Voltammetric behaviour at gold electrodes immersed in the BCR sequential extraction scheme media Application of underpotential deposition-stripping voltammetry to determination of copper in soil extracts

Energy Technology Data Exchange (ETDEWEB)

Beni, Valerio; Newton, Hazel V.; Arrigan, Damien W.M.; Hill, Martin; Lane, William A.; Mathewson, Alan

2004-01-30

The development of mercury-free electroanalytical systems for in-field analysis of pollutants requires a foundation on the electrochemical behaviour of the chosen electrode material in the target sample matrices. In this work, the behaviour of gold working electrodes in the media employed in the BCR sequential extraction protocol, for the fractionation of metals in solid environmental matrices, is reported. All three of the BCR sequential extraction media are redox active, on the basis of acidity and oxygen content as well as the inherent reducing or oxidising nature of some of the reagents employed: 0.11 M acetic acid, 0.1 M hydroxylammonium chloride (adjusted to pH 2) and 1 M ammonium acetate (adjusted to pH 2) with added trace hydrogen peroxide. The available potential ranges together with the demonstrated detection of target metals in these media are presented. Stripping voltammetry of copper or lead in the BCR extract media solutions reveal a multi-peak behaviour due to the stripping of both bulk metal and underpotential metal deposits. A procedure based on underpotential deposition-stripping voltammetry (UPD-SV) was evaluated for application to determination of copper in 0.11 M acetic acid soil extracts. A preliminary screening step in which different deposition times are applied to the sample enables a deposition time commensurate with UPD-SV to be selected so that no bulk deposition or stripping occurs thus simplifying the shape and features of the resulting voltammograms. Choice of the suitable deposition time is then followed by standards addition calibration. The method was validated by the analysis of a number of BCR 0.11 M acetic acid soil extracts. Good agreement was obtained been the UPD-SV method and atomic spectroscopic results.

Voltammetric behaviour at gold electrodes immersed in the BCR sequential extraction scheme media Application of underpotential deposition-stripping voltammetry to determination of copper in soil extracts

International Nuclear Information System (INIS)

Beni, Valerio; Newton, Hazel V.; Arrigan, Damien W.M.; Hill, Martin; Lane, William A.; Mathewson, Alan

2004-01-01

The development of mercury-free electroanalytical systems for in-field analysis of pollutants requires a foundation on the electrochemical behaviour of the chosen electrode material in the target sample matrices. In this work, the behaviour of gold working electrodes in the media employed in the BCR sequential extraction protocol, for the fractionation of metals in solid environmental matrices, is reported. All three of the BCR sequential extraction media are redox active, on the basis of acidity and oxygen content as well as the inherent reducing or oxidising nature of some of the reagents employed: 0.11 M acetic acid, 0.1 M hydroxylammonium chloride (adjusted to pH 2) and 1 M ammonium acetate (adjusted to pH 2) with added trace hydrogen peroxide. The available potential ranges together with the demonstrated detection of target metals in these media are presented. Stripping voltammetry of copper or lead in the BCR extract media solutions reveal a multi-peak behaviour due to the stripping of both bulk metal and underpotential metal deposits. A procedure based on underpotential deposition-stripping voltammetry (UPD-SV) was evaluated for application to determination of copper in 0.11 M acetic acid soil extracts. A preliminary screening step in which different deposition times are applied to the sample enables a deposition time commensurate with UPD-SV to be selected so that no bulk deposition or stripping occurs thus simplifying the shape and features of the resulting voltammograms. Choice of the suitable deposition time is then followed by standards addition calibration. The method was validated by the analysis of a number of BCR 0.11 M acetic acid soil extracts. Good agreement was obtained been the UPD-SV method and atomic spectroscopic results

Use of sequential extraction to assess metal partitioning in soils

International Nuclear Information System (INIS)

Kaasalainen, Marika; Yli-Halla, Markku

2003-01-01

The state of heavy metal pollution and the mobility of Cd, Cu, Ni, Cr, Pb and Zn were studied in three texturally different agricultural soil profiles near a Cu-Ni smelter in Harjavalta, Finland. The pseudo-total concentrations were determined by an aqua regia procedure. Metals were also determined after division into four fractions by sequential extraction with (1) acetic acid (exchangeable and specifically adsorbed metals), (2) a reducing agent (bound to Fe/Mn hydroxides), (3) an oxidizing agent (bound to soil organic matter) and (4) aqua regia (bound to mineral structures). Fallout from the smelter has increased the concentrations of Cd, Cu and Ni in the topsoil, where 75-90% of Cd, 49-72% of Cu and 22-52% of Ni occurred in the first two fractions. Slight Pb and Zn pollution was evident as well. High proportions of mobile Cd, Cu and Ni also deeper in the sandy soil, closest to the smelter, indicated some downward movement of metals. The hydroxide-bound fraction of Pb dominated in almost all soils and horizons, while Ni, Cr and Zn mostly occurred in mineral structures. Aqua regia extraction is usefully supplemented with sequential extraction, particularly in less polluted soils and in soils that exhibit substantial textural differences within the profiles. - Sequential extraction is most useful with soils with low metal pollutant levels

Sequential extraction procedures to ascertain the role of organic matter in the fate of iodine in soils

International Nuclear Information System (INIS)

Gavalda, D.; Colle, C.

2004-01-01

In the assessment of the radiological impact on man of radioactive substances the fate of the long-lived 129 I in soils is of special interest. In order to predict the behaviour of iodine in the environment the knowledge of soil parameters which are responsible for its sorption is necessary. Sequential extraction techniques were performed to investigate the degree of binding of iodine with soil components and more specifically with the different constituents of soil organic matter (humic acid, fulvic acid, humin) which are liable to change with time. A speciation scheme was especially developed to study the role of organic matter in iodine retention and complexation. In the first steps, several mineral fractions of iodine were extracted: water soluble (H 2 O), exchangeable (1M MgCl 2 ), carbonate bound (0.01N HCl), bound to Fe-Mn oxides (0.5 M NH 4 OH,HCl adjusted to pH=2 with HNO 3 ). After these preliminary steps, the extraction of organic matter was carried out with neutral pyrophosphate (Na 2 H 2 P 2 O 7 / K 4 P 2 O 7 1/1 0.1M pH=7) to determine iodine bound to organo-mineral complexes and sodium hydroxide (0.5 M NaOH) to quantify iodine bound to humic substances. For these extracts, the distribution of iodine between humic and fulvic acids was studied. Iodine bound to residual and insoluble organic matter (humin) was extracted with H 2 O 2 30% adjusted to pH=2 with HNO 3 . In the last step, iodine bound to the residual soil was extracted by wet digestion (H 2 SO 4 ). In this scheme, all the traditional organic reagents (acetate, acetic acid,..) were removed and replaced by mineral reagents to allow the monitoring of organic carbon in the soil extracts. (author)

Element fractionation by sequential extraction in a soil with high carbonate content

International Nuclear Information System (INIS)

Sulkowski, Margareta; Hirner, Alfred V.

2006-01-01

The influence of carbonate and other buffering substances in soils on the results of a 3-step sequential extraction procedure (BCR) used for metal fractionation was investigated. Deviating from the original extraction scheme, where the extracts are analysed only for a limited number of metals, almost all elements in the soils were quantified by X-ray fluorescence spectroscopy, in the initial samples as well as in the residues of all extraction steps. Additionally, the mineral contents were determined by X-ray diffractometry. Using this methodology, it was possible to correlate changes in soil composition caused by the extraction procedure with the release of elements. Furthermore, the pH values of all extracts were monitored, and certain extraction steps were repeated until no significant pH-rise occurred. A soil with high dolomite content (27%) and a carbonate free soil were extracted. Applying the original BCR-sequence to the calcareous soil, carbonate was found in the residues of the first two steps and extract pH-values rose by around two units in the first and second step, caused mainly by carbonate dissolution. This led to wrong assignment of the carbonate elements Ca, Mg, Sr, Ba, and also to decreased desorption and increased re-adsorption of ions in those steps. After repetition of the acetic acid step until extract pH remained low, the carbonate was completely destroyed and the distributions of the elements Ca, Mg, Sr, Ba as well as those of Co, Ni, Cu, Zn and Pb were found to be quite different to those determined in the original extraction. Furthermore, it could be shown that the effectiveness of the reduction process in step two was reduced by increasing pH: Fe oxides were not significantly attacked by the repeated acetic acid treatments, but a 10-fold amount of Fe was mobilized by hydroxylamine hydrochloride after complete carbonate destruction. On the other hand, only small amounts of Fe were released anyway. Even repeated reduction steps did not

Assessing potential forest and steel inter-industry residue utilisation by sequential chemical extraction

Energy Technology Data Exchange (ETDEWEB)

Makela, M.

2012-10-15

Traditional process industries in Finland and abroad are facing an emerging waste disposal problem due recent regulatory development which has increased the costs of landfill disposal and difficulty in acquiring new sites. For large manufacturers, such as the forest and ferrous metals industries, symbiotic cooperation of formerly separate industrial sectors could enable the utilisation waste-labeled residues in manufacturing novel residue-derived materials suitable for replacing commercial virgin alternatives. Such efforts would allow transforming the current linear resource use and disposal models to more cyclical ones and thus attain savings in valuable materials and energy resources. The work described in this thesis was aimed at utilising forest and carbon steel industry residues in the experimental manufacture of novel residue-derived materials technically and environmentally suitable for amending agricultural or forest soil properties. Single and sequential chemical extractions were used to compare the pseudo-total concentrations of trace elements in the manufactured amendment samples to relevant Finnish statutory limit values for the use of fertilizer products and to assess respective potential availability under natural conditions. In addition, the quality of analytical work and the suitability of sequential extraction in the analysis of an industrial solid sample were respectively evaluated through the analysis of a certified reference material and by X-ray diffraction of parallel sequential extraction residues. According to the acquired data, the incorporation of both forest and steel industry residues, such as fly ashes, lime wastes, green liquor dregs, sludges and slags, led to amendment liming capacities (34.9-38.3%, Ca equiv., d.w.) comparable to relevant commercial alternatives. Only the first experimental samples showed increased concentrations of pseudo-total cadmium and chromium, of which the latter was specified as the trivalent Cr(III). Based on

Comparison of sequential and single extraction in order to estimate environmental impact of metals from fly ash

Directory of Open Access Journals (Sweden)

Tasić Aleksandra M.

2016-01-01

Full Text Available The aim of this paper was to simulate leaching of metals from fly ash in different environmental conditions using ultrasound and microwave-assisted extraction techniques. Single-agent extraction and sequential extraction procedures were used to determine the levels of different metals leaching. The concentration of metals (Al, Fe, Mn, Cd, Co, Cr, Ni, Pb, Cu, As, Be in fly ash extracts were measured by Inductively Coupled Plasma-Atomic Emission Spectrometry. Single-agent extractions of metals were conducted during sonication times of 10, 20, 30, 40 and 50 min. Single-agent extraction with deionized water was also undertaken by exposing samples to microwave radiation at the temperature of 50°C. The sequential extraction was undertaken according to the BCR procedure which was modified and applied to study the partitioning of metals in coal fly ash. The microwave-assisted sequential extraction was performed at different extraction temperatures: 50, 100 and 150°C. The partitioning of metals between the individual fractions was investigated and discussed. The efficiency of the extraction process for each step was examined. In addition, the results of the microwave-assisted sequential extraction are compared to the results obtained by standard ASTM method. The mobility of most elements contained in fly ash is markedly pH sensitive. [Projekat Ministarstva nauke Republike Srbije, br. 172030, br. 176006 i br. III43009

Mobility of radionuclides based on sequential extraction of soils

International Nuclear Information System (INIS)

Salbu, B.; Oughton, D.H.; Lien, H.N.; Oestby, G.; Strand, P.

1992-01-01

Since 1989, core samples of soil and vegetation from semi-natural pastures have been collected at selected sites in Norway during the growing season. The activity concentrations in soil and vegetation as well as transfer coefficients vary significantly between regions, within regions and even within sampling plot areas. In order to differentiate between mobil and inert fractions of radioactive and stable isotopes of Cs and Sr in soils, samples were extracted sequentially using agents with increasing dissolution power. The reproducibility of the sequential extraction technique is good and the data obtained seems most informative. As the distribution pattern for radioactive and stable isotopes of Cs and Sr are similar, a high degree of isotopic exchange is indicated. Based on easily leachable fractions, mobility factors are calculated. In general the mobility of 90 Sr is higher than for 137 Cs. Mobility factors are not significantly influenced by seasonal variations, but a decrease in the mobile fraction in soil with time is indicated. Mobility factors should be considered useful for modelling purposes. (au)

Optimal Sales Schemes for Network Goods

DEFF Research Database (Denmark)

Parakhonyak, Alexei; Vikander, Nick

consumers simultaneously, serve them all sequentially, or employ any intermediate scheme. We show that the optimal sales scheme is purely sequential, where each consumer observes all previous sales before choosing whether to buy himself. A sequential scheme maximizes the amount of information available...

Fractionation of plutonium in environmental and bio-shielding concrete samples using dynamic sequential extraction

DEFF Research Database (Denmark)

Qiao, Jixin; Hou, Xiaolin

2010-01-01

Fractionation of plutonium isotopes (238Pu, 239,240Pu) in environmental samples (i.e. soil and sediment) and bio-shielding concrete from decommissioning of nuclear reactor were carried out by dynamic sequential extraction using an on-line sequential injection (SI) system combined with a specially...

Selenium Speciation Assessed by X-Ray Absorption Spectroscopy of Sequentially Extracted Anaerobic Biofilms

NARCIS (Netherlands)

Lenz, M.; Hullebusch, van E.D.; Farges, F.; Nikitenko, S.; Borca, C.N.; Grolimund, D.; Lens, P.N.L.

2008-01-01

Wet chemical methods such as sequential extraction procedures are commonly used to assess selenium fractionation in anoxic environments, allowing an estimation of the mobility and bioavailability of selenium. However, the interpretation can be biased by unselective extraction of targeted species and

A simple scheme for injection and extraction in compact rings

International Nuclear Information System (INIS)

Xu, H. S.; Huang, W. H.; Tang, C. X.

2014-01-01

There has been great interest in building compact synchrotrons for various applications, for example, inverse Compton scattering X-ray sources. However, the beam injection and extraction in compact rings require careful design for the lack of space. In this paper, we propose a simple combined injection-extraction scheme exploiting the fringe field of existing dipole magnets instead of additional septum magnets. This scheme is illustrated by using the 4.8 m ring proposed for Tsinghua Thomson scattering X-ray source as an example. Particle tracking is applied to demonstrate the validity of this scheme

Extraction and preconcentration of trace levels of cobalt using functionalized magnetic nanoparticles in a sequential injection lab-on-valve system with detection by electrothermal atomic absorption spectrometry

International Nuclear Information System (INIS)

Wang Yang; Luo Xiaoyu; Tang Jie; Hu Xiaoya; Xu Qin; Yang Chun

2012-01-01

Graphical abstract: An approach to performing extraction and preconcentration employing functionalized magnetic particles for the determination of cobalt in the sequential injection lab-on-valve system using detection by electrothermal atomic absorption spectrometry. Highlights: ► New SPE method for cobalt separation/preconcentration was reported. ► Functionalized magnetic nanoparticles were used as adsorbent. ► Extraction, elution, and detection procedures were performed in the LOV system. ► This automatic extraction technique provided a good platform for metal analysis. - Abstract: A new approach to performing extraction and preconcentration employing functionalized magnetic nanoparticles for the determination of trace metals is presented. Alumina-coated iron oxide nanoparticles were synthesized and used as the solid support. The nanoparticles were functionalized with sodium dodecyl sulfate and used as adsorbents for solid phase extraction of the analyte. Extraction, elution, and detection procedures were performed sequentially in the sequential injection lab-on-valve (SI-LOV) system followed by electrothermal atomic absorption spectrometry (ETAAS). Mixtures of hydrophobic analytes were successfully extracted from solution using the synthesized magnetic adsorbents. The potential use of the established scheme was demonstrated by taking cobalt as a model analyte. Under the optimal conditions, the calibration curve showed an excellent linearity in the concentration range of 0.01–5 μg L −1 , and the relative standard deviation was 2.8% at the 0.5 μg L −1 level (n = 11). The limit of detection was 6 ng L −1 with a sampling frequency of 18 h −1 . The present method has been successfully applied to cobalt determination in water samples and two certified reference materials.

Can standard sequential extraction determinations effectively define heavy metal species in superfund site soils?

Energy Technology Data Exchange (ETDEWEB)

Dahlin, Cheryl L.; Williamson, Connie A.; Collins, Wesley K.; Dahlin, David C.

2001-01-01

Speciation and distribution of heavy metals in soils controls the degree to which metals and their compounds are mobile, extractable, and plant-available. Consequently, speciation impacts the success of remediation efforts both by defining the relationship of the contaminants with their environment and by guiding development and evaluation of workable remediation strategies. The U.S. Department of Energy, Albany Research Center (Albany, OR), under a two-year interagency project with the U.S. Environmental Protection Agency (EPA), examined the suitability of sequential extraction as a definitive means to determine species of heavy metals in soil samples. Representative soil samples, contaminated with lead, arsenic, and/or chromium, were collected by EPA personnel from two Superfund sites, the National Lead Company site in Pedricktown, NJ, and the Roebling Steel, Inc., site in Florence, NJ. Data derived from Tessier=s standard three-stage sequential-extraction procedure were compared to data from a comprehensive characterization study that combined optical- and scanning-electron microscopy (with energy-dispersive x-ray and wavelength-dispersive x-ray analyses), x-ray diffraction, and chemical analyses. The results show that standard sequential-extraction procedures that were developed for characterizing species of contaminants in river sediments may be unsuitable for sole evaluation of contaminant species in industrial-site materials (particularly those that contain larger particles of the contaminants, encapsulated contaminants, and/or man-made materials such as slags, metals, and plastics). However, each sequential extraction or comprehensive characterization procedure has it=s own strengths and weaknesses. Findings of this study indicate that the use of both approaches, during the early stages of site studies, would be a best practice. The investigation also highlights the fact that an effective speciation study does not simply identify metal contaminants as

Development of a signal-extraction scheme for resonant sideband extraction

International Nuclear Information System (INIS)

Kokeyama, K; Kawazoe, F; Sugamoto, A; Somiya, K; Sato, S; Kawamura, S

2008-01-01

As a future plan, an advanced gravitational-wave detector will employ an optical configuration of resonant sideband extraction (RSE), achieved with an additional mirror at the signal-detection port of the power-recycled Fabry-Perot Michelson interferometer. To control the complex coupled cavity system, one of the most important design issues is how to extract the longitudinal control signals of the cavities. We have developed a new signal-extraction scheme which provides an appropriate sensing matrix. The new method uses two sets of sidebands: one of the sideband components satisfies the critical coupling condition for the RSE interferometer and reaches the signal-extraction port, and the other sideband is completely reflected by the Michelson interferometer. They provide a diagonalized sensing matrix and enable the RSE control to be robust

DUAL STATE-PARAMETER UPDATING SCHEME ON A CONCEPTUAL HYDROLOGIC MODEL USING SEQUENTIAL MONTE CARLO FILTERS

Science.gov (United States)

Noh, Seong Jin; Tachikawa, Yasuto; Shiiba, Michiharu; Kim, Sunmin

Applications of data assimilation techniques have been widely used to improve upon the predictability of hydrologic modeling. Among various data assimilation techniques, sequential Monte Carlo (SMC) filters, known as "particle filters" provide the capability to handle non-linear and non-Gaussian state-space models. This paper proposes a dual state-parameter updating scheme (DUS) based on SMC methods to estimate both state and parameter variables of a hydrologic model. We introduce a kernel smoothing method for the robust estimation of uncertain model parameters in the DUS. The applicability of the dual updating scheme is illustrated using the implementation of the storage function model on a middle-sized Japanese catchment. We also compare performance results of DUS combined with various SMC methods, such as SIR, ASIR and RPF.

Sequential Application of Soil Vapor Extraction and Bioremediation Processes for the Remediation of Ethylbenzene-Contaminated Soils

DEFF Research Database (Denmark)

Soares, António Carlos Alves; Pinho, Maria Teresa; Albergaria, José Tomás

2012-01-01

Soil vapor extraction (SVE) is an efficient, well-known and widely applied soil remediation technology. However, under certain conditions it cannot achieve the defined cleanup goals, requiring further treatment, for example, through bioremediation (BR). The sequential application of these technol......Soil vapor extraction (SVE) is an efficient, well-known and widely applied soil remediation technology. However, under certain conditions it cannot achieve the defined cleanup goals, requiring further treatment, for example, through bioremediation (BR). The sequential application...

Comparison of three sequential extraction procedures to describe metal fractionation in anaerobic granular sludges

NARCIS (Netherlands)

Hullebusch, van E.D.; Sudarno, S.; Zandvoort, M.H.; Lens, P.N.L.

2005-01-01

In the last few decades. several sequential extraction procedures have been developed to quantify the chemical status of metals in the solid phase. In this study. three extraction techniques (modified [A. Tessier, P.G.C. Campbell, M. Bisson, Anal. Chem. 51 (1979) 844]: [R.C. Stover. L.E. Sommers,

Distributions and concentrations of thallium in Korean soils determined by single and sequential extraction procedures.

Science.gov (United States)

Lee, Jin-Ho; Kim, Dong-Jin; Ahn, Byung-Koo

2015-06-01

The objectives of this study were to investigate the distribution of thallium in soils collected near suspected areas such as cement plants, active and closed mines, and smelters and to examine the extraction of thallium in the soils using 19 single chemical and sequential chemical extraction procedures. Thallium concentrations in soils near cement plants were distributed between 1.20 and 12.91 mg kg(-1). However, soils near mines and smelters contained relatively low thallium concentrations ranging from 0.18 to 1.09 mg kg(-1). Thallium extractability with 19 single chemical extractants from selected soils near cement plants ranged from 0.10% to 8.20% of the total thallium concentration. In particular, 1.0 M NH4Cl, 1.0 M (NH4)2SO4, and 1.0 M CH3COONH4 extracted more thallium than other extractants. Sequential fractionation results of thallium from different soils such as industrially and artificially contaminated soils varied with the soil properties, especially soil pH and the duration of thallium contamination.

Sequential extraction of heavy metals from urban dust and street sediments. Pt. 1. Sequential extraction of heavy metals in micro samples; Sequentielle Schwermetallextraktion aus Staubniederschlaegen und Strassensedimenten. T. 1. Sequentielle Schwermetallextraktion von Mikroproben

Energy Technology Data Exchange (ETDEWEB)

Heiser, U.; Norra, S.; Stueben, D.; Wagner, M. von [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Petrographie und Geochemie

1999-01-01

For the application of sequential extraction of heavy metals from samples that can only be obtained in amounts of a few milligrams (micro samples, e.g. airborne dust fallout), the method after Zeien and Bruemmer (1989) was progressed. A down scale to 1:100 was carried out and the accuracy of this method with variable sample amounts of about 20 mg and an extraction volume of 500 {mu}l was proofed with standard soil samples. The influence of variable extraction ratios (ratio of sample amount and volume of extraction solvent) and the influence of intensive treatment of dust sampled by the Bergerhoff-method (VDI 2119/2, 1972) prior sequential extraction, was within the precision of measurement of our method. Thus, we showed that sequential extraction can be applied for the investigation of heavy metal mobilization in micro samples with variable sample amounts. A first application of our method for microsamples was carried out to investigate airborne dust fallout and street sediments at two urban sites where different heavy metal immission rates due to traffic influence occur. These investigations will be presented in part 2 (`Sequential extraxction of heavy metals from urban dust`). (orig.) [Deutsch] Fuer die Anwendung der sequentiellen Schwermetallextraktion auf Proben, die nur im Milligramm-Bereich erhalten werden koennen (Mikroproben, wie z.B. Staubniederschlaege), wurde die Methode von Zeien und Bruemmer (1989) weiterentwickelt. Der Extraktionsmassstab wurde um den Faktor 1:100 verringert und die Reproduzierbarkeit des Verfahrens mit variablen Probenmengen um 20 mg und einem Extraktionsvolumen von 500 {mu}l mit Hilfe von Standardboeden nachgewiesen. Moegliche Einfluesse variabler Extraktionsverhaeltnisse (Verhaeltnis von Probenmenge zu Extraktionsvolumen) sowie eine aufwendige Vorbehandlung von Staubproben, die nach der Bergerhoff-Methode (VDI 2119/2, 1972) gesammelt wurden, lagen bei diesen Untersuchungen weitgehend im Variationsbereich des Verfahrens. Die

Sequential testing scheme for the assessment of the side-effects of plant protection products on the predatory bug Orius laevigatus

NARCIS (Netherlands)

Veire, Van de M.; Sterk, G.; Staaij, van der M.; Ramakers, P.M.J.; Tirry, L.

2002-01-01

This paper describes a number of test methods, to beused in a sequential scheme, for testing the side-effects ofplant protection products on anthocorid bugs. Orius laevigatuswas used as test species. A `worst case' laboratory method wasdeveloped for evaluating the effect on mortality of the

Pumpkin (Cucurbita maxima) seed proteins: sequential extraction processing and fraction characterization.

Science.gov (United States)

Rezig, Leila; Chibani, Farhat; Chouaibi, Moncef; Dalgalarrondo, Michèle; Hessini, Kamel; Guéguen, Jacques; Hamdi, Salem

2013-08-14

Seed proteins extracted from Tunisian pumpkin seeds ( Cucurbita maxima ) were investigated for their solubility properties and sequentially extracted according to the Osborne procedure. The solubility of pumpkin proteins from seed flour was greatly influenced by pH changes and ionic strength, with higher values in the alkaline pH regions. It also depends on the seed defatting solvent. Protein solubility was decreased by using chloroform/methanol (CM) for lipid extraction instead of pentane (P). On the basis of differential solubility fractionation and depending on the defatting method, the alkali extract (AE) was the major fraction (42.1 (P), 22.3% (CM)) compared to the salt extract (8.6 (P), 7.5% (CM)). In salt, alkali, and isopropanol extracts, all essential amino acids with the exceptions of threonine and lysine met the minimum requirements for preschool children (FAO/WHO/UNU). The denaturation temperatures were 96.6 and 93.4 °C for salt and alkali extracts, respectively. Pumpkin protein extracts with unique protein profiles and higher denaturation temperatures could impart novel characteristics when used as food ingredients.

FIR: An Effective Scheme for Extracting Useful Metadata from Social Media.

Science.gov (United States)

Chen, Long-Sheng; Lin, Zue-Cheng; Chang, Jing-Rong

2015-11-01

Recently, the use of social media for health information exchange is expanding among patients, physicians, and other health care professionals. In medical areas, social media allows non-experts to access, interpret, and generate medical information for their own care and the care of others. Researchers paid much attention on social media in medical educations, patient-pharmacist communications, adverse drug reactions detection, impacts of social media on medicine and healthcare, and so on. However, relatively few papers discuss how to extract useful knowledge from a huge amount of textual comments in social media effectively. Therefore, this study aims to propose a Fuzzy adaptive resonance theory network based Information Retrieval (FIR) scheme by combining Fuzzy adaptive resonance theory (ART) network, Latent Semantic Indexing (LSI), and association rules (AR) discovery to extract knowledge from social media. In our FIR scheme, Fuzzy ART network firstly has been employed to segment comments. Next, for each customer segment, we use LSI technique to retrieve important keywords. Then, in order to make the extracted keywords understandable, association rules mining is presented to organize these extracted keywords to build metadata. These extracted useful voices of customers will be transformed into design needs by using Quality Function Deployment (QFD) for further decision making. Unlike conventional information retrieval techniques which acquire too many keywords to get key points, our FIR scheme can extract understandable metadata from social media.

Modified sequential extraction for biochar and petroleum coke: Metal release potential and its environmental implications.

Science.gov (United States)

von Gunten, Konstantin; Alam, Md Samrat; Hubmann, Magdalena; Ok, Yong Sik; Konhauser, Kurt O; Alessi, Daniel S

2017-07-01

A modified Community Bureau of Reference (CBR) sequential extraction method was tested to assess the composition of untreated pyrogenic carbon (biochar) and oil sands petroleum coke. Wood biochar samples were found to contain lower concentrations of metals, but had higher fractions of easily mobilized alkaline earth and transition metals. Sewage sludge biochar was determined to be less recalcitrant and had higher total metal concentrations, with most of the metals found in the more resilient extraction fractions (oxidizable, residual). Petroleum coke was the most stable material, with a similar metal distribution pattern as the sewage sludge biochar. The applied sequential extraction method represents a suitable technique to recover metals from these materials, and is a valuable tool in understanding the metal retaining and leaching capability of various biochar types and carbonaceous petroleum coke samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sequential extraction for the speciation of some heavy metals in soils

International Nuclear Information System (INIS)

Zemberyova, M.; Zwaik, A.A.H.; Farkasovska, I.

1998-01-01

The five step sequential extraction for speciation of copper and nickel originally designed for sediments has been applied to soil samples. The extractant solutions were: 1 mol/l ammonium acetate, 1 mol/l hydroxylammonium chloride in 25% acetic acid (1:1), 0.1 mol/l hydrochlorid acid, 0.5 mol/l sodium hydroxide and 8 mol/l nitric acid. The residue was decomposed by HF and HNO 3 . Using this procedure the metal fraction bound to the organic matter can be distinguished. The concentrations of analytes were determined in the soil extracts by FAAS and ETAAS. Accuracy was assessed by comparing the sum of the contents of copper and nickel in soil extracts with the total certified values of CRMs of soils. The overall recovery values for nickel was 84-105% and for copper 105-114%. (author)

Selenium speciation in phosphate mine soils and evaluation of a sequential extraction procedure using XAFS

International Nuclear Information System (INIS)

Favorito, Jessica E.; Luxton, Todd P.; Eick, Matthew J.; Grossl, Paul R.

2017-01-01

Selenium is a trace element found in western US soils, where ingestion of Se-accumulating plants has resulted in livestock fatalities. Therefore, a reliable understanding of Se speciation and bioavailability is critical for effective mitigation. Sequential extraction procedures (SEP) are often employed to examine Se phases and speciation in contaminated soils but may be limited by experimental conditions. We examined the validity of a SEP using X-ray absorption spectroscopy (XAS) for both whole and a sequence of extracted soils. The sequence included removal of soluble, PO 4 -extractable, carbonate, amorphous Fe-oxide, crystalline Fe-oxide, organic, and residual Se forms. For whole soils, XANES analyses indicated Se(0) and Se(-II) predominated, with lower amounts of Se(IV) present, related to carbonates and Fe-oxides. Oxidized Se species were more elevated and residual/elemental Se was lower than previous SEP results from ICP-AES suggested. For soils from the SEP sequence, XANES results indicated only partial recovery of carbonate, Fe-oxide and organic Se. This suggests Se was incompletely removed during designated extractions, possibly due to lack of mineral solubilization or reagent specificity. Selenium fractions associated with Fe-oxides were reduced in amount or removed after using hydroxylamine HCl for most soils examined. XANES results indicate partial dissolution of solid-phases may occur during extraction processes. This study demonstrates why precautions should be taken to improve the validity of SEPs. Mineralogical and chemical characterizations should be completed prior to SEP implementation to identify extractable phases or mineral components that may influence extraction effectiveness. Sequential extraction procedures can be appropriately tailored for reliable quantification of speciation in contaminated soils. - Highlights: • XANES spectra indicated whole soils consisted of mostly elemental and organic Se and lower amounts of sorbed oxidized Se. �

Assessment of the BCR sequential extraction procedure for thallium fractionation using synthetic mineral mixtures

Czech Academy of Sciences Publication Activity Database

Vaněk, A.; Grygar, Tomáš; Chrastný, V.; Tejnecký, V.; Drahota, Petr; Komárek, M.

2010-01-01

Roč. 176, 1-3 (2010), s. 913-918 ISSN 0304-3894 Institutional research plan: CEZ:AV0Z4032918; CEZ:AV0Z30130516 Keywords : Metal * Sequential extraction * Goethite * Ferrihydrite * Birnessite * Illite Subject RIV: DD - Geochemistry Impact factor: 3.723, year: 2010

Sequential extraction applied to Peruibe black mud, SP, Brazil; Extracao sequencial aplicada a lama negra de Peruibe

Energy Technology Data Exchange (ETDEWEB)

Torrecilha, Jefferson Koyaishi

2014-07-01

The Peruibe Black mud is used in therapeutic treatments such as psoriasis, peripheral dermatitis, acne and seborrhoea, as well as in the treatment of myalgia, arthritis, rheumatism and non-articular processes. Likewise other medicinal clays, it may not be free from possible adverse health effects due to possible hazardous minerals leading to respiratory system occurrences and other effects, caused by the presence of toxic elements. Once used for therapeutic purposes, any given material should be fully characterized and thus samples of Peruibe black mud were analyzed to determine physical and chemical properties: moisture content, organic matter and loss on ignition; pH, particle size, cation exchange capacity and swelling index. The elemental composition was determined by Neutron Activation Analysis, Atomic Absorption Graphite Furnace and X-ray fluorescence; the mineralogical composition was determined by X-ray diffraction. Another tool widely used to evaluate the behavior of trace elements, in various environmental matrices, is the sequential extraction. Thus, a sequential extraction procedure was applied to fractionate the mud in specific geochemical forms and verify how and how much of the elements may be contained in it. Considering the several sequential extraction procedures, BCR-701 method (Community Bureau of Reference) was used since it is considered the most reproducible among them. A simple extraction with an artificial sweat was, also, applied in order to verify which components are potentially available for absorption by the patient skin during the topical treatment. The results indicated that the mud is basically composed by a silty-clay material, rich in organic matter and with good cation exchange capacity. There were no significant variations in mineralogy and elemental composition of both, in natura and mature mud forms. The analysis by sequential extraction and by simple extraction indicated that the elements possibly available in larger

On-line liquid phase micro-extraction based on drop-in-plug sequential injection lab-at-valve platform for metal determination

Energy Technology Data Exchange (ETDEWEB)

Mitani, Constantina [Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University, Thessaloniki 54124 (Greece); Anthemidis, Aristidis N., E-mail: anthemid@chem.auth.gr [Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University, Thessaloniki 54124 (Greece)

2013-04-10

Highlights: ► Drop-in-plug micro-extraction based on SI-LAV platform for metal preconcentration. ► Automatic liquid phase micro-extraction coupled with FAAS. ► Organic solvents with density higher than water are used. ► Lead determination in environmental water and urine samples. -- Abstract: A novel automatic on-line liquid phase micro-extraction method based on drop-in-plug sequential injection lab-at-valve (LAV) platform was proposed for metal preconcentration and determination. A flow-through micro-extraction chamber mounted at the selection valve was adopted without the need of sophisticated lab-on-valve components. Coupled to flame atomic absorption spectrometry (FAAS), the potential of this lab-at-valve scheme is demonstrated for trace lead determination in environmental and biological water samples. A hydrophobic complex of lead with ammonium pyrrolidine dithiocarbamate (APDC) was formed on-line and subsequently extracted into an 80 μL plug of chloroform. The extraction procedure was performed by forming micro-droplets of aqueous phase into the plug of the extractant. All critical parameters that affect the efficiency of the system were studied and optimized. The proposed method offered good performance characteristics and high preconcentration ratios. For 10 mL sample consumption an enhancement factor of 125 was obtained. The detection limit was 1.8 μg L{sup −1} and the precision expressed as relative standard deviation (RSD) at 50.0 μg L{sup −1} of lead was 2.9%. The proposed method was evaluated by analyzing certified reference materials and applied for lead determination in natural waters and urine samples.

Evaluation of degree of readsorption of radionuclides during sequential extraction in soil: comparison between batch and dynamic extraction systems

DEFF Research Database (Denmark)

Petersen, Roongrat; Hansen, Elo Harald; Hou, Xiaolin

. However, the techniques have an important problem with redistribution as a result of readsorption of dissolved analytes onto the remaining solids phases during extraction. Many authors have demonstrated the readsorption problem and inaccuracy from it. In our previous work, a dynamic extraction system......Sequential extraction techniques have been widely used to fractionate metals in solid samples (soils, sediments, solid wastes, etc.) due to their leachability. The results are useful for obtaining information about bioavailability, potential mobility and transport of element in natural environments...... developed in our laboratory for heavy metal fractionation has shown the reduction of readsorption problem in comparison with the batch techniques. Moreover, the system shows many advantages over the batch system such as speed of extraction, simple procedure, fully automatic, less risk of contamination...

Development of an automated sequential injection on-line solvent extraction-back extraction procedure as demonstrated for the determination of cadmium with detection by electrothermal atomic absorption spectrometry

DEFF Research Database (Denmark)

Wang, Jianhua; Hansen, Elo Harald

2002-01-01

An automated sequential injection (SI) on-line solvent extraction-back extraction separation/preconcentration procedure is described. Demonstrated for the assay of cadmium by electrothermal atomic absorption spectrometry (ETAAS), the analyte is initially complexed with ammonium pyrrolidinedithioc......An automated sequential injection (SI) on-line solvent extraction-back extraction separation/preconcentration procedure is described. Demonstrated for the assay of cadmium by electrothermal atomic absorption spectrometry (ETAAS), the analyte is initially complexed with ammonium....../preconcentration process of the ensuing sample. An enrichment factor of 21.4, a detection limit of 2.7 ng/l, along with a sampling frequency of 13s/h were obtained at a sample flow rate of 6.0mlmin/sup -1/. The precision (R.S.D.) at the 0.4 mug/l level was 1.8% as compared to 3.2% when quantifying the organic extractant...

Forced Sequence Sequential Decoding

DEFF Research Database (Denmark)

Jensen, Ole Riis; Paaske, Erik

1998-01-01

We describe a new concatenated decoding scheme based on iterations between an inner sequentially decoded convolutional code of rate R=1/4 and memory M=23, and block interleaved outer Reed-Solomon (RS) codes with nonuniform profile. With this scheme decoding with good performance is possible as low...... as Eb/N0=0.6 dB, which is about 1.25 dB below the signal-to-noise ratio (SNR) that marks the cutoff rate for the full system. Accounting for about 0.45 dB due to the outer codes, sequential decoding takes place at about 1.7 dB below the SNR cutoff rate for the convolutional code. This is possible since...... the iteration process provides the sequential decoders with side information that allows a smaller average load and minimizes the probability of computational overflow. Analytical results for the probability that the first RS word is decoded after C computations are presented. These results are supported...

Associations of cadmium, zinc, and lead in soils from a lead and zinc mining area as studied by single and sequential extractions.

Science.gov (United States)

Anju, M; Banerjee, D K

2011-05-01

An exploratory study of the area surrounding a historical Pb-Zn mining and smelting area in Zawar, India, detected significant contamination of the terrestrial environment by heavy metals. Soils (n=87) were analyzed for pH, EC, total organic matter (TOM), Pb, Zn, Mn, and Cd levels. The statistical analysis indicated that the frequency distribution of the analyzed parameters for these soils was not normal. The median concentrations of metals in surface soils were: Pb 420.21 μ g/g, Zn 870.25 μ g/g, Mn 696.70 μ g/g, and Cd 2.09 μ g/g. Zn concentrations were significantly correlated with Cd (r=0.867), indicating that levels of Cd are dependent on Zn. However, pH, electrical conductivity and total organic matter were not correlated significantly with Cd, Pb, Zn, and Mn. To assess the potential mobility of Cd, Pb, and Zn in soils, single (EDTA) as well as sequential extraction scheme (modified BCR) were applied to representative (n=23) soil samples. The amount of Cd, Pb, and Zn extracted by EDTA and their total concentrations showed linear positive correlation, which are statistically significant (r values for Cd, Pb, and Zn being 0.901, 0.971, and 0.795, respectively, and P values being soils from all the locations. As indicated by single extraction, the apparent mobility and potential bioavailability of metals in soils followed the order: Cd ≥ Pb > > Zn. Soil samples were sequentially extracted (modified BCR) so that solid pools of Cd, Zn, and Pb could be partitioned into four operationally defined fractions viz. acid-soluble, reducible, oxidizable, and residual. Cadmium was present appreciably (39.41%) in the acid-soluble fraction and zinc was predominantly associated (32.42%) with residual fraction. Pb (66.86%) and Zn (30.44%) were present mainly in the reducible fraction. Assuming that the mobility and bioavailability are related to solubility of geochemical forms of metals and decrease in the order of extraction, the apparent mobility and potential metal

SEQUENTIAL EXTRACTION OF PHOSPHORUS BY MEHLICH-1 AND ION EXCHANGE RESIN FROM B HORIZONS OF FERRIC AND PERFERRIC LATOSOLS (OXISOLS

Directory of Open Access Journals (Sweden)

Danilo de Lima Camêlo

2015-08-01

Full Text Available In general, Latosols have low levels of available P, however, the influence of the parent material seems to be decisive in defining the pool and predominant form of P in these soils. This study evaluated P availability by extraction with Mehlich-1 (M-1 and Ion Exchange Resin (IER, from samples of B horizons of Ferric and Perferric Latosols developed from different parent materials. To this end, in addition to the physical and chemical characterization of soils, 10 sequential extractions were performed with M-1 and IER from samples of B horizons (depth between 0.8 and 1.0 m. Total contents of Ca, P, Fe, Al, and Ti were determined after digestion with nitric, hydrofluoric and perchloric acids. The effects of sequential P extractions on Fe oxides were also evaluated from the analyses of dithionite-citrate-bicarbonate and ammonium acid oxalate. The high similarity between contents of P accumulated after sequential extractions with M-1 and IER in soils developed on tuffite indicated a predominance of P-Ca. Higher contents of P after a single IER extraction show greater efficiency in P removal from highly weathered soils, as from the Latosols studied here. The P contents also show the high sensitivity of extractant M-1 in highly buffered soils. Furthermore, a single extraction with extractant M-1 or IER is not sufficient to estimate the amount of labile P in these soils.

Selenium speciation in phosphate mine soils and evaluation of a sequential extraction procedure using XAFS

Energy Technology Data Exchange (ETDEWEB)

Favorito, Jessica E.; Luxton, Todd P.; Eick, Matthew J.; Grossl, Paul R. (VP); (Utah SU); (EPA)

2017-10-01

Selenium is a trace element found in western US soils, where ingestion of Se-accumulating plants has resulted in livestock fatalities. Therefore, a reliable understanding of Se speciation and bioavailability is critical for effective mitigation. Sequential extraction procedures (SEP) are often employed to examine Se phases and speciation in contaminated soils but may be limited by experimental conditions. We examined the validity of a SEP using X-ray absorption spectroscopy (XAS) for both whole and a sequence of extracted soils. The sequence included removal of soluble, PO4-extractable, carbonate, amorphous Fe-oxide, crystalline Fe-oxide, organic, and residual Se forms. For whole soils, XANES analyses indicated Se(0) and Se(-II) predominated, with lower amounts of Se(IV) present, related to carbonates and Fe-oxides. Oxidized Se species were more elevated and residual/elemental Se was lower than previous SEP results from ICP-AES suggested. For soils from the SEP sequence, XANES results indicated only partial recovery of carbonate, Fe-oxide and organic Se. This suggests Se was incompletely removed during designated extractions, possibly due to lack of mineral solubilization or reagent specificity. Selenium fractions associated with Fe-oxides were reduced in amount or removed after using hydroxylamine HCl for most soils examined. XANES results indicate partial dissolution of solid-phases may occur during extraction processes. This study demonstrates why precautions should be taken to improve the validity of SEPs. Mineralogical and chemical characterizations should be completed prior to SEP implementation to identify extractable phases or mineral components that may influence extraction effectiveness. Sequential extraction procedures can be appropriately tailored for reliable quantification of speciation in contaminated soils.

Preparative yield and properties of humic acids obtained by sequential alkaline extractions

Science.gov (United States)

Kholodov, V. A.; Yaroslavtseva, N. V.; Konstantinov, A. I.; Perminova, I. V.

2015-10-01

The preparative yield, composition, and structure of humic acids obtained by sequential alkaline extractions from two soils (a soddy-podzolic soil under forest and a typical chernozem in treatment with permanent black fallow of a long-term experiment since 1964) have been studied. The preparative yield of humic acids from the first extraction is 0.40 and 0.94% for the soddy-podzolic soil (Retisols) and the chernozem, respectively. The preparative yield from the second extraction is lower by several times, and the yield from the third extraction is lower by an order of magnitude. The study of the obtained preparations by elemental analysis, gel-permeation chromatography, and 13C NMR spectroscopy has shown insignificant changes in the elemental, molecular-weight, and structural-group composition of humic acids among the extractions. It has been supposed that this is related to the soil features: typical climatic factors for the formation of soil subtype in the case of soddy-podzolic soil and the land use in the long-term experiment in the case of typical chernozem. It has been concluded that that a single extraction is sufficient for the separation of humic acids and the preparation of a representative sample.

Vapor Extraction/Bioventing Sequential Treatment of Soil Contaminated with Volatile and SemiVolatile Hydrocarbon Mixtures

NARCIS (Netherlands)

Malina, G.; Grotenhuis, J.T.C.; Rulkens, W.H.

2002-01-01

A cost-effective removal strategy was studied in bench-scale columns that involved vapor extraction and bioventing sequential treatment of toluene- and decane-contaminated soil. The effect of operating mode on treatment performance was examined at a continuous air flow and consecutively at two

Physico-chemical and viscoelastic properties of high pressure homogenized lemon peel fiber fraction suspensions obtained after sequential pectin extraction

NARCIS (Netherlands)

Willemsen, K.L.D.D.; Panozzo, A.; Moelants, K.; Debon, S.J.J.; Desmet, C.; Cardinaels, R.M.; Moldenaers, P.; Wallecan, J.; Hendrickx, M.E.G.

2017-01-01

The viscoelastic properties of high pressure homogenized lemon peel cell wall fiber suspensions, obtained after sequential selective pectin extraction, were investigated in the current study. For comparison, a general pectin extraction was additionally performed on lemon peel under acid thermal

Development of a procedure for the sequential extraction of substances binding trace elements in plant biomass

Czech Academy of Sciences Publication Activity Database

Pavlíková, D.; Pavlík, Milan; Vašíčková, Soňa; Száková, J.; Vokáč, Karel; Balík, J.; Tlustoš, P.

2005-01-01

Roč. 381, - (2005), s. 863-872 ISSN 1618-2642 Institutional research plan: CEZ:AV0Z4055905 Keywords : organic compounds binding trace elements * spinach plant * sequential extraction Subject RIV: EI - Biotechnology ; Bionics Impact factor: 2.695, year: 2005

Multi-Stage Recognition of Speech Emotion Using Sequential Forward Feature Selection

Directory of Open Access Journals (Sweden)

Liogienė Tatjana

2016-07-01

Full Text Available The intensive research of speech emotion recognition introduced a huge collection of speech emotion features. Large feature sets complicate the speech emotion recognition task. Among various feature selection and transformation techniques for one-stage classification, multiple classifier systems were proposed. The main idea of multiple classifiers is to arrange the emotion classification process in stages. Besides parallel and serial cases, the hierarchical arrangement of multi-stage classification is most widely used for speech emotion recognition. In this paper, we present a sequential-forward-feature-selection-based multi-stage classification scheme. The Sequential Forward Selection (SFS and Sequential Floating Forward Selection (SFFS techniques were employed for every stage of the multi-stage classification scheme. Experimental testing of the proposed scheme was performed using the German and Lithuanian emotional speech datasets. Sequential-feature-selection-based multi-stage classification outperformed the single-stage scheme by 12–42 % for different emotion sets. The multi-stage scheme has shown higher robustness to the growth of emotion set. The decrease in recognition rate with the increase in emotion set for multi-stage scheme was lower by 10–20 % in comparison with the single-stage case. Differences in SFS and SFFS employment for feature selection were negligible.

Sequential injection-bead injection-lab-on-valve schemes for on-line solid phase extraction and preconcentration of ultra-trace levels of heavy metals with determination by electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Wang Jianhua; Hansen, Elo Harald; Miro, Manuel

2003-01-01

This communication presents an overview of the state-of-the-art of the exploitation of sequential injection (SI)-bead injection (BI)-lab-on-valve (LOV) schemes for automatic on-line sample pre-treatments interfaced with ETAAS and ICPMS detection as conducted in the authors' group. The discussions are focused on the applications of SI-BI-LOV protocols for on-line microcolumn based solid phase extraction of ultra-trace levels of heavy metals, employing the so-called renewable surface separation and preconcentration manipulatory scheme. Two types of sorbents have been employed as packing material, that is, the hydrophilic SP Sephadex C-25 cation exchange and iminodiacetate based Muromac A-1 chelating resins, and the hydrophobic poly(tetrafluoroethylene) (PTFE) and poly(styrene-divinylbenzene) copolymer alkylated with octadecyl groups (C 18 -PS/DVB). Using ETAAS as detection device, the easy-to-handle hydrophilic renewable reactors hold the features of improved R.S.D.s and LODs as compared to those operated in the conventional, permanent mode, in addition to the elimination of flow resistance. The hydrophobic columns fall into two categories, that is, the renewable one packed with C 18 -PS/DVB beads entails analogous R.S.D.s and LODs with respect to the conventional approach, while those with PTFE beads result in slightly inferior R.S.D.s and LODs by similar comparison, yet offering a wider dynamic range than when using an external permanent column. Moreover, the hydrophilic materials result in much higher enrichment of the analyte than the hydrophobic ones, although PTFE is the packing material that exhibits the best retention efficiency

Sequential extraction of flavonoids and pectin from yellow passion fruit rind using pressurized solvent or ultrasound.

Science.gov (United States)

de Souza, Caroline G; Rodrigues, Tigressa Hs; E Silva, Lorena Ma; Ribeiro, Paulo Rv; de Brito, Edy S

2018-03-01

Passion fruit rind (PFR) represents 90% of the total fruit weight and is wasted during juice processing. Passion fruit rind is known to contain flavonoids and pectin. An alternative use for this fruit juice industrial residue is to obtain these compounds. This study aimed to verify the influence of pressurized solvent extraction (PSE) or ultrasound assisted extraction (UAE) of flavonoid and pectin in a sequential process. The PSE using ethanol at 60:40 (v/v) yielded a total polyphenol content of 4.67 g GAE kg -1 PFR, orientin-7-O-glucoside (1.57 g kg -1 PFR) and luteolin-6-C-glucoside (2.44 g kg -1 PFR). Pectin yield was 165 g kg -1 PFR, either in PSE or UAE. Pectin characterization indicates that the pectic structure has basically homogalacturonans and galacturonate followed by a galacturonic acid ester unit, with methylation degree of 70%. With this study it can be concluded that mixtures of alcohols with water favor the extraction of bioactive compounds of passion fruit peel. Both PSE and UAE were effective in sequentially extracting flavonoids and pectin. The preferred solvent is ethanol due to its lower toxicity. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Comparison of three-stage sequential extraction and toxicity characteristic leaching tests to evaluate metal mobility in mining wastes

International Nuclear Information System (INIS)

Margui, E.; Salvado, V.; Queralt, I.; Hidalgo, M.

2004-01-01

Abandoned mining sites contain residues from ore processing operations that are characterised by high concentrations of heavy metals. The form in which a metal exists strongly influences its mobility and, thus, the effects on the environment. Operational methods of speciation analysis, such as the use of sequential extraction procedures, are commonly applied. In this work, the modified three-stage sequential extraction procedure proposed by the BCR (now the Standards, Measurements and Testing Programme) was applied for the fractionation of Ni, Zn, Pb and Cd in mining wastes from old Pb-Zn mining areas located in the Val d'Aran (NE Spain) and Cartagena (SE Spain). Analyses of the extracts were performed by inductively coupled plasma atomic emission spectrometry and electrothermal atomic absorption spectrometry. The procedure was evaluated by using a certified reference material, BCR-701. The results of the partitioning study indicate that more easily mobilised forms (acid exchangeable) were predominant for Cd and Zn, particularly in the sample from Cartagena. In contrast, the largest amount of lead was associated with the iron and manganese oxide fractions. On the other hand, the applicability of lixiviation tests commonly used to evaluate the leaching of toxic species from landfill disposal (US-EPA Toxicity Characteristic Leaching Procedure and DIN 38414-S4) to mining wastes was also investigated and the obtained results compared with the information on metal mobility derivable from the application of the three-stage sequential extraction procedure

Use of the modified BCR three-step sequential extraction procedure for the study of trace element dynamics in contaminated soils

International Nuclear Information System (INIS)

Pueyo, M.; Mateu, J.; Rigol, A.; Vidal, M.; Lopez-Sanchez, J.F.; Rauret, G.

2008-01-01

The modified BCR three-step sequential extraction procedure was used to examine the temporal dynamics of trace elements in soils contaminated by an accidental spill from an opencast mine in south-west Spain. Soils were mainly contaminated with pyritic sludge and acidic wastewater, whereas some soils were affected only by acidic wastewater. The distributions obtained for both some major (Ca, Fe and Mn) and trace elements (As, Cd, Cu, Pb and Zn) in the sludge and soil samples taken at different times after the accident, 1-3 months and 21 months, were compared. Sequential extractions were useful in identifying different sources of contamination, and in obtaining additional information on the solubility of secondary minerals formed by pyrite oxidation. Thus, the effectiveness of the BCR procedure has proved to be a useful tool for predicting short- and long-term mobility of trace elements, even in complex environmental scenarios. - The modified BCR three-step sequential extraction procedure has proved a useful prediction tool for short- and long-term mobility of trace elements in contaminated soils

Sequential injection/bead injection lab-on-valve schemes for on-line solid phase extraction and preconcentration of ultra-trace levels of heavy metals with determination by ETAAS and ICPMS

DEFF Research Database (Denmark)

Wang, Jianhua; Hansen, Elo Harald; Miró, Manuel

2003-01-01

are focused on the applications of SI-BI-LOV protocols for on-line microcolumn based solid phase extraction of ultra-trace levels of heavy metals, employing the so-called renewable surface separation and preconcentration manipulatory scheme. Two types of sorbents have been employed as packing material...

Forced Sequence Sequential Decoding

DEFF Research Database (Denmark)

Jensen, Ole Riis

In this thesis we describe a new concatenated decoding scheme based on iterations between an inner sequentially decoded convolutional code of rate R=1/4 and memory M=23, and block interleaved outer Reed-Solomon codes with non-uniform profile. With this scheme decoding with good performance...... is possible as low as Eb/No=0.6 dB, which is about 1.7 dB below the signal-to-noise ratio that marks the cut-off rate for the convolutional code. This is possible since the iteration process provides the sequential decoders with side information that allows a smaller average load and minimizes the probability...... of computational overflow. Analytical results for the probability that the first Reed-Solomon word is decoded after C computations are presented. This is supported by simulation results that are also extended to other parameters....

Mercury and trace element fractionation in Almaden soils by application of different sequential extraction procedures

Energy Technology Data Exchange (ETDEWEB)

Sanchez, D.M.; Quejido, A.J.; Fernandez, M.; Hernandez, C.; Schmid, T.; Millan, R.; Gonzalez, M.; Aldea, M.; Martin, R.; Morante, R. [CIEMAT, Madrid (Spain)

2005-04-01

A comparative evaluation of the mercury distribution in a soil sample from Almaden (Spain) has been performed by applying three different sequential extraction procedures, namely, modified BCR (three steps in sequence), Di Giulio-Ryan (four steps in sequence), and a specific SEP developed at CIEMAT (six steps in sequence). There were important differences in the mercury extraction results obtained by the three procedures according to the reagents applied and the sequence of their application. These findings highlight the difficulty of setting a universal SEP to obtain information on metal fractions of different mobility for any soil sample, as well as the requirement for knowledge about the mineralogical and chemical characteristics of the samples. The specific six-step CIEMAT sequential extraction procedure was applied to a soil profile (Ap, Ah, Bt1, and Bt2 horizons). The distribution of mercury and major, minor, and trace elements in the different fractions were determined. The results indicate that mercury is mainly released with 6 M HCl. The strong association of mercury with crystalline iron oxyhydroxides, present in all the horizons of the profile, and/or the solubility of some mercury compounds in such acid can explain this fact. Minor mercury is found in the fraction assigned to oxidizable matter and in the final insoluble residue (cinnabar). (orig.)

Assessment of a sequential extraction protocol by examining solution chemistry and mineralogical evolution

Science.gov (United States)

Maubec, Nicolas; Pauwels, Hélène; Noël, Hervé; Bourrat, Xavier

2015-04-01

Knowledge of the behavior of heavy metals, such as copper and zinc in sediments, is a key factor to improve the management of rivers. The mobility of these metals, which may be harmful to the environment, depends directly on their concentration and speciation , which in turn depend on physico-chemical parameters such as mineralogy of the sediment fraction, pH, redox potential, salinity etc ... (Anderson et al., 2000; Sterckeman et al., 2004; Van Oort et al., 2008). Several methods based on chemical extractions are currently applied to assess the behavior of heavy metals in soils and sediments. Among them, sequential extraction procedure is widely used in soil and sediment science and provides details about the origin, biological and physicochemical availability, mobilization and transports of trace metals elements. It is based on the use of a series of extracting reagents to extract selectively heavy metals according to their association within the solid phase (Cornu and Clozel, 2000) including the following different fraction : exchangeable, bound to carbonates, associated to oxides (reducible fraction), linked to organic matter and sulfides (oxidizable fraction) as well as silicate minerals so called residual fraction (Hickey and Kittrick, 1984; Tessier et al., 1979). Consequently sequential extraction method is expected to simulate a lot of potential natural and anthropogenic modifications of environmental conditions (Arey et al., 1999; Brannon and Patrick, 1987; Hickey and Kittrick, 1984; La Force et al., 1999; Tessier et al., 1979). For three decades, a large number of protocols has been proposed, characterized by specific reagents and experimental conditions (concentrations, number of steps, extraction orders and solid/solution ratio) (Das et al., 1995; Gomez Ariza et al., 2000; Quevauviller et al., 1994; Rauret, 1998; Tack and Verloo, 1995), but it appeared that several of them suffer from a lack of selectivity of applied reagents: besides target ones, some

BCR-701: A review of 10-years of sequential extraction analyses

International Nuclear Information System (INIS)

Sutherland, Ross A.

2010-01-01

A detailed quantitative analysis was performed on data presented in the literature that focused on the sequential extraction of cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) from the certified reference material BCR-701 (lake sediment) using the three-step harmonized BCR procedure. The accuracy of data reported in the literature, including precision and different measures of trueness, was assessed relative to the certified values for BCR-701. Forty data sets were accepted following extreme outlier removal, and statistically summarized with measures of central tendency, dispersion, and distribution form. In general, literature data were similar in their measurement precision to the expert laboratories used to certify the trace element contents in BCR-701. The overall median precision for literature reported data was 10% (range 6-19%), compared to certifying laboratories of 9% (range 4-33%). One measure of literature data trueness was assessed via a confirmatory approach using a robust bootstrap method. Only 22% of the comparisons indicated significantly different (all were lower) concentrations reported in the literature compared to certified values. The question of whether the differences are practically significant for environmental studies is raised. Bias was computed as a measure of trueness, and literature data were more frequently negatively biased, indicating lower concentrations reported in the literature for the six trace elements for the three-step sequential procedure compared to the certified values. However, 95% confidence intervals about the average bias for the 18 comparisons indicated only four instances when a mean bias of 0 (i.e., measured = certified) was not incorporated-suggesting statistical difference. Finally, Z-scores incorporating a Horwitz-type function were used to assess the general trueness of laboratory data. Of the 468 laboratory Z-score values computed, 92% were considered to be satisfactory, 5% were

Sequential Combination of Microwave- and Ultrasound-Assisted Extraction of Total Flavonoids from Osmanthus fragrans Lour. Flowers

Directory of Open Access Journals (Sweden)

Jianfeng Yu

2017-12-01

Full Text Available Microwave-assisted and ultrasound-assisted extraction assays were used to isolate total flavonoids (TF from Osmanthus fragrans flowers. The effects of the solid-liquid ratio, ethanol concentration, microwave power, microwave extraction time, ultrasonic power and ultrasonic extraction time on the yield of TF were studied. A sequential combination of microwave- and ultrasound-assisted extraction (SC-MUAE methods was developed, which was subsequently optimized by Box-Behnken design-response surface methodology (BBD-RSM. The interaction effects of the ethanol concentration (40–60%, microwave extraction time (5–7 min, ultrasonic extraction time (8–12 min and ultrasonic power (210–430 W on the yield of TF were investigated. The optimum operating parameters for the extraction of TF were determined to be as follows: ethanol concentration (48.15%, microwave extraction time (6.43 min, ultrasonic extraction time (10.09 min and ultrasonic power (370.9 W. Under these conditions, the extraction yield of TF was 7.86 mg/g.

Instant controlled pressure drop technology and ultrasound assisted extraction for sequential extraction of essential oil and antioxidants.

Science.gov (United States)

Allaf, Tamara; Tomao, Valérie; Ruiz, Karine; Chemat, Farid

2013-01-01

The instant controlled pressure drop (DIC) technology enabled both the extraction of essential oil and the expansion of the matrix itself which improved solvent extraction. The sequential use of DIC and Ultrasound Assisted Extraction (UAE) triggered complementary actions materialized by supplementary effects. We visualized these combination impacts by comparing them to standard techniques: Hydrodistillation (HD) and Solvent Extraction (SE). First, the extraction of orange peel Essential Oils (EO) was achieved by HD during 4h and DIC process (after optimization) during 2 min; EO yields was 1.97 mg/g dry material (dm) with HD compared to 16.57 mg/g d m with DIC. Second, the solid residue was recovered to extract antioxidant compounds (naringin and hesperidin) by SE and UAE. Scanning electron microscope showed that after HD the recovered solid shriveled as opposite to DIC treatment which expanded the product structure. HPLC analyses showed that the best kinetics and yields of naringin and hesperidin extraction was when DIC and UAE are combined. Indeed, after 1h of extraction, DIC treated orange peels with UAE were 0.825 ± 1.6 × 10(-2)g/g of dry material (dm) for hesperidin and 6.45 × 10(-2) ± 2.3 × 10(-4)g/g d m for naringin compared to 0.64 ± 2.7 × 10(-2)g/g of dry material (dm) and 5.7 × 10(-2) ± 1.6 × 10(-3)g/g d m, respectively with SE. By combining DIC to UAE, it was possible to enhance kinetics and yields of antioxidant extraction. Copyright © 2012 Elsevier B.V. All rights reserved.

