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Sample records for chemical fractionation

  1. Asphalt chemical fractionation

    International Nuclear Information System (INIS)

    Asphalt fractionation were carried out in the Esmeraldas Oil Refinery using n-pentane, SiO2 and different mixture of benzene- methane. The fractions obtained were analyzed by Fourier's Transformed Infrared Spectrophotometry (FTIR)

  2. Chemical Fractionation and Abundances in Coronal Plasma

    CERN Document Server

    Drake, J J

    2003-01-01

    Much of modern astrophysics is grounded on the observed chemical compositions of stars and the diffuse plasma that pervades the space between stars, galaxies and clusters of galaxies. X-ray and EUV spectra of the hot plasma in the outer atmospheres of stars have demonstrated that these environments are subject to chemical fractionation in which the abundances of elements can be enhanced and depleted by an order of magnitude or more. These coronal abundance anomalies are discussed and some of the physical mechanisms that might be responsible for producing them are examined. It is argued that coronal abundances can provide important new diagnostics on physical processes at work in solar and stellar coronae. It seems likely that other hot astrophysical plasmas will be subject to similar effects.

  3. Method for fractional solid-waste sampling and chemical analysis

    DEFF Research Database (Denmark)

    Riber, Christian; Rodushkin, I.; Spliid, Henrik;

    2007-01-01

    Chemical characterization of solid waste is a demanding task due to the heterogeneity of the waste. This article describes how 45 material fractions hand-sorted from Danish household waste were subsampled and prepared for chemical analysis of 61 substances. All material fractions were subject...

  4. Aqueous fractionation yields chemically stable lupin protein isolates

    NARCIS (Netherlands)

    Berghout, J.A.M.; Marmolejo-Garcia, C.; Berton-Carabin, C.C.; Nikiforidis, C.V.; Boom, R.M.; Goot, van der A.J.

    2015-01-01

    The chemical stability of lupin protein isolates (LPIs) obtained through aqueous fractionation (AF, i.e. fractionation without the use of an organic solvent) at 4 °C or 20 °C was assessed. AF of lupin seeds results in LPIs containing 2 wt.% oil. This oil is composed of mono- and poly-unsaturated fat

  5. Chemical composition of material fractions in Danish household waste

    DEFF Research Database (Denmark)

    Riber, Christian; Petersen, Claus; Christensen, Thomas Højlund

    2009-01-01

    The chemical composition of Danish household waste was determined by two approaches: a direct method where the chemical composition (61 substances) of 48 material fractions was determined after hand sorting of about 20 tonnes of waste collected from 2200 households; and an indirect method where...... batches of 80-1200 tonnes of unsorted household waste was incinerated and the content of the waste determined from the content of the outputs from the incinerator. The indirect method is believed to better represent the small but highly contaminated material fractions (e,g., batteries) than the direct...... method, because of the larger quantities included and the more homogenous material to sample from. Differences between the direct and the direct methods led to corrections in the of heavy metal concentration of a few fractions. The majority of the energy content of the waste originates from organic waste...

  6. Biological, chemical, electrochemical, and photochemical fractionation of Fe isotopes

    Science.gov (United States)

    John, S.; King, A.; Hutchins, D.; Adkins, J. F.; Fu, F.; Wasson, A.; Hodierne, C.

    2012-12-01

    Iron is an important nutrient for life in the ocean, where low Fe concentrations often limit the growth of marine phytoplankton. Fe stable isotope ratios (δ56Fe) are a potentially valuable new tool for studying the marine biological cycling of Fe. In order to effectively use Fe isotopes as a biological tracer, however, it is important to parameterize the isotope effect for biological uptake. We have therefore measured the biological fractionation of Fe isotopes by the marine diatoms Thalassiosira pseudonana, T. oceanica, and Phaeodactylum tricornutum in culture. During biological Fe acquisition, Fe(III) is often first reduced from Fe(III) to Fe(II), either in seawater or at the cell surface. Therefore, we have also measured the isotope effect for Fe(III) reduction by chemical, electrochemical, and photochemical processes. Diatoms were cultured in EDTA or NTA buffered media under varying Fe concentrations from Fe-sufficiency to Fe-limitation. Biological fractionation of Fe isotopes was determined by comparing δ56Fe of phytoplankton to the media. The use of a cell wash allows us to distinguish between isotopic fractionation during extracellular adsorption and intracellular uptake. The biological fractionation of Fe isotopes is highly dependent on culture conditions with Δδ56Fe ranging from +0.6 ‰ to -0.5 ‰ depending on ligand composition, species, and Fe-limitation status. Isotope effects for chemical, electrochemical, and photochemical reduction of Fe(III) to Fe(II) span an even larger range. For example, chemical reduction of Fe(III)-EDTA with hydroxylamine hydrochloride has an isotope effect of Δδ56Fe = -2.8 ‰. By contrast, photochemical reduction of Fe(III)-EDTA has an isotope effect of Δδ56Fe = +0.9 ‰. Isotope effects for electrochemical reduction of Fe(III) using a rotating disc electrode allow for greater control of experimental conditions, such as differentiating between the effects of electric potential (voltage) and mass transport (diffusion

  7. Chemical composition of volatile fraction of pakistani peanut and its

    International Nuclear Information System (INIS)

    Arachis hypogaea Linn (peanut or groundnut) is an economically important crop. Thousands of peanut cultivars are grown in the world and studies have been carried out on these but, to the best of our knowledge, no salient work has been done on Pakistani cultivar so far. Here, we report the chemical composition of volatile fraction of Pakistani cultivar of peanut and its anti radical activities using 1,I-Diphenyl-2-picrylhydrazyl radical (DPPH) scavenging and phospho molybdenum complex (PC) method. This study revealed that Pakistani cultivar exhibited an almost equal antioxidant potential to that of standard, butylated hydroxytoluene (BHT), which was obvious from their IC/sub 50/ values. The IC/sub 50/ value of peanut extract was found to be 13.42 +- 26 macro L/mL, relative to butylated hydroxytoluene, having 12.1 +- 0.92 macro/mL. (author)

  8. Physico-chemical characterisation of material fractions in household waste

    DEFF Research Database (Denmark)

    Götze, Ramona; Boldrin, Alessio; Scheutz, Charlotte;

    2016-01-01

    to the data selection from literature. Overall, 97 publications were reviewed with respect to employed characterisation method, regional origin of the waste, number of investigated parameters and material fractions and other qualitative aspects. Descriptive statistical analysis of the reported physico...

  9. Chemical composition and cytotoxic activity of the polysaccharide fractions in Sarcodon imbricatus (Basidiomycota)

    OpenAIRE

    Katarzyna Sułkowska-Ziaja; Bożena Muszyńska; Halina Ekiert

    2013-01-01

    The aim of the study was chemical analysis of polysaccharide fractions from sporocarps of Sarcodon imbricatus collected in natural sites and from the mycelium of in vitro cultures. Three polysaccharide fractions (FOI, FOII, FOIII) were isolated from sporocarps and two (FKI, FKII) from in vitro cultures. Qualitative analysis by HPLC method showed that they are composed of galactose and fucose (FOI, FKI) or glucose and fucose (FOII, FKII). FOIII fraction of the sporocarps consisted of glucose o...

  10. Fermentation, fractionation and purification of streptokinase by chemical reduction method

    Directory of Open Access Journals (Sweden)

    M Niakan

    2011-05-01

    Full Text Available Background and Objectives: Streptokinase is used clinically as an intravenous thrombolytic agent for the treatment of acute myocardial infarction and is commonly prepared from cultures of Streptococcus equisimilis strain H46A. The objective of the present study was the production of streptokinase from strain H46A and purification by chemical reduction method."nMaterials and Methods: The rate of streptokinase production evaluated under the effect of changes on some fermentation factors. Moreover, due to the specific structure of streptokinase, a chemical reduction method employed for the purification of streptokinase from the fermentation broth. The H46A strain of group C streptococcus, was grown in a fermentor. The proper pH adjusted with NaOH under glucose feeding in an optimum temperature. The supernatant of the fermentation product was sterilized by filtration and concentrated by ultrafiltration. The pH of the concentrate was adjusted, cooled, and precipitated by methanol. Protein solution was reduced with dithiothreitol (DTT. Impurities settled down by aldrithiol-2 and the biological activity of supernatant containing streptokinase was determined."nResults: In the fed -batch culture, the rate of streptokinase production increased over two times as compared with the batch culture and the impurities were effectively separated from streptokinase by reduction method."nConclusion: Improvements in SK production are due to a decrease in lag phase period and increase in the growth rate of logarithmic phase. The methods of purification often result in unacceptable losses of streptokinase, but the chemical reduction method give high yield of streptokinase and is easy to perform it.

  11. Understanding the solid phase chemical fractionation of uranium in soil and effect of ageing.

    Science.gov (United States)

    Rout, Sabyasachi; Kumar, Ajay; Ravi, P M; Tripathi, R M

    2016-11-01

    The aim of the present work is to understand the solid phase chemical fractionation of Uranium (U) in soil and the mechanism involved. This study integrated batch experiments of U(VI) adsorption to soil, study of U in different soil fractions, ageing impact on fractionation of U and spectroscopic investigation of adsorbed U(VI) using X-ray Photoelectron Spectroscopy (XPS). For the study three soils, pedogenically different (S1: Igneous, S2: Sedimentary and S3: Metamorphic) were amended with U(VI) and chemical fractionation of U was studied by sequential extraction after an interval of one month and 12 months. It was found that there occurs a significant rearrangement of U in different fractions with ageing and no correlation was observed between the U content in different fractions and the adsorbents of respective fractions such as soil organic matter (SOM), Fe/Mn oxides (hydroxides) carbonates, soil cation exchange capacity (CEC). XPS study revealed that surface enrichment of U mainly governed by the carbonate minerals and SOM, whereas bulk concentration was controlled by the oxides (hydroxides) of Si and Al. Occlusion of U-Fe-oxides (hydroxides) on silica was identified as an important mechanism for bulk enrichment (Increase in residual fraction) and depletion of U concentration in reducible fraction.

  12. Understanding the solid phase chemical fractionation of uranium in soil and effect of ageing.

    Science.gov (United States)

    Rout, Sabyasachi; Kumar, Ajay; Ravi, P M; Tripathi, R M

    2016-11-01

    The aim of the present work is to understand the solid phase chemical fractionation of Uranium (U) in soil and the mechanism involved. This study integrated batch experiments of U(VI) adsorption to soil, study of U in different soil fractions, ageing impact on fractionation of U and spectroscopic investigation of adsorbed U(VI) using X-ray Photoelectron Spectroscopy (XPS). For the study three soils, pedogenically different (S1: Igneous, S2: Sedimentary and S3: Metamorphic) were amended with U(VI) and chemical fractionation of U was studied by sequential extraction after an interval of one month and 12 months. It was found that there occurs a significant rearrangement of U in different fractions with ageing and no correlation was observed between the U content in different fractions and the adsorbents of respective fractions such as soil organic matter (SOM), Fe/Mn oxides (hydroxides) carbonates, soil cation exchange capacity (CEC). XPS study revealed that surface enrichment of U mainly governed by the carbonate minerals and SOM, whereas bulk concentration was controlled by the oxides (hydroxides) of Si and Al. Occlusion of U-Fe-oxides (hydroxides) on silica was identified as an important mechanism for bulk enrichment (Increase in residual fraction) and depletion of U concentration in reducible fraction. PMID:27322903

  13. Chemical composition and cytotoxic activity of the polysaccharide fractions in Sarcodon imbricatus (Basidiomycota

    Directory of Open Access Journals (Sweden)

    Katarzyna Sułkowska-Ziaja

    2013-12-01

    Full Text Available The aim of the study was chemical analysis of polysaccharide fractions from sporocarps of Sarcodon imbricatus collected in natural sites and from the mycelium of in vitro cultures. Three polysaccharide fractions (FOI, FOII, FOIII were isolated from sporocarps and two (FKI, FKII from in vitro cultures. Qualitative analysis by HPLC method showed that they are composed of galactose and fucose (FOI, FKI or glucose and fucose (FOII, FKII. FOIII fraction of the sporocarps consisted of glucose only. Molecular weights of isolated fractions ranged from 3.8 to 16.3 kDa for fractions from the sporocarps and from 5.8 to 14.7 kDa for that ones isolated from in vitro culture. The total percentage of sugar content for all fractions ranged from 97.8% to 99.1%. The percentage of uronic acids contents in acidic fractions was 2.6% and 2.7% for the FOI and FKI respectively. The work included also an assessment of cytotoxic activity of polysaccharide fractions in relation to tumor cell lines of human breast cancer MCV-7. FOI polysaccharide fraction of the sporocarps inhibited the growth of cancer cells in 50% compared to the control at a concentration of 0.0125%, while the polysaccharide fraction FKI from in vitro cultures inhibited cell growth in a concentration of 0.016%.

  14. Investigation of the chemical composition of mineral fractions of the Tsarev chondrite

    Energy Technology Data Exchange (ETDEWEB)

    Semenova, L.F.; Fisenko, A.V.; Kashkarova, V.G.; Melnikova, L.N.; Bezrogova, E.V.; Pomytkina, V.A.; Lavrukhina, A.K.

    1984-01-01

    A selective-dissolution method was used to study the chemical composition of mineral fractions of the Tsarev chondrite. Redistributions of Na, K, and P were found in mineral fractions of L-chondrites which have experienced different degrees of impact metamorphism. It is shown that the normative composition of inclusions in olivine in the Tsarev chondrite is characterized by a high content of diopside and anorthite components. 24 references.

  15. Effects-driven chemical fractionation of heavy fuel oil to isolate compounds toxic to trout embryos.

    Science.gov (United States)

    Bornstein, Jason M; Adams, Julie; Hollebone, Bruce; King, Thomas; Hodson, Peter V; Brown, R Stephen

    2014-04-01

    Heavy fuel oil (HFO) spills account for approximately 60% of ship-source oil spills and are up to 50 times more toxic than medium and light crude oils. Heavy fuel oils contain elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) and alkyl-PAHs, known to be toxic to fish; however, little direct characterization of HFO toxicity has been reported. An effects-driven chemical fractionation was conducted on HFO 7102 to separate compounds with similar chemical and physical properties, including toxicity, to isolate the groups of compounds most toxic to trout embryos. After each separation, toxicity tests directed the next phase of fractionation, and gas chromatography-mass spectrometry analysis correlated composition with toxicity, with a focus on PAHs. Low-temperature vacuum distillation permitted the separation of HFO into 3 fractions based on boiling point ranges. The most toxic of these fractions underwent wax precipitation to remove long-chain n-alkanes. The remaining PAH-rich extract was further separated using open column chromatography, which provided distinct fractions that were grouped according to increasing aromatic ring count. The most toxic of these fractions was richest in PAHs and alkyl-PAHs. The results of the present study were consistent with previous crude oil studies that identified PAH-rich fractions as the most toxic.

  16. Magnesium isotope fractionation by chemical diffusion in natural settings and in laboratory analogues

    Science.gov (United States)

    Chopra, Rahul; Richter, Frank M.; Bruce Watson, E.; Scullard, Christian R.

    2012-07-01

    Laboratory experiments are used to document isotopic fractionation of magnesium by chemical diffusion in a silicate melt and the results compared to the magnesium isotopic composition across contacts between igneous rocks of different composition in natural settings. The natural samples are from transects from felsic to mafic rocks at Vinal Cove in the Vinalhaven Intrusive Complex, Maine and from the Aztec Wash pluton in Nevada. Two laboratory diffusion couples made by juxtaposing melts made from powders of the felsic and mafic compositions sampled at Vinal Cove were annealed at about 1500 °C for 22.5 and 10 h, respectively. The transport of magnesium in the diffusion couples resulted in easily measured magnesium isotopic fractionations at the interface (δ26Mg∼1.5‰). These isotopic fractionations provide a distinctive isotopic “fingerprint” that we use to determine whether chemical gradients in natural settings where melts of different composition were juxtaposed were due to chemical diffusion. The magnesium isotopic fractionation along one profile at Vinal Cove is exactly what one would expect based on the fractionations found in the laboratory experiments. This is an important result in that it shows that the isotope fractionation by chemical diffusion found in highly controlled laboratory experiments can be found in a natural setting. This correspondence implies that chemical diffusion was the dominant process responsible for the transport of magnesium across this particular contact at Vinal Cove. A second Vinal Cove profile has a very similar gradient in magnesium concentration but with significantly less magnesium isotopic fractionation than expected. This suggests that mass transport at this location was only partly by diffusion and that some other mass transport mechanism such as mechanical mixing must have also played a role. The magnesium isotopic composition of samples from Aztec Wash shows no resolvable isotopic fractionation across the contact

  17. Chemical fractionation of some natural radionuclides in a soil contaminated by slags

    International Nuclear Information System (INIS)

    To investigate the chemical fractionation of 238U, 226Ra, 210Pb, and 228Ra in soils contaminated by slags from coal firing and from pyrite roasting, a sequential extraction method (modified Tessier procedure) has been applied. The following fractions were each extracted: 1, easily exchangeable; 2, bound to carbonates; 3, bound to iron-manganese oxides; 4; bound to organic matter; 5, persistently bound; 6, residual. In addition, the extractants were also analyzed for the insoluble matrix elements Al and Fe to provide some information on the effect of each extraction step on the dissolution of the matrix. The results show that the percentage amounts of these radio-nuclide in fractions 1 (238U and 210Pb released from the slag by the iron-manganese oxide extractant are subsequently reabsorbed rapidly to a considerable extent by soil minerals and thus do not appear in the iron-manganese oxide fraction 3 but rather in fractions 4 and 6. As a result of such redistribution processes, it will be almost impossible to predict quantitatively the chemical fractionation of radionuclides in contaminated soils by investigating pure slags only. 24 refs., 2 figs., 2 tabs

  18. Assessment of heavy metal removal technologies for biowaste by physico-chemical fractionation

    NARCIS (Netherlands)

    Veeken, A.H.M.; Hamelers, H.V.M.

    2003-01-01

    In the Netherlands, the heavy metal content of biowaste-compost frequently exceeds the legal standards for heavy metals. In order to assess heavy metal removal technologies, a physico-chemical fractionation scheme was developed to gain insight into the distribution of heavy metals (Cd, Cu, Pb and Zn

  19. Toxicological and chemical investigation of untreated municipal wastewater: Fraction- and species-specific toxicity.

    Science.gov (United States)

    Hrubik, Jelena; Glisic, Branka; Tubic, Aleksandra; Ivancev-Tumbas, Ivana; Kovacevic, Radmila; Samardzija, Dragana; Andric, Nebojsa; Kaisarevic, Sonja

    2016-05-01

    Absence of a municipal wastewater (WW) treatment plant results in the untreated WW discharge into the recipient. The present study investigated toxic effects and chemical composition of water extracts and fractions from untreated WW and recipient Danube River (DR). Samples were prepared by solid-phase extraction and silica gel fractionation and screened for EROD activity and cytotoxicity using aquatic models, comprising of fish liver cells (PLHC-1) and a model of the early development of zebrafish embryos, while rat (H4IIE) and human (HepG2) hepatoma cells served as mammalian models. Polar fraction caused cytotoxicity and increased the EROD activity in PLHC-1 cells, and increased mortality and developmental abnormalities in developing zebrafish embryos. In H4IIE, polar fraction induced inhibition of cell growth and increased EROD activity, whereas HepG2 exerted low or no response to the exposure. Non-polar and medium-polar fractions were ineffective. Tentative identification by GC/MS showed that WW is characterized by the hydrocarbons, alkylphenols, plasticizers, and a certain number of benzene derivatives and organic acids. In DR, smaller number of organic compounds was identified and toxicity was less pronounced than in WW treatments. The present study revealed the potent toxic effect of polar fraction of untreated WW, with biological responses varying in sensitivity across organisms. Obtained results confirmed that fraction- and species-specific toxicity should be considered when assessing health risk of environmental pollution. PMID:26829069

  20. Chemical composition of water-soluble fraction in soils on glaciolacustrine deposits of the Russian Plain

    Science.gov (United States)

    Panova, E. G.; Oleinikova, G. A.; Matinyan, N. N.; Bakhmatova, K. A.

    2016-06-01

    The behavior of some chemical elements was studied in soils and their liquid phase. Two reference soil profiles on glaciolacustrine clays (soddy-eluvial-metamorphic soil) and sands (soddy podzol) were investigated on the Russian Plain. A colloidal fraction (particles water from a soil sample of 30 g at the soil: water ratio of 1: 10. The suspension was mixed for 6 h, settled for 24 h, and filtrated using a membrane filter (soil sample and its water-soluble fraction (WSF) were analyzed by mass spectrometry with inductively coupled plasma. The chemical characteristics of the extracted liquid phase of the soil reflect its water-soluble component properties. The comparison of the data obtained with the results of the analysis for the whole soil allows assessment of a share of easily mobile and difficultly mobile forms of chemical compounds. This is the necessary basis for the development of a model describing the transport of metals in soil.

  1. Chemical composition of water-soluble fraction in soils on glaciolacustrine deposits of the Russian Plain

    Science.gov (United States)

    Panova, E. G.; Oleinikova, G. A.; Matinyan, N. N.; Bakhmatova, K. A.

    2016-06-01

    The behavior of some chemical elements was studied in soils and their liquid phase. Two reference soil profiles on glaciolacustrine clays (soddy-eluvial-metamorphic soil) and sands (soddy podzol) were investigated on the Russian Plain. A colloidal fraction (particles water from a soil sample of 30 g at the soil: water ratio of 1: 10. The suspension was mixed for 6 h, settled for 24 h, and filtrated using a membrane filter (water-soluble fraction (WSF) were analyzed by mass spectrometry with inductively coupled plasma. The chemical characteristics of the extracted liquid phase of the soil reflect its water-soluble component properties. The comparison of the data obtained with the results of the analysis for the whole soil allows assessment of a share of easily mobile and difficultly mobile forms of chemical compounds. This is the necessary basis for the development of a model describing the transport of metals in soil.

  2. Chemical fractionation of Cu and Zn in stormwater, roadway dust and stormwater pond sediments

    Science.gov (United States)

    Camponelli, Kimberly M.; Lev, Steven M.; Snodgrass, Joel W.; Landa, Edward R.; Casey, Ryan E.

    2010-01-01

    This study evaluated the chemical fractionation of Cu and Zn from source to deposition in a stormwater system. Cu and Zn concentrations and chemical fractionation were determined for roadway dust, roadway runoff and pond sediments. Stormwater Cu and Zn concentrations were used to generate cumulative frequency distributions to characterize potential exposure to pond-dwelling organisms. Dissolved stormwater Zn exceeded USEPA acute and chronic water quality criteria in approximately 20% of storm samples and 20% of the storm duration sampled. Dissolved Cu exceeded the previously published chronic criterion in 75% of storm samples and duration and exceeded the acute criterion in 45% of samples and duration. The majority of sediment Cu (92–98%) occurred in the most recalcitrant phase, suggesting low bioavailability; Zn was substantially more available (39–62% recalcitrant). Most sediment concentrations for Cu and Zn exceeded published threshold effect concentrations and Zn often exceeded probable effect concentrations in surface sediments.

  3. Chemical potential and internal energy of the noninteracting Fermi gas in fractional-dimensional space

    Indian Academy of Sciences (India)

    S Panda; B K Panda

    2010-09-01

    Chemical potential and internal energy of a noninteracting Fermi gas at low temperature are evaluated using the Sommerfeld method in the fractional-dimensional space. When temperature increases, the chemical potential decreases below the Fermi energy for any dimension equal to 2 and above due to the small entropy, while it increases above the Fermi energy for dimensions below 2 as a result of high entropy. The ranges of validity of the truncated series expansions of these quantities are extended from low to intermediate temperature regime as well as from high to relatively low density regime by using the Pad ́e approximant technique.

  4. The measurement of the chemically mobile fraction of lead in soil using isotopic dilution analysis

    International Nuclear Information System (INIS)

    The chemically available fraction of lead in eight soils measured by isotopic dilution analysis using 212Pb ranged from 7 to 16% of the total content of lead in soil. The soluble fractions achieved values up to 63% of the total content in 1 M NH4NO3, 1 M MgCl2 and 0.05 M DTPA solutions. Increasing the contact time between water and soil, the water-soil ratio from 1:1 to 5:1 and increasing the temperature of the soil-water suspension raised the chemically available fraction in soil. Comparing various soil parameters and the mobile fraction of lead, only pH shows a significant correlation. The amphoteric character of lead causes a minimum of mobility about pH 6; pH-values below are responsible for the higher mobility of lead as Pb2+, at pH-values above 6 soluble hydroxy and humic acid complexes are formed. (orig.)

  5. Chemical Composition and Antioxidant Activities of Three Polysaccharide Fractions from Pine Cones

    Directory of Open Access Journals (Sweden)

    Pu Wang

    2012-11-01

    Full Text Available The traditional method of gas chromatography-mass spectrometry for monosaccharide component analysis with pretreatment of acetylation is described with slight modifications and verified in detail in this paper. It was then successfully applied to the quantitative analysis of component monosaccharides in polysaccharides extracted from the pine cones. The results demonstrated that the three pine cone polysaccharides all consisted of ribose, rhamnose, arabinose, xylose, mannose, glucose and galactose in different molar ratios. According to the recovery experiment, the described method was proved accurate and practical for the analysis of pine cone polysaccharides, meeting the need in the field of chemical analysis of Pinus plants. Furthermore; the chemical characteristics, such as neutral sugar, uronic acids, amino acids, molecular weights, and antioxidant activities of the polysaccharides were investigated by chemical and instrumental methods. The results showed that the chemical compositions of the polysaccharides differed from each other, especially in the content of neutral sugar and uronic acid. In the antioxidant assays, the polysaccharide fractions exhibited effective scavenging activities on ABTS radical and hydroxyl radical, with their antioxidant capabilities decreasing in the order of PKP > PAP > PSP. Therefore, although the polysaccharide fractions had little effect on superoxide radical scavenging, they still have potential to be developed as natural antioxidant agents in functional foods or medicine.

  6. Occurrence of non extractable pesticide residues in physical and chemical fractions of two soils

    Science.gov (United States)

    Andreou, Kostas; Semple, Kirk; Jones, Kevin

    2010-05-01

    Soils are considered to be a significant sink for organic contaminants, including pesticides, in the environment. Understanding the distribution and localisation of aged pesticide residues in soil is of great importance for assessing the mobility and availability of these chemicals in the environment. This study aimed to characterise the distribution of radiolabeled herbicide isoproturon and the radiolabeled insecticides diazinon and cypermethrin in two organically managed soils. The soils were spiked and aged under laboratory conditions for 17 months. The labile fraction of the pesticides residues was recovered in CaCl2 (0.01M) and then subjected to physical size fractionation using sedimentation and centrifugation steps, with >20μm, 20-2μm and 2-0.1μm soil factions collected. Further, the distribution of the pesticide residues in the organic matter of the fractionated soil was investigated using a sequential alkaline extraction (0.1N NaOH) into humic and fulvic acid and humin. Soil fractions of 20-2μm and 2-0.1μm had the largest burden of the 14C-residues. Different soil constituents have different capacities to form non-extractable residues. Soil solid fractions of 20-2 µm and pesticide residues than the coarser fraction (>20 µm). Fulvic acid showed to play a vital role in the formation and stabilisation of non-extractable 14C-pesticide residues in most cases.Assessment of the likelihood of the pesticide residues to become available to soil biota requires an understanding of the structure of the SOM matrix and the definition of the kinetics of the pesticide residues in different SOM pools as a function of the time.

