  17. Special Properties of Coherence Scanning Interferometers for large Measurement Volumes

    International Nuclear Information System (INIS)

    Bauer, W

    2011-01-01

    In contrast to many other optical methods the uncertainty of Coherence Scanning Interferometer (CSI) in vertical direction is independent from the field of view. Therefore CSIs are ideal instruments for measuring 3D-profiles of larger areas (36x28mm 2 , e.g.) with high precision. This is of advantage for the determination of form parameters like flatness, parallelism and steps heights within a short time. In addition, using a telecentric beam path allows measurements of deep lying surfaces (<70mm) and the determination of form parameters with large step-heights. The lateral and spatial resolution, however, are reduced. In this presentation different metrological characteristics together with their potential errors are analyzed for large-scale measuring CSIs. Therefore these instruments are ideal tools in quality control for good/bad selections, e.g. The consequences for the practical use in industry and for standardization are discussed by examples of workpieces of automotive suppliers or from the steel industry.

  18. Optimization of the fractionated irradiation scheme considering physical doses to tumor and organ at risk based on dose–volume histograms

    Energy Technology Data Exchange (ETDEWEB)

    Sugano, Yasutaka [Graduate School of Health Sciences, Hokkaido University, Kita-12, Nishi-5, Kita-ku, Sapporo, Hokkaido 060-0812 (Japan); Mizuta, Masahiro [Laboratory of Advanced Data Science, Information Initiative Center, Hokkaido University, Kita-11, Nishi-5, Kita-ku, Sapporo, Hokkaido 060-0811 (Japan); Takao, Seishin; Shirato, Hiroki; Sutherland, Kenneth L. [Department of Radiation Medicine, Graduate School of Medicine, Hokkaido University, Kita-15, Nishi-5, Kita-ku, Sapporo, Hokkaido 060-8638 (Japan); Date, Hiroyuki, E-mail: date@hs.hokudai.ac.jp [Faculty of Health Sciences, Hokkaido University, Kita-12, Nishi-5, Kita-ku, Sapporo, Hokkaido 060-0812 (Japan)

    2015-11-15

    Purpose: Radiotherapy of solid tumors has been performed with various fractionation regimens such as multi- and hypofractionations. However, the ability to optimize the fractionation regimen considering the physical dose distribution remains insufficient. This study aims to optimize the fractionation regimen, in which the authors propose a graphical method for selecting the optimal number of fractions (n) and dose per fraction (d) based on dose–volume histograms for tumor and normal tissues of organs around the tumor. Methods: Modified linear-quadratic models were employed to estimate the radiation effects on the tumor and an organ at risk (OAR), where the repopulation of the tumor cells and the linearity of the dose-response curve in the high dose range of the surviving fraction were considered. The minimization problem for the damage effect on the OAR was solved under the constraint that the radiation effect on the tumor is fixed by a graphical method. Here, the damage effect on the OAR was estimated based on the dose–volume histogram. Results: It was found that the optimization of fractionation scheme incorporating the dose–volume histogram is possible by employing appropriate cell surviving models. The graphical method considering the repopulation of tumor cells and a rectilinear response in the high dose range enables them to derive the optimal number of fractions and dose per fraction. For example, in the treatment of prostate cancer, the optimal fractionation was suggested to lie in the range of 8–32 fractions with a daily dose of 2.2–6.3 Gy. Conclusions: It is possible to optimize the number of fractions and dose per fraction based on the physical dose distribution (i.e., dose–volume histogram) by the graphical method considering the effects on tumor and OARs around the tumor. This method may stipulate a new guideline to optimize the fractionation regimen for physics-guided fractionation.

  19. The capability of radial basis function to forecast the volume fractions of the annular three-phase flow of gas-oil-water.

    Science.gov (United States)

    Roshani, G H; Karami, A; Salehizadeh, A; Nazemi, E

    2017-11-01

    The problem of how to precisely measure the volume fractions of oil-gas-water mixtures in a pipeline remains as one of the main challenges in the petroleum industry. This paper reports the capability of Radial Basis Function (RBF) in forecasting the volume fractions in a gas-oil-water multiphase system. Indeed, in the present research, the volume fractions in the annular three-phase flow are measured based on a dual energy metering system including the 152 Eu and 137 Cs and one NaI detector, and then modeled by a RBF model. Since the summation of volume fractions are constant (equal to 100%), therefore it is enough for the RBF model to forecast only two volume fractions. In this investigation, three RBF models are employed. The first model is used to forecast the oil and water volume fractions. The next one is utilized to forecast the water and gas volume fractions, and the last one to forecast the gas and oil volume fractions. In the next stage, the numerical data obtained from MCNP-X code must be introduced to the RBF models. Then, the average errors of these three models are calculated and compared. The model which has the least error is picked up as the best predictive model. Based on the results, the best RBF model, forecasts the oil and water volume fractions with the mean relative error of less than 0.5%, which indicates that the RBF model introduced in this study ensures an effective enough mechanism to forecast the results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Radiation from Large Gas Volumes and Heat Exchange in Steam Boiler Furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Makarov, A. N., E-mail: tgtu-kafedra-ese@mail.ru [Tver State Technical University (Russian Federation)

    2015-09-15

    Radiation from large cylindrical gas volumes is studied as a means of simulating the flare in steam boiler furnaces. Calculations of heat exchange in a furnace by the zonal method and by simulation of the flare with cylindrical gas volumes are described. The latter method is more accurate and yields more reliable information on heat transfer processes taking place in furnaces.

  1. Evaluation of gamma prime volume fractions and lattice misfits in a nickel base superalloy using the external standard X-ray diffraction method

    Energy Technology Data Exchange (ETDEWEB)

    Tiley, J., E-mail: jaimie.tiley@wpafb.af.mil [Air Force Research Laboratory, Materials and Manufacturing Directorate, WPAFB, OH (United States); Viswanathan, G.B. [Air Force Research Laboratory, Materials and Manufacturing Directorate, WPAFB, OH (United States); Hwang, J.Y. [Materials Engineering Department, University of North Texas, Denton, TX (United States); Shiveley, A. [Air Force Research Laboratory, Materials and Manufacturing Directorate, WPAFB, OH (United States); Banerjee, R. [Materials Engineering Department, University of North Texas, Denton, TX (United States)

    2010-11-25

    The unconstrained lattice parameters and volume fractions of {gamma}' for a low misfit nickel based superalloy were evaluated using X-ray diffraction techniques. Extraction techniques were used to provide unconstrained {gamma}' powders for both water quenched and slow cooled samples that were aged at 760 deg. C for 0, 25, 50, 100, and 200 h. The external standard method was used to determine the volume fraction for the unaged water quenched sample and the slow cooled sample aged for 200 h. These two extremes in processing conditions provided an increase in the total volume fraction of {gamma}'.

  2. Wet spinning of PVA composite fibers with a large fraction of multi-walled carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Dengpan Lai

    2015-10-01

    Full Text Available PVA composites fibers with a large fraction of multi-walled carbon nanotubes modified by both covalent and non-covalent functionalization were produced by a wet-spinning process. Model XQ-1 tensile tester, thermogravimetric analysis, scanning electron microscopy, differential scanning calorimetry, and wide-angle X-ray diffraction were used to characterize the properties of PVA/MWNT composite fibers. The TGA results suggested that MWNTs content in composite fibers were ranged from 5.3 wt% to 27.6 wt%. The mechanical properties of PVA/MWNT composite fibers were obviously superior to pure PVA fiber. The Young׳s modulus of composite fibers enhanced with increasing the content of MWNTs, and it rised gradually from 6.7 GPa for the pure PVA fiber to 12.8 GPa for the composite fibers with 27.6 wt% MWNTs. Meanwhile, the tensile strength increased gradually from 0.39 GPa for the pure PVA fiber to 0.74 GPa for the composite fibers with 14.4 wt% MWNTs. Nevertheless, the tensile strength of the composite fibers decreased as the MWNTs content up to 27.6 wt%. SEM results indicated that the MWNTs homogeneously dispersed in the composite fibers, however some agglomerates also existed when the content of MWNTs reached 27.6 wt%. DSC results proved strong interfacial interaction between MWNTs and PVA chain, which benefited composite fibers in the efficient stress-transfer. WXAD characterization showed that the orientation of PVA molecules declined from 94.1% to 90.9% with the increasing of MWNTs content. The good dispersibility of MWNTs throughout PVA matrix and efficient stress-transfer between MWNTs and PVA matrix may contributed to significant enhancement in the mechanical properties.

  3. Prediction of gas volume fraction in fully-developed gas-liquid flow in a vertical pipe

    Energy Technology Data Exchange (ETDEWEB)

    Islam, A.S.M.A.; Adoo, N.A.; Bergstrom, D.J., E-mail: nana.adoo@usask.ca [University of Saskatchewan, Department of Mechanical Engineering, Saskatoon, SK (Canada); Wang, D.F. [Canadian Nuclear Laboratories, Chalk River, ON (Canada)

    2015-07-01

    An Eulerian-Eulerian two-fluid model has been implemented for the prediction of the gas volume fraction profile in turbulent upward gas-liquid flow in a vertical pipe. The two-fluid transport equations are discretized using the finite volume method and a low Reynolds number κ-ε turbulence model is used to predict the turbulence field for the liquid phase. The contribution to the effective turbulence by the gas phase is modeled by a bubble induced turbulent viscosity. For the fully-developed flow being considered, the gas volume fraction profile is calculated using the radial momentum balance for the bubble phase. The model potentially includes the effect of bubble size on the interphase forces and turbulence model. The results obtained are in good agreement with experimental data from the literature. The one-dimensional formulation being developed allows for the efficient assessment and further development of both turbulence and two-fluid models for multiphase flow applications in the nuclear industry. (author)

  4. Prediction of gas volume fraction in fully-developed gas-liquid flow in a vertical pipe

    International Nuclear Information System (INIS)

    Islam, A.S.M.A.; Adoo, N.A.; Bergstrom, D.J.; Wang, D.F.

    2015-01-01

    An Eulerian-Eulerian two-fluid model has been implemented for the prediction of the gas volume fraction profile in turbulent upward gas-liquid flow in a vertical pipe. The two-fluid transport equations are discretized using the finite volume method and a low Reynolds number κ-ε turbulence model is used to predict the turbulence field for the liquid phase. The contribution to the effective turbulence by the gas phase is modeled by a bubble induced turbulent viscosity. For the fully-developed flow being considered, the gas volume fraction profile is calculated using the radial momentum balance for the bubble phase. The model potentially includes the effect of bubble size on the interphase forces and turbulence model. The results obtained are in good agreement with experimental data from the literature. The one-dimensional formulation being developed allows for the efficient assessment and further development of both turbulence and two-fluid models for multiphase flow applications in the nuclear industry. (author)

  5. First experiences with super fractionated skin irradiations using large afterloading molds

    International Nuclear Information System (INIS)

    Fritz, Peter; Hensley, Frank W.; Berns, Christiane; Schraube, Peter; Wannenmacher, Michael

    1996-01-01

    Purpose: Radiotherapy of cutaneous metastases of breast cancer requires large radiation fields and high doses. This report examines the effectiveness and sequelae of super fractionated irradiation of cutaneous metastases of breast cancer with afterloading molds on preirradiated and nonirradiated skin. Methods and Materials: A flexible reusable skin mold was developed for use with a pulsed (PDR) after loader. An array of 18 parallel catheters was sewn between two foam rubber slabs 5 mm in thickness to provide a defined constant distance to the skin. By selection of appropriate dwell positions, arbitrarily shaped skin areas can be irradiated up to a maximal field size of 17 x 23.5 cm 2 . Irradiations are performed with a nominal 37 GBq 192 Ir stepping source in pulses of 1 Gy/h at the skin surface. The dose distribution is geometrically optimized. The 80 and 50% dose levels lie 5 and 27 mm below the skin surface. Sixteen patients suffering from metastases at the thoracic wall were treated with 18 fields (78-798 cm 2 ) and total doses of 40-50 Gy applying two PDR split courses with a pause of 4-6 weeks. Eleven of the fields had been previously irradiated with external beam therapy to doses of 50-60 Gy at 7-22 months in advance. Results: For preirradiated fields (n = 10) the results were as follows: follow-up 4.5-28.5 months (median 17); local control (LC): 8 of 10; acute skin reactions: Grade 2 (moist desquamation) 2 of 10; intermediate/late skin reactions after minimum follow-up of 3 months: Grade 1 (atrophy/pigmentation): 2 of 10, Grade 2-3a (minimal/marked telangiectasia): 7 of 10, Grade 4 (ulcer): 1 of 10; recurrencies: 2 of 10. For newly irradiated fields (n = 7) results were: follow-up: 2-20 months (median 5); LC: 6 of 7; acute reactions: Grade 1:4 of 7, Grade 2:3 of 7; intermediate/late skin reactions after minimum follow-up of 3 months (n = 5): Grade 2-3a: 2 of 5; recurrencies: 0 of 7. Local control could be achieved in 82% of the mold fields. Geometric

  6. Reference intervals for mean platelet volume and immature platelet fraction determined on a sysmex XE5000 hematology analyzer

    DEFF Research Database (Denmark)

    Jørgensen, Mikala Klok; Bathum, L.

    2016-01-01

    Background New parameters describing the platelet population of the blood are mean platelet volume (MPV), which is a crude estimate of thrombocyte reactivity, and immature platelet fraction (IPF), which reflects megakaryopoietic activity. This study aimed to define reference intervals for MPV...... and IPF and to investigate whether separate reference intervals according to smoking status, age or sex are necessary.Methods Blood samples were obtained from subjects participating in The Danish General Suburban Population Study. MPV and IPF measurements were performed by the use of the Sysmex XE-5000...

  7. Theoretical Model for Volume Fraction of UC, 235U Enrichment, and Effective Density of Final U 10Mo Alloy

    Energy Technology Data Exchange (ETDEWEB)

    Devaraj, Arun [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL); Prabhakaran, Ramprashad [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL); Joshi, Vineet V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL); Hu, Shenyang Y. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL); McGarrah, Eric J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)

    2016-04-12

    The purpose of this document is to provide a theoretical framework for (1) estimating uranium carbide (UC) volume fraction in a final alloy of uranium with 10 weight percent molybdenum (U-10Mo) as a function of final alloy carbon concentration, and (2) estimating effective 235U enrichment in the U-10Mo matrix after accounting for loss of 235U in forming UC. This report will also serve as a theoretical baseline for effective density of as-cast low-enriched U-10Mo alloy. Therefore, this report will serve as the baseline for quality control of final alloy carbon content

  8. Enrichment of circulating tumor cells from a large blood volume using leukapheresis and elutriation: proof of concept.

    Science.gov (United States)

    Eifler, Robert L; Lind, Judith; Falkenhagen, Dieter; Weber, Viktoria; Fischer, Michael B; Zeillinger, Robert

    2011-03-01

    The aim of this study was to determine the applicability of a sequential process using leukapheresis, elutriation, and fluorescence-activated cell sorting (FACS) to enrich and isolate circulating tumor cells from a large blood volume to allow further molecular analysis. Mononuclear cells were collected from 10 L of blood by leukapheresis, to which carboxyfluorescein succinimidyl ester prelabeled CaOV-3 tumor cells were spiked at a ratio of 26 to 10⁶ leukocytes. Elutriation separated the spiked leukapheresates primarily by cell size into distinct fractions, and leukocytes and tumor cells, characterized as carboxyfluorescein succinimidyl ester positive, EpCAM positive and CD45 negative events, were quantified by flow cytometry. Tumor cells were isolated from the last fraction using FACS or anti-EpCAM coupled immunomagnetic beads, and their recovery and purity determined by fluorescent microscopy and real-time PCR. Leukapheresis collected 13.5 x 10⁹ mononuclear cells with 87% efficiency. In total, 53 to 78% of spiked tumor cells were pre-enriched in the last elutriation fraction among 1.6 x 10⁹ monocytes. Flow cytometry predicted a circulating tumor cell purity of ~90% giving an enrichment of 100,000-fold following leukapheresis, elutriation, and FACS, where CaOV-3 cells were identified as EpCAM positive and CD45 negative events. FACS confirmed this purity. Alternatively, immunomagnetic bead adsorption recovered 10% of tumor cells with a median purity of 3.5%. This proof of concept study demonstrated that elutriation and FACS following leukapheresis are able to enrich and isolate tumor cells from a large blood volume for molecular characterization. Copyright © 2010 International Clinical Cytometry Society.

  9. Fractional order modeling and control of dissimilar redundant actuating system used in large passenger aircraft

    Directory of Open Access Journals (Sweden)

    Salman IJAZ

    2018-05-01

    Full Text Available In this paper, a methodology has been developed to address the issue of force fighting and to achieve precise position tracking of control surface driven by two dissimilar actuators. The nonlinear dynamics of both actuators are first approximated as fractional order models. Based on the identified models, three fractional order controllers are proposed for the whole system. Two Fractional Order PID (FOPID controllers are dedicated to improving transient response and are designed in a position feedback configuration. In order to synchronize the actuator dynamics, a third fractional order PI controller is designed, which feeds the force compensation signal in position feedback loop of both actuators. Nelder-Mead (N-M optimization technique is employed in order to optimally tune controller parameters based on the proposed performance criteria. To test the proposed controllers according to real flight condition, an external disturbance of higher amplitude that acts as airload is applied directly on the control surface. In addition, a disturbance signal function of system states is applied to check the robustness of proposed controller. Simulation results on nonlinear system model validated the performance of the proposed scheme as compared to optimal PID and high gain PID controllers. Keywords: Aerospace, Fractional order control, Model identification, Nelder-Mead optimization, Robustness

  10. Integer, fractional, and anomalous quantum Hall effects explained with Eyring's rate process theory and free volume concept.

    Science.gov (United States)

    Hao, Tian

    2017-02-22

    The Hall effects, especially the integer, fractional and anomalous quantum Hall effects, have been addressed using Eyring's rate process theory and free volume concept. The basic assumptions are that the conduction process is a common rate controlled "reaction" process that can be described with Eyring's absolute rate process theory; the mobility of electrons should be dependent on the free volume available for conduction electrons. The obtained Hall conductivity is clearly quantized as with prefactors related to both the magnetic flux quantum number and the magnetic quantum number via the azimuthal quantum number, with and without an externally applied magnetic field. This article focuses on two dimensional (2D) systems, but the approaches developed in this article can be extended to 3D systems.

  11. Prediction of the Soil Water Characteristic from Soil Particle Volume Fractions

    DEFF Research Database (Denmark)

    Naveed, Muhammad; Møldrup, Per; Tuller, Markus

    2012-01-01

    Modelling water distribution and flow in partially saturated soils requires knowledge of the soil-water characteristic (SWC). However, measurement of the SWC is challenging and time-consuming, and in some cases not feasible. This study introduces two predictive models (Xw-model and Xw......*-model) for the SWC, derived from readily available soil properties such as texture and bulk density. A total of 46 soils from different horizons at 15 locations across Denmark were used for models evaluation. The Xw-model predicts the volumetric water content as a function of volumetric fines content (organic matter...... (organic matter, clay, silt, fine and coarse sand), variably included in the model depending on the pF value. The volumetric content of a particular soil particle size fraction was included in the model if it was assumed to contribute to the pore size fraction still occupied with water at the given p...

  12. Center-stabilized Yang-Mills Theory:Confinement and Large N Volume Independence

    International Nuclear Information System (INIS)

    Unsal, Mithat; Yaffe, Laurence G.

    2008-01-01

    We examine a double trace deformation of SU(N) Yang-Mills theory which, for large N and large volume, is equivalent to unmodified Yang-Mills theory up to O(1/N 2 ) corrections. In contrast to the unmodified theory, large N volume independence is valid in the deformed theory down to arbitrarily small volumes. The double trace deformation prevents the spontaneous breaking of center symmetry which would otherwise disrupt large N volume independence in small volumes. For small values of N, if the theory is formulated on R 3 x S 1 with a sufficiently small compactification size L, then an analytic treatment of the non-perturbative dynamics of the deformed theory is possible. In this regime, we show that the deformed Yang-Mills theory has a mass gap and exhibits linear confinement. Increasing the circumference L or number of colors N decreases the separation of scales on which the analytic treatment relies. However, there are no order parameters which distinguish the small and large radius regimes. Consequently, for small N the deformed theory provides a novel example of a locally four-dimensional pure gauge theory in which one has analytic control over confinement, while for large N it provides a simple fully reduced model for Yang-Mills theory. The construction is easily generalized to QCD and other QCD-like theories

  13. Center-stabilized Yang-Mills theory: Confinement and large N volume independence

    International Nuclear Information System (INIS)

    Uensal, Mithat; Yaffe, Laurence G.

    2008-01-01

    We examine a double trace deformation of SU(N) Yang-Mills theory which, for large N and large volume, is equivalent to unmodified Yang-Mills theory up to O(1/N 2 ) corrections. In contrast to the unmodified theory, large N volume independence is valid in the deformed theory down to arbitrarily small volumes. The double trace deformation prevents the spontaneous breaking of center symmetry which would otherwise disrupt large N volume independence in small volumes. For small values of N, if the theory is formulated on R 3 xS 1 with a sufficiently small compactification size L, then an analytic treatment of the nonperturbative dynamics of the deformed theory is possible. In this regime, we show that the deformed Yang-Mills theory has a mass gap and exhibits linear confinement. Increasing the circumference L or number of colors N decreases the separation of scales on which the analytic treatment relies. However, there are no order parameters which distinguish the small and large radius regimes. Consequently, for small N the deformed theory provides a novel example of a locally four-dimensional pure-gauge theory in which one has analytic control over confinement, while for large N it provides a simple fully reduced model for Yang-Mills theory. The construction is easily generalized to QCD and other QCD-like theories.

  14. 21 CFR 201.323 - Aluminum in large and small volume parenterals used in total parenteral nutrition.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Aluminum in large and small volume parenterals... for Specific Drug Products § 201.323 Aluminum in large and small volume parenterals used in total parenteral nutrition. (a) The aluminum content of large volume parenteral (LVP) drug products used in total...

  15. Control-Oriented Model of Molar Scavenge Oxygen Fraction for Exhaust Recirculation in Large Diesel Engines

    DEFF Research Database (Denmark)

    Nielsen, Kræn Vodder; Blanke, Mogens; Eriksson, Lars

    2016-01-01

    the behavior of the scavenge oxygen fraction well over the entire envelope of load and blower speed range that are relevant for EGR. The simplicity of the new model makes it suitable for observer and control design, which are essential steps to meet the emission requirements for marine diesel engines that take...

  16. A glimpse beneath Antarctic sea ice: observation of platelet-layer thickness and ice-volume fraction with multifrequency EM

    Science.gov (United States)

    Hoppmann, Mario; Hunkeler, Priska A.; Hendricks, Stefan; Kalscheuer, Thomas; Gerdes, Rüdiger

    2016-04-01

    In Antarctica, ice crystals (platelets) form and grow in supercooled waters below ice shelves. These platelets rise, accumulate beneath nearby sea ice, and subsequently form a several meter thick, porous sub-ice platelet layer. This special ice type is a unique habitat, influences sea-ice mass and energy balance, and its volume can be interpreted as an indicator of the health of an ice shelf. Although progress has been made in determining and understanding its spatio-temporal variability based on point measurements, an investigation of this phenomenon on a larger scale remains a challenge due to logistical constraints and a lack of suitable methodology. In the present study, we applied a lateral constrained Marquardt-Levenberg inversion to a unique multi-frequency electromagnetic (EM) induction sounding dataset obtained on the ice-shelf influenced fast-ice regime of Atka Bay, eastern Weddell Sea. We adapted the inversion algorithm to incorporate a sensor specific signal bias, and confirmed the reliability of the algorithm by performing a sensitivity study using synthetic data. We inverted the field data for sea-ice and platelet-layer thickness and electrical conductivity, and calculated ice-volume fractions within the platelet layer using Archie's Law. The thickness results agreed well with drillhole validation datasets within the uncertainty range, and the ice-volume fraction yielded results comparable to other studies. Both parameters together enable an estimation of the total ice volume within the platelet layer, which was found to be comparable to the volume of landfast sea ice in this region, and corresponded to more than a quarter of the annual basal melt volume of the nearby Ekström Ice Shelf. Our findings show that multi-frequency EM induction sounding is a suitable approach to efficiently map sea-ice and platelet-layer properties, with important implications for research into ocean/ice-shelf/sea-ice interactions. However, a successful application of this

  17. A probabilistic method for determining the volume fraction of pre-embedded capsules in self-healing materials

    International Nuclear Information System (INIS)

    Lv, Zhong; Chen, Huisu

    2014-01-01

    Autonomous healing of cracks using pre-embedded capsules containing healing agent is becoming a promising approach to restore the strength of damaged structures. In addition to the material properties, the size and volume fraction of capsules influence crack healing in the matrix. Understanding the crack and capsule interaction is critical in the development and design of structures made of self-healing materials. Assuming that the pre-embedded capsules are randomly dispersed we theoretically model flat ellipsoidal crack interaction with capsules and determine the probability of a crack intersecting the pre-embedded capsules i.e. the self-healing probability. We also develop a probabilistic model of a crack simultaneously meeting with capsules and catalyst carriers in two-component self-healing system matrix. Using a risk-based healing approach, we determine the volume fraction and size of the pre-embedded capsules that are required to achieve a certain self-healing probability. To understand the effect of the shape of the capsules on self-healing we theoretically modeled crack interaction with spherical and cylindrical capsules. We compared the results of our theoretical model with Monte-Carlo simulations of crack interaction with capsules. The formulae presented in this paper will provide guidelines for engineers working with self-healing structures in material selection and sustenance. (paper)

  18. The Cytotoxic Effect of Small and Large Molecules of PMF Fraction Extracted from Camel Urine on Cancer Cells

    KAUST Repository

    Khorshid, Faten

    2015-01-10

    Aim of the work: Animal urine, including that of camels, has long been used for the therapeutic management of human ailments. In this study, we sought to characterize the cytotoxic properties of newly derived purified fractions from previously described camel urine extract (PMF) on various cancer cell lines. Methodology: Two new size dissimilar fractions of PMF (large and small) were obtained by fractionalizing PMF using 3kD and 50kD membrane filters. A SRB cytotoxicity assay of the PMF fractions was performed on cancer cell lines (A549, HCT116, HepG2, MCF-7, U251 and Hela) as well as normal cell lines (human fibroblast cell line and Vero). Results: This study showed that the newly derived and more purified fraction of PMF (new PMF) possesses effective and selective anti-cancer properties against several types of cancer cell lines. Conclusion: This study, as well as previous ones, suggests that camel urine extracts (old and new PMF) may provide newer therapeutic alternatives to clinically manage cancer patients. However, further studies are needed to verify these positive preliminary results.

  19. Evaluation of the clinical efficacy of fractional radiofrequency microneedle treatment in acne scars and large facial pores.

    Science.gov (United States)

    Cho, Soo Ick; Chung, Bo Young; Choi, Min Gyu; Baek, Ji Hwoon; Cho, Hee Jin; Park, Chun Wook; Lee, Cheol Heon; Kim, Hye One

    2012-07-01

    Fractional technology overcomes the problems of ablative lasers, such as inaccurate depth control and damage to the epidermis. Minimally invasive fractional radiofrequency microneedle devices allow for more-selective heating of the dermis. To evaluate the clinical efficacy of fractional radiofrequency microneedle (ERM) treatment in acne scars and large facial pores. Thirty patients with acne scars and large facial pores were enrolled. Bipolar radiofrequency energy was delivered to the skin through the electrodes of the FRM device. Skin lesions were evaluated according to grade of acne scars, Investigator Global Assessment of large pores, skin surface roughness, transepidermal water loss (TEWL), dermal density, microscopic and composite image, sebum measurement, and questionnaires regarding patient satisfaction. The grade of acne scars and Investigator Global Assessment of large pores improved in more than 70% of all patients. Skin surface roughness, dermal density, and microscopic and composite images also improved, whereas TEWL and sebum measurement did not change. Clinical improvement from FRM treatment appeared to be related to dermal matrix regeneration. FRM treatment may be effective in improving acne scars and facial pores. © 2012 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

  20. COMPARISON OF THE FRACTIONS OF COD IN RAW WASTEWATER INFLUENT FOR SMALL AND LARGE SEWAGE TREATMENT

    Directory of Open Access Journals (Sweden)

    Joanna Smyk

    2016-06-01

    Full Text Available The article presents a comparison of the share fraction of COD in raw wastewater in treatment plants which flow in a small amount of wastewater and the sewage treatment with high flow. Compared the constructed wetlands with an average capacity of 4 dm3/m,, the treatment plant with biological deposits with an average capacity of 8 dm3/m, and a sewage treatment plant with activated sludge in Bialystok with a capacity of about 70 000 dm3/m. The lowest percentages of dissolved fraction of soluble organic non-biodegradable substances SI was reported in raw sewage in small sewage treatment plants. Based on the available data wasn’t found significant correlation between the factions XI, SS, XS in raw sewage and the amount of wastewater.

  1. Large effect of irradiance on hydrogen isotope fractionation of alkenones in Emiliania huxleyi

    Science.gov (United States)

    van der Meer, Marcel T. J.; Benthien, Albert; French, Katherine L.; Epping, Eric; Zondervan, Ingrid; Reichart, Gert-Jan; Bijma, Jelle; Sinninghe Damsté, Jaap S.; Schouten, Stefan

    2015-07-01

    The hydrogen isotopic (δD) composition of long-chain alkenones produced by certain haptophyte algae has been suggested as a potential proxy for reconstructing paleo sea surface salinity. However, environmental parameters other than salinity may also affect the δD of alkenones. We investigated the impact of the level of irradiance on hydrogen isotopic fractionation of alkenones versus growth water by cultivating two strains of the cosmopolitan haptophyte Emiliania huxleyi at different light intensities. The hydrogen isotope fractionation decreased by approximately 40‰ when irradiance was increased from 15 to 200 μmol photons m-2 s-1 above which it was relatively constant. The response is likely a direct effect of photosystem I and II activity as the relationship of the fractionation factor α versus light intensity can be described by an Eilers-Peeters photosynthesis model. This irradiance effect is in agreement with published δD data of alkenones derived from suspended particulate matter collected from different depths in the photic zone of the Gulf of California and the eastern tropical North Pacific. However, haptophyte algae tend to bloom at relatively high light intensities (>500 μmol photons m-2 s-1) occurring at the sea surface, at which hydrogen isotope fractionation is relatively constant and not affected by changes in light intensity. Alkenones accumulating in the sediment are likely mostly derived from these surface water haptophyte blooms, when the largest amount of biomass is produced. Therefore, the observed irradiance effect is unlikely to affect the applicability of the hydrogen isotopic composition of sedimentary long chain alkenones as a proxy for paleosalinity.

  2. Large-scale isolation and fractionation of organs of Drosophila melanogaster larvae.

    Science.gov (United States)

    Zweidler, A; Cohen, L H

    1971-10-01

    Methods for the mass isolation of diverse organs from small animals are described. They involve novel devices: a mechanical dissecting system, a centrifugal agitator for the separation of fibrillar from globular particles, and a settling chamber for the fractionation at unit gravity of particles with sedimentation velocities above the useful range for centrifugation. The application of these methods to the isolation of polytene and nonpolytene nuclei from Drosophila melanogaster larvae is described.

  3. Agreement of left ventricular ejection fraction and volumes between adenosine stress TL-201 gated SPECT and echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Pai, M. S. [College of Medicine, Univ. of Ewha, Seoul (Korea, Republic of); Moon, D. H.; Kim, H. M.; Yang, Y. J.; Kang, D. H. [Asan Medical Center, Seoul (Korea, Republic of)

    2003-07-01

    Electrocardiogram-gated TI-201 SPECT measurements of left ventricular ejection fraction (EF), end-diastolic volume (EDV), and end-systolic volume (ESV) have shown high correlation with conventional methods. However, how much these parameters measured by TI-201 gated SPECT differ from those by echocardiography has not been assessed. Adenosine stress (Ad-G) and redistribution TI-201 gated SPECT (Re-G) and resting echocardiography were conducted in 337 patients (184 male, 153 female). EDV, ESV and LVEF measured by QGS software were compared with the results by echocardiography. Patients with arrhythmia (atrial fibrillation or frequent premature contractions) or evidence of fixed or reversible perfusion defects on TI-201 SPECT were excluded. EF, EDV and ESV measured by Ad-G (63.3{+-}9.8,73.8{+-}30.2,29.1{+-}20.1) and Re-G (65.2{+-}11.6,69.1{+-}30.1,26.5{+-}20.3) correlated well with those by Echo (61.4{+-}7.9,78.3{+-}2.7, 30.7{+-} 17.5 ; r of Ad-G=0.547, 0.850, 0.827, p<0.001 ; r of Re-G=0.585, 0.838, 0.819, p<0.001). However the difference (mean, SD, SEE of Echo - gated SPECT) was statistically significant (EF: Ad-G=1.71, 8.92, 0.48, Re-G=3.59, 10.39, 0.56, p<0.001 ; EDV: Ad-G=4.75, 16.21, 0.88, Re-G=9.53, 16.77, 0.91, p<0.001 ; ESV: Ad-G=1.75, 11.35, 0.61, p<0.05, Re-G=4.29, 11.7, 0.63, p<0.001). Bland-Altman plots showed that the difference of EDV and ESV did not vary in any systematic way over the range of measurement, whereas the difference of EF increased with increasing average EF by Echo and gated-SPECT. The difference of EF, EDV, and ESV between Ad-G and Echo was significantly smaller than those between Re-G and Echo (p<0.001). Gated TI-201 SPECT underestimates EDV and ESV over a wide range of volume. As a result, EF by gated TI-201 SPECT is overestimated especially in patients with small LV volume. Ad-G is preferable to Re-G in assessing left ventricular ejection fraction and volume in place of Echo because of smaller bias.

  4. Refined universal laws for hull volumes and perimeters in large planar maps

    International Nuclear Information System (INIS)

    Guitter, Emmanuel

    2017-01-01

    We consider ensembles of planar maps with two marked vertices at distance k from each other, and look at the closed line separating these vertices and lying at distance d from the first one ( d   <   k ). This line divides the map into two components, the hull at distance d which corresponds to the part of the map lying on the same side as the first vertex and its complementary. The number of faces within the hull is called the hull volume, and the length of the separating line the hull perimeter. We study the statistics of the hull volume and perimeter for arbitrary d and k in the limit of infinitely large planar quadrangulations, triangulations and Eulerian triangulations. We consider more precisely situations where both d and k become large with the ratio d / k remaining finite. For infinitely large maps, two regimes may be encountered: either the hull has a finite volume and its complementary is infinitely large, or the hull itself has an infinite volume and its complementary is of finite size. We compute the probability for the map to be in either regime as a function of d / k as well as a number of universal statistical laws for the hull perimeter and volume when maps are conditioned to be in one regime or the other. (paper)

  5. Large Volume, Behaviorally-relevant Illumination for Optogenetics in Non-human Primates.

    Science.gov (United States)

    Acker, Leah C; Pino, Erica N; Boyden, Edward S; Desimone, Robert

    2017-10-03

    This protocol describes a large-volume illuminator, which was developed for optogenetic manipulations in the non-human primate brain. The illuminator is a modified plastic optical fiber with etched tip, such that the light emitting surface area is > 100x that of a conventional fiber. In addition to describing the construction of the large-volume illuminator, this protocol details the quality-control calibration used to ensure even light distribution. Further, this protocol describes techniques for inserting and removing the large volume illuminator. Both superficial and deep structures may be illuminated. This large volume illuminator does not need to be physically coupled to an electrode, and because the illuminator is made of plastic, not glass, it will simply bend in circumstances when traditional optical fibers would shatter. Because this illuminator delivers light over behaviorally-relevant tissue volumes (≈ 10 mm 3 ) with no greater penetration damage than a conventional optical fiber, it facilitates behavioral studies using optogenetics in non-human primates.

  6. Rejecting escape events in large volume Ge detectors by a pulse shape selection procedure

    International Nuclear Information System (INIS)

    Del Zoppo, A.; Agodi, C.; Alba, R.; Bellia, G.; Coniglione, R.; Loukachine, K.; Maiolino, C.; Migneco, E.; Piattelli, P.; Santonocito, D.; Sapienza, P.

    1993-01-01

    The dependence of the response to γ-rays of a large volume Ge detector on the interval width of a selected initial rise pulse slope is investigated. The number of escape events associated with a small pulse slope is found to be greater than the corresponding number of full energy events. An escape event rejection procedure based on the observed correlation between energy deposition and pulse shape is discussed. Such a procedure seems particularly suited for the design of highly granular large volume Ge detector arrays. (orig.)

  7. Feasibility of large volume casting cementation process for intermediate level radioactive waste

    International Nuclear Information System (INIS)

    Chen Zhuying; Chen Baisong; Zeng Jishu; Yu Chengze

    1988-01-01

    The recent tendency of radioactive waste treatment and disposal both in China and abroad is reviewed. The feasibility of the large volume casting cementation process for treating and disposing the intermediate level radioactive waste from spent fuel reprocessing plant in shallow land is assessed on the basis of the analyses of the experimental results (such as formulation study, solidified radioactive waste properties measurement ect.). It can be concluded large volume casting cementation process is a promising, safe and economic process. It is feasible to dispose the intermediate level radioactive waste from reprocessing plant it the disposal site chosen has resonable geological and geographical conditions and some additional effective protection means are taken

  8. In vivo assessment of the tolerance dose of small liver volumes after single-fraction HDR irradiation

    International Nuclear Information System (INIS)

    Ricke, Jens; Seidensticker, Max; Luedemann, Lutz; Pech, Maciej; Wieners, Gero; Hengst, Susanne; Mohnike, Konrad; Cho, Chie Hee; Lopez Haenninen, Enrique; Al-Abadi, Hussain; Felix, Roland; Wust, Peter

    2005-01-01

    Purpose: To prospectively assess a dose-response relationship for small volumes of liver parenchyma after single-fraction irradiation. Methods and Materials: Twenty-five liver metastases were treated by computed tomography (CT)-guided interstitial brachytherapy. Magnetic resonance imaging was performed 1 day before and 3 days and 6, 12, and 24 weeks after therapy. MR sequences included T1-w gradient echo (GRE) enhanced by hepatocyte-targeted gadobenate dimeglumine. All MRI data sets were merged with 3D dosimetry data and evaluated by two radiologists. The reviewers indicated the border of hyperintensity on T2-w images (edema) or hypointensity on T1-w images (loss of hepatocyte function). Based on the total 3D data, a dose-volume histogram was calculated. We estimated the threshold dose for either edema or function loss as the D 90 , i.e., the dose achieved in at least 90% of the pseudolesion volume. Results: Between 3 days and 6 weeks, the extension of the edema increased significantly from the 12.9 Gy isosurface to 9.9 Gy (standard deviation [SD], 3.3 and 2.6). No significant change was detected between 6 and 12 weeks. After 24 weeks, the edematous tissue had shrunk significantly to 14.7 Gy (SD, 4.2). Three days postbrachytherapy, the D 90 for hepatocyte function loss reached the 14.9 Gy isosurface (SD, 3.9). At 6 weeks, the respective zone had increased significantly to 9.9 Gy (SD, 2.3). After 12 and 24 weeks, the dysfunction volume had decreased significantly to the 11.9 Gy and 15.2 Gy isosurface, respectively (SD, 3 and 4.1). Conclusions: The 95% interval from 7.6 to 12.2 Gy found as the minimal hepatocyte tolerance after 6 weeks accounts for the radiobiologic variations found in CT-guided brachytherapy, including heterogeneous dose rates by variable catheter arrays

  9. Comparison of 16-frame and 8-frame gated SPET imaging for determination of left ventricular volumes and ejection fraction

    International Nuclear Information System (INIS)

    Navare, Sachin M.; Liu, Yi-Hwa; Wackers, Frans J.T.

    2003-01-01

    Electrocardiographic (ECG) gated single-photon emission tomography (SPET) allows for simultaneous assessment of myocardial perfusion and left ventricular (LV) function. Presently 8-frame per cardiac cycle ECG gating of SPET images is standard. The aim of this study was to compare the effect of 8-frame and 16-frame gated SPET on measurements of LV volumes and to evaluate the effects of the presence of myocardial perfusion defects and of radiotracer dose administered on the calculation of LV volumes. A total of 86 patients underwent technetium-99m SPET myocardial perfusion imaging using 16-frame per cardiac cycle acquisition. Eight-frame gated SPET images were generated by summation of contiguous frames. Left ventricular end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) were calculated from the 16-frame and 8-frame data sets. The patients were divided into groups according to the administered dose of the radiotracer and the size of the perfusion defect. Results. Sixteen frame per cardiac cycle acquisition resulted in significantly larger EDV (122±72 ml vs 115±68 ml, P<0.0001), smaller ESV (64±58.6 ml vs 67.6±59.5 ml, P<0.0001), and higher LVEF (55.3%±18% vs 49%±17.4%, P<0.0001) as compared to 8-frame SPET imaging. This effect was seen regardless of whether a high or a low dose was administered and whether or not significant perfusion defects were present. This study shows that EDV, ESV and LVEF determined by 16-frame gated SPET are significantly different from those determined by 8-frame gated SPET. The radiotracer dose and perfusion defects do not affect estimation of LV parameters by 16-frame gated SPET. (orig.)

  10. Radiobiological restrictions and tolerance doses of repeated single-fraction hdr-irradiation of intersecting small liver volumes for recurrent hepatic metastases

    Directory of Open Access Journals (Sweden)

    Wust Peter

    2010-05-01

    Full Text Available Abstract Background To assess radiobiological restrictions and tolerance doses as well as other toxic effects derived from repeated applications of single-fraction high dose rate irradiation of small liver volumes in clinical practice. Methods Twenty patients with liver metastases were treated repeatedly (2 - 4 times at identical or intersecting locations by CT-guided interstitial brachytherapy with varying time intervals. Magnetic resonance imaging using the hepatocyte selective contrast media Gd-BOPTA was performed before and after treatment to determine the volume of hepatocyte function loss (called pseudolesion, and the last acquired MRI data set was merged with the dose distributions of all administered brachytherapies. We calculated the BED (biologically equivalent dose for a single dose d = 2 Gy for different α/β values (2, 3, 10, 20, 100 based on the linear-quadratic model and estimated the tolerance dose for liver parenchyma D90 as the BED exposing 90% of the pseudolesion in MRI. Results The tolerance doses D90 after repeated brachytherapy sessions were found between 22 - 24 Gy and proved only slightly dependent on α/β in the clinically relevant range of α/β = 2 - 10 Gy. Variance analysis showed a significant dependency of D90 with respect to the intervals between the first irradiation and the MRI control (p 90 and the pseudolesion's volume. No symptoms of liver dysfunction or other toxic effects such as abscess formation occurred during the follow-up time, neither acute nor on the long-term. Conclusions Inactivation of liver parenchyma occurs at a BED of approx. 22 - 24 Gy corresponding to a single dose of ~10 Gy (α/β ~ 5 Gy. This tolerance dose is consistent with the large potential to treat oligotopic and/or recurrent liver metastases by CT-guided HDR brachytherapy without radiation-induced liver disease (RILD. Repeated small volume irradiation may be applied safely within the limits of this study.

  11. Quantifying uncertainty in soot volume fraction estimates using Bayesian inference of auto-correlated laser-induced incandescence measurements

    Science.gov (United States)

    Hadwin, Paul J.; Sipkens, T. A.; Thomson, K. A.; Liu, F.; Daun, K. J.

    2016-01-01

    Auto-correlated laser-induced incandescence (AC-LII) infers the soot volume fraction (SVF) of soot particles by comparing the spectral incandescence from laser-energized particles to the pyrometrically inferred peak soot temperature. This calculation requires detailed knowledge of model parameters such as the absorption function of soot, which may vary with combustion chemistry, soot age, and the internal structure of the soot. This work presents a Bayesian methodology to quantify such uncertainties. This technique treats the additional "nuisance" model parameters, including the soot absorption function, as stochastic variables and incorporates the current state of knowledge of these parameters into the inference process through maximum entropy priors. While standard AC-LII analysis provides a point estimate of the SVF, Bayesian techniques infer the posterior probability density, which will allow scientists and engineers to better assess the reliability of AC-LII inferred SVFs in the context of environmental regulations and competing diagnostics.

  12. Effect of Volume Fraction of Particle on Wear Resistance of Al2O3/Steel Composites at Elevated Temperature

    Institute of Scientific and Technical Information of China (English)

    BAO Chong-gao; WANG En-ze; GAO Yi-min; XING Jian-dong

    2005-01-01

    Based on previous work,abrasive wear resistance of Al2 O3/steel composites with different Al2 O3 parti cle volume fraction (VOF) at 900 C was investigated.The experimental results showed that a suitable particle VOF is important to protect the metal matrix from wear at elevated temperature.Both too high and too low particle VOF lead to a poor abrasive wear because a bulk matrix is easily worn off by grits when it exceeds the suitable VOF and also because when VOF is low,the Al2O3 particles are easily dug out by grits during wearing as well.When the particle VOF is 39%,the wear resistance of tested composites is excellent.

  13. The Effect of Type and Volume Fraction (Vf) of Steel Fiber on the Mechanical Properties of Self-Compacting Concrete

    DEFF Research Database (Denmark)

    Ghanbarpour, S.; Mazaheripour, H.; Mirmoradi, S. H.

    2010-01-01

    is to investigate the effects of type and volume fraction of steel fiber on the compressive strength, split tensile strength, flexural strength and modulus of elasticity of steel fiber reinforced self-compacting concrete (SFRSCC). Design/methodology/approach – For this purpose, Micro wire and Wave type steel fibers......Purpose – Self-compacting concrete (SCC) offers several economic and technical benefits; the use of steel fibers extends its possibilities. Steel fibers bridge cracks, retard their propagation, and improve several characteristics and properties of the SCC. The purpose of this paper...... – It was found that, inclusion of steel fibers significantly affect the split tensile and flexural strength of SCC accordance with type and vf. Besides, mathematical expressions were developed to estimate the flexural, modulus of elasticity and split tensile strength of SFRSCCs regarding of compressive strength...

  14. 2D and 3D milled surface roughness of high volume fraction SiCp/Al composites

    Directory of Open Access Journals (Sweden)

    Tao Wang

    2015-06-01

    Full Text Available This paper presents a study on surface roughness generated by high speed milling of high volume fraction (65% silicon carbide particle-reinforced aluminum matrix (SiCp/Al composites. Typical 2D (Ra and Rz and 3D (Sa and Sq surface roughness parameters were selected to evaluate the influence of the milling parameters on the surface quality in comparison with aluminum alloy. The 3D topography of the milled surface was studied as well. The results indicate that 3D parameters (Sa and Sq are more capable to describe the influence of the milling parameters on the surface quality, and among them Sq is preferable due to its good sensitivity. Sq decreases with milling speed and increases with feed rate. The influence of axial depth of cut (ADOC is negligible.

  15. Synthesis and characterization of high volume fraction Al-Al2O3 nanocomposite powders by high-energy milling

    International Nuclear Information System (INIS)

    Prabhu, B.; Suryanarayana, C.; An, L.; Vaidyanathan, R.

    2006-01-01

    Al-Al 2 O 3 metal matrix composite (MMC) powders with volume fractions of 20, 30, and 50% Al 2 O 3 were synthesized by high-energy milling of the blended component powders. The particle sizes of Al 2 O 3 studied were 50 nm, 150 nm, and 5 μm. A uniform distribution of the Al 2 O 3 reinforcement in the Al matrix was successfully obtained after milling the powders for a period of 20 h at a ball-to-powder ratio of 10:1 in a SPEX mill. The uniform distribution of Al 2 O 3 in the Al matrix was confirmed by characterizing these nanocomposite powders by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray mapping, and X-ray diffraction (XRD) techniques

  16. Rapid estimate of solid volume in large tuff cores using a gas pycnometer

    International Nuclear Information System (INIS)

    Thies, C.; Geddis, A.M.; Guzman, A.G.