Generating unstable resonances for extraction schemes based on transverse splitting

Directory of Open Access Journals (Sweden)

M. Giovannozzi

2009-02-01

Full Text Available A few years ago, a novel multiturn extraction scheme was proposed, based on particle trapping inside stable resonances. Numerical simulations and experimental tests have confirmed the feasibility of such a scheme for low order resonances. While the third-order resonance is generically unstable and those higher than fourth order are generically stable, the fourth-order resonance can be either stable or unstable depending on the specifics of the system under consideration. By means of the normal form, a general approach to control the stability of the fourth-order resonance has been derived. This approach is based on the control of the amplitude detuning and the general form for a lattice with an arbitrary number of sextupole and octupole families is derived in this paper. Numerical simulations have confirmed the analytical results and have shown that, when crossing the unstable fourth-order resonance, the region around the center of the phase space is depleted and particles are trapped in only the four stable islands. A four-turn extraction could be designed using this technique.

Sequential sampling: a novel method in farm animal welfare assessment.

Science.gov (United States)

Heath, C A E; Main, D C J; Mullan, S; Haskell, M J; Browne, W J

2016-02-01

Lameness in dairy cows is an important welfare issue. As part of a welfare assessment, herd level lameness prevalence can be estimated from scoring a sample of animals, where higher levels of accuracy are associated with larger sample sizes. As the financial cost is related to the number of cows sampled, smaller samples are preferred. Sequential sampling schemes have been used for informing decision making in clinical trials. Sequential sampling involves taking samples in stages, where sampling can stop early depending on the estimated lameness prevalence. When welfare assessment is used for a pass/fail decision, a similar approach could be applied to reduce the overall sample size. The sampling schemes proposed here apply the principles of sequential sampling within a diagnostic testing framework. This study develops three sequential sampling schemes of increasing complexity to classify 80 fully assessed UK dairy farms, each with known lameness prevalence. Using the Welfare Quality herd-size-based sampling scheme, the first 'basic' scheme involves two sampling events. At the first sampling event half the Welfare Quality sample size is drawn, and then depending on the outcome, sampling either stops or is continued and the same number of animals is sampled again. In the second 'cautious' scheme, an adaptation is made to ensure that correctly classifying a farm as 'bad' is done with greater certainty. The third scheme is the only scheme to go beyond lameness as a binary measure and investigates the potential for increasing accuracy by incorporating the number of severely lame cows into the decision. The three schemes are evaluated with respect to accuracy and average sample size by running 100 000 simulations for each scheme, and a comparison is made with the fixed size Welfare Quality herd-size-based sampling scheme. All three schemes performed almost as well as the fixed size scheme but with much smaller average sample sizes. For the third scheme, an overall

Fractionation of potentially toxic elements in urban soils from five European cities by means of a harmonised sequential extraction procedure

International Nuclear Information System (INIS)

Davidson, Christine M.; Urquhart, Graham J.; Ajmone-Marsan, Franco; Biasioli, Mattia; Costa Duarte, Armando da; Diaz-Barrientos, Encarnacion; Grcman, Helena; Hossack, Iain; Hursthouse, Andrew S.; Madrid, Luis; Rodrigues, Sonia; Zupan, Marko

2006-01-01

The revised (four-step) BCR sequential extraction procedure has been applied to fractionate the chromium, copper, iron, manganese, nickel, lead and zinc contents in urban soil samples from public-access areas in five European cities. A preliminary inter-laboratory comparison was conducted and showed that data obtained by different laboratories participating in the study were sufficiently harmonious for comparisons to be made between cities and land types (e.g. parks, roadside, riverbanks, etc.). Analyte recoveries by sequential extraction, with respect to direct aqua regia digestion, were generally acceptable (100 ± 15%). Iron, nickel and, at most sites, chromium were found mainly in association with the residual phase of the soil matrix. Copper was present in the reducible, oxidisable and residual fractions, whilst zinc was found in all four sequential extracts. Manganese was strongly associated with reducible material as, in some cities, was lead. This is of concern because high lead concentrations were present in some soils (>500 mg kg -1 ) and the potential exists for remobilisation under reducing conditions. As would be expected, extractable metal contents were generally highest in older, more heavily industrialised cities. Copper, lead and zinc showed marked (and often correlated) variations in concentrations between sites within the same city whereas manganese and, especially, iron, did not. No overall relationships were, however, found between analyte concentrations and land use, nor between analyte partitioning and land use

Sequential healing at implants installed immediately into extraction sockets. An experimental study in dogs.

Science.gov (United States)

Mainetti, Tomaso; Lang, Niklaus P; Bengazi, Franco; Favero, Vittorio; Soto Cantero, Luis; Botticelli, Daniele

2016-01-01

To compare the sequential healing at implants installed in a healed alveolar bony ridge or immediately after tooth extraction without functional load. In the mandible of 12 dogs, the mesial roots of the first molars were endodontically treated, the tooth hemisected, and the distal roots extracted. After 3 months, the mesial roots of the fourth premolars were endodontically treated, the tooth hemisected, and the distal roots extracted in one side of the mandible. Implants were placed immediately into extraction sockets (IPIES) of the fourth premolar and in the healed sites in the molar regions. Healing abutments were placed, and the flaps were sutured to allow a non-submerged healing. The time of surgery and of sacrifices were planned in such a way to obtain biopsies representing the healing after 1 and 2 weeks and 1 and 3 months, respectively. Ground sections were prepared for histological evaluation of tissues components on the implant surface and the coronal termination level of osseointegration (M-B). New bone apposition on the implant surface was slightly higher at the healed compared to the IPIES sites, being 7.4% and 4.1% after 1 week, and 67.3% and 65.3% after 3 months, respectively. Old bone was progressively resorbed, from 27.0% and 21.9% after 1 week, to 2.5% and 2.0% after 3 months, at healed and IPIES sites, respectively. M-B was 1.4 mm and 2.6 mm after 1 week, 1.2 mm and 1.2 mm after 3 months, at healed and IPIES sites, respectively. Similar patterns of sequential osseointegration were found at implants installed in healed alveolar bone or in alveolar sockets immediately after tooth extraction. The coronal termination level of osseointegration, that was different after 1 week, was found similar at the 3-month observation. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Fractionation study in bioleached metallurgy wastes using six-step sequential extraction.

Science.gov (United States)

Krasnodebska-Ostrega, Beata; Pałdyna, Joanna; Kowalska, Joanna; Jedynak, Łukasz; Golimowski, Jerzy

2009-08-15

The stored metallurgy wastes contain residues from ore processing operations that are characterized by relatively high concentrations of heavy metals. The bioleaching process makes use of bacteria to recover elements from industrial wastes and to decrease potential risk of environmental contamination. Wastes were treated by solutions containing bacteria. In this work, the optimized six-stage sequential extraction procedure was applied for the fractionation of Ni, Cr, Fe, Mn, Cu and Zn in iron-nickel metallurgy wastes deposited in Southern Poland (Szklary). Fractionation and total concentrations of elements in wastes before and after various bioleaching treatments were studied. Analyses of the extracts were performed by ICP-MS and FAAS. To achieve the most effective bioleaching of Zn, Cr, Ni, Cu, Mn, Fe the usage of both autotrophic and heterotrophic bacteria in sequence, combined with flushing of the residue after bioleaching is required. 80-100% of total metal concentrations were mobilized after the proposed treatment. Wastes treated according to this procedure could be deposited without any risk of environmental contamination and additionally the metals could be recovered for industrial purposes.

Dynamic flow-through sequential extraction for assessment of fractional transformation and inter-element associations of arsenic in stabilized soil and sludge

International Nuclear Information System (INIS)

Buanuam, Janya; Wennrich, Rainer

2010-01-01

A dynamic flow-through extraction system was applied for the first time to ascertain the fractional transformation and inter-element associations of arsenic in stabilized environmental solids, as exemplified by the partitioning of soil and sludge stabilized with three additives, namely MnO 2 , Ca(OH) 2 and FeSO 4 . The extraction system used not only gave fractionation data, but also the extraction profiles (extractograms) which were used for investigation of the breaking down of phases, kinetic releasing of As and elemental association between As and inorganic additives. Five geochemical fractions of As were elucidated by accommodation in the flow manifold of a modified Wenzel's sequential extraction scheme, well established for fractionation of arsenic. The results revealed that MnO 2 and FeSO 4 have a slight effect on As phase transformation for soil and sludge samples amended for one week whereas the addition of Ca(OH) 2 increases As mobility due to the desorption of As from the solid Fe-oxides phase. The significant change in fractional transformation after 8 weeks of incubation can be seen in MnO 2 -treated soil. There was an increase of 17% in the non-mobilizable As fraction in MnO 2 -treated soil. From extractograms, arsenic in untreated soil was found to be rapidly leached and concurrently released with Fe. This may be evidence that the release of As is dependent on the dissolution of amorphous Fe oxides. In MnO 2 -treated soil, a strong affinity was observed between Mn and As in the amorphous Fe/Al oxides fraction, and this plays an important role in slowing down the kinetics of As releasing.

Fractionation of metals in street sediment samples by using the BCR sequential extraction procedure and multivariate statistical elucidation of the data

International Nuclear Information System (INIS)

Kartal, Senol; Aydin, Zeki; Tokalioglu, Serife

2006-01-01

The concentrations of metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in street sediment samples were determined by flame atomic absorption spectrometry (FAAS) using the modified BCR (the European Community Bureau of Reference) sequential extraction procedure. According to the BCR protocol for extracting the metals from the relevant target phases, 1.0 g of specimen of the sample was treated with 0.11 M acetic acid (exchangeable and bound to carbonates), 0.5 M hydroxylamine hydrochloride (bound to iron- and manganese-oxides), and 8.8 M hydrogen peroxide plus 1 M ammonium acetate (bound to sulphides and organics), sequentially. The residue was treated with aqua regia solution for recovery studies, although this step is not part of the BCR procedure. The mobility sequence based on the sum of the BCR sequential extraction stages was: Cd ∼ Zn (∼90%) > Pb (∼84%) > Cu (∼75%) > Mn (∼70%) > Co (∼57%) > Ni (∼43%) > Cr (∼40%) > Fe (∼17%). Enrichment factors as the criteria for examining the impact of the anthropogenic emission sources of heavy metals were calculated, and it was observed that the highest enriched elements were Cd, Pb, and Zn in the dust samples, average 190, 111, and 20, respectively. Correlation analysis (CA) and principal component analysis (PCA) were applied to the data matrix to evaluate the analytical results and to identify the possible pollution sources of metals. PCA revealed that the sampling area was mainly influenced from three pollution sources, namely; traffic, industrial, and natural sources. The results show that chemical sequential extraction is a precious operational tool. Validation of the analytical results was checked by both recovery studies and analysis of the standard reference material (NIST SRM 2711 Montana Soil)

Efficient authentication scheme based on near-ring root extraction problem

Science.gov (United States)

Muthukumaran, V.; Ezhilmaran, D.

2017-11-01

An authentication protocolis the type of computer communication protocol or cryptography protocol specifically designed for transfer of authentication data between two entities. We have planned a two new entity authentication scheme on the basis of root extraction problem near-ring in this article. We suggest that this problem is suitably difficult to serve as a cryptographic assumption over the platform of near-ring N. The security issues also discussed.

Comparison of two schemes for automatic keyword extraction from MEDLINE for functional gene clustering.

Science.gov (United States)

Liu, Ying; Ciliax, Brian J; Borges, Karin; Dasigi, Venu; Ram, Ashwin; Navathe, Shamkant B; Dingledine, Ray

2004-01-01

One of the key challenges of microarray studies is to derive biological insights from the unprecedented quatities of data on gene-expression patterns. Clustering genes by functional keyword association can provide direct information about the nature of the functional links among genes within the derived clusters. However, the quality of the keyword lists extracted from biomedical literature for each gene significantly affects the clustering results. We extracted keywords from MEDLINE that describes the most prominent functions of the genes, and used the resulting weights of the keywords as feature vectors for gene clustering. By analyzing the resulting cluster quality, we compared two keyword weighting schemes: normalized z-score and term frequency-inverse document frequency (TFIDF). The best combination of background comparison set, stop list and stemming algorithm was selected based on precision and recall metrics. In a test set of four known gene groups, a hierarchical algorithm correctly assigned 25 of 26 genes to the appropriate clusters based on keywords extracted by the TDFIDF weighting scheme, but only 23 og 26 with the z-score method. To evaluate the effectiveness of the weighting schemes for keyword extraction for gene clusters from microarray profiles, 44 yeast genes that are differentially expressed during the cell cycle were used as a second test set. Using established measures of cluster quality, the results produced from TFIDF-weighted keywords had higher purity, lower entropy, and higher mutual information than those produced from normalized z-score weighted keywords. The optimized algorithms should be useful for sorting genes from microarray lists into functionally discrete clusters.

Proposal for a new LEIR slow extraction scheme dedicated to biomedical research

CERN Document Server

Garonna, A; Abler, D

2014-01-01

A proposal is here presented for a new slow extraction scheme for the Low Energy Ion Ring (LEIR) in the context of the feasibility study for a future biomedical research facility at CERN. The new slow extraction system is based on the third-integer resonance. Two resonance driving mechanisms have been studied: the quadrupole-driven method and the RF-knockout technique. Both were made compatible with the tight constraints imposed by parallel operation of LEIR as heavy ion accumulator and care was taken to maximize the use of the available hardware.

Mental Task Classification Scheme Utilizing Correlation Coefficient Extracted from Interchannel Intrinsic Mode Function.

Science.gov (United States)

Rahman, Md Mostafizur; Fattah, Shaikh Anowarul

2017-01-01

In view of recent increase of brain computer interface (BCI) based applications, the importance of efficient classification of various mental tasks has increased prodigiously nowadays. In order to obtain effective classification, efficient feature extraction scheme is necessary, for which, in the proposed method, the interchannel relationship among electroencephalogram (EEG) data is utilized. It is expected that the correlation obtained from different combination of channels will be different for different mental tasks, which can be exploited to extract distinctive feature. The empirical mode decomposition (EMD) technique is employed on a test EEG signal obtained from a channel, which provides a number of intrinsic mode functions (IMFs), and correlation coefficient is extracted from interchannel IMF data. Simultaneously, different statistical features are also obtained from each IMF. Finally, the feature matrix is formed utilizing interchannel correlation features and intrachannel statistical features of the selected IMFs of EEG signal. Different kernels of the support vector machine (SVM) classifier are used to carry out the classification task. An EEG dataset containing ten different combinations of five different mental tasks is utilized to demonstrate the classification performance and a very high level of accuracy is achieved by the proposed scheme compared to existing methods.

Sequential healing of open extraction sockets. An experimental study in monkeys.

Science.gov (United States)

Scala, Alessandro; Lang, Niklaus P; Schweikert, Michael T; de Oliveira, José Américo; Rangel-Garcia, Idelmo; Botticelli, Daniele

2014-03-01

To describe the sequential healing of open extraction sockets at which no attempts to obtain a primary closure of the coronal access to the alveolus have been made. The third mandibular premolar was extracted bilaterally in 12 monkeys, and no sutures were applied to close the wound. The healing after 4, 10, 20, 30, 90 and 180 days was morphometrically studied. After 4 days of healing, a blood clot mainly occupied the extraction sockets, with the presence of an inflammatory cells' infiltrate. A void was confined in the central zones of the coronal and middle regions, in continuity with the entrance of the alveoli. At 10 days, the alveolus was occupied by a provisional matrix, with new bone formation lining the socket bony walls. At 20 days, the amount of woven bone was sensibly increasing. At 30 days, the alveolar socket was mainly occupied by mineralized immature bone at different stages of healing. At 90 and 180 days, the amount of mineralized bone decreased and substituted by trabecular bone and bone marrow. Bundle bone decreased from 95.5% at 4 days to 7.6% at 180 days, of the whole length of the inner alveolar surface. Modeling processes start from the lateral and apical walls of the alveolus, leading to the closure of the socket with newly formed bone within a month from extraction. Remodeling processes will follow the previous stages, resulting in trabecular and bone marrow formation and in a corticalization of the socket access. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

A multisyringe flow-through sequential extraction system for on-line monitoring of orthophosphate in soils and sediments

DEFF Research Database (Denmark)

Buanuam, Janya; Miró, Manuel; Hansen, Elo Harald

2007-01-01

A fully automated flow-through microcolumn fractionation system with on-line post-extraction derivatization is proposed for monitoring of orthophosphate in solid samples of environmental relevance. The system integrates dynamic sequential extraction using 1.0 mol l-1 NH4Cl, 0.1 mol l-1 NaOH and 0...... of the operational times from days to hours, highly temporal resolution of the leaching process, and the capability for immediate decision for stopping or proceeding with the ongoing extraction. Very importantly, accurate determination of the various orthophosphate pools is ensured by minimization of the hydrolysis...... of extracted organic phosphorus and condensed inorganic phosphates within the time frame of the assay. The potential of the novel system for accommodation of the harmonized protocol from the Standards, Measurement and Testing (SMT) Program of the Commission of the European Communities for inorganic phosphorus...

Development of a rapid method for the sequential extraction and subsequent quantification of fatty acids and sugars from avocado mesocarp tissue.

Science.gov (United States)

Meyer, Marjolaine D; Terry, Leon A

2008-08-27

Methods devised for oil extraction from avocado (Persea americana Mill.) mesocarp (e.g., Soxhlet) are usually lengthy and require operation at high temperature. Moreover, methods for extracting sugars from avocado tissue (e.g., 80% ethanol, v/v) do not allow for lipids to be easily measured from the same sample. This study describes a new simple method that enabled sequential extraction and subsequent quantification of both fatty acids and sugars from the same avocado mesocarp tissue sample. Freeze-dried mesocarp samples of avocado cv. Hass fruit of different ripening stages were extracted by homogenization with hexane and the oil extracts quantified for fatty acid composition by GC. The resulting filter residues were readily usable for sugar extraction with methanol (62.5%, v/v). For comparison, oil was also extracted using the standard Soxhlet technique and the resulting thimble residue extracted for sugars as before. An additional experiment was carried out whereby filter residues were also extracted using ethanol. Average oil yield using the Soxhlet technique was significantly (P < 0.05) higher than that obtained by homogenization with hexane, although the difference remained very slight, and fatty acid profiles of the oil extracts following both methods were very similar. Oil recovery improved with increasing ripeness of the fruit with minor differences observed in the fatty acid composition during postharvest ripening. After lipid removal, methanolic extraction was superior in recovering sucrose and perseitol as compared to 80% ethanol (v/v), whereas mannoheptulose recovery was not affected by solvent used. The method presented has the benefits of shorter extraction time, lower extraction temperature, and reduced amount of solvent and can be used for sequential extraction of fatty acids and sugars from the same sample.

Sequential heavy metal extraction from dust precipitates and road sediments. Part 2. Sequential heavy metal extraction from urban dust; Sequentielle Schwermetallextraktion aus Staubniederschlaegen und Strassensedimenten. T. 2. Sequentielle Schwermetallextraktion von staedtischen Staeuben

Energy Technology Data Exchange (ETDEWEB)

Heiser, U.; Norra, S.; Stueben, D.; Wagner, M. von [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Petrographie und Geochemie

1999-03-01

For the application of our method for the sequential extraction of heavy metals from microsamples presented in part 1 (`Sequentielle Schwermetallextraktion von Mikroproben` - `Sequential Extraction of Heavy Metals from Micro Samples`) an investigation was carried out to evaluate airborne dust fallout and street sediments at two urban sites where different heavy metal immission rates occur due to traffic influence. In the street sediments the total concentrations of zinc, copper and lead was three to fivefold higher in the silt and clay fraction (<63 {mu}m) than in the particle size fraction (<1,12 mm), but showed nearly the same mobilisation behaviour. The dust samples showed equal mobilisation behaviour as the street sediments for copper and lead, while zinc was considerably more mobile in the dust samples: In extraction steps I-IV (I: mobile fraction; II: easily deliverable fraction; III: fraction bound to manganese oxides; IV: fraction bound organic to matter) zinc, copper and lead in street sediments, as well as copper and lead in dust samples, were dissolved to 40-70%, whereas about 80% of zinc in the dust samples was already dissolved in extraction step I. (orig.) [Deutsch] Mit Hilfe des in Teil 1 (`Sequentielle Schwermetallextraktion von Mikroproben`) vorgestellten Verfahrens zur sequentiellen Schwermetallextraktion von Mikroproben wurden die Mobilisierbarkeiten von Zink, Kupfer und Blei aus Staubniederschlaegen und aus der Schluff- und Tonfraktion von Strassensedimenten an zwei urbanen Standorten mit unterschiedlicher, verkehrsbedingter Schwermetallbelastung untersucht und miteinander verglichen. In Strassensedimenten wiesen Zink, Kupfer und Blei in der Schluff- und Tonfraktion drei- bis fuenffach hoehere Gesamtgehalte auf als die Korngroessenfraktion <1,12 mm, zeigten aber aehnliches Verhalten in der Mobilisierbarkeit. Bei den Staubproben war die Mobilisierbarkeit von Kupfer und Blei aehnlich wie in den Strassensedimenten, waehrend sich Zink als erheblich

Information/disturbance trade-off in single and sequential measurements on a qudit signal

Energy Technology Data Exchange (ETDEWEB)

Genoni, Marco G; Paris, Matteo G A [Dipartimento di Fisica, Universita degli studi di Milano (Italy)

2007-05-15

We address the trade-off between information gain and state disturbance in measurement performed on qudit systems and devise a class of optimal measurement schemes that saturate the ultimate bound imposed by quantum mechanics to estimation and transmission fidelities. The schemes are minimal, i.e. they involve a single additional probe qudit, and optimal, i.e. they provide the maximum amount of information compatible with a given level of disturbance. The performances of optimal single-user schemes in extracting information by sequential measurements in a N-user transmission line are also investigated, and the optimality is analyzed by explicit evaluation of fidelities. We found that the estimation fidelity does not depend on the number of users, neither for single-measure inference nor for collective one, whereas the transmission fidelity decreases with N. The resulting trade-off is no longer optimal and degrades with increasing N. We found that optimality can be restored by an effective preparation of the probe states and present explicitly calculations for the 2-user case.

The CLIC Multi-Drive Beam Scheme

CERN Document Server

Corsini, R

1998-01-01

The CLIC study of an e+ / e- linear collider in the TeV energy range is based on Two-Beam Acceleration (TBA) in which the RF power needed to accelerate the beam is extracted from high intensity relativistic electron beams, the so-called drive beams. The generation, acceleration and transport of the high-intensity drive beams in an efficient and reliable way constitute a challenging task. An overview of a potentially very effective scheme is presented. It is based on the generation of trains of short bunches, accelerated sequentially in low frequency superconducting cavities in a c.w. mode, stored in an isochronous ring and combined at high energy by funnelling before injection by sectors into the drive linac for RF power production. The various systems of the complex are discussed.

Plutonium association with selected solid phases in soils of Rocky Flats, Colorado, using sequential extraction technique

International Nuclear Information System (INIS)

Litaor, M.I.; Ibrahim, S.A.

1996-01-01

Plutonium contamination in the soil environs of Rock Flats, CO, has been a potential health risk to the public since the late 1960s. Although the measurement of total activity of Pu-239 + 240 in the soil is important information in appraising this risk, total activity does not provide the information required to characterize the geochemical behavior that affects the transport of Pu from the soil and vadose zone to groundwater. A sequential extraction experiment was conducted to assess the geochemical association of Pu with selected mineralogical and chemical phases of the soil. In the surface horizons, Pu-239 + 240 was primarily associated with the organic C (45-65%), sesquioxides (20-40%), and the residual fraction (10-15%). A small portion of Pu-239+240 was associated with soluble (0.09-0.22%), exchangeable (0.04-0.08%), and carbonates (0.57-7.0%) phases. These results suggest that under the observed pH and oxic conditions, relatively little Pu-239 + 240 is available for geochemically induced transport processes. Uncommon hydrogeochemical conditions were observed during the spring of 1995, which may have facilitated a partial dissolution of sesquioxides followed by desorption of Pu resulting in increased Pu mobility. Systematic errors in the sequential extraction experiment due to postextraction readsorption were evaluated using Np-237 tracer as a surrogate to Pu-239. The results suggested that postextraction readsorption rates were insignificant during the first 30 min after extraction for most chemical and mineralogical phases under study. 50 refs., 2 figs., 5 tabs

Testing sequential extraction methods for the analysis of multiple stable isotope systems from a bone sample

Science.gov (United States)

Sahlstedt, Elina; Arppe, Laura

2017-04-01

Stable isotope composition of bones, analysed either from the mineral phase (hydroxyapatite) or from the organic phase (mainly collagen) carry important climatological and ecological information and are therefore widely used in paleontological and archaeological research. For the analysis of the stable isotope compositions, both of the phases, hydroxyapatite and collagen, have their more or less well established separation and analytical techniques. Recent development in IRMS and wet chemical extraction methods have facilitated the analysis of very small bone fractions (500 μg or less starting material) for PO43-O isotope composition. However, the uniqueness and (pre-) historical value of each archaeological and paleontological finding lead to preciously little material available for stable isotope analyses, encouraging further development of microanalytical methods for the use of stable isotope analyses. Here we present the first results in developing extraction methods for combining collagen C- and N-isotope analyses to PO43-O-isotope analyses from a single bone sample fraction. We tested sequential extraction starting with dilute acid demineralization and collection of both collagen and PO43-fractions, followed by further purification step by H2O2 (PO43-fraction). First results show that bone sample separates as small as 2 mg may be analysed for their δ15N, δ13C and δ18OPO4 values. The method may be incorporated in detailed investigation of sequentially developing skeletal material such as teeth, potentially allowing for the investigation of interannual variability in climatological/environmental signals or investigation of the early life history of an individual.

Characterization of phosphorus species in sediments from the Arabian Sea oxygen minimum zone: Combining sequential extractions and X-ray spectroscopy

NARCIS (Netherlands)

Kraal, Peter; Bostick, Benjamin C.; Behrends, Thilo; Reichart, Gert-Jan; Slomp, Caroline P.

2015-01-01

The bulk phosphorus (P) distribution in sediment samples from the oxygen minimum zone of the northern Arabian Sea was determined using two methods: sequential chemical extraction (the ‘SEDEX’ procedure) and X-ray absorption near-edge structure (XANES) spectroscopy of the phosphorus K-edge. Our

Generating Unstable Resonances for Extraction Schemes Based on Transverse Splitting

CERN Document Server

Giovannozzi, M; Turchetti, G

2009-01-01

A few years ago, a novel multi-turn extraction scheme was proposed, based on particle trapping inside stable resonances. Numerical simulations and experimental tests have confirmed the feasibility of such a scheme for low order resonances. While the third-order resonance is generically unstable and those higher than fourth-order are generically stable, the fourth-order resonance can be either stable or unstable depending on the specifics of the system under consideration. By means of the Normal Form a general approach to control the stability of the fourth-order resonance has been derived. This approach is based on the control of the amplitude detuning and the general form for a lattice with an arbitrary number of sextupole and octupole families is derived in this paper. Numerical simulations have confirmed the analytical results and have shown that, when crossing the unstable fourth-order resonance, the region around the centre of the phase space is depleted and particles are trapped in only the four stable ...

How update schemes influence crowd simulations

International Nuclear Information System (INIS)

Seitz, Michael J; Köster, Gerta

2014-01-01

Time discretization is a key modeling aspect of dynamic computer simulations. In current pedestrian motion models based on discrete events, e.g. cellular automata and the Optimal Steps Model, fixed-order sequential updates and shuffle updates are prevalent. We propose to use event-driven updates that process events in the order they occur, and thus better match natural movement. In addition, we present a parallel update with collision detection and resolution for situations where computational speed is crucial. Two simulation studies serve to demonstrate the practical impact of the choice of update scheme. Not only do density-speed relations differ, but there is a statistically significant effect on evacuation times. Fixed-order sequential and random shuffle updates with a short update period come close to event-driven updates. The parallel update scheme overestimates evacuation times. All schemes can be employed for arbitrary simulation models with discrete events, such as car traffic or animal behavior. (paper)

Lead isotopes combined with a sequential extraction procedure for source apportionment in the dry deposition of Asian dust and non-Asian dust

International Nuclear Information System (INIS)

Lee, Pyeong-Koo; Yu, Soonyoung

2016-01-01

Lead isotopic compositions were determined in leachates that were generated using sequential extractions of dry deposition samples of Asian dust (AD) and non-Asian dust (NAD) and Chinese desert soils, and used to apportion Pb sources. Results showed significant differences in "2"0"6Pb/"2"0"7Pb and "2"0"6Pb/"2"0"4Pb isotopic compositions in non-residual fractions between the dry deposition samples and the Chinese desert soils while "2"0"6Pb/"2"0"7Pb and "2"0"6Pb/"2"0"4Pb isotopic compositions in residual fraction of the dry deposition of AD and NAD were similar to the mean "2"0"6Pb/"2"0"7Pb and "2"0"6Pb/"2"0"4Pb in residual fraction of the Alashan Plateau soil. These results indicate that the geogenic materials of the dry deposition of AD and NAD were largely influenced by the Alashan Plateau soil, while the secondary sources of the dry deposition were different from those of the Chinese desert soils. In particular, the lead isotopic compositions in non-residual fractions of the dry deposition were homogenous, which implies that the non-residual four fractions (F1 to F4) shared the primary anthropogenic origin. "2"0"6Pb/"2"0"7Pb values and the predominant wind directions in the study area suggested that airborne particulates of heavily industrialized Chinese cities were one of the main Pb sources. Source apportionment calculations showed that the average proportion of anthropogenic Pb in the dry deposition of AD and NAD was 87% and 95% respectively in total Pb extraction, 92% and 97% in non-residual fractions, 15% and 49% in residual fraction. Approximately 81% and 80% of the anthropogenic Pb was contributed by coal combustion in China in the dry deposition of AD and NAD respectively while the remainder was derived from industrial Pb contamination. The research result proposes that sequential extractions with Pb isotope analysis are a useful tool for the discrimination of anthropogenic and geogenic origins in highly contaminated AD and NAD. - Highlights: �

Feature extraction and sensor selection for NPP initiating event identification

International Nuclear Information System (INIS)

Lin, Ting-Han; Wu, Shun-Chi; Chen, Kuang-You; Chou, Hwai-Pwu

2017-01-01

Highlights: • A two-stage feature extraction scheme for NPP initiating event identification. • With stBP, interrelations among the sensors can be retained for identification. • With dSFS, sensors that are crucial for identification can be efficiently selected. • Efficacy of the scheme is illustrated with data from the Maanshan NPP simulator. - Abstract: Initiating event identification is essential in managing nuclear power plant (NPP) severe accidents. In this paper, a novel two-stage feature extraction scheme that incorporates the proposed sensor type-wise block projection (stBP) and deflatable sequential forward selection (dSFS) is used to elicit the discriminant information in the data obtained from various NPP sensors to facilitate event identification. With the stBP, the primal features can be extracted without eliminating the interrelations among the sensors of the same type. The extracted features are then subjected to a further dimensionality reduction by selecting the sensors that are most relevant to the events under consideration. This selection is not easy, and a combinatorial optimization technique is normally required. With the dSFS, an optimal sensor set can be found with less computational load. Moreover, its sensor deflation stage allows sensors in the preselected set to be iteratively refined to avoid being trapped into a local optimum. Results from detailed experiments containing data of 12 event categories and a total of 112 events generated with a Taiwan’s Maanshan NPP simulator are presented to illustrate the efficacy of the proposed scheme.

A zero-liquid-discharge scheme for vanadium extraction process by electrodialysis-based technology

International Nuclear Information System (INIS)

Wang, Meng; Xing, Hong-bo; Jia, Yu-xiang; Ren, Qing-chun

2015-01-01

Highlights: • A zero discharge scheme for vanadiumextraction process is proposed. • The water transport in the electrodialysis process is analyzed quantitatively. • The influence of concentration ratio in the electrodialysis process is explored. - Abstract: The sharp increase of demand for vanadium makes the treatment of the wastewater generated from its extraction process become an urgent problem. In this study, a hybrid process coupling the electrodialysis with the cooling crystallization is put forward for upgrading the conventional vanadium extraction process to zero discharge. Accordingly, the objective of this work lies in evaluating the feasibility of the proposed scheme on the basis of a systematic study on the influences of membrane types and operating parameters on the electrodilysis performance. The results indicate that the relative importance of osmosis and electro-osmosis to overall water transport is closely related to the applied current density. The increase in the applied current density and the decrease in the mole ratio of water and salt flux will contribute to the concentration degree. Moreover, it is worth noting that a relatively large concentration ratio can result in the remarkable decrease of current efficiency and increase of energy consumption. In general, the reclamation scheme can easily achieve the recovered water with relatively low salt content and the highly concentrated Na 2 SO 4 solution (e.g., 300 g/L) for producing high-purity sodium sulphate crystals.

A zero-liquid-discharge scheme for vanadium extraction process by electrodialysis-based technology

Energy Technology Data Exchange (ETDEWEB)

Wang, Meng, E-mail: wangmeng@ouc.edu.cn [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education (China); College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100 (China); Xing, Hong-bo; Jia, Yu-xiang [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education (China); College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100 (China); Ren, Qing-chun [Beijing Unisplendour Empyreal Environmental Engineering Technology Co. Ltd., Beijing 100083 (China)

2015-12-30

Highlights: • A zero discharge scheme for vanadiumextraction process is proposed. • The water transport in the electrodialysis process is analyzed quantitatively. • The influence of concentration ratio in the electrodialysis process is explored. - Abstract: The sharp increase of demand for vanadium makes the treatment of the wastewater generated from its extraction process become an urgent problem. In this study, a hybrid process coupling the electrodialysis with the cooling crystallization is put forward for upgrading the conventional vanadium extraction process to zero discharge. Accordingly, the objective of this work lies in evaluating the feasibility of the proposed scheme on the basis of a systematic study on the influences of membrane types and operating parameters on the electrodilysis performance. The results indicate that the relative importance of osmosis and electro-osmosis to overall water transport is closely related to the applied current density. The increase in the applied current density and the decrease in the mole ratio of water and salt flux will contribute to the concentration degree. Moreover, it is worth noting that a relatively large concentration ratio can result in the remarkable decrease of current efficiency and increase of energy consumption. In general, the reclamation scheme can easily achieve the recovered water with relatively low salt content and the highly concentrated Na{sub 2}SO{sub 4} solution (e.g., 300 g/L) for producing high-purity sodium sulphate crystals.

Hybrid Modulation Scheme for Cascaded H-Bridge Inverter Cells ...

African Journals Online (AJOL)

This work proposes a switching technique for cascaded H-Bridge (CHB) cells. Single carrier Sinusoidal PWM (SCSPWM) scheme is employed in the generation of the gating signals. A sequential switching and base PWM circulation schemes are presented for this fundamental cascaded multilevel inverter topology.

Sequential extraction procedure for determination of uranium, thorium, radium, lead and polonium radionuclides by alpha spectrometry in environmental samples

Science.gov (United States)

Oliveira, J. M.; Carvalho, F. P.

2006-01-01

A sequential extraction technique was developed and tested for common naturally-occurring radionuclides. This technique allows the extraction and purification of uranium, thorium, radium, lead, and polonium radionuclides from the same sample. Environmental materials such as water, soil, and biological samples can be analyzed for those radionuclides without matrix interferences in the quality of radioelement purification and in the radiochemical yield. The use of isotopic tracers (232U, 229Th, 224Ra, 209Po, and stable lead carrier) added to the sample in the beginning of the chemical procedure, enables an accurate control of the radiochemical yield for each radioelement. The ion extraction procedure, applied after either complete dissolution of the solid sample with mineral acids or co-precipitation of dissolved radionuclide with MnO2 for aqueous samples, includes the use of commercially available pre-packed columns from Eichrom® and ion exchange columns packed with Bio-Rad resins, in altogether three chromatography columns. All radioactive elements but one are purified and electroplated on stainless steel discs. Polonium is spontaneously plated on a silver disc. The discs are measured using high resolution silicon surface barrier detectors. 210Pb, a beta emitter, can be measured either through the beta emission of 210Bi, or stored for a few months and determined by alpha spectrometry through the in-growth of 210Po. This sequential extraction chromatography technique was tested and validated with the analysis of certified reference materials from the IAEA. Reproducibility was tested through repeated analysis of the same homogeneous material (water sample).

Mining compressing sequential problems

NARCIS (Netherlands)

Hoang, T.L.; Mörchen, F.; Fradkin, D.; Calders, T.G.K.

2012-01-01

Compression based pattern mining has been successfully applied to many data mining tasks. We propose an approach based on the minimum description length principle to extract sequential patterns that compress a database of sequences well. We show that mining compressing patterns is NP-Hard and

Sequential blind identification of underdetermined mixtures using a novel deflation scheme.

Science.gov (United States)

Zhang, Mingjian; Yu, Simin; Wei, Gang

2013-09-01

In this brief, we consider the problem of blind identification in underdetermined instantaneous mixture cases, where there are more sources than sensors. A new blind identification algorithm, which estimates the mixing matrix in a sequential fashion, is proposed. By using the rank-1 detecting device, blind identification is reformulated as a constrained optimization problem. The identification of one column of the mixing matrix hence reduces to an optimization task for which an efficient iterative algorithm is proposed. The identification of the other columns of the mixing matrix is then carried out by a generalized eigenvalue decomposition-based deflation method. The key merit of the proposed deflation method is that it does not suffer from error accumulation. The proposed sequential blind identification algorithm provides more flexibility and better robustness than its simultaneous counterpart. Comparative simulation results demonstrate the superior performance of the proposed algorithm over the simultaneous blind identification algorithm.

Volatile profile characterisation of Chilean sparkling wines produced by traditional and Charmat methods via sequential stir bar sorptive extraction.

Science.gov (United States)

Ubeda, C; Callejón, R M; Troncoso, A M; Peña-Neira, A; Morales, M L

2016-09-15

The volatile compositions of Charmat and traditional Chilean sparkling wines were studied for the first time. For this purpose, EG-Silicone and PDMS polymeric phases were compared and, afterwards, the most adequate was selected. The best extraction method turned out to be a sequential extraction in the headspace and by immersion using two PDMS twisters. A total of 130 compounds were determined. In traditional Chilean sparkling wines, ethyl esters were significantly higher, while acetic esters and ketones were predominant in the Charmat wines. PCA and LDA confirmed the differences in the volatile profiles between the production methods (traditional vs. Charmat). Copyright © 2016 Elsevier Ltd. All rights reserved.

Trigeneration scheme for a natural gas liquids extraction plant in the Middle East

International Nuclear Information System (INIS)

Eveloy, Valérie; Rodgers, Peter; Popli, Sahil

2014-01-01

Highlights: • Trigeneration scheme tailored to natural gas liquids extraction plant. • High ambient temperature and RH conditions in the Persian Gulf. • Absorption refrigeration powered by gas turbine (GT) exhaust gas waste heat. • GT compressor inlet air- and process gas cooling, process gas heating. • Significant OPEX and primary energy savings, favorable payback period and net present value. - Abstract: Natural gas processing plants in the Persian Gulf face extreme climatic conditions that constrain their gas turbine (GT) power generation and cooling capacities. However, due to a past history of low hydrocarbon prices, such plants have not fully exploited their waste heat recovery potential to date. The techno-economic performance of a combined cooling, heating and power (CCHP) scheme designed to enhance the energy efficiency of a major natural gas liquids extraction plant in the Persian Gulf is assessed. The trigeneration scheme utilizes double-effect water–lithium bromide absorption refrigeration powered by steam generated from GT exhaust gas waste heat to provide both GT compressor inlet air- and process gas cooling. Part of the generated steam is also used for process gas heating. Thermodynamic modeling reveals that recovery of 82 MW of GT waste heat would provide additional cooling and heating capacities of 75 MW and 24 MW to the plant, respectively, thereby permitting elimination of a 28 MW GT, and existing cooling and heating equipment. GT compressor inlet air cooling alone yields approximately 151 GW h of additional electric power annually, highlighting the effectiveness of absorption refrigeration in meeting compressor inlet air cooling loads throughout the year in the Gulf climate. The overall net annual operating expenditure savings contributed by the CCHP system would average approximately 14.6 million US$ over its lifespan, which corresponds to average yearly savings of 190 MMSCM of natural gas. The CCHP scheme economic payback period is

Update schemes of multi-velocity floor field cellular automaton for pedestrian dynamics

Science.gov (United States)

Luo, Lin; Fu, Zhijian; Cheng, Han; Yang, Lizhong

2018-02-01

Modeling pedestrian movement is an interesting problem both in statistical physics and in computational physics. Update schemes of cellular automaton (CA) models for pedestrian dynamics govern the schedule of pedestrian movement. Usually, different update schemes make the models behave in different ways, which should be carefully recalibrated. Thus, in this paper, we investigated the influence of four different update schemes, namely parallel/synchronous scheme, random scheme, order-sequential scheme and shuffled scheme, on pedestrian dynamics. The multi-velocity floor field cellular automaton (FFCA) considering the changes of pedestrians' moving properties along walking paths and heterogeneity of pedestrians' walking abilities was used. As for parallel scheme only, the collisions detection and resolution should be considered, resulting in a great difference from any other update schemes. For pedestrian evacuation, the evacuation time is enlarged, and the difference in pedestrians' walking abilities is better reflected, under parallel scheme. In face of a bottleneck, for example a exit, using a parallel scheme leads to a longer congestion period and a more dispersive density distribution. The exit flow and the space-time distribution of density and velocity have significant discrepancies under four different update schemes when we simulate pedestrian flow with high desired velocity. Update schemes may have no influence on pedestrians in simulation to create tendency to follow others, but sequential and shuffled update scheme may enhance the effect of pedestrians' familiarity with environments.

Determination and partitioning of metals in sediments along the Suez Canal by sequential extraction

Science.gov (United States)

Abd El-Azim, H.; El-Moselhy, Kh. M.

2005-06-01

The application of sequential extraction technique was used to determine the chemical association of heavy metals in five different chemical phases (exchangeable F1, bound to carbonate F2, bound to Fe-Mn oxides F3, bound to organic matter F4 and residual F5) for sediment samples collected from the Suez Canal. From the obtained data, it can be seen that the surplus of metal contaminants introduced into the sediment from sources usually exists in relatively unstable chemical forms. A high proportion of the studied metals remained in the residual fraction. Most of remaining portion of metals was bound to ferromanganese oxides fraction. The low concentrations of metals in the exchangeable fraction indicated that the sediments of Suez Canal were relatively unpolluted.

Proposal for a new LEIR Slow Extraction Scheme dedicated to Biomedical Research

CERN Document Server

Garonna, A; Carli, C

2014-01-01

This report presents a proposal for a new slow extraction scheme for the Low Energy Ion Ring (LEIR) in the context of the feasibility study for a biomedical research facility at CERN. LEIR has to be maintained as a heavy ion accumulator ring for LHC and for fixed-target experiments with the SPS. In parallel to this on-going operation for physics experiments, an additional secondary use of LEIR for a biomedical research facility was proposed [Dosanjh2013, Holzscheiter2012, PHE2010]. This facility would complement the existing research beam-time available at other laboratories for studies related to ion beam therapy. The new slow extraction [Abler2013] is based on the third-integer resonance. The reference beam is composed of fully stripped carbon ions with extraction energies of 20-440 MeV/u, transverse physical emittances of 5-25 µm and momentum spreads of ±2-9•10-4. Two resonance driving mechanisms have been studied: the quadrupole-driven method and the RF-knockout technique. Both were made compatible...

A new perspective of using sequential extraction: To predict the deficiency of trace elements during anaerobic digestion.

Science.gov (United States)

Cai, Yafan; Wang, Jungang; Zhao, Yubin; Zhao, Xiaoling; Zheng, Zehui; Wen, Boting; Cui, Zongjun; Wang, Xiaofen

2018-09-01

Trace elements were commonly used as additives to facilitate anaerobic digestion. However, their addition is often blind because of the complexity of reaction conditions, which has impeded their widespread application. Therefore, this study was conducted to evaluate deficiencies in trace elements during anaerobic digestion by establishing relationships between changes in trace element bioavailability (the degree to which elements are available for interaction with biological systems) and digestion performance. To accomplish this, two batch experiments were conducted. In the first, sequential extraction was used to detect changes in trace element fractions and then to evaluate trace element bioavailability in the whole digestion cycle. In the second batch experiment, trace elements (Co, Fe, Cu, Zn, Mn, Mo and Se) were added to the reaction system at three concentrations (low, medium and high) and their effects were monitored. The results showed that sequential extraction was a suitable method for assessment of the bioavailability of trace elements (appropriate coefficient of variation and recovery rate). The results revealed that Se had the highest (44.2%-70.9%) bioavailability, while Fe had the lowest (1.7%-3.0%). A lack of trace elements was not directly related to their absolute bioavailability, but was instead associated with changes in their bioavailability throughout the digestion cycle. Trace elements were insufficient when their bioavailability was steady or increased over the digestion cycle. These results indicate that changes in trace element bioavailability during the digestion cycle can be used to predict their deficiency. Copyright © 2018 Elsevier Ltd. All rights reserved.

Evaluation of Heavy Metals Concentration and Sequential Extraction in Zahedan Compost

Directory of Open Access Journals (Sweden)

Safoora Javan

2016-03-01

Full Text Available Background: Producing compost out of municipal solid wastes and organic materials is one of the main ways to recycle organic materials which plays an important role in waste management. Compost can also bring some toxic substances such as heavy metals into the soil and food chain and these substances have negative effects on the living things. Methods: This research is a cross-sectional descriptive study which was carried out during two seasons of spring and summer on Zahedan vermicompost factory. There were 100 samples in the research and the rate of mobility of heavy metals of lead, cadmium, and nickel was measured through five-step sequential extraction method. Then the hazard of the metals was assessed too. Results: The results show that the highest rate of mobility is related to chromium and then cadmium and lead. Moreover, the risk assessment of heavy metals estimates the average risk of all three metals for the living things in the environment. Conclusion: Heavy metals of lead and cadmium and nickel in Zahedan compost are less than the standard that is set for Iran. 

Gearbox Fault Features Extraction Using Vibration Measurements and Novel Adaptive Filtering Scheme

Directory of Open Access Journals (Sweden)

Ghalib R. Ibrahim

2012-01-01

Full Text Available Vibration signals measured from a gearbox are complex multicomponent signals, generated by tooth meshing, gear shaft rotation, gearbox resonance vibration signatures, and a substantial amount of noise. This paper presents a novel scheme for extracting gearbox fault features using adaptive filtering techniques for enhancing condition features, meshing frequency sidebands. A modified least mean square (LMS algorithm is examined and validated using only one accelerometer, instead of using two accelerometers in traditional arrangement, as the main signal and a desired signal is artificially generated from the measured shaft speed and gear meshing frequencies. The proposed scheme is applied to a signal simulated from gearbox frequencies with a numerous values of step size. Findings confirm that 10−5 step size invariably produces more accurate results and there has been a substantial improvement in signal clarity (better signal-to-noise ratio, which makes meshing frequency sidebands more discernible. The developed scheme is validated via a number of experiments carried out using two-stage helical gearbox for a healthy pair of gears and a pair suffering from a tooth breakage with severity fault 1 (25% tooth removal and fault 2 (50% tooth removal under loads (0%, and 80% of the total load. The experimental results show remarkable improvements and enhance gear condition features. This paper illustrates that the new approach offers a more effective way to detect early faults.

An anomaly detection and isolation scheme with instance-based learning and sequential analysis

International Nuclear Information System (INIS)

Yoo, T. S.; Garcia, H. E.

2006-01-01

This paper presents an online anomaly detection and isolation (FDI) technique using an instance-based learning method combined with a sequential change detection and isolation algorithm. The proposed method uses kernel density estimation techniques to build statistical models of the given empirical data (null hypothesis). The null hypothesis is associated with the set of alternative hypotheses modeling the abnormalities of the systems. A decision procedure involves a sequential change detection and isolation algorithm. Notably, the proposed method enjoys asymptotic optimality as the applied change detection and isolation algorithm is optimal in minimizing the worst mean detection/isolation delay for a given mean time before a false alarm or a false isolation. Applicability of this methodology is illustrated with redundant sensor data set and its performance. (authors)

Arsenic release from arsenopyrite weathering: insights from sequential extraction and microscopic studies.

Science.gov (United States)

Basu, Ankan; Schreiber, Madeline E

2013-11-15

At a former As mine site, arsenopyrite oxidation has resulted in formation of scorodite and As-bearing iron hydroxide, both in host rock and mine tailings. Electron microprobe analysis documents that arsenopyrite weathers along two pathways: one that involves formation of sulfur, and one that does not. In both pathways, arsenopyrite oxidizes to form scorodite, which dissolves incongruently to form As-bearing iron hydroxides. From a mass balance perspective, arsenopyrite oxidation to scorodite conserves As, but as scorodite dissolves incongruently to iron hydroxides, As is released to solution, resulting in elevated As concentrations in the headwater stream adjacent to the site. The As-bearing iron hydroxide is the dominant solid phase reservoir of As in mine tailings and stream sediment, as suggested by sequential extraction. This As-bearing iron hydroxide is stable under the aerobic and pH 4-6 conditions at the site; however, changes in biogeochemical conditions resulting from sediment burial or future remedial efforts, which could promote As release from this reservoir due to reductive dissolution, should be avoided. Copyright © 2012 Elsevier B.V. All rights reserved.

A construction scheme of web page comment information extraction system based on frequent subtree mining

Science.gov (United States)

Zhang, Xiaowen; Chen, Bingfeng

2017-08-01

Based on the frequent sub-tree mining algorithm, this paper proposes a construction scheme of web page comment information extraction system based on frequent subtree mining, referred to as FSM system. The entire system architecture and the various modules to do a brief introduction, and then the core of the system to do a detailed description, and finally give the system prototype.

Sequential error concealment for video/images by weighted template matching

DEFF Research Database (Denmark)

Koloda, Jan; Østergaard, Jan; Jensen, Søren Holdt

2012-01-01

In this paper we propose a novel spatial error concealment algorithm for video and images based on convex optimization. Block-based coding schemes in packet loss environment are considered. Missing macro blocks are sequentially reconstructed by filling them with a weighted set of templates...

Sequential Analysis of Metals in Municipal Dumpsite Composts of ...

African Journals Online (AJOL)

... Ni) in Municipal dumpsite compost were determined by the sequential extraction method. Chemical parameters such as pH, conductivity, and organic carbon contents of the samples were also determined. Analysis of the extracts was carried out by atomic absorption spectrophotometer machine (Buck Scientific VPG 210).

The composite sequential clustering technique for analysis of multispectral scanner data

Science.gov (United States)

Su, M. Y.

1972-01-01

The clustering technique consists of two parts: (1) a sequential statistical clustering which is essentially a sequential variance analysis, and (2) a generalized K-means clustering. In this composite clustering technique, the output of (1) is a set of initial clusters which are input to (2) for further improvement by an iterative scheme. This unsupervised composite technique was employed for automatic classification of two sets of remote multispectral earth resource observations. The classification accuracy by the unsupervised technique is found to be comparable to that by traditional supervised maximum likelihood classification techniques. The mathematical algorithms for the composite sequential clustering program and a detailed computer program description with job setup are given.

Evaluation of dissipation gradients of polycyclic aromatic hydrocarbons in rice rhizosphere utilizing a sequential extraction procedure

International Nuclear Information System (INIS)

Ma Bin; Wang Jiaojiao; Xu Minmin; He Yan; Wang Haizhen; Wu Laosheng; Xu Jianming

2012-01-01

The aim of this study was to evaluate the spatial dissipation gradient of PAHs, including phenanthrene, pyrene, and benzo[a]pyrene, with various bioavailability represented with sequential extraction. Dissipation rates of PAHs in the rhizosphere were greater than those in the bulk soil. The n-butanol extracted fraction showed a general trend of dissipation during phytoremediation. Moreover, the formation of bound PAH residues was inhibited in the rhizosphere. While concerning the PAH toxicity, the reduction rates of PAH toxicity were significantly greater than total soil PAH concentrations. Microbial biomass was the highest at four mm away from the root surface. However, the PAH dissipation rates were the highest at one mm and two mm away from the root surface in high and low PAH treatments, respectively. These results suggest that rhizoremediation with rice is a useful approach to reduce the toxicity of PAHs in soil. - Highlights: ► Dissipation gradients were different in soils spiked with different PAHs concentrations. ► Butanol extracted fraction indicated the remediation in rhizosphere. ► Toxicity of PAHs was more efficiently reduced than total concentration. ► Promotion of PAHs degraders was not synchronized with microbial biomass. - Stimulation of PAH degradation in rice rhizosphere was not simultaneous with microbial biomass.

Systolic array processing of the sequential decoding algorithm

Science.gov (United States)

Chang, C. Y.; Yao, K.

1989-01-01

A systolic array processing technique is applied to implementing the stack algorithm form of the sequential decoding algorithm. It is shown that sorting, a key function in the stack algorithm, can be efficiently realized by a special type of systolic arrays known as systolic priority queues. Compared to the stack-bucket algorithm, this approach is shown to have the advantages that the decoding always moves along the optimal path, that it has a fast and constant decoding speed and that its simple and regular hardware architecture is suitable for VLSI implementation. Three types of systolic priority queues are discussed: random access scheme, shift register scheme and ripple register scheme. The property of the entries stored in the systolic priority queue is also investigated. The results are applicable to many other basic sorting type problems.

A sequential extraction procedure to determine Ra and U isotopes by alpha-particle spectrometry in selective leachates

International Nuclear Information System (INIS)

Aguado, J.L.; Bolivar, J.P.; San-Miguel, E.G.; Garcia-Tenorio, R.

2003-01-01

A radiochemical sequential extraction procedure has been developed in our laboratory to determine 226 Ra and 234,238 U by alpha spectrometry in environmental samples. This method has been validated for both radionuclides by comparing in selected samples the values obtained through its application with the results obtained by applying alternative procedures. Recoveries obtained, counting periods applied and background levels found in the alpha spectra give suitable detection limits to allow the Ra and U determination in operational forms defined in riverbed contaminated sediments. Results obtained in these speciation studies show that 226 Ra and 234,238 U contamination tend to be associated to precipitated forms of the sediments. (author)

Evaluation of the readsorption of plutonium and americium in dynamic fractionations of environmental solid samples

DEFF Research Database (Denmark)

Petersen, Roongrat; Hou, Xiaolin; Hansen, Elo Harald

2008-01-01

A dynamic extraction system exploiting sequential injection (SI) for sequential extractions incorporating a specially designed extraction column is developed to fractionate radionuclides in environmental solid samples such as soils and sediments. The extraction column can contain a large amount...... of soil sample (up to 5 g), and under optimal operational conditions it does not give rise to creation of back pressure. Attention has been placed on studies of the readsorption problems during sequential extraction using a modified Standards, Measurements and Testing (SM&T) scheme with 4-step sequential...

Anticancer Properties and Phenolic Contents of Sequentially Prepared Extracts from Different Parts of Selected Medicinal Plants Indigenous to Malaysia

Directory of Open Access Journals (Sweden)

Hadiza Altine Adamu

2012-05-01

Full Text Available Different parts of four edible medicinal plants (Casearia capitellata, Baccaurea motleyana, Phyllanthus pulcher and Strobilanthus crispus, indigenous to Malaysia, were extracted in different solvents, sequentially. The obtained 28 extracts were evaluated for their in vitro anticancer properties, using the MTS assay, on four human cancer cell lines: colon (HT-29, breast (MCF-7, prostate (DU-145 and lung (H460 cancers. The best anticancer activity was observed for the ethyl acetate (EA extract of Casearia capitellata leaves on MCF-7 cell lines with IC₅₀ 2.0 μg/mL and its methanolic (MeOH extract showed an outstanding activity against lung cancer cell lines. Dichloromethane (DCM extract of Phyllanthus pulcher aerial parts showed the highest anticancer activity against DU-145 cell lines, while significant activity was exhibited by DCM extract of Phyllanthus pulcher roots on colon cancer cell lines with IC₅₀ value of 8.1 μg/mL. Total phenolic content (TPC ranged over 1–40 mg gallic acid equivalents (GAE/g. For all the samples, highest yields of phenolics were obtained for MeOH extracts. Among all the extracts analyzed, the MeOH extracts of Strobilanthus crispus leaves exhibited the highest TPC than other samples (p < 0.05. This study shows that the nature of phenol determines its anticaner activity and not the number of phenols present.

Text analysis of MEDLINE for discovering functional relationships among genes: evaluation of keyword extraction weighting schemes.

Science.gov (United States)

Liu, Ying; Navathe, Shamkant B; Pivoshenko, Alex; Dasigi, Venu G; Dingledine, Ray; Ciliax, Brian J

2006-01-01

One of the key challenges of microarray studies is to derive biological insights from the gene-expression patterns. Clustering genes by functional keyword association can provide direct information about the functional links among genes. However, the quality of the keyword lists significantly affects the clustering results. We compared two keyword weighting schemes: normalised z-score and term frequency-inverse document frequency (TFIDF). Two gene sets were tested to evaluate the effectiveness of the weighting schemes for keyword extraction for gene clustering. Using established measures of cluster quality, the results produced from TFIDF-weighted keywords outperformed those produced from normalised z-score weighted keywords. The optimised algorithms should be useful for partitioning genes from microarray lists into functionally discrete clusters.

Development of a control scheme of homodyne detection for extracting ponderomotive squeezing from a Michelson interferometer

International Nuclear Information System (INIS)

Sakata, Shihori; Kawamura, Seiji; Sato, Shuichi; Somiya, Kentaro; Arai, Koji; Fukushima, Mitsuhiro; Sugamoto, Akio

2006-01-01

We developed a control scheme of homodyne detection. To operate the homodyne detector as easy as possible, a simple Michelson interferometer is used. Here a motivation that the control scheme of the homodyne detection is developed is for our future experiment of extracting the ponderomotively squeezed vacuum fluctuations. To obtain the best signalto- noise ratio using the homodyne detection, the homodyne phase should be optimized. The optimization of the homodyne phase is performed by changing a phase of a local oscillator for the homodyne detection from a point at which a signal is maximized. In fact, in this experiment, using the developed control scheme, we locked the Michelson interferometer with the homodyne detector and changed the phase of the local oscillator for the homodyne detection. Then, we measured signals quantity changed by changing the phase of the local oscillator for the homodyne detection. Here we used the output from the homodyne detection as the signal

SEQUENTIAL ELECTRODIALYTIC EXTRACTION OF PHOSPHORUS COMPOUNDS

DEFF Research Database (Denmark)

2017-01-01

The present invention relates to an apparatus for electrodialytic extraction of phosphorus from a particulate material in suspension and to a method for electrodialytic phosphorus recovery, which uses the apparatus. The method may be applied for wastewater treatment, and/or treatment of particulate...... material rich in phosphorus. The present invention provides an apparatus for electrodialytic extraction of phosphorus from a particulate material comprising acidic and/or alkaline soluble phosphorus compounds, in suspension, comprising: • a first electrodialytic cell comprising a first anolyte compartment...

Thermal, emulsifying and rheological properties of polysaccharides sequentially extracted from Vaccinium bracteatum Thunb leaves.

Science.gov (United States)

Xu, Qi-Xin; Shi, Jun-Jun; Zhang, Jian-Guo; Li, Ling; Jiang, Li; Wei, Zhao-Jun

2016-12-01

Plant polysaccharides are widely used in food industry as thickening and gelling agents and these attributes largely depend on their thermal, emulsifying and rheological properties. As known, the extraction methods always bring about the diversification of property and functions of polysaccharides. Thus, the Vaccinium bracteatum Thunb leaves polysaccharides (VBTLP) were sequentially extracted using hot buffer (HBSS), chelating agent (CHSS), dilute alkaline (DASS) and concentrated alkaline (CASS). The thermal, emulsifying and rheological properties of VBTLP were investigated in the present study. Within the range of 20-225°C, CHSS showed the highest peak temperature, whereas HBSS displayed the highest endothermic enthalpy and highest emulsifying activity, while, CASS showed the longest emulsifying stability. The VBTLP solutions exhibited non-Newtonian shear-thinning behavior within the concentrations of 0.6-2.5%. The apparent viscosity of VBTLP solution decreased under following conditions: acidic pH (4.0), alkaline pH (10.0), in the presence of Ca 2+ and at high temperature, while it increased in the presence of Na + and at freezing conditions. The modulus G' and G″ of VBTLP solutions were increased with increasing oscillation frequency, and the crossover frequency shifted to lower values when the polysaccharide content increased. The above results of thermal, emulsifying and rheological properties of VBTLPs supplied the basis for V. bracteatum leaves in potential industrial applications of foods. Copyright © 2016 Elsevier B.V. All rights reserved.

Strontium distribution and origins in a natural clayey formation (Callovian-Oxfordian, Paris Basin, France): a new sequential extraction procedure

International Nuclear Information System (INIS)

Lerouge, C.; Gaucher, E.C.; Tournassat, C.; Negrel, P.; Crouzet, C.; Guerrot, C.; Gautier, A.; Michel, P.; Vinsot, A.; Buschaert, S.