  7. Palm-based diacylglycerol fat dry fractionation: effect of crystallisation temperature, cooling rate and agitation speed on physical and chemical properties of fractions

    Directory of Open Access Journals (Sweden)

    Razam Ab Latip

    2013-05-01

    Full Text Available Fractionation which separates the olein (liquid and stearin (solid fractions of oil is used to modify the physicochemical properties of fats in order to extend its applications. Studies showed that the properties of fractionated end products can be affected by fractionation processing conditions. In the present study, dry fractionation of palm-based diacylglycerol (PDAG was performed at different: cooling rates (0.05, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0°C/min, end-crystallisation temperatures (30, 35, 40, 45 and 50°C and agitation speeds (30, 50, 70, 90 and 110 rpm to determine the effect of these parameters on the properties and yield of the solid and liquid portions. To determine the physicochemical properties of olein and stearin fraction: Iodine value (IV, fatty acid composition (FAC, acylglycerol composition, slip melting point (SMP, solid fat content (SFC, thermal behaviour tests were carried out. Fractionation of PDAG fat changes the chemical composition of liquid and solid fractions. In terms of FAC, the major fatty acid in olein and stearin fractions were oleic (C18:1 and palmitic (C16:0 respectively. Acylglycerol composition showed that olein and stearin fractions is concentrated with TAG and DAG respectively. Crystallization temperature, cooling rate and agitation speed does not affect the IV, SFC, melting and cooling properties of the stearin fraction. The stearin fraction was only affected by cooling rate which changes its SMP. On the other hand, olein fraction was affected by crystallization temperature and cooling rate but not agitation speed which caused changes in IV, SMP, SFC, melting and crystallization behavior. Increase in both the crystallization temperature and cooling rate caused a reduction of IV, increment of the SFC, SMP, melting and crystallization behaviour of olein fraction and vice versa. The fractionated stearin part melted above 65°C while the olein melted at 40°C. SMP in olein fraction also reduced to a range of

  8. Significance of oil droplets in chemically enhanced water-accommodated fraction

    Energy Technology Data Exchange (ETDEWEB)

    Ramachandran, S. [Queen' s Univ., Kingston, ON (Canada). School of Environmental Studies; Hodson, P.V.; Lee, K. [Department of Fisheries and Oceans, Dartmouth, NS (Canada). Bedford Inst. of Oceanography

    2003-07-01

    This presentation described the controversial use of chemical dispersions to treat oil spills on water. Dispersants break up the spill in order to reduce shoreline impacts, but the dispersant drives the oil into the water column in the form of droplets, thereby temporarily increasing hydrocarbon concentrations and causing negative impacts on aquatic organisms. Exposure experiments have been conducted on rainbow trout exposed to Mesa and Scotian Light Crude Oil, with and without oil droplets. The studies showed that the levels of polycyclic aromatic hydrocarbons (PAH) was higher in the trout exposed to Corexit water-accommodated fractions, compared to water-accommodated fractions. The results suggest that dispersing crude oil sustains hydrocarbon concentrations in a larger volume of water than if it were not dispersed. The oil droplets increase the partitioning of PAH into the water solution. They adhere to the gills of the fish, thereby facilitating direct uptake.

  9. The chemically driven phase transformation in a memristive abacus capable of calculating decimal fractions.

    Science.gov (United States)

    Xu, Hanni; Xia, Yidong; Yin, Kuibo; Lu, Jianxin; Yin, Qiaonan; Yin, Jiang; Sun, Litao; Liu, Zhiguo

    2013-01-01

    The accurate calculation of decimal fractions is still a challenge for the binary-coded computations that rely on von Neumann paradigm. Here, we report a kind of memristive abacus based on synaptic Ag-Ge-Se device, in which the memristive long-term potentiation and depression are caused by a chemically driven phase transformation. The growth and the rupture of conductive Ag₂Se dendrites are confirmed via in situ transmission electron microscopy. By detecting the change in memristive synaptic weight, the quantity of input signals applied onto the device can be "counted". This makes it possible to achieve the functions of abacus that is basically a counting frame. We demonstrate through experimental studies that this kind of memristive abacus can calculate decimal fractions in the light of the abacus algorithms. This approach opens up a new route to do decimal arithmetic in memristive devices without encoding binary-coded decimal.

  10. Chemical Hydrolysis and Thermophilic Anaerobic Digestion of Organic Fraction of Municipal Solid Waste

    Directory of Open Access Journals (Sweden)

    Yosvany Díaz Domínguez

    2014-03-01

    Full Text Available The hydrolysis of the macromolecules that compose the organic fraction of municipal solid waste canbe taken for chemical, physical and biological methods, having all as aim the unfolding of the complexmolecules in simplier monomer. Thereby the degradation of organic matter is enhanced and resultsmore efficient the process of biogas via anaerobic. Chemical pretreatments were employed in the workusing sodium hydroxide (NaOH and hydrogen peroxide (H2O2 as reagents.The soluble chemicaloxygen demand (COD, the maximum methane yield and the methane rates production were used toevaluate the pretreatment actions. The degradation of the waste was able to be increased by allowinga comparative analysis to determine the best working conditions for this stage and subsequently itsimpact in the generation of biogas, methane specifically.

  11. Phytotoxic activity and chemical composition of aqueous volatile fractions from Eucalyptus species.

    Directory of Open Access Journals (Sweden)

    Jinbiao Zhang

    Full Text Available The essential oils from four Eucalyptus species (E. spathulata, E. salubris, E. brockwayii and E. dundasii have been previously confirmed to have stronger inhibitory effects on germination and seedling growth of silverleaf nightshade (Solanum elaeagnifolium Cav.. The aqueous volatile fractions (AVFs were the water soluble volatile fractions produced together with the essential oils (water insoluble fractions during the steam distillation process. The aim of this study was to further assess the phytotoxicity of AVFs from the four Eucalyptus species and their chemical composition. The fresh leaves of the four Eucalyptus species were used for the extraction of AVFs. The AVFs were tested for their phytotoxic effects on the perennial weed, silverleaf nightshade under laboratory conditions. The chemical compositions of the AVFs were determined by gas chromatograph-mass spectrometry (GC-MS. Our results showed that the AVFs had strong inhibition on the germination and seedling growth of silverleaf nightshade. The inhibition index increased with the increasing concentrations of AVFs. The inhibitory effects of the AVFs varied between different Eucalyptus species. The AVF from E. salubris demonstrated the highest inhibitory activity on the weed tested, with complete inhibition on germination and seedling growth at a concentration of 75%. The GC-MS analysis revealed that 1,8-cineole, isopentyl isovalerate, isomenthol, pinocarvone, trans-pinocarveol, alpha-terpineol and globulol were the main compounds in the AVFs. These results indicated that all AVFs tested had differential inhibition on the germination and seedling growth of silverleaf nightshade, which could be due to the joint effects of compounds present in the AVFs as these compounds were present in different quantities and ratio between Eucalyptus species.

  12. Iron Isotope Fractionation Reveals Structural Change upon Microbial and Chemical Reduction of Nontronite NAu-1

    Science.gov (United States)

    Liu, K.; Wu, L.; Shi, B.; Smeaton, C. M.; Li, W.; Beard, B. L.; Johnson, C.; Roden, E. E.; Van Cappellen, P.

    2015-12-01

    Iron (Fe) isotope fractionations were determined during reduction of structural Fe(III) in nontronite NAu-1 biologically by Shewanella oneidensis MR-1 and Geobacter sulfurreducens PCA and chemically by dithionite. ~10% reduction was achieved in biological reactors, with similar reduction extents obtained by dithionite. We hypothesize that two stages occurred in our reactors. Firstly, reduction started from edge sites of clays and the produced Fe(II) partially remained in situ and partially was released into solution. Next aqueous Fe(II) adsorbed onto basal planes. The basal sorbed Fe(II) then undergoes electron transfer and atom exchange (ETAE) with octahedral Fe(III) in clays, with the most negative fractionation factor Δ56Febasal Fe(II)-structural Fe(III)of -1.7‰ when basal sorption reached a threshold value. Secondly, when the most reactive Fe(III) was exhausted, bioreduction significantly slowed down and chemical reduction was able to achieve 24% due to diffusion of small size dithionite. Importantly, no ETAE occurred between basal Fe(II) and structural Fe(III) due to blockage of pathways by collapsed clay layers. This two-stage process in our reduction experiments is distinctive from abiotic exchange experiments by mixing aqueous Fe(II) and NAu-1, where no structural change of clay would block ETAE between basal Fe(II) and structural Fe(III). The separation of reduction sites (clay edges) and sorption sites (basal planes) is unique to clay minerals with layered structure. In contrast, reduction and sorption occur on the same sites on the surfaces of Fe oxyhydroxides, where reduction does not induce structure change. Thus, the Fe isotope fractionations are the same for reduction and abiotic exchange experiments for Fe oxides. Our study reveals important changes in electron transfer and atom exchange pathways upon reduction of clay minerals by dissimilatory Fe reducing bacteria, which is prevalent in anoxic soils and sediments.

  13. Physico-chemical characteristics and nutraceutical distribution of crude palm oil and its fractions

    Directory of Open Access Journals (Sweden)

    Prasanth Kumar, P. K.

    2014-06-01

    Full Text Available Crude palm oil (CRPO was dry fractionated at 25 °C to get crude palm olein (CRPOL, 77% and crude palm stearin (CRPS, 23%. Low and high melting crude palm stearin (LMCRPS 14.3% and HMCRPS 8.7% were separated by further fractionation of CRPS with acetone. The physico-chemical parameters and nutraceutical distribution showed variation in different fractions. The CRPO contained 514.7 mg·Kg−1 of β-carotene and 82.6%, 16.1%, 12.5% and 3.1% of it was distributed in CRPOL, CRPS, LMCRPS and HMCRPS respectively. The distribution of phytosterols in fraction was 1870.2, 1996.8, 1190.9, 1290.4 and 115.4 mg·Kg−1 for CRPO, CRPOL, CRPS, LMCRPS and HMCRPS respectively. Total tocopherol composition was 535.5, 587.1, 308.0, 305.6 and 36.2 mg·Kg−1 for CRPO, CRPOL, CRPS, LMCRPS and HMCRPS respectively. The results show that the fractionation of CRPO may be helpful in the preparation of nutraceutical-rich fractions.Aceite de palma crudo (CRPO fue fraccionado en seco a 25 °C para obtener oleína de palma cruda (CRPOL, 77% y estearinas de palma cruda (CRPS, el 23%. Estearinas con bajo y alto punto de fusión (LMCRPS 14,3% y HMCRPS 8,7% se separan por fraccionamiento adicional de CRPS con acetona. Los parámetros físico- químicos y la distribución de nutracéuticos muestra diferencias entre las fracciones. El CRPO contenía 514,7 mg·Kg−1 de β-caroteno y el 82,6%, 16,1%, 12,5% y 3,1% de este se distribuye en CRPOL, CRPS, LMCRPS y HMCRPS respectivamente. Los fitosteroles en las fracciones fue de: 1870,2, 1996,8, 1190.9, 1290,4 y 115,4 mg·Kg−1 para CRPO, CRPOL, CRPS, LMCRPS y HMCRPS respectivamente. La composición total de tocoferol fue 535,5, 587,1 308,0, 305,6 y 36,2 mg·Kg−1, para CRPO, CRPOL, CRPS, LMCRPS y HMCRPS respectivamente. Los resultados mostraron que el fraccionamiento de CRPO puede ser útil en la preparación de fracciones ricas en nutracéuticos.

  14. Chemical fractionation resulting from the hypervelocity impact process on metallic targets

    Science.gov (United States)

    Libourel, Guy; Ganino, Clément; Michel, Patrick; Nakamura, Akiko

    2016-10-01

    In a regime of hypervelocity impact cratering, the internal energy deposited in target + projectile region is large enough to melt and/or vaporize part of the material involved, which expands rapidly away from the impact site. Fast and energetic impact processes have therefore important chemical consequences on the projectile and target rock transformations during major impact events. Several physical and chemical processes occurred indeed in the short duration of the impact, e.g., melting, coating, mixing, condensation, crystallization, redox reactions, quenching, etc., all concurring to alter both projectile and target composition on the irreversible way.In order to document such hypervelocity impact chemical fractionation, we have started a program of impact experiments by shooting doped (27 trace elements) millimeter–sized basalt projectiles on metallic target using a two stages light gas gun. With impact velocity in the range from 0.25 to 7 km.s-1, these experiments are aimed i) to characterize chemically and texturally all the post-mortem materials (e.g., target, crater, impact melt, condensates, and ejectas), in order ii) to make a chemical mass balance budget of the process, and iii) to relate it to the kinetic energy involved in the hypervelocity impacts for scaling law purpose. Irrespective of the incident velocities, our preliminary results show the importance of redox processes, the significant changes in the ejecta composition (e.g., iron enrichment) and the systematic coating of the crater by the impact melt [1]. On the target side, characterizations of the microstructure of the shocked iron alloys to better constrain the shielding processes. We also show how these results have great implications in our understanding on the current surface properties of small bodies, and chiefly in the case of M-type asteroids. [1] Ganino C, Libourel G, Nakamura AM & Michel P (2015) Goldschmidt Abstracts, 2015 990.

  15. Physico-chemical characterisation of material fractions in residual and source-segregated household waste in Denmark

    DEFF Research Database (Denmark)

    Götze, Ramona; Pivnenko, Kostyantyn; Boldrin, Alessio;

    2016-01-01

    recycling rates evaluation of source-segregation and recycling chains gain importance. This paper provides a consistent up-to-date dataset for 74 physico-chemical parameters in 49 material fractions from residual and 24 material fractions from source-segregated Danish household waste. Significant...... differences in the physico-chemical properties of residual and source-segregated waste fractions were found for many parameters related to organic matter, but also for elements of environmental concern. Considerable differences in potentially toxic metal concentrations between the individual recyclable...... fractions within one material type were observed. This indicates that careful planning and performance evaluation of recycling schemes are important to ensure a high quality of collected recyclables. Rare earth elements (REE) were quantified in all waste fractions analysed, with the highest concentrations...

  16. Isotopic fractionation of carbon, deuterium and nitrogen : a full chemical study

    CERN Document Server

    Roueff, E; Hickson, K M

    2015-01-01

    Context. The increased sensitivity and high spectral resolution of millimeter telescopes allow the detection of an increasing number of isotopically substituted molecules in the interstellar medium. The 14N/ 15N ratio is difficult to measure directly for carbon containing molecules. Aims. We want to check the underlying hypothesis that the 13C/ 12C ratio of nitriles and isonitriles is equal to the elemental value via a chemical time dependent gas phase chemical model. Methods. We have built a chemical network containing D, 13C and 15N molecular species after a careful check of the possible fractionation reactions at work in the gas phase. Results. Model results obtained for 2 different physical conditions corresponding respectively to a moderately dense cloud in an early evolutionary stage and a dense depleted pre-stellar core tend to show that ammonia and its singly deuterated form are somewhat enriched in 15N, in agreement with observations. The 14N/ 15N ratio in N2H+ is found to be close to the elemental v...

  17. New evidence for chemical fractionation of radioactive xenon precursors in fission chains

    Science.gov (United States)

    Meshik, A. P.; Pravdivtseva, O. V.; Hohenberg, C. M.

    2016-04-01

    Mass-spectrometric analyses of Xe released from acid-treated U ore reveal that apparent Xe fission yields significantly deviate from the normal values. The anomalous Xe structure is attributed to chemically fractionated fission (CFF), previously observed only in materials experienced neutron bursts. The least retentive CFF-Xe isotopes, 136Xe and 134Xe, typically escape in 2:1 proportion. Xe retained in the sample is complimentarily depleted in these isotopes. This nucleochemical process allows understanding of unexplained Xe isotopic structures in several geophysical environments, which include well gasses, ancient anorthosite, some mantle rocks, as well as terrestrial atmosphere. CFF is likely responsible for the isotopic difference in Xe in the Earth's and Martian atmospheres and it is capable of explaining the relationship between two major solar system Xe carriers: the Sun and phase-Q, found in meteorites.

  18. Chemical characteristics and source of size-fractionated atmospheric particle in haze episode in Beijing

    Science.gov (United States)

    Tan, Jihua; Duan, Jingchun; Zhen, Naijia; He, Kebin; Hao, Jiming

    2016-01-01

    The abundance, behavior, and source of chemical species in size-fractionated atmospheric particle were studied with a 13-stage low pressure impactor (ELPI) during high polluted winter episode in Beijing. Thirty three elements (Al, Ca, Fe, K, Mg, Na, Si, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Sr, Zr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, Hg, Tl, and Pb) and eight water soluble ions (Cl-, NO3-, SO42 -, NH4+, Na+, K+, Ca2 +, and Mg2 +) were determined by ICP/MS and IC, respectively. The size distribution of TC (OC + EC) was reconstructed. Averagely, 51.5 ± 5.3% and 74.1 ± 3.7% of the total aerosol mass was distributed in the sub-micron (PM1) and fine particle (PM2.5), respectively. A significant shift to larger fractions during heavy pollution episode was observed for aerosol mass, NH4+, SO42 -, NO3-, K, Fe, Cu, Zn, Cd, and Pb. The mass size distributions of NH4+, SO42 -, NO3-, and K were dominated by accumulation mode. Size distributions of elements were classified into four main types: (I) elements were enriched within the accumulation mode (water soluble ions. Dust, vehicle, aged coal combustion, and sea salt were identified, and the size resolved source apportionments were discussed. Aged coal combustion was the important source of fine particles and dust contributed most to coarse particle.

  19. Deterrent activities in the crude lipophilic fractions of Antarctic benthic organisms: chemical defences against keystone predators

    Directory of Open Access Journals (Sweden)

    Laura Núñez-Pons

    2014-04-01

    Full Text Available Generalist predation constitutes a driving force for the evolution of chemical defences. In the Antarctic benthos, asteroids and omnivore amphipods are keystone opportunistic predators. Sessile organisms are therefore expected to develop defensive mechanisms mainly against such consumers. However, the different habits characterizing each predator may promote variable responses in prey. Feeding-deterrence experiments were performed with the circumpolar asteroid macropredator Odontaster validus to evaluate the presence of defences within the apolar lipophilic fraction of Antarctic invertebrates and macroalgae. A total of 51% of the extracts were repellent, yielding a proportion of 17 defended species out of the 31 assessed. These results are compared with a previous study in which the same fractions were offered to the abundant circum-Antarctic amphipod Cheirimedon femoratus. Overall, less deterrence was reported towards asteroids (51% than against amphipods (80.8%, principally in sponge and algal extracts. Generalist amphipods, which establish casual host–prey sedentary associations with biosubstrata (preferentially sponges and macroalgae, may exert more localized predation pressure than sea stars on certain sessile prey, which would partly explain these results. The nutritional quality of prey may interact with feeding deterrents, whose production is presumed to be metabolically expensive. Although optimal defence theory posits that chemical defences are managed and distributed as to guarantee protection at the lowest cost, we found that only a few organisms localized feeding deterrents towards most exposed and/or valuable body regions. Lipophilic defensive metabolites are broadly produced in Antarctic communities to deter opportunistic predators, although several species combine different defensive traits.

  20. Animal manure phosphorus characterization by sequential chemical fractionation, release kinetics and 31P-NMR analysis

    Directory of Open Access Journals (Sweden)

    Tales Tiecher

    2014-10-01

    Full Text Available Phosphate release kinetics from manures are of global interest because sustainable plant nutrition with phosphate will be a major concern in the future. Although information on the bioavailability and chemical composition of P present in manure used as fertilizer are important to understand its dynamics in the soil, such studies are still scarce. Therefore, P extraction was evaluated in this study by sequential chemical fractionation, desorption with anion-cation exchange resin and 31P nuclear magnetic resonance (31P-NMR spectroscopy to assess the P forms in three different dry manure types (i.e. poultry, cattle and swine manure. All three methods showed that the P forms in poultry, cattle and swine dry manures are mostly inorganic and highly bioavailable. The estimated P pools showed that organic and recalcitrant P forms were negligible and highly dependent on the Ca:P ratio in manures. The results obtained here showed that the extraction of P with these three different methods allows a better understanding and complete characterization of the P pools present in the manures.

  1. Chemical characteristics and fractionation of proteins from Moringa oleifera Lam. leaves.

    Science.gov (United States)

    Teixeira, Estelamar Maria Borges; Carvalho, Maria Regina Barbieri; Neves, Valdir Augusto; Silva, Maraíza Apareci; Arantes-Pereira, Lucas

    2014-03-15

    Moringa oleifera Lam. is a leguminous plant, originally from Asia, which is cultivated in Brazil because of its low production cost. Although some people have used this plant as food, there is little information about its chemical and nutritional characteristics. The objective of this study was to characterise the leaves of M. oleifera in terms of their chemical composition, protein fractions obtained by solubility in different systems and also to assess their nutritional quality and presence of bioactive substances. The whole leaf flour contained 28.7% crude protein, 7.1% fat, 10.9% ashes, 44.4% carbohydrate and 3.0mg 100g(-1) calcium and 103.1mg 100g(-1) iron. The protein profile revealed levels of 3.1% albumin, 0.3% globulins, 2.2% prolamin, 3.5% glutelin and 70.1% insoluble proteins. The hydrolysis of the protein from leaf flour employing sodium dodecyl sulfate (SDS) and 2-mercaptoethanol (ME) resulted in 39.5% and 29.5%, respectively. The total protein showed low in vitro digestibility (31.8%). The antinutritional substances tested were tannins (20.7 mg g(-1)), trypsin inhibitor (1.45TIU mg g(-1)), nitrate (17 mg g(-1)) and oxalic acid (10.5 mg g(-1)), besides the absence of cyanogenic compounds. β-Carotene and lutein stood out as major carotenoids, with concentrations of 161.0 and 47.0 μg g(-1) leaf, respectively. Although M. oleifera leaves contain considerable amount of crude protein, this is mostly insoluble and has low in vitro digestibility, even after heat treatment and chemical attack. In vivo studies are needed to better assess the use of this leaf as a protein source in human feed.

  2. Physico-chemical characterisation of material fractions in residual and source-segregated household waste in Denmark.

    Science.gov (United States)

    Götze, R; Pivnenko, K; Boldrin, A; Scheutz, C; Astrup, T Fruergaard

    2016-08-01

    Physico-chemical waste composition data are paramount for the assessment and planning of waste management systems. However, the applicability of data is limited by the regional, temporal and technical scope of waste characterisation studies. As Danish and European legislation aims for higher recycling rates evaluation of source-segregation and recycling chains gain importance. This paper provides a consistent up-to-date dataset for 74 physico-chemical parameters in 49 material fractions from residual and 24 material fractions from source-segregated Danish household waste. Significant differences in the physico-chemical properties of residual and source-segregated waste fractions were found for many parameters related to organic matter, but also for elements of environmental concern. Considerable differences in potentially toxic metal concentrations between the individual recyclable fractions within one material type were observed. This indicates that careful planning and performance evaluation of recycling schemes are important to ensure a high quality of collected recyclables. Rare earth elements (REE) were quantified in all waste fractions analysed, with the highest concentrations of REE found in fractions with high content of mineral raw materials, soil materials and dust. The observed REE concentrations represent the background concentration level in non-hazardous waste materials that may serve as a reference point for future investigations related to hazardous waste management. The detailed dataset provided here can be used for assessments of waste management solutions in Denmark and for the evaluation of the quality of recyclable materials in waste. PMID:27216729

  3. Trachyspermum ammi (L.) sprague: chemical composition of essential oil and antimicrobial activities of respective fractions.

    Science.gov (United States)

    Moein, Mahmoodreza R; Zomorodian, Kamiar; Pakshir, Keyvan; Yavari, Farnoosh; Motamedi, Marjan; Zarshenas, Mohammad M

    2015-01-01

    Resistance to antibacterial agents has become a serious problem for global health. The current study evaluated the antimicrobial activities of essential oil and respective fractions of Trachyspermum ammi (L.) Sprague. Seeds of the essential oil were extracted and fractionated using column chromatography. All fractions were then analyzed by gas chromatography/mass spectrometry. Antifungal and antibacterial activities of the oil and its fractions were assessed using microdilution method. Compounds γ-terpinene (48.07%), ρ-cymene (33.73%), and thymol (17.41%) were determined as major constituents. The effect of fraction II was better than total essential oil, fraction I, and standard thymol. The greater effect of fraction II compared to standard thymol showed the synergistic effects of the ingredients in this fraction. As this fraction and also total oil were effective on the studied microorganism, the combination of these products with current antimicrobial agents could be considered as new antimicrobial compounds in further investigations.

  4. Radiocarbon and stable carbon isotope compositions of chemically fractionated soil organic matter in a temperate-zone forest

    International Nuclear Information System (INIS)

    To better understand the role of soil organic matter in terrestrial carbon cycle, carbon isotope compositions in soil samples from a temperate-zone forest were measured for bulk, acid-insoluble and base-insoluble organic matter fractions separated by a chemical fractionation method. The measurements also made it possible to estimate indirectly radiocarbon (14C) abundances of acid- and base-soluble organic matter fractions, through a mass balance of carbon among the fractions. The depth profiles of 14C abundances showed that (1) bomb-derived 14C has penetrated the first 16 cm mineral soil at least; (2) Δ14C values of acid-soluble organic matter fraction are considerably higher than those of other fractions; and (3) a significant amount of the bomb-derived 14C has been preserved as the base-soluble organic matter around litter-mineral soil boundary. In contrast, no or little bomb-derived 14C was observed for the base-insoluble fraction in all sampling depths, indicating that this recalcitrant fraction, accounting for approximately 15% of total carbon in this temperate-zone forest soil, plays a role as a long-term sink in the carbon cycle. These results suggest that bulk soil organic matter cannot provide a representative indicator as a source or a sink of carbon in soil, particularly on annual to decadal timescales

  5. Antirheumatoid Arthritis Activities and Chemical Compositions of Phenolic Compounds-Rich Fraction from Urtica atrichocaulis, an Endemic Plant to China

    OpenAIRE

    Mengyue Wang; Ke Li; Yuxiao Nie; Yingfang Wei; Xiaobo Li

    2012-01-01

    Urtica atrichocaulis, an endemic plant to China, is commonly used to treat rheumatoid arthritis even though its pharmaceutical activities and chemical constituents were not studied. Herein, we reported our investigations on the chemical compositions of the phenolic compounds-rich fraction from U. atrichocaulis (TFUA) and their antirheumatoid arthritis activities. We found that the TFUA significantly inhibited the adjuvant-induced rats arthritis, carrageenin-induced rats paw edema, cotton pell...

  6. Chemical and toxicological characterisation of water accommodated fractions relevant for oil spill situations

    International Nuclear Information System (INIS)

    The laboratory methodology and preliminary findings from an ongoing characterisation study of Water Accommodated Fraction solutions (WAF) (water systems with dissolved oil components, which is essentially free of dispersed oil droplets) derived from standardised low energy mixing of oils in seawater is presented. The study emphasises a tight connection between chemical characterisation and toxicological testing of WAF, and aims at obtaining improved and realistic data on potential environmental effects in the water column after an oil spill situation. Various oil types and the aspect of weathering (evaporative loss and photolysis) of oil is incorporated in the study. Preliminary results have identified large variation in the composition and toxicity of WAFs depending on the type of crude, oil loading rate (oil:water ratio) and weathering degree of the oils. Data from the study will be used for improving algorithms in present fate and effect models, which again will be used as quantitative tools in future damage assessment studies and in Net Environmental Benefit Analysis of response alternatives in various spill scenarios. (author)

  7. Modification of apparent fission yields by Chemical Fractionation following Fission (CFF)

    Science.gov (United States)

    Hohenberg, Charles; Meshik, Alex

    2008-04-01

    Grain-by-grain studies of the 2 billion year old Oklo natural reactor, using laser micro-extraction^1,2, yield detailed information about Oklo, a water-moderated pulsed reactor, cycle times, total neutron fluence and duration, but it also demonstrates Chemical Fractionation following Fission. In the CFF process, members of an isobaric yield chain with long half-lives are subject to migration before decay can occur. Of particular interest is the 129 isobar where 17 million ^129I can migrate out of the host grain before decay, and iodine compounds are water soluble. This is amply demonstated by the variation of Xe spectra between micron-sized uranium-bearing minerals and adjacent uranium-free minerals. Fission 129 yields for the spontaneous fission of ^238U generally come from measured ^129Xe in pitchblend^2, ores emplaced by aqueous activity, and are incorrect due to the CFF process. ^238U yields for the 131 and 129 chains, reported in Hyde^3, as 0.455 +- .02 and < 0.012, respectively, the latter being anomalously low. ^1A Meshik, C Hohenberg and O Pravdivtesva, PRL 93, 182302 (2004); A Meshik Sci. Am. Nov (2005), 55; ^2E K Hyde, Nucl Prop of Heavy Elements III (1964).