    1996-09-01

    A thermally insulated, rigid-volume gas pycnometer system has been developed. The pycnometer chambers have been machined from solid PVC cylinders. Two chambers confine dry high-purity helium at different pressures. A thick-walled design ensures minimal heat exchange with the surrounding environment and a constant volume system, while expansion takes place between the chambers. The internal energy of the gas is assumed constant over the expansion. The ideal gas law is used to estimate the volume of solid material sealed in one of the chambers. Temperature is monitored continuously and incorporated into the calculation of solid volume. Temperature variation between measurements is less than 0.1 degrees C. The data are used to compute grain density for oven-dried Apache Leap tuff core samples. The measured volume of solid and the sample bulk volume are used to estimate porosity and bulk density. Intrinsic permeability was estimated from the porosity and measured pore surface area and is compared to in-situ measurements by the air permeability method. The gas pycnometer accommodates large core samples (0.25 m length x 0.11 m diameter) and can measure solid volume greater than 2.20 cm 3 with less than 1% error

  17. Rapid estimate of solid volume in large tuff cores using a gas pycnometer

    Energy Technology Data Exchange (ETDEWEB)

    Thies, C. [ed.; Geddis, A.M.; Guzman, A.G. [and others

    1996-09-01

    A thermally insulated, rigid-volume gas pycnometer system has been developed. The pycnometer chambers have been machined from solid PVC cylinders. Two chambers confine dry high-purity helium at different pressures. A thick-walled design ensures minimal heat exchange with the surrounding environment and a constant volume system, while expansion takes place between the chambers. The internal energy of the gas is assumed constant over the expansion. The ideal gas law is used to estimate the volume of solid material sealed in one of the chambers. Temperature is monitored continuously and incorporated into the calculation of solid volume. Temperature variation between measurements is less than 0.1{degrees}C. The data are used to compute grain density for oven-dried Apache Leap tuff core samples. The measured volume of solid and the sample bulk volume are used to estimate porosity and bulk density. Intrinsic permeability was estimated from the porosity and measured pore surface area and is compared to in-situ measurements by the air permeability method. The gas pycnometer accommodates large core samples (0.25 m length x 0.11 m diameter) and can measure solid volume greater than 2.20 cm{sup 3} with less than 1% error.

  18. Study of geometry to obtain the volume fraction of multiphase flows using the MCNP-X code

    International Nuclear Information System (INIS)

    Peixoto, Philippe N.B.; Salgado, Cesar M.

    2015-01-01

    The gamma ray attenuation technique is used in many works to obtaining volume fraction of multiphase flows in the oil industry, because it is a noninvasive technique with good precision. In these studies are simulated various geometries with different flow regime, compositions of materials, source-detector positions and types of collimation for sources. This work aim evaluate the interference in the results of the geometry changes and obtaining the best measuring geometry to provide the volume fractions accurately by evaluating different geometries simulations (ranging the source-detector position, flow schemes and homogeneity Makeup) in the MCNP-X code. The study was performed for two types of biphasic compositions of materials (oil-water and oil-air), two flow regimes (annular and smooth stratified) and was varied the position of each material in relative to source and detector positions. Another study to evaluate the interference of homogeneity of the compositions in the results was also conducted in order to verify the possibility of removing part of the composition and make a homogeneous blend using a mixer equipment. All these variations were simulated with two different types of beam, divergent beam and pencil beam. From the simulated geometries, it was possible to compare the differences between the areas of the spectra generated for each model. The results indicate that the flow regime and the differences in the material's densities interfere in the results being necessary to establish a specific simulation geometry for each flows regime. However, the simulations indicate that changing the type of collimation of sources do not affect the results, but improving the counts statistics, increasing the accurate. (author)

  19. Study of geometry to obtain the volume fraction of multiphase flows using the MCNP-X code

    Energy Technology Data Exchange (ETDEWEB)

    Peixoto, Philippe N.B.; Salgado, Cesar M., E-mail: phbelache@hotmail.com, E-mail: otero@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The gamma ray attenuation technique is used in many works to obtaining volume fraction of multiphase flows in the oil industry, because it is a noninvasive technique with good precision. In these studies are simulated various geometries with different flow regime, compositions of materials, source-detector positions and types of collimation for sources. This work aim evaluate the interference in the results of the geometry changes and obtaining the best measuring geometry to provide the volume fractions accurately by evaluating different geometries simulations (ranging the source-detector position, flow schemes and homogeneity Makeup) in the MCNP-X code. The study was performed for two types of biphasic compositions of materials (oil-water and oil-air), two flow regimes (annular and smooth stratified) and was varied the position of each material in relative to source and detector positions. Another study to evaluate the interference of homogeneity of the compositions in the results was also conducted in order to verify the possibility of removing part of the composition and make a homogeneous blend using a mixer equipment. All these variations were simulated with two different types of beam, divergent beam and pencil beam. From the simulated geometries, it was possible to compare the differences between the areas of the spectra generated for each model. The results indicate that the flow regime and the differences in the material's densities interfere in the results being necessary to establish a specific simulation geometry for each flows regime. However, the simulations indicate that changing the type of collimation of sources do not affect the results, but improving the counts statistics, increasing the accurate. (author)

  20. Dose escalation by hypo fractionation in localized prostate cancer - a large single institution experience

    International Nuclear Information System (INIS)

    Mahadevan, A.; Klein, E.; Kupelian, P.

    2003-01-01

    To report the outcomes of high dose radiation therapy using Intensity Modulated Radiation Therapy (IMRT) with hypo fractionation in localized prostate cancer at the Cleveland Clinic Foundation. A total of 278 patients with localized prostate cancer were treated with IMRT between 1998 and 2001. All cases had available pretreatment PSA (iPSA) and biopsy Gleason scores (bGS), no nodal metastasis, a minimum 2 year follow-up, and >5 follow-up PSA levels. The frequency by T-stage was: T1-T2A in 86%, T2B-T2C in 9%, and T3 in 5%. The median iPSA was 8.35. The frequency by bGS was: =7 in 45%. The age range for the patients was from 48 to 85 years (median 68 years). The median follow-up was 33 months (range: 24-49 months). The median doses delivered were 83Gy (delivered at 2.5Gy per fraction to 70 Gy; this being equivalent to 83 Gy at standard fractionation of 1.8 Gy using an alpha/beta of 2). The ASTRO definition for biochemical failure was used. Toxicity was assessed using Radiation Therapy Oncology Group (RTOG) criteria. The 3-year biochemical relapse free survival (bRFS) for the entire cohort at three years was 91%. Any (grade 1 or higher) acute genito-urinary (GU) side effects were seen in 79% of patients. Grade 2 or higher acute GU toxicity was seen in 18% of patients. Any (grade 1 or higher) acute gastro-intestinal (GI) side effects were seen in 65% of patients. Grade 2 or higher acute GI toxicity was seen in 11% of patients. Any (grade 1 or higher) late GU side effects were seen in 3% of patients. Grade 2 or higher late GU toxicity was seen in 1.5% of patients. Any (grade 1 or higher) late GI side effects were seen in 13% of patients. Grade 2 or higher late GI toxicity was seen in 5% of patients. Higher doses of radiation delivered by IMRT resulted in excellent bRFS outcomes in patients with localized prostate cancer receiving external beam radiation therapy. IMRT can be effectively used to safely increase dose delivery without compromising on quality of life

  1. Large-volume static compression using nano-polycrystalline diamond for opposed anvils in compact cells

    International Nuclear Information System (INIS)

    Okuchi, T; Sasaki, S; Ohno, Y; Osakabe, T; Odake, S; Kagi, H

    2010-01-01

    In order to extend the pressure regime of intrinsically low-sensitivity methods of measurement, such as neutron scattering and NMR, sample volume to be compressed in compact opposed-anvil cells is desired to be significantly increased. We hereby conducted a series of experiments using two types of compact cells equipped with enforced loading mechanisms. Super-hard nano-polycrystalline diamond (NPD) anvils were carefully prepared for large-volume compression in these cells. These anvils are harder, larger and stronger than single crystal diamond anvils, so that they could play an ideal role to accept the larger forces. Supported and unsupported anvil geometries were separately tested to evaluate this expectation. In spite of insufficient support to the anvils, pressures to 14 GPa were generated for the sample volume of > 0.1 mm 3 , without damaging the NPD anvils. These results demonstrate a large future potential of compact cells equipped with NPD anvils and enforced loading mechanism.

  2. High Energy Performance Tests of Large Volume LaBr{sub 3}:Ce Detector

    Energy Technology Data Exchange (ETDEWEB)

    Naqvi, A.A.; Gondal, M.A.; Khiari, F.Z.; Dastageer, M.A. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Maslehuddin, M.M. [Center for Engineering Research, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Al-Amoudi, O.S.B. [Department of Civil Engineering, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia)

    2015-07-01

    High energy prompt gamma ray tests of a large volume cylindrical 100 mm x 100 mm (height x diameter) LaBr{sub 3}:Ce detector were carried out using a portable neutron generator-based Prompt Gamma Neutron Activation Analysis (PGNAA) setup. In this study prompt gamma-rays yield were measured from water samples contaminated with toxic elements such nickel, chromium and mercury compounds with gamma ray energies up to 10 MeV. The experimental yield of prompt gamma-rays from toxic elements were compared with the results of Monte Carlo calculations. In spite of its higher intrinsic background due to its larger volume, an excellent agreement between the experimental and calculated yields of high energy gamma-rays from Ni, Cr and Hg samples has been achieved for the large volume LaBr{sub 3}:Ce detector. (authors)

  3. On the surviving fraction in irradiated multicellular tumour spheroids: calculation of overall radiosensitivity parameters, influence of hypoxia and volume effects

    International Nuclear Information System (INIS)

    Horas, Jorge A; Olguin, Osvaldo R; Rizzotto, Marcos G

    2005-01-01

    We model the heterogeneous response to radiation of multicellular tumour spheroids assuming position- and volume-dependent radiosensitivity. We propose a method to calculate the overall radiosensitivity parameters to obtain the surviving fraction of tumours. A mathematical model of a spherical tumour with a hypoxic core and a viable rim which is a caricature of a real tumour is constructed. The model is embedded in a two-compartment linear-quadratic (LQ) model, assuming a mixed bivariated Gaussian distribution to attain the radiosensitivity parameters. Ergodicity, i.e., the equivalence between ensemble and volumetric averages is used to obtain the overall radiosensitivities for the two compartments. We obtain expressions for the overall radiosensitivity parameters resulting from the use of both a linear and a nonlinear dependence of the local radiosensitivity with position. The model's results are compared with experimental data of surviving fraction (SF) for multicellular spheroids of different sizes. We make one fit using only the smallest spheroid data and we are able to predict the SF for the larger spheroids. These predictions are acceptable particularly using bounded sensitivities. We conclude with the importance of taking into account the contribution of clonogenic hypoxic cells to radiosensitivity and with the convenience of using bounded local sensitivities to predict overall radiosensitivity parameters

  4. The impact of large tidal volume ventilation on the absorption of inhaled insulin in rabbits

    DEFF Research Database (Denmark)

    Petersen, Astrid Heide; Laursen, Torben; Ahrén, Bo

    2007-01-01

    Previous studies have shown that ventilation patterns affect absorption of inhaled compounds. Thus, the aim of this study was to investigate the effect of large tidal volume ventilation (LTVV) on the absorption of inhaled insulin in rabbits. Mechanically ventilated rabbits were given human insulin...

  5. Large volume liquid silicone injection in the upper thighs : a never ending story

    NARCIS (Netherlands)

    Hofer, SOP; Damen, A; Nicolai, JPA

    This report concerns a 26-year-old male-to-female transsexual who had received a large volume liquid silicone injection of unknown grade into her upper lateral thighs to gain female contour. She presented at our outpatient clinic 4 years after the silicone injection with complaints of pain and

  6. A New Electropositive Filter for Concentrating Enterovirus and Norovirus from Large Volumes of Water - MCEARD

    Science.gov (United States)

    The detection of enteric viruses in environmental water usually requires the concentration of viruses from large volumes of water. The 1MDS electropositive filter is commonly used for concentrating enteric viruses from water but unfortunately these filters are not cost-effective...

  7. Optimization of Large Volume Injection for Improved Detection of Polycyclic Aromatic Hydrocarbons (PAH) in Mussels

    DEFF Research Database (Denmark)

    Duedahl-Olesen, Lene; Ghorbani, Faranak

    2008-01-01

    Detection of PAH of six benzene rings is somewhat troublesome and lowering the limits of detection (LODs) for these compounds in food is necessary. For this purpose, we optimized a Programmable-Temperature-Vaporisation (PTV) injection with Large Volume Injection (LVI) with regard to the GC-MS det...

  8. Absolute activity determinations on large volume geological samples independent of self-absorption effects

    International Nuclear Information System (INIS)

    Wilson, W.E.

    1980-01-01

    This paper describes a method for measuring the absolute activity of large volume samples by γ-spectroscopy independent of self-absorption effects using Ge detectors. The method yields accurate matrix independent results at the expense of replicative counting of the unknown sample. (orig./HP)

  9. The use of cosmic muons in detecting heterogeneities in large volumes

    International Nuclear Information System (INIS)

    Grabski, V.; Reche, R.; Alfaro, R.; Belmont-Moreno, E.; Martinez-Davalos, A.; Sandoval, A.; Menchaca-Rocha, A.

    2008-01-01

    The muon intensity attenuation method to detect heterogeneities in large matter volumes is analyzed. Approximate analytical expressions to estimate the collection time and the signal to noise ratio, are proposed and validated by Monte Carlo simulations. Important parameters, including point spread function and coordinate reconstruction uncertainty are also estimated using Monte Carlo simulations

  10. Capillary gas chromatographic analysis of nerve agents using large volume injections

    NARCIS (Netherlands)

    Degenhardt, C.E.A.M.; Kientz, C.E.

    1996-01-01

    The use of large volume injections has been studied for the verification of intact organophosphorus chemical warfare agents in water samples. As the use of ethyl acetate caused severe detection problems new potential solvents were evaluated. With the developed procedure, the nerve agents sarin,

  11. SparseLeap: Efficient Empty Space Skipping for Large-Scale Volume Rendering

    KAUST Repository

    Hadwiger, Markus

    2017-08-28

    Recent advances in data acquisition produce volume data of very high resolution and large size, such as terabyte-sized microscopy volumes. These data often contain many fine and intricate structures, which pose huge challenges for volume rendering, and make it particularly important to efficiently skip empty space. This paper addresses two major challenges: (1) The complexity of large volumes containing fine structures often leads to highly fragmented space subdivisions that make empty regions hard to skip efficiently. (2) The classification of space into empty and non-empty regions changes frequently, because the user or the evaluation of an interactive query activate a different set of objects, which makes it unfeasible to pre-compute a well-adapted space subdivision. We describe the novel SparseLeap method for efficient empty space skipping in very large volumes, even around fine structures. The main performance characteristic of SparseLeap is that it moves the major cost of empty space skipping out of the ray-casting stage. We achieve this via a hybrid strategy that balances the computational load between determining empty ray segments in a rasterization (object-order) stage, and sampling non-empty volume data in the ray-casting (image-order) stage. Before ray-casting, we exploit the fast hardware rasterization of GPUs to create a ray segment list for each pixel, which identifies non-empty regions along the ray. The ray-casting stage then leaps over empty space without hierarchy traversal. Ray segment lists are created by rasterizing a set of fine-grained, view-independent bounding boxes. Frame coherence is exploited by re-using the same bounding boxes unless the set of active objects changes. We show that SparseLeap scales better to large, sparse data than standard octree empty space skipping.

  12. SparseLeap: Efficient Empty Space Skipping for Large-Scale Volume Rendering

    KAUST Repository

    Hadwiger, Markus; Al-Awami, Ali K.; Beyer, Johanna; Agus, Marco; Pfister, Hanspeter

    2017-01-01

    Recent advances in data acquisition produce volume data of very high resolution and large size, such as terabyte-sized microscopy volumes. These data often contain many fine and intricate structures, which pose huge challenges for volume rendering, and make it particularly important to efficiently skip empty space. This paper addresses two major challenges: (1) The complexity of large volumes containing fine structures often leads to highly fragmented space subdivisions that make empty regions hard to skip efficiently. (2) The classification of space into empty and non-empty regions changes frequently, because the user or the evaluation of an interactive query activate a different set of objects, which makes it unfeasible to pre-compute a well-adapted space subdivision. We describe the novel SparseLeap method for efficient empty space skipping in very large volumes, even around fine structures. The main performance characteristic of SparseLeap is that it moves the major cost of empty space skipping out of the ray-casting stage. We achieve this via a hybrid strategy that balances the computational load between determining empty ray segments in a rasterization (object-order) stage, and sampling non-empty volume data in the ray-casting (image-order) stage. Before ray-casting, we exploit the fast hardware rasterization of GPUs to create a ray segment list for each pixel, which identifies non-empty regions along the ray. The ray-casting stage then leaps over empty space without hierarchy traversal. Ray segment lists are created by rasterizing a set of fine-grained, view-independent bounding boxes. Frame coherence is exploited by re-using the same bounding boxes unless the set of active objects changes. We show that SparseLeap scales better to large, sparse data than standard octree empty space skipping.

  13. Analysis of albedo versus cloud fraction relationships in liquid water clouds using heuristic models and large eddy simulation

    Science.gov (United States)

    Feingold, Graham; Balsells, Joseph; Glassmeier, Franziska; Yamaguchi, Takanobu; Kazil, Jan; McComiskey, Allison

    2017-07-01

    The relationship between the albedo of a cloudy scene A and cloud fraction fc is studied with the aid of heuristic models of stratocumulus and cumulus clouds. Existing work has shown that scene albedo increases monotonically with increasing cloud fraction but that the relationship varies from linear to superlinear. The reasons for these differences in functional dependence are traced to the relationship between cloud deepening and cloud widening. When clouds deepen with no significant increase in fc (e.g., in solid stratocumulus), the relationship between A and fc is linear. When clouds widen as they deepen, as in cumulus cloud fields, the relationship is superlinear. A simple heuristic model of a cumulus cloud field with a power law size distribution shows that the superlinear A-fc behavior is traced out either through random variation in cloud size distribution parameters or as the cloud field oscillates between a relative abundance of small clouds (steep slopes on a log-log plot) and a relative abundance of large clouds (flat slopes). Oscillations of this kind manifest in large eddy simulation of trade wind cumulus where the slope and intercept of the power law fit to the cloud size distribution are highly correlated. Further analysis of the large eddy model-generated cloud fields suggests that cumulus clouds grow larger and deeper as their underlying plumes aggregate; this is followed by breakup of large plumes and a tendency to smaller clouds. The cloud and thermal size distributions oscillate back and forth approximately in unison.

  14. A two-phase debris-flow model that includes coupled evolution of volume fractions, granular dilatancy, and pore-fluid pressure

    Science.gov (United States)

    George, David L.; Iverson, Richard M.

    2011-01-01

    Pore-fluid pressure plays a crucial role in debris flows because it counteracts normal stresses at grain contacts and thereby reduces intergranular friction. Pore-pressure feedback accompanying debris deformation is particularly important during the onset of debrisflow motion, when it can dramatically influence the balance of forces governing downslope acceleration. We consider further effects of this feedback by formulating a new, depth-averaged mathematical model that simulates coupled evolution of granular dilatancy, solid and fluid volume fractions, pore-fluid pressure, and flow depth and velocity during all stages of debris-flow motion. To illustrate implications of the model, we use a finite-volume method to compute one-dimensional motion of a debris flow descending a rigid, uniformly inclined slope, and we compare model predictions with data obtained in large-scale experiments at the USGS debris-flow flume. Predictions for the first 1 s of motion show that increasing pore pressures (due to debris contraction) cause liquefaction that enhances flow acceleration. As acceleration continues, however, debris dilation causes dissipation of pore pressures, and this dissipation helps stabilize debris-flow motion. Our numerical predictions of this process match experimental data reasonably well, but predictions might be improved by accounting for the effects of grain-size segregation.

  15. GPU-Based 3D Cone-Beam CT Image Reconstruction for Large Data Volume

    Directory of Open Access Journals (Sweden)

    Xing Zhao

    2009-01-01

    Full Text Available Currently, 3D cone-beam CT image reconstruction speed is still a severe limitation for clinical application. The computational power of modern graphics processing units (GPUs has been harnessed to provide impressive acceleration of 3D volume image reconstruction. For extra large data volume exceeding the physical graphic memory of GPU, a straightforward compromise is to divide data volume into blocks. Different from the conventional Octree partition method, a new partition scheme is proposed in this paper. This method divides both projection data and reconstructed image volume into subsets according to geometric symmetries in circular cone-beam projection layout, and a fast reconstruction for large data volume can be implemented by packing the subsets of projection data into the RGBA channels of GPU, performing the reconstruction chunk by chunk and combining the individual results in the end. The method is evaluated by reconstructing 3D images from computer-simulation data and real micro-CT data. Our results indicate that the GPU implementation can maintain original precision and speed up the reconstruction process by 110–120 times for circular cone-beam scan, as compared to traditional CPU implementation.

  16. Large volume unresectable locally advanced non-small cell lung cancer: acute toxicity and initial outcome results with rapid arc

    Directory of Open Access Journals (Sweden)

    Fogliata Antonella

    2010-10-01

    Full Text Available Abstract Background To report acute toxicity, initial outcome results and planning therapeutic parameters in radiation treatment of advanced lung cancer (stage III with volumetric modulated arcs using RapidArc (RA. Methods Twenty-four consecutive patients were treated with RA. All showed locally advanced non-small cell lung cancer with stage IIIA-IIIB and with large volumes (GTV:299 ± 175 cm3, PTV:818 ± 206 cm3. Dose prescription was 66Gy in 33 fractions to mean PTV. Delivery was performed with two partial arcs with a 6 MV photon beam. Results From a dosimetric point of view, RA allowed us to respect most planning objectives on target volumes and organs at risk. In particular: for GTV D1% = 105.6 ± 1.7%, D99% = 96.7 ± 1.8%, D5%-D95% = 6.3 ± 1.4%; contra-lateral lung mean dose resulted in 13.7 ± 3.9Gy, for spinal cord D1% = 39.5 ± 4.0Gy, for heart V45Gy = 9.0 ± 7.0Gy, for esophagus D1% = 67.4 ± 2.2Gy. Delivery time was 133 ± 7s. At three months partial remission > 50% was observed in 56% of patients. Acute toxicities at 3 months showed 91% with grade 1 and 9% with grade 2 esophageal toxicity; 18% presented grade 1 and 9% with grade 2 pneumonia; no grade 3 acute toxicity was observed. The short follow-up does not allow assessment of local control and progression free survival. Conclusions RA proved to be a safe and advantageous treatment modality for NSCLC with large volumes. Long term observation of patients is needed to assess outcome and late toxicity.

  17. Quantitative grain-scale ferroic domain volume fractions and domain switching strains from three-dimensional X-ray diffraction data

    DEFF Research Database (Denmark)

    Oddershede, Jette; Majkut, Marta; Caosyd, Qinghua

    2015-01-01

    A method for the extension of the three-dimensional X-ray diffraction technique to allow the extraction of domain volume fractions in polycrystalline ferroic materials is presented. This method gives access to quantitative domain volume fractions of hundreds of independent embedded grains within...... are applied to tetragonal coarse-grained Ba0.88Ca0.12Zr0.06Ti0.94O3 and rhombohedral fine-grained (0.82)Bi0.5Na0.5TiO3–(0.18)Bi0.5K0.5TiO3 electroceramic materials. The fitted volume fraction information is used to calculate grain-scale non-180° ferroelectric domain switching strains. The absolute errors...

  18. Heat Load Measurements on a Large Superconducting Magnet An Application of a Void Fraction Meter

    CERN Document Server

    Pengo, R; Junker, S; Passardi, Giorgio; ten Kate, H H J

    2004-01-01

    ATLAS is one of the two major experiments of the LHC project at CERN using cryogenics. The superconducting magnet system of ATLAS is composed of the Barrel Toroid (BT), two End Caps Toroids and the Central Solenoid. The BT is formed of 8 race-track superconducting dipoles, each one 25 m long and 5 m wide. A reduced scale prototype (named B0) of one of the 8 dipoles, about one third of the length, has been constructed and tested in a dedicated cryogenic facility at CERN. To simulate the final thermal and hydraulic operating conditions, the B0 was cooled by a forced flow of 4.5 K saturated liquid helium provided by a centrifugal pump of 80 g/s nominal capacity. Both static and dynamic heat loads, generated by the induced currents on the B0 casing during a slow dump or a ramp up, have been measured to verify the expected thermal budget of the entire BT. The instrument used for the heat load measurements was a Void Fraction Meter (VFM) installed on the magnet return line. The instrument constructed at CERN was ca...

  19. Absorption and scattering coefficient dependence of laser-Doppler flowmetry models for large tissue volumes

    International Nuclear Information System (INIS)

    Binzoni, T; Leung, T S; Ruefenacht, D; Delpy, D T

    2006-01-01

    Based on quasi-elastic scattering theory (and random walk on a lattice approach), a model of laser-Doppler flowmetry (LDF) has been derived which can be applied to measurements in large tissue volumes (e.g. when the interoptode distance is >30 mm). The model holds for a semi-infinite medium and takes into account the transport-corrected scattering coefficient and the absorption coefficient of the tissue, and the scattering coefficient of the red blood cells. The model holds for anisotropic scattering and for multiple scattering of the photons by the moving scatterers of finite size. In particular, it has also been possible to take into account the simultaneous presence of both Brownian and pure translational movements. An analytical and simplified version of the model has also been derived and its validity investigated, for the case of measurements in human skeletal muscle tissue. It is shown that at large optode spacing it is possible to use the simplified model, taking into account only a 'mean' light pathlength, to predict the blood flow related parameters. It is also demonstrated that the 'classical' blood volume parameter, derived from LDF instruments, may not represent the actual blood volume variations when the investigated tissue volume is large. The simplified model does not need knowledge of the tissue optical parameters and thus should allow the development of very simple and cost-effective LDF hardware

  20. Nonperturbative volume reduction of large-N QCD with adjoint fermions

    International Nuclear Information System (INIS)

    Bringoltz, Barak; Sharpe, Stephen R.

    2009-01-01

    We use nonperturbative lattice techniques to study the volume-reduced 'Eguchi-Kawai' version of four-dimensional large-N QCD with a single adjoint Dirac fermion. We explore the phase diagram of this single-site theory in the space of quark mass and gauge coupling using Wilson fermions for a number of colors in the range 8≤N≤15. Our evidence suggests that these values of N are large enough to determine the nature of the phase diagram for N→∞. We identify the region in the parameter space where the (Z N ) 4 center symmetry is intact. According to previous theoretical work using the orbifolding paradigm, and assuming that translation invariance is not spontaneously broken in the infinite-volume theory, in this region volume reduction holds: the single-site and infinite-volume theories become equivalent when N→∞. We find strong evidence that this region includes both light and heavy quarks (with masses that are at the cutoff scale), and our results are consistent with this region extending toward the continuum limit. We also compare the action density and the eigenvalue density of the overlap Dirac operator in the fundamental representation with those obtained in large-N pure-gauge theory.

  1. Influence of primary α-phase volume fraction on the mechanical properties of Ti-6Al-4V alloy at different strain rates and temperatures

    Science.gov (United States)

    Ren, Yu; Zhou, Shimeng; Luo, Wenbo; Xue, Zhiyong; Zhang, Yajing

    2018-03-01

    Bimodal microstructures with primary α-phase volume fractions ranging from 14.3% to 57.1% were gained in Ti-6Al-4V (Ti-64) alloy through annealed in two-phase region at various temperatures below the β-transus point. Then the influence of the primary α-phase volume fraction on the mechanical properties of Ti-64 were studied. The results show that, at room temperature and a strain rate of 10‑3 s‑1, the yield stress decreases but the fracture strain augments with added primary α-phase volume fraction. The equiaxed primary α-phase possesses stronger ability to coordinate plastic deformation, leading to the improvement of the ductile as well as degradation of the strength of Ti-64 with higher primary α-phase volume fraction. As the temperature goes up to 473 K, the quasi-static yield stress and ultimate strength decrease first and then increase with the incremental primary α-phase volume fraction, due to the interaction between the work hardening and the softening caused by the DRX and the growth of the primary α-phase. At room temperature and a strain rate of 3×103 s‑1, the varying pattern of strength with the primary α-phase volume fraction resembles that at a quasi-static strain rate. However, the flow stress significantly increases but the strain-hardening rate decreases compared to those at quasi-static strain rate due to the competition between the strain rate hardening and the thermal softening during dynamic compression process.

  2. Right heart ejection fraction, ventricular volumes, and left to right cardiac shunt measurements with a conventional Anger camera in congenital heart disease

    International Nuclear Information System (INIS)

    Cook, S.A.; Go, R.T.; MacIntyre, W.J.; Moodie, D.S.; Houser, T.S.; Ceimo, J.; Underwood, D.; Yiannikas, J.

    1982-01-01

    The object of this investigation was to demonstrate that a conventional Anger camera can be used for measurement of right heart ejection fraction, ventricular volumes and left to right shunts in routine clinical determinations. The automatic selection of chamber and lung regions, the recirculation subtraction of recirculation, and the filtering of the right heart ejection fraction dilution curves are all done entirely without operator intervention. Thus, this entire evaluation has been incorporated into the routine procedures of patient care

  3. Large-Scale Multi-Resolution Representations for Accurate Interactive Image and Volume Operations

    KAUST Repository

    Sicat, Ronell B.

    2015-11-25

    The resolutions of acquired image and volume data are ever increasing. However, the resolutions of commodity display devices remain limited. This leads to an increasing gap between data and display resolutions. To bridge this gap, the standard approach is to employ output-sensitive operations on multi-resolution data representations. Output-sensitive operations facilitate interactive applications since their required computations are proportional only to the size of the data that is visible, i.e., the output, and not the full size of the input. Multi-resolution representations, such as image mipmaps, and volume octrees, are crucial in providing these operations direct access to any subset of the data at any resolution corresponding to the output. Despite its widespread use, this standard approach has some shortcomings in three important application areas, namely non-linear image operations, multi-resolution volume rendering, and large-scale image exploration. This dissertation presents new multi-resolution representations for large-scale images and volumes that address these shortcomings. Standard multi-resolution representations require low-pass pre-filtering for anti- aliasing. However, linear pre-filters do not commute with non-linear operations. This becomes problematic when applying non-linear operations directly to any coarse resolution levels in standard representations. Particularly, this leads to inaccurate output when applying non-linear image operations, e.g., color mapping and detail-aware filters, to multi-resolution images. Similarly, in multi-resolution volume rendering, this leads to inconsistency artifacts which manifest as erroneous differences in rendering outputs across resolution levels. To address these issues, we introduce the sparse pdf maps and sparse pdf volumes representations for large-scale images and volumes, respectively. These representations sparsely encode continuous probability density functions (pdfs) of multi-resolution pixel

  4. Rapid determination of vertebral fat fraction over a large range of vertebral bodies

    International Nuclear Information System (INIS)

    Martin, Jarad; Nicholson, Geoffrey; Cowin, Gary; Ilente, Clare; Wong, Winnie; Kennedy, Dominic

    2014-01-01

    Vertebral body fat fraction (FF) has been found to vary between lumbar vertebrae using magnetic resonance spectroscopy (MRS). We aim to more quickly assess a larger number of adjacent vertebrae using a single T2-weighted iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) sequence. Five men had dual-energy X-ray absorptometry (DEXA) and 1.5-T MR scans performed. MRS was performed at L3, and a sagittal IDEAL sequence was also performed, resulting in separate fat-only and water-only readings from T10 to S2. For the IDEAL measurements, two independent observers followed a set reading protocol, with five observations each per vertebra. Intra- and interobserver variability were assessed as deviations from the mean within and between observers, respectively. For FF measurements there was limited intra-observer variation, with observers being on average within 3.4% of the pooled mean value. Similarly, there was good interobserver agreement, with an average variation of 2.1%. All men showed a reduction in FF of 1.6–7% between L5 and S1. Otherwise, there was a trend of increasing FF moving inferiorly from T10 to S2. This averaged 2.7% per vertebra (range 1.1–3.8%) and may not have been dependent on MRS-measured FF at the L3 level. There was poor correlation between MRS-measured FF at L2–4 and bone mineral density measured using DEXA (R2=0.06). IDEAL measurements are generally reproducible between observers following a set protocol. There appears to be a gradient in FF moving from T10 to S2, with S1 showing a consistent decrease. This variation may better describe overall marrow function than a single-vertebra reading.

  5. The effect of different fibre volume fraction on mechanical properties of banana/pineapple leaf (PaLF)/glass hybrid composite

    Science.gov (United States)

    Hanafee, Z. M.; Khalina, A.; Norkhairunnisa, M.; Syams, Z. Edi; Liew, K. E.

    2017-09-01

    This paper investigates the effect of fibre volume fraction on mechanical properties of banana-pineapple leaf (PaLF)-glass reinforced epoxy resin under tensile loading. Uniaxial tensile tests were carried out on specimens with different fibre contents (30%, 40%, 50% in weight). The composite specimens consists of 13 different combinations. The effect of hybridisation between synthetic and natural fibre onto tensile properties was determined and the optimum fibre volume fraction was obtained at 50% for both banana and PaLF composites. Additional 1 layer of woven glass fibre increased the tensile strength of banana-PaLF composite up to 85%.

  6. Use of fractional dose–volume histograms to model risk of acute rectal toxicity among patients treated on RTOG 94-06

    International Nuclear Information System (INIS)

    Tucker, Susan L.; Michalski, Jeff M.; Bosch, Walter R.; Mohan, Radhe; Dong, Lei; Winter, Kathryn; Purdy, James A.; Cox, James D.

    2012-01-01

    Background and purpose: For toxicities occurring during the course of radiotherapy, it is conceptually inaccurate to perform normal-tissue complication probability analyses using the complete dose–volume histogram. The goal of this study was to analyze acute rectal toxicity using a novel approach in which the fit of the Lyman–Kutcher–Burman (LKB) model is based on the fractional rectal dose–volume histogram (DVH). Materials and methods: Grade ⩾2 acute rectal toxicity was analyzed in 509 patients treated on Radiation Therapy Oncology Group (RTOG) protocol 94-06. These patients had no field reductions or treatment-plan revisions during therapy, allowing the fractional rectal DVH to be estimated from the complete rectal DVH based on the total number of dose fractions delivered. Results: The majority of patients experiencing Grade ⩾2 acute rectal toxicity did so before completion of radiotherapy (70/80 = 88%). Acute rectal toxicity depends on fractional mean rectal dose, with no significant improvement in the LKB model fit when the volume parameter differs from n = 1. The incidence of toxicity was significantly lower for patients who received hormone therapy (P = 0.024). Conclusions: Variations in fractional mean dose explain the differences in incidence of acute rectal toxicity, with no detectable effect seen here for differences in numbers of dose fractions delivered.

  7. Paul Scherrer Institute Scientific and Technical Report 1999. Volume VI: Large Research Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Foroughi, Fereydoun; Bercher, Renate; Buechli, Carmen; Meyer, Rosa [eds.

    2000-07-01

    The department GFA (Grossforschungsanlagen, Large Research Facilities) has been established in October 1998. Its main duty is operation, maintenance and development of the PSI accelerators, the spallation neutron source and the beam transport systems for pions and muons. A large effort of this group concerns the planning and co-ordination of new projects like e.g. the assembly of the synchrotron light source (SLS), design studies of a new proton therapy facility, the ultracold neutron source and a new intensive secondary beam line for low energy muons. A large fraction of this report is devoted to research especially in the field of materials Science. The studies include large scale molecular dynamics computer simulations on the elastic and plastic behavior of nanostructured metals, complemented by experimental mechanical testing using micro-indentation and miniaturized tensile testing, as well as microstructural characterisation and strain field mapping of metallic coatings and thin ceramic layers, the latter done with synchrotron radiation.

  8. Paul Scherrer Institute Scientific and Technical Report 1999. Volume VI: Large Research Facilities

    International Nuclear Information System (INIS)

    Foroughi, Fereydoun; Bercher, Renate; Buechli, Carmen; Meyer, Rosa

    2000-01-01

    The department GFA (Grossforschungsanlagen, Large Research Facilities) has been established in October 1998. Its main duty is operation, maintenance and development of the PSI accelerators, the spallation neutron source and the beam transport systems for pions and muons. A large effort of this group concerns the planning and co-ordination of new projects like e.g. the assembly of the synchrotron light source (SLS), design studies of a new proton therapy facility, the ultracold neutron source and a new intensive secondary beam line for low energy muons. A large fraction of this report is devoted to research especially in the field of materials Science. The studies include large scale molecular dynamics computer simulations on the elastic and plastic behavior of nanostructured metals, complemented by experimental mechanical testing using micro-indentation and miniaturized tensile testing, as well as microstructural characterisation and strain field mapping of metallic coatings and thin ceramic layers, the latter done with synchrotron radiation

  9. Toxicity Profile With a Large Prostate Volume After External Beam Radiotherapy for Localized Prostate Cancer

    International Nuclear Information System (INIS)

    Pinkawa, Michael; Fischedick, Karin; Asadpour, Branka; Gagel, Bernd; Piroth, Marc D.; Nussen, Sandra; Eble, Michael J.

    2008-01-01

    Purpose: To assess the impact of prostate volume on health-related quality of life (HRQOL) before and at different intervals after radiotherapy for prostate cancer. Methods and Materials: A group of 204 patients was surveyed prospectively before (Time A), at the last day (Time B), 2 months after (Time C), and 16 months (median) after (Time D) radiotherapy, with a validated questionnaire (Expanded Prostate Cancer Index Composite). The group was divided into subgroups with a small (11-43 cm 3 ) and a large (44-151 cm 3 ) prostate volume. Results: Patients with large prostates presented with lower urinary bother scores (median 79 vs. 89; p = 0.01) before treatment. Urinary function/bother scores for patients with large prostates decreased significantly compared to patients with small prostates due to irritative/obstructive symptoms only at Time B (pain with urination more than once daily in 48% vs. 18%; p 3 vs. 47 cm 3 ; p < 0.01). Conclusions: Patients with a large prostate volume have a great risk of irritative/obstructive symptoms (particularly dysuria) in the acute radiotherapy phase. These symptoms recover rapidly and do not influence long-term HRQOL

  10. Imaging water velocity and volume fraction distributions in water continuous multiphase flows using inductive flow tomography and electrical resistance tomography

    International Nuclear Information System (INIS)

    Meng, Yiqing; Lucas, Gary P

    2017-01-01

    This paper presents the design and implementation of an inductive flow tomography (IFT) system, employing a multi-electrode electromagnetic flow meter (EMFM) and novel reconstruction techniques, for measuring the local water velocity distribution in water continuous single and multiphase flows. A series of experiments were carried out in vertical-upward and upward-inclined single phase water flows and ‘water continuous’ gas–water and oil–gas–water flows in which the velocity profiles ranged from axisymmetric (single phase and vertical-upward multiphase flows) to highly asymmetric (upward-inclined multiphase flows). Using potential difference measurements obtained from the electrode array of the EMFM, local axial velocity distributions of the continuous water phase were reconstructed using two different IFT reconstruction algorithms denoted RT#1, which assumes that the overall water velocity profile comprises the sum of a series of polynomial velocity components, and RT#2, which is similar to RT#1 but which assumes that the zero’th order velocity component may be replaced by an axisymmetric ‘power law’ velocity distribution. During each experiment, measurement of the local water volume fraction distribution was also made using the well-established technique of electrical resistance tomography (ERT). By integrating the product of the local axial water velocity and the local water volume fraction in the cross section an estimate of the water volumetric flow rate was made which was compared with a reference measurement of the water volumetric flow rate. In vertical upward flows RT#2 was found to give rise to water velocity profiles which are consistent with the previous literature although the profiles obtained in the multiphase flows had relatively higher central velocity peaks than was observed for the single phase profiles. This observation was almost certainly a result of the transfer of axial momentum from the less dense dispersed phases to the

  11. Imaging water velocity and volume fraction distributions in water continuous multiphase flows using inductive flow tomography and electrical resistance tomography

    Science.gov (United States)

    Meng, Yiqing; Lucas, Gary P.

    2017-05-01

    This paper presents the design and implementation of an inductive flow tomography (IFT) system, employing a multi-electrode electromagnetic flow meter (EMFM) and novel reconstruction techniques, for measuring the local water velocity distribution in water continuous single and multiphase flows. A series of experiments were carried out in vertical-upward and upward-inclined single phase water flows and ‘water continuous’ gas-water and oil-gas-water flows in which the velocity profiles ranged from axisymmetric (single phase and vertical-upward multiphase flows) to highly asymmetric (upward-inclined multiphase flows). Using potential difference measurements obtained from the electrode array of the EMFM, local axial velocity distributions of the continuous water phase were reconstructed using two different IFT reconstruction algorithms denoted RT#1, which assumes that the overall water velocity profile comprises the sum of a series of polynomial velocity components, and RT#2, which is similar to RT#1 but which assumes that the zero’th order velocity component may be replaced by an axisymmetric ‘power law’ velocity distribution. During each experiment, measurement of the local water volume fraction distribution was also made using the well-established technique of electrical resistance tomography (ERT). By integrating the product of the local axial water velocity and the local water volume fraction in the cross section an estimate of the water volumetric flow rate was made which was compared with a reference measurement of the water volumetric flow rate. In vertical upward flows RT#2 was found to give rise to water velocity profiles which are consistent with the previous literature although the profiles obtained in the multiphase flows had relatively higher central velocity peaks than was observed for the single phase profiles. This observation was almost certainly a result of the transfer of axial momentum from the less dense dispersed phases to the water

  12. Quality-assured evaluation of effective porosity using fit-for-purpose estimates of clay-mineral volume fraction

    Science.gov (United States)

    Worthington, Paul F.

    2010-05-01

    Reservoirs that contain dispersed clay minerals traditionally have been evaluated petrophysically using either the effective or the total porosity system. The major weakness of the former is its reliance on "shale" volume fraction ( Vsh) as a clay-mineral indicator in the determination of effective porosity from well logs. Downhole clay-mineral indicators have usually delivered overestimates of fractional clay-mineral volume ( Vcm) because they use as a reference nearby shale beds that are often assumed to comprise clay minerals exclusively, whereas those beds also include quartzitic silts and other detritus. For this reason, effective porosity is often underestimated significantly, and this shortfall transmits to computed hydrocarbons in place and thence to estimates of ultimate recovery. The problem is overcome here by using, as proxy groundtruths, core porosities that have been upscaled to match the spatial resolutions of porosity logs. Matrix and fluid properties are established over clean intervals in the usual way. Log-derived values of Vsh are tuned so that, on average, the resulting log-derived porosities match the corresponding core porosities over an evaluation interval. In this way, Vsh is rendered fit for purpose as an indicator of clay-mineral content Vcm for purposes of evaluating effective porosity. The method is conditioned to deliver a value of effective porosity that shows overall agreement with core porosity to within the limits of uncertainty of the laboratory measurements. This is achieved through function-, reservoir- and tool-specific Vsh reduction factors that can be applied to downhole estimates of clay-mineral content over uncored intervals of similar reservoir character. As expected, the reduction factors can also vary for different measurement conditions. The reduction factors lie in the range of 0.29-0.80, which means that in its raw form, log-derived Vsh can overestimate the clay-mineral content by more than a factor of three. This

  13. Intraoperative ventilation: incidence and risk factors for receiving large tidal volumes during general anesthesia

    Directory of Open Access Journals (Sweden)

    Fernandez-Bustamante Ana

    2011-11-01

    Full Text Available Abstract Background There is a growing concern of the potential injurious role of ventilatory over-distention in patients without lung injury. No formal guidelines exist for intraoperative ventilation settings, but the use of tidal volumes (VT under 10 mL/kg predicted body weight (PBW has been recommended in healthy patients. We explored the incidence and risk factors for receiving large tidal volumes (VT > 10 mL/kg PBW. Methods We performed a cross-sectional analysis of our prospectively collected perioperative electronic database for current intraoperative ventilation practices and risk factors for receiving large tidal volumes (VT > 10 mL/kg PBW. We included all adults undergoing prolonged (≥ 4 h elective abdominal surgery and collected demographic, preoperative (comorbidities, intraoperative (i.e. ventilatory settings, fluid administration and postoperative (outcomes information. We compared patients receiving exhaled tidal volumes > 10 mL/kg PBW with those that received 8-10 or Results Ventilatory settings were non-uniform in the 429 adults included in the analysis. 17.5% of all patients received VT > 10 mL/kg PBW. 34.0% of all obese patients (body mass index, BMI, ≥ 30, 51% of all patients with a height T > 10 mL/kg PBW. Conclusions Ventilation with VT > 10 mL/kg PBW is still common, although poor correlation with PBW suggests it may be unintentional. BMI ≥ 30, female gender and height

  14. Determination of volume fraction in biphasic flows oil-gas and water-gas using artificial neural network and gamma densitometry

    International Nuclear Information System (INIS)

    Peixoto, Philippe Netto Belache

    2016-01-01

    This study presents a methodology based on the principles of gamma ray attenuation to identify volume fractions in biphasic systems composed of oil-gas-water and gas which are found in the offshore oil industry. This methodology is based on the acknowledgment counts per second on the photopeak energy using a detection system composed of a NaI (Tl) detector, a source of 137 Cs without collimation positioned at 180 ° relative to the detector on a smooth stratified flow regime. The mathematical modeling for computational simulation using the code MCNP-X was performed using the experimental measurements of the detector characteristics (energy resolution and efficiency), characteristics of the material water and oil (density and coefficient attenuation) and measurement of the volume fractions. To predict these fractions were used artificial neural networks (ANNs), and to obtain an adequate training the ANNs for the prediction of volume fractions were simulated a larger number of volume fractions in MCNP-X. The experimental data were used in the set data necessary for validation of ANNs and the data generated using the computer code MCNP-X were used in training and test sets of the ANNs. Were used ANNs of type feed-forward Multilayer Perceptron (MLP) and analyzed two functions of training, Levenberg-Marquardt (LM) and gradient descent with momentum (GDM), both using the Backpropagation training algorithm. The ANNs identified correctly the volume fractions of the multiphase system with mean relative errors lower than 1.21 %, enabling the application of this methodology for this purpose. (author)

  15. Geophysics Under Pressure: Large-Volume Presses Versus the Diamond-Anvil Cell

    Science.gov (United States)

    Hazen, R. M.

    2002-05-01

    Prior to 1970, the legacy of Harvard physicist Percy Bridgman dominated high-pressure geophysics. Massive presses with large-volume devices, including piston-cylinder, opposed-anvil, and multi-anvil configurations, were widely used in both science and industry to achieve a range of crustal and upper mantle temperatures and pressures. George Kennedy of UCLA was a particularly influential advocate of large-volume apparatus for geophysical research prior to his death in 1980. The high-pressure scene began to change in 1959 with the invention of the diamond-anvil cell, which was designed simultaneously and independently by John Jamieson at the University of Chicago and Alvin Van Valkenburg at the National Bureau of Standards in Washington, DC. The compact, inexpensive diamond cell achieved record static pressures and had the advantage of optical access to the high-pressure environment. Nevertheless, members of the geophysical community, who favored the substantial sample volumes, geothermally relevant temperature range, and satisfying bulk of large-volume presses, initially viewed the diamond cell with indifference or even contempt. Several factors led to a gradual shift in emphasis from large-volume presses to diamond-anvil cells in geophysical research during the 1960s and 1970s. These factors include (1) their relatively low cost at time of fiscal restraint, (2) Alvin Van Valkenburg's new position as a Program Director at the National Science Foundation in 1964 (when George Kennedy's proposal for a Nation High-Pressure Laboratory was rejected), (3) the development of lasers and micro-analytical spectroscopic techniques suitable for analyzing samples in a diamond cell, and (4) the attainment of record pressures (e.g., 100 GPa in 1975 by Mao and Bell at the Geophysical Laboratory). Today, a more balanced collaborative approach has been adopted by the geophysics and mineral physics community. Many high-pressure laboratories operate a new generation of less expensive

  16. Assembly, operation and disassembly manual for the Battelle Large Volume Water Sampler (BLVWS)

    International Nuclear Information System (INIS)

    Thomas, V.W.; Campbell, R.M.

    1984-12-01

    Assembly, operation and disassembly of the Battelle Large Volume Water Sampler (BLVWS) are described in detail. Step by step instructions of assembly, general operation and disassembly are provided to allow an operator completely unfamiliar with the sampler to successfully apply the BLVWS to his research sampling needs. The sampler permits concentration of both particulate and dissolved radionuclides from large volumes of ocean and fresh water. The water sample passes through a filtration section for particle removal then through sorption or ion exchange beds where species of interest are removed. The sampler components which contact the water being sampled are constructed of polyvinylchloride (PVC). The sampler has been successfully applied to many sampling needs over the past fifteen years. 9 references, 8 figures

  17. Studies on a pulse shaping system for fast coincidence with very large volume HPGe detectors

    International Nuclear Information System (INIS)

    Bose, S.; Chatterjee, M.B.; Sinha, B.K.; Bhattacharya, R.

