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Sample records for sequential extraction method

  1. Two approaches for sequential extraction of radionuclides in soils: batch and column methods

    International Nuclear Information System (INIS)

    Vidal, M.; Rauret, G.

    1993-01-01

    A three-step sequential extraction designed by Community Bureau of Reference (BCR) is applied to two types of soil (sandy and sandy-loam) which had been previously contaminated with a radionuclide aerosol containing 134 Cs, 85 Sr and 110m Ag. This scheme is applied using both batch and column methods. The radionuclide distribution obtained with this scheme depends both on the method and on soil type. Compared with the batch method, column extraction is an inadvisable method. Kinetic aspects seem to be important, especially in the first and third fractions. The radionuclide distribution shows that radiostrontium has high mobility, radiocaesium is highly retained by clay minerals whereas Fe/Mn oxides and organic matter have an important role in radiosilver retention. (Author)

  2. 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.

  3. 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.

  4. Arsenic Mobility and Availability in Sediments by Application of BCR Sequential Extractions Method

    International Nuclear Information System (INIS)

    Larios, R.; Fernandez, R.; Rucandio, M. I.

    2011-01-01

    Arsenic is a metalloid found in nature, both naturally and due to anthropogenic activities. Among them, mining works are an important source of arsenic release to the environment. Asturias is a region where important mercury mines were exploited, and in them arsenic occurs in para genesis with mercury minerals. The toxicity and mobility of this element depends on the chemical species it is found. Fractionation studies are required to analyze the mobility of this metalloid in soils and sediments. Among them, the proposed by the Bureau Community of Reference (BCR) is one of the most employed. This method attempts to divide up, by operationally defined stages, the amount of this element associated with carbonates (fraction 1), iron and manganese oxy hydroxides (fraction 2), organic matter and sulphides (fraction 3), and finally as the amount associated residual fraction to primary and secondary minerals, that is, from the most labile fractions to the most refractory ones. Fractionation of arsenic in sediments from two mines in Asturias were studied, La Soterrana and Los Rueldos. Sediments from La Soterrana showed high levels of arsenic in the non-residual phases, indicating that the majority of arsenic has an anthropogenic origin. By contrast, in sediments from Los Rueldos most of the arsenic is concentrated in the residual phase, indicating that this element remains bound to very refractory primary minerals, as is also demonstrated by the strong correlation of arsenic fractionation and the fractionation of elements present in refractory minerals, such as iron, aluminum and titanium. (Author) 51 refs.

  5. 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.

  6. Optimisation of beryllium-7 gamma analysis following BCR sequential extraction

    International Nuclear Information System (INIS)

    Taylor, A.; Blake, W.H.; Keith-Roach, M.J.

    2012-01-01

    Graphical abstract: Showing decrease in analytical uncertainty using the optimal (combined preconcentrated sample extract) method. nv (no value) where extract activities were 7 Be geochemical behaviour is required to support tracer studies. ► Sequential extraction with natural 7 Be returns high analytical uncertainties. ► Preconcentrating extracts from a large sample mass improved analytical uncertainty. ► This optimised method can be readily employed in studies using low activity samples. - Abstract: The application of cosmogenic 7 Be as a sediment tracer at the catchment-scale requires an understanding of its geochemical associations in soil to underpin the assumption of irreversible adsorption. Sequential extractions offer a readily accessible means of determining the associations of 7 Be with operationally defined soil phases. However, the subdivision of the low activity concentrations of fallout 7 Be in soils into geochemical fractions can introduce high gamma counting uncertainties. Extending analysis time significantly is not always an option for batches of samples, owing to the on-going decay of 7 Be (t 1/2 = 53.3 days). Here, three different methods of preparing and quantifying 7 Be extracted using the optimised BCR three-step scheme have been evaluated and compared with a focus on reducing analytical uncertainties. The optimal method involved carrying out the BCR extraction in triplicate, sub-sampling each set of triplicates for stable Be analysis before combining each set and coprecipitating the 7 Be with metal oxyhydroxides to produce a thin source for gamma analysis. This method was applied to BCR extractions of natural 7 Be in four agricultural soils. The approach gave good counting statistics from a 24 h analysis period (∼10% (2σ) where extract activity >40% of total activity) and generated statistically useful sequential extraction profiles. Total recoveries of 7 Be fell between 84 and 112%. The stable Be data demonstrated that the

  7. Sequential extraction of uranium metal contamination

    International Nuclear Information System (INIS)

    Murry, M.M.; Spitz, H.B.; Connick, W.B.

    2016-01-01

    Samples of uranium contaminated dirt collected from the dirt floor of an abandoned metal rolling mill were analyzed for uranium using a sequential extraction protocol involving a series of five increasingly aggressive solvents. The quantity of uranium extracted from the contaminated dirt by each reagent can aid in predicting the fate and transport of the uranium contamination in the environment. Uranium was separated from each fraction using anion exchange, electrodeposition and analyzed by alpha spectroscopy analysis. Results demonstrate that approximately 77 % of the uranium was extracted using NH 4 Ac in 25 % acetic acid. (author)

  8. 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.

  9. Evaluation Using Sequential Trials Methods.

    Science.gov (United States)

    Cohen, Mark E.; Ralls, Stephen A.

    1986-01-01

    Although dental school faculty as well as practitioners are interested in evaluating products and procedures used in clinical practice, research design and statistical analysis can sometimes pose problems. Sequential trials methods provide an analytical structure that is both easy to use and statistically valid. (Author/MLW)

  10. Optimisation of beryllium-7 gamma analysis following BCR sequential extraction

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, A. [Plymouth University, School of Geography, Earth and Environmental Sciences, 8 Kirkby Place, Plymouth PL4 8AA (United Kingdom); Blake, W.H., E-mail: wblake@plymouth.ac.uk [Plymouth University, School of Geography, Earth and Environmental Sciences, 8 Kirkby Place, Plymouth PL4 8AA (United Kingdom); Keith-Roach, M.J. [Plymouth University, School of Geography, Earth and Environmental Sciences, 8 Kirkby Place, Plymouth PL4 8AA (United Kingdom); Kemakta Konsult, Stockholm (Sweden)

    2012-03-30

    Graphical abstract: Showing decrease in analytical uncertainty using the optimal (combined preconcentrated sample extract) method. nv (no value) where extract activities were Sequential extraction with natural {sup 7}Be returns high analytical uncertainties. Black-Right-Pointing-Pointer Preconcentrating extracts from a large sample mass improved analytical uncertainty. Black-Right-Pointing-Pointer This optimised method can be readily employed in studies using low activity samples. - Abstract: The application of cosmogenic {sup 7}Be as a sediment tracer at the catchment-scale requires an understanding of its geochemical associations in soil to underpin the assumption of irreversible adsorption. Sequential extractions offer a readily accessible means of determining the associations of {sup 7}Be with operationally defined soil phases. However, the subdivision of the low activity concentrations of fallout {sup 7}Be in soils into geochemical fractions can introduce high gamma counting uncertainties. Extending analysis time significantly is not always an option for batches of samples, owing to the on-going decay of {sup 7}Be (t{sub 1/2} = 53.3 days). Here, three different methods of preparing and quantifying {sup 7}Be extracted using the optimised BCR three-step scheme have been evaluated and compared with a focus on reducing analytical uncertainties. The optimal method involved carrying out the BCR extraction in triplicate, sub-sampling each set of triplicates for stable Be analysis before combining each set and coprecipitating the {sup 7}Be with metal oxyhydroxides to produce a thin source for gamma analysis. This method was applied to BCR extractions of natural {sup 7}Be in four agricultural soils. The approach gave good counting statistics from a 24 h analysis period ({approx}10% (2

  11. 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

  12. 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.

  13. Sequential extraction applied to Peruibe black mud, SP, Brazil

    International Nuclear Information System (INIS)

    Torrecilha, Jefferson Koyaishi

    2014-01-01

    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

  14. 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...

  15. 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…

  16. Manganese Fractionation Using a Sequential Extraction Method to Evaluate Welders' Shielded Metal Arc Welding Exposures During Construction Projects in Oil Refineries.

    Science.gov (United States)

    Hanley, Kevin W; Andrews, Ronnee; Bertke, Steven; Ashley, Kevin

    2015-01-01

    The National Institute for Occupational Safety and Health has conducted an occupational exposure assessment study of manganese (Mn) in welding fume of construction workers rebuilding tanks, piping, and process equipment at two oil refineries. The objective of this study was to evaluate exposures to different Mn fractions using a sequential extraction procedure. Seventy-two worker-days were monitored for either total or respirable Mn during stick welding and associated activities both within and outside of confined spaces. The samples were analyzed using an experimental method to separate different Mn fractions by valence states based on selective chemical solubility. The full-shift total particulate Mn time-weighted average (TWA) breathing zone concentrations ranged from 0.013-29 for soluble Mn in a mild ammonium acetate solution; from 0.26-250 for Mn(0,2+) in acetic acid; from non-detectable (ND) - 350 for Mn(3+,4+) in hydroxylamine-hydrochloride; and from ND - 39 micrograms per cubic meter (μg/m(3)) for insoluble Mn fractions in hydrochloric and nitric acid. The summation of all Mn fractions in total particulate TWA ranged from 0.52-470 μg/m(3). The range of respirable particulate Mn TWA concentrations were from 0.20-28 for soluble Mn; from 1.4-270 for Mn(0,2+); from 0.49-150 for Mn(3+,4+); from ND - 100 for insoluble Mn; and from 2.0-490 μg/m(3) for Mn (sum of fractions). For all jobs combined, total particulate TWA GM concentrations of the Mn(sum) were 99 (GSD = 3.35) and 8.7 (GSD = 3.54) μg/m(3) for workers inside and outside of confined spaces; respirable Mn also showed much higher levels for welders within confined spaces. Regardless of particle size and confined space work status, Mn(0,2+) fraction was the most abundant followed by Mn(3+,4+) fraction, typically >50% and ∼30-40% of Mn(sum), respectively. Eighteen welders' exposures exceeded the ACGIH Threshold Limit Values for total Mn (100 μg/m(3)) and 25 exceeded the recently adopted respirable

  17. A framework for sequential multiblock component methods

    NARCIS (Netherlands)

    Smilde, A.K.; Westerhuis, J.A.; Jong, S.de

    2003-01-01

    Multiblock or multiset methods are starting to be used in chemistry and biology to study complex data sets. In chemometrics, sequential multiblock methods are popular; that is, methods that calculate one component at a time and use deflation for finding the next component. In this paper a framework

  18. Extraction method

    International Nuclear Information System (INIS)

    Stary, J.; Kyrs, M.; Navratil, J.; Havelka, S.; Hala, J.

    1975-01-01

    Definitions of the basic terms and of relations are given and the knowledge is described of the possibilities of the extraction of elements, oxides, covalent-bound halogenides and heteropolyacids. Greatest attention is devoted to the detailed analysis of the extraction of chelates and ion associates using diverse agents. For both types of compounds detailed conditions are given of the separation and the effects of the individual factors are listed. Attention is also devoted to extractions using mixtures of organic agents, the synergic effects thereof, and to extractions in non-aqueous solvents. The effects of radiation on extraction and the main types of apparatus used for extractions carried out in the laboratory are described. (L.K.)

  19. 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

  20. 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

  1. 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

  2. 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.

  3. 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)

  4. Collaborative Filtering Based on Sequential Extraction of User-Item Clusters

    Science.gov (United States)

    Honda, Katsuhiro; Notsu, Akira; Ichihashi, Hidetomo

    Collaborative filtering is a computational realization of “word-of-mouth” in network community, in which the items prefered by “neighbors” are recommended. This paper proposes a new item-selection model for extracting user-item clusters from rectangular relation matrices, in which mutual relations between users and items are denoted in an alternative process of “liking or not”. A technique for sequential co-cluster extraction from rectangular relational data is given by combining the structural balancing-based user-item clustering method with sequential fuzzy cluster extraction appraoch. Then, the tecunique is applied to the collaborative filtering problem, in which some items may be shared by several user clusters.

  5. Phenolic Content and Antioxidant Activity of Hibiscus cannabinus L. Seed Extracts after Sequential Solvent Extraction

    Directory of Open Access Journals (Sweden)

    Shahid Iqbal

    2012-10-01

    Full Text Available A sequential solvent extraction scheme was employed for the extraction of antioxidant compounds from kenaf (Hibiscus cannabinus L. seeds. Yield of extracts varied widely among the solvents and was the highest for hexane extract (16.6% based on dry weight basis, while water extract exhibited the highest total phenolic content (18.78 mg GAE/g extract, total flavonoid content (2.49 mg RE/g extract, and antioxidant activities (p < 0.05. DPPH and hydroxyl radical scavenging, β-carotene bleaching, metal chelating activity, ferric thiocyanate and thiobarbituric acid reactive substances assays were employed to comprehensively assess the antioxidant potential of different solvent extracts prepared sequentially. Besides water, methanolic extract also exhibited high retardation towards the formation of hydroperoxides and thiobarbituric acid reactive substances in the total antioxidant activity tests (p < 0.05. As conclusion, water and methanol extracts of kenaf seed may potentially serve as new sources of antioxidants for food and nutraceutical applications.

  6. 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

  7. Further comments on the sequential probability ratio testing methods

    Energy Technology Data Exchange (ETDEWEB)

    Kulacsy, K. [Hungarian Academy of Sciences, Budapest (Hungary). Central Research Inst. for Physics

    1997-05-23

    The Bayesian method for belief updating proposed in Racz (1996) is examined. The interpretation of the belief function introduced therein is found, and the method is compared to the classical binary Sequential Probability Ratio Testing method (SPRT). (author).

  8. A sequential mixed methods research approach to investigating HIV ...

    African Journals Online (AJOL)

    2016-09-03

    Sep 3, 2016 ... Sequential mixed methods research is an effective approach for ... show the effectiveness of the research method. ... qualitative data before quantitative datasets ..... whereby both types of data are collected simultaneously.

  9. 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

  10. Utilizing a sequential injection system furnished with an extraction microcolumn as a novel approach for executing sequential extractions of metal species in solid samples

    DEFF Research Database (Denmark)

    Chomchoei, R.; Hansen, Elo Harald; Shiowatana, J.

    2007-01-01

    This communication presents a novel approach to perform sequential extraction of elements in solid samples by using a sequential injection (SI) system incorporating a specially designed extraction microcolumn. Based on the operation of the syringe pump, different modes of extraction are potentially...... that the system entails many advantages such as being fully automated, and besides being characterised by rapidity, ease of operation and robustness, it is less prone to risks of contamination and personal errors as encountered in traditional batch systems. Moreover, improvement of the precision and accuracy...... of the chemical fractionation of metal in solids as compared with previous reports are obtained. The system ensures that extraction is performed at designated pH values. Variation of sample weight to column volume ratios do not affect the amounts of extractable metals, nor do extraction flow rates ranging from 50...

  11. Solid phase speciation of arsenic by sequential extraction in standard reference materials and industrially contaminated soil samples

    International Nuclear Information System (INIS)

    Herreweghe, Samuel van; Swennen, Rudy; Vandecasteele, Carlo; Cappuyns, Valerie

    2003-01-01

    Leaching experiments, a mineralogical survey and larger samples are preferred when arsenic is present as discrete mineral phases. - Availability, mobility, (phyto)toxicity and potential risk of contaminants is strongly affected by the manner of appearance of elements, the so-called speciation. Operational fractionation methods like sequential extractions have been applied for a long time to determine the solid phase speciation of heavy metals since direct determination of specific chemical compounds can not always be easily achieved. The three-step sequential extraction scheme recommended by the BCR and two extraction schemes based on the phosphorus-like protocol proposed by Manful (1992, Occurrence and Ecochemical Behaviours of Arsenic in a Goldsmelter Impacted Area in Ghana, PhD dissertation, at the RUG) were applied to four standard reference materials (SRM) and to a batch of samples from industrially contaminated sites, heavily contaminated with arsenic and heavy metals. The SRM 2710 (Montana soil) was found to be the most useful reference material for metal (Mn, Cu, Zn, As, Cd and Pb) fractionation using the BCR sequential extraction procedure. Two sequential extraction schemes were developed and compared for arsenic with the aim to establish a better fractionation and recovery rate than the BCR-scheme for this element in the SRM samples. The major part of arsenic was released from the heavily contaminated samples after NaOH-extraction. Inferior extraction variability and recovery in the heavily contaminated samples compared to SRMs could be mainly contributed to subsample heterogeneity

  12. 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.

  13. 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...

  14. Assessment of chromium biostabilization in contaminated soils using standard leaching and sequential extraction techniques

    International Nuclear Information System (INIS)

    Papassiopi, Nymphodora; Kontoyianni, Athina; Vaxevanidou, Katerina; Xenidis, Anthimos

    2009-01-01

    The iron reducing microorganism Desulfuromonas palmitatis was evaluated as potential biostabilization agent for the remediation of chromate contaminated soils. D. palmitatis were used for the treatment of soil samples artificially contaminated with Cr(VI) at two levels, i.e. 200 and 500 mg kg -1 . The efficiency of the treatment was evaluated by applying several standard extraction techniques on the soil samples before and after treatment, such as the EN12457 standard leaching test, the US EPA 3060A alkaline digestion method and the BCR sequential extraction procedure. The water soluble chromium as evaluated with the EN leaching test, was found to decrease after the biostabilization treatment from 13 to less than 0.5 mg kg -1 and from 120 to 5.6 mg kg -1 for the soil samples contaminated with 200 and 500 mg Cr(VI) per kg soil respectively. The BCR sequential extraction scheme, although not providing accurate estimates about the initial chromium speciation in contaminated soils, proved to be a useful tool for monitoring the relative changes in element partitioning, as a consequence of the stabilization treatment. After bioreduction, the percentage of chromium retained in the two least soluble BCR fractions, i.e. the 'oxidizable' and 'residual' fractions, increased from 54 and 73% to more than 96% in both soils

  15. 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,

  16. Sequential Extraction Versus Comprehensive Characterization of Heavy Metal Species in Brownfield Soils

    Energy Technology Data Exchange (ETDEWEB)

    Dahlin, Cheryl L.; Williamson, Connie A.; Collins, W. Keith; Dahlin, David C.

    2002-06-01

    The applicability of sequential extraction as a means to determine species of heavy-metals was examined by a study on soil samples from two Superfund sites: the National Lead Company site in Pedricktown, NJ, and the Roebling Steel, Inc., site in Florence, NJ. Data from a standard sequential extraction procedure were compared to those from a comprehensive study that combined optical- and scanning-electron microscopy, X-ray diffraction, and chemical analyses. The study shows that larger particles of contaminants, encapsulated contaminants, and/or man-made materials such as slags, coke, metals, and plastics are subject to incasement, non-selectivity, and redistribution in the sequential extraction process. The results indicate that standard sequential extraction procedures that were developed for characterizing species of contaminants in river sediments may be unsuitable for stand-alone determinative evaluations of contaminant species in industrial-site materials. However, if employed as part of a comprehensive, site-specific characterization study, sequential extraction could be a very useful tool.

  17. 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

  18. A sequential mixed methods research approach to investigating HIV ...

    African Journals Online (AJOL)

    Sequential mixed methods research is an effective approach for investigating complex problems, but it has not been extensively used in construction management research. In South Africa, the HIV/AIDS pandemic has seen construction management taking on a vital responsibility since the government called upon the ...

  19. Standardized method for reproducing the sequential X-rays flap

    International Nuclear Information System (INIS)

    Brenes, Alejandra; Molina, Katherine; Gudino, Sylvia

    2009-01-01

    A method is validated to estandardize in the taking, developing and analysis of bite-wing radiographs taken in sequential way, in order to compare and evaluate detectable changes in the evolution of the interproximal lesions through time. A radiographic positioner called XCP® is modified by means of a rigid acrylic guide, to achieve proper of the X ray equipment core positioning relative to the XCP® ring and the reorientation during the sequential x-rays process. 16 subjects of 4 to 40 years old are studied for a total number of 32 registries. Two x-rays of the same block of teeth of each subject have been taken in sequential way, with a minimal difference of 30 minutes between each one, before the placement of radiographic attachment. The images have been digitized with a Super Cam® scanner and imported to a software. The measurements in X and Y-axis for both x-rays were performed to proceed to compare. The intraclass correlation index (ICI) has shown that the proposed method is statistically related to measurement (mm) obtained in the X and Y-axis for both sequential series of x-rays (p=0.01). The measures of central tendency and dispersion have shown that the usual occurrence is indifferent between the two measurements (Mode 0.000 and S = 0083 and 0.109) and that the probability of occurrence of different values is lower than expected. (author) [es

  20. 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

  1. Extraction Methods, Variability Encountered in

    NARCIS (Netherlands)

    Bodelier, P.L.E.; Nelson, K.E.

    2014-01-01

    Synonyms Bias in DNA extractions methods; Variation in DNA extraction methods Definition The variability in extraction methods is defined as differences in quality and quantity of DNA observed using various extraction protocols, leading to differences in outcome of microbial community composition

  2. 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

  3. 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.

  4. Investigations of Cu, Pb and Zn partitioning by sequential extraction in harbour sediments after electrodialytic remediation

    DEFF Research Database (Denmark)

    Kirkelund, Gunvor Marie; Ottosen, Lisbeth M.; Villumsen, Arne

    2010-01-01

    remediation time. A three step sequential extraction scheme (BCR), with an extra residual step, was used to evaluate the heavy metal distribution in the sediments before and after electrodialytic remediation. Cu was mainly associated with the oxidisable phase of the sediment, both before and after remediation...

  5. 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

  6. 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

  7. 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

  8. Breaking from binaries - using a sequential mixed methods design.

    Science.gov (United States)

    Larkin, Patricia Mary; Begley, Cecily Marion; Devane, Declan

    2014-03-01

    To outline the traditional worldviews of healthcare research and discuss the benefits and challenges of using mixed methods approaches in contributing to the development of nursing and midwifery knowledge. There has been much debate about the contribution of mixed methods research to nursing and midwifery knowledge in recent years. A sequential exploratory design is used as an exemplar of a mixed methods approach. The study discussed used a combination of focus-group interviews and a quantitative instrument to obtain a fuller understanding of women's experiences of childbirth. In the mixed methods study example, qualitative data were analysed using thematic analysis and quantitative data using regression analysis. Polarised debates about the veracity, philosophical integrity and motivation for conducting mixed methods research have largely abated. A mixed methods approach can contribute to a deeper, more contextual understanding of a variety of subjects and experiences; as a result, it furthers knowledge that can be used in clinical practice. The purpose of the research study should be the main instigator when choosing from an array of mixed methods research designs. Mixed methods research offers a variety of models that can augment investigative capabilities and provide richer data than can a discrete method alone. This paper offers an example of an exploratory, sequential approach to investigating women's childbirth experiences. A clear framework for the conduct and integration of the different phases of the mixed methods research process is provided. This approach can be used by practitioners and policy makers to improve practice.

  9. 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

  10. 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

  11. 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.

  12. A working-set framework for sequential convex approximation methods

    DEFF Research Database (Denmark)

    Stolpe, Mathias

    2008-01-01

    We present an active-set algorithmic framework intended as an extension to existing implementations of sequential convex approximation methods for solving nonlinear inequality constrained programs. The framework is independent of the choice of approximations and the stabilization technique used...... to guarantee global convergence of the method. The algorithm works directly on the nonlinear constraints in the convex sub-problems and solves a sequence of relaxations of the current sub-problem. The algorithm terminates with the optimal solution to the sub-problem after solving a finite number of relaxations....

  13. Comments on the sequential probability ratio testing methods

    Energy Technology Data Exchange (ETDEWEB)

    Racz, A. [Hungarian Academy of Sciences, Budapest (Hungary). Central Research Inst. for Physics

    1996-07-01

    In this paper the classical sequential probability ratio testing method (SPRT) is reconsidered. Every individual boundary crossing event of the SPRT is regarded as a new piece of evidence about the problem under hypothesis testing. The Bayes method is applied for belief updating, i.e. integrating these individual decisions. The procedure is recommended to use when the user (1) would like to be informed about the tested hypothesis continuously and (2) would like to achieve his final conclusion with high confidence level. (Author).

  14. 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.

  15. 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

  16. 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

  17. 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

  18. Sequential optimization and reliability assessment method for metal forming processes

    International Nuclear Information System (INIS)

    Sahai, Atul; Schramm, Uwe; Buranathiti, Thaweepat; Chen Wei; Cao Jian; Xia, Cedric Z.

    2004-01-01

    Uncertainty is inevitable in any design process. The uncertainty could be due to the variations in geometry of the part, material properties or due to the lack of knowledge about the phenomena being modeled itself. Deterministic design optimization does not take uncertainty into account and worst case scenario assumptions lead to vastly over conservative design. Probabilistic design, such as reliability-based design and robust design, offers tools for making robust and reliable decisions under the presence of uncertainty in the design process. Probabilistic design optimization often involves double-loop procedure for optimization and iterative probabilistic assessment. This results in high computational demand. The high computational demand can be reduced by replacing computationally intensive simulation models with less costly surrogate models and by employing Sequential Optimization and reliability assessment (SORA) method. The SORA method uses a single-loop strategy with a series of cycles of deterministic optimization and reliability assessment. The deterministic optimization and reliability assessment is decoupled in each cycle. This leads to quick improvement of design from one cycle to other and increase in computational efficiency. This paper demonstrates the effectiveness of Sequential Optimization and Reliability Assessment (SORA) method when applied to designing a sheet metal flanging process. Surrogate models are used as less costly approximations to the computationally expensive Finite Element simulations

  19. 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. 

  20. 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.

  1. On-line dynamic fractionation and automatic determination of inorganic phosphorous in environmental solid substrates exploiting sequential injection microcolumn extraction and flow injection analysi

    DEFF Research Database (Denmark)

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

    2006-01-01

    Sequential injection microcolumn extraction (SI-MCE) based on the implementation of a soil containing microcartridge as external reactor in a sequential injection network is, for the first time, proposed for dynamic fractionation of macronutrients in environmental solids, as exemplified by the pa......Sequential injection microcolumn extraction (SI-MCE) based on the implementation of a soil containing microcartridge as external reactor in a sequential injection network is, for the first time, proposed for dynamic fractionation of macronutrients in environmental solids, as exemplified...... by the partitioning of inorganic phosphorous in agricultural soils. The on-line fractionation method capitalises on the accurate metering and sequential exposure of the various extractants to the solid sample by application of programmable flow as precisely coordinated by a syringe pump. Three different soil phase...... associations for phosphorus, that is, exchangeable, Al- and Fe-bound and Ca-bound fractions, were elucidated by accommodation in the flow manifold of the 3 steps of the Hietjles-Litjkema (HL) scheme involving the use of 1.0 M NH4Cl, 0.1 M NaOH and 0.5 M HCl, respectively, as sequential leaching reagents...

  2. 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...

  3. 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.

  4. A Sequential Quadratically Constrained Quadratic Programming Method of Feasible Directions

    International Nuclear Information System (INIS)

    Jian Jinbao; Hu Qingjie; Tang Chunming; Zheng Haiyan

    2007-01-01

    In this paper, a sequential quadratically constrained quadratic programming method of feasible directions is proposed for the optimization problems with nonlinear inequality constraints. At each iteration of the proposed algorithm, a feasible direction of descent is obtained by solving only one subproblem which consist of a convex quadratic objective function and simple quadratic inequality constraints without the second derivatives of the functions of the discussed problems, and such a subproblem can be formulated as a second-order cone programming which can be solved by interior point methods. To overcome the Maratos effect, an efficient higher-order correction direction is obtained by only one explicit computation formula. The algorithm is proved to be globally convergent and superlinearly convergent under some mild conditions without the strict complementarity. Finally, some preliminary numerical results are reported

  5. 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)

  6. 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)

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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...

  12. 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.)

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. Selectivity assessment of an arsenic sequential extraction procedure for evaluating mobility in mine wastes

    International Nuclear Information System (INIS)

    Drahota, Petr; Grösslová, Zuzana; Kindlová, Helena

    2014-01-01

    Highlights: • Extraction efficiency and selectivity of phosphate and oxalate were tested. • Pure As-bearing mineral phases and mine wastes were used. • The reagents were found to be specific and selective for most major forms of As. • An optimized sequential extraction scheme for mine wastes has been developed. • It has been tested over a model mineral mixtures and natural mine waste materials. - Abstract: An optimized sequential extraction (SE) scheme for mine waste materials has been developed and tested for As partitioning over a range of pure As-bearing mineral phases, their model mixtures, and natural mine waste materials. This optimized SE procedure employs five extraction steps: (1) nitrogen-purged deionized water, 10 h; (2) 0.01 M NH 4 H 2 PO 4 , 16 h; (3) 0.2 M NH 4 -oxalate in the dark, pH3, 2 h; (4) 0.2 M NH 4 -oxalate, pH3/80 °C, 4 h; (5) KClO 3 /HCl/HNO 3 digestion. Selectivity and specificity tests on natural mine wastes and major pure As-bearing mineral phases showed that these As fractions appear to be primarily associated with: (1) readily soluble; (2) adsorbed; (3) amorphous and poorly-crystalline arsenates, oxides and hydroxosulfates of Fe; (4) well-crystalline arsenates, oxides, and hydroxosulfates of Fe; as well as (5) sulfides and arsenides. The specificity and selectivity of extractants, and the reproducibility of the optimized SE procedure were further verified by artificial model mineral mixtures and different natural mine waste materials. Partitioning data for extraction steps 3, 4, and 5 showed good agreement with those calculated in the model mineral mixtures (<15% difference), as well as that expected in different natural mine waste materials. The sum of the As recovered in the different extractant pools was not significantly different (89–112%) than the results for acid digestion. This suggests that the optimized SE scheme can reliably be employed for As partitioning in mine waste materials

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. Comparison of mentha extracts obtained by different extraction methods

    Directory of Open Access Journals (Sweden)

    Milić Slavica

    2006-01-01

    Full Text Available The different methods of mentha extraction, such as steam distillation, extraction by methylene chloride (Soxhlet extraction and supercritical fluid extraction (SFE by carbon dioxide (CO J were investigated. SFE by CO, was performed at pressure of 100 bar and temperature of40°C. The extraction yield, as well as qualitative and quantitative composition of obtained extracts, determined by GC-MS method, were compared.

  5. 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.

  6. Sequential method for the assessment of innovations in computer assisted industrial processes

    International Nuclear Information System (INIS)

    Suarez Antola R.

    1995-01-01

    A sequential method for the assessment of innovations in industrial processes is proposed, using suitable combinations of mathematical modelling and numerical simulation of dynamics. Some advantages and limitations of the proposed method are discussed. tabs

  7. 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.

  8. Arsenic Mobility and Availability in Sediments by Application of BCR Sequential Extractions Method; Movilidad y Disponibilidad de Arsenico en Sedimentos Mediante la Aplicacion del Metodo de Extracciones Secuenciales BCR

    Energy Technology Data Exchange (ETDEWEB)

    Larios, R.; Fernandez, R.; Rucandio, M. I.

    2011-05-13

    Arsenic is a metalloid found in nature, both naturally and due to anthropogenic activities. Among them, mining works are an important source of arsenic release to the environment. Asturias is a region where important mercury mines were exploited, and in them arsenic occurs in para genesis with mercury minerals. The toxicity and mobility of this element depends on the chemical species it is found. Fractionation studies are required to analyze the mobility of this metalloid in soils and sediments. Among them, the proposed by the Bureau Community of Reference (BCR) is one of the most employed. This method attempts to divide up, by operationally defined stages, the amount of this element associated with carbonates (fraction 1), iron and manganese oxy hydroxides (fraction 2), organic matter and sulphides (fraction 3), and finally as the amount associated residual fraction to primary and secondary minerals, that is, from the most labile fractions to the most refractory ones. Fractionation of arsenic in sediments from two mines in Asturias were studied, La Soterrana and Los Rueldos. Sediments from La Soterrana showed high levels of arsenic in the non-residual phases, indicating that the majority of arsenic has an anthropogenic origin. By contrast, in sediments from Los Rueldos most of the arsenic is concentrated in the residual phase, indicating that this element remains bound to very refractory primary minerals, as is also demonstrated by the strong correlation of arsenic fractionation and the fractionation of elements present in refractory minerals, such as iron, aluminum and titanium. (Author) 51 refs.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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

  16. Methods of Analysis by the U.S. Geological Survey Organic Geochemistry Research Group-Determination of Dissolved Isoxaflutole and Its Sequential Degradation Products, Diketonitrile and Benzoic Acid, in Water Using Solid-Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry

    Science.gov (United States)

    Meyer, Michael T.; Lee, Edward A.; Scribner, Elisabeth A.

    2007-01-01

    An analytical method for the determination of isoxaflutole and its sequential degradation products, diketonitrile and a benzoic acid analogue, in filtered water with varying matrices was developed by the U.S. Geological Survey Organic Geochemistry Research Group in Lawrence, Kansas. Four different water-sample matrices fortified at 0.02 and 0.10 ug/L (micrograms per liter) are extracted by vacuum manifold solid-phase extraction and analyzed by liquid chromatography/tandem mass spectrometry using electrospray ionization in negative-ion mode with multiple-reaction monitoring (MRM). Analytical conditions for mass spectrometry detection are optimized, and quantitation is carried out using the following MRM molecular-hydrogen (precursor) ion and product (p) ion transition pairs: 357.9 (precursor), 78.9 (p), and 277.6 (p) for isoxaflutole and diketonitrile, and 267.0 (precursor), 159.0 (p), and 223.1 (p) for benzoic acid. 2,4-dichlorophenoxyacetic acid-d3 is used as the internal standard, and alachlor ethanesulfonic acid-d5 is used as the surrogate standard. Compound detection limits and reporting levels are calculated using U.S. Environmental Protection Agency procedures. The mean solid-phase extraction recovery values ranged from 104 to 108 percent with relative standard deviation percentages ranging from 4.0 to 10.6 percent. The combined mean percentage concentration normalized to the theoretical spiked concentration of four water matrices analyzed eight times at 0.02 and 0.10 ug/L (seven times for the reagent-water matrix at 0.02 ug/L) ranged from approximately 75 to 101 percent with relative standard deviation percentages ranging from approximately 3 to 26 percent for isoxaflutole, diketonitrile, and benzoic acid. The method detection limit (MDL) for isoxaflutole and diketonitrile is 0.003 ug/L and 0.004 ug/L for benzoic acid. Method reporting levels (MRLs) are 0.011, 0.010, and 0.012 ug/L for isoxaflutole, diketonitrile, and benzoic acid, respectively. On the basis

  17. 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

  18. Study of Cu and Pb partitioning in mine tailings using the Tessier sequential extraction scheme

    Energy Technology Data Exchange (ETDEWEB)

    Andrei, Mariana Lucia, E-mail: marianaluciaandrei@yahoo.com [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Babes-Bolyai University, Environmental Science and Engineering Faculty, 30 Fantanele, 400294, Cluj-Napoca (Romania); Senila, Marin; Hoaghia, Maria Alexandra; Levei, Erika-Andrea [INCDO-INOE 2000, Research Institute for Analytical Instrumentation, 67 Donath, 400293, Cluj-Napoca (Romania); Borodi, Gheorghe [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania)

    2015-12-23

    The Cu and Pb partitioning in nonferrous mine tailings was investigated using the Tessier sequential extraction scheme. The contents of Cu and Pb found in the five operationally defined fractions were determined by inductively coupled plasma optical emission spectrometry. The results showed different partitioning patterns for Cu and Pb in the studied tailings. The total Cu and Pb contents were higher in tailings from Brazesti than in those from Saliste, while the Cu contents in the first two fractions considered as mobile were comparable and the content of mobile Pb was the highest in Brazesti tailings. In the tailings from Saliste about 30% of Cu and 3% of Pb were found in exchangeable fraction, while in those from Brazesti no metals were found in the exchangeable fraction, but the percent of Cu and Pb found in the bound to carbonate fraction were high (20% and 26%, respectively). The highest Pb content was found in the residual fraction in Saliste tailings and in bound to Fe and Mn oxides fraction in Brazesti tailings, while the highest Cu content was found in the fraction bound to organic matter in Saliste tailings and in the residual fraction in Brazesti tailings. In case of tailings of Brazesti medium environmental risk was found both for Pb and Cu, while in case of Saliste tailings low risk for Pb and high risk for Cu were found.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. Study of Cu and Pb partitioning in mine tailings using the Tessier sequential extraction scheme

    International Nuclear Information System (INIS)

    Andrei, Mariana Lucia; Senila, Marin; Hoaghia, Maria Alexandra; Levei, Erika-Andrea; Borodi, Gheorghe

    2015-01-01

    The Cu and Pb partitioning in nonferrous mine tailings was investigated using the Tessier sequential extraction scheme. The contents of Cu and Pb found in the five operationally defined fractions were determined by inductively coupled plasma optical emission spectrometry. The results showed different partitioning patterns for Cu and Pb in the studied tailings. The total Cu and Pb contents were higher in tailings from Brazesti than in those from Saliste, while the Cu contents in the first two fractions considered as mobile were comparable and the content of mobile Pb was the highest in Brazesti tailings. In the tailings from Saliste about 30% of Cu and 3% of Pb were found in exchangeable fraction, while in those from Brazesti no metals were found in the exchangeable fraction, but the percent of Cu and Pb found in the bound to carbonate fraction were high (20% and 26%, respectively). The highest Pb content was found in the residual fraction in Saliste tailings and in bound to Fe and Mn oxides fraction in Brazesti tailings, while the highest Cu content was found in the fraction bound to organic matter in Saliste tailings and in the residual fraction in Brazesti tailings. In case of tailings of Brazesti medium environmental risk was found both for Pb and Cu, while in case of Saliste tailings low risk for Pb and high risk for Cu were found

  4. Metabolic routes along digestive system of licorice: multicomponent sequential metabolism method in rat.

    Science.gov (United States)

    Zhang, Lei; Zhao, Haiyu; Liu, Yang; Dong, Honghuan; Lv, Beiran; Fang, Min; Zhao, Huihui

    2016-06-01

    This study was conducted to establish the multicomponent sequential metabolism (MSM) method based on comparative analysis along the digestive system following oral administration of licorice (Glycyrrhiza uralensis Fisch., leguminosae), a traditional Chinese medicine widely used for harmonizing other ingredients in a formulae. The licorice water extract (LWE) dissolved in Krebs-Ringer buffer solution (1 g/mL) was used to carry out the experiments and the comparative analysis was performed using HPLC and LC-MS/MS methods. In vitro incubation, in situ closed-loop and in vivo blood sampling were used to measure the LWE metabolic profile along the digestive system. The incubation experiment showed that the LWE was basically stable in digestive juice. A comparative analysis presented the metabolic profile of each prototype and its corresponding metabolites then. Liver was the major metabolic organ for LWE, and the metabolism by the intestinal flora and gut wall was also an important part of the process. The MSM method was practical and could be a potential method to describe the metabolic routes of multiple components before absorption into the systemic blood stream. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. Sequential Injection Method for Rapid and Simultaneous Determination of 236U, 237Np, and Pu Isotopes in Seawater

    DEFF Research Database (Denmark)

    Qiao, Jixin; Hou, Xiaolin; Steier, Peter

    2013-01-01

    An automated analytical method implemented in a novel dual-column tandem sequential injection (SI) system was developed for simultaneous determination of 236U, 237Np, 239Pu, and 240Pu in seawater samples. A combination of TEVA and UTEVA extraction chromatography was exploited to separate and purify...... target analytes, whereupon plutonium and neptunium were simultaneously isolated and purified on TEVA, while uranium was collected on UTEVA. The separation behavior of U, Np, and Pu on TEVA–UTEVA columns was investigated in detail in order to achieve high chemical yields and complete purification...

  12. Double tracer autoradiographic method for sequential evaluation of regional cerebral perfusion

    International Nuclear Information System (INIS)

    Matsuda, H.; Tsuji, S.; Oba, H.; Kinuya, K.; Terada, H.; Sumiya, H.; Shiba, K.; Mori, H.; Hisada, K.; Maeda, T.

    1989-01-01

    A new double tracer autoradiographic method for the sequential evaluation of altered regional cerebral perfusion in the same animal is presented. This method is based on the sequential injection of two tracers, 99m Tc-hexamethylpropyleneamine oxime and N-isopropyl-( 125 I)p-iodoamphetamine. This method is validated in the assessment of brovincamine effects on regional cerebral perfusion in an experimental model of chronic brain ischemia in the rat. The drug enhanced perfusion recovery in low-flow areas, selectively in surrounding areas of infarction. The results suggest that this technique is of potential use in the study of neuropharmacological effects applied during the experiment

  13. 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.

  14. 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....

  15. 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...

  16. Optimization of sequential decisions by least squares Monte Carlo method

    DEFF Research Database (Denmark)

    Nishijima, Kazuyoshi; Anders, Annett

    change adaptation measures, and evacuation of people and assets in the face of an emerging natural hazard event. Focusing on the last example, an efficient solution scheme is proposed by Anders and Nishijima (2011). The proposed solution scheme takes basis in the least squares Monte Carlo method, which...... is proposed by Longstaff and Schwartz (2001) for pricing of American options. The present paper formulates the decision problem in a more general manner and explains how the solution scheme proposed by Anders and Nishijima (2011) is implemented for the optimization of the formulated decision problem...

  17. Measurement of sequential change of regional ventilation by new developed Kr-81m method in asthmatics

    International Nuclear Information System (INIS)

    Shimada, Takao; Narita, Hiroto; Ishida, Hirohide; Terashima, Yoichi; Hirasawa, Korenori; Mori, Yutaka; Kawakami, Kenji

    1991-01-01

    Fazio has reported the distribution of Kr-81m by the continuous inhalation method indicates distribution of ventilation. To estimate sequential ventilation change with the continuous Kr-81m inhalation method, it is necessary to keep the concentration of Kr-81m constant. However this is frequently ignored. Because of this, we have developed the new method to maintain constant concentration of Kr-81m and compared the reliability of this method to the conventional method. The results of phantom study showed that the concentration of Kr-81m is kept constant, and sequential change of ventilation can be estimated only by our new method. On application of this method in asthmatics, we have discovered the existence of the region where ventilation reduced by inhalation of a bronchodilator. (author)

  18. A Robust Real Time Direction-of-Arrival Estimation Method for Sequential Movement Events of Vehicles.

    Science.gov (United States)

    Liu, Huawei; Li, Baoqing; Yuan, Xiaobing; Zhou, Qianwei; Huang, Jingchang

    2018-03-27

    Parameters estimation of sequential movement events of vehicles is facing the challenges of noise interferences and the demands of portable implementation. In this paper, we propose a robust direction-of-arrival (DOA) estimation method for the sequential movement events of vehicles based on a small Micro-Electro-Mechanical System (MEMS) microphone array system. Inspired by the incoherent signal-subspace method (ISM), the method that is proposed in this work employs multiple sub-bands, which are selected from the wideband signals with high magnitude-squared coherence to track moving vehicles in the presence of wind noise. The field test results demonstrate that the proposed method has a better performance in emulating the DOA of a moving vehicle even in the case of severe wind interference than the narrowband multiple signal classification (MUSIC) method, the sub-band DOA estimation method, and the classical two-sided correlation transformation (TCT) method.

  19. Physics-based, Bayesian sequential detection method and system for radioactive contraband

    Science.gov (United States)

    Candy, James V; Axelrod, Michael C; Breitfeller, Eric F; Chambers, David H; Guidry, Brian L; Manatt, Douglas R; Meyer, Alan W; Sale, Kenneth E

    2014-03-18

    A distributed sequential method and system for detecting and identifying radioactive contraband from highly uncertain (noisy) low-count, radionuclide measurements, i.e. an event mode sequence (EMS), using a statistical approach based on Bayesian inference and physics-model-based signal processing based on the representation of a radionuclide as a monoenergetic decomposition of monoenergetic sources. For a given photon event of the EMS, the appropriate monoenergy processing channel is determined using a confidence interval condition-based discriminator for the energy amplitude and interarrival time and parameter estimates are used to update a measured probability density function estimate for a target radionuclide. A sequential likelihood ratio test is then used to determine one of two threshold conditions signifying that the EMS is either identified as the target radionuclide or not, and if not, then repeating the process for the next sequential photon event of the EMS until one of the two threshold conditions is satisfied.

  20. Double-label autoradiographic deoxyglucose method for sequential measurement of regional cerebral glucose utilization

    Energy Technology Data Exchange (ETDEWEB)

    Redies, C; Diksic, M; Evans, A C; Gjedde, A; Yamamoto, Y L

    1987-08-01

    A new double-label autoradiographic glucose analog method for the sequential measurement of altered regional cerebral metabolic rates for glucose in the same animal is presented. This method is based on the sequential injection of two boluses of glucose tracer labeled with two different isotopes (short-lived /sup 18/F and long-lived /sup 3/H, respectively). An operational equation is derived which allows the determination of glucose utilization for the time period before the injection of the second tracer; this equation corrects for accumulation and loss of the first tracer from the metabolic pool occurring after the injection of the second tracer. An error analysis of this operational equation is performed. The double-label deoxyglucose method is validated in the primary somatosensory (''barrel'') cortex of the anesthetized rat. Two different rows of whiskers were stimulated sequentially in each rat; the two periods of stimulation were each preceded by an injection of glucose tracer. After decapitation, dried brain slices were first exposed, in direct contact, to standard X-ray film and then to uncoated, ''tritium-sensitive'' film. Results show that the double-label deoxyglucose method proposed in this paper allows the quantification and complete separation of glucose utilization patterns elicited by two different stimulations sequentially applied in the same animal.

  1. 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.

  2. 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

  3. Developing a Self-Report-Based Sequential Analysis Method for Educational Technology Systems: A Process-Based Usability Evaluation

    Science.gov (United States)

    Lin, Yi-Chun; Hsieh, Ya-Hui; Hou, Huei-Tse

    2015-01-01

    The development of a usability evaluation method for educational systems or applications, called the self-report-based sequential analysis, is described herein. The method aims to extend the current practice by proposing self-report-based sequential analysis as a new usability method, which integrates the advantages of self-report in survey…

  4. 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.

  5. 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...