  8. Chemical composition of Sacha Inchi (Plukenetia volubilis L.) seeds and characteristics of their lipid fraction

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrrez, L.F.; Rosada, L.M.; Jimenez, A.

    2011-07-01

    The seeds of Sacha inchi (Plukenetia volubilis L.) from Colombia were analyzed for their main chemical composition. Sacha inchi seeds (SIS) were rich in oil (41.4%) and protein (24.7%). The main minerals present in SIS were potassium (5563.5 ppm), magnesium (3210 ppm) and calcium (2406 ppm). A fatty acid analysis revealed that a-linolenic (50.8%) and linoleic (33.4%) acids were the main fatty acids in Sacha inchi oil (SIO). The lipid fractionation of SIO, obtained by solid phase extraction, yielded mainly neutral lipids (97.2%), and lower amounts of free fatty acids (1.2%) and phospholipids (0.8%). The physicochemical properties of the oil include: saponification number 185.2; iodine value 193.1; density 0.9187 g/cm3, refractive index 0.4791 and viscosity of 35.4 mPa.s. The melting profiles of SIO were characterized by the presence of one wide endothermic peak with a melting enthalpy of 23.2 J/g. Our results indicate that Sacha inchi is an important new crop with applications in the food and pharmaceutical industries. (Author).

  9. Chemical composition of Sacha Inchi (Plukenetia volubilis L.) seeds and characteristics of their lipid fraction

    International Nuclear Information System (INIS)

    The seeds of Sacha inchi (Plukenetia volubilis L.) from Colombia were analyzed for their main chemical composition. Sacha inchi seeds (SIS) were rich in oil (41.4%) and protein (24.7%). The main minerals present in SIS were potassium (5563.5 ppm), magnesium (3210 ppm) and calcium (2406 ppm). A fatty acid analysis revealed that a-linolenic (50.8%) and linoleic (33.4%) acids were the main fatty acids in Sacha inchi oil (SIO). The lipid fractionation of SIO, obtained by solid phase extraction, yielded mainly neutral lipids (97.2%), and lower amounts of free fatty acids (1.2%) and phospholipids (0.8%). The physicochemical properties of the oil include: saponification number 185.2; iodine value 193.1; density 0.9187 g/cm3, refractive index 0.4791 and viscosity of 35.4 mPa.s. The melting profiles of SIO were characterized by the presence of one wide endothermic peak with a melting enthalpy of 23.2 J/g. Our results indicate that Sacha inchi is an important new crop with applications in the food and pharmaceutical industries. (Author).

  10. Chaos suppression of fractional order Willamowski-Rössler chemical system and its synchronization using sliding mode control

    Science.gov (United States)

    Rajagopal, Karthikeyan; Karthikeyan, Anitha

    2016-09-01

    Most of the Real systems shows chaotic behavior when they approach complex states. Especially in physical and chemical systems these behaviors define the character of the system. The control of these chaotic behaviors is of very high practical importance and hence mathematical models of these chaotic systems proves vital in deciding the control structures. One such model of chemical reactors is the Willamowski-Rössler system (WR). In this paper we derive a fractional order sliding mode control scheme where the states of the WR system are driven back to the defined equilibrium points. We have also synchronized master and slave fractional order WR system using sliding mode control. As the entire control law is defined in fractional order, we derived a new methodology to prove the stability of the controller. The numerical simulation and analysis are achieved with LabVIEW.

  11. Chemical characteristics and source of size-fractionated atmospheric particle in haze episode in Beijing

    Science.gov (United States)

    Tan, Jihua; Duan, Jingchun; Zhen, Naijia; He, Kebin; Hao, Jiming

    2016-01-01

    The abundance, behavior, and source of chemical species in size-fractionated atmospheric particle were studied with a 13-stage low pressure impactor (ELPI) during high polluted winter episode in Beijing. Thirty three elements (Al, Ca, Fe, K, Mg, Na, Si, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Sr, Zr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, Hg, Tl, and Pb) and eight water soluble ions (Cl-, NO3-, SO42 -, NH4+, Na+, K+, Ca2 +, and Mg2 +) were determined by ICP/MS and IC, respectively. The size distribution of TC (OC + EC) was reconstructed. Averagely, 51.5 ± 5.3% and 74.1 ± 3.7% of the total aerosol mass was distributed in the sub-micron (PM1) and fine particle (PM2.5), respectively. A significant shift to larger fractions during heavy pollution episode was observed for aerosol mass, NH4+, SO42 -, NO3-, K, Fe, Cu, Zn, Cd, and Pb. The mass size distributions of NH4+, SO42 -, NO3-, and K were dominated by accumulation mode. Size distributions of elements were classified into four main types: (I) elements were enriched within the accumulation mode (fine, intermediate, and coarse modes; and (IV) those which were mainly found within particles larger than 2.7 μm (Al, Mg, Si, Ca, Sc, Tl, Fe, Sr, Zr, and Ba). [H+]cor showed an accumulation mode at 600-700 nm and the role of Ca2 + should be fully considered in the estimation of acidity. The acidity in accumulation mode particles suggested that generally gaseous NH3 was not enough to neutralize sulfate completely. PMF method was applied for source apportionment of elements combined with water soluble ions. Dust, vehicle, aged coal combustion, and sea salt were identified, and the size resolved source apportionments were discussed. Aged coal combustion was the important source of fine particles and dust contributed most to coarse particle.

  12. Chemical Composition, Nitrogen Fractions and Amino Acids Profile of Milk from Different Animal Species.

    Science.gov (United States)

    Rafiq, Saima; Huma, Nuzhat; Pasha, Imran; Sameen, Aysha; Mukhtar, Omer; Khan, Muhammad Issa

    2016-07-01

    Milk composition is an imperative aspect which influences the quality of dairy products. The objective of study was to compare the chemical composition, nitrogen fractions and amino acids profile of milk from buffalo, cow, sheep, goat, and camel. Sheep milk was found to be highest in fat (6.82%±0.04%), solid-not-fat (11.24%±0.02%), total solids (18.05%±0.05%), protein (5.15%±0.06%) and casein (3.87%±0.04%) contents followed by buffalo milk. Maximum whey proteins were observed in camel milk (0.80%±0.03%), buffalo (0.68%±0.02%) and sheep (0.66%±0.02%) milk. The non-protein-nitrogen contents varied from 0.33% to 0.62% among different milk species. The highest r-values were recorded for correlations between crude protein and casein in buffalo (r = 0.82), cow (r = 0.88), sheep (r = 0.86) and goat milk (r = 0.98). The caseins and whey proteins were also positively correlated with true proteins in all milk species. A favorable balance of branched-chain amino acids; leucine, isoleucine, and valine were found both in casein and whey proteins. Leucine content was highest in cow (108±2.3 mg/g), camel (96±2.2 mg/g) and buffalo (90±2.4 mg/g) milk caseins. Maximum concentrations of isoleucine, phenylalanine, and histidine were noticed in goat milk caseins. Glutamic acid and proline were dominant among non-essential amino acids. Conclusively, current exploration is important for milk processors to design nutritious and consistent quality end products. PMID:26954163

  13. Chemically fractionated fission-xenon in meteorites and on the earth

    Science.gov (United States)

    Shukolyukov, Yuri A.; Jessberger, Elmar K.; Meshik, Alexander P.; Vu Minh, Dang; Jordan, Jimmy L.

    1994-07-01

    This is a report on the nature of isotopically anomalous xenon, which has been detected in two Ca-Al-rich inclusions of the Allende carbonaceous chondrite. It is extremely enriched in 132Xe, 129Xe, and to a lesser extent in 131Xe. Similar large excesses of 132Xe as well as of 131Xe, 134Xe, and 129Xe have previously been found in material processed in a natural nuclear reactor (Oklo phenomenon). Excess of these isotopes had also been encountered in MORB-glasses, in an ancient Greenland anorthosite. Thus, this Xe-type, which had previously been termed "alien" ( JORDON et al., 1980a) does not seem to be unique. To determine the origin of "alien" Xe, we analysed Xe (a) in neutron irradiated pitchblende and in the irradiation capsule, (b) in non-irradiated extremely fine-grained pitchblende (so-called Colorado-type deposit), and (c) in sandstone taken from the epicentre of an atomic explosion. In addition, the isotopic composition of xenon released by stepwise degassing and after selective dissolving of rocks from the Oklo natural reactor was determined. The results of these dedicated experiments demonstrate that the formation of alien Xe is due to the migration of the radioactive precursors of the stable isotopes 134Xe, 132Xe, 131Xe, and 129Xe. Due to this reason we now call it CFF-Xe - Chemically Fractionated Fission Xenon. Prerequisites for its formation are the simultaneous prevalence of two conditions: (1) fission (of 238U, 235U, and/ or 244Pu) and (2) a physicochemical environment (temperature, pressure, fluidity) at which the precursors of xenon (mainly Te and I) are mobile. Taking into account the occurrence of xenon in meteorites and terrestrial rocks, not all excesses of 129Xe in mantle rocks and natural gases are necessarily connected with the decay of primordial 129I.

  14. Metal levels in street sediment from an industrial city. Spatial trends, chemical fractionation, and management implications

    Energy Technology Data Exchange (ETDEWEB)

    Irvine, Kim N.; Perrelli, Mary F. [State Univ. of New Yrok, Buffalo, NY (United States). Geography and Planning Dept., Buffalo State; Ngoen-klan, Ratchadawan [Chiang Mai Univ. (Thailand). Dept. of Parasitology; Droppo, Ian G. [Water Science and Technology Directorate, Science and Technology Branch, Environment Canada, Burlington, ONT (Canada). Aquatic Ecosystem Management Research Div.

    2009-08-15

    Background, aim and scope: Street sediment samples were collected at 50 locations in a mixed land use area of Hamilton, Ontario, Canada, and metal levels were analyzed using a sequential extraction procedure for different particle size classes to provide an estimate of potential toxicity as well as the potential for treatment through best management practices (BMPs). Methodology: The street sediment samples were dry sieved into four different particle size categories and a sequential extraction procedure was done on each size category following the methodology proposed by Tessier et al. 1979 using a Hitachi 180-80 Polarized Zeeman Atomic Absorption Spectrophotometer. Results and discussion: Analysis of variance, post hoc least-significant difference tests, and kriging analysis showed that spatially Mn and Fe levels were associated with a well-defined heavy industrial area that includes large iron- and steel-making operations; Cu and Pb were associated with both the industrial and high-volume traffic areas, while Zn tended to be more associated with high-volume traffic areas. The potential bioavailability of the metals, based on the sum of chemical fractions 1 (exchangeable) and 2 (carbonate-bound), decreased in order: Zn > Cd > Mn > Pb > Cu > Fe. Based on aquatic sediment quality guidelines, there is some concern regarding the potential impact of the street sediment when runoff reaches receiving waters. Conclusions: It is possible that a combination of BMPs, including street sweeping and constructed wetlands, could help to reduce street sediment impact on environmental quality in the Hamilton region. The data presented here would be important in developing and optimizing the design of these BMPs. (orig.)

  15. Chemical Composition, Nitrogen Fractions and Amino Acids Profile of Milk from Different Animal Species

    Science.gov (United States)

    Rafiq, Saima; Huma, Nuzhat; Pasha, Imran; Sameen, Aysha; Mukhtar, Omer; Khan, Muhammad Issa

    2016-01-01

    Milk composition is an imperative aspect which influences the quality of dairy products. The objective of study was to compare the chemical composition, nitrogen fractions and amino acids profile of milk from buffalo, cow, sheep, goat, and camel. Sheep milk was found to be highest in fat (6.82%±0.04%), solid-not-fat (11.24%±0.02%), total solids (18.05%±0.05%), protein (5.15%±0.06%) and casein (3.87%±0.04%) contents followed by buffalo milk. Maximum whey proteins were observed in camel milk (0.80%±0.03%), buffalo (0.68%±0.02%) and sheep (0.66%±0.02%) milk. The non-protein-nitrogen contents varied from 0.33% to 0.62% among different milk species. The highest r-values were recorded for correlations between crude protein and casein in buffalo (r = 0.82), cow (r = 0.88), sheep (r = 0.86) and goat milk (r = 0.98). The caseins and whey proteins were also positively correlated with true proteins in all milk species. A favorable balance of branched-chain amino acids; leucine, isoleucine, and valine were found both in casein and whey proteins. Leucine content was highest in cow (108±2.3 mg/g), camel (96±2.2 mg/g) and buffalo (90±2.4 mg/g) milk caseins. Maximum concentrations of isoleucine, phenylalanine, and histidine were noticed in goat milk caseins. Glutamic acid and proline were dominant among non-essential amino acids. Conclusively, current exploration is important for milk processors to design nutritious and consistent quality end products. PMID:26954163

  16. Chemical characterization of high-molar-mass fractions in a Norway spruce knotwood ethanol extract.

    Science.gov (United States)

    Smeds, Annika I; Eklund, Patrik C; Willför, Stefan M

    2016-10-01

    The low-molar-mass (LMM) fraction, only, i.e., the GC-eluting compounds, which are mainly lignans, has been characterized in Norway spruce knotwood hydrophilic extracts previously. Of this fraction, many lignans and sesquilignans and all GC peaks supposedly representing dilignans remain unidentified. In this work, dilignans and the GC non-eluting compounds (the high-molar mass fractions, HMM) were characterized in a 7-hydroxymatairesinol-reduced knotwood ethanol extract of Norway spruce by using several fractionation and analytical techniques. A methyl tert-butyl ether (MTBE) insoluble fraction of the extract contained mainly HMM material, of which the main part was shown to consist of lignan oligomers. The oligolignans (with a molar mass up to approximately 3700 Da) seemed to be linked by 55' bonds, some of them containing one or two guaiacylglycerol ether units linked to the lignan by βO4 or β5 bonds. Several oligolignans were identified or tentatively identified. The MTBE soluble fraction, which accounted for the major part (81%) of the extract, contained mainly LMM material (lignans, sesqui- and dilignans). The part of the HMM material in the MTBE soluble fraction that was easily isolable (2%) seemed to contain polymers of fatty acids and alcohols, resin acids, and sterols. PMID:27256310

  17. Quantitative structure-property relationships for chemical functional use and weight fractions in consumer articles

    Science.gov (United States)

    Chemical functional use -- the functional role a chemical plays in processes or products -- may be a useful heuristic for predicting human exposure potential in that it comprises information about the compound's likely physical properties and the product formulations or articles ...

  18. Quantification of chemical contaminants in the paper and board fractions of municipal solid waste

    DEFF Research Database (Denmark)

    Pivnenko, Kostyantyn; Olsson, Mikael Emil; Götze, Ramona;

    2016-01-01

    Chemicals are used in materials as additives in order to improve the performance of the material or the production process itself. The presence of these chemicals in recyclable waste materials may potentially affect the recyclability of the materials. The addition of chemicals may vary depending...... on the production technology or the potential end-use of the material. Paper has been previously shown to potentially contain a large variety of chemicals. Quantitative data on the presence of chemicals in paper are necessary for appropriate waste paper management, including the recycling and re-processing of paper...... residual and source-segregated materials, which were disposed of (e.g., through incineration) and recycled, respectively. The concentration of selected chemicals was quantified for all of the samples. The quantified chemicals included mineral oil hydrocarbons, phthalates, phenols, polychlorinated biphenyls...

  19. Application of chemical fractionation for monitoring some trace elements in street and industrial dust from Wadmedani, Sudan

    International Nuclear Information System (INIS)

    This study monitors some trace elements concentration in street and industrial dust from Wad Medani city, Gezira State in central Sudan. A total of 20 samples of dust were collected from crowded and non-crowded streets, material processing workshop and a tannery. Samples were treated by sequential chemical extraction in five fractions, which termed as exchangeable fraction, carbonate fraction, Fe-Mn oxides fraction, organic matter fraction and residual fraction. The same samples were digested by wet method. The obtained solutions were analyzed for Cr, Fe, Ni, Cu, Zn, and Pb content using Atomic Absorption Spectrometer (AAS) and for Na and K content using Flame Emission Spectrometer (FES). X-Ray Fluorescence Spectrometer (XRF) was used to determine the total content of Na, K, Cr, Fe, Ni, Cu, Zn and Pb in the bulk sample. Results of total content, which obtained by AAS, FES and XRF spectrometry, were compared with each other and with total content for the fractionated samples. Certified reference materials from IAEA were analyzed to make sure of the data obtained. The ranges of concentrations obtained are 113-3900 μg/g for Cr, 0.3-110.4 mg/g for Fe, 27-500 μg/g for Ni, 34.7-4390 μ/g for Cu, 62-1320 μg/g for Zn and 40-1250 μg/g for Pb dry weight. The obtained results were analyzed statistically using multivariate methods that include Correlation Matrices, Principal Component Analysis (PCA) and cluster analysis. The concentrations of trace elements in street and industrial dust of Wad Medani were compared with those values in literature. It has been observed that the dust from street and industrial area of wad Medani is slightly affected by anthropogenic sources.(Author)

  20. Determination of the composition of the organic matter chemically stabilized by agricultural soil clay minerals: Spectroscopy and Density Fractionation

    Science.gov (United States)

    Oufqir, Sofia; Bloom, Paul; Toner, Brandy; Hatcher, Patrick

    2014-05-01

    The interactions between soil organic matter and clay minerals are considered important processes because of their ability to sequester C in soil for long periods of time, and hence control C in the global C cycle when present. However, differing results have been reported regarding the composition of the soil organic matter - aromatic fractions versus aliphatic fractions - associated with clay minerals. To clarify this critical issue and better understand the C sequestration process in soils, we aimed to determine the nature of the chemically bound natural organic matter on clay surfaces, and to probe the speciation and spatial distribution of C in the soil clay nanoparticles using direct spectroscopic measurements namely solid-state CP-MAS and DP-MAS 13C NMR spectroscopy, x-ray diffraction spectroscopy (XRD), and scanning transmission x-ray microscopy (STXM). We tested the hypotheses that peptides and polysaccharides are stabilized by the smectite-illite clay while the lipids and black carbon are a separate phase; and that they are evenly distributed on clay surfaces. A soil clay fraction (5.5% organic C) was isolated from the surface of a prairie soil (Mollisol) in southwestern Minnesota, characterized by a pH 6.0, 32.5% clay content, and 3.7% organic carbon, using a sonication-sedimentation-siphoning process in distilled water. Then was subjected to density separation combined with low energy ultrasonic dispersion to separate the free organic and black C (light fraction) from the chemically bound C (heavy fraction). The XRD results indicated a dominance of interstratified smectite-illite clays in soil. The 13C-NMR spectra of the soil clay fraction suggested that polysaccharides and polypeptides are the prevailing components of the organic matter associated with the mineral clay, with only a minor component of aromatic C. The light fraction has strong alkyl C-H bands characteristic of fatty acids plus strong C-O bands characteristic of polysaccharides, including

  1. Chemical composition of Sacha Inchi (Plukenetia volubilis L. seeds and characteristics of their lipid fraction

    Directory of Open Access Journals (Sweden)

    Jiménez, Álvaro

    2011-03-01

    Full Text Available The seeds of Sacha inchi (Plukenetia volubilis L. from Colombia were analyzed for their main chemical composition. Sacha inchi seeds (SIS were rich in oil (41.4% and protein (24.7%. The main minerals present in SIS were potassium (5563.5 ppm, magnesium (3210 ppm and calcium (2406 ppm. A fatty acid analysis revealed that a-linolenic (50.8% and linoleic (33.4% acids were the main fatty acids in Sacha inchi oil (SIO. The lipid fractionation of SIO, obtained by solid phase extraction, yielded mainly neutral lipids (97.2%, and lower amounts of free fatty acids (1.2% and phospholipids (0.8%. The physicochemical properties of the oil include: saponification number 185.2; iodine value 193.1; density 0.9187 g/cm3, refractive index 1.4791 and viscosity of 35.4 mPa.s. The melting profiles of SIO were characterized by the presence of one wide endothermic peak with a melting enthalpy of 23.2 J/g. Our results indicate that Sacha inchi is an important new crop with applications in the food and pharmaceutical industries.Semillas de Sacha inchi (Plukenetia volubilis L. de Colombia fueron analizadas en su composición química. Las semillas de Sacha inchi (SIO fueron ricas en aceite (41.4% y proteína (24.7%. Los principales minerales presentes en las SIS fueron potasio (5563.5 ppm, magnesio (3210 ppm y calcio (2406 ppm. El análisis de ácidos grasos reveló que los ácidos a-linolénico (50.8% y linoleico (33.4% fueron los principales ácidos grasos presentes en el aceite de Sacha inchi (SIO. El fraccionamiento del SIO, realizado por extracción en fase sólida, produjo principalmente lípidos neutros (97.2%, y bajas cantidades de ácidos grasos libres (1.2% y fosfolípidos (0.8%. Las propiedades fisicoquímicas del aceite incluyen: índice de saponificación 185.2; índice de yodo 193.1; densidad 0.9187 g/cm3, índice de refracción 1.4791 y viscosidad 35.4 mPa.s. Los perfiles de fusión del SIO se caracterizaron por la presencia de un ancho pico endot

  2. Antirheumatoid Arthritis Activities and Chemical Compositions of Phenolic Compounds-Rich Fraction from Urtica atrichocaulis, an Endemic Plant to China

    Directory of Open Access Journals (Sweden)

    Mengyue Wang

    2012-01-01

    Full Text Available Urtica atrichocaulis, an endemic plant to China, is commonly used to treat rheumatoid arthritis even though its pharmaceutical activities and chemical constituents were not studied. Herein, we reported our investigations on the chemical compositions of the phenolic compounds-rich fraction from U. atrichocaulis (TFUA and their antirheumatoid arthritis activities. We found that the TFUA significantly inhibited the adjuvant-induced rats arthritis, carrageenin-induced rats paw edema, cotton pellet-induced mice granuloma, and the acetic acid-induced mice writhing response. Our phytochemical investigations on the TFUA resulted in the first-time isolation and identification of 17 phenolic constituents and a bis (5-formylfurfuryl ether. The extensive HPLC analysis also revealed the chemical compositions of TFUA. Our further biological evaluation of the main phenolic components, individually and collectively, indicated that the antirheumatoid arthritis activities of TFUA were the combined effect of multiple phenolic constituents.

  3. Chemical constituents in n-butanol fractions of Costus afer ker Gawl leaf and stem

    Directory of Open Access Journals (Sweden)

    Godswill Nduka Anyasor

    2014-04-01

    Conclusion: The bioactive compounds identified in the n-butanol fractions of C. afer leaves and stem may explain the folkloric use of C. afer plant in the treatment of chronic inflammatory and oxidative stress related diseases. [J Intercult Ethnopharmacol 2014; 3(2.000: 78-84

  4. Chemical extraction methods for assessment of phytoavailable fractions of elements in soils

    International Nuclear Information System (INIS)

    This study develops extraction methods of phytoavailable fractions of elements in soil for precise estimation of soil-to-plant transfer of radionuclides released from nuclear facilities, such as a reprocessing plant in Rokkasho. The soil-to-plant transfer factor based on the total concentration in soil generally scattered in a few orders of magnitude. This large variance is most likely attributable to ignorance of phytoavailability of radionuclides in soil. The transfer factor based on phytoavailable fractions of the radionuclides extracted from soil is expected to allow more precise estimation of their soil-to-plant transfer. Komatsuna (Brassica rapa L. var. perviridis) cultivated in experimental pots and actual fields was used for investigation. Soil samples collected from 19 agricultural fields in Aomori Prefecture were adapted for the pot experiment. We extracted 40 elements from the soil samples with pure water, 0.01 M HNO3, 1 M NH4OAc or 1 M NH4NO3, and analyzed their concentrations in the extracts. Their contents in komatsuna were determined, and their relationships with the concentrations in the extracts were investigated. Although the correlations between the concentrations in the plants and total concentration in the soils were not significant for most elements measured, zinc and lanthanide elements concentrations in the 0.01 M HNO3, 1 M NH4OAc and 1 M NH4NO3 extracts had significant positive correlations with those in the plants. These extraction methods were suitable for the estimation of phytoavailable fractions for those elements. Concentrations of Sr in the any extracted fractions did not correlate to those in the plants. However, Sr/Ca ratios in the NH4OAc extracted fraction showed significant correlation with the plant Sr concentrations. Although the Sr transfer factor was predicted by the NH4OAc-extractable Ca in soil, introducing the Mg concentration in that fraction and the total carbon concentration in soil as additional parameters could

  5. [Effect of Nano Zeolite on Chemical Fractions of Cd in Soil and Its Uptake by Cabbage].

    Science.gov (United States)

    Xiong, Shi-juan; Xu, Wei-hong; Xie, Wen-wen; Chen, Rong; Chen, Yong-qin; Chi, Sun-lin; Chen, Xu- gen; Zhang, Jin-zhong; Xiong, Zhi-ting; Wang, Zheng-yin; Xie, De-ti

    2015-12-01

    Incubation experiments were carried out to investigate the influence of different nano zeolite (NZ) and ordinary zeolite (OZ) levels(0, 5, 10 and 20 g · kg⁻¹) on the change trends in fraction distribution coefficient (FDC) of Cd when exposed to different Cadmium (Cd) levels (1, 5, 10 and 15 mg · kg⁻¹), and pot experiments were carried out to investigate their influence on soil Cd fraction and Cd uptake by cabbage. The results in incubation experiments showed that the application of nano zeolite as well as ordinary zeolite effectively decreased the FDC of exchangeable Cd and increased the FDC of Fe-Mn oxide fraction. The FDC of soil Cd from 0 d to 28 d was deceased at first, then increased and tended to be stable, and finally increased. At the end of incubation, the FDC of soil exchangeable Cd decreased from 72.0%-88.0% to 30.0%-66.4%. Exchangeable fraction Cd was the most dominant Cd fraction in soil during the whole incubation. The results in pot experiment indicated that the application of nano zeolite and ordinary zeolite decreased the concentration and FDC of soil exchangeable Cd, and concurrently the concentration and FDC of Cd in carbonate, Fe-Mn oxide, organic matter and residual fraction were increased. The lowest EX-Cd was observed in the treatment with high dose of nano zeolite (20 g · kg⁻¹). The FDC of exchangeable Cd showed significant negative relationship with the soil pH (P Cd concentration in shoot and root of cabbage (P Cd, respectively; FDC of exchangeable Cd decreased by 16.3%-47.7% and 16.2%-46.7%; Cd concentration in each tissues of cabbage decreased by 1.0%-75.0% and 3.8%-53.2%, respectively. Moreover, the reduction effect of nano zeolite on soil and plant Cd was better than that of ordinary zeolite. The growth of cabbage was stimulated by low and medium zeolite doses (≤ 10 g · kg⁻¹), while inhibited by high zeolite doses (20 g · kg⁻¹). Compared to ordinary zeolite, the biomass of Chinese cabbage was significantly

  6. [Effect of Nano Zeolite on Chemical Fractions of Cd in Soil and Its Uptake by Cabbage].