    1987-01-01

    A variant of the leading edge timing (LET) has been proposed which compensates the ''walk'' due to risetime spread in very large volume (∝100 cm 3 ) HPGe detectors. The method - shape compensated leading edge timing (SCLET) - can be used over a wide dynamic range of energies with 100% efficiency and has been compared with the LET and ARC methods. A time resolution of 10 ns fwhm and 21 ns fwtm has been obtained with 22 Na gamma rays and two HPGe detectors of 96 and 114 cm 3 volume. This circuit is easy to duplicate and use can be a low cost alternative to commercial circuits in experiments requiring a large number of detectors. (orig.)

  18. Measurement of Atmospheric Neutrino Oscillations with Very Large Volume Neutrino Telescopes

    Directory of Open Access Journals (Sweden)

    J. P. Yáñez

    2015-01-01

    Full Text Available Neutrino oscillations have been probed during the last few decades using multiple neutrino sources and experimental set-ups. In the recent years, very large volume neutrino telescopes have started contributing to the field. First ANTARES and then IceCube have relied on large and sparsely instrumented volumes to observe atmospheric neutrinos for combinations of baselines and energies inaccessible to other experiments. Using this advantage, the latest result from IceCube starts approaching the precision of other established technologies and is paving the way for future detectors, such as ORCA and PINGU. These new projects seek to provide better measurements of neutrino oscillation parameters and eventually determine the neutrino mass ordering. The results from running experiments and the potential from proposed projects are discussed in this review, emphasizing the experimental challenges involved in the measurements.

  19. Management of Large Volumes of Waste Arising in a Nuclear or Radiological Emergency

    International Nuclear Information System (INIS)

    2017-10-01

    This publication, prepared in light of the IAEA Action Plan on Nuclear Safety developed after the accident at the Fukushima Daiichi nuclear power plant, addresses the management of large volumes of radioactive waste arising in a nuclear or radiological emergency, as part of overall emergency preparedness. The management of large volumes of waste will be one of many efforts to be dealt with to allow recovery of affected areas, to support return of evacuated or relocated populations and preparations for normal social and economic activities, and/or to mitigate additional environmental impacts. The publication is intended to be of use to national planners and policy makers, facility and programme managers, and other professionals responsible for developing and implementing national plans and strategies to manage radioactive waste arising from nuclear or radiological emergencies.

  20. Hydrogen atom with a Yukawa potential: Perturbation theory and continued-fractions--Pade approximants at large order

    International Nuclear Information System (INIS)

    Vrscay, E.R.

    1986-01-01

    A simple power-series method is developed to calculate to large order the Rayleigh-Schroedinger perturbation expansions for energy levels of a hydrogen atom with a Yukawa-type screened Coulomb potential. Perturbation series for the 1s, 2s, and 2p levels, shown not to be of the Stieltjes type, are calculated to 100th order. Nevertheless, the poles of the Pade approximants to these series generally avoid the region of the positive real axis 0 < lambda < lambda(, where lambda( represents the coupling constant threshold. As a result, the Pade sums afford accurate approximations to E(lambda) in this domain. The continued-fraction representations to these perturbation series have been accurately calculated to large (100th) order and demonstrate a curious ''quasioscillatory,'' but non-Stieltjes, behavior. Accurate values of E(lambda) as well as lambda( for the 1s, 2s, and 2p levels are reported

  1. F-term stabilization of odd axions in LARGE volume scenario

    International Nuclear Information System (INIS)

    Gao, Xin; Shukla, Pramod

    2014-01-01

    In the context of the LARGE volume scenario, stabilization of axionic moduli is revisited. This includes both even and odd axions with their scalar potential being generated by F-term contributions via various tree-level and non-perturbative effects like fluxed E3-brane instantons and fluxed poly-instantons. In all the cases, we estimate the decay constants and masses of the axions involved

  2. Numerical simulation of seismic wave propagation from land-excited large volume air-gun source

    Science.gov (United States)

    Cao, W.; Zhang, W.

    2017-12-01

    The land-excited large volume air-gun source can be used to study regional underground structures and to detect temporal velocity changes. The air-gun source is characterized by rich low frequency energy (from bubble oscillation, 2-8Hz) and high repeatability. It can be excited in rivers, reservoirs or man-made pool. Numerical simulation of the seismic wave propagation from the air-gun source helps to understand the energy partitioning and characteristics of the waveform records at stations. However, the effective energy recorded at a distance station is from the process of bubble oscillation, which can not be approximated by a single point source. We propose a method to simulate the seismic wave propagation from the land-excited large volume air-gun source by finite difference method. The process can be divided into three parts: bubble oscillation and source coupling, solid-fluid coupling and the propagation in the solid medium. For the first part, the wavelet of the bubble oscillation can be simulated by bubble model. We use wave injection method combining the bubble wavelet with elastic wave equation to achieve the source coupling. Then, the solid-fluid boundary condition is implemented along the water bottom. And the last part is the seismic wave propagation in the solid medium, which can be readily implemented by the finite difference method. Our method can get accuracy waveform of land-excited large volume air-gun source. Based on the above forward modeling technology, we analysis the effect of the excited P wave and the energy of converted S wave due to different water shapes. We study two land-excited large volume air-gun fields, one is Binchuan in Yunnan, and the other is Hutubi in Xinjiang. The station in Binchuan, Yunnan is located in a large irregular reservoir, the waveform records have a clear S wave. Nevertheless, the station in Hutubi, Xinjiang is located in a small man-made pool, the waveform records have very weak S wave. Better understanding of

  3. First results on material identification and imaging with a large-volume muon tomography prototype

    Energy Technology Data Exchange (ETDEWEB)

    Pesente, S. [INFN Sezione di Padova, via Marzolo 8, 35131 Padova (Italy); Vanini, S. [University of Padova and INFN Sezione di Padova, via Marzolo 8, 35131 Padova (Italy)], E-mail: sara.vanini@pd.infn.it; Benettoni, M. [INFN Sezione di Padova, via Marzolo 8, 35131 Padova (Italy); Bonomi, G. [University of Brescia, via Branze 38, 25123 Brescia and INFN Sezione di Pavia, via Bassi 6, 27100 Pavia (Italy); Calvini, P. [University of Genova and INFN Sezione di Genova, via Dodecaneso 33, 16146 Genova (Italy); Checchia, P.; Conti, E.; Gonella, F.; Nebbia, G. [INFN Sezione di Padova, via Marzolo 8, 35131 Padova (Italy); Squarcia, S. [University of Genova and INFN Sezione di Genova, via Dodecaneso 33, 16146 Genova (Italy); Viesti, G. [University of Padova and INFN Sezione di Padova, via Marzolo 8, 35131 Padova (Italy); Zenoni, A. [University of Brescia, via Branze 38, 25123 Brescia and INFN Sezione di Pavia, via Bassi 6, 27100 Pavia (Italy); Zumerle, G. [University of Padova and INFN Sezione di Padova, via Marzolo 8, 35131 Padova (Italy)

    2009-06-11

    The muon tomography technique, based on the Multiple Coulomb Scattering of cosmic ray muons, has been proposed recently as a tool to perform non-destructive assays of large-volume objects without any radiation hazard. In this paper we discuss experimental results obtained with a scanning system prototype, assembled using two large-area CMS Muon Barrel drift chambers. The capability of the apparatus to produce 3D images of objects and to classify them according to their density is presented. We show that the absorption of low-momentum muons in the scanned objects produces an underestimate of their scattering density, making the discrimination of materials heavier than lead more difficult.

  4. First results on material identification and imaging with a large-volume muon tomography prototype

    Energy Technology Data Exchange (ETDEWEB)

    Viesti, G. [Dipartimento di Fisica, Universita di Padova, via Marzolo 8, I-35131 Padova (Italy); Pesente, S.; Benettoni, M.; Checchia, P.; Conti, E.; Gonella, F.; Nebbia, G. [INFN, Sez. di Padova, Via Marzolo 8, I-35131 Padova (Italy); Vanini, S.; Viesti, G.; Zumerle, G. [Dip. di Fisica G. Galilei, Universita di Padova, I-35131 Padova (Italy); INFN, Sez. di Padova, Via Marzolo 8, I-35131 Padova (Italy); Bonomi, G.; Zenoni, A. [Universita di Brescia, I-25133 Brescia (Italy); INFN, Sez. di Pavia, Via Valotti 9, I-25133 Brescia (Italy); Calvini, P.; Squarcia, S. [Dip. di Fisica, Universita di Genova, Genova (Italy); INFN, Sez. di Genova, Via Dodecaneso 33, I-16146 Genova (Italy)

    2009-07-01

    The muon tomography technique, based on the multiple Coulomb scattering of cosmic ray muons, has been proposed recently as a tool to perform non-destructive assays of large volume objects without any radiation hazard. In this paper we present the experimental results obtained with a scanning system prototype, assembled using two large area CMS Muon Barrel drift chambers. The imaging capability of the apparatus is shown, and the possibility to discriminate among different materials is discussed in a specific case of detecting lead objects inside a metal matrix. This specific case is dictated by a need in safely handling scrap metal cargoes in the steel industry. (authors)

  5. Effects of Low Volume Fraction of Polyvinyl Alcohol Fibers on the Mechanical Properties of Oil Palm Shell Lightweight Concrete

    Directory of Open Access Journals (Sweden)

    Ming Kun Yew

    2015-01-01

    Full Text Available This paper presents the effects of low volume fraction (Vf of polyvinyl alcohol (PVA fibers on the mechanical properties of oil palm shell (OPS high strength lightweight concrete mixtures. The slump, density, compressive strength, splitting tensile strength, flexural strength, and modulus of elasticity under various curing conditions have been measured and evaluated. The results indicate that an increase in PVA fibers decreases the workability of the concrete and decreases the density slightly. The 28-day compressive strength of oil palm shell fiber-reinforced concrete (OPSFRC high strength lightweight concrete (HSLWC subject to continuous moist curing was within the range of 43–49 MPa. The average modulus of elasticity (E value is found to be 16.1 GPa for all mixes, which is higher than that reported in previous studies and is within the range of normal weight concrete. Hence, the findings of this study revealed that the PVA fibers can be used as an alternative material to enhance the properties of OPS HSLWC for building and construction applications.

  6. Myocardial extracellular volume fraction quantified by cardiovascular magnetic resonance is increased in hypertension and associated with left ventricular remodeling

    International Nuclear Information System (INIS)

    Wang, Shuli; Li, Jinghui; Chen, Xiuyu; Yin, Gang; Lan, Tian; Dai, Linlin; Zhang, Yan; Yin, Xiaorong; Zhao, Shihua; Hu, Hongjie; Lu, Minjie; Sirajuddin, Arlene; Arai, Andrew E.; An, Jing; Song, Lei; Dang, Aimin; Kellman, Peter

    2017-01-01

    To determine whether extracellular volume fraction (ECV) quantification by cardiac magnetic resonance (CMR) can demonstrate left ventricle (LV) abnormalities and relationship between ECV and LV remodeling in hypertension (HTN) patients ECV quantification was prospectively performed in 134 consecutive HTN patients and 97 healthy subjects. Individual and regional ECV were compared to the regions on late gadolinium enhancement (LGE) images. Statistical analysis of the relationship between LV global functional parameters and ECV was carried out using Pearson's correlation, Student's t test and multiple regressions. In the HTN group, 70.1% (94/134) were LGE negative and 29.9% (40/134) LGE positive. The mean ECV after adjusting for age, sex, BMI, diabetes, smoking and dyslipidaemia in healthy controls and LGE-negative patients were 26.9 ± 2.67% and 28.5 ± 2.9% (p < 0.001), respectively. The differences in ECV reached statistical significance among the regions of LGE, LGE-Peri, LGE remote and the normal area between the control and LGE-positive subgroup (all p < 0.05). Global ECV significantly correlated with LVEF (r = -0.466, p < 0.001) and LV hypertrophy (r = 0.667, p < 0.001). ECV can identify LV abnormalities at an early stage in HTN patients without LGE. These abnormalities may reflect an increase in diffuse myocardial fibrosis and are associated with LV remodeling. (orig.)

  7. Myocardial extracellular volume fraction quantified by cardiovascular magnetic resonance is increased in hypertension and associated with left ventricular remodeling

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shuli; Li, Jinghui; Chen, Xiuyu; Yin, Gang; Lan, Tian; Dai, Linlin; Zhang, Yan; Yin, Xiaorong; Zhao, Shihua [Chinese Academy of Medical Sciences and Peking Union Medical College, Department of Magnetic Resonance Imaging, Cardiovascular Imaging and Intervention Center, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Beijing (China); Hu, Hongjie [Zhejiang University, Department of Radiology, Sir Run Run Shaw Hospital, School of Medicine, Hangzhou (China); Lu, Minjie [Chinese Academy of Medical Sciences and Peking Union Medical College, Department of Magnetic Resonance Imaging, Cardiovascular Imaging and Intervention Center, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Beijing (China); Laboratory for Advanced Cardiovascular Imaging, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Department of Health and Human Services, Bethesda, MD (United States); Sirajuddin, Arlene; Arai, Andrew E. [Laboratory for Advanced Cardiovascular Imaging, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Department of Health and Human Services, Bethesda, MD (United States); An, Jing [Siemens Shenzhen Magnetic Resonance Ltd., Siemens MRI Center, Shenzhen, Guangdong (China); Song, Lei; Dang, Aimin [Chinese Academy of Medical Sciences and Peking Union Medical College, Department of Cardiology, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Beijing (China); Kellman, Peter [National Heart, Lung and Blood Institute (NHLBI), National Institutes of Health (NIH), US Department of Health and Human Services, Cardiovascular and Pulmonary Branch, Bethesda, MD (United States)

    2017-11-15

    To determine whether extracellular volume fraction (ECV) quantification by cardiac magnetic resonance (CMR) can demonstrate left ventricle (LV) abnormalities and relationship between ECV and LV remodeling in hypertension (HTN) patients ECV quantification was prospectively performed in 134 consecutive HTN patients and 97 healthy subjects. Individual and regional ECV were compared to the regions on late gadolinium enhancement (LGE) images. Statistical analysis of the relationship between LV global functional parameters and ECV was carried out using Pearson's correlation, Student's t test and multiple regressions. In the HTN group, 70.1% (94/134) were LGE negative and 29.9% (40/134) LGE positive. The mean ECV after adjusting for age, sex, BMI, diabetes, smoking and dyslipidaemia in healthy controls and LGE-negative patients were 26.9 ± 2.67% and 28.5 ± 2.9% (p < 0.001), respectively. The differences in ECV reached statistical significance among the regions of LGE, LGE-Peri, LGE remote and the normal area between the control and LGE-positive subgroup (all p < 0.05). Global ECV significantly correlated with LVEF (r = -0.466, p < 0.001) and LV hypertrophy (r = 0.667, p < 0.001). ECV can identify LV abnormalities at an early stage in HTN patients without LGE. These abnormalities may reflect an increase in diffuse myocardial fibrosis and are associated with LV remodeling. (orig.)

  8. A mathematical model for the effects of volume fraction and fiber aspect ratio of biomass mixture during enzymatic hydrolysis

    Science.gov (United States)

    Jamil, Norazaliza Mohd; Wang, Qi

    2017-09-01

    Renewable energy or biofuel from lignocellulosic biomass is an alternative way to replace the depleting fossil fuels. The production cost can be reduced by increasing the concentration of biomass particles. However, lignocellulosic biomass is a suspension of natural fibres, and processing at high solid concentration is a challenging task. Thus, understanding the factors that affect the rheology of biomass suspension is crucial in order to maximize the production at a minimum cost. Our aim was to develop a mathematical model for enzymatic hydrolysis of cellulose by combining three scales: the macroscopic flow field, the mesoscopic particle orientation, and the microscopic reactive kinetics. The governing equations for the flow field, particle stress, kinetic equations, and particle orientation were coupled and were simultaneously solved using a finite element method based software, COMSOL. One of the main results was the changes in rheology of biomass suspension were not only due to the decrease in volume fraction of particles, but also due the types of fibres. The results from the simulation model agreed qualitatively with the experimental findings. This approach has enables us to obtain better predictive capabilities, hence increasing our understanding on the behaviour of biomass suspension.

  9. Application of artificial neural networks for the prediction of volume fraction using spectra of gamma rays backscattered by three-phase flows

    Science.gov (United States)

    Gholipour Peyvandi, R.; Islami Rad, S. Z.

    2017-12-01

    The determination of the volume fraction percentage of the different phases flowing in vessels using transmission gamma rays is a conventional method in petroleum and oil industries. In some cases, with access only to the one side of the vessels, attention was drawn toward backscattered gamma rays as a desirable choice. In this research, the volume fraction percentage was measured precisely in water-gasoil-air three-phase flows by using the backscatter gamma ray technique andthe multilayer perceptron (MLP) neural network. The volume fraction determination in three-phase flows requires two gamma radioactive sources or a dual-energy source (with different energies) while in this study, we used just a 137Cs source (with the single energy) and a NaI detector to analyze backscattered gamma rays. The experimental set-up provides the required data for training and testing the network. Using the presented method, the volume fraction was predicted with a mean relative error percentage less than 6.47%. Also, the root mean square error was calculated as 1.60. The presented set-up is applicable in some industries with limited access. Also, using this technique, the cost, radiation safety and shielding requirements are minimized toward the other proposed methods.

  10. Interfacial effect on physical properties of composite media: Interfacial volume fraction with non-spherical hard-core-soft-shell-structured particles.

    Science.gov (United States)

    Xu, Wenxiang; Duan, Qinglin; Ma, Huaifa; Chen, Wen; Chen, Huisu

    2015-11-02

    Interfaces are known to be crucial in a variety of fields and the interfacial volume fraction dramatically affects physical properties of composite media. However, it is an open problem with great significance how to determine the interfacial property in composite media with inclusions of complex geometry. By the stereological theory and the nearest-surface distribution functions, we first propose a theoretical framework to symmetrically present the interfacial volume fraction. In order to verify the interesting generalization, we simulate three-phase composite media by employing hard-core-soft-shell structures composed of hard mono-/polydisperse non-spherical particles, soft interfaces, and matrix. We numerically derive the interfacial volume fraction by a Monte Carlo integration scheme. With the theoretical and numerical results, we find that the interfacial volume fraction is strongly dependent on the so-called geometric size factor and sphericity characterizing the geometric shape in spite of anisotropic particle types. As a significant interfacial property, the present theoretical contribution can be further drawn into predicting the effective transport properties of composite materials.

  11. Dosimetric Coverage of the Prostate, Normal Tissue Sparing, and Acute Toxicity with High-Dose-Rate Brachytherapy for Large Prostate Volumes

    Directory of Open Access Journals (Sweden)

    George Yang

    2015-06-01

    Full Text Available ABSTRACTPurposeTo evaluate dosimetric coverage of the prostate, normal tissue sparing, and acute toxicity with HDR brachytherapy for large prostate volumes.Materials and MethodsOne hundred and two prostate cancer patients with prostate volumes >50 mL (range: 5-29 mL were treated with high-dose-rate (HDR brachytherapy ± intensity modulated radiation therapy (IMRT to 4,500 cGy in 25 daily fractions between 2009 and 2013. HDR brachytherapy monotherapy doses consisted of two 1,350-1,400 cGy fractions separated by 2-3 weeks, and HDR brachytherapy boost doses consisted of two 950-1,150 cGy fractions separated by 4 weeks. Twelve of 32 (38% unfavorable intermediate risk, high risk, and very high risk patients received androgen deprivation therapy. Acute toxicity was graded according to the Common Terminology Criteria for Adverse Events (CTCAE version 4.ResultsMedian follow-up was 14 months. Dosimetric goals were achieved in over 90% of cases. Three of 102 (3% patients developed Grade 2 acute proctitis. No variables were significantly associated with Grade 2 acute proctitis. Seventeen of 102 (17% patients developed Grade 2 acute urinary retention. American Urological Association (AUA symptom score was the only variable significantly associated with Grade 2 acute urinary retention (p=0.04. There was no ≥ Grade 3 acute toxicity.ConclusionsDosimetric coverage of the prostate and normal tissue sparing were adequate in patients with prostate volumes >50 mL. Higher pre-treatment AUA symptom scores increased the relative risk of Grade 2 acute urinary retention. However, the overall incidence of acute toxicity was acceptable in patients with large prostate volumes.

  12. Dosimetric coverage of the prostate, normal tissue sparing, and acute toxicity with high-dose-rate brachytherapy for large prostate volumes

    Energy Technology Data Exchange (ETDEWEB)

    Yang, George; Strom, Tobin J.; Shrinath, Kushagra; Mellon, Eric A.; Fernandez, Daniel C.; Biagioli, Matthew C. [Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL (United States); Wilder, Richard B., E-mail: mcbiagioli@yahoo.com [Cancer Treatment Centers of America, Newnan, GA (United States)

    2015-05-15

    Purpose: to evaluate dosimetric coverage of the prostate, normal tissue sparing, and acute toxicity with HDR brachytherapy for large prostate volumes. Materials and methods: one hundred and two prostate cancer patients with prostate volumes >50 mL (range: 5-29 mL) were treated with high-dose-rate (HDR) brachytherapy ± intensity modulated radiation therapy (IMRT) to 4,500 cGy in 25 daily fractions between 2009 and 2013. HDR brachytherapy monotherapy doses consisted of two 1,350-1,400 cGy fractions separated by 2-3 weeks, and HDR brachytherapy boost doses consisted of two 950-1,150 cGy fractions separated by 4 weeks. Twelve of 32 (38%) unfavorable intermediate risk, high risk, and very high risk patients received androgen deprivation therapy. Acute toxicity was graded according to the Common Terminology Criteria for Adverse Events (CTCAE) version 4. Results: median follow-up was 14 months. Dosimetric goals were achieved in over 90% of cases. Three of 102 (3%) patients developed Grade 2 acute proctitis. No variables were significantly associated with Grade 2 acute proctitis. Seventeen of 102 (17%) patients developed Grade 2 acute urinary retention. American Urological Association (AUA) symptom score was the only variable significantly associated with Grade 2 acute urinary retention (p-0.04). There was no ≥ Grade 3 acute toxicity. Conclusions: dosimetric coverage of the prostate and normal tissue sparing were adequate in patients with prostate volumes >50 mL. Higher pre-treatment AUA symptom scores increased the relative risk of Grade 2 acute urinary retention. However, the overall incidence of acute toxicity was acceptable in patients with large prostate volumes. (author)

  13. State-of-the-Art in GPU-Based Large-Scale Volume Visualization

    KAUST Repository

    Beyer, Johanna

    2015-05-01

    This survey gives an overview of the current state of the art in GPU techniques for interactive large-scale volume visualization. Modern techniques in this field have brought about a sea change in how interactive visualization and analysis of giga-, tera- and petabytes of volume data can be enabled on GPUs. In addition to combining the parallel processing power of GPUs with out-of-core methods and data streaming, a major enabler for interactivity is making both the computational and the visualization effort proportional to the amount and resolution of data that is actually visible on screen, i.e. \\'output-sensitive\\' algorithms and system designs. This leads to recent output-sensitive approaches that are \\'ray-guided\\', \\'visualization-driven\\' or \\'display-aware\\'. In this survey, we focus on these characteristics and propose a new categorization of GPU-based large-scale volume visualization techniques based on the notions of actual output-resolution visibility and the current working set of volume bricks-the current subset of data that is minimally required to produce an output image of the desired display resolution. Furthermore, we discuss the differences and similarities of different rendering and data traversal strategies in volume rendering by putting them into a common context-the notion of address translation. For our purposes here, we view parallel (distributed) visualization using clusters as an orthogonal set of techniques that we do not discuss in detail but that can be used in conjunction with what we present in this survey. © 2015 The Eurographics Association and John Wiley & Sons Ltd.

  14. State-of-the-Art in GPU-Based Large-Scale Volume Visualization

    KAUST Repository

    Beyer, Johanna; Hadwiger, Markus; Pfister, Hanspeter

    2015-01-01

    This survey gives an overview of the current state of the art in GPU techniques for interactive large-scale volume visualization. Modern techniques in this field have brought about a sea change in how interactive visualization and analysis of giga-, tera- and petabytes of volume data can be enabled on GPUs. In addition to combining the parallel processing power of GPUs with out-of-core methods and data streaming, a major enabler for interactivity is making both the computational and the visualization effort proportional to the amount and resolution of data that is actually visible on screen, i.e. 'output-sensitive' algorithms and system designs. This leads to recent output-sensitive approaches that are 'ray-guided', 'visualization-driven' or 'display-aware'. In this survey, we focus on these characteristics and propose a new categorization of GPU-based large-scale volume visualization techniques based on the notions of actual output-resolution visibility and the current working set of volume bricks-the current subset of data that is minimally required to produce an output image of the desired display resolution. Furthermore, we discuss the differences and similarities of different rendering and data traversal strategies in volume rendering by putting them into a common context-the notion of address translation. For our purposes here, we view parallel (distributed) visualization using clusters as an orthogonal set of techniques that we do not discuss in detail but that can be used in conjunction with what we present in this survey. © 2015 The Eurographics Association and John Wiley & Sons Ltd.

  15. Novel regenerative large-volume immobilized enzyme reactor: preparation, characterization and application.

    Science.gov (United States)

    Ruan, Guihua; Wei, Meiping; Chen, Zhengyi; Su, Rihui; Du, Fuyou; Zheng, Yanjie

    2014-09-15

    A novel large-volume immobilized enzyme reactor (IMER) on small column was prepared with organic-inorganic hybrid silica particles and applied for fast (10 min) and oriented digestion of protein. At first, a thin enzyme support layer was formed in the bottom of the small column by polymerization with α-methacrylic acid and dimethacrylate. After that, amino SiO2 particles was prepared by the sol-gel method with tetraethoxysilane and 3-aminopropyltriethoxysilane. Subsequently, the amino SiO2 particles were activated by glutaraldehyde for covalent immobilization of trypsin. Digestive capability of large-volume IMER for proteins was investigated by using bovine serum albumin (BSA), cytochrome c (Cyt-c) as model proteins. Results showed that although the sequence coverage of the BSA (20%) and Cyt-c (19%) was low, the large-volume IMER could produce peptides with stable specific sequence at 101-105, 156-160, 205-209, 212-218, 229-232, 257-263 and 473-451 of the amino sequence of BSA when digesting 1mg/mL BSA. Eight of common peptides were observed during each of the ten runs of large-volume IMER. Besides, the IMER could be easily regenerated by reactivating with GA and cross-linking with trypsin after breaking the -C=N- bond by 0.01 M HCl. The sequence coverage of BSA from regenerated IMER increased to 25% comparing the non-regenerated IMER (17%). 14 common peptides. accounting for 87.5% of first use of IMER, were produced both with IMER and regenerated IMER. When the IMER was applied for ginkgo albumin digestion, the sequence coverage of two main proteins of ginkgo, ginnacin and legumin, was 56% and 55%, respectively. (Reviewer 2) Above all, the fast and selective digestion property of the large-volume IMER indicated that the regenerative IMER could be tentatively used for the production of potential bioactive peptides and the study of oriented protein digestion. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Large-volume paracentesis with indwelling peritoneal catheter and albumin infusion: a community hospital study

    Directory of Open Access Journals (Sweden)

    Daniel K. Martin

    2016-10-01

    Full Text Available Background: The management of ascites can be problematic. This is especially true in patients with diuretic refractory ascites who develop a tense abdomen. This often results in hypotension and decreased venous return with resulting renal failure. In this paper, we further examine the risks and benefits of utilizing an indwelling peritoneal catheter to remove large-volume ascites over a 72-h period while maintaining intravascular volume and preventing renal failure. Methods: We retrospectively reviewed charts and identified 36 consecutive patients undergoing continuous large-volume paracentesis with an indwelling peritoneal catheter. At the time of drain placement, no patients had signs or laboratory parameters suggestive of spontaneous bacterial peritonitis. The patients underwent ascitic fluid removal through an indwelling peritoneal catheter and were supported with scheduled albumin throughout the duration. The catheter was used to remove up to 3 L every 8 h for a maximum of 72 h. Regular laboratory and ascitic fluid testing was performed. All patients had a clinical follow-up within 3 months after the drain placement. Results: An average of 16.5 L was removed over the 72-h time frame of indwelling peritoneal catheter maintenance. The albumin infusion utilized correlated to 12 mg/L removed. The average creatinine trend improved in a statistically significant manner from 1.37 on the day of admission to 1.21 on the day of drain removal. No patients developed renal failure during the hospital course. There were no documented episodes of neutrocytic ascites or bacterial peritonitis throughout the study review. Conclusion: Large-volume peritoneal drainage with an indwelling peritoneal catheter is safe and effective for patients with tense ascites. Concomitant albumin infusion allows for maintenance of renal function, and no increase in infectious complications was noted.

  17. Enhanced FIB-SEM systems for large-volume 3D imaging

    Science.gov (United States)

    Xu, C Shan; Hayworth, Kenneth J; Lu, Zhiyuan; Grob, Patricia; Hassan, Ahmed M; García-Cerdán, José G; Niyogi, Krishna K; Nogales, Eva; Weinberg, Richard J; Hess, Harald F

    2017-01-01

    Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) can automatically generate 3D images with superior z-axis resolution, yielding data that needs minimal image registration and related post-processing. Obstacles blocking wider adoption of FIB-SEM include slow imaging speed and lack of long-term system stability, which caps the maximum possible acquisition volume. Here, we present techniques that accelerate image acquisition while greatly improving FIB-SEM reliability, allowing the system to operate for months and generating continuously imaged volumes > 106 µm3. These volumes are large enough for connectomics, where the excellent z resolution can help in tracing of small neuronal processes and accelerate the tedious and time-consuming human proofreading effort. Even higher resolution can be achieved on smaller volumes. We present example data sets from mammalian neural tissue, Drosophila brain, and Chlamydomonas reinhardtii to illustrate the power of this novel high-resolution technique to address questions in both connectomics and cell biology. DOI: http://dx.doi.org/10.7554/eLife.25916.001 PMID:28500755

  18. Pre-chemotherapy values for left and right ventricular volumes and ejection fraction by gated tomographic radionuclide angiography using a cadmium-zinc-telluride detector gamma camera

    DEFF Research Database (Denmark)

    Haarmark, Christian; Haase, Christine; Jensen, Maria Maj

    2016-01-01

    age and both left and right ventricular volumes in women (r = -0.4, P right end systolic ventricular volume in men (r = -0.3, P = .001). CONCLUSION: A set of reference values for cardiac evaluation prior to chemotherapy in cancer patients without other known cardiopulmonary......BACKGROUND: Estimation of left ventricular ejection fraction (LVEF) using equilibrium radionuclide angiography is an established method for assessment of left ventricular function. The purpose of this study was to establish normative data on left and right ventricular volumes and ejection fraction......, using cadmium-zinc-telluride SPECT camera. METHODS AND RESULTS: From routine assessments of left ventricular function in 1172 patients, we included 463 subjects (194 men and 269 women) without diabetes, previous potentially cardiotoxic chemotherapy, known cardiovascular or pulmonary disease. The lower...

  19. A self-sampling method to obtain large volumes of undiluted cervicovaginal secretions.

    Science.gov (United States)

    Boskey, Elizabeth R; Moench, Thomas R; Hees, Paul S; Cone, Richard A

    2003-02-01

    Studies of vaginal physiology and pathophysiology sometime require larger volumes of undiluted cervicovaginal secretions than can be obtained by current methods. A convenient method for self-sampling these secretions outside a clinical setting can facilitate such studies of reproductive health. The goal was to develop a vaginal self-sampling method for collecting large volumes of undiluted cervicovaginal secretions. A menstrual collection device (the Instead cup) was inserted briefly into the vagina to collect secretions that were then retrieved from the cup by centrifugation in a 50-ml conical tube. All 16 women asked to perform this procedure found it feasible and acceptable. Among 27 samples, an average of 0.5 g of secretions (range, 0.1-1.5 g) was collected. This is a rapid and convenient self-sampling method for obtaining relatively large volumes of undiluted cervicovaginal secretions. It should prove suitable for a wide range of assays, including those involving sexually transmitted diseases, microbicides, vaginal physiology, immunology, and pathophysiology.

  20. Radiation Effect on Body Weight and Hematological Changes of Hybrid Mice by Conventional Fraction, Large Abdominal Field Irradiation

    International Nuclear Information System (INIS)

    Lee, Sung Heon; Shin, Sei One; Kim, Myung Se

    1985-01-01

    Radiation effect on mammals, especially on hematologic changes, has been studied since discovery of x-ray. Various experimental animals were tried for radiobiological studies. 72 hybrid mice with conventional fraction (5X/week), large abdominal field (2 x 3cm, from symphysis pubic to xyphoid process) were used. Body weight was declined gradually by increasing irradiation doses, nadir was about 29.7% in male ; 30.4% in female at 6000 rad irradiation group. Hemoglobin value was nearly normal throughout entire treatment. Significant dropping of WBC count was noted to 40-50% of pretreatment values by only 1000 rad irradiation. Change of differential count was interesting; lymphocyte proportion showed gradual reduction, instead of gradual increasing of segmented neutrophil. Those proportion were reversed after 6000 rad irradiation. Urinary protein tests showed + - +++, showing no correlation with dosage. Application. of our study in clinical combination therapy (radiation + chemotherapy) was discussed

  1. Mechanical properties of a co-extruded Metallic Glass/Alloy (MeGA) rod-Effect of the metallic glass volume fraction

    International Nuclear Information System (INIS)

    Gravier, S.; Blandin, J.J.; Suery, M.

    2010-01-01

    A Metallic Glass/Alloy (MeGA) rod with a core in zirconium-based bulk metallic glass and a sleeve in aluminium alloy has been successfully elaborated by co-extrusion. SEM observations of the cross-section of the rod show that the interface between the glass and the alloy is defect-free. Compression tests are carried out at room temperature on the MeGA rods containing various glass volume fractions. The yield stress is well described by the rule of mixtures which combines the strength of the glass and that of the alloy, suggesting isostrain behaviour as could be expected. During compression, a good mechanical bonding is observed in the MeGA-rod even after the first fracture of the metallic glass. Finally, push-out tests are performed to evaluate the bonding quality between the two materials. Large values of the shear strength are measured which confirms that co-extrusion leads to good bonding between the glass and the aluminium alloy.

  2. Influence of magnification on the calculated value of left ventricular ejection fraction and volumes using quantitative gated perfusion SPECT

    International Nuclear Information System (INIS)

    Nunez, M.; Beretta, M.; Alonso, O.; Alvarez, B.; Canepa, J.; Mut, F.

    2002-01-01

    Aim: To compare left ventricular ejection fraction (LVEF), end-diastolic volumes (EDV) and end-systolic volumes (ESV) measured by quantitative gated SPECT (QGSPECT) in studies acquired with and without magnification factor (zoom). Material and Methods: We studied 30 consecutive patients (17 men, ages 61±14 years) referred for myocardial perfusion evaluation with a 2-day protocol. Studies were performed after injection of 925 MBq (25 mCi) of 99mTc-MIBI in the resting state. Gated SPECT was first acquired using a x2 zoom factor and immediately repeated with x1 zoom (no magnification), using a 64x64 matrix and 8 frames/cardiac cycle. Patients with arrhythmia were not included in the investigation. According to the median EDV calculated with the x2 zoom acquisition, the population was further divided in two sub-groups regarding the size of the LV cavity. Average LVEF, EDV, ESV and difference between values (delta) were then calculated for the total population and for each sub-group (a and b). Results: For the total population, results are expressed.Pearson correlation showed r=0.954 between LVEF with and without zoom (p<0.0001), but linear regression analysis did not fit a specific model (p=0.18). Median EDV with zoom was 92.5 ml, allowing to separate 15 cases with EDV above (a) and 15 below that value (b). Results for both sub-groups are presented. Conclusion: Calculated LVEF is higher with no zoom, at the expense of decreasing both EDV and ESV. Although differences were very significant for all parameters, ESV changes were specially relevant with no zoom, particularly in patients with smaller hearts. Although good correlation was found between LVEF with and without zoom, no specific correction factor was found to convert one value into the other. Magnification factor should be kept constant in gated SPECT if calculated LVEF values QGSPECT are expected to be reliable, and validation of the method using different zoom factors should be considered

  3. High-accuracy power series solutions with arbitrarily large radius of convergence for the fractional nonlinear Schrödinger-type equations

    Science.gov (United States)

    Khawaja, U. Al; Al-Refai, M.; Shchedrin, Gavriil; Carr, Lincoln D.

    2018-06-01

    Fractional nonlinear differential equations present an interplay between two common and important effective descriptions used to simplify high dimensional or more complicated theories: nonlinearity and fractional derivatives. These effective descriptions thus appear commonly in physical and mathematical modeling. We present a new series method providing systematic controlled accuracy for solutions of fractional nonlinear differential equations, including the fractional nonlinear Schrödinger equation and the fractional nonlinear diffusion equation. The method relies on spatially iterative use of power series expansions. Our approach permits an arbitrarily large radius of convergence and thus solves the typical divergence problem endemic to power series approaches. In the specific case of the fractional nonlinear Schrödinger equation we find fractional generalizations of cnoidal waves of Jacobi elliptic functions as well as a fractional bright soliton. For the fractional nonlinear diffusion equation we find the combination of fractional and nonlinear effects results in a more strongly localized solution which nevertheless still exhibits power law tails, albeit at a much lower density.

  4. Hierarchical imaging: a new concept for targeted imaging of large volumes from cells to tissues.

    Science.gov (United States)

    Wacker, Irene; Spomer, Waldemar; Hofmann, Andreas; Thaler, Marlene; Hillmer, Stefan; Gengenbach, Ulrich; Schröder, Rasmus R

    2016-12-12

    Imaging large volumes such as entire cells or small model organisms at nanoscale resolution seemed an unrealistic, rather tedious task so far. Now, technical advances have lead to several electron microscopy (EM) large volume imaging techniques. One is array tomography, where ribbons of ultrathin serial sections are deposited on solid substrates like silicon wafers or glass coverslips. To ensure reliable retrieval of multiple ribbons from the boat of a diamond knife we introduce a substrate holder with 7 axes of translation or rotation specifically designed for that purpose. With this device we are able to deposit hundreds of sections in an ordered way in an area of 22 × 22 mm, the size of a coverslip. Imaging such arrays in a standard wide field fluorescence microscope produces reconstructions with 200 nm lateral resolution and 100 nm (the section thickness) resolution in z. By hierarchical imaging cascades in the scanning electron microscope (SEM), using a new software platform, we can address volumes from single cells to complete organs. In our first example, a cell population isolated from zebrafish spleen, we characterize different cell types according to their organelle inventory by segmenting 3D reconstructions of complete cells imaged with nanoscale resolution. In addition, by screening large numbers of cells at decreased resolution we can define the percentage at which different cell types are present in our preparation. With the second example, the root tip of cress, we illustrate how combining information from intermediate resolution data with high resolution data from selected regions of interest can drastically reduce the amount of data that has to be recorded. By imaging only the interesting parts of a sample considerably less data need to be stored, handled and eventually analysed. Our custom-designed substrate holder allows reproducible generation of section libraries, which can then be imaged in a hierarchical way. We demonstrate, that EM

  5. The roles of auxeticity and volume fraction on γ‧ precipitate microstructures in nickel-base alloys

    Science.gov (United States)

    Ardell, Alan J.

    2017-01-01

    New correlations are found between the elastic constants and late-stage precipitate microstructures in Ni-Al, Ni-Ga, Ni-Ge and Ni-Si alloys. The auxetic behaviour of Poisson's ratio, ν, measured parallel to [0 0 1] or ? in response to [1 1 0] loading, favours the amalgamation of Ni3Al and Ni3Ga precipitates into non-equilibrium shapes along cube directions when δν = (νγ‧ - νγ)/νγ‧ > 0, the superscripts referring to the γ‧ (Ni3X) and γ (Ni-X) phases, respectively. When δν 0 amalgamation of Ni3Al and Ni3Ga occurs readily, primarily producing laths of both phases. The γ‧ volume fraction, f, is also shown to play a role in the late-stage microstructures of Ni-Al alloys, with an increasing tendency to form Ni3Al laths, rather than plates, as f increases. The shapes of elastically soft γ precipitates in inverse Ni-Al and Ni-Ge alloys are different; Ni-Al precipitates are lath shaped, but Ni-Ge precipitates are plate shaped. The Ni-Ge plate shape, in a non-auxetic Ni3Ge matrix (Ni3Ge being the sole non-auxetic Ni3X phase of the four studied), is the only example of persistent plates in any of the Ni-base alloys investigated to date. The combination of an elastically soft precipitate (Ni-Ge) in a non-auxetic matrix suggests a connection between auxeticity and shape.

  6. Cardiac T1 mapping in congenital heart disease: bolus vs. infusion protocols for measurements of myocardial extracellular volume fraction.

    Science.gov (United States)

    Al-Wakeel-Marquard, Nadya; Rastin, Sanaz; Muench, Frédéric; O H-Ici, Darach; Yilmaz, Sevim; Berger, Felix; Kuehne, Titus; Messroghli, Daniel R

    2017-12-01

    Myocardial extracellular volume fraction (ECV) reflecting diffuse myocardial fibrosis can be measured with T1 mapping cardiovascular magnetic resonance (CMR) before and after the application of a gadolinium-based extracellular contrast agent. The equilibrium between blood and myocardium contrast concentration required for ECV measurements can be obtained with a primed contrast infusion (equilibrium contrast-CMR). We hypothesized that equilibrium can also be achieved with a single contrast bolus to accurately measure diffuse myocardial fibrosis in patients with congenital heart disease (CHD). Healthy controls (n = 17; median age 24.0 years) and patients with CHD (n = 19; 25.0 years) were prospectively enrolled. Using modified Look-Locker inversion recovery T1 mapping before, 15 min after bolus injection, and during constant infusion of gadolinium-DOTA, T1 values were obtained for blood pool and myocardium of the left ventricle (LV), the interventricular septum (IVS), and the right ventricle (RV) in a single midventricular plane in short axis or in transverse orientation. ECV of LV, IVS and RV by bolus-only and bolus-infusion correlated significantly in CHD patients (r = 0.94, 0.95, and 0.74; p < 0.01, respectively) and healthy controls (r = 0.96, 0.89, and 0.64; p < 0.05, respectively). Bland-Altman plots revealed no significant bias between the techniques for any of the analyzed regions. ECV of LV and RV myocardium measured by bolus-only T1 mapping agrees well with bolus-infusion measurements in patients with CHD. The use of a bolus-only approach facilitates the integration of ECV measurements into existing CMR imaging protocols, allowing for assessment of diffuse myocardial fibrosis in CHD in clinical routine.

  7. A Novel Technique for Endovascular Removal of Large Volume Right Atrial Tumor Thrombus

    Energy Technology Data Exchange (ETDEWEB)

    Nickel, Barbara, E-mail: nickel.ba@gmail.com [US Teleradiology and Quantum Medical Radiology Group (United States); McClure, Timothy, E-mail: tmcclure@gmail.com; Moriarty, John, E-mail: jmoriarty@mednet.ucla.edu [UCLA Medical Center, Department of Interventional Radiology (United States)

    2015-08-15

    Venous thromboembolic disease is a significant cause of morbidity and mortality, particularly in the setting of large volume pulmonary embolism. Thrombolytic therapy has been shown to be a successful treatment modality; however, its use somewhat limited due to the risk of hemorrhage and potential for distal embolization in the setting of large mobile thrombi. In patients where either thrombolysis is contraindicated or unsuccessful, and conventional therapies prove inadequate, surgical thrombectomy may be considered. We present a case of percutaneous endovascular extraction of a large mobile mass extending from the inferior vena cava into the right atrium using the Angiovac device, a venovenous bypass system designed for high-volume aspiration of undesired endovascular material. Standard endovascular methods for removal of cancer-associated thrombus, such as catheter-directed lysis, maceration, and exclusion, may prove inadequate in the setting of underlying tumor thrombus. Where conventional endovascular methods either fail or are unsuitable, endovascular thrombectomy with the Angiovac device may be a useful and safe minimally invasive alternative to open resection.

  8. A Novel Technique for Endovascular Removal of Large Volume Right Atrial Tumor Thrombus

    International Nuclear Information System (INIS)

    Nickel, Barbara; McClure, Timothy; Moriarty, John

    2015-01-01

    Venous thromboembolic disease is a significant cause of morbidity and mortality, particularly in the setting of large volume pulmonary embolism. Thrombolytic therapy has been shown to be a successful treatment modality; however, its use somewhat limited due to the risk of hemorrhage and potential for distal embolization in the setting of large mobile thrombi. In patients where either thrombolysis is contraindicated or unsuccessful, and conventional therapies prove inadequate, surgical thrombectomy may be considered. We present a case of percutaneous endovascular extraction of a large mobile mass extending from the inferior vena cava into the right atrium using the Angiovac device, a venovenous bypass system designed for high-volume aspiration of undesired endovascular material. Standard endovascular methods for removal of cancer-associated thrombus, such as catheter-directed lysis, maceration, and exclusion, may prove inadequate in the setting of underlying tumor thrombus. Where conventional endovascular methods either fail or are unsuitable, endovascular thrombectomy with the Angiovac device may be a useful and safe minimally invasive alternative to open resection

  9. Material inhomogeneities in Cd1-xZnxTe and their effects on large volume gamma-ray detectors

    International Nuclear Information System (INIS)

    Scyoc, J.M. Van; Lund, J.C.; Morse, D.H.

    1997-01-01

    Cadmium zinc telluride (Cd 1-x Zn x Te or CZT) has shown great promise as a material for room-temperature x-ray and gamma-ray detectors. In particular, polycrystalline material grown by the High Pressure Bridgman method with nominal Zn fraction (x) from 0.1 to 0.2 has been used to fabricate high resolution gamma-ray spectrometers with resolution approaching that of cooled high-purity Ge. For increased sensitivity, large areas (> 1 cm 2 ) are required, and for good sensitivity to high energy gamma photons, thick detectors (on the order of 1 cm) are required. Thus there has been a push for the development of CZT detectors with a volume greater than 1 cm 3 . However, nonuniformities in the material over this scale degrade the performance of the detectors. Variations in the zinc fraction, and thus the bandgap, and changes in the impurity distributions, both of which arise from the selective segregation of elements during crystal growth, result in spectral distortions. In this work several materials characterization techniques were combined with detector evaluations to determine the materials properties limiting detector performance. Materials measurements were performed on detectors found to have differing performance. Measurements conducted include infrared transmission (IR), particle induced x-ray emission (PIXE), photoluminescence (PL), and triaxial x-ray diffraction (TAXRD). To varying degrees, these measurements reveal that poor-performance detectors exhibit higher nonuniformities than spectrometer-grade detectors. This is reasonable, as regions of CZT material with different properties will give different localized spectral responses, which combine to result in a degraded spectrum for the total device

  10. Radionuclides and particles in seawater with the large volume in situ filtration and concentration system in the coastal waters off Japan

    International Nuclear Information System (INIS)

    Aono, Tatsuo; Nakanishi, Takahiro; Okubo, Ayako; Zheng, Jian; Yamada, Masatoshi; Kusakabe, Masashi

    2008-01-01

    It is necessary to determine the radionuclides in dissolved and particulate state in order to clarify the distributions and behavior of these in seawater. Because the concentrations of radionuclides and particles are very low in the ocean, it is difficult to concentrate and fractionate the particulate matters with the filtration systems in seawater. The large volume in situ filtration and concentration system (LV-FiCS) was developed to collect various forms of trace radionuclides and particles in seawater. The LV-FiCS has been operated during several cruises in the coastal waters off Japan, and several m 3 of seawaters were filtered through different kinds of filters and then pass through the adsorbents to concentrate radionuclides simultaneously. This system could be shown the vertical profiles of thorium with the size-fractionated method and the behavior of these nuclides in the ocean. (author)

  11. Open loop control of filament heating power supply for large volume plasma device

    Energy Technology Data Exchange (ETDEWEB)

    Sugandhi, R., E-mail: ritesh@ipr.res.in [Institute for Plasma Research, Gandhinagar, Gujarat 382428 (India); Homi Bhabha National Institute, Mumbai 400094 (India); Srivastava, P.K.; Sanyasi, A.K. [Homi Bhabha National Institute, Mumbai 400094 (India); Srivastav, Prabhakar [Institute for Plasma Research, Gandhinagar, Gujarat 382428 (India); Homi Bhabha National Institute, Mumbai 400094 (India); Awasthi, L.M., E-mail: kushagra.lalit@gmail.com [Institute for Plasma Research, Gandhinagar, Gujarat 382428 (India); Homi Bhabha National Institute, Mumbai 400094 (India); Mattoo, S.K. [Homi Bhabha National Institute, Mumbai 400094 (India)

    2017-02-15

    A power supply (20 V, 10 kA) for powering the filamentary cathode has been procured, interfaced and integrated with the centralized control system of Large Volume Plasma Device (LVPD). Software interface has been developed on the standard Modbus RTU communication protocol. It facilitates the dashboard for configuration, on line status monitoring, alarm management, data acquisition, synchronization and controls. It has been tested for stable operation of the power supply for the operational capabilities. The paper highlights the motivation, interface description, implementation and results obtained.