  6. Sequential Probability Ratio Testing with Power Projective Base Method Improves Decision-Making for BCI

    Science.gov (United States)

    Liu, Rong

    2017-01-01

    Obtaining a fast and reliable decision is an important issue in brain-computer interfaces (BCI), particularly in practical real-time applications such as wheelchair or neuroprosthetic control. In this study, the EEG signals were firstly analyzed with a power projective base method. Then we were applied a decision-making model, the sequential probability ratio testing (SPRT), for single-trial classification of motor imagery movement events. The unique strength of this proposed classification method lies in its accumulative process, which increases the discriminative power as more and more evidence is observed over time. The properties of the method were illustrated on thirteen subjects' recordings from three datasets. Results showed that our proposed power projective method outperformed two benchmark methods for every subject. Moreover, with sequential classifier, the accuracies across subjects were significantly higher than that with nonsequential ones. The average maximum accuracy of the SPRT method was 84.1%, as compared with 82.3% accuracy for the sequential Bayesian (SB) method. The proposed SPRT method provides an explicit relationship between stopping time, thresholds, and error, which is important for balancing the time-accuracy trade-off. These results suggest SPRT would be useful in speeding up decision-making while trading off errors in BCI. PMID:29348781

  7. Evaluation of sample extraction methods for proteomics analysis of green algae Chlorella vulgaris.

    Science.gov (United States)

    Gao, Yan; Lim, Teck Kwang; Lin, Qingsong; Li, Sam Fong Yau

    2016-05-01

    Many protein extraction methods have been developed for plant proteome analysis but information is limited on the optimal protein extraction method from algae species. This study evaluated four protein extraction methods, i.e. direct lysis buffer method, TCA-acetone method, phenol method, and phenol/TCA-acetone method, using green algae Chlorella vulgaris for proteome analysis. The data presented showed that phenol/TCA-acetone method was superior to the other three tested methods with regards to shotgun proteomics. Proteins identified using shotgun proteomics were validated using sequential window acquisition of all theoretical fragment-ion spectra (SWATH) technique. Additionally, SWATH provides protein quantitation information from different methods and protein abundance using different protein extraction methods was evaluated. These results highlight the importance of green algae protein extraction method for subsequent MS analysis and identification. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Metal fractionation of atmospheric aerosols via sequential chemical extraction: a review

    Energy Technology Data Exchange (ETDEWEB)

    Smichowski, Patricia; Gomez, Dario [Unidad de Actividad Quimica, Comision Nacional de Energia Atomica, San Martin (Argentina); Polla, Griselda [Unidad de Actividad Fisica, Comision Nacional de Energia Atomica, San Martin (Argentina)

    2005-01-01

    This review surveys schemes used to sequentially chemically fractionate metals and metalloids present in airborne particulate matter. It focuses mainly on sequential chemical fractionation schemes published over the last 15 years. These schemes have been classified into five main categories: (1) based on Tessier's procedure, (2) based on Chester's procedure, (3) based on Zatka's procedure, (4) based on BCR procedure, and (5) other procedures. The operational characteristics as well as the state of the art in metal fractionation of airborne particulate matter, fly ashes and workroom aerosols, in terms of applications, optimizations and innovations, are also described. Many references to other works in this area are provided. (orig.)

  9. 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.

  10. 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.

  11. 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.)

  12. 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...

  13. 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).

  14. A Sequential Optimization Sampling Method for Metamodels with Radial Basis Functions

    Science.gov (United States)

    Pan, Guang; Ye, Pengcheng; Yang, Zhidong

    2014-01-01

    Metamodels have been widely used in engineering design to facilitate analysis and optimization of complex systems that involve computationally expensive simulation programs. The accuracy of metamodels is strongly affected by the sampling methods. In this paper, a new sequential optimization sampling method is proposed. Based on the new sampling method, metamodels can be constructed repeatedly through the addition of sampling points, namely, extrema points of metamodels and minimum points of density function. Afterwards, the more accurate metamodels would be constructed by the procedure above. The validity and effectiveness of proposed sampling method are examined by studying typical numerical examples. PMID:25133206

  15. Elemental characterization of coal ash and its leachates using sequential extraction techniques

    International Nuclear Information System (INIS)

    Landsberger, S.; Cerbus, J.F.; Larson, S.

    1995-01-01

    Over 50 million tons of coal ash are produced annually in North America. Technological improvements in air pollution control have decreased stack emissions but have also increased contaminant concentrations in the ash of coal-fired boiler applications. The leaching of heavy metals and other elements during regulatory tests may cause coal ash to be classified as hazardous waste, complicating land disposal. The hazardous nature of coal ash remains unclear because current toxicity tests fail to effectively characterize the elemental distribution and chemical solubility of trace metals in the landfill environment. Leaching characteristics of ash samples can be investigated with various laboratory extraction procedures in association with multi-elemental analytical techniques (e.g., neutron activation analysis and inductively coupled plasma - atomic emission spectroscopy). Such methods provide more thorough analyses of coal ash leaching dynamics than the regulatory assessments can demonstrate. Regulatory elements including Ag, As, Ba, Cd, Cr, Hg, Pb, and Se were shown to remain in largely insoluble forms while elements such as B and S leached at higher levels. Experimental results may assist operators of coal-fired boiler industries in selecting coal types and disposal options to curtail the leaching of potentially toxic inorganic contaminants. (author) 12 refs.; 4 figs.; 3 tabs

  16. 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)

  17. Performance Analysis of Video Transmission Using Sequential Distortion Minimization Method for Digital Video Broadcasting Terrestrial

    Directory of Open Access Journals (Sweden)

    Novita Astin

    2016-12-01

    Full Text Available This paper presents about the transmission of Digital Video Broadcasting system with streaming video resolution 640x480 on different IQ rate and modulation. In the video transmission, distortion often occurs, so the received video has bad quality. Key frames selection algorithm is flexibel on a change of video, but on these methods, the temporal information of a video sequence is omitted. To minimize distortion between the original video and received video, we aimed at adding methodology using sequential distortion minimization algorithm. Its aim was to create a new video, better than original video without significant loss of content between the original video and received video, fixed sequentially. The reliability of video transmission was observed based on a constellation diagram, with the best result on IQ rate 2 Mhz and modulation 8 QAM. The best video transmission was also investigated using SEDIM (Sequential Distortion Minimization Method and without SEDIM. The experimental result showed that the PSNR (Peak Signal to Noise Ratio average of video transmission using SEDIM was an increase from 19,855 dB to 48,386 dB and SSIM (Structural Similarity average increase 10,49%. The experimental results and comparison of proposed method obtained a good performance. USRP board was used as RF front-end on 2,2 GHz.

  18. 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

  19. A Comparison of Sequential and GPU Implementations of Iterative Methods to Compute Reachability Probabilities

    Directory of Open Access Journals (Sweden)

    Elise Cormie-Bowins

    2012-10-01

    Full Text Available We consider the problem of computing reachability probabilities: given a Markov chain, an initial state of the Markov chain, and a set of goal states of the Markov chain, what is the probability of reaching any of the goal states from the initial state? This problem can be reduced to solving a linear equation Ax = b for x, where A is a matrix and b is a vector. We consider two iterative methods to solve the linear equation: the Jacobi method and the biconjugate gradient stabilized (BiCGStab method. For both methods, a sequential and a parallel version have been implemented. The parallel versions have been implemented on the compute unified device architecture (CUDA so that they can be run on a NVIDIA graphics processing unit (GPU. From our experiments we conclude that as the size of the matrix increases, the CUDA implementations outperform the sequential implementations. Furthermore, the BiCGStab method performs better than the Jacobi method for dense matrices, whereas the Jacobi method does better for sparse ones. Since the reachability probabilities problem plays a key role in probabilistic model checking, we also compared the implementations for matrices obtained from a probabilistic model checker. Our experiments support the conjecture by Bosnacki et al. that the Jacobi method is superior to Krylov subspace methods, a class to which the BiCGStab method belongs, for probabilistic model checking.

  20. Virgin almond oil: Extraction methods and composition

    Energy Technology Data Exchange (ETDEWEB)

    Roncero, J.M.; Alvarez-Orti, M.; Pardo-Gimenez, A.; Gomez, R.; Rabadan, A.; Pardo, J.E.

    2016-07-01

    In this paper the extraction methods of virgin almond oil and its chemical composition are reviewed. The most common methods for obtaining oil are solvent extraction, extraction with supercritical fluids (CO2) and pressure systems (hydraulic and screw presses). The best industrial performance, but also the worst oil quality is achieved by using solvents. Oils obtained by this method cannot be considered virgin oils as they are obtained by chemical treatments. Supercritical fluid extraction results in higher quality oils but at a very high price. Extraction by pressing becomes the best option to achieve high quality oils at an affordable price. With regards chemical composition, almond oil is characterized by its low content in saturated fatty acids and the predominance of monounsaturated, especially oleic acid. Furthermore, almond oil contains antioxidants and fat-soluble bioactive compounds that make it an oil with interesting nutritional and cosmetic properties.

  1. Virgin almond oil: Extraction methods and composition

    International Nuclear Information System (INIS)

    Roncero, J.M.; Alvarez-Orti, M.; Pardo-Gimenez, A.; Gomez, R.; Rabadan, A.; Pardo, J.E.

    2016-01-01

    In this paper the extraction methods of virgin almond oil and its chemical composition are reviewed. The most common methods for obtaining oil are solvent extraction, extraction with supercritical fluids (CO2) and pressure systems (hydraulic and screw presses). The best industrial performance, but also the worst oil quality is achieved by using solvents. Oils obtained by this method cannot be considered virgin oils as they are obtained by chemical treatments. Supercritical fluid extraction results in higher quality oils but at a very high price. Extraction by pressing becomes the best option to achieve high quality oils at an affordable price. With regards chemical composition, almond oil is characterized by its low content in saturated fatty acids and the predominance of monounsaturated, especially oleic acid. Furthermore, almond oil contains antioxidants and fat-soluble bioactive compounds that make it an oil with interesting nutritional and cosmetic properties.

  2. Sequential plasma activation methods for hydrophilic direct bonding at sub-200 °C

    Science.gov (United States)

    He, Ran; Yamauchi, Akira; Suga, Tadatomo

    2018-02-01

    We present our newly developed sequential plasma activation methods for hydrophilic direct bonding of silica glasses and thermally grown SiO2 films. N2 plasma was employed to introduce a metastable oxynitride layer on wafer surfaces for the improvement of bond energy. By using either O2-plasma/N2-plasma/N-radical or N2-plasma/N-radical sequential activation, the quartz-quartz bond energy was increased from 2.7 J/m2 to close to the quartz bulk fracture energy that was estimated to be around 9.0 J/m2 after post-bonding annealing at 200 °C. The silicon bulklike bond energy between thermal SiO2 films was also obtained. We suggest that the improvement is attributable to surface modification such as N-related defect formation and asperity softening by the N2 plasma surface treatment.

  3. A novel method for the sequential removal and separation of multiple heavy metals from wastewater.

    Science.gov (United States)

    Fang, Li; Li, Liang; Qu, Zan; Xu, Haomiao; Xu, Jianfang; Yan, Naiqiang

    2018-01-15

    A novel method was developed and applied for the treatment of simulated wastewater containing multiple heavy metals. A sorbent of ZnS nanocrystals (NCs) was synthesized and showed extraordinary performance for the removal of Hg 2+ , Cu 2+ , Pb 2+ and Cd 2+ . The removal efficiencies of Hg 2+ , Cu 2+ , Pb 2+ and Cd 2+ were 99.9%, 99.9%, 90.8% and 66.3%, respectively. Meanwhile, it was determined that solubility product (K sp ) of heavy metal sulfides was closely related to adsorption selectivity of various heavy metals on the sorbent. The removal efficiency of Hg 2+ was higher than that of Cd 2+ , while the K sp of HgS was lower than that of CdS. It indicated that preferential adsorption of heavy metals occurred when the K sp of the heavy metal sulfide was lower. In addition, the differences in the K sp of heavy metal sulfides allowed for the exchange of heavy metals, indicating the potential application for the sequential removal and separation of heavy metals from wastewater. According to the cumulative adsorption experimental results, multiple heavy metals were sequentially adsorbed and separated from the simulated wastewater in the order of the K sp of their sulfides. This method holds the promise of sequentially removing and separating multiple heavy metals from wastewater. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. 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...

  5. 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...

  6. EXTRACTIVE SPECTROPHOTOMETRIC METHOD FOR THE ...

    African Journals Online (AJOL)

    B. S. Chandravanshi

    The method has been applied to the analysis of carbaryl in its ... The extensive use of this insecticide poses a serious risk to both the environment and the human ... is the second most widely detected insecticide in the environmental samples ...

  7. A sequential fuzzy diagnosis method for rotating machinery using ant colony optimization and possibility theory

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hao; Ping, Xueliang; Cao, Yi; Lie, Ke [Jiangnan University, Wuxi (China); Chen, Peng [Mie University, Mie (Japan); Wang, Huaqing [Beijing University, Beijing (China)

    2014-04-15

    This study proposes a novel intelligent fault diagnosis method for rotating machinery using ant colony optimization (ACO) and possibility theory. The non-dimensional symptom parameters (NSPs) in the frequency domain are defined to reflect the features of the vibration signals measured in each state. A sensitive evaluation method for selecting good symptom parameters using principal component analysis (PCA) is proposed for detecting and distinguishing faults in rotating machinery. By using ACO clustering algorithm, the synthesizing symptom parameters (SSP) for condition diagnosis are obtained. A fuzzy diagnosis method using sequential inference and possibility theory is also proposed, by which the conditions of the machinery can be identified sequentially. Lastly, the proposed method is compared with a conventional neural networks (NN) method. Practical examples of diagnosis for a V-belt driving equipment used in a centrifugal fan are provided to verify the effectiveness of the proposed method. The results verify that the faults that often occur in V-belt driving equipment, such as a pulley defect state, a belt defect state and a belt looseness state, are effectively identified by the proposed method, while these faults are difficult to detect using conventional NN.

  8. Comparison of ERBS orbit determination accuracy using batch least-squares and sequential methods

    Science.gov (United States)

    Oza, D. H.; Jones, T. L.; Fabien, S. M.; Mistretta, G. D.; Hart, R. C.; Doll, C. E.

    1991-01-01

    The Flight Dynamics Div. (FDD) at NASA-Goddard commissioned a study to develop the Real Time Orbit Determination/Enhanced (RTOD/E) system as a prototype system for sequential orbit determination of spacecraft on a DOS based personal computer (PC). An overview is presented of RTOD/E capabilities and the results are presented of a study to compare the orbit determination accuracy for a Tracking and Data Relay Satellite System (TDRSS) user spacecraft obtained using RTOS/E on a PC with the accuracy of an established batch least squares system, the Goddard Trajectory Determination System (GTDS), operating on a mainframe computer. RTOD/E was used to perform sequential orbit determination for the Earth Radiation Budget Satellite (ERBS), and the Goddard Trajectory Determination System (GTDS) was used to perform the batch least squares orbit determination. The estimated ERBS ephemerides were obtained for the Aug. 16 to 22, 1989, timeframe, during which intensive TDRSS tracking data for ERBS were available. Independent assessments were made to examine the consistencies of results obtained by the batch and sequential methods. Comparisons were made between the forward filtered RTOD/E orbit solutions and definitive GTDS orbit solutions for ERBS; the solution differences were less than 40 meters after the filter had reached steady state.

  9. Comparison of ERBS orbit determination accuracy using batch least-squares and sequential methods

    Science.gov (United States)

    Oza, D. H.; Jones, T. L.; Fabien, S. M.; Mistretta, G. D.; Hart, R. C.; Doll, C. E.

    1991-10-01

    The Flight Dynamics Div. (FDD) at NASA-Goddard commissioned a study to develop the Real Time Orbit Determination/Enhanced (RTOD/E) system as a prototype system for sequential orbit determination of spacecraft on a DOS based personal computer (PC). An overview is presented of RTOD/E capabilities and the results are presented of a study to compare the orbit determination accuracy for a Tracking and Data Relay Satellite System (TDRSS) user spacecraft obtained using RTOS/E on a PC with the accuracy of an established batch least squares system, the Goddard Trajectory Determination System (GTDS), operating on a mainframe computer. RTOD/E was used to perform sequential orbit determination for the Earth Radiation Budget Satellite (ERBS), and the Goddard Trajectory Determination System (GTDS) was used to perform the batch least squares orbit determination. The estimated ERBS ephemerides were obtained for the Aug. 16 to 22, 1989, timeframe, during which intensive TDRSS tracking data for ERBS were available. Independent assessments were made to examine the consistencies of results obtained by the batch and sequential methods. Comparisons were made between the forward filtered RTOD/E orbit solutions and definitive GTDS orbit solutions for ERBS; the solution differences were less than 40 meters after the filter had reached steady state.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. An Improved Sequential Initiation Method for Multitarget Track in Clutter with Large Noise Measurement

    Directory of Open Access Journals (Sweden)

    Daxiong Ji

    2014-01-01

    Full Text Available This paper proposes an improved sequential method for underwater multiple objects tracks initiation in clutter, estimating the initial position for the trajectory. The underwater environment is complex and changeable, and the sonar data are not very ideal. When the detection distance is far, the error of measured data is also great. Besides that, the clutter has a grave effect on the tracks initiation. So it is hard to initialize a track and estimate the initial position. The new tracks initiation is that when at least six of ten points meet the requirements, then we determine that there is a new track and the initial states of the parameters are estimated by the linear least square method. Compared to the conventional tracks initiation methods, our method not only considers the kinematics information of targets, but also regards the error of the sonar sensors as an important element. Computer simulations confirm that the performance of our method is very nice.

  15. Newer methods of extraction of teeth

    Directory of Open Access Journals (Sweden)

    MHendra Chandha

    2016-06-01

    Full Text Available Atraumatic extraction methods are deemed to be important to minimize alveolar bone loss after tooth extraction. With the advent of such techniques, exodontia is no more a dreaded procedure in anxious patients. Newer system and techniques for extraction of teeth have evolved in the recent few decades. This article reviews and discusses new techniques to make simple and complex exodontias more efficient with improved patient outcomes. This includes physics forceps, powered periotome, piezosurgery, benex extractor, sonic instrument for bone surgery, lasers.

  16. Bilateral Sequential NAION following Cataract Extraction: Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Dana Barequet

    2014-09-01

    Full Text Available We report a 64-year-old patient who developed nonarteritic ischemic optic neuropathy (NAION in both eyes following cataract extraction. The cataract surgeries in both eyes were uneventful and performed within a year, and NAION occurred a few months postoperatively in both eyes. A review of the literature on this rare complication is provided. This case report serves to raise awareness among cataract surgeons about this potential complication associated with irreversible visual loss, and especially about its high risk of bilaterality.

  17. 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

  18. 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.

  19. Methods for determination of extractable complex composition

    International Nuclear Information System (INIS)

    Sergievskij, V.V.

    1984-01-01

    Specific features and restrictions of main methods for determining the extractable complex composition by the distribution data (methods of equilibrium shift, saturation, mathematical models) are considered. Special attention is given to the solution of inverse problems with account for hydration effect on the activity of organic phase components. By example of the systems lithium halides-isoamyl alcohol, thorium nitrate-n-hexyl alcohol, mineral acids tri-n-butyl phosphate (TBP), metal nitrates (uranium lanthanides) - TBP the results on determining stoichiometry of extraction equilibria obtained by various methods are compared

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. Simultaneous determination of two active components of pharmaceutical preparations by sequential injection method using heteropoly complexes

    Directory of Open Access Journals (Sweden)

    Mohammed Khair E. A. Al-Shwaiyat

    2014-12-01

    Full Text Available New approach has been proposed for the simultaneous determination of two reducing agents based on the dependence of their reaction rate with 18-molybdo-2-phosphate heteropoly complex on pH. The method was automated using the manifold typical for the sequential analysis method. Ascorbic acid and rutin were determined by successive injection of two samples acidified to different pH. The linear range for rutin determination was 0.6-20 mg/L and the detection limit was 0.2 mg/L (l = 1 cm. The determination of rutin was possible in the presence of up to a 20-fold excess of ascorbic acid. The method was successfully applied to the determination of ascorbic acid and rutin in ascorutin tablets. The applicability of the proposed method for the determination of total polyphenol content in natural plant samples was shown.

  5. A fast and efficient method for sequential cone-beam tomography

    International Nuclear Information System (INIS)

    Koehler, Th.; Proksa, R.; Grass, M.

    2001-01-01

    Sequential cone-beam tomography is a method that uses data of two or more parallel circular trajectories of a cone-beam scanner to reconstruct the object function. We propose a condition for the data acquisition that ensures that all object points between two successive circles are irradiated over an angular span of the x-ray source position of exactly 360 deg. in total as seen along the rotation axis. A fast and efficient approximative reconstruction method for the proposed acquisition is presented which uses data from exactly 360 deg. for every object point. It is based on the Tent-FDK method which was recently developed for single circular cone-beam CT. The measurement geometry does not provide sufficient data for exact reconstruction but it is shown that the proposed reconstruction method provides satisfying image quality for small cone angles

  6. Speciation of 210Po and 210Pb in air particulates determined by sequential extraction

    International Nuclear Information System (INIS)

    Al-Masri, M.S.; Al-Karfan, K.; Khalili, H.; Hassan, M.

    2006-01-01

    Speciation of 210 Po and 210 Pb in air particulates of two Syrian phosphate sites with different climate conditions has been studied. The sites are the mines and Tartous port at the Mediterranean Sea. Air filters were collected during September 2000 until February 2002 and extracted chemically using different selective fluids in an attempt to identify the different forms of these two radionuclides. The results have shown that the inorganic and insoluble 21 Po and 21 Pb (attached to silica and soluble in mineral acids) portion was found to be high in both sites and reached a maximum value of 94% and 77% in the mine site and Tartous port site, respectively. In addition, only 24% of 21 Pb in air particulates was found to be associated with organic materials probably produced from the incomplete burning of fuel vehicle and similar activities. Moreover, the 210 Po/ 21- Pb activity ratio in air particulates was higher than that in all samples at both sites and varied between 3.85 in November 2000 at Tartous port site and 20 in April 2001 at the mine area. These activity ratios were also higher than the natural levels. The 210 Po/ 210 Pb activity ratio was also determined in each portion resulting from the selective extraction and found to be higher than that in most samples. The sources of 210 Po excess in these portions are discussed. Soil suspension, which is common in the dry climate dominant in the area, sea water spray and heating of phosphate ores were considered; polonium is more volatile than the lead compounds at even moderate temperature. Furthermore, variations in the chemical forms of 210 Po and 210 Pb during the year were also investigated. However, the results of this study can also be utilized for dose assessment to phosphate industry workers

  7. Speciation of 210Po and 210Pb in air particulates determined by sequential extraction.

    Science.gov (United States)

    Al-Masri, M S; Al-Karfan, K; Khalili, H; Hassan, M

    2006-01-01

    Speciation of (210)Po and (210)Pb in air particulates of two Syrian phosphate sites with different climate conditions has been studied. The sites are the mines and Tartous port at the Mediterranean Sea. Air filters were collected during September 2000 until February 2002 and extracted chemically using different selective fluids in an attempt to identify the different forms of these two radionuclides. The results have shown that the inorganic and insoluble (210)Po and (210)Pb (attached to silica and soluble in mineral acids) portion was found to be high in both sites and reached a maximum value of 94% and 77% in the mine site and Tartous port site, respectively. In addition, only 24% of (210)Pb in air particulates was found to be associated with organic materials probably produced from the incomplete burning of fuel vehicle and similar activities. Moreover, the (210)Po/(210)Pb activity ratio in air particulates was higher than that in all samples at both sites and varied between 3.85 in November 2000 at Tartous port site and 20 in April 2001 at the mine area. These activity ratios were also higher than the natural levels. The (210)Po/(210)Pb activity ratio was also determined in each portion resulting from the selective extraction and found to be higher than that in most samples. The sources of (210)Po excess in these portions are discussed. Soil suspension, which is common in the dry climate dominant in the area, sea water spray and heating of phosphate ores were considered; polonium is more volatile than the lead compounds at even moderate temperature. Furthermore, variations in the chemical forms of (210)Po and (210)Pb during the year were also investigated. However, the results of this study can also be utilized for dose assessment to phosphate industry workers.

  8. Anomaly Detection in Gas Turbine Fuel Systems Using a Sequential Symbolic Method

    Directory of Open Access Journals (Sweden)

    Fei Li

    2017-05-01

    Full Text Available Anomaly detection plays a significant role in helping gas turbines run reliably and economically. Considering the collective anomalous data and both sensitivity and robustness of the anomaly detection model, a sequential symbolic anomaly detection method is proposed and applied to the gas turbine fuel system. A structural Finite State Machine is used to evaluate posterior probabilities of observing symbolic sequences and the most probable state sequences they may locate. Hence an estimation-based model and a decoding-based model are used to identify anomalies in two different ways. Experimental results indicate that both models have both ideal performance overall, but the estimation-based model has a strong robustness ability, whereas the decoding-based model has a strong accuracy ability, particularly in a certain range of sequence lengths. Therefore, the proposed method can facilitate well existing symbolic dynamic analysis- based anomaly detection methods, especially in the gas turbine domain.

  9. Phenolic compounds and antioxidant activity of Pecan [Carya illinoinensis (Wangenh. C. Koch] kernel cake extracts obtained by sequential extraction

    Directory of Open Access Journals (Sweden)

    Block, Jane Mara

    2009-12-01

    Full Text Available The total phenolic and condensed tannin contents of different Pecan kernel cake extracts (ether, acetone, alcohol and distilled water were estimated and their antioxidant activities were evaluated through ABTS, DPPH and ß-carotene/linoleic acid systems. Color variations of the Pecan kernel cake were determined through an instrumental analysis using the CIE Lab system. Significantly higher levels (p El contenido de taninos condensado y fenoles totales de diferentes extractos de tortas de almendra de pecana (éter, acetona, alcohol y agua destilada fueron estimados y sus actividades antioxidantes fueron evaluadas mediantes los métodos con ABTS, DPPH y el sistema ß-caroteno/ácido linoleico. Las variaciones de color de la torta de almendra de pecana fueron determinadas mediante análisis instrumental usando el sistema CIE Lab. Los contenidos de fenoles totales, taninos condensados y actividad antioxidante, medida mediante los métodos con ABTS Y DPPH (30 min y 24 h, fueron significativamente más altos (p < 0.05 con el extracto de acetona (16.4 mg GAE/g; 31.2 mg CE/g; 235.3 μmol TEAC/g and 68.6 and 100.3 mg TEAC/g, respectivamente. El porcentaje de inhibición de la oxidación en el sistema ß-caroteno/ ácido linoleico vario desde 37.9 a 93.1% con el extracto de acetona a 300 ppm, mostrando resultados significativamente superiores. Las muestras con una mayor tendencia a tonos rojos presento los niveles más altos de taninos condensados.

  10. 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

  11. Comparative sorption and desorption behaviors of PFHxS and PFOS on sequentially extracted humic substances

    Institute of Scientific and Technical Information of China (English)

    Lixia Zhao; Yifeng Zhang; Shuhong Fang; Lingyan Zhu; Zhengtao Liu

    2014-01-01

    The sorption and desorption behaviors of two perfluoroalkane sulfonates (PFSAs),including perfluorohexane sulfonate (PFHxS) and perfluorooctane sulfonate (PFOS) on two humic acids (HAs) and humin (HM),which were extracted from a peat soil,were investigated.The sorption kinetics and isotherms showed that the sorption of PFOS on the humic substances (HSs) was much higher than PFHxS.For the same PFSA compound,the sorption on HSs followed the order of HM > HA2 > HA1.These suggest that hydrophobic interaction plays a key role in the sorption of PFSAs on HSs.The sorption capacities of PFSAs on HSs were significantly related to their aliphaticity,but negatively correlated to aromatic carbons,indicating the importance of aliphatic groups in the sorption of PFSAs.Compared to PFOS,PFHxS displayed distinct desorption hysteresis,probably due to irreversible pore deformation after sorption of PFHxS.The sorption of the two PFSAs on HSs decreased with an increase in pH in the solution.This is ascribed to the electrostatic interaction and hydrogen bonding at lower pH.Hydrophobic interaction might also be stronger at lower pH due to the aggregation of HSs.

  12. [Using sequential indicator simulation method to define risk areas of soil heavy metals in farmland.

    Science.gov (United States)

    Yang, Hao; Song, Ying Qiang; Hu, Yue Ming; Chen, Fei Xiang; Zhang, Rui

    2018-05-01

    The heavy metals in soil have serious impacts on safety, ecological environment and human health due to their toxicity and accumulation. It is necessary to efficiently identify the risk area of heavy metals in farmland soil, which is of important significance for environment protection, pollution warning and farmland risk control. We collected 204 samples and analyzed the contents of seven kinds of heavy metals (Cu, Zn, Pb, Cd, Cr, As, Hg) in Zengcheng District of Guangzhou, China. In order to overcame the problems of the data, including the limitation of abnormal values and skewness distribution and the smooth effect with the traditional kriging methods, we used sequential indicator simulation method (SISIM) to define the spatial distribution of heavy metals, and combined Hakanson index method to identify potential ecological risk area of heavy metals in farmland. The results showed that: (1) Based on the similar accuracy of spatial prediction of soil heavy metals, the SISIM had a better expression of detail rebuild than ordinary kriging in small scale area. Compared to indicator kriging, the SISIM had less error rate (4.9%-17.1%) in uncertainty evaluation of heavy-metal risk identification. The SISIM had less smooth effect and was more applicable to simulate the spatial uncertainty assessment of soil heavy metals and risk identification. (2) There was no pollution in Zengcheng's farmland. Moderate potential ecological risk was found in the southern part of study area due to enterprise production, human activities, and river sediments. This study combined the sequential indicator simulation with Hakanson risk index method, and effectively overcame the outlier information loss and smooth effect of traditional kriging method. It provided a new way to identify the soil heavy metal risk area of farmland in uneven sampling.

  13. 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.

  14. 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

  15. Coupling surfactants with permanganate for DNAPL removal : coinjection or sequential application as delivery methods

    Energy Technology Data Exchange (ETDEWEB)

    Dugan, P.J. [Carus Corp., Peru, IL (United States); Siegrist, R.L. [Colorado School of Mines, Golden, CO (United States); Crimi, M.L. [Clarkson Univ., Potsdam, NY (United States)

    2010-07-01

    This PowerPoint presentation described a study conducted to test the effectiveness of surfactant-enhanced permanganate for the remediation of dense nonaqueous phase liquids (DNAPL). When DNAPL enters the environment, it can pollute millions of gallons of ground water and create huge dissolved plumes that act as long-term sources of contamination. Surfactants were used to enhance the solubilization and mobilization of DNAPL during the remediation process. In situ chemical oxidation (ISCO) was then used to deliver oxidants into the sub-surface to destroy organic contaminants in the soil and ground water. Experimental 2-D flow-through cell studies of 72 surfactants were conducted with the permanganate to evaluate delivery methods and determine compatible co-solvents for the surfactant process. Delivery methods included co-injection and sequential application. Four compatible surfactants were found to be compatible with the permanganate. A 90 percent DNAPL remediation rate was achieved using relatively low surfactant and oxidant concentrations. tabs., figs.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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...

  1. a method of gravity and seismic sequential inversion and its GPU implementation

    Science.gov (United States)

    Liu, G.; Meng, X.

    2011-12-01

    In this abstract, we introduce a gravity and seismic sequential inversion method to invert for density and velocity together. For the gravity inversion, we use an iterative method based on correlation imaging algorithm; for the seismic inversion, we use the full waveform inversion. The link between the density and velocity is an empirical formula called Gardner equation, for large volumes of data, we use the GPU to accelerate the computation. For the gravity inversion method , we introduce a method based on correlation imaging algorithm,it is also a interative method, first we calculate the correlation imaging of the observed gravity anomaly, it is some value between -1 and +1, then we multiply this value with a little density ,this value become the initial density model. We get a forward reuslt with this initial model and also calculate the correaltion imaging of the misfit of observed data and the forward data, also multiply the correaltion imaging result a little density and add it to the initial model, then do the same procedure above , at last ,we can get a inversion density model. For the seismic inveron method ,we use a mothod base on the linearity of acoustic wave equation written in the frequency domain,with a intial velociy model, we can get a good velocity result. In the sequential inversion of gravity and seismic , we need a link formula to convert between density and velocity ,in our method , we use the Gardner equation. Driven by the insatiable market demand for real time, high-definition 3D images, the programmable NVIDIA Graphic Processing Unit (GPU) as co-processor of CPU has been developed for high performance computing. Compute Unified Device Architecture (CUDA) is a parallel programming model and software environment provided by NVIDIA designed to overcome the challenge of using traditional general purpose GPU while maintaining a low learn curve for programmers familiar with standard programming languages such as C. In our inversion processing

  2. A Sequential Kriging reliability analysis method with characteristics of adaptive sampling regions and parallelizability

    International Nuclear Information System (INIS)

    Wen, Zhixun; Pei, Haiqing; Liu, Hai; Yue, Zhufeng

    2016-01-01

    The sequential Kriging reliability analysis (SKRA) method has been developed in recent years for nonlinear implicit response functions which are expensive to evaluate. This type of method includes EGRA: the efficient reliability analysis method, and AK-MCS: the active learning reliability method combining Kriging model and Monte Carlo simulation. The purpose of this paper is to improve SKRA by adaptive sampling regions and parallelizability. The adaptive sampling regions strategy is proposed to avoid selecting samples in regions where the probability density is so low that the accuracy of these regions has negligible effects on the results. The size of the sampling regions is adapted according to the failure probability calculated by last iteration. Two parallel strategies are introduced and compared, aimed at selecting multiple sample points at a time. The improvement is verified through several troublesome examples. - Highlights: • The ISKRA method improves the efficiency of SKRA. • Adaptive sampling regions strategy reduces the number of needed samples. • The two parallel strategies reduce the number of needed iterations. • The accuracy of the optimal value impacts the number of samples significantly.

  3. THE FACE EXTRACTION METHOD FOR MOBILE DEVICES

    Directory of Open Access Journals (Sweden)

    Viktor Borodin

    2013-10-01

    Full Text Available Normal 0 false false false MicrosoftInternetExplorer4 The problem of automatic face recognition on images is considered. The method of face ellipse extraction from photo and methods for face special points extraction are proposed /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Обычная таблица"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;}

  4. Alternative perspectives of safety in home delivered health care: a sequential exploratory mixed method study.

    Science.gov (United States)

    Jones, Sarahjane

    2016-10-01

    The aim of this study was to discover and describe how patients, carers and case management nurses define safety and compare it to the traditional risk reduction and harm avoidance definition of safety. Care services are increasingly being delivered in the home for patients with complex long-term conditions. However, the concept of safety remains largely unexplored. A sequential, exploratory mixed method design. A qualitative case study of the UK National Health Service case management programme in the English UK National Health Service was deployed during 2012. Thirteen interviews were conducted with patients (n = 9) and carers (n = 6) and three focus groups with nurses (n = 17) from three community care providers. The qualitative element explored the definition of safety. Data were subjected to framework analysis and themes were identified by participant group. Sequentially, a cross-sectional survey was conducted during 2013 in a fourth community care provider (patient n = 35, carer n = 19, nurse n = 26) as a form of triangulation. Patients and carers describe safety differently to case management nurses, choosing to focus on meeting needs. They use more positive language and recognize the role they have in safety in home-delivered health care. In comparison, case management nurses described safety similarly to the definitions found in the literature. However, when offered the patient and carer definition of safety, they preferentially selected this definition to their own or the literature definition. Patients and carers offer an alternative perspective on patient safety in home-delivered health care that identifies their role in ensuring safety and is more closely aligned with the empowerment philosophy of case management. © 2016 John Wiley & Sons Ltd.

  5. Automated magnetic sorbent extraction based on octadecylsilane functionalized maghemite magnetic particles in a sequential injection system coupled with electrothermal atomic absorption spectrometry for metal determination.

    Science.gov (United States)

    Giakisikli, Georgia; Anthemidis, Aristidis N

    2013-06-15

    A new automatic sequential injection (SI) system for on-line magnetic sorbent extraction coupled with electrothermal atomic absorption spectrometry (ETAAS) has been successfully developed for metal determination. In this work, we reported effective on-line immobilization of magnetic silica particles into a microcolumn by the external force of two strong neodymium iron boron (NdFeB) magnets across it, avoiding the use of frits. Octadecylsilane functionalized maghemite magnetic particles were used as sorbent material. The potentials of the system were demonstrated for trace cadmium determination in water samples. The method was based on the on-line complex formation with diethyldithiocarbamate (DDTC), retention of Cd-DDTC on the surface of the MPs and elution with isobutyl methyl ketone (IBMK). The formation mechanism of the magnetic solid phase packed column and all critical parameters (chemical, flow, graphite furnace) influencing the performance of the system were optimized and offered good analytical characteristics. For 5 mL sample volume, a detection limit of 3 ng L(-1), a relative standard deviation of 3.9% at 50 ng L(-1) level (n=11) and a linear range of 9-350 ng L(-1) were obtained. The column remained stable for more than 600 cycles keeping the cost down in routine analysis. The proposed method was evaluated by analyzing certified reference materials and natural waters. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. 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...

  7. The facilitators and barriers to nurses' participation in continuing education programs: a mixed method explanatory sequential study.

    Science.gov (United States)

    Shahhosseini, Zohreh; Hamzehgardeshi, Zeinab

    2014-11-30

    Since several factors affect nurses' participation in Continuing Education, and that nurses' Continuing Education affects patients' and community health status, it is essential to know facilitators and barriers of participation in Continuing Education programs and plan accordingly. This mixed approach study aimed to investigate the facilitators and barriers of nurses' participation, to explore nurses' perception of the most common facilitators and barriers. An explanatory sequential mixed methods design with follow up explanations variant were used, and it involved collecting quantitative data (361 nurses) first and then explaining the quantitative results with in-depth interviews during a qualitative study. The results showed that the mean score of facilitators to nurses' participation in Continuing Education was significantly higher than the mean score of barriers (61.99 ± 10.85 versus 51.17 ± 12.83; pEducation was related to "Update my knowledge". By reviewing the handwritings in qualitative phase, two main levels of updating information and professional skills were extracted as the most common facilitators and lack of support as the most common barrier to nurses' participation in continuing education program. According to important role Continuing Education on professional skills, nurse managers should facilitate the nurse' participation in the Continues Education.

  8. Method for Extracting and Sequestering Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Rau, Gregory H.; Caldeira, Kenneth G.

    2005-05-10

    A method and apparatus to extract and sequester carbon dioxide (CO2) from a stream or volume of gas wherein said method and apparatus hydrates CO2, and reacts the resulting carbonic acid with carbonate. Suitable carbonates include, but are not limited to, carbonates of alkali metals and alkaline earth metals, preferably carbonates of calcium and magnesium. Waste products are metal cations and bicarbonate in solution or dehydrated metal salts, which when disposed of in a large body of water provide an effective way of sequestering CO2 from a gaseous environment.

  9. 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)

  10. Enhanced Silver Nanoparticle Chemiluminescence Method for the Determination of Gemifloxacin Mesylate using Sequential Injection Analysis

    International Nuclear Information System (INIS)

    Alarfaj, N.A.; Aly, F.A.; Tamimi, A.A.

    2013-01-01

    A sequential injection analysis (SIA) with chemiluminescence detection has been proposed for the determination of the antibiotic gemifloxacin mesylate (GFX). The developed method is based on the enhancement effect of silver nanoparticles (Ag NPs) on the chemiluminescence (CL) signal of luminol-potassium ferricyanide reaction in alkaline medium. The introduction of gemifloxacin in this system produced a significant decrease in the CL intensity in presence of (Ag NPs). The optimum conditions for CL emission were investigated. Linear relationship between the decrease in CL intensity and concentration was obtained in the range 0.01-1000 ng mL-1, (r = 0.9997) with detection limit of 2.0 pg mL-1 and quantification limit of 0.01 pg mL-1. The relative standard deviation was 1.3 %. The proposed method was employed for the determination of gemifloxacin in bulk drug, in its pharmaceutical dosage forms and biological fluids such as human serum and urine. The interference of some common additive compounds such as glucose, lactose, starch, talc and magnesium stearate was investigated, and no interference was found from these excipients. The obtained SIA results were statistically compared with those obtained from a reported method and did not show any significant difference at confidence level 95%. (author)

  11. Simple, miniaturized blood plasma extraction method.

    Science.gov (United States)

    Kim, Jin-Hee; Woenker, Timothy; Adamec, Jiri; Regnier, Fred E

    2013-12-03

    A rapid plasma extraction technology that collects a 2.5 μL aliquot of plasma within three minutes from a finger-stick derived drop of blood was evaluated. The utility of the plasma extraction cards used was that a paper collection disc bearing plasma was produced that could be air-dried in fifteen minutes and placed in a mailing envelop for transport to an analytical laboratory. This circumvents the need for venipuncture and blood collection in specialized vials by a phlebotomist along with centrifugation and refrigerated storage. Plasma extraction was achieved by applying a blood drop to a membrane stack through which plasma was drawn by capillary action. During the course of plasma migration to a collection disc at the bottom of the membrane stack blood cells were removed by a combination of adsorption and filtration. After the collection disc filled with an aliquot of plasma the upper membranes were stripped from the collection card and the collection disc was air-dried. Intercard differences in the volume of plasma collected varied approximately 1% while volume variations of less than 2% were seen with hematocrit levels ranging from 20% to 71%. Dried samples bearing metabolites and proteins were then extracted from the disc and analyzed. 25-Hydroxy vitamin D was quantified by LC-MS/MS analysis following derivatization with a secosteroid signal enhancing tag that imparted a permanent positive charge to the vitamin and reduced the limit of quantification (LOQ) to 1 pg of collected vitamin on the disc; comparable to values observed with liquid-liquid extraction (LLE) of a venipuncture sample. A similar study using conventional proteomics methods and spectral counting for quantification was conducted with yeast enolase added to serum as an internal standard. The LOQ with extracted serum samples for enolase was 1 μM, linear from 1 to 40 μM, the highest concentration examined. In all respects protein quantification with extracted serum samples was comparable to

  12. 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

  13. Influence of extraction methods on the hepatotoxicity of Azadirachta ...

    African Journals Online (AJOL)

    The influence of extraction methods: Cold aqueous (CA) hot aqueous (HA) and alcoholic extraction (AE) methods on the hepatotoxic effect of Azadirachta indica bark extract (ABC) was investigated using albino rats. A total of forty eight rats were divided into three groups of sixteen rats equally for the extraction methods.

  14. About a sequential method for non destructive testing of structures by mechanical vibrations

    International Nuclear Information System (INIS)

    Suarez Antola, R.

    2001-01-01

    The presence and growth of cracks voids or fields of pores under applied forces or environmental actions can produce a meaningful lowering in the proper frequencies of normal modes of mechanical vibration in structures.A quite general expression for the square of modes proper frequency as a functional of displacement field,density field and elastic moduli fields is used as a starting point.The effect of defects on frequency are modeled as equivalent changes in density and elastic moduli fields,introducing the concept of region of influence of each defect.An approximate expression is obtained which relates the relative lowering in the square of modes proper frequency with position,size,shape and orientation of defects in mode displacement field.Some simple examples of structural elements with cracks or fields of pores are considered.the connection with linear elastic fracture mechanics is briefly exemplified.A sequential method is proposed for non-destructive testing of structures using mechanical vibrations combined with properly chosen local nondestructive testing methods

  15. Improving multiple-point-based a priori models for inverse problems by combining Sequential Simulation with the Frequency Matching Method

    DEFF Research Database (Denmark)

    Cordua, Knud Skou; Hansen, Thomas Mejer; Lange, Katrine

    In order to move beyond simplified covariance based a priori models, which are typically used for inverse problems, more complex multiple-point-based a priori models have to be considered. By means of marginal probability distributions ‘learned’ from a training image, sequential simulation has...... proven to be an efficient way of obtaining multiple realizations that honor the same multiple-point statistics as the training image. The frequency matching method provides an alternative way of formulating multiple-point-based a priori models. In this strategy the pattern frequency distributions (i.......e. marginals) of the training image and a subsurface model are matched in order to obtain a solution with the same multiple-point statistics as the training image. Sequential Gibbs sampling is a simulation strategy that provides an efficient way of applying sequential simulation based algorithms as a priori...

  16. A method for multiple sequential analyses of macrophage functions using a small single cell sample

    Directory of Open Access Journals (Sweden)

    F.R.F. Nascimento

    2003-09-01

    Full Text Available Microbial pathogens such as bacillus Calmette-Guérin (BCG induce the activation of macrophages. Activated macrophages can be characterized by the increased production of reactive oxygen and nitrogen metabolites, generated via NADPH oxidase and inducible nitric oxide synthase, respectively, and by the increased expression of major histocompatibility complex class II molecules (MHC II. Multiple microassays have been developed to measure these parameters. Usually each assay requires 2-5 x 10(5 cells per well. In some experimental conditions the number of cells is the limiting factor for the phenotypic characterization of macrophages. Here we describe a method whereby this limitation can be circumvented. Using a single 96-well microassay and a very small number of peritoneal cells obtained from C3H/HePas mice, containing as little as <=2 x 10(5 macrophages per well, we determined sequentially the oxidative burst (H2O2, nitric oxide production and MHC II (IAk expression of BCG-activated macrophages. More specifically, with 100 µl of cell suspension it was possible to quantify H2O2 release and nitric oxide production after 1 and 48 h, respectively, and IAk expression after 48 h of cell culture. In addition, this microassay is easy to perform, highly reproducible and more economical.

  17. A Generalizable Top-Down Nanostructuring Method of Bulk Oxides: Sequential Oxygen-Nitrogen Exchange Reaction.

    Science.gov (United States)

    Lee, Lanlee; Kang, Byungwuk; Han, Suyoung; Kim, Hee-Eun; Lee, Moo Dong; Bang, Jin Ho

    2018-05-27

    A thermal reaction route that induces grain fracture instead of grain growth is devised and developed as a top-down approach to prepare nanostructured oxides from bulk solids. This novel synthesis approach, referred to as the sequential oxygen-nitrogen exchange (SONE) reaction, exploits the reversible anion exchange between oxygen and nitrogen in oxides that is driven by a simple two-step thermal treatment in ammonia and air. Internal stress developed by significant structural rearrangement via the formation of (oxy)nitride and the creation of oxygen vacancies and their subsequent combination into nanopores transforms bulk solid oxides into nanostructured oxides. The SONE reaction can be applicable to most transition metal oxides, and when utilized in a lithium-ion battery, the produced nanostructured materials are superior to their bulk counterparts and even comparable to those produced by conventional bottom-up approaches. Given its simplicity and scalability, this synthesis method could open a new avenue to the development of high-performance nanostructured electrode materials that can meet the industrial demand of cost-effectiveness for mass production. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Sequential multi-nuclide emission rate estimation method based on gamma dose rate measurement for nuclear emergency management

    International Nuclear Information System (INIS)

    Zhang, Xiaole; Raskob, Wolfgang; Landman, Claudia; Trybushnyi, Dmytro; Li, Yu

    2017-01-01

    Highlights: • Sequentially reconstruct multi-nuclide emission using gamma dose rate measurements. • Incorporate a priori ratio of nuclides into the background error covariance matrix. • Sequentially augment and update the estimation and the background error covariance. • Suppress the generation of negative estimations for the sequential method. • Evaluate the new method with twin experiments based on the JRODOS system. - Abstract: In case of a nuclear accident, the source term is typically not known but extremely important for the assessment of the consequences to the affected population. Therefore the assessment of the potential source term is of uppermost importance for emergency response. A fully sequential method, derived from a regularized weighted least square problem, is proposed to reconstruct the emission and composition of a multiple-nuclide release using gamma dose rate measurement. The a priori nuclide ratios are incorporated into the background error covariance (BEC) matrix, which is dynamically augmented and sequentially updated. The negative estimations in the mathematical algorithm are suppressed by utilizing artificial zero-observations (with large uncertainties) to simultaneously update the state vector and BEC. The method is evaluated by twin experiments based on the JRodos system. The results indicate that the new method successfully reconstructs the emission and its uncertainties. Accurate a priori ratio accelerates the analysis process, which obtains satisfactory results with only limited number of measurements, otherwise it needs more measurements to generate reasonable estimations. The suppression of negative estimation effectively improves the performance, especially for the situation with poor a priori information, where it is more prone to the generation of negative values.