    Science.gov (United States)

    Xiong, Shi-juan; Xu, Wei-hong; Xie, Wen-wen; Chen, Rong; Chen, Yong-qin; Chi, Sun-lin; Chen, Xu- gen; Zhang, Jin-zhong; Xiong, Zhi-ting; Wang, Zheng-yin; Xie, De-ti

    2015-12-01

    Incubation experiments were carried out to investigate the influence of different nano zeolite (NZ) and ordinary zeolite (OZ) levels(0, 5, 10 and 20 g · kg⁻¹) on the change trends in fraction distribution coefficient (FDC) of Cd when exposed to different Cadmium (Cd) levels (1, 5, 10 and 15 mg · kg⁻¹), and pot experiments were carried out to investigate their influence on soil Cd fraction and Cd uptake by cabbage. The results in incubation experiments showed that the application of nano zeolite as well as ordinary zeolite effectively decreased the FDC of exchangeable Cd and increased the FDC of Fe-Mn oxide fraction. The FDC of soil Cd from 0 d to 28 d was deceased at first, then increased and tended to be stable, and finally increased. At the end of incubation, the FDC of soil exchangeable Cd decreased from 72.0%-88.0% to 30.0%-66.4%. Exchangeable fraction Cd was the most dominant Cd fraction in soil during the whole incubation. The results in pot experiment indicated that the application of nano zeolite and ordinary zeolite decreased the concentration and FDC of soil exchangeable Cd, and concurrently the concentration and FDC of Cd in carbonate, Fe-Mn oxide, organic matter and residual fraction were increased. The lowest EX-Cd was observed in the treatment with high dose of nano zeolite (20 g · kg⁻¹). The FDC of exchangeable Cd showed significant negative relationship with the soil pH (P < 0.05), and was concurrently extremely positively correlated with Cd concentration in shoot and root of cabbage (P < 0.01). Soil pH increased by 1.8%-45.5% and 6.1%-54.3% in the presence of zeolite when exposed to 5 mg · kg⁻¹ 1 and Cd, respectively; FDC of exchangeable Cd decreased by 16.3%-47.7% and 16.2%-46.7%; Cd concentration in each tissues of cabbage decreased by 1.0%-75.0% and 3.8%-53.2%, respectively. Moreover, the reduction effect of nano zeolite on soil and plant Cd was better than that of ordinary zeolite. The growth of cabbage was stimulated by low and

  7. Chemical properties and antioxidant activity of exopolysaccharides fractions from mycelial culture of Inonotus obliquus in a ground corn stover medium.

    Science.gov (United States)

    Xiang, Yuling; Xu, Xiangqun; Li, Juan

    2012-10-15

    The medicinal mushroom Inonotus obliquus has been a folk remedy for a long time in East-European and Asian countries. We first reported the enhancement in production and antioxidant activity of exopolysaccharides by I. obliquus culture under lignocellulose decomposition. In this study, the two different sources of exopolysaccharides from the control medium and the lignocellulose (corn stover) containing medium by I. obliquus in submerged fermentation were fractionated and purified by chromatography. The exopolysaccharides from the corn stover-containing medium presented significantly stronger hydroxyl and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity than the control. Three fractions from the control medium and the corn stover-containing medium were isolated respectively. The fraction of DEPL3 from the corn stover-containing medium with the highest protein content (38.3%), mannose content (49.6%), and the lowest molecular weight (29 kDa) had the highest antioxidant activity with the lowest IC50 values. In conclusion, lignocellulose decomposition changed the chemical characterisation and significantly enhanced the antioxidant activity of exopolysaccharide fractions.

  8. Chemical properties and antioxidant activity of exopolysaccharides fractions from mycelial culture of Inonotus obliquus in a ground corn stover medium.

    Science.gov (United States)

    Xiang, Yuling; Xu, Xiangqun; Li, Juan

    2012-10-15

    The medicinal mushroom Inonotus obliquus has been a folk remedy for a long time in East-European and Asian countries. We first reported the enhancement in production and antioxidant activity of exopolysaccharides by I. obliquus culture under lignocellulose decomposition. In this study, the two different sources of exopolysaccharides from the control medium and the lignocellulose (corn stover) containing medium by I. obliquus in submerged fermentation were fractionated and purified by chromatography. The exopolysaccharides from the corn stover-containing medium presented significantly stronger hydroxyl and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity than the control. Three fractions from the control medium and the corn stover-containing medium were isolated respectively. The fraction of DEPL3 from the corn stover-containing medium with the highest protein content (38.3%), mannose content (49.6%), and the lowest molecular weight (29 kDa) had the highest antioxidant activity with the lowest IC50 values. In conclusion, lignocellulose decomposition changed the chemical characterisation and significantly enhanced the antioxidant activity of exopolysaccharide fractions. PMID:23442636

  9. Simplifying Chemical Reactor Design by using Molar Quantities Instead of Fractional Conversion.

    Science.gov (United States)

    Brown, Lee F.; Falconer, John L.

    1987-01-01

    Explains the advantages of using molar quantities in chemical reactor design. Advocates the use of differential versions of reactor mass balances rather than the integrated forms. Provides specific examples and cases to illustrate the principles. (ML)

  10. Chemical and cellular antioxidative properties of threadfin bream (Nemipterus spp.) surimi byproduct hydrolysates fractionated by ultrafiltration.

    Science.gov (United States)

    Wiriyaphan, Chompoonuch; Xiao, Hang; Decker, Eric A; Yongsawatdigul, Jirawat

    2015-01-15

    Protein hydrolysate from frame, bone and skin (FBSH) of threadfin bream was prepared using Virgibacillus sp. SK33 proteinase and fractionated using sequential ultrafiltration membranes with molecular weight cut-offs (MWCO) of 30, 5 and 1 kDa, respectively. Four fractions, namely FBSH-I (>30 kDa), FBSH-II (5-30 kDa), FBSH-III (1-5 kDa), and FBSH-IV (<1 kDa), were obtained. All fractions were rich in Lys, Glu/Gln, Gly, Pro, Ala, Asp/Asn, and Arg. FBSH-III and FBSH-IV showed the highest surface hydrophobicity measured by 8-anilino-1-naphthalenesulfonic acid (ANS) probe (p<0.05). FBSH-III showed the highest antioxidant activity and cytoprotective effects against tert-butyl hydroperoxide (TBHP)-induced cytotoxicity of Caco-2 cells. In addition, FBSH-III inhibited lactate dehydrogenase (LDH) leakage and intracellular reactive species (ROS) production in a dose-dependent manner. FBSH-III retained antioxidant activity and cytoprotective capacity after in vitro simulated gastrointestinal digestion. These results suggested that FBSH-III might potentially be nutraceutical peptides with antioxidative properties. PMID:25148952

  11. Comparison of Chemical Characteristics of High Oleic Acid Fraction of Moringa oleifera Oil with Some Vegetable Oils

    Directory of Open Access Journals (Sweden)

    F. Rahman1

    2014-06-01

    Full Text Available Chemical characteristics of High oleic acid fraction (HOF of Moringa oleifera oil (MOO was compared with sunflower, soybean and canola oils. HOF of MOO was obtained by dry fractionation at 0oC. Iodine value and C18:1 in HOF increased from 61.55 to 82.47 points and 70.29% to 81.15%, respectively. Cloud point of HOF was 1.1oC as compared to 10.2oC in MOO. The induction period of HOF was greater than all the vegetable oils tested in this investigation. HOF can be used as a source of edible oil with better health attributes and superior storage stability.

  12. Chemical extraction methods for assessment of phytoavailable fractions of elements in soils

    International Nuclear Information System (INIS)

    This study develops extraction methods of phytoavailable fractions of elements in soil for precise estimation of soil-to-plant transfer of radionuclides released from nuclear facilities, such as a reprocessing plant in Rokkasho. The soil-to-plant transfer factor based on the total concentration in soil is generally scattered over a few orders of magnitude. This large variance is likely attributable to ignorance of phytoavailability of radionuclides in soil. The transfer factor based on phytoavailable fractions of the radionuclides extracted from soil is expected to allow more precise estimation of their soil-to-plant transfer. Plant samples cultivated in experimental pots and actual fields were used for investigation. Soil samples collected from 19 agricultural fields in Aomori Prefecture were adapted for the pot experiment. We extracted 40 elements from the soil samples using pure water, 0.01 M HNO3, 1 M NH4OAc or 1 M NH4NO3, and analyzed their concentrations in the extracts. Their contents in the plant samples were determined, and their relations with the concentrations in the extracts were investigated. We had previously studied the relations using Komatsuna (Brassica rapa L. va. perviridis) in fiscal 2004, and reported the following results. The concentrations of Zn and lanthanide elements in the 0.01 M HNO3, 1 M CH3COONH4 and 1 M NH4NO3 extracts had significant positive correlations with those in the plants. Therefore, these extraction methods were suitable for estimation of phytoavailable fractions for the elements. Ratios of Sr/Ca in the NH4OAc extracted fraction also showed a significant correlation with the plant Sr concentrations. The transfer factors based on the ratios were confirmed to explain the Sr concentration in the Komatsuna samples collected from the actual fields, and they showed good agreement. We carried out the same experiment using orchardgrass (Dactylis glomerata), red clover (Trifolium pratense L.) and radish (Raphanus sativus L.) in

  13. THE CHEMICAL COMPOSITION ASSESSMENT OF THE FETEASCĂ NEAGRĂ GRAPE POMACE AND ITS FRACTIONS OBTAINED FROM WINE INDUSTRY IN DIFFERENT YEARS

    Directory of Open Access Journals (Sweden)

    Pascariu Mariana Silvia

    2015-12-01

    Full Text Available The aim of the hereby study was to analyze and to compare the chemical content of the grape pomace and its fractions: skins and seeds from the red grape variety Fetească neagră (from Iași area, obtained in different years 2013 and 2014 respectively, from the winemaking process. Measurements targeted the dry matter content (DM%, organic matter (OM%, crude ash (CA%, crude protein (CP%, crude fat (EE%, crude fiber (CF%, neazotate extractive substances (SEN%, total polyphenols (TP% and tannins (Ta%. The results obtained showed significant differences in the chemical composition in favour of the grape pomace obtained in the 2014 climatic conditions: in the case of the seed for the content of DM%, SEN%, TP% and Ta%, in the case of the skins for the content of DM%, OM%, CF%, TP%, Ta% and in the case of the grape pomace for the content of DM%, OM%, CF%, SEN%, TP%, and Ta%. Comparative analysis of the chemical composition showed an annual variation of the chemical components, which may be due to climatic conditions and winemaking process. Therefore, an annual chemical quality assessment of the grape pomace is necessary, for the efficient use in the animal feed.

  14. Modeling deuterium fractionation in cold and warm molecular environments with large chemical networks

    CERN Document Server

    Albertsson, T; Henning, Th

    2013-01-01

    Observations of deuterated species have long proven essential to probe properties and thermal history of various astrophysical environments. We present an elaborated chemical model that includes tens of thousands of reactions with multi-deuterated species, both gas-phase and surface, in which the most recent information on deuterium chemistry is implemented. A detailed study of the chemical evolution under wide range of temperatures and densities typical of cold molecular cores, warm protostellar envelopes, and hot cores/corinos is performed. We consider two cases of initial abundances, with 1) mainly atomic composition and all deuterium locked in HD, and 2) molecular abundances accumulated at 1 Myr of the evolution of a cold prestellar core. We indicate deuterated species that are particularly sensitive to temperature gradients and initial chemical composition. Many multiply-deuterated species produced at 10 K by exothermic ion-molecule chemistry retain large abundances even when temperature rises above 100 ...

  15. Chemical composition of Sacha Inchi (Plukenetia volubilis L.) seeds and characteristics of their lipid fraction

    OpenAIRE

    Jiménez, Álvaro; Rosada, Lina María; Gutiérrez, Luis Felipe

    2011-01-01

    The seeds of Sacha inchi (Plukenetia volubilis L.) from Colombia were analyzed for their main chemical composition. Sacha inchi seeds (SIS) were rich in oil (41.4%) and protein (24.7%). The main minerals present in SIS were potassium (5563.5 ppm), magnesium (3210 ppm) and calcium (2406 ppm). A fatty acid analysis revealed that a-linolenic (50.8%) and linoleic (33.4%) acids were the main fatty acids in Sacha inchi oil (SIO). The lipid fractionation of SIO, obtained by solid phase extraction, y...

  16. A chemical model for generating the sources of mare basalts - Combined equilibrium and fractional crystallization of the lunar magmasphere

    Science.gov (United States)

    Snyder, Gregory A.; Taylor, Lawrence A.; Neal, Clive R.

    1992-01-01

    A chemical model for simulating the sources of the lunar mare basalts was developed by considering a modified mafic cumulate source formed during the combined equilibrium and fractional crystallization of a lunar magma ocean (LMO). The parameters which influence the initial LMO and its subsequent crystallization are examined, and both trace and major elements are modeled. It is shown that major elements tightly constrain the composition of mare basalt sources and the pathways to their creation. The ability of this LMO model to generate viable mare basalt source regions was tested through a case study involving the high-Ti basalts.

  17. Comprehensive comparison of the chemical and structural characterization of landfill leachate and leonardite humic fractions.

    Science.gov (United States)

    Tahiri, Abdelghani; Richel, Aurore; Destain, Jacqueline; Druart, Philippe; Thonart, Philippe; Ongena, Marc

    2016-03-01

    Humic substances (HS) are complex and heterogeneous mixtures of organic compounds that occur everywhere in the environment. They represent most of the dissolved organic matter in soils, sediments (fossil), water, and landfills. The exact structure of HS macromolecules has not yet been determined because of their complexity and heterogeneity. Various descriptions of HS are used depending on specific environments of origin and research interests. In order to improve the understanding of the structure of HS extracted from landfill leachate (LHS) and commercial HS from leonardite (HHS), this study sought to compare the composition and characterization of the structure of LHS and HHS using elemental composition, chromatographic (high-performance liquid chromatography (HPLC)), and spectroscopic techniques (UV-vis, FTIR, NMR, and MALDI-TOF). The results showed that LHS molecules have a lower molecular weight and less aromatic structure than HHS molecules. The characteristics of functional groups of both LHS and HHS, however, were basically similar, but there was some differences in absorbance intensity. There were also less aliphatic and acidic functional groups and more aromatic and polyphenolic compounds in the humic acid (HA) fraction than in the fulvic acid (FA) and other molecules (OM) fractions of both origins. The differences between LHS and HHS might be due to the time course of humification. Combining the results obtained from these analytical techniques cold improve our understanding of the structure of HS of different origins and thus enhance their potential use. PMID:26781101

  18. Chemical attributes, total organic carbon stock and humified fractions of organic matter soil submitted to different systems of sugarcane management

    Directory of Open Access Journals (Sweden)

    Jean Sérgio Rosset

    2014-10-01

    Full Text Available Mechanized harvesting maintenance of trash from cane sugar and soil application of waste as vinasse and filter cake can improve the system of crop yield. Thus, this study aimed to evaluate the changes in the chemical, the stock of total organic carbon and humified organic matter fractions in an Oxisol cultivated with cane sugar with the following management systems: with sugarcane vinasse application (CCV, without application of burnt cane waste (CQS, with burnt cane vinasse application (CQV, with application of burnt cane filter cake (CQTF and burnt cane with joint application of vinasse and filter cake (CQVTF. For reference we used an area of natural vegetation (NV, Cerrado sensu stricto. Treatment CQVTF showed improvement in soil chemical properties, increased inventory levels of total organic carbon – TOC (values ranging from 21.28 to 40.02 Mg ha-1 and humified fractions of soil organic matter in relation to other treatments. The CQS area at a depth of 0-0.05 m, showed the greatest losses of soil TOC stocks (56.3% compared to NV. The adoption of management presented CCV and chemical attributes of the soil TOC stocks equivalent to those observed in areas with CQV CQTF and despite the short period of adoption (3 years. The TOC correlated with the sum of bases (r = 0.76 **, cation exchange capacity (r = 0.59 ** and base saturation (r = 0.63 **, while the humic acids (r = 0.40 ** fulvic acids (r = 0.49 ** and humin (r = 0.59 ** correlated with the cation exchange capacity of the soil. These results indicate that the preservation of trash in the management of cane sugar added to the application of vinasse and filter cake increases the TOC stocks promoting improvement in soil chemical properties.

  19. Identification of compounds in heavy fuel oil that are chronically toxic to rainbow trout embryos by effects-driven chemical fractionation.

    Science.gov (United States)

    Adams, Julie; Bornstein, Jason M; Munno, Keenan; Hollebone, Bruce; King, Thomas; Brown, R Stephen; Hodson, Peter V

    2014-04-01

    The present study isolated and identified compounds in heavy fuel oil 7102 (HFO 7102) that are bioavailable and chronically toxic to rainbow trout embryos (Oncorhynchus mykiss). An effects-driven chemical fractionation combined the chemical separation of oil with toxicity testing and chemical analyses of each fraction to identify the major classes of compounds associated with embryo toxicity. Toxicity was assessed with 2 exposure methods, a high-energy chemical dispersion of oil in water, which included oil droplets in test solutions, and water accommodated fractions which were produced by oiled gravel desorption columns, and which did not contain visible oil droplets. Fractions of HFO with high concentrations of naphthalenes, alkanes, asphaltenes, and resins were nontoxic to embryos over the range of concentrations tested. In contrast, fractions enriched with 3- to 4-ringed alkyl polycyclic aromatic hydrocarbons (PAHs) were embryotoxic, consistent with published studies of crude oils and individual alkyl PAHs. The rank order of fraction toxicity did not vary between the exposure methods and was consistent with their PAH content; fractions with higher-molecular weight alkyl PAHs were the most toxic. Exposure of juvenile trout to most fractions of HFO induced higher activities of cytochrome P450 enzymes, with a rank order of potency that varied with exposure method and differed somewhat from that of embryotoxicity. Induction reflected the bioavailability of PAHs but did not accurately predict embryotoxicity.

  20. High Resolution Gamma Ray Tomography and its Application to the Measurement of Phase Fractions in Chemical Reactors

    Science.gov (United States)

    Hampel, Uwe; Bieberle, Andre; Schleicher, Eckhard; Hessel, Günther; Zippe, Cornelius; Friedrich, Hans-Jürgen

    2007-06-01

    We applied gamma ray tomography to the problem of phase fraction measurement in chemical reactors. Therefore, we used a new tomography device that is operated with a Cs-137 source and a high resolution gamma ray detector. One application example is the reconstruction of the fluid distribution and the measurement of radial gas fraction profiles in a laboratory scale stirred vessel. The tomograph was used to obtain radiographic projections of the averaged gamma ray attenuation for different stirrer speeds along the height of the vessel. With tomographic reconstruction techniques we calculated the angularly averaged radial distribution of the attenuation coefficient for as many as 150 single cross-sectional planes and synthesised from this data set the axial and radial fluid distribution pattern. Further, we exemplarily reconstructed the radial gas fraction distributions induced by the stirrer in the area of the stirrer blades. In a second application the gamma ray measurement system was used to visualise gas inclusions in a water cleaning column that is used to remove hazardous heavy metal species from water.

  1. Pyrolysis temperature affects phosphorus transformation in biochar: Chemical fractionation and (31)P NMR analysis.

    Science.gov (United States)

    Xu, Gang; Zhang, You; Shao, Hongbo; Sun, Junna

    2016-11-01

    Phosphorus (P) recycling or reuse by pyrolyzing crop residue has recently elicited increased research interest. However, the effects of feedstock and pyrolysis conditions on P species have not been fully understood. Such knowledge is important in identifying the agronomic and environmental uses of biochar. Residues of three main Chinese agricultural crops and the biochars (produced at 300°C-600°C) derived from these crops were used to determine P transformations during pyrolysis. Hedley sequential fractionation and (31)P NMR analyses were used in the investigation. Our results showed that P transformation in biochar was significantly affected by pyrolysis temperature regardless of feedstock (Wheat straw, maize straw and peanut husk). Pyrolysis treatment transformed water soluble P into a labile (NaHCO3-Pi) or semi-labile pool (NaOH-Pi) and into a stable pool (Dil. HCl P and residual-P). At the same time, organic P was transformed into inorganic P fractions which was identified by the rapid decomposition of organic P detected with solution (31)P NMR. The P transformation during pyrolysis process suggested more stable P was formed at a higher pyrolysis temperature. This result was also evidenced by the presence of less soluble or stable P species, such as such as poly-P, crandallite (CaAl3(OH)5(PO4)2) and Wavellite (Al3(OH)3(PO4)2·5H2O), as detected by solid-state (31)P NMR in biochars formed at a higher pyrolysis temperature. Furthermore, a significant proportion of less soluble pyrophosphate was identified by solution (2%-35%) and solid-state (8%-53%) (31)P NMR, which was also responsible for the stable P forms at higher pyrolysis temperature although their solubility or stability requires further investigation. Results suggested that a relatively lower pyrolysis temperature retains P availability regardless of feedstock during pyrolysis process. PMID:27343937

  2. Chemical characterization and genotoxic potential related to boiling point for fractionally distilled SRC-I coal liquids

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, B.W.; Pelroy, R.A.; Mahlum, D.D.

    1982-07-01

    This report summarizes selected research efforts oriented toward ameliorating the genotoxic potential of direct coal liquefaction materials through modification or optimization of process conditions. The studies described were conducted to evaluate the utility of optimized distillation for coal liquids from the SRC-I process. SRC-I process solvent was distilled into 50/sup 0/F-range boiling point (bp) cuts. Analysis of amino-PAH (APAH) showed that mutagenic APAHs containing 3 or more rings were found primarily in fractions boiling above 750/sup 0/F. Three microbial tester strains were used to screen for genetically active agents in the SRC-I distillate bp cuts. Reverse mutation with the Ames tester strain TA98 demonstrated that mutagens were concentrated in the bp cuts boiling above 700/sup 0/F. For this tester strain most of the genetic activity in these distillates was attributable to chemical fractions enriched in APAH having 3 or more rings. Mutagenicity data obtained with TA98 was in good agreement with sk in carcinogenesis results from the mouse-skin initiation/promotion (in vivo) test system. The strongest response in the forward mutation assay did not occur in the most carcinogenically active fractions. Results of initiation/promotion experiments used to measure the relative potency of bp cuts as initiators of mouse skin carcinogenesis again showed that fractions boiling above 750/sup 0/F. Compounds reaching their highest concentrations in the highest boiling and most carcinogenically active cut included known carcinogens such as benzo(a)pyrene and dimethyl benzanthracene. Thus, all biomedical test results indicate that consideration should be given to conducting distillation so as to minimize, in the distillate product, the concentrations of those biologically active compounds found in cuts boiling above 700/sup 0/C.

  3. Can a fractionally crystallized magma ocean explain the thermo-chemical evolution of Mars?

    CERN Document Server

    Plesa, A -C; Breuer, D

    2014-01-01

    The impact heat accumulated during the late stage of planetary accretion can melt a significant part or even the entire mantle of a terrestrial body, giving rise to a global magma ocean. [...] Assuming fractional crystallization of the magma ocean, dense cumulates are produced close to the surface, largely due to iron enrichment in the evolving magma ocean liquid (Elkins-Tanton et al., 2003). A gravitationally unstable mantle thus forms, which is prone to overturn. We investigate the cumulate overturn and its influence on the thermal evolution of Mars using mantle convection simulations in 2D cylindrical geometry. We present a suite of simulations using different initial conditions and a strongly temperature-dependent viscosity. We assume that all radiogenic heat sources have been enriched during the freezing-phase of the magma ocean in the uppermost 50 km and that the initial steam-atmosphere created by the degassing of the freezing magma ocean was rapidly lost, implying that the surface temperature is set t...

  4. Chemical fractionations in meteorites. VIII - Iron meteorites and the cosmochemical history of the metal phase

    Science.gov (United States)

    Kelly, W. R.; Larimer, J. W.

    1977-01-01

    The chemical composition of the metal phase of iron meteorites is traced through an idealized traditional history from condensation, oxidation, and accretion in the nebula to melting, segregation, and freezing in a parent body, considering the following fifteen elements: Au, Co, Cu, Fe, Ga, Ge, Ir, Mo, Ni, Os, Pd, Pt, Re, Rh, and Ru. Twelve iron meteorite groups resolved by Scott and Wasson (1975) are considered in the framework of cosmochemical historical analysis. The parent bodies of five of these groups seem to have had a traditional history. The others seem to have had more unusual histories. For example, the composition of the metal in group IVB matches that predicted for the metal condensate at 1270 K, implying accretion at high temperatures; and the metal in group IVA has a composition indicative of aggregates undergoing progressive stages of partial melting.

  5. Trace element distribution in different chemical fractions of False Bay sediments

    International Nuclear Information System (INIS)

    Trace metals in the aquatic environment are generally concentrated on solid geochemical phases which eventually become incorporated into estuarine and marine sediments. The mechanism of trace metal concentration is believed to be adsorption on various geochemical phases, such as hydrous metal oxides, clays and organic matter. Metals in estuarine sediments can thus be expected to be partitioned between different phases, depending on the concentration of the phase and the strength of the adsorption bond. The bioavailability of sediment-bound metals to deposit-feeding organisms will depend on trace metal partitioning and the kinetics of biological metal uptake from each geochemical phase. The major objective of this study was to establish an analytical procedure involving sequential chemical extractions for the partitioning of particulate trace metals in sediment samples, collected from False Bay. Eight metals were examined, i.e. Cd, Cu, Cr, Fe, Mn, Ni, Pb and Zn. X-ray diffraction was also used in the study

  6. Wintertime chemical compositions of coarse and fine fractions of particulate matter in Bolu, Turkey.

    Science.gov (United States)

    Öztürk, Fatma; Keleş, Melek

    2016-07-01

    Coarse (particulate matter (PM)2.5-10) and fine (PM2.5) fraction of PM samples were collected between December 2014 and February 2015 at an urban sampling site located at the Bolu plain, of the western Black Sea region of Turkey. The collected samples were analyzed in terms of metals (Al, As, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Pb, S, Si, Ti, V, and Zn); elemental carbon (EC); and organic carbon (OC). Elevated concentrations measured in this wintertime study were ∼7.8 μg/m(3) in sum of PM2.5-10 and PM2.5 for SO4 (2-) and ∼59.9 μg/m(3) in PM2.5 for OC. The contributions of primary and secondary OC (POC and SOC, respectively) to total OC mass were 60 and 40 %, respectively, while contribution of SOC to OC increased by up to 74 % in stable atmospheric conditions. The significantly high OC/EC ratio (∼10.1) found in this study relative to other wintertime studies was attributed to increased emissions from residential heating and lower mixing height observed during the study. Two and three factors were resolved by factor analysis for PM2.5-10 and PM2.5, respectively. Two Saharan dust episodes were observed on 31 January and 1 February, during which crustal PM components such as Mg, Si, and Al increased as much as three times their background concentrations. PMID:27048328

  7. Identification of Lilial as a fragrance sensitizer in a perfume by bioassay-guided chemical fractionation and structure-activity relationships

    DEFF Research Database (Denmark)

    Arnau, E G; Andersen, Klaus Ejner; Bruze, M;

    2000-01-01

    Fragrance materials are among the most common causes of allergic contact dermatitis. The aim of this study was to identify in a perfume fragrance allergens not included in the fragrance mix, by use of bioassay-guided chemical fractionation and chemical analysis/structure-activity relationships...... (SARs). The basis for the investigation was a 45-year-old woman allergic to her own perfume. She had a negative patch test to the fragrance mix and agreed to participate in the study. Chemical fractionation of the perfume concentrate was used for repeated patch testing and/or repeated open application...

  8. Identification of Lilial as a fragrance sensitizer in a perfume by bioassay-guided chemical fractionation and structure-activity relationships.

    Science.gov (United States)

    Arnau, E G; Andersen, K E; Bruze, M; Frosch, P J; Johansen, J D; Menné, T; Rastogi, S C; White, I R; Lepoittevin, J P

    2000-12-01

    Fragrance materials are among the most common causes of allergic contact dermatitis. The aim of this study was to identify in a perfume fragrance allergens not included in the fragrance mix, by use of bioassay-guided chemical fractionation and chemical analysis/structure-activity relationships (SARs). The basis for the investigation was a 45-year-old woman allergic to her own perfume. She had a negative patch test to the fragrance mix and agreed to participate in the study. Chemical fractionation of the perfume concentrate was used for repeated patch testing and/or repeated open application test on the pre-sensitized patient. The chemical composition of the fractions giving a positive patch-test response and repeated open application test reactions was obtained by gas chromatography-mass spectrometry. From the compounds identified, those that contained a "structural alert" in their chemical structure, indicating an ability to modify skin proteins and thus behave as a skin sensitizer, were tested on the patient. The patient reacted positively to the synthetic fragrance p-t-butyl-alpha-methylhydrocinnamic aldehyde (Lilial), a widely used fragrance compound not present in the fragrance mix. The combination of bioassay-guided chemical fractionation and chemical analysis/structure-activity relationships seems to be a valuable tool for the investigation of contact allergy to fragrance materials.