  12. Open loop control of filament heating power supply for large volume plasma device

    International Nuclear Information System (INIS)

    Sugandhi, R.; Srivastava, P.K.; Sanyasi, A.K.; Srivastav, Prabhakar; Awasthi, L.M.; Mattoo, S.K.

    2017-01-01

    A power supply (20 V, 10 kA) for powering the filamentary cathode has been procured, interfaced and integrated with the centralized control system of Large Volume Plasma Device (LVPD). Software interface has been developed on the standard Modbus RTU communication protocol. It facilitates the dashboard for configuration, on line status monitoring, alarm management, data acquisition, synchronization and controls. It has been tested for stable operation of the power supply for the operational capabilities. The paper highlights the motivation, interface description, implementation and results obtained.

  13. Complex Security System for Premises Under Conditions of Large Volume of Passenger Traffic

    Directory of Open Access Journals (Sweden)

    Yakubov Vladimir

    2016-01-01

    Full Text Available Subsystems of the design of a complex security system for premises under conditions of large volume of passenger traffic are considered. These subsystems provide video- and thermal imaging control, radio wave tomography, and gas analysis. Simultaneous application of all examined variants will essentially increase the probability of timely prevention of dangerous situations with the probability of false alarm as low as possible. It is important that finally, this will provide protection of population and will facilitate the work of intelligence services.

  14. Fan-beam scanning laser optical computed tomography for large volume dosimetry

    Science.gov (United States)

    Dekker, K. H.; Battista, J. J.; Jordan, K. J.

    2017-05-01

    A prototype scanning-laser fan beam optical CT scanner is reported which is capable of high resolution, large volume dosimetry with reasonable scan time. An acylindrical, asymmetric aquarium design is presented which serves to 1) generate parallel-beam scan geometry, 2) focus light towards a small acceptance angle detector, and 3) avoid interference fringe-related artifacts. Preliminary experiments with uniform solution phantoms (11 and 15 cm diameter) and finger phantoms (13.5 mm diameter FEP tubing) demonstrate that the design allows accurate optical CT imaging, with optical CT measurements agreeing within 3% of independent Beer-Lambert law calculations.

  15. Mass anomalous dimension of Adjoint QCD at large N from twisted volume reduction

    CERN Document Server

    Pérez, Margarita García; Keegan, Liam; Okawa, Masanori

    2015-01-01

    In this work we consider the $SU(N)$ gauge theory with two Dirac fermions in the adjoint representation, in the limit of large $N$. In this limit the infinite-volume physics of this model can be studied by means of the corresponding twisted reduced model defined on a single site lattice. Making use of this strategy we study the reduced model for various values of $N$ up to 289. By analyzing the eigenvalue distribution of the adjoint Dirac operator we test the conformality of the theory and extract the corresponding mass anomalous dimension.

  16. Mass anomalous dimension of adjoint QCD at large N from twisted volume reduction

    Energy Technology Data Exchange (ETDEWEB)

    Pérez, Margarita García [Instituto de Física Teórica UAM-CSIC, Nicolás Cabrera 13-15, Universidad Autónoma de Madrid,E-28049-Madrid (Spain); González-Arroyo, Antonio [Instituto de Física Teórica UAM-CSIC, Nicolás Cabrera 13-15, Universidad Autónoma de Madrid,E-28049-Madrid (Spain); Departamento de Física Teórica, C-XI, Universidad Autónoma de Madrid,E-28049-Madrid (Spain); Keegan, Liam [PH-TH, CERN,CH-1211 Geneva 23 (Switzerland); Okawa, Masanori [Graduate School of Science, Hiroshima University,Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Core of Research for the Energetic Universe, Hiroshima University,Higashi-Hiroshima, Hiroshima 739-8526 (Japan)

    2015-08-07

    In this work we consider the SU(N) gauge theory with two Dirac fermions in the adjoint representation, in the limit of large N. In this limit the infinite-volume physics of this model can be studied by means of the corresponding twisted reduced model defined on a single site lattice. Making use of this strategy we study the reduced model for various values of N up to 289. By analyzing the eigenvalue distribution of the adjoint Dirac operator we test the conformality of the theory and extract the corresponding mass anomalous dimension.

  17. Biological intrusion barriers for large-volume waste-disposal sites

    International Nuclear Information System (INIS)

    Hakonson, T.E.; Cline, J.F.; Rickard, W.H.

    1982-01-01

    intrusion of plants and animals into shallow land burial sites with subsequent mobilization of toxic and radiotoxic materials has occured. Based on recent pathway modeling studies, such intrusions can contribute to the dose received by man. This paper describes past work on developing biological intrusion barrier systems for application to large volume waste site stabilization. State-of-the-art concepts employing rock and chemical barriers are discussed relative to long term serviceability and cost of application. The interaction of bio-intrusion barrier systems with other processes affecting trench cover stability are discussed to ensure that trench cover designs minimize the potential dose to man. 3 figures, 6 tables

  18. Characteristics of the NE-213 large-volume neutron counters for muon catalyzed fusion investigation

    International Nuclear Information System (INIS)

    Bystritsky, V.M.; Wozniak, J.; Zinov, V.G.

    1984-01-01

    The Monte-Carlo method was used to establish the properties and feasibility of a large-volume NE-213 scin illator as an efficient neutron detector. The recoil proton spectra, calculated efficiencies for different detection thresholds and scintillator sizes are presented for the neutron energy up to 15 MeV. The time characteristics, e. g., time resolution, are discussed. It is also shown that no strong influence of light attenuation by the scintilla or itself on calculated efficiencies is observed, when gamma-calibration technique is used. The detector vol me of approximately 100 l is suggested for application in investigations of μ-atom and μ-molecular processes

  19. Fan-beam scanning laser optical computed tomography for large volume dosimetry

    International Nuclear Information System (INIS)

    Dekker, K H; Battista, J J; Jordan, K J

    2017-01-01

    A prototype scanning-laser fan beam optical CT scanner is reported which is capable of high resolution, large volume dosimetry with reasonable scan time. An acylindrical, asymmetric aquarium design is presented which serves to 1) generate parallel-beam scan geometry, 2) focus light towards a small acceptance angle detector, and 3) avoid interference fringe-related artifacts. Preliminary experiments with uniform solution phantoms (11 and 15 cm diameter) and finger phantoms (13.5 mm diameter FEP tubing) demonstrate that the design allows accurate optical CT imaging, with optical CT measurements agreeing within 3% of independent Beer-Lambert law calculations. (paper)

  20. Assessment of vasodilator therapy in patients with severe congestive heart failure: limitations of measurements of left ventricular ejection fraction and volumes

    International Nuclear Information System (INIS)

    Firth, B.G.; Dehmer, G.J.; Markham, R.V. Jr.; Willerson, J.T.; Hillis, L.D.

    1982-01-01

    Although noninvasive techniques are often used to assess the effect of vasodilator therapy in patients with congestive heart failure, it is unknown whether changes in noninvasively determined left ventricular ejection fraction, volume, or dimension reliably reflect alterations in intracardiac pressure and flow. Accordingly, we compared the acute effect of sodium nitroprusside on left ventricular volume and ejection fraction (determined scintigraphically) with its effect on intracardiac pressure and forward cardiac index (determined by thermodilution) in 12 patients with severe, chronic congestive heart failure and a markedly dilated left ventricle. Nitroprusside (infused at 1.3 +/- 1.1 [mean +/- standard deviation] microgram/kg/min) caused a decrease in mean systemic arterial, mean pulmonary arterial, and mean pulmonary capillary wedge pressure as well as a concomitant increase in forward cardiac index. Simultaneously, left ventricular end-diastolic and end-systolic volume indexes decreased, but the scintigraphically determined cardiac index did not change significantly. Left ventricular ejection fraction averaged 0.19 +/- 0.05 before nitroprusside administration and increased by less than 0.05 units in response to nitroprusside in 11 of 12 patients. The only significant correlation between scintigraphically and invasively determined variables was that between the percent change in end-diastolic volume index and the percent change in pulmonary capillary wedge pressure (r . 0.68, p . 0.01). Although nitroprusside produced changes in scintigraphically determined left ventricular ejection fraction, end-systolic volume index, and cardiac index, these alterations bore no predictable relation to changes in intracardiac pressure, forward cardiac index, or vascular resistance. Furthermore, nitroprusside produced a considerably greater percent change in the invasively measured variables than in the scintigraphically determined ones

  1. Calculation of left ventricular volumes and ejection fraction from dynamic cardiac-gated 15O-water PET/CT: 5D-PET.

    Science.gov (United States)

    Nordström, Jonny; Kero, Tanja; Harms, Hendrik Johannes; Widström, Charles; Flachskampf, Frank A; Sörensen, Jens; Lubberink, Mark

    2017-11-14

    Quantitative measurement of myocardial blood flow (MBF) is of increasing interest in the clinical assessment of patients with suspected coronary artery disease (CAD). 15 O-water positron emission tomography (PET) is considered the gold standard for non-invasive MBF measurements. However, calculation of left ventricular (LV) volumes and ejection fraction (EF) is not possible from standard 15 O-water uptake images. The purpose of the present work was to investigate the possibility of calculating LV volumes and LVEF from cardiac-gated parametric blood volume (V B ) 15 O-water images and from first pass (FP) images. Sixteen patients with mitral or aortic regurgitation underwent an eight-gate dynamic cardiac-gated 15 O-water PET/CT scan and cardiac MRI. V B and FP images were generated for each gate. Calculations of end-systolic volume (ESV), end-diastolic volume (EDV), stroke volume (SV) and LVEF were performed with automatic segmentation of V B and FP images, using commercially available software. LV volumes and LVEF were calculated with surface-, count-, and volume-based methods, and the results were compared with gold standard MRI. Using V B images, high correlations between PET and MRI ESV (r = 0.89, p  0.86, p dynamic 15 O-water PET is feasible and shows good correlation with MRI. However, the analysis method is laborious, and future work is needed for more automation to make the method more easily applicable in a clinical setting.

  2. Fractional thermoelasticity

    CERN Document Server

    Povstenko, Yuriy

    2015-01-01

    This book is devoted to fractional thermoelasticity, i.e. thermoelasticity based on the heat conduction equation with differential operators of fractional order. Readers will discover how time-fractional differential operators describe memory effects and space-fractional differential operators deal with the long-range interaction. Fractional calculus, generalized Fourier law, axisymmetric and central symmetric problems and many relevant equations are featured in the book. The latest developments in the field are included and the reader is brought up to date with current research.  The book contains a large number of figures, to show the characteristic features of temperature and stress distributions and to represent the whole spectrum of order of fractional operators.  This work presents a picture of the state-of-the-art of fractional thermoelasticity and is suitable for specialists in applied mathematics, physics, geophysics, elasticity, thermoelasticity and engineering sciences. Corresponding sections of ...

  3. K$^{-}$ over K$^{+}$ multiplicity ratio for kaons produced in DIS with a large fraction of the virtual-photon energy

    CERN Document Server

    Akhunzyanov, R.; The COMPASS collaboration; Alexeev, G.D.; Amoroso, A.; Andrieux, V.; Anfimov, N.V.; Anosov, V.; Antoshkin, A.; Augsten, K.; Augustyniak, W.; Austregesilo, A.; Azevedo, C.D.R.; Badełek, B.; Balestra, F.; Ball, M.; Barth, J.; Beck, R.; Bedfer, Y.; Bernhard, J.; Bicker, K.; Bielert, E.R.; Birsa, R.; Bodlak, M.; Bordalo, P.; Bradamante, F.; Bressan, A.; Büchele, M.; Burtsev, V.E.; Capozza, L.; Chang, W.-C.; Chatterjee, C.; Chiosso, M.; Chumakov, A.G.; Chung, S.-U.; Cicuttin, A.; Crespo, M.L.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S.S.; Dasgupta, S.; Denisov, O.Yu.; Dhara, L.; Donskov, S.V.; Doshita, N.; Dreisbach, Ch.; Dünnweber, W.; Dusaev, R.R.; Dziewiecki, M.; Efremov, A.; Eversheim, P.D.; Faessler, M.; Ferrero, A.; Finger, M.; jr., M.Finger; Fischer, H.; Franco, C.; du Fresne von Hohenesche, N.; Friedrich, J.M.; Frolov, V.; Gautheron, F.; Gavrichtchouk, O.P.; Gerassimov, S.; Giarra, J.; Gnesi, I.; Gorzellik, M.; Grasso, A.; Gridin, A.; Grosse Perdekamp, M.; Grube, B.; Guskov, A.; Hahne, D.; Hamar, G.; von Harrach, D.; Heitz, R.; Herrmann, F.; Horikawa, N.; d'Hose, N.; Hsieh, C.-Y.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jary, V.; Joosten, R.; Jörg, P.; Kabuß, E.; Kerbizi, A.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu.A.; Kisselev, Yu.; Klein, F.; Koivuniemi, J.H.; Kolosov, V.N.; Kondo, K.; Konorov, I.; Konstantinov, V.F.; Kotzinian, A.M.; Kouznetsov, O.M.; Kral, Z.; Krämer, M.; Krinner, F.; Kroumchtein, Z.V.; Kulinich, Y.; Kunne, F.; Kurek, K.; Kurjata, R.P.; Kuznetsov, I.I.; Kveton, A.; Lednev, A.A.; Levchenko, E.A.; Levorato, S.; Lian, Y.-S.; Lichtenstadt, J.; Longo, R.; Lyubovitskij, V.E.; Maggiora, A.; Magnon, A.; Makins, N.; Makke, N.; Mallot, G.K.; Mamon, S.A.; Marchand, C.; Marianski, B.; Martin, A.; Marzec, J.; Matoušek, J.; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.V.; Meyer, M.; Meyer, W.; Mikhailov, Yu.V.; Mikhasenko, M.; Mitrofanov, E.; Mitrofanov, N.; Miyachi, Y.; Moretti, A.; Nagaytsev, A.; Nerling, F.; Neyret, D.; Nový, J.; Nowak, W.-D.; Nukazuka, G.; Nunes, A.S.; Olshevsky, A.G.; Orlov, I.; Ostrick, M.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peng, J.-C.; Pereira, F.; Pesaro, G.; Pešek, M.; Pešková, M.; Peshekhonov, D.V.; Pierre, N.; Platchkov, S.; Pochodzalla, J.; Polyakov, V.A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Riedl, C.; Ryabchikov, D.I.; Rybnikov, A.; Rychter, A.; Salac, R.; Samoylenko, V.D.; Sandacz, A.; Sarkar, S.; Savin, I.A.; Sawada, T.; Sbrizzai, G.; Schiavon, P.; Schmieden, H.; Seder, E.; Selyunin, A.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sozzi, F.; Smolik, J.; Srnka, A.; Steffen, D.; Stolarski, M.; Subrt, O.; Sulc, M.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Tasevsky, M.; Tessaro, S.; Tessarotto, F.; Thiel, A.; Tomsa, J.; Tosello, F.; Tskhay, V.; Uhl, S.; Vasilishin, B.I.; Vauth, A.; Veit, B.M.; Veloso, J.; Vidon, A.; Virius, M.; Wallner, S.; Wilfert, M.; Windmolders, R.; Zaremba, K.; Zavada, P.; Zavertyaev, M.; Zemlyanichkina, E.; Zhuravlev, N.; Ziembicki, M.

    2018-01-01

    The K$^{-}$ over K$^{+}$ multiplicity ratio is measured in deep-inelastic scattering, for the first time for kaons carrying a large fraction $z$ of the virtual-photon energy. The data were obtained by the COMPASS collaboration using a 160 GeV muon beam and an isoscalar $^6$LiD target. The regime of deep-inelastic scattering is ensured by requiring $Q^2>1$ (GeV/$c)^2$ for the photon virtuality and $W>5$ GeV/$c^2$ for the invariant mass of the produced hadronic system. Kaons are identified in the momentum range from 12 GeV/$c$ to 40 GeV/$c$, thereby restricting the range in Bjorken-$x$ to $0.010.75$. For very large values of $z$, $i.e.$ $z>0.8$, the results contradict expectations obtained using the formalism of (next-to-)leading order perturbative quantum chromodynamics. This may imply that cross-section factorisation or/and universality of (kaon) fragmentation functions do not hold. Our studies suggest that within this formalism an additional correction may be required, which takes into account th...

  4. Electro-mechanical probe positioning system for large volume plasma device

    Science.gov (United States)

    Sanyasi, A. K.; Sugandhi, R.; Srivastava, P. K.; Srivastav, Prabhakar; Awasthi, L. M.

    2018-05-01

    An automated electro-mechanical system for the positioning of plasma diagnostics has been designed and implemented in a Large Volume Plasma Device (LVPD). The system consists of 12 electro-mechanical assemblies, which are orchestrated using the Modbus communication protocol on 4-wire RS485 communications to meet the experimental requirements. Each assembly has a lead screw-based mechanical structure, Wilson feed-through-based vacuum interface, bipolar stepper motor, micro-controller-based stepper drive, and optical encoder for online positioning correction of probes. The novelty of the system lies in the orchestration of multiple drives on a single interface, fabrication and installation of the system for a large experimental device like the LVPD, in-house developed software, and adopted architectural practices. The paper discusses the design, description of hardware and software interfaces, and performance results in LVPD.

  5. SDSS Log Viewer: visual exploratory analysis of large-volume SQL log data

    Science.gov (United States)

    Zhang, Jian; Chen, Chaomei; Vogeley, Michael S.; Pan, Danny; Thakar, Ani; Raddick, Jordan

    2012-01-01

    User-generated Structured Query Language (SQL) queries are a rich source of information for database analysts, information scientists, and the end users of databases. In this study a group of scientists in astronomy and computer and information scientists work together to analyze a large volume of SQL log data generated by users of the Sloan Digital Sky Survey (SDSS) data archive in order to better understand users' data seeking behavior. While statistical analysis of such logs is useful at aggregated levels, efficiently exploring specific patterns of queries is often a challenging task due to the typically large volume of the data, multivariate features, and data requirements specified in SQL queries. To enable and facilitate effective and efficient exploration of the SDSS log data, we designed an interactive visualization tool, called the SDSS Log Viewer, which integrates time series visualization, text visualization, and dynamic query techniques. We describe two analysis scenarios of visual exploration of SDSS log data, including understanding unusually high daily query traffic and modeling the types of data seeking behaviors of massive query generators. The two scenarios demonstrate that the SDSS Log Viewer provides a novel and potentially valuable approach to support these targeted tasks.

  6. A retrospective analysis of complications of large volume liposuction; local perspective from a third world country

    International Nuclear Information System (INIS)

    Arshad, S.M.; Latif, S.; Altaf, H.N.

    2017-01-01

    This study was aimed at evaluating the complications that occurred in patients undergoing large volume liposuction and to see if there was a correlation between amount of aspirate and the rate of complications. Methodology: A detailed history, complete physical examination, BMI, and anthropometric measurements were documented for all patients. All patients under went liposuction using tumescent technique under general anesthesia in Yusra General Hospital. Patients were discharged home after 24 to 48 hours. Pressure garments were advised for 6 weeks and were called for weekly follow up for 6 weeks. Pressure garments were advised for 6 weeks. Complications were documented. SPSS version 20 was used for analysis of data. Results: Out of 217 patients, 163 (75%) were female and 54 male. Mean age was 37.1 SD+-6.7 years. Bruising and seroma were most common complications; 4.1% and 2.3%, respectively. The incidence of infection was 0.9%. One patient had over-correction and four patients (1.8%) had under-correction. Significant blood loss was encountered in one patient. Two patients (0.9%) had pulmonary embolism and 2(0.9%) suffered from necrotizing fasciitis. None of our patients undergoing large volume liposuction had fat embolism and there was no mortality. Conclusion: Careful patient selection and strict adherence to guidelines can ensure a good outcome and can minimize risk of complications. Both physicians and patients should be educated to have realistic expectations to avoid complications and improve patient safety. (author)

  7. Broadband frequency ECR ion source concepts with large resonant plasma volumes

    International Nuclear Information System (INIS)

    Alton, G.D.

    1995-01-01

    New techniques are proposed for enhancing the performances of ECR ion sources. The techniques are based on the use of high-power, variable-frequency, multiple-discrete-frequency, or broadband microwave radiation, derived from standard TWT technology, to effect large resonant ''volume'' ECR sources. The creation of a large ECR plasma ''volume'' permits coupling of more power into the plasma, resulting in the heating of a much larger electron population to higher energies, the effect of which is to produce higher charge state distributions and much higher intensities within a particular charge state than possible in present forms of the ECR ion source. If successful, these developments could significantly impact future accelerator designs and accelerator-based, heavy-ion-research programs by providing multiply-charged ion beams with the energies and intensities required for nuclear physics research from existing ECR ion sources. The methods described in this article can be used to retrofit any ECR ion source predicated on B-minimum plasma confinement techniques

  8. Colloids Versus Albumin in Large Volume Paracentesis to Prevent Circulatory Dysfunction: Evidence-based Case Report.

    Science.gov (United States)

    Widjaja, Felix F; Khairan, Paramita; Kamelia, Telly; Hasan, Irsan

    2016-04-01

    Large volume paracentesis may cause paracentesis induced circulatory dysfunction (PICD). Albumin is recommended to prevent this abnormality. Meanwhile, the price of albumin is too expensive and there should be another alternative that may prevent PICD. This report aimed to compare albumin to colloids in preventing PICD. Search strategy was done using PubMed, Scopus, Proquest, dan Academic Health Complete from EBSCO with keywords of "ascites", "albumin", "colloid", "dextran", "hydroxyethyl starch", "gelatin", and "paracentesis induced circulatory dysfunction". Articles was limited to randomized clinical trial and meta-analysis with clinical question of "In hepatic cirrhotic patient undergone large volume paracentesis, whether colloids were similar to albumin to prevent PICD". We found one meta-analysis and four randomized clinical trials (RCT). A meta analysis showed that albumin was still superior of which odds ratio 0.34 (0.23-0.51). Three RCTs showed the same results and one RCT showed albumin was not superior than colloids. We conclude that colloids could not constitute albumin to prevent PICD, but colloids still have a role in patient who undergone paracentesis less than five liters.

  9. Capillary gas chromatographic analysis of nerve agents using large volume injections. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Deinum, T.; Nieuwenhuy, C.

    1994-11-01

    The procedure developed at TNO-Prins Maurits Laboratory (TNO-PML) for the verification of intact organophosphorus chemical warfare agents in water samples was improved. The last step in this procedure, the laborious and non-reproducible transfer of an ethyl acetate extract onto a Tenax-adsorption tube followed by thermal desorption of the Tenax-tube, was replaced by large volume injection of the extract onto a capillary gas chromatographic system. The parameters controlling the injection of a large volume of an extract (200 ul) were investigated and optimized. As ethyl acetate caused severe problems, potential new solvents were evaluated. With the improved procedure, the nerve agents sarin, tabun, soman, diisopropyl fluorophosphate (DFP) and VX could be determined in freshly prepared water samples at pg/ml (ppt) levels. The fate of the nerve agents under study in water at two pH`s (4.8 and 6) was investigated. For VX, the pH should be adjusted before extraction. Moreover, it is worthwhile to acidify water samples to diminish hydrolysis.

  10. About the use of the Monte-Carlo code based tracing algorithm and the volume fraction method for S n full core calculations

    Energy Technology Data Exchange (ETDEWEB)

    Gurevich, M. I.; Oleynik, D. S. [RRC Kurchatov Inst., Kurchatov Sq., 1, 123182, Moscow (Russian Federation); Russkov, A. A.; Voloschenko, A. M. [Keldysh Inst. of Applied Mathematics, Miusskaya Sq., 4, 125047, Moscow (Russian Federation)

    2006-07-01

    The tracing algorithm that is implemented in the geometrical module of Monte-Carlo transport code MCU is applied to calculate the volume fractions of original materials by spatial cells of the mesh that overlays problem geometry. In this way the 3D combinatorial geometry presentation of the problem geometry, used by MCU code, is transformed to the user defined 2D or 3D bit-mapped ones. Next, these data are used in the volume fraction (VF) method to approximate problem geometry by introducing additional mixtures for spatial cells, where a few original materials are included. We have found that in solving realistic 2D and 3D core problems a sufficiently fast convergence of the VF method takes place if the spatial mesh is refined. Virtually, the proposed variant of implementation of the VF method seems as a suitable geometry interface between Monte-Carlo and S{sub n} transport codes. (authors)

  11. Characterization of the evolution of the volume fraction of precipitates in aged AlMgSiCu alloys using DSC technique

    International Nuclear Information System (INIS)

    Esmaeili, Shahrzad; Lloyd, David J.

    2005-01-01

    Differential scanning calorimetry is used to quantify the evolution of the volume fraction of precipitates during age hardening in AlMgSiCu alloys. The calorimetry tests are run on alloy samples after aging for various times at 180 deg. C and the change in the collective heat effects from the major precipitation and dissolution processes in each run are used to determine the precipitation state of the samples. The method is implemented on alloys with various thermal histories prior to artificial aging, including commercial pre-aging histories. The estimated values for the relative volume fraction of precipitates are compared with the results from a newly developed analytical method using isothermal calorimetry and a related quantitative transmission electron microscopy work. Excellent agreement is obtained between the results from various methods

  12. Variability of left ventricular ejection fraction and volumes with quantitative gated SPECT: influence of algorithm, pixel size and reconstruction parameters in small and normal-sized hearts

    International Nuclear Information System (INIS)

    Hambye, Anne-Sophie; Vervaet, Ann; Dobbeleir, Andre

    2004-01-01

    Several software packages are commercially available for quantification of left ventricular ejection fraction (LVEF) and volumes from myocardial gated single-photon emission computed tomography (SPECT), all of which display a high reproducibility. However, their accuracy has been questioned in patients with a small heart. This study aimed to evaluate the performances of different software and the influence of modifications in acquisition or reconstruction parameters on LVEF and volume measurements, depending on the heart size. In 31 patients referred for gated SPECT, 64 2 and 128 2 matrix acquisitions were consecutively obtained. After reconstruction by filtered back-projection (Butterworth, 0.4, 0.5 or 0.6 cycles/cm cut-off, order 6), LVEF and volumes were computed with different software [three versions of Quantitative Gated SPECT (QGS), the Emory Cardiac Toolbox (ECT) and the Stanford University (SU-Segami) Medical School algorithm] and processing workstations. Depending upon their end-systolic volume (ESV), patients were classified into two groups: group I (ESV>30 ml, n=14) and group II (ESV 2 to 128 2 were associated with significantly larger volumes as well as lower LVEF values. Increasing the filter cut-off frequency had the same effect. With SU-Segami, a larger matrix was associated with larger end-diastolic volumes and smaller ESVs, resulting in a highly significant increase in LVEF. Increasing the filter sharpness, on the other hand, had no influence on LVEF though the measured volumes were significantly larger. (orig.)

  13. Large volume recycling of oceanic lithosphere over short time scales: geochemical constraints from the Caribbean Large Igneous Province

    Science.gov (United States)

    Hauff, F.; Hoernle, K.; Tilton, G.; Graham, D. W.; Kerr, A. C.

    2000-01-01

    isochron diagrams suggests that the age of separation of enriched and depleted components from the depleted MORB source mantle could have been ≤500 Ma before CLIP formation and interpreted to reflect the recycling time of the CLIP source. Mantle plume heads may provide a mechanism for transporting large volumes of possibly young recycled oceanic lithosphere residing in the lower mantle back into the shallow MORB source mantle.

  14. Comparison of automatic quantification software for the measurement of ventricular volume and ejection fraction in gated myocardial perfusion SPECT

    International Nuclear Information System (INIS)

    Van Staden, J.A.; Herbst, C.P.; Du Raan, H.; Lotter, M.G.; Otto, A.C.

    2004-01-01

    Full text: Introduction: Gated myocardial perfusion SPECT has been used to calculate left ventricular ejection fraction (LVEF) and left ventricular end-diastolic volume (LVEDV) and has correlated well with conventional methods. However, the comparative accuracy of and correlations across various types of gated SPECT software are not well understood. Materials and methods: Twelve patients participated in a radionuclide gated blood-pool (GBP) study in addition to undergoing 99m Tc-sestamibi gated SPECT. Three different software algorithms, Quantitative Gated SPECT (QGS) from Cedars-Sinai, MultiDim from Stanford University Medical School and GQUANT from Alfa Nuclear were used to compute LVEF and LVEDV. These software algorithms operate in 3-dimensional space, two dependent on surface detection and the other on statistical parameters. The LVEF as calculated from gated SPECT myocardial perfusion images were compared with LVEF calculated from the GBP studies in the same patients to assess accuracy of the three software algorithms. Results: The software success-rate was 92% (11/12 pts) for MultiDim and 100% for the QGS and GQUANT. Agreement between LVEF measured with MultiDim and QGS, MultiDim and GQUANT and QGS and GQUANT were excellent (LVEF-MuItidim 0.80 LVEF QGS +5.02, r = 0.93, LVEF GQUANT = 1.10 LVEF MuItidim -1.33, r 0.90 and LVEF GQUANT = 1.02 LVEF QGS -1.40, r = 0.96). The correlation coefficient for LVEF between gated SPECT and the GBP study was 0.95, 0.95 and 0.97, for MultiDim, GQUANT and QGS, respectively. Conclusion: All 3 software programs showed good correlation between LVEF for gated SPECT and the GBP study. Good agreement for LVEF was observed also between the three software algorithms. However, because each method has unique characteristics that depend on its specific algorithm and thus behaves differently in the various patients, the methods should not be used interchangeably. (author)

  15. Calculation of left ventricular volumes and ejection fraction from dynamic cardiac-gated 15O-water PET/CT: 5D-PET

    OpenAIRE

    Jonny Nordström; Tanja Kero; Hendrik Johannes Harms; Charles Widström; Frank A. Flachskampf; Jens Sörensen; Mark Lubberink

    2017-01-01

    BACKGROUND: Quantitative measurement of myocardial blood flow (MBF) is of increasing interest in the clinical assessment of patients with suspected coronary artery disease (CAD). (15)O-water positron emission tomography (PET) is considered the gold standard for non-invasive MBF measurements. However, calculation of left ventricular (LV) volumes and ejection fraction (EF) is not possible from standard (15)O-water uptake images. The purpose of the present work was to investigate the possibility...

  16. Large electrically induced height and volume changes in poly(3,4- ethylenedioxythiophene) /poly(styrenesulfonate) thin films

    NARCIS (Netherlands)

    Charrier, D.S.H.; Janssen, R.A.J.; Kemerink, M.

    2010-01-01

    We demonstrate large, partly reversible height and volume changes of thin films of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS) on the anode of interdigitating gold electrodes under ambient conditions by applying an electrical bias. The height and volume changes were monitored

  17. [Effect of SO2 volume fraction in flue gas on the adsorption behaviors adsorbed by ZL50 activated carbon and kinetic analysis].

    Science.gov (United States)

    Gao, Ji-xian; Wang, Tie-feng; Wang, Jin-fu

    2010-05-01

    The influence of SO2 dynamic adsorption behaviors using ZL50 activated carbon for flue gas desulphurization and denitrification under different SO2 volume fraction was investigated experimentally, and the kinetic analysis was conducted by kinetic models. With the increase of SO2 volume fraction in flue gas, the SO2 removal ratio and the activity ratio of ZL50 activated carbon decreased, respectively, and SO2 adsorption rate and capacity increased correspondingly. The calculated results indicate that Bangham model has the best prediction effect, the chemisorption processes of SO2 was significantly affected by catalytic oxidative reaction. The adsorption rate constant of Lagergren's pseudo first order model increased with the increase of inlet SO, volume fraction, which indicated that catalytic oxidative reaction of SO2 adsorbed by ZL50 activated carbon may be the rate controlling step in earlier adsorption stage. The Lagergren's and Bangham's initial adsorption rate were deduced and defined, respectively. The Ho's and Elovich's initial adsorption rate were also deduced in this paper. The Bangham's initial adsorption rate values were defined in good agreement with those of experiments. The defined Bangham's adsorptive reaction kinetic model can describe the SO2 dynamic adsorption rate well. The studied results indicated that the SO2 partial order of initial reaction rate was one or adjacent to one, while the O2 and water vapor partial order of initial reaction rate were constants ranging from 0.15-0.20 and 0.45-0.50, respectively.

  18. The effect of the volume fraction and viscosity on the compression and tension behavior of the cobalt-ferrite magneto-rheological fluids

    Directory of Open Access Journals (Sweden)

    H. Shokrollahi

    2016-03-01

    Full Text Available The purpose of this work is to investigate the effects of the volume fraction and bimodal distribution of solid particles on the compression and tension behavior of the Co-ferrite-based magneto-rheological fluids (MRFs containing silicon oil as a carrier. Hence, Co-ferrite particles (CoFe2O4 with two various sizes were synthesized by the chemical co-precipitation method and mixed so as to prepare the bimodal MRF. The X-Ray Diffraction (XRD analysis, Fourier Transform Infrared Spectroscopy (FTIR, Laser Particle Size Analysis (LPSA and Vibrating Sample Magnetometer (VSM were conducted to examine the structural and magnetic properties, respectively. The results indicated that the increase of the volume fraction has a direct increasing influence on the values of the compression and tension strengths of fluids. In addition, the compression and tension strengths of the mixed MRF sample (1.274 and 0.647 MPa containing 60 and 550 nm samples were higher than those of the MRF sample with the same volume fraction and uniform particle size of 550 nm.

  19. Study on the detection of three-dimensional soot temperature and volume fraction fields of a laminar flame by multispectral imaging system

    International Nuclear Information System (INIS)

    Ni, Mingjiang; Zhang, Haidan; Wang, Fei; Xie, Zhengchao; Huang, Qunxing; Yan, Jianhua; Cen, Kefa

    2016-01-01

    Highlights: • Multispectral flame images were used to reconstruct the soot temperature and volume fraction. • The proposed multi-wavelength method and the original two-color method were compared. • The effect of signal to noise ratio (SNR) was discussed. • The best number of selected wavelengths was determined to be 6–11. - Abstract: Charge-coupled device (CCD) cameras with liquid crystal tunable filters (LCTF) were introduced to capture the multispectral flame images for obtaining the line-of-sight radiation intensities. A least square QR decomposition method was applied to solve the reconstruction matrix equation and obtain the multi-wavelength local emission distributions from which temperature and volume fraction profiles can be retrieved. Compared with the original two-color method, the use of a wide range of spectral data was proved to be capable of reducing the reconstruction error. Reconstruction results of the two methods with different signal to noise ratio (SNR) were discussed. The effect of selected wavelength number is analyzed and the best number is determined to be in the range of 6–11. The proposed multispectral imaging system was verified to be feasible for the reconstruction of temperature and soot volume fraction distributions according to the experimental measurement results.

  20. System of large transport containers for waste from dismantling light water and gas-cooled nuclear reactors. Volume 2

    International Nuclear Information System (INIS)

    Price, M.S.T.; Lafontaine, I.

    1985-01-01

    The purpose of this volume is to assess the means of transportation of decommissioning wastes, costs of transport, radiological detriment attributable to transport and develops conceptual designs of large transport containers. The document ends with Conclusions and Recommendations

  1. Estimation of the algal-available phosphorus pool in sediments of a large, shallow eutrophic lake (Taihu, China) using profiled SMT fractional analysis

    International Nuclear Information System (INIS)

    Zhu Mengyuan; Zhu Guangwei; Li Wei; Zhang Yunlin; Zhao Linlin; Gu Zhao

    2013-01-01

    Because large, shallow lakes are heavily influenced by wind–wave disturbance, it is difficult to estimate internal phosphorus load using traditional methods. To estimate the potential contribution of phosphorus from sediment to overlying water in eutrophic Lake Taihu, phosphorus fractions of surface and deep layer sediments were quantified and analyzed for algal bloom potential using a Standard Measurements and Testing (SMT) sequential extraction method and incubation experiments. Phosphorus bound to Fe, Al and Mn oxides and hydroxides (Fe–P) and organic phosphorus (OP) were to be found bioactive. The difference in Fe–P and OP contents between surface and deep layers equates to the sediment pool of potentially algal-available phosphorus. This pool was estimated at 5168 tons for the entire lake and was closely related to pollution input and algal blooms. Profiled SMT fractionation analysis is thus a potentially useful tool for estimating internal phosphorus loading in large, shallow lakes. - Highlights: ► We used profiled sediment P activity by SMT fractionation to evaluate the P release potential in large and shallow lakes. ► We built the relationship between sediment SMT fractionations of P and the P release by algal bloom degradation process. ► We discussed the supporting mechanism of sediment P release to Microcystis algal bloom in a large and shallow lake. ► We discussed the nutrient control strategy of algal bloom in shallow lakes in highly human activities disturbance catchment. - Profiled SMT fractional analysis of internal phosphorus pool in large, shallow lake.

  2. Safe total corporal contouring with large-volume liposuction for the obese patient.

    Science.gov (United States)

    Dhami, Lakshyajit D; Agarwal, Meenakshi

    2006-01-01

    The advent of the tumescent technique in 1987 allowed for safe total corporal contouring as an ambulatory, single-session megaliposuction with the patient under regional anesthesia supplemented by local anesthetic only in selected areas. Safety and aesthetic issues define large-volume liposuction as having a 5,000-ml aspirate, mega-volume liposuction as having an 8,000-ml aspirate, and giganto-volume liposuction as having an aspirate of 12,000 ml or more. Clinically, a total volume comprising 5,000 ml of fat and wetting solution aspirated during the procedure qualifies for megaliposuction/large-volume liposuction. Between September 2000 and August 2005, 470 cases of liposuction were managed. In 296 (63%) of the 470 cases, the total volume of aspirate exceeded 5 l (range, 5,000-22,000 ml). Concurrent limited or total-block lipectomy was performed in 70 of 296 cases (23.6%). Regional anesthesia with conscious sedation was preferred, except where liposuction targeted areas above the subcostal region (the upper trunk, lateral chest, gynecomastia, breast, arms, and face), or when the patient so desired. Tumescent infiltration was achieved with hypotonic lactated Ringer's solution, adrenalin, triamcinalone, and hyalase in all cases during the last one year of the series. This approach has clinically shown less tissue edema in the postoperative period than with conventional physiologic saline used in place of the Ringer's lactate solution. The amount injected varied from 1,000 to 8,000 ml depending on the size, site, and area. Local anesthetic was included only for the terminal portion of the tumescent mixture, wherever the subcostal regions were infiltrated. The aspirate was restricted to the unstained white/yellow fat, and the amount of fat aspirated did not have any bearing on the amount of solution infiltrated. There were no major complications, and no blood transfusions were administered. The hospital stay ranged from 8 to 24 h for both liposuction and liposuction

  3. Large volume serial section tomography by Xe Plasma FIB dual beam microscopy.

    Science.gov (United States)

    Burnett, T L; Kelley, R; Winiarski, B; Contreras, L; Daly, M; Gholinia, A; Burke, M G; Withers, P J

    2016-02-01

    Ga(+) Focused Ion Beam-Scanning Electron Microscopes (FIB-SEM) have revolutionised the level of microstructural information that can be recovered in 3D by block face serial section tomography (SST), as well as enabling the site-specific removal of smaller regions for subsequent transmission electron microscope (TEM) examination. However, Ga(+) FIB material removal rates limit the volumes and depths that can be probed to dimensions in the tens of microns range. Emerging Xe(+) Plasma Focused Ion Beam-Scanning Electron Microscope (PFIB-SEM) systems promise faster removal rates. Here we examine the potential of the method for large volume serial section tomography as applied to bainitic steel and WC-Co hard metals. Our studies demonstrate that with careful control of milling parameters precise automated serial sectioning can be achieved with low levels of milling artefacts at removal rates some 60× faster. Volumes that are hundreds of microns in dimension have been collected using fully automated SST routines in feasible timescales (<24h) showing good grain orientation contrast and capturing microstructural features at the tens of nanometres to the tens of microns scale. Accompanying electron back scattered diffraction (EBSD) maps show high indexing rates suggesting low levels of surface damage. Further, under high current Ga(+) FIB milling WC-Co is prone to amorphisation of WC surface layers and phase transformation of the Co phase, neither of which have been observed at PFIB currents as high as 60nA at 30kV. Xe(+) PFIB dual beam microscopes promise to radically extend our capability for 3D tomography, 3D EDX, 3D EBSD as well as correlative tomography. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  4. Volume changes of extremely large and giant intracranial aneurysms after treatment with flow diverter stents

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Angelo; Byrne, James V. [ohn Radcliffe Hospital, Oxford Neurovascular and Neuroradiology Research Unit, Nuffield Department of Surgical Sciences, Oxford (United Kingdom); Rane, Neil; Kueker, Wilhelm; Cellerini, Martino; Corkill, Rufus [John Radcliffe Hospital, Department of Neuroradiology, Oxford (United Kingdom)

    2014-01-15

    This study assessed volume changes of unruptured large and giant aneurysms (greatest diameter >20 mm) after treatment with flow diverter (FD) stents. Clinical audit of the cases treated in a single institution, over a 5-year period. Demographic and clinical data were retrospectively collected from the hospital records. Aneurysm volumes were measured by manual outlining at sequential slices using computerised tomography (CT) or magnetic resonance (MR) angiography data. The audit included eight patients (seven females) with eight aneurysms. Four aneurysms involved the cavernous segment of the internal carotid artery (ICA), three the supraclinoid ICA and one the basilar artery. Seven patients presented with signs and symptoms of mass effect and one with seizures. All but one aneurysm was treated with a single FD stent; six aneurysms were also coiled (either before or simultaneously with FD placement). Minimum follow-up time was 6 months (mean 20 months). At follow-up, three aneurysms decreased in size, three were unchanged and two increased. Both aneurysms that increased in size showed persistent endosaccular flow at follow-up MR; in one case, failure was attributed to suboptimal position of the stent; in the other case, it was attributed to persistence of a side branch originating from the aneurysm (similar to the endoleak phenomenon of aortic aneurysms). At follow-up, five aneurysms were completely occluded; none of these increased in volume. Complete occlusion of the aneurysms leads, in most cases, to its shrinkage. In cases of late aneurysm growth or regrowth, consideration should be given to possible endoleak as the cause. (orig.)

  5. Tumor Volume Decrease via Feeder Occlusion for Treating a Large, Firm Trigone Meningioma.

    Science.gov (United States)

    Nakashima, Takuma; Hatano, Norikazu; Kanamori, Fumiaki; Muraoka, Shinsuke; Kawabata, Teppei; Takasu, Syuntaro; Watanabe, Tadashi; Kojima, Takao; Nagatani, Tetsuya; Seki, Yukio

    2018-01-01

    Trigone meningiomas are considered a surgical challenge, as they tend to be considerably large and hypervascularized at the time of presentation. We experienced a case of a large and very hard trigone meningioma that was effectively treated using initial microsurgical feeder occlusion followed by surgery in stages. A 19-year-old woman who presented with loss of consciousness was referred to our hospital for surgical treatment of a brain tumor. Radiological findings were compatible with a left ventricular trigone meningioma extending laterally in proximity to the Sylvian fissure. At initial surgery using the transsylvian approach, main feeders originating from the anterior and lateral posterior choroidal arteries were occluded at the inferior horn; however, only a small section of the tumor could initially be removed because of its firmness. Over time, feeder occlusion resulted in tumor necrosis and a 20% decrease in its diameter; the mass effect was alleviated within 1 year. The residual meningioma was then totally excised in staged surgical procedures after resection became more feasible owing to ischemia-induced partial softening of the tumor. When a trigone meningioma is large and very hard, initial microsurgical feeder occlusion in the inferior horn can be a safe and effective option, and can lead to necrosis, volume decrease, and partial softening of the residual tumor to allow for its staged surgical excision.

  6. A large volume uniform plasma generator for the experiments of electromagnetic wave propagation in plasma

    International Nuclear Information System (INIS)

    Yang Min; Li Xiaoping; Xie Kai; Liu Donglin; Liu Yanming

    2013-01-01

    A large volume uniform plasma generator is proposed for the experiments of electromagnetic (EM) wave propagation in plasma, to reproduce a “black out” phenomenon with long duration in an environment of the ordinary laboratory. The plasma generator achieves a controllable approximate uniform plasma in volume of 260 mm× 260 mm× 180 mm without the magnetic confinement. The plasma is produced by the glow discharge, and the special discharge structure is built to bring a steady approximate uniform plasma environment in the electromagnetic wave propagation path without any other barriers. In addition, the electron density and luminosity distributions of plasma under different discharge conditions were diagnosed and experimentally investigated. Both the electron density and the plasma uniformity are directly proportional to the input power and in roughly reverse proportion to the gas pressure in the chamber. Furthermore, the experiments of electromagnetic wave propagation in plasma are conducted in this plasma generator. Blackout phenomena at GPS signal are observed under this system and the measured attenuation curve is of reasonable agreement with the theoretical one, which suggests the effectiveness of the proposed method.

  7. Calculation of left ventricular volumes and ejection fraction from dynamic cardiac-gated 15O-water PET/CT: 5D-PET

    Directory of Open Access Journals (Sweden)

    Jonny Nordström

    2017-11-01

    Full Text Available Abstract Background Quantitative measurement of myocardial blood flow (MBF is of increasing interest in the clinical assessment of patients with suspected coronary artery disease (CAD. 15O-water positron emission tomography (PET is considered the gold standard for non-invasive MBF measurements. However, calculation of left ventricular (LV volumes and ejection fraction (EF is not possible from standard 15O-water uptake images. The purpose of the present work was to investigate the possibility of calculating LV volumes and LVEF from cardiac-gated parametric blood volume (V B 15O-water images and from first pass (FP images. Sixteen patients with mitral or aortic regurgitation underwent an eight-gate dynamic cardiac-gated 15O-water PET/CT scan and cardiac MRI. V B and FP images were generated for each gate. Calculations of end-systolic volume (ESV, end-diastolic volume (EDV, stroke volume (SV and LVEF were performed with automatic segmentation of V B and FP images, using commercially available software. LV volumes and LVEF were calculated with surface-, count-, and volume-based methods, and the results were compared with gold standard MRI. Results Using V B images, high correlations between PET and MRI ESV (r = 0.89, p  0.86, p < 0.001. Conclusion Calculation of LV volumes and LVEF from dynamic 15O-water PET is feasible and shows good correlation with MRI. However, the analysis method is laborious, and future work is needed for more automation to make the method more easily applicable in a clinical setting.

  8. Effect of Coarse Particle Volume Fraction on the Yield Stress of Muddy Sediments from Marennes Oléron Bay

    Directory of Open Access Journals (Sweden)

    A. Pantet

    2010-01-01

    Full Text Available Coastal erosion results from a combination of various factors, both natural and humaninduced, which have different time and space patterns. In addition, uncertainties still remain about the interactions of the forcing agents, as well as on the significance of non-local causes of erosion. We focused about the surface sediments in the Marennes Oléron bay, after a general description of the site that has many various activities. The superficial sediments show a mechanical behavior, mainly depends on the fine fraction for a composition that contains up to 60% of sandy material. Fine sediments fraction has a typical yield stress depending naturally of concentration or water content. This yield could be modified slightly or significantly by adding silt or sand. As a result, the rheological measurement sensitivity allows us to characterize five typical sediments that correlate with solid fraction and fine fraction.

  9. Rugged Large Volume Injection for Sensitive Capillary LC-MS Environmental Monitoring

    Directory of Open Access Journals (Sweden)

    Hanne Roberg-Larsen

    2017-08-01

    Full Text Available A rugged and high throughput capillary column (cLC LC-MS switching platform using large volume injection and on-line automatic filtration and filter back-flush (AFFL solid phase extraction (SPE for analysis of environmental water samples with minimal sample preparation is presented. Although narrow columns and on-line sample preparation are used in the platform, high ruggedness is achieved e.g., injection of 100 non-filtrated water samples did not result in a pressure rise/clogging of the SPE/capillary columns (inner diameter 300 μm. In addition, satisfactory retention time stability and chromatographic resolution were also features of the system. The potential of the platform for environmental water samples was demonstrated with various pharmaceutical products, which had detection limits (LOD in the 0.05–12.5 ng/L range. Between-day and within-day repeatability of selected analytes were <20% RSD.

  10. Improved tolerance of abdominal large-volume radiotherapy due to ornithine aspartate

    International Nuclear Information System (INIS)

    Kuttig, H.