  19. Sequential multi-nuclide emission rate estimation method based on gamma dose rate measurement for nuclear emergency management

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiaole, E-mail: zhangxiaole10@outlook.com [Institute for Nuclear and Energy Technologies, Karlsruhe Institute of Technology, Karlsruhe, D-76021 (Germany); Institute of Public Safety Research, Department of Engineering Physics, Tsinghua University, Beijing, 100084 (China); Raskob, Wolfgang; Landman, Claudia; Trybushnyi, Dmytro; Li, Yu [Institute for Nuclear and Energy Technologies, Karlsruhe Institute of Technology, Karlsruhe, D-76021 (Germany)

    2017-03-05

    Highlights: • Sequentially reconstruct multi-nuclide emission using gamma dose rate measurements. • Incorporate a priori ratio of nuclides into the background error covariance matrix. • Sequentially augment and update the estimation and the background error covariance. • Suppress the generation of negative estimations for the sequential method. • Evaluate the new method with twin experiments based on the JRODOS system. - Abstract: In case of a nuclear accident, the source term is typically not known but extremely important for the assessment of the consequences to the affected population. Therefore the assessment of the potential source term is of uppermost importance for emergency response. A fully sequential method, derived from a regularized weighted least square problem, is proposed to reconstruct the emission and composition of a multiple-nuclide release using gamma dose rate measurement. The a priori nuclide ratios are incorporated into the background error covariance (BEC) matrix, which is dynamically augmented and sequentially updated. The negative estimations in the mathematical algorithm are suppressed by utilizing artificial zero-observations (with large uncertainties) to simultaneously update the state vector and BEC. The method is evaluated by twin experiments based on the JRodos system. The results indicate that the new method successfully reconstructs the emission and its uncertainties. Accurate a priori ratio accelerates the analysis process, which obtains satisfactory results with only limited number of measurements, otherwise it needs more measurements to generate reasonable estimations. The suppression of negative estimation effectively improves the performance, especially for the situation with poor a priori information, where it is more prone to the generation of negative values.

  20. A comparison of five extraction methods for extracellular polymeric ...

    African Journals Online (AJOL)

    Two physical methods (centrifugation and ultrasonication) and 3 chemical methods (extraction with EDTA, extraction with formaldehyde, and extraction with formaldehyde plus NaOH) for extraction of EPS from alga-bacteria biofilm were assessed. Pretreatment with ultrasound at low intensity doubled the EPS yield without ...

  1. A comparative study of Averrhoabilimbi extraction method

    Science.gov (United States)

    Zulhaimi, H. I.; Rosli, I. R.; Kasim, K. F.; Akmal, H. Muhammad; Nuradibah, M. A.; Sam, S. T.

    2017-09-01

    In recent year, bioactive compound in plant has become a limelight in the food and pharmaceutical market, leading to research interest to implement effective technologies for extracting bioactive substance. Therefore, this study is focusing on extraction of Averrhoabilimbi by different extraction technique namely, maceration and ultrasound-assisted extraction. Fewplant partsof Averrhoabilimbiweretaken as extraction samples which are fruits, leaves and twig. Different solvents such as methanol, ethanol and distilled water were utilized in the process. Fruit extractsresult in highest extraction yield compared to other plant parts. Ethanol and distilled water have significant role compared to methanol in all parts and both extraction technique. The result also shows that ultrasound-assisted extraction gave comparable result with maceration. Besides, the shorter period on extraction process gives useful in term of implementation to industries.

  2. [Sequential degradation of p-cresol by photochemical and biological methods].

    Science.gov (United States)

    Karetnikova, E A; Chaĭkovskaia, O N; Sokolova, I V; Nikitina, L I

    2008-01-01

    Sequential photo- and biodegradation of p-cresol was studied using a mercury lamp, as well as KrCl and XeCl excilamps. Preirradiation of p-cresol at a concentration of 10(-4) M did not affect the rate of its subsequent biodegradation. An increase in the concentration of p-cresol to 10(-3) M and in the duration preliminary UV irradiation inhibited subsequent biodegradation. Biodegradation of p-cresol was accompanied by the formation of a product with a fluorescence maximum at 365 nm (lambdaex 280 nm), and photodegradation yielded a compound fluorescing at 400 nm (lambdaex 330 nm). Sequential UV and biodegradation led to the appearance of bands in the fluorescence spectra that were ascribed to p-cresol and its photolysis products. It was shown that sequential use of biological and photochemical degradation results in degradation of not only the initial toxicant but also the metabolites formed during its biodegradation.

  3. 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

  4. Haemodialysis work environment contributors to job satisfaction and stress: a sequential mixed methods study.

    Science.gov (United States)

    Hayes, Bronwyn; Bonner, Ann; Douglas, Clint

    2015-01-01

    Haemodialysis nurses form long term relationships with patients in a technologically complex work environment. Previous studies have highlighted that haemodialysis nurses face stressors related to the nature of their work and also their work environments leading to reported high levels of burnout. Using Kanters (1997) Structural Empowerment Theory as a guiding framework, the aim of this study was to explore the factors contributing to satisfaction with the work environment, job satisfaction, job stress and burnout in haemodialysis nurses. Using a sequential mixed-methods design, the first phase involved an on-line survey comprising demographic and work characteristics, Brisbane Practice Environment Measure (B-PEM), Index of Work Satisfaction (IWS), Nursing Stress Scale (NSS) and the Maslach Burnout Inventory (MBI). The second phase involved conducting eight semi-structured interviews with data thematically analyzed. From the 417 nurses surveyed the majority were female (90.9 %), aged over 41 years of age (74.3 %), and 47.4 % had worked in haemodialysis for more than 10 years. Overall the work environment was perceived positively and there was a moderate level of job satisfaction. However levels of stress and emotional exhaustion (burnout) were high. Two themes, ability to care and feeling successful as a nurse, provided clarity to the level of job satisfaction found in phase 1. While two further themes, patients as quasi-family and intense working teams, explained why working as a haemodialysis nurse was both satisfying and stressful. Nurse managers can use these results to identify issues being experienced by haemodialysis nurses working in the unit they are supervising.

  5. Extraction Methods for the Isolation of Isoflavonoids from Plant Material

    Directory of Open Access Journals (Sweden)

    Blicharski Tomasz

    2017-03-01

    Full Text Available The purpose of this review is to describe and compare selected traditional and modern extraction methods employed in the isolation of isoflavonoids from plants. Conventional methods such as maceration, percolation, or Soxhlet extraction are still frequently used in phytochemical analysis. Despite their flexibility, traditional extraction techniques have significant drawbacks, including the need for a significant investment of time, energy, and starting material, and a requirement for large amounts of potentially toxic solvents. Moreover, these techniques are difficult to automate, produce considerable amount of waste and pose a risk of degradation of thermolabile compounds. Modern extraction methods, such as: ultrasound-assisted extraction, microwave-assisted extraction, accelerated solvent extraction, supercritical fluid extraction, and negative pressure cavitation extraction, can be regarded as remedies for the aforementioned problems. This manuscript discusses the use of the most relevant extraction techniques in the process of isolation of isoflavonoids, secondary metabolites that have been found to have a plethora of biological and pharmacological activities.

  6. Implementing Quality Criteria in Designing and Conducting a Sequential Quan [right arrow] Qual Mixed Methods Study of Student Engagement with Learning Applied Research Methods Online

    Science.gov (United States)

    Ivankova, Nataliya V.

    2014-01-01

    In spite of recent methodological developments related to quality assurance in mixed methods research, practical examples of how to implement quality criteria in designing and conducting sequential QUAN [right arrow] QUAL mixed methods studies to ensure the process is systematic and rigorous remain scarce. This article discusses a three-step…

  7. On the equivalence of optimality criterion and sequential approximate optimization methods in the classical layout problem

    NARCIS (Netherlands)

    Groenwold, A.A.; Etman, L.F.P.

    2008-01-01

    We study the classical topology optimization problem, in which minimum compliance is sought, subject to linear constraints. Using a dual statement, we propose two separable and strictly convex subproblems for use in sequential approximate optimization (SAO) algorithms.Respectively, the subproblems

  8. Development of sequential analytical method for the determination of U-238, U-234, Th-232, Th-230, Th-228, Ra-226 and Ra-228 and its application in mineral waters

    International Nuclear Information System (INIS)

    Costa Lauria, D. da.

    1986-01-01

    A sequential analytical method for the determination of U-238, U-234, Th-232, Th-230, Th-228, Ra-226 and Ra-228 in environmental samples and applied to the analysis of mineral waters is studied. Thorium isotopes are coprecipitated with lanthanium fluoride before counting in alpha spectrometer, the uranium isotopes are determined by alpha spectrometry following extraction with TOPO onto a polymenic membrane. Radium-226 is determined with the radom emanation technique. (M.J.C.) [pt

  9. 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...

  10. Full-Color LCD Microdisplay System Based on OLED Backlight Unit and Field-Sequential Color Driving Method

    Directory of Open Access Journals (Sweden)

    Sungho Woo

    2011-01-01

    Full Text Available We developed a single-panel LCD microdisplay system using a field-sequential color (FSC driving method and an organic light-emitting diode (OLED as a backlight unit (BLU. The 0.76′′ OLED BLU with red, green, and blue (RGB colors was fabricated by a conventional UV photolithography patterning process and by vacuum deposition of small molecule organic layers. The field-sequential driving frequency was set to 255 Hz to allow each of the RGB colors to be generated without color mixing at the given display frame rate. A prototype FSC LCD microdisplay system consisting of a 0.7′′ LCD microdisplay panel and the 0.76′′ OLED BLU successfully exhibited color display and moving picture images using the FSC driving method.

  11. 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:

  12. Application of a modified BCR sequential extraction (three-step) procedure for the determination of extractable trace metal contents in a sewage sludge amended soil reference material (CRM 483), complemented by a three-year stability study of acetic acid and EDTA extractable metal content.

    Science.gov (United States)

    Rauret, G; López-Sánchez, J F; Sahuquillo, A; Barahona, E; Lachica, M; Ure, A M; Davidson, C M; Gomez, A; Lück, D; Bacon, J; Yli-Halla, M; Muntau, H; Quevauviller, P

    2000-06-01

    This paper provides additional data on a sewage sludge amended soil certified reference material, CRM 483, which was certified in 1997 for its EDTA and acetic acid extractable contents of some trace metals, following standardised extraction procedures. The additional work aimed to test the long-term stability of the material and the applicability of an improved version of the BCR three-step sequential extraction procedure on the sewage sludge amended soil (CRM 483). The paper demonstrates the CRM 483 long-term stability for EDTA and acetic acid extractable contents of Cd, Cr, Cu, Ni, Pb and Zn and gives the results (obtained in the framework of an interlaboratory study) for the extractable contents of the same elements in the CRM 483, following the BCR three-step sequential extraction scheme. The aqua regia extractable contents following the ISO 11466 Standard are also given. The data are given as indicative (not certified) values.

  13. Secretome data from Trichoderma reesei and Aspergillus niger cultivated in submerged and sequential fermentation methods

    Directory of Open Access Journals (Sweden)

    Camila Florencio

    2016-09-01

    Full Text Available The cultivation procedure and the fungal strain applied for enzyme production may influence levels and profile of the proteins produced. The proteomic analysis data presented here provide critical information to compare proteins secreted by Trichoderma reesei and Aspergillus niger when cultivated through submerged and sequential fermentation processes, using steam-explosion sugarcane bagasse as inducer for enzyme production. The proteins were organized according to the families described in CAZy database as cellulases, hemicellulases, proteases/peptidases, cell-wall-protein, lipases, others (catalase, esterase, etc., glycoside hydrolases families, predicted and hypothetical proteins. Further detailed analysis of this data is provided in “Secretome analysis of Trichoderma reesei and Aspergillus niger cultivated by submerged and sequential fermentation process: enzyme production for sugarcane bagasse hydrolysis” C. Florencio, F.M. Cunha, A.C Badino, C.S. Farinas, E. Ximenes, M.R. Ladisch (2016 [1]. Keywords: Tricoderma reesei, Aspergillus Niger, Enzyme Production, Secretome

  14. Sequential method for the assessment of innovations in computer assisted industrial processes; Metodo secuencial para evaluacion de innovaciones en procesos industriales asistido por computadora

    Energy Technology Data Exchange (ETDEWEB)

    Suarez Antola, R [Universidad Catolica del Uruguay, Montevideo (Uruguay); Artucio, G [Ministerio de Industria Energia y Mineria. Direccion Nacional de Tecnologia Nuclear, Montevideo (Uruguay)

    1995-08-01

    A sequential method for the assessment of innovations in industrial processes is proposed, using suitable combinations of mathematical modelling and numerical simulation of dynamics. Some advantages and limitations of the proposed method are discussed. tabs.

  15. Simulation based sequential Monte Carlo methods for discretely observed Markov processes

    OpenAIRE

    Neal, Peter

    2014-01-01

    Parameter estimation for discretely observed Markov processes is a challenging problem. However, simulation of Markov processes is straightforward using the Gillespie algorithm. We exploit this ease of simulation to develop an effective sequential Monte Carlo (SMC) algorithm for obtaining samples from the posterior distribution of the parameters. In particular, we introduce two key innovations, coupled simulations, which allow us to study multiple parameter values on the basis of a single sim...

  16. Online sequential condition prediction method of natural circulation systems based on EOS-ELM and phase space reconstruction

    International Nuclear Information System (INIS)

    Chen, Hanying; Gao, Puzhen; Tan, Sichao; Tang, Jiguo; Yuan, Hongsheng

    2017-01-01

    Highlights: •An online condition prediction method for natural circulation systems in NPP was proposed based on EOS-ELM. •The proposed online prediction method was validated using experimental data. •The training speed of the proposed method is significantly fast. •The proposed method can achieve good accuracy in wide parameter range. -- Abstract: Natural circulation design is widely used in the passive safety systems of advanced nuclear power reactors. The irregular and chaotic flow oscillations are often observed in boiling natural circulation systems so it is difficult for operators to monitor and predict the condition of these systems. An online condition forecasting method for natural circulation system is proposed in this study as an assisting technique for plant operators. The proposed prediction approach was developed based on Ensemble of Online Sequential Extreme Learning Machine (EOS-ELM) and phase space reconstruction. Online Sequential Extreme Learning Machine (OS-ELM) is an online sequential learning neural network algorithm and EOS-ELM is the ensemble method of it. The proposed condition prediction method can be initiated by a small chunk of monitoring data and it can be updated by newly arrived data at very fast speed during the online prediction. Simulation experiments were conducted on the data of two natural circulation loops to validate the performance of the proposed method. The simulation results show that the proposed predication model can successfully recognize different types of flow oscillations and accurately forecast the trend of monitored plant variables. The influence of the number of hidden nodes and neural network inputs on prediction performance was studied and the proposed model can achieve good accuracy in a wide parameter range. Moreover, the comparison results show that the proposed condition prediction method has much faster online learning speed and better prediction accuracy than conventional neural network model.

  17. Comparative study of methods for extraction and purification of ...

    African Journals Online (AJOL)

    USER

    2010-08-02

    Aug 2, 2010 ... and or enzymatic lysis for direct or indirect extraction of. DNA followed by ... strength wastewater sludge in order to determine the best. DNA extraction protocol ... Ammonium acetate purification method was used to remove the.

  18. 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.

  19. Optimization of the analysis by means of liquid chromatography of metabolites of the Uncaria Tomentosa plant (cat's claw) using the sequential simplex method

    International Nuclear Information System (INIS)

    Romero Blanco, Eric

    2005-01-01

    A new method was developed for the analysis using liquid chromatography of the metabolites present in extracts of root bark of Uncaria Tomentosa (cat's claw) by applying the simplex sequential technique to determine the magnitude of the chromatographic variables; i.e. flow, temperature and stationary-phase composition, which allowed the optimizing the elusion time and the resolution of the chromatographic separation. The chromatographic analysis was performed in isocratic mode using a C12 (-urea) column of 15 cm in length and 4,6 mm of diameter and a UV detector. The magnitude of the chromatographic variables that optimized the separation turned out to be: flow of 1.80 mL/min, temperature of 27.5 centigrade and a mobile phase composition of 22:78 (Methanol: to butter). (Author) [es

  20. A comparison of sequential and information-based methods for determining the co-integration rank in heteroskedastic VAR MODELS

    DEFF Research Database (Denmark)

    Cavaliere, Giuseppe; Angelis, Luca De; Rahbek, Anders

    2015-01-01

    In this article, we investigate the behaviour of a number of methods for estimating the co-integration rank in VAR systems characterized by heteroskedastic innovation processes. In particular, we compare the efficacy of the most widely used information criteria, such as Akaike Information Criterion....... The relative finite-sample properties of the different methods are investigated by means of a Monte Carlo simulation study. For the simulation DGPs considered in the analysis, we find that the BIC-based procedure and the bootstrap sequential test procedure deliver the best overall performance in terms......-based method to over-estimate the co-integration rank in relatively small sample sizes....

  1. System and method for free-boundary surface extraction

    KAUST Repository

    Algarni, Marei

    2017-10-26

    A method of extracting surfaces in three-dimensional data includes receiving as inputs three-dimensional data and a seed point p located on a surface to be extracted. The method further includes propagating a front outwardly from the seed point p and extracting a plurality of ridge curves based on the propagated front. A surface boundary is detected based on a comparison of distances between adjacent ridge curves and the desired surface is extracted based on the detected surface boundary.

  2. A Practical Framework for Evaluating Health Services Management Educational Program: The Application of The Mixed-Method Sequential Explanatory Design

    Directory of Open Access Journals (Sweden)

    Bazrafshan Azam

    2015-07-01

    Full Text Available Introduction:Health services managers are responsible for improving the efficiency and quality in delivering healthcare services. In this regard, Health Services Management (HSM programs have been widely established to provide health providers with skilled, professional managers to address those needs. It is therefore important to ascertain the quality of these programs. The purpose of this study was to synthesize and develop a framework to evaluate the quality of the Health Services Management (HSM program at Kerman University of Medical Sciences. Methods: This study followed a mixed-method sequential explanatory approach in which data were collected through a CIPP survey and semi-structured interviews. In phase 1, participants included 10 faculty members, 64 students and 90 alumni. In phase 2, in-depth semi-structured interviews and purposeful sampling were conducted with 27 participants to better understand their perceptions of the HSM program. All interviews were audio-taped and transcribed verbatim. NVivo N8 was used to analyze the qualitative data and extract the themes. Results: The data analysis revealed both positive and negative attitudes toward the HSM program. According to the CIPP survey, program objectives (74%, curriculum content (59.5% and graduate skills (79% were the major sources of dissatisfaction. However, most respondents (n=48 reported that the classes are well equipped and learning resources are well prepared (n=41. Most respondents (n=41 reported that the students are actively involved in classroom activities. The majority of respondents (n=43 pointed out that the instructors implemented appropriate teaching strategies. Qualitative analysis of interviews revealed that a regular community needs assessment, content revision and directing attention to graduate skills and expertise are the key solutions to improve the program’s quality.Conclusion: This study revealed to what extent the HSM program objectives is being

  3. 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.

  4. Evolution of biogeochemical cycling of phosphorus during 45~50 Ma revealed by sequential extraction analysis of IODP Expedition 302 cores from the Arctic Ocean

    Science.gov (United States)

    Hashimoto, S.; Yamaguchi, K. E.; Takahashi, K.

    2012-12-01

    The modern Arctic Ocean plays crucial roles in controlling global climate system with the driving force of global thermohaline circulation through the formation of dense deep water and high albedo due to the presence of perennial sea-ice. However, the Arctic sea-ice has not always existed in the past. Integrated Ocean Drilling Program (IODP) Expedition 302 Arctic Coring Expedition (ACEX) has clarified that global warming (water temperature: ca. 14~16○C) during 48~49 Ma Azolla Event induced the loss of sea-ice and desalination of surface ocean, and that sea-ice formed again some million years later (45 Ma). In the Arctic Ocean, warming and cooling events repeated over and over (e.g., Brinkhuis et al., 2006; Moran et al., 2006; März et al., 2010). Large variations in the extent of thermohaline circulation through time often caused stagnation of seawater and appearance of anaerobic environment where hydrogen sulfide was produced by bacterial sulfate reduction. Ogawa et al. (2009) confirmed occurrence of framboidal pyrite in the ACEX sediments, and suggested that the Arctic Ocean at the time was anoxic, analogous to the modern Black Sea, mainly based on sulfur isotope analysis. To further clarify the variations in the nutrient status of the Arctic Ocean, we focus on the geochemical cycle of phosphorus. We performed sequential extraction analysis of sedimentary phosphorus in the ACEX sediments, using the method that we improvped based on the original SEDEX method by Ruttenberg (1992) and Schenau et al. (2000). In our method, phosphorus fractions are divided into five forms; (1) absorbed P, (2) Feoxide-P, (4) carbonate fluorapatite (CFAP) + CaCO3-P + hydroxylapatite (HAP), (4) detrital P, and (5) organic P. Schenau et al. (2000) divided the (3) fraction into non-biological CFAP and biological HAP and CaCO3-P. When the Arctic Ocean was closed and in its warming period, the water mass was most likely stratified and an anaerobic condition would have prevailed where

  5. Evaluation of urinary cortisol excretion by radioimmunoassay through two methods (extracted and non-extracted)

    International Nuclear Information System (INIS)

    Fonte Kohek, M.B. da; Mendonca, B.B. de; Nicolau, W.

    1993-01-01

    The objective of this paper is to compare the feasibility, sensitivity and specificity of both methods (extracted versus non-extracted) in the hypercortisolism diagnosis. It used Gamma Coat 125 cortisol Kit provided by Clinical Assays, Incstar, USA, for both methods extracting it with methylene chloride in order to measure the extracted cortisol. It was performed 32 assays from which it was obtained from 0.1 to 0.47 u g/d l of sensitivity. The intra-run precision was varied from 8.29 +- 3.38% and 8.19 +-4.72% for high and low levels, respectively for non-extracted cortisol, and 9.72 +- 1.94% and 9.54 +- 44% for high and low levels, respectively, for extracted cortisol. The inter-run precision was 15.98% and 16.15% for high level of non-extracted cortisol, respectively. For the low level it obtained 17.25% and 18.59% for non-extracted and extracted cortisol respectively. It was evaluated 24-hour urine basal samples from 43 normal subjects, and 53 obese (body mass index > 30) and 53 Cushing's syndrome patients. The sensitivity of the methods were similar (100% and 98.1% for non-extracted and extracted methods, respectively) and the specificity was the same for both methods (100%). It was noticed a positive correlation between the two methods in all the groups studied (p s syndrome. (author)

  6. Natural colorants: Pigment stability and extraction yield enhancement via utilization of appropriate pretreatment and extraction methods.

    Science.gov (United States)

    Ngamwonglumlert, Luxsika; Devahastin, Sakamon; Chiewchan, Naphaporn

    2017-10-13

    Natural colorants from plant-based materials have gained increasing popularity due to health consciousness of consumers. Among the many steps involved in the production of natural colorants, pigment extraction is one of the most important. Soxhlet extraction, maceration, and hydrodistillation are conventional methods that have been widely used in industry and laboratory for such a purpose. Recently, various non-conventional methods, such as supercritical fluid extraction, pressurized liquid extraction, microwave-assisted extraction, ultrasound-assisted extraction, pulsed-electric field extraction, and enzyme-assisted extraction have emerged as alternatives to conventional methods due to the advantages of the former in terms of smaller solvent consumption, shorter extraction time, and more environment-friendliness. Prior to the extraction step, pretreatment of plant materials to enhance the stability of natural pigments is another important step that must be carefully taken care of. In this paper, a comprehensive review of appropriate pretreatment and extraction methods for chlorophylls, carotenoids, betalains, and anthocyanins, which are major classes of plant pigments, is provided by using pigment stability and extraction yield as assessment criteria.

  7. The method for simultaneous extraction and back extraction in liquid three-phase system and equipment for simultaneous extraction and back extraction in liquid three-phase system

    International Nuclear Information System (INIS)

    Palyska, W.; Chmielewski, A.G.

    1992-01-01

    The method for simultaneous extraction and back extraction in liquid three-phase system has been worked out. The equipment designed for that process has been also subject of the patent. The interesting component is extracted first to intermediate phase consists of magnetic solvent keeping two extracting phases separately. The intermediate magnetic liquid has been kept in its position using a stable magnet maintained on the surface of the extraction vessel. Then the component pass from intermediate phase to the third phase as a result of back extraction. Mixing in the extraction and back extraction zones is organized by means of rotating shaft going along the whole apparatus. The extraction and back extraction processes occur simultaneously as a result of continuous flow of solvent in their zones. The single extraction back extraction facilities can be joined in larger batteries. 3 figs

  8. Social network extraction based on Web: 1. Related superficial methods

    Science.gov (United States)

    Khairuddin Matyuso Nasution, Mahyuddin

    2018-01-01

    Often the nature of something affects methods to resolve the related issues about it. Likewise, methods to extract social networks from the Web, but involve the structured data types differently. This paper reveals several methods of social network extraction from the same sources that is Web: the basic superficial method, the underlying superficial method, the description superficial method, and the related superficial methods. In complexity we derive the inequalities between methods and so are their computations. In this case, we find that different results from the same tools make the difference from the more complex to the simpler: Extraction of social network by involving co-occurrence is more complex than using occurrences.

  9. 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

  10. Optimization-based Method for Automated Road Network Extraction

    International Nuclear Information System (INIS)

    Xiong, D

    2001-01-01

    Automated road information extraction has significant applicability in transportation. It provides a means for creating, maintaining, and updating transportation network databases that are needed for purposes ranging from traffic management to automated vehicle navigation and guidance. This paper is to review literature on the subject of road extraction and to describe a study of an optimization-based method for automated road network extraction

  11. Steroid hormones in environmental matrices: extraction method comparison.

    Science.gov (United States)

    Andaluri, Gangadhar; Suri, Rominder P S; Graham, Kendon

    2017-11-09

    The U.S. Environmental Protection Agency (EPA) has developed methods for the analysis of steroid hormones in water, soil, sediment, and municipal biosolids by HRGC/HRMS (EPA Method 1698). Following the guidelines provided in US-EPA Method 1698, the extraction methods were validated with reagent water and applied to municipal wastewater, surface water, and municipal biosolids using GC/MS/MS for the analysis of nine most commonly detected steroid hormones. This is the first reported comparison of the separatory funnel extraction (SFE), continuous liquid-liquid extraction (CLLE), and Soxhlet extraction methods developed by the U.S. EPA. Furthermore, a solid phase extraction (SPE) method was also developed in-house for the extraction of steroid hormones from aquatic environmental samples. This study provides valuable information regarding the robustness of the different extraction methods. Statistical analysis of the data showed that SPE-based methods provided better recovery efficiencies and lower variability of the steroid hormones followed by SFE. The analytical methods developed in-house for extraction of biosolids showed a wide recovery range; however, the variability was low (≤ 7% RSD). Soxhlet extraction and CLLE are lengthy procedures and have been shown to provide highly variably recovery efficiencies. The results of this study are guidance for better sample preparation strategies in analytical methods for steroid hormone analysis, and SPE adds to the choice in environmental sample analysis.

  12. 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).

  13. Evaluation of urinary excretion of cortisol by radioimmunoassay through two methods (extracted and non-extracted)

    International Nuclear Information System (INIS)

    Fonte Kohek, M.B. da.

    1992-01-01

    The radioimmunoassay of urinary cortisol extracted by organic solvent (free cortisol) has been used for along time in the hypercortisolism diagnosis. With the development of more specific antisera it became possible to measure urinary cortisol without extracting it. The objective of this paper is to compare the feasibility, sensitivity and specificity of both methods (extracted versus non-extracted) in the hypercortisolism diagnosis. It was used Gamma Coat 125 I - cortisol kit provided by Clinical Assay, Incstar, US, for both methods extracting it with methylene chloride in order to measure the extracted cortisol. The sensitivity of the methods were similar (100% and 98,1%, for non-extracted and extracted methods, respectively). A positive correlation between the two methods was noticed in all groups studied (p < 0.05). It was concluded that both methods are efficient for the investigation of hypercortisolism. However, it's suggested that non-extracted urinary cortisol measurement should be the method of choice since it's an easy-to-perform and affordable method to diagnose Cushing's syndrome. (author)

  14. Comparative exergy analyses of Jatropha curcas oil extraction methods: Solvent and mechanical extraction processes

    International Nuclear Information System (INIS)

    Ofori-Boateng, Cynthia; Keat Teong, Lee; JitKang, Lim

    2012-01-01

    Highlights: ► Exergy analysis detects locations of resource degradation within a process. ► Solvent extraction is six times exergetically destructive than mechanical extraction. ► Mechanical extraction of jatropha oil is 95.93% exergetically efficient. ► Solvent extraction of jatropha oil is 79.35% exergetically efficient. ► Exergy analysis of oil extraction processes allow room for improvements. - Abstract: Vegetable oil extraction processes are found to be energy intensive. Thermodynamically, any energy intensive process is considered to degrade the most useful part of energy that is available to produce work. This study uses literature values to compare the efficiencies and degradation of the useful energy within Jatropha curcas oil during oil extraction taking into account solvent and mechanical extraction methods. According to this study, J. curcas seeds on processing into J. curcas oil is upgraded with mechanical extraction but degraded with solvent extraction processes. For mechanical extraction, the total internal exergy destroyed is 3006 MJ which is about six times less than that for solvent extraction (18,072 MJ) for 1 ton J. curcas oil produced. The pretreatment processes of the J. curcas seeds recorded a total internal exergy destructions of 5768 MJ accounting for 24% of the total internal exergy destroyed for solvent extraction processes and 66% for mechanical extraction. The exergetic efficiencies recorded are 79.35% and 95.93% for solvent and mechanical extraction processes of J. curcas oil respectively. Hence, mechanical oil extraction processes are exergetically efficient than solvent extraction processes. Possible improvement methods are also elaborated in this study.

  15. Sequential injection titration method using second-order signals: determination of acidity in plant oils and biodiesel samples.

    Science.gov (United States)

    del Río, Vanessa; Larrechi, M Soledad; Callao, M Pilar

    2010-06-15

    A new concept of flow titration is proposed and demonstrated for the determination of total acidity in plant oils and biodiesel. We use sequential injection analysis (SIA) with a diode array spectrophotometric detector linked to chemometric tools such as multivariate curve resolution-alternating least squares (MCR-ALS). This system is based on the evolution of the basic specie of an acid-base indicator, alizarine, when it comes into contact with a sample that contains free fatty acids. The gradual pH change in the reactor coil due to diffusion and reaction phenomenona allows the sequential appearance of both species of the indicator in the detector coil, recording a data matrix for each sample. The SIA-MCR-ALS method helps to reduce the amounts of sample, the reagents and the time consumed. Each determination consumes 0.413ml of sample, 0.250ml of indicator and 3ml of carrier (ethanol) and generates 3.333ml of waste. The frequency of the analysis is high (12 samples h(-1) including all steps, i.e., cleaning, preparing and analysing). The utilized reagents are of common use in the laboratory and it is not necessary to use the reagents of perfect known concentration. The method was applied to determine acidity in plant oil and biodiesel samples. Results obtained by the proposed method compare well with those obtained by the official European Community method that is time consuming and uses large amounts of organic solvents.

  16. 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.

  17. Methods for microbial DNA extraction from soil for PCR amplification

    Directory of Open Access Journals (Sweden)

    Yeates C

    1998-01-01

    Full Text Available Amplification of DNA from soil is often inhibited by co-purified contaminants. A rapid, inexpensive, large-scale DNA extraction method involving minimal purification has been developed that is applicable to various soil types (1. DNA is also suitable for PCR amplification using various DNA targets. DNA was extracted from 100g of soil using direct lysis with glass beads and SDS followed by potassium acetate precipitation, polyethylene glycol precipitation, phenol extraction and isopropanol precipitation. This method was compared to other DNA extraction methods with regard to DNA purity and size.

  18. Method for sequentially processing a multi-level interconnect circuit in a vacuum chamber

    Science.gov (United States)

    Routh, D. E.; Sharma, G. C. (Inventor)

    1984-01-01

    An apparatus is disclosed which includes a vacuum system having a vacuum chamber in which wafers are processed on rotating turntables. The vacuum chamber is provided with an RF sputtering system and a dc magnetron sputtering system. A gas inlet introduces various gases to the vacuum chamber and creates various gas plasma during the sputtering steps. The rotating turntables insure that the respective wafers are present under the sputtering guns for an average amount of time such that consistency in sputtering and deposition is achieved. By continuous and sequential processing of the wafers in a common vacuum chamber without removal, the adverse affects of exposure to atmospheric conditions are eliminated providing higher quality circuit contacts and functional device.

  19. 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

  20. The speciation of radionuclides in sediments and soils. Part II. Studies with a sequential organic extraction procedure

    International Nuclear Information System (INIS)

    Voss, H.A.; Williams, G.A.; Cooper, M.B.

    1983-07-01

    A series of chemical extractions with a range of organic solvents has been performed to investigate the speciation of radionuclides in soil and sediment samples from the Mt. Brockman area in the Northern Territory. The major result is that of all the organic solvents used in the extractions, only acetic acid removes large proportions of the radionuclides 210 Pb (ca. 30-70%) and 226 Ra (10-55%) from the soil and sediment samples. The failure of the other organic solvents, and in particular dimethylformamide, to extract appreciable amounts of these radionuclides is taken to indicate that 210 Pb and 226 Ra are not present as discrete metal complexes of organic ligands. The overriding conclusion, that the acidic nature of the solvent is the most important property in releasing the bound radionuclides into solution, suggests that even under mildly acidic conditions encountered in the environment significant amounts of 210 Pb and 226 Ra may be released for transportation

  1. 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

  2. Effect of mucin extraction method on some properties of ...

    African Journals Online (AJOL)

    Effect of mucin extraction method on some properties of metronidazole mucoadhesive loaded patches. MI Arhewoh, SO Eraga, PF Builders, MA Ibobiri. Abstract. To evaluate the effects of mucin extraction method and plasticizer concentration on the bioadhesive strength and metronidazole release profile from mucin-based ...

  3. Method of purifying phosphoric acid after solvent extraction

    International Nuclear Information System (INIS)

    Kouloheris, A.P.; Lefever, J.A.

    1979-01-01

    A method of purifying phosphoric acid after solvent extraction is described. The phosphoric acid is contacted with a sorbent which sorbs or takes up the residual amount of organic carrier and the phosphoric acid separated from the organic carrier-laden sorbent. The method is especially suitable for removing residual organic carrier from phosphoric acid after solvent extraction uranium recovery. (author)

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. Method of extracting tritium from heavy water

    International Nuclear Information System (INIS)

    Tsuchiya, Hiroyuki; Kikuchi, Makoto; Asakura, Yamato; Yusa, Hideo.

    1979-01-01

    Purpose: To extract tritium in heavy water by combining isotope exchange reaction with liquefaction distillation to increase the concentration of recovered tritium, thereby reducing the quantity of radioactive wastes recovered. Constitution: Heavy water containing tritium from a reactor is introduced into a tritium separator through a conduit pipe. On the other hand, a D 2 gas is introduced through the conduit pipe in the lower part of a tritium separator to transfer tritium into D 2 gas by isotope exchange. The D 2 gas containing DT is introduced into a liquefaction distillation tower together with an outlet gas of a converter supplied through a pipeline. The converter is filled with net-like metals of platinum group such as Pt, Ni, Pd and the like, and the D 2 gas affluent in DT, extracted from the distillation tower is converted into D 2 and T 2 . The gas which has been introduced into the liquefaction distillation tower is liquefied. The D 2 gas of low boiling point components reaches the tower top, and the T 2 gas of high boiling point components is concentrated at the tower bottom, and is rendered into tritium water in a recoupler and stored in a water storage apparatus. (Yoshino, Y.)

  9. 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

  10. Double-radionuclide autoradiographic method using N-isopropyl-iodoamphetamine for sequential measurements of local cerebral blood flow

    International Nuclear Information System (INIS)

    Obrenovitch, T.P.; Clayton, C.B.; Strong, A.J.

    1987-01-01

    A double-radionuclide autoradiographic method has been assessed for sequential determinations of local CBF (LCBF). It is based on two successive intravascular injections of N-isopropyl-p-iodoamphetamine (IMP) labelled with different radionuclides, whose concentrations can later be differentiated in the same tissue section using double-radionuclide autoradiography. Previous studies suggested that the distribution of IMP, up to 30 min after its administration, still represents LCBFs. Our data indicate that, provided the tracer is injected directly into the left ventricle, there is little back diffusion from normal brain to blood under physiological conditions for at least 35 min following the tracer injection and an injection of unlabelled IMP, in a dose larger than that used for blood flow determination, does not displace any labelled IMP previously taken up by the brain, nor does it displace any labelled IMP previously accumulated in the lung that would lead to secondary brain uptake. On the basis of these results, we conclude that sequential autoradiographic determinations of LCBF using IMP labelled with different radionuclides is possible. This is a promising experimental method for the simultaneous investigation of changes in LCBF in several CNS structures

  11. Comparison of /sup 32/P therapy and sequential hemibody irradiation (HBI) for bony metastases as methods of whole body irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Aziz, H.; Choi, K.; Sohn, C.; Yaes, R.; Rotman, M.

    1986-06-01

    We report a retrospective study of 15 patients with prostate carcinoma and diffuse bone metastases treated with sodium /sup 32/P for palliation of pain at Downstate Medical Center and Kings County Hospital from 1973 to 1978. The response rates, duration of response, and toxicities are compared with those of other series of patients treated with /sup 32/P and with sequential hemibody irradiation. The response rates and duration of response are similar with both modalities ranging from 58 to 95% with a duration of 3.3 to 6 months with /sup 32/P and from 75 to 86% with a median duration of 5.5 months with hemibody irradiation. There are significant differences in the patterns of response and in the toxicities of the two treatment methods. Both methods cause significant bone marrow depression. Acute radiation syndrome, radiation pneumonitis, and alopecia are seen with sequential hemibody irradiation and not with /sup 32/P, but their incidence can be reduced by careful treatment planning. Hemibody irradiation can provide pain relief within 24 to 48 h, while /sup 32/P may produce an initial exacerbation of pain. Lower hemibody irradiation alone is less toxic than either upper hemibody irradiation or /sup 32/P treatment.

  12. Effects of Different Extraction Methods and Conditions on the Phenolic Composition of Mate Tea Extracts

    Directory of Open Access Journals (Sweden)

    Jelena Vladic

    2012-03-01

    Full Text Available A simple and rapid HPLC method for determination of chlorogenic acid (5-O-caffeoylquinic acid in mate tea extracts was developed and validated. The chromatography used isocratic elution with a mobile phase of aqueous 1.5% acetic acid-methanol (85:15, v/v. The flow rate was 0.8 mL/min and detection by UV at 325 nm. The method showed good selectivity, accuracy, repeatability and robustness, with detection limit of 0.26 mg/L and recovery of 97.76%. The developed method was applied for the determination of chlorogenic acid in mate tea extracts obtained by ethanol extraction and liquid carbon dioxide extraction with ethanol as co-solvent. Different ethanol concentrations were used (40, 50 and 60%, v/v and liquid CO2 extraction was performed at different pressures (50 and 100 bar and constant temperature (27 ± 1 °C. Significant influence of extraction methods, conditions and solvent polarity on chlorogenic acid content, antioxidant activity and total phenolic and flavonoid content of mate tea extracts was established. The most efficient extraction solvent was liquid CO2 with aqueous ethanol (40% as co-solvent using an extraction pressure of 100 bar.

  13. Extraction and identification of cyclobutanones from irradiated cheese employing a rapid direct solvent extraction method.

    Science.gov (United States)

    Tewfik, Ihab

    2008-01-01

    2-Alkylcyclobutanones (cyclobutanones) are accepted as chemical markers for irradiated foods containing lipid. However, current extraction procedures (Soxhlet-florisil chromatography) for the isolation of these markers involve a long and tedious clean-up regime prior to gas chromatography-mass spectrophotometry identification. This paper outlines an alternative isolation and clean-up method for the extraction of cyclobutanones in irradiated Camembert cheese. The newly developed direct solvent extraction method enables the efficient screening of large numbers of food samples and is not as resource intensive as the BS EN 1785:1997 method. Direct solvent extraction appears to be a simple, robust method and has the added advantage of a considerably shorter extraction time for the analysis of foods containing lipid.

  14. Impact of different extraction methods on the quality of Dipteryx alata extracts

    Directory of Open Access Journals (Sweden)

    Frederico S. Martins

    2013-05-01

    Full Text Available This study aimed to impact of different extraction methods on the quality of Dipteryx alata Vogel, Fabaceae, extracts from fruits. The major compounds found were the lipids 38.9% (w/w and proteins 26.20% (w/w. The residual moisture was 7.20% (w/w, total fiber 14.50% (w/w, minerals 4.10% (w/w and carbohydrate 9.10 % (w/w. The species studied has great potential in producing oil, but the content and type of fatty acids obtained is dependent on the method of extraction. The Blingh & Dyer method was more selective for unsaturated fatty acids and Shoxlet method was more selective for saturated fatty acids. The tannin extraction by ultrasound (33.70 % w/w was 13.90% more efficient than extraction by decoction (29 % w/w.

  15. 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.

  16. Method of extraction under pressure of fossil material

    Energy Technology Data Exchange (ETDEWEB)

    Fredenmark, G L

    1942-02-24

    A method is described of extraction under pressure of fossil material, such as coal, brown coal (lignite), peat, oil shale. It is characterized by carrying out the process of extraction by utilization of fractions of shale oils and/or peat tar with a boiling point above 170/sup 0/C and under such as pressure that the medium of extraction is in a liquid state.

  17. Direct methods and residue type specific isotope labeling in NMR structure determination and model-driven sequential assignment

    International Nuclear Information System (INIS)

    Schedlbauer, Andreas; Auer, Renate; Ledolter, Karin; Tollinger, Martin; Kloiber, Karin; Lichtenecker, Roman; Ruedisser, Simon; Hommel, Ulrich; Schmid, Walther; Konrat, Robert; Kontaxis, Georg

    2008-01-01

    Direct methods in NMR based structure determination start from an unassigned ensemble of unconnected gaseous hydrogen atoms. Under favorable conditions they can produce low resolution structures of proteins. Usually a prohibitively large number of NOEs is required, to solve a protein structure ab-initio, but even with a much smaller set of distance restraints low resolution models can be obtained which resemble a protein fold. One problem is that at such low resolution and in the absence of a force field it is impossible to distinguish the correct protein fold from its mirror image. In a hybrid approach these ambiguous models have the potential to aid in the process of sequential backbone chemical shift assignment when 13 C β and 13 C' shifts are not available for sensitivity reasons. Regardless of the overall fold they enhance the information content of the NOE spectra. These, combined with residue specific labeling and minimal triple-resonance data using 13 C α connectivity can provide almost complete sequential assignment. Strategies for residue type specific labeling with customized isotope labeling patterns are of great advantage in this context. Furthermore, this approach is to some extent error-tolerant with respect to data incompleteness, limited precision of the peak picking, and structural errors caused by misassignment of NOEs

  18. Assessment of proposed electromagnetic quantum vacuum energy extraction methods

    OpenAIRE

    Moddel, Garret

    2009-01-01

    In research articles and patents several methods have been proposed for the extraction of zero-point energy from the vacuum. None has been reliably demonstrated, but the proposals remain largely unchallenged. In this paper the feasibility of these methods is assessed in terms of underlying thermodynamics principles of equilibrium, detailed balance, and conservation laws. The methods are separated into three classes: nonlinear processing of the zero-point field, mechanical extraction using Cas...

  19. Development of an extraction method for perchlorate in soils.

    Science.gov (United States)

    Cañas, Jaclyn E; Patel, Rashila; Tian, Kang; Anderson, Todd A

    2006-03-01

    Perchlorate originates as a contaminant in the environment from its use in solid rocket fuels and munitions. The current US EPA methods for perchlorate determination via ion chromatography using conductivity detection do not include recommendations for the extraction of perchlorate from soil. This study evaluated and identified appropriate conditions for the extraction of perchlorate from clay loam, loamy sand, and sandy soils. Based on the results of this evaluation, soils should be extracted in a dry, ground (mortar and pestle) state with Milli-Q water in a 1 ratio 1 soil ratio water ratio and diluted no more than 5-fold before analysis. When sandy soils were extracted in this manner, the calculated method detection limit was 3.5 microg kg(-1). The findings of this study have aided in the establishment of a standardized extraction method for perchlorate in soil.

  20. Effects of Extraction Method on the Physicochemical and ...

    African Journals Online (AJOL)

    The effects of improved method of extraction on the physicochemical, mycological and stability of crude Canarium Schweinfurthii fruit oil were studied. The extracted oils were then stored at 25±5oC for 24 months with samples analyzed at 6months interval for; pH, saponification value, acid value, peroxide value and iodine ...

  1. Comparison of protein extraction methods suitable for proteomics ...

    African Journals Online (AJOL)

    An efficient protein extraction method is a prerequisite for successful implementation of proteomics. In this study, seedling roots of Jerusalem artichoke were treated with the concentration of 250 mM NaCl for 36 h. Subsequently, six different protocols of protein extraction were applied to seedling roots of Jerusalem artichoke ...

  2. Chemical Compounds and Extraction Methods of ?Maollahm?

    OpenAIRE

    Sadeghpoor, Omid; Dayeni, Manijeh; Razi, Samane

    2016-01-01

    Background: Maollahm or meat juice, a by-product of meat, is a traditional remedy in Persian medicine. This product was used as a nourishment or treatment substance for sick people. According to the ancient Persian medicine, animal meat has more affinity with the human body and the body easily absorbs its nutrition. Therefore, one could resort to maollahm for patients requiring urgent nourishment to boost and strengthen their body. Methods: In this work, different ways of preparing maollahm f...

  3. Microbial diversity in fecal samples depends on DNA extraction method

    DEFF Research Database (Denmark)

    Mirsepasi, Hengameh; Persson, Søren; Struve, Carsten

    2014-01-01

    was to evaluate two different DNA extraction methods in order to choose the most efficient method for studying intestinal bacterial diversity using Denaturing Gradient Gel Electrophoresis (DGGE). FINDINGS: In this study, a semi-automatic DNA extraction system (easyMag®, BioMérieux, Marcy I'Etoile, France......BACKGROUND: There are challenges, when extracting bacterial DNA from specimens for molecular diagnostics, since fecal samples also contain DNA from human cells and many different substances derived from food, cell residues and medication that can inhibit downstream PCR. The purpose of the study...... by easyMag® from the same fecal samples. Furthermore, DNA extracts obtained using easyMag® seemed to contain inhibitory compounds, since in order to perform a successful PCR-analysis, the sample should be diluted at least 10 times. DGGE performed on PCR from DNA extracted by QIAamp DNA Stool Mini Kit DNA...