  9. Komposisi Kimiawi dan Fraksinasi Protein Susu Kuda Sumba (THE CHEMICAL COMPOSITION AND PROTEIN FRACTIONATION OF SUMBA MARE’S MILK

    Directory of Open Access Journals (Sweden)

    Annytha Ina Rohi Detha

    2015-05-01

    Full Text Available The aims of this study were to determine both chemical composition and fraction of the proteincompounds of sumba mare’s milk. Determination of the chemical compositions of sumba mare’s milk havedone by analyzing protein content using the Kjeldahl method, fat content using Gerber method, lactosecontent and the total solids content. Identification of antimicrobial compounds of whey proteins in milkusing high performance liquid chromatography (HPLC method. The results showed that the average ofsumba mare’s milk contained protein, fat, lactose and total solids were; 1.82%, 1.67%, 6.48% and 11.37%respectively. The average value of protein and fat in sumba mare’s milk was decrease significantly at fifthmonth of lactation period. Based on identification of antimicrobial compounds using HPLC method, thereare six main peaks with different polarities and retention times. In conclusion, sumba mare’s milk havea balance composition that can be used as a source of nutritious food and the milk likely also has six mainantimicrobial compounds in its whey protein.

  10. Chemical composition and antioxidant-prooxidant potential of a polyphenolic extract and a proanthocyanidin-rich fraction of apple skin.

    Science.gov (United States)

    Mendoza-Wilson, Ana María; Castro-Arredondo, Sergio Ivan; Espinosa-Plascencia, Angélica; Robles-Burgueño, María Del Refugio; Balandrán-Quintana, René Renato; Bermúdez-Almada, María Del Carmen

    2016-02-01

    The apple is a food rich in diverse classes of polyphenols (PP), among which the proanthocyanidins (PCs), which are primarily concentrated in the skin, are one of the most abundant. These compounds are of considerable interest for their possible positive health effects because of their antioxidant properties. However, depending on the classes of PP present (chemical composition) and their relative concentrations in the apple skin, their antioxidant effects vary and some of their components can even generate prooxidant effects. This work determined the chemical composition and antioxidant-prooxidant potential of a polyphenolic extract (PPE) and a proanthocyanidin-rich fraction (PRF) of apple skin, along with the contribution of their most abundant individual compounds, based on their copper chelating ability, ease in reducing peroxidase-generated free radicals and TEAC (Trolox-Equivalent Antioxidant Capacity) assay. For this purpose, chromatographic and colorimetric methods were used. The majority compounds identified in PPE were flavan-3-ols (44.58%), flavonols (42.89%) and dihydrochalcones (11.60%). In PRF, we detected monomers and oligomers from dimers to heptamers, which were composed of 97% (-)-epicatechin and 3% (+)-catechin. The antioxidant potential was notably higher in PRF than in PPE. The (-)-epicatechin monomer and the procyanidin B2 dimer showed more ease in reducing peroxidase-generated free radicals compared to other compounds of the apple skin, whereas phloridzin dihydrochalcone produced prooxidant effects. PMID:27441252

  11. Chemical characterization by GC-MS and phytotoxic potential of non-polar and polar fractions of seeds of Dioteryx odorata (Aubl. Willd. from Venezuelan regions

    Directory of Open Access Journals (Sweden)

    Alberto de J. Oliveros-Bastidas

    2013-01-01

    Full Text Available Dipteryx odorata (Aubl. Willd. is a tall arboreal species native to Central and Northern South America. This paper describes the chemical characterization and phytotoxic potential of polar and non-polar extracts from D. odorata seeds. Structural determinations were accomplished by chemical derivatization and analyzed by GC/MS. The chemical composition of the non-polar fraction (hexane and dichloromethane presented fatty acids as major constituent. Medium polar and polar fractions (ethyl acetate and ethanol: water contained carboxylic acid and high 6,7-Dyhidroxycoumarin-β-D-glucopyranoside content, not previously reported for seeds of D. odorata. Extracts showed a significant level of phytotoxic activity, correlated to the content of coumarin derivatives, predominantly in the polar fraction.

  12. Factors controlling the chemical composition of colloidal and dissolved fractions in soil solutions and the mobility of trace elements in soils

    Science.gov (United States)

    Gangloff, Sophie; Stille, Peter; Schmitt, Anne-Désirée; Chabaux, François

    2016-09-01

    The objectives of this study were to determine the processes and physico-chemical conditions that affect the composition of the soil solutions of a forest soil and to elucidate their impact on the transport of major and trace elements through the colloidal (0.2 μm to 5 kDa) and dissolved (environment. Thus, under anoxic conditions, the soil solution is enriched in Ca, P, Mn and Zn, whereas under oxic conditions it is enriched in Al and Fe. The physico-chemical conditions are more seasonally dependent in the upper soil horizons than in the deeper ones and have an impact on the variability of the chemical composition of the soil solutions. The colloidal and dissolved fractions of the soil solutions were obtained by tangential flow ultra-filtration. The experimental results reveal that nutrients, such as NO3- and P, are primarily in the dissolved fraction and consequently bioavailable; secondary minerals may be dissolved and/or precipitate in the colloidal fraction, such as pyromorphite (Pb5(PO4)3(OH, Cl, F)). The results further indicate that microbial activity influences the composition of the colloidal and dissolved fractions, and possibly enriches the colloidal fraction in Ca, Mn and P, diminishes the concentrations of Pb, V, Cr and Fe in the dissolved fraction, and changes the structure of organic carbon (OC). These results are important for a better understanding of the role of the colloidal and dissolved (pollutants and the bioavailability of nutrients for forested ecosystems.

  13. Antioxidant activity of proanthocyanidins-rich fractions from Choerospondias axillaris peels using a combination of chemical-based methods and cellular-based assay.

    Science.gov (United States)

    Li, Qian; Wang, Xieyi; Chen, Jun; Liu, Chengmei; Li, Ti; McClements, David Julian; Dai, Taotao; Liu, Jiyan

    2016-10-01

    An extract isolated from Choerospondias axillaris peels was separated into five fractions using size-exclusion chromatography. The structural composition and mean degree of polymerization (mDP) of these fractions were then characterized by acid-catalysis followed by HPLC analysis. The antioxidant activity of each fraction was determined using a combination of chemical-based methods (DPPH, ABTS(+) radical scavenging activity, ferric-reducing antioxidant power, and phosphomolybdate assay) and a cellular-based assay. All fractions tested were found to have high total phenolics contents and were rich in proanthocyanidins. The mDP of fractions (F1-F5) ranged from 1.92 to 9.25. When tested by the chemical-based assays, the antioxidant activity of the fractions did not depend on molecular weight of the phenolics. Conversely, when tested by the cellular-based assay the antioxidant activity actually decreased with increasing molecular weight of the proanthocyanidins. These experiments highlight the limitations of using chemical-based assays to establish the antioxidant activity of proanthocyanidins within biological systems. PMID:27132855

  14. Chemical fractionation of the waste fuels - A comparison of methods; Kemisk fraktionering av avfallsbraenslen - En jaemfoerelse av metoder

    Energy Technology Data Exchange (ETDEWEB)

    Pettersson, Anita; Claesson, Frida

    2009-07-01

    Striving to improve the waste handling in an energy and environmental manner has led to an increased flow of waste fractions interesting for energy recovery by combustion, both for heat and power production. The increased flow of various waste fractions with varying chemical compositions results in new demands on the combustion plants. This because operational problems, such as bed sintering, corrosion and deposit formation resulting in expensive shut downs can be caused by relatively small changes in the fuel stream. It is primarily alkali metals in combination with chlorine that cause problems like fouling and corrosion. To avoid these problems, tools for characterization of these fuels to predict combustion processes are needed. Two such tools are the Aabo- and the CEN/TS 15105 methods which both are chemical characterization methods based on leaching. The Aabo-method is a more advanced method and also more time consuming compared to the CEN/TS 15105-method. These methods aim to dissolve and identify the compounds that are reactive during combustion and therefore able to cause combustion problems. Both these methods are developed for the characterization of biofuels but only the Aabo-method has been evaluated for waste fuels. The aim of this study was to evaluate the two methods by characterization of six waste fuels with different composition. In addition also four more homogeneous fuels: coal, straw, wood pellets and municipal sewage sludge. The analyses showed that the Aabo-method gave a more clear picture of the reactive elements in the waste fuel in comparison to the CEN/TS 15105-method. An advantage with the Aabo-method is also that the solid rest obtained after the leaching is analysed giving an element balance of the sample without having to make assumptions. The comparison of the methods showed that the CEN/TS 15105-method does not dissolve large parts of the available calcium in the waste fuel resulting in a large underestimation of the reactive

  15. Chemical characterization of the inorganic fraction of aerosols and mechanisms of the neutralization of atmospheric acidity in Athens, Greece

    Directory of Open Access Journals (Sweden)

    E. T. Karageorgos

    2007-06-01

    Full Text Available The PM10 mass concentration levels and inorganic chemical composition were determined on 12-h resolution sampling during August 2003 and March 2004, in the centre of Athens, Greece. The August 2003 campaign mean PM10 mass concentration, obtained by Beta Attenuation at 5 m above ground in Athinas Street, was 56 μg m−3 while the corresponding value for March 2004 was 92 μg m−3. In both campaigns the E.U. imposed daily limit of 50 μg m−3 was exceeded on several days. During the March campaign, in Athinas Street, additionally obtained DSFU-PM10 (PM10-2.5+PM2.5 gravimetric mass concentrations (mean: 121 μg m−3 in the "breathing zone", at 1.5 m above ground were significantly higher compared to the respective mean PM10 mass concentrations obtained by the same method at 25 m above ground, in a second site (AEDA; mean: 86 μg m−3 also in the centre of the city. The above findings suggest that, for a realistic estimation of the exposure of citizens to particulate matter, PM10 sampling in the "breathing zone" (1.5–3 m above ground is necessary. Such data are presented for the first time for the centre of Athens. In both campaigns, calcium was found to be the predominant component of the coarse fraction while crust-related aluminosilicates and iron were the other major components. The above elements constitute the most important components of the fine fraction, together with the predominant sulphur. All toxic metals were found in concentrations below the established air quality limits, and most of them in lower concentrations compared to older studies. Lead in particular, appeared mostly in the fine fraction and in very low concentrations compared to studies dating more than a decade back. The predominant ions of the coarse fraction have been found to be Ca2+, NO3, Na

  16. Chemical fractionation and speciation modelling for optimization of ion-exchange processes to recover palladium from industrial wastewater.

    Science.gov (United States)

    Folens, K; Van Hulle, S; Vanhaecke, F; Du Laing, G

    2016-01-01

    Palladium is used in several industrial applications and, given its high intrinsic value, intense efforts are made to recover the element. In this hydrometallurgic perspective, ion-exchange (IEX) technologies are principal means. Yet, without incorporating the chemical and physical properties of the Pd present in real, plant-specific conditions, the recovery cannot reach its technical nor economic optimum. This study characterized a relevant Pd-containing waste stream of a mirror manufacturer to provide input for a speciation model, predicting the Pd speciation as a function of pH and chloride concentration. Besides the administered neutral PdCl2 form, both positively and negatively charged [PdCln](2-n) species occur depending on the chloride concentration in solution. Purolite C100 and Relite 2AS IEX resins were selected and applied in combination with other treatment steps to optimize the Pd recovery. A combination of the cation and anion exchange resins was found successful to quantitatively recover Pd. Given the fact that Pd was also primarily associated with particles, laboratory-scale experiments focused on physical removal of the Pd-containing flow were conducted, which showed that particle-bound Pd can already be removed by physical pre-treatment prior to IEX, while the ionic fraction remains fully susceptible to the IEX mechanism.

  17. Improving the technology for sulfuric acid purification of BTK fraction at the Makeyevsk Coke Chemical Plant. Sovershenstvovaniye tekhnologii sernokislotnoy ochistki fraktsii BTK na Makeyevskom koksokhimzavode

    Energy Technology Data Exchange (ETDEWEB)

    Korobchanskiy, V.I.; Dobrovolskaya, L.Ye.; Dzekunov, S.N.; Grebennikova, S.S.; Korobchanskiy, Yu.V.

    1983-01-01

    Data are cited about a study of the operation of an installation for sulfuric acid purification of a BTK fraction at the Makeyevsk Coke Chemical Plant (KKhZ). The purification is performed in a radiator mixer with the addition of unsaturated compounds, a piperylene fraction. The capability is shown of producing benzene for nitration of a high quality in existing equipment with an unchanged expenditure of raw material and secondary materials. The following ways for improvement are recommended: reduce the final boiling point of the fraction to 125 to 130 degrees; feed the piperylene fraction in two stages: behind the mixer pump and in the central part of the radiator mixer; and reduce the process length to 6 to 8 minutes.

  18. Fracionamento a seco da farinha de aveia e modificação química da fração rica em amido Dry fractionation of oatmeal and chemical modification of starch rich fraction

    Directory of Open Access Journals (Sweden)

    Ana Paula Daniel

    2006-12-01

    Full Text Available O estudo teve por objetivo obter frações de farinha de aveia enriquecidas em amido e em fibras pelo fracionamento a seco e modificar quimicamente (fosfatação o amido da fração rica neste constituinte, avaliando suas propriedades funcionais. O fracionamento foi efetuado utilizando-se as granulometrias > 300, 212-300, 150-212, e 300 µm e 212-300 µm foram semelhantes, com aumento de aproximadamente 1,5 e 2,7 vezes nos teores de proteína e fibra, e redução de 0,5-0,6 vezes no teor de amido, quando comparadas à farinha integral. As frações 212-150 µm e The objective of this study was to obtain starch and fiber enriched oatmeal fractions through sieving, chemically modifying (phosphorylation the starch enriched fraction, and evaluating its functional properties. Fractionation was performed using > 300, 212-300, 150-212, and 300 µm and 212-300 µm were similar and had increased protein and fiber content (1.5 and 2.7 fold, but reduced starch content (0.5-0.6 fold when compared to whole oatmeal. Fractions 212-150 µm and < 150 µm were similar and had the highest starch content (around 70%. The starch-rich fraction < 150 µm that had the highest yield during sieving (35.5% was phosphorylated with sodium tripolyphosphate at 150-155 °C for 20 and 40 min, yielding 0.39 and 0.32% phosphorus bound, respectively. Cold water binding capacity increased (1.9-3.3 fold, while syneresis at 5 °C or after freezing/thawing was significantly reduced (6-20 and 5-6 fold, respectively in phosphorylated starch fraction when compared to the native starch fraction. Phosphorylation reduced the increase of pasta opacity during storage at 5 °C, which indicates a lower retrogradation tendency. Thus, oatmeal sieving yielded fractions either enriched in fiber and protein or enriched in starch. Moreover, phosphorylation of the starch-rich fraction improved their functional properties, which may increase the potential applicability and economic value of this

  19. Chemical Profile and Biological Potential of Non-Polar Fractions from Centroceras clavulatum (C. Agardh) Montagne (Ceramiales, Rhodophyta)

    OpenAIRE

    Hosana M. Debonsi; Rocha, Otávio P.; Rafael de Felício; Maria Claudia M. Young; Nair S. Yokoya; Sérgio de Albuquerque; Regina Maria B. Cicarelli; Daniela L Ambrósio; Rodrigues, Ana Helena B.

    2011-01-01

    The present study reports the Gas Chromatography-Mass Spectrometry (GC-MS) evaluation of the hexanes and dichloromethane fractions from extracts of the red alga Centroceras clavulatum (C. Agardh) Montagne. Twenty three compounds were identified, totaling ca. 42% of both fractions (0.18 g mass extract). The main constituents of the fractions were hexadecanoic acid (17.6%) and pentadecanoic acid (15.9%). Several secondary metabolites with interesting biological activity, such as (-)-loliolide, ...

  20. Changes in the chemical and physicochemical properties of the solid fraction of cattle slurry during composting using different aeration strategies.

    Science.gov (United States)

    Cáceres, Rafaela; Flotats, Xavier; Marfà, Oriol

    2006-01-01

    Replacement of peat as a growing medium by a renewable material, such as an organic waste, is an issue of concern since harvesting of peat has a considerable environmental impact and, actually, it is a non-renewable resource. Cattle manure is a readily available organic waste, which means that once it goes through the composting process, it can be used as an alternative to peat, specifically, the solid fraction obtained from mechanical liquid-solid separation of cattle slurry (SF). Studies have shown it to be suitable for such uses. The purpose of this study was to detect possible changes in the physicochemical and chemical properties of SF when it is composted using different aeration strategies, with an emphasis on the changes that would make it feasible for use as a substrate. With this aim in mind, an experiment was designed with three aeration strategies that would be used during composting. The first consisted of applying air through a static method (forced ventilation). The second involved improving aeration by adding a bulking agent and a dynamic turning method. In the third strategy, aeration was carried out by turning (control). The results show that the different aeration strategies had a clear effect on the evolution of pH, electrical conductivity (EC), nitrate-N, ammonia-N and bicarbonate content. Nitrification was favored under good aeration conditions using the static composting method, probably due to the greater availability of ammonia-N that was transformed into nitrate-N. In general, the low buffering capacity allowed for a reduction of the pH during the curing stage of composting (in conjunction with low temperatures during this period), a characteristic that favors the use of this compost as a growing medium. We also conclude that measuring bicarbonate levels during composting could be used as an indicator of the possible acidification of the material and as a way of evaluating the level of material aeration.

  1. Changes in the chemical and physicochemical properties of the solid fraction of cattle slurry during composting using different aeration strategies.

    Science.gov (United States)

    Cáceres, Rafaela; Flotats, Xavier; Marfà, Oriol

    2006-01-01

    Replacement of peat as a growing medium by a renewable material, such as an organic waste, is an issue of concern since harvesting of peat has a considerable environmental impact and, actually, it is a non-renewable resource. Cattle manure is a readily available organic waste, which means that once it goes through the composting process, it can be used as an alternative to peat, specifically, the solid fraction obtained from mechanical liquid-solid separation of cattle slurry (SF). Studies have shown it to be suitable for such uses. The purpose of this study was to detect possible changes in the physicochemical and chemical properties of SF when it is composted using different aeration strategies, with an emphasis on the changes that would make it feasible for use as a substrate. With this aim in mind, an experiment was designed with three aeration strategies that would be used during composting. The first consisted of applying air through a static method (forced ventilation). The second involved improving aeration by adding a bulking agent and a dynamic turning method. In the third strategy, aeration was carried out by turning (control). The results show that the different aeration strategies had a clear effect on the evolution of pH, electrical conductivity (EC), nitrate-N, ammonia-N and bicarbonate content. Nitrification was favored under good aeration conditions using the static composting method, probably due to the greater availability of ammonia-N that was transformed into nitrate-N. In general, the low buffering capacity allowed for a reduction of the pH during the curing stage of composting (in conjunction with low temperatures during this period), a characteristic that favors the use of this compost as a growing medium. We also conclude that measuring bicarbonate levels during composting could be used as an indicator of the possible acidification of the material and as a way of evaluating the level of material aeration. PMID:16146687

  2. Chemical Profile and Biological Potential of Non-Polar Fractions from Centroceras clavulatum (C. Agardh Montagne (Ceramiales, Rhodophyta

    Directory of Open Access Journals (Sweden)

    Hosana M. Debonsi

    2011-08-01

    Full Text Available The present study reports the Gas Chromatography-Mass Spectrometry (GC-MS evaluation of the hexanes and dichloromethane fractions from extracts of the red alga Centroceras clavulatum (C. Agardh Montagne. Twenty three compounds were identified, totaling ca. 42% of both fractions (0.18 g mass extract. The main constituents of the fractions were hexadecanoic acid (17.6% and pentadecanoic acid (15.9%. Several secondary metabolites with interesting biological activity, such as (--loliolide, neophytadiene, phytol were identified. In addition, several classes of secondary metabolites, including phenolic compounds (e.g., phenylacetic acid, terpene derivatives, fatty acids, halogenated compound (e.g., 2-chlorocyclohexenol, lignoids, steroids, esters, amides (e.g., hexadecanamide, ketones, carboxylic acids, aldehydes and alcohols were observed. The occurrence of several of these structural classes is described for the first time in this species. The same fractions analyzed by GC-MS, and a separate set of polar fractions, were evaluated against two life cycle stages (epimastigote and trypomastigote forms of the protozoan Trypanosoma cruzi and against phytopatogenic fungi Cladosporium cladosporiodes and C. sphaerospermum. The dichloromethane fraction was active against both T. cruzi forms (epimastigote IC50 = 19.1 μg.mL−1 and trypomastigote IC50 = 76.2 μg.mL−1. The hexanes and ethyl acetate fractions also displayed activity against both fungi species (200 μg by TLC-bioautography.

  3. Quantification and chemical composition of mixed bacteria harvested from solid fractions of rumen digesta: Effects of detachment procedure

    International Nuclear Information System (INIS)

    Four ewes were given two diets made up with two ratios of rolled barley grain and ammonia treated straw (80/20, diet C and 20/80, diet R). The animals were fed twice a day. Two microbial markers, purine bases (PB) and 15N, were used as internal and external markers, respectively. Ruminal bacteria from the liquid (LAB) and solid (SAB) fractions of digesta were harvested from samples obtained at 1 and 6 h after feeding. Bacteria were separated from the particulate material by cooling plus homogenisation (B), by applying tertiary butanol (TB) or methylcellulose (M), or by changes of temperature (CHT). The most effective procedures to remove bacteria from the solid phase were M and CHT treatments. CHT, however, showed the highest level of losses and the lowest total recovery of the bacterial pellet. There were no differences between B and TB treatments in either detaching efficiency or total recovery ratio of adherent bacteria. Ratio of recovery of detached material as a bacterial pellet was 32.0, 32.2, 33.3 and 27.8% for B, TB, M and CHT treatments, respectively. Diet did not interact with detaching efficiency of the experimental treatments although concentration of total N (g/100g OM) and PB (μmol/g OM) were higher in pellets obtained with diet C (9.11 and 125) than with diet R (8.20 and 107), respectively (P < 0.05). Postpandrial differences were not significant. Bacterial samples extracted from the liquid phase contained significantly (P < 0.001) more total N (9.21 vs 8.51), PB (160.5 vs 104.3) and PB/N (1.73 vs 1.23 μmol/mg) than those samples extracted from the solid phase. There were no differences in the chemical composition of the microbial sample after detachment by B, TB and M treatments but the bacterial extract obtained after CHT treatment showed significant changes in PB, N content and PB/N ratio (P < 0.01). (author)

  4. Chemical comparison and acute toxicity of water accommodated fraction (WAF) of source and field collected Macondo oils from the Deepwater Horizon spill.

    Science.gov (United States)

    Faksness, Liv-Guri; Altin, Dag; Nordtug, Trond; Daling, Per S; Hansen, Bjørn Henrik

    2015-02-15

    Two Source oils and five field collected oil residues from the Deepwater Horizon incident were chemically characterized. Water accommodated fractions (WAFs) of the Source oils and two of the field-weathered oils were prepared to evaluate the impact of natural weathering on the chemical composition and the acute toxicity of the WAFs. Toxicity test species representing different tropic levels were used (the primary producer Skeletonema costatum (algae) and the herbivorous copepod Acartia tonsa). The results suggest that the potential for acute toxicity is higher in WAFs from non-weathered oils than WAFs from the field weathered oils. The Source oils contained a large fraction of soluble and bioavailable components (such as BTEX (benzene, toluene, ethyl benzene, xylenes) and naphthalene), whereas in the surface collected oils these components were depleted by dissolution into the water column as the oil rose to the surface and by evaporative loss after reaching the sea surface. PMID:25534626

  5. Factors controlling the chemical composition of colloidal and dissolved fractions in soil solutions and the mobility of trace elements in soils

    Science.gov (United States)

    Gangloff, Sophie; Stille, Peter; Schmitt, Anne-Désirée; Chabaux, François

    2016-09-01

    The objectives of this study were to determine the processes and physico-chemical conditions that affect the composition of the soil solutions of a forest soil and to elucidate their impact on the transport of major and trace elements through the colloidal (0.2 μm to 5 kDa) and dissolved (soil. All experiments were performed with soil solutions obtained using lysimeter plates situated on an experimental spruce parcel of the Strengbach catchment (Northeastern France). The surface samples filtered at 0.2 μm facilitated the examination of the influence of litter decomposition on the chemical composition of the upper soil solutions. The impact of the soils biogeochemical conditions (pH, moisture, temperature, oxic or anoxic conditions) on litter decomposition was also examined. More particularly, the increase in NH4+ and NO2- compounds in some of the soil solutions points to denitrification processes in an anoxic environment. Thus, under anoxic conditions, the soil solution is enriched in Ca, P, Mn and Zn, whereas under oxic conditions it is enriched in Al and Fe. The physico-chemical conditions are more seasonally dependent in the upper soil horizons than in the deeper ones and have an impact on the variability of the chemical composition of the soil solutions. The colloidal and dissolved fractions of the soil solutions were obtained by tangential flow ultra-filtration. The experimental results reveal that nutrients, such as NO3- and P, are primarily in the dissolved fraction and consequently bioavailable; secondary minerals may be dissolved and/or precipitate in the colloidal fraction, such as pyromorphite (Pb5(PO4)3(OH, Cl, F)). The results further indicate that microbial activity influences the composition of the colloidal and dissolved fractions, and possibly enriches the colloidal fraction in Ca, Mn and P, diminishes the concentrations of Pb, V, Cr and Fe in the dissolved fraction, and changes the structure of organic carbon (OC). These results are important

  6. Chemical and rheological properties of a starch-rich fraction from the pulp of the fruit cupuassu (Theobroma grandiflorum)

    International Nuclear Information System (INIS)

    The pulp obtained from the fruit of cupuassu (Theobroma grandiflorum) was extracted with hot aqueous 0.1% citric acid to give fraction 0.1CA-2 in 15% yield. This was the predominant component polysaccharide, 91% of which was composed of starch, by an iodine test and monosaccharide composition, and its 13C NMR spectrum was consistent with that of a high amylose starch. The content of amylose found in fraction 0.1CA-2 was 71%. This value is higher than those of common starches of cereal grains, tubers, roots, and other fruits. The fraction was submitted to rheological examination, gels being prepared on heating with concentrations of 4 to 7% (w/w). A non-Newtonian behavior was observed, and gel viscosity and strength depended on the concentration. The presence of starch, as well as the presence of previously investigated pectin, conferred the high viscosity and gelling capability of the pulp

  7. Chemical and rheological properties of a starch-rich fraction from the pulp of the fruit cupuassu (Theobroma grandiflorum)

    Energy Technology Data Exchange (ETDEWEB)

    Vriesmann, Lucia C.; Silveira, Joana L.M. [Universidade Federal do Parana, Departamento de Bioquimica e Biologia Molecular, CP 19046, CEP 81531-990, Curitiba-PR (Brazil); Petkowicz, Carmen L. de O [Universidade Federal do Parana, Departamento de Bioquimica e Biologia Molecular, CP 19046, CEP 81531-990, Curitiba-PR (Brazil)], E-mail: clop@ufpr.br

    2009-03-01

    The pulp obtained from the fruit of cupuassu (Theobroma grandiflorum) was extracted with hot aqueous 0.1% citric acid to give fraction 0.1CA-2 in 15% yield. This was the predominant component polysaccharide, 91% of which was composed of starch, by an iodine test and monosaccharide composition, and its {sup 13}C NMR spectrum was consistent with that of a high amylose starch. The content of amylose found in fraction 0.1CA-2 was 71%. This value is higher than those of common starches of cereal grains, tubers, roots, and other fruits. The fraction was submitted to rheological examination, gels being prepared on heating with concentrations of 4 to 7% (w/w). A non-Newtonian behavior was observed, and gel viscosity and strength depended on the concentration. The presence of starch, as well as the presence of previously investigated pectin, conferred the high viscosity and gelling capability of the pulp.