    1983-01-01

    The influence of ornithine aspartate on supporting the hepatic function was investigated in a group of 47 patients with tumour dissemination in the pelvic and abdominal region, randomised on the basis of the progress of the serum enzymes GOT, GPT, LAD, LDH, LAP and the alkaline phosphatase during and following completion of a course of large-volume radiotherapy. The adjuvant therapy with ornithine aspartate resulted in reduced enzyme movement with an earlier tendency to normalisation. The results, which are borne out by statistics, clearly show an improvement in the hepatic function on detoxication of toxic degradation products of radiotherapy with reduced impairment of the body's own defence mechanisms. Subjectively too, the course of treatment with ornithine aspartate showed a reduced ratio of side effects as regards lassitude and impairment of the patient's general well-being as compared with the group of patients to whom ornithine aspartate was not simultaneously administered. (orig.) [de

  11. The position response of a large-volume segmented germanium detector

    International Nuclear Information System (INIS)

    Descovich, M.; Nolan, P.J.; Boston, A.J.; Dobson, J.; Gros, S.; Cresswell, J.R.; Simpson, J.; Lazarus, I.; Regan, P.H.; Valiente-Dobon, J.J.; Sellin, P.; Pearson, C.J.

    2005-01-01

    The position response of a large-volume segmented coaxial germanium detector is reported. The detector has 24-fold segmentation on its outer contact. The output from each contact was sampled with fast digital signal processing electronics in order to determine the position of the γ-ray interaction from the signal pulse shape. The interaction position was reconstructed in a polar coordinate system by combining the radial information, contained in the rise-time of the pulse leading edge, with the azimuthal information, obtained from the magnitude of the transient charge signals induced on the neighbouring segments. With this method, a position resolution of 3-7mm is achieved in both the radial and the azimuthal directions

  12. The position response of a large-volume segmented germanium detector

    Energy Technology Data Exchange (ETDEWEB)

    Descovich, M. [Oliver Lodge Laboratory, Physics Department, University of Liverpool, Liverpool L69 7ZE (United Kingdom)]. E-mail: mdescovich@lbl.gov; Nolan, P.J. [Oliver Lodge Laboratory, Physics Department, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Boston, A.J. [Oliver Lodge Laboratory, Physics Department, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Dobson, J. [Oliver Lodge Laboratory, Physics Department, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Gros, S. [Oliver Lodge Laboratory, Physics Department, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Cresswell, J.R. [Oliver Lodge Laboratory, Physics Department, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Simpson, J. [CCLRC Daresbury Laboratory, Daresbury, Warrington, Cheshire WA4 4AD (United Kingdom); Lazarus, I. [CCLRC Daresbury Laboratory, Daresbury, Warrington, Cheshire WA4 4AD (United Kingdom); Regan, P.H. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Valiente-Dobon, J.J. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Sellin, P. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Pearson, C.J. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2005-11-21

    The position response of a large-volume segmented coaxial germanium detector is reported. The detector has 24-fold segmentation on its outer contact. The output from each contact was sampled with fast digital signal processing electronics in order to determine the position of the {gamma}-ray interaction from the signal pulse shape. The interaction position was reconstructed in a polar coordinate system by combining the radial information, contained in the rise-time of the pulse leading edge, with the azimuthal information, obtained from the magnitude of the transient charge signals induced on the neighbouring segments. With this method, a position resolution of 3-7mm is achieved in both the radial and the azimuthal directions.

  13. Floating substructure flexibility of large-volume 10MW offshore wind turbine platforms in dynamic calculations

    International Nuclear Information System (INIS)

    Borg, Michael; Hansen, Anders Melchior; Bredmose, Henrik

    2016-01-01

    Designing floating substructures for the next generation of 10MW and larger wind turbines has introduced new challenges in capturing relevant physical effects in dynamic simulation tools. In achieving technically and economically optimal floating substructures, structural flexibility may increase to the extent that it becomes relevant to include in addition to the standard rigid body substructure modes which are typically described through linear radiation-diffraction theory. This paper describes a method for the inclusion of substructural flexibility in aero-hydro-servo-elastic dynamic simulations for large-volume substructures, including wave-structure interactions, to form the basis of deriving sectional loads and stresses within the substructure. The method is applied to a case study to illustrate the implementation and relevance. It is found that the flexible mode is significantly excited in an extreme event, indicating an increase in predicted substructure internal loads. (paper)

  14. Development of metallic molds for the large volume plastic scintillator fabrication

    International Nuclear Information System (INIS)

    Calvo, Wilson A.P.; Vieira, Jose M.; Rela, Paulo R.; Bruzinga, Wilson A.; Araujo, Eduardo P.; Costa Junior, Nelson P.; Hamada, Margarida M.

    1997-01-01

    The plastic scintillators are radiation detectors made of organic fluorescent compounds dissolved in a solidified polymer matrix. The manufacturing process of large volume detectors (55 liters) at low cost, by polymerization of the styrene monomer plus PPO and POPOP scintillators, was studied in this paper. Metallic molds of ASTM 1200 aluminum and AISI 304 stainless steel were produced by TIG welding process since the polymerization reaction is very exothermic. The measurements of transmittance, luminescence, X-ray fluorescence and light output were carried out in the plastic scintillators made using different metallic molds. The characterization results of the detectors produced in an open system using ASTM 1200 aluminum mold show that there is not quality change in the scintillator, even with aluminum being considered as unstable for styrene monomer. Therefore, the ASTM 1200 aluminum was found to be the best alternative to produce the detector by an open system polymerization. (author). 11 refs., 8 figs., 1 tab

  15. The core collapse supernova rate from 24 years of data of the Large Volume Detector

    Science.gov (United States)

    Bruno, G.; Fulgione, W.; Molinario, A.; Vigorito, C.; LVD Collaboration

    2017-09-01

    The Large Volume Detector (LVD) at INFN Laboratori Nazionali del Gran Sasso, Italy is a 1 kt liquid scintillator neutrino observatory mainly designed to study low energy neutrinos from Gravitational Stellar Collapses (GSC) with 100% efficiency over the entire Galaxy. Here we summarize the results of the search for supernova neutrino bursts over the full data set lasting from June 1992 to May 2016 for a total live time of 8211 days. In the lack of a positive observation, either in standalone mode or in coincidence with other experiments, we establish the upper limit to the rate of GSC event in the Milky Way: 0.1 year-1 at 90% c.l..

  16. Dynamic illumination of spatially restricted or large brain volumes via a single tapered optical fiber.

    Science.gov (United States)

    Pisanello, Ferruccio; Mandelbaum, Gil; Pisanello, Marco; Oldenburg, Ian A; Sileo, Leonardo; Markowitz, Jeffrey E; Peterson, Ralph E; Della Patria, Andrea; Haynes, Trevor M; Emara, Mohamed S; Spagnolo, Barbara; Datta, Sandeep Robert; De Vittorio, Massimo; Sabatini, Bernardo L

    2017-08-01

    Optogenetics promises precise spatiotemporal control of neural processes using light. However, the spatial extent of illumination within the brain is difficult to control and cannot be adjusted using standard fiber optics. We demonstrate that optical fibers with tapered tips can be used to illuminate either spatially restricted or large brain volumes. Remotely adjusting the light input angle to the fiber varies the light-emitting portion of the taper over several millimeters without movement of the implant. We use this mode to activate dorsal versus ventral striatum of individual mice and reveal different effects of each manipulation on motor behavior. Conversely, injecting light over the full numerical aperture of the fiber results in light emission from the entire taper surface, achieving broader and more efficient optogenetic activation of neurons, compared to standard flat-faced fiber stimulation. Thus, tapered fibers permit focal or broad illumination that can be precisely and dynamically matched to experimental needs.

  17. Development of a spatially uniform fast ionization wave in a large-volume discharge

    International Nuclear Information System (INIS)

    Zatsepin, D.V.; Starikovskaya, S.M.; Starikovskii, A.Yu.

    1998-01-01

    A study is made of a high-voltage nanosecond breakdown in the form of a fast ionization wave produced in a large-volume (401) discharge chamber. The propagation speed of the wave front and the integral energy deposition in a plasma are measured for various regimes of the air discharge at pressures of 10 -2 -4 Torr. A high degree of both the spatial uniformity of the discharge and the reproducibility of the discharge parameters is obtained. The possibility of the development of a fast ionization wave in an electrodeless system is demonstrated. A transition of the breakdown occurring in the form of a fast ionization wave into the streamer breakdown is observed. It is shown that such discharges are promising for technological applications

  18. Radio-chemical dosage of 90Sr in large volumes of drinking water

    International Nuclear Information System (INIS)

    Jeanmaire, L.; Patti, F.; Bullier, D.

    1965-01-01

    I. Principle of the method: 1. Fixing on a resin of all the cations present in the water. 2. Elution using 5 N nitric acid and precipitation of strontium as the carbonate. 3. Concentration of the strontium using the fuming nitric acid method. 4. Purification of the strontium on a resin by selective elution with ammonium citrate. 5. The strontium-90 is measured by separation at the 90 Y equilibrium in the form of the oxalate which is then counted. II. Advantages of the method The concentration of the radio-activity starting from large volumes (100 l) is generally tedious but this method which makes use of a fixation on a cationic resin makes it very simple. The rest of the method consists of a series of simple chemical operations using ion-exchange on resins and coprecipitation. Finally, it is possible to dose stable strontium. (authors) [fr

  19. Aerodynamics of the Large-Volume, Flow-Through Detector System. Final report

    International Nuclear Information System (INIS)

    Reed, H.; Saric, W.; Laananen, D.; Martinez, C.; Carrillo, R.; Myers, J.; Clevenger, D.

    1996-03-01

    The Large-Volume Flow-Through Detector System (LVFTDS) was designed to monitor alpha radiation from Pu, U, and Am in mixed-waste incinerator offgases; however, it can be adapted to other important monitoring uses that span a number of potential markets, including site remediation, indoor air quality, radon testing, and mine shaft monitoring. Goal of this effort was to provide mechanical design information for installation of LVFTDS in an incinerator, with emphasis on ability to withstand the high temperatures and high flow rates expected. The work was successfully carried out in three stages: calculation of pressure drop through the system, materials testing to determine surrogate materials for wind-tunnel testing, and wind-tunnel testing of an actual configuration

  20. Flow-through electroporation based on constant voltage for large-volume transfection of cells.

    Science.gov (United States)

    Geng, Tao; Zhan, Yihong; Wang, Hsiang-Yu; Witting, Scott R; Cornetta, Kenneth G; Lu, Chang

    2010-05-21

    Genetic modification of cells is a critical step involved in many cell therapy and gene therapy protocols. In these applications, cell samples of large volume (10(8)-10(9)cells) are often processed for transfection. This poses new challenges for current transfection methods and practices. Here we present a novel flow-through electroporation method for delivery of genes into cells at high flow rates (up to approximately 20 mL/min) based on disposable microfluidic chips, a syringe pump, and a low-cost direct current (DC) power supply that provides a constant voltage. By eliminating pulse generators used in conventional electroporation, we dramatically lowered the cost of the apparatus and improved the stability and consistency of the electroporation field for long-time operation. We tested the delivery of pEFGP-C1 plasmids encoding enhanced green fluorescent protein into Chinese hamster ovary (CHO-K1) cells in the devices of various dimensions and geometries. Cells were mixed with plasmids and then flowed through a fluidic channel continuously while a constant voltage was established across the device. Together with the applied voltage, the geometry and dimensions of the fluidic channel determined the electrical parameters of the electroporation. With the optimal design, approximately 75% of the viable CHO cells were transfected after the procedure. We also generalize the guidelines for scaling up these flow-through electroporation devices. We envision that this technique will serve as a generic and low-cost tool for a variety of clinical applications requiring large volume of transfected cells. Copyright 2010 Elsevier B.V. All rights reserved.

  1. Reirradiation of Large-Volume Recurrent Glioma With Pulsed Reduced-Dose-Rate Radiotherapy

    International Nuclear Information System (INIS)

    Adkison, Jarrod B.; Tome, Wolfgang; Seo, Songwon; Richards, Gregory M.; Robins, H. Ian; Rassmussen, Karl; Welsh, James S.; Mahler, Peter A.; Howard, Steven P.

    2011-01-01

    Purpose: Pulsed reduced-dose-rate radiotherapy (PRDR) is a reirradiation technique that reduces the effective dose rate and increases the treatment time, allowing sublethal damage repair during irradiation. Patients and Methods: A total of 103 patients with recurrent glioma underwent reirradiation using PRDR (86 considered to have Grade 4 at PRDR). PRDR was delivered using a series of 0.2-Gy pulses at 3-min intervals, creating an apparent dose rate of 0.0667 Gy/min to a median dose of 50 Gy (range, 20-60) delivered in 1.8-2.0-Gy fractions. The mean treatment volume was 403.5 ± 189.4 cm 3 according to T 2 -weighted magnetic resonance imaging and a 2-cm margin. Results: For the initial or upgraded Grade 4 cohort (n = 86), the median interval from the first irradiation to PRDR was 14 months. Patients undergoing PRDR within 14 months of the first irradiation (n = 43) had a median survival of 21 weeks. Those treated ≥14 months after radiotherapy had a median survival of 28 weeks (n = 43; p = 0.004 and HR = 1.82 with a 95% CI ranging from 1.25 to 3.10). These data compared favorably to historical data sets, because only 16% of the patients were treated at first relapse (with 46% treated at the second relapse, 32% at the third or fourth relapse, and 4% at the fourth or fifth relapse). The median survival since diagnosis and retreatment was 6.3 years and 11.4 months for low-grade, 4.1 years and 5.6 months for Grade 3, and 1.6 years and 5.1 months for Grade 4 tumors, respectively, according to the initial histologic findings. Multivariate analysis revealed age at the initial diagnosis, initial low-grade disease, and Karnofsky performance score of ≥80 to be significant predictors of survival after initiation of PRDR. Conclusion: PRDR allowed for safe retreatment of larger volumes to high doses with palliative benefit.

  2. Large volume serial section tomography by Xe Plasma FIB dual beam microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Burnett, T.L. [School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); FEI Company, Achtseweg Noord 5, Bldg, 5651 GG, Eindhoven (Netherlands); Kelley, R. [FEI Company, 5350 NE Dawson Creek Drive, Hillsboro, OR 97124 (United States); Winiarski, B. [School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); FEI Company, Achtseweg Noord 5, Bldg, 5651 GG, Eindhoven (Netherlands); Contreras, L. [FEI Company, 5350 NE Dawson Creek Drive, Hillsboro, OR 97124 (United States); Daly, M.; Gholinia, A.; Burke, M.G. [School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); Withers, P.J., E-mail: P.J.Withers@manchester.ac.uk [School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); BP International Centre for Advanced Materials, University of Manchester, Manchester M13 9PL (United Kingdom)

    2016-02-15

    Ga{sup +} Focused Ion Beam-Scanning Electron Microscopes (FIB-SEM) have revolutionised the level of microstructural information that can be recovered in 3D by block face serial section tomography (SST), as well as enabling the site-specific removal of smaller regions for subsequent transmission electron microscope (TEM) examination. However, Ga{sup +} FIB material removal rates limit the volumes and depths that can be probed to dimensions in the tens of microns range. Emerging Xe{sup +} Plasma Focused Ion Beam-Scanning Electron Microscope (PFIB-SEM) systems promise faster removal rates. Here we examine the potential of the method for large volume serial section tomography as applied to bainitic steel and WC–Co hard metals. Our studies demonstrate that with careful control of milling parameters precise automated serial sectioning can be achieved with low levels of milling artefacts at removal rates some 60× faster. Volumes that are hundreds of microns in dimension have been collected using fully automated SST routines in feasible timescales (<24 h) showing good grain orientation contrast and capturing microstructural features at the tens of nanometres to the tens of microns scale. Accompanying electron back scattered diffraction (EBSD) maps show high indexing rates suggesting low levels of surface damage. Further, under high current Ga{sup +} FIB milling WC–Co is prone to amorphisation of WC surface layers and phase transformation of the Co phase, neither of which have been observed at PFIB currents as high as 60 nA at 30 kV. Xe{sup +} PFIB dual beam microscopes promise to radically extend our capability for 3D tomography, 3D EDX, 3D EBSD as well as correlative tomography. - Highlights: • The uptake of dual beam FIBs has been rapid but long milling times have limited imaged volumes to tens of micron dimensions. • Emerging plasma Xe{sup +} PFIB-SEM technology offers materials removal rates at least 60× greater than conventional Ga{sup +} FIB systems with

  3. Volume Visualization and Compositing on Large-Scale Displays Using Handheld Touchscreen Interaction

    KAUST Repository

    Gastelum, Cristhopper Jacobo Armenta

    2011-07-27

    Advances in the physical sciences have progressively delivered ever increasing, already extremely large data sets to be analyzed. High performance volume rendering has become critical to the scientists for a better understanding of the massive amounts of data to be visualized. Cluster based rendering systems have become the base line to achieve the power and flexibility required to perform such task. Furthermore, display arrays have become the most suitable solution to display these data sets at their natural size and resolution which can be critical for human perception and evaluation. The work in this thesis aims at improving the scalability and usability of volume rendering systems that target visualization on display arrays. The first part deals with improving the performance by introducing the implementations of two parallel compositing algorithms for volume rendering: direct send and binary swap. The High quality Volume Rendering (HVR) framework has been extended to accommodate parallel compositing where previously only serial compositing was possible. The preliminary results show improvements in the compositing times for direct send even for a small number of processors. Unfortunately, the results of binary swap exhibit a negative behavior. This is due to the naive use of the graphics hardware blending mechanism. The expensive transfers account for the lengthy compositing times. The second part targets the development of scalable and intuitive interaction mechanisms. It introduces the development of a new client application for multitouch tablet devices, like the Apple iPad. The main goal is to provide the HVR framework, that has been extended to use tiled displays, a more intuitive and portable interaction mechanism that can get advantage of the new environment. The previous client is a PC application for the typical desktop settings that use a mouse and keyboard as sources of interaction. The current implementation of the client lets the user steer and

  4. Large volume serial section tomography by Xe Plasma FIB dual beam microscopy

    International Nuclear Information System (INIS)

    Burnett, T.L.; Kelley, R.; Winiarski, B.; Contreras, L.; Daly, M.; Gholinia, A.; Burke, M.G.; Withers, P.J.

    2016-01-01

    Ga + Focused Ion Beam-Scanning Electron Microscopes (FIB-SEM) have revolutionised the level of microstructural information that can be recovered in 3D by block face serial section tomography (SST), as well as enabling the site-specific removal of smaller regions for subsequent transmission electron microscope (TEM) examination. However, Ga + FIB material removal rates limit the volumes and depths that can be probed to dimensions in the tens of microns range. Emerging Xe + Plasma Focused Ion Beam-Scanning Electron Microscope (PFIB-SEM) systems promise faster removal rates. Here we examine the potential of the method for large volume serial section tomography as applied to bainitic steel and WC–Co hard metals. Our studies demonstrate that with careful control of milling parameters precise automated serial sectioning can be achieved with low levels of milling artefacts at removal rates some 60× faster. Volumes that are hundreds of microns in dimension have been collected using fully automated SST routines in feasible timescales (<24 h) showing good grain orientation contrast and capturing microstructural features at the tens of nanometres to the tens of microns scale. Accompanying electron back scattered diffraction (EBSD) maps show high indexing rates suggesting low levels of surface damage. Further, under high current Ga + FIB milling WC–Co is prone to amorphisation of WC surface layers and phase transformation of the Co phase, neither of which have been observed at PFIB currents as high as 60 nA at 30 kV. Xe + PFIB dual beam microscopes promise to radically extend our capability for 3D tomography, 3D EDX, 3D EBSD as well as correlative tomography. - Highlights: • The uptake of dual beam FIBs has been rapid but long milling times have limited imaged volumes to tens of micron dimensions. • Emerging plasma Xe + PFIB-SEM technology offers materials removal rates at least 60× greater than conventional Ga + FIB systems with comparable or less damage. • The

  5. Process automation system for integration and operation of Large Volume Plasma Device

    International Nuclear Information System (INIS)

    Sugandhi, R.; Srivastava, P.K.; Sanyasi, A.K.; Srivastav, Prabhakar; Awasthi, L.M.; Mattoo, S.K.

    2016-01-01

    Highlights: • Analysis and design of process automation system for Large Volume Plasma Device (LVPD). • Data flow modeling for process model development. • Modbus based data communication and interfacing. • Interface software development for subsystem control in LabVIEW. - Abstract: Large Volume Plasma Device (LVPD) has been successfully contributing towards understanding of the plasma turbulence driven by Electron Temperature Gradient (ETG), considered as a major contributor for the plasma loss in the fusion devices. Large size of the device imposes certain difficulties in the operation, such as access of the diagnostics, manual control of subsystems and large number of signals monitoring etc. To achieve integrated operation of the machine, automation is essential for the enhanced performance and operational efficiency. Recently, the machine is undergoing major upgradation for the new physics experiments. The new operation and control system consists of following: (1) PXIe based fast data acquisition system for the equipped diagnostics; (2) Modbus based Process Automation System (PAS) for the subsystem controls and (3) Data Utilization System (DUS) for efficient storage, processing and retrieval of the acquired data. In the ongoing development, data flow model of the machine’s operation has been developed. As a proof of concept, following two subsystems have been successfully integrated: (1) Filament Power Supply (FPS) for the heating of W- filaments based plasma source and (2) Probe Positioning System (PPS) for control of 12 number of linear probe drives for a travel length of 100 cm. The process model of the vacuum production system has been prepared and validated against acquired pressure data. In the next upgrade, all the subsystems of the machine will be integrated in a systematic manner. The automation backbone is based on 4-wire multi-drop serial interface (RS485) using Modbus communication protocol. Software is developed on LabVIEW platform using

  6. Process automation system for integration and operation of Large Volume Plasma Device

    Energy Technology Data Exchange (ETDEWEB)

    Sugandhi, R., E-mail: ritesh@ipr.res.in; Srivastava, P.K.; Sanyasi, A.K.; Srivastav, Prabhakar; Awasthi, L.M.; Mattoo, S.K.

    2016-11-15

    Highlights: • Analysis and design of process automation system for Large Volume Plasma Device (LVPD). • Data flow modeling for process model development. • Modbus based data communication and interfacing. • Interface software development for subsystem control in LabVIEW. - Abstract: Large Volume Plasma Device (LVPD) has been successfully contributing towards understanding of the plasma turbulence driven by Electron Temperature Gradient (ETG), considered as a major contributor for the plasma loss in the fusion devices. Large size of the device imposes certain difficulties in the operation, such as access of the diagnostics, manual control of subsystems and large number of signals monitoring etc. To achieve integrated operation of the machine, automation is essential for the enhanced performance and operational efficiency. Recently, the machine is undergoing major upgradation for the new physics experiments. The new operation and control system consists of following: (1) PXIe based fast data acquisition system for the equipped diagnostics; (2) Modbus based Process Automation System (PAS) for the subsystem controls and (3) Data Utilization System (DUS) for efficient storage, processing and retrieval of the acquired data. In the ongoing development, data flow model of the machine’s operation has been developed. As a proof of concept, following two subsystems have been successfully integrated: (1) Filament Power Supply (FPS) for the heating of W- filaments based plasma source and (2) Probe Positioning System (PPS) for control of 12 number of linear probe drives for a travel length of 100 cm. The process model of the vacuum production system has been prepared and validated against acquired pressure data. In the next upgrade, all the subsystems of the machine will be integrated in a systematic manner. The automation backbone is based on 4-wire multi-drop serial interface (RS485) using Modbus communication protocol. Software is developed on LabVIEW platform using

  7. 'Finite' non-Gaussianities and tensor-scalar ratio in large volume Swiss-cheese compactifications

    International Nuclear Information System (INIS)

    Misra, Aalok; Shukla, Pramod

    2009-01-01

    Developing on the ideas of (Section 4 of) [A. Misra, P. Shukla, Moduli stabilization, large-volume dS minimum without anti-D3-branes, (non-)supersymmetric black hole attractors and two-parameter Swiss cheese Calabi-Yau's, Nucl. Phys. B 799 (2008) 165-198, (arXiv: 0707.0105)] and [A. Misra, P. Shukla, Large volume axionic Swiss-cheese inflation, Nucl. Phys. B 800 (2008) 384-400, (arXiv: 0712.1260 [hep-th])] and using the formalisms of [S. Yokoyama, T. Suyama, T. Tanaka, Primordial non-Gaussianity in multi-scalar slow-roll inflation, (arXiv: 0705.3178 [astro-ph]); S. Yokoyama, T. Suyama, T. Tanaka, Primordial non-Gaussianity in multi-scalar inflation, Phys. Rev. D 77 (2008) 083511, (arXiv: 0711.2920 [astro-ph])], after inclusion of perturbative and non-perturbative α' corrections to the Kaehler potential and (D1- and D3-)instanton generated superpotential, we show the possibility of getting finite values for the non-linear parameter f NL while looking for non-Gaussianities in type IIB compactifications on orientifolds of the Swiss cheese Calabi-Yau WCP 4 [1,1,1,6,9] in the L(arge) V(olume) S(cenarios) limit. We show the same in two contexts. First is multi-field slow-roll inflation with D3-instanton contribution coming from a large number of multiple wrappings of a single (Euclidean) D3-brane around the 'small' divisor yielding f NL ∼O(1). The second is when the slow-roll conditions are violated and for the number of the aforementioned D3-instanton wrappings being of O(1) but more than one, yielding f NL ∼O(1). Based on general arguments not specific to our (string-theory) set-up, we argue that requiring curvature perturbations not to grow at horizon crossing and at super-horizon scales, automatically picks out hybrid inflationary scenarios which in our set up can yield f NL ∼O(1) and tensor-scalar ratio of O(10 -2 ). For all our calculations, the world-sheet instanton contributions to the Kaehler potential coming from the non-perturbative α ' corrections

  8. Investigating the evolution of the phase behavior of AOT-based w/o microemulsions in dodecane as a function of droplet volume fraction.

    Science.gov (United States)

    Ganguly, R; Choudhury, N

    2012-04-15

    AOT-based water in oil (w/o) microemulsions are one of the most extensively studied reverse micellar systems because of their rich phase behavior and their ability to form in the absence of any co-surfactant. The aggregation characteristics and interaction of the microemulsion droplets in these systems are known to be governed by AOT-oil compatibility and water to AOT molar ratio (w). In this manuscript by using Dynamic Light Scattering (DLS) and viscometry techniques, we show that droplet volume fraction too plays an important role in shaping the phase behavior of these microemulsions in dodecane. The phase separation characteristics and the evolution of the viscosity and the hydrodynamic radius of the microemulsion droplets on approaching the cloud points have thus been found to undergo complete transformation as one goes from low to high droplet volume fraction even at a fixed 'w'. Modeling of the DLS data attributes this to the weakening of inter droplet attractive interaction caused by the growing dominance of the excluded volume effect with increase in droplet volume fraction. In the literature, the inter droplet attractive interaction driven phase separation in these microemulsions is explained based on gas-liquid type phase transition, conceptualized in the framework of Baxter adhesive hard sphere theory. The modeling of our viscosity data, however, does not support such proposition as the characteristic stickiness parameter (τ(-1)) of the microemulsion droplets in this system remains much lower than the critical value (τ(c)(-1)≈10.25) required to enforce such phase transition. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Major risk from rapid, large-volume landslides in Europe (EU Project RUNOUT)

    Science.gov (United States)

    Kilburn, Christopher R. J.; Pasuto, Alessandro

    2003-08-01

    Project RUNOUT has investigated methods for reducing the risk from large-volume landslides in Europe, especially those involving rapid rates of emplacement. Using field data from five test sites (Bad Goisern and Köfels in Austria, Tessina and Vajont in Italy, and the Barranco de Tirajana in Gran Canaria, Spain), the studies have developed (1) techniques for applying geomorphological investigations and optical remote sensing to map landslides and their evolution; (2) analytical, numerical, and cellular automata models for the emplacement of sturzstroms and debris flows; (3) a brittle-failure model for forecasting catastrophic slope failure; (4) new strategies for integrating large-area Global Positioning System (GPS) arrays with local geodetic monitoring networks; (5) methods for raising public awareness of landslide hazards; and (6) Geographic Information System (GIS)-based databases for the test areas. The results highlight the importance of multidisciplinary studies of landslide hazards, combining subjects as diverse as geology and geomorphology, remote sensing, geodesy, fluid dynamics, and social profiling. They have also identified key goals for an improved understanding of the physical processes that govern landslide collapse and runout, as well as for designing strategies for raising public awareness of landslide hazards and for implementing appropriate land management policies for reducing landslide risk.

  10. Active species in a large volume N2-O2 post-discharge reactor

    International Nuclear Information System (INIS)

    Kutasi, K; Pintassilgo, C D; Loureiro, J; Coelho, P J

    2007-01-01

    A large volume post-discharge reactor placed downstream from a flowing N 2 -O 2 microwave discharge is modelled using a three-dimensional hydrodynamic model. The density distributions of the most populated active species present in the reactor-O( 3 P), O 2 (a 1 Δ g ), O 2 (b 1 Σ g + ), NO(X 2 Π), NO(A 2 Σ + ), NO(B 2 Π), NO 2 (X), O 3 , O 2 (X 3 Σ g - ) and N( 4 S)-are calculated and the main source and loss processes for each species are identified for two discharge conditions: (i) p = 2 Torr, f = 2450 MHz, and (ii) p = 8 Torr, f = 915 MHz; in the case of a N 2 -2%O 2 mixture composition and gas flow rate of 2 x 10 3 sccm. The modification of the species relative densities by changing the oxygen percentage in the initial gas mixture composition, in the 0.2%-5% range, are presented. The possible tuning of the species concentrations in the reactor by changing the size of the connecting afterglow tube between the active discharge and the large post-discharge reactor is investigated as well

  11. Large-scale hydrogen combustion experiments: Volume 2, Data plots: Final report

    International Nuclear Information System (INIS)

    Thompson, R.T.; Torok, R.C.; Randall, D.S.; Sullivan, J.S.; Thompson, L.B.; Haugh, J.J.

    1988-10-01

    Forty large-scale experiments to investigate the combustion behavior of hydrogen during postulated degraded core accidents were conducted in a 16 m (52 ft) diameter sphere. The performance of safety related equipment and cable also was examined. Combustion was initiated by thermal igniters in both premixed hydrogen air-steam atmospheres and during the continuous injection of hydrogen and steam. The effects of steam, igniter location, water sprays, fans and injection rates were studied. Measurements were made of gas concentrations, combustion pressures, temperatures and heat fluxes. Burn fractions and flame speeds also were determined. Near-infrared seeing cameras permitted direct observation of the hydrogen burns. Combustion pressures and temperatures in premixed atmospheres with hydrogen concentrations up to 13 vol% (steam saturated) were less than the theoretical maximum values. Multiple deflagrations were not encountered during continuous hydrogen injection with pre-activated igniters. Moderate pressure rises resulted from diffusion flames. These flames generally were found above the source. Combustion results have been compared to smaller scale experiments. Several safety related equipment items exhibited degraded performance after a number of tests. Most cable samples passed their electrical checks at the end of the test series. These experiments confirm the effectiveness of the deliberate ignition approach to controlling hydrogen. They also provide data for validating computer codes used to predict hydrogen combustion during degraded core accidents, and for assessing the performance of safety related equipment in such environments

  12. Analytical and Experimental Investigation of Mixing in Large Passive Containment Volumes

    International Nuclear Information System (INIS)

    Peterson, Per F.

    2002-01-01

    This final report details results from the past three years of the three-year UC Berkeley NEER investigation of mixing phenomena in large-scale passive reactor containments. We have completed all of our three-year deliverables specified in our proposal, as summarized for each deliverable in the body of this report, except for the experiments of steam condensation in the presence of noncondensable gas. We have particularly exiting results from the experiments studying the mixing in large insulated containment with a vertical cooling plate. These experiments now have shown why augmentation has been observed in wall-condensation experiments due to the momentum of the steam break-flow entering large volumes. More importantly, we also have shown that the forced-jet augmentation can be predicted using relatively simple correlations, and that it is independent of the break diameter and depends only on the break flow orientation, location, and momentum. This suggests that we will now be able to take credit for this augmentation in reactor safety analysis, improving safety margins for containment structures. We have finished the version 1 of 1-D Lagrangian flow and heat transfer code BMIX++. This version has ability to solve many complex stratified problems, such as multi-components problems, multi-enclosures problems (two enclosures connected by one connection for the current version), incompressible and compressible problems, multi jets, plumes, sinks in one enclosure problems, problems with wall conduction, and the combinations of the above problems. We believe the BMIX++ code is a very powerful computation tool to study stratified enclosures mixing problems

  13. Albumin infusion in patients undergoing large-volume paracentesis: a meta-analysis of randomized trials.

    Science.gov (United States)

    Bernardi, Mauro; Caraceni, Paolo; Navickis, Roberta J; Wilkes, Mahlon M

    2012-04-01

    Albumin infusion reduces the incidence of postparacentesis circulatory dysfunction among patients with cirrhosis and tense ascites, as compared with no treatment. Treatment alternatives to albumin, such as artificial colloids and vasoconstrictors, have been widely investigated. The aim of this meta-analysis was to determine whether morbidity and mortality differ between patients receiving albumin versus alternative treatments. The meta-analysis included randomized trials evaluating albumin infusion in patients with tense ascites. Primary endpoints were postparacentesis circulatory dysfunction, hyponatremia, and mortality. Eligible trials were sought by multiple methods, including computer searches of bibliographic and abstract databases and the Cochrane Library. Results were quantitatively combined under a fixed-effects model. Seventeen trials with 1,225 total patients were included. There was no evidence of heterogeneity or publication bias. Compared with alternative treatments, albumin reduced the incidence of postparacentesis circulatory dysfunction (odds ratio [OR], 0.39; 95% confidence interval [CI], 0.27-0.55). Significant reductions in that complication by albumin were also shown in subgroup analyses versus each of the other volume expanders tested (e.g., dextran, gelatin, hydroxyethyl starch, and hypertonic saline). The occurrence of hyponatremia was also decreased by albumin, compared with alternative treatments (OR, 0.58; 95% CI, 0.39-0.87). In addition, mortality was lower in patients receiving albumin than alternative treatments (OR, 0.64; 95% CI, 0.41-0.98). This meta-analysis provides evidence that albumin reduces morbidity and mortality among patients with tense ascites undergoing large-volume paracentesis, as compared with alternative treatments investigated thus far. Copyright © 2011 American Association for the Study of Liver Diseases.

  14. PVR: Patch-to-Volume Reconstruction for Large Area Motion Correction of Fetal MRI.

    Science.gov (United States)

    Alansary, Amir; Rajchl, Martin; McDonagh, Steven G; Murgasova, Maria; Damodaram, Mellisa; Lloyd, David F A; Davidson, Alice; Rutherford, Mary; Hajnal, Joseph V; Rueckert, Daniel; Kainz, Bernhard

    2017-10-01

    In this paper, we present a novel method for the correction of motion artifacts that are present in fetal magnetic resonance imaging (MRI) scans of the whole uterus. Contrary to current slice-to-volume registration (SVR) methods, requiring an inflexible anatomical enclosure of a single investigated organ, the proposed patch-to-volume reconstruction (PVR) approach is able to reconstruct a large field of view of non-rigidly deforming structures. It relaxes rigid motion assumptions by introducing a specific amount of redundant information that is exploited with parallelized patchwise optimization, super-resolution, and automatic outlier rejection. We further describe and provide an efficient parallel implementation of PVR allowing its execution within reasonable time on commercially available graphics processing units, enabling its use in the clinical practice. We evaluate PVR's computational overhead compared with standard methods and observe improved reconstruction accuracy in the presence of affine motion artifacts compared with conventional SVR in synthetic experiments. Furthermore, we have evaluated our method qualitatively and quantitatively on real fetal MRI data subject to maternal breathing and sudden fetal movements. We evaluate peak-signal-to-noise ratio, structural similarity index, and cross correlation with respect to the originally acquired data and provide a method for visual inspection of reconstruction uncertainty. We further evaluate the distance error for selected anatomical landmarks in the fetal head, as well as calculating the mean and maximum displacements resulting from automatic non-rigid registration to a motion-free ground truth image. These experiments demonstrate a successful application of PVR motion compensation to the whole fetal body, uterus, and placenta.

  15. BASIC program to compute uranium density and void volume fraction in laboratory-scale uranium silicide aluminum dispersion plate-type fuel

    International Nuclear Information System (INIS)

    Ugajin, Mitsuhiro

    1991-05-01

    BASIC program simple and easy to operate has been developed to compute uranium density and void volume fraction for laboratory-scale uranium silicide aluminum dispersion plate-type fuel, so called miniplate. An example of the result of calculation is given in order to demonstrate how the calculated void fraction correlates with the microstructural distribution of the void in a miniplate prepared in our laboratory. The program is also able to constitute data base on important parameters for miniplates from experimentally-determined values of density, weight of each constituent and dimensions of miniplates. Utility programs pertinent to the development of the BASIC program are also given which run in the popular MS-DOS environment. All the source lists are attached and brief description for each program is made. (author)

  16. P08.52 Proton therapy re-Irradiation in large-volume recurrent glioblastoma.

    Science.gov (United States)

    Amelio, D.; Widesott, L.; Vennarini, S.; Fellin, F.; Maines, F.; Righetto, R.; Lorentini, S.; Farace, P.; Schwarz, M.; Amichetti, M.

    2016-01-01

    Abstract Purpose: To report preliminary results of re-irradiation with proton therapy (PT) in large-volume recurrent glioblastoma (rGBM). Matherial/Methods: Between January and December 2015 ten patients (pts) with rGBM were re-irradiated with PT. All pts were previously treated with photon radiotherapy (60 Gy) with concomitant and adjuvant TMZ for 1–20 cycles (median, 7). Seven pts were re-irradiated at first relapse/progression. Four patients were re-irradiated after partial tumor resection. Median age and Karnofsky performance status at re-irradiation were 57 years (range, 41–68) and 80%, (range, 70–100), respectively. Median time between prior radiotherapy and PT was 9 months (range, 5–24). Target definition was based on CT, MR, and 18F-DOPA PET imaging. GTV included any area of contrast enhancement after contrast medium administration plus any pathological PET uptake regions. CTV was generated by adding to GTV a 3-mm uniform margin manually corrected in proximity of anatomical barriers. CTV was expanded by 4 mm to create PTV. Median PTV volume was 90 cc (range, 46–231). All pts received 36 GyRBE in 18 fractions. Four pts also received concomitant temozolomide (75 mg/m2/die, 7 days/week). All pts were treated with active beam scanning PT using 2–3 fields with single field optimization technique. Results: All pts completed the treatment without breaks. Registered acute side effects (according to Common Terminology Criteria for Adverse Events version 4.0 - CTCAE) include grade 1–2 skin erythema, alopecia, fatigue, conjunctivitis, concentration impairment, dysphasia, and headache. There were no grade 3 or higher toxicities. One patient developed grade 1 neutropenia. Five pts started PT under steroids (2–7 mg/daily); two of them reduced the dose during PT, while three kept the same steroids dose. None of remaining pts needed steroids therapy. Registered late side effects (according to CTCAE version 4.0) include grade 1–2 alopecia, fatigue

  17. Annealing as grown large volume CZT single crystals for increased spectral resolution

    International Nuclear Information System (INIS)

    Li, Longxia

    2008-01-01

    The spectroscopic performance of current large-volume Cadmium 10% Zinc Telluride, Cd 0.9 Zn 0.1 Te, (CZT) detectors is impaired by cumulative effect of tellurium precipitates (secondary phases) presented in CZT single-crystal grown by low-pressure Bridgman techniques(1). This statistical effect may limit the energy resolution of large-volume CZT detectors (typically 2-5% at 662 keV for 12-mm thick devices). The stochastic nature of the interaction prevents the use of any electronic or digital charge correction techniques without a significant reduction in the detector efficiency. This volume constraint hampers the utility of CZT since the detectors are inefficient at detecting photons >1MeV and/or in low fluency situations. During the project, seven runs CZT ingots have been grown, in these ingots the indium dopant concentrations have been changed in the range between 0.5ppm to 6ppm. The I-R mapping imaging method has been employed to study the Te-precipitates. The Teprecipitates in as-grown CZT wafers, and after annealing wafers have been systematically studied by using I-R mapping system (home installed, resolution of 1.5 (micro)m). We employed our I-R standard annealing CZT (Zn=4%) procedure or two-steps annealing into radiation CZT (Zn=10%), we achieved the 'non'-Te precipitates (size 10 9-10 (Omega)-cm. We believe that the Te-precipitates are the p-type defects, its reducing number causes the CZT became n+-type, therefore we varied or reduced the indium dapant concentration during the growth and changed the Te-precipitates size and density by using different Cd-temperature and different annealing procedures. We have made the comparisons among Te-precipitates size, density and Indium dopant concentrations, and we found that the CZT with smaller size of Te-precipitates is suitable for radiation uses but non-Te precipitates is impossible to be used in the radiation detectors, because the CZT would became un-dopant or 'intrinsic' with non radiation affection (we

  18. 11C-methionine PET improves the target volume delineation of meningiomas treated with stereotactic fractionated radiotherapy

    International Nuclear Information System (INIS)

    Grosu, Anca-Ligia; Weber, Wolfgang A.; Astner, Sabrina T.; Adam, Markus; Krause, Bernd J.; Schwaiger, Markus; Molls, Michael; Nieder, Carsten

    2006-01-01

    Purpose: To evaluate the role of 11 C-methionine positron emission tomography (MET-PET) in target volume delineation for meningiomas and to determine the interobserver variability. Methods and Materials: Two independent observers performed treatment planning in 10 patients according to a prospective written protocol. In the first step, they used coregistered computed tomography (CT) and magnetic resonance imaging (MRI). In the second step, MET-PET was added to CT/MRI (image fusion based on mutual information). Results: The correlation between gross tumor volume (GTVs) delineated by the two observers based on CT/MRI was r = 0.855 (Spearman's correlation coefficient, p = 0.002) and r = 0.988 (p = 0.000) when MET-PET/CT/MRI were used. The number of patients with agreement in more then 80% of the outlined volume increased with the availability of MET-PET from 1 in 10 to 5 in 10. The median volume of intersection between the regions delineated by two observers increased significantly from 69% (from the composite volume) to 79%, by the addition of MET-PET (p = 0.005). The information of MET-PET was useful to delineate GTV in the area of cavernous sinus, orbit, and base of the skull. Conclusions: The hypothesis-generating findings of potential normal tissue sparing and reduced interobserver variability provide arguments for invasive studies of the correlation between MET-PET images and histologic tumor extension and for prospective trials of target volume delineation with CT/MRI/MET-PET image fusion

  19. A new large-volume metal reference standard for radioactive waste management.

    Science.gov (United States)

    Tzika, F; Hult, M; Stroh, H; Marissens, G; Arnold, D; Burda, O; Kovář, P; Suran, J; Listkowska, A; Tyminski, Z

    2016-03-01

    A new large-volume metal reference standard has been developed. The intended use is for calibration of free-release radioactivity measurement systems and is made up of cast iron tubes placed inside a box of the size of a Euro-pallet (80 × 120 cm). The tubes contain certified activity concentrations of (60)Co (0.290 ± 0.006 Bq g(-1)) and (110m)Ag (3.05 ± 0.09 Bq g(-1)) (reference date: 30 September 2013). They were produced using centrifugal casting from a smelt into which (60)Co was first added and then one piece of neutron irradiated silver wire was progressively diluted. The iron castings were machined to the desirable dimensions. The final material consists of 12 iron tubes of 20 cm outer diameter, 17.6 cm inner diameter, 40 cm length/height and 245.9 kg total mass. This paper describes the reference standard and the process of determining the reference activity values. © The Author 2015. Published by Oxford University Press.

  20. Low Energy Neutrino Astronomy in the future large-volume liquid-scintillator detector LENA

    International Nuclear Information System (INIS)

    Wurm, Michael; Feilitzsch, F V; Goeger-Neff, M; Lewke, T; Undagoitia, T Marrodan; Oberauer, L; Potzel, W; Todor, S; Winter, J

    2008-01-01

    The recent successes in neutrino physics prove that liquid-scintillator detectors allow to combine high energy resolution, efficient means of background reduction, and a large detection volume. In the planned LENA (Low Energy Neutrino Astronomy) experiment, a target mass of 50 kt will enable the investigation of a variety of terrestrial and astrophysical neutrino sources. The high-statistics spectroscopy of geoneutrinos, solar neutrinos and supernova neutrinos will provide new insights in the heat production processes of Earth and Sun, and the workings of a gravitational collapse. The same measurements will as well investigate neutrino properties as oscillation parameters and mass hierarchy. A first spectroscopic measurement of the low flux of diffuse supernova neutrino background is within the sensitivity of the LENA detector. Finally, a life-time limit of several 1034 years can be set to the proton decay into proton and anti-neutrino, testing the predictions of SUSY theory. The present contribution includes a review of the scientific studies that were performed in the last years as well as a report on currently on-going R and D activities.

  1. Plasma response to electron energy filter in large volume plasma device

    International Nuclear Information System (INIS)

    Sanyasi, A. K.; Awasthi, L. M.; Mattoo, S. K.; Srivastava, P. K.; Singh, S. K.; Singh, R.; Kaw, P. K.

    2013-01-01

    An electron energy filter (EEF) is embedded in the Large Volume Plasma Device plasma for carrying out studies on excitation of plasma turbulence by a gradient in electron temperature (ETG) described in the paper of Mattoo et al. [S. K. Mattoo et al., Phys. Rev. Lett. 108, 255007 (2012)]. In this paper, we report results on the response of the plasma to the EEF. It is shown that inhomogeneity in the magnetic field of the EEF switches on several physical phenomena resulting in plasma regions with different characteristics, including a plasma region free from energetic electrons, suitable for the study of ETG turbulence. Specifically, we report that localized structures of plasma density, potential, electron temperature, and plasma turbulence are excited in the EEF plasma. It is shown that structures of electron temperature and potential are created due to energy dependence of the electron transport in the filter region. On the other hand, although structure of plasma density has origin in the particle transport but two distinct steps of the density structure emerge from dominance of collisionality in the source-EEF region and of the Bohm diffusion in the EEF-target region. It is argued and experimental evidence is provided for existence of drift like flute Rayleigh-Taylor in the EEF plasma

  2. On 'light' fermions and proton stability in 'big divisor' D3/D7 large volume compactifications

    International Nuclear Information System (INIS)

    Misra, Aalok; Shukla, Pramod

    2011-01-01

    Building on our earlier work (Misra and Shukla, Nucl. Phys. B 827:112, 2010; Phys. Lett. B 685:347-352, 2010), we show the possibility of generating ''light'' fermion mass scales of MeV-GeV range (possibly related to the first two generations of quarks/leptons) as well as eV (possibly related to first two generations of neutrinos) in type IIB string theory compactified on Swiss-Cheese orientifolds in the presence of a mobile space-time filling D3-brane restricted to (in principle) stacks of fluxed D7-branes wrapping the ''big'' divisor Σ B . This part of the paper is an expanded version of the latter half of Sect. 3 of a published short invited review (Misra, Mod. Phys. Lett. A 26:1, 2011) written by one of the authors [AM ]. Further, we also show that there are no SUSY GUT-type dimension-five operators corresponding to proton decay, and we estimate the proton lifetime from a SUSY GUT-type four-fermion dimension-six operator to be 10 61 years. Based on GLSM calculations in (Misra and Shukla, Nucl. Phys. B 827:112, 2010) for obtaining the geometric Kaehler potential for the ''big divisor,'' using further the Donaldson's algorithm, we also briefly discuss in the first of the two appendices the metric for the Swiss-Cheese Calabi-Yau used, which we obtain and which becomes Ricci flat in the large-volume limit. (orig.)

  3. Detecting Boosted Dark Matter from the Sun with Large Volume Neutrino Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Joshua; /SLAC; Cui, Yanou; /Perimeter Inst. Theor. Phys.; Zhao, Yue; /Stanford U., ITP /Stanford U., Phys. Dept.

    2015-04-02

    We study novel scenarios where thermal dark matter (DM) can be efficiently captured in the Sun and annihilate into boosted dark matter. In models with semi-annihilating DM, where DM has a non-minimal stabilization symmetry, or in models with a multi-component DM sector, annihilations of DM can give rise to stable dark sector particles with moderate Lorentz boosts. We investigate both of these possibilities, presenting concrete models as proofs of concept. Both scenarios can yield viable thermal relic DM with masses O(1)-O(100) GeV. Taking advantage of the energetic proton recoils that arise when the boosted DM scatters off matter, we propose a detection strategy which uses large volume terrestrial detectors, such as those designed to detect neutrinos or proton decays. In particular, we propose a search for proton tracks pointing towards the Sun. We focus on signals at Cherenkov-radiation-based detectors such as Super-Kamiokande (SK) and its upgrade Hyper-Kamiokande (HK). We find that with spin-dependent scattering as the dominant DM-nucleus interaction at low energies, boosted DM can leave detectable signals at SK or HK, with sensitivity comparable to DM direct detection experiments while being consistent with current constraints. Our study provides a new search path for DM sectors with non-minimal structure.