  4. Comparison of protein extraction methods suitable for proteomics ...

    African Journals Online (AJOL)

    Jane

    2011-07-27

    Jul 27, 2011 ... An efficient protein extraction method is a prerequisite for successful implementation of proteomics. ... research, it is noteworthy to discover a proteome ..... Proteomic analysis of rice (Oryza sativa) seeds during germination.

  5. effects of extraction method on the physicochemical and mycological

    African Journals Online (AJOL)

    DR. AMINU

    Canarium Schweinfurthii fruit oil obtained by the improved method of extraction had better quality and stability ... application due to the believe that it enhances the oil flavours, also the fruit ..... starters on coconut oil recovery. Proceeding.

  6. Solid phase extraction method for determination of mitragynine in ...

    African Journals Online (AJOL)

    All rights reserved. ... 1Department of Pharmacology, 2Department of Applied Science, 3Police Forensic Science Center 10, Yala 95000, 4Natural ... Purpose: To develop a solid phase extraction (SPE) method that utilizes reverse-phase high.

  7. Extracting natural dyes from wool--an evaluation of extraction methods.

    Science.gov (United States)

    Manhita, Ana; Ferreira, Teresa; Candeias, António; Dias, Cristina Barrocas

    2011-05-01

    The efficiency of eight different procedures used for the extraction of natural dyes was evaluated using contemporary wool samples dyed with cochineal, madder, woad, weld, brazilwood and logwood. Comparison was made based on the LC-DAD peak areas of the natural dye's main components which had been extracted from the wool samples. Among the tested methods, an extraction procedure with Na(2)EDTA in water/DMF (1:1, v/v) proved to be the most suitable for the extraction of the studied dyes, which presented a wide range of chemical structures. The identification of the natural dyes used in the making of an eighteenth century Arraiolos carpet was possible using the Na(2)EDTA/DMF extraction of the wool embroidery samples and an LC-DAD-MS methodology. The effectiveness of the Na(2)EDTA/DMF extraction method was particularly observed in the extraction of weld dye components. Nine flavone derivatives previously identified in weld extracts could be identified in a single historical sample, confirming the use of this natural dye in the making of Arraiolos carpets. Indigo and brazilwood were also identified in the samples, and despite the fact that these natural dyes were referred in the historical recipes of Arraiolos dyeing, it is the first time that the use of brazilwood is confirmed. Mordant analysis by ICP-MS identified the widespread use of alum in the dyeing process, but in some samples with darker hues, high amounts of iron were found instead.

  8. Sequential Strategy Of Experimental Design I: Optimization Of Extractive Distillation Process Of Ethanol-water Using [bmim][n(cn)(2)] As Entrainer

    OpenAIRE

    Jaimes Figueroa; Jaiver Efren; Rodrigues; Maria Isabel; Wolf Maciel; Maria Regina

    2016-01-01

    Nowadays, one of the methods available to obtain the anhydrous ethanol is the extractive distillation process, which presents great potential depending on the solvent used. It is imperative that the solvent promotes dehydration, but low cost, the low energy consumption, and low waste generation and emissions must be taken into account. Within this context, there is high demand for new efficient solvents for extractive distillation of ethanol-water mixture, so, the ionic liquids (ILs) have som...

  9. Effect of extraction method and orientin content on radio-protective effect of tulsi extracts

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, Mrinalini; Dwarakanath, B. S.; Agrawala, Paban K., E-mail: pkagrawal@gmail.com [Institute of Nuclear Medicine and Allied Sciences, Delhi (India); Murugan, R.; Parimelazhagan, T. [Department of Botany, Bharathiar University, Coimbatore (India); Uma Devi, P. [ARA-B-3SA, Plavilakonam,Trivandrum (India); Gota, V.; Sarin, R. K. [Advanced Centre for Treatment Research and Education in Cancer, Navi Mumbai (India)

    2014-07-01

    Extract of tulsi leaves (Ocimum sanctum) has been reported for its radioprotective efficacy. In our initial studies we observed significant variation in the survival of irradiated mice with different batches of tulsi extracts and therefore we employed different extraction methods on leaves collected during various seasons from different localities to study any variation in the radioprotective efficacy. Orientin, a component of tulsi extract, was considered a marker. Mice whole body survival (at 10 Gy lethal whole body irradiation) study and day 11 endo-CFU-s assay (at 5 Gy WBI) were performed employing 3 treatment schedules, 50 mg/kg or 25 mg/kg b.w (single injection, 30 min irradiation), and 10 mg/kgb.w (one injection per day for 5 day, last injection being 30 min before irradiation). Single dose of 25 mg/kg b.w (both aqueous and alcoholic) did not provide any significant survival benefit. The orientin concentrations in the extracts tested varied from 3.3 to 9.91 mg/g extract as studied by HPLC method. With a single administration (i.p) of 50 mg/kg, the aqueous extract from leaves of monsoon season had an orientin content of 9.91 mg/g extract and gave a survival of 60% with a CFU-s count of 37, while extract of leaf summer leaves had an orientin content of 4.15 mg/g extract and gave a survival of 50% with a CFU-s count of 11.6. At the same dose (50 mg/kg), the aqueous extract from the winter season had an orientin content of 3.30 mg/g extract and gave 25% survival with a CFU-s count of 19, while the ethanolic extract had an orientin content of 7.70 mg/g extract and gave a survival of 50% with a CFU-s count of 13. These observations suggest that different climatic factors, orientin content and the doses of administration are important factors regulating radioprotection afforded by different extracts of tulsi. (author)

  10. Chemical Compounds and Extraction Methods of "Maollahm".

    Science.gov (United States)

    Sadeghpoor, Omid; Dayeni, Manijeh; Razi, Samane

    2016-05-01

    Maollahm or meat juice, a by-product of meat, is a traditional remedy in Persian medicine. This product was used as a nourishment or treatment substance for sick people. According to the ancient Persian medicine, animal meat has more affinity with the human body and the body easily absorbs its nutrition. Therefore, one could resort to maollahm for patients requiring urgent nourishment to boost and strengthen their body. In this work, different ways of preparing maollahm from poultry, goat, cow, and sheep meat are studied. Most of these methods are based on distillation or barbecue before distillation, as prescribed by traditional medicine books. The reactions, chemical processes, and volatile compounds related to different types of cooked meat are also compared with the outcome of recent research studies. The difference between various types of meat is related to their compounds. Different cooking processes such as barbecuing, roasting, cooking, and boiling have an effect on the taste, smell and the chemical constituents of maollahm. Additionally, the type of meat, animal feed, as well as using or removing the fat during the cooking process, have an effect on the produced volatile compounds. Cooking process and the type of meat have a direct effect on the compounds of maollahm. Possible reactions in the preparation process of maollahm are investigated and presented according to the new research studies.

  11. Three-point method for measuring the geometric error components of linear and rotary axes based on sequential multilateration

    International Nuclear Information System (INIS)

    Zhang, Zhenjiu; Hu, Hong

    2013-01-01

    The linear and rotary axes are fundamental parts of multi-axis machine tools. The geometric error components of the axes must be measured for motion error compensation to improve the accuracy of the machine tools. In this paper, a simple method named the three point method is proposed to measure the geometric error of the linear and rotary axes of the machine tools using a laser tracker. A sequential multilateration method, where uncertainty is verified through simulation, is applied to measure the 3D coordinates. Three noncollinear points fixed on the stage of each axis are selected. The coordinates of these points are simultaneously measured using a laser tracker to obtain their volumetric errors by comparing these coordinates with ideal values. Numerous equations can be established using the geometric error models of each axis. The geometric error components can be obtained by solving these equations. The validity of the proposed method is verified through a series of experiments. The results indicate that the proposed method can measure the geometric error of the axes to compensate for the errors in multi-axis machine tools.

  12. The effectiveness of electro-remediation of aged, metal-contaminated sediment in relation to sequential extraction of metals

    NARCIS (Netherlands)

    Merkx, O.K.; Loch, J.P.G.; Lima, A.T.; Dijk, J.A.; Kreuk, J.F. de; Kleingeld, P.J.

    2013-01-01

    Soil pollution is a universal environmental issue, and the clean-up of contaminated soils can be costly and time consuming. Traditional methods often do not provide an effective solution when it comes to fine-grained and highly impermeable soils and/or immobile contaminants. Electro-remediation,

  13. A Karnaugh-Map based fingerprint minutiae extraction method

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Singla

    2010-07-01

    Full Text Available Fingerprint is one of the most promising method among all the biometric techniques and has been used for thepersonal authentication for a long time because of its wide acceptance and reliability. Features (Minutiae are extracted fromthe fingerprint in question and are compared with the features already stored in the database for authentication. Crossingnumber (CN is the most commonly used minutiae extraction method for fingerprints. In this paper, a new Karnaugh-Mapbased fingerprint minutiae extraction method has been proposed and discussed. In the proposed algorithm the 8 neighborsof a pixel in a 33 window are arranged as 8 bits of a byte and corresponding hexadecimal (hex value is calculated. Thesehex values are simplified using standard Karnaugh-Map (K-map technique to obtain the minimized logical expression.Experiments conducted on the FVC2002/Db1_a database reveals that the developed method is better than the crossingnumber (CN method.

  14. 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

  15. 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.

  16. Evolution of phosphorus complexation and mineralogy during (hydro)thermal treatments of activated and anaerobically digested sludge: Insights from sequential extraction and P K-edge XANES.

    Science.gov (United States)

    Huang, Rixiang; Tang, Yuanzhi

    2016-09-01

    (Hydro)thermal treatments of sewage sludge is a promising option that can simultaneously target safe waste disposal, energy recovery, and nutrient recovery/recycling. The speciation of phosphorus (P) in sludge is of great relevance to P reclamation/recycling and soil application of sludge-derived products, thus it is critical to understand the effects of different treatment techniques and conditions on P speciation. This study systematically characterized P speciation (i.e. complexation and mineral forms) in chars derived from pyrolysis and hydrothermal carbonization (HTC) of municipal sewage sludges. Combined sequential extraction and P K-edge X-ray absorption near edge structure (XANES) spectroscopy analysis revealed the dependence of P transformation on treatment conditions and metal composition in the feedstocks. Pyrolysis of sludges decreased the relative abundance of phytic acid while increased the abundance of Al-associated P. HTC thoroughly homogenized and exposed P for interaction with various metals/minerals, with the final P speciation closely related to the composition/speciation of metals and their affinities to P. Results from this study revealed the mechanisms of P transformation during (hydro)thermal treatments of sewage sludges, and might be applicable to other biosolids. It also provided fundamental knowledge basis for the design and selection of waste management strategies for better P (re)cycling and reclamation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. 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.

  18. 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.

  19. 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.

  20. Presentation of a method for the sequential analysis of incidents - NPP safety

    Energy Technology Data Exchange (ETDEWEB)

    Delage, M; Giroux, C; Quentin, P

    1989-04-01

    This paper presents a method which is designed to assist in the analysis of safety and based on the graphic representation of the occurrence of incidents significant for safety in 900-MWe PWR units. The graphs obtained are linked together to produce a general tree of events. With this tool, and on the basis of operating experience, it is then possible to imagine complex incident scenarios, to evaluate the potential consequences of a particular incident, or to seed out the causes which could lead to a given event. Interactions between systems or common mode faults can also be evidenced with this method.

  1. An efficient method for DNA extraction from Cladosporioid fungi

    OpenAIRE

    Moslem, M.A.; Bahkali, A.H.; Abd-Elsalam, K.A.; Wit, de, P.J.G.M.

    2010-01-01

    We developed an efficient method for DNA extraction from Cladosporioid fungi, which are important fungal plant pathogens. The cell wall of Cladosporioid fungi is often melanized, which makes it difficult to extract DNA from their cells. In order to overcome this we grew these fungi for three days on agar plates and extracted DNA from mycelium mats after manual or electric homogenization. High-quality DNA was isolated, with an A260/A280 ratio ranging between 1.6 and 2.0. Isolated genomic DNA w...

  2. Sequential Spectrophotometric Method for the Simultaneous Determination of Amlodipine, Valsartan, and Hydrochlorothiazide in Coformulated Tablets

    Directory of Open Access Journals (Sweden)

    Hany W. Darwish

    2013-01-01

    Full Text Available A new, simple and specific spectrophotometric method was developed and validated in accordance with ICH guidelines for the simultaneous estimation of Amlodipine (AML, Valsartan (VAL, and Hydrochlorothiazide (HCT in their ternary mixture. In this method three techniques were used, namely, direct spectrophotometry, ratio subtraction, and isoabsorptive point. Amlodipine (AML was first determined by direct spectrophotometry and then ratio subtraction was applied to remove the AML spectrum from the mixture spectrum. Hydrochlorothiazide (HCT could then be determined directly without interference from Valsartan (VAL which could be determined using the isoabsorptive point theory. The calibration curve is linear over the concentration ranges of 4–32, 4–44 and 6–20 μg/mL for AML, VAL, and HCT, respectively. This method was tested by analyzing synthetic mixtures of the above drugs and was successfully applied to commercial pharmaceutical preparation of the drugs, where the standard deviation is <2 in the assay of raw materials and tablets. The method was validated according to the ICH guidelines and accuracy, precision, repeatability, and robustness were found to be within the acceptable limits.

  3. Analyzing Gender Differences in Black Faculty Marginalization through a Sequential Mixed-Methods Design

    Science.gov (United States)

    Griffin, Kimberly A.; Bennett, Jessica C.; Harris, Jessica

    2011-01-01

    In this article, the authors demonstrate how researchers can integrate qualitative and quantitative methods to gain a deeper understanding of the prevalence and nature of cultural taxation among black professors. In doing so, they show how the impact of cultural taxation on the experiences of black faculty in the academy is best captured using…

  4. Multi-volatile method for aroma analysis using sequential dynamic headspace sampling with an application to brewed coffee.

    Science.gov (United States)

    Ochiai, Nobuo; Tsunokawa, Jun; Sasamoto, Kikuo; Hoffmann, Andreas

    2014-12-05

    A novel multi-volatile method (MVM) using sequential dynamic headspace (DHS) sampling for analysis of aroma compounds in aqueous sample was developed. The MVM consists of three different DHS method parameters sets including choice of the replaceable adsorbent trap. The first DHS sampling at 25 °C using a carbon-based adsorbent trap targets very volatile solutes with high vapor pressure (>20 kPa). The second DHS sampling at 25 °C using the same type of carbon-based adsorbent trap targets volatile solutes with moderate vapor pressure (1-20 kPa). The third DHS sampling using a Tenax TA trap at 80 °C targets solutes with low vapor pressure (0.9910) and high sensitivity (limit of detection: 1.0-7.5 ng mL(-1)) even with MS scan mode. The feasibility and benefit of the method was demonstrated with analysis of a wide variety of aroma compounds in brewed coffee. Ten potent aroma compounds from top-note to base-note (acetaldehyde, 2,3-butanedione, 4-ethyl guaiacol, furaneol, guaiacol, 3-methyl butanal, 2,3-pentanedione, 2,3,5-trimethyl pyrazine, vanillin, and 4-vinyl guaiacol) could be identified together with an additional 72 aroma compounds. Thirty compounds including 9 potent aroma compounds were quantified in the range of 74-4300 ng mL(-1) (RSD<10%, n=5). Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Inorganic arsenic in seafood: does the extraction method matter?

    Science.gov (United States)

    Pétursdóttir, Ásta H; Gunnlaugsdóttir, Helga; Krupp, Eva M; Feldmann, Jörg

    2014-05-01

    Nine different extraction methods were evaluated for three seafood samples to test whether the concentration of inorganic arsenic (iAs) determined in seafood is dependent on the extraction method. Certified reference materials (CRM) DOLT-4 (Dogfish Liver) and TORT-2 (Lobster Hepatopancreas), and a commercial herring fish meal were evaluated. All experimental work described here was carried out by the same operator using the same instrumentation, thus eliminating possible differences in results caused by laboratory related factors. Low concentrations of iAs were found in CRM DOLT-4 (0.012±0.003mgkg(-1)) and the herring fish meal sample (0.007±0.002mgkg(-1)) for all extraction methods. When comparing the concentration of iAs in CRM TORT-2 found in this study and in the literature dilute acids, HNO3 and HCl, showed the highest extracted iAs wheras dilute NaOH (in 50% ethanol) showed significantly lower extracted iAs. However, most other extraction solvents were not statistically different from one another. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Extraction methods of Amaranthus sp. grain oil isolation.

    Science.gov (United States)

    Krulj, Jelena; Brlek, Tea; Pezo, Lato; Brkljača, Jovana; Popović, Sanja; Zeković, Zoran; Bodroža Solarov, Marija

    2016-08-01

    Amaranthus sp. is a fast-growing crop with well-known beneficial nutritional values (rich in protein, fat, dietary fiber, ash, and minerals, especially calcium and sodium, and containing a higher amount of lysine than conventional cereals). Amaranthus sp. is an underexploited plant source of squalene, a compound of high importance in the food, cosmetic and pharmaceutical industries. This paper has examined the effects of the different extraction methods (Soxhlet, supercritical fluid and accelerated solvent extraction) on the oil and squalene yield of three genotypes of Amaranthus sp. grain. The highest yield of the extracted oil (78.1 g kg(-1) ) and squalene (4.7 g kg(-1) ) in grain was obtained by accelerated solvent extraction (ASE) in genotype 16. Post hoc Tukey's HSD test at 95% confidence limit showed significant differences between observed samples. Principal component analysis (PCA) and cluster analysis (CA) were used for assessing the effect of different genotypes and extraction methods on oil and squalene yield, and also the fatty acid composition profile. Using coupled PCA and CA of observed samples, possible directions for improving the quality of product can be realized. The results of this study indicate that it is very important to choose both the right genotype and the right method of extraction for optimal oil and squalene yield. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  7. METHOD OF RARE TERM CONTRASTIVE EXTRACTION FROM NATURAL LANGUAGE TEXTS

    Directory of Open Access Journals (Sweden)

    I. A. Bessmertny

    2017-01-01

    Full Text Available The paper considers a problem of automatic domain term extraction from documents corpus by means of a contrast collection. Existing contrastive methods successfully extract often used terms but mishandle rare terms. This could yield poorness of the resulting thesaurus. Assessment of point-wise mutual information is one of the known statistical methods of term extraction and it finds rare terms successfully. Although, it extracts many false terms at that. The proposed approach consists of point-wise mutual information application for rare terms extraction and filtering of candidates by criterion of joint occurrence with the other candidates. We build “documents-by-terms” matrix that is subjected to singular value decomposition to eliminate noise and reveal strong interconnections. Then we pass on to the resulting matrix “terms-by-terms” that reproduces strength of interconnections between words. This approach was approved on a documents collection from “Geology” domain with the use of contrast documents from such topics as “Politics”, “Culture”, “Economics” and “Accidents” on some Internet resources. The experimental results demonstrate operability of this method for rare terms extraction.

  8. Using qualitative repertory grid interviews to gather shared perspectives in a sequential mixed methods research design

    OpenAIRE

    Rojon, C; Saunders, M.N.K.; McDowall, Almuth

    2016-01-01

    In this chapter, we consider a specific example of applying mixed methods designs combining both qualitative and quantitative data collection and analysis approaches, giving particular attention to issues including reliability and validity. Human resource management (HRM) researchers, like others setting out to examine a novel or insufficiently defined research topic, frequently favour qualitative approaches to gather data during initial stages, to facilitate an in-depth exploration of indivi...

  9. An effective method for extraction and polymerase chain reaction ...

    African Journals Online (AJOL)

    The PCR amplification with the NaOH and PBS treatment had a success rate of 30 to 100% for both mitochondrial and nuclear markers. The PBS method is the best method for extraction of DNA from formalin-preserved samples of longer period (two to seven years) because of higher success rate in amplifying mitochondrial ...

  10. Analysis of arsenic speciation in mine contaminated lacustrine sediment using selective sequential extraction, HR-ICPMS and TEM

    International Nuclear Information System (INIS)

    Haus, Kelly L.; Hooper, Robert L.; Strumness, Laura A.; Mahoney, J. Brian

    2008-01-01

    In order to determine how As speciation in lacustrine sediment changes as a function of local conditions, sediment cores were taken from three lakes with differing hydrologic regimes and subjected to extensive chemical and TEM analysis. The lakes (Killarney, Thompson and Swan Lakes) are located within the Coeur d' Alene River system (northern Idaho, USA), which has been contaminated with trace metals and As, from over 100 a of sulfide mining. Previous analyses of these lakebed sediments have shown an extensive amount of contaminant metals and As associated with sub-μm grains, making them extremely difficult to analyze using standard methods (scanning electron microscopy, X-ray diffraction). Transmission electron microscopy offers great advantages in spatial resolution and can be invaluable in determining As speciation when combined with other techniques. Data indicate that because of differences in local redox conditions, As speciation and stability is dramatically different in these lakes. Killarney and Thompson Lakes experience seasonal water-level fluctuations due to drawdown on a downstream dam, causing changes in O 2 content in sediment exposed during drawdown. Swan Lake has relatively constant water levels as its only inlet is dammed. Consequently, Killarney and Thompson Lakes show an increase in labile As-bearing phases with depth, while Swan Lake data indicate stable As hosts throughout the sediment profile. Based on these observations it can be stated that As in lakebed sediments is much less mobile, and therefore less bioavailable, when water is kept at a constant level

  11. Analysis of arsenic speciation in mine contaminated lacustrine sediment using selective sequential extraction, HR-ICPMS and TEM

    Energy Technology Data Exchange (ETDEWEB)

    Haus, Kelly L. [Department of Geology, Phillips 157, University of Wisconsin - Eau Claire, Eau Claire, WI 54702-4004 (United States)], E-mail: khaus@vt.edu; Hooper, Robert L.; Strumness, Laura A.; Mahoney, J. Brian [Department of Geology, Phillips 157, University of Wisconsin - Eau Claire, Eau Claire, WI 54702-4004 (United States)

    2008-04-15

    In order to determine how As speciation in lacustrine sediment changes as a function of local conditions, sediment cores were taken from three lakes with differing hydrologic regimes and subjected to extensive chemical and TEM analysis. The lakes (Killarney, Thompson and Swan Lakes) are located within the Coeur d' Alene River system (northern Idaho, USA), which has been contaminated with trace metals and As, from over 100 a of sulfide mining. Previous analyses of these lakebed sediments have shown an extensive amount of contaminant metals and As associated with sub-{mu}m grains, making them extremely difficult to analyze using standard methods (scanning electron microscopy, X-ray diffraction). Transmission electron microscopy offers great advantages in spatial resolution and can be invaluable in determining As speciation when combined with other techniques. Data indicate that because of differences in local redox conditions, As speciation and stability is dramatically different in these lakes. Killarney and Thompson Lakes experience seasonal water-level fluctuations due to drawdown on a downstream dam, causing changes in O{sub 2} content in sediment exposed during drawdown. Swan Lake has relatively constant water levels as its only inlet is dammed. Consequently, Killarney and Thompson Lakes show an increase in labile As-bearing phases with depth, while Swan Lake data indicate stable As hosts throughout the sediment profile. Based on these observations it can be stated that As in lakebed sediments is much less mobile, and therefore less bioavailable, when water is kept at a constant level.

  12. Variability of bronchial measurements obtained by sequential CT using two computer-based methods

    International Nuclear Information System (INIS)

    Brillet, Pierre-Yves; Fetita, Catalin I.; Mitrea, Mihai; Preteux, Francoise; Capderou, Andre; Dreuil, Serge; Simon, Jean-Marc; Grenier, Philippe A.

    2009-01-01

    This study aimed to evaluate the variability of lumen (LA) and wall area (WA) measurements obtained on two successive MDCT acquisitions using energy-driven contour estimation (EDCE) and full width at half maximum (FWHM) approaches. Both methods were applied to a database of segmental and subsegmental bronchi with LA > 4 mm 2 containing 42 bronchial segments of 10 successive slices that best matched on each acquisition. For both methods, the 95% confidence interval between repeated MDCT was between -1.59 and 1.5 mm 2 for LA, and -3.31 and 2.96 mm 2 for WA. The values of the coefficient of measurement variation (CV 10 , i.e., percentage ratio of the standard deviation obtained from the 10 successive slices to their mean value) were strongly correlated between repeated MDCT data acquisitions (r > 0.72; p 2 , whereas WA values were lower for bronchi with WA 2 ; no systematic EDCE underestimation or overestimation was observed for thicker-walled bronchi. In conclusion, variability between CT examinations and assessment techniques may impair measurements. Therefore, new parameters such as CV 10 need to be investigated to study bronchial remodeling. Finally, EDCE and FWHM are not interchangeable in longitudinal studies. (orig.)

  13. Influence of Extraction Methods on the Yield of Steviol Glycosides and Antioxidants in Stevia rebaudiana Extracts.

    Science.gov (United States)

    Periche, Angela; Castelló, Maria Luisa; Heredia, Ana; Escriche, Isabel

    2015-06-01

    This study evaluated the application of ultrasound techniques and microwave energy, compared to conventional extraction methods (high temperatures at atmospheric pressure), for the solid-liquid extraction of steviol glycosides (sweeteners) and antioxidants (total phenols, flavonoids and antioxidant capacity) from dehydrated Stevia leaves. Different temperatures (from 50 to 100 °C), times (from 1 to 40 min) and microwave powers (1.98 and 3.30 W/g extract) were used. There was a great difference in the resulting yields according to the treatments applied. Steviol glycosides and antioxidants were negatively correlated; therefore, there is no single treatment suitable for obtaining the highest yield in both groups of compounds simultaneously. The greatest yield of steviol glycosides was obtained with microwave energy (3.30 W/g extract, 2 min), whereas, the conventional method (90 °C, 1 min) was the most suitable for antioxidant extraction. Consequently, the best process depends on the subsequent use (sweetener or antioxidant) of the aqueous extract of Stevia leaves.

  14. A Vector Flow Imaging Method for Portable Ultrasound Using Synthetic Aperture Sequential Beamforming

    DEFF Research Database (Denmark)

    di Ianni, Tommaso; Villagómez Hoyos, Carlos Armando; Ewertsen, Caroline

    2017-01-01

    for the velocity estimation along the lateral and axial directions using a phase-shift estimator. The performance of the method was investigated with constant flow measurements in a flow rig system using the SARUS scanner and a 4.1-MHz linear array. A sequence was designed with interleaved B-mode and flow......, and the standard deviation (SD) was between 6% and 9.6%. The axial bias was lower than 1% with an SD around 2%. The mean estimated angles were 66.70° ± 2.86°, 72.65° ± 2.48°, and 89.13° ± 0.79° for the three cases. A proof-of-concept demonstration of the real-time processing and wireless transmission was tested...

  15. BMAA extraction of cyanobacteria samples: which method to choose?

    Science.gov (United States)

    Lage, Sandra; Burian, Alfred; Rasmussen, Ulla; Costa, Pedro Reis; Annadotter, Heléne; Godhe, Anna; Rydberg, Sara

    2016-01-01

    β-N-Methylamino-L-alanine (BMAA), a neurotoxin reportedly produced by cyanobacteria, diatoms and dinoflagellates, is proposed to be linked to the development of neurological diseases. BMAA has been found in aquatic and terrestrial ecosystems worldwide, both in its phytoplankton producers and in several invertebrate and vertebrate organisms that bioaccumulate it. LC-MS/MS is the most frequently used analytical technique in BMAA research due to its high selectivity, though consensus is lacking as to the best extraction method to apply. This study accordingly surveys the efficiency of three extraction methods regularly used in BMAA research to extract BMAA from cyanobacteria samples. The results obtained provide insights into possible reasons for the BMAA concentration discrepancies in previous publications. In addition and according to the method validation guidelines for analysing cyanotoxins, the TCA protein precipitation method, followed by AQC derivatization and LC-MS/MS analysis, is now validated for extracting protein-bound (after protein hydrolysis) and free BMAA from cyanobacteria matrix. BMAA biological variability was also tested through the extraction of diatom and cyanobacteria species, revealing a high variance in BMAA levels (0.0080-2.5797 μg g(-1) DW).

  16. 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...

  17. Analysis of medicinal plant extracts by neutron activation method

    International Nuclear Information System (INIS)

    Vaz, Sandra Muntz

    1995-01-01

    This dissertation has presented the results from analysis of medicinal plant extracts using neutron activation method. Instrumental neutron activation analysis was applied to the determination of the elements Al, Br, Ca, Ce, Cl, Cr, Cs, Fe, K, La, Mg, Mn, Na, Rb, Sb, Sc and Zn in medicinal extracts obtained from Achyrolcline satureoides DC, Casearia sylvestris, Centella asiatica, Citrus aurantium L., Solano lycocarpum, Solidago microglossa, Stryphnondedron barbatiman and Zingiber officinale R. plants. The elements Hg and Se were determined using radiochemical separation by means of retention of Se in HMD inorganic exchanger and solvent extraction of Hg by bismuth diethyl-dithiocarbamate solution. Precision and accuracy of the results have been evaluated by analysing reference materials. The therapeutic action of some elements found in plant extracts analyzed was briefly discussed

  18. A novel method of genomic DNA extraction for Cactaceae1

    Science.gov (United States)

    Fehlberg, Shannon D.; Allen, Jessica M.; Church, Kathleen

    2013-01-01

    • Premise of the study: Genetic studies of Cactaceae can at times be impeded by difficult sampling logistics and/or high mucilage content in tissues. Simplifying sampling and DNA isolation through the use of cactus spines has not previously been investigated. • Methods and Results: Several protocols for extracting DNA from spines were tested and modified to maximize yield, amplification, and sequencing. Sampling of and extraction from spines resulted in a simplified protocol overall and complete avoidance of mucilage as compared to typical tissue extractions. Sequences from one nuclear and three plastid regions were obtained across eight genera and 20 species of cacti using DNA extracted from spines. • Conclusions: Genomic DNA useful for amplification and sequencing can be obtained from cactus spines. The protocols described here are valuable for any cactus species, but are particularly useful for investigators interested in sampling living collections, extensive field sampling, and/or conservation genetic studies. PMID:25202521

  19. Extração seqüencial de cobre, ferro e zinco em ervas medicinais Sequential extraction of copper, iron and zinc in medicinal plants

    Directory of Open Access Journals (Sweden)

    Édira Castello Branco de Andrade

    2005-12-01

    initially for the pharmacists, indicates the ratio of the nutrient that is absorbed and used by the organism. This way, the determination of the total content of the metal ingested by the organism does not make possible to trace a profile of the efficiency of its absorption. Techniques of chemical speciation, as the sequential extraction, can assist in the evaluation of the bioavailability of minerals. Samples of medicinal grass of two lots were analyzed in relation to the total content of copper, iron and zinc for spectroscopy of atomic absorption in the flame, and the sequential extraction was applied. F, Dixon and t-student tests were used. One observed that, in average, the samples presented copper, iron and zinc total content of respectively 1.37 mg%, 5.13 mg% and 2.96 mg%. When comparing these values with the content of these metals in foods of vegetal origin, it can be verified that the analyzed medicinal grass can be considered a good source of metals. It was still observed that the metals have copper, iron and zinc can be found in the samples under at least four distinct chemical species and that extractors I and Iv were more efficient. Techniques of chemical speciation that can identify the compounds obtained from different extractors can assist in the evaluation of their bioavailability, as well as in the absorption processes.

  20. 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

  1. Comparison of RNA extraction methods in Thai aromatic coconut water

    Directory of Open Access Journals (Sweden)

    Nopporn Jaroonchon

    2015-10-01

    Full Text Available Many researches have reported that nucleic acid in coconut water is in free form and at very low yields which makes it difficult to process in molecular studies. Our research attempted to compare two extraction methods to obtain a higher yield of total RNA in aromatic coconut water and monitor its change at various fruit stages. The first method used ethanol and sodium acetate as reagents; the second method used lithium chloride. We found that extraction using only lithium chloride gave a higher total RNA yield than the method using ethanol to precipitate nucleic acid. In addition, the total RNA from both methods could be used in amplification of betaine aldehyde dehydrogenase2 (Badh2 genes, which is involved in coconut aroma biosynthesis, and could be used to perform further study as we expected. From the molecular study, the nucleic acid found in coconut water increased with fruit age.

  2. DNA extraction method for PCR in mycorrhizal fungi.

    Science.gov (United States)

    Manian, S; Sreenivasaprasad, S; Mills, P R

    2001-10-01

    To develop a simple and rapid DNA extraction protocol for PCR in mycorrhizal fungi. The protocol combines the application of rapid freezing and boiling cycles and passage of the extracts through DNA purification columns. PCR amplifiable DNA was obtained from a number of endo- and ecto-mycorrhizal fungi using minute quantities of spores and mycelium, respectively. DNA extracted following the method, was used to successfully amplify regions of interest from high as well as low copy number genes. The amplicons were suitable for further downstream applications such as sequencing and PCR-RFLPs. The protocol described is simple, short and facilitates rapid isolation of PCR amplifiable genomic DNA from a large number of fungal isolates in a single day. The method requires only minute quantities of starting material and is suitable for mycorrhizal fungi as well as a range of other fungi.

  3. An efficient method for DNA extraction from Cladosporioid fungi.

    Science.gov (United States)

    Moslem, M A; Bahkali, A H; Abd-Elsalam, K A; Wit, P J G M

    2010-11-23

    We developed an efficient method for DNA extraction from Cladosporioid fungi, which are important fungal plant pathogens. The cell wall of Cladosporioid fungi is often melanized, which makes it difficult to extract DNA from their cells. In order to overcome this we grew these fungi for three days on agar plates and extracted DNA from mycelium mats after manual or electric homogenization. High-quality DNA was isolated, with an A(260)/A(280) ratio ranging between 1.6 and 2.0. Isolated genomic DNA was efficiently digested with restriction enzymes and produced distinct banding patterns on agarose gels for the different Cladosporium species. Clear DNA fragments from the isolated DNA were amplified by PCR using small and large subunit rDNA primers, demonstrating that this method provides DNA of sufficiently high quality for molecular analyses.

  4. Non-Pilot-Aided Sequential Monte Carlo Method to Joint Signal, Phase Noise, and Frequency Offset Estimation in Multicarrier Systems

    Directory of Open Access Journals (Sweden)

    Christelle Garnier

    2008-05-01

    Full Text Available We address the problem of phase noise (PHN and carrier frequency offset (CFO mitigation in multicarrier receivers. In multicarrier systems, phase distortions cause two effects: the common phase error (CPE and the intercarrier interference (ICI which severely degrade the accuracy of the symbol detection stage. Here, we propose a non-pilot-aided scheme to jointly estimate PHN, CFO, and multicarrier signal in time domain. Unlike existing methods, non-pilot-based estimation is performed without any decision-directed scheme. Our approach to the problem is based on Bayesian estimation using sequential Monte Carlo filtering commonly referred to as particle filtering. The particle filter is efficiently implemented by combining the principles of the Rao-Blackwellization technique and an approximate optimal importance function for phase distortion sampling. Moreover, in order to fully benefit from time-domain processing, we propose a multicarrier signal model which includes the redundancy information induced by the cyclic prefix, thus leading to a significant performance improvement. Simulation results are provided in terms of bit error rate (BER and mean square error (MSE to illustrate the efficiency and the robustness of the proposed algorithm.

  5. The respective effects of soil heavy metal fractions by sequential extraction procedure and soil properties on the accumulation of heavy metals in rice grains and brassicas.

    Science.gov (United States)

    Xiao, Ling; Guan, Dongsheng; Peart, M R; Chen, Yujuan; Li, Qiqi

    2017-01-01

    This study was carried out to examine heavy metal accumulation in rice grains and brassicas and to identify the different controls, such as soil properties and soil heavy metal fractions obtained by the Community Bureau of Reference (BCR) sequential extraction, in their accumulation. In Guangdong Province, South China, rice grain and brassica samples, along with their rhizospheric soil, were collected from fields on the basis of distance downstream from electroplating factories, whose wastewater was used for irrigation. The results showed that long-term irrigation using the electroplating effluent has not only enriched the rhizospheric soil with Cd, Cr, Cu, and Zn but has also increased their mobility and bioavailability. The average concentrations of Cd and Cr in rice grains and brassicas from closest to the electroplating factories were significantly higher than those from the control areas. Results from hybrid redundancy analysis (hRDA) and redundancy analysis (RDA) showed that the BCR fractions of soil heavy metals could explain 29.0 and 46.5 % of total eigenvalue for heavy metal concentrations in rice grains and brassicas, respectively, while soil properties could only explain 11.1 and 33.4 %, respectively. This indicated that heavy metal fractions exerted more control upon their concentrations in rice grains and brassicas than soil properties. In terms of metal interaction, an increase of residual Zn in paddy soil or a decrease of acid soluble Cd in the brassica soil could enhance the accumulation of Cd, Cu, Cr, and Pb in both rice grains and brassicas, respectively, while the reducible or oxidizable Cd in soil could enhance the plants' accumulation of Cr and Pb. The RDA showed an inhibition effect of sand content and CFO on the accumulation of heavy metals in rice grains and brassicas. Moreover, multiple stepwise linear regression could offer prediction for Cd, Cu, Cr, and Zn concentrations in the two crops by soil heavy metal fractions and soil properties.

  6. Calculation of radon concentration in water by toluene extraction method

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Masaaki [Tokyo Metropolitan Isotope Research Center (Japan)

    1997-02-01

    Noguchi method and Horiuchi method have been used as the calculation method of radon concentration in water. Both methods have two problems in the original, that is, the concentration calculated is changed by the extraction temperature depend on the incorrect solubility data and the concentration calculated are smaller than the correct values, because the radon calculation equation does not true to the gas-liquid equilibrium theory. However, the two problems are solved by improving the radon equation. I presented the Noguchi-Saito equation and the constant B of Horiuchi-Saito equation. The calculating results by the improved method showed about 10% of error. (S.Y.)

  7. Development of {sup 99m}Tc extraction-recovery by solvent extraction method

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Akihiro; Nishikata, Kaori; Izumo, Hironobu; Tsuchiya, Kunihiko; Ishihara, Masahiro [Japan Atomic Energy Agency, Oarai Research and Development Center, Oarai, Ibaraki (Japan); Tanase, Masakazu; Fujisaki, Saburo; Shiina, Takayuki; Ohta, Akio; Takeuchi, Nobuhiro [Chiyoda Technol Corp., Tokyo (Japan)

    2012-03-15

    {sup 99m}Tc is used as a radiopharmaceutical in the medical field for the diagnosis, and manufactured from {sup 99}Mo, the parent nuclide. In this study, the solvent extraction with MEK was selected, and preliminary experiments were carried out using Re instead of {sup 99m}Tc. Two tests were carried out in the experiments; the one is the Re extraction test with MEK from Re-Mo solution, the other is the Re recovery test from the Re-MEK. As to the Re extraction test, and it was clear that the Re extraction yield was more than 90%. Two kinds of Re recovery tests, which are an evaporation method using the evaporator and an adsorption/elution method using the alumina column, were carried out. As to the evaporation method, the Re concentration in the collected solution increased more than 150 times. As to the adsorption/elution method, the Re concentration increased in the eluted solution more than 20 times. (author)

  8. An Improved Method for Extraction and Separation of Photosynthetic Pigments

    Science.gov (United States)

    Katayama, Nobuyasu; Kanaizuka, Yasuhiro; Sudarmi, Rini; Yokohama, Yasutsugu

    2003-01-01

    The method for extracting and separating hydrophobic photosynthetic pigments proposed by Katayama "et al." ("Japanese Journal of Phycology," 42, 71-77, 1994) has been improved to introduce it to student laboratories at the senior high school level. Silica gel powder was used for removing water from fresh materials prior to…

  9. Genomic DNA extraction method from pearl millet ( Pennisetum ...

    African Journals Online (AJOL)

    DNA extraction is difficult in a variety of plants because of the presence of metabolites that interfere with DNA isolation procedures and downstream applications such as DNA restriction, amplification, and cloning. Here we describe a modified procedure based on the hexadecyltrimethylammonium bromide (CTAB) method to ...

  10. Genomic DNA extraction method from Annona senegalensis Pers ...

    African Journals Online (AJOL)

    Extraction of DNA in many plants is difficult because of the presence of metabolites that interfere with DNA isolation procedures and downstream applications such as DNA restriction, replications, amplification, as well as cloning. Modified procedure based on the hexadecyltrimethyl ammoniumbromide (CTAB) method is ...

  11. 7 CFR 51.1179 - Method of juice extraction.

    Science.gov (United States)

    2010-01-01

    ... STANDARDS) United States Standards for Grades of Florida Oranges and Tangelos Standards for Internal Quality... 7 Agriculture 2 2010-01-01 2010-01-01 false Method of juice extraction. 51.1179 Section 51.1179 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards...

  12. Extraction chromatographic method for the separation of actinides and lanthanides using EDHBA grafted AXAD-16 polymer

    Energy Technology Data Exchange (ETDEWEB)

    Akhila Maheswari, M.; Subramanian, M.S. [Department of Chemistry, Indian Institute of Technology, Chennai (India)

    2005-02-15

    A new extraction chromatographic method has been developed by grafting chloromethylated polymer support with 4-ethoxy-N,N-dihexylbutanamide (EDHBA), for the selective extraction of U(VI), Th(IV), La(III) and Nd(III) from highly acidic matrices. The developed grafted polymer has been characterized using {sup 13}C-CPMAS NMR spectroscopy, FT-NIR spectroscopy and also by CHN elemental analysis. The water regaining capacity of the grafted polymer is studied by TGA measurements and the active participation of the amide moiety towards metal ion complexation has been confirmed by Far IR spectroscopy. For the quantitative extraction of metal ions to the resin phase, various physico-chemical parameters are optimized by both static and dynamic methods. The developed amide grafted polymeric matrix shows good distribution ratio values even at high acidities, with the maximum metal sorption capacity values being 0.36, 0.69, 0.32 and 0.42mmolg{sup -1} for U(VI), Th(IV), La(III) and Nd(III), respectively, at 6M HNO{sub 3} medium. The kinetics of metal ion phase equilibration is found to be moderately fast, with t{sub 1/2} values of <6min, for all the analytes of interest. The limits of analyte quantification (LOQ) using the developed method are in the range of 15-30{mu}gL{sup -1}. Moreover, the sequential separation of the sorbed actinides and lanthanides could be achieved by first eluting with 100mL of distilled water (for actinides) followed by elution with 20mL of 0.1M EDTA (for lanthanides). The selectivity behavior and the practical applicability of the developed resin are tested using synthetic low level nuclear reprocessing mixtures and also with monazite sand. The analytical data are within 3.8% relative standard deviation, reflecting the reproducibility and reliability of the developed method.

  13. Extraction of uranium from simulated ore by the supercritical carbon dioxide fluid extraction method with nitric acid-TBP complex

    International Nuclear Information System (INIS)

    Dung, Le Thi Kim; Imai, Tomoki; Tomioka, Osamu; Nakashima, Mikio; Takahashi, Kuniaki; Meguro, Yoshihiro

    2006-01-01

    The supercritical fluid extraction (SFE) method using CO 2 as a medium with an extractant of HNO 3 -tri-n-butyl phosphate (TBP) complex was applied to extract uranium from several uranyl phosphate compounds and simulated uranium ores. An extraction method consisting of a static extraction process and a dynamic one was established, and the effects of the experimental conditions, such as pressure, temperature, and extraction time, on the extraction of uranium were ascertained. It was found that uranium could be efficiently extracted from both the uranyl phosphates and simulated ores by the SFE method using CO 2 . It was thus demonstrated that the SFE method using CO 2 is useful as a pretreatment method for the analysis of uranium in ores. (author)

  14. Sequential diffusion of ammonium and nitrate from soil extracts to a polytetrafluoroethylene trap for 15N determination

    DEFF Research Database (Denmark)

    Sørensen, P.; Jensen, E.S.

    1991-01-01

    A novel diffusion method was used for preparation of NH4+- and NO3--N samples from soil extracts for N-15 determination. Ammonium, and nitrate following reduction to ammonia, are allowed to diffuse to an acid-wetted glass filter enclosed in polytetrafluoroethylene tape. The method was evaluated...... with simulated soil extracts obtained using 50 ml of 2 M potassium chloride solution containing 130-mu-g of NH4+-N (2.3 atom% N-15) and 120-mu-g of NO3--N (natural N-15 abundance). No cross-over in the N-15 abundances of NH4+-N and NO3--N was observed, indicating a quantitative diffusion process (72 h, 25...

  15. Exploring selection and recruitment processes for newly qualified nurses: a sequential-explanatory mixed-method study.

    Science.gov (United States)

    Newton, Paul; Chandler, Val; Morris-Thomson, Trish; Sayer, Jane; Burke, Linda

    2015-01-01

    To map current selection and recruitment processes for newly qualified nurses and to explore the advantages and limitations of current selection and recruitment processes. The need to improve current selection and recruitment practices for newly qualified nurses is highlighted in health policy internationally. A cross-sectional, sequential-explanatory mixed-method design with 4 components: (1) Literature review of selection and recruitment of newly qualified nurses; and (2) Literature review of a public sector professions' selection and recruitment processes; (3) Survey mapping existing selection and recruitment processes for newly qualified nurses; and (4) Qualitative study about recruiters' selection and recruitment processes. Literature searches on the selection and recruitment of newly qualified candidates in teaching and nursing (2005-2013) were conducted. Cross-sectional, mixed-method data were collected from thirty-one (n = 31) individuals in health providers in London who had responsibility for the selection and recruitment of newly qualified nurses using a survey instrument. Of these providers who took part, six (n = 6) purposively selected to be interviewed qualitatively. Issues of supply and demand in the workforce, rather than selection and recruitment tools, predominated in the literature reviews. Examples of tools to measure values, attitudes and skills were found in the nursing literature. The mapping exercise found that providers used many selection and recruitment tools, some providers combined tools to streamline process and assure quality of candidates. Most providers had processes which addressed the issue of quality in the selection and recruitment of newly qualified nurses. The 'assessment centre model', which providers were adopting, allowed for multiple levels of assessment and streamlined recruitment. There is a need to validate the efficacy of the selection tools. © 2014 John Wiley & Sons Ltd.

  16. Deep Learning Methods for Underwater Target Feature Extraction and Recognition

    Directory of Open Access Journals (Sweden)

    Gang Hu

    2018-01-01

    Full Text Available The classification and recognition technology of underwater acoustic signal were always an important research content in the field of underwater acoustic signal processing. Currently, wavelet transform, Hilbert-Huang transform, and Mel frequency cepstral coefficients are used as a method of underwater acoustic signal feature extraction. In this paper, a method for feature extraction and identification of underwater noise data based on CNN and ELM is proposed. An automatic feature extraction method of underwater acoustic signals is proposed using depth convolution network. An underwater target recognition classifier is based on extreme learning machine. Although convolution neural networks can execute both feature extraction and classification, their function mainly relies on a full connection layer, which is trained by gradient descent-based; the generalization ability is limited and suboptimal, so an extreme learning machine (ELM was used in classification stage. Firstly, CNN learns deep and robust features, followed by the removing of the fully connected layers. Then ELM fed with the CNN features is used as the classifier to conduct an excellent classification. Experiments on the actual data set of civil ships obtained 93.04% recognition rate; compared to the traditional Mel frequency cepstral coefficients and Hilbert-Huang feature, recognition rate greatly improved.