2010-01-01

Document available in extended abstract form only. Strontium is a minor element in the Callovian-Oxfordian clayey formation of Bure (ANDRA Underground Research laboratory, France) and may be interesting as a natural analogue of cationic radionuclides. The objective of our study was to better understand the chemical behaviour of this element since the sediment deposition. Previous mineralogical work showed that main strontium-bearing minerals in the clay-stones, in addition to clay minerals, are celestite, carbonates and accessory micas and K-feldspars. In order to establish the strontium distribution and determine its origins across the clayey formation and establish a strontium diffusion profile, a four step sequential extraction procedure combined with strontium isotopes was developed and adapted to the mineralogy of the Bure clay-stones. The four-steps sequential extraction developed and applied to sixteen samples of Callovian-Oxfordian clay-stones showed that the exchangeable fraction (27 to 48% of the total strontium) and the carbonate fraction (38-47% of the total strontium) are the two main fractions carrying the strontium, the detrital fraction being secondary (< 15%). Celestite is the major strontium-carrier mineral that can perturb the results of the sequential extraction but not significantly modify the distribution of strontium at the scale of the formation. The celestite was studied on micronic to centi-metric crystals, separated by hand-picking on core samples. The development of this sequential extraction procedure for the Callovian-Oxfordian formation shows the importance of the first cobalt hexamine trichloride step to extract the exchangeable strontium adsorbed on clay minerals and block the exchangeable sites with cobalt for the following steps, allowing a good separation of exchangeable fraction and carbonates. However the reagent/solid ratio of 20 seems to be less adapted to carbonate-rich samples. The good separation between exchangeable

Sequential extraction combined with isotope analysis as a tool for the investigation of lead mobilisation in soils: Application to organic-rich soils in an upland catchment in Scotland

International Nuclear Information System (INIS)

Bacon, Jeffrey R.; Farmer, John G.; Dunn, Sarah M.; Graham, Margaret C.; Vinogradoff, Susan I.

2006-01-01

Sequential extraction (modified BCR procedure) combined with isotope analysis has been investigated as a tool for assessing mobilisation of lead into streams at an upland catchment in NE Scotland. The maximum lead concentrations (up to 110 mg kg -1 in air-dried soil) occurred not at the surface but at about 10 cm depth. The lowest 206 Pb/ 207 Pb ratios in any profile occurred, with one exception, at 2.5-5 cm depth. In the one exception, closest to the only road in the area, significantly lower 206 Pb/ 207 Pb ratios in the surface soil together with much increased chloride concentrations (in comparison to other surface waters) indicated the possible mobilisation of roadside lead and transfer to the stream. The 206 Pb/ 207 Pb ratios in extractable fractions tended at depth towards the ratio measured in the residual phase but the ratios in the oxidizable fraction increased to a value higher than that of the residual phase. - Sequential extraction combined with isotope analysis was used as a tool to assess mobilisation of lead into streams

Zips : mining compressing sequential patterns in streams

NARCIS (Netherlands)

Hoang, T.L.; Calders, T.G.K.; Yang, J.; Mörchen, F.; Fradkin, D.; Chau, D.H.; Vreeken, J.; Leeuwen, van M.; Faloutsos, C.

2013-01-01

We propose a streaming algorithm, based on the minimal description length (MDL) principle, for extracting non-redundant sequential patterns. For static databases, the MDL-based approach that selects patterns based on their capacity to compress data rather than their frequency, was shown to be

Remediation of soils contaminated with particulate depleted uranium by multi stage chemical extraction

Energy Technology Data Exchange (ETDEWEB)

Crean, Daniel E. [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield (United Kingdom); Centre for Radiochemistry Research, School of Chemistry, The University of Manchester (United Kingdom); Livens, Francis R.; Sajih, Mustafa [Centre for Radiochemistry Research, School of Chemistry, The University of Manchester (United Kingdom); Stennett, Martin C. [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield (United Kingdom); Grolimund, Daniel; Borca, Camelia N. [Swiss Light Source, Paul Scherrer Institute, Villigen (Switzerland); Hyatt, Neil C., E-mail: n.c.hyatt@sheffield.ac.uk [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield (United Kingdom)

2013-12-15

Highlights: • Batch leaching was examined to remediate soils contaminated with munitions depleted uranium. • Site specific maximum extraction was 42–50% total U in single batch with NH{sub 4}HCO{sub 3}. • Analysis of residues revealed partial leaching and secondary carbonate phases. • Sequential batch leaching alternating between NH{sub 4}HCO{sub 3} and citric acid was designed. • Site specific extraction was increased to 68–87% total U in three batch steps. -- Abstract: Contamination of soils with depleted uranium (DU) from munitions firing occurs in conflict zones and at test firing sites. This study reports the development of a chemical extraction methodology for remediation of soils contaminated with particulate DU. Uranium phases in soils from two sites at a UK firing range, MOD Eskmeals, were characterised by electron microscopy and sequential extraction. Uranium rich particles with characteristic spherical morphologies were observed in soils, consistent with other instances of DU munitions contamination. Batch extraction efficiencies for aqueous ammonium bicarbonate (42–50% total DU extracted), citric acid (30–42% total DU) and sulphuric acid (13–19% total DU) were evaluated. Characterisation of residues from bicarbonate-treated soils by synchrotron microfocus X-ray diffraction and X-ray absorption spectroscopy revealed partially leached U(IV)-oxide particles and some secondary uranyl-carbonate phases. Based on these data, a multi-stage extraction scheme was developed utilising leaching in ammonium bicarbonate followed by citric acid to dissolve secondary carbonate species. Site specific U extraction was improved to 68–87% total U by the application of this methodology, potentially providing a route to efficient DU decontamination using low cost, environmentally compatible reagents.

Application of sequential extraction analysis to electrokinetic remediation of cadmium, nickel and zinc from contaminated soils

International Nuclear Information System (INIS)

Giannis, Apostolos; Pentari, Despina; Wang, Jing-Yuan; Gidarakos, Evangelos

2010-01-01

An enhanced electrokinetic process for the removal of cadmium (Cd), nickel (Ni) and zinc (Zn) from contaminated soils was performed. The efficiency of the chelate agents nitrilotriacetic acid (NTA), diethylenetriaminepentaacetic acid (DTPA) and diaminocycloexanetetraacetic acid (DCyTA) was examined under constant potential gradient (1.23 V/cm). The results showed that chelates were effective in desorbing metals at a high pH, with metal-chelate anion complexes migrating towards the anode. At low pH, metals existing as dissolved cations migrated towards the cathode. In such conflicting directions, the metals accumulated in the middle of the cell. Speciation of the metals during the electrokinetic experiments was performed to provide an understanding of the distribution of the Cd, Ni and Zn. The results of sequential extraction analysis revealed that the forms of the metals could be altered from one fraction to another due to the variation of physico-chemical conditions throughout the cell, such as pH, redox potential and the chemistry of the electrolyte solution during the electrokinetic treatment. It was found that binding forms of metals were changed from the difficult type to easier extraction type.

Application of sequential extraction analysis to electrokinetic remediation of cadmium, nickel and zinc from contaminated soils

Energy Technology Data Exchange (ETDEWEB)

Giannis, Apostolos, E-mail: apostolos.giannis@enveng.tuc.gr [Department of Environmental Engineering, Technical University of Crete, Politechnioupolis, Chania 73100 (Greece); Pentari, Despina [Department of Mineral Resources Engineering, Technical University of Crete, Politechnioupolis, Chania 73100 (Greece); Wang, Jing-Yuan [Residues and Resource Reclamation Centre (R3C), Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); Gidarakos, Evangelos, E-mail: gidarako@mred.tuc.gr [Department of Environmental Engineering, Technical University of Crete, Politechnioupolis, Chania 73100 (Greece)

2010-12-15

An enhanced electrokinetic process for the removal of cadmium (Cd), nickel (Ni) and zinc (Zn) from contaminated soils was performed. The efficiency of the chelate agents nitrilotriacetic acid (NTA), diethylenetriaminepentaacetic acid (DTPA) and diaminocycloexanetetraacetic acid (DCyTA) was examined under constant potential gradient (1.23 V/cm). The results showed that chelates were effective in desorbing metals at a high pH, with metal-chelate anion complexes migrating towards the anode. At low pH, metals existing as dissolved cations migrated towards the cathode. In such conflicting directions, the metals accumulated in the middle of the cell. Speciation of the metals during the electrokinetic experiments was performed to provide an understanding of the distribution of the Cd, Ni and Zn. The results of sequential extraction analysis revealed that the forms of the metals could be altered from one fraction to another due to the variation of physico-chemical conditions throughout the cell, such as pH, redox potential and the chemistry of the electrolyte solution during the electrokinetic treatment. It was found that binding forms of metals were changed from the difficult type to easier extraction type.

A node linkage approach for sequential pattern mining.

Directory of Open Access Journals (Sweden)

Osvaldo Navarro

Full Text Available Sequential Pattern Mining is a widely addressed problem in data mining, with applications such as analyzing Web usage, examining purchase behavior, and text mining, among others. Nevertheless, with the dramatic increase in data volume, the current approaches prove inefficient when dealing with large input datasets, a large number of different symbols and low minimum supports. In this paper, we propose a new sequential pattern mining algorithm, which follows a pattern-growth scheme to discover sequential patterns. Unlike most pattern growth algorithms, our approach does not build a data structure to represent the input dataset, but instead accesses the required sequences through pseudo-projection databases, achieving better runtime and reducing memory requirements. Our algorithm traverses the search space in a depth-first fashion and only preserves in memory a pattern node linkage and the pseudo-projections required for the branch being explored at the time. Experimental results show that our new approach, the Node Linkage Depth-First Traversal algorithm (NLDFT, has better performance and scalability in comparison with state of the art algorithms.

Extraction, fatty acid profile and antioxidant activity of sesame extract (Sesamum Indicum L.

Directory of Open Access Journals (Sweden)

R. H. R. Carvalho

2012-06-01

Full Text Available This article carried out the extraction of sesame oil by using three extraction techniques: supercritical fluid extraction (SFE, Soxhlet and sequential extraction. The SFE was performed using supercritical carbon dioxide (SC-CO2 as solvent and ethanol as cosolvent. Tests were performed at 20 MPa, 35ºC and a flow rate of 2.5 g CO2/min with a total extraction time of 210 minutes. The Soxhlet extraction was performed for 8 hours, using petroleum ether and ethanol as solvents, until the exhaustion of the oil contained in the seeds. The sequential extraction used ethyl ether, ethanol and water as solvents. The Soxhlet extraction was the most effective (58.93%, while the SFE technique obtained 26.47% as the best result. The antioxidant activity (AA was determined by the β-carotene/linoleic acid system, with good oxidation inhibition percentages (29.32-83.49% for all the extracts. The main fatty acids (FA in sesame oil were oleic and linoleic acids.

Evaluation of uranium and arsenic retention by soil from a low level radioactive waste management site using sequential extraction

International Nuclear Information System (INIS)

Evans, G.J.; Dhoum, R.T.

1998-01-01

The European Communities Bureau of Reference (BCR) and Chunguo sequential extraction procedures were employed to evaluate the retention of U and As by a soil contaminated with low level radioactive waste. Modifications were made to both procedures to optimize the measurement of soil and extractant samples using epithermal neutron activation analysis. Based on the BCR procedure, approximately 20% of the U appeared to be bound to the carbonate fraction, 10% to the mineral oxide fraction and 20% to the organic fraction. In the case of As, the majority was strongly bound in the residue fraction. The results obtained with the Chunguo procedure supported these conclusions to some extent, in that the majority of the U and As was found to be strongly bound to the soil in a manner consistent with its presence in the residue fraction. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

A Novel Iris Segmentation Scheme

Directory of Open Access Journals (Sweden)

Chen-Chung Liu

2014-01-01

Full Text Available One of the key steps in the iris recognition system is the accurate iris segmentation from its surrounding noises including pupil, sclera, eyelashes, and eyebrows of a captured eye-image. This paper presents a novel iris segmentation scheme which utilizes the orientation matching transform to outline the outer and inner iris boundaries initially. It then employs Delogne-Kåsa circle fitting (instead of the traditional Hough transform to further eliminate the outlier points to extract a more precise iris area from an eye-image. In the extracted iris region, the proposed scheme further utilizes the differences in the intensity and positional characteristics of the iris, eyelid, and eyelashes to detect and delete these noises. The scheme is then applied on iris image database, UBIRIS.v1. The experimental results show that the presented scheme provides a more effective and efficient iris segmentation than other conventional methods.

Feature Extraction in Sequential Multimedia Images: with Applications in Satellite Images and On-line Videos

Science.gov (United States)

Liang, Yu-Li

Multimedia data is increasingly important in scientific discovery and people's daily lives. Content of massive multimedia is often diverse and noisy, and motion between frames is sometimes crucial in analyzing those data. Among all, still images and videos are commonly used formats. Images are compact in size but do not contain motion information. Videos record motion but are sometimes too big to be analyzed. Sequential images, which are a set of continuous images with low frame rate, stand out because they are smaller than videos and still maintain motion information. This thesis investigates features in different types of noisy sequential images, and the proposed solutions that intelligently combined multiple features to successfully retrieve visual information from on-line videos and cloudy satellite images. The first task is detecting supraglacial lakes above ice sheet in sequential satellite images. The dynamics of supraglacial lakes on the Greenland ice sheet deeply affect glacier movement, which is directly related to sea level rise and global environment change. Detecting lakes above ice is suffering from diverse image qualities and unexpected clouds. A new method is proposed to efficiently extract prominent lake candidates with irregular shapes, heterogeneous backgrounds, and in cloudy images. The proposed system fully automatize the procedure that track lakes with high accuracy. We further cooperated with geoscientists to examine the tracked lakes and found new scientific findings. The second one is detecting obscene content in on-line video chat services, such as Chatroulette, that randomly match pairs of users in video chat sessions. A big problem encountered in such systems is the presence of flashers and obscene content. Because of various obscene content and unstable qualities of videos capture by home web-camera, detecting misbehaving users is a highly challenging task. We propose SafeVchat, which is the first solution that achieves satisfactory

Recovery of Cobalt as Cobalt Oxalate from Cobalt Tailings Using Moderately Thermophilic Bioleaching Technology and Selective Sequential Extraction

Directory of Open Access Journals (Sweden)

Guobao Chen

2016-07-01

Full Text Available Cobalt is a very important metal which is widely applied in various critical areas, however, it is difficult to recover cobalt from minerals since there is a lack of independent cobalt deposits in nature. This work is to provide a complete process to recover cobalt from cobalt tailings using the moderately thermophilic bioleaching technology and selective sequential extraction. It is found that 96.51% Co and 26.32% Cu were extracted after bioleaching for four days at 10% pulp density. The mean compositions of the leach solutions contain 0.98 g·L−1 of Co, 6.52 g·L−1 of Cu, and 24.57 g·L−1 of Fe (III. The copper ion was then recovered by a solvent extraction process and the ferric ions were selectively removed by applying a goethite deironization process. The technological conditions of the above purification procedures were deliberately discussed. Over 98.6% of copper and 99.9% of ferric ions were eliminated from the leaching liquor. Cobalt was finally produced as cobalt oxalate and its overall recovery during the whole process was greater than 95%. The present bioleaching process of cobalt is worth using for reference to deal with low-grade cobalt ores.

Arsenic fractionation in agricultural soil using an automated three-step sequential extraction method coupled to hydride generation-atomic fluorescence spectrometry

Energy Technology Data Exchange (ETDEWEB)

Rosas-Castor, J.M. [Universidad Autónoma de Nuevo León, UANL, Facultad de Ciencias Químicas, Cd. Universitaria, San Nicolás de los Garza, Nuevo León, C.P. 66451 Nuevo León (Mexico); Group of Analytical Chemistry, Automation and Environment, University of Balearic Islands, Cra. Valldemossa km 7.5, 07122 Palma de Mallorca (Spain); Portugal, L.; Ferrer, L. [Group of Analytical Chemistry, Automation and Environment, University of Balearic Islands, Cra. Valldemossa km 7.5, 07122 Palma de Mallorca (Spain); Guzmán-Mar, J.L.; Hernández-Ramírez, A. [Universidad Autónoma de Nuevo León, UANL, Facultad de Ciencias Químicas, Cd. Universitaria, San Nicolás de los Garza, Nuevo León, C.P. 66451 Nuevo León (Mexico); Cerdà, V. [Group of Analytical Chemistry, Automation and Environment, University of Balearic Islands, Cra. Valldemossa km 7.5, 07122 Palma de Mallorca (Spain); Hinojosa-Reyes, L., E-mail: laura.hinojosary@uanl.edu.mx [Universidad Autónoma de Nuevo León, UANL, Facultad de Ciencias Químicas, Cd. Universitaria, San Nicolás de los Garza, Nuevo León, C.P. 66451 Nuevo León (Mexico)

2015-05-18

Highlights: • A fully automated flow-based modified-BCR extraction method was developed to evaluate the extractable As of soil. • The MSFIA–HG-AFS system included an UV photo-oxidation step for organic species degradation. • The accuracy and precision of the proposed method were found satisfactory. • The time analysis can be reduced up to eight times by using the proposed flow-based BCR method. • The labile As (F1 + F2) was <50% of total As in soil samples from As-contaminated-mining zones. - Abstract: A fully automated modified three-step BCR flow-through sequential extraction method was developed for the fractionation of the arsenic (As) content from agricultural soil based on a multi-syringe flow injection analysis (MSFIA) system coupled to hydride generation-atomic fluorescence spectrometry (HG-AFS). Critical parameters that affect the performance of the automated system were optimized by exploiting a multivariate approach using a Doehlert design. The validation of the flow-based modified-BCR method was carried out by comparison with the conventional BCR method. Thus, the total As content was determined in the following three fractions: fraction 1 (F1), the acid-soluble or interchangeable fraction; fraction 2 (F2), the reducible fraction; and fraction 3 (F3), the oxidizable fraction. The limits of detection (LOD) were 4.0, 3.4, and 23.6 μg L{sup −1} for F1, F2, and F3, respectively. A wide working concentration range was obtained for the analysis of each fraction, i.e., 0.013–0.800, 0.011–0.900 and 0.079–1.400 mg L{sup −1} for F1, F2, and F3, respectively. The precision of the automated MSFIA–HG-AFS system, expressed as the relative standard deviation (RSD), was evaluated for a 200 μg L{sup −1} As standard solution, and RSD values between 5 and 8% were achieved for the three BCR fractions. The new modified three-step BCR flow-based sequential extraction method was satisfactorily applied for arsenic fractionation in real agricultural

Arabinose and ferulic acid rich pectic polysaccharides extracted from sugar beet pulp.

NARCIS (Netherlands)

Oosterveld, A.; Beldman, G.; Schols, H.A.; Voragen, A.G.J.

1996-01-01

Arabinose and ferulic acid rich polysaccharides were extracted from sugar beet pulp using two extraction methods: a sequential extraction with H2O (2 times), NaOH/EDTA (2 times), and 4 M NaOH (2 times; method A) and a sequential extraction in which the NaOH/EDTA extraction was replaced by an

The sequential structure of brain activation predicts skill.

Science.gov (United States)

Anderson, John R; Bothell, Daniel; Fincham, Jon M; Moon, Jungaa

2016-01-29

In an fMRI study, participants were trained to play a complex video game. They were scanned early and then again after substantial practice. While better players showed greater activation in one region (right dorsal striatum) their relative skill was better diagnosed by considering the sequential structure of whole brain activation. Using a cognitive model that played this game, we extracted a characterization of the mental states that are involved in playing a game and the statistical structure of the transitions among these states. There was a strong correspondence between this measure of sequential structure and the skill of different players. Using multi-voxel pattern analysis, it was possible to recognize, with relatively high accuracy, the cognitive states participants were in during particular scans. We used the sequential structure of these activation-recognized states to predict the skill of individual players. These findings indicate that important features about information-processing strategies can be identified from a model-based analysis of the sequential structure of brain activation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sequential determination of important ecotoxic radionuclides in nuclear waste samples

International Nuclear Information System (INIS)

Bilohuscin, J.

2016-01-01

In the dissertation thesis we focused on the development and optimization of a sequential determination method for radionuclides 93 Zr, 94 Nb, 99 Tc and 126 Sn, employing extraction chromatography sorbents TEVA (R) Resin and Anion Exchange Resin, supplied by Eichrom Industries. Prior to the attestation of sequential separation of these proposed radionuclides from radioactive waste samples, a unique sequential procedure of 90 Sr, 239 Pu, 241 Am separation from urine matrices was tried, using molecular recognition sorbents of AnaLig (R) series and extraction chromatography sorbent DGA (R) Resin. On these experiments, four various sorbents were continually used for separation, including PreFilter Resin sorbent, which removes interfering organic materials present in raw urine. After the acquisition of positive results of this sequential procedure followed experiments with a 126 Sn separation using TEVA (R) Resin and Anion Exchange Resin sorbents. Radiochemical recoveries obtained from samples of radioactive evaporate concentrates and sludge showed high efficiency of the separation, while values of 126 Sn were under the minimum detectable activities MDA. Activity of 126 Sn was determined after ingrowth of daughter nuclide 126m Sb on HPGe gamma detector, with minimal contamination of gamma interfering radionuclides with decontamination factors (D f ) higher then 1400 for 60 Co and 47000 for 137 Cs. Based on the acquired experiments and results of these separation procedures, a complex method of sequential separation of 93 Zr, 94 Nb, 99 Tc and 126 Sn was proposed, which included optimization steps similar to those used in previous parts of the dissertation work. Application of the sequential separation method for sorbents TEVA (R) Resin and Anion Exchange Resin on real samples of radioactive wastes provided satisfactory results and an economical, time sparing, efficient method. (author)

A Temporal Domain Decomposition Algorithmic Scheme for Large-Scale Dynamic Traffic Assignment

Directory of Open Access Journals (Sweden)

Eric J. Nava

2012-03-01

This paper presents a temporal decomposition scheme for large spatial- and temporal-scale dynamic traffic assignment, in which the entire analysis period is divided into Epochs. Vehicle assignment is performed sequentially in each Epoch, thus improving the model scalability and confining the peak run-time memory requirement regardless of the total analysis period. A proposed self-turning scheme adaptively searches for the run-time-optimal Epoch setting during iterations regardless of the characteristics of the modeled network. Extensive numerical experiments confirm the promising performance of the proposed algorithmic schemes.

Fractionation of metals by sequential extraction procedures (BCR and Tessier) in soil exposed to fire of wide temperature range

Science.gov (United States)

Fajkovic, Hana; Rončević, Sanda; Nemet, Ivan; Prohić, Esad; Leontić-Vazdar, Dana

2017-04-01

Forest fire presents serious problem, especially in Mediterranean Region. Effects of fire are numerous, from climate change and deforestation to loss of soil organic matter and changes in soil properties. One of the effects, not well documented, is possible redistribution and/or remobilisation of pollutants previously deposited in the soil, due to the new physical and chemical soil properties and changes in equilibrium conditions. For understanding and predicting possible redistribution and/or remobilisation of potential pollutants from soil, affected by fire different in temperature, several laboratory investigations were carried out. To evaluate the influence of organic matter on soil under fire, three soil samples were analysed and compared: (a) the one with added coniferous organic matter; (b) deciduous organic matter (b) and (c) soil without additional organic matter. Type of organic matter is closely related to pH of soil, as pH is influencing the mobility of some pollutants, e.g. metals. For that reason pH was also measured through all experimental steps. Each of mentioned soil samples (a, b and c) were heated at 1+3 different temperatures (25°C, 200°C, 500°C and 850°C). After heating, whereby fire effect on soil was simulated, samples were analysed by BCR protocol with the addition of a first step of sequential extraction procedure by Tessier and analysis of residual by aqua regia. Element fractionation of heavy metals by this procedure was used to determine the amounts of selected elements (Al, Cd, Cr, Co, Cu, Fe, Mn, Ni, Pb and Zn). Selected metal concentrations were determined using inductively coupled plasma atomic emission spectrometer. Further on, loss of organic matter was calculated after each heating procedure as well as the mineral composition. The mineral composition was determined using an X-ray diffraction. From obtained results, it can be concluded that temperature has an influence on concentration of elements in specific step of

Speciation Analysis of ¹²⁹I and ¹²⁷I in Aerosols Using Sequential Extraction and Mass Spectrometry Detection

DEFF Research Database (Denmark)

Zhang, Luyuan; Hou, Xiaolin; Xu, Sheng

2015-01-01

A new analytical method has been developed for speciation analysis of 127I and 129I in aerosols collected on polypropylene (PP) filter paper. Iodide, iodate, NaOH soluble iodine, and insoluble iodine were separated from aerosols using sequential extraction, chromatography separation, and alkaline...... ashing and measured using inductive coupled plasma mass spectrometry (ICP-MS) for 127I and accelerator mass spectrometry (AMS) for 129I. Parameters affecting the leaching efficiency and stability of iodine species, such as leaching time and temperature, amount of alkaline reagent for ashing, ashing...... temperature and time, and iodine protective agent, were investigated and optimized. It was observed that long time water leaching would change inorganic iodine species due to photochemical oxidation of iodide on the PP filter surface. NaOH leaching can only extract less than 60% of iodine from the studied...

Arsenic release from arsenopyrite weathering: Insights from sequential extraction and microscopic studies

Energy Technology Data Exchange (ETDEWEB)

Basu, Ankan [Marshall Miller and Associates, Bluefield VA (United States); Department of Geosciences, Virginia Tech, 4044 Derring Hall, Blacksburg VA 24061 (United States); Schreiber, Madeline E., E-mail: mschreib@vt.edu [Department of Geosciences, Virginia Tech, 4044 Derring Hall, Blacksburg VA 24061 (United States)

2013-11-15

Highlights: ► We studied arsenopyrite weathering reactions in rocks and sediments at mine site. ► Arsenopyrite oxidizes to scorodite, which dissolves incongruently to Fe hydroxide. ► Weathering of arsenopyrite to Fe hydroxide releases As to water. ► Dominant As reservoir in sediment is Fe hydroxide. -- Abstract: At a former As mine site, arsenopyrite oxidation has resulted in formation of scorodite and As-bearing iron hydroxide, both in host rock and mine tailings. Electron microprobe analysis documents that arsenopyrite weathers along two pathways: one that involves formation of sulfur, and one that does not. In both pathways, arsenopyrite oxidizes to form scorodite, which dissolves incongruently to form As-bearing iron hydroxides. From a mass balance perspective, arsenopyrite oxidation to scorodite conserves As, but as scorodite dissolves incongruently to iron hydroxides, As is released to solution, resulting in elevated As concentrations in the headwater stream adjacent to the site. The As-bearing iron hydroxide is the dominant solid phase reservoir of As in mine tailings and stream sediment, as suggested by sequential extraction. This As-bearing iron hydroxide is stable under the aerobic and pH 4–6 conditions at the site; however, changes in biogeochemical conditions resulting from sediment burial or future remedial efforts, which could promote As release from this reservoir due to reductive dissolution, should be avoided.

Arsenic release from arsenopyrite weathering: Insights from sequential extraction and microscopic studies

International Nuclear Information System (INIS)

Basu, Ankan; Schreiber, Madeline E.

2013-01-01

Highlights: ► We studied arsenopyrite weathering reactions in rocks and sediments at mine site. ► Arsenopyrite oxidizes to scorodite, which dissolves incongruently to Fe hydroxide. ► Weathering of arsenopyrite to Fe hydroxide releases As to water. ► Dominant As reservoir in sediment is Fe hydroxide. -- Abstract: At a former As mine site, arsenopyrite oxidation has resulted in formation of scorodite and As-bearing iron hydroxide, both in host rock and mine tailings. Electron microprobe analysis documents that arsenopyrite weathers along two pathways: one that involves formation of sulfur, and one that does not. In both pathways, arsenopyrite oxidizes to form scorodite, which dissolves incongruently to form As-bearing iron hydroxides. From a mass balance perspective, arsenopyrite oxidation to scorodite conserves As, but as scorodite dissolves incongruently to iron hydroxides, As is released to solution, resulting in elevated As concentrations in the headwater stream adjacent to the site. The As-bearing iron hydroxide is the dominant solid phase reservoir of As in mine tailings and stream sediment, as suggested by sequential extraction. This As-bearing iron hydroxide is stable under the aerobic and pH 4–6 conditions at the site; however, changes in biogeochemical conditions resulting from sediment burial or future remedial efforts, which could promote As release from this reservoir due to reductive dissolution, should be avoided

Quantum Watermarking Scheme Based on INEQR

Science.gov (United States)

Zhou, Ri-Gui; Zhou, Yang; Zhu, Changming; Wei, Lai; Zhang, Xiafen; Ian, Hou

2018-04-01

Quantum watermarking technology protects copyright by embedding invisible quantum signal in quantum multimedia data. In this paper, a watermarking scheme based on INEQR was presented. Firstly, the watermark image is extended to achieve the requirement of embedding carrier image. Secondly, the swap and XOR operation is used on the processed pixels. Since there is only one bit per pixel, XOR operation can achieve the effect of simple encryption. Thirdly, both the watermark image extraction and embedding operations are described, where the key image, swap operation and LSB algorithm are used. When the embedding is made, the binary image key is changed. It means that the watermark has been embedded. Of course, if the watermark image is extracted, the key's state need detected. When key's state is |1>, this extraction operation is carried out. Finally, for validation of the proposed scheme, both the Signal-to-noise ratio (PSNR) and the security of the scheme are analyzed.

Sequential and parallel image restoration: neural network implementations.

Science.gov (United States)

Figueiredo, M T; Leitao, J N

1994-01-01

Sequential and parallel image restoration algorithms and their implementations on neural networks are proposed. For images degraded by linear blur and contaminated by additive white Gaussian noise, maximum a posteriori (MAP) estimation and regularization theory lead to the same high dimension convex optimization problem. The commonly adopted strategy (in using neural networks for image restoration) is to map the objective function of the optimization problem into the energy of a predefined network, taking advantage of its energy minimization properties. Departing from this approach, we propose neural implementations of iterative minimization algorithms which are first proved to converge. The developed schemes are based on modified Hopfield (1985) networks of graded elements, with both sequential and parallel updating schedules. An algorithm supported on a fully standard Hopfield network (binary elements and zero autoconnections) is also considered. Robustness with respect to finite numerical precision is studied, and examples with real images are presented.

Iris image recognition wavelet filter-banks based iris feature extraction schemes

CERN Document Server

Rahulkar, Amol D

2014-01-01

This book provides the new results in wavelet filter banks based feature extraction, and the classifier in the field of iris image recognition. It provides the broad treatment on the design of separable, non-separable wavelets filter banks, and the classifier. The design techniques presented in the book are applied on iris image analysis for person authentication. This book also brings together the three strands of research (wavelets, iris image analysis, and classifier). It compares the performance of the presented techniques with state-of-the-art available schemes. This book contains the compilation of basic material on the design of wavelets that avoids reading many different books. Therefore, it provide an easier path for the new-comers, researchers to master the contents. In addition, the designed filter banks and classifier can also be effectively used than existing filter-banks in many signal processing applications like pattern classification, data-compression, watermarking, denoising etc.  that will...

Improving performance of breast cancer risk prediction using a new CAD-based region segmentation scheme

Science.gov (United States)

Heidari, Morteza; Zargari Khuzani, Abolfazl; Danala, Gopichandh; Qiu, Yuchen; Zheng, Bin

2018-02-01

Objective of this study is to develop and test a new computer-aided detection (CAD) scheme with improved region of interest (ROI) segmentation combined with an image feature extraction framework to improve performance in predicting short-term breast cancer risk. A dataset involving 570 sets of "prior" negative mammography screening cases was retrospectively assembled. In the next sequential "current" screening, 285 cases were positive and 285 cases remained negative. A CAD scheme was applied to all 570 "prior" negative images to stratify cases into the high and low risk case group of having cancer detected in the "current" screening. First, a new ROI segmentation algorithm was used to automatically remove useless area of mammograms. Second, from the matched bilateral craniocaudal view images, a set of 43 image features related to frequency characteristics of ROIs were initially computed from the discrete cosine transform and spatial domain of the images. Third, a support vector machine model based machine learning classifier was used to optimally classify the selected optimal image features to build a CAD-based risk prediction model. The classifier was trained using a leave-one-case-out based cross-validation method. Applying this improved CAD scheme to the testing dataset, an area under ROC curve, AUC = 0.70+/-0.04, which was significantly higher than using the extracting features directly from the dataset without the improved ROI segmentation step (AUC = 0.63+/-0.04). This study demonstrated that the proposed approach could improve accuracy on predicting short-term breast cancer risk, which may play an important role in helping eventually establish an optimal personalized breast cancer paradigm.

Development of a simple extraction cell with bi-directional continuous flow coupled on-line to ICP-MS for assessment of elemental associations in solid samples

DEFF Research Database (Denmark)

Buanuam, Janya; Tiptanasup, Kasipa; Shiowatana, Juwadee

2006-01-01

A continuous-flow system comprising a novel, custom-built extraction module and hyphenated with inductively coupled plasma-mass spectrometric (ICP-MS) detection is proposed for assessing metal mobilities and geochemical associations in soil compartments as based on using the three step BCR (now...... the Measurements and Testing Programme of the European Commission) sequential extraction scheme. Employing a peristaltic pump as liquid driver, alternate directional flows of the extractants are used to overcome compression of the solid particles within the extraction unit to ensure a steady partitioning flow rate...... and thus to maintain constant operationally defined extraction conditions. The proposed flow set-up is proven to allow for trouble-free handling of soil samples up to 1 g and flow rates ≤ 10 mL min–1. The miniaturized extraction system was coupled to ICP-MS through a flow injection interface in order...

A New Graph Drawing Scheme for Social Network

Directory of Open Access Journals (Sweden)

Eric Ke Wang

2014-01-01

visualization is employed to extract the potential information from the large scale of social network data and present the information briefly as visualized graphs. In the process of information visualization, graph drawing is a crucial part. In this paper, we study the graph layout algorithms and propose a new graph drawing scheme combining multilevel and single-level drawing approaches, including the graph division method based on communities and refining approach based on partitioning strategy. Besides, we compare the effectiveness of our scheme and FM3 in experiments. The experiment results show that our scheme can achieve a clearer diagram and effectively extract the community structure of the social network to be applied to drawing schemes.

Speciation of mercury in soil and sediment by selective solvent and acid extraction

Energy Technology Data Exchange (ETDEWEB)

Han, Y. [Metara Inc., 1225 East Arques Ave, Sunnyvale, CA (United States); Kingston, H.M.; Boylan, H.M.; Rahman, G.M.M.; Shah, S.; Richter, R.C.; Link, D.D.; Bhandari, S. [Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA (United States)

2003-02-01

In order to characterize the mercury hazard in soil, a sequential extraction scheme has been developed to classify mercury species based on their environmental mobility and/or toxicity for either routine lab analysis or on-site screening purposes. The alkyl mercury species and soluble inorganic species that contribute to the major portion of potential mercury toxicity in the soil are extracted by an acidic ethanol solution (2% HCl+10% ethanol solution) from soil matrices as ''mobile and toxic'' species. A High-Performance Liquid Chromatography (HPLC) system coupled with Inductively Coupled Plasma Mass Spectrometry (ICP-MS) detection has been developed to further resolve the species information into soluble inorganic species (Hg{sup 2+}), methylmercury(II) (MeHg{sup +}) and ethylmercury(II) (EtHg{sup +}) species. Alternatively, these species can be separated into ''soluble inorganic mercury'' and ''alkyl mercury'' sub-categories by Solid-Phase Extraction (SPE). A custom Sulfydryl Cotton Fiber (SCF) material is used as the solid phase medium. Optimization of the SCF SPE technique is discussed. Combined with a direct mercury analyzer (DMA-80), the SCF SPE technique is a promising candidate for on-site screening purposes. Following the ethanol extraction, the inorganic mercury species remaining in soil are further divided into ''semi-mobile'' and ''non-mobile'' sub-categories by sequential acid extractions. The ''semi-mobile'' mercury species include mainly elemental mercury (Hg) and mercury-metal amalgams. The non-mobile mercury species mainly include mercuric sulfide (HgS) and mercurous chloride (Hg{sub 2}Cl{sub 2}). (orig.)

Sequential extraction of heavy metals in river sediments of an abandoned pyrite mining area: pollution detection and affinity series

International Nuclear Information System (INIS)

Pagnanelli, F.; Moscardini, E.; Giuliano, V.; Toro, L.

2004-01-01

In this paper heavy metal pollution at an abandoned Italian pyrite mine has been investigated by comparing total concentrations and speciation of heavy metals (Fe, Cu, Mn, Zn, Pb and As) in a red mud sample and a river sediment. Acid digestions show that all the investigated heavy metals present larger concentrations in the sediment than in the tailing. A modified Tessier's procedure has been used to discriminate heavy metal bound to organic fraction from those originally present in the mineral sulphide matrix and to detect a possible trend of metal mobilisation from red mud to river sediment. Sequential extractions on bulk and size fractionated samples denote that sediment samples present larger percent concentrations of the investigated heavy metals in the first extractive steps (I-IV) especially in lower dimension size fractionated samples suggesting that heavy metals in the sediment are significantly bound by superficial adsorption mechanisms. - Capsule: A modified Tessier's procedure, discriminating organic and sulphide bound metals, was used to detect pollutant mobilisation from red mud to river sediment in an abandoned pyrite mine

Rapid and simultaneous determination of neptunium and plutonium isotopes in environmental samples by extraction chromatography using sequential injection analysis and ICP-MS

DEFF Research Database (Denmark)

Qiao, Jixin; Hou, Xiaolin; Roos, Per

2010-01-01

plutonium and neptunium in three reference materials were in agreement with the recommended or literature values at the 0.05 significance level. The developed method is suitable for the analysis of up to 10 g of soil and 20 g of seaweed samples. The extraction chromatographic separation within the SI system......This paper reports an automated analytical method for rapid and simultaneous determination of plutonium isotopes (239Pu and 240Pu) and neptunium (237Np) in environmental samples. An extraction chromatographic column packed with TrisKem TEVA® resin was incorporated in a sequential injection (SI...... for a single sample takes less than 1.5 h. As compared to batchwise procedures, the developed method significantly improves the analysis efficiency, reduces the labor intensity and expedites the simultaneous determination of plutonium and neptunium as demanded in emergency actions....

Trace metal distribution in the Arosa estuary (N.W. Spain): The application of a recently developed sequential extraction procedure for metal partitioning

International Nuclear Information System (INIS)

Santamaria-Fernandez, Rebeca; Cave, Mark R.; Hill, Steve J.

2006-01-01

A study of the trace metal distribution in sediment samples from the Galician coast (Spain) has been performed. A multielement extraction method optimised via experimental design has been employed. The method uses centrifugation to pass the extractant solution at varying pH, through the sediment sample. The sequential leaches were collected and analysed by ICP-AES. Chemometric approaches were utilised to identify the composition of the physico-chemical components in order to characterise the sample. The samples collected at different sites could be classified according to their differences in metal bio-availability and important information regarding element distribution within the physico-chemical components is given. The method has proved to be a quick and reliable way to evaluate sediment samples for environmental geochemistry analysis. In addition, this approach has potential as fast screening method for the bio-availability of metals in the environment

Ab-initio validation of a simple heuristic expression for the sequential-double-ionization contribution to the double ionization of helium by ultrashort XUV pulses

International Nuclear Information System (INIS)

Liu, Aihua; Thumm, Uwe

2015-01-01

We study two-photon double ionization of helium by short XUV pulses by numerically solving the time-dependent Schrodinger equation in full dimensionality within a finite-element discrete-variable-representation scheme. Based on the emission asymmetries in joint photoelectron angular distributions, we identify sequential and non-sequential contributions to two-photon double ionization for ultrashort pulses whose spectrum overlaps the sequential (ħω > 54.4 eV) and non-sequential (39.5 eV < ħω < 54.4 eV) double-ionization regimes. (paper)

Estimating the extractability of potentially toxic metals in urban soils: A comparison of several extracting solutions

International Nuclear Information System (INIS)

Madrid, F.; Reinoso, R.; Florido, M.C.; Diaz Barrientos, E.; Ajmone-Marsan, F.; Davidson, C.M.; Madrid, L.

2007-01-01

Metals released by the extraction with aqua regia, EDTA, dilute HCl and sequential extraction (SE) by the BCR protocol were studied in urban soils of Sevilla, Torino, and Glasgow. By multivariate analysis, the amounts of Cu, Pb and Zn liberated by any method were statistically associated with one another, whereas other metals were not. The mean amounts of all metals extracted by HCl and by SE were well correlated, but SE was clearly underestimated by HCl. Individual data for Cu, Pb and Zn by both methods were correlated only if each city was considered separately. Other metals gave poorer relationships. Similar conclusions were reached comparing EDTA and HCl, with much lower values for EDTA. Dilute HCl extraction cannot thus be recommended for general use as alternative to BCR SE in urban soils. - Dilute HCl extraction is tested as an alternative to the BCR sequential extraction in urban soils

Moving mesh generation with a sequential approach for solving PDEs

DEFF Research Database (Denmark)

In moving mesh methods, physical PDEs and a mesh equation derived from equidistribution of an error metrics (so-called the monitor function) are simultaneously solved and meshes are dynamically concentrated on steep regions (Lim et al., 2001). However, the simultaneous solution procedure...... a simple and robust moving mesh algorithm in one or multidimension. In this study, we propose a sequential solution procedure including two separate parts: prediction step to obtain an approximate solution to a next time level (integration of physical PDEs) and regriding step at the next time level (mesh...... generation and solution interpolation). Convection terms, which appear in physical PDEs and a mesh equation, are discretized by a WENO (Weighted Essentially Non-Oscillatory) scheme under the consrvative form. This sequential approach is to keep the advantages of robustness and simplicity for the static...

Sequential segmental classification of feline congenital heart disease.

Science.gov (United States)

Scansen, Brian A; Schneider, Matthias; Bonagura, John D

2015-12-01

Feline congenital heart disease is less commonly encountered in veterinary medicine than acquired feline heart diseases such as cardiomyopathy. Understanding the wide spectrum of congenital cardiovascular disease demands a familiarity with a variety of lesions, occurring both in isolation and in combination, along with an appreciation of complex nomenclature and variable classification schemes. This review begins with an overview of congenital heart disease in the cat, including proposed etiologies and prevalence, examination approaches, and principles of therapy. Specific congenital defects are presented and organized by a sequential segmental classification with respect to their morphologic lesions. Highlights of diagnosis, treatment options, and prognosis are offered. It is hoped that this review will provide a framework for approaching congenital heart disease in the cat, and more broadly in other animal species based on the sequential segmental approach, which represents an adaptation of the common methodology used in children and adults with congenital heart disease. Copyright © 2015 Elsevier B.V. All rights reserved.

Optimized variational analysis scheme of single Doppler radar wind data

Science.gov (United States)

Sasaki, Yoshi K.; Allen, Steve; Mizuno, Koki; Whitehead, Victor; Wilk, Kenneth E.

1989-01-01

A computer scheme for extracting singularities has been developed and applied to single Doppler radar wind data. The scheme is planned for use in real-time wind and singularity analysis and forecasting. The method, known as Doppler Operational Variational Extraction of Singularities is outlined, focusing on the principle of local symmetry. Results are presented from the application of the scheme to a storm-generated gust front in Oklahoma on May 28, 1987.

The sequential-separation of Tc, Np and residual U from metal ions -30% TBP/0.5% TOA/n-dodecane extraction system

International Nuclear Information System (INIS)

Lee, I. H.; Kim, S. H.; Lim, J. K.; Kim, K. W.; Kwon, S. K.

2002-01-01

This study on the enhancement of Tc extraction and the selective separation of Tc, Np and residual U by means of adding a small amount of tri-n-octylamine(TOA) in the 30% vol. tributyl phosphate(TBP)/n-dodecane was performed. Co-extraction of Tc, Np and U from the 10 components simulated radwaste solution containing the 0.005M-K 2 Cr 2 O 7 as an oxidant of Np by 30% TBP/0.5% TOA, and selective stripping of Tc, Np and U from the loaded organic phase were investigated, and their operation conditions were evaluated. Tc, Np and U was effectively co-extracted at O/A=1 and 1M HNO 3 . In this condition, the co-extraction yields of Tc, Np and U were 81.9%, 86%, 89.2%, respectively and those of Am, Eu, Nd, Mo and Fe were below 5%. For the selective stripping of extracted Tc, Np and U, however, sequentially 5M HNO 3 and O/A=1 for Tc, reduction of Np(VI) to Np(V) with 0.175M n-butyraldehyde (NBA) and O/A=2 for Np, and 0.15M Na 2 CO 3 and O/A=1 for U were used, respectively. In this case, 79% of Tc(co-stripping of less than 4% Np and U), 84% of Np(co-stripping of about 6% U), above 99% of U could be recovered, respectively

Sequential extraction results in improved proteome profiling of medicinal plant Pinellia ternata tubers, which contain large amounts of high-abundance proteins.

Directory of Open Access Journals (Sweden)

Xiaolin Wu

Full Text Available Pinellia ternata tuber is one of the well-known Chinese traditional medicines. In order to understand the pharmacological properties of tuber proteins, it is necessary to perform proteome analysis of P. ternata tubers. However, a few high-abundance proteins (HAPs, mainly mannose-binding lectin (agglutinin, exist in aggregates of various sizes in the tubers and seriously interfere with proteome profiling by two-dimensional electrophoresis (2-DE. Therefore, selective depletion of these HAPs is a prerequisite for enhanced proteome analysis of P. ternata tubers. Based on differential protein solubility, we developed a novel protocol involving two sequential extractions for depletion of some HAPs and prefractionation of tuber proteins prior to 2-DE. The first extraction using 10% acetic acid selectively extracted acid-soluble HAPs and the second extraction using the SDS-containing buffer extracted remaining acid-insoluble proteins. After application of the protocol, 2-DE profiles of P. ternata tuber proteins were greatly improved and more protein spots were detected, especially low-abundance proteins. Moreover, the subunit composition of P. ternata lectin was analyzed by electrophoresis. Native lectin consists of two hydrogen-bonded subunits (11 kDa and 25 kDa and the 11 kDa subunit was a glycoprotein. Subsequently, major HAPs in the tubers were analyzed by mass spectrometry, with nine protein spots being identified as lectin isoforms. The methodology was easy to perform and required no specialized apparatus. It would be useful for proteome analysis of other tuber plants of Araceae.

Sequential cloud-point extraction for toxicological screening analysis of medicaments in human plasma by high pressure liquid chromatography with diode array detector.

Science.gov (United States)

Madej, Katarzyna; Persona, Karolina; Wandas, Monika; Gomółka, Ewa

2013-10-18

A complex extraction system with the use of cloud-point extraction technique (CPE) was developed for sequential isolation of basic and acidic/neutral medicaments from human plasma/serum, screened by HPLC/DAD method. Eight model drugs (paracetamol, promazine, chlorpromazine, amitriptyline, salicyclic acid, opipramol, alprazolam and carbamazepine) were chosen for the study of optimal CPE conditions. The CPE technique consists in partition of an aqueous sample with addition of a surfactant into two phases: micelle-rich phase with the isolated compounds and water phase containing a surfactant below the critical micellar concentration, mainly under influence of temperature change. The proposed extraction system consists of two chief steps: isolation of basic compounds (from pH 12) and then isolation of acidic/neutral compounds (from pH 6) using surfactant Triton X-114 as the extraction medium. Extraction recovery varied from 25.2 to 107.9% with intra-day and inter-day precision (RSD %) ranged 0.88-1087 and 5.32-17.96, respectively. The limits of detection for the studied medicaments at λ 254nm corresponded to therapeutic or low toxic plasma concentration levels. Usefulness of the proposed CPE-HPLC/DAD method for toxicological drug screening was tested via its application to analysis of two serum samples taken from patients suspected of drug overdosing. Published by Elsevier B.V.

On Lattice Sequential Decoding for Large MIMO Systems

KAUST Repository

Ali, Konpal S.

2014-04-01

Due to their ability to provide high data rates, Multiple-Input Multiple-Output (MIMO) wireless communication systems have become increasingly popular. Decoding of these systems with acceptable error performance is computationally very demanding. In the case of large overdetermined MIMO systems, we employ the Sequential Decoder using the Fano Algorithm. A parameter called the bias is varied to attain different performance-complexity trade-offs. Low values of the bias result in excellent performance but at the expense of high complexity and vice versa for higher bias values. We attempt to bound the error by bounding the bias, using the minimum distance of a lattice. Also, a particular trend is observed with increasing SNR: a region of low complexity and high error, followed by a region of high complexity and error falling, and finally a region of low complexity and low error. For lower bias values, the stages of the trend are incurred at lower SNR than for higher bias values. This has the important implication that a low enough bias value, at low to moderate SNR, can result in low error and low complexity even for large MIMO systems. Our work is compared against Lattice Reduction (LR) aided Linear Decoders (LDs). Another impressive observation for low bias values that satisfy the error bound is that the Sequential Decoder\\'s error is seen to fall with increasing system size, while it grows for the LR-aided LDs. For the case of large underdetermined MIMO systems, Sequential Decoding with two preprocessing schemes is proposed – 1) Minimum Mean Square Error Generalized Decision Feedback Equalization (MMSE-GDFE) preprocessing 2) MMSE-GDFE preprocessing, followed by Lattice Reduction and Greedy Ordering. Our work is compared against previous work which employs Sphere Decoding preprocessed using MMSE-GDFE, Lattice Reduction and Greedy Ordering. For the case of large systems, this results in high complexity and difficulty in choosing the sphere radius. Our schemes

A novel quantum steganography scheme for color images

Science.gov (United States)

Li, Panchi; Liu, Xiande

In quantum image steganography, embedding capacity and security are two important issues. This paper presents a novel quantum steganography scheme using color images as cover images. First, the secret information is divided into 3-bit segments, and then each 3-bit segment is embedded into the LSB of one color pixel in the cover image according to its own value and using Gray code mapping rules. Extraction is the inverse of embedding. We designed the quantum circuits that implement the embedding and extracting process. The simulation results on a classical computer show that the proposed scheme outperforms several other existing schemes in terms of embedding capacity and security.

Iodine speciation in coastal and inland bathing waters and seaweeds extracts using a sequential injection standard addition flow-batch method.

Science.gov (United States)

Santos, Inês C; Mesquita, Raquel B R; Bordalo, Adriano A; Rangel, António O S S

2015-02-01

The present work describes the development of a sequential injection standard addition method for iodine speciation in bathing waters and seaweeds extracts without prior sample treatment. Iodine speciation was obtained by assessing the iodide and iodate content, the two inorganic forms of iodine in waters. For the determination of iodide, an iodide ion selective electrode (ISE) was used. The indirect determination of iodate was based on the spectrophotometric determination of nitrite (Griess reaction). For the iodate measurement, a mixing chamber was employed (flow batch approach) to explore the inherent efficient mixing, essential for the indirect determination of iodate. The application of the standard addition method enabled detection limits of 0.14 µM for iodide and 0.02 µM for iodate, together with the direct introduction of the target water samples, coastal and inland bathing waters. The results obtained were in agreement with those obtained by ICP-MS and a colorimetric reference procedure. Recovery tests also confirmed the accuracy of the developed method which was effectively applied to bathing waters and seaweed extracts. Copyright © 2014 Elsevier B.V. All rights reserved.

Reliability assessment of restructured power systems using reliability network equivalent and pseudo-sequential simulation techniques

International Nuclear Information System (INIS)

Ding, Yi; Wang, Peng; Goel, Lalit; Billinton, Roy; Karki, Rajesh

2007-01-01

This paper presents a technique to evaluate reliability of a restructured power system with a bilateral market. The proposed technique is based on the combination of the reliability network equivalent and pseudo-sequential simulation approaches. The reliability network equivalent techniques have been implemented in the Monte Carlo simulation procedure to reduce the computational burden of the analysis. Pseudo-sequential simulation has been used to increase the computational efficiency of the non-sequential simulation method and to model the chronological aspects of market trading and system operation. Multi-state Markov models for generation and transmission systems are proposed and implemented in the simulation. A new load shedding scheme is proposed during generation inadequacy and network congestion to minimize the load curtailment. The IEEE reliability test system (RTS) is used to illustrate the technique. (author)

Sequential automated fusion/extraction chromatography methodology for the dissolution of uranium in environmental samples for mass spectrometric determination

Energy Technology Data Exchange (ETDEWEB)

Milliard, Alex; Durand-Jezequel, Myriam [Laboratoire de Radioecologie, Departement de chimie, Universite Laval, 1045 Avenue de la Medecine, Quebec, QC, G1V 0A6 (Canada); Lariviere, Dominic, E-mail: dominic.lariviere@chm.ulaval.ca [Laboratoire de Radioecologie, Departement de chimie, Universite Laval, 1045 Avenue de la Medecine, Quebec, QC, G1V 0A6 (Canada)

2011-01-17

An improved methodology has been developed, based on dissolution by automated fusion followed by extraction chromatography for the detection and quantification of uranium in environmental matrices by mass spectrometry. A rapid fusion protocol (<8 min) was investigated for the complete dissolution of various samples. It could be preceded, if required, by an effective ashing procedure using the M4 fluxer and a newly designed platinum lid. Complete dissolution of the sample was observed and measured using standard reference materials (SRMs) and experimental data show no evidence of cross-contamination of crucibles when LiBO{sub 2}/LiBr melts were used. The use of a M4 fusion unit also improved repeatability in sample preparation over muffle furnace fusion. Instrumental issues originating from the presence of high salt concentrations in the digestate after lithium metaborate fusion was also mitigated using an extraction chromatography (EXC) protocol aimed at removing lithium and interfering matrix constituants prior to the elution of uranium. The sequential methodology, which can be performed simultaneously on three samples, requires less than 20 min per sample for fusion and separation. It was successfully coupled to inductively coupled plasma mass spectrometry (ICP-MS) achieving detection limits below 100 pg kg{sup -1} for 5-300 mg of sample.

Remediation of soils contaminated with particulate depleted uranium by multi stage chemical extraction.

Science.gov (United States)

Crean, Daniel E; Livens, Francis R; Sajih, Mustafa; Stennett, Martin C; Grolimund, Daniel; Borca, Camelia N; Hyatt, Neil C

2013-12-15

Contamination of soils with depleted uranium (DU) from munitions firing occurs in conflict zones and at test firing sites. This study reports the development of a chemical extraction methodology for remediation of soils contaminated with particulate DU. Uranium phases in soils from two sites at a UK firing range, MOD Eskmeals, were characterised by electron microscopy and sequential extraction. Uranium rich particles with characteristic spherical morphologies were observed in soils, consistent with other instances of DU munitions contamination. Batch extraction efficiencies for aqueous ammonium bicarbonate (42-50% total DU extracted), citric acid (30-42% total DU) and sulphuric acid (13-19% total DU) were evaluated. Characterisation of residues from bicarbonate-treated soils by synchrotron microfocus X-ray diffraction and X-ray absorption spectroscopy revealed partially leached U(IV)-oxide particles and some secondary uranyl-carbonate phases. Based on these data, a multi-stage extraction scheme was developed utilising leaching in ammonium bicarbonate followed by citric acid to dissolve secondary carbonate species. Site specific U extraction was improved to 68-87% total U by the application of this methodology, potentially providing a route to efficient DU decontamination using low cost, environmentally compatible reagents. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Sequential Total Variation Denoising for the Extraction of Fetal ECG from Single-Channel Maternal Abdominal ECG.

Science.gov (United States)

Lee, Kwang Jin; Lee, Boreom

2016-07-01

Fetal heart rate (FHR) is an important determinant of fetal health. Cardiotocography (CTG) is widely used for measuring the FHR in the clinical field. However, fetal movement and blood flow through the maternal blood vessels can critically influence Doppler ultrasound signals. Moreover, CTG is not suitable for long-term monitoring. Therefore, researchers have been developing algorithms to estimate the FHR using electrocardiograms (ECGs) from the abdomen of pregnant women. However, separating the weak fetal ECG signal from the abdominal ECG signal is a challenging problem. In this paper, we propose a method for estimating the FHR using sequential total variation denoising and compare its performance with that of other single-channel fetal ECG extraction methods via simulation using the Fetal ECG Synthetic Database (FECGSYNDB). Moreover, we used real data from PhysioNet fetal ECG databases for the evaluation of the algorithm performance. The R-peak detection rate is calculated to evaluate the performance of our algorithm. Our approach could not only separate the fetal ECG signals from the abdominal ECG signals but also accurately estimate the FHR.

Determination of Cd, Pb, Zn and Cu in Sediment Compartments by Sequential Extraction and Isotope Dilution Inductively Coupled Plasma Mass Spectrometry (ID-ICP-MS

Directory of Open Access Journals (Sweden)

Gardolinski Paulo C. F. C.

2002-01-01

Full Text Available Trace concentrations of Cd, Cu, Pb and Zn in four different sediment fractions extracted in sequence were determined by isotope dilution inductively coupled mass spectrometry (IDICPMS. The metals from each fraction were extracted following the sequential extraction procedure recommended by the Bureau Commun de Référence (BCR of the Commission of the European Communities. As an alternative to external calibration, the elements were quantified by spiking the extracted solutions with 112Cd, 63Cu, 208Pb and 66Zn and application of isotope dilution. The proposed approach was applied to a sample collected from a lake and two standard reference materials, NIST2704 river sediment from the National Institute of Standards & Technology and the BCR-277 estuarine sediment. Detection limits, for each extracted solution, varied from 0.31 to 0.53 mug L¹ for Cd, 0.92 to 2.9 mug L¹ for Cu, 0.22 to 1.1 mug L¹ for Pb and 1.3 to 7.6 mug L¹ for Zn. The sum of the metals concentration in the different fractions was compatible with 95% confidence level found amounts obtained with complete digestion of the samples and with the certified values of the standard reference materials.

Effect of chemical pollution on forms of 137Cs, 90Sr and 239,240Pu in arctic soil studied by sequential extraction.

Science.gov (United States)

Puhakainen, M; Riekkinen, I; Heikkinen, T; Jaakkola, T; Steinnes, E; Rissanen, K; Suomela, M; Thørring, H

2001-01-01

The aim of the present study was to determine the forms of 137Cs, 90Sr and 239,240Pu occurring in different soil horizons using sequential extraction of samples taken from four sites located along a pollution gradient from the copper-nickel smelter at Monchegorsk in the Kola Peninsula, Russia, and from a reference site in Finnish Lapland in 1997. A selective sequential-leaching procedure was employed using a modification of the method of Tessier, Cambell and Bisson ((1979). Analytical Chemistry, 51, 844-851). For 137Cs the organic (O) and uppermost mineral (E1) layer were studied, for 90Sr and 239,240Pu only the uppermost organic layer (Of). The fraction of 137Cs occurring in readily exchangeable form in the organic layer was about 50% at the reference site and decreased as a function of pollution, being 15% at the most polluted site in the Kola Peninsula. There was a clear positive correlation in the O layer between the distance from the smelter and the percentage of 137Cs extracted in the readily exchangeable fraction (Spearman correlation rsp = 0.7805, p = 0.0001), whereas in the E1 layer no correlation was evident. The distribution of 90Sr in the Of layer was similar at all sites, with the highest amounts occurring in exchangeable form and bound to organic matter, whereas stable Sr showed a somewhat different distribution with the highest amount in the oxide fraction. Most of the 239,240Pu was bound to organic matter. Chemical pollution affected the exchangeable fraction of 239,240Pu, which was about 1% at the most polluted site and 4-6% at the other sites.

Hypotension Risk Prediction via Sequential Contrast Patterns of ICU Blood Pressure.

Science.gov (United States)

Ghosh, Shameek; Feng, Mengling; Nguyen, Hung; Li, Jinyan

2016-09-01

Acute hypotension is a significant risk factor for in-hospital mortality at intensive care units. Prolonged hypotension can cause tissue hypoperfusion, leading to cellular dysfunction and severe injuries to multiple organs. Prompt medical interventions are thus extremely important for dealing with acute hypotensive episodes (AHE). Population level prognostic scoring systems for risk stratification of patients are suboptimal in such scenarios. However, the design of an efficient risk prediction system can significantly help in the identification of critical care patients, who are at risk of developing an AHE within a future time span. Toward this objective, a pattern mining algorithm is employed to extract informative sequential contrast patterns from hemodynamic data, for the prediction of hypotensive episodes. The hypotensive and normotensive patient groups are extracted from the MIMIC-II critical care research database, following an appropriate clinical inclusion criteria. The proposed method consists of a data preprocessing step to convert the blood pressure time series into symbolic sequences, using a symbolic aggregate approximation algorithm. Then, distinguishing subsequences are identified using the sequential contrast mining algorithm. These subsequences are used to predict the occurrence of an AHE in a future time window separated by a user-defined gap interval. Results indicate that the method performs well in terms of the prediction performance as well as in the generation of sequential patterns of clinical significance. Hence, the novelty of sequential patterns is in their usefulness as potential physiological biomarkers for building optimal patient risk stratification systems and for further clinical investigation of interesting patterns in critical care patients.

Trends and perspectives of flow injection/sequential injection on-line sample-pretreatment schemes coupled to ETAAS

DEFF Research Database (Denmark)

Wang, Jianhua; Hansen, Elo Harald

2005-01-01

Flow injection (FI) analysis, the first generation of this technique, became in the 1990s supplemented by its second generation, sequential injection (SI), and most recently by the third generation (i.e.,Lab-on-Valve). The dominant role played by FI in automatic, on-line, sample pretreatments in ...

Optimal Face-Iris Multimodal Fusion Scheme

Directory of Open Access Journals (Sweden)

Omid Sharifi

2016-06-01

Full Text Available Multimodal biometric systems are considered a way to minimize the limitations raised by single traits. This paper proposes new schemes based on score level, feature level and decision level fusion to efficiently fuse face and iris modalities. Log-Gabor transformation is applied as the feature extraction method on face and iris modalities. At each level of fusion, different schemes are proposed to improve the recognition performance and, finally, a combination of schemes at different fusion levels constructs an optimized and robust scheme. In this study, CASIA Iris Distance database is used to examine the robustness of all unimodal and multimodal schemes. In addition, Backtracking Search Algorithm (BSA, a novel population-based iterative evolutionary algorithm, is applied to improve the recognition accuracy of schemes by reducing the number of features and selecting the optimized weights for feature level and score level fusion, respectively. Experimental results on verification rates demonstrate a significant improvement of proposed fusion schemes over unimodal and multimodal fusion methods.