  8. The Chemical Speciation and Behavior of Mercury and Selenium in the Insoluble Fraction of Striped Dolphin Liver

    Institute of Scientific and Technical Information of China (English)

    Xiao Rong HU; Hui LI; Yong Xiang ZHANG

    2004-01-01

    Most of the mercury and selenium exist in the insoluble fraction of dolphin liver. After the insoluble fraction was digested by alkaline protease in the presence of 1%SDS, approximately 50% of Hg and Se consisted in the supernatant and the others in the residue. Gel filtration chromatography of the hydrolysate showed that 96% of Hg and 87% of Se were combined with the high molecular weight proteins stably, which cannot be substituted by the complex reagents. Mercury and selenium in the residue were confirmed as HgSe crystal.

  9. Redox activity and in vitro bioactivity of the water-soluble fraction of urban particulate matter in relation to particle size and chemical composition.

    Science.gov (United States)

    Velali, Ekaterini; Papachristou, Eleni; Pantazaki, Anastasia; Choli-Papadopoulou, Theodora; Planou, Styliani; Kouras, Athanasios; Manoli, Evangelia; Besis, Athanasios; Voutsa, Dimitra; Samara, Constantini

    2016-01-01

    Chemical and toxicological characterization of the water-soluble fraction of size-segregated urban particulate matter (PM) (7.2 μm) was carried out at two urban sites, traffic and urban background, during the cold and the warm period. Chemical analysis of the water-soluble PM fraction included ionic species (NO3(-), SO4(2-), Cl(-), Na(+), NH4(+), K(+), Mg(2+), Ca(2+)), water-soluble organic carbon (WSOC), and trace elements (Al, As, Ba, Cd, Cr, Cu, Fe, Pb, Mn, Ni, Zn, Pt, Pd, Rh, Ru, Ir, Ca, and Mg). The dithiothreitol (DTT) assay was employed for the abiotic assessment of the oxidative PM activity. Cytotoxic responses were investigated in vitro by applying the mitochondrial dehydrogenase (MTT) and the lactate dehydrogenase (LDH) bioassays on human lung cells (MRC-5), while DNA damage was estimated by the single cell gel electrophoresis assay, known as Comet assay. The correlations between the observed bioactivity responses and the concentrations of water-soluble chemical PM constituents in the various size ranges were investigated. The results of the current study corroborate that short-term bioassays using lung human cells and abiotic assays, such as the DTT assay, could be relevant to complete the routine chemical analysis and to obtain a preliminary screening of the potential effects of PM-associated airborne pollutants on human health. PMID:26586634

  10. Fractionation, solid-phase immobilization and chemical degradation of long pectin oligogalacturonides. Initial steps towards sequencin of oligosaccharides

    DEFF Research Database (Denmark)

    Guillaumie, Fanny; Justesen, Sune F. L.; Mutenda, Kudzai E.;

    2006-01-01

    were produced in excellent purity (>95%). Elution of OGAs followed by direct analysis of the peak fractions by MALDI-TOF MS. Purified OGAs (DP 5-7) were chemoselectively immobilized onto aminooxy-terminated polyethylene glycol polyacrylamide (PEGA) supports. Solid-phase anchoring took place...

  11. Fractionation, solid-phase immobilization and chemical degradation of long pectin oligogalacturonides. Initial steps towards sequencing of oligosaccharides

    DEFF Research Database (Denmark)

    Guillaumie, Fanny; Justesen, Sune Frederik Lamdahl; Mutenda, K.E.;

    2006-01-01

    were produced in excellent purity (> 95%). Elution of OGAs followed by direct analysis of the peak fractions by MALDI-TOF MS. Purified OGAs (DP 5-7) were chemoselectively immobilized onto aminooxy-terminated polyethylene glycol polyacrylamide (PEGA) supports. Solid-phase anchoring took place...

  12. Chemical fractionation of arsenic and heavy metals in fine particle matter and its implications for risk assessment: A case study in Nanjing, China

    Science.gov (United States)

    Li, Huiming; Wang, Jinhua; Wang, Qin'geng; Qian, Xin; Qian, Yu; Yang, Meng; Li, Fengying; Lu, Hao; Wang, Cheng

    2015-02-01

    A four-step sequential extraction procedure was used to study the chemical fractionation of As and heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in fine particulate matter (PM2.5) collected from Nanjing, China. The mass concentrations of most PM2.5 samples exceeded the 24 h standard (75 μg/m3) recommended by the new national ambient air quality standard of China. The most abundant elements were Fe, Zn and Pb, while As and Cd were present at the lowest concentrations. As, Cd, Cu, Mn, Pb and Zn were mostly present in the two mobile fractions, including the soluble and exchangeable fraction (F1), and carbonates, oxides and reducible fraction (F2). Fe had the highest proportion present in the residual fraction (F4). Relatively high proportions of the metals Ni and Cr were present in the oxidizable and sulfidic fraction (F3). High proportions of Zn, As and Cu and lower proportions of Cd, Cr and Fe were present in the potentially mobile phases. The enrichment factor, contamination factor and risk assessment code were calculated to analyze the main sources and assess the environmental risks of the metals in PM2.5. The carcinogenic risks of As, Cd, Ni and Pb were all lower than the accepted criterion of 10-6, whereas the carcinogenic risks of Cr for children and As and Cr for adults were higher than 10-6. The non-carcinogenic health risk of As and heavy metals because of PM2.5 exposure for children and adults were lower than but close to the safe level of 1.

  13. Effect of Gamma Rays on the Distribution of Toxigenic Fusarium Moulds and Chemical Changes in Whole and Dry Milled Fractions of Wheat

    International Nuclear Information System (INIS)

    The influence of gamma-irradiation on Fusarium-mycotoxins and the chemical composition of whole and dry-milled fractions of wheat grains was investigated. Wheat samples collected from the Egyptian markets were found to be heavily contaminated by, Fusarium graminearum (70-100%), F. moniliforme (40-60%) and F.subglutinilils (10-30%). Fusarium counts in wheat fractions were 1.1-2.7 x 101 CFU/g in flour; 1.1 x 103 to 3.7 X 104 CFU/g in bran and 1.4 x 102 to 1.6 X 103 in shorts. The levels of deoxynivalenol (DON) and zearalenone were generally highest in the bran and lowest in the flour. The levels of DON and zearalenone. in whole wheat samples were generally lower than the levels in the bran and shorts. Irradiation at a dose 5.0 kGy reduced the Fusarium moulds growth greatly relative to unirradiated controls and there was no growth at 7.0 kGy. Application of radiation at 15.0 kGy reduced the levels of DON and zearalenon by less than 1 ppm and Fusarium toxins were eliminated at 20.0 kGy. The chemical composition of the raw and irradiated whole and dry- milled fractions of-wheat grains up to 20.0 kGy was similar

  14. Assessment of heavy metals contamination in sediments from three adjacent regions of the Yellow River using metal chemical fractions and multivariate analysis techniques.

    Science.gov (United States)

    Ma, Xiaoling; Zuo, Hang; Tian, Mengjing; Zhang, Liyang; Meng, Jia; Zhou, Xuening; Min, Na; Chang, Xinyuan; Liu, Ying

    2016-02-01

    Metal chemical fractions obtained by optimized BCR three-stage extraction procedure and multivariate analysis techniques were exploited for assessing 7 heavy metals (Cr, Pb, Cd, Co, Cu, Zn and Ni) in sediments from Gansu province, Ningxia and Inner Mongolia Autonomous Regions of the Yellow River in Northern China. The results indicated that higher susceptibility and bioavailability of Cr and Cd with a strong anthropogenic source were due to their higher availability in the exchangeable fraction. A portion of Pb, Cd, Co, Zn, and Ni in reducible fraction may be due to the fact that they can form stable complexes with Fe and Mn oxides. Substantial amount of Pb, Co, Ni and Cu was observed as oxidizable fraction because of their strong affinity to the organic matters so that they can complex with humic substances in sediments. The high geo-accumulation indexes (I(geo)) for Cr and Cd showed their higher environmental risk to the aquatic biota. Principal component analysis (PCA) revealed that high toxic Cr and Cd in polluted sites (Cd in S10, S11 and Cr in S13) may be contributed to anthropogenic sources, it was consistent with the results of dual hierarchical clustering analysis (DHCA), which could give more details about contributing sources.

  15. Carbon and Nitrogen Mineralization in Relation to Soil Particle-Size Fractions after 32 Years of Chemical and Manure Application in a Continuous Maize Cropping System.

    Science.gov (United States)

    Cai, Andong; Xu, Hu; Shao, Xingfang; Zhu, Ping; Zhang, Wenju; Xu, Minggang; Murphy, Daniel V

    2016-01-01

    Long-term manure application is recognized as an efficient management practice to enhance soil organic carbon (SOC) accumulation and nitrogen (N) mineralization capacity. A field study was established in 1979 to understand the impact of long-term manure and/or chemical fertilizer application on soil fertility in a continuous maize cropping system. Soil samples were collected from field plots in 2012 from 9 fertilization treatments (M0CK, M0N, M0NPK, M30CK, M30N, M30NPK, M60CK, M60N, and M60NPK) where M0, M30, and M60 refer to manure applied at rates of 0, 30, and 60 t ha(-1) yr(-1), respectively; CK indicates no fertilizer; N and NPK refer to chemical fertilizer in the forms of either N or N plus phosphorus (P) and potassium (K). Soils were separated into three particle-size fractions (2000-250, 250-53, and fertilization application, on the accumulation and mineralization of SOC and total N in each fraction. Results showed that long-term manure application significantly increased SOC and total N content and enhanced C and N mineralization in the three particle-size fractions. The content of SOC and total N followed the order 2000-250 μm > 250-53 μm > 53 μm fraction, whereas the amount of C and N mineralization followed the reverse order. In the fertilizers, resulted in increased soil microbial biomass C and N, and a decreased microbial metabolic quotient. Consequently, long-term manure fertilization was beneficial to both soil C and N turnover and microbial activity, and had significant effect on the microbial metabolic quotient. PMID:27031697

  16. Carbon and Nitrogen Mineralization in Relation to Soil Particle-Size Fractions after 32 Years of Chemical and Manure Application in a Continuous Maize Cropping System.

    Directory of Open Access Journals (Sweden)

    Andong Cai

    Full Text Available Long-term manure application is recognized as an efficient management practice to enhance soil organic carbon (SOC accumulation and nitrogen (N mineralization capacity. A field study was established in 1979 to understand the impact of long-term manure and/or chemical fertilizer application on soil fertility in a continuous maize cropping system. Soil samples were collected from field plots in 2012 from 9 fertilization treatments (M0CK, M0N, M0NPK, M30CK, M30N, M30NPK, M60CK, M60N, and M60NPK where M0, M30, and M60 refer to manure applied at rates of 0, 30, and 60 t ha(-1 yr(-1, respectively; CK indicates no fertilizer; N and NPK refer to chemical fertilizer in the forms of either N or N plus phosphorus (P and potassium (K. Soils were separated into three particle-size fractions (2000-250, 250-53, and 250-53 μm > 53 μm fraction, whereas the amount of C and N mineralization followed the reverse order. In the <53 μm fraction, the M60NPK treatment significantly increased the amount of C and N mineralized (7.0 and 10.1 times, respectively compared to the M0CK treatment. Long-term manure application, especially when combined with chemical fertilizers, resulted in increased soil microbial biomass C and N, and a decreased microbial metabolic quotient. Consequently, long-term manure fertilization was beneficial to both soil C and N turnover and microbial activity, and had significant effect on the microbial metabolic quotient.

  17. Isolation, fractionation and identification of chemical constituents from the leaves crude extracts of Mentha piperita L grown in Sultanate of Oman

    Institute of Scientific and Technical Information of China (English)

    Mohammad Amzad Hossain; Seham Salim Al-Hdhrami; Afaf Mohammed Weli; Qasim Al-Riyami; Jamal Nasser Al-Sabahi

    2014-01-01

    Objective: To analyze and identify the chemical compositions of different organic plants crude extracts of Mentha piperita (M. piperita) grown in Sultanate of Oman by gas chromatography-mass spectrometry (GC-MS). Methods: The powder sample was extracted with methanol by using Soxhlet extractor. Methanol crude extracts of M. piperita and its derived fractions of hexane, chloroform, ethyl acetate and butanol were prepared.Results:MS showed that majority of these compounds are bioactive.Conclusions:According to the results of the present study, the plant crude extracts could be Qualitative analyses of various organic plant crude extracts of M. piperita by using GC-used as medicine for the treatment of different diseases. The analysis and identification of the chemical compounds in the plant crude extracts by using GC-MS was the first time.

  18. Characterization of Leached Phosphorus from Soil, Manure, and Manure-Amended Soil by Physical and Chemical Fractionation and Diffusive Gradients in Thin Films (DGT)

    DEFF Research Database (Denmark)

    Glæsner, Nadia; Donner, Erica; Magid, Jakob;

    2012-01-01

    We are challenged to date to fully understand mechanisms controlling phosphorus (P) mobilization in soil. In this study we evaluated physical properties, chemical reactivity, and potential bioavailability of P mobilized in soil during a leaching event and examined how the amounts and properties...... of leached P were influenced by surface application of cattle manure. Leaching experiments on manure itself, and on intact soil columns (14.1 cm inner dia., 25 cm height) before and after manure application, were carried out at an irrigation rate of 1 mm h−1 for 48 h. High concentrations of dissolved...... with manure. Manure particles themselves were also largely retained by the soil. Combined physical (centrifugation) and chemical (molybdate reactiveness) fractionation of leached P showed that leachates in the manure treated soils were dominated by dissolved unreactive P (DUP), mainly originating from manure...

  19. Chemical fingerprint and metabolic profile analysis of ethyl acetate fraction of Gastrodia elata by ultra performance liquid chromatography/quadrupole-time of flight mass spectrometry.

    Science.gov (United States)

    Tang, Chunlan; Wang, Li; Liu, Xinxin; Cheng, Mengchun; Xiao, Hongbin

    2016-02-01

    The chemical fingerprint and metabolic profile of traditional Chinese medicine is very complicated and has been a great challenge. In the present study, chemical fingerprint of ethyl acetate fraction of Gastrodia elata (EtAcGE) and metabolic profile of rat plasma sample after intragastric administration of EtAcGE (2.5g/kg) were investigated using ultra-high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (UPLC/Q-TOF MS). A total of 38 chemical constituents of EtAcGE were identified by comparing their retention time, accurate molecular mass and characteristic fragment ions with those of references, or tentatively characterized by comparing molecular formula, fragment ions with that of known compound or information available in literature. And 40 compounds were detected in dosed rat plasma sample, including 16 prototypes and 24 metabolites underwent metabolic process of glucuronidation, glucosylation, sulfation, methylation, hydroxylation, dehydrogenation or mixed modes. The metabolic "soft spots" was hydroxyl or carboxy group. This is the first research for chemical fingerprint and metabolic profile of EtAcGE, which lay a foundation for the further investigation of EtAcGE.

  20. Chemical fingerprint and metabolic profile analysis of ethyl acetate fraction of Gastrodia elata by ultra performance liquid chromatography/quadrupole-time of flight mass spectrometry.

    Science.gov (United States)

    Tang, Chunlan; Wang, Li; Liu, Xinxin; Cheng, Mengchun; Xiao, Hongbin

    2016-02-01

    The chemical fingerprint and metabolic profile of traditional Chinese medicine is very complicated and has been a great challenge. In the present study, chemical fingerprint of ethyl acetate fraction of Gastrodia elata (EtAcGE) and metabolic profile of rat plasma sample after intragastric administration of EtAcGE (2.5g/kg) were investigated using ultra-high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (UPLC/Q-TOF MS). A total of 38 chemical constituents of EtAcGE were identified by comparing their retention time, accurate molecular mass and characteristic fragment ions with those of references, or tentatively characterized by comparing molecular formula, fragment ions with that of known compound or information available in literature. And 40 compounds were detected in dosed rat plasma sample, including 16 prototypes and 24 metabolites underwent metabolic process of glucuronidation, glucosylation, sulfation, methylation, hydroxylation, dehydrogenation or mixed modes. The metabolic "soft spots" was hydroxyl or carboxy group. This is the first research for chemical fingerprint and metabolic profile of EtAcGE, which lay a foundation for the further investigation of EtAcGE. PMID:26621783

  1. COMPARISON BETWEEN ASPHALTENES (SUB)FRACTIONS EXTRACTED FROM TWO DIFFERENT ASPHALTIC RESIDUES: CHEMICAL CHARACTERIZATION AND PHASE BEHAVIOR

    OpenAIRE

    Silas R. Ferreira; Fabio R. Barreira; Luciana S. Spinelli; Katia Z. Leal; Peter Seidl; Elizabete F. Lucas

    2016-01-01

    Asphaltenes are blamed for various problems in the petroleum industry, especially formation of solid deposits and stabilization of water-in-oil emulsions. Many studies have been conducted to characterize chemical structures of asphaltenes and assess their phase behavior in crude oil or in model-systems of asphaltenes extracted from oil or asphaltic residues from refineries. However, due to the diversity and complexity of these structures, there is still much to be investigated. In this study,...

  2. Polycyclic organic material (POM) in urban air. Fractionation, chemical analysis and genotoxicity of particulate and vapour phases in an industrial town in Finland

    Science.gov (United States)

    Pyysalo, Heikki; Tuominen, Jari; Wickström, Kim; Skyttä, Eija; Tikkanen, Leena; Salomaa, Sisko; Sorsa, Marja; Nurmela, Tuomo; Mattila, Tiina; Pohjola, Veijo

    Polycyclic organic material (POM) was collected by high-volume sampling on filter and on XAD-2 resin from the air of a small industrial town in Finland. Concurrent chemical analysis and the assays for genotoxic activity were performed on the particulate and the vapour phases of ambient air POM and their chemical fractions. Furthermore, correlations between seasonal meteorological parameters and POM concentrations were studied to reveal characteristic POM profiles for various emission sources. The range of total POM concentrations varied from 115 to 380 ng m -3 in late spring and from 17 to 83 ng m -3 in early winter. No direct correlation of ambient POM was seen with the temperature, but rather with the wind direction from various emission sources. Especially the low molecular weight compounds were associated with wind direction from industrial sources. Genotoxic activity, as detected by the Ames Salmonella/microsome test and the SCE assay in CHO cells, was found not only in the paniculate phase samples but also in the vapour phase. The polar fractions of some of the samples showed genotoxic activity, and also direct mutagenicity was observed with both the assay systems; these facts support the significance of compounds other than conventional polycyclic aromatic hydrocarbons (PAH) in the samples.

  3. Long-term combined chemical and manure fertilizations increase soil organic carbon and total nitrogen in aggregate fractions at three typical cropland soils in China.

    Science.gov (United States)

    He, Y T; Zhang, W J; Xu, M G; Tong, X G; Sun, F X; Wang, J Z; Huang, S M; Zhu, P; He, X H

    2015-11-01

    Soil organic carbon (SOC), total nitrogen (TN), microbial biomass carbon (MBC) and nitrogen (MBN) are important factors of soil fertility. However, effects of the combined chemical fertilizer and organic manure or straw on these factors and their relationships are less addressed under long-term fertilizations. This study addressed changes in SOC, TN, MBC and MBN at 0-20 cm soil depth under three 17 years (September 1990-September 2007) long-term fertilization croplands along a heat and water gradient in China. Four soil physical fractions (coarse free and fine free particulate organic C, cfPOC and ffPOC; intra-microaggregate POC, iPOC; and mineral associated organic C, MOC) were examined under five fertilizations: unfertilized control, chemical nitrogen (N), phosphorus (P) and potassium (K) (NPK), NPK plus straw (NPKS, hereafter straw return), and NPK plus manure (NPKM and 1.5NPKM, hereafter manure). Compared with Control, manure significantly increased all tested parameters. SOC and TN in fractions distributed as MOC > iPOC > cfPOC > ffPOC with the highest increase in cfPOC (329.3%) and cfPTN (431.1%), and the lowest in MOC (40.8%) and MTN (45.4%) under manure. SOC significantly positively correlated with MBC, cfPOC, ffPOC, iPOC and MOC (R(2) = 0.51-0.84, P fertilization for improving soil fertility while straw return should take into account climate factors in Chinese croplands. PMID:26119378

  4. Determination of polycyclic aromatic hydrocarbons in fractions in asphalt mixtures using liquid chromatography coupled to mass spectrometry with atmospheric pressure chemical ionization.

    Science.gov (United States)

    Nascimento, Paulo Cicero; Gobo, Luciana Assis; Bohrer, Denise; Carvalho, Leandro Machado; Cravo, Margareth Coutinho; Leite, Leni Figueiredo Mathias

    2015-07-01

    An analytical method using liquid chromatography coupled to mass spectrometry with atmospheric pressure chemical ionization for the determination of polycyclic aromatic hydrocarbons in asphalt fractions has been developed. The 14 compounds determined, characterized by having two or more condensed aromatic rings, are expected to be present in asphalt and are considered carcinogenic and mutagenic. The parameters of the atmospheric pressure chemical ionization interface were optimized to obtain the highest possible sensitivity for all of the compounds. The limits of detection ranged from 0.5 to 346.5 μg/L and the limits of quantification ranged from 1.7 to 1550 μg/L. The method was validated against a diesel particulate extract standard reference material (NIST SRM 1975), and the obtained concentrations agreed with the certified values. The method was applied to asphalt samples after its fractionation according to ASTM D4124 and the method of Green. The concentrations of the seven polycyclic aromatic hydrocarbons quantified in the sample ranged from 0.86 mg/kg for benzo[ghi]perylene to 98.32 mg/kg for fluorene.

  5. Long-term combined chemical and manure fertilizations increase soil organic carbon and total nitrogen in aggregate fractions at three typical cropland soils in China.

    Science.gov (United States)

    He, Y T; Zhang, W J; Xu, M G; Tong, X G; Sun, F X; Wang, J Z; Huang, S M; Zhu, P; He, X H

    2015-11-01

    Soil organic carbon (SOC), total nitrogen (TN), microbial biomass carbon (MBC) and nitrogen (MBN) are important factors of soil fertility. However, effects of the combined chemical fertilizer and organic manure or straw on these factors and their relationships are less addressed under long-term fertilizations. This study addressed changes in SOC, TN, MBC and MBN at 0-20 cm soil depth under three 17 years (September 1990-September 2007) long-term fertilization croplands along a heat and water gradient in China. Four soil physical fractions (coarse free and fine free particulate organic C, cfPOC and ffPOC; intra-microaggregate POC, iPOC; and mineral associated organic C, MOC) were examined under five fertilizations: unfertilized control, chemical nitrogen (N), phosphorus (P) and potassium (K) (NPK), NPK plus straw (NPKS, hereafter straw return), and NPK plus manure (NPKM and 1.5NPKM, hereafter manure). Compared with Control, manure significantly increased all tested parameters. SOC and TN in fractions distributed as MOC > iPOC > cfPOC > ffPOC with the highest increase in cfPOC (329.3%) and cfPTN (431.1%), and the lowest in MOC (40.8%) and MTN (45.4%) under manure. SOC significantly positively correlated with MBC, cfPOC, ffPOC, iPOC and MOC (R(2) = 0.51-0.84, P fertilization for improving soil fertility while straw return should take into account climate factors in Chinese croplands.

  6. Carbon and Nitrogen Mineralization in Relation to Soil Particle-Size Fractions after 32 Years of Chemical and Manure Application in a Continuous Maize Cropping System.

    Science.gov (United States)

    Cai, Andong; Xu, Hu; Shao, Xingfang; Zhu, Ping; Zhang, Wenju; Xu, Minggang; Murphy, Daniel V

    2016-01-01

    Long-term manure application is recognized as an efficient management practice to enhance soil organic carbon (SOC) accumulation and nitrogen (N) mineralization capacity. A field study was established in 1979 to understand the impact of long-term manure and/or chemical fertilizer application on soil fertility in a continuous maize cropping system. Soil samples were collected from field plots in 2012 from 9 fertilization treatments (M0CK, M0N, M0NPK, M30CK, M30N, M30NPK, M60CK, M60N, and M60NPK) where M0, M30, and M60 refer to manure applied at rates of 0, 30, and 60 t ha(-1) yr(-1), respectively; CK indicates no fertilizer; N and NPK refer to chemical fertilizer in the forms of either N or N plus phosphorus (P) and potassium (K). Soils were separated into three particle-size fractions (2000-250, 250-53, and 250-53 μm > 53 μm fraction, whereas the amount of C and N mineralization followed the reverse order. In the soil microbial biomass C and N, and a decreased microbial metabolic quotient. Consequently, long-term manure fertilization was beneficial to both soil C and N turnover and microbial activity, and had significant effect on the microbial metabolic quotient.

  7. Fractional enrichment of proteins using [2-{sup 13}C]-glycerol as the carbon source facilitates measurement of excited state {sup 13}Cα chemical shifts with improved sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Ahlner, Alexandra; Andresen, Cecilia; Khan, Shahid N. [Linköping University, Division of Chemistry, Department of Physics, Chemistry and Biology (Sweden); Kay, Lewis E. [The University of Toronto, Departments of Molecular Genetics, Biochemistry and Chemistry, One King’s College Circle (Canada); Lundström, Patrik, E-mail: patlu@ifm.liu.se [Linköping University, Division of Chemistry, Department of Physics, Chemistry and Biology (Sweden)

    2015-07-15

    A selective isotope labeling scheme based on the utilization of [2-{sup 13}C]-glycerol as the carbon source during protein overexpression has been evaluated for the measurement of excited state {sup 13}Cα chemical shifts using Carr–Purcell–Meiboom–Gill (CPMG) relaxation dispersion (RD) experiments. As expected, the fractional incorporation of label at the Cα positions is increased two-fold relative to labeling schemes based on [2-{sup 13}C]-glucose, effectively doubling the sensitivity of NMR experiments. Applications to a binding reaction involving an SH3 domain from the protein Abp1p and a peptide from the protein Ark1p establish that accurate excited state {sup 13}Cα chemical shifts can be obtained from RD experiments, with errors on the order of 0.06 ppm for exchange rates ranging from 100 to 1000 s{sup −1}, despite the small fraction of {sup 13}Cα–{sup 13}Cβ spin-pairs that are present for many residue types. The labeling approach described here should thus be attractive for studies of exchanging systems using {sup 13}Cα spin probes.

  8. Drive tube 60009 - A chemical study of magnetic separates of size fractions from five strata. [lunar soil analysis

    Science.gov (United States)

    Blanchard, D. P.; Jacobs, J. W.; Brannon, J. C.; Brown, R. W.

    1976-01-01

    Each bulk soil and both the magnetic and nonmagnetic components of the 90-150 micron and below 20 micron fractions of five soils from drive tube 60009 were analyzed. Samples were analyzed for FeO, Na2O, Sc, Cr, Co, Ni, Hf, Ta, Th, La, Ce, Sm, Eu, Tb, Yb, and Lu by neutron activation analysis. Several samples were fused and analyzed for major elements by electron microprobe analysis. Compositional variations are not systematically related to depth. The compositions of the five soils studied are well explained by a two-component mixing model whose end members are a submature Apollo 16-type soil and an extremely immature anorthositic material similar to 60025. There is evidence that the anorthositic component had received a small amount of exposure before these soils were mixed. After mixing, the soils received little exposure suggesting mixing and deposition on a rapid time scale.

  9. Determination of oxygen and nitrogen derivatives of polycyclic aromatic hydrocarbons in fractions of asphalt mixtures using liquid chromatography coupled to mass spectrometry with atmospheric pressure chemical ionization.