  17. Analytical methods and problems for the diamides type of extractants

    International Nuclear Information System (INIS)

    Cuillerdier, C.; Nigond, L.; Musikas, C.; Vitart, H.; Hoel, P.

    1989-01-01

    Diamides of carboxylic acids and especially malonamides are able to extract alpha emitters (including trivalent ions such as Am and Cm) contained in the wastes solutions of the nuclear industry. As they are completely incinerable and easy to purify, they could be an alternative to the mixture CMPO-TBP which is used in the TRUEX process. A large oxyalkyl radical enhances the distribution coefficients of americium in nitric acid sufficiently to permit the decontamination of wastes solutions in a classical mixers-settlers battery. Now researches are pursued with the aim of optimizing the formula of extractant, the influence of the structure of the extractant on its basicity and stability under radiolysis and hydrolysis is investigated. Analytical methods (potentiometry and NMR of C 13 ) have been developed for solvent titration and to evaluate the percentage of degradation and to identify some of the degradation products

  18. Analysis of Feature Extraction Methods for Speaker Dependent Speech Recognition

    Directory of Open Access Journals (Sweden)

    Gurpreet Kaur

    2017-02-01

    Full Text Available Speech recognition is about what is being said, irrespective of who is saying. Speech recognition is a growing field. Major progress is taking place on the technology of automatic speech recognition (ASR. Still, there are lots of barriers in this field in terms of recognition rate, background noise, speaker variability, speaking rate, accent etc. Speech recognition rate mainly depends on the selection of features and feature extraction methods. This paper outlines the feature extraction techniques for speaker dependent speech recognition for isolated words. A brief survey of different feature extraction techniques like Mel-Frequency Cepstral Coefficients (MFCC, Linear Predictive Coding Coefficients (LPCC, Perceptual Linear Prediction (PLP, Relative Spectra Perceptual linear Predictive (RASTA-PLP analysis are presented and evaluation is done. Speech recognition has various applications from daily use to commercial use. We have made a speaker dependent system and this system can be useful in many areas like controlling a patient vehicle using simple commands.

  19. Isolation and Identification of Volatile Components in Tempe by Simultaneous Distillation-Extraction Method by Modified Extraction Method

    Directory of Open Access Journals (Sweden)

    Syahrial Syahrial

    2010-06-01

    Full Text Available An isolation and identification of volatile components in temps for 2, 5 and 8 days fermentation by simultaneous distillation-extraction method was carried out. Simultaneous distillation-extraction apparatus was modified by Muchalal from the basic Likens-Nickerson's design. Steam distillation and benzena as an extraction solvent was used in this system. The isolation was continuously carried out for 3 hours which maximum water temperature In the Liebig condenser was 8 °C. The extract was concentrated by freeze concentration method, and the volatile components were analyzed and identified by combined gas chromatography-mass spectrophotometry (GC-MS. The Muchalal's simultaneous distillation extraction apparatus have some disadvantage in cold finger condenser, and it's extractor did not have condenser. At least 47, 13 and 5 volatile components were found in 2, 5 and 8 days fermentation, respectively. The volatile components in the 2 days fermentation were nonalal, ɑ-pinene, 2,4-decadienal, 5-phenyldecane, 5-phenylundecane, 4-phenylundecane, 5-phenyldodecane, 4-phenyldodecane, 3-phenyldodecane, 2-phenyldodecane, 5-phenyltridecane, and caryophyllene; in the 5 days fermentation were nonalal, caryophyllene, 4-phenylundecane, 5-phenyldodecane, 4-phenyldodecane, 3-phenyldodecane, 2-phenyldodecane; and in the 8 days fermentation were ethenyl butanoic, 2-methy1-3-(methylethenylciclohexyl etanoic and 3,7-dimethyl-5-octenyl etanoic.

  20. Lipid Extraction Methods from Microalgae: A Comprehensive Review

    Energy Technology Data Exchange (ETDEWEB)

    Ranjith Kumar, Ramanathan [Department of Plant Biology and Plant Biotechnology, Shree Chandraprabhu Jain College, Chennai (India); Hanumantha Rao, Polur [Department of Microbiology, Madras Christian College, Chennai (India); Arumugam, Muthu, E-mail: arumugam@niist.res.in [Division of Biotechnology, CSIR – National Institute for Interdisciplinary Science and Technology (NIIST), Trivandrum (India)

    2015-01-08

    Energy security has become a serious global issue and a lot of research is being carried out to look for economically viable and environment-friendly alternatives. The only solution that appears to meet futuristic needs is the use of renewable energy. Although various forms of renewable energy are being currently used, the prospects of producing carbon-neutral biofuels from microalgae appear bright because of their unique features such as suitability of growing in open ponds required for production of a commodity product, high CO{sub 2}-sequestering capability, and ability to grow in wastewater/seawater/brackish water and high-lipid productivity. The major process constraint in microalgal biofuel technology is the cost-effective and efficient extraction of lipids. The objective of this article is to provide a comprehensive review on various methods of lipid extraction from microalgae available, to date, as well as to discuss their advantages and disadvantages. The article covers all areas of lipid extraction procedures including solvent extraction procedures, mechanical approaches, and solvent-free procedures apart from some of the latest extraction technologies. Further research is required in this area for successful implementation of this technology at the production scale.

  1. Lipid Extraction Methods from Microalgae: A Comprehensive Review

    International Nuclear Information System (INIS)

    Ranjith Kumar, Ramanathan; Hanumantha Rao, Polur; Arumugam, Muthu

    2015-01-01

    Energy security has become a serious global issue and a lot of research is being carried out to look for economically viable and environment-friendly alternatives. The only solution that appears to meet futuristic needs is the use of renewable energy. Although various forms of renewable energy are being currently used, the prospects of producing carbon-neutral biofuels from microalgae appear bright because of their unique features such as suitability of growing in open ponds required for production of a commodity product, high CO 2 -sequestering capability, and ability to grow in wastewater/seawater/brackish water and high-lipid productivity. The major process constraint in microalgal biofuel technology is the cost-effective and efficient extraction of lipids. The objective of this article is to provide a comprehensive review on various methods of lipid extraction from microalgae available, to date, as well as to discuss their advantages and disadvantages. The article covers all areas of lipid extraction procedures including solvent extraction procedures, mechanical approaches, and solvent-free procedures apart from some of the latest extraction technologies. Further research is required in this area for successful implementation of this technology at the production scale.

  2. Multiple and sequential data acquisition method: an improved method for fragmentation and detection of cross-linked peptides on a hybrid linear trap quadrupole Orbitrap Velos mass spectrometer.

    Science.gov (United States)

    Rudashevskaya, Elena L; Breitwieser, Florian P; Huber, Marie L; Colinge, Jacques; Müller, André C; Bennett, Keiryn L

    2013-02-05

    The identification and validation of cross-linked peptides by mass spectrometry remains a daunting challenge for protein-protein cross-linking approaches when investigating protein interactions. This includes the fragmentation of cross-linked peptides in the mass spectrometer per se and following database searching, the matching of the molecular masses of the fragment ions to the correct cross-linked peptides. The hybrid linear trap quadrupole (LTQ) Orbitrap Velos combines the speed of the tandem mass spectrometry (MS/MS) duty circle with high mass accuracy, and these features were utilized in the current study to substantially improve the confidence in the identification of cross-linked peptides. An MS/MS method termed multiple and sequential data acquisition method (MSDAM) was developed. Preliminary optimization of the MS/MS settings was performed with a synthetic peptide (TP1) cross-linked with bis[sulfosuccinimidyl] suberate (BS(3)). On the basis of these results, MSDAM was created and assessed on the BS(3)-cross-linked bovine serum albumin (BSA) homodimer. MSDAM applies a series of multiple sequential fragmentation events with a range of different normalized collision energies (NCE) to the same precursor ion. The combination of a series of NCE enabled a considerable improvement in the quality of the fragmentation spectra for cross-linked peptides, and ultimately aided in the identification of the sequences of the cross-linked peptides. Concurrently, MSDAM provides confirmatory evidence from the formation of reporter ions fragments, which reduces the false positive rate of incorrectly assigned cross-linked peptides.

  3. The sequentially discounting autoregressive (SDAR) method for on-line automatic seismic event detecting on long term observation

    Science.gov (United States)

    Wang, L.; Toshioka, T.; Nakajima, T.; Narita, A.; Xue, Z.

    2017-12-01

    In recent years, more and more Carbon Capture and Storage (CCS) studies focus on seismicity monitoring. For the safety management of geological CO2 storage at Tomakomai, Hokkaido, Japan, an Advanced Traffic Light System (ATLS) combined different seismic messages (magnitudes, phases, distributions et al.) is proposed for injection controlling. The primary task for ATLS is the seismic events detection in a long-term sustained time series record. Considering the time-varying characteristics of Signal to Noise Ratio (SNR) of a long-term record and the uneven energy distributions of seismic event waveforms will increase the difficulty in automatic seismic detecting, in this work, an improved probability autoregressive (AR) method for automatic seismic event detecting is applied. This algorithm, called sequentially discounting AR learning (SDAR), can identify the effective seismic event in the time series through the Change Point detection (CPD) of the seismic record. In this method, an anomaly signal (seismic event) can be designed as a change point on the time series (seismic record). The statistical model of the signal in the neighborhood of event point will change, because of the seismic event occurrence. This means the SDAR aims to find the statistical irregularities of the record thought CPD. There are 3 advantages of SDAR. 1. Anti-noise ability. The SDAR does not use waveform messages (such as amplitude, energy, polarization) for signal detecting. Therefore, it is an appropriate technique for low SNR data. 2. Real-time estimation. When new data appears in the record, the probability distribution models can be automatic updated by SDAR for on-line processing. 3. Discounting property. the SDAR introduces a discounting parameter to decrease the influence of present statistic value on future data. It makes SDAR as a robust algorithm for non-stationary signal processing. Within these 3 advantages, the SDAR method can handle the non-stationary time-varying long

  4. Evaluation of in vitro antioxidant potential of different polarities stem crude extracts by different extraction methods of Adenium obesum

    Directory of Open Access Journals (Sweden)

    Mohammad Amzad Hossain

    2014-09-01

    Full Text Available Objective: To select best extraction method for the isolated antioxidant compounds from the stems of Adenium obesum. Methods: Two methods used for the extraction are Soxhlet and maceration methods. Methanol solvent was used for both extraction method. The methanol crude extract was defatted with water and extracted successively with hexane, chloroform, ethyl acetate and butanol solvents. The antioxidant potential for all crude extracts were determined by using 1, 1-diphenyl-2- picrylhydrazyl method. Results: The percentage of extraction yield by Soxhlet method is higher compared to maceration method. The antioxidant potential for methanol and its derived fractions by Soxhlet extractor method was highest in ethyl acetate and lowest in hexane crude extracts and found in the order of ethyl acetate>butanol>water>chloroform>methanol>hexane. However, the antioxidant potential for methanol and its derived fractions by maceration method was highest in butanol and lowest in hexane followed in the order of butanol>methanol>chloroform>water>ethyl acetate>hexane. Conclusions: The results showed that isolate antioxidant compounds effected on the extraction method and condition of extraction.

  5. SAR Data Fusion Imaging Method Oriented to Target Feature Extraction

    Directory of Open Access Journals (Sweden)

    Yang Wei

    2015-02-01

    Full Text Available To deal with the difficulty for target outlines extracting precisely due to neglect of target scattering characteristic variation during the processing of high-resolution space-borne SAR data, a novel fusion imaging method is proposed oriented to target feature extraction. Firstly, several important aspects that affect target feature extraction and SAR image quality are analyzed, including curved orbit, stop-and-go approximation, atmospheric delay, and high-order residual phase error. Furthermore, the corresponding compensation methods are addressed as well. Based on the analysis, the mathematical model of SAR echo combined with target space-time spectrum is established for explaining the space-time-frequency change rule of target scattering characteristic. Moreover, a fusion imaging strategy and method under high-resolution and ultra-large observation angle range conditions are put forward to improve SAR quality by fusion processing in range-doppler and image domain. Finally, simulations based on typical military targets are used to verify the effectiveness of the fusion imaging method.

  6. Exact extraction method for road rutting laser lines

    Science.gov (United States)

    Hong, Zhiming

    2018-02-01

    This paper analyzes the importance of asphalt pavement rutting detection in pavement maintenance and pavement administration in today's society, the shortcomings of the existing rutting detection methods are presented and a new rutting line-laser extraction method based on peak intensity characteristic and peak continuity is proposed. The intensity of peak characteristic is enhanced by a designed transverse mean filter, and an intensity map of peak characteristic based on peak intensity calculation for the whole road image is obtained to determine the seed point of the rutting laser line. Regarding the seed point as the starting point, the light-points of a rutting line-laser are extracted based on the features of peak continuity, which providing exact basic data for subsequent calculation of pavement rutting depths.

  7. Integrated Phoneme Subspace Method for Speech Feature Extraction

    Directory of Open Access Journals (Sweden)

    Park Hyunsin

    2009-01-01

    Full Text Available Speech feature extraction has been a key focus in robust speech recognition research. In this work, we discuss data-driven linear feature transformations applied to feature vectors in the logarithmic mel-frequency filter bank domain. Transformations are based on principal component analysis (PCA, independent component analysis (ICA, and linear discriminant analysis (LDA. Furthermore, this paper introduces a new feature extraction technique that collects the correlation information among phoneme subspaces and reconstructs feature space for representing phonemic information efficiently. The proposed speech feature vector is generated by projecting an observed vector onto an integrated phoneme subspace (IPS based on PCA or ICA. The performance of the new feature was evaluated for isolated word speech recognition. The proposed method provided higher recognition accuracy than conventional methods in clean and reverberant environments.

  8. Combining selective sequential extractions, X-Ray Absorption Spectroscopy, and X-Ray Powder Diffraction for Cu (II speciation in soil and mineral phases

    Directory of Open Access Journals (Sweden)

    Tatiana Minkina

    2017-04-01

    Full Text Available Interaction of Cu (II ions with the matrix of soil and mineral phases of layered silicates was assessed by the Miller method of selective sequential fractionation and a set of synchrotron X-ray methods, including X-ray powder diffraction (XRD and X-ray absorption spectroscopy (XANES. It was shown that the input of Cu into Calcic Chernozem in the form of monoxide (CuO and salt (Cu(NO32 affected the transformation of Cu compounds and their affinity for metal-bearing phases. It was found that the contamination of soil with a soluble Cu(II salt increased the bioavailability of the metal and the role of organic matter and Fe oxides in the fixation and retention of Cu. During the incubation of soil with Cu monoxide, the content of the metal in the residual fractions increased, which was related to the possible entry of Cu in the form of isomorphic impurities into silicates, as well as to the incomplete dissolution of exogenic compounds at the high level of their input into the soil. A mechanism for the structural transformation of minerals was revealed, which showed that ion exchange processes result in the sorption of Cu (II ions from the saturated solution by active sites on the internal surface of the lattice of dioctahedral aluminosilicates. Surface hydroxyls at the octahedral aluminum atom play the main role. X-ray diagnostics revealed that excess Cu(II ions are removed from the system due to the formation and precipitation of coarsely crystalline Cu(NO3(OH3.

  9. Exploring Liquid Sequential Injection Chromatography to Teach Fundamentals of Separation Methods: A Very Fast Analytical Chemistry Experiment

    Science.gov (United States)

    Penteado, Jose C.; Masini, Jorge Cesar

    2011-01-01

    Influence of the solvent strength determined by the addition of a mobile-phase organic modifier and pH on chromatographic separation of sorbic acid and vanillin has been investigated by the relatively new technique, liquid sequential injection chromatography (SIC). This technique uses reversed-phase monolithic stationary phase to execute fast…

  10. EFFECTS OF EXTRACTION METHODS ON PHYSICO-CHEMICAL ...

    African Journals Online (AJOL)

    The relative density value ranged from 0.9 to 0.92 at 29°C (room temperature). Both oil samples were in liquid state at room temperature and boiling points varied from 94°C-to 98°C for solvent extracted oil and hydraulic press oil respectively. The results showed thatJhe method ofextraction imposed significant changes on ...

  11. Effects of Feature Extraction and Classification Methods on Cyberbully Detection

    OpenAIRE

    ÖZEL, Selma Ayşe; SARAÇ, Esra

    2016-01-01

    Cyberbullying is defined as an aggressive, intentional action against a defenseless person by using the Internet, or other electronic contents. Researchers have found that many of the bullying cases have tragically ended in suicides; hence automatic detection of cyberbullying has become important. In this study we show the effects of feature extraction, feature selection, and classification methods that are used, on the performance of automatic detection of cyberbullying. To perform the exper...

  12. A method for extracting chaotic signal from noisy environment

    International Nuclear Information System (INIS)

    Shang, L.-J.; Shyu, K.-K.

    2009-01-01

    In this paper, we propose a approach for extracting chaos signal from noisy environment where the chaotic signal has been contaminated by white Gaussian noise. The traditional type of independent component analysis (ICA) is capable of separating mixed signals and retrieving them independently; however, the separated signal shows unreal amplitude. The results of this study show with our method the real chaos signal can be effectively recovered.

  13. Extractive method for obtaining gas inclusions from ice

    International Nuclear Information System (INIS)

    Strauch, G.; Kowski, P.

    1982-01-01

    Doubtless important for glaciological investigations of firn and ice is the knowledge about the chemical composition of gases included in ice. A method for quantitative extraction of gases from about 30 kg ice under vacuum is presented in this paper. The procedure was tested with ice cores from a thermoelectrical drill hole near Soviet Antarctic station Novolazarevskaya. The chemical compositions of inclusion gases and the specific gas contents from 6 horizons are pointed out by a table and some graphics. (author)

  14. Methods for extracting social network data from chatroom logs

    Science.gov (United States)

    Osesina, O. Isaac; McIntire, John P.; Havig, Paul R.; Geiselman, Eric E.; Bartley, Cecilia; Tudoreanu, M. Eduard

    2012-06-01

    Identifying social network (SN) links within computer-mediated communication platforms without explicit relations among users poses challenges to researchers. Our research aims to extract SN links in internet chat with multiple users engaging in synchronous overlapping conversations all displayed in a single stream. We approached this problem using three methods which build on previous research. Response-time analysis builds on temporal proximity of chat messages; word context usage builds on keywords analysis and direct addressing which infers links by identifying the intended message recipient from the screen name (nickname) referenced in the message [1]. Our analysis of word usage within the chat stream also provides contexts for the extracted SN links. To test the capability of our methods, we used publicly available data from Internet Relay Chat (IRC), a real-time computer-mediated communication (CMC) tool used by millions of people around the world. The extraction performances of individual methods and their hybrids were assessed relative to a ground truth (determined a priori via manual scoring).

  15. Mechanomyographic Parameter Extraction Methods: An Appraisal for Clinical Applications

    Directory of Open Access Journals (Sweden)

    Morufu Olusola Ibitoye

    2014-12-01

    Full Text Available The research conducted in the last three decades has collectively demonstrated that the skeletal muscle performance can be alternatively assessed by mechanomyographic signal (MMG parameters. Indices of muscle performance, not limited to force, power, work, endurance and the related physiological processes underlying muscle activities during contraction have been evaluated in the light of the signal features. As a non-stationary signal that reflects several distinctive patterns of muscle actions, the illustrations obtained from the literature support the reliability of MMG in the analysis of muscles under voluntary and stimulus evoked contractions. An appraisal of the standard practice including the measurement theories of the methods used to extract parameters of the signal is vital to the application of the signal during experimental and clinical practices, especially in areas where electromyograms are contraindicated or have limited application. As we highlight the underpinning technical guidelines and domains where each method is well-suited, the limitations of the methods are also presented to position the state of the art in MMG parameters extraction, thus providing the theoretical framework for improvement on the current practices to widen the opportunity for new insights and discoveries. Since the signal modality has not been widely deployed due partly to the limited information extractable from the signals when compared with other classical techniques used to assess muscle performance, this survey is particularly relevant to the projected future of MMG applications in the realm of musculoskeletal assessments and in the real time detection of muscle activity.

  16. A Data-Driven Method for Selecting Optimal Models Based on Graphical Visualisation of Differences in Sequentially Fitted ROC Model Parameters

    Directory of Open Access Journals (Sweden)

    K S Mwitondi

    2013-05-01

    Full Text Available Differences in modelling techniques and model performance assessments typically impinge on the quality of knowledge extraction from data. We propose an algorithm for determining optimal patterns in data by separately training and testing three decision tree models in the Pima Indians Diabetes and the Bupa Liver Disorders datasets. Model performance is assessed using ROC curves and the Youden Index. Moving differences between sequential fitted parameters are then extracted, and their respective probability density estimations are used to track their variability using an iterative graphical data visualisation technique developed for this purpose. Our results show that the proposed strategy separates the groups more robustly than the plain ROC/Youden approach, eliminates obscurity, and minimizes over-fitting. Further, the algorithm can easily be understood by non-specialists and demonstrates multi-disciplinary compliance.

  17. Vanadium extraction from slimes by the lime-bicarbonate method

    International Nuclear Information System (INIS)

    Lishchenko, T.V.; Vdovina, L.V.; Slobodchikova, R.I.

    1978-01-01

    Some main parameters of the lime-bicarbonate method of extracting vanadium from residues obtained in washing waters of mazut boilers on thermal stations have been determined. To study the process of vanadium extraction during caking of the residues with lime and subsequent leaching of water-soluble vanadium, a ''Minsk-22'' computer has been used for computation. Analysis of the equation derived has shown that a change in temperature of vanadium leaching, density of pulp, and a kind of heating of the charge affect the process only slightly. It has also been shown that the calcination temperature is expedient to be kept above 850 deg C and consumption temperature is expedient to be kept above 85O deg C and consumption of lime must not exceed 20% of the residues weight. Bicarbonate consumption exerts a decisive influence on completeness of vanadium extraction and must be increased up to >35%; duration of leaching should be raised up to 30-45 minutes. With increasing calcination temperature the duration of leaching decreases. When temperature and duration of calcination increase, the formation of water-soluble vanadium intensifies. With the aid of optimization program seven variants have been chosen, which ensure vanadium extraction into solution by 95-100%

  18. Development of a fully automated sequential injection solid-phase extraction procedure coupled to liquid chromatography to determine free 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-methoxybenzophenone-5-sulphonic acid in human urine.

    Science.gov (United States)

    León, Zacarías; Chisvert, Alberto; Balaguer, Angel; Salvador, Amparo

    2010-04-07

    2-Hydroxy-4-methoxybenzophenone and 2-hydroxy-4-methoxybenzophenone-5-sulphonic acid, commonly known as benzophenone-3 (BZ3) and benzophenone-4 (BZ4), respectively, are substances widely used as UV filters in cosmetic products in order to absorb UV radiation and protect human skin from direct exposure to the deleterious wavelengths of sunlight. As with other UV filters, there is evidence of their percutaneous absorption. This work describes an analytical method developed to determine trace levels of free BZ3 and BZ4 in human urine. The methodology is based on a solid-phase extraction (SPE) procedure for clean-up and pre-concentration, followed by the monitoring of the UV filters by liquid chromatography-ultraviolet spectrophotometry detection (LC-UV). In order to improve not only the sensitivity and selectivity, but also the precision of the method, the principle of sequential injection analysis was used to automate the SPE process and to transfer the eluates from the SPE to the LC system. The application of a six-channel valve as an interface for the switching arrangements successfully allowed the on-line connection of SPE sample processing with LC analysis. The SPE process for BZ3 and BZ4 was performed using octadecyl (C18) and diethylaminopropyl (DEA) modified silica microcolumns, respectively, in which the analytes were retained and eluted selectively. Due to the matrix effects, the determination was based on standard addition quantification and was fully validated. The relative standard deviations of the results were 13% and 6% for BZ3 and BZ4, respectively, whereas the limits of detection were 60 and 30 ng mL(-1), respectively. The method was satisfactorily applied to determine BZ3 and BZ4 in urine from volunteers that had applied a sunscreen cosmetic containing both UV filters. Copyright 2010 Elsevier B.V. All rights reserved.

  19. Development of a fully automated sequential injection solid-phase extraction procedure coupled to liquid chromatography to determine free 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-methoxybenzophenone-5-sulphonic acid in human urine

    International Nuclear Information System (INIS)

    Leon, Zacarias; Chisvert, Alberto; Balaguer, Angel; Salvador, Amparo

    2010-01-01

    2-Hydroxy-4-methoxybenzophenone and 2-hydroxy-4-methoxybenzophenone-5-sulphonic acid, commonly known as benzophenone-3 (BZ3) and benzophenone-4 (BZ4), respectively, are substances widely used as UV filters in cosmetic products in order to absorb UV radiation and protect human skin from direct exposure to the deleterious wavelengths of sunlight. As with other UV filters, there is evidence of their percutaneous absorption. This work describes an analytical method developed to determine trace levels of free BZ3 and BZ4 in human urine. The methodology is based on a solid-phase extraction (SPE) procedure for clean-up and pre-concentration, followed by the monitoring of the UV filters by liquid chromatography-ultraviolet spectrophotometry detection (LC-UV). In order to improve not only the sensitivity and selectivity, but also the precision of the method, the principle of sequential injection analysis was used to automate the SPE process and to transfer the eluates from the SPE to the LC system. The application of a six-channel valve as an interface for the switching arrangements successfully allowed the on-line connection of SPE sample processing with LC analysis. The SPE process for BZ3 and BZ4 was performed using octadecyl (C18) and diethylaminopropyl (DEA) modified silica microcolumns, respectively, in which the analytes were retained and eluted selectively. Due to the matrix effects, the determination was based on standard addition quantification and was fully validated. The relative standard deviations of the results were 13% and 6% for BZ3 and BZ4, respectively, whereas the limits of detection were 60 and 30 ng mL -1 , respectively. The method was satisfactorily applied to determine BZ3 and BZ4 in urine from volunteers that had applied a sunscreen cosmetic containing both UV filters.

  20. Portable Rule Extraction Method for Neural Network Decisions Reasoning

    Directory of Open Access Journals (Sweden)

    Darius PLIKYNAS

    2005-08-01

    Full Text Available Neural network (NN methods are sometimes useless in practical applications, because they are not properly tailored to the particular market's needs. We focus thereinafter specifically on financial market applications. NNs have not gained full acceptance here yet. One of the main reasons is the "Black Box" problem (lack of the NN decisions explanatory power. There are though some NN decisions rule extraction methods like decompositional, pedagogical or eclectic, but they suffer from low portability of the rule extraction technique across various neural net architectures, high level of granularity, algorithmic sophistication of the rule extraction technique etc. The authors propose to eliminate some known drawbacks using an innovative extension of the pedagogical approach. The idea is exposed by the use of a widespread MLP neural net (as a common tool in the financial problems' domain and SOM (input data space clusterization. The feedback of both nets' performance is related and targeted through the iteration cycle by achievement of the best matching between the decision space fragments and input data space clusters. Three sets of rules are generated algorithmically or by fuzzy membership functions. Empirical validation of the common financial benchmark problems is conducted with an appropriately prepared software solution.

  1. Biodiesel Production from Microalgae by Extraction – Transesterification Method

    Directory of Open Access Journals (Sweden)

    Nguyen Thi Phuong Thao

    2013-11-01

    Full Text Available The environmental impact of using petroleum fuels has led to a quest to find a suitable alternative fuel source. In this study, microalgae were explored as a highly potential feedstock to produce biodiesel fuel. Firstly, algal oil is extracted from algal biomass by using organic solvents (n–hexan.  Lipid is contained in microalgae up to 60% of their weight. Then, Biodiesel is created through a chemical reaction known as transesterification between algal oil and alcohol (methanol with strong acid (such as H2SO4 as the catalyst. The extraction – transesterification method resulted in a high biodiesel yield (10 % of algal biomass and high FAMEs content (5.2 % of algal biomass. Biodiesel production from microalgae was studied through experimental investigation of transesterification conditions such as reaction time, methanol to oil ration and catalyst dosage which are deemed to have main impact on reaction conversion efficiency. All the parameters which were characterized for purified biodiesel such as free glycerin, total glycerin, flash point, sulfur content were analyzed according to ASTM standardDoi: http://dx.doi.org/10.12777/wastech.1.1.6-9Citation:  Thao, N.T.P., Tin, N.T., and Thanh, B.X. 2013. Biodiesel Production from Microalgae by Extraction – Transesterification Method. Waste Technology 1(1:6-9. Doi: http://dx.doi.org/10.12777/wastech.1.1.6-9

  2. AN ITERATIVE SEGMENTATION METHOD FOR REGION OF INTEREST EXTRACTION

    Directory of Open Access Journals (Sweden)

    Volkan CETIN

    2013-01-01

    Full Text Available In this paper, a method is presented for applications which include mammographic image segmentation and region of interest extraction. Segmentation is a very critical and difficult stage to accomplish in computer aided detection systems. Although the presented segmentation method is developed for mammographic images, it can be used for any medical image which resembles the same statistical characteristics with mammograms. Fundamentally, the method contains iterative automatic thresholding and masking operations which is applied to the original or enhanced mammograms. Also the effect of image enhancement to the segmentation process was observed. A version of histogram equalization was applied to the images for enhancement. Finally, the results show that enhanced version of the proposed segmentation method is preferable because of its better success rate.

  3. A fast, simple and green method for the extraction of carbamate pesticides from rice by microwave assisted steam extraction coupled with solid phase extraction.

    Science.gov (United States)

    Song, Weitao; Zhang, Yiqun; Li, Guijie; Chen, Haiyan; Wang, Hui; Zhao, Qi; He, Dong; Zhao, Chun; Ding, Lan

    2014-01-15

    This paper presented a fast, simple and green sample pretreatment method for the extraction of 8 carbamate pesticides in rice. The carbamate pesticides were extracted by microwave assisted water steam extraction method, and the extract obtained was immediately applied on a C18 solid phase extraction cartridge for clean-up and concentration. The eluate containing target compounds was finally analysed by high performance liquid chromatography with mass spectrometry. The parameters affecting extraction efficiency were investigated and optimised. The limits of detection ranging from 1.1 to 4.2ngg(-1) were obtained. The recoveries of 8 carbamate pesticides ranged from 66% to 117% at three spiked levels, and the inter- and intra-day relative standard deviation values were less than 9.1%. Compared with traditional methods, the proposed method cost less extraction time and organic solvent. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Advanced Extraction Methods for Actinide/Lanthanide Separations

    International Nuclear Information System (INIS)

    Scott, M.J.

    2005-01-01

    The separation of An(III) ions from chemically similar Ln(III) ions is perhaps one of the most difficult problems encountered during the processing of nuclear waste. In the 3+ oxidation states, the metal ions have an identical charge and roughly the same ionic radius. They differ strictly in the relative energies of their f- and d-orbitals, and to separate these metal ions, ligands will need to be developed that take advantage of this small but important distinction. The extraction of uranium and plutonium from nitric acid solution can be performed quantitatively by the extraction with the TBP (tributyl phosphate). Commercially, this process has found wide use in the PUREX (plutonium uranium extraction) reprocessing method. The TRUEX (transuranium extraction) process is further used to coextract the trivalent lanthanides and actinides ions from HLLW generated during PUREX extraction. This method uses CMPO [(N, N-diisobutylcarbamoylmethyl) octylphenylphosphineoxide] intermixed with TBP as a synergistic agent. However, the final separation of trivalent actinides from trivalent lanthanides still remains a challenging task. In TRUEX nitric acid solution, the Am(III) ion is coordinated by three CMPO molecules and three nitrate anions. Taking inspiration from this data and previous work with calix[4]arene systems, researchers on this project have developed a C3-symmetric tris-CMPO ligand system using a triphenoxymethane platform as a base. The triphenoxymethane ligand systems have many advantages for the preparation of complex ligand systems. The compounds are very easy to prepare. The steric and solubility properties can be tuned through an extreme range by the inclusion of different alkoxy and alkyl groups such as methyoxy, ethoxy, t-butoxy, methyl, octyl, t-pentyl, or even t-pentyl at the ortho- and para-positions of the aryl rings. The triphenoxymethane ligand system shows promise as an improved extractant for both tetravalent and trivalent actinide recoveries form

  5. Advanced Extraction Methods for Actinide/Lanthanide Separations

    Energy Technology Data Exchange (ETDEWEB)

    Scott, M.J.

    2005-12-01

    The separation of An(III) ions from chemically similar Ln(III) ions is perhaps one of the most difficult problems encountered during the processing of nuclear waste. In the 3+ oxidation states, the metal ions have an identical charge and roughly the same ionic radius. They differ strictly in the relative energies of their f- and d-orbitals, and to separate these metal ions, ligands will need to be developed that take advantage of this small but important distinction. The extraction of uranium and plutonium from nitric acid solution can be performed quantitatively by the extraction with the TBP (tributyl phosphate). Commercially, this process has found wide use in the PUREX (plutonium uranium extraction) reprocessing method. The TRUEX (transuranium extraction) process is further used to coextract the trivalent lanthanides and actinides ions from HLLW generated during PUREX extraction. This method uses CMPO [(N, N-diisobutylcarbamoylmethyl) octylphenylphosphineoxide] intermixed with TBP as a synergistic agent. However, the final separation of trivalent actinides from trivalent lanthanides still remains a challenging task. In TRUEX nitric acid solution, the Am(III) ion is coordinated by three CMPO molecules and three nitrate anions. Taking inspiration from this data and previous work with calix[4]arene systems, researchers on this project have developed a C3-symmetric tris-CMPO ligand system using a triphenoxymethane platform as a base. The triphenoxymethane ligand systems have many advantages for the preparation of complex ligand systems. The compounds are very easy to prepare. The steric and solubility properties can be tuned through an extreme range by the inclusion of different alkoxy and alkyl groups such as methyoxy, ethoxy, t-butoxy, methyl, octyl, t-pentyl, or even t-pentyl at the ortho- and para-positions of the aryl rings. The triphenoxymethane ligand system shows promise as an improved extractant for both tetravalent and trivalent actinide recoveries form

  6. Feature extraction from mammographic images using fast marching methods

    International Nuclear Information System (INIS)

    Bottigli, U.; Golosio, B.

    2002-01-01

    Features extraction from medical images represents a fundamental step for shape recognition and diagnostic support. The present work faces the problem of the detection of large features, such as massive lesions and organ contours, from mammographic images. The regions of interest are often characterized by an average grayness intensity that is different from the surrounding. In most cases, however, the desired features cannot be extracted by simple gray level thresholding, because of image noise and non-uniform density of the surrounding tissue. In this work, edge detection is achieved through the fast marching method (Level Set Methods and Fast Marching Methods, Cambridge University Press, Cambridge, 1999), which is based on the theory of interface evolution. Starting from a seed point in the shape of interest, a front is generated which evolves according to an appropriate speed function. Such function is expressed in terms of geometric properties of the evolving interface and of image properties, and should become zero when the front reaches the desired boundary. Some examples of application of such method to mammographic images from the CALMA database (Nucl. Instr. and Meth. A 460 (2001) 107) are presented here and discussed

  7. Sequential Events in the Irreversible Thermal Denaturation of Human Brain-Type Creatine Kinase by Spectroscopic Methods

    Directory of Open Access Journals (Sweden)

    Yan-Song Gao

    2010-06-01

    Full Text Available The non-cooperative or sequential events which occur during protein thermal denaturation are closely correlated with protein folding, stability, and physiological functions. In this research, the sequential events of human brain-type creatine kinase (hBBCK thermal denaturation were studied by differential scanning calorimetry (DSC, CD, and intrinsic fluorescence spectroscopy. DSC experiments revealed that the thermal denaturation of hBBCK was calorimetrically irreversible. The existence of several endothermic peaks suggested that the denaturation involved stepwise conformational changes, which were further verified by the discrepancy in the transition curves obtained from various spectroscopic probes. During heating, the disruption of the active site structure occurred prior to the secondary and tertiary structural changes. The thermal unfolding and aggregation of hBBCK was found to occur through sequential events. This is quite different from that of muscle-type CK (MMCK. The results herein suggest that BBCK and MMCK undergo quite dissimilar thermal unfolding pathways, although they are highly conserved in the primary and tertiary structures. A minor difference in structure might endow the isoenzymes dissimilar local stabilities in structure, which further contribute to isoenzyme-specific thermal stabilities.

  8. 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

  9. 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

  10. Effects of Feature Extraction and Classification Methods on Cyberbully Detection

    Directory of Open Access Journals (Sweden)

    Esra SARAÇ

    2016-12-01

    Full Text Available Cyberbullying is defined as an aggressive, intentional action against a defenseless person by using the Internet, or other electronic contents. Researchers have found that many of the bullying cases have tragically ended in suicides; hence automatic detection of cyberbullying has become important. In this study we show the effects of feature extraction, feature selection, and classification methods that are used, on the performance of automatic detection of cyberbullying. To perform the experiments FormSpring.me dataset is used and the effects of preprocessing methods; several classifiers like C4.5, Naïve Bayes, kNN, and SVM; and information gain and chi square feature selection methods are investigated. Experimental results indicate that the best classification results are obtained when alphabetic tokenization, no stemming, and no stopwords removal are applied. Using feature selection also improves cyberbully detection performance. When classifiers are compared, C4.5 performs the best for the used dataset.

  11. A method of ECG template extraction for biometrics applications.

    Science.gov (United States)

    Zhou, Xiang; Lu, Yang; Chen, Meng; Bao, Shu-Di; Miao, Fen

    2014-01-01

    ECG has attracted widespread attention as one of the most important non-invasive physiological signals in healthcare-system related biometrics for its characteristics like ease-of-monitoring, individual uniqueness as well as important clinical value. This study proposes a method of dynamic threshold setting to extract the most stable ECG waveform as the template for the consequent ECG identification process. With the proposed method, the accuracy of ECG biometrics using the dynamic time wraping for difference measures has been significantly improved. Analysis results with the self-built electrocardiogram database show that the deployment of the proposed method was able to reduce the half total error rate of the ECG biometric system from 3.35% to 1.45%. Its average running time on the platform of android mobile terminal was around 0.06 seconds, and thus demonstrates acceptable real-time performance.

  12. A Sequential Chemical Extraction and Spectroscopic Assessment of the Potential Bioavailability of Mercury Released From the Inoperative New Idria Mercury Mine, San Benito Co., CA

    Science.gov (United States)

    Jew, A. D.; Luong, P. N.; Rytuba, J. J.; Brown, G. E.

    2012-12-01

    The inoperative New Idria mercury mine in San Benito Co., CA, is a potential point source of Hg to the Central Valley of California. To determine the phases and the potential bioavailability of Hg present in stream bed deposits downstream of the mine, sequential chemical extractions (SCEs) targeting Hg-bearing phases and synchrotron-based spectroscopic and imaging techniques were used on sediment samples taken from the acid mine drainage (AMD) system, Hg sorbed in the laboratory to ferrihydrite (synthetic 2-line and natural), and Hg associated with diatom-rich samples. In all field samples examined, both the wet and dry seasons, removal of > 97% of the Hg required 1M KOH or harsher chemical treatments. X-ray absorption spectroscopy (XAS) showed that HgS was the dominant inorganic Hg phase present, with no detectable Hg associated with the ferrihydrite. Uptake and subsequent SCE analysis of Hg to both synthetic and natural ferrihydrite showed that 1M MgCl2 removed ≥ 90% of the total Hg, suggesting that Hg does not sorb strongly to ferrihydrite. This finding is surprising, because in most settings ferrihydrite is considered to be a strong adsorbent of heavy metals. Due to the lack of Hg sorption to ferrihydrite in field samples, another pool for the non-HgS/HgSe fraction in sediments is needed. SEM analysis of the downstream samples showed that regardless of pH, freshwater diatoms were present. To determine if diatoms were the sink for dissolved Hg in this system, SCE analysis on commercially available and diatom-rich field samples from the New Idria site and Harley Gulch (Lake County, CA) were completed. The vast majority of Hg in diatom-rich samples was removed by 1M KOH, which corresponds to the non-HgS/HgSe fraction of the New Idria field samples. Analysis for carbon and nitrogen in the diatom-rich samples showed no detectable nitrogen, indicating little to no organic material was left in the samples. We therefore infer that Hg in the diatoms is contained in

  13. Method of extracting heat from dry geothermal reservoirs

    Science.gov (United States)

    Potter, R.M.; Robinson, E.S.; Smith, M.C.

    1974-01-22

    Hydraulic fracturing is used to interconnect two or more holes that penetrate a previously dry geothermal reservoir, and to produce within the reservoir a sufficiently large heat-transfer surface so that heat can be extracted from the reservoir at a usefully high rate by a fluid entering it through one hole and leaving it through another. Introduction of a fluid into the reservoir to remove heat from it and establishment of natural (unpumped) convective circulation through the reservoir to accomplish continuous heat removal are important and novel features of the method. (auth)

  14. 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)

  15. Coconut oil extraction by the traditional Java method : An investigation of its potential application in aqueous Jatropha oil extraction

    NARCIS (Netherlands)

    Marasabessy, Ahmad; Moeis, Maelita R.; Sanders, Johan P. M.; Weusthuis, Ruud A.

    A traditional Java method of coconut oil extraction assisted by paddy crabs was investigated to find out if crabs or crab-derived components can be used to extract oil from Jatropha curcas seed kernels. Using the traditional Java method the addition of crab paste liberated 54% w w(-1) oil from

  16. Coconut oil extraction by the Java method: An investigation of its potential application in aqueous Jatropha oil extraction

    NARCIS (Netherlands)

    Marasabessy, A.; Moeis, M.R.; Sanders, J.P.M.; Weusthuis, R.A.

    2010-01-01

    A traditional Java method of coconut oil extraction assisted by paddy crabs was investigated to find out if crabs or crab-derived components can be used to extract oil from Jatropha curcas seed kernels. Using the traditional Java method the addition of crab paste liberated 54% w w-1 oil from grated

  17. Chemical Profiling of Acalypha Indica Obtained from Supercritical Carbon Dioxide Extraction and Soxhlet Extraction Methods

    OpenAIRE

    Surangkana Chaichoowong; Jan Bernd Bol; Pornprapa Bol; Thomas Gamse; Malinee Sriariyanun

    2017-01-01

    Acalypha indica is a weed that grows in South-East Asia. It contains several valuable compounds that can be used for curing various diseases such as rheumatism, skin infection and blood dysentery. Here, the extraction of A. indica using Soxhlet extraction with two different solvents and supercritical CO2 extraction (SCE) with two different temperatures (40 and 60°C) was performed. In Soxhlet extraction, ethanol solvent provided the highest extraction yield of 34.36%. For SCE, the increased te...

  18. DNA extraction on bio-chip: history and preeminence over conventional and solid-phase extraction methods.

    Science.gov (United States)

    Ayoib, Adilah; Hashim, Uda; Gopinath, Subash C B; Md Arshad, M K

    2017-11-01

    This review covers a developmental progression on early to modern taxonomy at cellular level following the advent of electron microscopy and the advancement in deoxyribonucleic acid (DNA) extraction for expatiation of biological classification at DNA level. Here, we discuss the fundamental values of conventional chemical methods of DNA extraction using liquid/liquid extraction (LLE) followed by development of solid-phase extraction (SPE) methods, as well as recent advances in microfluidics device-based system for DNA extraction on-chip. We also discuss the importance of DNA extraction as well as the advantages over conventional chemical methods, and how Lab-on-a-Chip (LOC) system plays a crucial role for the future achievements.

  19. Alternative and Efficient Extraction Methods for Marine-Derived Compounds

    Directory of Open Access Journals (Sweden)

    Clara Grosso

    2015-05-01

    Full Text Available Marine ecosystems cover more than 70% of the globe’s surface. These habitats are occupied by a great diversity of marine organisms that produce highly structural diverse metabolites as a defense mechanism. In the last decades, these metabolites have been extracted and isolated in order to test them in different bioassays and assess their potential to fight human diseases. Since traditional extraction techniques are both solvent- and time-consuming, this review emphasizes alternative extraction techniques, such as supercritical fluid extraction, pressurized solvent extraction, microwave-assisted extraction, ultrasound-assisted extraction, pulsed electric field-assisted extraction, enzyme-assisted extraction, and extraction with switchable solvents and ionic liquids, applied in the search for marine compounds. Only studies published in the 21st century are considered.

  20. What do results of common sequential fractionation and single-step extractions tell us about P binding with Fe and Al compounds in non-calcareous sediments?

    Czech Academy of Sciences Publication Activity Database

    Jan, Jiří; Borovec, Jakub; Kopáček, Jiří; Hejzlar, Josef

    2013-01-01

    Roč. 47, č. 2 (2013), s. 547-557 ISSN 0043-1354 R&D Projects: GA ČR(CZ) GA206/09/1764; GA MZe(CZ) QH81012; GA MZe(CZ) QI102A265 Institutional support: RVO:60077344 Keywords : sequential fractionation * ascorbate and oxalate extration * non-calcareous sediments Subject RIV: DA - Hydrology ; Limnology Impact factor: 5.323, year: 2013

  1. GPR Signal Denoising and Target Extraction With the CEEMD Method

    KAUST Repository

    Li, Jing

    2015-04-17

    In this letter, we apply a time and frequency analysis method based on the complete ensemble empirical mode decomposition (CEEMD) method in ground-penetrating radar (GPR) signal processing. It decomposes the GPR signal into a sum of oscillatory components, with guaranteed positive and smoothly varying instantaneous frequencies. The key idea of this method relies on averaging the modes obtained by empirical mode decomposition (EMD) applied to several realizations of Gaussian white noise added to the original signal. It can solve the mode-mixing problem in the EMD method and improve the resolution of ensemble EMD (EEMD) when the signal has a low signal-to-noise ratio. First, we analyze the difference between the basic theory of EMD, EEMD, and CEEMD. Then, we compare the time and frequency analysis with Hilbert-Huang transform to test the results of different methods. The synthetic and real GPR data demonstrate that CEEMD promises higher spectral-spatial resolution than the other two EMD methods in GPR signal denoising and target extraction. Its decomposition is complete, with a numerically negligible error.

  2. A new method for the extraction of Au(III) with ethyl thioacetoacetate into chloroform

    International Nuclear Information System (INIS)

    Khan, S.Z.; Turel, Z.R.