Sequential Ensembles Tolerant to Synthetic Aperture Radar (SAR Soil Moisture Retrieval Errors

Directory of Open Access Journals (Sweden)

Ju Hyoung Lee

2016-04-01

Full Text Available Due to complicated and undefined systematic errors in satellite observation, data assimilation integrating model states with satellite observations is more complicated than field measurements-based data assimilation at a local scale. In the case of Synthetic Aperture Radar (SAR soil moisture, the systematic errors arising from uncertainties in roughness conditions are significant and unavoidable, but current satellite bias correction methods do not resolve the problems very well. Thus, apart from the bias correction process of satellite observation, it is important to assess the inherent capability of satellite data assimilation in such sub-optimal but more realistic observational error conditions. To this end, time-evolving sequential ensembles of the Ensemble Kalman Filter (EnKF is compared with stationary ensemble of the Ensemble Optimal Interpolation (EnOI scheme that does not evolve the ensembles over time. As the sensitivity analysis demonstrated that the surface roughness is more sensitive to the SAR retrievals than measurement errors, it is a scope of this study to monitor how data assimilation alters the effects of roughness on SAR soil moisture retrievals. In results, two data assimilation schemes all provided intermediate values between SAR overestimation, and model underestimation. However, under the same SAR observational error conditions, the sequential ensembles approached a calibrated model showing the lowest Root Mean Square Error (RMSE, while the stationary ensemble converged towards the SAR observations exhibiting the highest RMSE. As compared to stationary ensembles, sequential ensembles have a better tolerance to SAR retrieval errors. Such inherent nature of EnKF suggests an operational merit as a satellite data assimilation system, due to the limitation of bias correction methods currently available.

Supercritical Fluid Extraction of Plutonium and Americium from Soil

International Nuclear Information System (INIS)

Fox, R.V.; Mincher, B.J.

2002-01-01

Supercritical fluid extraction (SFE) of plutonium and americium from soil was successfully demonstrated using supercritical fluid carbon dioxide solvent augmented with organophosphorus and beta-diketone complexants. Spiked Idaho soils were chemically and radiologically characterized, then extracted with supercritical fluid carbon dioxide at 2,900 psi and 65 C containing varying concentrations of tributyl phosphate (TBP) and thenoyltrifluoroacetone (TTA). A single 45 minute SFE with 2.7 mol% TBP and 3.2 mol% TTA provided as much as 88% ± 6.0 extraction of americium and 69% ± 5.0 extraction of plutonium. Use of 5.3 mol% TBP with 6.8 mol% of the more acidic beta-diketone hexafluoroacetylacetone (HFA) provided 95% ± 3.0 extraction of americium and 83% ± 5.0 extraction of plutonium in a single 45 minute SFE at 3,750 psi and 95 C. Sequential chemical extraction techniques were used to chemically characterize soil partitioning of plutonium and americium in pre-SFE soil samples. Sequential chemical extraction techniques demonstrated that spiked plutonium resides primarily (76.6%) in the sesquioxide fraction with minor amounts being absorbed by the oxidizable fraction (10.6%) and residual fractions (12.8%). Post-SFE soils subjected to sequential chemical extraction characterization demonstrated that 97% of the oxidizable, 78% of the sesquioxide and 80% of the residual plutonium could be removed using SFE. These preliminary results show that SFE may be an effective solvent extraction technique for removal of actinide contaminants from soil

Comparison of first pass bolus AIFs extracted from sequential 18F-FDG PET and DSC-MRI of mice

International Nuclear Information System (INIS)

Evans, Eleanor; Sawiak, Stephen J.; Ward, Alexander O.; Buonincontri, Guido; Hawkes, Robert C.; Adrian Carpenter, T.

2014-01-01

Accurate kinetic modelling of in vivo physiological function using positron emission tomography (PET) requires determination of the tracer time–activity curve in plasma, known as the arterial input function (AIF). The AIF is usually determined by invasive blood sampling methods, which are prohibitive in murine studies due to low total blood volumes. Extracting AIFs from PET images is also challenging due to large partial volume effects (PVE). We hypothesise that in combined PET with magnetic resonance imaging (PET/MR), a co-injected bolus of MR contrast agent and PET ligand can be tracked using fast MR acquisitions. This protocol would allow extraction of a MR AIF from MR contrast agent concentration–time curves, at higher spatial and temporal resolution than an image-derived PET AIF. A conversion factor could then be applied to the MR AIF for use in PET kinetic analysis. This work has compared AIFs obtained from sequential DSC-MRI and PET with separate injections of gadolinium contrast agent and 18 F-FDG respectively to ascertain the technique′s validity. An automated voxel selection algorithm was employed to improve MR AIF reproducibility. We found that MR and PET AIFs displayed similar character in the first pass, confirmed by gamma variate fits (p<0.02). MR AIFs displayed reduced PVE compared to PET AIFs, indicating their potential use in PET/MR studies

Adaptive Online Sequential ELM for Concept Drift Tackling

Directory of Open Access Journals (Sweden)

Arif Budiman

2016-01-01

Full Text Available A machine learning method needs to adapt to over time changes in the environment. Such changes are known as concept drift. In this paper, we propose concept drift tackling method as an enhancement of Online Sequential Extreme Learning Machine (OS-ELM and Constructive Enhancement OS-ELM (CEOS-ELM by adding adaptive capability for classification and regression problem. The scheme is named as adaptive OS-ELM (AOS-ELM. It is a single classifier scheme that works well to handle real drift, virtual drift, and hybrid drift. The AOS-ELM also works well for sudden drift and recurrent context change type. The scheme is a simple unified method implemented in simple lines of code. We evaluated AOS-ELM on regression and classification problem by using concept drift public data set (SEA and STAGGER and other public data sets such as MNIST, USPS, and IDS. Experiments show that our method gives higher kappa value compared to the multiclassifier ELM ensemble. Even though AOS-ELM in practice does not need hidden nodes increase, we address some issues related to the increasing of the hidden nodes such as error condition and rank values. We propose taking the rank of the pseudoinverse matrix as an indicator parameter to detect “underfitting” condition.

OPTIMIZATION OF AGGREGATION AND SEQUENTIAL-PARALLEL EXECUTION MODES OF INTERSECTING OPERATION SETS

Directory of Open Access Journals (Sweden)

G. М. Levin

2016-01-01

Full Text Available A mathematical model and a method for the problem of optimization of aggregation and of sequential- parallel execution modes of intersecting operation sets are proposed. The proposed method is based on the two-level decomposition scheme. At the top level the variant of aggregation for groups of operations is selected, and at the lower level the execution modes of operations are optimized for a fixed version of aggregation.

Multivariate Analyses and Evaluation of Heavy Metals by Chemometric BCR Sequential Extraction Method in Surface Sediments from Lingdingyang Bay, South China

Directory of Open Access Journals (Sweden)

Linglong Cao

2015-04-01

Full Text Available Sediments in estuary areas are recognized as the ultimate reservoirs for numerous contaminants, e.g., toxic metals. Multivariate analyses by chemometric evaluation were performed to classify metal ions (Cu, Zn, As, Cr, Pb, Ni and Cd in superficial sediments from Lingdingyang Bay and to determine whether or not there were potential contamination risks based on the BCR sequential extraction scheme. The results revealed that Cd was mainly in acid-soluble form with an average of 75.99% of its total contents and thus of high potential availability, indicating significant anthropogenic sources, while Cr, As, Ni were enriched in the residual fraction which could be considered as the safest ingredients to the environment. According to the proportion of secondary to primary phases (KRSP, Cd had the highest bioavailable fraction and represented high or very high risk, followed by Pb and Cu with medium risks in most of samples. The combined evaluation of the Pollution Load Index (PLI and the mean Effect Range Median Quotient (mERM-Q highlighted that the greatest potential environmental risk area was in the northwest of Lingdingyang Bay. Almost all of the sediments had a 21% probability of toxicity. Additionally, Principal Component Analysis (PCA revealed that the survey region was significantly affected by two main sources of anthropogenic contributions: PC1 showed increased loadings of variables in acid-soluble and reducible fractions that were consistent with the input from industrial wastes (such as manufacturing, metallurgy, chemical industry and domestic sewages; PC2 was characterized by increased loadings of variables in residual fraction that could be attributed to leaching and weathering of parent rocks. The results obtained demonstrated the need for appropriate remediation measures to alleviate soil pollution problem due to the more aggregation of potentially risky metals. Therefore, it is of crucial significance to implement the targeted

Human visual system automatically encodes sequential regularities of discrete events.

Science.gov (United States)

Kimura, Motohiro; Schröger, Erich; Czigler, István; Ohira, Hideki

2010-06-01

For our adaptive behavior in a dynamically changing environment, an essential task of the brain is to automatically encode sequential regularities inherent in the environment into a memory representation. Recent studies in neuroscience have suggested that sequential regularities embedded in discrete sensory events are automatically encoded into a memory representation at the level of the sensory system. This notion is largely supported by evidence from investigations using auditory mismatch negativity (auditory MMN), an event-related brain potential (ERP) correlate of an automatic memory-mismatch process in the auditory sensory system. However, it is still largely unclear whether or not this notion can be generalized to other sensory modalities. The purpose of the present study was to investigate the contribution of the visual sensory system to the automatic encoding of sequential regularities using visual mismatch negativity (visual MMN), an ERP correlate of an automatic memory-mismatch process in the visual sensory system. To this end, we conducted a sequential analysis of visual MMN in an oddball sequence consisting of infrequent deviant and frequent standard stimuli, and tested whether the underlying memory representation of visual MMN generation contains only a sensory memory trace of standard stimuli (trace-mismatch hypothesis) or whether it also contains sequential regularities extracted from the repetitive standard sequence (regularity-violation hypothesis). The results showed that visual MMN was elicited by first deviant (deviant stimuli following at least one standard stimulus), second deviant (deviant stimuli immediately following first deviant), and first standard (standard stimuli immediately following first deviant), but not by second standard (standard stimuli immediately following first standard). These results are consistent with the regularity-violation hypothesis, suggesting that the visual sensory system automatically encodes sequential

Zinc fractionation in contaminated soils by sequential and single extractions: influence of soil properties and zinc content.

Science.gov (United States)

Voegelin, Andreas; Tokpa, Gerome; Jacquat, Olivier; Barmettler, Kurt; Kretzschmar, Ruben

2008-01-01

We studied the fractionation of zinc (Zn) in 49 contaminated soils as influenced by Zn content and soil properties using a seven-step sequential extraction procedure (F1: NH4NO3; F2: NH4-acetate, pH 6; F3: NH3OHCl, pH 6; F4: NH4-EDTA, pH 4.6; F5: NH4-oxalate, pH 3; F6: NH4-oxalate/ascorbic acid, pH 3; F7: residual). The soils had developed from different geologic materials and covered a wide range in soil pH (4.0-7.3), organic C content (9.3-102 g kg(-1)), and clay content (38-451 g kg(-1)). Input of aqueous Zn with runoff water from electricity towers during 26 to 74 yr resulted in total soil Zn contents of 3.8 to 460 mmol kg(-1). In acidic soils (n = 24; pH soils (n = 25; pH > or =6.0), most Zn was extracted in the mobilizable fraction (F2) and the intermediate fractions (F4 and F5). The extractability of Zn increased with increasing Zn contamination of the soils. The sum of mobile (F1) and mobilizable (F2) Zn was independent of soil pH, the ratio of Zn in F1 over F1+F2 plotted against soil pH, exhibited the typical shape of a pH sorption edge and markedly increased from pH 6 to pH 5, reflecting the increasing lability of mobilizable Zn with decreasing soil pH. In conclusion, the extractability of Zn from soils contaminated with aqueous Zn after decades of aging under field conditions systematically varied with soil pH and Zn content. The same trends are expected to apply to aqueous Zn released from decomposing Zn-bearing contaminants, such as sewage sludge or smelter slag. The systematic trends in Zn fractionation with varying soil pH and Zn content indicate the paramount effect of these two factors on molecular scale Zn speciation. Further research is required to characterize the link between the fractionation and speciation of Zn and to determine how Zn loading and soil physicochemical properties affect Zn speciation in soils.

Sequential fractionation and differences in binding forms of risk elements in spinach biomass

Czech Academy of Sciences Publication Activity Database

Pavlíková, D.; Pavlík, Milan; Vašíčková, Soňa; Száková, J.; Tlustoš, P.; Balík, J.

2005-01-01

Roč. 12, 1/2 (2005), s. 101-108 ISSN 1231-7098 R&D Projects: GA MZe(CZ) QF4063 Institutional research plan: CEZ:AV0Z40550506 Keywords : sequential extraction * spinach * risk elements Subject RIV: CC - Organic Chemistry

Applying the sequential neural-network approximation and orthogonal array algorithm to optimize the axial-flow cooling system for rapid thermal processes

International Nuclear Information System (INIS)

Hung, Shih-Yu; Shen, Ming-Ho; Chang, Ying-Pin

2009-01-01

The sequential neural-network approximation and orthogonal array (SNAOA) were used to shorten the cooling time for the rapid cooling process such that the normalized maximum resolved stress in silicon wafer was always below one in this study. An orthogonal array was first conducted to obtain the initial solution set. The initial solution set was treated as the initial training sample. Next, a back-propagation sequential neural network was trained to simulate the feasible domain to obtain the optimal parameter setting. The size of the training sample was greatly reduced due to the use of the orthogonal array. In addition, a restart strategy was also incorporated into the SNAOA so that the searching process may have a better opportunity to reach a near global optimum. In this work, we considered three different cooling control schemes during the rapid thermal process: (1) downward axial gas flow cooling scheme; (2) upward axial gas flow cooling scheme; (3) dual axial gas flow cooling scheme. Based on the maximum shear stress failure criterion, the other control factors such as flow rate, inlet diameter, outlet width, chamber height and chamber diameter were also examined with respect to cooling time. The results showed that the cooling time could be significantly reduced using the SNAOA approach

Experimental investigation of a control scheme for a zero-detuning resonant sideband extraction interferometer for next-generation gravitational-wave detectors

Energy Technology Data Exchange (ETDEWEB)

Kawazoe, Fumiko; Sugamoto, Akio [Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo 112-8610 (Japan); Leonhardt, Volker; Sato, Shuichi; Yamazaki, Toshitaka; Fukushima, Mitsuhiro; Kawamura, Seiji [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka-shi, Tokyo 181-8588 (Japan); Miyakawa, Osamu [LIGO Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Somiya, Kentaro [Max-Planck-Institut fuer Gravitationsphysik, Am Muehlenberg 1, 14476 Potsdam (Germany); Morioka, Tomoko [University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Nishizawa, Atsushi [Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501 (Japan)], E-mail: fumiko.kawazoe@aei.mpg.de

2008-10-07

Some next-generation gravitational-wave detectors, such as the American Advanced LIGO project and the Japanese LCGT project, plan to use power recycled resonant sideband extraction (RSE) interferometers for their interferometer's optical configuration. A power recycled zero-detuning (PRZD) RSE interferometer, which is the default design for LCGT, has five main length degrees of freedom that need to be controlled in order to operate a gravitational-wave detector. This task is expected to be very challenging because of the complexity of optical configuration. A new control scheme for a PRZD RSE interferometer has been developed and tested with a prototype interferometer. The PRZD RSE interferometer was successfully locked with the control scheme. It is the first experimental demonstration of a PRZD RSE interferometer with suspended test masses. The result serves as an important step for the operation of LCGT.

Experimental investigation of a control scheme for a zero-detuning resonant sideband extraction interferometer for next-generation gravitational-wave detectors

International Nuclear Information System (INIS)

Kawazoe, Fumiko; Sugamoto, Akio; Leonhardt, Volker; Sato, Shuichi; Yamazaki, Toshitaka; Fukushima, Mitsuhiro; Kawamura, Seiji; Miyakawa, Osamu; Somiya, Kentaro; Morioka, Tomoko; Nishizawa, Atsushi

2008-01-01

Some next-generation gravitational-wave detectors, such as the American Advanced LIGO project and the Japanese LCGT project, plan to use power recycled resonant sideband extraction (RSE) interferometers for their interferometer's optical configuration. A power recycled zero-detuning (PRZD) RSE interferometer, which is the default design for LCGT, has five main length degrees of freedom that need to be controlled in order to operate a gravitational-wave detector. This task is expected to be very challenging because of the complexity of optical configuration. A new control scheme for a PRZD RSE interferometer has been developed and tested with a prototype interferometer. The PRZD RSE interferometer was successfully locked with the control scheme. It is the first experimental demonstration of a PRZD RSE interferometer with suspended test masses. The result serves as an important step for the operation of LCGT

A sequential approach to control gas for the extraction of multi-gassy coal seams from traditional gas well drainage to mining-induced stress relief

International Nuclear Information System (INIS)

Kong, Shengli; Cheng, Yuanping; Ren, Ting; Liu, Hongyong

2014-01-01

Highlights: • The gas reservoirs characteristics are measured and analyzed. • A sequential approach to control gas of multi-gassy coal seams is proposed. • The design of gas drainage wells has been improved. • The utilization ways of different concentrations of gas production are shown. - Abstract: As coal resources become exhausted in shallow mines, mining operations will inevitably progress from shallow depth to deep and gassy seams due to increased demands for more coal products. However, during the extraction process of deeper and gassier coal seams, new challenges to current gas control methods have emerged, these include the conflict between the coal mine safety and the economic benefits, the difficulties in reservoirs improvement, as well as the imbalance between pre-gas drainage, roadway development and coal mining. To solve these problems, a sequential approach is introduced in this paper. Three fundamental principles are proposed: the mining-induced stress relief effect of the first-mined coalbed should be sufficient to improve the permeability of the others; the coal resource of the first-mined seams must be abundant to guarantee the economic benefits; the arrangement of the vertical wells must fit the underground mining panel. Tunlan coal mine is taken as a typical example to demonstrate the effectiveness of this approach. The approach of integrating surface coalbed methane (CBM) exploitation with underground gas control technologies brings three major benefits: the improvement of underground coal mining safety, the implementation of CBM extraction, and the reduction of greenhouse gas emissions. This practice could be used as a valuable example for other coal mines having similar geological conditions

Comparison of first pass bolus AIFs extracted from sequential {sup 18}F-FDG PET and DSC-MRI of mice

Energy Technology Data Exchange (ETDEWEB)

Evans, Eleanor, E-mail: ee244@cam.ac.uk [Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0QQ (United Kingdom); Sawiak, Stephen J. [Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0QQ (United Kingdom); Behavioural and Clinical Neuroscience Institute, Department of Experimental Psychology, University of Cambridge, Cambridge, CB2 3EB (United Kingdom); Ward, Alexander O.; Buonincontri, Guido; Hawkes, Robert C.; Adrian Carpenter, T. [Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0QQ (United Kingdom)

2014-01-11

Accurate kinetic modelling of in vivo physiological function using positron emission tomography (PET) requires determination of the tracer time–activity curve in plasma, known as the arterial input function (AIF). The AIF is usually determined by invasive blood sampling methods, which are prohibitive in murine studies due to low total blood volumes. Extracting AIFs from PET images is also challenging due to large partial volume effects (PVE). We hypothesise that in combined PET with magnetic resonance imaging (PET/MR), a co-injected bolus of MR contrast agent and PET ligand can be tracked using fast MR acquisitions. This protocol would allow extraction of a MR AIF from MR contrast agent concentration–time curves, at higher spatial and temporal resolution than an image-derived PET AIF. A conversion factor could then be applied to the MR AIF for use in PET kinetic analysis. This work has compared AIFs obtained from sequential DSC-MRI and PET with separate injections of gadolinium contrast agent and {sup 18}F-FDG respectively to ascertain the technique′s validity. An automated voxel selection algorithm was employed to improve MR AIF reproducibility. We found that MR and PET AIFs displayed similar character in the first pass, confirmed by gamma variate fits (p<0.02). MR AIFs displayed reduced PVE compared to PET AIFs, indicating their potential use in PET/MR studies.

Sequential Extractions and Toxicity Potential of Trace Metals Absorbed into Airborne Particles in an Urban Atmosphere of Southwestern Nigeria

Directory of Open Access Journals (Sweden)

Emmanuel Gbenga Olumayede

2018-01-01

Full Text Available The paper investigates the hypothesis that biotoxicities of trace metals depend not only on the concentration as expressed by the total amount, but also on their geochemical fractions and bioavailability. Airborne particles were collected using SKC Air Check XR 5000 high volume Sampler at a human breathing height of 1.5–2.0 meters, during the dry season months from November 2014 to March 2015 at different locations in Akure (7°10′N and 5°15′E. The geochemical-based sequential extractions were performed on the particles using a series of increasingly stringent solutions selected to extract metals (Cd, Cu, Cr, Ni, Pb, Zn, and Mn into four operational geochemical phases—exchangeable, reducible, organic, and residual—and then quantified using an Atomic Absorption Spectrophotometer. The results showed metals concentration of order Pb > Cr > Cd > Zn > Ni > Cu > Mn. However, most metals in the samples exist in nonmobile fractions: exchangeable (6.43–16.2%, reducible (32.58–47.39%, organic (4.73–9.88%, and residual (18.28–27.53%. The pollution indices show ingestion as the leading route of metal exposure, with noncarcinogenic (HQ and cancer risk (HI for humans in the area being higher than 1.0 × 10−4, indicating a health threat.

A Spatial Domain Quantum Watermarking Scheme

International Nuclear Information System (INIS)

Wei Zhan-Hong; Chen Xiu-Bo; Niu Xin-Xin; Yang Yi-Xian; Xu Shu-Jiang

2016-01-01

This paper presents a spatial domain quantum watermarking scheme. For a quantum watermarking scheme, a feasible quantum circuit is a key to achieve it. This paper gives a feasible quantum circuit for the presented scheme. In order to give the quantum circuit, a new quantum multi-control rotation gate, which can be achieved with quantum basic gates, is designed. With this quantum circuit, our scheme can arbitrarily control the embedding position of watermark images on carrier images with the aid of auxiliary qubits. Besides reversely acting the given quantum circuit, the paper gives another watermark extracting algorithm based on quantum measurements. Moreover, this paper also gives a new quantum image scrambling method and its quantum circuit. Differ from other quantum watermarking schemes, all given quantum circuits can be implemented with basic quantum gates. Moreover, the scheme is a spatial domain watermarking scheme, and is not based on any transform algorithm on quantum images. Meanwhile, it can make sure the watermark be secure even though the watermark has been found. With the given quantum circuit, this paper implements simulation experiments for the presented scheme. The experimental result shows that the scheme does well in the visual quality and the embedding capacity. (paper)

Sequential Power-Dependence Theory

NARCIS (Netherlands)

Buskens, Vincent; Rijt, Arnout van de

2008-01-01

Existing methods for predicting resource divisions in laboratory exchange networks do not take into account the sequential nature of the experimental setting. We extend network exchange theory by considering sequential exchange. We prove that Sequential Power-Dependence Theory—unlike

Fractionation characterization and speciation of heavy metals in composts and compost and compost-amended soils

International Nuclear Information System (INIS)

Lwegbue, C. M.A.; Emuh, F.N.; Isirimah, N.O.; Egun, A.C.

2007-01-01

Speciation of heavy metals in soils determines the availability for metals for plant uptake and potential for contamination of groundwater following application of composts to agricultural lands. Methods used to characterize heavy metals in solid phase of composts and compost amended soils include physical fractionation and chemical extraction. Chemical extraction schemes are most frequently used approach to fractionate trace metals in soils, sewage sludge and composts. Several variations exist in the sequential extraction procedures. These variations include reagent types, strength, volume and extraction time. A main drawback shared by all sequential extraction schemes is that the procedures themselves are complex and time consuming. This setback has been overcome by the use of ultrasound accelerated extraction which reduce the extraction time for the entire extraction steps to about 90 minutes allowing composting process to be monitored more frequently which help to provide detailed understanding of the partitioning behaviour of heavy metals. Inspite of the variability the sequential extraction schemes, they all aimed at correlating each fraction with the mobility and plant availability of each metal. Several studies have shown that phase association of heavy metal in composts include water-soluble, exchangeable, precipitated as discrete phases, co-precipitate in metal oxides and adsorbed or complexed by organic ligands and residual forms. The phase association and solubility of metals changes over composting time thereby altering metal availability. It is apparent that the positive effects of resulting from compost application far outweigh the negative effect, but more research is needed on a wide range of municipal solid waste compost with more precise determination of the fate of municipal solid waste compost applied trace metals in the environment. (author)

Mobility of arsenic, cadmium and zinc in a multi-element contaminated soil profile assessed by in-situ soil pore water sampling, column leaching and sequential extraction

International Nuclear Information System (INIS)

Beesley, Luke; Moreno-Jimenez, Eduardo; Clemente, Rafael; Lepp, Nicholas; Dickinson, Nicholas

2010-01-01

Three methods for predicting element mobility in soils have been applied to an iron-rich soil, contaminated with arsenic, cadmium and zinc. Soils were collected from 0 to 30 cm, 30 to 70 cm and 70 to 100 cm depths in the field and soil pore water was collected at different depths from an adjacent 100 cm deep trench. Sequential extraction and a column leaching test in the laboratory were compared to element concentrations in pore water sampled directly from the field. Arsenic showed low extractability, low leachability and occurred at low concentrations in pore water samples. Cadmium and zinc were more labile and present in higher concentrations in pore water, increasing with soil depth. Pore water sampling gave the best indication of short term element mobility when field conditions were taken into account, but further extraction and leaching procedures produced a fuller picture of element dynamics, revealing highly labile Cd deep in the soil profile. - Mobility of arsenic, cadmium and zinc in a polluted soil can be realistically interpreted by in-situ soil pore water sampling.

Insights into physicochemical and functional properties of polysaccharides sequentially extracted from onion (Allium cepa L.).

Science.gov (United States)

Zhu, Dan-Ye; Ma, Yi-Long; Wang, Cai-Hong; Wang, Hao; Ren, Ya-Fei; Zhang, Jian-Guo; Thakur, Kiran; Wei, Zhao-Jun

2017-12-01

Onion polysaccharides (ACLP) were sequentially extracted with four different solvents (hot buffer, chelating agent, dilute alkaline and concentrated alkaline) and obtained four fractions, named as HBSS, CHSS, DASS and CASS, respectively. The present studies characterized the ACLP concerning its physicochemical and functional properties. Monosaccharides analysis revealed that mannose (81.68%) was the dominant sugar in HBSS and galactose (67.59%) was the most in CASS. Similarly, CHSS and DASS possessed mannose and galactose as major sugar, which were 25.80% and 31.37%, 20.33% and 33.96%, respectively. The obtained molecular weight of ACLPs were 7.702×10 3 (HBSS), 4.690×10 3 (CHSS), 4.943×10 3 (DASS) and 1.390×10 3 kDa (CASS). CASS resulted in the strongest solubility, fat-binding capacity, foam capacity and foam stability whereas, HBSS showed the highest thermal stability. DASS showed the best hygroscopicity and the best moisture retention was obtained by CHSS. Subsequently, the emulsifying activity and emulsifying stability were the highest for HBSS and the longest for of CASS, respectively. The rheological properties of CHSS exhibited the largest viscosity. Our results indicated that all factions could be considered as functional polysaccharides according to their respective characteristics, which have vast potential in food production. Copyright © 2017 Elsevier B.V. All rights reserved.

Learning Orthographic Structure With Sequential Generative Neural Networks.

Science.gov (United States)

Testolin, Alberto; Stoianov, Ivilin; Sperduti, Alessandro; Zorzi, Marco

2016-04-01

Learning the structure of event sequences is a ubiquitous problem in cognition and particularly in language. One possible solution is to learn a probabilistic generative model of sequences that allows making predictions about upcoming events. Though appealing from a neurobiological standpoint, this approach is typically not pursued in connectionist modeling. Here, we investigated a sequential version of the restricted Boltzmann machine (RBM), a stochastic recurrent neural network that extracts high-order structure from sensory data through unsupervised generative learning and can encode contextual information in the form of internal, distributed representations. We assessed whether this type of network can extract the orthographic structure of English monosyllables by learning a generative model of the letter sequences forming a word training corpus. We show that the network learned an accurate probabilistic model of English graphotactics, which can be used to make predictions about the letter following a given context as well as to autonomously generate high-quality pseudowords. The model was compared to an extended version of simple recurrent networks, augmented with a stochastic process that allows autonomous generation of sequences, and to non-connectionist probabilistic models (n-grams and hidden Markov models). We conclude that sequential RBMs and stochastic simple recurrent networks are promising candidates for modeling cognition in the temporal domain. Copyright © 2015 Cognitive Science Society, Inc.

Effect of different extracting solvents on antioxidant activity and phenolic compounds of a fruit and vegetable residue flour

Directory of Open Access Journals (Sweden)

Mônica C. P. Santos

2016-01-01

Full Text Available In order to quantify antioxidant capacity in food products, several methods have been proposed over the years. Among them, DPPH radical is widely used to determine the antioxidant capacity of different substrates. However, it is known that different types of extractants, providing different responses, can extract a variety of bioactive compounds. Besides, storage time seems to interfere in the stability of these substances. Integral use of fruits and vegetables has been proposed along the years as a means of reducing environmental pollution and give a better destination to by-products from food industries. Thus, this study aimed to evaluate the antioxidant potential of a fruit and vegetables residue flour (FVR with sequential and non-sequential extraction, in order to evaluate its antioxidant activity and phenolic compounds. And these compounds stability during storage of 180 days. It was observed that in non-sequential extraction, water was able to reduce by 74% the radical; however, at sequential extraction process, using six different extractors, each one was able to reduce at least 40% of DPPH. The total soluble phenolic contents in sequential extraction were 22.49 ± 1.59 mg GAE/g FVR on the first day and 5.35 ± 0.32 mg GAE/g FVR after 180 days.

Susceptibility of Aedes aegypti pupae to neem seed kernal extracts ...

African Journals Online (AJOL)

Azadirachta indica) seed kernel extracts (NSKE) on Aedes aegypti. The neem seed kernel powder was sequentially extracted with hexane, benzene, ethyl acetate, acetone, DMSO, 2-propanol, ethanol, methanol and dstiledwater.

Evolution from sequential decay to simultaneous multifragmentation with increasing beam energy

International Nuclear Information System (INIS)

He Zhiyong; Jin Genming; Li Zuyu

1996-01-01

Two-fragment correlation functions have been measured for 40 Ar + 197 Au collisions at E/A = 25 MeV. Based on the three-body trajectory calculation, a mean emission time of τ∼450 fm/c for light fragments was extracted from the measured correlation functions. This result suggests that the sequential decay occurs at this energy

Sequential separation of copper(II), silver(I) and gold(III) (Paper No. RA-10)

International Nuclear Information System (INIS)

Amlani, A.M.; Turel, Z.R.

1990-02-01

A sequential separation procedure for the separation of Cu(II), Ag(I) and Au(III) employing solvent extraction technique of these three elements with 1, 2, 3-benzotriazole into chloroform under different experimental conditions has been developed. (author). 1 tab

Rapid Determination of Plutonium Isotopes in Environmental Samples Using Sequential Injection Extraction Chromatography and Detection by Inductively Coupled Plasma Mass Spectrometry

DEFF Research Database (Denmark)

Qiao, Jixin; Hou, Xiaolin; Roos, Per

2009-01-01

This article presents an automated method for the rapid determination of 239Pu and 240Pu in various environmental samples. The analytical method involves the in-line separation of Pu isotopes using extraction chromatography (TEVA) implemented in a sequential injection (SI) network followed...... by detection of isolated analytes with inductively coupled plasma mass spectrometry (ICP-MS). The method has been devised for the determination of Pu isotopes at environmentally relevant concentrations, whereby it has been successfully applied to the analyses of large volumes/amounts of samples, for example......, 100−200 g of soil and sediment, 20 g of seaweed, and 200 L of seawater following analyte preconcentration. The investigation of the separation capability of the assembled SI system revealed that up to 200 g of soil or sediment can be treated using a column containing about 0.70 g of TEVA resin...

Better together: reduced compliance after sequential versus simultaneous bilateral hearing aids fitting.

Science.gov (United States)

Lavie, Limor; Banai, Karen; Attias, Joseph; Karni, Avi

2014-03-01

The purpose of this study was to determine the effects of sequential versus simultaneous bilateral hearing aids fitting on patient compliance. Thirty-six older adults with hearing impairment participated in this study. Twelve were fitted with bilateral hearing aids simultaneously. The remaining participants were fitted sequentially: One hearing aid (to the left or to the right ear) was used initially; 1 month later, the other ear was also fitted with a hearing aid for bilateral use. Self-reports on usefulness and compliance were elicited after the first and second months of hearing aid use. In addition, the number of hours the hearing aids were used was extracted from the data loggings of each device. Simultaneous fitting resulted in high levels of compliance and consistent usage throughout the study period. Sequential fitting resulted in abrupt reduction in compliance and hours of use once the second hearing aid was added, both in the clinical scoring and in the data loggings. Simultaneous fitting of bilateral hearing aids results in better compliance compared with sequential fitting. The addition of a second hearing aid after a relatively short period of monaural use may lead to inconsistent use of both hearing aids.

Exploiting Sequential Injection on-line Solvent Extraction/Back Extraction with Detection by ETAAS or ICPMS

DEFF Research Database (Denmark)

Wang, Jianhua; Hansen, Elo Harald

presents an on-line SI-solvent extraction/back extraction procedure used in connection with detection by either ETAAS or ICPMS. Incorporating two newly designed dual-conical gravitational phase separators, its performance is demonstrated for the determination of various metals in reference materials.......Electrothermal atomic absorption spectrometry (ETAAS) and inductively coupled plasma mass spectrometry (ICPMS) are highly sensitive techniques for trace metal analyses. Nevertheless, separation/preconcentration procedures are often called for in order to overcome their inherent low matrix...... tolerances. With detection by ETAAS, separation/preconcentration by solvent extraction has enjoyed much use. However, this approach is not necessarily the optimal one since introduction of organic eluates directly into the graphite tube might lead to deteriorated reproducibility and lower sensitivity...

Sequential solvent extraction for the modes of occurrence of selenium in coals of different ranks from the Huaibei Coalfield, China

Directory of Open Access Journals (Sweden)

Wang Lei

2007-12-01

Full Text Available Abstract Forms of selenium in bituminous coal, anthracite, and cokeite (natural coke from Huaibei Coalfield, Anhui, China, have been determined by sequential solvent extraction. The selenium content in bulk samples is 4.0, 2.4, and 2.0 μg/g in bituminous coal, anthracite, and cokeite, respectively. The six forms of selenium determined by six-step solvent extraction are water-leachable, ion-exchangeable, organic matter-associated, carbonate-associated, silicate-associated, and sulfide-associated. The predominant forms of selenium in bituminous coal are organic matter-associated (39.0%, sulfide-associated (21.1%, and silicate bound (31.8%; these three forms account for 92% of the total. The organic matter bound-selenium decrease dramatically from bituminous coal (39.0% to anthracite (11.6% and to cokeite (0%, indicating that organic matter bound selenium is converted to other forms during metamorphism of the coal, most likely sulfide-form. The sulfide-associated form increased remarkably from bituminous coal (21.1% to anthracite (50.4% and cokeite (54.5%, indicating the formation of selenium sulfide, possibly in pyrite during the transformation of bituminous coal to anthracite and cokeite. The silicate-associated selenium in bituminous coal (31.8% is much higher than that in anthracite (16.4% and cokeite (15.8%, indicating that silicate-associated selenium is partly converted to sulfide during metamorphism.

Sequential decoding of intramuscular EMG signals via estimation of a Markov model.

Science.gov (United States)

Monsifrot, Jonathan; Le Carpentier, Eric; Aoustin, Yannick; Farina, Dario

2014-09-01

This paper addresses the sequential decoding of intramuscular single-channel electromyographic (EMG) signals to extract the activity of individual motor neurons. A hidden Markov model is derived from the physiological generation of the EMG signal. The EMG signal is described as a sum of several action potentials (wavelet) trains, embedded in noise. For each train, the time interval between wavelets is modeled by a process that parameters are linked to the muscular activity. The parameters of this process are estimated sequentially by a Bayes filter, along with the firing instants. The method was tested on some simulated signals and an experimental one, from which the rates of detection and classification of action potentials were above 95% with respect to the reference decomposition. The method works sequentially in time, and is the first to address the problem of intramuscular EMG decomposition online. It has potential applications for man-machine interfacing based on motor neuron activities.

Simultaneous optimization of sequential IMRT plans

International Nuclear Information System (INIS)

Popple, Richard A.; Prellop, Perri B.; Spencer, Sharon A.; Santos, Jennifer F. de los; Duan, Jun; Fiveash, John B.; Brezovich, Ivan A.

2005-01-01

Radiotherapy often comprises two phases, in which irradiation of a volume at risk for microscopic disease is followed by a sequential dose escalation to a smaller volume either at a higher risk for microscopic disease or containing only gross disease. This technique is difficult to implement with intensity modulated radiotherapy, as the tolerance doses of critical structures must be respected over the sum of the two plans. Techniques that include an integrated boost have been proposed to address this problem. However, clinical experience with such techniques is limited, and many clinicians are uncomfortable prescribing nonconventional fractionation schemes. To solve this problem, we developed an optimization technique that simultaneously generates sequential initial and boost IMRT plans. We have developed an optimization tool that uses a commercial treatment planning system (TPS) and a high level programming language for technical computing. The tool uses the TPS to calculate the dose deposition coefficients (DDCs) for optimization. The DDCs were imported into external software and the treatment ports duplicated to create the boost plan. The initial, boost, and tolerance doses were specified and used to construct cost functions. The initial and boost plans were optimized simultaneously using a gradient search technique. Following optimization, the fluence maps were exported to the TPS for dose calculation. Seven patients treated using sequential techniques were selected from our clinical database. The initial and boost plans used to treat these patients were developed independently of each other by dividing the tolerance doses proportionally between the initial and boost plans and then iteratively optimizing the plans until a summation that met the treatment goals was obtained. We used the simultaneous optimization technique to generate plans that met the original planning goals. The coverage of the initial and boost target volumes in the simultaneously optimized

Extraction of uranium and lead from mixed waste debris using a variety of metal/ligand complexes

International Nuclear Information System (INIS)

Needham, D.A.; Duran, B.L.; Ehler, D.S.; Sauer, N.N.

1997-01-01

To ensure the safety of our Nation's nuclear stockpile, Los Alamos National Laboratory is in the process of constructing the DARHT (Dual Axis Radiographic Hydrodynamic Test) facility. DARHT will examine the effects of aging and the stability of our stockpile. Contained testing will be phased in to reduce the impact of these tests, which contain depleted uranium, on our environment. The main focus of this research is to develop a treatment scheme for the recovery of depleted uranium and lead from shot debris that will result from these tests. The goals of this research are to optimize the conditions on a bench scale using a commercially available water soluble polymer to bind the lead and a variety of metal/ligand complexes such as 4,5-dihydroxy-1,3-benzene-disulfonic acid, dithionite, sodium carbonate/bicarbonate, and sodium hypochlorite to bind the uranium. Studies were conducted on a mixture of debris, such as wood, cable, paper towels, and tubing that contained both uranium and lead ranging in concentration from 10-1000's of ppm of contaminants. Experiments were done varying combinations and successions of extractant solutions as well as a number of sequential extractions. Studies show that a mixture of sodium hypochlorite and carbonate removed 90+% of both uranium and lead. We then focused on a separation scheme for the lead and uranium

Dynamics of a Rydberg hydrogen atom near a metal surface in the electron-extraction scheme

Energy Technology Data Exchange (ETDEWEB)

Iñarrea, Manuel [Área de Física Aplicada, Universidad de La Rioja, Logroño (Spain); Lanchares, Víctor [Departamento de Matemáticas y Computación, Universidad de La Rioja, Logroño, La Rioja (Spain); Palacián, Jesús [Departamento de Ingeniería Matemática e Informática, Universidad Pública de Navarra, Pamplona (Spain); Pascual, Ana I. [Departamento de Matemáticas y Computación, Universidad de La Rioja, Logroño, La Rioja (Spain); Salas, J. Pablo, E-mail: josepablo.salas@unirioja.es [Área de Física Aplicada, Universidad de La Rioja, Logroño (Spain); Yanguas, Patricia [Departamento de Ingeniería Matemática e Informática, Universidad Pública de Navarra, Pamplona (Spain)

2015-01-23

We study the classical dynamics of a Rydberg hydrogen atom near a metal surface in the presence of a constant electric field in the electron-extraction situation [1], e.g., when the field attracts the electron to the vacuum. From a dynamical point of view, this field configuration provides a dynamics richer than in the usual ion-extraction scheme, because, depending on the values of field and the atom–surface distance, the atom can be ionized only towards the metal surface, only to the vacuum or to the both sides. The evolution of the phase space structure as a function of the atom–surface distance is explored in the bound regime of the atom. In the high energy regime, the ionization mechanism is also investigated. We find that the classical results of this work are in good agreement with the results obtained in the wave-packet propagation study carried out by So et al. [1]. - Highlights: • We study a classical hydrogen atom near a metal surface plus a electric field. • We explore the phase space structure as a function of the field strength. • We find most of the electronic orbits are oriented along the field direction. • We study the ionization of the atom for several atom–surface distances. • This classical study is in good agreement with the quantum results.

The Bacterial Sequential Markov Coalescent.

Science.gov (United States)

De Maio, Nicola; Wilson, Daniel J

2017-05-01

Bacteria can exchange and acquire new genetic material from other organisms directly and via the environment. This process, known as bacterial recombination, has a strong impact on the evolution of bacteria, for example, leading to the spread of antibiotic resistance across clades and species, and to the avoidance of clonal interference. Recombination hinders phylogenetic and transmission inference because it creates patterns of substitutions (homoplasies) inconsistent with the hypothesis of a single evolutionary tree. Bacterial recombination is typically modeled as statistically akin to gene conversion in eukaryotes, i.e. , using the coalescent with gene conversion (CGC). However, this model can be very computationally demanding as it needs to account for the correlations of evolutionary histories of even distant loci. So, with the increasing popularity of whole genome sequencing, the need has emerged for a faster approach to model and simulate bacterial genome evolution. We present a new model that approximates the coalescent with gene conversion: the bacterial sequential Markov coalescent (BSMC). Our approach is based on a similar idea to the sequential Markov coalescent (SMC)-an approximation of the coalescent with crossover recombination. However, bacterial recombination poses hurdles to a sequential Markov approximation, as it leads to strong correlations and linkage disequilibrium across very distant sites in the genome. Our BSMC overcomes these difficulties, and shows a considerable reduction in computational demand compared to the exact CGC, and very similar patterns in simulated data. We implemented our BSMC model within new simulation software FastSimBac. In addition to the decreased computational demand compared to previous bacterial genome evolution simulators, FastSimBac provides more general options for evolutionary scenarios, allowing population structure with migration, speciation, population size changes, and recombination hotspots. FastSimBac is

Exploiting sequential injection on-line solvent extraction/back extraction with detection by ETAAS and ICPMS

DEFF Research Database (Denmark)

Wang, Jianhua; Hansen, Elo Harald

presents an on-line SI-solvent extraction/back extraction procedure used in connection with detection by either ETAAS or ICPMS. Incorporating two newly designed dual-conical gravitational phase separators, its performance is demonstrated for the determination of various metals in reference materials.......Electrothermal atomic absorption spectrometry (ETAAS) and inductively coupled plasma mass spectrometry (ICPMS) are highly sensitive techniques for trace metal analyses. Nevertheless, separation/preconcentration procedures are often called for in order to overcome their inherent low matrix tolerance....... With detection by ETAAS, separation/preconcentration by solvent extraction has enjoyed much use. However, this approach is not necessarily the optimal one since introduction of organic eluates directly into the graphite tube might lead to deteriorated reproducibility and lower sensitivity. And for ICPMS...

Determining the speciation of Zn in soils around the sediment ponds of chemical plants by XRD and XAFS spectroscopy and sequential extraction.

Science.gov (United States)

Minkina, Tatiana; Nevidomskaya, Dina; Bauer, Tatiana; Shuvaeva, Victoria; Soldatov, Alexander; Mandzhieva, Saglara; Zubavichus, Yan; Trigub, Alexander

2018-09-01

For a correct assessment of risk of polluted soil, it is crucial to establish the speciation and mobility of the contaminants. The aim of this study was to investigate the speciation and transformation of Zn in strongly technogenically transformed contaminated Spolic Technosols for a long time in territory of sludge collectors by combining analytical techniques and synchrotron techniques. Sequential fractionation of Zn compounds in studied soils revealed increasing metal mobility. Phyllosilicates and Fe and Mn hydroxides were the main stabilizers of Zn mobility. A high degree of transformation was identified for the composition of the mineral phase in Spolic Technosols by X-ray powder diffraction. Technogenic phases (Zn-containing authigenic minerals) were revealed in Spolic Technosols samples through the analysis of their Zn K-edge EXAFS and XANES spectra. In one of the samples Zn local environment was formed by predominantly oxygen atoms, and in the other one mixed ZnS and ZnO bonding was found. Zn speciation in the studied technogenically transformed soils was due to the composition of pollutants contaminating the floodplain landscapes for a long time, and, second, this is the combination of physicochemical properties controlling the buffer properties of investigated soils. X-ray spectroscopic and X-ray powder diffraction analyses combined with sequential extraction assays is an effective tool to check the affinity of the soil components for heavy metal cations. Copyright © 2018 Elsevier B.V. All rights reserved.

Sequential cloud point extraction for the speciation of mercury in seafood by inductively coupled plasma optical emission spectrometry

Energy Technology Data Exchange (ETDEWEB)

Li Yingjie [Department of Chemistry, Wuhan University, Wuhan 430072 (China); Hu Bin [Department of Chemistry, Wuhan University, Wuhan 430072 (China)], E-mail: binhu@whu.edu.cn

2007-10-15

A novel nonchromatographic speciation technique for the speciation of mercury by sequential cloud point extraction (CPE) combined with inductively coupled plasma optical emission spectrometry (ICP-OES) was developed. The method based on Hg{sup 2+} was complexed with I{sup -} to form HgI{sub 4}{sup 2-}, and the HgI{sub 4}{sup 2-} reacted with the methyl green (MG) cation to form hydrophobic ion-associated complex, and the ion-associated complex was then extracted into the surfactant-rich phase of the non-ionic surfactant octylphenoxypolyethoxyethanol (Triton X-114), which are subsequently separated from methylmercury (MeHg{sup +}) in the initial solution by centrifugation. The surfactant-rich phase containing Hg(II) was diluted with 0.5 mol L{sup -1} HNO{sub 3} for ICP-OES determination. The supernatant is also subjected to the similar CPE procedure for the preconcentration of MeHg{sup +} by the addition of a chelating agent, ammonium pyrrolidine dithiocarbamate (APDC), in order to form water-insolvable complex with MeHg{sup +}. The MeHg{sup +} in the micelles was directly analyzed after disposal as describe above. Under the optimized conditions, the extraction efficiency was 93.5% for Hg(II) and 51.5% for MeHg{sup +} with the enrichment factor of 18.7 for Hg(II) and 10.3 for MeHg{sup +}, respectively. The limits of detection (LODs) were 56.3 ng L{sup -1} for Hg(II) and 94.6 ng L{sup -1} for MeHg{sup +} (as Hg) with the relative standard deviations (RSDs) of 3.6% for Hg(II) and 4.5% for MeHg{sup +} (C = 10 {mu}g L{sup -1}, n = 7), respectively. The developed technique was applied to the speciation of mercury in real seafood samples and the recoveries for spiked samples were found to be in the range of 93.2-108.7%. For validation, a certified reference material of DORM-2 (dogfish muscle) was analyzed and the determined values are in good agreement with the certified values.

Sequential cloud point extraction for the speciation of mercury in seafood by inductively coupled plasma optical emission spectrometry

International Nuclear Information System (INIS)

Li Yingjie; Hu Bin

2007-01-01

A novel nonchromatographic speciation technique for the speciation of mercury by sequential cloud point extraction (CPE) combined with inductively coupled plasma optical emission spectrometry (ICP-OES) was developed. The method based on Hg 2+ was complexed with I - to form HgI 4 2- , and the HgI 4 2- reacted with the methyl green (MG) cation to form hydrophobic ion-associated complex, and the ion-associated complex was then extracted into the surfactant-rich phase of the non-ionic surfactant octylphenoxypolyethoxyethanol (Triton X-114), which are subsequently separated from methylmercury (MeHg + ) in the initial solution by centrifugation. The surfactant-rich phase containing Hg(II) was diluted with 0.5 mol L -1 HNO 3 for ICP-OES determination. The supernatant is also subjected to the similar CPE procedure for the preconcentration of MeHg + by the addition of a chelating agent, ammonium pyrrolidine dithiocarbamate (APDC), in order to form water-insolvable complex with MeHg + . The MeHg + in the micelles was directly analyzed after disposal as describe above. Under the optimized conditions, the extraction efficiency was 93.5% for Hg(II) and 51.5% for MeHg + with the enrichment factor of 18.7 for Hg(II) and 10.3 for MeHg + , respectively. The limits of detection (LODs) were 56.3 ng L -1 for Hg(II) and 94.6 ng L -1 for MeHg + (as Hg) with the relative standard deviations (RSDs) of 3.6% for Hg(II) and 4.5% for MeHg + (C = 10 μg L -1 , n = 7), respectively. The developed technique was applied to the speciation of mercury in real seafood samples and the recoveries for spiked samples were found to be in the range of 93.2-108.7%. For validation, a certified reference material of DORM-2 (dogfish muscle) was analyzed and the determined values are in good agreement with the certified values

Joint multiuser switched diversity and adaptive modulation schemes for spectrum sharing systems

KAUST Repository

Qaraqe, Marwa

2012-12-01

In this paper, we develop multiuser access schemes for spectrum sharing systems whereby secondary users are allowed to share the spectrum with primary users under the condition that the interference observed at the primary receiver is below a predetermined threshold. In particular, we devise two schemes for selecting a user among those that satisfy the interference constraint and achieve an acceptable signal-to-noise ratio level. The first scheme selects the user that reports the best channel quality. In order to alleviate the high feedback load associated with the first scheme, we develop a second scheme based on the concept of switched diversity where the base station scans the users in a sequential manner until an acceptable user is found. In addition to these two selection schemes, we consider two power adaptive settings at the secondary users based on the amount of interference available at the secondary transmitter. In the On/Off power setting, users are allowed to transmit based on whether the interference constraint is met or not, while in the full power adaptive setting, the users are allowed to vary their transmission power to satisfy the interference constraint. Finally, we present numerical results for our proposed algorithms where we show the trade-off between the average spectral efficiency and average feedback load for both schemes. © 2012 IEEE.

Joint multiuser switched diversity and adaptive modulation schemes for spectrum sharing systems

KAUST Repository

Qaraqe, Marwa; Abdallah, Mohamed M.; Serpedin, Erchin; Alouini, Mohamed-Slim; Alnuweiri, Hussein M.

2012-01-01

In this paper, we develop multiuser access schemes for spectrum sharing systems whereby secondary users are allowed to share the spectrum with primary users under the condition that the interference observed at the primary receiver is below a predetermined threshold. In particular, we devise two schemes for selecting a user among those that satisfy the interference constraint and achieve an acceptable signal-to-noise ratio level. The first scheme selects the user that reports the best channel quality. In order to alleviate the high feedback load associated with the first scheme, we develop a second scheme based on the concept of switched diversity where the base station scans the users in a sequential manner until an acceptable user is found. In addition to these two selection schemes, we consider two power adaptive settings at the secondary users based on the amount of interference available at the secondary transmitter. In the On/Off power setting, users are allowed to transmit based on whether the interference constraint is met or not, while in the full power adaptive setting, the users are allowed to vary their transmission power to satisfy the interference constraint. Finally, we present numerical results for our proposed algorithms where we show the trade-off between the average spectral efficiency and average feedback load for both schemes. © 2012 IEEE.

Speciation of Fe(II) and Fe(III) in Contaminated Aquifer Sediments Using Chemical Extraction Techniques

DEFF Research Database (Denmark)

Heron, Gorm; Crouzet, Catherine.; Bourg, Alain C. M.

1994-01-01

The iron mineralogy of aquifer sediments was described by chemical extraction techniques. Single-step extractions including 1 M CaC12, NaAc, oxalate, dithionite, Ti(II1)- EDTA, 0.5 M HC1,5 M HC1, hot 6 M HC1, and a sequential extraction by HI and CrIIHC1 were tested on standard iron minerals...... species are distinguished as AVS (acid volatile sulfide, hot 6 M HC1 extraction) and pyrite (sequential HI and CrIIHC1 extraction). By including a cold 5 M HC1 extraction, the total distribution of the major reactive Fe(I1) and Fe(II1) fractions in aquifer sediments can be assessed....

Maximum power extraction under different vector-control schemes and grid-synchronization strategy of a wind-driven Brushless Doubly-Fed Reluctance Generator.

Science.gov (United States)

Mousa, Mohamed G; Allam, S M; Rashad, Essam M

2018-01-01

This paper proposes an advanced strategy to synchronize the wind-driven Brushless Doubly-Fed Reluctance Generator (BDFRG) to the grid-side terminals. The proposed strategy depends mainly upon determining the electrical angle of the grid voltage, θ v and using the same transformation matrix of both the power winding and grid sides to ensure that the generated power-winding voltage has the same phase-sequence of the grid-side voltage. On the other hand, the paper proposes a vector-control (power-winding flux orientation) technique for maximum wind-power extraction under two schemes summarized as; unity power-factor operation and minimum converter-current. Moreover, a soft-starting method is suggested to avoid the employed converter over-current. The first control scheme is achieved by adjusting the command power-winding reactive power at zero for a unity power-factor operation. However, the second scheme depends on setting the command d-axis control-winding current at zero to maximize the ratio of the generator electromagnetic-torque per the converter current. This enables the system to get a certain command torque under minimum converter current. A sample of the obtained simulation and experimental results is presented to check the effectiveness of the proposed control strategies. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Aloe plant extracts as alternative larvicides for mosquito control ...

African Journals Online (AJOL)

The larvicidal activity of extracts from Aloe turkanensis, Aloe ngongensis and Aloe fibrosa against the common malaria vector, Anopheles gambie, was determined. Ground Aloe leaves from the three plants were sequentially extracted with hexane, ethyl acetate, chloroform, acetone and methanol. Only the ethyl acetate ...

Bioactive Lipidic Extracts from Octopus (Paraoctopus limaculatus: Antimutagenicity and Antiproliferative Studies

Directory of Open Access Journals (Sweden)

Carolina Moreno-Félix

2013-01-01

Full Text Available Fractions from an organic extract from fresh octopus (Paraoctopus limaculatus were studied for biological activities such as antimutagenic and antiproliferative properties using Salmonella tester strains TA98 and TA100 with metabolic activation (S9 and a cancer cell line (B-cell lymphoma, respectively. A chloroform extract obtained from octopus tentacles was sequentially fractionated using thin layer chromatography (TLC, and each fraction was tested for antimutagenic and antiproliferative activities. Organic extract reduced the number of revertants caused by aflatoxin B1 showing a dose-response type of relationship. Sequential TLC fractionation of the active extracts produced several antimutagenic and/or antiproliferative fractions. Based on the results obtained, the isolated fractions obtained from octopus contain compounds with chemoprotective properties that reduce the mutagenicity of AFB1 and proliferation of cancer cell lines.

Sequential Fuzzy Diagnosis Method for Motor Roller Bearing in Variable Operating Conditions Based on Vibration Analysis

Directory of Open Access Journals (Sweden)

Yi Cao

2013-06-01

Full Text Available A novel intelligent fault diagnosis method for motor roller bearings which operate under unsteady rotating speed and load is proposed in this paper. The pseudo Wigner-Ville distribution (PWVD and the relative crossing information (RCI methods are used for extracting the feature spectra from the non-stationary vibration signal measured for condition diagnosis. The RCI is used to automatically extract the feature spectrum from the time-frequency distribution of the vibration signal. The extracted feature spectrum is instantaneous, and not correlated with the rotation speed and load. By using the ant colony optimization (ACO clustering algorithm, the synthesizing symptom parameters (SSP for condition diagnosis are obtained. The experimental results shows that the diagnostic sensitivity of the SSP is higher than original symptom parameter (SP, and the SSP can sensitively reflect the characteristics of the feature spectrum for precise condition diagnosis. Finally, a fuzzy diagnosis method based on sequential inference and possibility theory is also proposed, by which the conditions of the machine can be identified sequentially as well.

Comparison of wavelet based denoising schemes for gear condition monitoring: An Artificial Neural Network based Approach

Science.gov (United States)

Ahmed, Rounaq; Srinivasa Pai, P.; Sriram, N. S.; Bhat, Vasudeva

2018-02-01

Vibration Analysis has been extensively used in recent past for gear fault diagnosis. The vibration signals extracted is usually contaminated with noise and may lead to wrong interpretation of results. The denoising of extracted vibration signals helps the fault diagnosis by giving meaningful results. Wavelet Transform (WT) increases signal to noise ratio (SNR), reduces root mean square error (RMSE) and is effective to denoise the gear vibration signals. The extracted signals have to be denoised by selecting a proper denoising scheme in order to prevent the loss of signal information along with noise. An approach has been made in this work to show the effectiveness of Principal Component Analysis (PCA) to denoise gear vibration signal. In this regard three selected wavelet based denoising schemes namely PCA, Empirical Mode Decomposition (EMD), Neighcoeff Coefficient (NC), has been compared with Adaptive Threshold (AT) an extensively used wavelet based denoising scheme for gear vibration signal. The vibration signals acquired from a customized gear test rig were denoised by above mentioned four denoising schemes. The fault identification capability as well as SNR, Kurtosis and RMSE for the four denoising schemes have been compared. Features extracted from the denoised signals have been used to train and test artificial neural network (ANN) models. The performances of the four denoising schemes have been evaluated based on the performance of the ANN models. The best denoising scheme has been identified, based on the classification accuracy results. PCA is effective in all the regards as a best denoising scheme.

Neuroprotective Effect of Total and Sequential Extract of Scrophularia striata Boiss. in Rat Cerebellar Granule Neurons Following Glutamate- Induced Neurotoxicity: An In-vitro Study

Science.gov (United States)

Salavati, Parvin; Ramezani, Mina; Monsef-Esfahani, Hamid R; Hajiagha, Reza; Parsa, Maliheh; Tavajohi, Shoreh; Ostad, Seyed Nasser

2013-01-01

Neuroprotective effect of the extract from aerial parts of Scrophularia striata Boiss (Scrophulariaceae) was investigated against glutamate-induced neurotoxicity on cultured rat pups Cerebellar Granule Neurons (CGNs). CGNs from 8 days old Sprague-Dawley rat were prepared and cultured. The experiments were performed after 8 days in culture. The plant was collected from the northeastern part (Ruin region) of Iran and air-dried at room temperature. The total extract was prepared with maceration of prepared powder in ethanol 80% for three times. Sequential extracts were obtained using dried and powdered aerial parts with increasingly polar solvents: petroleum ether, chloroform, ethyl acetate and methanol 80% solution. Cultured cells were exposed to 125 μM of glutamate for 12 h following a 24 h of incubation with test fractions at concentration of 10 mcg/mL. Morphological assay was performed using invert light microscope after fixation and staining with haematoxylin. Neuronal viability was measured using MTT assay. Statistical analysis was done using SPSS software. One way analysis of variance (ANOVA) was performed by Tukey post-hoc test. Values were considered statistically significant when p-value ≤ 0.05. Results of this study showed a significant neuroprotective activity of high polarity methanolic fraction of aerial parts of Scrophularia striata against glutamate-induced neurotoxicity in a dosedependent manner. Treatment with 10 mcg/mL of the fractions showed the best result. PMID:24250613

Modelling sequentially scored item responses

NARCIS (Netherlands)

Akkermans, W.

2000-01-01

The sequential model can be used to describe the variable resulting from a sequential scoring process. In this paper two more item response models are investigated with respect to their suitability for sequential scoring: the partial credit model and the graded response model. The investigation is

High-Order Multioperator Compact Schemes for Numerical Simulation of Unsteady Subsonic Airfoil Flow

Science.gov (United States)

Savel'ev, A. D.

2018-02-01

On the basis of high-order schemes, the viscous gas flow over the NACA2212 airfoil is numerically simulated at a free-stream Mach number of 0.3 and Reynolds numbers ranging from 103 to 107. Flow regimes sequentially varying due to variations in the free-stream viscosity are considered. Vortex structures developing on the airfoil surface are investigated, and a physical interpretation of this phenomenon is given.

Extraction and desorption of accessible uranium

International Nuclear Information System (INIS)

Payne, T.