  4. On `light' fermions and proton stability in `big divisor' D3/ D7 large volume compactifications

    Science.gov (United States)

    Misra, Aalok; Shukla, Pramod

    2011-06-01

    Building on our earlier work (Misra and Shukla, Nucl. Phys. B 827:112, 2010; Phys. Lett. B 685:347-352, 2010), we show the possibility of generating "light" fermion mass scales of MeV-GeV range (possibly related to the first two generations of quarks/leptons) as well as eV (possibly related to first two generations of neutrinos) in type IIB string theory compactified on Swiss-Cheese orientifolds in the presence of a mobile space-time filling D3-brane restricted to (in principle) stacks of fluxed D7-branes wrapping the "big" divisor Σ B . This part of the paper is an expanded version of the latter half of Sect. 3 of a published short invited review (Misra, Mod. Phys. Lett. A 26:1, 2011) written by one of the authors [AM]. Further, we also show that there are no SUSY GUT-type dimension-five operators corresponding to proton decay, and we estimate the proton lifetime from a SUSY GUT-type four-fermion dimension-six operator to be 1061 years. Based on GLSM calculations in (Misra and Shukla, Nucl. Phys. B 827:112, 2010) for obtaining the geometric Kähler potential for the "big divisor," using further the Donaldson's algorithm, we also briefly discuss in the first of the two appendices the metric for the Swiss-Cheese Calabi-Yau used, which we obtain and which becomes Ricci flat in the large-volume limit.

  5. Translational and Brownian motion in laser-Doppler flowmetry of large tissue volumes

    International Nuclear Information System (INIS)

    Binzoni, T; Leung, T S; Seghier, M L; Delpy, D T

    2004-01-01

    This study reports the derivation of a precise mathematical relationship existing between the different p-moments of the power spectrum of the photoelectric current, obtained from a laser-Doppler flowmeter (LDF), and the red blood cell speed. The main purpose is that both the Brownian (defining the 'biological zero') and the translational movements are taken into account, clarifying in this way what the exact contribution of each parameter is to the LDF derived signals. The derivation of the equations is based on the quasi-elastic scattering theory and holds for multiple scattering (i.e. measurements in large tissue volumes and/or very high red blood cell concentration). The paper also discusses why experimentally there exists a range in which the relationship between the first moment of the power spectrum and the average red blood cells speed may be considered as 'linear' and what are the physiological determinants that can result in nonlinearity. A correct way to subtract the biological zero from the LDF data is also proposed. The findings should help in the design of improved LDF instruments and in the interpretation of experimental data

  6. Coupled Finite Volume and Finite Element Method Analysis of a Complex Large-Span Roof Structure

    Science.gov (United States)

    Szafran, J.; Juszczyk, K.; Kamiński, M.

    2017-12-01

    The main goal of this paper is to present coupled Computational Fluid Dynamics and structural analysis for the precise determination of wind impact on internal forces and deformations of structural elements of a longspan roof structure. The Finite Volume Method (FVM) serves for a solution of the fluid flow problem to model the air flow around the structure, whose results are applied in turn as the boundary tractions in the Finite Element Method problem structural solution for the linear elastostatics with small deformations. The first part is carried out with the use of ANSYS 15.0 computer system, whereas the FEM system Robot supports stress analysis in particular roof members. A comparison of the wind pressure distribution throughout the roof surface shows some differences with respect to that available in the engineering designing codes like Eurocode, which deserves separate further numerical studies. Coupling of these two separate numerical techniques appears to be promising in view of future computational models of stochastic nature in large scale structural systems due to the stochastic perturbation method.

  7. Low Energy Neutrino Astronomy in the future large-volume liquid-scintillator detector LENA

    Energy Technology Data Exchange (ETDEWEB)

    Wurm, Michael; Feilitzsch, F V; Goeger-Neff, M; Lewke, T; Undagoitia, T Marrodan; Oberauer, L; Potzel, W; Todor, S; Winter, J [E15 Chair for Astroparticle Physics, Technische Universitat Miinchen, Physik Department, James-Franck-Str., D-85748 Garching (Germany)

    2008-11-01

    The recent successes in neutrino physics prove that liquid-scintillator detectors allow to combine high energy resolution, efficient means of background reduction, and a large detection volume. In the planned LENA (Low Energy Neutrino Astronomy) experiment, a target mass of 50 kt will enable the investigation of a variety of terrestrial and astrophysical neutrino sources. The high-statistics spectroscopy of geoneutrinos, solar neutrinos and supernova neutrinos will provide new insights in the heat production processes of Earth and Sun, and the workings of a gravitational collapse. The same measurements will as well investigate neutrino properties as oscillation parameters and mass hierarchy. A first spectroscopic measurement of the low flux of diffuse supernova neutrino background is within the sensitivity of the LENA detector. Finally, a life-time limit of several 1034 years can be set to the proton decay into proton and anti-neutrino, testing the predictions of SUSY theory. The present contribution includes a review of the scientific studies that were performed in the last years as well as a report on currently on-going R and D activities.

  8. High-Dimensional Function Approximation With Neural Networks for Large Volumes of Data.

    Science.gov (United States)

    Andras, Peter

    2018-02-01

    Approximation of high-dimensional functions is a challenge for neural networks due to the curse of dimensionality. Often the data for which the approximated function is defined resides on a low-dimensional manifold and in principle the approximation of the function over this manifold should improve the approximation performance. It has been show that projecting the data manifold into a lower dimensional space, followed by the neural network approximation of the function over this space, provides a more precise approximation of the function than the approximation of the function with neural networks in the original data space. However, if the data volume is very large, the projection into the low-dimensional space has to be based on a limited sample of the data. Here, we investigate the nature of the approximation error of neural networks trained over the projection space. We show that such neural networks should have better approximation performance than neural networks trained on high-dimensional data even if the projection is based on a relatively sparse sample of the data manifold. We also find that it is preferable to use a uniformly distributed sparse sample of the data for the purpose of the generation of the low-dimensional projection. We illustrate these results considering the practical neural network approximation of a set of functions defined on high-dimensional data including real world data as well.

  9. A Parallel, Finite-Volume Algorithm for Large-Eddy Simulation of Turbulent Flows

    Science.gov (United States)

    Bui, Trong T.

    1999-01-01

    A parallel, finite-volume algorithm has been developed for large-eddy simulation (LES) of compressible turbulent flows. This algorithm includes piecewise linear least-square reconstruction, trilinear finite-element interpolation, Roe flux-difference splitting, and second-order MacCormack time marching. Parallel implementation is done using the message-passing programming model. In this paper, the numerical algorithm is described. To validate the numerical method for turbulence simulation, LES of fully developed turbulent flow in a square duct is performed for a Reynolds number of 320 based on the average friction velocity and the hydraulic diameter of the duct. Direct numerical simulation (DNS) results are available for this test case, and the accuracy of this algorithm for turbulence simulations can be ascertained by comparing the LES solutions with the DNS results. The effects of grid resolution, upwind numerical dissipation, and subgrid-scale dissipation on the accuracy of the LES are examined. Comparison with DNS results shows that the standard Roe flux-difference splitting dissipation adversely affects the accuracy of the turbulence simulation. For accurate turbulence simulations, only 3-5 percent of the standard Roe flux-difference splitting dissipation is needed.

  10. A model for steady-state large-volume plasma generation

    International Nuclear Information System (INIS)

    Uhm, H.S.; Miller, J.D.; Schneider, R.F.

    1991-01-01

    In this paper, a simple, new scheme to generate a uniform, steady-state, large-volume plasma is presented. The weakly magnetized plasma is created by direct ionization of the background gas by low-energy electrons generated from thermionic filaments. An annular arrangement of the filaments ensures a uniform plasma density in the radial direction as predicted by theory. Experiments have been performed to characterize the plasma generated in such a configuration. In order to explain the experimental observation, we develop a bulk plasma theory based on plasma transport via cross-field diffusion. As assumed in the theoretical model, the experimental measurements indicate a uniform plasma density along the axis. Both the theory and experiment indicate that the plasma density is a function of the square of the external magnetic field. The theory also predicts the plasma density to be proportional to the neutral density to the two-thirds power in agreement with the experimental data. We also observe the experimental data to agree remarkably well with theoretical prediction for a broad range of system parameters

  11. A uniform laminar air plasma plume with large volume excited by an alternating current voltage

    Science.gov (United States)

    Li, Xuechen; Bao, Wenting; Chu, Jingdi; Zhang, Panpan; Jia, Pengying

    2015-12-01

    Using a plasma jet composed of two needle electrodes, a laminar plasma plume with large volume is generated in air through an alternating current voltage excitation. Based on high-speed photography, a train of filaments is observed to propagate periodically away from their birth place along the gas flow. The laminar plume is in fact a temporal superposition of the arched filament train. The filament consists of a negative glow near the real time cathode, a positive column near the real time anode, and a Faraday dark space between them. It has been found that the propagation velocity of the filament increases with increasing the gas flow rate. Furthermore, the filament lifetime tends to follow a normal distribution (Gaussian distribution). The most probable lifetime decreases with increasing the gas flow rate or decreasing the averaged peak voltage. Results also indicate that the real time peak current decreases and the real time peak voltage increases with the propagation of the filament along the gas flow. The voltage-current curve indicates that, in every discharge cycle, the filament evolves from a Townsend discharge to a glow one and then the discharge quenches. Characteristic regions including a negative glow, a Faraday dark space, and a positive column can be discerned from the discharge filament. Furthermore, the plasma parameters such as the electron density, the vibrational temperature and the gas temperature are investigated based on the optical spectrum emitted from the laminar plume.

  12. Reduced Albumin Dosing During Large-Volume Paracentesis Is Not Associated with Adverse Clinical Outcomes.

    Science.gov (United States)

    Johnson, Kara B; Mueller, Jessica L; Simon, Tracey G; Zheng, Hui; King, Lindsay Y; Makar, Robert S; Gervais, Debra A; Chung, Raymond T

    2015-07-01

    LVP is used to manage diuretic-resistant ascites in cirrhotic patients. Albumin administration prevents complications including acute kidney injury and paracentesis-induced circulatory dysfunction, but the optimal dose is unclear. We sought to assess adherence to guidelines enacted in July 2011 at our center for reducing the albumin dose administered at large-volume paracentesis (LVP) and evaluate the cost and rate of complications of LVPs before and after guideline enactment. All LVPs performed on cirrhotic patients in our center's Department of Radiology between July 2009 and January 2014 were studied. Outcomes included adherence to guidelines, LVP complications, and administered albumin cost. Groups were compared using Student's t tests for continuous data and Chi-square or Fisher's exact tests for categorical data. A repeated measurements model accounted for patients with multiple LVPs. Of the 935 LVPs, 288 occurred before guideline implementation (group 1) and 647 occurred after (group 2). The mean dose of albumin administered was 13.7 g/L of ascites removed in group 1 versus 10.3 g/L in group 2 (p albumin administration and associated cost savings was still observed. There was no increase in LVP-related complications after guideline implementation or in the adherent group, suggesting that albumin dose can be safely reduced. Future efforts should be directed at enhancing guideline adherence and potentially further reducing albumin dosing.

  13. A simple method for the production of large volume 3D macroporous hydrogels for advanced biotechnological, medical and environmental applications

    Science.gov (United States)

    Savina, Irina N.; Ingavle, Ganesh C.; Cundy, Andrew B.; Mikhalovsky, Sergey V.

    2016-02-01

    The development of bulk, three-dimensional (3D), macroporous polymers with high permeability, large surface area and large volume is highly desirable for a range of applications in the biomedical, biotechnological and environmental areas. The experimental techniques currently used are limited to the production of small size and volume cryogel material. In this work we propose a novel, versatile, simple and reproducible method for the synthesis of large volume porous polymer hydrogels by cryogelation. By controlling the freezing process of the reagent/polymer solution, large-scale 3D macroporous gels with wide interconnected pores (up to 200 μm in diameter) and large accessible surface area have been synthesized. For the first time, macroporous gels (of up to 400 ml bulk volume) with controlled porous structure were manufactured, with potential for scale up to much larger gel dimensions. This method can be used for production of novel 3D multi-component macroporous composite materials with a uniform distribution of embedded particles. The proposed method provides better control of freezing conditions and thus overcomes existing drawbacks limiting production of large gel-based devices and matrices. The proposed method could serve as a new design concept for functional 3D macroporous gels and composites preparation for biomedical, biotechnological and environmental applications.

  14. Calculation of left ventricular volume and ejection fraction from ECG-gated myocardial SPECT. Automatic detection of endocardial borders by threshold method

    International Nuclear Information System (INIS)

    Fukushi, Shoji; Teraoka, Satomi.

    1997-01-01

    A new method which calculate end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (LVEF) of the left ventricle from myocardial short axis images of ECG-gated SPECT using 99m Tc myocardial perfusion tracer has been designed. Eight frames per cardiac cycle ECG-gated 180 degrees SPECT was performed. Threshold method was used to detect myocardial borders automatically. The optimal threshold was 45% by myocardial SPECT phantom. To determine if EDV, ESV and LVEF can also be calculated by this method, 12 patients were correlated ventriculography (LVG) for 10 days each. The correlation coefficient with LVG was 0.918 (EDV), 0.935 (ESV) and 0.900 (LVEF). This method is excellent at objectivity and reproductivity because of the automatic detection of myocardial borders. It also provides useful information on heart function in addition to myocardial perfusion. (author)

  15. Endochondral fracture healing with external fixation in the Sost knockout mouse results in earlier fibrocartilage callus removal and increased bone volume fraction and strength.

    Science.gov (United States)

    Morse, A; Yu, N Y C; Peacock, L; Mikulec, K; Kramer, I; Kneissel, M; McDonald, M M; Little, D G

    2015-02-01

    Sclerostin deficiency, via genetic knockout or anti-Sclerostin antibody treatment, has been shown to cause increased bone volume, density and strength of calluses following endochondral bone healing. However, there is limited data on the effect of Sclerostin deficiency on the formative early stage of fibrocartilage (non-bony tissue) formation and removal. In this study we extensively investigate the early fibrocartilage callus. Closed tibial fractures were performed on Sost(-/-) mice and age-matched wild type (C57Bl/6J) controls and assessed at multiple early time points (7, 10 and 14days), as well as at 28days post-fracture after bony union. External fixation was utilized, avoiding internal pinning and minimizing differences in stability stiffness, a variable that has confounded previous research in this area. Normal endochondral ossification progressed in wild type and Sost(-/-) mice with equivalent volumes of fibrocartilage formed at early day 7 and day 10 time points, and bony union in both genotypes by day 28. There were no significant differences in rate of bony union; however there were significant increases in fibrocartilage removal from the Sost(-/-) fracture calluses at day 14 suggesting earlier progression of endochondral healing. Earlier bone formation was seen in Sost(-/-) calluses over wild type with greater bone volume at day 10 (221%, p<0.01). The resultant Sost(-/-) united bony calluses at day 28 had increased bone volume fraction compared to wild type calluses (24%, p<0.05), and the strength of the fractured Sost(-/-) tibiae was greater than that that of wild type fractured tibiae. In summary, bony union was not altered by Sclerostin deficiency in externally-fixed closed tibial fractures, but fibrocartilage removal was enhanced and the resultant united bony calluses had increased bone fraction and increased strength. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

  16. Evaluation of a laser scanner for large volume coordinate metrology: a comparison of results before and after factory calibration

    International Nuclear Information System (INIS)

    Ferrucci, M; Muralikrishnan, B; Sawyer, D; Phillips, S; Petrov, P; Yakovlev, Y; Astrelin, A; Milligan, S; Palmateer, J

    2014-01-01

    Large volume laser scanners are increasingly being used for a variety of dimensional metrology applications. Methods to evaluate the performance of these scanners are still under development and there are currently no documentary standards available. This paper describes the results of extensive ranging and volumetric performance tests conducted on a large volume laser scanner. The results demonstrated small but clear systematic errors that are explained in the context of a geometric error model for the instrument. The instrument was subsequently returned to the manufacturer for factory calibration. The ranging and volumetric tests were performed again and the results are compared against those obtained prior to the factory calibration. (paper)

  17. “Finite” non-Gaussianities and tensor-scalar ratio in large volume Swiss-cheese compactifications

    Science.gov (United States)

    Misra, Aalok; Shukla, Pramod

    2009-03-01

    Developing on the ideas of (Section 4 of) [A. Misra, P. Shukla, Moduli stabilization, large-volume dS minimum without anti-D3-branes, (non-)supersymmetric black hole attractors and two-parameter Swiss cheese Calabi-Yau's, Nucl. Phys. B 799 (2008) 165-198, arXiv: 0707.0105] and [A. Misra, P. Shukla, Large volume axionic Swiss-cheese inflation, Nucl. Phys. B 800 (2008) 384-400, arXiv: 0712.1260 [hep-th

  18. Large parallel volumes of finite and compact sets in d-dimensional Euclidean space

    DEFF Research Database (Denmark)

    Kampf, Jürgen; Kiderlen, Markus

    The r-parallel volume V (Cr) of a compact subset C in d-dimensional Euclidean space is the volume of the set Cr of all points of Euclidean distance at most r > 0 from C. According to Steiner’s formula, V (Cr) is a polynomial in r when C is convex. For finite sets C satisfying a certain geometric...

  19. Effect of the metallic glass volume fraction on the mechanical properties of Zr-based metallic glass reinforced with porous W composite

    International Nuclear Information System (INIS)

    Zhang, X.Q.; Wang, L.; Xue, Y.F.; Cheng, X.W.; Wang, Y.D.; Nie, Z.H.; Zhang, H.F.; Fu, H.M.; Ma, L.L.; Ren, Y.

    2013-01-01

    The mechanical properties of both as-cast and as-extruded Zr-based metallic glass reinforced with tungsten composites with 33, 28, and 21 vol. % of metallic glass were investigated under quasi-static compression at strain rates from 10 −4 s −1 to 10 −1 s −1 . These two types of composites exhibited a strain rate sensitivity exponent that increased with the increase of the tungsten volume fraction. Compared to the composites with 33 and 21 vol. % of the metallic glass, the two types of composites with 28 vol. % of the metallic glass phase exhibited superior fracture energies. The in-situ compression test on the as-cast composites using high-energy synchrotron X-ray diffraction (HEXRD) revealed that the yield stress of the tungsten phase increased with a decrease in the metallic glass volume fraction. The as-cast composite with 28 vol. % of the metallic glass exhibited relatively great mechanical properties compared to the composites that contained 33 and 21 vol. % of the metallic glass. This result was attributed to the great coupling of the load distribution between the two phases and the high lattice strain in the tungsten phase.

  20. Temperature effect on the inter-micellar collision and maximum packaging volume fraction in water/AOT/isooctane micro-emulsions

    International Nuclear Information System (INIS)

    Guettari, Moez; Ben Naceur, Imen; Kassab, Ghazi; Tajouri, Tahar

    2016-01-01

    We have studied the viscosity behaviour of water/AOT/isooctane micro-emulsions as a function of the volume fraction of the dispersed phase over a temperature range from the (298.15 to 328.15) K. For all the studied temperature range, a sharp increase of the viscosities is observed when the droplets concentration was varied. Several equations based on hard sphere model were examined to explain the behaviours of micro-emulsions under temperature and concentration effects. According to these equations, the shape factor and the inter-particle interaction parameters were found to be dependent on temperature which is in contradiction with experimental results reported in the literature. A modified Vand equation, taking into account the inter-particle collision time, is used to interpret the results obtained. This deviation is attributed to the aggregation of the droplets which becomes important by increasing temperature. The maximum packaging volume fraction of particles Φ_d_m and the intrinsic viscosity [η] were determined according to the Krieger and Dougherty equation through the temperature range studied. These two parameters were shown to be dependent on temperature but their product was found to be constant and close to 2 as reported in theory.

  1. Type IIB orientifolds, D-brane instantons and the large volume scenario

    Energy Technology Data Exchange (ETDEWEB)

    Plauschinn, Erik

    2009-07-28

    This thesis is concerned with a branch of research in String Theory called String Phenomenology which aims for a better understanding of the connection between String Theory and Particle Physics. In particular, in this work we cover three topics which are important in order to establish this connection. The first topic is about String Theory model building in the context of so-called type IIB orientifolds with orientifold three- and seven-planes. After giving a brief overview, we work out in detail an important consistency condition for String Theory constructions, the so-called tadpole cancellation condition, and we verify explicitly that chiral anomalies are cancelled via the generalised Green-Schwarz mechanism. The second topic is concerned with so-called D-brane instantons which are nonperturbative effects in type II String Theory constructions. We recall the instanton calculus for such configurations, we derive the so-called A eck-Dine-Seiberg superpotential in String Theory and we develop an important constraint, a chiral zero-mode constraint, for instanton contributions in the presence of a realistic Particle Physics sector. The third topic is about moduli stabilisation in type IIB string compactifications. More concretely, we review the so-called KKLT as well as Large Volume Scenario, and we construct and study a model for the latter scenario where the constraint mentioned above has been taken into account explicitly. Although the three topics studied in this thesis are slightly different in nature, there is nevertheless a complex interplay between them with many interrelations. In order to uncover these connections, a detailed study of each individual subject has been performed which has led to new results such as the chiral zero-mode constraint. (orig.)

  2. Addressing challenges in bar-code scanning of large-volume infusion bags.

    Science.gov (United States)

    Raman, Kirthana; Heelon, Mark; Kerr, Gary; Higgins, Thomas L

    2011-08-01

    A hospital pharmacy's efforts to identify and address challenges with bedside scanning of bar codes on large-volume parenteral (LVP) infusion bags are described. Bar-code-assisted medication administration (BCMA) has been shown to reduce medication errors and improve patient safety. After the pilot implementation of a BCMA system and point-of-care scanning procedures at a medical center's intensive care unit, it was noted that nurses' attempted bedside scans of certain LVP bags for product identification purposes often were not successful. An investigation and root-cause analysis, including observation of nurses' scanning technique by a multidisciplinary team, determined that the scanning failures stemmed from the placement of two bar-code imprints-one with the product identification code and another, larger imprint with the expiration date and lot number-adjacently on the LVP bags. The nursing staff was educated on a modified scanning technique, which resulted in significantly improved success rates in the scanning of the most commonly used LVP bags. Representatives of the LVP bag manufacturer met with hospital staff to discuss the problem and corrective measures. As part of a subsequent infusion bag redesign, the manufacturer discontinued the use of the bar-code imprint implicated in the scanning failures. Failures in scanning LVP bags were traced to problematic placement of bar-code imprints on the bags. Interdisciplinary collaboration, consultation with the bag manufacturer, and education of the nursing and pharmacy staff resulted in a reduction in scanning failures and the manufacturer's removal of one of the bar codes from its LVP bags.

  3. Type IIB orientifolds, D-brane instantons and the large volume scenario

    International Nuclear Information System (INIS)

    Plauschinn, Erik

    2009-01-01

    This thesis is concerned with a branch of research in String Theory called String Phenomenology which aims for a better understanding of the connection between String Theory and Particle Physics. In particular, in this work we cover three topics which are important in order to establish this connection. The first topic is about String Theory model building in the context of so-called type IIB orientifolds with orientifold three- and seven-planes. After giving a brief overview, we work out in detail an important consistency condition for String Theory constructions, the so-called tadpole cancellation condition, and we verify explicitly that chiral anomalies are cancelled via the generalised Green-Schwarz mechanism. The second topic is concerned with so-called D-brane instantons which are nonperturbative effects in type II String Theory constructions. We recall the instanton calculus for such configurations, we derive the so-called A eck-Dine-Seiberg superpotential in String Theory and we develop an important constraint, a chiral zero-mode constraint, for instanton contributions in the presence of a realistic Particle Physics sector. The third topic is about moduli stabilisation in type IIB string compactifications. More concretely, we review the so-called KKLT as well as Large Volume Scenario, and we construct and study a model for the latter scenario where the constraint mentioned above has been taken into account explicitly. Although the three topics studied in this thesis are slightly different in nature, there is nevertheless a complex interplay between them with many interrelations. In order to uncover these connections, a detailed study of each individual subject has been performed which has led to new results such as the chiral zero-mode constraint. (orig.)

  4. A pomegranate-inspired nanoscale design for large-volume-change lithium battery anodes

    Science.gov (United States)

    Liu, Nian; Lu, Zhenda; Zhao, Jie; McDowell, Matthew T.; Lee, Hyun-Wook; Zhao, Wenting; Cui, Yi

    2014-03-01

    Silicon is an attractive material for anodes in energy storage devices, because it has ten times the theoretical capacity of its state-of-the-art carbonaceous counterpart. Silicon anodes can be used both in traditional lithium-ion batteries and in more recent Li-O2 and Li-S batteries as a replacement for the dendrite-forming lithium metal anodes. The main challenges associated with silicon anodes are structural degradation and instability of the solid-electrolyte interphase caused by the large volume change (~300%) during cycling, the occurrence of side reactions with the electrolyte, and the low volumetric capacity when the material size is reduced to a nanometre scale. Here, we propose a hierarchical structured silicon anode that tackles all three of these problems. Our design is inspired by the structure of a pomegranate, where single silicon nanoparticles are encapsulated by a conductive carbon layer that leaves enough room for expansion and contraction following lithiation and delithiation. An ensemble of these hybrid nanoparticles is then encapsulated by a thicker carbon layer in micrometre-size pouches to act as an electrolyte barrier. As a result of this hierarchical arrangement, the solid-electrolyte interphase remains stable and spatially confined, resulting in superior cyclability (97% capacity retention after 1,000 cycles). In addition, the microstructures lower the electrode-electrolyte contact area, resulting in high Coulombic efficiency (99.87%) and volumetric capacity (1,270 mAh cm-3), and the cycling remains stable even when the areal capacity is increased to the level of commercial lithium-ion batteries (3.7 mAh cm-2).

  5. Is 16-frame really superior to 8-frame gated SPECT for the assessment of left ventricular volumes and ejection fraction? Comparison of two simultaneously acquired gated SPECT studies

    International Nuclear Information System (INIS)

    Montelatici, Giulia; Sciagra, Roberto; Passeri, Alessandro; Dona, Manjola; Pupi, Alberto

    2008-01-01

    Conflicting data exist about the difference between 8- and 16-frame gated single-photon emission computed tomography (SPECT) left ventricular volumes and ejection fraction (EF); moreover, the influence of framing on detection of stress-induced functional changes is unknown. In 133 patients, two separate gated SPECT studies, one with 8 and one with 16 frames, were simultaneously acquired during a single gantry orbit using dedicated software. In 33 of 133 patients, two additional studies (with 8 and 16 frames, respectively) were acquired using arrhythmia rejection. Left ventricular EF and volumes were calculated using the QGS software. Stress-induced ischemia was identified on summed perfusion images. Arrhythmia-rejection did not influence volumes and EF independently of framing rate. Using data without arrhythmia-rejection, there was a significant difference in volumes and EF between 8 and 16 frames both in resting and post-stress gated SPECT. However, the difference was small: 2.6% for resting and 2.8% for post-stress EF. Both using 8 and 16 frames, there were significantly larger volumes and lower EF in patients with than without stress-induced ischemia. A stress-induced decrease >5 EF units was observed in 26 of 133 patients using 8 and in 23 of 133 using 16 frames, respectively, with finding agreement in 19 patients. Comparing two simultaneously acquired studies, the use of 16 instead of 8 frames has minor and predictable influence on functional data. Furthermore, there are no differences in the detection of stress-induced functional changes. The advantage of 16 over 8 frames in the daily clinical practice appears questionable. (orig.)

  6. Comparison of echocardiographic and cardiac magnetic resonance imaging measurements of functional single ventricular volumes, mass, and ejection fraction (from the Pediatric Heart Network Fontan Cross-Sectional Study).

    Science.gov (United States)

    Margossian, Renee; Schwartz, Marcy L; Prakash, Ashwin; Wruck, Lisa; Colan, Steven D; Atz, Andrew M; Bradley, Timothy J; Fogel, Mark A; Hurwitz, Lynne M; Marcus, Edward; Powell, Andrew J; Printz, Beth F; Puchalski, Michael D; Rychik, Jack; Shirali, Girish; Williams, Richard; Yoo, Shi-Joon; Geva, Tal

    2009-08-01

    Assessment of the size and function of a functional single ventricle (FSV) is a key element in the management of patients after the Fontan procedure. Measurement variability of ventricular mass, volume, and ejection fraction (EF) among observers by echocardiography and cardiac magnetic resonance imaging (CMR) and their reproducibility among readers in these patients have not been described. From the 546 patients enrolled in the Pediatric Heart Network Fontan Cross-Sectional Study (mean age 11.9 +/- 3.4 years), 100 echocardiograms and 50 CMR studies were assessed for measurement reproducibility; 124 subjects with paired studies were selected for comparison between modalities. Interobserver agreement for qualitative grading of ventricular function by echocardiography was modest for left ventricular (LV) morphology (kappa = 0.42) and weak for right ventricular (RV) morphology (kappa = 0.12). For quantitative assessment, high intraclass correlation coefficients were found for echocardiographic interobserver agreement (LV 0.87 to 0.92, RV 0.82 to 0.85) of systolic and diastolic volumes, respectively. In contrast, intraclass correlation coefficients for LV and RV mass were moderate (LV 0.78, RV 0.72). The corresponding intraclass correlation coefficients by CMR were high (LV 0.96, RV 0.85). Volumes by echocardiography averaged 70% of CMR values. Interobserver reproducibility for the EF was similar for the 2 modalities. Although the absolute mean difference between modalities for the EF was small (<2%), 95% limits of agreement were wide. In conclusion, agreement between observers of qualitative FSV function by echocardiography is modest. Measurements of FSV volume by 2-dimensional echocardiography underestimate CMR measurements, but their reproducibility is high. Echocardiographic and CMR measurements of FSV EF demonstrate similar interobserver reproducibility, whereas measurements of FSV mass and LV diastolic volume are more reproducible by CMR.

  7. A glimpse beneath Antarctic sea ice: observation of platelet-layer thickness and ice-volume fraction with multi-frequency EM

    Science.gov (United States)

    Hendricks, S.; Hoppmann, M.; Hunkeler, P. A.; Kalscheuer, T.; Gerdes, R.

    2015-12-01

    In Antarctica, ice crystals (platelets) form and grow in supercooled waters below ice shelves. These platelets rise and accumulate beneath nearby sea ice to form a several meter thick sub-ice platelet layer. This special ice type is a unique habitat, influences sea-ice mass and energy balance, and its volume can be interpreted as an indicator for ice - ocean interactions. Although progress has been made in determining and understanding its spatio-temporal variability based on point measurements, an investigation of this phenomenon on a larger scale remains a challenge due to logistical constraints and a lack of suitable methodology. In the present study, we applied a lateral constrained Marquardt-Levenberg inversion to a unique multi-frequency electromagnetic (EM) induction sounding dataset obtained on the ice-shelf influenced fast-ice regime of Atka Bay, eastern Weddell Sea. We adapted the inversion algorithm to incorporate a sensor specific signal bias, and confirmed the reliability of the algorithm by performing a sensitivity study using synthetic data. We inverted the field data for sea-ice and sub-ice platelet-layer thickness and electrical conductivity, and calculated ice-volume fractions from platelet-layer conductivities using Archie's Law. The thickness results agreed well with drill-hole validation datasets within the uncertainty range, and the ice-volume fraction also yielded plausible results. Our findings imply that multi-frequency EM induction sounding is a suitable approach to efficiently map sea-ice and platelet-layer properties. However, we emphasize that the successful application of this technique requires a break with traditional EM sensor calibration strategies due to the need of absolute calibration with respect to a physical forward model.

  8. Morphological pyramids in multiresolution MIP rendering of large volume data : Survey and new results

    NARCIS (Netherlands)

    Roerdink, J.B.T.M.

    We survey and extend nonlinear signal decompositions based on morphological pyramids, and their application to multiresolution maximum intensity projection (MIP) volume rendering with progressive refinement and perfect reconstruction. The structure of the resulting multiresolution rendering

  9. Design and performance of large-pixel-size high-fill-fraction TES arrays for future X-ray astrophysics missions

    International Nuclear Information System (INIS)

    Figueroa-Feliciano, E.; Bandler, S.R.; Chervenak, J.; Finkbeiner, F.; Iyomoto, N.; Kelley, R.L.; Kilbourne, C.A.; Porter, F.S.; Saab, T.; Sadleir, J.; White, J.

    2006-01-01

    We have designed, modeled, fabricated and tested a 600μm high-fill-fraction microcalorimeter array that will be a good match to the requirements of future X-ray missions. Our devices use transition-edge sensors coupled to overhanging bismuth/copper absorbers to produce arrays with 97% or higher fill fraction. An extensive modeling effort was undertaken in order to accommodate large pixel sizes (500-1000μm) and maintain the best energy resolution possible. The finite thermalization time of the large absorber and the associated position dependence of the pulse shape on absorption position constrain the time constants of the system given a desired energy-resolution performance. We show the results of our analysis and our new pixel design, consisting of a novel TES-on-the-side architecture which creates a controllable TES-absorber conductance

  10. Effect of crowd size on patient volume at a large, multipurpose, indoor stadium.

    Science.gov (United States)

    De Lorenzo, R A; Gray, B C; Bennett, P C; Lamparella, V J

    1989-01-01

    A prediction of patient volume expected at "mass gatherings" is desirable in order to provide optimal on-site emergency medical care. While several methods of predicting patient loads have been suggested, a reliable technique has not been established. This study examines the frequency of medical emergencies at the Syracuse University Carrier Dome, a 50,500-seat indoor stadium. Patient volume and level of care at collegiate basketball and football games as well as rock concerts, over a 7-year period were examined and tabulated. This information was analyzed using simple regression and nonparametric statistical methods to determine level of correlation between crowd size and patient volume. These analyses demonstrated no statistically significant increase in patient volume for increasing crowd size for basketball and football events. There was a small but statistically significant increase in patient volume for increasing crowd size for concerts. A comparison of similar crowd size for each of the three events showed that patient frequency is greatest for concerts and smallest for basketball. The study suggests that crowd size alone has only a minor influence on patient volume at any given event. Structuring medical services based solely on expected crowd size and not considering other influences such as event type and duration may give poor results.

  11. Dosimetric Comparison of Split Field and Fixed Jaw Techniques for Large IMRT Target Volumes in the Head and Neck

    International Nuclear Information System (INIS)

    Srivastava, Shiv P.; Das, Indra J.; Kumar, Arvind; Johnstone, Peter A.S.

    2011-01-01

    Some treatment planning systems (TPSs), when used for large-field (>14 cm) intensity-modulated radiation therapy (IMRT), create split fields that produce excessive multiple-leaf collimator segments, match-line dose inhomogeneity, and higher treatment times than nonsplit fields. A new method using a fixed-jaw technique (FJT) forces the jaw to stay at a fixed position during optimization and is proposed to reduce problems associated with split fields. Dosimetric comparisons between split-field technique (SFT) and FJT used for IMRT treatment is presented. Five patients with head and neck malignancies and regional target volumes were studied and compared with both techniques. Treatment planning was performed on an Eclipse TPS using beam data generated for Varian 2100C linear accelerator. A standard beam arrangement consisting of nine coplanar fields, equally spaced, was used in both techniques. Institutional dose-volume constraints used in head and neck cancer were kept the same for both techniques. The dosimetric coverage for the target volumes between SFT and FJT for head and neck IMRT plan is identical within ±1% up to 90% dose. Similarly, the organs at risk (OARs) have dose-volume coverage nearly identical for all patients. When the total monitor unit (MU) and segments were analyzed, SFT produces statistically significant higher segments (17.3 ± 6.3%) and higher MU (13.7 ± 4.4%) than the FJT. There is no match line in FJT and hence dose uniformity in the target volume is superior to the SFT. Dosimetrically, SFT and FJT are similar for dose-volume coverage; however, the FJT method provides better logistics, lower MU, shorter treatment time, and better dose uniformity. The number of segments and MU also has been correlated with the whole body radiation dose with long-term complications. Thus, FJT should be the preferred option over SFT for large target volumes.

  12. Process Improvement to Enhance Quality in a Large Volume Labor and Birth Unit.

    Science.gov (United States)

    Bell, Ashley M; Bohannon, Jessica; Porthouse, Lisa; Thompson, Heather; Vago, Tony

    using the Lean process, frontline clinicians identified areas that needed improvement, developed and implemented successful strategies that addressed each gap, and enhanced the quality and safety of care for a large volume perinatal service.

  13. State of art data acquisition system for large volume plasma device

    International Nuclear Information System (INIS)

    Sugandhi, Ritesh; Srivastava, Pankaj; Sanyasi, Amulya Kumar; Srivastav, Prabhakar; Awasthi, Lalit Mohan; Mattoo, Shiban Krishna; Parmar, Vijay; Makadia, Keyur; Patel, Ishan; Shah, Sandeep

    2015-01-01

    The Large volume plasma device (LVPD) is a cylindrical device (ϕ = 2m, L = 3m) dedicated for carrying out investigations on plasma physics problems ranging from excitation of whistler structures to plasma turbulence especially, exploring the linear and nonlinear aspects of electron temperature gradient(ETG) driven turbulence, plasma transport over the entire cross section of LVPD. The machine operates in a pulsed mode with repetition cycle of 1 Hz and acquisition pulse length of duration of 15 ms, presently, LVPD has VXI data acquisition system but this is now in phasing out mode because of non-functioning of its various amplifier stages, expandability and unavailability of service support. The VXI system has limited capabilities to meet new experimental requirements in terms of numbers of channel (16), bit resolutions (8 bit), record length (30K points) and calibration support. Recently, integration of new acquisition system for simultaneous sampling of 40 channels of data, collected over multiple time scales with high speed is successfully demonstrated, by configuring latest available hardware and in-house developed software solutions. The operational feasibility provided by LabVIEW platform is not only for operating DAQ system but also for providing controls to various subsystems associated with the device. The new system is based on PXI express instrumentation bus and supersedes the existing VXI based data acquisition system in terms of instrumentation capabilities. This system has capability to measure 32 signals at 60 MHz sampling frequency and 8 signals with 1.25 GHz with 10 bit and 12 bit resolution capability for amplitude measurements. The PXI based system successfully addresses and demonstrate the issues concerning high channel count, high speed data streaming and multiple I/O modules synchronization. The system consists of chassis (NI 1085), 4 high sampling digitizers (NI 5105), 2 very high sampling digitizers (NI 5162), data streaming RAID drive (NI

  14. Temperature monitoring in large volume spread footing foundations: case study "Parque da Cidade" - São Paulo

    Directory of Open Access Journals (Sweden)

    D. Couto

    Full Text Available ABSTRACT In recent years, the construction of foundation elements from large-volume reinforced concrete is becoming increasingly common. This implies a potential increase in the risk of cracks of thermal origin, due to the heat of hydration of cement. Under these circumstances, these concrete elements need to be treated using the mass concrete theory, widespread in dam construction, but little used when designing buildings. This paper aims to present a case study about the procedures and problems involved in the construction of a spread footing with a volume of approximately 800m³ designed for the foundation of a shopping center in São Paulo, Brazil.

  15. County-Level Climate Uncertainty for Risk Assessments: Volume 21 Appendix T - Forecast Sea Ice Area Fraction.

    Energy Technology Data Exchange (ETDEWEB)

    Backus, George A.; Lowry, Thomas Stephen; Jones, Shannon M; Walker, La Tonya Nicole; Roberts, Barry L; Malczynski, Leonard A.

    2017-06-01

    This report uses the CMIP5 series of climate model simulations to produce country- level uncertainty distributions for use in socioeconomic risk assessments of climate change impacts. It provides appropriate probability distributions, by month, for 169 countries and autonomous-areas on temperature, precipitation, maximum temperature, maximum wind speed, humidity, runoff, soil moisture and evaporation for the historical period (1976-2005), and for decadal time periods to 2100. It also provides historical and future distributions for the Arctic region on ice concentration, ice thickness, age of ice, and ice ridging in 15-degree longitude arc segments from the Arctic Circle to 80 degrees latitude, plus two polar semicircular regions from 80 to 90 degrees latitude. The uncertainty is meant to describe the lack of knowledge rather than imprecision in the physical simulation because the emphasis is on unfalsified risk and its use to determine potential socioeconomic impacts. The full report is contained in 27 volumes.

  16. County-Level Climate Uncertainty for Risk Assessments: Volume 20 Appendix S - Historical Sea Ice Area Fraction

    Energy Technology Data Exchange (ETDEWEB)

    Backus, George A.; Lowry, Thomas Stephen; Jones, Shannon M; Walker, La Tonya Nicole; Roberts, Barry L; Malczynski, Leonard A.

    2017-06-01

    This report uses the CMIP5 series of climate model simulations to produce country- level uncertainty distributions for use in socioeconomic risk assessments of climate change impacts. It provides appropriate probability distributions, by month, for 169 countries and autonomous-areas on temperature, precipitation, maximum temperature, maximum wind speed, humidity, runoff, soil moisture and evaporation for the historical period (1976-2005), and for decadal time periods to 2100. It also provides historical and future distributions for the Arctic region on ice concentration, ice thickness, age of ice, and ice ridging in 15-degree longitude arc segments from the Arctic Circle to 80 degrees latitude, plus two polar semicircular regions from 80 to 90 degrees latitude. The uncertainty is meant to describe the lack of knowledge rather than imprecision in the physical simulation because the emphasis is on unfalsified risk and its use to determine potential socioeconomic impacts. The full report is contained in 27 volumes.

  17. Forced transport of thermal energy in magmatic and phreatomagmatic large volume ignimbrites: Paleomagnetic evidence from the Colli Albani volcano, Italy

    Science.gov (United States)

    Trolese, Matteo; Giordano, Guido; Cifelli, Francesca; Winkler, Aldo; Mattei, Massimo

    2017-11-01

    Few studies have detailed the thermal architecture of large-volume pyroclastic density current deposits, although such work has a clear importance for understanding the dynamics of eruptions of this magnitude. Here we examine the temperature of emplacement of large-volume caldera-forming ignimbrites related to magmatic and phreatomagmatic eruptions at the Colli Albani volcano, Italy, by using thermal remanent magnetization analysis on both lithic and juvenile clasts. Results show that all the magmatic ignimbrites were deposited at high temperature, between the maximum blocking temperature of the magnetic carrier (600-630 °C) and the glass transition temperature (about 710 °C). Temperature estimations for the phreatomagmatic ignimbrite range between 200 and 400 °C, with most of the clasts emplaced between 200 and 320 °C. Because all the investigated ignimbrites, magmatic and phreatomagmatic, share similar magma composition, volume and mobility, we attribute the temperature difference to magma-water interaction, highlighting its pronounced impact on thermal dissipation, even in large-volume eruptions. The homogeneity of the deposit temperature of each ignimbrite across its areal extent, which is maintained across topographic barriers, suggests that these systems are thermodynamically isolated from the external environment for several tens of kilometers. Based on these findings, we propose that these large-volume ignimbrites are dominated by the mass flux, which forces the lateral transport of mass, momentum, and thermal energy for distances up to tens of kilometers away from the vent. We conclude that spatial variation of the emplacement temperature can be used as a proxy for determining the degree of forced-convection flow.

  18. Effects of perfusion detect on the measurement of left ventricular mass, ventricular volume and post-stress left ventricular ejection fraction in gated myocardial perfusion SPECT

    International Nuclear Information System (INIS)

    Ahn, Byeong Cheol; Bae, Sun Keun; Lee, Sang Woo; Jeong, Sin Young; Lee, Jae Tae; Lee, Kyu Bo

    2002-01-01

    The presence of perfusion defect may influence the left ventricular mass (LVM) measurement by quantitative gated myocardial perfusion SPECT (QGS), and ischemic myocardium, usually showing perfusion defect may produce post-stress LV dysfunction. This study was aimed to evaluated the effects of extent and reversibility of perfusion defect on the automatic measurement of LVM by QGS and to investigate the effect of reversibility of perfusion defect on post-stress LV dysfunction. Forty-six patients (male/female=34:12, mean age=64 years) with perfusion defect on myocardial perfusion SPECT underwent rest and post-stress QGS. Forty patients (87%) showed reversible defect. End-diastolic volume (EDV), end-systolic volume (ESV), LV ejection fraction (EF), and LV myocardial volume were obtained from QGS by autoquant program, and LVM was calculated by multiplying the LV myocardial volume by the specific gravity of myocardium. LVMs measured at rest and post-stress QGS showed good correlation, and higher correlation was founded in the subjects with fixed perfusion defect and with small defect (smaller than 20%). There were no significant differences in EDVs, ESVs and EFs between obtained by rest and post-stress QGS in patients with fixed myocardial defect. Whereas, EF obtained by post-stress QGS was lower than that by rest QGS in patients with reversible defect and 10 (25%) of them showed decreases in EF more than 5% in post-stress QGS, as compared to that of rest QGS. Excellent correlations of EDVs, ESVs, EFs between rest and post-stress QGS were noted. Patients with fixed defect had higher correlation between defect can affect LVM measurement by QGS and patients with reversible defect shows post-stress LV dysfunction more frequently than patients with fixed perfusion defect

  19. Multi-slice CT (MSCT) in cardiac function imaging: threshold-value-supported 3D volume reconstructions to determine the left ventricular ejection fraction in comparison to MRI

    International Nuclear Information System (INIS)

    Ehrhard, K.; Oberholzer, K.; Gast, K.; Mildenberger, P.; Kreitner, K.F.; Thelen, M.

    2002-01-01

    Purpose: To assess MSCT of the heart to determining left ventricular ejection fraction (EF) based on threshold-value-supported 3D volume reconstructions compared to MRI. Methods: Cardiac MSCT was performed in 7 patients. Images were reconstructed during end-systolic and end-diastolic phases of the cardiac cycle and transformed to 3D volumes to determine end-systolic (ESV) and end-diastolic volume (EDV) by using different lower threshold values: besides fixed lower threshold values, identical for each image sequence, individual lower threshold values dependent on contrast enhancement of the left ventricle were applied. The latter represent the mean value calculated by combining the average CT-density of the myocardium and the contrast-enhanced blood in the left ventricle. The EF derived from ESV and EDV. Results: The best correlation with MR imaging was obtained for ESV and EDV by using the individual lower threshold values for the respective sequence. The correlation coefficient for ESV was 0.95 and for EDV it was 0.93. On average, the ESV was overestimated by 3.72 ml, while the ESD was underestimated by 2.85 ml. The respective standard deviation for the ESV was 14,87 ml, for the EDV it was 26.83 ml. On average, the EF was underestimated by 3.57% with a standard deviation of 9.43% and a correlation coefficient of 0.83 in comparison to MRI. Conclusion: The threshold-value-supported 3D volume reconstruction of the left ventricle represents a good method to determine the left ventricular function parameters. Due to the differences in the contrast enhancement, the use of an individual lower threshold value for every image sequence is of particular importance. (orig.) [de

  20. AGN Populations in Large-volume X-Ray Surveys: Photometric Redshifts and Population Types Found in the Stripe 82X Survey

    Science.gov (United States)

    Ananna, Tonima Tasnin; Salvato, Mara; LaMassa, Stephanie; Urry, C. Megan; Cappelluti, Nico; Cardamone, Carolin; Civano, Francesca; Farrah, Duncan; Gilfanov, Marat; Glikman, Eilat; Hamilton, Mark; Kirkpatrick, Allison; Lanzuisi, Giorgio; Marchesi, Stefano; Merloni, Andrea; Nandra, Kirpal; Natarajan, Priyamvada; Richards, Gordon T.; Timlin, John

    2017-11-01

    Multiwavelength surveys covering large sky volumes are necessary to obtain an accurate census of rare objects such as high-luminosity and/or high-redshift active galactic nuclei (AGNs). Stripe 82X is a 31.3 X-ray survey with Chandra and XMM-Newton observations overlapping the legacy Sloan Digital Sky Survey Stripe 82 field, which has a rich investment of multiwavelength coverage from the ultraviolet to the radio. The wide-area nature of this survey presents new challenges for photometric redshifts for AGNs compared to previous work on narrow-deep fields because it probes different populations of objects that need to be identified and represented in the library of templates. Here we present an updated X-ray plus multiwavelength matched catalog, including Spitzer counterparts, and estimated photometric redshifts for 5961 (96% of a total of 6181) X-ray sources that have a normalized median absolute deviation, σnmad=0.06, and an outlier fraction, η = 13.7%. The populations found in this survey and the template libraries used for photometric redshifts provide important guiding principles for upcoming large-area surveys such as eROSITA and 3XMM (in X-ray) and the Large Synoptic Survey Telescope (optical).