    1985-01-01

    A method was developed for rapid and selective extraction of Au(III) with ethyl thioacetoacetate (HETAcAc) into chloroform at pH 4. The effect of various parameters on the extraction coefficient values were studied. The substoichiometry of the extracted species of 1:3 was obtained by slope ratio and substoichiometric extraction method, respectively. (author)

  3. Highly efficient DNA extraction method from skeletal remains

    Directory of Open Access Journals (Sweden)

    Irena Zupanič Pajnič

    2011-03-01

    Full Text Available Background: This paper precisely describes the method of DNA extraction developed to acquire high quality DNA from the Second World War skeletal remains. The same method is also used for molecular genetic identification of unknown decomposed bodies in routine forensic casework where only bones and teeth are suitable for DNA typing. We analysed 109 bones and two teeth from WWII mass graves in Slovenia. Methods: We cleaned the bones and teeth, removed surface contaminants and ground the bones into powder, using liquid nitrogen . Prior to isolating the DNA in parallel using the BioRobot EZ1 (Qiagen, the powder was decalcified for three days. The nuclear DNA of the samples were quantified by real-time PCR method. We acquired autosomal genetic profiles and Y-chromosome haplotypes of the bones and teeth with PCR amplification of microsatellites, and mtDNA haplotypes 99. For the purpose of traceability in the event of contamination, we prepared elimination data bases including genetic profiles of the nuclear and mtDNA of all persons who have been in touch with the skeletal remains in any way. Results: We extracted up to 55 ng DNA/g of the teeth, up to 100 ng DNA/g of the femurs, up to 30 ng DNA/g of the tibias and up to 0.5 ng DNA/g of the humerus. The typing of autosomal and YSTR loci was successful in all of the teeth, in 98 % dekalof the femurs, and in 75 % to 81 % of the tibias and humerus. The typing of mtDNA was successful in all of the teeth, and in 96 % to 98 % of the bones. Conclusions: We managed to obtain nuclear DNA for successful STR typing from skeletal remains that were over 60 years old . The method of DNA extraction described here has proved to be highly efficient. We obtained 0.8 to 100 ng DNA/g of teeth or bones and complete genetic profiles of autosomal DNA, Y-STR haplotypes, and mtDNA haplotypes from only 0.5g bone and teeth samples.

  4. A method to extract soil water for stable isotope analysis

    Science.gov (United States)

    Revesz, Kinga; Woods, Peter H.

    1990-07-01

    A method has been developed to extract soil water for determination of deuterium (D) and 18O content. The principle of this method is based on the observation that water and toluene form an azeotropic mixture at 84.1°C, but are completely immiscible at ambient temperature. In a specially designed distillation apparatus, the soil water is distilled at 84.1°C with toluene and is separated quantitatively in the collecting funnel at ambient temperature. Traces of toluene are removed and the sample can be analyzed by mass spectrometry. Kerosene may be substituted for toluene. The accuracy of this technique is ± 2 and ± 0.2‰, respectively, for δD and δ 18O. Reduced accuracy is obtained at low water contents.

  5. Sistema de extração seqüencial da solução na macro e microporosidade do solo System of sequential extraction of solution in macro and microporosity of soil

    Directory of Open Access Journals (Sweden)

    Thomas V. Gloaguen

    2009-10-01

    ² = 0.998 between applied suction and soil matrix potencial, which was assessed by a tensiometer within the soil column, validated the proposed method for sequential soil solution extraction. Ionic concentrations were highly variable in different soil pore sizes, with low concentrations in the soil macroporosity, except for K+, which demonstrated the necessity of standardizing the sampling methodology to avoid incorrect estimation of concentration of solute in soil.

  6. How far away is far enough for extracting numerical waveforms, and how much do they depend on the extraction method?

    Energy Technology Data Exchange (ETDEWEB)

    Pazos, Enrique [Department of Physics and Astronomy, 202 Nicholson Hall, Louisiana State University, Baton Rouge, LA 70803 (United States); Dorband, Ernst Nils [Department of Physics and Astronomy, 202 Nicholson Hall, Louisiana State University, Baton Rouge, LA 70803 (United States); Nagar, Alessandro [Dipartimento di Fisica, Politecnico di Torino, Corso Duca Degli Abruzzi 24, 10129 Torino (Italy); Palenzuela, Carlos [Department of Physics and Astronomy, 202 Nicholson Hall, Louisiana State University, Baton Rouge, LA 70803 (United States); Schnetter, Erik [Center for Computation and Technology, 216 Johnston Hall, Louisiana State University, Baton Rouge, LA 70803 (United States); Tiglio, Manuel [Department of Physics and Astronomy, 202 Nicholson Hall, Louisiana State University, Baton Rouge, LA 70803 (United States)

    2007-06-21

    We present a method for extracting gravitational waves from numerical spacetimes which generalizes and refines one of the standard methods based on the Regge-Wheeler-Zerilli perturbation formalism. At the analytical level, this generalization allows a much more general class of slicing conditions for the background geometry, and is thus not restricted to Schwarzschild-like coordinates. At the numerical level, our approach uses high-order multi-block methods, which improve both the accuracy of our simulations and of our extraction procedure. In particular, the latter is simplified since there is no need for interpolation, and we can afford to extract accurate waves at large radii with only little additional computational effort. We then present fully nonlinear three-dimensional numerical evolutions of a distorted Schwarzschild black hole in Kerr-Schild coordinates with an odd parity perturbation and analyse the improvement that we gain from our generalized wave extraction, comparing our new method to the standard one. In particular, we analyse in detail the quasinormal frequencies of the extracted waves, using both methods. We do so by comparing the extracted waves with one-dimensional high resolution solutions of the corresponding generalized Regge-Wheeler equation. We explicitly see that the errors in the waveforms extracted with the standard method at fixed, finite extraction radii do not converge to zero with increasing resolution. We find that even with observers as far out as R = 80M-which is larger than what is commonly used in state-of-the-art simulations-the assumption in the standard method that the background is close to having Schwarzschild-like coordinates increases the error in the extracted waves considerably. Furthermore, those errors are dominated by the extraction method itself and not by the accuracy of our simulations. For extraction radii between 20M and 80M and for the resolutions that we use in this paper, our new method decreases the errors

  7. How far away is far enough for extracting numerical waveforms, and how much do they depend on the extraction method?

    International Nuclear Information System (INIS)

    Pazos, Enrique; Dorband, Ernst Nils; Nagar, Alessandro; Palenzuela, Carlos; Schnetter, Erik; Tiglio, Manuel

    2007-01-01

    We present a method for extracting gravitational waves from numerical spacetimes which generalizes and refines one of the standard methods based on the Regge-Wheeler-Zerilli perturbation formalism. At the analytical level, this generalization allows a much more general class of slicing conditions for the background geometry, and is thus not restricted to Schwarzschild-like coordinates. At the numerical level, our approach uses high-order multi-block methods, which improve both the accuracy of our simulations and of our extraction procedure. In particular, the latter is simplified since there is no need for interpolation, and we can afford to extract accurate waves at large radii with only little additional computational effort. We then present fully nonlinear three-dimensional numerical evolutions of a distorted Schwarzschild black hole in Kerr-Schild coordinates with an odd parity perturbation and analyse the improvement that we gain from our generalized wave extraction, comparing our new method to the standard one. In particular, we analyse in detail the quasinormal frequencies of the extracted waves, using both methods. We do so by comparing the extracted waves with one-dimensional high resolution solutions of the corresponding generalized Regge-Wheeler equation. We explicitly see that the errors in the waveforms extracted with the standard method at fixed, finite extraction radii do not converge to zero with increasing resolution. We find that even with observers as far out as R = 80M-which is larger than what is commonly used in state-of-the-art simulations-the assumption in the standard method that the background is close to having Schwarzschild-like coordinates increases the error in the extracted waves considerably. Furthermore, those errors are dominated by the extraction method itself and not by the accuracy of our simulations. For extraction radii between 20M and 80M and for the resolutions that we use in this paper, our new method decreases the errors

  8. Influence of different extraction methods on the yield and linalool content of the extracts of Eugenia uniflora L.

    Science.gov (United States)

    Galhiane, Mário S; Rissato, Sandra R; Chierice, Gilberto O; Almeida, Marcos V; Silva, Letícia C

    2006-09-15

    This work has been developed using a sylvestral fruit tree, native to the Brazilian forest, the Eugenia uniflora L., one of the Mirtaceae family. The main goal of the analytical study was focused on extraction methods themselves. The method development pointed to the Clevenger extraction as the best yield in relation to SFE and Soxhlet. The SFE method presented a good yield but showed a big amount of components in the final extract, demonstrating low selectivity. The essential oil extracted was analyzed by GC/FID showing a large range of polarity and boiling point compounds, where linalool, a widely used compound, was identified. Furthermore, an analytical solid phase extraction method was used to clean it up and obtain separated classes of compounds that were fractionated and studied by GC/FID and GC/MS.

  9. Polyphenols: Extraction Methods, Antioxidative Action, Bioavailability and Anticarcinogenic Effects

    Directory of Open Access Journals (Sweden)

    Eva Brglez Mojzer

    2016-07-01

    Full Text Available Being secondary plant metabolites, polyphenols represent a large and diverse group of substances abundantly present in a majority of fruits, herbs and vegetables. The current contribution is focused on their bioavailability, antioxidative and anticarcinogenic properties. An overview of extraction methods is also given, with supercritical fluid extraction highlighted as a promising eco-friendly alternative providing exceptional separation and protection from degradation of unstable polyphenols. The protective role of polyphenols against reactive oxygen and nitrogen species, UV light, plant pathogens, parasites and predators results in several beneficial biological activities giving rise to prophylaxis or possibly even to a cure for several prevailing human diseases, especially various cancer types. Omnipresence, specificity of the response and the absence of or low toxicity are crucial advantages of polyphenols as anticancer agents. The main problem represents their low bioavailability and rapid metabolism. One of the promising solutions lies in nanoformulation of polyphenols that prevents their degradation and thus enables significantly higher concentrations to reach the target cells. Another, more practiced, solution is the use of mixtures of various polyphenols that bring synergistic effects, resulting in lowering of the required therapeutic dose and in multitargeted action. The combination of polyphenols with existing drugs and therapies also shows promising results and significantly reduces their toxicity.

  10. A window-based time series feature extraction method.

    Science.gov (United States)

    Katircioglu-Öztürk, Deniz; Güvenir, H Altay; Ravens, Ursula; Baykal, Nazife

    2017-10-01

    This study proposes a robust similarity score-based time series feature extraction method that is termed as Window-based Time series Feature ExtraCtion (WTC). Specifically, WTC generates domain-interpretable results and involves significantly low computational complexity thereby rendering itself useful for densely sampled and populated time series datasets. In this study, WTC is applied to a proprietary action potential (AP) time series dataset on human cardiomyocytes and three precordial leads from a publicly available electrocardiogram (ECG) dataset. This is followed by comparing WTC in terms of predictive accuracy and computational complexity with shapelet transform and fast shapelet transform (which constitutes an accelerated variant of the shapelet transform). The results indicate that WTC achieves a slightly higher classification performance with significantly lower execution time when compared to its shapelet-based alternatives. With respect to its interpretable features, WTC has a potential to enable medical experts to explore definitive common trends in novel datasets. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Carbon extraction methods for radiocarbon dating of pottery

    International Nuclear Information System (INIS)

    Delque-Kolic, E.

    1995-01-01

    Pottery is a direct witness of human activity and gives, through its macroscopic and microscopic studies, lots of information about its manufacturers. Nevertheless, radiocarbon dating, currently applied in archaeology to charcoals, wood and bones has only been rarely employed with ceramic. The problem is that many different carbon sources, of different radiocarbon age, may contribute to the potsherd carbon content. So, the aim of all dating projects is to separate carbon related to the period when the potsherd was manufactured and used. In a first time, we have made our own samples with raw materials (clay and temper) known in nature and age. We have fired them with wood of known age under reducing atmosphere. Under these conditions, soot produced by wood burning forms a more or less important deposit on the surface of the pots. It is this source of carbon, present in many archaeological sherds, that we first tried to select. Burning these potsherds at low temperature under an O 2 flow, we have noticed that carbon from kiln wood was preferentially extracted. This treatment applied to a thin lamella cut in a smoked part of the potsherd provides, almost exclusively, carbon from smoke. These techniques, applied to known archaeological sherds, have given encouraging results. We have also explored a new method which consists in oxidizing carbon with a laser beam at the surface of the sample. The use of this process for extracting carbon from smoke seems promising if serious experimental precautions are taken when working with so low carbon content. (author)

  12. A SIMPLE METHOD FOR THE EXTRACTION AND QUANTIFICATION OF PHOTOPIGMENTS FROM SYMBIODINIUM SPP.

    Science.gov (United States)

    John E. Rogers and Dragoslav Marcovich. Submitted. Simple Method for the Extraction and Quantification of Photopigments from Symbiodinium spp.. Limnol. Oceanogr. Methods. 19 p. (ERL,GB 1192). We have developed a simple, mild extraction procedure using methanol which, when...

  13. Development of a sequential injection-square wave voltammetry method for determination of paraquat in water samples employing the hanging mercury drop electrode.

    Science.gov (United States)

    dos Santos, Luciana B O; Infante, Carlos M C; Masini, Jorge C

    2010-03-01

    This work describes the development and optimization of a sequential injection method to automate the determination of paraquat by square-wave voltammetry employing a hanging mercury drop electrode. Automation by sequential injection enhanced the sampling throughput, improving the sensitivity and precision of the measurements as a consequence of the highly reproducible and efficient conditions of mass transport of the analyte toward the electrode surface. For instance, 212 analyses can be made per hour if the sample/standard solution is prepared off-line and the sequential injection system is used just to inject the solution towards the flow cell. In-line sample conditioning reduces the sampling frequency to 44 h(-1). Experiments were performed in 0.10 M NaCl, which was the carrier solution, using a frequency of 200 Hz, a pulse height of 25 mV, a potential step of 2 mV, and a flow rate of 100 µL s(-1). For a concentration range between 0.010 and 0.25 mg L(-1), the current (i(p), µA) read at the potential corresponding to the peak maximum fitted the following linear equation with the paraquat concentration (mg L(-1)): i(p) = (-20.5 ± 0.3)C (paraquat) - (0.02 ± 0.03). The limits of detection and quantification were 2.0 and 7.0 µg L(-1), respectively. The accuracy of the method was evaluated by recovery studies using spiked water samples that were also analyzed by molecular absorption spectrophotometry after reduction of paraquat with sodium dithionite in an alkaline medium. No evidence of statistically significant differences between the two methods was observed at the 95% confidence level.

  14. Applying Sparse Machine Learning Methods to Twitter: Analysis of the 2012 Change in Pap Smear Guidelines. A Sequential Mixed-Methods Study.

    Science.gov (United States)

    Lyles, Courtney Rees; Godbehere, Andrew; Le, Gem; El Ghaoui, Laurent; Sarkar, Urmimala

    2016-06-10

    It is difficult to synthesize the vast amount of textual data available from social media websites. Capturing real-world discussions via social media could provide insights into individuals' opinions and the decision-making process. We conducted a sequential mixed methods study to determine the utility of sparse machine learning techniques in summarizing Twitter dialogues. We chose a narrowly defined topic for this approach: cervical cancer discussions over a 6-month time period surrounding a change in Pap smear screening guidelines. We applied statistical methodologies, known as sparse machine learning algorithms, to summarize Twitter messages about cervical cancer before and after the 2012 change in Pap smear screening guidelines by the US Preventive Services Task Force (USPSTF). All messages containing the search terms "cervical cancer," "Pap smear," and "Pap test" were analyzed during: (1) January 1-March 13, 2012, and (2) March 14-June 30, 2012. Topic modeling was used to discern the most common topics from each time period, and determine the singular value criterion for each topic. The results were then qualitatively coded from top 10 relevant topics to determine the efficiency of clustering method in grouping distinct ideas, and how the discussion differed before vs. after the change in guidelines . This machine learning method was effective in grouping the relevant discussion topics about cervical cancer during the respective time periods (~20% overall irrelevant content in both time periods). Qualitative analysis determined that a significant portion of the top discussion topics in the second time period directly reflected the USPSTF guideline change (eg, "New Screening Guidelines for Cervical Cancer"), and many topics in both time periods were addressing basic screening promotion and education (eg, "It is Cervical Cancer Awareness Month! Click the link to see where you can receive a free or low cost Pap test.") It was demonstrated that machine learning

  15. The Effect of Homogenization Pressures on Extraction of Avocado Oil by Wet Method

    OpenAIRE

    Basuni Hamzah

    2013-01-01

    Avocado tree usually planted by people of Indonesia in rural are small in scale. Mostly, in the modern and high scale industry especially company has a large avocado farm the extraction of avocado oil is extracted through vacuum drying in low temperature. However, in rural area avocado tree spread out in small number of tree, so it needs alternative method of avocado oil extraction. In this experiment, wet method of avocado extraction was applied similar to traditional extraction of coconut o...

  16. Distant Supervision for Relation Extraction with Ranking-Based Methods

    Directory of Open Access Journals (Sweden)

    Yang Xiang

    2016-05-01

    Full Text Available Relation extraction has benefited from distant supervision in recent years with the development of natural language processing techniques and data explosion. However, distant supervision is still greatly limited by the quality of training data, due to its natural motivation for greatly reducing the heavy cost of data annotation. In this paper, we construct an architecture called MIML-sort (Multi-instance Multi-label Learning with Sorting Strategies, which is built on the famous MIML framework. Based on MIML-sort, we propose three ranking-based methods for sample selection with which we identify relation extractors from a subset of the training data. Experiments are set up on the KBP (Knowledge Base Propagation corpus, one of the benchmark datasets for distant supervision, which is large and noisy. Compared with previous work, the proposed methods produce considerably better results. Furthermore, the three methods together achieve the best F1 on the official testing set, with an optimal enhancement of F1 from 27.3% to 29.98%.

  17. Cat's claw oxindole alkaloid isomerization induced by common extraction methods

    Directory of Open Access Journals (Sweden)

    Samuel Kaiser

    2013-01-01

    Full Text Available Cat's claw oxindole alkaloids are prone to isomerization in aqueous solution. However, studies on their behavior in extraction processes are scarce. This paper addressed the issue by considering five commonly used extraction processes. Unlike dynamic maceration (DM and ultrasound-assisted extraction, substantial isomerization was induced by static maceration, turbo-extraction and reflux extraction. After heating under reflux in DM, the kinetic order of isomerization was established and equations were fitted successfully using a four-parameter Weibull model (R² > 0.999. Different isomerization rates and equilibrium constants were verified, revealing a possible matrix effect on alkaloid isomerization.

  18. Effect of extraction method on the yield of furanocoumarins from fruits of Archangelica officinalis Hoffm.

    Science.gov (United States)

    Waksmundzka-Hajnos, M; Petruczynik, A; Dragan, A; Wianowska, D; Dawidowicz, A L

    2004-01-01

    Optimal conditions for the extraction and analysis of furanocoumarins from fruits of Archangelica officinalis Hoffm. have been determined. The following extraction methods were used: exhaustive extraction in a Soxhlet apparatus, ultrasonication at 25 and 60 degrees C, microwave-assisted solvent extraction in open and closed systems, and accelerated solvent extraction (ASE). In most cases the yields of furanocoumarins were highest using the ASE method. The effects of extracting solvent, temperature and time of extraction using this method were investigated. The highest yield of furanocoumarins by ASE was obtained with methanol at 100-130 degrees C for 10 min. The extraction yields of furanocoumarins from plant material by ultrasonication at 60 degrees C and microwave-assisted solvent extraction in an open system were comparable to the extraction yields obtained in the time- and solvent-consuming exhaustive process involving the Soxhlet apparatus.

  19. A comparative study: the impact of different lipid extraction methods on current microalgal lipid research

    Science.gov (United States)

    2014-01-01

    Microalgae cells have the potential to rapidly accumulate lipids, such as triacylglycerides that contain fatty acids important for high value fatty acids (e.g., EPA and DHA) and/or biodiesel production. However, lipid extraction methods for microalgae cells are not well established, and there is currently no standard extraction method for the determination of the fatty acid content of microalgae. This has caused a few problems in microlagal biofuel research due to the bias derived from different extraction methods. Therefore, this study used several extraction methods for fatty acid analysis on marine microalga Tetraselmis sp. M8, aiming to assess the potential impact of different extractions on current microalgal lipid research. These methods included classical Bligh & Dyer lipid extraction, two other chemical extractions using different solvents and sonication, direct saponification and supercritical CO2 extraction. Soxhlet-based extraction was used to weigh out the importance of solvent polarity in the algal oil extraction. Coupled with GC/MS, a Thermogravimetric Analyser was used to improve the quantification of microalgal lipid extractions. Among these extractions, significant differences were observed in both, extract yield and fatty acid composition. The supercritical extraction technique stood out most for effective extraction of microalgal lipids, especially for long chain unsaturated fatty acids. The results highlight the necessity for comparative analyses of microalgae fatty acids and careful choice and validation of analytical methodology in microalgal lipid research. PMID:24456581

  20. Nucleic acid extraction, oligonucleotide probes and PCR methods

    International Nuclear Information System (INIS)

    Zhongtang Yu; Forster, R.J.

    2005-01-01

    analysis, and hybridization-based methods, such as RNA-targeted hybridization, fluorescence in situ hybridization (FISH), and microarray, have been employed. The application of these molecular techniques has been changing our perspectives about ruminal and GI microbiota. Except for FISH, all these methods analyse DNA or RNA extracted from samples collected from rumen or GI tracts. Therefore, reliable and efficient DNA/RNA extraction is the pre-requisite of molecular ecological studies of ruminal microbiota

  1. 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.

  2. Development of a flow method for the determination of phosphate in estuarine and freshwaters-Comparison of flow cells in spectrophotometric sequential injection analysis

    International Nuclear Information System (INIS)

    Mesquita, Raquel B.R.; Ferreira, M. Teresa S.O.B.; Toth, Ildiko V.; Bordalo, Adriano A.; McKelvie, Ian D.; Rangel, Antonio O.S.S.

    2011-01-01

    Highlights: → Sequential injection determination of phosphate in estuarine and freshwaters. → Alternative spectrophotometric flow cells are compared. → Minimization of schlieren effect was assessed. → Proposed method can cope with wide salinity ranges. → Multi-reflective cell shows clear advantages. - Abstract: A sequential injection system with dual analytical line was developed and applied in the comparison of two different detection systems viz; a conventional spectrophotometer with a commercial flow cell, and a multi-reflective flow cell coupled with a photometric detector under the same experimental conditions. The study was based on the spectrophotometric determination of phosphate using the molybdenum-blue chemistry. The two alternative flow cells were compared in terms of their response to variation of sample salinity, susceptibility to interferences and to refractive index changes. The developed method was applied to the determination of phosphate in natural waters (estuarine, river, well and ground waters). The achieved detection limit (0.007 μM PO 4 3- ) is consistent with the requirement of the target water samples, and a wide quantification range (0.024-9.5 μM) was achieved using both detection systems.

  3. General Methods for Analysis of Sequential “n-step” Kinetic Mechanisms: Application to Single Turnover Kinetics of Helicase-Catalyzed DNA Unwinding

    Science.gov (United States)

    Lucius, Aaron L.; Maluf, Nasib K.; Fischer, Christopher J.; Lohman, Timothy M.

    2003-01-01

    Helicase-catalyzed DNA unwinding is often studied using “all or none” assays that detect only the final product of fully unwound DNA. Even using these assays, quantitative analysis of DNA unwinding time courses for DNA duplexes of different lengths, L, using “n-step” sequential mechanisms, can reveal information about the number of intermediates in the unwinding reaction and the “kinetic step size”, m, defined as the average number of basepairs unwound between two successive rate limiting steps in the unwinding cycle. Simultaneous nonlinear least-squares analysis using “n-step” sequential mechanisms has previously been limited by an inability to float the number of “unwinding steps”, n, and m, in the fitting algorithm. Here we discuss the behavior of single turnover DNA unwinding time courses and describe novel methods for nonlinear least-squares analysis that overcome these problems. Analytic expressions for the time courses, fss(t), when obtainable, can be written using gamma and incomplete gamma functions. When analytic expressions are not obtainable, the numerical solution of the inverse Laplace transform can be used to obtain fss(t). Both methods allow n and m to be continuous fitting parameters. These approaches are generally applicable to enzymes that translocate along a lattice or require repetition of a series of steps before product formation. PMID:14507688

  4. General methods for analysis of sequential "n-step" kinetic mechanisms: application to single turnover kinetics of helicase-catalyzed DNA unwinding.

    Science.gov (United States)

    Lucius, Aaron L; Maluf, Nasib K; Fischer, Christopher J; Lohman, Timothy M

    2003-10-01

    Helicase-catalyzed DNA unwinding is often studied using "all or none" assays that detect only the final product of fully unwound DNA. Even using these assays, quantitative analysis of DNA unwinding time courses for DNA duplexes of different lengths, L, using "n-step" sequential mechanisms, can reveal information about the number of intermediates in the unwinding reaction and the "kinetic step size", m, defined as the average number of basepairs unwound between two successive rate limiting steps in the unwinding cycle. Simultaneous nonlinear least-squares analysis using "n-step" sequential mechanisms has previously been limited by an inability to float the number of "unwinding steps", n, and m, in the fitting algorithm. Here we discuss the behavior of single turnover DNA unwinding time courses and describe novel methods for nonlinear least-squares analysis that overcome these problems. Analytic expressions for the time courses, f(ss)(t), when obtainable, can be written using gamma and incomplete gamma functions. When analytic expressions are not obtainable, the numerical solution of the inverse Laplace transform can be used to obtain f(ss)(t). Both methods allow n and m to be continuous fitting parameters. These approaches are generally applicable to enzymes that translocate along a lattice or require repetition of a series of steps before product formation.

  5. Development of a flow method for the determination of phosphate in estuarine and freshwaters-Comparison of flow cells in spectrophotometric sequential injection analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Raquel B.R. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, R. Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal); Laboratory of Hydrobiology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Institute of Marine Research (CIIMAR), Universidade do Porto, Lg. Abel Salazar 2, 4099-003 Porto (Portugal); Ferreira, M. Teresa S.O.B. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, R. Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal); Toth, Ildiko V. [REQUIMTE, Departamento de Quimica, Faculdade de Farmacia, Universidade de Porto, Rua Anibal Cunha, 164, 4050-047 Porto (Portugal); Bordalo, Adriano A. [Laboratory of Hydrobiology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Institute of Marine Research (CIIMAR), Universidade do Porto, Lg. Abel Salazar 2, 4099-003 Porto (Portugal); McKelvie, Ian D. [School of Chemistry, University of Melbourne, Victoria 3010 (Australia); Rangel, Antonio O.S.S., E-mail: aorangel@esb.ucp.pt [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, R. Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal)

    2011-09-02

    Highlights: {yields} Sequential injection determination of phosphate in estuarine and freshwaters. {yields} Alternative spectrophotometric flow cells are compared. {yields} Minimization of schlieren effect was assessed. {yields} Proposed method can cope with wide salinity ranges. {yields} Multi-reflective cell shows clear advantages. - Abstract: A sequential injection system with dual analytical line was developed and applied in the comparison of two different detection systems viz; a conventional spectrophotometer with a commercial flow cell, and a multi-reflective flow cell coupled with a photometric detector under the same experimental conditions. The study was based on the spectrophotometric determination of phosphate using the molybdenum-blue chemistry. The two alternative flow cells were compared in terms of their response to variation of sample salinity, susceptibility to interferences and to refractive index changes. The developed method was applied to the determination of phosphate in natural waters (estuarine, river, well and ground waters). The achieved detection limit (0.007 {mu}M PO{sub 4}{sup 3-}) is consistent with the requirement of the target water samples, and a wide quantification range (0.024-9.5 {mu}M) was achieved using both detection systems.

  6. A sequential and fast method for low level of 226Ra , 228Ra, 210Pb e 210Po in mine effluents and uranium processing plant

    International Nuclear Information System (INIS)

    Taddei, M.H.T.; Taddei, J.F.A.C.

    2005-01-01

    Due to biological risk and long half lives, the radionuclides 228 Ra, 226 Ra, 210 Pb and 210 Po should be frequently monitored to check for any environmental contamination around mines and uranium plants. Currently, the methods used for the determination of these radionuclides take about thirty days to reach the radioactive equilibrium of the 210 Pb and 226 Ra daughter's. The evaluation of effluent discharges and leakage of deposits to water bodies in monitoring programs, require quick answers to implement corrective measures. Thereby fast determination methods must be implemented. This work presents a fast and sequential method to, in three days, determine accurately and sensitively, 226 Ra, 228 Ra, 210 Pb, 210 Po, in water and effluent samples

  7. Measurement of Tritium Activity in Plants by Ice Extraction Method

    International Nuclear Information System (INIS)

    Pelled, O.; Ovad, S.; Tubul, Y.; Tsroya, S.; Gonen, R.; Abraham, A.; Weinstein, M.; German, U.

    2014-01-01

    Tritium is produced primarily by interactions of cosmic rays with the atmosphere. However, nuclear installations may add significantly tritium to the surroundings, increasing its concentration. The main sources of tritium released by man are linked to the nuclear power cycle: nuclear power stations, nuclear fuel reprocessing plants or tritium production plants. Tritium is found in the environment mainly as tritiated water, in gaseous or liquid form (HTO, T2O), in the surrounding air and in soil. It accumulates in plants, which may use as a measure to the level of tritium concentration in the environment. The most common routes of tritium uptake from the environment in plants are from atmospheric humidity and by precipitation water which entered the soil. The fraction of tritium bound to the plant tissue is small compared to that present as tritiated water in the plant (from 0.06% to 0.3% for growing crops). The tritiated water uptake is through the roots, as tritiated water from the soil follows a pathway similar to that of ordinary water. As most tritium in plants consists of tritiated water, the measurements of only the tissue free water tritium concentration (as HTO or T2O) gives an accurate estimate of the tritium content in the plant. Analyzing free tritium in biological matrices usually requires using the freeze-drying method to extract the water from the sample, and then measure the water collected in a cold trap with a Liquid Scintillation Counter (LSC). The 'freeze-drying' occurs because of the sublimation of the frozen water inside the plant, that takes place when the temperature is beneath the triple point and the vapour pressure is low. In the temperature range of -5° to -10° C the mechanism that plants use to avoid freezing is drawing of water from the cell protoplasm into the intercellular spaces. Changes in cell membrane permeability allow water to leave the cell and enter the spaces between the cells where it freezes instead of freezing within the

  8. Determination of the antioxidant capacity of two seagrass species according to the extraction method

    Directory of Open Access Journals (Sweden)

    Kethia L. González

    2016-10-01

    Full Text Available Context: There is a wide variety of methods for obtaining of plant extracts that enable a good yield of bioactive metabolites. For several years, extractive techniques have been perfected for obtaining natural extracts with powerful pharmacological properties. Aims: To determine the influence of various extraction methods (infusion, decoction, microwave, maceration with heat and agitation, and constant heat and agitation on the content of solids, phenolic compounds and antioxidant capacity of marine angiosperms Thalassia testudinum Banks ex König (Hyrocharitacea and Syringodium filiforme kützing (Cymodoceaceae. Methods: The soluble solids content was determined by the gravimetric method; total phenolic content, using Folin-Ciocalteu method, and the antioxidant capacity by 2,2-diphenyl-1 picrylhydrazyl (DPPH method. Results: Results showed the effectiveness of extraction by decoction for T. testudinum and by microwave for S. filiforme, among the methods that use water as the extraction solvent. In the case those that use the hydroalcoholic mixture as solvent extraction, maceration with agitation and heat extraction showed the higher yields of soluble solids and total polyphenols, as well as a higher antioxidant activity for both species. Conclusions: Results showed the effectiveness of extraction by decoction for T. testudinum and by microwave for S. filiforme, among the methods that use water as extraction solvent. In the case those that use hydroalcoholic mixture as solvent extraction, maceration with agitation and heat extraction showed the higher yields of soluble solids and total polyphenols, as well as a higher antioxidant activity for both species.

  9. Method for extracting copper, silver and related metals

    Science.gov (United States)

    Moyer, Bruce A.; McDowell, W. J.

    1990-01-01

    A process for selectively extracting precious metals such as silver and gold concurrent with copper extraction from aqueous solutions containing the same. The process utilizes tetrathiamacrocycles and high molecular weight organic acids that exhibit a synergistic relationship when complexing with certain metal ions thereby removing them from ore leach solutions.

  10. Efficient point cloud data processing in shipbuilding: Reformative component extraction method and registration method

    Directory of Open Access Journals (Sweden)

    Jingyu Sun

    2014-07-01

    Full Text Available To survive in the current shipbuilding industry, it is of vital importance for shipyards to have the ship components’ accuracy evaluated efficiently during most of the manufacturing steps. Evaluating components’ accuracy by comparing each component’s point cloud data scanned by laser scanners and the ship’s design data formatted in CAD cannot be processed efficiently when (1 extract components from point cloud data include irregular obstacles endogenously, or when (2 registration of the two data sets have no clear direction setting. This paper presents reformative point cloud data processing methods to solve these problems. K-d tree construction of the point cloud data fastens a neighbor searching of each point. Region growing method performed on the neighbor points of the seed point extracts the continuous part of the component, while curved surface fitting and B-spline curved line fitting at the edge of the continuous part recognize the neighbor domains of the same component divided by obstacles’ shadows. The ICP (Iterative Closest Point algorithm conducts a registration of the two sets of data after the proper registration’s direction is decided by principal component analysis. By experiments conducted at the shipyard, 200 curved shell plates are extracted from the scanned point cloud data, and registrations are conducted between them and the designed CAD data using the proposed methods for an accuracy evaluation. Results show that the methods proposed in this paper support the accuracy evaluation targeted point cloud data processing efficiently in practice.

  11. Influence of layer compositions and annealing conditions on complete formation of ternary PdAgCu alloys prepared by sequential electroless and electroplating methods

    Energy Technology Data Exchange (ETDEWEB)

    Sumrunronnasak, Sarocha [Graduate Program of Petrochemistry and Polymer Science, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Tantayanon, Supawan, E-mail: supawan.t@chula.ac.th [Green Chemistry Research Laboratory, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Kiatgamolchai, Somchai [Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand)

    2017-01-01

    PdAgCu ternary alloy membranes were synthesized by the sequential electroless plating of Pd following by electroplating of Ag and Cu onto stainless steel substrate. The composition of the composite was varied by changing the deposition times. The fabricated layers were annealed at the temperatures between 500 and 600 °C for 20–60 h. The Energy Dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) were employed to investigate the element distribution in the membrane which provided the insight on membrane alloying process. Complete formation of the alloy could be obtained when the Pd composition was greater than a critical value of 60 wt%, and Ag and Cu contents were in the range of 18–30 wt% and 2–13 wt%, respectively. Deposition times of Ag and Cu were found to affect the completion of alloy formation. Excess amount of the deposited Cu particularly tended to segregate on the surface of the membrane. - Highlights: • Ternary PdAgCu alloy membranes were successfully prepared by the sequential electroless and electroplating methods. • The average Pd composition required to form alloy was found to be approximately at least 60%wt. • The alloy region was achieved for f Pd 60–73 wt%, Cu 18–30 wt% and Ag 2–13 wt%. • Suitable annealing temperature in the range of 500–600 °C for an adequate period of treating time (20–60 h).

  12. Effects of extraction methods of phenolic compounds from Xanthium strumarium L. and their antioxidant activity

    Directory of Open Access Journals (Sweden)

    R. Scherer

    2014-03-01

    Full Text Available The effect of extraction methods and solvents on overall yield, total phenolic content, antioxidant activity, and the composition of the phenolic compounds in Xanthium strumarium extracts were studied. The antioxidant activity was determined by using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH, and the composition of the phenolic compounds was determined by HPLC-DAD and LC/MS. All results were affected by the extraction method, especially by the solvent used, and the best results were obtained with the methanol extract. The methanolic and ethanolic extracts exhibited strong antioxidant activity, and the chlorogenic and ferulic acids were the most abundant phenolic compounds in the extracts.

  13. A simple and fast method for extraction and quantification of cryptophyte phycoerythrin

    OpenAIRE

    Thoisen, Christina; Hansen, Benni Winding; Nielsen, S?ren Laurentius

    2017-01-01

    The microalgal pigment phycoerythrin (PE) is of commercial interest as natural colorant in food and cosmetics, as well as fluoroprobes for laboratory analysis. Several methods for extraction and quantification of PE are available but they comprise typically various extraction buffers, repetitive freeze-thaw cycles and liquid nitrogen, making extraction procedures more complicated. A simple method for extraction of PE from cryptophytes is described using standard laboratory materials and equip...

  14. Pressurised liquid extraction of flavonoids in onions. Method development and validation

    DEFF Research Database (Denmark)

    Søltoft, Malene; Christensen, J.H.; Nielsen, J.

    2009-01-01

    A rapid and reliable analytical method for quantification of flavonoids in onions was developed and validated. Five extraction methods were tested on freeze-dried onions and subsequently high performance liquid chromatography (HPLC) with UV detection was used for quantification of seven flavonoids...... extraction methods. However. PLE was the preferred extraction method because the method can be highly automated, use only small amounts of solvents, provide the cleanest extracts, and allow the extraction of light and oxygen-sensitive flavonoids to be carried out in an inert atmosphere protected from light......-step PLE method showed good selectivity, precision (RSDs = 3.1-11%) and recovery of the extractable flavonoids (98-99%). The method also appeared to be a multi-method, i.e. generally applicable to, e.g. phenolic acids in potatoes and carrots....

  15. Antioxidative and Antimelanoma Effects of Various Tea Extracts via a Green Extraction Method

    Directory of Open Access Journals (Sweden)

    Yihui Chen

    2018-01-01

    Full Text Available Tea (Camellia sinensis contains high level of antioxidant elements and is a well-known beverage consumed worldwide. The purpose of this study is to compare different concentrations of green tea, black tea, oolong tea 861, oolong tea 732, and jasmine green tea. These five types of tea extracts were known to have antioxidative properties, reducing power, and metal ion chelating activity. The current study compared these five extracts in terms of their inhibiting effects on human malignant melanoma: A2058 and A375. To determine the cell viability between normal cell and malignant melanoma cells, an MTT assay was applied to evaluate the cytotoxic potential on human melanoma cells, with all tea extracts showing decreased cell viability with increasing tea extract concentrations. Cytotoxicity on HaCat (normal skin cells showed no effect on the cell viabilities at lower concentrations of the tea extracts. These results suggest the antioxidative effect of five tea extracts that protect against oxidation and melanoma production, with green tea and jasmine green tea showing the lowest cell viability when tested against malignant melanoma cells.

  16. Genomic DNA extraction method from Annona senegalensis Pers ...

    African Journals Online (AJOL)

    aghomotsegin

    2014-02-05

    SDS) or cetyl-methyl ammonium bromide (CTAB). The released DNA should be protected from endogenous nuclease. Ethylenediaminetetra acetate. (EDTA) is often included in the extraction buffer to chelate magnesium ions ...

  17. Development and Application of Solid Phase Extraction Method for ...

    African Journals Online (AJOL)

    NICO

    for the addition of organic modifier, sample load volume, conditioning solvent, washing solvent and ... Solid phase extraction, polycyclic aromatic hydrocarbons, water samples, ... such as polymeric, activated carbon or silica modified with.

  18. Ions extraction and collection using the RF resonance method and taking into consideration the sputtering loss

    International Nuclear Information System (INIS)

    Xie Guofeng; Wang Dewu; Ying Chuntong

    2005-01-01

    One-dimensional ions extraction and collection using the RF resonance method is studied by PIC-MCC simulation. The energy and angle distribution of extracted ions is recorded and the sputtering loss is calculated. The results show that compared with parallel electrode method, RF resonance method has advantages such as shorter extraction time, lower collision loss and sputtering loss and higher collection ratio; the extraction time and collision loss are decreased with increasing extraction voltage, but the sputtering loss increases and collection ratio decreases; collision loss is decreased with increasing magnetic field, but the sputtering loss increases and collection ratio decreases. (authors)

  19. Hydrolysis constants of tetravalent neptunium by using solvent extraction method

    International Nuclear Information System (INIS)

    Fujiwara, K.; Kohara, Y.

    2008-01-01

    The hydrolysis constants of tetravalent neptunium (Np(IV)) were determined by solvent extraction method using thenoyltrifluoroacetone(TTA). In order to avoid colloid formation, a stock solution of carrier-free 239 Np(V) was from 243 Am milked. The valence of Np in the solution was then reduced to Np(IV) by using zinc amalgam. The hydrolysis constants (β m ) of the reactions, Np 4+ + mOH - = Np(OH) m (4-m)+ was evaluated by using distribution ratios at ionic strengths (I) = 0.1, 0.5 and 1.0. All experiments were performed in oxygen-free 0.5% H 2 -N 2 atmosphere (below 1.0 ppm of O 2 ) in a glove-box at room temperature (23 ± 2 C) to avoid oxidation of Np(IV). The β m values were extrapolated to the standard state (I = 0) by using the specific ion interaction theory (SIT), and the formation constants at I = 0 were determined to be log β 1 = 13.91 ± 0.23, log β 2 = 27.13 ± 0.15, log β 3 = 37.70 ± 0.30 and log β 4 = 46.16 ± 0.30. The ion interaction coefficients were also evaluated to be ε(NpOH 3+ , ClO 4 - ) = 0.49 ± 0.15, ε(Np(OH) 2 2+ , ClO 4 - ) = 0.35 ± 0.11, and ε(Np(OH) 3 + , ClO 4 - ) = 0.29 ± 0.15. (orig.)

  20. Hydrolysis constants of tetravalent neptunium by using solvent extraction method

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, K. [Japan Atomic Energy Agency (JAEA), Naka-gun, Ibaraki-ken (Japan); Kohara, Y. [Inspection and Development Co., Naka-gun, Ibaraki-ken (Japan)

    2008-07-01

    The hydrolysis constants of tetravalent neptunium (Np(IV)) were determined by solvent extraction method using thenoyltrifluoroacetone(TTA). In order to avoid colloid formation, a stock solution of carrier-free {sup 239}Np(V) was from {sup 243}Am milked. The valence of Np in the solution was then reduced to Np(IV) by using zinc amalgam. The hydrolysis constants ({beta}{sub m}) of the reactions, Np{sup 4+} + mOH{sup -} = Np(OH){sub m}{sup (4-m)+} was evaluated by using distribution ratios at ionic strengths (I) = 0.1, 0.5 and 1.0. All experiments were performed in oxygen-free 0.5% H{sub 2}-N{sub 2} atmosphere (below 1.0 ppm of O{sub 2}) in a glove-box at room temperature (23 {+-} 2 C) to avoid oxidation of Np(IV). The {beta}{sub m} values were extrapolated to the standard state (I = 0) by using the specific ion interaction theory (SIT), and the formation constants at I = 0 were determined to be log {beta}{sub 1} = 13.91 {+-} 0.23, log {beta}{sub 2} = 27.13 {+-} 0.15, log {beta}{sub 3} = 37.70 {+-} 0.30 and log {beta}{sub 4} = 46.16 {+-} 0.30. The ion interaction coefficients were also evaluated to be {epsilon}(NpOH{sup 3+}, ClO{sub 4}{sup -}) = 0.49 {+-} 0.15, {epsilon}(Np(OH){sub 2}{sup 2+}, ClO{sub 4}{sup -}) = 0.35 {+-} 0.11, and {epsilon}(Np(OH){sub 3}{sup +}, ClO{sub 4}{sup -}) = 0.29 {+-} 0.15. (orig.)

  1. Selective dissolution of magnetic iron oxides in the acid-ammonium oxalate/ferrous iron extraction method-I. Synthetic samples

    NARCIS (Netherlands)

    Oorschot, I.H.M. van; Dekkers, M.J.

    2000-01-01

    In soil magnetism, the magnetic parameters alone are not always sufficient to distinguish the lithogenic from the pedogenic magnetic fractions. Sequential extraction techniques have therefore been incorporated into magnetic studies to constrain the environmental interpretation. Here we report on

  2. Effect of soil contaminant extraction method in determining toxicity using the Microtox(reg.) assay

    International Nuclear Information System (INIS)

    Harkey, G.A.; Young, T.M.

    2000-01-01

    This project examined the influence of different extraction methods on the measured toxicity of contaminated soils collected from manufactured gas plant (MGP) sites differing in soil composition and contaminant concentration. Aged soils from a number of MGP sites were extracted using a saline solution, supercritical fluid extraction (SFE), and Soxhlet extraction. Toxicity was assessed using two forms of Microtox tests: acute aqueous tests on saline and SFE soil extracts and solid-phase tests (SPTs) on soil particles. Microtox SPTs were performed on soils before and after SFE to determine resulting toxicity reduction. Three hypotheses were tested: (1) Toxicity of soil extracts is related to contaminant concentrations of the extracts, (2) measured toxicity significantly decreases with less vigorous methods of extraction, and (3) supercritical fluid extractability correlates with measured toxicity. The EC50s for SPTs performed before and after SFE were not different for some soils but were significantly greater after extraction for other soils tested. The most significant toxicity reductions were observed for soils exhibiting the highest toxicity in both preextraction SPTs and acute aqueous tests. Acute Microtox tests performed on SFE extracts showed significantly lower EC50s than those reported from saline-based extraction procedures. Toxicity of the soils measured by Microtox SPTs was strongly correlated with both SFE efficiency and measures of contaminant aging. Data from this project provide evidence of sequestration and reduced availability of polycyclic aromatic hydrocarbons (PAHs) from soils extracted via physiologically based procedures compared to vigorous physical extraction protocols

  3. Novel Approaches to Extraction Methods in Recovery of Capsaicin from Habanero Pepper (CNPH 15.192).

    Science.gov (United States)

    Martins, Frederico S; Borges, Leonardo L; Ribeiro, Claudia S C; Reifschneider, Francisco J B; Conceição, Edemilson C

    2017-07-01

    The objective of this study was to compare three capsaicin extraction methods: Shoxlet, Ultrasound-assisted Extraction (UAE), and Shaker-assisted Extraction (SAE) from Habanero pepper, CNPH 15.192. The different parameters evaluated were alcohol degree, time extraction, and solid-solvent ratio using response surface methodology (RSM). The three parameters found significant ( p Soxhlet increased the extraction in 10-25%; however, long extraction times (45 minutes) degraded 2% capsaicin. The extraction of capsaicin was influenced by extraction method and by the operating conditions chosen. The optimized conditions provided savings of time, solvent, and herbal material. Prudent choice of the extraction method is essential to ensure optimal yield of extract, thereby making the study relevant and the knowledge gained useful for further exploitation and application of this resource. Habanero pepper , line CNPH 15.192, possess capsaicin in higher levels when compared with others speciesHigher levels of ethanolic strength are more suitable to obtain a higher levels of capsaicinBox-Behnken design indicates to be useful to explore the best conditions of ultrasound assisted extraction of capsaicin. Abbreviations used: Nomenclature UAE: Ultrasound-assisted Extraction; SAE: Shaker-assisted Extraction.

  4. Human DNA Extraction by Two Extraction Methods for Forensic Typification from Human Feces on FTA Paper

    Directory of Open Access Journals (Sweden)

    Shirleny Monserrat Sandoval-Arias

    2014-11-01

    Full Text Available The identification of suspects in criminal investigations has been facilitated since DNA test are executed on different samples. The application of this technology for forensic typification from human fecal samples still presents complications therefore this research evaluated two DNA extraction protocols with modifications to determine that of major efficiency. Organic extractions and extractions using the commercial kit “IQTM DNA Casework Sample Kit for Maxwell ® 16” on FTA portions of 4cm2 and 1cm2 impregnated with feces from the same individual were done to accomplish the objective. In all the assays the results were useful, however; the best forensic typification (by the electropherogram characteristics was obtained by using the commercial kit in an area of 1 cm2 of FTA paper impregnated in a 1:4 dilution.