1987-01-01

The proportion of the uranium in natural ore samples which is in isotopic equilibrium with the uranium in the groundwater may be designated accessible uranium, and can be regarded as being in short-term exchange with the aqueous phase. Some of the natural uranium is secured in resistant crystalline minerals, and is described as inaccessible, because it may not be brought into solution unless the mineral is subjected to extreme chemical attack. It is not available for groundwater transport in the short term. An estimate of the proportion of accessible uranium is therefore useful when modeling radionuclide migration. The amount of accessible natural uranium is some uranium ore samples from the Ranger deposit has been determined by combining a sequential extraction with isotopic measurements of the extracted phases. The solid samples were crushed drill core form Ranger S1/146 which had previously been used for uranium adsorption experiments and therefore contained 236 U as well as natural uranium. This Section discusses how the uranium partitioning found with the sequential extraction procedure predicts the leaching behavior of these samples

Programming scheme based optimization of hybrid 4T-2R OxRAM NVSRAM

Science.gov (United States)

Majumdar, Swatilekha; Kingra, Sandeep Kaur; Suri, Manan

2017-09-01

In this paper, we present a novel single-cycle programming scheme for 4T-2R NVSRAM, exploiting pulse engineered input signals. OxRAM devices based on 3 nm thick bi-layer active switching oxide and 90 nm CMOS technology node were used for all simulations. The cell design is implemented for real-time non-volatility rather than last-bit, or power-down non-volatility. Detailed analysis of the proposed single-cycle, parallel RRAM device programming scheme is presented in comparison to the two-cycle sequential RRAM programming used for similar 4T-2R NVSRAM bit-cells. The proposed single-cycle programming scheme coupled with the 4T-2R architecture leads to several benefits such as- possibility of unconventional transistor sizing, 50% lower latency, 20% improvement in SNM and ∼20× reduced energy requirements, when compared against two-cycle programming approach.

Sequential extraction and availability of copper in Cu fungicide-amended vineyard soils from Southern Brazil

International Nuclear Information System (INIS)

Correa Nogueirol, Roberta; Ferracciu Alleoni, Luis Reynaldo; Ribeiro Nachtigall, Gilmar; Wellington de Melo, George

2010-01-01

The continuous use of cupric fungicides in vineyards, mainly copper sulfate (as a component of the bordeaux mixture), has increased Cu concentration in soils to levels near or even above the maximum established by the Commission of Soil Chemistry and Fertility of the States of Santa Catarina and Rio Grande do Sul, Brazil. Besides the total content, the fractions of the element along the soil profile must be known, because the total content of Cu in the soil is not sufficient to express its environmental impact. The objective of this study was to evaluate the variation of Cu contentes along the soil profile and its speciation and partitioning in 29 soil samples from vineyards in the state of Rio Grande do Sul, Brazil. Samples were collected in areas cropped with vineyards older than 15 years that had been frequently treated with the bordeaux mixture. These samples were from Nitosols, Acrisols, Cambisols and Leptosols and were analysed by sequential extractions and several chemical extractors. Soils had diverse chemical and physical attributes: clay content in the plowed layer (0-0.2 m) ranged from 120 to 610 g kg -1 , pH ranged from 5.3 to 7.3 and organic carbon contents varied from 2.9 to 51 g dm -3 . Among the 29 samples, 16 had the total Cu above the maximum limit allowed by the European Community regulations (140 mg kg -1 ). The average amount of Cu bonded to the oxide fraction accounted for 49.5% of the total Cu.

Sequential extraction and availability of copper in Cu fungicide-amended vineyard soils from Southern Brazil

Energy Technology Data Exchange (ETDEWEB)

Correa Nogueirol, Roberta [University of Sao Paulo (ESALQ/USP), C.P. 9, Piracicaba 13418-900, SP (Brazil); Ferracciu Alleoni, Luis Reynaldo, E-mail: alleoni@esalq.usp.br [Department of Soil Science, ESALQ/USP. C.P. 9, Piracicaba 13418-900, SP (Brazil); Ribeiro Nachtigall, Gilmar; Wellington de Melo, George [National Research Center of Grapes and Wine - Embrapa Uva e Vinho, C.P. 130, Bento Goncalves 95700-000, RS (Brazil)

2010-09-15

The continuous use of cupric fungicides in vineyards, mainly copper sulfate (as a component of the bordeaux mixture), has increased Cu concentration in soils to levels near or even above the maximum established by the Commission of Soil Chemistry and Fertility of the States of Santa Catarina and Rio Grande do Sul, Brazil. Besides the total content, the fractions of the element along the soil profile must be known, because the total content of Cu in the soil is not sufficient to express its environmental impact. The objective of this study was to evaluate the variation of Cu contentes along the soil profile and its speciation and partitioning in 29 soil samples from vineyards in the state of Rio Grande do Sul, Brazil. Samples were collected in areas cropped with vineyards older than 15 years that had been frequently treated with the bordeaux mixture. These samples were from Nitosols, Acrisols, Cambisols and Leptosols and were analysed by sequential extractions and several chemical extractors. Soils had diverse chemical and physical attributes: clay content in the plowed layer (0-0.2 m) ranged from 120 to 610 g kg{sup -1}, pH ranged from 5.3 to 7.3 and organic carbon contents varied from 2.9 to 51 g dm{sup -3}. Among the 29 samples, 16 had the total Cu above the maximum limit allowed by the European Community regulations (140 mg kg{sup -1}). The average amount of Cu bonded to the oxide fraction accounted for 49.5% of the total Cu.

EXTRACTION OF SEDIMENT-BOUND CHLORINATED ORGANIC COMPOUNDS: IMPLICATIONS ON FATE AND HAZARD ASSESSMENT. (R825513C007)

Science.gov (United States)

Five methods were used for the extraction of hexachlorobutadiene and chlorobenzenes from a contaminated estuarine sediment. The following extraction methods were used: Soxhlet extraction, sonication and solvent extraction, sequential solvent extraction, saponification and solv...

Deciphering Intrinsic Inter-subunit Couplings that Lead to Sequential Hydrolysis of F 1 -ATPase Ring

Science.gov (United States)

Dai, Liqiang; Flechsig, Holger; Yu, Jin

2017-10-01

The rotary sequential hydrolysis of metabolic machine F1-ATPase is a prominent feature to reveal high coordination among multiple chemical sites on the stator F1 ring, which also contributes to tight coupling between the chemical reaction and central {\\gamma}-shaft rotation. High-speed AFM experiments discovered that the sequential hydrolysis was maintained on the F1 ring even in the absence of the {\\gamma} rotor. To explore how the intrinsic sequential performance arises, we computationally investigated essential inter-subunit couplings on the hexameric ring of mitochondrial and bacterial F1. We first reproduced the sequential hydrolysis schemes as experimentally detected, by simulating tri-site ATP hydrolysis cycles on the F1 ring upon kinetically imposing inter-subunit couplings to substantially promote the hydrolysis products release. We found that it is key for certain ATP binding and hydrolysis events to facilitate the neighbor-site ADP and Pi release to support the sequential hydrolysis. The kinetically feasible couplings were then scrutinized through atomistic molecular dynamics simulations as well as coarse-grained simulations, in which we enforced targeted conformational changes for the ATP binding or hydrolysis. Notably, we detected the asymmetrical neighbor-site opening that would facilitate the ADP release upon the enforced ATP binding, and computationally captured the complete Pi release through charge hopping upon the enforced neighbor-site ATP hydrolysis. The ATP-hydrolysis triggered Pi release revealed in current TMD simulation confirms a recent prediction made from statistical analyses of single molecule experimental data in regard to the role ATP hydrolysis plays. Our studies, therefore, elucidate both the concerted chemical kinetics and underlying structural dynamics of the inter-subunit couplings that lead to the rotary sequential hydrolysis of the F1 ring.

Fermentation characteristics of polysaccharide fractions extracted from the cell walls of maize endosperm

NARCIS (Netherlands)

Laar, van H.; Tamminga, S.; Williams, B.A.; Verstegen, M.W.A.; Schols, H.A.

2002-01-01

Cell walls were extracted from maize endosperm and separated into different polysaccharide fractions by sequential extraction with solutions of saturated Ba(OH)2, demineralised water and 1 and 4 M KOH. Solubilised polysaccharides were collected after each extraction. Residues were collected

Privacy-Preserving Billing Scheme against Free-Riders for Wireless Charging Electric Vehicles

Directory of Open Access Journals (Sweden)

Xingwen Zhao

2017-01-01

Full Text Available Recently, scientists in South Korea developed on-line electric vehicle (OLEV, which is a kind of electric vehicle that can be charged wirelessly while it is moving on the road. The battery in the vehicle can absorb electric energy from the power transmitters buried under the road without any contact with them. Several billing schemes have been presented to offer privacy-preserving billing for OLEV owners. However, they did not consider the existence of free-riders. When some vehicles are being charged after showing the tokens, vehicles that are running ahead or behind can switch on their systems and drive closely for a free charging. We describe a billing scheme against free-riders by using several cryptographic tools. Each vehicle should authenticate with a compensation-prepaid token before it can drive on the wireless-charging-enabled road. The service provider can obtain compensation if it can prove that certain vehicle is a free-rider. Our scheme is privacy-preserving so the charging will not disclose the locations and routine routes of each vehicle. In fact, our scheme is a fast authentication scheme that anonymously authenticates each user on accessing a sequence of services. Thus, it can be applied to sequential data delivering services in future 5G systems.

Human visual system automatically represents large-scale sequential regularities.

Science.gov (United States)

Kimura, Motohiro; Widmann, Andreas; Schröger, Erich

2010-03-04

Our brain recordings reveal that large-scale sequential regularities defined across non-adjacent stimuli can be automatically represented in visual sensory memory. To show that, we adopted an auditory paradigm developed by Sussman, E., Ritter, W., and Vaughan, H. G. Jr. (1998). Predictability of stimulus deviance and the mismatch negativity. NeuroReport, 9, 4167-4170, Sussman, E., and Gumenyuk, V. (2005). Organization of sequential sounds in auditory memory. NeuroReport, 16, 1519-1523 to the visual domain by presenting task-irrelevant infrequent luminance-deviant stimuli (D, 20%) inserted among task-irrelevant frequent stimuli being of standard luminance (S, 80%) in randomized (randomized condition, SSSDSSSSSDSSSSD...) and fixed manners (fixed condition, SSSSDSSSSDSSSSD...). Comparing the visual mismatch negativity (visual MMN), an event-related brain potential (ERP) index of memory-mismatch processes in human visual sensory system, revealed that visual MMN elicited by deviant stimuli was reduced in the fixed compared to the randomized condition. Thus, the large-scale sequential regularity being present in the fixed condition (SSSSD) must have been represented in visual sensory memory. Interestingly, this effect did not occur in conditions with stimulus-onset asynchronies (SOAs) of 480 and 800 ms but was confined to the 160-ms SOA condition supporting the hypothesis that large-scale regularity extraction was based on perceptual grouping of the five successive stimuli defining the regularity. 2010 Elsevier B.V. All rights reserved.

Extraction mechanics in lingual orthodontics: Challenges and solutions

Directory of Open Access Journals (Sweden)

Tushar M Hegde

2016-01-01

Full Text Available The 21st century has witnessed a slow but sure incorporation of lingual orthodontic protocols into the orthodontic mainstream. Extraction mechanics with lingual orthodontic appliance poses challenges to even the most experienced clinician. This article is a case series of three cases treated by extraction mechanics in a detailed and sequential manner.

Multi-agent sequential hypothesis testing

KAUST Repository

Kim, Kwang-Ki K.

2014-12-15

This paper considers multi-agent sequential hypothesis testing and presents a framework for strategic learning in sequential games with explicit consideration of both temporal and spatial coordination. The associated Bayes risk functions explicitly incorporate costs of taking private/public measurements, costs of time-difference and disagreement in actions of agents, and costs of false declaration/choices in the sequential hypothesis testing. The corresponding sequential decision processes have well-defined value functions with respect to (a) the belief states for the case of conditional independent private noisy measurements that are also assumed to be independent identically distributed over time, and (b) the information states for the case of correlated private noisy measurements. A sequential investment game of strategic coordination and delay is also discussed as an application of the proposed strategic learning rules.

Antimutagenicity and Antiproliferative Studies of Lipidic Extracts from White Shrimp (Litopenaeus vannamei

Directory of Open Access Journals (Sweden)

Carolina Moreno-Félix

2010-11-01

Full Text Available An organic extract from fresh shrimp (Litopenaeus vannamei was studied for antimutagenic and antiproliferative properties using Salmonella typhimurium tester strains TA98 and TA100 with metabolic activation (S9 and a cancer cell line (B-cell lymphoma, respectively. Shrimp extract was sequentially fractionated by thin layer chromatography (TLC and each fraction was tested for antimutagenic and antiproliferative activities. Crude organic extracts obtained from shrimp reduced the number of revertants caused by aflatoxina B1, showing a dose-response type of relationship. Sequential TLC fractionation of the active extracts produced several antimutagenic and/or antiproliferative fractions. These results suggested that the lipid fraction of the tested species contained compounds with chemoprotective properties that reduce the mutagenicity of AFB1 and proliferation of a cancer cell line.

Sequential charged particle reaction

International Nuclear Information System (INIS)

Hori, Jun-ichi; Ochiai, Kentaro; Sato, Satoshi; Yamauchi, Michinori; Nishitani, Takeo

2004-01-01

The effective cross sections for producing the sequential reaction products in F82H, pure vanadium and LiF with respect to the 14.9-MeV neutron were obtained and compared with the estimation ones. Since the sequential reactions depend on the secondary charged particles behavior, the effective cross sections are corresponding to the target nuclei and the material composition. The effective cross sections were also estimated by using the EAF-libraries and compared with the experimental ones. There were large discrepancies between estimated and experimental values. Additionally, we showed the contribution of the sequential reaction on the induced activity and dose rate in the boundary region with water. From the present study, it has been clarified that the sequential reactions are of great importance to evaluate the dose rates around the surface of cooling pipe and the activated corrosion products. (author)

Sediment quality assessment in a coastal lagoon (Ravenna, NE Italy) based on SEM-AVS and sequential extraction procedure.

Science.gov (United States)

Pignotti, Emanuela; Guerra, Roberta; Covelli, Stefano; Fabbri, Elena; Dinelli, Enrico

2018-09-01

Sediments from the Pialassa Piomboni coastal lagoon (NE Italy) were studied to assess the degree of contamination and ecological risk related to trace metals by combining a geochemical characterization of bulk sediments with the assessment of the bioavailable forms of trace metals. With this purpose, sediment contamination (Cd, Cu, Hg, Ni, Pb, and Zn) was assessed by Enrichment Factors (EFs), and potential bioavailability by the Simultaneously Extracted Metals and Acid Volatile Sulfides (SEM-AVS) approach (Cd, Cu, Ni, Pb, and Zn), and by Sequential Extraction Procedure (Co, Cr, Cu, Ni, Pb, and Zn). On average, Cr and Ni exhibited no contamination (EF ≤1.5), and a predominance in the residual fraction of the sediment, indicating natural origin for these metals. Cu, Pb and Zn displayed a local contamination, which resulted in a higher proportion of Cu bound to the reducible and oxidizable fractions (~30% and ~40% as median, respectively), and Pb mostly associated with the reducible phase (~60% as median). Hence, Cu and Pb could be mobilized when environmental conditions become reducing or oxidizing. Zn resulted mainly partitioned into the reducible and residual fractions (~50% as median, in both fractions). The Risk Assessment Code (RAC) indicated that approximately 30% of samples had >10% of total Zn weakly bound to the sediment, suggesting a medium risk of exposure for aquatic organisms. RAC results were consistent with the ∑SEM-AVS findings, pointing to possible adverse effects for aquatic biota in ~30% of samples, with Zn mostly accounting for the total metal bioavailability. Hg showed a moderate to very severe enrichment, indicating that a substantial amount of this metal derives from anthropogenic sources and may pose adverse effects on the aquatic biota of the Pialassa Piomboni lagoon. Copyright © 2018 Elsevier B.V. All rights reserved.

Evaluation of the mobility and pollution index of selected essential/toxic metals in paddy soil by sequential extraction method.

Science.gov (United States)

Hasan, Maria; Kausar, Dilshad; Akhter, Gulraiz; Shah, Munir H

2018-01-01

Comparative distribution and mobility of selected essential and toxic metals in the paddy soil from district Sargodha, Pakistan was evaluated by the modified Community Bureau of Reference (mBCR) sequential extraction procedure. Most of the soil samples showed slightly alkaline nature while the soil texture was predominantly silty loam in nature. The metal contents were quantified in the exchangeable, reducible, oxidisable and residual fractions of the soil by flame atomic absorption spectrophotometry and the metal data were subjected to the statistical analyses in order to evaluate the mutual relationships among the metals in each fraction. Among the metals, Ca, Sr and Mn were found to be more mobile in the soil. A number of significant correlations between different metal pairs were noted in various fractions. Contamination factor, geoaccumulation index and enrichment factor revealed extremely severe enrichment/contamination for Cd; moderate to significant enrichment/contamination for Ni, Zn, Co and Pb while Cr, Sr, Cu and Mn revealed minimal to moderate contamination and accumulation in the soil. Multivariate cluster analysis showed significant anthropogenic intrusions of the metals in various fractions. Copyright © 2017 Elsevier Inc. All rights reserved.

Eyewitness confidence in simultaneous and sequential lineups: a criterion shift account for sequential mistaken identification overconfidence.

Science.gov (United States)

Dobolyi, David G; Dodson, Chad S

2013-12-01

Confidence judgments for eyewitness identifications play an integral role in determining guilt during legal proceedings. Past research has shown that confidence in positive identifications is strongly associated with accuracy. Using a standard lineup recognition paradigm, we investigated accuracy using signal detection and ROC analyses, along with the tendency to choose a face with both simultaneous and sequential lineups. We replicated past findings of reduced rates of choosing with sequential as compared to simultaneous lineups, but notably found an accuracy advantage in favor of simultaneous lineups. Moreover, our analysis of the confidence-accuracy relationship revealed two key findings. First, we observed a sequential mistaken identification overconfidence effect: despite an overall reduction in false alarms, confidence for false alarms that did occur was higher with sequential lineups than with simultaneous lineups, with no differences in confidence for correct identifications. This sequential mistaken identification overconfidence effect is an expected byproduct of the use of a more conservative identification criterion with sequential than with simultaneous lineups. Second, we found a steady drop in confidence for mistaken identifications (i.e., foil identifications and false alarms) from the first to the last face in sequential lineups, whereas confidence in and accuracy of correct identifications remained relatively stable. Overall, we observed that sequential lineups are both less accurate and produce higher confidence false identifications than do simultaneous lineups. Given the increasing prominence of sequential lineups in our legal system, our data argue for increased scrutiny and possibly a wholesale reevaluation of this lineup format. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Innovative process scheme for removal of organic matter, phosphorus and nitrogen from pig manure

DEFF Research Database (Denmark)

Karakashev, Dimitar Borisov; Schmidt, Jens Ejbye; Angelidaki, Irini

2008-01-01

blanket (UASB) reactor, partial oxidation), nitrogen (oxygen-limited autotrophic nitrification-denitrification, OLAND) and phosphorus (phosphorus removal by precipitation as struvite, PRS) from pig manure were tested. Results obtained showed that microfiltration was unsuitable for pig manure treatment....... PRS treated effluent was negatively affecting the further processing of the pig manure in UASB, and was therefore not included in the final process flow scheme. In a final scheme (PIGMAN concept) combination of the following successive process steps was used: thermophilic anaerobic digestion...... with sequential separation by decanter centrifuge, post-digestion in UASB reactor, partial oxidation and finally OLAND process. This combination resulted in reduction of the total organic, nitrogen and phosphorus contents by 96%, 88%, and 81%, respectively....

Modeling two-phase ferroelectric composites by sequential laminates

International Nuclear Information System (INIS)

Idiart, Martín I

2014-01-01

Theoretical estimates are given for the overall dissipative response of two-phase ferroelectric composites with complex particulate microstructures under arbitrary loading histories. The ferroelectric behavior of the constituent phases is described via a stored energy density and a dissipation potential in accordance with the theory of generalized standard materials. An implicit time-discretization scheme is used to generate a variational representation of the overall response in terms of a single incremental potential. Estimates are then generated by constructing sequentially laminated microgeometries of particulate type whose overall incremental potential can be computed exactly. Because they are realizable, by construction, these estimates are guaranteed to conform with any material constraints, to satisfy all pertinent bounds and to exhibit the required convexity properties with no duality gap. Predictions for representative composite and porous systems are reported and discussed in the light of existing experimental data. (paper)

In vitro insulinotropic actions of various extracts of Moringa oleifera ...

African Journals Online (AJOL)

This study investigated the in vitro insulin-releasing and cytotoxic effects of various extracts of Moringa oleifera leaves. Pulverized Moringa oleifera leaves were sequentially extracted with dichloromethane, acetone, ethylacetate and water. Clonal pancreatic beta cells, BRIN-BD11, were grown in an atmosphere of 5% CO2 ...

Sequentially optimized reconstruction strategy: A meta-strategy for perimetry testing.

Directory of Open Access Journals (Sweden)

Şerife Seda Kucur

Full Text Available Perimetry testing is an automated method to measure visual function and is heavily used for diagnosing ophthalmic and neurological conditions. Its working principle is to sequentially query a subject about perceived light using different brightness levels at different visual field locations. At a given location, this query-patient-feedback process is expected to converge at a perceived sensitivity, such that a shown stimulus intensity is observed and reported 50% of the time. Given this inherently time-intensive and noisy process, fast testing strategies are necessary in order to measure existing regions more effectively and reliably. In this work, we present a novel meta-strategy which relies on the correlative nature of visual field locations in order to strongly reduce the necessary number of locations that need to be examined. To do this, we sequentially determine locations that most effectively reduce visual field estimation errors in an initial training phase. We then exploit these locations at examination time and show that our approach can easily be combined with existing perceived sensitivity estimation schemes to speed up the examinations. Compared to state-of-the-art strategies, our approach shows marked performance gains with a better accuracy-speed trade-off regime for both mixed and sub-populations.

Mining Sequential Update Summarization with Hierarchical Text Analysis

Directory of Open Access Journals (Sweden)

Chunyun Zhang

2016-01-01

Full Text Available The outbreak of unexpected news events such as large human accident or natural disaster brings about a new information access problem where traditional approaches fail. Mostly, news of these events shows characteristics that are early sparse and later redundant. Hence, it is very important to get updates and provide individuals with timely and important information of these incidents during their development, especially when being applied in wireless and mobile Internet of Things (IoT. In this paper, we define the problem of sequential update summarization extraction and present a new hierarchical update mining system which can broadcast with useful, new, and timely sentence-length updates about a developing event. The new system proposes a novel method, which incorporates techniques from topic-level and sentence-level summarization. To evaluate the performance of the proposed system, we apply it to the task of sequential update summarization of temporal summarization (TS track at Text Retrieval Conference (TREC 2013 to compute four measurements of the update mining system: the expected gain, expected latency gain, comprehensiveness, and latency comprehensiveness. Experimental results show that our proposed method has good performance.

Remarks on sequential designs in risk assessment

International Nuclear Information System (INIS)

Seidenfeld, T.

1982-01-01

The special merits of sequential designs are reviewed in light of particular challenges that attend risk assessment for human population. The kinds of ''statistical inference'' are distinguished and the problem of design which is pursued is the clash between Neyman-Pearson and Bayesian programs of sequential design. The value of sequential designs is discussed and the Neyman-Pearson vs. Bayesian sequential designs are probed in particular. Finally, warnings with sequential designs are considered, especially in relation to utilitarianism

Study on demetalization of sewage sludge by sequential extraction before liquefaction for the production of cleaner bio-oil and bio-char.

Science.gov (United States)

Leng, Lijian; Yuan, Xingzhong; Shao, Jianguang; Huang, Huajun; Wang, Hou; Li, Hui; Chen, Xiaohong; Zeng, Guangming

2016-01-01

Demetalization of sewage sludge (SS) by sequential extraction before liquefaction was implemented to produce cleaner bio-char and bio-oil. Demetalization steps 1 and 2 did not cause much organic matter loss on SS, and thus the bio-oil and bio-char yields and the compositions of bio-oils were also not affected significantly. However, the demetalization procedures resulted in the production of cleaner bio-chars and bio-oils. The total concentrations and the acid soluble/exchangeable fraction (F1 fraction, the most toxic heavy metal fraction) of heavy metals (Cu, Cr, Pb, Zn, and Cd) in these products were significantly reduced and the environmental risks of these products were also relived considerably compared with those produced from raw SS, respectively. Additionally, these bio-oils had less heavy fractions. Demetalization processes with removal of F1 and F2 fractions of heavy metals would benefit the production of cleaner bio-char and bio-oil by liquefaction of heavy metal abundant biomass like SS. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sequential lineup laps and eyewitness accuracy.

Science.gov (United States)

Steblay, Nancy K; Dietrich, Hannah L; Ryan, Shannon L; Raczynski, Jeanette L; James, Kali A

2011-08-01

Police practice of double-blind sequential lineups prompts a question about the efficacy of repeated viewings (laps) of the sequential lineup. Two laboratory experiments confirmed the presence of a sequential lap effect: an increase in witness lineup picks from first to second lap, when the culprit was a stranger. The second lap produced more errors than correct identifications. In Experiment 2, lineup diagnosticity was significantly higher for sequential lineup procedures that employed a single versus double laps. Witnesses who elected to view a second lap made significantly more errors than witnesses who chose to stop after one lap or those who were required to view two laps. Witnesses with prior exposure to the culprit did not exhibit a sequential lap effect.

On-line dynamic extraction and automated determination of readily bioavailable hexavalent chromium in solid substrates using micro-sequential injection bead-injection lab-on-valve hyphenated with electrothermal atomic absorption spectrometry

DEFF Research Database (Denmark)

Long, Xiangbao; Miró, Manuel; Hansen, Elo Harald

2006-01-01

A novel and miniaturized micro-sequential injection bead injection lab-on-valve (μSI-BI-LOV) fractionation system was developed for in-line microcolumn soil extraction under simulated environmental scenarios and accurate monitoring of the content of easily mobilisable hexavalent chromium in soil...... environments at the sub-low parts-per-million level. The flow system integrates dynamic leaching of hexavalent chromium using deionized water as recommended by the German Standard DIN 38414-S4 method; on-line pH adjustment of the extract by a 0.01 mol L-1 Tris-HNO3 buffer solution; isolation of the chromate...... polluted agricultural soil material (San Joaquin Soil-Baseline Trace Element Concentrations) with water-soluble Cr(VI) salts at different concentration levels. The potential of the μSI-BI-LOV set-up with renewable surfaces for flame-AAS determination of high levels of readily bioavailable chromate...

Robustness of the Sequential Lineup Advantage

Science.gov (United States)

Gronlund, Scott D.; Carlson, Curt A.; Dailey, Sarah B.; Goodsell, Charles A.

2009-01-01

A growing movement in the United States and around the world involves promoting the advantages of conducting an eyewitness lineup in a sequential manner. We conducted a large study (N = 2,529) that included 24 comparisons of sequential versus simultaneous lineups. A liberal statistical criterion revealed only 2 significant sequential lineup…

Biometric feature extraction using local fractal auto-correlation

International Nuclear Information System (INIS)

Chen Xi; Zhang Jia-Shu

2014-01-01

Image texture feature extraction is a classical means for biometric recognition. To extract effective texture feature for matching, we utilize local fractal auto-correlation to construct an effective image texture descriptor. Three main steps are involved in the proposed scheme: (i) using two-dimensional Gabor filter to extract the texture features of biometric images; (ii) calculating the local fractal dimension of Gabor feature under different orientations and scales using fractal auto-correlation algorithm; and (iii) linking the local fractal dimension of Gabor feature under different orientations and scales into a big vector for matching. Experiments and analyses show our proposed scheme is an efficient biometric feature extraction approach. (condensed matter: structural, mechanical, and thermal properties)

Characteristics of reverse overwrite process in shingled recording scheme at ultra-high track density

Energy Technology Data Exchange (ETDEWEB)

Li Shaoping, E-mail: shaoping_li_2000@yahoo.com [Western Digital Inc. 1250 Reliance Way, Fremont, CA 94539 (United States); Mendez, Hector; Terrill, Dave; Liu Feng; Bai, Daniel; Mao Sining [Western Digital Inc. 1250 Reliance Way, Fremont, CA 94539 (United States)

2012-02-15

A systematic experimental study of the reverse overwrite (ReOVW) process in the shingled recording scheme has been conducted in conjunction with characterization of corresponding recording performances from recording heads with different geometries. It was found that there is no ReOVW reduction as the track density increases in a strict shingled recording fashion. Nonetheless, ReOVW is indeed slightly decreased from 300 to 700 kpi in a so-called one write shingled recording process. Overall our obtained data suggest that conventional magnetic recording technology might be able to extend all the way beyond an areal density of one Tbit/in{sup 2} by using the shingled recording scheme. - Research Highlights: > This paper discusses the most advanced recording scheme, e.g., shingled recording process, for next generation magnetic data storage devices. > The paper shows that the write-ability of magnetic recording is sufficient in the shingled recording scheme even when the areal density is beyond 1.0 Tb/in{sup 2}. > Our results also shows that the writer's edge write-ability is essential for reducing noise during the write process in shingled recording scheme. > The paper also demonstrates that a multiple and sequential write process ensures the normal erasure-ability in shingled recording scheme. > Our results also indicate that the noise nature in the write process still could be attributed to the hard-easy transition and imprint effect.

Characteristics of reverse overwrite process in shingled recording scheme at ultra-high track density

International Nuclear Information System (INIS)

Li Shaoping; Mendez, Hector; Terrill, Dave; Liu Feng; Bai, Daniel; Mao Sining

2012-01-01

A systematic experimental study of the reverse overwrite (ReOVW) process in the shingled recording scheme has been conducted in conjunction with characterization of corresponding recording performances from recording heads with different geometries. It was found that there is no ReOVW reduction as the track density increases in a strict shingled recording fashion. Nonetheless, ReOVW is indeed slightly decreased from 300 to 700 kpi in a so-called one write shingled recording process. Overall our obtained data suggest that conventional magnetic recording technology might be able to extend all the way beyond an areal density of one Tbit/in 2 by using the shingled recording scheme. - Research highlights: → This paper discusses the most advanced recording scheme, e.g., shingled recording process, for next generation magnetic data storage devices. → The paper shows that the write-ability of magnetic recording is sufficient in the shingled recording scheme even when the areal density is beyond 1.0 Tb/in 2 . → Our results also shows that the writer's edge write-ability is essential for reducing noise during the write process in shingled recording scheme. → The paper also demonstrates that a multiple and sequential write process ensures the normal erasure-ability in shingled recording scheme. → Our results also indicate that the noise nature in the write process still could be attributed to the hard-easy transition and imprint effect.

Multi-agent sequential hypothesis testing

KAUST Repository

Kim, Kwang-Ki K.; Shamma, Jeff S.

2014-01-01

incorporate costs of taking private/public measurements, costs of time-difference and disagreement in actions of agents, and costs of false declaration/choices in the sequential hypothesis testing. The corresponding sequential decision processes have well

Combining Sequential Extractions and X-ray Absorption Spectroscopy for Quantitative and Qualitative Zinc Speciation in Soil

Science.gov (United States)

Bauer, Tatiana; Minkina, Tatiana; Batukaev, Abdulmalik; Nevidomskaya, Dina; Burachevskaya, Marina; Tsitsuashvili, Viktoriya; Urazgildieva, Kamilya

2017-04-01

The combined use of X-ray absorption spectrometry and extractive fractionation is an effective approach for studying the interaction of metal ions with soil compounds and identifying the phases-carriers of metals in soil and their stable fixation. These studies were carried out using the technique of X-ray absorption spectroscopy and chemical extractive fractionation. In a model experiment the samples taken in Calcic Chernozem were artificially contaminated with higher portion of Zn(NO3)2 (2000 mg/kg). The metal were incubated in soil samples for 2 year. The samples of soil mineral and organic phases (calcite, kaolinite, bentonite, humic acids) were saturated with Zn2+ from a solution of nitrate salts of metal. The total content of Zn in soil and soil various phases was determined using the X-ray fluorescence method. Extended X-ray absorption fine structure (EXAFS) Zn was measured at the Structural Materials Science beamline of the Kurchatov Center for Synchrotron Radiation. Sequential fractionation of Zn in soil conducted by Tessier method (Tessier et al., 1979) which determining 5 fractions of metals in soil: exchangeable, bound to Fe-Mn oxide, bound to carbonate, bound to the organic matter, and bound to silicate (residual). This methodology has so far more than 4000 citations (Web of Science), which demonstrates the popularity of this approach. Much Zn compounds are contained in uncontaminated soils in stable primary and secondary silicates inherited from the parental rocks (67% of the total concentrations in all fractions), which is a regional trait of soils in the fore-Caucasian plain. Extracted fractionation of metal compounds in soil samples, artificially contaminated with Zn salts, indicates the priority holding of Zn2+ ions by silicates, carbonates and Fe-Mn oxides. The Zn content significantly increases in the exchangeable fraction. Atomic structure study of the soil various phases saturated with Zn2+ ion by using (XANES) X-ray absorption spectroscopy

Toxic trace element assessment for soils/sediments deposited during Hurricanes Katrina and Rita from southern Louisiana, USA: a sequential extraction analysis.

Science.gov (United States)

Shi, Honglan; Witt, Emitt C; Shu, Shi; Su, Tingzhi; Wang, Jianmin; Adams, Craig

2010-07-01

Analysis of soil/sediment samples collected in the southern Louisiana, USA, region three weeks after Hurricanes Katrina and Rita passed was performed using sequential extraction procedures to determine the origin, mode of occurrence, biological availability, mobilization, and transport of trace elements in the environment. Five fractions: exchangeable, bound to carbonates, bound to iron (Fe)-manganese (Mn) oxides, bound to organic matter, and residual, were subsequently extracted. The toxic trace elements Pb, As, V, Cr, Cu, and Cd were analyzed in each fraction, together with Fe in 51 soil/sediment samples. Results indicated that Pb and As were at relatively high concentrations in many of the soil/sediment samples. Because the forms in which Pb and As are present tend to be highly mobile under naturally occurring environmental conditions, these two compounds pose an increased health concern.Vanadium and Cr were mostly associated with the crystal line nonmobile residual fraction. A large portion of the Cu was associated with organic matter and residual fraction. Cadmium concentrations were low in all soil/sediment samples analyzed and most of this element tended to be associated with the mobile fractions. An average of 21% of the Fe was found in the Fe-Mn oxide fraction, indicating that a substantial part of the Fe was in an oxidized form. The significance of the overall finding of the present study indicated that the high concentrations and high availabilities of the potentially toxic trace elements As and Pb may impact the environment and human health in southern Louisiana and, in particular, the New Orleans area. Copyright (c) 2010 SETAC.

Sequential stochastic optimization

CERN Document Server

Cairoli, Renzo

1996-01-01

Sequential Stochastic Optimization provides mathematicians and applied researchers with a well-developed framework in which stochastic optimization problems can be formulated and solved. Offering much material that is either new or has never before appeared in book form, it lucidly presents a unified theory of optimal stopping and optimal sequential control of stochastic processes. This book has been carefully organized so that little prior knowledge of the subject is assumed; its only prerequisites are a standard graduate course in probability theory and some familiarity with discrete-paramet

Additive operator-difference schemes splitting schemes

CERN Document Server

Vabishchevich, Petr N

2013-01-01

Applied mathematical modeling isconcerned with solving unsteady problems. This bookshows how toconstruct additive difference schemes to solve approximately unsteady multi-dimensional problems for PDEs. Two classes of schemes are highlighted: methods of splitting with respect to spatial variables (alternating direction methods) and schemes of splitting into physical processes. Also regionally additive schemes (domain decomposition methods)and unconditionally stable additive schemes of multi-component splitting are considered for evolutionary equations of first and second order as well as for sy

Sanitizing sensitive association rules using fuzzy correlation scheme

International Nuclear Information System (INIS)

Hameed, S.; Shahzad, F.; Asghar, S.

2013-01-01

Data mining is used to extract useful information hidden in the data. Sometimes this extraction of information leads to revealing sensitive information. Privacy preservation in Data Mining is a process of sanitizing sensitive information. This research focuses on sanitizing sensitive rules discovered in quantitative data. The proposed scheme, Privacy Preserving in Fuzzy Association Rules (PPFAR) is based on fuzzy correlation analysis. In this work, fuzzy set concept is integrated with fuzzy correlation analysis and Apriori algorithm to mark interesting fuzzy association rules. The identified rules are called sensitive. For sanitization, we use modification technique where we substitute maximum value of fuzzy items with zero, which occurs most frequently. Experiments demonstrate that PPFAR method hides sensitive rules with minimum modifications. The technique also maintains the modified data's quality. The PPFAR scheme has applications in various domains e.g. temperature control, medical analysis, travel time prediction, genetic behavior prediction etc. We have validated the results on medical dataset. (author)

Exploring the sequential lineup advantage using WITNESS.

Science.gov (United States)

Goodsell, Charles A; Gronlund, Scott D; Carlson, Curt A

2010-12-01

Advocates claim that the sequential lineup is an improvement over simultaneous lineup procedures, but no formal (quantitatively specified) explanation exists for why it is better. The computational model WITNESS (Clark, Appl Cogn Psychol 17:629-654, 2003) was used to develop theoretical explanations for the sequential lineup advantage. In its current form, WITNESS produced a sequential advantage only by pairing conservative sequential choosing with liberal simultaneous choosing. However, this combination failed to approximate four extant experiments that exhibited large sequential advantages. Two of these experiments became the focus of our efforts because the data were uncontaminated by likely suspect position effects. Decision-based and memory-based modifications to WITNESS approximated the data and produced a sequential advantage. The next step is to evaluate the proposed explanations and modify public policy recommendations accordingly.

Sequential and simultaneous choices: testing the diet selection and sequential choice models.

Science.gov (United States)

Freidin, Esteban; Aw, Justine; Kacelnik, Alex

2009-03-01

We investigate simultaneous and sequential choices in starlings, using Charnov's Diet Choice Model (DCM) and Shapiro, Siller and Kacelnik's Sequential Choice Model (SCM) to integrate function and mechanism. During a training phase, starlings encountered one food-related option per trial (A, B or R) in random sequence and with equal probability. A and B delivered food rewards after programmed delays (shorter for A), while R ('rejection') moved directly to the next trial without reward. In this phase we measured latencies to respond. In a later, choice, phase, birds encountered the pairs A-B, A-R and B-R, the first implementing a simultaneous choice and the second and third sequential choices. The DCM predicts when R should be chosen to maximize intake rate, and SCM uses latencies of the training phase to predict choices between any pair of options in the choice phase. The predictions of both models coincided, and both successfully predicted the birds' preferences. The DCM does not deal with partial preferences, while the SCM does, and experimental results were strongly correlated to this model's predictions. We believe that the SCM may expose a very general mechanism of animal choice, and that its wider domain of success reflects the greater ecological significance of sequential over simultaneous choices.

Extraction efficiency of hydrophilic and lipophilic antioxidants from lyophilized foods using pressurized liquid extraction and manual extraction.

Science.gov (United States)

Watanabe, Jun; Oki, Tomoyuki; Takebayashi, Jun; Takano-Ishikawa, Yuko

2014-09-01

The efficient extraction of antioxidants from food samples is necessary in order to accurately measure their antioxidant capacities. α-Tocopherol and gallic acid were spiked into samples of 5 lyophilized and pulverized vegetables and fruits (onion, cabbage, Satsuma mandarin orange, pumpkin, and spinach). The lipophilic and hydrophilic antioxidants in the samples were sequentially extracted with a mixed solvent of n-hexane and dichloromethane, and then with acetic acid-acidified aqueous methanol. Duplicate samples were extracted: one set was extracted using an automated pressurized liquid extraction apparatus, and the other set was extracted manually. Spiked α-tocopherol and gallic acid were recovered almost quantitatively in the extracted lipophilic and hydrophilic fractions, respectively, especially when pressurized liquid extraction was used. The expected increase in lipophilic oxygen radical absorbance capacity (L-ORAC) due to spiking with α-tocopherol, and the expected increase in 2,2-diphenyl-1-picrylhydrazyl radical scavenging activities and total polyphenol content due to spiking with gallic acid, were all recovered in high yield. Relatively low recoveries, as reflected in the hydrophilic ORAC (H-ORAC) value, were obtained following spiking with gallic acid, suggesting an interaction between gallic acid and endogenous antioxidants. The H-ORAC values of gallic acid-spiked samples were almost the same as those of postadded (spiked) samples. These results clearly indicate that lipophilic and hydrophilic antioxidants are effectively extracted from lyophilized food, especially when pressurized liquid extraction is used. © 2014 Institute of Food Technologists®

Sequential memory: Binding dynamics

Science.gov (United States)

Afraimovich, Valentin; Gong, Xue; Rabinovich, Mikhail

2015-10-01

Temporal order memories are critical for everyday animal and human functioning. Experiments and our own experience show that the binding or association of various features of an event together and the maintaining of multimodality events in sequential order are the key components of any sequential memories—episodic, semantic, working, etc. We study a robustness of binding sequential dynamics based on our previously introduced model in the form of generalized Lotka-Volterra equations. In the phase space of the model, there exists a multi-dimensional binding heteroclinic network consisting of saddle equilibrium points and heteroclinic trajectories joining them. We prove here the robustness of the binding sequential dynamics, i.e., the feasibility phenomenon for coupled heteroclinic networks: for each collection of successive heteroclinic trajectories inside the unified networks, there is an open set of initial points such that the trajectory going through each of them follows the prescribed collection staying in a small neighborhood of it. We show also that the symbolic complexity function of the system restricted to this neighborhood is a polynomial of degree L - 1, where L is the number of modalities.

Efficient scheme for parametric fitting of data in arbitrary dimensions.

Science.gov (United States)

Pang, Ning-Ning; Tzeng, Wen-Jer; Kao, Hisen-Ching

2008-07-01

We propose an efficient scheme for parametric fitting expressed in terms of the Legendre polynomials. For continuous systems, our scheme is exact and the derived explicit expression is very helpful for further analytical studies. For discrete systems, our scheme is almost as accurate as the method of singular value decomposition. Through a few numerical examples, we show that our algorithm costs much less CPU time and memory space than the method of singular value decomposition. Thus, our algorithm is very suitable for a large amount of data fitting. In addition, the proposed scheme can also be used to extract the global structure of fluctuating systems. We then derive the exact relation between the correlation function and the detrended variance function of fluctuating systems in arbitrary dimensions and give a general scaling analysis.

Injection and extraction for cyclotrons

International Nuclear Information System (INIS)

Heikkinen, P.

1994-01-01

External ion sources for cyclotrons are needed for polarised and heavy ions. This calls for injection systems, either radial or axial. Radial injection is also needed when a cyclotron works as a booster after another cyclotron or a linear accelerator (usually tandem). Requirements for injection differ from separated sector cyclotrons where there is plenty of room to house inflectors and/or strippers, to superconducting cyclotrons where the space is limited by a small magnet gap, and high magnetic field puts other limitations to the inflectors. Several extraction schemes are used in cyclotrons. Stripping injection is used for H - and also for heavy ions where the q/m ratio is usually doubled. For other cases, electric and magnetic deflection has to be used. To increase the turn separation before the first deflector, both resonant and non-resonant schemes are used. In this lecture, external injection systems are surveyed and some rules to thumb for injection parameters are given. Extraction schemes are also reviewed. (orig.)

Sequential Probability Ration Tests : Conservative and Robust

NARCIS (Netherlands)

Kleijnen, J.P.C.; Shi, Wen

2017-01-01

In practice, most computers generate simulation outputs sequentially, so it is attractive to analyze these outputs through sequential statistical methods such as sequential probability ratio tests (SPRTs). We investigate several SPRTs for choosing between two hypothesized values for the mean output

Fermentation characteristics of polysaccharide fractions extracted from the cell walls of soya bean cotyledons

NARCIS (Netherlands)

Laar, van H.; Tamminga, S.; Williams, B.A.; Verstegen, M.W.A.; Schols, H.A.

2000-01-01

Full-fat soya beans were separated into hulls and cotyledons. After separation the cell wall fraction was extracted from the cotyledons. These purified cell walls were sequentially extracted with 0.05 M cyclohexane-trans-1,2-diamine-N,N,N ,N -tetraacetate (CDTA) 0.05 M NH4 oxalate (extract 1), 0.05

Characterization of plant-derived carbon and phosphorus in lakes by sequential fractionation and NMR spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Liu, Shasha [College of Water Sciences, Beijing Normal University, Beijing 100875 (China); State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Zhu, Yuanrong, E-mail: zhuyuanrong07@mails.ucas.ac.cn [State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Wu, Fengchang, E-mail: wufengchang@vip.skleg.cn [State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Meng, Wei [State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); He, Zhongqi [USDA-ARS Southern Regional Research Center, 1100 Robert E Lee Blvd, New Orleans, LA 70124 (United States); Giesy, John P. [State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Department of Biomedical and Veterinary Biosciences and Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan (Canada)

2016-10-01

Although debris from aquatic macrophytes is one of the most important endogenous sources of organic matter (OM) and nutrients in lakes, its biogeochemical cycling and contribution to internal load of nutrients in eutrophic lakes are still poorly understood. In this study, sequential fractionation by H{sub 2}O, 0.1 M NaOH and 1.0 M HCl, combined with {sup 13}C and {sup 31}P NMR spectroscopy, was developed and used to characterize organic carbon (C) and phosphorus (P) in six aquatic plants collected from Tai Lake (Ch: Taihu), China. Organic matter, determined by total organic carbon (TOC), was unequally distributed in H{sub 2}O (21.2%), NaOH (29.9%), HCl (3.5%) and residual (45.3%) fractions. For P in debris of aquatic plants, 53.3% was extracted by H{sub 2}O, 31.9% by NaOH, and 11% by HCl, with 3.8% in residual fractions. Predominant OM components extracted by H{sub 2}O and NaOH were carbohydrates, proteins and aliphatic acids. Inorganic P (P{sub i}) was the primary form of P in H{sub 2}O fractions, whereas organic P (P{sub o}) was the primary form of P in NaOH fractions. The subsequent HCl fractions extracted fewer species of C and P. Some non-extractable carbohydrates, aromatics and metal phytate compounds remained in residual fractions. Based on sequential extraction and NMR analysis, it was proposed that those forms of C (54.7% of TOC) and P (96.2% of TP) in H{sub 2}O, NaOH and HCl fractions are potentially released to overlying water as labile components, while those in residues are stable and likely preserved in sediments of lakes. These results will be helpful in understanding internal loading of nutrients from debris of aquatic macrophytes and their recycling in lakes. - Highlights: • Sequential fractionation combined with NMR analysis was applied on aquatic plants. • Labile and stable C and P forms in aquatic plants were characterized. • 54.7% of OM and 96.2% of P in aquatic plants are potentially available. • 45.3% of OM and 3.8% of P in aquatic

Sequential lineup presentation: Patterns and policy

OpenAIRE

Lindsay, R C L; Mansour, Jamal K; Beaudry, J L; Leach, A-M; Bertrand, M I

2009-01-01

Sequential lineups were offered as an alternative to the traditional simultaneous lineup. Sequential lineups reduce incorrect lineup selections; however, the accompanying loss of correct identifications has resulted in controversy regarding adoption of the technique. We discuss the procedure and research relevant to (1) the pattern of results found using sequential versus simultaneous lineups; (2) reasons (theory) for differences in witness responses; (3) two methodological issues; and (4) im...

Sequential Product of Quantum Effects: An Overview

Science.gov (United States)

Gudder, Stan

2010-12-01

This article presents an overview for the theory of sequential products of quantum effects. We first summarize some of the highlights of this relatively recent field of investigation and then provide some new results. We begin by discussing sequential effect algebras which are effect algebras endowed with a sequential product satisfying certain basic conditions. We then consider sequential products of (discrete) quantum measurements. We next treat transition effect matrices (TEMs) and their associated sequential product. A TEM is a matrix whose entries are effects and whose rows form quantum measurements. We show that TEMs can be employed for the study of quantum Markov chains. Finally, we prove some new results concerning TEMs and vector densities.

Optimal Sequential Rules for Computer-Based Instruction.

Science.gov (United States)

Vos, Hans J.

1998-01-01

Formulates sequential rules for adapting the appropriate amount of instruction to learning needs in the context of computer-based instruction. Topics include Bayesian decision theory, threshold and linear-utility structure, psychometric model, optimal sequential number of test questions, and an empirical example of sequential instructional…

Scheme for analysis of oily waters

Energy Technology Data Exchange (ETDEWEB)

Lysyj, I.; Rushworth, R.; Melvold, R.; Russell, E.C.

1980-01-01

A scheme is described for gross and detailed chemical characterization of oily waters. Total, suspended, and dissolved organic content and hydrocarbon levels of the sample are determined. Volatile and water-soluble fractions are characterized in greater detail. Lower aliphatic and aromatic hydrocarbons are separated from the water by nitrogen sparging and are collected in an activated carbon absorption column. They are then extracted into carbon disulfide and analyzed gas chromatographically. The water-soluble fraction is extracted into chloroform or adsorbed on Amberlite XAD type of resin. Class characterization of this fraction is performed using the HPLC procedure. GC-MS-C is used for detailed analysis. The methodology was used for studying the effectiveness of bilge and ballast water treatments.

A Stochastic Slow Extraction Scheme For U70 Synchrotron

CERN Document Server

Ivanov, S

2004-01-01

Outcomes of a feasibility study for a low-budget sto-chastic slow extraction system in the U70 proton synchro-tron of IHEP are reported. The existing 200 MHz (spill) RF system is to be employed as a longitudinal kicker. It will be driven by a sum of a non-random RF carrier plus an additive random amplitude-modulated signal - either quadrature or in-phase, or both. A few novel solutions to be implemented in the longitudinal diffusion technique that would force protons into the conventional 3-rd order transverse extraction resonance are foreseen so as to com-ply with the technical constraints inherent in U70. Getting a-few-seconds-long and high-quality spills is assessed as being viable with the system in question.

HTGR fuel reprocessing pilot plant: results of the sequential equipment operation

International Nuclear Information System (INIS)

Strand, J.B.; Fields, D.E.; Kergis, C.A.

1979-05-01

The second sequential operation of the HTGR fuel reprocessing cold-dry head-end pilot plant equipment has been successfully completed. Twenty standard LHGTR fuel elements were crushed to a size suitable for combustion in a fluid bed burner. The graphite was combusted leaving a product of fissile and fertile fuel particles. These particles were separated in a pneumatic classifier. The fissile particles were fractured and reburned in a fluid bed to remove the inner carbon coatings. The remaining products are ready for dissolution and solvent extraction fuel recovery

Stepwise effects of the BCR sequential chemical extraction procedure on dissolution and metal release from common ferromagnesian clay minerals: A combined solution chemistry and X-ray powder diffraction study

Energy Technology Data Exchange (ETDEWEB)

Ryan, P.C. [Geology Department, Middlebury College, Middlebury, Vermont 05753 (United States)], E-mail: pryan@middlebury.edu; Hillier, S. [Macaulay Institute, Aberdeen, AB15 8QH UK (United Kingdom); Wall, A.J. [Department of Geosciences, Penn State University, University Park, Pennsylvania, 16802 (United States)

2008-12-15

Sequential extraction procedures (SEPs) are commonly used to determine speciation of trace metals in soils and sediments. However, the non-selectivity of reagents for targeted phases has remained a lingering concern. Furthermore, potentially reactive phases such as phyllosilicate clay minerals often contain trace metals in structural sites, and their reactivity has not been quantified. Accordingly, the objective of this study is to analyze the behavior of trace metal-bearing clay minerals exposed to the revised BCR 3-step plus aqua regia SEP. Mineral quantification based on stoichiometric analysis and quantitative powder X-ray diffraction (XRD) documents progressive dissolution of chlorite (CCa-2 ripidolite) and two varieties of smectite (SapCa-2 saponite and SWa-1 nontronite) during steps 1-3 of the BCR procedure. In total, 8 ({+-} 1) % of ripidolite, 19 ({+-} 1) % of saponite, and 19 ({+-} 3) % of nontronite (% mineral mass) dissolved during extractions assumed by many researchers to release trace metals from exchange sites, carbonates, hydroxides, sulfides and organic matter. For all three reference clays, release of Ni into solution is correlated with clay dissolution. Hydrolysis of relatively weak Mg-O bonds (362 kJ/mol) during all stages, reduction of Fe(III) during hydroxylamine hydrochloride extraction and oxidation of Fe(II) during hydrogen peroxide extraction are the main reasons for clay mineral dissolution. These findings underscore the need for precise mineral quantification when using SEPs to understand the origin/partitioning of trace metals with solid phases.

Quantum Inequalities and Sequential Measurements

International Nuclear Information System (INIS)

Candelpergher, B.; Grandouz, T.; Rubinx, J.L.

2011-01-01

In this article, the peculiar context of sequential measurements is chosen in order to analyze the quantum specificity in the two most famous examples of Heisenberg and Bell inequalities: Results are found at some interesting variance with customary textbook materials, where the context of initial state re-initialization is described. A key-point of the analysis is the possibility of defining Joint Probability Distributions for sequential random variables associated to quantum operators. Within the sequential context, it is shown that Joint Probability Distributions can be defined in situations where not all of the quantum operators (corresponding to random variables) do commute two by two. (authors)

Distribution of six heavy metals in contaminated clay soils before and after extractive cleaning

NARCIS (Netherlands)

Tuin, B.J.W.; Tels, M.

1990-01-01

A sequential extraction procedure according to Tessier et al. is carried out to compare the distribution of six metals (Cd, Cr, Cu, Ni, Pb and Zn) in contaminated clay soils before and after extractive cleaning. Extraction of metals from the ‘soil fractions’ with 0.1 N HC1 or 0.1 M EDTA becomes more

Separation of left and right lungs using 3D information of sequential CT images and a guided dynamic programming algorithm

Science.gov (United States)

Park, Sang Cheol; Leader, Joseph Ken; Tan, Jun; Lee, Guee Sang; Kim, Soo Hyung; Na, In Seop; Zheng, Bin

2011-01-01

Objective this article presents a new computerized scheme that aims to accurately and robustly separate left and right lungs on CT examinations. Methods we developed and tested a method to separate the left and right lungs using sequential CT information and a guided dynamic programming algorithm using adaptively and automatically selected start point and end point with especially severe and multiple connections. Results the scheme successfully identified and separated all 827 connections on the total 4034 CT images in an independent testing dataset of CT examinations. The proposed scheme separated multiple connections regardless of their locations, and the guided dynamic programming algorithm reduced the computation time to approximately 4.6% in comparison with the traditional dynamic programming and avoided the permeation of the separation boundary into normal lung tissue. Conclusions The proposed method is able to robustly and accurately disconnect all connections between left and right lungs and the guided dynamic programming algorithm is able to remove redundant processing. PMID:21412104

Chemical and sequential analysis of some metals in sediments from the North Coast of the Gulf of Mexico

International Nuclear Information System (INIS)

Trinidad Martinez; Brenda Estanol; Miguel Angel Zuniga

2016-01-01

Sediments collected from the North Coast of the Gulf of Mexico got carefully mixed, dried, and finally subjected to physical and chemical analysis. Metal concentration was determined by energy dispersive X-ray fluorescence (EDXRF). Sequential chemical analysis was performed by modified TESSIER technique. Results and statistical analysis (α = 0.05) show concentrations of most elements (excepting Mn, Ca, Ga, As and Pb) in the range of those of the earth crust's values, which set a sampling zone base line. Sequential extraction shows the potential risk of mobilization of metals sequestered in particulate phases by oxidation of anoxic sediments or intense organic matter degradation. (author)

A Fingerprint Encryption Scheme Based on Irreversible Function and Secure Authentication

Directory of Open Access Journals (Sweden)

Yijun Yang

2015-01-01

Full Text Available A fingerprint encryption scheme based on irreversible function has been designed in this paper. Since the fingerprint template includes almost the entire information of users’ fingerprints, the personal authentication can be determined only by the fingerprint features. This paper proposes an irreversible transforming function (using the improved SHA1 algorithm to transform the original minutiae which are extracted from the thinned fingerprint image. Then, Chinese remainder theorem is used to obtain the biokey from the integration of the transformed minutiae and the private key. The result shows that the scheme has better performance on security and efficiency comparing with other irreversible function schemes.

Antioxidant activity of extracts from the bark of Chamaecyparis lawsoniana (A. Murrary) Parl.

Science.gov (United States)

Heng Gao; Todd F. Shupe; Chung Y. Hse; Thomas L. Eberhardt

2006-01-01

The bark of Chamaecyparis lawsoniana (A. Murray) Parl. was extracted with methanol and sequentially partitioned with n-hexane, ethyl acetate, n-butanol and deionized water. The antioxidant activities of the four extracts were evaluated using the DPPH• and ABTS+• methods. The total phenolic...

The role of chemometrics in single and sequential extraction assays: a review. Part II. Cluster analysis, multiple linear regression, mixture resolution, experimental design and other techniques.

Science.gov (United States)

Giacomino, Agnese; Abollino, Ornella; Malandrino, Mery; Mentasti, Edoardo

2011-03-04

Single and sequential extraction procedures are used for studying element mobility and availability in solid matrices, like soils, sediments, sludge, and airborne particulate matter. In the first part of this review we reported an overview on these procedures and described the applications of chemometric uni- and bivariate techniques and of multivariate pattern recognition techniques based on variable reduction to the experimental results obtained. The second part of the review deals with the use of chemometrics not only for the visualization and interpretation of data, but also for the investigation of the effects of experimental conditions on the response, the optimization of their values and the calculation of element fractionation. We will describe the principles of the multivariate chemometric techniques considered, the aims for which they were applied and the key findings obtained. The following topics will be critically addressed: pattern recognition by cluster analysis (CA), linear discriminant analysis (LDA) and other less common techniques; modelling by multiple linear regression (MLR); investigation of spatial distribution of variables by geostatistics; calculation of fractionation patterns by a mixture resolution method (Chemometric Identification of Substrates and Element Distributions, CISED); optimization and characterization of extraction procedures by experimental design; other multivariate techniques less commonly applied. Copyright © 2010 Elsevier B.V. All rights reserved.

Sequential recycling of enzymatic lipid-extracted hydrolysate in fermentations with a thraustochytrid.

Science.gov (United States)

Lowrey, Joshua; Armenta, Roberto E; Brooks, Marianne S

2016-06-01

This study extends the findings of prior studies proposing and validating nutrient recycling for the heterotrophic microalgae, Thraustochytrium sp. (T18), grown in optimized fed-batch conditions. Sequential nutrient recycling of enzymatically-derived hydrolysate in fermentors succeeded at growing the tested thraustochytrid strain, with little evidence of inhibition or detrimental effects upon culture health. The average maximum biomass obtained in the recycled hydrolysate was 63.68±1.46gL(-1) in 90h the first recycle followed by 65.27±1.15gL(-1) in 90h in the subsequent recycle of the same material. These compared to 58.59gL(-1) and 64.92gL(-1) observed in fresh media in the same time. Lipid production was slightly impaired, however, with a maximum total fatty acid content of 62.2±0.30% in the recycled hydrolysate compared to 69.4% in fresh control media. Copyright © 2016 Elsevier Ltd. All rights reserved.

Incentive schemes in development of socio-economic systems

Science.gov (United States)

Grachev, V. V.; Ivushkin, K. A.; Myshlyaev, L. P.

2018-05-01

The paper is devoted to the study of incentive schemes when developing socio-economic systems. The article analyzes the existing incentive schemes. It is established that the traditional incentive mechanisms do not fully take into account the specifics of the creation of each socio-economic system and, as a rule, are difficult to implement. The incentive schemes based on the full-scale simulation approach, which allow the most complete information from the existing projects of creation of socio-economic systems to be extracted, are proposed. The statement of the problem is given, the method and algorithm of the full-scale simulation study of the efficiency of incentive functions is developed. The results of the study are presented. It is shown that the use of quadratic and piecewise linear functions of incentive allows the time and costs for creating social and economic systems to be reduced by 10%-15%.

Axisymmetric alternating direction explicit scheme for efficient coupled simulation of hydro-mechanical interaction in geotechnical engineering—Application to circular footing and deep tunnel in saturated ground

Directory of Open Access Journals (Sweden)

Simon Heru Prassetyo

2018-04-01

Full Text Available Explicit solution techniques have been widely used in geotechnical engineering for simulating the coupled hydro-mechanical (H-M interaction of fluid flow and deformation induced by structures built above and under saturated ground, i.e. circular footing and deep tunnel. However, the technique is only conditionally stable and requires small time steps, portending its inefficiency for simulating large-scale H-M problems. To improve its efficiency, the unconditionally stable alternating direction explicit (ADE scheme could be used to solve the flow problem. The standard ADE scheme, however, is only moderately accurate and is restricted to uniform grids and plane strain flow conditions. This paper aims to remove these drawbacks by developing a novel high-order ADE scheme capable of solving flow problems in non-uniform grids and under axisymmetric conditions. The new scheme is derived by performing a fourth-order finite difference (FD approximation to the spatial derivatives of the axisymmetric fluid–diffusion equation in a non-uniform grid configuration. The implicit Crank-Nicolson technique is then applied to the resulting approximation, and the subsequent equation is split into two alternating direction sweeps, giving rise to a new axisymmetric ADE scheme. The pore pressure solutions from the new scheme are then sequentially coupled with an existing geomechanical simulator in the computer code fast Lagrangian analysis of continua (FLAC. This coupling procedure is called the sequentially-explicit coupling technique based on the fourth-order axisymmetric ADE scheme or SEA-4-AXI. Application of SEA-4-AXI for solving axisymmetric consolidation of a circular footing and of advancing tunnel in deep saturated ground shows that SEA-4-AXI reduces computer runtime up to 42%–50% that of FLAC's basic scheme without numerical instability. In addition, it produces high numerical accuracy of the H-M solutions with average percentage difference of only 0.5%�

Sequential Generalized Transforms on Function Space

Directory of Open Access Journals (Sweden)

Jae Gil Choi

2013-01-01

Full Text Available We define two sequential transforms on a function space Ca,b[0,T] induced by generalized Brownian motion process. We then establish the existence of the sequential transforms for functionals in a Banach algebra of functionals on Ca,b[0,T]. We also establish that any one of these transforms acts like an inverse transform of the other transform. Finally, we give some remarks about certain relations between our sequential transforms and other well-known transforms on Ca,b[0,T].