    Science.gov (United States)

    Nascimento, Paulo Cicero; Gobo, Luciana Assis; Bohrer, Denise; Carvalho, Leandro Machado; Cravo, Margareth Coutinho; Leite, Leni Figueiredo Mathias

    2015-12-01

    Liquid chromatography coupled to mass spectrometry with atmospheric pressure chemical ionization was used for the determination of polycyclic aromatic hydrocarbon derivatives, the oxygenated polycyclic aromatic hydrocarbons and nitrated polycyclic aromatic hydrocarbons, formed in asphalt fractions. Two different methods have been developed for the determination of five oxygenated and seven nitrated polycyclic aromatic hydrocarbons that are characterized by having two or more condensed aromatic rings and present mutagenic and carcinogenic properties. The parameters of the atmospheric pressure chemical ionization interface were optimized to obtain the highest possible sensitivity for all compounds. The detection limits of the methods ranged from 0.1 to 57.3 μg/L for nitrated and from 0.1 to 6.6 μg/L for oxygenated derivatives. The limits of quantification were in the range of 4.6-191 μg/L for nitrated and 0.3-8.9 μg/L for oxygenated derivatives. The methods were validated against a diesel particulate extract standard reference material (National Institute of Standards and Technology SRM 1975), and the obtained concentrations (two nitrated derivatives) agreed with the certified values. The methods were applied in the analysis of asphalt samples after their fractionation into asphaltenes and maltenes, according to American Society for Testing and Material D4124, where the maltenic fraction was further separated into its basic, acidic, and neutral parts following the method of Green. Only two nitrated derivatives were found in the asphalt sample, quinoline and 2-nitrofluorene, with concentrations of 9.26 and 2146 mg/kg, respectively, whereas no oxygenated derivatives were detected. PMID:26446274

  10. Determination of oxygen and nitrogen derivatives of polycyclic aromatic hydrocarbons in fractions of asphalt mixtures using liquid chromatography coupled to mass spectrometry with atmospheric pressure chemical ionization.

    Science.gov (United States)

    Nascimento, Paulo Cicero; Gobo, Luciana Assis; Bohrer, Denise; Carvalho, Leandro Machado; Cravo, Margareth Coutinho; Leite, Leni Figueiredo Mathias

    2015-12-01

    Liquid chromatography coupled to mass spectrometry with atmospheric pressure chemical ionization was used for the determination of polycyclic aromatic hydrocarbon derivatives, the oxygenated polycyclic aromatic hydrocarbons and nitrated polycyclic aromatic hydrocarbons, formed in asphalt fractions. Two different methods have been developed for the determination of five oxygenated and seven nitrated polycyclic aromatic hydrocarbons that are characterized by having two or more condensed aromatic rings and present mutagenic and carcinogenic properties. The parameters of the atmospheric pressure chemical ionization interface were optimized to obtain the highest possible sensitivity for all compounds. The detection limits of the methods ranged from 0.1 to 57.3 μg/L for nitrated and from 0.1 to 6.6 μg/L for oxygenated derivatives. The limits of quantification were in the range of 4.6-191 μg/L for nitrated and 0.3-8.9 μg/L for oxygenated derivatives. The methods were validated against a diesel particulate extract standard reference material (National Institute of Standards and Technology SRM 1975), and the obtained concentrations (two nitrated derivatives) agreed with the certified values. The methods were applied in the analysis of asphalt samples after their fractionation into asphaltenes and maltenes, according to American Society for Testing and Material D4124, where the maltenic fraction was further separated into its basic, acidic, and neutral parts following the method of Green. Only two nitrated derivatives were found in the asphalt sample, quinoline and 2-nitrofluorene, with concentrations of 9.26 and 2146 mg/kg, respectively, whereas no oxygenated derivatives were detected.

  11. Chemical fractionation of geogenic molybdenum and arsenic in a limestone aquifer and their impact on groundwater quality

    Science.gov (United States)

    Mozaffari Khalf Badam, A.; Pichler, T.

    2014-12-01

    Mobilization of naturally occurring molybdenum (Mo) and arsenic (As) in sedimentary rocks, mainly carbonates, contaminate groundwater in the Lithia area. The sedimentary rocks contains up to 825 mg kg-1 Mo and 144 mg kg-1 As. Mo and As groundwater concentrations reached up to 5000 μg L-1 and 300 μg L-1 and exceed the WHO guidelines of 70 and 10 μg L-1, respectively. In order to asses their fractions and origins, a modified five-step (adsorbed/exchangeable, carbonates, hydrous iron oxides, crystalline iron oxides, sulfides and organic matter (OM)) sequential extraction procedure (SEP) was applied to 10 samples. Determination of the elements was carried out by ICP-MS. The SEP results were compared to values obtained by total digestion with aqua regia. The recovery ranged from 88 to 111 % for Mo and 75 to 116 % for As and RSD was better than 10%. In most samples up to 90 % of the Mo was present in the adsorbed/exchangeable fraction (step 1), characterizing a major Mo source. Pyrite, which is present in the aquifer matrix beneath Lithia, is generally considered a source for Mo. Electron microprobe analysis, did not confirm the presence of Mo in pyrite. Thus oxidation of OM is the main reason for the high Mo content in step 1 and groundwater. Another possible source for Mo in groundwater could be the mineral powellite (CaMoO4). To investigate this possibility powellite saturation was calculated with PHREEQC under alkaline conditions. Powellite was super saturated once Mo concentrations exceeded 3000 μg L-1. Thus powellite was not considered a source, but rather a sink for Mo released form OM. In contrast to Mo, As was present in each extraction step in somewhat similar abundance: step 1 (17%), step 2 (11% ), step 3 (30 %), step 4 (23 %) and step 5 (18%). Hydrous and crystalline iron oxides which were dissolved in step 3 and 4 contained the highest As concentrations. Electron microprobe analysis of pyrite, which was dissolved in step 5, showed concentrations of up to

  12. Development of preparative and analytical methods of the hop bitter acid oxide fraction and chemical properties of its components.

    Science.gov (United States)

    Taniguchi, Yoshimasa; Matsukura, Yasuko; Taniguchi, Harumi; Koizumi, Hideki; Katayama, Mikio

    2015-01-01

    The bitter acids in hops (Humulus lupulus L.) and beer, such as α-, β-, and iso-α-acids, are known to affect beer quality and display various physiological effects. However, these compounds readily oxidize, and the effect of the oxides on the properties of beer or their potential health benefits are not well understood. In this study, we developed a simple preparative method for the bitter acid oxide fraction derived from hops and designated the constituents as matured hop bitter acids (MHBA). HPLC-PDA-ESI/HRMS and MS(2) revealed that MHBA are primarily composed of α-acid-derived oxides, which possess a common β-tricarbonyl moiety in their structures similar to α-, β-, and iso-α-acids. We also developed a quantitative analytical method of whole MHBA by HPLC, which showed high precision and reproducibility. Using our newly developed method, the concentration of whole MHBA in several commercial beers was evaluated. Our results will promote the study of bitter acid oxides. PMID:25996959

  13. PM chemical composition and oxidative potential of the soluble fraction of particles at two sites in the urban area of Milan, Northern Italy

    Science.gov (United States)

    Perrone, Maria Grazia; Zhou, Jun; Malandrino, Mery; Sangiorgi, Giorgia; Rizzi, Cristiana; Ferrero, Luca; Dommen, Josef; Bolzacchini, Ezio

    2016-03-01

    Recent epidemiological evidence support the hypothesis that health effects from inhalation of air particles are governed by more than just particle mass, since specific chemical components have been identified as important contributors to mortality and hospitality admissions. We studied the chemical composition and the oxidative potential (OP) of total suspended particle (TSP) samples from Milan at two sites with different traffic loads: a site in the low emission zone (LEZ) and a traffic site (TR) outside. Two a-cellular assays; dithiothreitol (OPDTT) and 2‧,7' dichlorofluorescin (OPDCFH) were used to characterize the OP of the soluble fraction of particles. TSP samples from LEZ showed significantly lower concentrations of traffic-related chemical components compared to TR. The decrease in the concentrations from TR to LEZ was maximum for EC, with a LEZ/TR ratio of 0.64 (±0.18), and a significant reduction (p cellular assays gave complementary information on the OP of particles in Milan. The two OP assays resulted to be sensitive to different chemical properties of PM samples. OPDTT correlated positively only with Global Radiation (Spearman's rs = 0.38, p < 0.05), which could be considered as a proxy for high concentrations of secondary oxidizing organics, while OPDCFH was related to various PM chemical species, mainly correlated with total mass (rs = 0.65; p < 0.01), elements (e.g. Zn, rs = 0.67; As, rs = 0.65; p < 0.01) and the sum of sulfate and nitrate (rs = 0.63; p < 0.01), a proxy for secondary aerosol.

  14. Acute Toxicity of Water-Accommodated Fraction and Chemically Enhanced WAF of Bunker C Oil and Dispersant to a Microalga Tetraselmis tetrathele.

    Science.gov (United States)

    Santander-Avanceña, Sheryll S; Sadaba, Resurreccion B; Taberna, Hilario S; Tayo, Gilma T; Koyama, Jiro

    2016-01-01

    This study assessed the toxicity of water-accommodated fraction (WAF) and chemically enhanced WAF (CEWAF) of bunker C oil and dispersant (DISP) to a microalga, Tetraselmis tetrathele. The 72-h median effective concentration (72-h EC50) of CEWAF and DISP were determined at 3.30% and 2.40%, respectively. The no observed effect concentration (NOEC) of CEWAF to T. tetrathele was at 2.0% and lowest observed effect concentration (LOEC) was at 3.0% while NOEC and LOEC of DISP to T. tetrathele were determined at 1.0% and 2.0%, respectively. The addition of dispersant to oil increased the amount of total PAH present in the CEWAF test solutions. DISP alone was highly toxic, and the toxicity of CEWAF was primarily caused by the presence of dispersant.

  15. Antioxidant properties of chemical extracts and bioaccessible fractions obtained from six Spanish monovarietal extra virgin olive oils: assays in Caco-2 cells.

    Science.gov (United States)

    Borges, Thays H; Cabrera-Vique, Carmen; Seiquer, Isabel

    2015-07-01

    The antioxidant activity and the total phenolic content (TPC) of six Spanish commercial monovarietal extra virgin olive oils (Arbequina, Cornicabra, Hojiblanca, Manzanilla, Picual and Picudo) were evaluated in chemical extracts and in bioaccessible fractions (BF) obtained after in vitro digestion. Moreover, the effects of the BF on cell viability and the generation of reactive oxygen species (ROS) were investigated in Caco-2 cell cultures. The in vitro digestion process increased the TPC and antioxidant activity evaluated by different methods (ABTS, DPPH and FRAP) compared with chemical extracts. After digestion, the Picual variety showed better beneficial effects in preserving cell integrity than the other varieties studied. Significant reductions of ROS production were observed after incubation of Caco-2 cells with the BF of all the varieties and, moreover, a protective effect against the oxidative stress induced by t-BOOH was shown for Arbequina, Cornicabra, Hojiblanca, Manzanilla and Picual. These findings seem to be an additional reason supporting the health benefits of Spanish extra virgin olive oil varieties. Multivariate factor analysis and principal component analysis were applied to assess the contribution of antioxidant activity and TPC, before and after digestion, to the characterization of the different varieties. PMID:26087367

  16. Chromatographic speciation of Cr(III)-species, inter-species equilibrium isotope fractionation and improved chemical purification strategies for high-precision isotope analysis.

    Science.gov (United States)

    Larsen, K K; Wielandt, D; Schiller, M; Bizzarro, M

    2016-04-22

    Chromatographic purification of chromium (Cr), which is required for high-precision isotope analysis, is complicated by the presence of multiple Cr-species with different effective charges in the acid digested sample aliquots. The differing ion exchange selectivity and sluggish reaction rates of these species can result in incomplete Cr recovery during chromatographic purification. Because of large mass-dependent inter-species isotope fractionation, incomplete recovery can affect the accuracy of high-precision Cr isotope analysis. Here, we demonstrate widely differing cation distribution coefficients of Cr(III)-species (Cr(3+), CrCl(2+) and CrCl2(+)) with equilibrium mass-dependent isotope fractionation spanning a range of ∼1‰/amu and consistent with theory. The heaviest isotopes partition into Cr(3+), intermediates in CrCl(2+) and the lightest in CrCl2(+)/CrCl3°. Thus, for a typical reported loss of ∼25% Cr (in the form of Cr(3+)) through chromatographic purification, this translates into 185 ppm/amu offset in the stable Cr isotope ratio of the residual sample. Depending on the validity of the mass-bias correction during isotope analysis, this further results in artificial mass-independent effects in the mass-bias corrected (53)Cr/(52)Cr (μ(53)Cr* of 5.2 ppm) and (54)Cr/(52)Cr (μ(54)Cr* of 13.5 ppm) components used to infer chronometric and nucleosynthetic information in meteorites. To mitigate these fractionation effects, we developed strategic chemical sample pre-treatment procedures that ensure high and reproducible Cr recovery. This is achieved either through 1) effective promotion of Cr(3+) by >5 days exposure to HNO3H2O2 solutions at room temperature, resulting in >∼98% Cr recovery for most types of sample matrices tested using a cationic chromatographic retention strategy, or 2) formation of Cr(III)-Cl complexes through exposure to concentrated HCl at high temperature (>120 °C) for several hours, resulting in >97.5% Cr recovery using a

  17. Antioxidant activity and chemical composition of the non polar fraction of Gracilaria domingensis (Kützing Sonder ex Dickie and Gracilaria birdiae (Plastino & Oliveira

    Directory of Open Access Journals (Sweden)

    Thais Guaratini

    2012-08-01

    Full Text Available Gracilaria domingensis (Kützing Sonder ex Dickie and Gracilaria birdiae (Plastino & Oliveira (Gracilariales, Rhodophyta are seaweeds that occur on the Brazilian coast. Based on their economic and pharmaceutical importance, we investigated the antioxidant activity of the methanolic, ethyl acetate and hexane extracts of both species. The hexane extracts display a high antioxidant activity and comparative analyses indicated G. birdiae as the most active species. Chemical investigation of these fractions showed several carotenoids and fatty acids, as well as cholesterol and sitosterol derivatives. HPLC-DAD analysis of G. birdiae showed violaxanthin (0.04 μg.mg-1 of dry material, antheraxanthin (5.31 μg.mg-1, aloxanthin (0.09 μg.mg-1, zeaxanthin (0.45 μg.mg-1 and β-carotene (0.37 μg.mg-1 as the major carotenoids. G. domingensis showed a similar carotenoid profile, however, with much lower concentration than G. birdiae. Gas chromatography coupled to mass spectrometry was used to determine other nonpolar compounds of these seaweeds. The main compounds detected in both studied species were the fatty acids 16:0; 18:1 Δ9; 20:3 Δ6,9,12, 20:4 Δ5,8,11,14. We found no specificity of compounds in either species. However, G. birdiae, presented higher contents of carotenoids and arachidonic acid than G. domingensis.

  18. Comparative proteomic analysis of a membrane-enriched fraction from flag leaves reveals responses to chemical hybridization agent SQ-1 in wheat.

    Science.gov (United States)

    Song, Qilu; Wang, Shuping; Zhang, Gaisheng; Li, Ying; Li, Zheng; Guo, Jialin; Niu, Na; Wang, Junwei; Ma, Shoucai

    2015-01-01

    The induction of wheat male fertile lines by using the chemical hybridizing agent SQ-1 (CHA-SQ-1) is an effective approach in the utilization of heterosis; however, the molecular basis of male fertility remains unknown. Wheat flag leaves are the initial receptors of CHA-SQ-1 and their membrane structure plays a vital role in response to CHA-SQ-1 stress. To investigate the response of wheat flag leaves to CHA-SQ-1 stress, we compared their quantitative proteomic profiles in the absence and presence of CHA-SQ-1. Our results indicated that wheat flag leaves suffered oxidative stress during CHA-SQ-1 treatments. Leaf O2 (-), H2O2, and malonaldehyde levels were significantly increased within 10 h after CHA-SQ-1 treatment, while the activities of major antioxidant enzymes such as superoxide dismutase, catalase, and guaiacol peroxidase were significantly reduced. Proteome profiles of membrane-enriched fraction showed a change in the abundance of a battery of membrane proteins involved in multiple biological processes. These variable proteins mainly impaired photosynthesis, ATP synthesis protein mechanisms and were involved in the response to stress. These results provide an explanation of the relationships between membrane proteomes and anther abortion and the practical application of CHA for hybrid breeding. PMID:26379693

  19. Comparative proteomic analysis of a membrane-enriched fraction from flag leaves reveals responses to chemical hybridization agent SQ-1 in wheat

    Directory of Open Access Journals (Sweden)

    Qilu eSong

    2015-08-01

    Full Text Available The induction of wheat male fertile lines by using the chemical hybridizing agent SQ-1 (CHA-SQ-1 is an effective approach in the utilization of heterosis; however, the molecular basis of male fertility remains unknown. Wheat flag leaves are the initial receptors of CHA-SQ-1 and their membrane structure plays a vital role in response to CHA-SQ-1 stress. To investigate the response of wheat flag leaves to CHA-SQ-1 stress, we compared their quantitative proteomic profiles in the absence and presence of CHA-SQ-1. Our results indicated that wheat flag leaves suffered oxidative stress during CHA-SQ-1 treatments. Leaf O2-, H2O2, and malonaldehyde levels were significantly increased within 10 h after CHA-SQ-1 treatment, while the activities of major antioxidant enzymes such as superoxide dismutase, catalase, and guaiacol peroxidase were significantly reduced. Proteome profiles of membrane-enriched fraction showed a change in the abundance of a battery of membrane proteins involved in multiple biological processes. These variable proteins mainly impaired photosynthesis, ATP synthesis protein mechanisms and were involved in the response to stress. These results provide an explanation of the relationships between membrane proteomes and anther abortion and the practical application of CHA for hybrid breeding.

  20. Contact allergy to oak moss: search for sensitizing molecules using combined bioassay-guided chemical fractionation, GC-MS, and structure-activity relationship analysis.

    Science.gov (United States)

    Bernard, Guillaume; Giménez-Arnau, Elena; Rastogi, Suresh Chandra; Heydorn, Siri; Johansen, Jeanne Duus; Menné, Torkil; Goossens, An; Andersen, Klaus; Lepoittevin, Jean-Pierre

    2003-11-01

    In addition to pure synthetic fragrance materials several natural extracts are still in use in the perfume industry. Among them oak moss absolute, prepared from the lichen Evernia prunastri (L.) Arch., is considered a major contact sensitizer and is therefore included in the fragrance mix used for diagnosing perfume allergy. The process of preparing oak moss absolute has changed during recent years and, even though several potential sensitizers have been identified from former benzene extracts, its present constituents and their allergenic status are not clear. In the study reported here, we applied a method developed for the identification of contact allergens present in natural complex mixtures to oak moss absolute. The method is based on the combination of bioassay-guided chemical fractionation, gas chromatography-mass spectrometry analysis and structure-activity relationship studies. Our first results showed that atranol and chloroatranol, formed by transesterification and decarboxylation of the lichen depsides, atranorin and chloroatranorin, during the preparation of oak moss absolute, are strong elicitants in most patients sensitized to oak moss. Methyl-beta-orcinol carboxylate, a depside degradation product and the most important monoaryl derivative of oak moss from an olfactory standpoint, was also found to elicit a reaction in most patients. PMID:13680271

  1. Fractional Echoes

    CERN Document Server

    Karras, G; Billard, F; Lavorel, B; Siour, G; Hartmann, J -M; Faucher, O; Gershnabel, Erez; Prior, Yehiam; Averbukh, Ilya Sh

    2016-01-01

    We report the observation of fractional echoes in a double-pulse excited nonlinear system. Unlike standard echoes which appear periodically at delays which are integer multiple of the delay between the two exciting pulses, the fractional echoes appear at rational fractions of this delay. We discuss the mechanism leading to this phenomenon, and provide the first experimental demonstration of fractional echoes by measuring third harmonic generation in a thermal gas of CO2 molecules excited by a pair of femtosecond laser pulses.

  2. Fractional randomness

    Science.gov (United States)

    Tapiero, Charles S.; Vallois, Pierre

    2016-11-01

    The premise of this paper is that a fractional probability distribution is based on fractional operators and the fractional (Hurst) index used that alters the classical setting of random variables. For example, a random variable defined by its density function might not have a fractional density function defined in its conventional sense. Practically, it implies that a distribution's granularity defined by a fractional kernel may have properties that differ due to the fractional index used and the fractional calculus applied to define it. The purpose of this paper is to consider an application of fractional calculus to define the fractional density function of a random variable. In addition, we provide and prove a number of results, defining the functional forms of these distributions as well as their existence. In particular, we define fractional probability distributions for increasing and decreasing functions that are right continuous. Examples are used to motivate the usefulness of a statistical approach to fractional calculus and its application to economic and financial problems. In conclusion, this paper is a preliminary attempt to construct statistical fractional models. Due to the breadth and the extent of such problems, this paper may be considered as an initial attempt to do so.

  3. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  4. Fractional thermoelasticity

    CERN Document Server

    Povstenko, Yuriy

    2015-01-01

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

  5. Study on Chemical Constituents of Ethyl Acetate Fraction of Euscaphis japonica%鸡眼睛乙酸乙酯部位化学成分研究

    Institute of Scientific and Technical Information of China (English)

    周雯; 刘智; 王海军; 李勇军; 王爱民; 许祖超; 廖尚高

    2013-01-01

    Objective; To investigate the chemical constituents of the ethyl acetate fraction of ethanol extract of Euscaphis japonica. Method; Various preparative chromatographic techniques were used for the isolation and purification of the compounds and their structures were determined by comparison of their chromatographic and spectral data with those of the authentic samples and those reported in the literature. Result; Seven compounds were obtained and identified as vanillin (1) , vanillic acid (2) , 5-hydroxymethylfurfural (3) , sinapic aldehyde (4), oleanolic acid (5), gallic acid (6), and protocatechuic acid (7). Conclusion; Compounds 2-7 were isolated from the genus Euscaphis for the first time.%目的:研究鸡眼睛乙醇提取物中等极性的乙酸乙酯萃取部位的化学成分,为民族药鸡眼睛的开发应用提供科学依据.方法:通过各种色谱分离技术对鸡眼睛乙醇提取物乙酸乙酯萃取部位进行分离纯化,根据化合物的理化性质和波谱数据鉴定其结构.结果:从鸡眼睛乙醇提取物乙酸乙酯萃取部位分离得到7个化合物,分别鉴定为:香草醛(vanillin,1),香草酸(vanillic acid,2),5-羟甲基糠醛(5-hydroxymethylfurfural,3),芥子醛(sinapic aldehyde,4),齐墩果酸(oleanolic acid,5),没食子酸(gallic acid,6),原儿茶酸(protocatechuic acid,7).结论:其中化合物2~7为首次从该属植物中分离得到.

  6. Isolation of the volatile fraction from Apium graveolens L. (Apiaceae) by supercritical carbon dioxide extraction and hydrodistillation: chemical composition and antifungal activity.

    Science.gov (United States)

    Marongiu, B; Piras, A; Porcedda, S; Falconieri, D; Maxia, A; Frau, M A; Gonçalves, M J; Cavaleiro, C; Salgueiro, L

    2013-01-01

    Apium graveolens L. (wild celery), belonging to the family of Apiaceae, is a scaposus hemicryptophyte. Instead, the cultivate plant is an annual or biennial herb widely used as a spice and seasoning in food. A broad range of biological activities have been attributed to A. graveolens. These include antimicrobial activity, larvicidal activity, hepatoprotective activity, nematicidal and mosquito repellent potential and antihyperlipidaemic properties.In this study, the authors compare the composition of the volatile fractions of A. graveolens collected in natural populations in Portugal and Italy and evaluate their potential as antifungal agents.The composition of the volatile oils obtained by hydrodistillation and their antifungal activity are reported. The oils were analysed by gas chromatography-flame ionisation detector and gas chromatography-mass spectrometry methods and their composition were compared with that of the volatile extracts isolated by supercritical CO2. A chemical variability in the extracts depending on the origin of the plants and on the extraction method was observed. The results showed the presence of sedanenolide, neocnidilide and neophytadiene as main components. The minimal inhibitory concentration (MIC) and the minimal lethal concentration were used to evaluate the antifungal activity of the oils against Candida albicans, Candida tropicalis, Candida krusei, Candida guilliermondii, Candida parapsilosis, Cryptococcus neoformans, Trichophyton rubrum, Trichophyton mentagrophytes, T. mentagrophytes var. interdigitale, Trichophyton verrucosum, Microsporum canis, Microsporum gypseum, Epidermophyton floccosum, Aspergillus niger, Aspergillus fumigatus and Aspergillus flavus. The oil from Italy rich in neophytadiene is the more active, with MIC values of 0.04-0.64 µL mL(-1). Our results show that A. graveolens volatile extracts may be useful in the clinical treatment of fungal diseases. PMID:22974401

  7. Chemical characterization of a polar portion in the neutral fraction derived from airborne particulate extracts responsible for the embryotoxicity in the chicken embryo

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, H.

    1988-01-01

    Airborne particulate matter was collected with a high-volume air sampler between June 1984 and May 1985 on the roof top of the authors institute. The tar material extracted was separated into six fractions by liquid-liquid partition and silica gel column chromatography. These fractions were then tested for their embryotoxicities by a chicken embryo assay. A moderately polar fraction per weight and a fraction containing polycyclic aromatic hydrocarbons (PAHs) had the greatest toxicity for chicken embryos. When the polar fraction was purified by high-pressure liquid chromatography, the purified fraction was 3.7 times more toxic than the original polar fraction. To determine the responsible components for the toxicity, the purified fraction as well as the original fraction was analyzed by capillary gas chromatography and gas chromatography-mass spectrometry. The characterized components were classified into oxygenated PAHs (containing ketones, quinones, and aldehydes), nitrogen-containing PAHS, diphenyl-substituted aliphatic ketones (or diketones), and esters of aliphatic acids.

  8. Chemical and isotopic fractionation of wet andesite in a temperature gradient: Experiments and models suggesting a new mechanism of magma differentiation

    Science.gov (United States)

    Huang, F.; Lundstrom, C. C.; Glessner, J.; Ianno, A.; Boudreau, A.; Li, J.; Ferré, E. C.; Marshak, S.; DeFrates, J.

    2009-02-01

    offsets are 2.8‰ and 9.9‰, respectively, much greater than the range of Fe-Mg isotope variation in high-temperature terrestrial samples. In contrast, no obvious chemical differentiation was observed in a similar experiment (of 33 days duration) where the temperature ranged from 550 to 350 °C, indicating the critical role of the melt in causing the differentiation observed in the 950-350 °C experiment. If temperature gradients can be sustained for the multi-million-year time scales implied by geochronology in some plutonic systems, thermal migration could play a heretofore unrecognized role in the development of differentiated plutons. Elemental distributions, dominated by phase equilibria, cannot be used to discriminate thermal migration from conventional magma differentiation processes such as fractional crystallization. However, the observation of Fe-Mg isotopic variations in partially molten portions of the experiment indicates that these isotopic systems could provide a unique fingerprint to this process. This result could also provide a possible explanation for the Fe-Mg isotope variations observed in high-temperature silicate rocks and minerals.

  9. Chemical and biological profiles of sediments as indicators of sources of contamination in Hamilton Harbour. Part II: bioassay-directed fractionation using the Ames Salmonella/microsome assay

    Energy Technology Data Exchange (ETDEWEB)

    Marvin, C.H.; McCarry, B.E.; Villella, J.; Allan, L.W.; Bryant, D.W. [McMaster University, Hamilton, ON (Canada). Dept. of Chemistry

    2000-07-01

    Bottom sediment and suspended sediment samples from Hamilton Harbour (western Lake Ontario) and from a major tributary were profiled using a bioassay-directed fractionation approach. Fractions which exhibited mutagenic activity contained PAH with molecular masses of 252, 276 and 278 amu; these fractions contained over 80% of the genotoxicity attributable to PAH. Suspended sediments collected near areas known to contain high levels of coal tar-contamination in the bottom sediments contained higher levels of genotoxic PAH than suspended sediments collected from other areas of the harbour.

  10. THE CHANGE OF TOTAL PROTEIN FRACTION OF MUSCLE TISSUE OF PORK WITH BIO- AND PHYSICO-CHEMICAL SPECIFIC IN THE PROCESS OF COOKING AT DIFFERENT TEMPERATURES

    Directory of Open Access Journals (Sweden)

    O. Shalimova

    2012-03-01

    Full Text Available The character of changes in total protein fraction of muscle tissue of pork with PSE defects in the process of cooking at temperatures ranging from 40 to 72 g.C in steps of 2 g.C is investigated. Our studies have revealed differences in the change of state the total fraction of muscle proteins with defects PSE pork during cooking.