  5. Potato tuber proteomics: Comparison of two complementary extraction methods designed for 2-DE of acidic proteins

    NARCIS (Netherlands)

    Delaplace, P.; Wal, van der F.; Dierick, J.F.; Cordewener, J.H.G.; Fauconnier, M.L.; Jardin, du P.; America, A.H.P.

    2006-01-01

    Two protein extraction procedures were tested in order to remove interfering compounds prior to 2-DE of potato tubers. These methods using SDS lysis buffer and phenol-phase extraction were compared regarding the quality of the resulting 2-D gel. While the resolution of SDS extracts on

  6. Synthetic Aperture Sequential Beamforming

    DEFF Research Database (Denmark)

    Kortbek, Jacob; Jensen, Jørgen Arendt; Gammelmark, Kim Løkke

    2008-01-01

    A synthetic aperture focusing (SAF) technique denoted Synthetic Aperture Sequential Beamforming (SASB) suitable for 2D and 3D imaging is presented. The technique differ from prior art of SAF in the sense that SAF is performed on pre-beamformed data contrary to channel data. The objective is to im......A synthetic aperture focusing (SAF) technique denoted Synthetic Aperture Sequential Beamforming (SASB) suitable for 2D and 3D imaging is presented. The technique differ from prior art of SAF in the sense that SAF is performed on pre-beamformed data contrary to channel data. The objective...... is to improve and obtain a more range independent lateral resolution compared to conventional dynamic receive focusing (DRF) without compromising frame rate. SASB is a two-stage procedure using two separate beamformers. First a set of Bmode image lines using a single focal point in both transmit and receive...... is stored. The second stage applies the focused image lines from the first stage as input data. The SASB method has been investigated using simulations in Field II and by off-line processing of data acquired with a commercial scanner. The performance of SASB with a static image object is compared with DRF...

  7. Comparison of nine DNA extraction methods for the diagnosis of bovine tuberculosis by real time PCR

    OpenAIRE

    Moura, André; Hodon, Mikael Arrais; Soares Filho, Paulo Martins; Issa, Marina de Azevedo; Oliveira, Ana Paula Ferreira de; Fonseca Júnior, Antônio Augusto

    2016-01-01

    ABSTRACT: Bovine tuberculosis is an infectious disease with a high impact on the cattle industry, particularly in developing countries. PCR is a very sensitive method for detection of infectious agents, but the sensitivity of molecular diagnosis is largely dependent on the efficiency of the DNA extraction methods. The objective of this study was to evaluate DNA extraction methods for direct detection of Mycobacterium bovis in bovine tissue. Nine commercial kits for DNA extraction were evalua...

  8. Comparison of the methods for tissue triiodothyronine T(3) extraction and subsequent radioimmunoassay

    International Nuclear Information System (INIS)

    Takaishi, M.; Miyachi, Y.; Aoki, M.; Shishiba, Y.; Asahi Life Foundation, Tokyo

    1978-01-01

    Although there have been various reports on tissue T 3 concentration, the examination of the quality of radioimmunoassay has not been available. In the present study, we tried to determine whether the available methods for T 3 extraction are adequate for the various methods of T 3 radioimmunoassays used. T 3 was extracted from liver by ethanol extraction or by acid butanol extraction (Flock's method) and the extract was applied to radioimmunoassay either by Seralute T 3 column, ANS-double antibody or the ANS-charcoal method. The values of T 3 were compared with those obtained by isotope-equilibration method. The dilution curve of ethanol extract was not parallel with that of the standard in ANS-charcoal or ANS-double antibody technique. When the extract was tested by Seralate method, the dilution curve was parallel to the standard, whereas the T 3 value obtained with this method was two-fold higher than that with the isotope equilibration technique. The analysis of the ethanol extract suggested that the lipid extracted by ethanol interfered with the assay. The acid butanol extract when tested either by the ANS-double antibody or Seralate method, showed parallelism to the standard curve and gave T 3 values almost identical with those by the isotope-equilibration method. When tested by ANS-charcoal method, the dilution curve of the acid butanol extract was not parallel to the standard. Thus, to obtain reliable results, tissue extraction by Flock's method and subsequent T 3 radioimmunoassay by either ANS-double antibody or Seralate T 3 method are recommended. (author)

  9. Improvement of extraction method of coagulation active components from Moringa oleifera seed

    OpenAIRE

    Okuda, Tetsuji; Baes, Aloysius U.; Nishijima, Wataru; Okada, Mitsumasa

    1999-01-01

    A new method for the extraction of the active coagulation component from Moringa oleifera seeds was developed and compared with the ordinary water extraction method (MOC–DW). In the new method, 1.0 mol l-1 solution of sodium chloride (MOC–SC) and other salts were used for extraction of the active coagulation component. Batch coagulation experiments were conducted using 500 ml of low turbid water (50 NTU). Coagulation efficiencies were evaluated based on the dosage required to remove kaolinite...

  10. A rapid and low-cost DNA extraction method for isolating ...

    African Journals Online (AJOL)

    The price of commercial DNA extraction methods makes the routine use of polymerase chain reaction amplification (PCR) based methods rather costly for scientists in developing countries. A guanidium thiocayante-based DNA extraction method was investigated in this study for the isolation of Escherichia coli (E. coli) DNA ...

  11. Extraction method for the determination of inorganic iodides in Rose Bengal labelled with 131I

    International Nuclear Information System (INIS)

    Lengyel, J.; Krtil, J.; Vecernik, J.

    1982-01-01

    An extraction method for the determination of inorganic iodides in Rose Bengal preparations labelled with 131 I is described. The method is based on the quantitative extraction of Rose Bengal into chloroform from acidic medium while the inorganic iodides remain in the aqueous phase. The method is simple, rapid, and reproducible. (author)

  12. Comparison of DNA extraction methods for detection of citrus huanglongbing in Colombia

    Directory of Open Access Journals (Sweden)

    Jorge Evelio Ángel

    2014-04-01

    Full Text Available Four DNA citrus plant tissue extraction protocols and three methods of DNA extraction from vector psyllid Diaphorina citri Kuwayama (Hemiptera: Psyllidae were compared as part of the validation process and standardization for detection of huanglongbing (HLB. The comparison was done using several criterias such as integrity, purity and concentration. The best quality parameters presented in terms of extraction of DNA from plant midribs tissue of citrus, were cited by Murray and Thompson (1980 and Rodríguez et al. (2010, while for the DNA extraction from psyllid vectors of HLB, the best extraction method was suggested by Manjunath et al.(2008.

  13. Exploring the response process of culturally differing survey respondents with a response style: A sequential mixed-methods study

    NARCIS (Netherlands)

    Morren, M.H.; Gelissen, J.P.T.M.; Vermunt, J.K.

    2013-01-01

    This article presents a mixed methods approach that integrates quantitative and qualitative methods to analyze why the four largest minorities in the Netherlands-Turks, Moroccans, Antilleans, and Surinamese-respond differently to items treating cultural topics. First, we conducted latent class

  14. Critical assessment of extracellular polymeric substances extraction methods from mixed culture biomass

    DEFF Research Database (Denmark)

    Pellicer i Nàcher, Carles; Domingo Felez, Carlos; Mutlu, Ayten Gizem

    2013-01-01

    . This study presents a rigorous and critical assessment of existing physical and chemical EPS extraction methods applied to mixed-culture biomass samples (nitrifying, nitritation-anammox, and activated sludge biomass). A novel fluorescence-based method was developed and calibrated to quantify the lysis...... potential of different EPS extraction protocols. We concluded that commonly used methods to assess cell lysis (DNA concentrations or G6PDH activities in EPS extracts) do not correlate with cell viability. Furthermore, we discovered that the presence of certain chemicals in EPS extracts results in severe...... underestimation of protein and carbohydrate concentrations by using standard analytical methods. Keeping both maximum EPS extraction yields and minimal biomass lysis as criteria, it was identified a sonication-based extraction method as the best to determine and compare tightly-bound EPS fractions in different...

  15. Chemical composition and antibacterial activity of Cordia verbenacea extracts obtained by different methods.

    Science.gov (United States)

    Michielin, Eliane M Z; Salvador, Ana A; Riehl, Carlos A S; Smânia, Artur; Smânia, Elza F A; Ferreira, Sandra R S

    2009-12-01

    The present study describes the chemical composition and the antibacterial activity of extracts from Cordia verbenacea DC (Borraginaceae), a traditional medicinal plant that grows widely along the southeastern coast of Brazil. The extracts were obtained using different extraction techniques: high-pressure operations and low-pressure methods. The high-pressure technique was applied to obtain C. verbenacea extracts using pure CO(2) and CO(2) with co-solvent at pressures up to 30MPa and temperatures of 30, 40 and 50 degrees C. Organic solvents such as n-hexane, ethyl acetate, ethanol, acetone and dichloromethane were used to obtain extracts by low-pressure processes. The antibacterial activity of the extracts was also subjected to screening against four strains of bacteria using the agar dilution method. The extraction yields were up to 5.0% w/w and up to 8.6% w/w for supercritical fluid extraction with pure CO(2) and with ethyl acetate as co-solvent, respectively, while the low-pressure extraction indicates yields up to 24.0% w/w in the soxhlet extraction using water and aqueous mixture with 50% ethanol as solvents. The inhibitory activity of the extracts in gram-positive bacteria was significantly higher than in gram-negative. The quantification and the identification of the extracts recovered were accomplished using GC/MS analysis. The most important components identified in the extract were artemetin, beta-sitosterol, alpha-humulene and beta-caryophyllene, among others.

  16. Extraction method for high free radical scavenging activity of Siamese neem tree flowers

    Directory of Open Access Journals (Sweden)

    Worarat Chaisawangwong

    2009-10-01

    Full Text Available Siamese neem tree (Azadirachta indica A. Juss. var. siamensis Valeton is a medicinal plant found in Thailand. Youngleaves and young flowers of this plant are commonly consumed as a bitter tonic vegetable. The flowers are also used fortreatment of fever. The flower extract has been reported to exhibit in vitro free radical scavenging activity and can inhibitlipid peroxidation of bronchogenic cancer cell line. Active compounds in the flowers are flavonoids such as rutin andquercetin. The content of these compounds in the crude extract depends on the method of extraction. Therefore, the appropriateextraction method promoting high yield of total flavonoids and high free radical scavenging activity was investigated inthis study. Six different extraction methods, i.e. maceration, percolation, decoction, soxhlet extraction, ultrasonic extraction(UE, and microwave assisted extraction (MA were carried out for extracting dried powder of Siamese neem tree young flowers. The solvent used for maceration, percolation, and soxhlet extraction was 50% ethanol, while distilled water was used for decoction and MA, and both solvents were used for UE. The content of crude extract, free radical scavenging activity, and total flavonoids content of each extract were investigated and compared. Comparing the various extraction methods, decoction provided an extract containing a high amount of total flavonoids (17.54 mgRE/g extract and promoting the highest scavenging activity at EC50 11.36 g/ml. Decoction is also simple, cheap, and convenient and could be used in developing countries. Thus, it should be the recommended extraction method for the flowers of Siamese neem tree for furtherdevelopment of antioxidant pharmaceutical preparations.

  17. A method for efficient extraction of rotifers (Rotifera) from soils

    Czech Academy of Sciences Publication Activity Database

    Devetter, Miloslav

    2010-01-01

    Roč. 53, č. 2 (2010), s. 115-118 ISSN 0031-4056 R&D Projects: GA ČR(CZ) GP206/06/P405 Institutional research plan: CEZ:AV0Z60660521 Keywords : soil rotifers * Bdelloids * quantitative extraction Subject RIV: EH - Ecology, Behaviour Impact factor: 1.474, year: 2010

  18. An improved method of DNA extraction from plants for pathogen ...

    African Journals Online (AJOL)

    Polymerase chain reaction (PCR)-based applications in plant molecular biology and molecular diagnostics for plant pathogens require good quality DNA for reliable and reproducible results. Leaf tissue is often the choice for DNA extraction, but the use of other sources such as tubers, stems, or seeds, is not uncommon.

  19. comparison of protein extraction methods for the leaves of ficus

    African Journals Online (AJOL)

    F. I. Abdullah

    2017-05-01

    May 1, 2017 ... extraction technique is highly relied on the protein structure and its chemical characteristics. ..... EDTA, 1% Triton X 100, 80% glycerol, 1M DTT and distilled water) and vortexed ..... prot5438, doi : 10.1101/pdb.prot5438.

  20. Efficient method for the extraction of genomic DNA from wormwood ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-09-17

    Sep 17, 2008 ... DNA is extracted from plant material it will also contain. *Corresponding author. ... an important issue in the field of plant molecular biology. Various plants ..... An excellent guide to over 500 of the more well known medicinal ...

  1. A new method for microwave assisted ethanolic extraction of Mentha rotundifolia bioactive terpenoids.

    Science.gov (United States)

    García-Sarrió, María Jesús; Sanz, María Luz; Sanz, Jesús; González-Coloma, Azucena; Cristina Soria, Ana

    2018-04-14

    A new microwave-assisted extraction (MAE) method using ethanol as solvent has been optimized by means of a Box-Behnken experimental design for the enhanced extraction of bioactive terpenoids from Mentha rotundifolia leaves; 100°C, 5 min, 1.125 g dry sample: 10 mL solvent and a single extraction cycle were selected as optimal conditions. Improved performance of MAE method in terms of extraction yield and/or reproducibility over conventional solid-liquid extraction and ultrasound assisted extraction was also previously assessed. A comprehensive characterization of MAE extracts was carried out by GC-MS. A total of 46 compounds, mostly terpenoids, were identified; piperitenone oxide and piperitenone were the major compounds determined. Several neophytadiene isomers were also detected for the first time in MAE extracts. Different procedures (solid-phase extraction and activated charcoal (AC) treatment) were also evaluated for clean-up of MAE extracts, with AC providing the highest enrichment in bioactive terpenoids. Finally, the MAE method here developed is shown as a green, fast, efficient and reproducible liquid extraction methodology to obtain M. rotundifolia bioactive extracts for further application, among others, as food preservatives. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Power system state estimation using an iteratively reweighted least squares method for sequential L{sub 1}-regression

    Energy Technology Data Exchange (ETDEWEB)

    Jabr, R.A. [Electrical, Computer and Communication Engineering Department, Notre Dame University, P.O. Box 72, Zouk Mikhael, Zouk Mosbeh (Lebanon)

    2006-02-15

    This paper presents an implementation of the least absolute value (LAV) power system state estimator based on obtaining a sequence of solutions to the L{sub 1}-regression problem using an iteratively reweighted least squares (IRLS{sub L1}) method. The proposed implementation avoids reformulating the regression problem into standard linear programming (LP) form and consequently does not require the use of common methods of LP, such as those based on the simplex method or interior-point methods. It is shown that the IRLS{sub L1} method is equivalent to solving a sequence of linear weighted least squares (LS) problems. Thus, its implementation presents little additional effort since the sparse LS solver is common to existing LS state estimators. Studies on the termination criteria of the IRLS{sub L1} method have been carried out to determine a procedure for which the proposed estimator is more computationally efficient than a previously proposed non-linear iteratively reweighted least squares (IRLS) estimator. Indeed, it is revealed that the proposed method is a generalization of the previously reported IRLS estimator, but is based on more rigorous theory. (author)

  3. The Obstacles for the Teaching of 8th Grade TR History of Revolution and Kemalism Course According to the Constructivist Approach (An Example of Exploratory Sequential Mixed Method Design)

    Science.gov (United States)

    Karademir, Yavuz; Demir, Selcuk Besir

    2015-01-01

    The aim of this study is to ascertain the problems social studies teachers face in the teaching of topics covered in 8th grade TRHRK Course. The study was conducted in line with explanatory sequential mixed method design, which is one of the mixed research method, was used. The study involves three phases. In the first step, exploratory process…

  4. Comparing a recursive digital filter with the moving-average and sequential probability-ratio detection methods for SNM portal monitors

    International Nuclear Information System (INIS)

    Fehlau, P.E.

    1993-01-01

    The author compared a recursive digital filter proposed as a detection method for French special nuclear material monitors with the author's detection methods, which employ a moving-average scaler or a sequential probability-ratio test. Each of these nine test subjects repeatedly carried a test source through a walk-through portal monitor that had the same nuisance-alarm rate with each method. He found that the average detection probability for the test source is also the same for each method. However, the recursive digital filter may have on drawback: its exponentially decreasing response to past radiation intensity prolongs the impact of any interference from radiation sources of radiation-producing machinery. He also examined the influence of each test subject on the monitor's operation by measuring individual attenuation factors for background and source radiation, then ranked the subjects' attenuation factors against their individual probabilities for detecting the test source. The one inconsistent ranking was probably caused by that subject's unusually long stride when passing through the portal

  5. Excavation-drier method of energy-peat extraction reduces long-term climatic impact

    Energy Technology Data Exchange (ETDEWEB)

    Silvan, N.; Silvan, K.; Laine, J. [Finnish Forest Research Inst., Parkano (Finland)], e-mail: niko.silvan@metla.fi; Vaisanen, S.; Soukka, R. [Lappeenranta Univ.of Techology (Finland)

    2012-11-01

    Climatic impacts of energy-peat extraction are of increasing concern due to EU emissions trading requirements. A new excavation-drier peat extraction method has been developed to reduce the climatic impact and increase the efficiency of peat extraction. To quantify and compare the soil GHG fluxes of the excavation drier and the traditional milling methods, as well as the areas from which the energy peat is planned to be extracted in the future (extraction reserve area types), soil CO{sub 2}, CH{sub 4} and N{sub 2}O fluxes were measured during 2006-2007 at three sites in Finland. Within each site, fluxes were measured from drained extraction reserve areas, extraction fields and stockpiles of both methods and additionally from the biomass driers of the excavation-drier method. The Life Cycle Assessment (LCA), described at a principal level in ISO Standards 14040:2006 and 14044:2006, was used to assess the long-term (100 years) climatic impact from peatland utilisation with respect to land use and energy production chains where utilisation of coal was replaced with peat. Coal was used as a reference since in many cases peat and coal can replace each other in same power plants. According to this study, the peat extraction method used was of lesser significance than the extraction reserve area type in regards to the climatic impact. However, the excavation-drier method seems to cause a slightly reduced climatic impact as compared with the prevailing milling method. (orig.)

  6. Current lipid extraction methods are significantly enhanced adding a water treatment step in Chlorella protothecoides.

    Science.gov (United States)

    Ren, Xiaojie; Zhao, Xinhe; Turcotte, François; Deschênes, Jean-Sébastien; Tremblay, Réjean; Jolicoeur, Mario

    2017-02-11

    Microalgae have the potential to rapidly accumulate lipids of high interest for the food, cosmetics, pharmaceutical and energy (e.g. biodiesel) industries. However, current lipid extraction methods show efficiency limitation and until now, extraction protocols have not been fully optimized for specific lipid compounds. The present study thus presents a novel lipid extraction method, consisting in the addition of a water treatment of biomass between the two-stage solvent extraction steps of current extraction methods. The resulting modified method not only enhances lipid extraction efficiency, but also yields a higher triacylglycerols (TAG) ratio, which is highly desirable for biodiesel production. Modification of four existing methods using acetone, chloroform/methanol (Chl/Met), chloroform/methanol/H 2 O (Chl/Met/H 2 O) and dichloromethane/methanol (Dic/Met) showed respective lipid extraction yield enhancement of 72.3, 35.8, 60.3 and 60.9%. The modified acetone method resulted in the highest extraction yield, with 68.9 ± 0.2% DW total lipids. Extraction of TAG was particularly improved with the water treatment, especially for the Chl/Met/H 2 O and Dic/Met methods. The acetone method with the water treatment led to the highest extraction level of TAG with 73.7 ± 7.3 µg/mg DW, which is 130.8 ± 10.6% higher than the maximum value obtained for the four classical methods (31.9 ± 4.6 µg/mg DW). Interestingly, the water treatment preferentially improved the extraction of intracellular fractions, i.e. TAG, sterols, and free fatty acids, compared to the lipid fractions of the cell membranes, which are constituted of phospholipids (PL), acetone mobile polar lipids and hydrocarbons. Finally, from the 32 fatty acids analyzed for both neutral lipids (NL) and polar lipids (PL) fractions, it is clear that the water treatment greatly improves NL-to-PL ratio for the four standard methods assessed. Water treatment of biomass after the first solvent extraction step

  7. Measures of Ruleset Quality for General Rules Extraction Methods

    Czech Academy of Sciences Publication Activity Database

    Holeňa, Martin

    2009-01-01

    Roč. 50, č. 6 (2009), s. 867-879 ISSN 0888-613X R&D Projects: GA ČR GA201/08/0802 Institutional research plan: CEZ:AV0Z10300504 Keywords : rules extraction from data * quality measures * ruleset measures * ROC curves * observational logic * fuzzy logic Subject RIV: IN - Informatics, Computer Science Impact factor: 2.090, year: 2009

  8. GA Based Optimal Feature Extraction Method for Functional Data Classification

    OpenAIRE

    Jun Wan; Zehua Chen; Yingwu Chen; Zhidong Bai

    2010-01-01

    Classification is an interesting problem in functional data analysis (FDA), because many science and application problems end up with classification problems, such as recognition, prediction, control, decision making, management, etc. As the high dimension and high correlation in functional data (FD), it is a key problem to extract features from FD whereas keeping its global characters, which relates to the classification efficiency and precision to heavens. In this paper...

  9. Accelerated solvent extraction method with one-step clean-up for hydrocarbons in soil

    International Nuclear Information System (INIS)

    Nurul Huda Mamat Ghani; Norashikin Sain; Rozita Osman; Zuraidah Abdullah Munir

    2007-01-01

    The application of accelerated solvent extraction (ASE) using hexane combined with neutral silica gel and sulfuric acid/ silica gel (SA/ SG) to remove impurities prior to analysis by gas chromatograph with flame ionization detector (GC-FID) was studied. The efficiency of extraction was evaluated based on the three hydrocarbons; dodecane, tetradecane and pentadecane spiked to soil sample. The effect of ASE operating conditions (extraction temperature, extraction pressure, static time) was evaluated and the optimized condition obtained from the study was extraction temperature of 160 degree Celsius, extraction pressure of 2000 psi with 5 minutes static extraction time. The developed ASE with one-step clean-up method was applied in the extraction of hydrocarbons from spiked soil and the amount extracted was comparable to ASE extraction without clean-up step with the advantage of obtaining cleaner extract with reduced interferences. Therefore in the developed method, extraction and clean-up for hydrocarbons in soil can be achieved rapidly and efficiently with reduced solvent usage. (author)

  10. Full coverage of perovskite layer onto ZnO nanorods via a modified sequential two-step deposition method for efficiency enhancement in perovskite solar cells

    Science.gov (United States)

    Ruankham, Pipat; Wongratanaphisan, Duangmanee; Gardchareon, Atcharawon; Phadungdhitidhada, Surachet; Choopun, Supab; Sagawa, Takashi

    2017-07-01

    Full coverage of perovskite layer onto ZnO nanorod substrates with less pinholes is crucial for achieving high-efficiency perovskite solar cells. In this work, a two-step sequential deposition method is modified to achieve an appropriate property of perovskite (MAPbI3) film. Surface treatment of perovskite layer and its precursor have been systematically performed and their morphologies have been investigated. By pre-wetting of lead iodide (PbI2) and letting it dry before reacting with methylammonium iodide (MAI) provide better coverage of perovskite film onto ZnO nanorod substrate than one without any treatment. An additional MAI deposition followed with toluene drop-casting technique on the perovskite film is also found to increase the coverage and enhance the transformation of PbI2 to MAPbI3. These lead to longer charge carrier lifetime, resulting in an enhanced power conversion efficiency (PCE) from 1.21% to 3.05%. The modified method could been applied to a complex ZnO nanorods/TiO2 nanoparticles substrate. The enhancement in PCE to 3.41% is observed. These imply that our introduced method provides a simple way to obtain the full coverage and better transformation to MAPbI3 phase for enhancement in performances of perovskite solar cells.

  11. Rapid method for the sequential measurement of isotopes of Am and Pu in liquid matrices by alpha spectrometry

    International Nuclear Information System (INIS)

    Mantero Cabrera, J.

    2014-01-01

    : In radiological emergencies it's necessary a fast response from the laboratories in the quantification of certain radionuclides, in order to take decisions. In these cases, is the reaction time the key parameter to consider (without neglecting the quality of the measurement). In this work, it is shown a method for aqueous matrices that generates Pu and Am isotopes sources in one single day of work, to be measured subsequently by alpha spectrometry. The developed methodology has been validated through its application to reference samples and also taking part intercom- parison exercises, having in both cases, satisfactory results. This way, we check the validity of this fast method that let us generate in 24 hours (since the sample arrives our laboratory), one measurement with a Minimun Detectable Activity (MDA) of about 0.004Bq/L for Pu and Am isotopes in liquid matrices. [es

  12. How Well Can We Detect Lineage-Specific Diversification-Rate Shifts? A Simulation Study of Sequential AIC Methods.

    Science.gov (United States)

    May, Michael R; Moore, Brian R

    2016-11-01

    Evolutionary biologists have long been fascinated by the extreme differences in species numbers across branches of the Tree of Life. This has motivated the development of statistical methods for detecting shifts in the rate of lineage diversification across the branches of phylogenic trees. One of the most frequently used methods, MEDUSA, explores a set of diversification-rate models, where each model assigns branches of the phylogeny to a set of diversification-rate categories. Each model is first fit to the data, and the Akaike information criterion (AIC) is then used to identify the optimal diversification model. Surprisingly, the statistical behavior of this popular method is uncharacterized, which is a concern in light of: (1) the poor performance of the AIC as a means of choosing among models in other phylogenetic contexts; (2) the ad hoc algorithm used to visit diversification models, and; (3) errors that we reveal in the likelihood function used to fit diversification models to the phylogenetic data. Here, we perform an extensive simulation study demonstrating that MEDUSA (1) has a high false-discovery rate (on average, spurious diversification-rate shifts are identified [Formula: see text] of the time), and (2) provides biased estimates of diversification-rate parameters. Understanding the statistical behavior of MEDUSA is critical both to empirical researchers-in order to clarify whether these methods can make reliable inferences from empirical datasets-and to theoretical biologists-in order to clarify the specific problems that need to be solved in order to develop more reliable approaches for detecting shifts in the rate of lineage diversification. [Akaike information criterion; extinction; lineage-specific diversification rates; phylogenetic model selection; speciation.]. © The Author(s) 2016. Published by Oxford University Press, on behalf of the Society of Systematic Biologists.

  13. The influence of extraction methods on composition and antioxidant properties of rice bran oil

    Directory of Open Access Journals (Sweden)

    Noppawat Pengkumsri

    2015-09-01

    Full Text Available AbstractThe current study was employed to assess the influence of the different extraction methods on total tocols, γ-oryzanol content, and antioxidant properties of Chiang Mai Black rice, Mali Red rice, and Suphanburi-1 Brown rice bran oil. Rice bran oil (RBO was extracted by Hexane, Hot pressed, Cold pressed, and Supercritical Fluid Extraction (SFe methods. High yield of RBO was extracted by hexane and SFe methods. Total and subgroups of tocols, and γ-oryzanol content were determined by HPLC. The hexane extracted sample accounts for high content of γ-oryzanol and tocols. Besides, all of RBO extracts contain a significantly high amount of γ-tocotrienol. In vitro antioxidant assay results indicated that superior quality of oil was recovered by hexane extraction. The temperature in the extraction process also affects the value of the oil. Superior quality of oil was recovered by hexane extraction, in terms of phytochemical contents and antioxidant properties compared to other tested extraction methods. Further, thorough study of factors compromising the quality and quantity of RBO recovery is required for the development of enhanced functional foods and other related products.

  14. Methods for producing extracted and digested products from pretreated lignocellulosic biomass

    Science.gov (United States)

    Chundawat, Shishir; Sousa, Leonardo Da Costa; Cheh, Albert M.; Balan; , Venkatesh; Dale, Bruce

    2017-05-16

    Methods for producing extracted and digested products from pretreated lignocellulosic biomass are provided. The methods include converting native cellulose I.sub..beta. to cellulose III.sub.I by pretreating the lignocellulosic biomass with liquid ammonia under certain conditions, and performing extracting or digesting steps on the pretreated/converted lignocellulosic biomass.

  15. Optimizing pressurized liquid extraction of microbial lipids using the response surface method.

    Science.gov (United States)

    Cescut, J; Severac, E; Molina-Jouve, C; Uribelarrea, J-L

    2011-01-21

    Response surface methodology (RSM) was used for the determination of optimum extraction parameters to reach maximum lipid extraction yield with yeast. Total lipids were extracted from oleaginous yeast (Rhodotorula glutinis) using pressurized liquid extraction (PLE). The effects of extraction parameters on lipid extraction yield were studied by employing a second-order central composite design. The optimal condition was obtained as three cycles of 15 min at 100°C with a ratio of 144 g of hydromatrix per 100 g of dry cell weight. Different analysis methods were used to compare the optimized PLE method with two conventional methods (Soxhlet and modification of Bligh and Dyer methods) under efficiency, selectivity and reproducibility criteria thanks to gravimetric analysis, GC with flame ionization detector, High Performance Liquid Chromatography linked to Evaporative Light Scattering Detector (HPLC-ELSD) and thin-layer chromatographic analysis. For each sample, the lipid extraction yield with optimized PLE was higher than those obtained with referenced methods (Soxhlet and Bligh and Dyer methods with, respectively, a recovery of 78% and 85% compared to PLE method). Moreover, the use of PLE led to major advantages such as an analysis time reduction by a factor of 10 and solvent quantity reduction by 70%, compared with traditional extraction methods. Copyright © 2010 Elsevier B.V. All rights reserved.

  16. Efficient method for extracting DNA of parasites causing bovine babesiosis from tick vectors

    Science.gov (United States)

    The southern cattle tick, Rhipicephalus (Boophilus) microplus, is an economically important pest costing animal agriculture billions of dollars worldwide. This research focuses on a comparison of three different tick DNA extraction methods: phenol-chloroform extraction (method 1), a modified version...

  17. Optimization design and application of composite ultrasonic extraction method for effective constituents of green tea

    Directory of Open Access Journals (Sweden)

    Cheng-Chi Wang

    2015-12-01

    Full Text Available A composite ultrasonic process is used to extract five constituent components of green tea, namely caffeine, catechin, epigallocatechin gallate, epicatechin, and chlorogenic acid. The optimal parameters of the extraction process are determined using the robust Taguchi design method. The extracted products are analyzed using gas chromatography and high-performance liquid chromatography. The experimental results confirm the effectiveness of the proposed ultrasonic technique in extracting the components of interest. Moreover, it is shown that the optimal extraction parameters depend on the particular component. In general, the present findings provide a useful reference for further research on the processing of green tea.

  18. A simple and fast method for extraction and quantification of cryptophyte phycoerythrin.

    Science.gov (United States)

    Thoisen, Christina; Hansen, Benni Winding; Nielsen, Søren Laurentius

    2017-01-01

    The microalgal pigment phycoerythrin (PE) is of commercial interest as natural colorant in food and cosmetics, as well as fluoroprobes for laboratory analysis. Several methods for extraction and quantification of PE are available but they comprise typically various extraction buffers, repetitive freeze-thaw cycles and liquid nitrogen, making extraction procedures more complicated. A simple method for extraction of PE from cryptophytes is described using standard laboratory materials and equipment. The cryptophyte cells on the filters were disrupted at -80 °C and added phosphate buffer for extraction at 4 °C followed by absorbance measurement. The cryptophyte Rhodomonas salina was used as a model organism. •Simple method for extraction and quantification of phycoerythrin from cryptophytes.•Minimal usage of equipment and chemicals, and low labor costs.•Applicable for industrial and biological purposes.

  19. A simple and fast method for extraction and quantification of cryptophyte phycoerythrin

    DEFF Research Database (Denmark)

    Thoisen, Christina Vinum; Hansen, Benni Winding; Nielsen, Søren Laurentius

    2017-01-01

    The microalgal pigment phycoerythrin (PE) is of commercial interest as natural colorant in food and cosmetics, as well as fluoroprobes for laboratory analysis. Several methods for extraction and quantification of PE are available but they comprise typically various extraction buffers, repetitive...... freeze-thaw cycles and liquid nitrogen, making extraction procedures more complicated. A simple method for extraction of PE from cryptophytes is described using standard laboratory materials and equipment. Filters with the cryptophyte were frozen (−80 °C) and added phosphate buffer for extraction at 4 °C...... followed by absorbance measurement. The cryptophyte Rhodomonas salina was used as a model organism. •Simple method for extraction and quantification of phycoerythrin from cryptophytes. •Minimal usage of equipment and chemicals, and low labor costs. •Applicable for industrial and biological purposes....

  20. A Robust Gradient Based Method for Building Extraction from LiDAR and Photogrammetric Imagery

    Directory of Open Access Journals (Sweden)

    Fasahat Ullah Siddiqui

    2016-07-01

    Full Text Available Existing automatic building extraction methods are not effective in extracting buildings which are small in size and have transparent roofs. The application of large area threshold prohibits detection of small buildings and the use of ground points in generating the building mask prevents detection of transparent buildings. In addition, the existing methods use numerous parameters to extract buildings in complex environments, e.g., hilly area and high vegetation. However, the empirical tuning of large number of parameters reduces the robustness of building extraction methods. This paper proposes a novel Gradient-based Building Extraction (GBE method to address these limitations. The proposed method transforms the Light Detection And Ranging (LiDAR height information into intensity image without interpolation of point heights and then analyses the gradient information in the image. Generally, building roof planes have a constant height change along the slope of a roof plane whereas trees have a random height change. With such an analysis, buildings of a greater range of sizes with a transparent or opaque roof can be extracted. In addition, a local colour matching approach is introduced as a post-processing stage to eliminate trees. This stage of our proposed method does not require any manual setting and all parameters are set automatically from the data. The other post processing stages including variance, point density and shadow elimination are also applied to verify the extracted buildings, where comparatively fewer empirically set parameters are used. The performance of the proposed GBE method is evaluated on two benchmark data sets by using the object and pixel based metrics (completeness, correctness and quality. Our experimental results show the effectiveness of the proposed method in eliminating trees, extracting buildings of all sizes, and extracting buildings with and without transparent roof. When compared with current state

  1. Comparison of two methods of surface profile extraction from multiple ultrasonic range measurements

    NARCIS (Netherlands)

    Barshan, B; Baskent, D

    Two novel methods for surface profile extraction based on multiple ultrasonic range measurements are described and compared. One of the methods employs morphological processing techniques, whereas the other employs a spatial voting scheme followed by simple thresholding. Morphological processing

  2. The BUME method: a new rapid and simple chloroform-free method for total lipid extraction of animal tissue.

    Science.gov (United States)

    Löfgren, Lars; Forsberg, Gun-Britt; Ståhlman, Marcus

    2016-06-10

    In this study we present a simple and rapid method for tissue lipid extraction. Snap-frozen tissue (15-150 mg) is collected in 2 ml homogenization tubes. 500 μl BUME mixture (butanol:methanol [3:1]) is added and automated homogenization of up to 24 frozen samples at a time in less than 60 seconds is performed, followed by a 5-minute single-phase extraction. After the addition of 500 μl heptane:ethyl acetate (3:1) and 500 μl 1% acetic acid a 5-minute two-phase extraction is performed. Lipids are recovered from the upper phase by automated liquid handling using a standard 96-tip robot. A second two-phase extraction is performed using 500 μl heptane:ethyl acetate (3:1). Validation of the method showed that the extraction recoveries for the investigated lipids, which included sterols, glycerolipids, glycerophospholipids and sphingolipids were similar or better than for the Folch method. We also applied the method for lipid extraction of liver and heart and compared the lipid species profiles with profiles generated after Folch and MTBE extraction. We conclude that the BUME method is superior to the Folch method in terms of simplicity, through-put, automation, solvent consumption, economy, health and environment yet delivering lipid recoveries fully comparable to or better than the Folch method.

  3. The BUME method: a new rapid and simple chloroform-free method for total lipid extraction of animal tissue

    Science.gov (United States)

    Löfgren, Lars; Forsberg, Gun-Britt; Ståhlman, Marcus

    2016-06-01

    In this study we present a simple and rapid method for tissue lipid extraction. Snap-frozen tissue (15-150 mg) is collected in 2 ml homogenization tubes. 500 μl BUME mixture (butanol:methanol [3:1]) is added and automated homogenization of up to 24 frozen samples at a time in less than 60 seconds is performed, followed by a 5-minute single-phase extraction. After the addition of 500 μl heptane:ethyl acetate (3:1) and 500 μl 1% acetic acid a 5-minute two-phase extraction is performed. Lipids are recovered from the upper phase by automated liquid handling using a standard 96-tip robot. A second two-phase extraction is performed using 500 μl heptane:ethyl acetate (3:1). Validation of the method showed that the extraction recoveries for the investigated lipids, which included sterols, glycerolipids, glycerophospholipids and sphingolipids were similar or better than for the Folch method. We also applied the method for lipid extraction of liver and heart and compared the lipid species profiles with profiles generated after Folch and MTBE extraction. We conclude that the BUME method is superior to the Folch method in terms of simplicity, through-put, automation, solvent consumption, economy, health and environment yet delivering lipid recoveries fully comparable to or better than the Folch method.

  4. Comparison of different methods for extraction from Tetraclinis articulata: yield, chemical composition and antioxidant activity.

    Science.gov (United States)

    Herzi, Nejia; Bouajila, Jalloul; Camy, Séverine; Romdhane, Mehrez; Condoret, Jean-Stéphane

    2013-12-15

    In the present study, three techniques of extraction: hydrodistillation (HD), solvent extraction (conventional 'Soxhlet' technique) and an innovative technique, i.e., the supercritical fluid extraction (SFE), were applied to ground Tetraclinis articulata leaves and compared for extraction duration, extraction yield, and chemical composition of the extracts as well as their antioxidant activities. The extracts were analyzed by GC-FID and GC-MS. The antioxidant activity was measured using two methods: ABTS(•+) and DPPH(•). The yield obtained using HD, SFE, hexane and ethanol Soxhlet extractions were found to be 0.6, 1.6, 40.4 and 21.2-27.4 g/kg respectively. An original result of this study is that the best antioxidant activity was obtained with an SFE extract (41 mg/L). The SFE method offers some noteworthy advantages over traditional alternatives, such as shorter extraction times, low environmental impact, and a clean, non-thermally-degraded final product. Also, a good correlation between the phenolic contents and the antioxidant activity was observed with extracts obtained by SFE at 9 MPa. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Evaluation of Extraction and Degradation Methods to Obtain Chickpeasaponin B1 from Chickpea (Cicer arietinum L.

    Directory of Open Access Journals (Sweden)

    Kun Cheng

    2017-02-01

    Full Text Available The objective of this research is to implement extraction and degradation methods for the obtainment of 3-O-[α-l-rhamnopyranosyl-(1→2-β-d-galactopyranosyl] soyasapogenol B (chickpeasaponin B1 from chickpea. The effects of microwave-assisted extraction (MAE processing parameters—such as ethanol concentration, solvent/solid ratio, extraction temperature, microwave irradiation power, and irradiation time—were evaluated. Using 1g of material with 8 mL of 70% aqueous ethanol and an extraction time of 10 min at 70 °C under irradiation power 400W provided optimal extraction conditions. Compared with the conventional extraction techniques, including heat reflux extraction (HRE, Soxhlet extraction (SE, and ultrasonic extraction (UE, MAE produced higher extraction efficiency under a lower extraction time. DDMP (2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one saponin can be degraded to structurally stable saponin B by the loss of its DDMP group. The influence of pH and the concentration of potassium hydroxide on transformation efficiency of the target compound was investigated. A solution of 0.25 M potassium hydroxide in 75% aqueous ethanol was suitable for converting the corresponding DDMP saponins of chickpeasaponin B1. The implementation by the combining MAE technique and alkaline hydrolysis method for preparing chickpeasaponin B1 provides a convenient technology for future applications.

  6. Evaluation of Extraction and Degradation Methods to Obtain Chickpeasaponin B1 from Chickpea (Cicer arietinum L.).

    Science.gov (United States)

    Cheng, Kun; Gao, Hua; Wang, Rong-Rong; Liu, Yang; Hou, Yu-Xue; Liu, Xiao-Hong; Liu, Kun; Wang, Wei

    2017-02-21

    The objective of this research is to implement extraction and degradation methods for the obtainment of 3- O -[α-l-rhamnopyranosyl-(1→2)-β-d-galactopyranosyl] soyasapogenol B (chickpeasaponin B1) from chickpea. The effects of microwave-assisted extraction (MAE) processing parameters-such as ethanol concentration, solvent/solid ratio, extraction temperature, microwave irradiation power, and irradiation time-were evaluated. Using 1g of material with 8 mL of 70% aqueous ethanol and an extraction time of 10 min at 70 °C under irradiation power 400W provided optimal extraction conditions. Compared with the conventional extraction techniques, including heat reflux extraction (HRE), Soxhlet extraction (SE), and ultrasonic extraction (UE), MAE produced higher extraction efficiency under a lower extraction time. DDMP (2,3-dihydro-2,5-dihydroxy-6-methyl-4 H -pyran-4-one) saponin can be degraded to structurally stable saponin B by the loss of its DDMP group. The influence of pH and the concentration of potassium hydroxide on transformation efficiency of the target compound was investigated. A solution of 0.25 M potassium hydroxide in 75% aqueous ethanol was suitable for converting the corresponding DDMP saponins of chickpeasaponin B1. The implementation by the combining MAE technique and alkaline hydrolysis method for preparing chickpeasaponin B1 provides a convenient technology for future applications.

  7. EXTRACT

    DEFF Research Database (Denmark)

    Pafilis, Evangelos; Buttigieg, Pier Luigi; Ferrell, Barbra

    2016-01-01

    The microbial and molecular ecology research communities have made substantial progress on developing standards for annotating samples with environment metadata. However, sample manual annotation is a highly labor intensive process and requires familiarity with the terminologies used. We have the...... and text-mining-assisted curation revealed that EXTRACT speeds up annotation by 15-25% and helps curators to detect terms that would otherwise have been missed.Database URL: https://extract.hcmr.gr/......., organism, tissue and disease terms. The evaluators in the BioCreative V Interactive Annotation Task found the system to be intuitive, useful, well documented and sufficiently accurate to be helpful in spotting relevant text passages and extracting organism and environment terms. Comparison of fully manual...

  8. Developing management capacity building package to district health manager in northwest of Iran: A sequential mixed method study.

    Science.gov (United States)

    Tabrizi, Jafar Sadegh; Gholipour, Kamal; Farahbakhsh, Mostafa; Jahanbin, Hasan; Karamuz, Majid

    2016-11-01

    To assess districts health managers educational needs and develop management training programmes. This mixed-method study was carried out between August 2014 and August 2015 in Tabriz, Iran. Four focus group discussion sessions and three semi-structured face-to-face interviews were conducted among district health managers and experts of a health centre. Besides, 52 questionnaires were completed to weigh and finalise management education module and courses. Interviews and focus group discussions were tape-recorded, transcribed and analysed using content analysis method. Data was analysed using SPSS17. There were 52 participants, of whom 40(78.8%) were men and 12(21.2%) were women. All of the subjects (100%) took part in the quantitative phase, while 25(48.08%) participated in the qualitative phase. In the qualitative section, 11(44%) participants were heads of unit/departments in provincial health centre and 14(56%) were district health managers. In the quantitative phase, 30(57.7%) participants were district health managers and 8(28.8%) were heads of units/departments. Moreover, 33(63.4%) participants had medical education. The job experience of 3(5.8%) participants in the current position was below five years. Districts health management training programme consisted of 10modules with 53 educational topics. The normalised score out of a total of 100 for rules and ethics was 75.51, health information management 71.19, management and leadership 69.27, district management 68.08, human resources and organisational creativity 67.58,quality improvement 66.6, health resources management 62.37, planning and evaluation 61.87, research in health system 59.15, and community participation was 53.15. Considering district health managers' qualification in health and medicine, they had not been trained in basic management. Almost all the management and leadership courses were prioritised as most necessary.

  9. Methods for extracting climate indicator data from social media.

    Science.gov (United States)

    Fuka, M. Z.; Fuka, D. R.

    2011-12-01

    This paper shows how we've used the R software suite to extract climate indicator data from Twitter. In the course of this research we've collected extensive data sets of unsolicited observations ("tweets") for hundreds of climate-related phenological, biological, epidemiological and meteorological effects. R has proved itself in our work as a useful tool for manipulating those large data sets. Our experience from this effort has yielded a variety of insights on using R to extract geophysics-specific information from publicly accessible social media sources. We illustrate our methodology by mapping tweeted US armadillo sightings to explore the impact of climate variability on the extent of the animal's range. This example usefully demonstrates R's technical capabilities in collecting, time-stamping, geolocating, analyzing, visualizing and otherwise processing climate-related data derived from unsolicited social media postings. We also "mash-up" the data sets with those acquired by more traditional means, for example, temperature and precipitation data across the armadillo's US range. Our data-handling practice is extendable to social sharing services other than Twitter, providing the environmental modeling community an opportunity to access largely untapped resources of non-traditional climate indicator data to better understand the effects of climate change at local, regional and global scales.

  10. Sequential Dip-spin Coating Method: Fully Infiltration of MAPbI 3-x Cl x into Mesoporous TiO 2 for Stable Hybrid Perovskite Solar Cells

    KAUST Repository

    Kim, Woochul

    2017-05-31

    Organic-inorganic hybrid perovskite solar cells (PSCs) have reached a power conversion efficiency of 22.1% in a short period (∼7 years), which has been obtainable in silicon-based solar cells for decades. The high power conversion efficiency and simple fabrication process render perovskite solar cells as potential future power generators, after overcoming the lack of long-term stability, for which the deposition of void-free and pore-filled perovskite films on mesoporous TiO2 layers is the key pursuit. In this research, we developed a sequential dip-spin coating method in which the perovskite solution can easily infiltrate the pores within the TiO2 nanoparticulate layer, and the resultant film has large crystalline grains without voids between them. As a result, a higher short circuit current is achieved owing to the large interfacial area of TiO2/perovskite, along with enhanced power conversion efficiency, compared to the conventional spin coating method. The as-made pore-filled and void-free perovskite film avoids intrinsic moisture and air and can effectively protect the diffusion of degradation factors into the perovskite film, which is advantageous for the long-term stability of PSCs.

  11. A Novel Lipid Extraction Method from Wet Microalga Picochlorum sp. at Room Temperature

    Directory of Open Access Journals (Sweden)

    Fangfang Yang

    2014-03-01

    Full Text Available A novel method using ethanol was proposed for extracting lipids from wet microalga Picochlorum sp. at room temperature and pressure. In this study, Central Composite design (CCD was applied to investigate the optimum conditions of lipid extraction. The results revealed that the solvent to biomass ratio had the largest effect on lipid extraction efficiency, followed by extraction time and temperature. A high lipid extraction yield (33.04% of the dry weight was obtained under the following extraction conditions: 5 mL solvents per gram of wet biomass for 37 min with gentle stirring at room temperature. The extraction yield was comparable to that obtained by the widely used Bligh-Dyer method. Furthermore, no significant differences in the distribution of lipid classes and fatty acid composition were observed according to different extraction methods. In conclusion, these results indicated that the proposed procedure using ethanol could extract lipids from wet biomass efficiently and had giant potential for lipid extraction at large scale.