Formation of non-extractable pesticide residues: observations on compound differences, measurement and regulatory issues

Energy Technology Data Exchange (ETDEWEB)

Mordaunt, Catriona J.; Gevao, Bondi; Jones, Kevin C.; Semple, Kirk T

2005-01-01

Six major use pesticides (Atrazine, Dicamba, Isoproturon, Lindane, Paraquat and Trifluralin) with differing physico-chemical properties were evaluated for the significance of 'bound' or non extractable residue formation. Investigations were carried out in purpose-built microcosms where mineralization, volatilisation, 'soil water' extractable and organic solvent extractable residues could be quantified. Extractable residues were defined as those accessible by sequential extraction where the solvent used became increasingly non-polar. Dichloromethane was the 'harshest' solvent used at the end of the sequential extraction procedure. {sup 14}C-labelled volatilised and {sup 14}CO{sub 2} fractions were trapped on exit from the microcosm. The pesticides were categorised into 3 classes based on their behaviour. (i) Type A (Atrazine, Lindane and Trifluralin) in which ring degradation was limited as was the formation of non-extractable residues; the remainder of the {sup 14}C-activity was found in the extractable fraction. (ii) Type B (Dicamba and Isoproturon) in which approximately 25% of the {sup 14}C-activity was mineralised and a large portion was found in the non-extractable fraction after 91 days. Finally, Type C (Paraquat) in which almost all of the {sup 14}C-activity was quickly incorporated into the non-extractable fraction. The implications of the data are discussed, with respect to the variability and significance of regulatory aspects of non-extractable residues.

Formation of non-extractable pesticide residues: observations on compound differences, measurement and regulatory issues

International Nuclear Information System (INIS)

Mordaunt, Catriona J.; Gevao, Bondi; Jones, Kevin C.; Semple, Kirk T.

2005-01-01

Six major use pesticides (Atrazine, Dicamba, Isoproturon, Lindane, Paraquat and Trifluralin) with differing physico-chemical properties were evaluated for the significance of 'bound' or non extractable residue formation. Investigations were carried out in purpose-built microcosms where mineralization, volatilisation, 'soil water' extractable and organic solvent extractable residues could be quantified. Extractable residues were defined as those accessible by sequential extraction where the solvent used became increasingly non-polar. Dichloromethane was the 'harshest' solvent used at the end of the sequential extraction procedure. 14 C-labelled volatilised and 14 CO 2 fractions were trapped on exit from the microcosm. The pesticides were categorised into 3 classes based on their behaviour. (i) Type A (Atrazine, Lindane and Trifluralin) in which ring degradation was limited as was the formation of non-extractable residues; the remainder of the 14 C-activity was found in the extractable fraction. (ii) Type B (Dicamba and Isoproturon) in which approximately 25% of the 14 C-activity was mineralised and a large portion was found in the non-extractable fraction after 91 days. Finally, Type C (Paraquat) in which almost all of the 14 C-activity was quickly incorporated into the non-extractable fraction. The implications of the data are discussed, with respect to the variability and significance of regulatory aspects of non-extractable residues

Forged Signature Distinction Using Convolutional Neural Network for Feature Extraction

Directory of Open Access Journals (Sweden)

Seungsoo Nam

2018-01-01

Full Text Available This paper proposes a dynamic verification scheme for finger-drawn signatures in smartphones. As a dynamic feature, the movement of a smartphone is recorded with accelerometer sensors in the smartphone, in addition to the moving coordinates of the signature. To extract high-level longitudinal and topological features, the proposed scheme uses a convolution neural network (CNN for feature extraction, and not as a conventional classifier. We assume that a CNN trained with forged signatures can extract effective features (called S-vector, which are common in forging activities such as hesitation and delay before drawing the complicated part. The proposed scheme also exploits an autoencoder (AE as a classifier, and the S-vector is used as the input vector to the AE. An AE has high accuracy for the one-class distinction problem such as signature verification, and is also greatly dependent on the accuracy of input data. S-vector is valuable as the input of AE, and, consequently, could lead to improved verification accuracy especially for distinguishing forged signatures. Compared to the previous work, i.e., the MLP-based finger-drawn signature verification scheme, the proposed scheme decreases the equal error rate by 13.7%, specifically, from 18.1% to 4.4%, for discriminating forged signatures.

Dynamic spectro-polarimeter based on a modified Michelson interferometric scheme.

Science.gov (United States)

Dembele, Vamara; Jin, Moonseob; Baek, Byung-Joon; Kim, Daesuk

2016-06-27

A simple dynamic spectro-polarimeter based on a modified Michelson interferometric scheme is described. The proposed system can extract a spectral Stokes vector of a transmissive anisotropic object. Detail theoretical background is derived and experiments are conducted to verify the feasibility of the proposed novel snapshot spectro-polarimeter. The proposed dynamic spectro-polarimeter enables us to extract highly accurate spectral Stokes vector of any transmissive anisotropic object with a frame rate of more than 20Hz.

Screening antimutagenic and antiproliferative properties of extracts isolated from Jackfruit pulp (Artocarpus heterophyllus Lam).

Science.gov (United States)

Ruiz-Montañez, G; Burgos-Hernández, A; Calderón-Santoyo, M; López-Saiz, C M; Velázquez-Contreras, C A; Navarro-Ocaña, A; Ragazzo-Sánchez, J A

2015-05-15

The present focused on the study of the antimutagenic and antiproliferative potential of pulp Jackfruit (Artocarpus heterophyllus Lam) extract, using Salmonella typhimurium tester strains TA98 and TA100 with metabolic activation (S9) and a cancer cell line M12.C3.F6 (murine B-cell lymphoma), respectively. Jackfruit pulp extract was sequentially fractionated by chromatography (RP-HPLC) and each fraction was tested for antimutagenic and antiproliferative activities. The organic extracts obtained from Jackfruit pulp reduced the number of revertants caused by aflatoxin B1 (AFB1) and proliferation of cells M12.C3.F6; a dose-response relationship was showed. Sequential RP-HPLC fractionation of the active extracts produced both antimutagenic and/or antiproliferative fractions. These results suggested that the Jackfruit contained compounds with chemoprotective properties to reduce the mutagenicity of AFB1, also proliferation of a cancer cell line. Copyright © 2014 Elsevier Ltd. All rights reserved.

Fast determination of trace elements in organic fertilizers using a cup-horn reactor for ultrasound-assisted extraction and fast sequential flame atomic absorption spectrometry.

Science.gov (United States)

Teixeira, Leonel Silva; Vieira, Heulla Pereira; Windmöller, Cláudia Carvalhinho; Nascentes, Clésia Cristina

2014-02-01

A fast and accurate method based on ultrasound-assisted extraction in a cup-horn sonoreactor was developed to determine the total content of Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn in organic fertilizers by fast sequential flame atomic absorption spectrometry (FS FAAS). Multivariate optimization was used to establish the optimal conditions for the extraction procedure. An aliquot containing approximately 120 mg of the sample was added to a 500 µL volume of an acid mixture (HNO3/HCl/HF, 5:3:3, v/v/v). After a few minutes, 500 µL of deionized water was added and eight samples were simultaneously sonicated for 10 min at 50% amplitude, allowing a sample throughput of 32 extractions per hour. The performance of the method was evaluated with a certified reference material of sewage sludge (CRM 029). The precision, expressed as the relative standard deviation, ranged from 0.58% to 5.6%. The recoveries of analytes were found to 100%, 109%, 96%, 92%, 101%, 104% and 102% for Cd, Cr, Cu, Mn, Ni, Pb and Zn, respectively. The linearity, limit of detection and limit of quantification were calculated and the values obtained were adequate for the quality control of organic fertilizers. The method was applied to the analysis of several commercial organic fertilizers and organic wastes used as fertilizers, and the results were compared with those obtained using the microwave digestion procedure. A good agreement was found between the results obtained by microwave and ultrasound procedures with recoveries ranging from 80.4% to 117%. Two organic waste samples were not in accordance with the Brazilian legislation regarding the acceptable levels of contaminants. © 2013 Published by Elsevier B.V.

Sequential probability ratio controllers for safeguards radiation monitors

International Nuclear Information System (INIS)

Fehlau, P.E.; Coop, K.L.; Nixon, K.V.

1984-01-01

Sequential hypothesis tests applied to nuclear safeguards accounting methods make the methods more sensitive to detecting diversion. The sequential tests also improve transient signal detection in safeguards radiation monitors. This paper describes three microprocessor control units with sequential probability-ratio tests for detecting transient increases in radiation intensity. The control units are designed for three specific applications: low-intensity monitoring with Poisson probability ratios, higher intensity gamma-ray monitoring where fixed counting intervals are shortened by sequential testing, and monitoring moving traffic where the sequential technique responds to variable-duration signals. The fixed-interval controller shortens a customary 50-s monitoring time to an average of 18 s, making the monitoring delay less bothersome. The controller for monitoring moving vehicles benefits from the sequential technique by maintaining more than half its sensitivity when the normal passage speed doubles

Performance analysis of switch-based multiuser scheduling schemes with adaptive modulation in spectrum sharing systems

KAUST Repository

Qaraqe, Marwa

2014-04-01

This paper focuses on the development of multiuser access schemes for spectrum sharing systems whereby secondary users are allowed to share the spectrum with primary users under the condition that the interference observed at the primary receiver is below a predetermined threshold. In particular, two scheduling schemes are proposed for selecting a user among those that satisfy the interference constraint and achieve an acceptable signal-to-noise ratio level. The first scheme focuses on optimizing the average spectral efficiency by selecting the user that reports the best channel quality. In order to alleviate the relatively high feedback required by the first scheme, a second scheme based on the concept of switched diversity is proposed, where the base station (BS) scans the secondary users in a sequential manner until a user whose channel quality is above an acceptable predetermined threshold is found. We develop expressions for the statistics of the signal-to-interference and noise ratio as well as the average spectral efficiency, average feedback load, and the delay at the secondary BS. We then present numerical results for the effect of the number of users and the interference constraint on the optimal switching threshold and the system performance and show that our analysis results are in perfect agreement with the numerical results. © 2014 John Wiley & Sons, Ltd.

Biased lineups: sequential presentation reduces the problem.

Science.gov (United States)

Lindsay, R C; Lea, J A; Nosworthy, G J; Fulford, J A; Hector, J; LeVan, V; Seabrook, C

1991-12-01

Biased lineups have been shown to increase significantly false, but not correct, identification rates (Lindsay, Wallbridge, & Drennan, 1987; Lindsay & Wells, 1980; Malpass & Devine, 1981). Lindsay and Wells (1985) found that sequential lineup presentation reduced false identification rates, presumably by reducing reliance on relative judgment processes. Five staged-crime experiments were conducted to examine the effect of lineup biases and sequential presentation on eyewitness recognition accuracy. Sequential lineup presentation significantly reduced false identification rates from fair lineups as well as from lineups biased with regard to foil similarity, instructions, or witness attire, and from lineups biased in all of these ways. The results support recommendations that police present lineups sequentially.

A new Identity Based Encryption (IBE) scheme using extended Chebyshev polynomial over finite fields Zp

International Nuclear Information System (INIS)

Benasser Algehawi, Mohammed; Samsudin, Azman

2010-01-01

We present a method to extract key pairs needed for the Identity Based Encryption (IBE) scheme from extended Chebyshev polynomial over finite fields Z p . Our proposed scheme relies on the hard problem and the bilinear property of the extended Chebyshev polynomial over Z p . The proposed system is applicable, secure, and reliable.

The Origin of Sequential Chromospheric Brightenings

Science.gov (United States)

Kirk, M. S.; Balasubramaniam, K. S.; Jackiewicz, J.; Gilbert, H. R.

2017-06-01

Sequential chromospheric brightenings (SCBs) are often observed in the immediate vicinity of erupting flares and are associated with coronal mass ejections. Since their initial discovery in 2005, there have been several subsequent investigations of SCBs. These studies have used differing detection and analysis techniques, making it difficult to compare results between studies. This work employs the automated detection algorithm of Kirk et al. (Solar Phys. 283, 97, 2013) to extract the physical characteristics of SCBs in 11 flares of varying size and intensity. We demonstrate that the magnetic substructure within the SCB appears to have a significantly smaller area than the corresponding Hα emission. We conclude that SCBs originate in the lower corona around 0.1 R_{⊙} above the photosphere, propagate away from the flare center at speeds of 35 - 85 km s^{-1}, and have peak photosphere magnetic intensities of 148±2.9 G. In light of these measurements, we infer SCBs to be distinctive chromospheric signatures of erupting coronal mass ejections.

Lineup composition, suspect position, and the sequential lineup advantage.

Science.gov (United States)

Carlson, Curt A; Gronlund, Scott D; Clark, Steven E

2008-06-01

N. M. Steblay, J. Dysart, S. Fulero, and R. C. L. Lindsay (2001) argued that sequential lineups reduce the likelihood of mistaken eyewitness identification. Experiment 1 replicated the design of R. C. L. Lindsay and G. L. Wells (1985), the first study to show the sequential lineup advantage. However, the innocent suspect was chosen at a lower rate in the simultaneous lineup, and no sequential lineup advantage was found. This led the authors to hypothesize that protection from a sequential lineup might emerge only when an innocent suspect stands out from the other lineup members. In Experiment 2, participants viewed a simultaneous or sequential lineup with either the guilty suspect or 1 of 3 innocent suspects. Lineup fairness was varied to influence the degree to which a suspect stood out. A sequential lineup advantage was found only for the unfair lineups. Additional analyses of suspect position in the sequential lineups showed an increase in the diagnosticity of suspect identifications as the suspect was placed later in the sequential lineup. These results suggest that the sequential lineup advantage is dependent on lineup composition and suspect position. (c) 2008 APA, all rights reserved

An adaptive hybrid EnKF-OI scheme for efficient state-parameter estimation of reactive contaminant transport models

KAUST Repository

El Gharamti, Mohamad; Valstar, Johan R.; Hoteit, Ibrahim

2014-01-01

Reactive contaminant transport models are used by hydrologists to simulate and study the migration and fate of industrial waste in subsurface aquifers. Accurate transport modeling of such waste requires clear understanding of the system's parameters, such as sorption and biodegradation. In this study, we present an efficient sequential data assimilation scheme that computes accurate estimates of aquifer contamination and spatially variable sorption coefficients. This assimilation scheme is based on a hybrid formulation of the ensemble Kalman filter (EnKF) and optimal interpolation (OI) in which solute concentration measurements are assimilated via a recursive dual estimation of sorption coefficients and contaminant state variables. This hybrid EnKF-OI scheme is used to mitigate background covariance limitations due to ensemble under-sampling and neglected model errors. Numerical experiments are conducted with a two-dimensional synthetic aquifer in which cobalt-60, a radioactive contaminant, is leached in a saturated heterogeneous clayey sandstone zone. Assimilation experiments are investigated under different settings and sources of model and observational errors. Simulation results demonstrate that the proposed hybrid EnKF-OI scheme successfully recovers both the contaminant and the sorption rate and reduces their uncertainties. Sensitivity analyses also suggest that the adaptive hybrid scheme remains effective with small ensembles, allowing to reduce the ensemble size by up to 80% with respect to the standard EnKF scheme. © 2014 Elsevier Ltd.

An adaptive hybrid EnKF-OI scheme for efficient state-parameter estimation of reactive contaminant transport models

KAUST Repository

El Gharamti, Mohamad

2014-09-01

Reactive contaminant transport models are used by hydrologists to simulate and study the migration and fate of industrial waste in subsurface aquifers. Accurate transport modeling of such waste requires clear understanding of the system\\'s parameters, such as sorption and biodegradation. In this study, we present an efficient sequential data assimilation scheme that computes accurate estimates of aquifer contamination and spatially variable sorption coefficients. This assimilation scheme is based on a hybrid formulation of the ensemble Kalman filter (EnKF) and optimal interpolation (OI) in which solute concentration measurements are assimilated via a recursive dual estimation of sorption coefficients and contaminant state variables. This hybrid EnKF-OI scheme is used to mitigate background covariance limitations due to ensemble under-sampling and neglected model errors. Numerical experiments are conducted with a two-dimensional synthetic aquifer in which cobalt-60, a radioactive contaminant, is leached in a saturated heterogeneous clayey sandstone zone. Assimilation experiments are investigated under different settings and sources of model and observational errors. Simulation results demonstrate that the proposed hybrid EnKF-OI scheme successfully recovers both the contaminant and the sorption rate and reduces their uncertainties. Sensitivity analyses also suggest that the adaptive hybrid scheme remains effective with small ensembles, allowing to reduce the ensemble size by up to 80% with respect to the standard EnKF scheme. © 2014 Elsevier Ltd.

Extraction and separation of U(VI and Th(IV from hydrobromic acid media using Cyanex-923 extractant

Directory of Open Access Journals (Sweden)

Ghag Snehal M.

2010-01-01

Full Text Available A systematic study of the solvent extraction of uranium(VI and thorium(IV from hydrobromic acid media was performed using the neutral phosphine oxide extractant Cyanex-923 in toluene. These metal ions were found to be quantitatively extracted with Cyanex-923 in toluene in the acidity range 5x10-5-1x10-4 M and 5x10-5-5x10-3 M, respectively, and they are stripped from the organic phase with 7.0 M HClO4 and 2.0- 4.0 M HCl, respectively. The effect of the equilibrium period, diluents, diverse ions and stripping agent on the extraction of U(VI and Th(IV was studied. The stoichiometry of the extracted species of these metal ions was determined based on the slope analysis method. The extraction reactions proceed by solvation and their probable extracted species found in the organic phase were UO2Br2•2Cyanex-923 and ThBr4•2Cyanex-923. Based on these results, a sequential procedure for their separation from each other was developed.

Tradable permit allocations and sequential choice

Energy Technology Data Exchange (ETDEWEB)

MacKenzie, Ian A. [Centre for Economic Research, ETH Zuerich, Zurichbergstrasse 18, 8092 Zuerich (Switzerland)

2011-01-15

This paper investigates initial allocation choices in an international tradable pollution permit market. For two sovereign governments, we compare allocation choices that are either simultaneously or sequentially announced. We show sequential allocation announcements result in higher (lower) aggregate emissions when announcements are strategic substitutes (complements). Whether allocation announcements are strategic substitutes or complements depends on the relationship between the follower's damage function and governments' abatement costs. When the marginal damage function is relatively steep (flat), allocation announcements are strategic substitutes (complements). For quadratic abatement costs and damages, sequential announcements provide a higher level of aggregate emissions. (author)

Sequential chemical extraction for a phosphogypsum environmental impact evaluation

Science.gov (United States)

Gennari, R. F.; Garcia, I.; Medina, N. H.; Silveira, M. A. G.

2013-05-01

Phosphogypsum (PG) is gypsum generated during phosphoric acid production. PG is stocked in large stacks or accumulated in lakes; it contains heavy metals and naturally occurring radioactive elements. The metal contamination may affect the functionality, sustainability and biodiversity of ecosystems. In this work, PG samples were analyzed by Plasma Spectrometry. Total metal content and in the extractable fraction of chemical elements were determined. For K, Ni, Zn, Cr, Cd, Ba, Pb and U, the results obtained are lower than those obtained in a Idaho plant are including and also lower than those found in the soil, indicating this PG sample analyzed probably will not cause any additional metal neither natural radiation contamination.

Applying the minimax principle to sequential mastery testing

NARCIS (Netherlands)

Vos, Hendrik J.

2002-01-01

The purpose of this paper is to derive optimal rules for sequential mastery tests. In a sequential mastery test, the decision is to classify a subject as a master, a nonmaster, or to continue sampling and administering another random item. The framework of minimax sequential decision theory (minimum

Sequential combination of k-t principle component analysis (PCA) and partial parallel imaging: k-t PCA GROWL.

Science.gov (United States)

Qi, Haikun; Huang, Feng; Zhou, Hongmei; Chen, Huijun

2017-03-01

k-t principle component analysis (k-t PCA) is a distinguished method for high spatiotemporal resolution dynamic MRI. To further improve the accuracy of k-t PCA, a combination with partial parallel imaging (PPI), k-t PCA/SENSE, has been tested. However, k-t PCA/SENSE suffers from long reconstruction time and limited improvement. This study aims to improve the combination of k-t PCA and PPI on both reconstruction speed and accuracy. A sequential combination scheme called k-t PCA GROWL (GRAPPA operator for wider readout line) was proposed. The GRAPPA operator was performed before k-t PCA to extend each readout line into a wider band, which improved the condition of the encoding matrix in the following k-t PCA reconstruction. k-t PCA GROWL was tested and compared with k-t PCA and k-t PCA/SENSE on cardiac imaging. k-t PCA GROWL consistently resulted in better image quality compared with k-t PCA/SENSE at high acceleration factors for both retrospectively and prospectively undersampled cardiac imaging, with a much lower computation cost. The improvement in image quality became greater with the increase of acceleration factor. By sequentially combining the GRAPPA operator and k-t PCA, the proposed k-t PCA GROWL method outperformed k-t PCA/SENSE in both reconstruction speed and accuracy, suggesting that k-t PCA GROWL is a better combination scheme than k-t PCA/SENSE. Magn Reson Med 77:1058-1067, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Classical and sequential limit analysis revisited

Science.gov (United States)

Leblond, Jean-Baptiste; Kondo, Djimédo; Morin, Léo; Remmal, Almahdi

2018-04-01

Classical limit analysis applies to ideal plastic materials, and within a linearized geometrical framework implying small displacements and strains. Sequential limit analysis was proposed as a heuristic extension to materials exhibiting strain hardening, and within a fully general geometrical framework involving large displacements and strains. The purpose of this paper is to study and clearly state the precise conditions permitting such an extension. This is done by comparing the evolution equations of the full elastic-plastic problem, the equations of classical limit analysis, and those of sequential limit analysis. The main conclusion is that, whereas classical limit analysis applies to materials exhibiting elasticity - in the absence of hardening and within a linearized geometrical framework -, sequential limit analysis, to be applicable, strictly prohibits the presence of elasticity - although it tolerates strain hardening and large displacements and strains. For a given mechanical situation, the relevance of sequential limit analysis therefore essentially depends upon the importance of the elastic-plastic coupling in the specific case considered.

Sequential Modular Position and Momentum Measurements of a Trapped Ion Mechanical Oscillator

Science.gov (United States)

Flühmann, C.; Negnevitsky, V.; Marinelli, M.; Home, J. P.

2018-04-01

The noncommutativity of position and momentum observables is a hallmark feature of quantum physics. However, this incompatibility does not extend to observables that are periodic in these base variables. Such modular-variable observables have been suggested as tools for fault-tolerant quantum computing and enhanced quantum sensing. Here, we implement sequential measurements of modular variables in the oscillatory motion of a single trapped ion, using state-dependent displacements and a heralded nondestructive readout. We investigate the commutative nature of modular variable observables by demonstrating no-signaling in time between successive measurements, using a variety of input states. Employing a different periodicity, we observe signaling in time. This also requires wave-packet overlap, resulting in quantum interference that we enhance using squeezed input states. The sequential measurements allow us to extract two-time correlators for modular variables, which we use to violate a Leggett-Garg inequality. Signaling in time and Leggett-Garg inequalities serve as efficient quantum witnesses, which we probe here with a mechanical oscillator, a system that has a natural crossover from the quantum to the classical regime.

Simultaneous versus sequential penetrating keratoplasty and cataract surgery.

Science.gov (United States)

Hayashi, Ken; Hayashi, Hideyuki

2006-10-01

To compare the surgical outcomes of simultaneous penetrating keratoplasty and cataract surgery with those of sequential surgery. Thirty-nine eyes of 39 patients scheduled for simultaneous keratoplasty and cataract surgery and 23 eyes of 23 patients scheduled for sequential keratoplasty and secondary phacoemulsification surgery were recruited. Refractive error, regular and irregular corneal astigmatism determined by Fourier analysis, and endothelial cell loss were studied at 1 week and 3, 6, and 12 months after combined surgery in the simultaneous surgery group or after subsequent phacoemulsification surgery in the sequential surgery group. At 3 and more months after surgery, mean refractive error was significantly greater in the simultaneous surgery group than in the sequential surgery group, although no difference was seen at 1 week. The refractive error at 12 months was within 2 D of that targeted in 15 eyes (39%) in the simultaneous surgery group and within 2 D in 16 eyes (70%) in the sequential surgery group; the incidence was significantly greater in the sequential group (P = 0.0344). The regular and irregular astigmatism was not significantly different between the groups at 3 and more months after surgery. No significant difference was also found in the percentage of endothelial cell loss between the groups. Although corneal astigmatism and endothelial cell loss were not different, refractive error from target refraction was greater after simultaneous keratoplasty and cataract surgery than after sequential surgery, indicating a better outcome after sequential surgery than after simultaneous surgery.

Tank waste remediation system optimized processing strategy with an altered treatment scheme

International Nuclear Information System (INIS)

Slaathaug, E.J.

1996-03-01

This report provides an alternative strategy evolved from the current Hanford Site Tank Waste Remediation System (TWRS) programmatic baseline for accomplishing the treatment and disposal of the Hanford Site tank wastes. This optimized processing strategy with an altered treatment scheme performs the major elements of the TWRS Program, but modifies the deployment of selected treatment technologies to reduce the program cost. The present program for development of waste retrieval, pretreatment, and vitrification technologies continues, but the optimized processing strategy reuses a single facility to accomplish the separations/low-activity waste (LAW) vitrification and the high-level waste (HLW) vitrification processes sequentially, thereby eliminating the need for a separate HLW vitrification facility

Solubility and Potential Mobility of Heavy Metals in Two Contaminated Urban Soils from Stockholm, Sweden

International Nuclear Information System (INIS)

Oborn, Ingrid; Linde, Mats

2001-01-01

The solubility and potential mobility of heavy metals (Cd, Cu,Hg, Pb and Zn) in two urban soils were studied by sequential and leaching extractions (rainwater). Compared to rural (arable) soils on similar parent material, the urban soils were highly contaminated with Hg and Pb and to a lesser extent also with Cd,Cu and Zn. Metal concentrations in rainwater leachates were related to sequential extractions and metal levels reported from Stockholm groundwater. Cadmium and Zn in the soils were mainly recovered in easily extractable fractions, whereas Cu and Pb were complex bound. Concentrations of Pb in the residual fraction were between two- and eightfold those in arable soils, indicating that the sequential extraction scheme did not reflect the solid phases affected by anthropogenic inputs. Cadmium and Zn conc. in the rainwater leachates were within the range detected in Stockholm groundwater, while Cu and Pb conc. were higher, which suggests that Cu and Pb released from the surface soil were immobilised in deeper soil layers. In a soil highly contaminated with Hg, the Hg conc. in the leachate was above the median concentration, but still 50 times lower than the max concentration found in groundwater, indicating the possibility of other sources. In conclusion, it proved difficult to quantitatively predict the mobility of metals in soils by sequential extractions

A blind video watermarking scheme resistant to rotation and collusion attacks

Directory of Open Access Journals (Sweden)

Amlan Karmakar

2016-04-01

Full Text Available In this paper, Discrete Cosine Transform (DCT based blind video watermarking algorithm is proposed, which is perceptually invisible and robust against rotation and collusion attacks. To make the scheme resistant against rotation, watermark is embedded within the square blocks, placed on the middle position of every luminance channel. Then Zernike moments of those square blocks are calculated. The rotation invariance property of the Complex Zernike moments is exploited to predict the rotation angle of the video at the time of extraction of watermark bits. To make the scheme robust against collusion, design of the scheme is done in such a way that the embedding blocks will vary for the successive frames of the video. A Pseudo Random Number (PRN generator and a permutation vector are used to achieve the goal. The experimental results show that the scheme is robust against conventional video attacks, rotation attack and collusion attacks.

A Secure Watermarking Scheme for Buyer-Seller Identification and Copyright Protection

Science.gov (United States)

Ahmed, Fawad; Sattar, Farook; Siyal, Mohammed Yakoob; Yu, Dan

2006-12-01

We propose a secure watermarking scheme that integrates watermarking with cryptography for addressing some important issues in copyright protection. We address three copyright protection issues—buyer-seller identification, copyright infringement, and ownership verification. By buyer-seller identification, we mean that a successful watermark extraction at the buyer's end will reveal the identities of the buyer and seller of the watermarked image. For copyright infringement, our proposed scheme enables the seller to identify the specific buyer from whom an illegal copy of the watermarked image has originated, and further prove this fact to a third party. For multiple ownership claims, our scheme enables a legal seller to claim his/her ownership in the court of law. We will show that the combination of cryptography with watermarking not only increases the security of the overall scheme, but it also enables to associate identities of buyer/seller with their respective watermarked images.

The LOCAL attack: Cryptanalysis of the authenticated encryption scheme ALE

DEFF Research Database (Denmark)

Khovratovich, Dmitry; Rechberger, Christian

2014-01-01

We show how to produce a forged (ciphertext, tag) pair for the scheme ALE with data and time complexity of 2102 ALE encryptions of short messages and the same number of authentication attempts. We use a differential attack based on a local collision, which exploits the availability of extracted...

A Novel Quantum Image Steganography Scheme Based on LSB

Science.gov (United States)

Zhou, Ri-Gui; Luo, Jia; Liu, XingAo; Zhu, Changming; Wei, Lai; Zhang, Xiafen

2018-06-01

Based on the NEQR representation of quantum images and least significant bit (LSB) scheme, a novel quantum image steganography scheme is proposed. The sizes of the cover image and the original information image are assumed to be 4 n × 4 n and n × n, respectively. Firstly, the bit-plane scrambling method is used to scramble the original information image. Then the scrambled information image is expanded to the same size of the cover image by using the key only known to the operator. The expanded image is scrambled to be a meaningless image with the Arnold scrambling. The embedding procedure and extracting procedure are carried out by K 1 and K 2 which are under control of the operator. For validation of the presented scheme, the peak-signal-to-noise ratio (PSNR), the capacity, the security of the images and the circuit complexity are analyzed.

Exploiting flow Injection and sequential injection schemes for trace metal determinations by electrothermal atomic absorption spectrometry

DEFF Research Database (Denmark)

Hansen, Elo Harald

Determination of low or trace-level amounts of metals by electrothermal atomic absorption spectrometry (ETAAS) often requires the use of suitable preconcentration and/or separation procedures in order to attain the necessary sensitivity and selectivity. Such schemes are advantageously executed...... by superior performance and versatility. In fact, two approaches are conceivable: The analyte-loaded ion-exchange beads might either be transported directly into the graphite tube where they are pyrolized and the measurand is atomized and quantified; or the loaded beads can be eluted and the eluate forwarded...

Trial Sequential Methods for Meta-Analysis

Science.gov (United States)

Kulinskaya, Elena; Wood, John

2014-01-01

Statistical methods for sequential meta-analysis have applications also for the design of new trials. Existing methods are based on group sequential methods developed for single trials and start with the calculation of a required information size. This works satisfactorily within the framework of fixed effects meta-analysis, but conceptual…

Sequentially pulsed traveling wave accelerator

Science.gov (United States)

Caporaso, George J [Livermore, CA; Nelson, Scott D [Patterson, CA; Poole, Brian R [Tracy, CA

2009-08-18

A sequentially pulsed traveling wave compact accelerator having two or more pulse forming lines each with a switch for producing a short acceleration pulse along a short length of a beam tube, and a trigger mechanism for sequentially triggering the switches so that a traveling axial electric field is produced along the beam tube in synchronism with an axially traversing pulsed beam of charged particles to serially impart energy to the particle beam.

Scheme for entanglement concentration of unknown atomic entangled states by interference of polarized photons

Energy Technology Data Exchange (ETDEWEB)

Wang, Hong-Fu; Zhu, Ai-Dong; Zhang, Shou [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Yeon, Kyu-Hwang, E-mail: hfwang@ybu.edu.c, E-mail: szhang@ybu.edu.c [Department of Physics and BK21 Program for Device Physics, College of Natural Science, Chungbuk National University, Cheongju, Chungbuk 361-763 (Korea, Republic of)

2010-12-14

Based on the interference effect of polarized photons, we propose a practical scheme for entanglement concentration of unknown atomic entangled states. In the scheme, two {lambda}{lambda}-type atoms belonging to different entangled pairs are individually trapped in two spatially separated cavities. By the subsequent detection of the polarized photons leaking out of the separate optical cavities, Alice and Bob as two distant parties can probabilistically extract one maximally entangled four-atom Greenberger-Horne-Zeilinger (GHZ) state from two identical partially entangled Einstein-Podolsky-Rosen (EPR) pairs. We also discuss the influence of cavity decay on the success probability of the scheme. The scheme is feasible and within the reach of current experimental technology.

A fully-automated multiscale kernel graph cuts based particle localization scheme for temporal focusing two-photon microscopy

Science.gov (United States)

Huang, Xia; Li, Chunqiang; Xiao, Chuan; Sun, Wenqing; Qian, Wei

2017-03-01

The temporal focusing two-photon microscope (TFM) is developed to perform depth resolved wide field fluorescence imaging by capturing frames sequentially. However, due to strong nonignorable noises and diffraction rings surrounding particles, further researches are extremely formidable without a precise particle localization technique. In this paper, we developed a fully-automated scheme to locate particles positions with high noise tolerance. Our scheme includes the following procedures: noise reduction using a hybrid Kalman filter method, particle segmentation based on a multiscale kernel graph cuts global and local segmentation algorithm, and a kinematic estimation based particle tracking method. Both isolated and partial-overlapped particles can be accurately identified with removal of unrelated pixels. Based on our quantitative analysis, 96.22% isolated particles and 84.19% partial-overlapped particles were successfully detected.

Phytochemical constituents and antimicrobial activity of leaf extracts ...

African Journals Online (AJOL)

USER

2010-05-24

May 24, 2010 ... conventionally used to control microbial growth and survival (Nascimento et al., ... The leaves were air-dried to crispiness in the laboratory at room temperature of 25. - 260C. ... and sequentially extracted in cold with 2 × 1L of distilled hexane, ethyl acetate ..... medicinal plants on smooth muscle. AB Abstract ...

On Converting Secret Sharing Scheme to Visual Secret Sharing Scheme

Directory of Open Access Journals (Sweden)

Wang Daoshun

2010-01-01

Full Text Available Abstract Traditional Secret Sharing (SS schemes reconstruct secret exactly the same as the original one but involve complex computation. Visual Secret Sharing (VSS schemes decode the secret without computation, but each share is m times as big as the original and the quality of the reconstructed secret image is reduced. Probabilistic visual secret sharing (Prob.VSS schemes for a binary image use only one subpixel to share the secret image; however the probability of white pixels in a white area is higher than that in a black area in the reconstructed secret image. SS schemes, VSS schemes, and Prob. VSS schemes have various construction methods and advantages. This paper first presents an approach to convert (transform a -SS scheme to a -VSS scheme for greyscale images. The generation of the shadow images (shares is based on Boolean XOR operation. The secret image can be reconstructed directly by performing Boolean OR operation, as in most conventional VSS schemes. Its pixel expansion is significantly smaller than that of VSS schemes. The quality of the reconstructed images, measured by average contrast, is the same as VSS schemes. Then a novel matrix-concatenation approach is used to extend the greyscale -SS scheme to a more general case of greyscale -VSS scheme.

Discretisation Schemes for Level Sets of Planar Gaussian Fields

Science.gov (United States)

Beliaev, D.; Muirhead, S.

2018-01-01

Smooth random Gaussian functions play an important role in mathematical physics, a main example being the random plane wave model conjectured by Berry to give a universal description of high-energy eigenfunctions of the Laplacian on generic compact manifolds. Our work is motivated by questions about the geometry of such random functions, in particular relating to the structure of their nodal and level sets. We study four discretisation schemes that extract information about level sets of planar Gaussian fields. Each scheme recovers information up to a different level of precision, and each requires a maximum mesh-size in order to be valid with high probability. The first two schemes are generalisations and enhancements of similar schemes that have appeared in the literature (Beffara and Gayet in Publ Math IHES, 2017. https://doi.org/10.1007/s10240-017-0093-0; Mischaikow and Wanner in Ann Appl Probab 17:980-1018, 2007); these give complete topological information about the level sets on either a local or global scale. As an application, we improve the results in Beffara and Gayet (2017) on Russo-Seymour-Welsh estimates for the nodal set of positively-correlated planar Gaussian fields. The third and fourth schemes are, to the best of our knowledge, completely new. The third scheme is specific to the nodal set of the random plane wave, and provides global topological information about the nodal set up to `visible ambiguities'. The fourth scheme gives a way to approximate the mean number of excursion domains of planar Gaussian fields.

Immobilization of Pb, Cd, and Zn in a contaminated soil using eggshell and banana stem amendments: metal leachability and a sequential extraction study.

Science.gov (United States)

Ashrafi, Mehrnaz; Mohamad, Sharifah; Yusoff, Ismail; Shahul Hamid, Fauziah

2015-01-01

Heavy-metal-contaminated soil is one of the major environmental pollution issues all over the world. In this study, two low-cost amendments, inorganic eggshell and organic banana stem, were applied to slightly alkaline soil for the purpose of in situ immobilization of Pb, Cd, and Zn. The artificially metal-contaminated soil was treated with 5% eggshell or 10% banana stem. To simulate the rainfall conditions, a metal leaching experiment for a period of 12 weeks was designed, and the total concentrations of the metals in the leachates were determined every 2 weeks. The results from the metal leaching analysis revealed that eggshell amendment generally reduced the concentrations of Pb, Cd, and Zn in the leachates, whereas banana stem amendment was effective only on the reduction of Cd concentration in the leachates. A sequential extraction analysis was carried out at the end of the experiment to find out the speciation of the heavy metals in the amended soils. Eggshell amendment notably decreased mobility of Pb, Cd, and Zn in the soil by transforming their readily available forms to less accessible fractions. Banana stem amendment also reduced exchangeable form of Cd and increased its residual form in the soil.

An Efficient System Based On Closed Sequential Patterns for Web Recommendations

OpenAIRE

Utpala Niranjan; R.B.V. Subramanyam; V-Khana

2010-01-01

Sequential pattern mining, since its introduction has received considerable attention among the researchers with broad applications. The sequential pattern algorithms generally face problems when mining long sequential patterns or while using very low support threshold. One possible solution of such problems is by mining the closed sequential patterns, which is a condensed representation of sequential patterns. Recently, several researchers have utilized the sequential pattern discovery for d...

A Multigrid NLS-4DVar Data Assimilation Scheme with Advanced Research WRF (ARW)

Science.gov (United States)

Zhang, H.; Tian, X.

2017-12-01

The motions of the atmosphere have multiscale properties in space and/or time, and the background error covariance matrix (Β) should thus contain error information at different correlation scales. To obtain an optimal analysis, the multigrid three-dimensional variational data assimilation scheme is used widely when sequentially correcting errors from large to small scales. However, introduction of the multigrid technique into four-dimensional variational data assimilation is not easy, due to its strong dependence on the adjoint model, which has extremely high computational costs in data coding, maintenance, and updating. In this study, the multigrid technique was introduced into the nonlinear least-squares four-dimensional variational assimilation (NLS-4DVar) method, which is an advanced four-dimensional ensemble-variational method that can be applied without invoking the adjoint models. The multigrid NLS-4DVar (MG-NLS-4DVar) scheme uses the number of grid points to control the scale, with doubling of this number when moving from a coarse to a finer grid. Furthermore, the MG-NLS-4DVar scheme not only retains the advantages of NLS-4DVar, but also sufficiently corrects multiscale errors to achieve a highly accurate analysis. The effectiveness and efficiency of the proposed MG-NLS-4DVar scheme were evaluated by several groups of observing system simulation experiments using the Advanced Research Weather Research and Forecasting Model. MG-NLS-4DVar outperformed NLS-4DVar, with a lower computational cost.

Porting Gravitational Wave Signal Extraction to Parallel Virtual Machine (PVM)

Science.gov (United States)

Thirumalainambi, Rajkumar; Thompson, David E.; Redmon, Jeffery

2009-01-01

Laser Interferometer Space Antenna (LISA) is a planned NASA-ESA mission to be launched around 2012. The Gravitational Wave detection is fundamentally the determination of frequency, source parameters, and waveform amplitude derived in a specific order from the interferometric time-series of the rotating LISA spacecrafts. The LISA Science Team has developed a Mock LISA Data Challenge intended to promote the testing of complicated nested search algorithms to detect the 100-1 millihertz frequency signals at amplitudes of 10E-21. However, it has become clear that, sequential search of the parameters is very time consuming and ultra-sensitive; hence, a new strategy has been developed. Parallelization of existing sequential search algorithms of Gravitational Wave signal identification consists of decomposing sequential search loops, beginning with outermost loops and working inward. In this process, the main challenge is to detect interdependencies among loops and partitioning the loops so as to preserve concurrency. Existing parallel programs are based upon either shared memory or distributed memory paradigms. In PVM, master and node programs are used to execute parallelization and process spawning. The PVM can handle process management and process addressing schemes using a virtual machine configuration. The task scheduling and the messaging and signaling can be implemented efficiently for the LISA Gravitational Wave search process using a master and 6 nodes. This approach is accomplished using a server that is available at NASA Ames Research Center, and has been dedicated to the LISA Data Challenge Competition. Historically, gravitational wave and source identification parameters have taken around 7 days in this dedicated single thread Linux based server. Using PVM approach, the parameter extraction problem can be reduced to within a day. The low frequency computation and a proxy signal-to-noise ratio are calculated in separate nodes that are controlled by the master

Industrial wastewater treatment network based on recycling and rerouting strategies for retrofit design schemes

DEFF Research Database (Denmark)

Sueviriyapan, Natthapong; Suriyapraphadilok, Uthaiporn; Siemanond, Kitipat

2015-01-01

a generic model-based synthesis and design framework for retrofit wastewater treatment networks (WWTN) of an existing industrial process. The developed approach is suitable for grassroots and retrofit systems and adaptable to a wide range of wastewater treatment problems. A sequential solution procedure...... is employed to solve a network superstructure-based optimization problem formulated as Mixed Integer Linear and/or Non-Linear Programming (MILP/MINLP). Data from a petroleum refinery effluent treatment plant together with special design constraints are employed to formulate different design schemes based...... for the future development of the existing wastewater treatment process....

Sequential chemical extraction of heavy metals in a study of the chemical alteration of mine tailings at Ticapampa (Huaraz, Peru); Extraccion quimica secuencial de metales pesados en el estudio de alteracion quimica de relaves de mina en Ticapampa (Huaraz, Peru)

Energy Technology Data Exchange (ETDEWEB)

Jara Facundo, M. A.

2011-07-01

The upper reaches of the Rio Santa (Huaraz, Peru) are highly affected by the mining activities of generally small and very small mining companies located in two specific areas, Cordillera Blanca, and Cordillera Negra, with the largest mining claims located in the districts of Recuay and Ticapampa. To assess the mobility and bioavailability of heavy metals in the abandoned tailings pond belonging to the Alianza mining company in the district of Ticapampa, and to identify the fractions to which they are associated we applied a sequential chemical extraction. The results were compared with studies into their mineralogical characterization, a quantitative chemical analysis and a determination of potential acidity and potential neutralization by the ABA (acid-base accounting) method applied to samples of tailings. The sequential extraction procedure confirmed the mode of general alteration observed in the area through mineralogical studies: a relatively easy mobility of Pb, and Cd, and considerable immobility with regard to Ag, Cr and Co, as well as an intermediate mobility of Cu, Zn, and As. Significant cadmium and lead contents found in the most mobile fractions of the tailings may represent an environmental threat, bearing in mind the toxic nature of these elements. Despite the low mobility of arsenic, the total quantities of this element are so high that the waters of the Rio Santa are being affected. (Author) 22 refs.

Speciation of heavy metals Cu, Ni and Zn by modified BCR sequential extraction procedure in sediments from Banten Bay, Banten Province, Indonesia

Science.gov (United States)

Lestari; Budiyanto, F.; Hindarti, D.

2018-02-01

Banten Bay is categorized as a marine area that is busy with marine tourism activities, settlements and also industries. One potential impact of the condition is the occurrence of pollution from both industrial and domestic sources, erosion and sedimentation in the coastal environment. Samples were collected from 25 representative stations in April 2016. Chemical speciation of three heavy metals (Cu, Ni, and Zn) was studied using a modified sequential extraction procedure proposed by the European Standard, Measurements and Testing (SM&T) program, formerly the Community Bureau of Reference (BCR). The aims of this study are to determine geochemical speciation of 4 bounds of metal: acid-soluble, reducible, oxidizable and residual, and to assess their impacts in the sediments of Banten Bay, Indonesia. The result shows that the percentage of Copper (45.90-83.75%), Nickel (18.28-65.66%), and Zinc (30.45-79.51%) were mostly accumulated in residual fraction of the total concentrations. The Risk Assessment Code (RAC) reveals that about 0-7.07% of Copper and 1.11-24.35 % of Zinc at sites exist in exchangeable fraction and therefore, they are in low risk category. While 7.34-34.90 of Ni at sites exists in exchangeable fraction and therefore, it is in medium risk category to aquatic environment.

Heavy metal speciation in solid-phase materials from a bacterial sulfate reducing bioreactor using sequential extraction procedure combined with acid volatile sulfide analysis.

Science.gov (United States)

Jong, Tony; Parry, David L

2004-04-01

Heavy metal mobility, bioavailability and toxicity depends largely on the chemical form of metals and ultimately determines potential for environmental pollution. For this reason, determining the chemical form of heavy metals and metalloids, immobilized in sludges by biological mediated sulfate reduction, is important to evaluate their mobility and bioavailability. A modified Tessier sequential extraction procedure (SEP), complemented with acid volatile sulfide (AVS) and simultaneous extracted metals (SEM) measurements, were applied to determine the partitioning of five heavy metals (defined as Fe, Ni, Zn and Cu, and the metalloid As) in anoxic solid-phase material (ASM) from an anaerobic, sulfate reducing bioreactor into six operationally defined fractions. These fractions were water soluble, exchangeable, bound to carbonates (acid soluble), bound to Fe-Mn oxides (reducible), bound to organic matter and sulfides (oxidizable) and residual. It was found that the distribution of Fe, Ni, Zn, Cu and As in ASM was strongly influenced by its association with the above solid fractions. The fraction corresponding to organic matter and sulfides appeared to be the most important scavenging phases of As, Fe, Ni, Zn and Cu in ASM (59.8-86.7%). This result was supported by AVS and SEM (Sigma Zn, Ni and Cu) measurements, which indicated that the heavy metals existed overwhelmingly as sulfides in the organic matter and sulfide fraction. A substantial amount of Fe and Ni at 16.4 and 20.1%, respectively, were also present in the carbonate fraction, while an appreciable portion of As (18.3%) and Zn (19.4%) was bound to Fe-Mn oxides. A significant amount of heavy metals was also associated with the residual fraction, ranging from 2.1% for Zn to 18.8% for As. Based on the average total extractable heavy metal (TEHM) values, the concentration of heavy metals in the ASM was in the order of Cu > Ni > Zn > Fe > As. If the mobility and bioavailability of heavy metals are assumed to be

Distortion product otoacoustic emissions: comparison of sequential vs. simultaneous presentation of primary tones.

Science.gov (United States)

Kumar, U Ajith; Maruthy, Sandeep; Chandrakant, Vishwakarma

2009-03-01

Distortion product otoacoustic emissions are one form of evoked otoacoustic emissions. DPOAEs provide the frequency specific information about the hearing status in mid and high frequency regions. But in most screening protocols TEOAEs are preferred as it requires less time compared to DPOAE. This is because, in DPOAE each stimulus is presented one after the other and responses are analyzed. Grason and Stadler Incorporation 60 (GSI-60) offer simultaneous presentation of four sets of primary tones at a time and checks for the DPOAE. In this mode of presentation, all the pairs are presented at a time and following that response is extracted separately whereas, in sequential mode primaries are presented in orderly fashion one after the other. In this article simultaneous and sequential protocols were used to compare the Distortion product otoacoustic emission amplitude, noise floor and administration time in individuals with normal hearing and mild sensori-neural (SN) hearing loss. In simultaneous protocols four sets of primary tones (i.e. 8 tones) were presented together whereas, in sequential presentation mode one set of primary tones was presented each time. Simultaneous protocol was completed in less than half the time required for the completion of sequential protocol. Two techniques yielded similar results at frequencies above 1000 Hz only in normal hearing group. In SN hearing loss group simultaneous presentation yielded signifi cantly higher noise floors and distortion product amplitudes. This result challenges the use of simultaneous presentation technique in neonatal hearing screening programmes and on other pathologies. This discrepancy between two protocols may be due to some changes in biomechanical process in the cochlear and/or due to higher distortion/noise produced by the system during the simultaneous presentation mode.

Evaluation of Effectiveness of Wavelet Based Denoising Schemes Using ANN and SVM for Bearing Condition Classification

Directory of Open Access Journals (Sweden)

Vijay G. S.

2012-01-01

Full Text Available The wavelet based denoising has proven its ability to denoise the bearing vibration signals by improving the signal-to-noise ratio (SNR and reducing the root-mean-square error (RMSE. In this paper seven wavelet based denoising schemes have been evaluated based on the performance of the Artificial Neural Network (ANN and the Support Vector Machine (SVM, for the bearing condition classification. The work consists of two parts, the first part in which a synthetic signal simulating the defective bearing vibration signal with Gaussian noise was subjected to these denoising schemes. The best scheme based on the SNR and the RMSE was identified. In the second part, the vibration signals collected from a customized Rolling Element Bearing (REB test rig for four bearing conditions were subjected to these denoising schemes. Several time and frequency domain features were extracted from the denoised signals, out of which a few sensitive features were selected using the Fisher’s Criterion (FC. Extracted features were used to train and test the ANN and the SVM. The best denoising scheme identified, based on the classification performances of the ANN and the SVM, was found to be the same as the one obtained using the synthetic signal.

Extraction of Plutonium From Spiked INEEL Soil Samples Using the Ligand-Assisted Supercritical Fluid Extraction (LA-SFE) Technique

International Nuclear Information System (INIS)

Fox, R.V.; Mincher, B.J.; Holmes, R.G.G.

1999-01-01

In order to investigate the effectiveness of ligand-assisted supercritical fluid extraction for the removal of transuranic contaminations from soils an Idaho National Engineering and Environmental Laboratory (INEEL) silty-clay soil sample was obtained from near the Radioactive Waste Management Complex area and subjected to three different chemical preparations before being spiked with plutonium. The spiked INEEL soil samples were subjected to a sequential aqueous extraction procedure to determine radionuclide portioning in each sample. Results from those extractions demonstrate that plutonium consistently partitioned into the residual fraction across all three INEEL soil preparations whereas americium partitioned 73% into the iron/manganese fraction for soil preparation A, with the balance partitioning into the residual fraction. Plutonium and americium were extracted from the INEEL soil samples using a ligand-assisted supercritical fluid extraction technique. Initial supercritical fluid extraction runs produced plutonium extraction technique. Initial supercritical fluid extraction runs produced plutonium extraction efficiencies ranging from 14% to 19%. After a second round wherein the initial extraction parameters were changed, the plutonium extraction efficiencies increased to 60% and as high as 80% with the americium level in the post-extracted soil samples dropping near to the detection limits. The third round of experiments are currently underway. These results demonstrate that the ligand-assisted supercritical fluid extraction technique can effectively extract plutonium from the spiked INEEL soil preparations

DREAM: Classification scheme for dialog acts in clinical research query mediation.

Science.gov (United States)

Hoxha, Julia; Chandar, Praveen; He, Zhe; Cimino, James; Hanauer, David; Weng, Chunhua

2016-02-01

Clinical data access involves complex but opaque communication between medical researchers and query analysts. Understanding such communication is indispensable for designing intelligent human-machine dialog systems that automate query formulation. This study investigates email communication and proposes a novel scheme for classifying dialog acts in clinical research query mediation. We analyzed 315 email messages exchanged in the communication for 20 data requests obtained from three institutions. The messages were segmented into 1333 utterance units. Through a rigorous process, we developed a classification scheme and applied it for dialog act annotation of the extracted utterances. Evaluation results with high inter-annotator agreement demonstrate the reliability of this scheme. This dataset is used to contribute preliminary understanding of dialog acts distribution and conversation flow in this dialog space. Copyright © 2015 Elsevier Inc. All rights reserved.

Macroscopic Dynamic Modeling of Sequential Batch Cultures of Hybridoma Cells: An Experimental Validation

Directory of Open Access Journals (Sweden)

Laurent Dewasme

2017-02-01

Full Text Available Hybridoma cells are commonly grown for the production of monoclonal antibodies (MAb. For monitoring and control purposes of the bioreactors, dynamic models of the cultures are required. However these models are difficult to infer from the usually limited amount of available experimental data and do not focus on target protein production optimization. This paper explores an experimental case study where hybridoma cells are grown in a sequential batch reactor. The simplest macroscopic reaction scheme translating the data is first derived using a maximum likelihood principal component analysis. Subsequently, nonlinear least-squares estimation is used to determine the kinetic laws. The resulting dynamic model reproduces quite satisfactorily the experimental data, as evidenced in direct and cross-validation tests. Furthermore, model predictions can also be used to predict optimal medium renewal time and composition.

A sequential threshold cure model for genetic analysis of time-to-event data

DEFF Research Database (Denmark)

Ødegård, J; Madsen, Per; Labouriau, Rodrigo S.

2011-01-01

In analysis of time-to-event data, classical survival models ignore the presence of potential nonsusceptible (cured) individuals, which, if present, will invalidate the inference procedures. Existence of nonsusceptible individuals is particularly relevant under challenge testing with specific...... pathogens, which is a common procedure in aquaculture breeding schemes. A cure model is a survival model accounting for a fraction of nonsusceptible individuals in the population. This study proposes a mixed cure model for time-to-event data, measured as sequential binary records. In a simulation study...... survival data were generated through 2 underlying traits: susceptibility and endurance (risk of dying per time-unit), associated with 2 sets of underlying liabilities. Despite considerable phenotypic confounding, the proposed model was largely able to distinguish the 2 traits. Furthermore, if selection...

Chaos-based CAZAC scheme for secure transmission in OFDM-PON

Science.gov (United States)

Fu, Xiaosong; Bi, Meihua; Zhou, Xuefang; Yang, Guowei; Lu, Yang; Hu, Miao

2018-01-01

To effectively resist malicious eavesdropping and performance deterioration, a novel chaos-based secure transmission scheme is proposed to enhance the physical layer security and reduce peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing passive optical network (OFDM-PON). By the randomly extracting operation of common CAZAC values, the specially-designed constant amplitude zero autocorrelation (CAZAC) is created for system encryption and PAPR reduction enhancing the transmission security. This method is verified in {10-Gb/s encrypted OFDM-PON with 20-km fiber transmission. Results show that, compared to common OFDM-PON, our scheme achieves {3-dB PAPR reduction and {1-dB receiver sensitivity improvement.

Discrimination between sequential and simultaneous virtual channels with electrical hearing.

Science.gov (United States)

Landsberger, David; Galvin, John J

2011-09-01

In cochlear implants (CIs), simultaneous or sequential stimulation of adjacent electrodes can produce intermediate pitch percepts between those of the component electrodes. However, it is unclear whether simultaneous and sequential virtual channels (VCs) can be discriminated. In this study, CI users were asked to discriminate simultaneous and sequential VCs; discrimination was measured for monopolar (MP) and bipolar + 1 stimulation (BP + 1), i.e., relatively broad and focused stimulation modes. For sequential VCs, the interpulse interval (IPI) varied between 0.0 and 1.8 ms. All stimuli were presented at comfortably loud, loudness-balanced levels at a 250 pulse per second per electrode (ppse) stimulation rate. On average, CI subjects were able to reliably discriminate between sequential and simultaneous VCs. While there was no significant effect of IPI or stimulation mode on VC discrimination, some subjects exhibited better VC discrimination with BP + 1 stimulation. Subjects' discrimination between sequential and simultaneous VCs was correlated with electrode discrimination, suggesting that spatial selectivity may influence perception of sequential VCs. To maintain equal loudness, sequential VC amplitudes were nearly double those of simultaneous VCs, presumably resulting in a broader spread of excitation. These results suggest that perceptual differences between simultaneous and sequential VCs might be explained by differences in the spread of excitation. © 2011 Acoustical Society of America

Sequential versus simultaneous market delineation

DEFF Research Database (Denmark)

Haldrup, Niels; Møllgaard, Peter; Kastberg Nielsen, Claus

2005-01-01

and geographical markets. Using a unique data setfor prices of Norwegian and Scottish salmon, we propose a methodologyfor simultaneous market delineation and we demonstrate that comparedto a sequential approach conclusions will be reversed.JEL: C3, K21, L41, Q22Keywords: Relevant market, econometric delineation......Delineation of the relevant market forms a pivotal part of most antitrustcases. The standard approach is sequential. First the product marketis delineated, then the geographical market is defined. Demand andsupply substitution in both the product dimension and the geographicaldimension...

Advances in sequential data assimilation and numerical weather forecasting: An Ensemble Transform Kalman-Bucy Filter, a study on clustering in deterministic ensemble square root filters, and a test of a new time stepping scheme in an atmospheric model

Science.gov (United States)

Amezcua, Javier

This dissertation deals with aspects of sequential data assimilation (in particular ensemble Kalman filtering) and numerical weather forecasting. In the first part, the recently formulated Ensemble Kalman-Bucy (EnKBF) filter is revisited. It is shown that the previously used numerical integration scheme fails when the magnitude of the background error covariance grows beyond that of the observational error covariance in the forecast window. Therefore, we present a suitable integration scheme that handles the stiffening of the differential equations involved and doesn't represent further computational expense. Moreover, a transform-based alternative to the EnKBF is developed: under this scheme, the operations are performed in the ensemble space instead of in the state space. Advantages of this formulation are explained. For the first time, the EnKBF is implemented in an atmospheric model. The second part of this work deals with ensemble clustering, a phenomenon that arises when performing data assimilation using of deterministic ensemble square root filters in highly nonlinear forecast models. Namely, an M-member ensemble detaches into an outlier and a cluster of M-1 members. Previous works may suggest that this issue represents a failure of EnSRFs; this work dispels that notion. It is shown that ensemble clustering can be reverted also due to nonlinear processes, in particular the alternation between nonlinear expansion and compression of the ensemble for different regions of the attractor. Some EnSRFs that use random rotations have been developed to overcome this issue; these formulations are analyzed and their advantages and disadvantages with respect to common EnSRFs are discussed. The third and last part contains the implementation of the Robert-Asselin-Williams (RAW) filter in an atmospheric model. The RAW filter is an improvement to the widely popular Robert-Asselin filter that successfully suppresses spurious computational waves while avoiding any distortion

Sequential high pressure extractions applied to recover piceatannol and scirpusin B from passion fruit bagasse.

Science.gov (United States)

Viganó, Juliane; Aguiar, Ana C; Moraes, Damila R; Jara, José L P; Eberlin, Marcos N; Cazarin, Cinthia B B; Maróstica, Mário R; Martínez, Julian

2016-07-01

Passion fruit seeds are currently discarded on the pulp processing but are known for their high piceatannol and scirpusin B contents. Using pressurized liquid extraction (PLE), these highly valuable phenolic compounds were efficiently extracted from defatted passion fruit bagasse (DPFB). PLE was performed using mixtures of ethanol and water (50 to 100% ethanol, w/w) as solvent, temperatures from 50 to 70°C and pressure at 10MPa. The extraction methods were compared in terms of the global yield, total phenolic content (TPC), piceatannol content and the antioxidant capacity of the extracts. The DPFB extracts were also compared with those from non-defatted passion fruit bagasse (nDPFB). Identification and quantification of piceatannol were performed using UHPLC-MS/MS. The results showed that high TPC and piceatannol content were achieved for the extracts obtained from DPFB through PLE at 70°C and using 50 and 75% ethanol as the solvent. The best PLE conditions for TPC (70°C, 75% ethanol) resulted in 55.237mgGAE/g dried and defatted bagasse, whereas PLE at 70°C and 50% ethanol achieved 18.590mg of piceatannol/g dried and defatted bagasse, and such yields were significantly higher than those obtained using conventional extraction techniques. The antioxidant capacity assays showed high correlation with the TPC (r>0.886) and piceatannol (r>0.772). The passion fruit bagasse has therefore proved to be a rich source of piceatannol and PLE showed high efficiency to recover phenolic compounds from defatted passion fruit bagasse. Copyright © 2016 Elsevier Ltd. All rights reserved.

A new and fast image feature selection method for developing an optimal mammographic mass detection scheme.

Science.gov (United States)

Tan, Maxine; Pu, Jiantao; Zheng, Bin

2014-08-01

Selecting optimal features from a large image feature pool remains a major challenge in developing computer-aided detection (CAD) schemes of medical images. The objective of this study is to investigate a new approach to significantly improve efficacy of image feature selection and classifier optimization in developing a CAD scheme of mammographic masses. An image dataset including 1600 regions of interest (ROIs) in which 800 are positive (depicting malignant masses) and 800 are negative (depicting CAD-generated false positive regions) was used in this study. After segmentation of each suspicious lesion by a multilayer topographic region growth algorithm, 271 features were computed in different feature categories including shape, texture, contrast, isodensity, spiculation, local topological features, as well as the features related to the presence and location of fat and calcifications. Besides computing features from the original images, the authors also computed new texture features from the dilated lesion segments. In order to select optimal features from this initial feature pool and build a highly performing classifier, the authors examined and compared four feature selection methods to optimize an artificial neural network (ANN) based classifier, namely: (1) Phased Searching with NEAT in a Time-Scaled Framework, (2) A sequential floating forward selection (SFFS) method, (3) A genetic algorithm (GA), and (4) A sequential forward selection (SFS) method. Performances of the four approaches were assessed using a tenfold cross validation method. Among these four methods, SFFS has highest efficacy, which takes 3%-5% of computational time as compared to GA approach, and yields the highest performance level with the area under a receiver operating characteristic curve (AUC) = 0.864 ± 0.034. The results also demonstrated that except using GA, including the new texture features computed from the dilated mass segments improved the AUC results of the ANNs optimized

Air extraction in gas turbines burning coal-derived gas

Energy Technology Data Exchange (ETDEWEB)

Yang, Tah-teh; Agrawal, A.K.; Kapat, J.S.