  1. The relationship between I{sub H{sub {alpha}}} /(I{sub SiH}{sup *}){sup 2} and crystalline volume fraction in microcrystalline silicon growth

    Energy Technology Data Exchange (ETDEWEB)

    Chantana, Jakapan; Higuchi, Takuya; Nagai, Tomoyuki; Sasaki, Shota; Sobajima, Yasushi; Toyama, Toshihiko; Sada, Chitose; Matsuda, Akihisa; Okamoto, Hiroaki [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531 (Japan)

    2010-03-15

    Optical-emission-intensity ratio of I{sub H{sub {alpha}}} /(I{sub SiH}{sup *}) during film growth has been used as a simple indicator to predict crystallinity (crystal-volume fraction: X{sub C}) in the resulting microcrystalline silicon ({mu}c-Si:H) thin films. The relationship between I{sub H{sub {alpha}}} /(I{sub SiH}{sup *}) and X{sub C} has been checked under a wide variety of film-preparation conditions including low-deposition-rate (<0.1 nm/s) and high-deposition-rate (>5 nm/s) cases. On the basis of theoretical consideration, we have proposed optical-emission-intensity ratio of I{sub H{sub {alpha}}} /(I{sub SiH}{sup *}) {sup 2} as a new indicator of X{sub C} during film growth of {mu}c-Si:H. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  2. Systems and methods for the detection of low-level harmful substances in a large volume of fluid

    Science.gov (United States)

    Carpenter, Michael V.; Roybal, Lyle G.; Lindquist, Alan; Gallardo, Vincente

    2016-03-15

    A method and device for the detection of low-level harmful substances in a large volume of fluid comprising using a concentrator system to produce a retentate and analyzing the retentate for the presence of at least one harmful substance. The concentrator system performs a method comprising pumping at least 10 liters of fluid from a sample source through a filter. While pumping, the concentrator system diverts retentate from the filter into a container. The concentrator system also recirculates at least part of the retentate in the container again through the filter. The concentrator system controls the speed of the pump with a control system thereby maintaining a fluid pressure less than 25 psi during the pumping of the fluid; monitors the quantity of retentate within the container with a control system, and maintains a reduced volume level of retentate and a target volume of retentate.

  3. In vivo assessment of the gastric mucosal tolerance dose after single fraction, small volume irradiation of liver malignancies by computed tomography-guided, high-dose-rate brachytherapy

    International Nuclear Information System (INIS)

    Streitparth, Florian; Pech, Maciej; Boehmig, Michael; Ruehl, Ricarda; Peters, Nils; Wieners, Gero; Steinberg, Johannes; Lopez-Haenninen, Enrique; Felix, Roland; Wust, Peter; Ricke, Jens

    2006-01-01

    Purpose: The aim of this study was to assess the tolerance dose of gastric mucosa for single-fraction computed tomography (CT)-guided, high-dose-rate (HDR) brachytherapy of liver malignancies. Methods and Materials: A total of 33 patients treated by CT-guided HDR brachytherapy of liver malignancies in segments II and/or III were included. Dose planning was performed upon a three-dimensional CT data set acquired after percutaneous applicator positioning. All patients received gastric protection post-treatment. For further analysis, the contours of the gastric wall were defined in every CT slice using Brachyvision Software. Dose-volume histograms were calculated for each treatment and correlated with clinical data derived from questionnaires assessing Common Toxicity Criteria (CTC). All patients presenting symptoms of upper GI toxicity were examined endoscopically. Results: Summarizing all patients the minimum dose applied to 1 ml of the gastric wall (D 1ml ) ranged from 6.3 to 34.2 Gy; median, 14.3 Gy. Toxicity was present in 18 patients (55%). We found nausea in 16 (69%), emesis in 9 (27%), cramping in 13 (39%), weight loss in 12 (36%), gastritis in 4 (12%), and ulceration in 5 patients (15%). We found a threshold dose D 1ml of 11 Gy for general gastric toxicity and 15.5 Gy for gastric ulceration verified by an univariate analysis (p = 0.01). Conclusions: For a single fraction, small volume irradiation we found in the upper abdomen a threshold dose D 1ml of 15.5 Gy for the clinical endpoint ulceration of the gastric mucosa. This in vivo assessment is in accordance with previously published tolerance data

  4. Effects of nano anatase-rutile TiO2 volume fraction with natural dye containing anthocyanin on the dye sensitized solar cell performance

    Science.gov (United States)

    Agustini, S.; Wahyuono, R. A.; Sawitri, D.; Risanti, D. D.

    2013-09-01

    Since its first development, efforts to improve efficiency of Dye Sensitized Solar Cell (DSSC) are continuously carried out, either through selection of dye materials, the type of semiconductor, counter electrode design or the sandwiched structure. It is widely known that anatase and rutile are phases of TiO2 that often being used for fabrication of DSSC. Rutile is thermodynamically more stable phase having band-gap suitable for absorption of sunlight spectrum. On the other hand, anatase has higher electrical conductivity, capability to adsorp dye as well as higher electron diffusion coefficient than those of rutile. Present research uses mangosteen pericarp and Rhoeo spathacea extracted in ethanol as natural dye containing anthocyanin. These dyes were characterized by using UV-Vis and FTIR, showing that the absorption maxima peaks obtained at 389 nm and 413 nm, for mangosteen and Rhoeo spathacea, respectively. The nano TiO2 was prepared by means of co-precipitation method. The particle size were 9-11 nm and 54.5 nm for anatase and rutile, respectively, according to Scherrer's equation. DSSCs were fabricated in various volume fractions of anatase and rutile TiO2. The fabricated DSSCs were tested under 17 mW/cm2 of solar irradiation. The current-voltage (I-V) characteristic of DSSCs employing 75%: 25% volume fraction of anatase and rutile TiO2 have outstanding result than others. The highest conversion efficiencies of 0.037% and 0.013% are obtained for DSSC employing natural dye extract from mangosteen pericarp and Rhoeo spathacea, respectively.

  5. The effect of sintering conditions and ZrN volume fraction on the mechanical properties of spark plasma sintered W/ZrN composites

    International Nuclear Information System (INIS)

    Lee, Dongju; Umer, Malik Adeel; Shin, Yoochul; Jeon, Seokwoo; Hong, Soonhyung

    2012-01-01

    Highlights: ► Effect of sintering conditions on properties of W composites was investigated. ► Effect of ZrN volume fraction on properties of W composites was investigated. ► The grain size and relative density increased with increasing sintering temperature. ► ZrN particles led to an increase in strength of W and a decrease in grain size. ► Highest flexural strength was obtained for 10 vol.% W/ZrN with lowest agglomeration. - Abstract: In an effort to improve the room temperature mechanical properties of tungsten, W/ZrN composites were fabricated by high energy ball milling followed by spark plasma sintering at temperatures in a range of 1200–1700 °C under a pressure of 50 MPa. The effects of sintering conditions and ZrN volume fraction on the mechanical properties of the W/ZrN composites were studied and the results were compared to the properties of monolithic tungsten. The grain size of monolith tungsten and W/ZrN composites was found to increase with an increase in sintering temperature and time. In the case of the W/ZrN composites, ZrN particles led to an increase in the compressive strength of tungsten and a decrease in grain size. The increase in compressive strength of the composites was attributed to a reinforcement effect of ZrN particles as well as grain size refinement according to the Hall–Petch relation. Compressive strength of the composites increased with increasing ZrN content while the flexural strength decreased for samples with ZrN content exceeding 10 vol.%. This was attributed to the effects of ZrN agglomeration within the tungsten matrix.

  6. Target volume geometric change and/or deviation from the cranium during fractionated stereotactic radiotherapy for brain metastases: potential pitfalls in image guidance based on bony anatomy alignment.

    Science.gov (United States)

    Ohtakara, Kazuhiro; Hoshi, Hiroaki

    2014-12-01

    This study sought to evaluate the potential geometrical change and/or displacement of the target relative to the cranium during fractionated stereotactic radiotherapy (FSRT) for treating newly developed brain metastases. For 16 patients with 21 lesions treated with image-guided frameless FSRT in 5 or 10 fractions using a 6-degree-of-freedom image guidance system-integrated platform, the unenhanced computed tomography or T2-weighted magnetic resonance images acquired until the completion of FSRT were fused to the planning image datasets for comparison. Significant change was defined as ≥3-mm change in the tumour diameter or displacement of the tumour centroid. FSRT was started 1 day after planning image acquisition. Tumour shrinkage, deviation and both were observed in 2, 1 and 1 of the 21 lesions, respectively, over a period of 7-13 days. Tumour shrinkage or deviation resulted in an increase or decrease in the marginal dose to the tumour, respectively, and a substantial increase in the irradiated volume for the surrounding tissue irrespective of the pattern of alteration. No obvious differences in the clinical and treatment characteristics were noted among the populations with or without significant changes in tumour volume or position. Target deformity and/or deviation can unexpectedly occur even during relatively short-course FSRT, inevitably leading to a gradual discrepancy between the planned and actually delivered doses to the tumour and surrounding tissue. To appropriately weigh the treatment outcome against the planned dose distribution, target deformity and/or deviation should also be considered in addition to the immobilisation accuracy, as image guidance with bony anatomy alignment does not necessarily guarantee accurate target localisation until completion of FSRT. © 2014 The Royal Australian and New Zealand College of Radiologists.

  7. Measurement of Mechanical Coherency Temperature and Solid Volume Fraction in Al-Zn Alloys Using In Situ X-ray Diffraction During Casting

    Science.gov (United States)

    Drezet, Jean-Marie; Mireux, Bastien; Kurtuldu, Güven; Magdysyuk, Oxana; Drakopoulos, Michael

    2015-09-01

    During solidification of metallic alloys, coalescence leads to the formation of solid bridges between grains or grain clusters when both solid and liquid phases are percolated. As such, it represents a key transition with respect to the mechanical behavior of solidifying alloys and to the prediction of solidification cracking. Coalescence starts at the coherency point when the grains begin to touch each other, but are unable to sustain any tensile loads. It ends up at mechanical coherency when the solid phase is sufficiently coalesced to transmit macroscopic tensile strains and stresses. Temperature at mechanical coherency is a major input parameter in numerical modeling of solidification processes as it defines the point at which thermally induced deformations start to generate internal stresses in a casting. This temperature has been determined for Al-Zn alloys using in situ X-ray diffraction during casting in a dog-bone-shaped mold. This setup allows the sample to build up internal stress naturally as its contraction is prevented. The cooling on both extremities of the mold induces a hot spot at the middle of the sample which is irradiated by X-ray. Diffraction patterns were recorded every 0.5 seconds using a detector covering a 426 × 426 mm2 area. The change of diffraction angles allowed measuring the general decrease of the lattice parameter of the fcc aluminum phase. At high solid volume fraction, a succession of strain/stress build up and release is explained by the formation of hot tears. Mechanical coherency temperatures, 829 K to 866 K (556 °C to 593 °C), and solid volume fractions, ca. 98 pct, are shown to depend on solidification time for grain refined Al-6.2 wt pct Zn alloys.

  8. Effects of ductile phase volume fraction on the mechanical properties of Ti-Al3Ti metal-intermetallic laminate (MIL) composites

    International Nuclear Information System (INIS)

    Price, Richard D.; Jiang Fengchun; Kulin, Robb M.; Vecchio, Kenneth S.

    2011-01-01

    Research highlights: → Residual Al improves the mechanical properties of Ti-Al 3 Ti MIL composites. → Residual Al can eliminate intermetallic centerline delaminations in MILs. → Low levels of residual Al increase fracture toughness in MIL composites. → MIL stiffness, strength, and fracture toughness can be optimized at low Al levels. - Abstract: Metal-intermetallic laminate (MIL) composites consisting of alternating layers of Ti, Al, and the intermetallic Al 3 Ti have been fabricated by reactive foil sintering in open air. Six initially identical stacks of alternating Ti-3Al-2.5 V and 1100-Al foils were processed for different lengths of time, yielding specimens with different metal and intermetallic volume fractions. Their mechanical properties have been investigated with an emphasis on the effect of residual Al at the intermetallic centerline on composite strength and fracture toughness, as well as fracture and failure modes. Samples were cut from each composite plate (in layer orientations parallel and perpendicular to the intended load direction) for mechanical testing in compression and four-point bending under quasi-static and high-rate loading conditions. Examination of the damaged specimens and their fracture surfaces by optical and scanning electron microscopy was performed to establish a correlation between the failure mechanisms present, composite strength, and microstructure. Results indicated that regardless of loading direction, cracks always initiated in the intermetallic region, rarely at the centerline, and crack propagation and failure were heavily influenced by the thickness of the residual aluminum layers. There is an ideal residual aluminum volume fraction that represents the amount of ductile reinforcement that maximizes the combined properties of strength, toughness and stiffness.

  9. An immunomagnetic separator for concentration of pathogenic micro-organisms from large volume samples

    International Nuclear Information System (INIS)

    Rotariu, Ovidiu; Ogden, Iain D.; MacRae, Marion; Badescu, Vasile; Strachan, Norval J.C.

    2005-01-01

    The standard method of immunomagnetic separation of pathogenic bacteria from food and environmental matrices processes 1 ml volumes. Pathogens present at low levels ( 50 ml). Preliminary results show that between 70 and 113 times more Escherchia coli O157 are recovered compared with the standard 1 ml method

  10. Void fraction development in gas-liquid flow after a U-bend in a vertically upwards serpentine-configuration large-diameter pipe

    Science.gov (United States)

    Almabrok, Almabrok A.; Aliyu, Aliyu M.; Baba, Yahaya D.; Lao, Liyun; Yeung, Hoi

    2018-01-01

    We investigate the effect of a return U-bend on flow behaviour in the vertical upward section of a large-diameter pipe. A wire mesh sensor was employed to study the void fraction distributions at axial distances of 5, 28 and 47 pipe diameters after the upstream bottom bend. The study found that, the bottom bend has considerable impacts on up-flow behaviour. In all conditions, centrifugal action causes appreciable misdistribution in the adjacent straight section. Plots from WMS measurements show that flow asymmetry significantly reduces along the axis at L/D = 47. Regime maps generated from three axial locations showed that, in addition to bubbly, intermittent and annular flows, oscillatory flow occurred particularly when gas and liquid flow rates were relatively low. At this position, mean void fractions were in agreement with those from other large-pipe studies, and comparisons were made with existing void fraction correlations. Among the correlations surveyed, drift flux-type correlations were found to give the best predictive results.

  11. Chromatographic lipophilicity determination using large volume injections of the solvents non-miscible with the mobile phase.

    Science.gov (United States)

    Sârbu, Costel; Naşcu-Briciu, Rodica Domnica; Casoni, Dorina; Kot-Wasik, Agata; Wasik, Andrzej; Namieśnik, Jacek

    2012-11-30

    A new perspective in the lipophilicity evaluation through RP-HPLC is permitted by analysis of the retention factor (k) obtained by injecting large volumes of test samples prepared in solvents immiscible with mobile phase. The experiment is carried out on representative groups of compounds with increased toxicity (mycotoxins and alkaloids) and amines with important biological activity (naturally occurring monoamine compounds and related drugs), which are covering a large interval of lipophilicity. The stock solution of each compound was prepared in hexane and the used mobile phases were mixtures of methanol or acetonitrile and water, in suited volume ratio. The injected volume was between 10 and 100 μL, while the used stationary phases were RP-18 and RP-8. On both reverse stationary phases the retention factors were linearly decreasing while the injection volume was increasing. In all cases, the linear models were highly statistically significant. On the basis of the obtained results new lipophilicity indices were purposed and discussed. The developed lipophilicity indices and the computationally expressed ones are correlated at a high level of statistical significance. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Estimation of dependence between mean of fractionation of photons and neutrons dose and intensity of post-irradiation reaction of mouse large intestine

    International Nuclear Information System (INIS)

    Gasinska, A.

    1995-01-01

    The aim of the work was verification of mouse large intestine tolerance on fractionated 250 kV X-rays and 2.3 MeV neutrons doses. Two cm of large intestine of mouse CBA/HT strain were irradiated with various fraction doses: from 0.25 to 35 Gy of X-rays and 0.05-12 Gy of neutrons. The measure of injury was handicap of intestine function. Early post-irradiation reaction was measured by loss of body weight (2-3 weeks after irradiation) and mouse mortality (till 2 months after irradiation, LD50/2). The late reaction was measured on the base of maximal body weight in 1 year period after irradiation, deformation of excrements (after 10 months) and death of animals (till 12. month after irradiation, LD50/12). Fractionation of X-ray dose influenced on decrease of intensification of late irradiation effects. After fractionation of neutrons this effect has not been observed. α/β coefficient for X-rays was 19.9 Gy [15.2; 27.0] for body weight nadir, 13.4 Gy [9.3; 19.5] for early mortality (LD50/2), 6.4 Gy [3.6;11.0] for maximal body weight and 6.9 [4.2; 10.8] for late mortality (LD50/12). Analysis of influence of low doses of photons 90.25-4 Gy) and neutrons (0.05-0.8 Gy) showed trend to reduction α/β for photons only (LD50/2=5.4 Gy; LD50/12=4.6 Gy). α/β coefficient for neutrons was defined by LQ model only for maximal body weight and was 19.9 Gy [9.5; 61.0]. In application of graphic method α/β for neutrons was 230 Gy for early and 48 Gy for late effects. Lower values of α/β coefficient for late irradiation effects for photon radiation demonstrate the big influence of fractionation of photons dose on large intestine tolerance (decrease intensity in all biological effects). Author did not observe increase of intestine tolerance in fractionation of neutrons dose. Effect of irradiation damages repair in interfraction pauses, measured by percent of regenerated dose (F r ) was much bigger for photons. For X-rays it was 50% for early and 63% for late effects. In case of

  13. Phase volume fractions and strain measurements in an ultrafine-grained NiTi shape-memory alloy during tensile loading

    International Nuclear Information System (INIS)

    Young, M.L.; Wagner, M.F.-X.; Frenzel, J.; Schmahl, W.W.; Eggeler, G.

    2010-01-01

    An ultrafine-grained pseudoelastic NiTi shape-memory alloy wire with 50.9 at.% Ni was examined using synchrotron X-ray diffraction during in situ uniaxial tensile loading (up to 1 GPa) and unloading. Both macroscopic stress-strain measurements and volume-averaged lattice strains are reported and discussed. The loading behavior is described in terms of elasto-plastic deformation of austenite, emergence of R phase, stress-induced martensitic transformation, and elasto-plastic deformation, grain reorientation and detwinning of martensite. The unloading behavior is described in terms of stress relaxation and reverse plasticity of martensite, reverse transformation of martensite to austenite due to stress relaxation, and stress relaxation of austenite. Microscopically, lattice strains in various crystallographic directions in the austenitic B2, martensitic R, and martensitic B19' phases are examined during loading and unloading. It is shown that the phase transformation occurs in a localized manner along the gage length at the plateau stress. Phase volume fractions and lattice strains in various crystallographic reflections in the austenite and martensite phases are examined over two transition regions between austenite and martensite, which have a width on the order of the wire diameter. Anisotropic effects observed in various crystallographic reflections of the austenitic phase are also discussed. The results contribute to a better understanding of the tensile loading behavior, both macroscopically and microscopically, of NiTi shape-memory alloys.

  14. A Monte-Carlo code for neutron efficiency calculations for large volume Gd-loaded liquid scintillation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Trzcinski, A.; Zwieglinski, B. [Soltan Inst. for Nuclear Studies, Warsaw (Poland); Lynen, U. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Pochodzalla, J. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    1998-10-01

    This paper reports on a Monte-Carlo program, MSX, developed to evaluate the performance of large-volume, Gd-loaded liquid scintillation detectors used in neutron multiplicity measurements. The results of simulations are presented for the detector intended to count neutrons emitted by the excited target residue in coincidence with the charged products of the projectile fragmentation following relativistic heavy-ion collisions. The latter products could be detected with the ALADIN magnetic spectrometer at GSI-Darmstadt. (orig.) 61 refs.

  15. Comparison of Gated SPECT Myocardial Perfusion Imaging with Echocardiography for the Measurement of Left Ventricular Volumes and Ejection Fraction in Patients With Severe Heart Failure

    Science.gov (United States)

    Shojaeifard, Maryam; Ghaedian, Tahereh; Yaghoobi, Nahid; Malek, Hadi; Firoozabadi, Hasan; Bitarafan-Rajabi, Ahmad; Haghjoo, Majid; Amin, Ahmad; Azizian, Nasrin; Rastgou, Feridoon

    2015-01-01

    Background: Gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is known as a feasible tool for the measurement of left ventricular ejection fraction (EF) and volumes, which are of great importance in the management and follow-up of patients with coronary artery diseases. However, considering the technical shortcomings of SPECT in the presence of perfusion defect, the accuracy of this method in heart failure patients is still controversial. Objectives: The aim of the present study was to compare the results from gated SPECT MPI with those from echocardiography in heart failure patients to compare echocardiographically-derived left ventricular dimension and function data to those from gated SPECT MPI in heart failure patients. Patients and Methods: Forty-one patients with severely reduced left ventricular systolic function (EF ≤ 35%) who were referred for gated SPECT MPI were prospectively enrolled. Quantification of EF, end-diastolic volume (EDV), and end-systolic volume (ESV) was performed by using quantitative gated spect (QGS) (QGS, version 0.4, May 2009) and emory cardiac toolbox (ECTb) (ECTb, revision 1.0, copyright 2007) software packages. EF, EDV, and ESV were also measured with two-dimensional echocardiography within 3 days after MPI. Results: A good correlation was found between echocardiographically-derived EF, EDV, and ESV and the values derived using QGS (r = 0.67, r = 0.78, and r = 0.80 for EF, EDV, and ESV, respectively; P echocardiography. ECTb-derived EDV was also significantly higher than the EDV measured with echocardiography and QGS. The highest correlation between echocardiography and gated SPECT MPI was found for mean values of ESV different. Conclusions: Gated SPECT MPI has a good correlation with echocardiography for the measurement of left ventricular EF, EDV, and ESV in patients with severe heart failure. However, the absolute values of these functional parameters from echocardiography and gated

  16. Considerations in reviewing the waste volume reduction program in a large utility

    International Nuclear Information System (INIS)

    Kohout, R.; Calzolari, L.M.

    1987-01-01

    A program is underway at Ontario Hydro to establish a desirable future scheme for central processing/volume reduction of solid radioactive Low-Level Wastes (LLW) prior to their placement into the centralized storage, and in the future into a disposal facility. The approach being investigated is to furnish the current Waste Volume Reduction Facility (WVRF) with state-of-art processes, reclassify the waste categories and segregate the wastes such that each volume reduction (VR) process is then applied where it would be most effective. The ''optimized'' approach is then compared with other, specific schemes, which basically differ in that each scheme omits one of the major VR processes, thus allowing the next most effective process to take over its role. Each scheme is assessed quantitatively from the viewpoint of cost and VR effectiveness, and qualitatively from the viewpoint of resultant waste form. The economic assessments take into consideration the long term (20 year) impact of selected VR schemes on the overall waste management cost, including construction and operation of the storage facility. This paper highlights the overall study, includes the major results, and identifies aspects that need to be addressed in the selection of a desirable combination of VR processes in absence of knowledge of future waste disposal costs

  17. Electric-field-dependent phase volume fractions and enhanced piezoelectricity near the polymorphic phase boundary of (K0.5Na0.5)1-xLixNbO3 textured ceramics

    Science.gov (United States)

    Ge, Wenwei; Li, Jiefang; Viehland, D.; Chang, Yunfei; Messing, Gary L.

    2011-06-01

    The structure, ferroelectric and piezoelectric properties of textured (K0.5Na0.5)0.98Li0.02NbO3 ceramics were investigated as a function of temperature and dc bias E. X-ray diffraction revealed an orthorhombic (O) → tetragonal (T) polymorphic phase boundary (PPB). Phase coexistence was found near the PPB over a 30 °C temperature range, where the relative phase volume fractions changed with temperature. Furthermore, increasing E applied along the texture direction resulted in a notable increase in the volume fraction of the T phase at the expense of the O phase, effectively shifting the O → T boundary to lower temperature. An enhancement in the piezoelectric properties was found to accompany this increase in the T volume fraction.

  18. Paul Scherrer Institute Scientific Report 1998. Volume VI: Large Research Facilities

    International Nuclear Information System (INIS)

    Bauer, Guenter; Bercher, Renate; Buechli, Carmen; Foroughi, Fereydoun; Meyer, Rosa

    1999-01-01

    The department GFA (Grossforschungsanlagen, Large Research Facilities) has been established in October 1998 and its main duty is operation, maintenance and development of the PSI accelerators, the spallation neutron source and the beam transport systems for pions and muons. A large effort of this group concerns the planning and co-ordination of the assembly of the Swiss Light Source (SLS). (author)

  19. Very Large Data Volumes Analysis of Collaborative Systems with Finite Number of States

    Science.gov (United States)

    Ivan, Ion; Ciurea, Cristian; Pavel, Sorin

    2010-01-01

    The collaborative system with finite number of states is defined. A very large database is structured. Operations on large databases are identified. Repetitive procedures for collaborative systems operations are derived. The efficiency of such procedures is analyzed. (Contains 6 tables, 5 footnotes and 3 figures.)

  20. CALCULATION OF EFFICIENCY OF PROCESS OF FRACTIONATION OF LOOSE MIX IN THE WORKING VOLUME OF A PNEUMATIC SEPARATOR

    Directory of Open Access Journals (Sweden)

    E. V. Semenov

    2015-01-01

    Full Text Available Summary. The process of separation bulk mixtures in the air stream is widespread in production associated with the cleaning of grain from impurity. In doing so, in order to effectively use the force of gravity appropriate cleaning grain in vertical air stream. Quantitative analysis of the separation process considering based on the model of the motion of an isolated particles in the stream. We used law of conservation of impulse in the form of the second law of Newton. Movement of particles in the air stream develops in conditions of large of number Reynolds. Therefore, the resistance force particles chosen by quadratic depending on its relative speed. Based on the quantitative analysis of the equations of motion of a particle moving on a specific trajectory, determine the critical diameter of the particles. As a process control setting chosen by the speed of the airflow. Based on the dispersion factor mixture of granular calculated coefficient of lightening. A specific example of equipment based on geometrical and physical-mechanical parameters of the process graphically presents the results of a qualitative and meaningful analysis on trajectories and velocities of the particles, the critical diameter of particle, coefficient of lightening.

  1. A dosimetric comparison of 3D-CRT, IMRT, and static tomotherapy with an SIB for large and small breast volumes

    Energy Technology Data Exchange (ETDEWEB)

    Michalski, Andrea [Department of Health Science (MRS), The University of Sydney, Lidcombe, New South Wales (Australia); Central Coast Cancer Centre, Gosford Hospital, Gosford, New South Wales (Australia); Atyeo, John, E-mail: john.atyeo@sydney.edu.au [Department of Health Science (MRS), The University of Sydney, Lidcombe, New South Wales (Australia); Cox, Jennifer [Department of Health Science (MRS), The University of Sydney, Lidcombe, New South Wales (Australia); Department of Radiation Oncology, Royal North Shore Hospital, St Leonards, New South Wales (Australia); Rinks, Marianne [Department of Health Science (MRS), The University of Sydney, Lidcombe, New South Wales (Australia); Radiation Oncology, Cancer Services, Illawarra Shoalhaven Local Health District, Wollongong, New South Wales (Australia); Morgia, Marita; Lamoury, Gillian [Department of Radiation Oncology, Royal North Shore Hospital, St Leonards, New South Wales (Australia)

    2014-07-01

    Radiation therapy to the breast is a complex task, with many different techniques that can be employed to ensure adequate dose target coverage while minimizing doses to the organs at risk. This study compares the dose planning outcomes of 3 radiation treatment modalities, 3 dimensional conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), and static tomotherapy, for left-sided whole-breast radiation treatment with a simultaneous integrated boost (SIB). Overall, 20 patients with left-sided breast cancer were separated into 2 cohorts, small and large, based on breast volume. Dose plans were produced for each patient using 3D-CRT, IMRT, and static tomotherapy. All patients were prescribed a dose of 45 Gy in 20 fractions to the breast with an SIB of 56 Gy in 20 fractions to the tumor bed and normalized so that D{sub 98%} > 95% of the prescription dose. Dosimetric comparisons were made between the 3 modalities and the interaction of patient size. All 3 modalities offered adequate planning target volume (PTV) coverage with D{sub 98%} > 95% and D{sub 2%} < 107%. Static tomotherapy offered significantly improved (p = 0.006) dose homogeneity to the PTV{sub boost} {sub eval} (0.079 ± 0.011) and breast minus the SIB volume (Breast{sub SIB}) (p < 0.001, 0.15 ± 0.03) compared with the PTV{sub boost} {sub eval} (0.085 ± 0.008, 0.088 ± 0.12) and Breast{sub SIB} (0.22 ± 0.05, 0.23 ± 0.03) for IMRT and 3D-CRT, respectively. Static tomotherapy also offered statistically significant reductions (p < 0.001) in doses to the ipsilateral lung mean dose of 6.79 ± 2.11 Gy compared with 7.75 ± 2.54 Gy and 8.29 ± 2.76 Gy for IMRT and 3D-CRT, respectively, and significantly (p < 0.001) reduced heart doses (mean = 2.83 ± 1.26 Gy) compared to both IMRT and 3D-CRT (mean = 3.70 ± 1.44 Gy and 3.91 ± 1.58 Gy). Static tomotherapy is the dosimetrically superior modality for the whole breast with an SIB compared with IMRT and 3D-CRT. IMRT is superior to 3D

  2. Resuscitation of a Polytraumatized Patient with Large Volume Crystalloid-Colloid Infusions – Correlation Between Global and Regional Hemodynamics: Case Report

    OpenAIRE

    Lončarić-Katušin, Mirjana; Belavić, Matija; Žunić, Josip; Gučanin, Snježana; Žilić, Antonio; Korać, Želimir

    2010-01-01

    Aggressive large volume resuscitation is obligatory to achieve necessary tissue oxygenation. An adequate venous preload normalizes global hemodynamics and avoids multiorgan failure (MOF) and death in patients with multiple injuries. Large volume resuscitation is associated with complications in minimally monitored patients. A properly guided resuscitation procedure will finally prevent MOF and patient death. Transpulmonary thermodilution technique and gastric tonometry are used in venous prel...

  3. Environmental gamma radiation monitoring system with a large volume air ionization chamber

    International Nuclear Information System (INIS)

    Duftschmid, K.E.; Strachotinsky, C.; Witzani, J.

    1986-01-01

    An improved environmental monitoring system has been designed and tested consisting of an ionization chamber with 120 l sensitive volume, operated at atmospheric pressure, and a commercial electrometer amplifier with digital voltmeter. The system is controlled by a desk calculator with printer for automated operation and calculation of dose and doserate. The ionization chamber provides superior dosimetric performance as compared to usual GM-counters and high pressure chambers. The system has been field-tested during the 'European Intercomparison Programme for Environmental Monitoring Instruments' organized by the Commission of the European Communities. (Author)

  4. Large-Scale Context-Aware Volume Navigation using Dynamic Insets

    KAUST Repository

    Al-Awami, Ali

    2012-07-01

    Latest developments in electron microscopy (EM) technology produce high resolution images that enable neuro-scientists to identify and put together the complex neural connections in a nervous system. However, because of the massive size and underlying complexity of this kind of data, processing, navigation and analysis suffer drastically in terms of time and effort. In this work, we propose the use of state-of- the-art navigation techniques, such as dynamic insets, built on a peta-scale volume visualization framework to provide focus and context-awareness to help neuro-scientists in their mission to analyze, reconstruct, navigate and explore EM neuroscience data.

  5. Paul Scherrer Institute Scientific Report 1998. Volume VI: Large Research Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Guenter; Bercher, Renate; Buechli, Carmen; Foroughi, Fereydoun; Meyer, Rosa [eds.

    1999-09-01

    The department GFA (Grossforschungsanlagen, Large Research Facilities) has been established in October 1998 and its main duty is operation, maintenance and development of the PSI accelerators, the spallation neutron source and the beam transport systems for pions and muons. A large effort of this group concerns the planning and co-ordination of the assembly of the Swiss Light Source (SLS). (author) figs., tabs., refs.

  6. A bench evaluation of fraction of oxygen in air delivery and tidal volume accuracy in home care ventilators available for hospital use

    Science.gov (United States)

    Baboi, Loredana; Subtil, Fabien

    2016-01-01

    Background Turbine-powered ventilators are not only designed for long-term ventilation at home but also for hospital use. It is important to verify their capabilities in delivering fraction of oxygen in air (FIO2) and tidal volume (VT). Methods We assessed the FIO2 accuracy and the VT delivery in four home care ventilators (HCV) on the bench. The four HCV were Astral 150, Elisée 150, Monnal T50 and Trilogy 200 HCV, which were connected to a lung model (ASL 5000). For assessing FIO2 accuracy, lung model was set to mimic an obstructive lung and HCV were set in volume controlled mode (VC). They supplied with air, 3 or 15 L/min oxygen and FIO2 was measured by using a ventilator tester (Citrex H4TM). For the VT accuracy, the lung model was set in a way to mimic three adult configurations (normal, obstructive, or restrictive respiratory disorder) and one pediatric configuration. Each HCV was set in VC. Two VT (300 and 500 mL) in adult lung configuration and one 50 mL VT in pediatric lung configuration, at two positive end expiratory pressures 5 and 10 cmH2O, were tested. VT accuracy was measured as volume error (the relative difference between set and measured VT). Statistical analysis was performed by suing one-factor ANOVA with a Bonferroni correction for multiple tests. Results For Astral 150, Elisée 150, Monnal T50 and Trilogy 200, FIO2 averaged 99.2%, 93.7%, 86.3%, and 62.1%, respectively, at 15 L/min oxygen supplementation rate (P<0.001). Volume error was 0.5%±0%, −38%±0%, −9%±0%, −29%±0% and −36%±0% for pediatric lung condition (P<0.001). In adult lung configurations, Monnal T50 systematically over delivered VT and Trilogy 150 was sensitive to lung configuration when VT was set to 300 mL at either positive end-expiratory pressure (PEEP). Conclusions HCV are different in terms of FIO2 efficiency and VT delivery. PMID:28149559

  7. Nuclear waste calorimeter for very large drums with 385 litres sample volume

    Energy Technology Data Exchange (ETDEWEB)

    Jossens, G.; Mathonat, C. [SETARAM Instrumentation, Caluire (France); Bachelet, F. [CEA Valduc, Is sur Tille (France)

    2015-03-15

    Calorimetry is a very precise and well adapted tool for the classification of drums containing nuclear waste material depending on their level of activities (low, medium, high). A new calorimeter has been developed by SETARAM Instrumentation and the CEA Valduc in France. This new calorimeter is designed for drums having a volume bigger than 100 liters. It guarantees high operator safety by optimizing drum handling and air circulation for cooling, and optimized software for direct measurement of the quantity of nuclear material. The LVC1380 calorimeter makes it possible to work over the range 10 to 3000 mW, which corresponds to approximately 0.03 to 10 g of tritium or 3 to 955 g of {sup 241}Pu in a volume up to 385 liters. This calorimeter is based on the heat flow measurement using Peltier elements which surround the drum in the 3 dimensions and therefore measure all the heat coming from the radioactive stuff whatever its position inside the drum. Calorimeter's insulating layers constitute a thermal barrier designed to filter disturbances until they represent less than 0.001 Celsius degrees and to eliminate long term disturbances associated, for example, with laboratory temperature variations between day and night. A calibration device based on Joule effect has also been designed. Measurement time has been optimized but remains long compared with other methods of measurement such as gamma spectrometry but its main asset is to have a good accuracy for low level activities.

  8. Construction and Start-up of a Large-Volume Thermostat for Dielectric-Constant Gas Thermometry

    Science.gov (United States)

    Merlone, A.; Moro, F.; Zandt, T.; Gaiser, C.; Fellmuth, B.

    2010-07-01

    A liquid-bath thermostat with a volume of about 800 L was designed to provide a suitable thermal environment for a dielectric-constant gas thermometer (DCGT) in the range from the triple point of mercury to the melting point of gallium. In the article, results obtained with the unique, huge thermostat without the DCGT measuring chamber are reported to demonstrate the capability of controlling the temperature of very large systems at a metrological level. First tests showed that the bath together with its temperature controller provide a temperature variation of less than ±0.5mK peak-to-peak. This temperature instability could be maintained over a period of several days. In the central working volume (diameter—500mm, height—650mm), in which the vacuum chamber containing the measuring system of the DCGT will be placed later, the temperature inhomogeneity has been demonstrated to be also well below 1mK.

  9. Glass-covering of large building volumes. An interdisciplinary evaluation of a shopping centre

    Energy Technology Data Exchange (ETDEWEB)

    Oeman, R [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Building Technology

    1994-12-31

    Systematized experiences of the function of large glass-covered spaces related to shopping centres, hotels, office buildings etc. are still relatively limited. With the glazed pedestrian precincts of the rebuilt Skaerholmen Centre in Stockholm as the main object of interdisciplinary studies, the aim of this thesis is to provide additional knowledge of large glass-covered spaces (atrium buildings). The studies comprises thermal comfort, temperature conditions, ventilation, energy balance, humidity - mycology, acoustics, operation - maintenance - durability and sociology. To sum up, it is clear that in the Scandinavian climate there is every likelihood of large glass-covered spaces in the public places functioning well from a technical as well as a social point of view. The energy consumption on heating the whole complex, based on theoretical calculations and measurement, is shown to have been reduced by the order of 10%. figs., tabs., refs.

  10. Large-volume heat storage tank made of GFK; Grosswaermespeichertank aus GFK

    Energy Technology Data Exchange (ETDEWEB)

    Buehl, J.; Schultheis, P. [Technische Univ. Ilmenau (Germany). Fachgebiet Technische Thermodynamik

    1998-12-31

    The Technical University of Ilmenau, the company Verbundwerkstoff- und Kunststoffanwendungstechnik Schoenbrunn, the Institute for Aerospace and Light-weight construction of Dresden University with its approved testing facilities for plastics and the Institute for Construction Engineering in Berlin and several other institutions co-operated since 1996 in developing a concept for a series of long-term heat storage tanks up to 6,000 cubic metres storage volume made of plastic (GFK components) with a combined thermal insulation. A model tank (sandwich body with proportional thermal insulation layer and selected mixed laminates) with a volume of 1.5 cubic metres was built and installed in November 1996. The tank has been continuously operated at various test levels. The experiment proves the longevity of the materials used. (orig.) [Deutsch] In Zusammenarbeit der TU Ilmenau mit der Fa. Verbundwerkstoff - und Kunststoffanwendungstechnik Schoenbrunn und dem Institut fuer Luftfahrttechnik und Leichtbau Dresden, seiner akkredierten Pruefstelle fuer Kunststoffe, in Abstimmung mit dem Institut fuer Bautechnik Berlin und weiteren Einrichtungen und Partnern wird seit 1996 an einem Konzept fuer eine Typenreihe Langzeitwaermespeicher bis vorerst 6.000 m{sup 3} Speichervolumen aus Kunststoff (GFK-Komponenten) und kombinierter integrierter thermischer Isolation gearbeitet. Im Vorfeld dieser Entwicklung wurde auf der Basis vorausgewaehlter Materialien und Kompositionen ein Musterspeicher (ein Sandwich - Modellkoerper mit proportionaler Waermedaemmschicht sowie ausgewaehlten Mischlaminaten) mit einem Speichervolumen von 1,5 m{sup 3} realisiert. Dieser Musterspeicher wurde im November 1996 installiert und wird seither kontinuierlich in den entsprechenden Erprobungsstufen betrieben. Der Nachweis der Langlebigkeit der eingesetzten Materialien wurde experimentell erbracht. (orig.)

  11. A large volume striped bass egg incubation chamber: design and comparison with a traditional method

    Science.gov (United States)

    Harper, C.J.

    2009-01-01

    I conducted a comparative study of a new jar design (experimental chamber) with a standard egg incubation vessel (McDonald jar). Experimental chambers measured 0.4 m in diameter by 1.3 m in height and had a volume of 200 L. McDonald hatching jars measured 16 cm in diameter by 45 cm in height and had a volume of 6 L. Post-hatch survival was estimated at 48, 96 and 144 h. Stocking rates resulted in an average egg density of 21.9 eggs ml-1 (range = 21.6 – 22.1) for McDonald jars and 10.9 eggs ml-1 (range = 7.0 – 16.8) for experimental chambers. I was unable to detect an effect of container type on survival to 48, 96 or 144 h. At 144 h striped bass fry survival averaged 37.3% for McDonald jars and 34.2% for experimental chambers. Survival among replicates was significantly different. Survival of striped bass significantly decreased between 96 and 144 h. Mean survival among replicates ranged from 12.4 to 57.3%. I was unable to detect an effect of initial stocking density on survival. Experimental jars allow for incubation of a larger number of eggs in a much smaller space. As hatchery production is often limited by space or water supply, experimental chambers offer an alternative to extending spawning activities, thereby reducing manpower and cost. However, the increase in the number of eggs per rearing container does increase the risk associated with catastrophic loss of a production unit. I conclude the experimental chamber is suitable for striped bass egg incubation.

  12. The BREAST-V: a unifying predictive formula for volume assessment in small, medium, and large breasts.

    Science.gov (United States)

    Longo, Benedetto; Farcomeni, Alessio; Ferri, Germano; Campanale, Antonella; Sorotos, Micheal; Santanelli, Fabio

    2013-07-01

    Breast volume assessment enhances preoperative planning of both aesthetic and reconstructive procedures, helping the surgeon in the decision-making process of shaping the breast. Numerous methods of breast size determination are currently reported but are limited by methodologic flaws and variable estimations. The authors aimed to develop a unifying predictive formula for volume assessment in small to large breasts based on anthropomorphic values. Ten anthropomorphic breast measurements and direct volumes of 108 mastectomy specimens from 88 women were collected prospectively. The authors performed a multivariate regression to build the optimal model for development of the predictive formula. The final model was then internally validated. A previously published formula was used as a reference. Mean (±SD) breast weight was 527.9 ± 227.6 g (range, 150 to 1250 g). After model selection, sternal notch-to-nipple, inframammary fold-to-nipple, and inframammary fold-to-fold projection distances emerged as the most important predictors. The resulting formula (the BREAST-V) showed an adjusted R of 0.73. The estimated expected absolute error on new breasts is 89.7 g (95 percent CI, 62.4 to 119.1 g) and the expected relative error is 18.4 percent (95 percent CI, 12.9 to 24.3 percent). Application of reference formula on the sample yielded worse predictions than those derived by the formula, showing an R of 0.55. The BREAST-V is a reliable tool for predicting small to large breast volumes accurately for use as a complementary device in surgeon evaluation. An app entitled BREAST-V for both iOS and Android devices is currently available for free download in the Apple App Store and Google Play Store. Diagnostic, II.

  13. Assessment of a simplified set of momentum closure relations for low volume fraction regimes in STAR-CCM+ and OpenFOAM

    International Nuclear Information System (INIS)

    Sugrue, Rosemary; Magolan, Ben; Lubchenko, Nazar; Baglietto, Emilio

    2017-01-01

    Highlights: •A simplified set of momentum closures – Bubbly And Moderate void Fraction (BAMF) – is proposed. •BAMF model is assessed by simulation of 12 cases from the Liu and Bankoff experimental database. •Portability between STAR-CCM+ and OpenFOAM CFD softwares is demonstrated. •Both CFD softwares yield mean flow predictions in close agreement with experimental results. -- Abstract: Multiphase computational fluid dynamics (M-CFD) modeling approaches provide three-dimensional resolution of complex two-phase flow and boiling heat transfer phenomena, which makes them an invaluable tool for nuclear reactor design applications. By virtue of the Eulerian-Eulerian spatial and temporal averaging framework, additional terms manifest in the phase momentum equations that require closure through prescription of interfacial forces in the stream-wise and lateral flow directions, as well as in the near-wall region. These momentum closures are critical to M-CFD prediction of mean flow profiles, including velocity and volume fraction distributions, and yet while an overwhelming number of them has been developed, no consensus exists on how to assemble them to achieve a simplified set of closures that is numerically robust and extensible to a wide array of flow configurations; further, no consistent demonstration has been shown of the cross-code portability of these closures between CFD softwares. To address these challenges, we propose in this work a simplified set of momentum closures for stream-wise drag and lateral redistribution mechanisms—collectively referred to as the Bubbly And Moderate void Fraction (BAMF) model—and assess its performance by simulation of 12 cases from the Liu and Bankoff experimental database using STAR-CCM+ and OpenFOAM. Both CFD softwares yield mean flow predictions that are in close agreement with the experimental results, and also in close agreement with each other. These results confirm the effectiveness of the BAMF model and its

  14. Identification of radiation response genes and proteins from mouse pulmonary tissues after high-dose per fraction irradiation of limited lung volumes.

    Science.gov (United States)

    Jin, Hee; Jeon, Seulgi; Kang, Ga-Young; Lee, Hae-June; Cho, Jaeho; Lee, Yun-Sil

    2017-02-01

    The molecular effects of focal exposure of limited lung volumes to high-dose per fraction irradiation (HDFR) such as stereotactic body radiotherapy (SBRT) have not been fully characterized. In this study, we used such an irradiation system and identified the genes and proteins after HDFR to mouse lung, similar to those associated with human therapy. High focal radiation (90 Gy) was applied to a 3-mm volume of the left lung of C57BL6 mice using a small-animal stereotactic irradiator. As well as histological examination for lungs, a cDNA micro array using irradiated lung tissues and a protein array of sera were performed until 4 weeks after irradiation, and radiation-responsive genes and proteins were identified. For comparison, the long-term effects (12 months) of 20 Gy radiation wide-field dose to the left lung were also investigated. The genes ermap, epb4.2, cd200r3 (up regulation) and krt15, hoxc4, gdf2, cst9, cidec, and bnc1 (down-regulation) and the proteins of AIF, laminin, bNOS, HSP27, β-amyloid (upregulation), and calponin (downregulation) were identified as being responsive to 90 Gy HDFR. The gdf2, cst9, and cidec genes also responded to 20 Gy, suggesting that they are universal responsive genes in irradiated lungs. No universal proteins were identified in both 90 Gy and 20 Gy. Calponin, which was downregulated in protein antibody array analysis, showed a similar pattern in microarray data, suggesting a possible HDFR responsive serum biomarker that reflects gene alteration of irradiated lung tissue. These genes and proteins also responded to the lower doses of 20 Gy and 50 Gy HDFR. These results suggest that identified candidate genes and proteins are HDFR-specifically expressed in lung damage induced by HDFR relevant to SBRT in humans.

  15. Factors affecting accuracy of ventricular volume and ejection fraction measured by gated Tl-201 myocardial perfusion single photon emission computed tomography

    International Nuclear Information System (INIS)

    Pai, Moon Sun; Yang, You Jung; Im, Ki Chun; Hong, Il Ki; Yun, Sung Cheol; Kang, Duk Hyun; Song, Jae Kwan; Moon, Dae Hyuk

    2005-01-01

    Systemic errors in the gated single photon emission computed tomography (SPECT) measurement of left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) may occur. We evaluated whether patient-related factors affected the accuracy of EDV, ESV, and EF measured by electrocardiogram-gated Tl-201 SPECT. A total of 518 patients without perfusion defects on Tl-201 SPECT or coronary artery disease were studied. EDV, ESV, and EF were measured from echocardiography and adenosine stress/redistribution gated Tl-201 SPECT using commercially available software packages (QGS and 4D-MSPECT). We identified factors affecting the accuracy of gated SPECT via multiple linear regression analysis of the differences between echocardiography and gated SPECT. Gated SPECT analyzed with QGS underestimated EDV and ESV, and overestimated EF, but 4D-MSPECT overestimated all those values (p<0.001). Independent variables that increased the difference in EDV between echocardiography and gated SPECT were decreasing LV end-diastolic wall thickness, decreasing body surface area, female sex and increasing EDV (p< 0.001). Those for ESV were decreasing LV end-systolic wall thickness, female sex, and decreasing ESV (p<0.001). Increasing end-systolic wall thickness, male sex and decreasing age were independent determinants associated with an increased difference in EF (p< 0.001). Adenosine stress SPECT showed significantly higher EDV and ESV values and a lower EF than did redistribution SPECT (p< 0.001). In determination of EF, QGS demonstrated a smaller bias than did 4D-MSPECT. However, in men with LV hypertrophy, 4D-MSPECT was superior to QGS. Systemic error by gated Tl-201 SPECT is determined by individual patient-characteristics

  16. VOLUMETRIC LEAK DETECTION IN LARGE UNDERGROUND STORAGE TANKS - VOLUME II: APPENDICES A-E

    Science.gov (United States)

    The program of experiments conducted at Griffiss Air Force Base was devised to expand the understanding of large underground storage tank behavior as it impacts the performance of volumetric leak detection testing. The report addresses three important questions about testing the ...