  12. An effective placental cotyledons proteins extraction method for 2D gel electrophoresis.

    Science.gov (United States)

    Tan, Niu J; Daim, Leona D J; Jamil, Amilia A M; Mohtarrudin, Norhafizah; Thilakavathy, Karuppiah

    2017-03-01

    Effective protein extraction is essential especially in producing a well-resolved proteome on 2D gels. A well-resolved placental cotyledon proteome, with good reproducibility, have allowed researchers to study the proteins underlying the physiology and pathophysiology of pregnancy. The aim of this study is to determine the best protein extraction protocol for the extraction of protein from placental cotyledons tissues for a two-dimensional gel electrophoresis (2D-GE). Based on widely used protein extraction strategies, 12 different extraction methodologies were carefully selected, which included one chemical extraction, two mechanical extraction coupled protein precipitations, and nine chemical extraction coupled protein precipitations. Extracted proteins were resolved in a one-dimensional gel electrophoresis and 2D-GE; then, it was compared with set criteria: extraction efficacy, protein resolution, reproducibility, and recovery efficiency. Our results revealed that a better profile was obtained by chemical extraction in comparison to mechanical extraction. We further compared chemical extraction coupled protein precipitation methodologies, where the DNase/lithium chloride-dense sucrose homogenization coupled dichloromethane-methanol precipitation (DNase/LiCl-DSH-D/MPE) method showed good protein extraction efficiency. This, however, was carried out with the best protein resolution and proteome reproducibility on 2D-gels. DNase/LiCl-DSH-D/MPE was efficient in the extraction of proteins from placental cotyledons tissues. In addition, this methodology could hypothetically allow the protein extraction of any tissue that contains highly abundant lipid and glycogen. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Text extraction method for historical Tibetan document images based on block projections

    Science.gov (United States)

    Duan, Li-juan; Zhang, Xi-qun; Ma, Long-long; Wu, Jian

    2017-11-01

    Text extraction is an important initial step in digitizing the historical documents. In this paper, we present a text extraction method for historical Tibetan document images based on block projections. The task of text extraction is considered as text area detection and location problem. The images are divided equally into blocks and the blocks are filtered by the information of the categories of connected components and corner point density. By analyzing the filtered blocks' projections, the approximate text areas can be located, and the text regions are extracted. Experiments on the dataset of historical Tibetan documents demonstrate the effectiveness of the proposed method.

  14. Extraction of solubles from plant biomass for use as microbial growth stimulant and methods related thereto

    Energy Technology Data Exchange (ETDEWEB)

    Lau, Ming Woei

    2015-12-08

    A method for producing a microbial growth stimulant (MGS) from a plant biomass is described. In one embodiment, an ammonium hydroxide solution is used to extract a solution of proteins and ammonia from the biomass. Some of the proteins and ammonia are separated from the extracted solution to provide the MGS solution. The removed ammonia can be recycled and the proteins are useful as animal feeds. In one embodiment, the method comprises extracting solubles from pretreated lignocellulosic biomass with a cellulase enzyme-producing growth medium (such T. reesei) in the presence of water and an aqueous extract.

  15. Evaluation of DNA Extraction Methods Suitable for PCR-based Detection and Genotyping of Clostridium botulinum

    DEFF Research Database (Denmark)

    Auricchio, Bruna; Anniballi, Fabrizio; Fiore, Alfonsina

    2013-01-01

    in terms of cost, time, labor, and supplies. Eleven botulinum toxin–producing clostridia strains and 25 samples (10 food, 13 clinical, and 2 environmental samples) naturally contaminated with botulinum toxin–producing clostridia were used to compare 4 DNA extraction procedures: Chelex® 100 matrix, Phenol......Sufficient quality and quantity of extracted DNA is critical to detecting and performing genotyping of Clostridium botulinum by means of PCR-based methods. An ideal extraction method has to optimize DNA yield, minimize DNA degradation, allow multiple samples to be extracted, and be efficient...

  16. A comparison of tissue preparation methods for protein extraction of cocoa (Theobroma cacao L. pod

    Directory of Open Access Journals (Sweden)

    Ascensión Martínez-Márquez

    2017-04-01

    Full Text Available Cocoa, Theobroma cacao L. is one of the main tropical industrial crops. Cocoa has a very high level of interfering substances, such as polysaccharides and phenolic compounds that could prevent the isolation of suitable protein. Efficient methods of protein extraction are a priority to successfully apply proteomic analyses. We compared and evaluated two methods (A and B of tissue preparation for total protein extract by phenol/SDS extraction protocol. The difference in the application of the two methods was that extensively washed dry powder of pod tissue were made in Method A, whereas that crude extract were prepared Method B. Extracted proteins were examined using one-dimensional electrophoresis (1-D. Results show that each extraction method isolated a unique subset of cocoa pod proteome. Principal component analysis showed little variation in the data obtained using Method A, while that in Methods B showed no low reproducibility, thus demonstrating that Method A is a reliable for preparing cocoa pod proteins. The protocol is expected to be applicable to other recalcitrant plant tissues and to be of interest to laboratories involved in plant proteomics analyses. A combination of extraction approaches is recommended for increasing proteome coverage when using gel-based isolation techniques.

  17. Realization of Personalized Services for Intelligent Residential Space based on User Identification Method using Sequential Walking Footprints

    Directory of Open Access Journals (Sweden)

    Jin-Woo Jung

    2005-04-01

    Full Text Available A new human-friendly assistive home environment, Intelligent Sweet Home (ISH, developed at KAIST, Korea for testing advanced concepts for independent living of the elderly/the physically handicapped. The concept of ISH is to consider the home itself as an intelligent robot. ISH always checks the intention or health status of the resident. Therefore, ISH can do actively the most proper services considering the resident's life-style by the detected intention or emergency information. But, when there are more than two residents, ISH cannot consider the residents' characteristics or tastes if ISH cannot identify who he/she is before. To realize a personalized service system in the intelligent residential space like ISH, we deal with a human-friendly user identification method for ubiquitous computing environment, specially focused on dynamic human footprint recognition. And then, we address some case studies of personalized services that have been experienced by Human-friendly Welfare Robot System research center, KAIST.

  18. Methods for sequential resonance assignment in solid, uniformly 13C, 15N labelled peptides: Quantification and application to antamanide

    International Nuclear Information System (INIS)

    Detken, Andreas; Hardy, Edme H.; Ernst, Matthias; Kainosho, Masatsune; Kawakami, Toru; Aimoto, Saburo; Meier, Beat H.

    2001-01-01

    The application of adiabatic polarization-transfer experiments to resonance assignment in solid, uniformly 13 C- 15 N-labelled polypeptides is demonstrated for the cyclic decapeptide antamanide. A homonuclear correlation experiment employing the DREAM sequence for adiabatic dipolar transfer yields a complete assignment of the C α and aliphatic side-chain 13 C resonances to amino acid types. The same information can be obtained from a TOBSY experiment using the recently introduced P9 1 12 TOBSY sequence, which employs the J couplings as a transfer mechanism. A comparison of the two methods is presented. Except for some aromatic phenylalanine resonances, a complete sequence-specific assignment of the 13 C and 15 N resonances in antamanide is achieved by a series of selective or broadband adiabatic triple-resonance experiments. Heteronuclear transfer by adiabatic-passage Hartmann-Hahn cross polarization is combined with adiabatic homonuclear transfer by the DREAM and rotational-resonance tickling sequences into two- and three-dimensional experiments. The performance of these experiments is evaluated quantitatively

  19. Review on the Extraction Methods of Crude oil from all Generation Biofuels in last few Decades

    Science.gov (United States)

    Bhargavi, G.; Nageswara Rao, P.; Renganathan, S.

    2018-03-01

    The ever growing demand for the energy fuels, economy of oil, depletion of energy resources and environmental protection are the inevitable challenges required to be solved meticulously in future decades in order to sustain the life of humans and other creatures. Switching to alternate fuels that are renewable, biodegradable, economically and environmentally friendly can quench the minimum thirst of fuel demands, in addition to mitigation of climate changes. At this moment, production of biofuels has got prominence. The term biofuels broadly refer to the fuels derived from living matter either animals or plants. Among the competent biofuels, biodiesel is one of the promising alternates for diesel engines. Biodiesel is renewable, environmentally friendly, safe to use with wide applications and biodegradable. Due to which, it has become a major focus of intensive global research and development of alternate energy. The present review has been focused specifically on biodiesel. Concerning to the biodiesel production, the major steps includes lipid extraction followed by esterification/transesterification. For the extraction of lipids, several extraction techniques have been put forward irrespective of the generations and feed stocks used. This review provides theoretical background on the two major extraction methods, mechanical and chemical extraction methods. The practical issues of each extraction method such as efficiency of extraction, extraction time, oil sources and its pros and cons are discussed. It is conceived that congregating information on oil extraction methods may helpful in further research advancements to ease biofuel production.

  20. Quality and characteristics of fermented ginseng seed oil based on bacterial strain and extraction method

    Directory of Open Access Journals (Sweden)

    Myung-Hee Lee

    2017-07-01

    Results and Conclusion: The color of the fermented ginseng seed oil did not differ greatly according to the fermentation or extraction method. The highest phenolic compound content recovered with the use of supercritical fluid extraction combined with fermentation using the Bacillus subtilis Korea Food Research Institute (KFRI 1127 strain. The fatty acid composition did not differ greatly according to fermentation strain and extraction method. The phytosterol content of ginseng seed oil fermented with Bacillus subtilis KFRI 1127 and extracted using the supercritical fluid method was highest at 983.58 mg/100 g. Therefore, our results suggested that the ginseng seed oil fermented with Bacillus subtilis KFRI 1127 and extracted using the supercritical fluid method can yield a higher content of bioactive ingredients, such as phenolics, and phytosterols, without impacting the color or fatty acid composition of the product.

  1. An automatic rat brain extraction method based on a deformable surface model.

    Science.gov (United States)

    Li, Jiehua; Liu, Xiaofeng; Zhuo, Jiachen; Gullapalli, Rao P; Zara, Jason M

    2013-08-15

    The extraction of the brain from the skull in medical images is a necessary first step before image registration or segmentation. While pre-clinical MR imaging studies on small animals, such as rats, are increasing, fully automatic imaging processing techniques specific to small animal studies remain lacking. In this paper, we present an automatic rat brain extraction method, the Rat Brain Deformable model method (RBD), which adapts the popular human brain extraction tool (BET) through the incorporation of information on the brain geometry and MR image characteristics of the rat brain. The robustness of the method was demonstrated on T2-weighted MR images of 64 rats and compared with other brain extraction methods (BET, PCNN, PCNN-3D). The results demonstrate that RBD reliably extracts the rat brain with high accuracy (>92% volume overlap) and is robust against signal inhomogeneity in the images. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. An Improved AAM Method for Extracting Human Facial Features

    Directory of Open Access Journals (Sweden)

    Tao Zhou

    2012-01-01

    Full Text Available Active appearance model is a statistically parametrical model, which is widely used to extract human facial features and recognition. However, intensity values used in original AAM cannot provide enough information for image texture, which will lead to a larger error or a failure fitting of AAM. In order to overcome these defects and improve the fitting performance of AAM model, an improved texture representation is proposed in this paper. Firstly, translation invariant wavelet transform is performed on face images and then image structure is represented using the measure which is obtained by fusing the low-frequency coefficients with edge intensity. Experimental results show that the improved algorithm can increase the accuracy of the AAM fitting and express more information for structures of edge and texture.

  3. Comparative Properties of Amazonian Oils Obtained by Different Extraction Methods

    Directory of Open Access Journals (Sweden)

    Cláudio Galuppo Diniz

    2011-07-01

    Full Text Available Pequi (Caryocar brasiliense Camb., babaçu (Orbignya phalerata Mart., buriti (Mauritia flexuosa, and passion fruit (Passiflora edulis oils were studied to determine their antibacterial, antioxidant and cytotoxic activities, as well as their total phenol and carotenoid contents. The fatty acid contents were determined by GC-MS. The three types of passion fruit oils studied were refined, cold pressed or extracted from seeds in a Soxhlet apparatus. The oils thus obtained showed differences in antioxidant activity and carotenoid content, but were similar in regard to total phenols. Buriti and pequi had the highest carotenoid contents, while refined and cold pressed passion fruit oil displayed the highest antioxidant activity. Pequi oil was the only oil to display antibacterial and cytotoxic activity.

  4. A Survey On Various Web Template Detection And Extraction Methods

    Directory of Open Access Journals (Sweden)

    Neethu Mary Varghese

    2015-03-01

    Full Text Available Abstract In todays digital world reliance on the World Wide Web as a source of information is extensive. Users increasingly rely on web based search engines to provide accurate search results on a wide range of topics that interest them. The search engines in turn parse the vast repository of web pages searching for relevant information. However majority of web portals are designed using web templates which are designed to provide consistent look and feel to end users. The presence of these templates however can influence search results leading to inaccurate results being delivered to the users. Therefore to improve the accuracy and reliability of search results identification and removal of web templates from the actual content is essential. A wide range of approaches are commonly employed to achieve this and this paper focuses on the study of the various approaches of template detection and extraction that can be applied across homogenous as well as heterogeneous web pages.

  5. Optimization of cloud point extraction and solid phase extraction methods for speciation of arsenic in natural water using multivariate technique.

    Science.gov (United States)

    Baig, Jameel A; Kazi, Tasneem G; Shah, Abdul Q; Arain, Mohammad B; Afridi, Hassan I; Kandhro, Ghulam A; Khan, Sumaira

    2009-09-28

    The simple and rapid pre-concentration techniques viz. cloud point extraction (CPE) and solid phase extraction (SPE) were applied for the determination of As(3+) and total inorganic arsenic (iAs) in surface and ground water samples. The As(3+) was formed complex with ammonium pyrrolidinedithiocarbamate (APDC) and extracted by surfactant-rich phases in the non-ionic surfactant Triton X-114, after centrifugation the surfactant-rich phase was diluted with 0.1 mol L(-1) HNO(3) in methanol. While total iAs in water samples was adsorbed on titanium dioxide (TiO(2)); after centrifugation, the solid phase was prepared to be slurry for determination. The extracted As species were determined by electrothermal atomic absorption spectrometry. The multivariate strategy was applied to estimate the optimum values of experimental factors for the recovery of As(3+) and total iAs by CPE and SPE. The standard addition method was used to validate the optimized methods. The obtained result showed sufficient recoveries for As(3+) and iAs (>98.0%). The concentration factor in both cases was found to be 40.

  6. Reference Proteome Extracts for Mass Spec Instrument Performance Validation and Method Development

    Science.gov (United States)

    Rosenblatt, Mike; Urh, Marjeta; Saveliev, Sergei

    2014-01-01

    Biological samples of high complexity are required to test protein mass spec sample preparation procedures and validate mass spec instrument performance. Total cell protein extracts provide the needed sample complexity. However, to be compatible with mass spec applications, such extracts should meet a number of design requirements: compatibility with LC/MS (free of detergents, etc.)high protein integrity (minimal level of protein degradation and non-biological PTMs)compatibility with common sample preparation methods such as proteolysis, PTM enrichment and mass-tag labelingLot-to-lot reproducibility Here we describe total protein extracts from yeast and human cells that meet the above criteria. Two extract formats have been developed: Intact protein extracts with primary use for sample preparation method development and optimizationPre-digested extracts (peptides) with primary use for instrument validation and performance monitoring

  7. Solid phase extraction-electrospray ionization mass spectrometric method for the determination of palladium

    International Nuclear Information System (INIS)

    Pranaw Kumar; Telmore, Vijay M.; Jaison, P.G.; Sarkar, Arnab; Alamelu, D.; Aggarwal, S.K.

    2015-01-01

    Platinum group of element (PGEs) are extensively used as a catalyst and anticancer reagent. Due to the soft nature of PGEs, sulphur based donar ligands are used for the separation of these elements. Studies on the formation of different species are helpful for obtaining the ideas about separation of these elements from the complex matrices. Palladium (Pd) is studied as a representative element which is also formed by nuclear fission of fissile nuclides. In view of the relatively small amount of solvent required for separation, solid phase extraction is preferred over most of the separation methods. Solid phase extraction method using DPX as a stationary phase was previously reported for the separation of Pd in SHLLW using benzoylthiourea as a ligand. However, in case of large volume samples manual extraction by DPX is tedious task. In the present studies, the feasibility of extraction using benzoylthiourea on automated solid phase extraction system was carried out for the extraction of Pd

  8. 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

  9. Method development for the determination of arsenic by sequential injection/anodic stripping voltammetry using long-lasting gold-modified screen-printed carbon electrode.

    Science.gov (United States)

    Punrat, Eakkasit; Chuanuwatanakul, Suchada; Kaneta, Takashi; Motomizu, Shoji; Chailapakul, Orawon

    2013-11-15

    An automated method has been developed for determining the concentration of inorganic arsenic. The technique uses sequential injection/anodic stripping voltammetry with a long-lasting gold-modified screen-printed carbon electrode. The long-lasting gold electrode was electrochemically deposited onto a screen-printed carbon electrode at a potential of -0.5 V vs. Ag/AgCl in a supporting electrolyte solution of 1M hydrochloric acid. Under optimal conditions and the applied potentials, the electrode demonstrated that it can be used for a long time without a renewal process. The linear range for the determination of arsenic(III) was 1-100 μg L(-1), and the limit of detection (LOD) in standard solutions was as low as 0.03 μg L(-1) for a deposition time of 120 s and sample volume of 1 mL. This method was used to determine the concentration of arsenic(III) in water samples with satisfactory results. The LOD in real samples was found to be 0.5 μg L(-1). In addition, speciation between arsenic(III) and arsenic(V) has been achieved with the proposed method using deposition potentials of -0.5 V and -1.5 V for the determination of the arsenic(III) concentration and the total arsenic concentration, respectively; the results were acceptable. The proposed method is an automated system that offers a less expensive alternative for determining trace amounts of inorganic arsenic. © 2013 Elsevier B.V. All rights reserved.

  10. Chemical composition of mate tea leaves (Ilex paraguariensis): a study of extraction methods.

    Science.gov (United States)

    Assis Jacques, Rosângela; dos Santos Freitas, Lisiane; Flores Peres, Valéria; Dariva, Cláudio; de Oliveira, José Vladimir; Bastos Caramão, Elina

    2006-12-01

    The objective of this work was to investigate the extraction of Ilex paraguariensis leaves by means of three extraction techniques: pressurized liquid extraction (PLE, also called accelerated solvent extraction--ASE), maceration, and sonication. Samples of mate tea leaves were collected from an experiment conducted under agronomic control at Indfistria e Comércio de Erva-Mate Barão LTDA, Brazil. Six solvents with increasing polarities (n-hexane, toluene, dichloromethane, ethyl acetate, acetone, and methanol) were used in this investigation. Chemical analysis of the extracts was performed by GC coupled with a mass spectrometer detector. The identification and quantification were accomplished by coinjections of certified standards. The results showed that no significant differences in the qualities of the extracts were noticed regarding the extraction methods. On the other hand, the PLE technique was found to be more effective for the extractions of caffeine, phytol, palmitic, and stearic acid. The use of PLE led to a significant decrease in the total extraction time, amount of solvent consumption, and manipulation of samples compared to maceration and ultrasound-assisted extraction methods.

  11. Effects of Extraction Methods on Phytochemicals of Rice Bran Oils Produced from Colored Rice.

    Science.gov (United States)

    Mingyai, Sukanya; Srikaeo, Khongsak; Kettawan, Aikkarach; Singanusong, Riantong; Nakagawa, Kiyotaka; Kimura, Fumiko; Ito, Junya

    2018-02-01

    Rice bran oil (RBO) especially from colored rice is rich in phytochemicals and has become popular in food, cosmetic, nutraceutical and pharmaceutical applications owing to its offering health benefits. This study determined the contents of phytochemicals including oryzanols, phytosterols, tocopherols (Toc) and tocotrienols (T3) in RBOs extracted using different methods namely cold-press extraction (CPE), solvent extraction (SE) and supercritical CO 2 extraction (SC-CO 2 ). Two colored rice, Red Jasmine rice (RJM, red rice) and Hom-nin rice (HN, black rice), were studied in comparison with the popular Thai fragrant rice Khao Dawk Mali 105 (KDML 105, white rice). RBOs were found to be the rich source of oryzanols, phytosterols, Toc and T3. Rice varieties had a greater effect on the phytochemicals concentrations than extraction methods. HN rice showed the significantly highest concentration of all phytochemicals, followed by RJM and KDML 105 rice, indicating that colored rice contained high concentration of phytochemicals in the oil than non-colored rice. The RBO samples extracted by the CPE method had a greater concentration of the phytochemicals than those extracted by the SC-CO 2 and SE methods, respectively. In terms of phytochemical contents, HN rice extracted using CPE method was found to be the best.

  12. A Method of Road Extraction from High-resolution Remote Sensing Images Based on Shape Features

    Directory of Open Access Journals (Sweden)

    LEI Xiaoqi

    2016-02-01

    Full Text Available Road extraction from high-resolution remote sensing image is an important and difficult task.Since remote sensing images include complicated information,the methods that extract roads by spectral,texture and linear features have certain limitations.Also,many methods need human-intervention to get the road seeds(semi-automatic extraction,which have the great human-dependence and low efficiency.The road-extraction method,which uses the image segmentation based on principle of local gray consistency and integration shape features,is proposed in this paper.Firstly,the image is segmented,and then the linear and curve roads are obtained by using several object shape features,so the method that just only extract linear roads are rectified.Secondly,the step of road extraction is carried out based on the region growth,the road seeds are automatic selected and the road network is extracted.Finally,the extracted roads are regulated by combining the edge information.In experiments,the images that including the better gray uniform of road and the worse illuminated of road surface were chosen,and the results prove that the method of this study is promising.

  13. Comparison of three mycobacterial DNA extraction methods from extrapulmonary samples for PCR assay

    Directory of Open Access Journals (Sweden)

    Khandaker Shadia

    2012-01-01

    Full Text Available Sensitivity of the molecular diagnostic tests of extrapulmonary tuberculosis largely depends upon the efficiency of DNA extraction methods. The objective of our study was to compare three methods of extracting DNA of Mycobacterium tuberculosis for testing by polymerase chain reaction. All three methods; heating, heating with sonication and addition of lysis buffer with heating and sonication were implicated on 20 extrapulmonary samples. PCR positivity was 2 (10%, 4 (20% and 7 (35% in the samples extracted by heating, heat+sonication and heat+sonication+lysis buffer method respectively. Of the extraction methods evaluated, maximum PCR positive results were achieved by combined heat, sonication and lysis buffer method which can be applied in routine clinical practice. Ibrahim Med. Coll. J. 2012; 6(1: 9-11

  14. Extractive Spectrophotometric Methods for the Determination of Etoricoxib in Tablets

    Directory of Open Access Journals (Sweden)

    Kamal Shah

    2009-01-01

    Full Text Available Two simple, rapid, sensitive, precise and economic spectrophotometric methods have been developed for the estimation of etoricoxib in tablet formulation. During the course of study, it was observed that acidic solution of the drug formed colored ion-association complexes with Bromocresol Green (BCG and Bromocresol Purple (BCP which were soluble in chloroform. This property of the drug was followed for the development of colorimetric methods for analysis of drug. The complex of etoricoxib with BCG and BCP showed λmax at 416 nm and 408 nm respectively. These methods were validated statistically. Recovery studies gave satisfactory results indicating that none of common additives and excipients interfere the assay method. The proposed methods are found to be simple, accurate and reproducible that was successfully applied for the analysis of tablet formulation.

  15. Development of a system for simultaneous - sequential determinations of major and minor actinides (Th, Np, U, Pu, Am, Cm) by on-line extraction chromatography - ion concentration - inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Trivellone, E.; Mariani, M.; Carlos-Marquez, R.; Aldave de las Heras, L.; Betti, M.; )

    2009-01-01

    Full text: Because of the great complexity and time consuming of traditional methods for actinides determination, a procedure for their simultaneous and sequential separation and quantification was developed. A complete circuit constituted by three analytical chromatographic columns packed with TEVA, UTEVA and TRU resins (Eichrom Inc) for retention of tetra-, hexa- and tri-valent actinides and three cation concentrator columns TCC-II (from Dionex Corporation) connected by six (4-way and 6-way) valves is coupled on-line to an ICPMS detector. The use of TCC-II columns just prior of the ICPMS determination allows to improve sensitivity and detection limits down to the ng/l level. The use of a coupled HPLC to an ICPMS system enables the complete analysis of all the six actinides in almost 2 hours. (author)

  16. Advanced RF-KO slow-extraction method for the reduction of spill ripple

    CERN Document Server

    Noda, K; Shibuya, S; Uesugi, T; Muramatsu, M; Kanazawa, M; Takada, E; Yamada, S

    2002-01-01

    Two advanced RF-knockout (RF-KO) slow-extraction methods have been developed at HIMAC in order to reduce the spill ripple for accurate heavy-ion cancer therapy: the dual frequency modulation (FM) method and the separated function method. As a result of simulations and experiments, it was verified that the spill ripple could be considerably reduced using these advanced methods, compared with the ordinary RF-KO method. The dual FM method and the separated function method bring about a low spill ripple within standard deviations of around 25% and of 15% during beam extraction within around 2 s, respectively, which are in good agreement with the simulation results.

  17. An unsupervised text mining method for relation extraction from biomedical literature.

    Directory of Open Access Journals (Sweden)

    Changqin Quan

    Full Text Available The wealth of interaction information provided in biomedical articles motivated the implementation of text mining approaches to automatically extract biomedical relations. This paper presents an unsupervised method based on pattern clustering and sentence parsing to deal with biomedical relation extraction. Pattern clustering algorithm is based on Polynomial Kernel method, which identifies interaction words from unlabeled data; these interaction words are then used in relation extraction between entity pairs. Dependency parsing and phrase structure parsing are combined for relation extraction. Based on the semi-supervised KNN algorithm, we extend the proposed unsupervised approach to a semi-supervised approach by combining pattern clustering, dependency parsing and phrase structure parsing rules. We evaluated the approaches on two different tasks: (1 Protein-protein interactions extraction, and (2 Gene-suicide association extraction. The evaluation of task (1 on the benchmark dataset (AImed corpus showed that our proposed unsupervised approach outperformed three supervised methods. The three supervised methods are rule based, SVM based, and Kernel based separately. The proposed semi-supervised approach is superior to the existing semi-supervised methods. The evaluation on gene-suicide association extraction on a smaller dataset from Genetic Association Database and a larger dataset from publicly available PubMed showed that the proposed unsupervised and semi-supervised methods achieved much higher F-scores than co-occurrence based method.

  18. Sequential Optimization Methods for Augmentation of Marine Enzymes Production in Solid-State Fermentation: l-Glutaminase Production a Case Study.

    Science.gov (United States)

    Sathish, T; Uppuluri, K B; Veera Bramha Chari, P; Kezia, D

    There is an increased l-glutaminase market worldwide due to its relevant industrial applications. Salt tolerance l-glutaminases play a vital role in the increase of flavor of different types of foods like soya sauce and tofu. This chapter is presenting the economically viable l-glutaminases production in solid-state fermentation (SSF) by Aspergillus flavus MTCC 9972 as a case study. The enzyme production was improved following a three step optimization process. Initially mixture design (MD) (augmented simplex lattice design) was employed to optimize the solid substrate mixture. Such solid substrate mixture consisted of 59:41 of wheat bran and Bengal gram husk has given higher amounts of l-glutaminase. Glucose and l-glutamine were screened as a finest additional carbon and nitrogen sources for l-glutaminase production with help of Plackett-Burman Design (PBD). l-Glutamine also acting as a nitrogen source as well as inducer for secretion of l-glutaminase from A. flavus MTCC 9972. In the final step of optimization various environmental and nutritive parameters such as pH, temperature, moisture content, inoculum concentration, glucose, and l-glutamine levels were optimized through the use of hybrid feed forward neural networks (FFNNs) and genetic algorithm (GA). Through sequential optimization methods MD-PBD-FFNN-GA, the l-glutaminase production in SSF could be improved by 2.7-fold (453-1690U/g). © 2016 Elsevier Inc. All rights reserved.

  19. Orbital angular momentum transfer and spin desalignment mechanisms in the deep inelastic collisions Ar+Bi and Ni+Pb using the sequential fission method

    International Nuclear Information System (INIS)

    Steckmeyer, J.C.

    1984-10-01

    Angular momentum transfer and spin dealignment mechanisms have been studied in the deep inelastic collisions Ar+Bi and Ni+Pb using the sequential fission method. This experimental technique consists to measure the angular distribution of the fission fragments of a heavy nucleus in coincidence with the reaction partner, and leads to a complete determination of the heavy nucleus spin distribution. High spin values are transferred to the heavy nucleus in the interaction and indicate that the dinuclear system has reached the rigid rotation limit. A theoretical model, taking into account the excitation of surface vibrations of the nuclei and the nucleon transfer between the two partners, is able to reproduce the high spin values measured in our experiments. The spin fluctuations are important, with values of the order of 15 to 20 h units. These fluctuations increase with the charge transfer from the projectile to the target and the total kinetic energy loss. The spin dealignment mechanisms act mainly in a plane approximately perpendicular to the heavy recoil direction in the laboratory system. These results are well described by a dynamical transport model based on the stochastic exchange of individual nucleons between the two nuclei during the interaction. The origin of the dealignment mechanisms in the spin transfer processes is then related to the statistical nature of the nucleon exchange. However other mechanisms can contribute to the spin dealignment as the surface vibrations, the nuclear deformations as well their relative orientations [fr

  20. Effects of a self-management education program on self-efficacy in patients with COPD: a mixed-methods sequential explanatory designed study

    Science.gov (United States)

    Ng, Wai I; Smith, Graeme Drummond

    2017-01-01

    Background Self-management education programs (SMEPs) are potentially effective in the symptomatic management of COPD. Little is presently known about the effectiveness of these programs in Chinese COPD patients. The objective of this study was to evaluate the effectiveness of a specifically designed SMEP on levels of self-efficacy in Chinese patients with COPD. Materials and methods Based on the Medical Research Council framework for evaluating complex interventions, an exploratory phase randomized controlled trial was employed to examine the effects of an SMEP. Self-efficacy was the primary outcome using the COPD Self-efficacy Scale, measured at baseline and 6 months after the program. Qualitative data were sequentially collected from these patients via three focus groups to supplement the quantitative findings. Results The experimental group displayed significant improvement in their general self-efficacy (Z =−2.44, P=0.015) and specifically in confronting 1) physical exertion (Z =−2.57, P=0.01), 2) weather/environment effects (Z =−2.63, PChinese patients with COPD. Further attention should be given to cultural considerations when developing this type of intervention in Chinese populations with COPD and other chronic diseases. PMID:28790816

  1. The GC/MS Analysis of Volatile Components Extracted by Different Methods from Exocarpium Citri Grandis

    Directory of Open Access Journals (Sweden)

    Zhisheng Xie

    2013-01-01

    Full Text Available Volatile components from Exocarpium Citri Grandis (ECG were, respectively, extracted by three methods, that is, steam distillation (SD, headspace solid-phase microextraction (HS-SPME, and solvent extraction (SE. A total of 81 compounds were identified by gas chromatography-mass spectrometry including 77 (SD, 56 (HS-SPME, and 48 (SE compounds, respectively. Despite of the extraction method, terpenes (39.98~57.81% were the main volatile components of ECG, mainly germacrene-D, limonene, 2,6,8,10,14-hexadecapentaene, 2,6,11,15-tetramethyl-, (E,E,E-, and trans-caryophyllene. Comparison was made among the three methods in terms of extraction profile and property. SD relatively gave an entire profile of volatile in ECG by long-time extraction; SE enabled the analysis of low volatility and high molecular weight compounds but lost some volatiles components; HS-SPME generated satisfactory extraction efficiency and gave similar results to those of SD at analytical level when consuming less sample amount, shorter extraction time, and simpler procedure. Although SD and SE were treated as traditionally preparative extractive techniques for volatiles in both small batches and large scale, HS-SPME coupled with GC/MS could be useful and appropriative for the rapid extraction and qualitative analysis of volatile components from medicinal plants at analytical level.

  2. Effect of extraction methods on property and bioactivity of water-soluble polysaccharides from Amomum villosum.

    Science.gov (United States)

    Yan, Yajuan; Li, Xia; Wan, Mianjie; Chen, Jingping; Li, Shijie; Cao, Man; Zhang, Danyan

    2015-03-06

    In the present study, effect of different extraction methods on property and bioactivity of water-soluble polysaccharides (WSP) from the seeds of Amomum villosum were investigated. Firstly, four different extraction methods were used to extract WSP, which include hot water extraction (HWE), ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE) and enzyme-assisted extraction (EAE). As a result, four WSP samples, WSP(H), WSP(U), WSP(M) and WSP(E) were acquired. Then, the difference of four WSP samples in yield, characterization and antioxidant activities in vitro were further compared. Experimental results showed that the four WSP samples had the same monosaccharide composition, but mere difference in the content; they all had typical IR spectra characteristic of polysaccharides. WSP(U) contained the highest contents of uronic acid and sulfate. The yield of WSP(U) was the highest and its antioxidant activity was the best. These results suggested that ultrasonic-assisted extraction was the best extraction method for WSP. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. The extraction of essential oil from patchouli leaves (Pogostemon cablin Benth) using microwave hydrodistillation and solvent-free microwave extraction methods

    Science.gov (United States)

    Putri, D. K. Y.; Kusuma, H. S.; Syahputra, M. E.; Parasandi, D.; Mahfud, M.

    2017-12-01

    Patchouli plant (Pogostemon cablin Benth) is one of the important essential oil-producing plant, contributes more than 50% of total exports of Indonesia’s essential oil. However, the extraction of patchouli oil that has been done in Indonesia is generally still used conventional methods that require enormous amount of energy, high solvent usage, and long time of extraction. Therefore, in this study, patchouli oil extraction was carried out by using microwave hydrodistillation and solvent-free microwave extraction methods. Based on this research, it is known that the extraction of patchouli oil using microwave hydrodistillation method with longer extraction time (240 min) only produced patchouli oil’s yield 1.2 times greater than solvent-free microwave extraction method which require faster extraction time (120 min). Otherwise the analysis of electric consumption and the environmental impact, the solvent-free microwave extraction method showed a smaller amount when compared with microwave hydrodistillation method. It is conclude that the use of solvent-free microwave extraction method for patchouli oil extraction is suitably method as a new green technique.

  4. [Comparison of two nucleic acid extraction methods for norovirus in oysters].

    Science.gov (United States)

    Yuan, Qiao; Li, Hui; Deng, Xiaoling; Mo, Yanling; Fang, Ling; Ke, Changwen

    2013-04-01

    To explore a convenient and effective method for norovirus nucleic acid extraction from oysters suitable for long-term viral surveillance. Two methods, namely method A (glycine washing and polyethylene glycol precipitation of the virus followed by silica gel centrifugal column) and method B (protease K digestion followed by application of paramagnetic silicon) were compared for their performance in norovirus nucleic acid extraction from oysters. Real-time RT-PCR was used to detect norovirus in naturally infected oysters and in oysters with induced infection. The two methods yielded comparable positive detection rates for the samples, but the recovery rate of the virus was higher with method B than with method A. Method B is a more convenient and rapid method for norovirus nucleic acid extraction from oysters and suitable for long-term surveillance of norovirus.

  5. The early identification of risk factors on the pathway to school dropout in the SIODO study: a sequential mixed-methods study

    Directory of Open Access Journals (Sweden)

    Theunissen Marie-José

    2012-11-01

    Full Text Available Abstract Background School dropout is a persisting problem with major socioeconomic consequences. Although poor health probably contributes to pathways leading to school dropout and health is likely negatively affected by dropout, these issues are relatively absent on the public health agenda. This emphasises the importance of integrative research aimed at identifying children at risk for school dropout at an early stage, discovering how socioeconomic status and gender affect health-related pathways that lead to dropout and developing a prevention tool that can be used in public health services for youth. Methods/design The SIODO study is a sequential mixed-methods study. A case–control study will be conducted among 18 to 24 year olds in the south of the Netherlands (n = 580. Data are currently being collected from compulsory education departments at municipalities (dropout data, regional public health services (developmental data from birth onwards and an additional questionnaire has been sent to participants (e.g. personality data. Advanced analyses, including cluster and factor analyses, will be used to identify children at risk at an early stage. Using the quantitative data, we have planned individual interviews with participants and focus groups with important stakeholders such as parents, teachers and public health professionals. A thematic content analysis will be used to analyse the qualitative data. Discussion The SIODO study will use a life-course perspective, the ICF-CY model to group the determinants and a mixed-methods design. In this respect, the SIODO study is innovative because it both broadens and deepens the study of health-related determinants of school dropout. It examines how these determinants contribute to socioeconomic and gender differences in health and contributes to the development of a tool that can be used in public health practice to tackle the problem of school dropout at its roots.

  6. The metabolic network of Clostridium acetobutylicum: Comparison of the approximate Bayesian computation via sequential Monte Carlo (ABC-SMC) and profile likelihood estimation (PLE) methods for determinability analysis.

    Science.gov (United States)

    Thorn, Graeme J; King, John R

    2016-01-01

    The Gram-positive bacterium Clostridium acetobutylicum is an anaerobic endospore-forming species which produces acetone, butanol and ethanol via the acetone-butanol (AB) fermentation process, leading to biofuels including butanol. In previous work we looked to estimate the parameters in an ordinary differential equation model of the glucose metabolism network using data from pH-controlled continuous culture experiments. Here we combine two approaches, namely the approximate Bayesian computation via an existing sequential Monte Carlo (ABC-SMC) method (to compute credible intervals for the parameters), and the profile likelihood estimation (PLE) (to improve the calculation of confidence intervals for the same parameters), the parameters in both cases being derived from experimental data from forward shift experiments. We also apply the ABC-SMC method to investigate which of the models introduced previously (one non-sporulation and four sporulation models) have the greatest strength of evidence. We find that the joint approximate posterior distribution of the parameters determines the same parameters as previously, including all of the basal and increased enzyme production rates and enzyme reaction activity parameters, as well as the Michaelis-Menten kinetic parameters for glucose ingestion, while other parameters are not as well-determined, particularly those connected with the internal metabolites acetyl-CoA, acetoacetyl-CoA and butyryl-CoA. We also find that the approximate posterior is strongly non-Gaussian, indicating that our previous assumption of elliptical contours of the distribution is not valid, which has the effect of reducing the numbers of pairs of parameters that are (linearly) correlated with each other. Calculations of confidence intervals using the PLE method back this up. Finally, we find that all five of our models are equally likely, given the data available at present. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. A RAPID DNA EXTRACTION METHOD FOR PCR IDENTIFICATION OF FUNGAL INDOOR AIR CONTAMINANTS

    Science.gov (United States)

    Following air sampling, fungal DNA needs to be extracted and purified to a state suitable for laboratory use. Our laboratory has developed a simple method of extraction and purification of fungal DNA appropriate for enzymatic manipulation and polymerase chain reaction (PCR) appli...

  8. Adaptation Method Bligh & Dyer a Lipid Extraction of Colomb ian Microalgas Biodiesel Production for Third Generation

    Directory of Open Access Journals (Sweden)

    González Delgado Ángel

    2012-06-01

    Full Text Available In the biodiesel production process from microalgae, the cell disruption and lipid extraction stages are important for obtaining triglycerides that can be transesterified to biodiesel and glycerol. In this work, the Bligh & Dyer method was adapted for lipid extraction from native microalgae using organosolv pretreatment or acid hydrolysis as cell disruption mechanism for improve the extraction process. Chloroform-methanol-water are the solvents employed in the Bligh & Dyer extraction method. The microalgae species Botryococcus braunii, Nannocloropsis, Closterium, Guinardia y Amphiprora were employed for the experimental part. Adaptation of the method was found the best extraction conditions, these were: 1:20 biomass/solvent ratio, initial ratio solvents CHCl3:CH3OH:H2O (1:2:0, stirring conditions of 5000 rpm for 14 minutes and centrifuge of 3400 rpm for 15 minutes. The cell disruption mechanisms allowed to obtain extracts with high lipid content after performing the extraction with Bligh & Dyer method, but decreases significantly the total extraction yield. Finally, the fatty acids profiles showed that Botryococcus braunii specie contains higher acylglycerol percentage area suitable for the production of biodiesel.

  9. Recent developments in the extraction separation method for treatment of high-level liquid waste

    International Nuclear Information System (INIS)

    Jiao Rongzhou; Song Chongli; Zhu Yongjun

    2000-01-01

    A description and review of the recent developments in the extraction separation method for partitioning transuranium elements from high-level liquid waste (HLLW) is presented. The extraction separation processes such as TRUEX process, DIAMEX process, DIDPA process, CTH process, TRPO process are briefly discussed

  10. Insect lipid profile: aqueous versus organic solvent-based extraction methods

    NARCIS (Netherlands)

    Tzompa Sosa, D.A.; Yi, L.; Valenberg, van H.J.F.; Boekel, van M.A.J.S.; Lakemond, C.M.M.

    2014-01-01

    In view of future expected industrial bio-fractionation of insects, we investigated the influence of extraction methods on chemical characteristics of insect lipids. Lipids from Tenebrio molitor, Alphitobius diaperinus, Acheta domesticus and Blaptica dubia, reared in the Netherlands, were extracted

  11. Determination of copper in natural waters and sediments by extraction spectroscopic method

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.; Raju, G.R.K.

    A sensitive extraction spectrophotometric method has been developed based on the formation and extraction of Cu(II)-neocuproine-rosenbengal into chloroform. The molar extinction coefficient of the system is 55.500 and Beer's law is obeyed up to 15...

  12. Soil sampling and extraction methods with possible application to pear thrips (Thysanoptera: Thripidae)

    Science.gov (United States)

    John E. Bater

    1991-01-01

    Techniques are described for the sampling and extraction of microarthropods from soil and the potential of these methods to extract the larval stages of the pear thrips, Taeniothrips inconsequens (Uzel), from soil cores taken in sugar maple stands. Also described is a design for an emergence trap that could be used to estimate adult thrips...

  13. Evaluation and comparison of FTA card and CTAB DNA extraction methods for non-agricultural taxa.

    Science.gov (United States)

    Siegel, Chloe S; Stevenson, Florence O; Zimmer, Elizabeth A

    2017-02-01

    An efficient, effective DNA extraction method is necessary for comprehensive analysis of plant genomes. This study analyzed the quality of DNA obtained using paper FTA cards prepared directly in the field when compared to the more traditional cetyltrimethylammonium bromide (CTAB)-based extraction methods from silica-dried samples. DNA was extracted using FTA cards according to the manufacturer's protocol. In parallel, CTAB-based extractions were done using the automated AutoGen DNA isolation system. DNA quality for both methods was determined for 15 non-agricultural species collected in situ, by gel separation, spectrophotometry, fluorometry, and successful amplification and sequencing of nuclear and chloroplast gene markers. The FTA card extraction method yielded less concentrated, but also less fragmented samples than the CTAB-based technique. The card-extracted samples provided DNA that could be successfully amplified and sequenced. The FTA cards are also useful because the collected samples do not require refrigeration, extensive laboratory expertise, or as many hazardous chemicals as extractions using the CTAB-based technique. The relative success of the FTA card method in our study suggested that this method could be a valuable tool for studies in plant population genetics and conservation biology that may involve screening of hundreds of individual plants. The FTA cards, like the silica gel samples, do not contain plant material capable of propagation, and therefore do not require permits from the U.S. Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) for transportation.

  14. New method for extracting tumors in PET/CT images based on the probability distribution

    International Nuclear Information System (INIS)

    Nitta, Shuhei; Hontani, Hidekata; Hukami, Tadanori

    2006-01-01

    In this report, we propose a method for extracting tumors from PET/CT images by referring to the probability distribution of pixel values in the PET image. In the proposed method, first, the organs that normally take up fluorodeoxyglucose (FDG) (e.g., the liver, kidneys, and brain) are extracted. Then, the tumors are extracted from the images. The distribution of pixel values in PET images differs in each region of the body. Therefore, the threshold for detecting tumors is adaptively determined by referring to the distribution. We applied the proposed method to 37 cases and evaluated its performance. This report also presents the results of experiments comparing the proposed method and another method in which the pixel values are normalized for extracting tumors. (author)

  15. Accelerated H-LBP-based edge extraction method for digital radiography

    Energy Technology Data Exchange (ETDEWEB)

    Qiao, Shuang; Zhao, Chen-yi; Huang, Ji-peng [School of Physics, Northeast Normal University, Changchun 130024 (China); Sun, Jia-ning, E-mail: sunjn118@nenu.edu.cn [School of Mathematics and Statistics, Northeast Normal University, Changchun 130024 (China)

    2015-01-11

    With the goal of achieving real time and efficient edge extraction for digital radiography, an accelerated H-LBP-based edge extraction method (AH-LBP) is presented in this paper by improving the existing framework of local binary pattern with the H function (H-LBP). Since the proposed method avoids computationally expensive operations with no loss of quality, it possesses much lower computational complexity than H-LBP. Experimental results on real radiographies show desirable performance of our method. - Highlights: • An accelerated H-LBP method for edge extraction on digital radiography is proposed. • The novel AH-LBP relies on numerical analysis of the existing H-LBP method. • Aiming at accelerating, H-LBP is reformulated as a direct binary processing. • AH-LBP provides the same edge extraction result as H-LBP does. • AH-LBP has low computational complexity satisfying real time requirements.

  16. 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.

  17. 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

  18. Evaluation of Extraction and Degradation Methods to Obtain Chickpeasaponin B1 from Chickpea (Cicer arietinum L.)

    OpenAIRE

    Kun Cheng; Hua Gao; Rong-Rong Wang; Yang Liu; Yu-Xue Hou; Xiao-Hong Liu; Kun Liu; Wei Wang

    2017-01-01

    The objective of this research is to implement extraction and degradation methods for the obtainment of 3-O-[α-l-rhamnopyranosyl-(1→2)-β-d-galactopyranosyl] soyasapogenol B (chickpeasaponin B1) from chickpea. The effects of microwave-assisted extraction (MAE) processing parameters—such as ethanol concentration, solvent/solid ratio, extraction temperature, microwave irradiation power, and irradiation time—were evaluated. Using 1g of material with 8 mL of 70% aqueous ethanol and an extraction t...

  19. Efficacy of premixed versus sequential administration of ...

    African Journals Online (AJOL)

    sequential administration in separate syringes on block characteristics, haemodynamic parameters, side effect profile and postoperative analgesic requirement. Trial design: This was a prospective, randomised clinical study. Method: Sixty orthopaedic patients scheduled for elective lower limb surgery under spinal ...