1993-11-01

In the first phase of this contracted research, a comprehensive investigation was performed. Principally, the effort was directed to identify the technical barriers which might exist in integrating the air-blown coal gasification process with a hot gas cleanup scheme and the state-of-the-art, US made, heavy-frame gas turbine. The guiding rule of the integration is to keep the compressor and the expander unchanged if possible. Because of the low-heat content of coal gas and of the need to accommodate air extraction, the combustor and perhaps, the flow region between the compressor exit and the expander inlet might need to be modified. In selecting a compressed air extraction scheme, one must consider how the scheme affects the air supply to the hot section of the turbine and the total pressure loss in the flow region. Air extraction must preserve effective cooling of the hot components, such as the transition pieces. It must also ensure proper air/fuel mixing in the combustor, hence the combustor exit pattern factor. The overall thermal efficiency of the power plant can be increased by minimizing the total pressure loss in the diffusers associated with the air extraction. Therefore, a study of airflow in the pre- and dump-diffusers with and without air extraction would provide information crucial to attaining high-thermal efficiency and to preventing hot spots. The research group at Clemson University suggested using a Griffith diffuser for the prediffuser and extracting air from the diffuser inlet. The present research establishes that the analytically identified problems in the impingement cooling flow are factual. This phase of the contracted research substantiates experimentally the advantage of using the Griffith diffuser with air extraction at the diffuser inlet.

Group-sequential analysis may allow for early trial termination

DEFF Research Database (Denmark)

Gerke, Oke; Vilstrup, Mie H; Halekoh, Ulrich

2017-01-01

BACKGROUND: Group-sequential testing is widely used in pivotal therapeutic, but rarely in diagnostic research, although it may save studies, time, and costs. The purpose of this paper was to demonstrate a group-sequential analysis strategy in an intra-observer study on quantitative FDG-PET/CT mea......BACKGROUND: Group-sequential testing is widely used in pivotal therapeutic, but rarely in diagnostic research, although it may save studies, time, and costs. The purpose of this paper was to demonstrate a group-sequential analysis strategy in an intra-observer study on quantitative FDG...

Sequential logic analysis and synthesis

CERN Document Server

Cavanagh, Joseph

2007-01-01

Until now, there was no single resource for actual digital system design. Using both basic and advanced concepts, Sequential Logic: Analysis and Synthesis offers a thorough exposition of the analysis and synthesis of both synchronous and asynchronous sequential machines. With 25 years of experience in designing computing equipment, the author stresses the practical design of state machines. He clearly delineates each step of the structured and rigorous design principles that can be applied to practical applications. The book begins by reviewing the analysis of combinatorial logic and Boolean a

ANTHOCYANINS ALIPHATIC ALCOHOLS EXTRACTION FEATURES

Directory of Open Access Journals (Sweden)

P. N. Savvin

2015-01-01

Full Text Available Anthocyanins red pigments that give color a wide range of fruits, berries and flowers. In the food industry it is widely known as a dye a food additive E163. To extract from natural vegetable raw materials traditionally used ethanol or acidified water, but in same technologies it’s unacceptable. In order to expand the use of anthocyanins as colorants and antioxidants were explored extracting pigments alcohols with different structures of the carbon skeleton, and the position and number of hydroxyl groups. For the isolation anthocyanins raw materials were extracted sequentially twice with t = 60 C for 1.5 hours. The evaluation was performed using extracts of classical spectrophotometric methods and modern express chromaticity. Color black currant extracts depends on the length of the carbon skeleton and position of the hydroxyl group, with the alcohols of normal structure have higher alcohols compared to the isomeric structure of the optical density and index of the red color component. This is due to the different ability to form hydrogen bonds when allocating anthocyanins and other intermolecular interactions. During storage blackcurrant extracts are significant structural changes recoverable pigments, which leads to a significant change in color. In this variation, the stronger the higher the length of the carbon skeleton and branched molecules extractant. Extraction polyols (ethyleneglycol, glycerol are less effective than the corresponding monohydric alcohols. However these extracts saved significantly higher because of their reducing ability at interacting with polyphenolic compounds.

An optimization approach for extracting and encoding consistent maps in a shape collection

KAUST Repository

Huang, Qi-Xing; Zhang, Guo-Xin; Gao, Lin; Hu, Shi-Min; Butscher, Adrian; Guibas, Leonidas

2012-01-01

by compositions of maps through a single base shape. In general, multiple base shapes are needed to adequately cover a diverse collection. Our algorithm sequentially extracts such a small collection of base shapes and creates correspondences from each

Migration and chemical extractability of 137Cs and 90Sr in Swedish long-term experimental pastures

International Nuclear Information System (INIS)

Forsberg, S.; Strandmark, M.

1999-01-01

Vertical migration and chemical extractability were studied on two experimental pastures, a sandy soil and a clay soil, contaminated with 137 Cs and 90 Sr in 1961. Migration was studied by measuring the total nuclide content in soil samples to 55 cm depth, chemical extractability by sequential extraction. Both 137 Cs and 90 Sr were found at all depths in both soils, and 90 Sr had moved deeper than 137 Cs. 137 Cs was mainly found in the upper 10 cm, and no difference was seen between clay and sandy soil, due to retention in the root mat of the sandy soil. 90 Sr had moved deeper in sandy than in clay soil, the reason being the higher exchange capacity of the clay soil. Sequential extractions showed that 90 Sr was much more extractable than 137 Cs. 96-98% of 137 Cs was found in the HNO 3 and residual fractions. 137 Cs was more extractable in the sandy soil than in clay, and in the sandy soil the extractability of 137 Cs increased slightly with depth. Regarding 90 Sr, 63-75% was found in the easily exchangeable fractions, the higher figure was in clay soil. A large proportion, 18-30%, was extracted in the reducible fraction, showing that availability of 90 Sr might increase under reducing conditions. (au)

Person Recognition Method using Sequential Walking Footprints via Overlapped Foot Shape and Center-Of-Pressure Trajectory

Directory of Open Access Journals (Sweden)

Jin-Woo Jung

2013-08-01

Full Text Available One emerging biometric identification method is the use of human footprint. However, in the previous research, there were some limitations resulting from the spatial resolution of sensors. One possible method to overcome this limitation is through the use additional information such as dynamic walking information in sequential walking footprint. In this study, we suggest a new person recognition scheme based on both overlapped foot shape and COP (Center Of Pressure trajectory during one-step walking. And, we show the usefulness of the suggested method, obtaining a 98.6% recognition rate in our experiment with eleven people. In addition, we show an application of the suggested method, automatic door-opening system for intelligent residential space.

Structural Consistency, Consistency, and Sequential Rationality.

OpenAIRE

Kreps, David M; Ramey, Garey

1987-01-01

Sequential equilibria comprise consistent beliefs and a sequentially ra tional strategy profile. Consistent beliefs are limits of Bayes ratio nal beliefs for sequences of strategies that approach the equilibrium strategy. Beliefs are structurally consistent if they are rationaliz ed by some single conjecture concerning opponents' strategies. Consis tent beliefs are not necessarily structurally consistent, notwithstan ding a claim by Kreps and Robert Wilson (1982). Moreover, the spirit of stru...

Speciation fingerprints of binary mixtures by the optimized sequential two-phase separation

International Nuclear Information System (INIS)

Macasek, F.

1995-01-01

The analysis of the separation methods suitable for chemical speciation of radionuclides and metals, and advantages of sequential (double) distribution technique were discussed. The equilibria are relatively easy to control and the method enables to minimize a matrix composition adjustment, and therefore it minimizes also the disturbance of original (native) state of elements. The technique may consist in the repeat solvent extraction of sample, or the replicate equilibration with sorbent. The common condition of applicability is a linear separation isotherm of the species, what is mostly a reasonable condition in case of trace concentrations. The equations used for simultaneous fitting were written in general form. 1 tab., 1 fig., 2 refs

Sequential determination of actinides in a variety of matrices

International Nuclear Information System (INIS)

Olsen, S.C.

2002-01-01

A large number of analytical procedures for the actinides have been published, each catering for a specific need. Due to the bioassay programme in our laboratory, a need arose for a method to determine natural (Th and U) and anthropogenic actinides (Np, Pu and Am/Cm) together in a variety of samples. The method would have to be suitable for routine application: simple, inexpensive, rapid and robust. In some cases, the amount of material available is not sufficient for the determination of separate groups of actinides, and a sequential separation and measurement of the analytes would therefore be required. The types of matrices vary from aqueous samples to radiological surveillance (urine and faeces) to environmental studies (soil, sediment and fish), but the separation procedure should be able to service all of these. The working range of the method would have to cater for lower levels of the transuranium actinides in particular sample types containing higher levels of the natural actinides (U and Th). The first analytical problem to be discussed, is how to get the different sample types into the same loading solution required by a single separation approach. This entails sample dissolution or decomposition in some cases, and pre-concentration or pre-separation in others. A separation scheme is presented for the clean separation of all the actinides in a form suitable for alpha spectrometry. The development of a single column separation of the analytes of interest are looked at, as well as observations made during the development of the separation scheme, such as concentration effects. Results for test samples and certified reference materials are be presented. (author)

Generalized infimum and sequential product of quantum effects

International Nuclear Information System (INIS)

Li Yuan; Sun Xiuhong; Chen Zhengli

2007-01-01

The quantum effects for a physical system can be described by the set E(H) of positive operators on a complex Hilbert space H that are bounded above by the identity operator I. For A, B(set-membership sign)E(H), the operation of sequential product A(convolution sign)B=A 1/2 BA 1/2 was proposed as a model for sequential quantum measurements. A nice investigation of properties of the sequential product has been carried over [Gudder, S. and Nagy, G., 'Sequential quantum measurements', J. Math. Phys. 42, 5212 (2001)]. In this note, we extend some results of this reference. In particular, a gap in the proof of Theorem 3.2 in this reference is overcome. In addition, some properties of generalized infimum A sqcap B are studied

Electricity storage using a thermal storage scheme

Energy Technology Data Exchange (ETDEWEB)

White, Alexander, E-mail: ajw36@cam.ac.uk [Hopkinson Laboratory, Cambridge University Engineering Department, Trumpington Street, Cambridge. CB2 1PZ (United Kingdom)

2015-01-22

The increasing use of renewable energy technologies for electricity generation, many of which have an unpredictably intermittent nature, will inevitably lead to a greater demand for large-scale electricity storage schemes. For example, the expanding fraction of electricity produced by wind turbines will require either backup or storage capacity to cover extended periods of wind lull. This paper describes a recently proposed storage scheme, referred to here as Pumped Thermal Storage (PTS), and which is based on “sensible heat” storage in large thermal reservoirs. During the charging phase, the system effectively operates as a high temperature-ratio heat pump, extracting heat from a cold reservoir and delivering heat to a hot one. In the discharge phase the processes are reversed and it operates as a heat engine. The round-trip efficiency is limited only by process irreversibilities (as opposed to Second Law limitations on the coefficient of performance and the thermal efficiency of the heat pump and heat engine respectively). PTS is currently being developed in both France and England. In both cases, the schemes operate on the Joule-Brayton (gas turbine) cycle, using argon as the working fluid. However, the French scheme proposes the use of turbomachinery for compression and expansion, whereas for that being developed in England reciprocating devices are proposed. The current paper focuses on the impact of the various process irreversibilities on the thermodynamic round-trip efficiency of the scheme. Consideration is given to compression and expansion losses and pressure losses (in pipe-work, valves and thermal reservoirs); heat transfer related irreversibility in the thermal reservoirs is discussed but not included in the analysis. Results are presented demonstrating how the various loss parameters and operating conditions influence the overall performance.

RELATING BOTTOM QUARK MASS IN DR-BAR AND MS-BAR REGULARIZATION SCHEMES

International Nuclear Information System (INIS)

2002-01-01

The value of the bottom quark mass at Q = M Z in the (bar D)(bar R) scheme is an important input for the analysis of supersymmetric models with a large value of tan β. Conventionally, however, the running bottom quark mass extracted from experimental data is quoted in the (bar M)(bar S) scheme at the scale Q = m b . We describe a two loop procedure for the conversion of the bottom quark mass from (bar M)(bar S) to (bar D)(bar R) scheme. The Particle Data Group value m b # bar M# # bar S#(m b # bar M# # bar S#) = 4.2 ± 0.2 GeV corresponds to a range of 2.65-3.03 GeV for m b # bar D# # bar R#(M Z )

GC–MS analysis of bioactive compounds present in different extracts of an endemic plant Broussonetia luzonica (Blanco) (Moraceae) leaves

OpenAIRE

Franelyne Pataueg Casuga; Agnes Llamasares Castillo; Mary Jho-Anne Tolentino Corpuz

2016-01-01

Objective: To investigate and characterize the chemical composition of the different crude extracts from the leaves of Broussonetia luzonica (Blanco) (Moraceae) (B. luzonica), an endemic plant in the Philippines. Methods: The air dried leaves were powdered and subjected to selective sequential extraction using solvents of increasing polarity through percolation, namely, n-hexane, ethyl acetate and methanol to obtain three different extracts. Then, each of the extracts was further subjected...

Energy harvesting schemes for building interior environment monitoring

Science.gov (United States)

Zylka, Pawel; Pociecha, Dominik

2016-11-01

A vision to supply microelectronic devices without batteries making them perpetual or extending time of service in battery-oriented mobile supply schemes is the driving force of the research related to ambient energy harvesting. Energy harnessing aims thus at extracting energy from various ambient energy "pools", which generally are cost- or powerineffective to be scaled up for full-size, power-plant energy generation schemes supplying energy in electric form. These include - but are not limited to - waste heat, electromagnetic hum, vibrations, or human-generated power in addition to traditional renewable energy resources like water flow, tidal and wind energy or sun radiation which can also be exploited at the miniature scale by energy scavengers. However, in case of taking advantage of energy harvesting strategies to power up sensors monitoring environment inside buildings adaptable energy sources are restrained to only some which additionally are limited in spatial and temporal accessibility as well as available power. The paper explores experimentally an energy harvesting scheme exploiting human kinesis applicable in indoor environment for supplying a wireless indoor micro-system, monitoring ambient air properties (pressure, humidity and temperature).

A SCHEME FOR TEMPLATE SECURITY AT FEATURE FUSION LEVEL IN MULTIMODAL BIOMETRIC SYSTEM

Directory of Open Access Journals (Sweden)

Arvind Selwal

2016-09-01

Full Text Available Biometric is the science of human recognition based upon using their biological, chemical or behavioural traits. These systems are used in many real life applications simply from biometric based attendance system to providing security at very sophisticated level. A biometric system deals with raw data captured using a sensor and feature template extracted from raw image. One of the challenges being faced by designers of these systems is to secure template data extracted from the biometric modalities of the user and protect the raw images. To minimize spoof attacks on biometric systems by unauthorised users one of the solutions is to use multi-biometric systems. Multi-modal biometric system works by using fusion technique to merge feature templates generated from different modalities of the human. In this work a new scheme is proposed to secure template during feature fusion level. Scheme is based on union operation of fuzzy relations of templates of modalities during fusion process of multimodal biometric systems. This approach serves dual purpose of feature fusion as well as transformation of templates into a single secured non invertible template. The proposed technique is cancelable and experimentally tested on a bimodal biometric system comprising of fingerprint and hand geometry. Developed scheme removes the problem of an attacker learning the original minutia position in fingerprint and various measurements of hand geometry. Given scheme provides improved performance of the system with reduction in false accept rate and improvement in genuine accept rate.

Efficient sequential and parallel algorithms for finding edit distance based motifs.

Science.gov (United States)

Pal, Soumitra; Xiao, Peng; Rajasekaran, Sanguthevar

2016-08-18

Motif search is an important step in extracting meaningful patterns from biological data. The general problem of motif search is intractable and there is a pressing need to develop efficient, exact and approximation algorithms to solve this problem. In this paper, we present several novel, exact, sequential and parallel algorithms for solving the (l,d) Edit-distance-based Motif Search (EMS) problem: given two integers l,d and n biological strings, find all strings of length l that appear in each input string with atmost d errors of types substitution, insertion and deletion. One popular technique to solve the problem is to explore for each input string the set of all possible l-mers that belong to the d-neighborhood of any substring of the input string and output those which are common for all input strings. We introduce a novel and provably efficient neighborhood exploration technique. We show that it is enough to consider the candidates in neighborhood which are at a distance exactly d. We compactly represent these candidate motifs using wildcard characters and efficiently explore them with very few repetitions. Our sequential algorithm uses a trie based data structure to efficiently store and sort the candidate motifs. Our parallel algorithm in a multi-core shared memory setting uses arrays for storing and a novel modification of radix-sort for sorting the candidate motifs. The algorithms for EMS are customarily evaluated on several challenging instances such as (8,1), (12,2), (16,3), (20,4), and so on. The best previously known algorithm, EMS1, is sequential and in estimated 3 days solves up to instance (16,3). Our sequential algorithms are more than 20 times faster on (16,3). On other hard instances such as (9,2), (11,3), (13,4), our algorithms are much faster. Our parallel algorithm has more than 600 % scaling performance while using 16 threads. Our algorithms have pushed up the state-of-the-art of EMS solvers and we believe that the techniques introduced in

Sequential analysis in neonatal research-systematic review.

Science.gov (United States)

Lava, Sebastiano A G; Elie, Valéry; Ha, Phuong Thi Viet; Jacqz-Aigrain, Evelyne

2018-05-01

As more new drugs are discovered, traditional designs come at their limits. Ten years after the adoption of the European Paediatric Regulation, we performed a systematic review on the US National Library of Medicine and Excerpta Medica database of sequential trials involving newborns. Out of 326 identified scientific reports, 21 trials were included. They enrolled 2832 patients, of whom 2099 were analyzed: the median number of neonates included per trial was 48 (IQR 22-87), median gestational age was 28.7 (IQR 27.9-30.9) weeks. Eighteen trials used sequential techniques to determine sample size, while 3 used continual reassessment methods for dose-finding. In 16 studies reporting sufficient data, the sequential design allowed to non-significantly reduce the number of enrolled neonates by a median of 24 (31%) patients (IQR - 4.75 to 136.5, p = 0.0674) with respect to a traditional trial. When the number of neonates finally included in the analysis was considered, the difference became significant: 35 (57%) patients (IQR 10 to 136.5, p = 0.0033). Sequential trial designs have not been frequently used in Neonatology. They might potentially be able to reduce the number of patients in drug trials, although this is not always the case. What is known: • In evaluating rare diseases in fragile populations, traditional designs come at their limits. About 20% of pediatric trials are discontinued, mainly because of recruitment problems. What is new: • Sequential trials involving newborns were infrequently used and only a few (n = 21) are available for analysis. • The sequential design allowed to non-significantly reduce the number of enrolled neonates by a median of 24 (31%) patients (IQR - 4.75 to 136.5, p = 0.0674).

Sequential enzymatic derivatization coupled with online microdialysis sampling for simultaneous profiling of mouse tumor extracellular hydrogen peroxide, lactate, and glucose.

Science.gov (United States)

Su, Cheng-Kuan; Tseng, Po-Jen; Chiu, Hsien-Ting; Del Vall, Andrea; Huang, Yu-Fen; Sun, Yuh-Chang

2017-03-01

Probing tumor extracellular metabolites is a vitally important issue in current cancer biology. In this study an analytical system was constructed for the in vivo monitoring of mouse tumor extracellular hydrogen peroxide (H 2 O 2 ), lactate, and glucose by means of microdialysis (MD) sampling and fluorescence determination in conjunction with a smart sequential enzymatic derivatization scheme-involving a loading sequence of fluorogenic reagent/horseradish peroxidase, microdialysate, lactate oxidase, pyruvate, and glucose oxidase-for step-by-step determination of sampled H 2 O 2 , lactate, and glucose in mouse tumor microdialysate. After optimization of the overall experimental parameters, the system's detection limit reached as low as 0.002 mM for H 2 O 2 , 0.058 mM for lactate, and 0.055 mM for glucose, based on 3 μL of microdialysate, suggesting great potential for determining tumor extracellular concentrations of lactate and glucose. Spike analyses of offline-collected mouse tumor microdialysate and monitoring of the basal concentrations of mouse tumor extracellular H 2 O 2 , lactate, and glucose, as well as those after imparting metabolic disturbance through intra-tumor administration of a glucose solution through a prior-implanted cannula, were conducted to demonstrate the system's applicability. Our results evidently indicate that hyphenation of an MD sampling device with an optimized sequential enzymatic derivatization scheme and a fluorescence spectrometer can be used successfully for multi-analyte monitoring of tumor extracellular metabolites in living animals. Copyright © 2016 Elsevier B.V. All rights reserved.

Group-sequential analysis may allow for early trial termination

DEFF Research Database (Denmark)

Gerke, Oke; Vilstrup, Mie H; Halekoh, Ulrich

2017-01-01

BACKGROUND: Group-sequential testing is widely used in pivotal therapeutic, but rarely in diagnostic research, although it may save studies, time, and costs. The purpose of this paper was to demonstrate a group-sequential analysis strategy in an intra-observer study on quantitative FDG-PET/CT mea......BACKGROUND: Group-sequential testing is widely used in pivotal therapeutic, but rarely in diagnostic research, although it may save studies, time, and costs. The purpose of this paper was to demonstrate a group-sequential analysis strategy in an intra-observer study on quantitative FDG...... assumed to be normally distributed, and sequential one-sided hypothesis tests on the population standard deviation of the differences against a hypothesised value of 1.5 were performed, employing an alpha spending function. The fixed-sample analysis (N = 45) was compared with the group-sequential analysis...... strategies comprising one (at N = 23), two (at N = 15, 30), or three interim analyses (at N = 11, 23, 34), respectively, which were defined post hoc. RESULTS: When performing interim analyses with one third and two thirds of patients, sufficient agreement could be concluded after the first interim analysis...

Solvent extraction in the nuclear fuel cycle

International Nuclear Information System (INIS)

Eccles, H.; Naylor, A.

1987-01-01

Solvent extraction techniques have been used in the uranium nuclear fuel cycle in three main areas; concentration of uranium from ore leach liquor, purification of ore concentrates and fuel reprocessing. Solvent extraction has been extended to the removal of transuranic elements from active waste liquor, the recovery of uranium from natural sources and the recovery of noble metals from active waste liquor. Schemes are presented for solvent extraction of uranium using the Amex or Dapex process; spent fuel reprocessing and the Purex process. Recent and future developments of the techniques are outlined. (UK)

Comparison of ablation centration after bilateral sequential versus simultaneous LASIK.

Science.gov (United States)

Lin, Jane-Ming; Tsai, Yi-Yu

2005-01-01

To compare ablation centration after bilateral sequential and simultaneous myopic LASIK. A retrospective randomized case series was performed of 670 eyes of 335 consecutive patients who had undergone either bilateral sequential (group 1) or simultaneous (group 2) myopic LASIK between July 2000 and July 2001 at the China Medical University Hospital, Taichung, Taiwan. The ablation centrations of the first and second eyes in the two groups were compared 3 months postoperatively. Of 670 eyes, 274 eyes (137 patients) comprised the sequential group and 396 eyes (198 patients) comprised the simultaneous group. Three months post-operatively, 220 eyes of 110 patients (80%) in the sequential group and 236 eyes of 118 patients (60%) in the simultaneous group provided topographic data for centration analysis. For the first eyes, mean decentration was 0.39 +/- 0.26 mm in the sequential group and 0.41 +/- 0.19 mm in the simultaneous group (P = .30). For the second eyes, mean decentration was 0.28 +/- 0.23 mm in the sequential group and 0.30 +/- 0.21 mm in the simultaneous group (P = .36). Decentration in the second eyes significantly improved in both groups (group 1, P = .02; group 2, P sequential group and 0.32 +/- 0.18 mm in the simultaneous group (P = .33). The difference of ablation center angles between the first and second eyes was 43.2 sequential group and 45.1 +/- 50.8 degrees in the simultaneous group (P = .42). Simultaneous bilateral LASIK is comparable to sequential surgery in ablation centration.

A Survey of Multi-Objective Sequential Decision-Making

NARCIS (Netherlands)

Roijers, D.M.; Vamplew, P.; Whiteson, S.; Dazeley, R.

2013-01-01

Sequential decision-making problems with multiple objectives arise naturally in practice and pose unique challenges for research in decision-theoretic planning and learning, which has largely focused on single-objective settings. This article surveys algorithms designed for sequential

Sequential lineups: shift in criterion or decision strategy?

Science.gov (United States)

Gronlund, Scott D

2004-04-01

R. C. L. Lindsay and G. L. Wells (1985) argued that a sequential lineup enhanced discriminability because it elicited use of an absolute decision strategy. E. B. Ebbesen and H. D. Flowe (2002) argued that a sequential lineup led witnesses to adopt a more conservative response criterion, thereby affecting bias, not discriminability. Height was encoded as absolute (e.g., 6 ft [1.83 m] tall) or relative (e.g., taller than). If a sequential lineup elicited an absolute decision strategy, the principle of transfer-appropriate processing predicted that performance should be best when height was encoded absolutely. Conversely, if a simultaneous lineup elicited a relative decision strategy, performance should be best when height was encoded relatively. The predicted interaction was observed, providing direct evidence for the decision strategies explanation of what happens when witnesses view a sequential lineup.

Predicting FLDs Using a Multiscale Modeling Scheme

Science.gov (United States)

Wu, Z.; Loy, C.; Wang, E.; Hegadekatte, V.

2017-09-01

The measurement of a single forming limit diagram (FLD) requires significant resources and is time consuming. We have developed a multiscale modeling scheme to predict FLDs using a combination of limited laboratory testing, crystal plasticity (VPSC) modeling, and dual sequential-stage finite element (ABAQUS/Explicit) modeling with the Marciniak-Kuczynski (M-K) criterion to determine the limit strain. We have established a means to work around existing limitations in ABAQUS/Explicit by using an anisotropic yield locus (e.g., BBC2008) in combination with the M-K criterion. We further apply a VPSC model to reduce the number of laboratory tests required to characterize the anisotropic yield locus. In the present work, we show that the predicted FLD is in excellent agreement with the measured FLD for AA5182 in the O temper. Instead of 13 different tests as for a traditional FLD determination within Novelis, our technique uses just four measurements: tensile properties in three orientations; plane strain tension; biaxial bulge; and the sheet crystallographic texture. The turnaround time is consequently far less than for the traditional laboratory measurement of the FLD.

How to Read the Tractatus Sequentially

Directory of Open Access Journals (Sweden)

Tim Kraft

2016-11-01

Full Text Available One of the unconventional features of Wittgenstein’s Tractatus Logico-Philosophicus is its use of an elaborated and detailed numbering system. Recently, Bazzocchi, Hacker und Kuusela have argued that the numbering system means that the Tractatus must be read and interpreted not as a sequentially ordered book, but as a text with a two-dimensional, tree-like structure. Apart from being able to explain how the Tractatus was composed, the tree reading allegedly solves exegetical issues both on the local (e. g. how 4.02 fits into the series of remarks surrounding it and the global level (e. g. relation between ontology and picture theory, solipsism and the eye analogy, resolute and irresolute readings. This paper defends the sequential reading against the tree reading. After presenting the challenges generated by the numbering system and the two accounts as attempts to solve them, it is argued that Wittgenstein’s own explanation of the numbering system, anaphoric references within the Tractatus and the exegetical issues mentioned above do not favour the tree reading, but a version of the sequential reading. This reading maintains that the remarks of the Tractatus form a sequential chain: The role of the numbers is to indicate how remarks on different levels are interconnected to form a concise, surveyable and unified whole.

A minimax procedure in the context of sequential mastery testing

NARCIS (Netherlands)

Vos, Hendrik J.

1999-01-01

The purpose of this paper is to derive optimal rules for sequential mastery tests. In a sequential mastery test, the decision is to classify a subject as a master or a nonmaster, or to continue sampling and administering another random test item. The framework of minimax sequential decision theory

A hybrid sales forecasting scheme by combining independent component analysis with K-means clustering and support vector regression.

Science.gov (United States)

Lu, Chi-Jie; Chang, Chi-Chang

2014-01-01

Sales forecasting plays an important role in operating a business since it can be used to determine the required inventory level to meet consumer demand and avoid the problem of under/overstocking. Improving the accuracy of sales forecasting has become an important issue of operating a business. This study proposes a hybrid sales forecasting scheme by combining independent component analysis (ICA) with K-means clustering and support vector regression (SVR). The proposed scheme first uses the ICA to extract hidden information from the observed sales data. The extracted features are then applied to K-means algorithm for clustering the sales data into several disjoined clusters. Finally, the SVR forecasting models are applied to each group to generate final forecasting results. Experimental results from information technology (IT) product agent sales data reveal that the proposed sales forecasting scheme outperforms the three comparison models and hence provides an efficient alternative for sales forecasting.

Sequential Extraction as Novel Approach to Compare 12 Medicinal Plants From Kenya Regarding Their Potential to Release Chromium, Manganese, Copper, and Zinc.

Science.gov (United States)

Mogwasi, R; Zor, S; Kariuki, D K; Getenga, M Z; Nischwitz, V

2018-04-01

This study is focusing on a novel approach to screen a large number of medicinal plants from Kenya regarding their contents and availability of selected metals potentially relevant for treatment of diabetes patients. For this purpose, total levels of zinc, chromium, manganese, and copper were determined by flame atomic absorption spectrometry and inductively coupled plasma mass spectrometry as well as BCR sequential extraction to fractionate the elemental species in anti-diabetic medicinal plants collected from five natural locations in two sub counties in Nyamira County, Kenya. Solanum mauense had the highest zinc level of 123.0 ± 3.1 mg/kg while Warburgia ugandensis had the lowest level of 13.9 ± 0.4 mg/kg. The highest level of copper was in Bidens pilosa (29.0 ± 0.6 mg/kg) while the lowest was in Aloe vera (3.0 ± 0.1 mg/kg). Croton macrostachyus had the highest manganese level of 1630 ± 40 mg/kg while Clerodendrum myricoides had the lowest (80.2 ± 1.2 mg/kg). The highest level of chromium was in Solanum mauense (3.20 ± 0.06 mg/kg) while the lowest (0.04 ± 0.01 mg/kg) were in Clerodendrum myricoides and Warburgia ugandesis among the medicinal plants from Nyamira and Borabu, respectively. The levels of the elements were statistically different from that of other elements while the level of a given element was not statistically different in the medicinal plants from the different sub counties. Sequential extraction was performed to determine the solubility and thus estimate the bioavailability of the four investigated essential and potentially therapeutically relevant metals. The results showed that the easily bioavailable fraction (EBF) of chromium, manganese, zinc, and copper ranged from 6.7 to 13.8%, 4.1 to 10%, 2.4 to 10.2%, and 3.2 to 12.0% while the potentially bioavailable fraction (PBF) ranged from 50.1 to 67.6%, 32.2 to 48.7%, 23.0 to 41.1%, and 34.6 to 53.1%, respectively. Bidens pilosa, Croton macrostachyus, Ultrica dioica

40 Gbit/s NRZ Packet-Length Insensitive Header Extraction for Optical Label Switching Networks

DEFF Research Database (Denmark)

Seoane, Jorge; Kehayas, E; Avramopoulos, H.

2006-01-01

A simple method for 40 Gbit/s NRZ header extraction based on envelope detection for optical label switching networks is presented. The scheme is insensitive to packet length and spacing and can be single-chip integrated cost-effectively......A simple method for 40 Gbit/s NRZ header extraction based on envelope detection for optical label switching networks is presented. The scheme is insensitive to packet length and spacing and can be single-chip integrated cost-effectively...

Multichannel, sequential or combined X-ray spectrometry

International Nuclear Information System (INIS)

Florestan, J.

1979-01-01

X-ray spectrometer qualities and defects are evaluated for sequential and multichannel categories. Multichannel X-ray spectrometer has time-coherency advantage and its results could be more reproducible; on the other hand some spatial incoherency limits low percentage and traces applications, specially when backgrounds are very variable. In this last case, sequential X-ray spectrometer would find again great usefulness [fr

Stochastic porous media modeling and high-resolution schemes for numerical simulation of subsurface immiscible fluid flow transport

Science.gov (United States)

Brantson, Eric Thompson; Ju, Binshan; Wu, Dan; Gyan, Patricia Semwaah

2018-04-01

This paper proposes stochastic petroleum porous media modeling for immiscible fluid flow simulation using Dykstra-Parson coefficient (V DP) and autocorrelation lengths to generate 2D stochastic permeability values which were also used to generate porosity fields through a linear interpolation technique based on Carman-Kozeny equation. The proposed method of permeability field generation in this study was compared to turning bands method (TBM) and uniform sampling randomization method (USRM). On the other hand, many studies have also reported that, upstream mobility weighting schemes, commonly used in conventional numerical reservoir simulators do not accurately capture immiscible displacement shocks and discontinuities through stochastically generated porous media. This can be attributed to high level of numerical smearing in first-order schemes, oftentimes misinterpreted as subsurface geological features. Therefore, this work employs high-resolution schemes of SUPERBEE flux limiter, weighted essentially non-oscillatory scheme (WENO), and monotone upstream-centered schemes for conservation laws (MUSCL) to accurately capture immiscible fluid flow transport in stochastic porous media. The high-order schemes results match well with Buckley Leverett (BL) analytical solution without any non-oscillatory solutions. The governing fluid flow equations were solved numerically using simultaneous solution (SS) technique, sequential solution (SEQ) technique and iterative implicit pressure and explicit saturation (IMPES) technique which produce acceptable numerical stability and convergence rate. A comparative and numerical examples study of flow transport through the proposed method, TBM and USRM permeability fields revealed detailed subsurface instabilities with their corresponding ultimate recovery factors. Also, the impact of autocorrelation lengths on immiscible fluid flow transport were analyzed and quantified. A finite number of lines used in the TBM resulted into visual

Induction of simultaneous and sequential malolactic fermentation in durian wine.

Science.gov (United States)

Taniasuri, Fransisca; Lee, Pin-Rou; Liu, Shao-Quan

2016-08-02

This study represented for the first time the impact of malolactic fermentation (MLF) induced by Oenococcus oeni and its inoculation strategies (simultaneous vs. sequential) on the fermentation performance as well as aroma compound profile of durian wine. There was no negative impact of simultaneous inoculation of O. oeni and Saccharomyces cerevisiae on the growth and fermentation kinetics of S. cerevisiae as compared to sequential fermentation. Simultaneous MLF did not lead to an excessive increase in volatile acidity as compared to sequential MLF. The kinetic changes of organic acids (i.e. malic, lactic, succinic, acetic and α-ketoglutaric acids) varied with simultaneous and sequential MLF relative to yeast alone. MLF, regardless of inoculation mode, resulted in higher production of fermentation-derived volatiles as compared to control (alcoholic fermentation only), including esters, volatile fatty acids, and terpenes, except for higher alcohols. Most indigenous volatile sulphur compounds in durian were decreased to trace levels with little differences among the control, simultaneous and sequential MLF. Among the different wines, the wine with simultaneous MLF had higher concentrations of terpenes and acetate esters while sequential MLF had increased concentrations of medium- and long-chain ethyl esters. Relative to alcoholic fermentation only, both simultaneous and sequential MLF reduced acetaldehyde substantially with sequential MLF being more effective. These findings illustrate that MLF is an effective and novel way of modulating the volatile and aroma compound profile of durian wine. Copyright © 2016 Elsevier B.V. All rights reserved.

Analytical, antioxidant and hepatoprotective studies on extracts of oxalis corniculata linn

International Nuclear Information System (INIS)

Hussain, I.S.; Islam, M.; Khan, M.T.

2014-01-01

Despite a number of traditional medicinal uses and pharmacological properties, the usefulness of Oxalis corniculata Linn. (Family: Oxalidaceae) is a question due to its high oxalate content which can form insoluble salts with physiological calcium. Therefore, the present study aimed to reduce oxalates in extracts and to investigate such extracts chemically and biologically. The extraction was carried out using different solvents and methods, and analytical studies of extracts indicated that oxalate contents decrease on drying the material. Furthermore, extraction of both fresh and dried materials using 1 % aqueous calcium chloride and ferric chloride solutions resulted in lowering oxalate contents. Methanolic extracts of stems and leaves having lower oxalates were obtained using sequential extraction, which showed good in vitro antioxidant activity - by DPPH and beta-carotene linoleate models - and in vivo hepatoprotective activity in isoniazid and rifampicin-induced oxidative stressed rats (P < 0.05). It was concluded that methanolic extracts of leaves and stems of Oxalis corniculata had lower oxalates and showed promising antioxidant and hepatoprotective activities. (author)

Sequential Banking.

OpenAIRE

Bizer, David S; DeMarzo, Peter M

1992-01-01

The authors study environments in which agents may borrow sequentially from more than one leader. Although debt is prioritized, additional lending imposes an externality on prior debt because, with moral hazard, the probability of repayment of prior loans decreases. Equilibrium interest rates are higher than they would be if borrowers could commit to borrow from at most one bank. Even though the loan terms are less favorable than they would be under commitment, the indebtedness of borrowers i...

Optimization, formulation, and characterization of multiflavonoids-loaded flavanosome by bulk or sequential technique.

Science.gov (United States)

Karthivashan, Govindarajan; Masarudin, Mas Jaffri; Kura, Aminu Umar; Abas, Faridah; Fakurazi, Sharida

2016-01-01

This study involves adaptation of bulk or sequential technique to load multiple flavonoids in a single phytosome, which can be termed as "flavonosome". Three widely established and therapeutically valuable flavonoids, such as quercetin (Q), kaempferol (K), and apigenin (A), were quantified in the ethyl acetate fraction of Moringa oleifera leaves extract and were commercially obtained and incorporated in a single flavonosome (QKA-phosphatidylcholine) through four different methods of synthesis - bulk (M1) and serialized (M2) co-sonication and bulk (M3) and sequential (M4) co-loading. The study also established an optimal formulation method based on screening the synthesized flavonosomes with respect to their size, charge, polydispersity index, morphology, drug-carrier interaction, antioxidant potential through in vitro 1,1-diphenyl-2-picrylhydrazyl kinetics, and cytotoxicity evaluation against human hepatoma cell line (HepaRG). Furthermore, entrapment and loading efficiency of flavonoids in the optimal flavonosome have been identified. Among the four synthesis methods, sequential loading technique has been optimized as the best method for the synthesis of QKA-phosphatidylcholine flavonosome, which revealed an average diameter of 375.93±33.61 nm, with a zeta potential of -39.07±3.55 mV, and the entrapment efficiency was >98% for all the flavonoids, whereas the drug-loading capacity of Q, K, and A was 31.63%±0.17%, 34.51%±2.07%, and 31.79%±0.01%, respectively. The in vitro 1,1-diphenyl-2-picrylhydrazyl kinetics of the flavonoids indirectly depicts the release kinetic behavior of the flavonoids from the carrier. The QKA-loaded flavonosome had no indication of toxicity toward human hepatoma cell line as shown by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide result, wherein even at the higher concentration of 200 µg/mL, the flavonosomes exert >85% of cell viability. These results suggest that sequential loading technique may be a promising

Extraction and separation studies of Ga(III, In(III and Tl(III using the neutral organophosphorous extractant, Cyanex-923

Directory of Open Access Journals (Sweden)

P. M. DHADKE

2003-07-01

Full Text Available The neutral extractant, Cyanes-923 has been used for the extraction and separation of gallium(III, indium(III and thallium(III from acidic solution. These metal ions were found to be quantitatively extracted with Cyanex-923 in toluene in the pH range 4.5–5.5, 5.0–6.5 and 1.5–3.0, respectively, and from the organic phase they can be stripped with 2.0 mol dm-3 HNO3, 3.0 mol dm-3 HNO3 and 3.0 mol dm-3 HCl, respectively. The effect of pH equilibration period, diluents, diverse ions and stripping agents on the extraction of Ga(III, In(III and Tl(III has been studied. The stroichiometry of the extracted species of these metal ions was determined on the basis of the slope analysis method. The reaction proceed by solvation and the probable extracted species found were [MCl3. 3Cyanex-923] [where M = Ga(III or In(III ] and [HTlCl4. 3Cyanex-923]. Based on these results a sequential procedure for the separation of Ga(III, In(III and Tl(III from each other was developed.

An Automated Scheme for the Large-Scale Survey of Herbig-Haro Objects

Science.gov (United States)

Deng, Licai; Yang, Ji; Zheng, Zhongyuan; Jiang, Zhaoji

2001-04-01

Owing to their spectral properties, Herbig-Haro (HH) objects can be discovered using photometric methods through a combination of filters, sampling the characteristic spectral lines and the nearby continuum. The data are commonly processed through direct visual inspection of the images. To make data reduction more efficient and the results more uniform and complete, an automated searching scheme for HH objects is developed to manipulate the images using IRAF. This approach helps to extract images with only intrinsic HH emissions. By using this scheme, the pointlike stellar sources and extended nebulous sources with continuum emission can be eliminated from the original images. The objects with only characteristic HH emission become prominent and can be easily picked up. In this paper our scheme is illustrated by a sample field and has been applied to our surveys for HH objects.

Sequential Exposure of Bortezomib and Vorinostat is Synergistic in Multiple Myeloma Cells

Science.gov (United States)

Nanavati, Charvi; Mager, Donald E.

2018-01-01

Purpose To examine the combination of bortezomib and vorinostat in multiple myeloma cells (U266) and xenografts, and to assess the nature of their potential interactions with semi-mechanistic pharmacodynamic models and biomarkers. Methods U266 proliferation was examined for a range of bortezomib and vorinostat exposure times and concentrations (alone and in combination). A non-competitive interaction model was used with interaction parameters that reflect the nature of drug interactions after simultaneous and sequential exposures. p21 and cleaved PARP were measured using immunoblotting to assess critical biomarker dynamics. For xenografts, data were extracted from literature and modeled with a PK/PD model with an interaction parameter. Results Estimated model parameters for simultaneous in vitro and xenograft treatments suggested additive drug effects. The sequence of bortezomib preincubation for 24 hours, followed by vorinostat for 24 hours, resulted in an estimated interaction term significantly less than 1, suggesting synergistic effects. p21 and cleaved PARP were also up-regulated the most in this sequence. Conclusions Semi-mechanistic pharmacodynamic modeling suggests synergistic pharmacodynamic interactions for the sequential administration of bortezomib followed by vorinostat. Increased p21 and cleaved PARP expression can potentially explain mechanisms of their enhanced effects, which require further PK/PD systems analysis to suggest an optimal dosing regimen. PMID:28101809

Modified Sequential Therapy Regimen versus Conventional Triple Therapy for Helicobacter pylori Eradication in Duodenal Ulcer Patients in China: A Multicenter Clinical Comparative Study

Directory of Open Access Journals (Sweden)

Ying-Qun Zhou

2012-01-01

Full Text Available Objective. Antimicrobial resistance has decreased eradication rates for Helicobacter pylori infection worldwide. To observe the effect of eradicating Helicobacter pylori (H. pylori and the treatment of duodenal ulcer by 2 kinds of modified sequential therapy through comparing with that of 10-day standard triple therapy. Methods. A total of 210 patients who were confirmed in duodenal ulcer active or heal period by gastroscopy and H. pylori positive confirmed by rapid urease test, serum anti-H. pylori antibody (ELASE, or histological examination enrolled in the study. All the patients were randomly divided into three groups: group A (70 cases and group B (70 cases were provided 10-day modified sequential therapy; group C (70 cases was provided 10-day standard triple therapy. Patients of group A received 20 mg of Esomeprazole, 500 mg of Clarithromycin for the first 5 days, followed by 20 mg of Esomeprazole, 500 mg of Clarithromycin, and 1000 mg of Amoxicillin for the remaining 5 days. Group B received 20 mg of Esomeprazole, 1000 mg of Amoxicillin for the first 5 days, followed by 20 mg of Esomeprazole, 500 mg of Clarithromycin, and 1000 mg of Amoxicillin for the remaining 5 days. Group C received 20 mg of Esomeprazole, 500 mg of Clarithromycin, and 1000 mg of Amoxicillin for standard 10-day therapy. All drugs were given twice daily. H. pylori eradication rate was checked four to eight weeks after taking the medicine by using a 13C urea breath test. In the first, second, third, seventh, twenty-first, thirty-fifth days respectively, the symptoms of patients such as epigastric gnawing, burning pain, and acidity were evaluated simultaneously. Results. Overall, 210 patients accomplished all therapy schemes, 9 case patients were excluded. The examination result indicated that the H. pylori eradication rate of each group was as follows: group A 92.5% (62/67, group B 86.8% (59/68, and group C 78.8% (52/66. The H. pylori

Equivalence between quantum simultaneous games and quantum sequential games

OpenAIRE

Kobayashi, Naoki

2007-01-01

A framework for discussing relationships between different types of games is proposed. Within the framework, quantum simultaneous games, finite quantum simultaneous games, quantum sequential games, and finite quantum sequential games are defined. In addition, a notion of equivalence between two games is defined. Finally, the following three theorems are shown: (1) For any quantum simultaneous game G, there exists a quantum sequential game equivalent to G. (2) For any finite quantum simultaneo...

Structural investigation of water-soluble polysaccharides extracted from the fruit bodies of Coprinus comatus

NARCIS (Netherlands)

Li, Bo; Dobruchowska, Justyna M.; Gerwig, Gerrit J.; Dijkhuizen, Lubbert; Kamerling, Johannis P.

2013-01-01

Water-soluble polysaccharide material, extracted from the stipes of the fruit bodies of Coprinus comatus by hot water, was fractionated by sequential weak anion-exchange and size-exclusion chromatography. The relevant fractions were subjected to structural analysis, including (D/L)

Accounting for Heterogeneous Returns in Sequential Schooling Decisions

NARCIS (Netherlands)

Zamarro, G.

2006-01-01

This paper presents a method for estimating returns to schooling that takes into account that returns may be heterogeneous among agents and that educational decisions are made sequentially.A sequential decision model is interesting because it explicitly considers that the level of education of each

Simultaneous Versus Sequential Ptosis and Strabismus Surgery in Children.

Science.gov (United States)

Revere, Karen E; Binenbaum, Gil; Li, Jonathan; Mills, Monte D; Katowitz, William R; Katowitz, James A

The authors sought to compare the clinical outcomes of simultaneous versus sequential ptosis and strabismus surgery in children. Retrospective, single-center cohort study of children requiring both ptosis and strabismus surgery on the same eye. Simultaneous surgeries were performed during a single anesthetic event; sequential surgeries were performed at least 7 weeks apart. Outcomes were ptosis surgery success (margin reflex distance 1 ≥ 2 mm, good eyelid contour, and good eyelid crease); strabismus surgery success (ocular alignment within 10 prism diopters of orthophoria and/or improved head position); surgical complications; and reoperations. Fifty-six children were studied, 38 had simultaneous surgery and 18 sequential. Strabismus surgery was performed first in 38/38 simultaneous and 6/18 sequential cases. Mean age at first surgery was 64 months, with mean follow up 27 months. A total of 75% of children had congenital ptosis; 64% had comitant strabismus. A majority of ptosis surgeries were frontalis sling (59%) or Fasanella-Servat (30%) procedures. There were no significant differences between simultaneous and sequential groups with regards to surgical success rates, complications, or reoperations (all p > 0.28). In the first comparative study of simultaneous versus sequential ptosis and strabismus surgery, no advantage for sequential surgery was seen. Despite a theoretical risk of postoperative eyelid malposition or complications when surgeries were performed in a combined manner, the rate of such outcomes was not increased with simultaneous surgeries. Performing ptosis and strabismus surgery together appears to be clinically effective and safe, and reduces anesthesia exposure during childhood.

A PCA aided cross-covariance scheme for discriminative feature extraction from EEG signals.

Science.gov (United States)

Zarei, Roozbeh; He, Jing; Siuly, Siuly; Zhang, Yanchun

2017-07-01

Feature extraction of EEG signals plays a significant role in Brain-computer interface (BCI) as it can significantly affect the performance and the computational time of the system. The main aim of the current work is to introduce an innovative algorithm for acquiring reliable discriminating features from EEG signals to improve classification performances and to reduce the time complexity. This study develops a robust feature extraction method combining the principal component analysis (PCA) and the cross-covariance technique (CCOV) for the extraction of discriminatory information from the mental states based on EEG signals in BCI applications. We apply the correlation based variable selection method with the best first search on the extracted features to identify the best feature set for characterizing the distribution of mental state signals. To verify the robustness of the proposed feature extraction method, three machine learning techniques: multilayer perceptron neural networks (MLP), least square support vector machine (LS-SVM), and logistic regression (LR) are employed on the obtained features. The proposed methods are evaluated on two publicly available datasets. Furthermore, we evaluate the performance of the proposed methods by comparing it with some recently reported algorithms. The experimental results show that all three classifiers achieve high performance (above 99% overall classification accuracy) for the proposed feature set. Among these classifiers, the MLP and LS-SVM methods yield the best performance for the obtained feature. The average sensitivity, specificity and classification accuracy for these two classifiers are same, which are 99.32%, 100%, and 99.66%, respectively for the BCI competition dataset IVa and 100%, 100%, and 100%, for the BCI competition dataset IVb. The results also indicate the proposed methods outperform the most recently reported methods by at least 0.25% average accuracy improvement in dataset IVa. The execution time

ESCL8R and LEVIT8R: interactive graphical analysis of {gamma}-{gamma} and {gamma}-{gamma}-{gamma} coincidence data for level schemes

Energy Technology Data Exchange (ETDEWEB)

Radford, D C [Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs.

1992-08-01

The extraction of complete and consistent nuclear level schemes from high-fold coincidence data will require intelligent computer programs. These will need to present the relevant data in an easily assimilated manner, keep track of all {gamma}-ray assignments and expected coincidence intensities, and quickly find significant discrepancies between a proposed level scheme and the data. Some steps in this direction have been made at Chalk River. The programs ESCL8R and LEVIT8R, for analysis of two-fold and three-fold data sets respectively, allow fast and easy inspection of the data, and compare the results to expectations calculations on the basis of a proposed level scheme. Least-squares fits directly to the 2D and/or 3D data, with the intensities and energies of the level scheme transitions as parameters, allow fast and easy extraction of the optimum physics results. (author). 4 refs., 3 figs.

Design of extraction system in BRing at HIAF

Science.gov (United States)

Ruan, Shuang; Yang, Jiancheng; Zhang, Jinquan; Shen, Guodong; Ren, Hang; Liu, Jie; Shangguan, Jingbing; Zhang, Xiaoying; Zhang, Jingjing; Mao, Lijun; Sheng, Lina; Yin, Dayu; Wang, Geng; Wu, Bo; Yao, Liping; Tang, Meitang; Cai, Fucheng; Chen, Xiaoqiang

2018-06-01

The Booster Ring (BRing), which is the key part of HIAF (High Intensity heavy ion Accelerator Facility) complex at IMP (Institute of Modern Physics, Chinese Academy of Sciences), can provide uranium (A / q = 7) beam with a wide extraction energy range of 200-800 MeV/u. To fulfill a flexible beam extraction for multi-purpose experiments, both fast and slow extraction systems will be accommodated in the BRing. The fast extraction system is used for extracting short bunched beam horizontally in single-turn. The slow extraction system is used to provide quasi-continuous beam by the third order resonance and RF-knockout scheme. To achieve a compact structure, the two extraction systems are designed to share the same extraction channel. The general design of the fast and slow extraction systems and simulation results are discussed in this paper.

Reading Remediation Based on Sequential and Simultaneous Processing.

Science.gov (United States)

Gunnison, Judy; And Others

1982-01-01

The theory postulating a dichotomy between sequential and simultaneous processing is reviewed and its implications for remediating reading problems are reviewed. Research is cited on sequential-simultaneous processing for early and advanced reading. A list of remedial strategies based on the processing dichotomy addresses decoding and lexical…

Sequential injection approach for simultaneous determination of ultratrace plutonium and neptunium in urine with accelerator mass spectrometry

DEFF Research Database (Denmark)

Qiao, Jixin; Hou, Xiaolin; Roos, Per

2013-01-01

An analytical method was developed for simultaneous determination of ultratrace level plutonium (Pu) and neptunium (Np) using iron hydroxide coprecipitation in combination with automated sequential injection extraction chromatography separation and accelerator mass spectrometry (AMS) measurement...... show that preboiling and aging are important for obtaining high chemical yields for both Pu and Np, which is possibly related to the aggregation and adsorption behavior of organic substances contained in urine. Although the optimal condition for Np and Pu simultaneous determination requires 5-day aging...

Operator mixing in the ɛ -expansion: Scheme and evanescent-operator independence

Science.gov (United States)

Di Pietro, Lorenzo; Stamou, Emmanuel

2018-03-01

We consider theories with fermionic degrees of freedom that have a fixed point of Wilson-Fisher type in noninteger dimension d =4 -2 ɛ . Due to the presence of evanescent operators, i.e., operators that vanish in integer dimensions, these theories contain families of infinitely many operators that can mix with each other under renormalization. We clarify the dependence of the corresponding anomalous-dimension matrix on the choice of renormalization scheme beyond leading order in ɛ -expansion. In standard choices of scheme, we find that eigenvalues at the fixed point cannot be extracted from a finite-dimensional block. We illustrate in examples a truncation approach to compute the eigenvalues. These are observable scaling dimensions, and, indeed, we find that the dependence on the choice of scheme cancels. As an application, we obtain the IR scaling dimension of four-fermion operators in QED in d =4 -2 ɛ at order O (ɛ2).

A novel lost packets recovery scheme based on visual secret sharing

Science.gov (United States)

Lu, Kun; Shan, Hong; Li, Zhi; Niu, Zhao

2017-08-01

In this paper, a novel lost packets recovery scheme which encrypts the effective parts of an original packet into two shadow packets based on (2, 2)-threshold XOR-based visual Secret Sharing (VSS) is proposed. The two shadow packets used as watermarks would be embedded into two normal data packets with digital watermarking embedding technology and then sent from one sensor node to another. Each shadow packet would reveal no information of the original packet, which can improve the security of original packet delivery greatly. The two shadow packets which can be extracted from the received two normal data packets delivered from a sensor node can recover the original packet lossless based on XOR-based VSS. The Performance analysis present that the proposed scheme provides essential services as long as possible in the presence of selective forwarding attack. The proposed scheme would not increase the amount of additional traffic, namely, lower energy consumption, which is suitable for Wireless Sensor Network (WSN).

Quantum dual signature scheme based on coherent states with entanglement swapping

International Nuclear Information System (INIS)

Liu Jia-Li; Shi Rong-Hua; Shi Jin-Jing; Lv Ge-Li; Guo Ying

2016-01-01

A novel quantum dual signature scheme, which combines two signed messages expected to be sent to two diverse receivers Bob and Charlie, is designed by applying entanglement swapping with coherent states. The signatory Alice signs two different messages with unitary operations (corresponding to the secret keys) and applies entanglement swapping to generate a quantum dual signature. The dual signature is firstly sent to the verifier Bob who extracts and verifies the signature of one message and transmits the rest of the dual signature to the verifier Charlie who verifies the signature of the other message. The transmission of the dual signature is realized with quantum teleportation of coherent states. The analysis shows that the security of secret keys and the security criteria of the signature protocol can be greatly guaranteed. An extensional multi-party quantum dual signature scheme which considers the case with more than three participants is also proposed in this paper and this scheme can remain secure. The proposed schemes are completely suited for the quantum communication network including multiple participants and can be applied to the e-commerce system which requires a secure payment among the customer, business and bank. (paper)

Massive parallel 3D PIC simulation of negative ion extraction

Science.gov (United States)

Revel, Adrien; Mochalskyy, Serhiy; Montellano, Ivar Mauricio; Wünderlich, Dirk; Fantz, Ursel; Minea, Tiberiu

2017-09-01

The 3D PIC-MCC code ONIX is dedicated to modeling Negative hydrogen/deuterium Ion (NI) extraction and co-extraction of electrons from radio-frequency driven, low pressure plasma sources. It provides valuable insight on the complex phenomena involved in the extraction process. In previous calculations, a mesh size larger than the Debye length was used, implying numerical electron heating. Important steps have been achieved in terms of computation performance and parallelization efficiency allowing successful massive parallel calculations (4096 cores), imperative to resolve the Debye length. In addition, the numerical algorithms have been improved in terms of grid treatment, i.e., the electric field near the complex geometry boundaries (plasma grid) is calculated more accurately. The revised model preserves the full 3D treatment, but can take advantage of a highly refined mesh. ONIX was used to investigate the role of the mesh size, the re-injection scheme for lost particles (extracted or wall absorbed), and the electron thermalization process on the calculated extracted current and plasma characteristics. It is demonstrated that all numerical schemes give the same NI current distribution for extracted ions. Concerning the electrons, the pair-injection technique is found well-adapted to simulate the sheath in front of the plasma grid.

Speciation of heavy metals in garden soils. Evidences from selective and sequential chemical leaching

Energy Technology Data Exchange (ETDEWEB)

Cheng, Zhongqi; Lee, Leda; Dayan, Sara; Grinshtein, Michael [Brooklyn College of The City Univ. of New York, Brooklyn, NY (United States). Environmental Sciences Analytical Cnter; Shaw, Richard [USDA-NRCS NYC Soil Survey, Staten Island, NY (United States)

2011-06-15

Purpose: Gardening (especially food growing) in urban areas is becoming popular, but urban soils are often very contaminated for historical reasons. There is lack of sufficient information as to the bioavailability of soil heavy metals to plants and human in urban environments. This study examines the relative leachability of Cr, Ni, As, Cd, Zn, and Pb for soils with varying characteristics. The speciation and mobility of these metals can be qualitatively inferred from the leaching experiments. The goal is to use the data to shed some light on their bioavailability to plant and human, as well as the basis for soil remediation. Materials and methods: Selective and sequential chemical leaching methods were both used to evaluate the speciation of Cr, Ni, As, Cd, Zn, and Pb in soil samples collected from New York City residential and community gardens. The sequential leaching experiment followed a standard BCR four-step procedure, while selective leaching involved seven different chemical extractants. Results and discussion: The results from selective and sequential leaching methods are consistent. In general, very little of the heavy metals were found in the easily soluble or exchangeable fractions. Larger fractions of Cd and Zn can be leached out than other metals. Lead appears predominantly in the organic or carbonate fractions, of which {proportional_to} 30-60% is in the easily soluble organic fraction. Most As cannot be leached out by any of the extractants used, but it could have been complicated by the ineffective dissolution of oxides by ammonium hydroxylamine. Ni and Cr were mostly in the residual fractions but some released in the oxidizable fractions. Therefore, the leachability of metals follow the order Cd/Zn > Pb > Ni/Cr. Conclusions: Despite of the controversy and inaccuracy surrounding chemical leaching methods for the speciation of metals, chemical leaching data provide important, general, and easy-to-access information on the mobility of heavy metals

Field-scale multi-phase LNAPL remediation: Validating a new computational framework against sequential field pilot trials.

Science.gov (United States)

Sookhak Lari, Kaveh; Johnston, Colin D; Rayner, John L; Davis, Greg B

2018-03-05

Remediation of subsurface systems, including groundwater, soil and soil gas, contaminated with light non-aqueous phase liquids (LNAPLs) is challenging. Field-scale pilot trials of multi-phase remediation were undertaken at a site to determine the effectiveness of recovery options. Sequential LNAPL skimming and vacuum-enhanced skimming, with and without water table drawdown were trialled over 78days; in total extracting over 5m 3 of LNAPL. For the first time, a multi-component simulation framework (including the multi-phase multi-component code TMVOC-MP and processing codes) was developed and applied to simulate the broad range of multi-phase remediation and recovery methods used in the field trials. This framework was validated against the sequential pilot trials by comparing predicted and measured LNAPL mass removal rates and compositional changes. The framework was tested on both a Cray supercomputer and a cluster. Simulations mimicked trends in LNAPL recovery rates (from 0.14 to 3mL/s) across all remediation techniques each operating over periods of 4-14days over the 78day trial. The code also approximated order of magnitude compositional changes of hazardous chemical concentrations in extracted gas during vacuum-enhanced recovery. The verified framework enables longer term prediction of the effectiveness of remediation approaches allowing better determination of remediation endpoints and long-term risks. Copyright © 2017 Commonwealth Scientific and Industrial Research Organisation. Published by Elsevier B.V. All rights reserved.

Sequential effects of severe drought and defoliation on tree growth and survival in a diverse temperate mesic forest

Science.gov (United States)

Matthes, J. H.; Pederson, N.; David, O.; Martin-Benito, D.

2017-12-01

Understanding the effects of climate change and biotic disturbance within diverse temperate mesic forests is complicated by the need to scale between impacts within individuals and across species in the community. It is not clear how these impacts within individuals and across a community influences the stand- and regional-scale response. Furthermore, co-occurring or sequential disturbances can make it challenging to interpret forest responses from observational data. In the northeastern United States, the 1960s drought was perhaps the most severe period of climatic stress within the past 300 years and negatively impacted the growth of individual trees across all species, but unevenly. Additionally, in 1981 the northeast experienced an outbreak of the defoliator Lymantria dispar, which preferentially consumes oak leaves, but in 1981 impacted a high proportion of other species as well. To investigate the effects of drought (across functional groups) and defoliation (within a functional group), we combined a long-term tree-ring dataset from an old-growth forest within the Palmaghatt Ravine in New York with a version of the Ecosystem Demography model that includes a scheme for representing forest insects and pathogens. We explored the sequential impacts of severe drought and defoliation on tree growth, community composition, and ecosystem-atmosphere interactions (carbon, water, and heat flux). W­e also conducted a set of modeling experiments with climate and defoliation disturbance scenarios to bound the potential long-term response of this forest to co-occurring and sequential drought-defoliator disturbances over the next fifty years.