  17. Prognostic value of defining the systemic tumor volume with FDG-PET in diffuse large b cell lymphoma

    International Nuclear Information System (INIS)

    Byun, Byung Hyun; Lim, Sang Moo; Cheon, Gi Jeong; Choi, Chang Woon; Kang, Hye Jin; Na, Im Il; Ryoo, Baek Yeol; Yang, Sung Hyun

    2007-01-01

    We measured the systemic tumor volume using FDG-PET in patients with diffuse large B cell lymphoma (DLBL). We also investigated its prognostic role, and compared it with that of other prognostic factors. FDG PET was performed in 38 newly diagnosed DLBL patients (20 men, 18 women, age 55.715.1 years) at pre-treatment of chemotherapy. Clinical staging of lymphoma was evaluated by Ann Arbor system. On each FDG PET scan, we acquired volume of interest (VOl) at the cut-off value of SUV=2.5 in every measurable tumor by the automatic edge detection software. According to the VOI, we measured the metabolic volume and mean SUV, and estimated volume-activity indexes (SUV Vol) as mean SUV times metabolic volume. And then, we calculated the summed metabolic volume (VOLsum) and summed SUV Vol (SUV Volsum) in every FDG PET scan. Maximum SUV of involved lesion (SUVmax) was also acquired on each FDG PET scan. Time to treatment failure (TTF) was compared among VOLsum (median), SUV Volsum (median), SUVmax (median), clinical stage, gender, age, LDH, and performance status-assigned response designations by Kaplan-Meier survival analysis. Initial stages of DLBL patients were stage I in 4, II in 14, III in 15, and IV in 4 by Ann Arbor system. Median follow up period was 15.5months, and estimated mean TTF was 22.3 months. Univariate analysis demonstrated that TTF is statistically significantly reduced in those with high VOLsum (>215.1cm2, p=0.004), high SUV Volsum (>1577.5, p=0.003), and increased LDH (p=0.036). TTF did not correlate with SUVmax (p=0.571), clinical stage (p=0.194), gender (p=0.549), and age (p=0.128), and performance status =2 (p=0.074). Multivariate analysis using VOLsum, SUV Volsum, LDH, and performance status demonstrated no statistically significant predictor of TTF (p>0.05). Systemic tumor volume measurement using FDG-PET is suggestive to be the significant prognostic factor in patients with DLBL

  18. Ultra-large scale AFM of lipid droplet arrays: investigating the ink transfer volume in dip pen nanolithography

    International Nuclear Information System (INIS)

    Förste, Alexander; Pfirrmann, Marco; Sachs, Johannes; Gröger, Roland; Walheim, Stefan; Brinkmann, Falko; Hirtz, Michael; Fuchs, Harald; Schimmel, Thomas

    2015-01-01

    There are only few quantitative studies commenting on the writing process in dip-pen nanolithography with lipids. Lipids are important carrier ink molecules for the delivery of bio-functional patters in bio-nanotechnology. In order to better understand and control the writing process, more information on the transfer of lipid material from the tip to the substrate is needed. The dependence of the transferred ink volume on the dwell time of the tip on the substrate was investigated by topography measurements with an atomic force microscope (AFM) that is characterized by an ultra-large scan range of 800 × 800 μm 2 . For this purpose arrays of dots of the phospholipid1,2-dioleoyl-sn-glycero-3-phosphocholine were written onto planar glass substrates and the resulting pattern was imaged by large scan area AFM. Two writing regimes were identified, characterized of either a steady decline or a constant ink volume transfer per dot feature. For the steady state ink transfer, a linear relationship between the dwell time and the dot volume was determined, which is characterized by a flow rate of about 16 femtoliters per second. A dependence of the ink transport from the length of pauses before and in between writing the structures was observed and should be taken into account during pattern design when aiming at best writing homogeneity. The ultra-large scan range of the utilized AFM allowed for a simultaneous study of the entire preparation area of almost 1 mm 2 , yielding good statistic results. (paper)

  19. Soft SUSY breaking parameters and RG running of squark and slepton masses in large volume Swiss Cheese compactifications

    International Nuclear Information System (INIS)

    Misra, Aalok; Shukla, Pramod

    2010-01-01

    We consider type IIB large volume compactifications involving orientifolds of the Swiss Cheese Calabi-Yau WCP 4 [1,1,1,6,9] with a single mobile space-time filling D3-brane and stacks of D7-branes wrapping the 'big' divisor Σ B (as opposed to the 'small' divisor usually done in the literature thus far) as well as supporting D7-brane fluxes. After reviewing our proposal of (Misra and Shukla, 2010) for resolving a long-standing tension between large volume cosmology and phenomenology pertaining to obtaining a 10 12 GeV gravitino in the inflationary era and a TeV gravitino in the present era, and summarizing our results of (Misra and Shukla, 2010) on soft supersymmetry breaking terms and open-string moduli masses, we discuss the one-loop RG running of the squark and slepton masses in mSUGRA-like models (using the running of the gaugino masses) to the EW scale in the large volume limit. Phenomenological constraints and some of the calculated soft SUSY parameters identify the D7-brane Wilson line moduli as the first two generations/families of squarks and sleptons and the D3-brane (restricted to the big divisor) position moduli as the two Higgses for MSSM-like models at TeV scale. We also discuss how the obtained open-string/matter moduli make it easier to impose FCNC constraints, as well as RG flow of off-diagonal squark mass(-squared) matrix elements.

  20. Soft SUSY breaking parameters and RG running of squark and slepton masses in large volume Swiss Cheese compactifications

    Science.gov (United States)

    Misra, Aalok; Shukla, Pramod

    2010-03-01

    We consider type IIB large volume compactifications involving orientifolds of the Swiss Cheese Calabi-Yau WCP[1,1,1,6,9] with a single mobile space-time filling D3-brane and stacks of D7-branes wrapping the “big” divisor ΣB (as opposed to the “small” divisor usually done in the literature thus far) as well as supporting D7-brane fluxes. After reviewing our proposal of [1] (Misra and Shukla, 2010) for resolving a long-standing tension between large volume cosmology and phenomenology pertaining to obtaining a 10 GeV gravitino in the inflationary era and a TeV gravitino in the present era, and summarizing our results of [1] (Misra and Shukla, 2010) on soft supersymmetry breaking terms and open-string moduli masses, we discuss the one-loop RG running of the squark and slepton masses in mSUGRA-like models (using the running of the gaugino masses) to the EW scale in the large volume limit. Phenomenological constraints and some of the calculated soft SUSY parameters identify the D7-brane Wilson line moduli as the first two generations/families of squarks and sleptons and the D3-brane (restricted to the big divisor) position moduli as the two Higgses for MSSM-like models at TeV scale. We also discuss how the obtained open-string/matter moduli make it easier to impose FCNC constraints, as well as RG flow of off-diagonal squark mass(-squared) matrix elements.

  1. the Preliminary Research Based on Seismic Signals Generated by Hutubi Transmitting Seismic Station with One Large-volume Airgun Array

    Science.gov (United States)

    Wang, Q.; Su, J.; Wei, Y.; Zhang, W.; Wang, H.; Wang, B.; Ji, Z.

    2017-12-01

    For studying the subsurface structure and its subtle changes, we built the Hutubi transmitting seismic station with one large-volume airgun array at one artificial water pool in the northern segment of Tianshan mountain, where earthquakes occurred frequently. The airgun array consists of six airguns with every airgun capacity of 2000in3, and the artificial water pool with the top diameter of 100m, bottom diameter of 20m and the depth of 18m.We started the regular excitation experiment with the large-volume airgun source every week since June, 2013. Using seismic signals geneated by the Hutubi airgun source, we made the preliminary research on the airgun source, waveform characteristics and the subsurface velocity changes in the northern Tiansh mountain. The results are as follows: The seismic signal exited by the airgun source is characteristic of low-frequency ,and the dominant frequency is in the range of 2 6Hz. The Hutubi transmitting seismic station can continuously generate long-distance detectable and highly repeatable signals, and the correlation coefficient of sigals is greater than 0.95; and the longest propagation distance arrives to 380km, in addition, the 5000-shot stacked sigal using the phase weighted stack technique can be identified in the station, which is about 1300km from the Hutubi transmitting seismic station. Hutubi large-volume airgun source is fitted to detect and monitor the regional-scale subsurface stress state. Applying correlation test method, we measured weak subsurface velocity changes in the northern Tianshan mountain, and found that the several stations, which are within 150km from the the Hutubi transmitting seismic station, appeared 0.1 0.2% relative velocity changes before the Hutubi MS6.2 earthquake on Dec.8, 2016.

  2. Percutaneous Image-Guided Cryoablation of Challenging Mediastinal Lesions Using Large-Volume Hydrodissection: Technical Considerations and Outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Garnon, Julien, E-mail: juliengarnon@gmail.com; Koch, Guillaume, E-mail: Guillaume.koch@gmail.com; Caudrelier, Jean, E-mail: caudjean@yahoo.fr [University Hospital of Strasbourg, Department of Interventional Radiology (France); Ramamurthy, Nitin, E-mail: Nitin-ramamurthy@hotmail.com [Norfolk and Norwich University Hospital, Department of Radiology (United Kingdom); Rao, Pramod, E-mail: pramodrao@me.com [University of Strasbourg, ICube (France); Tsoumakidou, Georgia, E-mail: Georgia.tsoumakidou@chru-strasbourg.fr; Cazzato, Roberto Luigi, E-mail: cazzatorobertoluigi@gmail.com; Gangi, Afshin, E-mail: Afshin.gangi@chru-strasbourg.fr [University Hospital of Strasbourg, Department of Interventional Radiology (France)

    2016-11-15

    ObjectiveThis study was designed to describe the technique of percutaneous image-guided cryoablation with large-volume hydrodissection for the treatment of challenging mediastinal lesions.MethodsBetween March 2014 and June 2015, three patients (mean age 62.7 years) with four neoplastic anterior mediastinal lesions underwent five cryoablation procedures using large-volume hydrodissection. Procedures were performed under general anaesthesia using CT guidance. Lesion characteristics, hydrodissection and cryoablation data, technical success, complications, and clinical outcomes were assessed using retrospective chart review.ResultsLesions (mean size 2.7 cm; range 2–4.3 cm) were in contact with great vessels (n = 13), trachea (n = 3), and mediastinal nerves (n = 6). Hydrodissection was performed intercostally (n = 4), suprasternally (n = 2), transsternally (n = 1), or via the sternoclavicular joint (n = 1) using 1–3 spinal needles over 13.4 (range 7–26) minutes; 450 ml of dilute contrast was injected (range 300–600 ml) and increased mean lesion-collateral structure distance from 1.9 to 7.7 mm. Vulnerable mediastinal nerves were identified in four of five procedures. Technical success was 100 %, with one immediate complication (recurrent laryngeal nerve injury). Mean follow-up period was 15 months. One lesion demonstrated residual disease on restaging PET-CT and was retreated to achieve complete ablation. At last follow-up, two patients remained disease-free, and one patient developed distant disease after 1 year without local recurrence.ConclusionsCryoablation using large-volume hydrodissection is a feasible technique, enabling safe and effective treatment of challenging mediastinal lesions.

  3. Ultra-large scale AFM of lipid droplet arrays: investigating the ink transfer volume in dip pen nanolithography

    Science.gov (United States)

    Förste, Alexander; Pfirrmann, Marco; Sachs, Johannes; Gröger, Roland; Walheim, Stefan; Brinkmann, Falko; Hirtz, Michael; Fuchs, Harald; Schimmel, Thomas

    2015-05-01

    There are only few quantitative studies commenting on the writing process in dip-pen nanolithography with lipids. Lipids are important carrier ink molecules for the delivery of bio-functional patters in bio-nanotechnology. In order to better understand and control the writing process, more information on the transfer of lipid material from the tip to the substrate is needed. The dependence of the transferred ink volume on the dwell time of the tip on the substrate was investigated by topography measurements with an atomic force microscope (AFM) that is characterized by an ultra-large scan range of 800 × 800 μm2. For this purpose arrays of dots of the phospholipid1,2-dioleoyl-sn-glycero-3-phosphocholine were written onto planar glass substrates and the resulting pattern was imaged by large scan area AFM. Two writing regimes were identified, characterized of either a steady decline or a constant ink volume transfer per dot feature. For the steady state ink transfer, a linear relationship between the dwell time and the dot volume was determined, which is characterized by a flow rate of about 16 femtoliters per second. A dependence of the ink transport from the length of pauses before and in between writing the structures was observed and should be taken into account during pattern design when aiming at best writing homogeneity. The ultra-large scan range of the utilized AFM allowed for a simultaneous study of the entire preparation area of almost 1 mm2, yielding good statistic results.

  4. Large Deployable Reflector (LDR) system concept and technology definition study. Volume 1: Executive summary, analyses and trades, and system concepts

    Science.gov (United States)

    Agnew, Donald L.; Jones, Peter A.

    1989-01-01

    A study was conducted to define reasonable and representative large deployable reflector (LDR) system concepts for the purpose of defining a technology development program aimed at providing the requisite technological capability necessary to start LDR development by the end of 1991. This volume includes the executive summary for the total study, a report of thirteen system analysis and trades tasks (optical configuration, aperture size, reflector material, segmented mirror, optical subsystem, thermal, pointing and control, transportation to orbit, structures, contamination control, orbital parameters, orbital environment, and spacecraft functions), and descriptions of three selected LDR system concepts. Supporting information is contained in appendices.

  5. Implication on the core collapse supernova rate from 21 years of data of the Large Volume Detector

    CERN Document Server

    Agafonova, N Y; Antonioli, P; Ashikhmin, V V; Badino, G.; Bari, G; Bertoni, R; Bressan, E; Bruno, G; Dadykin, V L; Dobrynina, E A; Enikeev, R I; Fulgione, W; Galeotti, P; Garbini, M; Ghia, P L; Giusti, P; Gomez, F; Kemp, E; Malgin, A S; Molinario, A; Persiani, R; Pless, I A; Porta, A; Ryasny, V G; Ryazhskaya, O G; Saavedra, O; Sartorelli, G; Shakiryanova, I R; Selvi, M; Trinchero, G C; Vigorito, C; Yakushev, V F; Zichichi, A

    2015-01-01

    The Large Volume Detector (LVD) has been continuously taking data since 1992 at the INFN Gran Sasso National Laboratory. LVD is sensitive to neutrino bursts from gravitational stellar collapses with full detection probability over the Galaxy. We have searched for neutrino bursts in LVD data taken in 7335 days of operation. No evidence of neutrino signals has been found between June 1992 and December 2013. The 90% C.L. upper limit on the rate of core-collapse and failed supernova explosions out to distances of 25 kpc is found to be 0.114/y.

  6. Influence of copper volume fraction on tensile strain/stress tolerances of critical current in a copper-plated DyBCO-coated conductor

    International Nuclear Information System (INIS)

    Ochiai, Shojiro; Okuda, Hiroshi; Arai, Takahiro; Sugano, Michinaka; Osamura, Kozo; Prusseit, Werner

    2013-01-01

    The influence of the volume fraction (V f ) of copper, plated at room temperature over a DyBa 2 Cu 3 O 7-δ -coated conductor, on the tensile strain tolerance and stress tolerance of critical current at 77 K was studied over a wide range of copper V f values. The copper plating exerts a tensile stress during cooling because copper has a higher coefficient of thermal expansion than the substrate conductor. Before application of tensile strain, the copper plated at room temperature yielded at 77 K when the copper V f was lower than a critical value, and was in an elastic state at 77 K when the copper V f was higher than the critical value. The strain tolerance of critical current increased with increasing copper V f due to an increase in thermally induced compressive strain in the substrate tape. The stress tolerance of critical current decreased with increasing copper V f because copper is softer than the substrate tape. These results, together with the trade-off between strain tolerance and stress tolerance (i.e., stress tolerance decreases with increasing strain tolerance), were analyzed by modeling. The results show that the restriction imposed by the trade-off, which limits the ability to simultaneously obtain a high strain tolerance and a high stress tolerance, can be relaxed by strengthening the copper. (author)

  7. NUMERICAL METHOD OF MIXED FINITE VOLUME-MODIFIED UPWIND FRACTIONAL STEP DIFFERENCE FOR THREE-DIMENSIONAL SEMICONDUCTOR DEVICE TRANSIENT BEHAVIOR PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    Yirang YUAN; Qing YANG; Changfeng LI; Tongjun SUN

    2017-01-01

    Transient behavior of three-dimensional semiconductor device with heat conduction is described by a coupled mathematical system of four quasi-linear partial differential equations with initial-boundary value conditions.The electric potential is defined by an elliptic equation and it appears in the following three equations via the electric field intensity.The electron concentration and the hole concentration are determined by convection-dominated diffusion equations and the temperature is interpreted by a heat conduction equation.A mixed finite volume element approximation,keeping physical conservation law,is used to get numerical values of the electric potential and the accuracy is improved one order.Two concentrations and the heat conduction are computed by a fractional step method combined with second-order upwind differences.This method can overcome numerical oscillation,dispersion and decreases computational complexity.Then a three-dimensional problem is solved by computing three successive one-dimensional problems where the method of speedup is used and the computational work is greatly shortened.An optimal second-order error estimate in L2 norm is derived by using prior estimate theory and other special techniques of partial differential equations.This type of mass-conservative parallel method is important and is most valuable in numerical analysis and application of semiconductor device.

  8. Influence of the Metal Volume Fraction on the permanent dent depth and energy absorption of GLARE plates subjected to low velocity impact

    Science.gov (United States)

    Bikakis, GSE; Savaidis, A.; Zalimidis, P.; Tsitos, S.

    2016-11-01

    Fiber-metal laminates are hybrid composite materials, consisting of alternating metal layers bonded to fiber-reinforced prepreg layers. GLARE (GLAss REinforced) belongs to this new family of materials. GLARE is the most successful fiber-metal laminate up to now and is currently being used for the construction of primary aerospace structures, such as the fuselage of the Airbus A380 air plane. Impact properties are very important in aerospace structures, since impact damage is caused by various sources, such as maintenance damage from dropped tools, collision between service cars or cargo and the structure, bird strikes and hail. The principal objective of this article is to evaluate the influence of the Metal Volume Fraction (MVF) on the low velocity impact response of GLARE fiber-metal laminates. Previously published differential equations of motion are employed for this purpose. The low velocity impact behavior of various circular GLARE plates is predicted and characteristic values of impact variables, which represent the impact phenomenon, are evaluated versus the corresponding MVF of the examined GLARE material grades. The considered GLARE plates are subjected to low velocity impact under identical impact conditions. A strong effect of the MVF on the maximum impact load and a significant effect on the maximum plate deflection of GLARE plates has been found.

  9. Influence of the Metal Volume Fraction on the maximum deflection and impact load of GLARE plates subjected to low velocity impact

    Science.gov (United States)

    Bikakis, GSE; Savaidis, A.; Zalimidis, P.; Tsitos, S.

    2016-11-01

    Fiber-metal laminates are hybrid composite materials, consisting of alternating metal layers bonded to fiber-reinforced prepreg layers. GLARE (GLAss REinforced) belongs to this new family of materials. GLARE is the most successful fiber-metal laminate up to now and is currently being used for the construction of primary aerospace structures, such as the fuselage of the Airbus A380 air plane. Impact properties are very important in aerospace structures, since impact damage is caused by various sources, such as maintenance damage from dropped tools, collision between service cars or cargo and the structure, bird strikes and hail. The principal objective of this article is to evaluate the influence of the Metal Volume Fraction (MVF) on the low velocity impact response of GLARE fiber-metal laminates. Previously published differential equations of motion are employed for this purpose. The low velocity impact behavior of various circular GLARE plates is predicted and characteristic values of impact variables, which represent the impact phenomenon, are evaluated versus the corresponding MVF of the examined GLARE material grades. The considered GLARE plates are subjected to low velocity impact under identical impact conditions. A strong effect of the MVF on the maximum impact load and a significant effect on the maximum plate deflection of GLARE plates has been found.

  10. Deformation mechanisms in a fine-grained Udimet 720LI nickel-base superalloy with high volume fractions of γ′ phases

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jiayu, E-mail: chenjiayu975@126.com; Dong, Jianxin; Zhang, Maicang; Yao, Zhihao

    2016-09-15

    Hot-deformation behaviors and mechanisms below γ′ solvus of U720LI with fine-grained microstructure and high volume fractions of γ′ phases were studied. MTS hot-compressed samples under hot-deformation parameters (Temperatures of 1040 °C, 1070 °C, 1100 °C, 1130 °C, strain rates of 0.01 s{sup −1}, 0.1 s{sup −1}, 0.5 s{sup −1} and strains of 0.11, 0.36, 0.69 and 1.2) were investigated by using multiple microstructural analysis methods, such as transmission electron microscopy (TEM), electron channeling contrast image (ECCI), et al.. Rare recovery and recrystallization were observed indicating that other deformation mechanisms might be enhanced during the deformation process. Except for the pinning effect, deformation happened within γ′ phases and also γ′ phase promoted the deformation of the matrix. When the slipping was inhibited by γ′ phases, twinning acted as a deformation mechanism in fine-grained U720LI. Due to the retardation effect of γ′ phases in the early stage of the deformation process, local grain boundary migration took effect. Once grain boundaries crossed γ′ phases, it made recrystallization by strain induced boundary motion(SIBM) easier.

  11. Contrast-enhanced T1 mapping-based extracellular volume fraction independently predicts clinical outcome in patients with non-ischemic dilated cardiomyopathy: a prospective cohort study

    Energy Technology Data Exchange (ETDEWEB)

    Youn, Jong-Chan [Hallym University College of Medicine, Division of Cardiology, Dongtan Sacred Heart Hospital, Hwaseong (Korea, Republic of); Yonsei University College of Medicine, Division of Cardiology, Severance Cardiovascular Hospital, Seoul (Korea, Republic of); Hong, Yoo Jin; Lee, Hye-Jeong; Han, Kyunghwa; Suh, Young Joo; Hur, Jin; Kim, Young Jin; Choi, Byoung Wook [Yonsei University College of Medicine, Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Seoul (Korea, Republic of); Shim, Chi Young; Hong, Geu-Ru; Kang, Seok-Min [Yonsei University College of Medicine, Division of Cardiology, Severance Cardiovascular Hospital, Seoul (Korea, Republic of)

    2017-09-15

    We aimed to evaluate the prognostic role of cardiac magnetic resonance imaging (CMR)-based extracellular volume fraction (ECV) in patients with non-ischemic dilated cardiomyopathy (NIDCM) and compare it with late gadolinium enhancement (LGE) parameters. This was a single-center, prospective, cohort study of 117 NIDCM patients (71 men, 51.9 ± 16.7 years) who underwent clinical 3.0-T CMR. Myocardial ECV and LGE were quantified on the left ventricular myocardium. The presence of midwall LGE was also detected. Nineteen healthy subjects served as controls. The primary end points were cardiovascular (CV) events defined by CV death, rehospitalization due to heart failure, and heart transplantation. During the follow-up period (median duration, 11.2 months; 25{sup th}-75{sup th} percentile, 7.8-21.9 months), the primary end points occurred in 19 patients (16.2%). The ECV (per 3% and 1% increase) was associated with a hazard ratio of 1.80 and 1.22 (95% confidence interval [CI], 1.48-2.20 and 1.14-1.30, respectively; p < 0.001) for the CV events. Multivariable analysis also indicated that ECV was an independent prognostic factor and had a higher prognostic value (Harrell's c statistic, 0.88) than LGE quantification values (0.77) or midwall LGE (0.80). CMR-based ECV independently predicts the clinical outcome in NIDCM patients. (orig.)

  12. Extraterrestrial processing and manufacturing of large space systems. Volume 3: Executive summary

    Science.gov (United States)

    Miller, R. H.; Smith, D. B. S.

    1979-01-01

    Facilities and equipment are defined for refining processes to commercial grade of lunar material that is delivered to a 'space manufacturing facility' in beneficiated, primary processed quality. The manufacturing facilities and the equipment for producing elements of large space systems from these materials and providing programmatic assessments of the concepts are also defined. In-space production processes of solar cells (by vapor deposition) and arrays, structures and joints, conduits, waveguides, RF equipment radiators, wire cables, converters, and others are described.

  13. Extraterrestrial processing and manufacturing of large space systems, volume 1, chapters 1-6

    Science.gov (United States)

    Miller, R. H.; Smith, D. B. S.

    1979-01-01

    Space program scenarios for production of large space structures from lunar materials are defined. The concept of the space manufacturing facility (SMF) is presented. The manufacturing processes and equipment for the SMF are defined and the conceptual layouts are described for the production of solar cells and arrays, structures and joints, conduits, waveguides, RF equipment radiators, wire cables, and converters. A 'reference' SMF was designed and its operation requirements are described.

  14. Hierarchical storage of large volume of multidector CT data using distributed servers

    Science.gov (United States)

    Ratib, Osman; Rosset, Antoine; Heuberger, Joris; Bandon, David

    2006-03-01

    Multidector scanners and hybrid multimodality scanners have the ability to generate large number of high-resolution images resulting in very large data sets. In most cases, these datasets are generated for the sole purpose of generating secondary processed images and 3D rendered images as well as oblique and curved multiplanar reformatted images. It is therefore not essential to archive the original images after they have been processed. We have developed an architecture of distributed archive servers for temporary storage of large image datasets for 3D rendering and image processing without the need for long term storage in PACS archive. With the relatively low cost of storage devices it is possible to configure these servers to hold several months or even years of data, long enough for allowing subsequent re-processing if required by specific clinical situations. We tested the latest generation of RAID servers provided by Apple computers with a capacity of 5 TBytes. We implemented a peer-to-peer data access software based on our Open-Source image management software called OsiriX, allowing remote workstations to directly access DICOM image files located on the server through a new technology called "bonjour". This architecture offers a seamless integration of multiple servers and workstations without the need for central database or complex workflow management tools. It allows efficient access to image data from multiple workstation for image analysis and visualization without the need for image data transfer. It provides a convenient alternative to centralized PACS architecture while avoiding complex and time-consuming data transfer and storage.

  15. Onco plastic volume replacement with latissimus dorsi myocutaneous flap in patients with large ptotic breasts. Is it feasible?

    International Nuclear Information System (INIS)

    El-Marakby, H.H.; Kotb, M.H.

    2011-01-01

    Onco plastic breast conservative surgery has evolved as a safe alternative to the standard mastectomy in the treatment of early breast cancer. The procedure involves tumour resection with an adequate safety margin and either breast reshaping with volume displacement procedures (large or pt otic breasts) or volume replacement with latissimus dorsi myocutaneous flap (LDF) (small to medium sized non-ptotic breasts). A contra lateral mastopexy procedure is usually necessary with the volume displacement Onco plastic surgery, a procedure that is often rejected by a significant number of patients. This limits the choice of the reconstruction of breast defects in such patients to autologous tissues i.e. LDF. Aim: Aim is to evaluate the feasibility of volume replacement onco plastic breast conservative surgery with lemmatise dorsi myocutaneous flaps for patients with large ptotic breasts. This involves testing the oncologic safety in terms of adequate safety margin, the complications rate and the final cosmetic outcome. The loco regional recurrence rate will be recorded and compared with oncoplastic volume displacement for similar sized breast defects. Patients and methods: A group of 50 female patients with early breast cancers (T2) who presented to the department of surgery at the National Cancer Institute, Cairo, Egypt in the period between carried out in all patient groups and was used to annually follow up the patients. All patients were detected with T2 NO breast cancer by both clinical and radiological examinations. All patients underwent partial mastectomy was and reconstruction with LDFs. Results: The average age at presentation was 46.5 ± 9 years and the range was 26-65 years. Most of the patients were subjected to partial mastectomy in 30 patients (60%), excision of a single quadrant from the four major quadrants was carried out in 15 patients (30%) where skin sparing wide local excision was carried out in only five patients (10%). The safety margin ranged from

  16. No evidence of a threshold in traffic volume affecting road-kill mortality at a large spatio-temporal scale

    Energy Technology Data Exchange (ETDEWEB)

    Grilo, Clara, E-mail: clarabentesgrilo@gmail.com [Departamento de Biología de la Conservación, Estación Biológica de Doñana (EBD-CSIC), Calle Américo Vespucio s/n, E-41092 Sevilla (Spain); Centro Brasileiro de Estudos em Ecologia de Estradas, Departamento de Biologia, Universidade Federal de Lavras, Campus Universitário, 37200-000 Lavras, Minas Gerais (Brazil); Ferreira, Flavio Zanchetta; Revilla, Eloy [Departamento de Biología de la Conservación, Estación Biológica de Doñana (EBD-CSIC), Calle Américo Vespucio s/n, E-41092 Sevilla (Spain)

    2015-11-15

    Previous studies have found that the relationship between wildlife road mortality and traffic volume follows a threshold effect on low traffic volume roads. We aimed at evaluating the response of several species to increasing traffic intensity on highways over a large geographic area and temporal period. We used data of four terrestrial vertebrate species with different biological and ecological features known by their high road-kill rates: the barn owl (Tyto alba), hedgehog (Erinaceus europaeus), red fox (Vulpes vulpes) and European rabbit (Oryctolagus cuniculus). Additionally, we checked whether road-kill likelihood varies when traffic patterns depart from the average. We used annual average daily traffic (AADT) and road-kill records observed along 1000 km of highways in Portugal over seven consecutive years (2003–2009). We fitted candidate models using Generalized Linear Models with a binomial distribution through a sample unit of 1 km segments to describe the effect of traffic on the probability of finding at least one victim in each segment during the study. We also assigned for each road-kill record the traffic of that day and the AADT on that year to test for differences using Paired Student's t-test. Mortality risk declined significantly with traffic volume but varied among species: the probability of finding road-killed red foxes and rabbits occurs up to moderate traffic volumes (< 20,000 AADT) whereas barn owls and hedgehogs occurred up to higher traffic volumes (40,000 AADT). Perception of risk may explain differences in responses towards high traffic highway segments. Road-kill rates did not vary significantly when traffic intensity departed from the average. In summary, we did not find evidence of traffic thresholds for the analysed species and traffic intensities. We suggest mitigation measures to reduce mortality be applied in particular on low traffic roads (< 5000 AADT) while additional measures to reduce barrier effects should take into

  17. No evidence of a threshold in traffic volume affecting road-kill mortality at a large spatio-temporal scale

    International Nuclear Information System (INIS)

    Grilo, Clara; Ferreira, Flavio Zanchetta; Revilla, Eloy

    2015-01-01

    Previous studies have found that the relationship between wildlife road mortality and traffic volume follows a threshold effect on low traffic volume roads. We aimed at evaluating the response of several species to increasing traffic intensity on highways over a large geographic area and temporal period. We used data of four terrestrial vertebrate species with different biological and ecological features known by their high road-kill rates: the barn owl (Tyto alba), hedgehog (Erinaceus europaeus), red fox (Vulpes vulpes) and European rabbit (Oryctolagus cuniculus). Additionally, we checked whether road-kill likelihood varies when traffic patterns depart from the average. We used annual average daily traffic (AADT) and road-kill records observed along 1000 km of highways in Portugal over seven consecutive years (2003–2009). We fitted candidate models using Generalized Linear Models with a binomial distribution through a sample unit of 1 km segments to describe the effect of traffic on the probability of finding at least one victim in each segment during the study. We also assigned for each road-kill record the traffic of that day and the AADT on that year to test for differences using Paired Student's t-test. Mortality risk declined significantly with traffic volume but varied among species: the probability of finding road-killed red foxes and rabbits occurs up to moderate traffic volumes (< 20,000 AADT) whereas barn owls and hedgehogs occurred up to higher traffic volumes (40,000 AADT). Perception of risk may explain differences in responses towards high traffic highway segments. Road-kill rates did not vary significantly when traffic intensity departed from the average. In summary, we did not find evidence of traffic thresholds for the analysed species and traffic intensities. We suggest mitigation measures to reduce mortality be applied in particular on low traffic roads (< 5000 AADT) while additional measures to reduce barrier effects should take into

  18. Large fractions of CO2-fixing microorganisms in pristine limestone aquifers appear to be involved in the oxidation of reduced sulfur and nitrogen compounds

    Science.gov (United States)

    Herrmann, Martina; Rusznyák, Anna; Akob, Denise M.; Schulze, Isabel; Opitz, Sebastian; Totsche, Kai Uwe; Küsel, Kirsten

    2015-01-01

    The traditional view of the dependency of subsurface environments on surface-derived allochthonous carbon inputs is challenged by increasing evidence for the role of lithoautotrophy in aquifer carbon flow. We linked information on autotrophy (Calvin-Benson-Bassham cycle) with that from total microbial community analysis in groundwater at two superimposed—upper and lower—limestone groundwater reservoirs (aquifers). Quantitative PCR revealed that up to 17% of the microbial population had the genetic potential to fix CO2 via the Calvin cycle, with abundances of cbbM and cbbL genes, encoding RubisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) forms I and II, ranging from 1.14 × 103 to 6 × 106 genes liter−1 over a 2-year period. The structure of the active microbial communities based on 16S rRNA transcripts differed between the two aquifers, with a larger fraction of heterotrophic, facultative anaerobic, soil-related groups in the oxygen-deficient upper aquifer. Most identified CO2-assimilating phylogenetic groups appeared to be involved in the oxidation of sulfur or nitrogen compounds and harbored both RubisCO forms I and II, allowing efficient CO2 fixation in environments with strong oxygen and CO2 fluctuations. The genera Sulfuricellaand Nitrosomonas were represented by read fractions of up to 78 and 33%, respectively, within the cbbM and cbbL transcript pool and accounted for 5.6 and 3.8% of 16S rRNA sequence reads, respectively, in the lower aquifer. Our results indicate that a large fraction of bacteria in pristine limestone aquifers has the genetic potential for autotrophic CO2 fixation, with energy most likely provided by the oxidation of reduced sulfur and nitrogen compounds.

  19. Paul Scherrer Institute Scientific and Technical Report 2000. Volume VI: Large Research Facilities

    International Nuclear Information System (INIS)

    Foroughi, Fereydoun; Bercher, Renate; Buechli, Carmen; Zumkeller, Lotty

    2001-01-01

    The PSI Department Large Research Facilities (GFA) joins the efforts to provide an excellent research environment to Swiss and foreign research groups on the experimental facilities driven by our high intensity proton accelerator complex. Its divisions care for the running, maintenance and enhancement of the accelerator complex, the primary proton beamlines, the targets and the secondary beams as well as the neutron spallation source SINQ. The division for technical support and coordination provides for technical support to the research facility complementary to the basic logistic available from the department for logistics and marketing. Besides running the facilities, the staff of the department is also involved in theoretical and experimental research projects. Some of them address basic scientific questions mainly concerning the properties of micro- or nanostructured materials: experiments as well as large scale computer simulations of molecular dynamics were performed to investigate nonclassical materials properties. Others are related to improvements or extensions of the capabilities of our facilities. We also report on intriguing results from applications of the neutron capture radiography, the prompt gamma activation method and the isotope production facility at SINQ

  20. Paul Scherrer Institute Scientific and Technical Report 2000. Volume VI: Large Research Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Foroughi, Fereydoun; Bercher, Renate; Buechli, Carmen; Zumkeller, Lotty [eds.

    2001-07-01

    The PSI Department Large Research Facilities (GFA) joins the efforts to provide an excellent research environment to Swiss and foreign research groups on the experimental facilities driven by our high intensity proton accelerator complex. Its divisions care for the running, maintenance and enhancement of the accelerator complex, the primary proton beamlines, the targets and the secondary beams as well as the neutron spallation source SINQ. The division for technical support and coordination provides for technical support to the research facility complementary to the basic logistic available from the department for logistics and marketing. Besides running the facilities, the staff of the department is also involved in theoretical and experimental research projects. Some of them address basic scientific questions mainly concerning the properties of micro- or nanostructured materials: experiments as well as large scale computer simulations of molecular dynamics were performed to investigate nonclassical materials properties. Others are related to improvements or extensions of the capabilities of our facilities. We also report on intriguing results from applications of the neutron capture radiography, the prompt gamma activation method and the isotope production facility at SINQ.

  1. Radio-chemical dosage of {sup 90}Sr in large volumes of drinking water; Dosage radiochimique du {sup 90}Sr sur des volumes importants d'eaux potables

    Energy Technology Data Exchange (ETDEWEB)

    Jeanmaire, L; Patti, F; Bullier, D [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1965-07-01

    I. Principle of the method: 1. Fixing on a resin of all the cations present in the water. 2. Elution using 5 N nitric acid and precipitation of strontium as the carbonate. 3. Concentration of the strontium using the fuming nitric acid method. 4. Purification of the strontium on a resin by selective elution with ammonium citrate. 5. The strontium-90 is measured by separation at the {sup 90}Y equilibrium in the form of the oxalate which is then counted. II. Advantages of the method The concentration of the radio-activity starting from large volumes (100 l) is generally tedious but this method which makes use of a fixation on a cationic resin makes it very simple. The rest of the method consists of a series of simple chemical operations using ion-exchange on resins and coprecipitation. Finally, it is possible to dose stable strontium. (authors) [French] I. Principe du dosage 1. Fixation sur resine de tous les cations presents dans l'eau, 2. Elution par l'acide nitrique 5 N et precipitation du strontium sous forme de carbonate. 3. Concentration du strontium par la methode a l'acide nitrique fumant. 4. Purification du strontium sur resine par elution selective au citrate d'ammonium. 5. Le strontium-90 est dose par separation a l'equilibre du {sup 90}Y sous forme d'oxalate qui est compte. II. Interet de la methode La concentration de la radioactivite a partir de volumes importants (100 l) est generalement fastidieuse, la technique proposee rend cette phase tres simple en utilisant une fixation sur resine cationique. Le reste de la technique est une suite d'operations chimiques simples a realiser, faisant appel a l'echange d'ions sur resine et a la coprecipitation. Enfin, il est possible de realiser le dosage du strontium stable. (auteurs)

  2. Material properties of large-volume cadmium zinc telluride crystals and their relationship to nuclear detector performance

    Energy Technology Data Exchange (ETDEWEB)

    James, R.B.; Lund, J. [Sandia National Labs., Livermore, CA (United States); Yoon, H. [Sandia National Labs., Livermore, CA (United States)]|[Univ. of California, Los Angeles, CA (United States)] [and others

    1997-09-01

    The material showing the greatest promise today for production of large-volume gamma-ray spectrometers operable at room temperature is cadmium zinc telluride (CZT). Unfortunately, because of deficiencies in the quality of the present material, high-resolution CZT spectrometers have thus far been limited to relatively small dimensions, which makes them inefficient at detecting high photon energies and ineffective for weak radiation signals except in near proximity. To exploit CZT fully, it will be necessary to make substantial improvements in the material quality. Improving the material involves advances in the purity, crystallinity, and control of the electrical compensation mechanism. Sandia National Laboratories, California, in close collaboration with US industry and academia, has initiated efforts to develop a detailed understanding of the underlying material problems limiting the performance of large volume gamma-ray spectrometers and to overcome them through appropriate corrections therein. A variety of analytical and numerical techniques are employed to quantify impurities, compositional and stoichiometric variations, crystallinity, strain, bulk and surface defect states, carrier mobilities and lifetimes, electric field distributions, and contact chemistry. Data from these measurements are correlated with spatial maps of the gamma-ray and alpha particle spectroscopic response to determine improvements in the material purification, crystal growth, detector fabrication, and surface passivation procedures. The results of several analytical techniques will be discussed. The intended accomplishment of this work is to develop a low-cost, high-efficiency CZT spectrometer with an active volume of 5 cm{sup 3} and energy resolution of 1--2% (at 662 keV), which would give the US a new field capability for screening radioactive substances.

  3. SyPRID sampler: A large-volume, high-resolution, autonomous, deep-ocean precision plankton sampling system

    Science.gov (United States)

    Billings, Andrew; Kaiser, Carl; Young, Craig M.; Hiebert, Laurel S.; Cole, Eli; Wagner, Jamie K. S.; Van Dover, Cindy Lee

    2017-03-01

    The current standard for large-volume (thousands of cubic meters) zooplankton sampling in the deep sea is the MOCNESS, a system of multiple opening-closing nets, typically lowered to within 50 m of the seabed and towed obliquely to the surface to obtain low-spatial-resolution samples that integrate across 10 s of meters of water depth. The SyPRID (Sentry Precision Robotic Impeller Driven) sampler is an innovative, deep-rated (6000 m) plankton sampler that partners with the Sentry Autonomous Underwater Vehicle (AUV) to obtain paired, large-volume plankton samples at specified depths and survey lines to within 1.5 m of the seabed and with simultaneous collection of sensor data. SyPRID uses a perforated Ultra-High-Molecular-Weight (UHMW) plastic tube to support a fine mesh net within an outer carbon composite tube (tube-within-a-tube design), with an axial flow pump located aft of the capture filter. The pump facilitates flow through the system and reduces or possibly eliminates the bow wave at the mouth opening. The cod end, a hollow truncated cone, is also made of UHMW plastic and includes a collection volume designed to provide an area where zooplankton can collect, out of the high flow region. SyPRID attaches as a saddle-pack to the Sentry vehicle. Sentry itself is configured with a flight control system that enables autonomous survey paths to low altitudes. In its verification deployment at the Blake Ridge Seep (2160 m) on the US Atlantic Margin, SyPRID was operated for 6 h at an altitude of 5 m. It recovered plankton samples, including delicate living larvae, from the near-bottom stratum that is seldom sampled by a typical MOCNESS tow. The prototype SyPRID and its next generations will enable studies of plankton or other particulate distributions associated with localized physico-chemical strata in the water column or above patchy habitats on the seafloor.

  4. Material properties of large-volume cadmium zinc telluride crystals and their relationship to nuclear detector performance

    International Nuclear Information System (INIS)

    James, R.B.; Lund, J.; Yoon, H.

    1997-01-01

    The material showing the greatest promise today for production of large-volume gamma-ray spectrometers operable at room temperature is cadmium zinc telluride (CZT). Unfortunately, because of deficiencies in the quality of the present material, high-resolution CZT spectrometers have thus far been limited to relatively small dimensions, which makes them inefficient at detecting high photon energies and ineffective for weak radiation signals except in near proximity. To exploit CZT fully, it will be necessary to make substantial improvements in the material quality. Improving the material involves advances in the purity, crystallinity, and control of the electrical compensation mechanism. Sandia National Laboratories, California, in close collaboration with US industry and academia, has initiated efforts to develop a detailed understanding of the underlying material problems limiting the performance of large volume gamma-ray spectrometers and to overcome them through appropriate corrections therein. A variety of analytical and numerical techniques are employed to quantify impurities, compositional and stoichiometric variations, crystallinity, strain, bulk and surface defect states, carrier mobilities and lifetimes, electric field distributions, and contact chemistry. Data from these measurements are correlated with spatial maps of the gamma-ray and alpha particle spectroscopic response to determine improvements in the material purification, crystal growth, detector fabrication, and surface passivation procedures. The results of several analytical techniques will be discussed. The intended accomplishment of this work is to develop a low-cost, high-efficiency CZT spectrometer with an active volume of 5 cm 3 and energy resolution of 1--2% (at 662 keV), which would give the US a new field capability for screening radioactive substances

  5. Potential of electrical gas discharges for pollution control of large gas volumes

    International Nuclear Information System (INIS)

    Kogelschatz, U.

    1997-01-01

    Non-equilibrium gas discharges in many cases offer an innovative approach to the solution cf industrial air pollution problems. Negative corona discharges are used in electrostatic precipitators to collect dust and fly ash particles. Pulsed positive streamer coronas, dielectric-barrier discharges and possibly also flow-stabilised high pressure glow discharges are emerging technologies for the destruction of air pollutants like nitrogen oxides and sulfur dioxide in flue gases and volatile organic compounds (VOCs) in industrial effluents. The different discharge types are discussed with special emphasis on their potential for upscaling. Major applications are expected particularly in the removal of dilute concentrations of air pollutants, in odour control and in the simultaneous removal of different pollutants. Dielectric-barrier discharges exhibit disposal efficiencies similar to those of pulsed positive streamer coronas and require less sophisticated feeding circuits in large-scale industrial applications. (author)

  6. Critical joints in large composite primary aircraft structures. Volume 2: Technology demonstration test report

    Science.gov (United States)

    Bunin, Bruce L.

    1985-01-01

    A program was conducted to develop the technology for critical structural joints in composite wing structure that meets all the design requirements of a 1990 commercial transport aircraft. The results of four large composite multirow bolted joint tests are presented. The tests were conducted to demonstrate the technology for critical joints in highly loaded composite structure and to verify the analytical methods that were developed throughout the program. The test consisted of a wing skin-stringer transition specimen representing a stringer runout and skin splice on the wing lower surface at the side of the fuselage attachment. All tests were static tension tests. The composite material was Toray T-300 fiber with Ciba-Geigy 914 resin in 10 mil tape form. The splice members were metallic, using combinations of aluminum and titanium. Discussions are given of the test article, instrumentation, test setup, test procedures, and test results for each of the four specimens. Some of the analytical predictions are also included.

  7. Critical joints in large composite primary aircraft structures. Volume 1: Technical summary

    Science.gov (United States)

    Bunin, Bruce L.

    1985-01-01

    A program was conducted at Douglas Aircraft Company to develop the technology for critical joints in composite wing structure that meets all the design requirements of a 1990 commercial transport aircraft. In fulfilling this objective, analytical procedures for joint design and analysis were developed during Phase 1 of the program. Tests were conducted at the element level to supply the empirical data required for methods development. Large composite multirow joints were tested to verify the selected design concepts and for correlation with analysis predictions. The Phase 2 program included additional tests to provide joint design and analysis data, and culminated with several technology demonstration tests of a major joint area representative of a commercial transport wing. The technology demonstration program of Phase 2 is discussed. The analysis methodology development, structural test program, and correlation between test results and analytical strength predictions are reviewed.

  8. Periodic long-range transport in a large volume dc glow discharge dusty plasma

    International Nuclear Information System (INIS)

    Thomas, Edward Jr.; Amatucci, William E.; Compton, Christopher; Christy, Brian; Jackson, Jon David

    2003-01-01

    In an earlier paper, the authors reported on observations of a variety of particle transport phenomena observed in DUPLEX--the DUsty PLasma EXperiment at the Naval Research Laboratory [E. Thomas, Jr., W. E. Amatucci, C. Compton, and B. Christy, Phys. Plasmas 9, 3154 (2002)]. DUPLEX is a large, transparent polycarbonate cylinder that is 40 cm in radius and 80 cm in height. dc glow discharge argon plasmas are generated in DUPLEX. In this paper, the authors expand upon one particular feature of particle transport in DUPLEX, the long-range (i.e., greater than 15 cm), periodic (T∼2.5 min) transport of suspended alumina particles through the plasma. A detailed description of this particle motion through the plasma is presented. Finally, a qualitative model describing the phenomena that lead to this transport is also given

  9. Fractional statistics and fractional quantized Hall effect

    International Nuclear Information System (INIS)

    Tao, R.; Wu, Y.S.

    1985-01-01

    The authors suggest that the origin of the odd-denominator rule observed in the fractional quantized Hall effect (FQHE) may lie in fractional statistics which govern quasiparticles in FQHE. A theorem concerning statistics of clusters of quasiparticles implies that fractional statistics do not allow coexistence of a large number of quasiparticles at fillings with an even denominator. Thus, no Hall plateau can be formed at these fillings, regardless of the presence of an energy gap. 15 references

  10. Small changes in Cu redox state and speciation generate large isotope fractionation during adsorption and incorporation of Cu by a phototrophic biofilm

    Science.gov (United States)

    Coutaud, Margot; Méheut, Merlin; Glatzel, Pieter; Pokrovski, Gleb S.; Viers, Jérôme; Rols, Jean-Luc; Pokrovsky, Oleg S.

    2018-01-01

    Despite the importance of phototrophic biofilms in metal cycling in freshwater systems, metal isotope fractionation linked to metal adsorption and uptake by biofilm remains very poorly constrained. Here, copper isotop