Biodiesel production from wet microalgae feedstock using sequential wet extraction/transesterification and direct transesterification processes.

Science.gov (United States)

Chen, Ching-Lung; Huang, Chien-Chang; Ho, Kao-Chia; Hsiao, Ping-Xuan; Wu, Meng-Shan; Chang, Jo-Shu

2015-10-01

Although producing biodiesel from microalgae seems promising, there is still a lack of technology for the quick and cost-effective conversion of biodiesel from wet microalgae. This study was aimed to develop a novel microalgal biodiesel producing method, consisting of an open system of microwave disruption, partial dewatering (via combination of methanol treatment and low-speed centrifugation), oil extraction, and transesterification without the pre-removal of the co-solvent, using Chlamydomonas sp. JSC4 with 68.7 wt% water content as the feedstock. Direct transesterification with the disrupted wet microalgae was also conducted. The biomass content of the wet microalgae increased to 56.6 and 60.5 wt%, respectively, after microwave disruption and partial dewatering. About 96.2% oil recovery was achieved under the conditions of: extraction temperature, 45°C; hexane/methanol ratio, 3:1; extraction time, 80 min. Transesterification of the extracted oil reached 97.2% conversion within 15 min at 45°C and 6:1 solvent/methanol ratio with simultaneous Chlorophyll removal during the process. Nearly 100% biodiesel conversion was also obtained while conducting direct transesterification of the disrupted oil-bearing microalgal biomass. Copyright © 2015 Elsevier Ltd. All rights reserved.

Exact analysis of Packet Reversed Packet Combining Scheme and Modified Packet Combining Scheme; and a combined scheme

International Nuclear Information System (INIS)

Bhunia, C.T.

2007-07-01

Packet combining scheme is a well defined simple error correction scheme for the detection and correction of errors at the receiver. Although it permits a higher throughput when compared to other basic ARQ protocols, packet combining (PC) scheme fails to correct errors when errors occur in the same bit locations of copies. In a previous work, a scheme known as Packet Reversed Packet Combining (PRPC) Scheme that will correct errors which occur at the same bit location of erroneous copies, was studied however PRPC does not handle a situation where a packet has more than 1 error bit. The Modified Packet Combining (MPC) Scheme that can correct double or higher bit errors was studied elsewhere. Both PRPC and MPC schemes are believed to offer higher throughput in previous studies, however neither adequate investigation nor exact analysis was done to substantiate this claim of higher throughput. In this work, an exact analysis of both PRPC and MPC is carried out and the results reported. A combined protocol (PRPC and MPC) is proposed and the analysis shows that it is capable of offering even higher throughput and better error correction capability at high bit error rate (BER) and larger packet size. (author)

C-quence: a tool for analyzing qualitative sequential data.

Science.gov (United States)

Duncan, Starkey; Collier, Nicholson T

2002-02-01

C-quence is a software application that matches sequential patterns of qualitative data specified by the user and calculates the rate of occurrence of these patterns in a data set. Although it was designed to facilitate analyses of face-to-face interaction, it is applicable to any data set involving categorical data and sequential information. C-quence queries are constructed using a graphical user interface. The program does not limit the complexity of the sequential patterns specified by the user.

Experimental investigation of a control scheme for a tuned resonant sideband extraction interferometer for next-generation gravitational-wave detectors

Energy Technology Data Exchange (ETDEWEB)

Kawazoe, F; Sugamoto, A [Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo 112-8610 (Japan); Sato, S; Leonhardt, V; Yamazaki, T; Fukushima, M; Kawamura, S [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka-shi, Tokyo 112-8610 (Japan); Miyakawa, O [California Institute of Technology, Pasadena, CA 91125 (United States); Morioka, T [University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Nishizawa, A [Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)], E-mail: kawazoe@gravity.mtk.nao.ac.jp

2008-07-15

LCGT plans to use tuned RSE as the optical configuration for its interferometer. A tuned RSE interferometer has five degrees of freedom that need to be controlled in order to operate a gravitational-wave detector, although it is expected to be very challenging because of the complexity of its optical configuration. A new control scheme for a tuned RSE interferometer has been developed and tested with a prototype interferometer to demonstrate successful control of the tuned RSE interferometer. The whole RSE interferometer was successfully locked with the control scheme. Here the control scheme and the current status of the experiment are presented.

Experimental investigation of a control scheme for a tuned resonant sideband extraction interferometer for next-generation gravitational-wave detectors

International Nuclear Information System (INIS)

Kawazoe, F; Sugamoto, A; Sato, S; Leonhardt, V; Yamazaki, T; Fukushima, M; Kawamura, S; Miyakawa, O; Morioka, T; Nishizawa, A

2008-01-01

LCGT plans to use tuned RSE as the optical configuration for its interferometer. A tuned RSE interferometer has five degrees of freedom that need to be controlled in order to operate a gravitational-wave detector, although it is expected to be very challenging because of the complexity of its optical configuration. A new control scheme for a tuned RSE interferometer has been developed and tested with a prototype interferometer to demonstrate successful control of the tuned RSE interferometer. The whole RSE interferometer was successfully locked with the control scheme. Here the control scheme and the current status of the experiment are presented

A computerized scheme for lung nodule detection in multiprojection chest radiography

International Nuclear Information System (INIS)

Guo Wei; Li Qiang; Boyce, Sarah J.; McAdams, H. Page; Shiraishi, Junji; Doi, Kunio; Samei, Ehsan

2012-01-01

Purpose: Our previous study indicated that multiprojection chest radiography could significantly improve radiologists' performance for lung nodule detection in clinical practice. In this study, the authors further verify that multiprojection chest radiography can greatly improve the performance of a computer-aided diagnostic (CAD) scheme. Methods: Our database consisted of 59 subjects, including 43 subjects with 45 nodules and 16 subjects without nodules. The 45 nodules included 7 real and 38 simulated ones. The authors developed a conventional CAD scheme and a new fusion CAD scheme to detect lung nodules. The conventional CAD scheme consisted of four steps for (1) identification of initial nodule candidates inside lungs, (2) nodule candidate segmentation based on dynamic programming, (3) extraction of 33 features from nodule candidates, and (4) false positive reduction using a piecewise linear classifier. The conventional CAD scheme processed each of the three projection images of a subject independently and discarded the correlation information between the three images. The fusion CAD scheme included the four steps in the conventional CAD scheme and two additional steps for (5) registration of all candidates in the three images of a subject, and (6) integration of correlation information between the registered candidates in the three images. The integration step retained all candidates detected at least twice in the three images of a subject and removed those detected only once in the three images as false positives. A leave-one-subject-out testing method was used for evaluation of the performance levels of the two CAD schemes. Results: At the sensitivities of 70%, 65%, and 60%, our conventional CAD scheme reported 14.7, 11.3, and 8.6 false positives per image, respectively, whereas our fusion CAD scheme reported 3.9, 1.9, and 1.2 false positives per image, and 5.5, 2.8, and 1.7 false positives per patient, respectively. The low performance of the conventional

Low-overhead interference mitigation scheme for collaborative channel assignment in overloaded multiantenna femtocells

KAUST Repository

Radaydeh, Redha Mahmoud Mesleh

2012-09-01

This paper proposes a collaborative-based scheme for a transmit antenna channel assignment in overloaded multiantenna femtocells, with the aim of reducing the overhead load. It is assumed that multiple femtocell access points (FAPs) are deployed to sequentially allocate the available resources to scheduled users while reducing the interference experienced by each active user. The FAPs operate concurrently and each of them is allocated an orthogonal channel and employs a transmit array of arbitrary size. The suitable FAP and its associated transmit channel are then identified based on the noncoherently predicted interference power levels on available channels when feedback links are capacity limited. The effect of possible FAP failure or infeasibility to collaborate is characterized for different operating conditions. The applicability of the proposed scheme for specific cases, such as the use of directional antennas in each FAP or shared channels among different FAPs, is also discussed. For arbitrary statistical models of interference power levels on different channels, the average numbers of collaboration requests and examined transmit antenna channels are quantified. Moreover, the statistics of the resulting interference power are derived, which are then used to study various system performance measures. The effect of the interference threshold on the aforementioned measures for processing load and achieved performance is investigated. Numerical and simulations results are presented to support the analytical development and to clarify the tradeoff between the achieved performance enhancement using the proposed scheme and the required processing load for different operating scenarios. © 1967-2012 IEEE.

Low-overhead interference mitigation scheme for collaborative channel assignment in overloaded multiantenna femtocells

KAUST Repository

Radaydeh, Redha Mahmoud Mesleh; Alouini, Mohamed-Slim

2012-01-01

This paper proposes a collaborative-based scheme for a transmit antenna channel assignment in overloaded multiantenna femtocells, with the aim of reducing the overhead load. It is assumed that multiple femtocell access points (FAPs) are deployed to sequentially allocate the available resources to scheduled users while reducing the interference experienced by each active user. The FAPs operate concurrently and each of them is allocated an orthogonal channel and employs a transmit array of arbitrary size. The suitable FAP and its associated transmit channel are then identified based on the noncoherently predicted interference power levels on available channels when feedback links are capacity limited. The effect of possible FAP failure or infeasibility to collaborate is characterized for different operating conditions. The applicability of the proposed scheme for specific cases, such as the use of directional antennas in each FAP or shared channels among different FAPs, is also discussed. For arbitrary statistical models of interference power levels on different channels, the average numbers of collaboration requests and examined transmit antenna channels are quantified. Moreover, the statistics of the resulting interference power are derived, which are then used to study various system performance measures. The effect of the interference threshold on the aforementioned measures for processing load and achieved performance is investigated. Numerical and simulations results are presented to support the analytical development and to clarify the tradeoff between the achieved performance enhancement using the proposed scheme and the required processing load for different operating scenarios. © 1967-2012 IEEE.

Extraction of scandium by organic substance melts

International Nuclear Information System (INIS)

Gladyshev, V.P.; Lobanov, F.I.; Zebreva, A.I.; Andreeva, N.N.; Manuilova, O.A.; Il'yukevich, Yu.A.

1984-01-01

Regularities of scandium extraction by the melts of octadecanicoic acid, n-carbonic acids of C 17 -C 20 commerical fraction and mixtures of tributylphosphate (TBP) with paraffin at (70+-1) deg C have been studied. The optimum conditions for scandium extraction in the melt of organic substances are determined. A scheme of the extraction by the melts of higher carbonic acids at ninitial metal concentrations of 10 -5 to 10 -3 mol/l has been suggested. The scandium compound has been isolated in solid form, its composition having been determined. The main advantages of extraction by melts are as follows: a possibility to attain high distribution coefficients, distinct separation of phases after extraction, the absence of emulsions, elimination of employing inflammable and toxic solvents, a possibility of rapid X-ray fluorescence determinatinon of scandium directly in solid extract

Extraction of rare earth elements from a contaminated cropland soil using nitric acid, citric acid, and EDTA.

Science.gov (United States)

Tang, Hailong; Shuai, Weitao; Wang, Xiaojing; Liu, Yangsheng

2017-08-01

Rare earth elements (REEs) contamination to the surrounding soil has increased the concerns of health risk to the local residents. Soil washing was first attempted in our study to remediate REEs-contaminated cropland soil using nitric acid, citric acid, and ethylene diamine tetraacetic acid (EDTA) for soil decontamination and possible recovery of REEs. The extraction time, washing agent concentration, and pH value of the washing solution were optimized. The sequential extraction analysis proposed by Tessier was adopted to study the speciation changes of the REEs before and after soil washing. The extract containing citric acid was dried to obtain solid for the X-ray fluorescence (XRF) analysis. The results revealed that the optimal extraction time was 72 h, and the REEs extraction efficiency increased as the agent concentration increased from 0.01 to 0.1 mol/L. EDTA was efficient to extract REEs over a wide range of pH values, while citric acid was around pH 6.0. Under optimized conditions, the average extraction efficiencies of the major REEs in the contaminated soil were 70.96%, 64.38%, and 62.12% by EDTA, nitric acid, and citric acid, respectively. The sequential extraction analyses revealed that most soil-bounded REEs were mobilized or extracted except for those in the residual fraction. Under a comprehensive consideration of the extraction efficiency and the environmental impact, citric acid was recommended as the most suitable agent for extraction of the REEs from the contaminated cropland soils. The XRF analysis revealed that Mn, Al, Si, Pb, Fe, and REEs were the major elements in the extract indicating a possibile recovery of the REEs.

Top-down attention affects sequential regularity representation in the human visual system.

Science.gov (United States)

Kimura, Motohiro; Widmann, Andreas; Schröger, Erich

2010-08-01

Recent neuroscience studies using visual mismatch negativity (visual MMN), an event-related brain potential (ERP) index of memory-mismatch processes in the visual sensory system, have shown that although sequential regularities embedded in successive visual stimuli can be automatically represented in the visual sensory system, an existence of sequential regularity itself does not guarantee that the sequential regularity will be automatically represented. In the present study, we investigated the effects of top-down attention on sequential regularity representation in the visual sensory system. Our results showed that a sequential regularity (SSSSD) embedded in a modified oddball sequence where infrequent deviant (D) and frequent standard stimuli (S) differing in luminance were regularly presented (SSSSDSSSSDSSSSD...) was represented in the visual sensory system only when participants attended the sequential regularity in luminance, but not when participants ignored the stimuli or simply attended the dimension of luminance per se. This suggests that top-down attention affects sequential regularity representation in the visual sensory system and that top-down attention is a prerequisite for particular sequential regularities to be represented. Copyright 2010 Elsevier B.V. All rights reserved.

AN ANALYTICAL METHOD FOR CHEMICAL SPECIATION OF SELENIUM IN SOIL

Directory of Open Access Journals (Sweden)

Constantin Luca

2010-10-01

Full Text Available Selenium is an essential microelement, sometimes redoubtable, through its beneficial role - risk depending on its concentration in the food chain, at low dose is an important nutrient in the life of humans and animals, contrary at high doses, it becomes toxic. Selenium may be find itself in the environment (soil, sediment, water in many forms (oxidized, reduced, organometallic which determine their mobility and toxicity. Determination of chemical speciation (identification of different chemical forms provides much more complete information for a better understanding of the behavior and the potential impact on the environment. In this work we present the results of methodological research on the extraction of sequential forms of selenium in the soil and the coupling of analytical methods capable of identifying very small amounts of selenium in soils An efficient scheme of sequential extractions forms of selenium (SES consisting in atomic absorption spectrometry coupled with hydride generation (HGAAS has been developed into five experimental steps, detailed in the paper. This operational scheme has been applied to the analysis of chemical speciation in the following areas: the Bărăgan Plain and Central Dobrogea of Romania.

On the Optimal Taxation of an Exhaustible Resource Under Monopolistic Extraction

NARCIS (Netherlands)

Daubanes, J.

2007-01-01

In a simple model of resource depletion (isoelastic demand and constant unit extraction cost), we fully characterize the set of linear effiency-inducing tax/subsidy schemes. We show that this set is infinite and all the larger as the cost of extraction is low. Depending on the magnitude of the

Fast sequential Monte Carlo methods for counting and optimization

CERN Document Server

Rubinstein, Reuven Y; Vaisman, Radislav

2013-01-01

A comprehensive account of the theory and application of Monte Carlo methods Based on years of research in efficient Monte Carlo methods for estimation of rare-event probabilities, counting problems, and combinatorial optimization, Fast Sequential Monte Carlo Methods for Counting and Optimization is a complete illustration of fast sequential Monte Carlo techniques. The book provides an accessible overview of current work in the field of Monte Carlo methods, specifically sequential Monte Carlo techniques, for solving abstract counting and optimization problems. Written by authorities in the

A Blind Adaptive Color Image Watermarking Scheme Based on Principal Component Analysis, Singular Value Decomposition and Human Visual System

Directory of Open Access Journals (Sweden)

M. Imran

2017-09-01

Full Text Available A blind adaptive color image watermarking scheme based on principal component analysis, singular value decomposition, and human visual system is proposed. The use of principal component analysis to decorrelate the three color channels of host image, improves the perceptual quality of watermarked image. Whereas, human visual system and fuzzy inference system helped to improve both imperceptibility and robustness by selecting adaptive scaling factor, so that, areas more prone to noise can be added with more information as compared to less prone areas. To achieve security, location of watermark embedding is kept secret and used as key at the time of watermark extraction, whereas, for capacity both singular values and vectors are involved in watermark embedding process. As a result, four contradictory requirements; imperceptibility, robustness, security and capacity are achieved as suggested by results. Both subjective and objective methods are acquired to examine the performance of proposed schemes. For subjective analysis the watermarked images and watermarks extracted from attacked watermarked images are shown. For objective analysis of proposed scheme in terms of imperceptibility, peak signal to noise ratio, structural similarity index, visual information fidelity and normalized color difference are used. Whereas, for objective analysis in terms of robustness, normalized correlation, bit error rate, normalized hamming distance and global authentication rate are used. Security is checked by using different keys to extract the watermark. The proposed schemes are compared with state-of-the-art watermarking techniques and found better performance as suggested by results.

Computing sequential equilibria for two-player games

DEFF Research Database (Denmark)

Miltersen, Peter Bro

2006-01-01

Koller, Megiddo and von Stengel showed how to efficiently compute minimax strategies for two-player extensive-form zero-sum games with imperfect information but perfect recall using linear programming and avoiding conversion to normal form. Their algorithm has been used by AI researchers...... for constructing prescriptive strategies for concrete, often fairly large games. Koller and Pfeffer pointed out that the strategies obtained by the algorithm are not necessarily sequentially rational and that this deficiency is often problematic for the practical applications. We show how to remove this deficiency...... by modifying the linear programs constructed by Koller, Megiddo and von Stengel so that pairs of strategies forming a sequential equilibrium are computed. In particular, we show that a sequential equilibrium for a two-player zero-sum game with imperfect information but perfect recall can be found in polynomial...

Computing Sequential Equilibria for Two-Player Games

DEFF Research Database (Denmark)

Miltersen, Peter Bro; Sørensen, Troels Bjerre

2006-01-01

Koller, Megiddo and von Stengel showed how to efficiently compute minimax strategies for two-player extensive-form zero-sum games with imperfect information but perfect recall using linear programming and avoiding conversion to normal form. Koller and Pfeffer pointed out that the strategies...... obtained by the algorithm are not necessarily sequentially rational and that this deficiency is often problematic for the practical applications. We show how to remove this deficiency by modifying the linear programs constructed by Koller, Megiddo and von Stengel so that pairs of strategies forming...... a sequential equilibrium are computed. In particular, we show that a sequential equilibrium for a two-player zero-sum game with imperfect information but perfect recall can be found in polynomial time. In addition, the equilibrium we find is normal-form perfect. Our technique generalizes to general-sum games...

High-resolution extraction of particle size via Fourier Ptychography

Science.gov (United States)

Li, Shengfu; Zhao, Yu; Chen, Guanghua; Luo, Zhenxiong; Ye, Yan

2017-11-01

This paper proposes a method which can extract the particle size information with a resolution beyond λ/NA. This is achieved by applying Fourier Ptychographic (FP) ideas to the present problem. In a typical FP imaging platform, a 2D LED array is used as light sources for angle-varied illuminations, a series of low-resolution images was taken by a full sequential scan of the array of LEDs. Here, we demonstrate the particle size information is extracted by turning on each single LED on a circle. The simulated results show that the proposed method can reduce the total number of images, without loss of reliability in the results.

FI/SI on-line solvent extraction/back extraction preconcentration coupled to direct injection nebulization inductively coupled plasma mass spectrometry for determination of copper and lead

DEFF Research Database (Denmark)

Wang, Jianhua; Hansen, Elo Harald

2002-01-01

An automated sequential injection on-line preconcentration procedure for determination of trace levels of copper and lead via solvent extraction/back extraction coupled to ICP-MS is described. In citrate buffer of pH 3, neutral complexes between the analytes and the chelating reagent, ammonium...... loop, the content of which is subsequently introduced into the ICP-MS, via a direct injection high efficiency nebulizer (DIHEN), for quantification. Enrichment factors of 29.6 (Cu) and 23.3 (Pb), detection limits of 17 ng/l (Cu) and 11 ng/l (Pb), along with a sampling frequency of 13 s/h were obtained...

Extraction, isolation and identification of flavonoid from Euphorbia neriifolia leaves

Directory of Open Access Journals (Sweden)

Veena Sharma

2017-05-01

Full Text Available The flavonoids contained in Euphorbia neriifolia leaves were extracted, identified and characterized. Direct and sequential soxhlet extraction and its concentrated fractions were subjected to thin layer chromatography and high performance thin layer chromatography. The results showed that maximum yield of the flavonoid (6.53 g was obtained from ethanolic extract. The Rf value of isolated flavonoid and phytochemical screening has been compared with standard Quercetin. Characterization of isolated flavonoid was done by IR, 1H NMR, and MS. On the basis of chemical and spectral analysis structure was elucidated as 2-(3,4-dihydroxy-5-methoxy-phenyl-3,5-dihydroxy-6,7-dimethoxychromen-4-one, a flavonoid. This compound was isolated for the first time from this plant.

Sensitivity Analysis in Sequential Decision Models.

Science.gov (United States)

Chen, Qiushi; Ayer, Turgay; Chhatwal, Jagpreet

2017-02-01

Sequential decision problems are frequently encountered in medical decision making, which are commonly solved using Markov decision processes (MDPs). Modeling guidelines recommend conducting sensitivity analyses in decision-analytic models to assess the robustness of the model results against the uncertainty in model parameters. However, standard methods of conducting sensitivity analyses cannot be directly applied to sequential decision problems because this would require evaluating all possible decision sequences, typically in the order of trillions, which is not practically feasible. As a result, most MDP-based modeling studies do not examine confidence in their recommended policies. In this study, we provide an approach to estimate uncertainty and confidence in the results of sequential decision models. First, we provide a probabilistic univariate method to identify the most sensitive parameters in MDPs. Second, we present a probabilistic multivariate approach to estimate the overall confidence in the recommended optimal policy considering joint uncertainty in the model parameters. We provide a graphical representation, which we call a policy acceptability curve, to summarize the confidence in the optimal policy by incorporating stakeholders' willingness to accept the base case policy. For a cost-effectiveness analysis, we provide an approach to construct a cost-effectiveness acceptability frontier, which shows the most cost-effective policy as well as the confidence in that for a given willingness to pay threshold. We demonstrate our approach using a simple MDP case study. We developed a method to conduct sensitivity analysis in sequential decision models, which could increase the credibility of these models among stakeholders.

Parallel-Sequential Texture Analysis

NARCIS (Netherlands)

van den Broek, Egon; Singh, Sameer; Singh, Maneesha; van Rikxoort, Eva M.; Apte, Chid; Perner, Petra

2005-01-01

Color induced texture analysis is explored, using two texture analysis techniques: the co-occurrence matrix and the color correlogram as well as color histograms. Several quantization schemes for six color spaces and the human-based 11 color quantization scheme have been applied. The VisTex texture

Preliminary evaluation of the physical impacts of a nearshore sand extraction project

International Nuclear Information System (INIS)

Anctil, F.; Ouellet, Y.

1991-01-01

A review is presented of the potential physical impacts of a nearshore sand extraction project in the Gulf of St. Lawrence. In Canada, sand extraction is mainly limited to the Beaufort Sea area, where in 1982 alone 15 million tonnes of aggregate was dredged to satisfy the requirements of offshore petroleum exploration; but there is much experience in nearshore dredging in Europe. Criteria related to impacts, developed for conditions prevailing in the North Sea (England) and the Gulf of Gascogne (France) are adapted to meet the more moderate hydrodynamic impacts of an extraction project in the Gulf of St. Lawrence. Potential impacts of extraction projects include destruction of sand bars or dunes, direct erosion resulting from beach drawdown or sedimentation interference, and impacts on littoral drift due to modified wave refraction patterns. Three schemes for the sand extraction are considered, and from the results, a fourth scheme is elaborated in such a way as to limit the negative impacts to the minor category. 17 refs., 5 figs., 4 tabs

A one-sided sequential test

Energy Technology Data Exchange (ETDEWEB)

Racz, A.; Lux, I. [Hungarian Academy of Sciences, Budapest (Hungary). Atomic Energy Research Inst.

1996-04-16

The applicability of the classical sequential probability ratio testing (SPRT) for early failure detection problems is limited by the fact that there is an extra time delay between the occurrence of the failure and its first recognition. Chien and Adams developed a method to minimize this time for the case when the problem can be formulated as testing the mean value of a Gaussian signal. In our paper we propose a procedure that can be applied for both mean and variance testing and that minimizes the time delay. The method is based on a special parametrization of the classical SPRT. The one-sided sequential tests (OSST) can reproduce the results of the Chien-Adams test when applied for mean values. (author).

Finite Boltzmann schemes

NARCIS (Netherlands)

Sman, van der R.G.M.

2006-01-01

In the special case of relaxation parameter = 1 lattice Boltzmann schemes for (convection) diffusion and fluid flow are equivalent to finite difference/volume (FD) schemes, and are thus coined finite Boltzmann (FB) schemes. We show that the equivalence is inherent to the homology of the

Effect of operating methods of wind turbine generator system on net power extraction under wind velocity fluctuations in fields

Energy Technology Data Exchange (ETDEWEB)

Wakui, Tetsuya; Yamaguchi, Kazuya; Hashizume, Takumi [Waseda Univ., Advanced Research Inst. for Science and Engineering, Tokyo (Japan); Outa, Eisuke [Waseda Univ., Mechanical Engineering Dept., Tokyo (Japan); Tanzawa, Yoshiaki [Nippon Inst. of Technology, Mechanical Engineering Dept., Saitama (Japan)

1999-01-01

The effect of how a wind turbine generator system is operated is discussed from the viewpoint of net power extraction with wind velocity fluctuation in relation to the scale and the dynamic behaviour of the system. On a wind turbine generator system consisting of a Darrieus-Savonius hybrid wind turbine, a load generator and a battery, we took up two operating methods: constant tip speed ratio operation for a stand-alone system (Scheme 1) and synchronous operation by connecting a grid (Scheme 2). With our simulation model, using the result of the net extracting power, we clarified that Scheme 1 is more effective than Scheme 2 for small-scale systems. Furthermore, in Scheme 1, the appropriate rated power output of the system under each wind condition can be confirmed. (Author)

Mining Emerging Sequential Patterns for Activity Recognition in Body Sensor Networks

DEFF Research Database (Denmark)

Gu, Tao; Wang, Liang; Chen, Hanhua

2010-01-01

Body Sensor Networks oer many applications in healthcare, well-being and entertainment. One of the emerging applications is recognizing activities of daily living. In this paper, we introduce a novel knowledge pattern named Emerging Sequential Pattern (ESP)|a sequential pattern that discovers...... signicant class dierences|to recognize both simple (i.e., sequential) and complex (i.e., interleaved and concurrent) activities. Based on ESPs, we build our complex activity models directly upon the sequential model to recognize both activity types. We conduct comprehensive empirical studies to evaluate...

Discrimination between sequential and simultaneous virtual channels with electrical hearing

OpenAIRE

Landsberger, David; Galvin, John J.

2011-01-01

In cochlear implants (CIs), simultaneous or sequential stimulation of adjacent electrodes can produce intermediate pitch percepts between those of the component electrodes. However, it is unclear whether simultaneous and sequential virtual channels (VCs) can be discriminated. In this study, CI users were asked to discriminate simultaneous and sequential VCs; discrimination was measured for monopolar (MP) and bipolar + 1 stimulation (BP + 1), i.e., relatively broad and focused stimulation mode...

Assessment of heavy metals pollution in bottom sediments of the Arabian Gulf after the Gulf War oil spill 1991

International Nuclear Information System (INIS)

Nasr, S.M.; Ahmed, M.H.; El-Raey, M.; Frihy, O.E.; Abdel Motti, A.

1999-01-01

The major objective of this study was to carry out a sequential geochemical extraction scheme for the partitioning of Fe, Mn, Co, Cu, Zn, Ni, Cr and Pb in the bottom sediments of the Arabian Gulf to detect any potential pollution impact on the gulf sediments following the 1991 gulf war oil spill, and to differentiate between anthropogenic inputs and natural background of heavy metals

Hybrid Computerized Adaptive Testing: From Group Sequential Design to Fully Sequential Design

Science.gov (United States)

Wang, Shiyu; Lin, Haiyan; Chang, Hua-Hua; Douglas, Jeff

2016-01-01

Computerized adaptive testing (CAT) and multistage testing (MST) have become two of the most popular modes in large-scale computer-based sequential testing. Though most designs of CAT and MST exhibit strength and weakness in recent large-scale implementations, there is no simple answer to the question of which design is better because different…

Simultaneous application of chemical oxidation and extraction processes is effective at remediating soil Co-contaminated with petroleum and heavy metals.

Science.gov (United States)

Yoo, Jong-Chan; Lee, Chadol; Lee, Jeung-Sun; Baek, Kitae

2017-01-15

Chemical extraction and oxidation processes to clean up heavy metals and hydrocarbon from soil have a higher remediation efficiency and take less time than other remediation processes. In batch extraction/oxidation process, 3% hydrogen peroxide (H 2 O 2 ) and 0.1 M ethylenediaminetetraacetic acid (EDTA) could remove approximately 70% of the petroleum and 60% of the Cu and Pb in the soil, respectively. In particular, petroleum was effectively oxidized by H 2 O 2 without addition of any catalysts through dissolution of Fe oxides in natural soils. Furthermore, heavy metals bound to Fe-Mn oxyhydroxides could be extracted by metal-EDTA as well as Fe-EDTA complexation due to the high affinity of EDTA for metals. However, the strong binding of Fe-EDTA inhibited the oxidation of petroleum in the extraction-oxidation sequential process because Fe was removed during the extraction process with EDTA. The oxidation-extraction sequential process did not significantly enhance the extraction of heavy metals from soil, because a small portion of heavy metals remained bound to organic matter. Overall, simultaneous application of oxidation and extraction processes resulted in highly efficient removal of both contaminants; this approach can be used to remove co-contaminants from soil in a short amount of time at a reasonable cost. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sequential dependencies in magnitude scaling of loudness

DEFF Research Database (Denmark)

Joshi, Suyash Narendra; Jesteadt, Walt

2013-01-01

Ten normally hearing listeners used a programmable sone-potentiometer knob to adjust the level of a 1000-Hz sinusoid to match the loudness of numbers presented to them in a magnitude production task. Three different power-law exponents (0.15, 0.30, and 0.60) and a log-law with equal steps in d......B were used to program the sone-potentiometer. The knob settings systematically influenced the form of the loudness function. Time series analysis was used to assess the sequential dependencies in the data, which increased with increasing exponent and were greatest for the log-law. It would be possible......, therefore, to choose knob properties that minimized these dependencies. When the sequential dependencies were removed from the data, the slope of the loudness functions did not change, but the variability decreased. Sequential dependencies were only present when the level of the tone on the previous trial...

Visual short-term memory for sequential arrays.

Science.gov (United States)

Kumar, Arjun; Jiang, Yuhong

2005-04-01

The capacity of visual short-term memory (VSTM) for a single visual display has been investigated in past research, but VSTM for multiple sequential arrays has been explored only recently. In this study, we investigate the capacity of VSTM across two sequential arrays separated by a variable stimulus onset asynchrony (SOA). VSTM for spatial locations (Experiment 1), colors (Experiments 2-4), orientations (Experiments 3 and 4), and conjunction of color and orientation (Experiment 4) were tested, with the SOA across the two sequential arrays varying from 100 to 1,500 msec. We find that VSTM for the trailing array is much better than VSTM for the leading array, but when averaged across the two arrays VSTM has a constant capacity independent of the SOA. We suggest that multiple displays compete for retention in VSTM and that separating information into two temporally discrete groups does not enhance the overall capacity of VSTM.

The target-to-foils shift in simultaneous and sequential lineups.

Science.gov (United States)

Clark, Steven E; Davey, Sherrie L

2005-04-01

A theoretical cornerstone in eyewitness identification research is the proposition that witnesses, in making decisions from standard simultaneous lineups, make relative judgments. The present research considers two sources of support for this proposal. An experiment by G. L. Wells (1993) showed that if the target is removed from a lineup, witnesses shift their responses to pick foils, rather than rejecting the lineups, a result we will term a target-to-foils shift. Additional empirical support is provided by results from sequential lineups which typically show higher accuracy than simultaneous lineups, presumably because of a decrease in the use of relative judgments in making identification decisions. The combination of these two lines of research suggests that the target-to-foils shift should be reduced in sequential lineups relative to simultaneous lineups. Results of two experiments showed an overall advantage for sequential lineups, but also showed a target-to-foils shift equal in size for simultaneous and sequential lineups. Additional analyses indicated that the target-to-foils shift in sequential lineups was moderated in part by an order effect and was produced with (Experiment 2) or without (Experiment 1) a shift in decision criterion. This complex pattern of results suggests that more work is needed to understand the processes which underlie decisions in simultaneous and sequential lineups.

Identifying technology barriers in adapting a state-of-the-art gas turbine for IGCC applications and an experimental investigation of air extraction schemes for IGCC operations. Final report

Energy Technology Data Exchange (ETDEWEB)

Yang, Tah-teh; Agrawal, A.K.; Kapat, J.S.

1993-06-01

Under contracted work with Morgantown Energy Technology Center, Clemson University, the prime contractor, and General Electric (GE) and CRSS, the subcontractors, made a comprehensive study in the first phase of research to investigate the technology barriers of integrating a coal gasification process with a hot gas cleanup scheme and the state-of-the-art industrial gas turbine, the GE MS-7001F. This effort focused on (1) establishing analytical tools necessary for modeling combustion phenomenon and emissions in gas turbine combustors operating on multiple species coal gas, (2) estimates the overall performance of the GE MS-7001F combined cycle plant, (3) evaluating material issues in the hot gas path, (4) examining the flow and temperature fields when air extraction takes place at both the compressor exit and at the manhole adjacent to the combustor, and (5) examining the combustion/cooling limitations of such a gas turbine by using 3-D numerical simulation of a MS-7001F combustor operated with gasified coal. In the second phase of this contract, a 35% cool flow model was built similar to GE`s MS-7001F gas turbine for mapping the flow region between the compressor exit and the expander inlet. The model included sufficient details, such as the combustor`s transition pieces, the fuel nozzles, and the supporting struts. Four cases were studied: the first with a base line flow field of a GE 7001F without air extraction; the second with a GE 7001F with air extraction; and the third and fourth with a GE 7001F using a Griffith diffuser to replace the straight wall diffuser and operating without air extraction and with extraction, respectively.

Sequential assignment of proline-rich regions in proteins: Application to modular binding domain complexes

International Nuclear Information System (INIS)

Kanelis, Voula; Donaldson, Logan; Muhandiram, D.R.; Rotin, Daniela; Forman-Kay, Julie D.; Kay, Lewis E.

2000-01-01

Many protein-protein interactions involve amino acid sequences containing proline-rich motifs and even poly-proline stretches. The lack of amide protons in such regions complicates assignment, since 1 HN-based triple-resonance assignment strategies cannot be employed. Two such systems that we are currently studying include an SH2 domain from the protein Crk with a region containing 9 prolines in a 14 amino acid sequence, as well as a WW domain that interacts with a proline-rich target. A modified version of the HACAN pulse scheme, originally described by Bax and co-workers [Wang et al. (1995) J. Biomol. NMR, 5, 376-382], and an experiment which correlates the intra-residue 1 H α , 13 C α / 13 C β chemical shifts with the 15 N shift of the subsequent residue are presented and applied to the two systems listed above, allowing sequential assignment of the molecules

Statistical analysis of dose heterogeneity in circulating blood: Implications for sequential methods of total body irradiation

International Nuclear Information System (INIS)

Molloy, Janelle A.

2010-01-01

Purpose: Improvements in delivery techniques for total body irradiation (TBI) using Tomotherapy and intensity modulated radiation therapy have been proven feasible. Despite the promise of improved dose conformality, the application of these ''sequential'' techniques has been hampered by concerns over dose heterogeneity to circulating blood. The present study was conducted to provide quantitative evidence regarding the potential clinical impact of this heterogeneity. Methods: Blood perfusion was modeled analytically as possessing linear, sinusoidal motion in the craniocaudal dimension. The average perfusion period for human circulation was estimated to be approximately 78 s. Sequential treatment delivery was modeled as a Gaussian-shaped dose cloud with a 10 cm length that traversed a 183 cm patient length at a uniform speed. Total dose to circulating blood voxels was calculated via numerical integration and normalized to 2 Gy per fraction. Dose statistics and equivalent uniform dose (EUD) were calculated for relevant treatment times, radiobiological parameters, blood perfusion rates, and fractionation schemes. The model was then refined to account for random dispersion superimposed onto the underlying periodic blood flow. Finally, a fully stochastic model was developed using binomial and trinomial probability distributions. These models allowed for the analysis of nonlinear sequential treatment modalities and treatment designs that incorporate deliberate organ sparing. Results: The dose received by individual blood voxels exhibited asymmetric behavior that depended on the coherence among the blood velocity, circulation phase, and the spatiotemporal characteristics of the irradiation beam. Heterogeneity increased with the perfusion period and decreased with the treatment time. Notwithstanding, heterogeneity was less than ±10% for perfusion periods less than 150 s. The EUD was compromised for radiosensitive cells, long perfusion periods, and short treatment times

Statistical analysis of dose heterogeneity in circulating blood: implications for sequential methods of total body irradiation.

Science.gov (United States)

Molloy, Janelle A

2010-11-01

Improvements in delivery techniques for total body irradiation (TBI) using Tomotherapy and intensity modulated radiation therapy have been proven feasible. Despite the promise of improved dose conformality, the application of these "sequential" techniques has been hampered by concerns over dose heterogeneity to circulating blood. The present study was conducted to provide quantitative evidence regarding the potential clinical impact of this heterogeneity. Blood perfusion was modeled analytically as possessing linear, sinusoidal motion in the craniocaudal dimension. The average perfusion period for human circulation was estimated to be approximately 78 s. Sequential treatment delivery was modeled as a Gaussian-shaped dose cloud with a 10 cm length that traversed a 183 cm patient length at a uniform speed. Total dose to circulating blood voxels was calculated via numerical integration and normalized to 2 Gy per fraction. Dose statistics and equivalent uniform dose (EUD) were calculated for relevant treatment times, radiobiological parameters, blood perfusion rates, and fractionation schemes. The model was then refined to account for random dispersion superimposed onto the underlying periodic blood flow. Finally, a fully stochastic model was developed using binomial and trinomial probability distributions. These models allowed for the analysis of nonlinear sequential treatment modalities and treatment designs that incorporate deliberate organ sparing. The dose received by individual blood voxels exhibited asymmetric behavior that depended on the coherence among the blood velocity, circulation phase, and the spatiotemporal characteristics of the irradiation beam. Heterogeneity increased with the perfusion period and decreased with the treatment time. Notwithstanding, heterogeneity was less than +/- 10% for perfusion periods less than 150 s. The EUD was compromised for radiosensitive cells, long perfusion periods, and short treatment times. However, the EUD was

CELLS v1.0: updated and parallelized version of an electrical scheme to simulate multiple electrified clouds and flashes over large domains

Directory of Open Access Journals (Sweden)

C. Barthe

2012-01-01

Full Text Available The paper describes the fully parallelized electrical scheme CELLS which is suitable to simulate explicitly electrified storm systems on parallel computers. Our motivation here is to show that a cloud electricity scheme can be developed for use on large grids with complex terrain. Large computational domains are needed to perform real case meteorological simulations with many independent convective cells.

The scheme computes the bulk electric charge attached to each cloud particle and hydrometeor. Positive and negative ions are also taken into account. Several parametrizations of the dominant non-inductive charging process are included and an inductive charging process as well. The electric field is obtained by inverting the Gauss equation with an extension to terrain-following coordinates. The new feature concerns the lightning flash scheme which is a simplified version of an older detailed sequential scheme. Flashes are composed of a bidirectional leader phase (vertical extension from the triggering point and a phase obeying a fractal law (with horizontal extension on electrically charged zones. The originality of the scheme lies in the way the branching phase is treated to get a parallel code.

The complete electrification scheme is tested for the 10 July 1996 STERAO case and for the 21 July 1998 EULINOX case. Flash characteristics are analysed in detail and additional sensitivity experiments are performed for the STERAO case. Although the simulations were run for flat terrain conditions, they show that the model behaves well on multiprocessor computers. This opens a wide area of application for this electrical scheme with the next objective of running real meterological case on large domains.

Dynamics-based sequential memory: Winnerless competition of patterns

International Nuclear Information System (INIS)

Seliger, Philip; Tsimring, Lev S.; Rabinovich, Mikhail I.

2003-01-01

We introduce a biologically motivated dynamical principle of sequential memory which is based on winnerless competition (WLC) of event images. This mechanism is implemented in a two-layer neural model of sequential spatial memory. We present the learning dynamics which leads to the formation of a WLC network. After learning, the system is capable of associative retrieval of prerecorded sequences of patterns

Sequential, progressive, equal-power, reflective beam-splitter arrays

Science.gov (United States)

Manhart, Paul K.

2017-11-01

The equations to calculate equal-power reflectivity of a sequential series of beam splitters is presented. Non-sequential optical design examples are offered for uniform illumination using diode lasers. Objects created using Boolean operators and Swept Surfaces can create objects capable of reflecting light into predefined elevation and azimuth angles. Analysis of the illumination patterns for the array are also presented.

Basal ganglia and cortical networks for sequential ordering and rhythm of complex movements

Directory of Open Access Journals (Sweden)

Jeffery G. Bednark

2015-07-01

Full Text Available Voluntary actions require the concurrent engagement and coordinated control of complex temporal (e.g. rhythm and ordinal motor processes. Using high-resolution functional magnetic resonance imaging (fMRI and multi-voxel pattern analysis (MVPA, we sought to determine the degree to which these complex motor processes are dissociable in basal ganglia and cortical networks. We employed three different finger-tapping tasks that differed in the demand on the sequential temporal rhythm or sequential ordering of submovements. Our results demonstrate that sequential rhythm and sequential order tasks were partially dissociable based on activation differences. The sequential rhythm task activated a widespread network centered around the SMA and basal-ganglia regions including the dorsomedial putamen and caudate nucleus, while the sequential order task preferentially activated a fronto-parietal network. There was also extensive overlap between sequential rhythm and sequential order tasks, with both tasks commonly activating bilateral premotor, supplementary motor, and superior/inferior parietal cortical regions, as well as regions of the caudate/putamen of the basal ganglia and the ventro-lateral thalamus. Importantly, within the cortical regions that were active for both complex movements, MVPA could accurately classify different patterns of activation for the sequential rhythm and sequential order tasks. In the basal ganglia, however, overlapping activation for the sequential rhythm and sequential order tasks, which was found in classic motor circuits of the putamen and ventro-lateral thalamus, could not be accurately differentiated by MVPA. Overall, our results highlight the convergent architecture of the motor system, where complex motor information that is spatially distributed in the cortex converges into a more compact representation in the basal ganglia.

The sequential price of anarchy for atomic congestion games

NARCIS (Netherlands)

de Jong, Jasper; Uetz, Marc Jochen; Liu, Tie-Yan; Qi, Qi; Ye, Yinyu

2014-01-01

In situations without central coordination, the price of anarchy relates the quality of any Nash equilibrium to the quality of a global optimum. Instead of assuming that all players choose their actions simultaneously, we consider games where players choose their actions sequentially. The sequential

Native Frames: Disentangling Sequential from Concerted Three-Body Fragmentation

Science.gov (United States)

Rajput, Jyoti; Severt, T.; Berry, Ben; Jochim, Bethany; Feizollah, Peyman; Kaderiya, Balram; Zohrabi, M.; Ablikim, U.; Ziaee, Farzaneh; Raju P., Kanaka; Rolles, D.; Rudenko, A.; Carnes, K. D.; Esry, B. D.; Ben-Itzhak, I.

2018-03-01

A key question concerning the three-body fragmentation of polyatomic molecules is the distinction of sequential and concerted mechanisms, i.e., the stepwise or simultaneous cleavage of bonds. Using laser-driven fragmentation of OCS into O++C++S+ and employing coincidence momentum imaging, we demonstrate a novel method that enables the clear separation of sequential and concerted breakup. The separation is accomplished by analyzing the three-body fragmentation in the native frame associated with each step and taking advantage of the rotation of the intermediate molecular fragment, CO2 + or CS2 + , before its unimolecular dissociation. This native-frame method works for any projectile (electrons, ions, or photons), provides details on each step of the sequential breakup, and enables the retrieval of the relevant spectra for sequential and concerted breakup separately. Specifically, this allows the determination of the branching ratio of all these processes in OCS3 + breakup. Moreover, we find that the first step of sequential breakup is tightly aligned along the laser polarization and identify the likely electronic states of the intermediate dication that undergo unimolecular dissociation in the second step. Finally, the separated concerted breakup spectra show clearly that the central carbon atom is preferentially ejected perpendicular to the laser field.

BossPro: a biometrics-based obfuscation scheme for software protection

Science.gov (United States)

Kuseler, Torben; Lami, Ihsan A.; Al-Assam, Hisham

2013-05-01

This paper proposes to integrate biometric-based key generation into an obfuscated interpretation algorithm to protect authentication application software from illegitimate use or reverse-engineering. This is especially necessary for mCommerce because application programmes on mobile devices, such as Smartphones and Tablet-PCs are typically open for misuse by hackers. Therefore, the scheme proposed in this paper ensures that a correct interpretation / execution of the obfuscated program code of the authentication application requires a valid biometric generated key of the actual person to be authenticated, in real-time. Without this key, the real semantics of the program cannot be understood by an attacker even if he/she gains access to this application code. Furthermore, the security provided by this scheme can be a vital aspect in protecting any application running on mobile devices that are increasingly used to perform business/financial or other security related applications, but are easily lost or stolen. The scheme starts by creating a personalised copy of any application based on the biometric key generated during an enrolment process with the authenticator as well as a nuance created at the time of communication between the client and the authenticator. The obfuscated code is then shipped to the client's mobile devise and integrated with real-time biometric extracted data of the client to form the unlocking key during execution. The novelty of this scheme is achieved by the close binding of this application program to the biometric key of the client, thus making this application unusable for others. Trials and experimental results on biometric key generation, based on client's faces, and an implemented scheme prototype, based on the Android emulator, prove the concept and novelty of this proposed scheme.

Multi-Temporal Land Cover Classification with Sequential Recurrent Encoders

Science.gov (United States)

Rußwurm, Marc; Körner, Marco

2018-03-01

Earth observation (EO) sensors deliver data with daily or weekly temporal resolution. Most land use and land cover (LULC) approaches, however, expect cloud-free and mono-temporal observations. The increasing temporal capabilities of today's sensors enables the use of temporal, along with spectral and spatial features. Domains, such as speech recognition or neural machine translation, work with inherently temporal data and, today, achieve impressive results using sequential encoder-decoder structures. Inspired by these sequence-to-sequence models, we adapt an encoder structure with convolutional recurrent layers in order to approximate a phenological model for vegetation classes based on a temporal sequence of Sentinel 2 (S2) images. In our experiments, we visualize internal activations over a sequence of cloudy and non-cloudy images and find several recurrent cells, which reduce the input activity for cloudy observations. Hence, we assume that our network has learned cloud-filtering schemes solely from input data, which could alleviate the need for tedious cloud-filtering as a preprocessing step for many EO approaches. Moreover, using unfiltered temporal series of top-of-atmosphere (TOA) reflectance data, we achieved in our experiments state-of-the-art classification accuracies on a large number of crop classes with minimal preprocessing compared to other classification approaches.

Campbell and moment measures for finite sequential spatial processes

NARCIS (Netherlands)

M.N.M. van Lieshout (Marie-Colette)

2006-01-01

textabstractWe define moment and Campbell measures for sequential spatial processes, prove a Campbell-Mecke theorem, and relate the results to their counterparts in the theory of point processes. In particular, we show that any finite sequential spatial process model can be derived as the vector

Sequential Dependencies in Driving

Science.gov (United States)

Doshi, Anup; Tran, Cuong; Wilder, Matthew H.; Mozer, Michael C.; Trivedi, Mohan M.

2012-01-01

The effect of recent experience on current behavior has been studied extensively in simple laboratory tasks. We explore the nature of sequential effects in the more naturalistic setting of automobile driving. Driving is a safety-critical task in which delayed response times may have severe consequences. Using a realistic driving simulator, we find…

Research on parallel algorithm for sequential pattern mining

Science.gov (United States)

Zhou, Lijuan; Qin, Bai; Wang, Yu; Hao, Zhongxiao

2008-03-01

Sequential pattern mining is the mining of frequent sequences related to time or other orders from the sequence database. Its initial motivation is to discover the laws of customer purchasing in a time section by finding the frequent sequences. In recent years, sequential pattern mining has become an important direction of data mining, and its application field has not been confined to the business database and has extended to new data sources such as Web and advanced science fields such as DNA analysis. The data of sequential pattern mining has characteristics as follows: mass data amount and distributed storage. Most existing sequential pattern mining algorithms haven't considered the above-mentioned characteristics synthetically. According to the traits mentioned above and combining the parallel theory, this paper puts forward a new distributed parallel algorithm SPP(Sequential Pattern Parallel). The algorithm abides by the principal of pattern reduction and utilizes the divide-and-conquer strategy for parallelization. The first parallel task is to construct frequent item sets applying frequent concept and search space partition theory and the second task is to structure frequent sequences using the depth-first search method at each processor. The algorithm only needs to access the database twice and doesn't generate the candidated sequences, which abates the access time and improves the mining efficiency. Based on the random data generation procedure and different information structure designed, this paper simulated the SPP algorithm in a concrete parallel environment and implemented the AprioriAll algorithm. The experiments demonstrate that compared with AprioriAll, the SPP algorithm had excellent speedup factor and efficiency.

Determination of Low Level Concentrations of Metals by Means of Sequential Injection (SI) and Lab-on-Valve (LOV) Methodologies

DEFF Research Database (Denmark)

Hansen, Elo Harald; Miró, Manuel; Petersen, Roongrat

/emission spectrometry (FAAS, ETAAS, ICP-AES, ICP-MS). The lecture will initially give an overview of various automated alternatives for facilitating appropriate SI/LOV-separation and pre-concentration schemes of metals in liquid samples, including examples of solid-phase extraction with permanent columns or renewable...

Scheme for efficient extraction of low-frequency signal beyond the quantum limit by frequency-shift detection.

Science.gov (United States)

Yang, R G; Zhang, J; Zhai, Z H; Zhai, S Q; Liu, K; Gao, J R

2015-08-10

Low-frequency (Hz~kHz) squeezing is very important in many schemes of quantum precision measurement. But it is more difficult than that at megahertz-frequency because of the introduction of laser low-frequency technical noise. In this paper, we propose a scheme to obtain a low-frequency signal beyond the quantum limit from the frequency comb in a non-degenerate frequency and degenerate polarization optical parametric amplifier (NOPA) operating below threshold with type I phase matching by frequency-shift detection. Low-frequency squeezing immune to laser technical noise is obtained by a detection system with a local beam of two-frequency intense laser. Furthermore, the low-frequency squeezing can be used for phase measurement in Mach-Zehnder interferometer, and the signal-to-noise ratio (SNR) can be enhanced greatly.

Studies of Flerovium and Element 115 Homologs with Macrocyclic Extractants

Energy Technology Data Exchange (ETDEWEB)

Despotopulos, John D. [Univ. of Nevada, Las Vegas, NV (United States)

2015-03-12

Study of the chemistry of the heaviest elements, Z ≥ 104, poses a unique challenge due to their low production cross-sections and short half-lives. Chemistry also must be studied on the one-atom-at-a-time scale, requiring automated, fast, and very efficient chemical schemes. Recent studies of the chemical behavior of copernicium (Cn, element 112) and flerovium (Fl, element 114) together with the discovery of isotopes of these elements with half-lives suitable for chemical studies have spurred a renewed interest in the development of rapid systems designed to study the chemical properties of elements with Z ≥ 114. This dissertation explores both extraction chromatography and solvent extraction as methods for development of a rapid chemical separation scheme for the homologs of flerovium (Pb, Sn, Hg) and element 115 (Bi, Sb), with the goal of developing a chemical scheme that, in the future, can be applied to on-line chemistry of both Fl and element 115. Carrier-free radionuclides, used in these studies, of the homologs of Fl and element 115 were obtained by proton activation of high-purity metal foils at the Lawrence Livermore National Laboratory (LLNL) Center for Accelerator Mass Spectrometry (CAMS): ^natIn(p,n)¹¹³Sn, ^natSn(p,n)¹²⁴Sb, and Au(p,n)^197m,gHg. The carrier-free activity was separated from the foils by novel separation schemes based on ion exchange and extraction chromatography techniques. Carrier-free Pb and Bi isotopes were obtained from development of a novel generator based on cation exchange chromatography using the ²³²U parent to generate ²¹²Pb and ²¹²Bi. Macrocyclic extractants, specifically crown ethers and their derivatives, were chosen for these studies; crown ethers show high selectivity for metal ions. Finally. a potential chemical system for Fl was established based on the Eichrom Pb resin, and insight to an improved system based on thiacrown ethers is

CAD for CT colonography: toward a preparation-independent scheme

International Nuclear Information System (INIS)

Naeppi, J.

2007-01-01

Computer-aided detection (CAD) systems can be used to automatically detect and display the locations of polyps and masses in computed tomographic colonography (CTC) data for assisting radiologists' image interpretation. Rapid technical advancements over the last few years have established a fundamental CAD scheme for CTC that includes the steps of colon extraction, polyp detection, and false-positive (FP) reduction. Several CAD prototype systems have demonstrated clinically acceptable high polyp detection sensitivity with relatively few FP detections in cathartic CTC, and observer studies have demonstrated the potential benefit of such systems in improving the accuracy and consistency of radiologists' detection performance. Some CAD prototype systems have also demonstrated promising performance in reduced cathartic and non-cathartic CTC. Recent advancements suggest that CAD systems can soon be expected to provide a preparation-independent scheme that can yield consistently high detection sensitivity with moderately low FP rate not only with cathartic CTC protocols but over a wide range of cathartic, reduced cathartic, and non-cathartic CTC protocols. (orig.)

Adaptive protection scheme

Directory of Open Access Journals (Sweden)

R. Sitharthan

2016-09-01

Full Text Available This paper aims at modelling an electronically coupled distributed energy resource with an adaptive protection scheme. The electronically coupled distributed energy resource is a microgrid framework formed by coupling the renewable energy source electronically. Further, the proposed adaptive protection scheme provides a suitable protection to the microgrid for various fault conditions irrespective of the operating mode of the microgrid: namely, grid connected mode and islanded mode. The outstanding aspect of the developed adaptive protection scheme is that it monitors the microgrid and instantly updates relay fault current according to the variations that occur in the system. The proposed adaptive protection scheme also employs auto reclosures, through which the proposed adaptive protection scheme recovers faster from the fault and thereby increases the consistency of the microgrid. The effectiveness of the proposed adaptive protection is studied through the time domain simulations carried out in the PSCAD⧹EMTDC software environment.

Comparative study of numerical schemes of TVD3, UNO3-ACM and optimized compact scheme

Science.gov (United States)

Lee, Duck-Joo; Hwang, Chang-Jeon; Ko, Duck-Kon; Kim, Jae-Wook

1995-01-01

Three different schemes are employed to solve the benchmark problem. The first one is a conventional TVD-MUSCL (Monotone Upwind Schemes for Conservation Laws) scheme. The second scheme is a UNO3-ACM (Uniformly Non-Oscillatory Artificial Compression Method) scheme. The third scheme is an optimized compact finite difference scheme modified by us: the 4th order Runge Kutta time stepping, the 4th order pentadiagonal compact spatial discretization with the maximum resolution characteristics. The problems of category 1 are solved by using the second (UNO3-ACM) and third (Optimized Compact) schemes. The problems of category 2 are solved by using the first (TVD3) and second (UNO3-ACM) schemes. The problem of category 5 is solved by using the first (TVD3) scheme. It can be concluded from the present calculations that the Optimized Compact scheme and the UN03-ACM show good resolutions for category 1 and category 2 respectively.

Sequential Scintigraphy in Renal Transplantation

Energy Technology Data Exchange (ETDEWEB)

Winkel, K. zum; Harbst, H.; Schenck, P.; Franz, H. E.; Ritz, E.; Roehl, L.; Ziegler, M.; Ammann, W.; Maier-Borst, W. [Institut Fuer Nuklearmedizin, Deutsches Krebsforschungszentrum, Heidelberg, Federal Republic of Germany (Germany)

1969-05-15

Based on experience gained from more than 1600 patients with proved or suspected kidney diseases and on results on extended studies with dogs, sequential scintigraphy was performed after renal transplantation in dogs. After intravenous injection of 500 {mu}Ci. {sup 131}I-Hippuran scintiphotos were taken during the first minute with an exposure time of 15 sec each and thereafter with an exposure of 2 min up to at least 16 min.. Several examinations were evaluated digitally. 26 examinations were performed on 11 dogs with homotransplanted kidneys. Immediately after transplantation the renal function was almost normal arid the bladder was filled in due time. At the beginning of rejection the initial uptake of radioactive Hippuran was reduced. The intrarenal transport became delayed; probably the renal extraction rate decreased. Corresponding to the development of an oedema in the transplant the uptake area increased in size. In cases of thrombosis of the main artery there was no evidence of any uptake of radioactivity in the transplant. Similar results were obtained in 41 examinations on 15 persons. Patients with postoperative anuria due to acute tubular necrosis showed still some uptake of radioactivity contrary to those with thrombosis of the renal artery, where no uptake was found. In cases of rejection the most frequent signs were a reduced initial uptake and a delayed intrarenal transport of radioactive Hippuran. Infarction could be detected by a reduced uptake in distinct areas of the transplant. (author)

Framework for sequential approximate optimization

NARCIS (Netherlands)

Jacobs, J.H.; Etman, L.F.P.; Keulen, van F.; Rooda, J.E.

2004-01-01

An object-oriented framework for Sequential Approximate Optimization (SAO) isproposed. The framework aims to provide an open environment for thespecification and implementation of SAO strategies. The framework is based onthe Python programming language and contains a toolbox of Python

Brine shrimp lethality and antibacterial activity of extracts from the bark of Schleichera oleosa

Directory of Open Access Journals (Sweden)

Laxman Pokhrel

2015-08-01

Full Text Available Objective: To determine the antibacterial efficacy and brine shrimp toxicity of extracts (hexane, dichloromethane, ethyl acetate, methanol and water obtained from the bark of Schleichera oleosa. Methods: The powdered bark sample was Soxhlet extracted sequentially in hexanes, dichloromethane, ethyl acetate, methanol and water. Antibacterial evaluation was carried out by following the agar diffusion method and amoxicillin disc was used as a reference. Slightly modified Meyer’s method was used to determine the toxicity of the extracts in brine shrimps. Results: Among the nine bacterial strains tested, the methanolic and aqueous extracts showed promising antibacterial efficacy against Serratia marcescens, Escherarichia coli, Bacillus subtilis and Micrococcus luteus. None of the extracts were found significantly toxic to brine shrimps. Conclusions: Strong antibacterial activity and low brine shrimp toxicity of methanolic and aqueous extracts can provide new antibacterial compounds.

A Survey of Multi-Objective Sequential Decision-Making

OpenAIRE

Roijers, D.M.; Vamplew, P.; Whiteson, S.; Dazeley, R.

2013-01-01

Sequential decision-making problems with multiple objectives arise naturally in practice and pose unique challenges for research in decision-theoretic planning and learning, which has largely focused on single-objective settings. This article surveys algorithms designed for sequential decision-making problems with multiple objectives. Though there is a growing body of literature on this subject, little of it makes explicit under what circumstances special methods are needed to solve multi-obj...

PRACTICAL PROPOSALS AS A RESULT OF THEORETICAL AND EXPERIMENTAL STUDIES OF THE PROCESS OF EXTRACTION FROM RAW MATERIALS OF PLANT ORIGIN

Directory of Open Access Journals (Sweden)

I. I. Shishatskii

2014-01-01

Full Text Available Summary. Theoretical and experimental researches of extraction processes from plant origin raw materials: barley, acorns and chicory with liquid carbon dioxide, as well as lupin with cheese whey were carried out. Quality indicators of extracts and secondary raw materials are defined. It is established that they are perspective raw sources for the enriched and functional products as they contain amino acids, vitamins and microelements. The dairy-vegetative lupine extract, for example, contains 17 amino acids, including the essential as well as vitamins and minerals. The studies of secondary raw materials, barley, acorns, chicory and lupine quality showed the expediency of their use for foods enrichment. Quality indicators of secondary raw materials are presented in the tables form in the given work. It formed the basis for the development of hardware-technological schemes of obtaining СО2-extracts and their use. The hardware-technological scheme of obtaining СО2-extracts from barley, acorns and chicory includes a number of equipment units: motor transport for raw materials delivery to the enterprise, the scraper hydroconveyor, the jet washer, a photoseparator for of poor-quality raw materials and impurities removal, a blowing machine for removing surface moisture from the raw materials, a jet washer for peeling, a cutter, drying and frying device, a crusher, a roller machine tool and an extracting unit. Hardware providing for yoghurt technology enriched with amino acids, microelements and vitamins which are present in a dairy-plant extract differs from the mentioned above one in the following. The extract used is a cheese whey, and the extraction of a target component is carried out in a vibrating extractor. The hardwaretechnological scheme is made according to Russian technology of yoghurt and furnished with the equipment for dairy-vegetative extract feeding into a product. It includes the following: a vibrating extractor (not shown in fig