  11. Polymer fractionation

    Energy Technology Data Exchange (ETDEWEB)

    Hadermann, A. F.

    1985-04-09

    Soluble polymers are fractionated according to molecular weight by cryogenically comminuting the polymer and introducing the polymer particles, while still in the active state induced by cryogenic grinding, into a liquid having a solvent power selected to produce a coacervate fraction containing high molecular weight polymer species and a dilute polymer solution containing lower molecular weight polymer species. The coacervate may be physically separated from the solution and finds use in the production of antimisting jet fuels and the like.

  12. Chemical characterization by GC-MS and in vitro activity against Candida albicans of volatile fractions prepared from Artemisia dracunculus, Artemisia abrotanum, Artemisia absinthium and Artemisia vulgaris

    OpenAIRE

    Obistioiu, Diana; Cristina, Romeo T; Schmerold, Ivo; Chizzola, Remigius; Stolze, Klaus; Nichita, Ileana; Chiurciu, Viorica

    2014-01-01

    Background A large number of essential oils is reported to have significant activity against Candida albicans. But the different chemical composition influences the degree of their activity. The intention of this study was to investigate the chemical composition and the activity against Candida albicans of volatile oils obtained from Artemisia dracunculus, A. abrotanum, A. absinthium and A. vulgaris (Asteraceae). The aim of the study was to identify new chemical compounds that have effect aga...

  13. Chemical composition and antimicrobial activity of the volatile fractions from leaves and flowers of the wild Iraqi Kurdish plant Prangos peucedanifolia FENZL.

    Science.gov (United States)

    Brusotti, Gloria; Ibrahim, Mohammed Farhad; Dentamaro, Alessandra; Gilardoni, Gianluca; Tosi, Solveig; Grisoli, Pietro; Dacarro, Cesare; Guglielminetti, Maria Lidia; Hussain, Faiq Hama Saeed; Caccialanza, Gabriele; Vidari, Giovanni

    2013-02-01

    The volatile fractions isolated from Prangos peucedanifolia FENZL leaves and flowers were investigated for their phytochemical composition and biological properties. Flower and leaf hydrodistillation afforded 3.14 and 0.49 g of yellowish oils in 1.25 and 0.41% yields, respectively, from dry vegetable materials. According to the GC-FID and GC/MS analyses, 36 (99.35% of the total oil composition) and 26 compounds (89.12%) were identified in the two oils, respectively. The major constituents in the flower volatile fraction were β-pinene (35.58%), α-pinene (22.13%), and β-phellandrene (12.54%), while m-cresol (50.38%) was the main constituent of the leaf volatile fraction. The antimicrobial activity was evaluated against several bacterial and fungal strains, on the basis of the minimum inhibitory concentration (MIC) by the micro- and macrodilution methods. The two volatile fractions showed moderate antifungal and antibacterial activities, especially against Trichophyton rubrum (MIC of 2×10(3) μg/ml), Streptococcus mutans, Streptococcus pyogenes, and Staphylococcus aureus (MIC≤1.9×10(3) μg/ml for all). PMID:23418174

  14. Effect of farm yard manure on chemical fractionation of cadmium and its bio-availability to maize crop grown on sewage irrigated coarse textured soil.

    Science.gov (United States)

    Khurana, M P S; Kansal, B D

    2014-03-01

    Cadmium is a potentially toxic heavy metal that enters food chain from the soil through various anthropogenic sources. Availability of metal ions in contaminated soils can be reduced by the addition of organic amendments. In this study, effect of organic matter -farm yard manure (FYM) amendment on fractionation and availability of Cd to maize was evaluated. A green house experiment was conducted to determine the toxicity and uptake of Cd by maize in sandy loam soil with and without organic matter. Four levels of Cd (0, 10, 20 and 40 mg kg(-1) soil) and two levels of FYM (0 and 20 tonnes ha(-1)) with three replication in a completely randomized factorial design. Concentration of Cd in maize increased with increasing rate of Cd application. Application of organic matter increased the dry matter yield of maize while reduced the uptake of metal. All the fractions exhibited increase with Cd rates. The addition of organic amendment declined significantly the concentration of water soluble and exchangeable Cd, but increased the amounts of these metals into less mobile fractions (Fe/Mn oxide, organic matter and residual). Dominance of insoluble forms of Cd after the application of organic amendments may be ascribed to the increases of soil OM, pH, EC and available P contents which caused transformation or redistribution of the sorbed phases. This resulted in increasing Cd retention in the more persistent fractions with application of FYM at the expense of reductions in the loosely bound fractions. Thus FYM appears to be agronomically feasible way to off set the adverse effect of Cd toxicity.

  15. Fractional statistic

    OpenAIRE

    Bergère, M. C.

    1999-01-01

    We improve Haldane's formula which gives the number of configurations for $N$ particles on $d$ states in a fractional statistic defined by the coupling $g=l/m$. Although nothing is changed in the thermodynamic limit, the new formula makes sense for finite $N=pm+r$ with $p$ integer and $0

  16. Chemical protection against long-term effects of whole-body exposure of mice to ionizing radiation. III. The effects of fractionated exposure to C57Bl mice

    International Nuclear Information System (INIS)

    Mice of the C57Bl/Cnb strain were exposed to four fractionated doses delivered at weekly intervals (total doses from 4 x 50 to 4 x 375 R). One group of mice received a mixture of radioprotectors. The animals were followed to their natural death and investigated for histopathology. Life-shortening showed a sigmoid dependency on the dose in nonprotected and protected mice with a dose reduction factor of 2.1 at 50% life-shorteining. Thymic lymphoma was the most predominant cause of death in irradiated C57Bl mice. Radioprotectors diminished significantly the incidence of this disease but apparently did not reduce other causes of death. Reticulum cell sarcoma B also increased at the same low doses as thymic lymphoma. Both thymic lymphoma and reticulum cell sarcoma B increased in frequency after a fractionated dose compared to a single exposure with doses of 600 to 700 R and 300 to 400 R, respectively

  17. Distribution of Pb and its chemical fractions in liquid and solid phases of digested pig and dairy slurries%猪、奶牛粪厌氧发酵中Pb的形态转化及其分布特征

    Institute of Scientific and Technical Information of China (English)

    靳红梅; 付广青; 常志州; 叶小梅

    2013-01-01

    Anaerobic digestion treatment effectively degrades the organic matter and causes obvious variations in physical and chemical properties of digested slurries, such as water content, pH, oxidation reduction potential and microbial activities. These changes may influence the chemical fraction of Pb, which is a critical factor in predicting its toxicity, environmental mobility, bioavailability and optimum removal methods. The speciation and phytotoxic effects of lead from sewage sludge and composted manure have been widely studied. There has been no study about the transfer and distribution of Pb during anaerobic digestion of manure slurries. The aim of the present work was to analyze the distribution of Pb in both liquid and solid phase after anaerobic digestion of pig slurries and dairy slurries, and their chemical speciation in solid fraction of digested residuals. The continuous stirred tank reactor (CSTR) at condition of medium temperature [(37 ± 2)℃] was operated for 130 d. Lead in liquid and solid phases of raw materials and digested slurries was analyzed by first passing through a 0.45 µm filter paper. The chemical fractions in digested slurry solids were extracted by BCR method. Results showed that total amount of Pb was decreased 70% and 19% in digested pig slurries (DPS) and dairy slurries (DDS), respectively, , compared with raw slurries. The percentages of Pb in liquid fractions of DPS and DDS were 29%and 17%, which decreased by 17%and 58%. The decrease of Pb in DDS was significantly lower than that in DPS. One reason is that 90%of solids in DDS were discharged during the anaerobic digestion. Another reason is that Pb in digested slurries mainly exists as the solid form. Thus the amount of Pb left in the reactor for dairy manure digestion was significantly lower than that for pig manure digest. Due to the high removal efficiency, easy operation and low treatment cost of heavy metals in solid phase, transformation of liquid phase of heavy metals to the

  18. Chemical fractionations and bioavailability of cadmium and zinc to cole (Brassica campestris L.) grown in the multi-metals contaminated oasis soil, northwest of China

    Institute of Scientific and Technical Information of China (English)

    Yiming Yang; Zhongren Nan; Zhuanjun Zhao; Shengli Wang; Zhaowei Wang; Xia Wang

    2011-01-01

    A pot experiment was conducted to study the relationship between distribution of cadmium (Cd) and zinc (Zn) and their availability.to cole (Brassica canpestris L.) grown in the multi-metal contaminated oasis soil in northwest of China. The results showed that Cd and Zn in the unpolluted oasis soil was mainly found in the residual fractionation, however, with increasing contents of Cd and Zn in the oasis soil, the distribution of Cd and Zn changed significantly. The growth of cole could be promoted by low Cd and Zn concentration,but significantly restrained by high concentrations. There was antagonistic effect among Cd and Zn in the multi-metals contaminated oasis soil. Stepwise regression analysis between fractionations distribution coefficients of the two meals in the soil and their contents in cole showed that both Cd and Zn in the exchangeable fractionation in the oasis soil made the most contribution on the uptake of Cd and Zn in cole. The bio-concentration factor (BCF) of Cd was greater than Zn in cole, and BCFs of the two metals in leaves were greater than those in roots. The translocation factors of the two metals in cole were greater than 1, and the two metals mainly accumulated in the edible parts in cole. Therefore, cole is not a suitable vegetable for the oasis soil because of the plants notable contamination by heavy metals.

  19. The effect of propylene glycol on the P450-dependent metabolism of acetaminophen and other chemicals in subcellular fractions of mouse liver

    Energy Technology Data Exchange (ETDEWEB)

    Snawder, J.E.; Benson, R.W.; Leakey, J.E.A.; Roberts, D.W. (National Center for Toxicological Research, Jefferson, AR (United States))

    1993-01-01

    Propylene glycol (PG) decreases the hepatotoxicity of acetominophen (APAP). To elucidate the mechanism for this response, the authors measured the effect of PG on the in vitro metabolism of APAP by subcellular liver fractions from 6-10 week-old male B6C3F1 mice. The fractions were assayed for their ability to bioactivate APAP to N-acetyl-p-benzoquinone imine, which was trapped as APAP-glutathione conjugates or APAP-protein adducts, and for dimethyl-nitrosamine-N-demethylase (DMN), 4-nitrophenol hydroxylase (4-NPOH), and phenacetin-O-deethylase (PAD) activities. Activity in the crude mitochondrial-rich (10,000 [times] g pellet) fraction was low and PG had no effect. PG inhibited DMN and 4-NPOH, indicators of IIE1-dependent activity, and the formation of APAP-glutathione conjugates and APAP-protein adducts in both heavy (15,000 [times] g pellet) and light (100,000 [times] g pellet) microsomes. PAD, a measure of IA2-dependent activity, was not inhibited. These data demonstrate that PG selectively inhibits IIE1 activity, including the bioactivation of APAP, and implicates this as the mechanism for PG-mediated protection of APAP hepatotoxicity in mice. 27 refs., 1 fig., 1 tab.

  20. Anticholinesterase activity and chemical profile of an active chromatographic fraction of ethanolic extract from Bellis perennis L. (Asteraceae) flowers; Atividade anticolinesterasica e perfil quimico de uma fracao cromatografica ativa do extrato etanolico das flores Bellis perennis L. (Asteraceae)

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Thiago Henrique Costa; Santos, Pauline Sousa dos; Freitas, Rivelilson Mendes de, E-mail: rivelilson@pq.cnpq.br [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil). Centro de Ciencias da Saude. Departamento de Bioquimica e Farmacologia; Carvalho, Rusbene Bruno Fonseca de; Melo, Cassio Herbert Santos de [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil). Centro de Ciencias da Natureza. Departamento de Quimica; David, Juceni Pereira [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Faculdade de Farmacia; David, Jorge Mauricio; Lima, Luciano Silva [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Instituto de Quimica

    2013-09-01

    This work describes the isolation of an active flavonoid fraction and identification of isorhamnetin 3-O-{beta}-D-(6''-acetyl)- alactopyranoside from flowers of B. perennis, and also the evaluation of anticholinesterase (AChE) activity of ethanolic extract from flowers (EEF) and the active fraction. The chemical structure of the flavonoid was defined on the basis of spectroscopic {sup 1}H NMR, IR and UV data. EEF or flavonoid reduces AChE activity in vivo, while flavonoid also reduces AChE activity in vitro, showing a value of 1.49 {mu}M for 50% inhibitory concentration (IC{sub 50}), suggesting potential use as an insecticide or in the treatment of neurodegenerative diseases such as Alzheimer's disease. (author)

  1. Fraction Reduction through Continued Fractions

    Science.gov (United States)

    Carley, Holly

    2011-01-01

    This article presents a method of reducing fractions without factoring. The ideas presented may be useful as a project for motivated students in an undergraduate number theory course. The discussion is related to the Euclidean Algorithm and its variations may lead to projects or early examples involving efficiency of an algorithm.

  2. Fractional Coins and Fractional Derivatives

    Directory of Open Access Journals (Sweden)

    J. A. Tenreiro Machado

    2013-01-01

    Full Text Available This paper discusses the fundamentals of negative probabilities and fractional calculus. The historical evolution and the main mathematical concepts are discussed, and several analogies between the two apparently unrelated topics are established. Based on the new conceptual perspective, some experiments are performed shading new light into possible future progress.

  3. Isolation, fractionation and identification of chemical constituents from the leaves crude extracts of Mentha piperita L grown in Sultanate of Oman

    Directory of Open Access Journals (Sweden)

    Mohammad Amzad Hossain

    2014-05-01

    Conclusions: According to the results of the present study, the plant crude extracts could be used as medicine for the treatment of different diseases. The analysis and identification of the chemical compounds in the plant crude extracts by using GC-MS was the first time.

  4. Mineralogical and chemical composition of the mud fraction from the surface sediments of Sharm Al-Kharrar, a Red Sea coastal lagoon

    Directory of Open Access Journals (Sweden)

    Ali S. Basaham

    2008-12-01

    Full Text Available Interaction between continental and marine end-members gives rise to thenatural biogeochemical processes in Sharm Al-Kharrar, a lagoon in the arid RedSea region. Twenty-nine surface sediment samples were collected from the areaand their mud fraction analysed for grain size, OC, CaCO$_3$, mineralogy andelemental composition. The mud fraction consisted of a mixture ofsiliciclastic/calcareous materials, dominated by silt size materials andcharacterised by low OC (average 0.71% $pm$0.13; CaCO$_3$ varied widely,with anaverage of 45\\% $pm$18. Concentrations of Al, Fe, Mn, Cu, Ni, Cr, V and Bashoweda wide range of variation throughout the Sharm. The results were normalised toAl and subjected to cluster analysis in order to examine the relations betweenthe mineralogy and the elemental composition. The contents of Al, Fe, Mn, Cu,Ni, Cr, V and Ba appeared to be influenced by the mixing of the twoend-members in addition to the physiochemical processes associated with themixing between episodic freshwater flooding and seawater. Zn was the singleelement that showed a slight departure from the mixing model.

  5. Quantitative chemical exchange saturation transfer (qCEST) MRI--RF spillover effect-corrected omega plot for simultaneous determination of labile proton fraction ratio and exchange rate.

    Science.gov (United States)

    Sun, Phillip Zhe; Wang, Yu; Dai, ZhuoZhi; Xiao, Gang; Wu, Renhua

    2014-01-01

    Chemical exchange saturation transfer (CEST) MRI is sensitive to dilute proteins and peptides as well as microenvironmental properties. However, the complexity of the CEST MRI effect, which varies with the labile proton content, exchange rate and experimental conditions, underscores the need for developing quantitative CEST (qCEST) analysis. Towards this goal, it has been shown that omega plot is capable of quantifying paramagnetic CEST MRI. However, the use of the omega plot is somewhat limited for diamagnetic CEST (DIACEST) MRI because it is more susceptible to direct radio frequency (RF) saturation (spillover) owing to the relatively small chemical shift. Recently, it has been found that, for dilute DIACEST agents that undergo slow to intermediate chemical exchange, the spillover effect varies little with the labile proton ratio and exchange rate. Therefore, we postulated that the omega plot analysis can be improved if RF spillover effect could be estimated and taken into account. Specifically, simulation showed that both labile proton ratio and exchange rate derived using the spillover effect-corrected omega plot were in good agreement with simulated values. In addition, the modified omega plot was confirmed experimentally, and we showed that the derived labile proton ratio increased linearly with creatine concentration (p plot for quantitative analysis of DIACEST MRI.

  6. Phosphorus transformation in poultry litter and litter-treated Oxisol of Brazil assessed by 31P-NMR and wet chemical fractionation

    Directory of Open Access Journals (Sweden)

    César Roriz de Souza

    2012-11-01

    Full Text Available Large quantities of poultry litter are being produced in Brazil, which contain appreciable amounts of phosphorus (P that could be of environmental concern. To assess the immediate environmental threat, five poultry litters composed of diverse bedding material were incubated for 43 days under greenhouse conditions. The litters consisted of: coffee bean husk (CH; wood chips (WC; rice husk (RH; ground corn cobs (CC and ground napier grass (NG (Pennisetum purpureum Schum., in which the change in forms of soluble P was evaluated using 31P NMR spectroscopy. On average, 80.2 and 19.8 % of the total P in the extract, respectively, accounted for the inorganic and organic forms before incubation and 48 % of the organic P was mineralized to inorganic P in 43 days of incubation. Wide variation in the organic P mineralization rate (from 82 % -WC to 4 % - NG was observed among litters. Inorganic orthophosphate (99.9 % and pyrophosphate (0.1 % were the only inorganic P forms, whereas the organic P forms orthophosphate monoesters (76.3 % and diester (23.7 % were detected. Diester P compounds were mineralized almost completely in all litters, except in the CH litter, within the incubation period. Pyrophosphates contributed with less than 0.5% and remained unaltered during the incubation period. Wood-chip litter had a higher organic P (40 % content and a higher diester: monoester ratio; it was therefore mineralized rapidly, within the first 15 days, achieving steady state by the 29th day. Distinct mineralization patterns were observed in the litter when incubated with a clayey Oxisol. The substantial decrease observed in the organic P fraction (Po of the litter types followed the order: CH (45 % > CC (25 % > RH (13 % ≈ NG (12 % > WC (5 %, whereas the Pi fraction increased. Incubation of RH litter in soil slowed down the mineralization of organic P.

  7. Distribution of Pb and its chemical fractions in liquid and solid phases of digested pig and dairy slurries%猪、奶牛粪厌氧发酵中Pb的形态转化及其分布特征

    Institute of Scientific and Technical Information of China (English)

    靳红梅; 付广青; 常志州; 叶小梅

    2013-01-01

    Anaerobic digestion treatment effectively degrades the organic matter and causes obvious variations in physical and chemical properties of digested slurries, such as water content, pH, oxidation reduction potential and microbial activities. These changes may influence the chemical fraction of Pb, which is a critical factor in predicting its toxicity, environmental mobility, bioavailability and optimum removal methods. The speciation and phytotoxic effects of lead from sewage sludge and composted manure have been widely studied. There has been no study about the transfer and distribution of Pb during anaerobic digestion of manure slurries. The aim of the present work was to analyze the distribution of Pb in both liquid and solid phase after anaerobic digestion of pig slurries and dairy slurries, and their chemical speciation in solid fraction of digested residuals. The continuous stirred tank reactor (CSTR) at condition of medium temperature [(37 ± 2)℃] was operated for 130 d. Lead in liquid and solid phases of raw materials and digested slurries was analyzed by first passing through a 0.45 µm filter paper. The chemical fractions in digested slurry solids were extracted by BCR method. Results showed that total amount of Pb was decreased 70% and 19% in digested pig slurries (DPS) and dairy slurries (DDS), respectively, , compared with raw slurries. The percentages of Pb in liquid fractions of DPS and DDS were 29%and 17%, which decreased by 17%and 58%. The decrease of Pb in DDS was significantly lower than that in DPS. One reason is that 90%of solids in DDS were discharged during the anaerobic digestion. Another reason is that Pb in digested slurries mainly exists as the solid form. Thus the amount of Pb left in the reactor for dairy manure digestion was significantly lower than that for pig manure digest. Due to the high removal efficiency, easy operation and low treatment cost of heavy metals in solid phase, transformation of liquid phase of heavy metals to the

  8. Fractional Complex Transform for Fractional Differential Equations

    OpenAIRE

    Li, Zheng-Biao; He, Ji-Huan

    2010-01-01

    Fractional complex transform is proposed to convert fractional differential equations into ordinary differential equations, so that all analytical methods devoted to advanced calculus can be easily applied to fractional calculus. Two examples are given.

  9. Constituintes químicos das frações de lichia in natura e submetidas à secagem: potencial nutricional dos subprodutos Chemical constituents of the in natura and dried fractions of litchi: nutritional potential of by-products

    Directory of Open Access Journals (Sweden)

    Estela de Rezende Queiroz

    2012-12-01

    Full Text Available A lichieira (Litchi chinensis Sonn. é uma planta da família das Sapindáceas, perfeitamente adaptada às condições climáticas brasileiras e pouco estudada quanto à composição química de seus frutos, sobretudo das frações casca e semente, frequentemente descartadas pela indústria e consumidores. Objetivou-se com este trabalho determinar os constituintes químicos das frações casca, polpa e semente in natura, e da casca e semente submetidas à secagem a 45ºC. Cada fração foi avaliada em sete repetições (de 20 frutos, quanto à massa e à proporção de cada fração em relação ao fruto inteiro, à composição centesimal, ao valor energético total (VET e aos parâmetros químicos e fisico-químicos: sólidos solúveis, pH e acidez titulável. As frações casca e semente de lichia, juntas, representam cerca de 50% da massa do fruto. A casca e a semente da lichia apresentam elevados VETs e teores de carboidratos. A casca possui os maiores teores de fibra (bruta e alimentar, lipídeos, cinzas e proteínas, e a polpa apresenta maior acidez, menor pH e maiores teores de sólidos solúveis. A secagem aumentou o pH da semente e os teores de sólidos solúveis da casca e semente. As frações de lichia apresentaram elevados potenciais energéticos e nutricionais, podendo ser aproveitadas como fonte alternativa de nutrientes, desde que não apresentem fatores antinutricionais em quantidades prejudiciais ao organismo.The litchi (Litchi chinensis Sonn. is a plant of the family Sapindacea, perfectly adapted to Brazilian climatic conditions and little studied in relation to the chemical composition of its fruits, especially the skin and seed fractions which are usually discarded by industry and consumers. The aim of this work was to determine the chemical constituents of the fresh fractions of the skin, pulp and seed, and of the drying fractions of the seed and skin at 45°C. Each fraction was evaluated in seven replicates (20 fruits, in

  10. Relevance of the bioavailable fraction of DDT and its metabolites in freshwater sediment toxicity: New insight into the mode of action of these chemicals on Dictyostelium discoideum.

    Science.gov (United States)

    Sforzini, Susanna; Governa, Daniela; Boeri, Marta; Oliveri, Laura; Oldani, Alessandro; Vago, Fabio; Viarengo, Aldo; Borrelli, Raffaella

    2016-10-01

    In this work, the toxicity of lake sediments contaminated with DDT and its metabolites DDD and DDE (collectively, DDX) was evaluated with widely used toxicity tests (i.e., Vibrio fischeri, Daphnia magna, Pseudokirchneriella subcapitata, and Lumbriculus variegatus) and with the social amoeba Dictyostelium discoideum, a model organism that is also suitable for studying pollutant-induced alterations at the molecular and cellular levels. Although the DDX concentration in the sediments was high (732.5 ppb), the results suggested a minimal environmental risk; in fact, no evidence of harmful effects was found using the different bioassays or when we considered the results of more sensitive sublethal biomarkers in D. discoideum amoebae. In line with the biological results, the chemical data showed that the concentration of DDX in the pore water (in general a highly bioavailable phase) showed a minimal value (0.0071ppb). To confirm the importance of the bioavailability of the toxic chemicals in determining their biological effects and to investigate the mechanisms of DDX toxicity, we exposed D. discoideum amoebae to 732.5ppb DDX in water solution. DDX had no effect on cell viability; however, a strong reduction in amoebae replication rate was observed, which depended mainly on a reduction in endocytosis rate and on lysosomal and mitochondrial alterations. In the presence of a moderate and transient increase in reactive oxygen species, the glutathione level in DDX-exposed amoebae drastically decreased. These results highlight that studies of the bioavailability of pollutants in environmental matrices and their biological effects are essential for site-specific ecological risk assessment. Moreover, glutathione depletion in DDX-exposed organisms is a new finding that could open the possibility of developing new pesticide mixtures that are more effective against DDT-resistant malaria vectors. PMID:27340883

  11. 城市污泥重金属形态及其生物有效性的研究%STUDY ON CHEMICAL FRACTIONS AND BIOAVAILABILITY OF HEAVY METALS IN SEWAGE SLUDGE

    Institute of Scientific and Technical Information of China (English)

    李淑更; 张可方; 周少奇; 陈秋丽; 张立秋

    2008-01-01

    The total contents and chemical fractions of heavy metals (Zn,Cu,Cd,Cr,Pb and Ni) in sewage sludge were analyzed in the present study with Tessier's procedure. The bioavailability of these heavy metals was also studied by potting planting of Dockleaf Knot-weed. The results showed that the total contents of Zn,Cu,Cd,Cr,Pb and Ni were all less than the Chinese sewage sludge criteria for agricuh.ural use (soil pH≥6.5). As for Zn,Cd,Cr and Pb,residual fraction was the predominant fraction,while for Cu and Ni,organic frac-tion was the predominant fraction. The proportions of unbioavailable forms of Zn,Cd,Cr and Pb were more than 50%,which was favorable for using sludge in agriculture. The roots of Dockleaf Knotweed could accumulate more heavy metals than shoots. The heavy metals absorbed by potted plant included not only exchangeable and carbonate forms,but also iron-manganese oxides and organic forms which were released under certain conditions.%采用Tessier连续提取法对城市污泥中的Zn、Cu、Cd、Cr、Pb、Ni进行了形态及总量分析,并通过盆栽实验研究了污泥中重金属的生物有效性.结果表明,污泥中Zn、Cu、Cd、Cr、Pb、Ni的含量均低于污泥农用控制标准值(土壤pH≥6.5);Zn、CA、Cr、Pb主要以残渣态存在,Cu、Ni主要存在形式为有机结合态;Zn、Cd、Cr、Pb的不可利用态所占比例均在50%以上,这对污泥农用是非常有利的.盆栽植物酸模叶蓼的根部对重金属的富集作用大于茎叶,其吸收的重金属不仅包括可交换态和碳酸盐结合态,还包括了在一定条件下释放出来的铁锰氧化态和有机结合态.

  12. Fractionation statistics

    Directory of Open Access Journals (Sweden)

    Zheng Chunfang

    2011-10-01

    Full Text Available Abstract Background Paralog reduction, the loss of duplicate genes after whole genome duplication (WGD is a pervasive process. Whether this loss proceeds gene by gene or through deletion of multi-gene DNA segments is controversial, as is the question of fractionation bias, namely whether one homeologous chromosome is more vulnerable to gene deletion than the other. Results As a null hypothesis, we first assume deletion events, on one homeolog only, excise a geometrically distributed number of genes with unknown mean µ, and these events combine to produce deleted runs of length l, distributed approximately as a negative binomial with unknown parameter r, itself a random variable with distribution π(·. A more realistic model requires deletion events on both homeologs distributed as a truncated geometric. We simulate the distribution of run lengths l in both models, as well as the underlying π(r, as a function of µ, and show how sampling l allows us to estimate µ. We apply this to data on a total of 15 genomes descended from 6 distinct WGD events and show how to correct the bias towards shorter runs caused by genome rearrangements. Because of the difficulty in deriving π(· analytically, we develop a deterministic recurrence to calculate each π(r as a function of µ and the proportion of unreduced paralog pairs. Conclusions The parameter µ can be estimated based on run lengths of single-copy regions. Estimates of µ in real data do not exclude the possibility that duplicate gene deletion is largely gene by gene, although it may sometimes involve longer segments.

  13. Chemical composition and acidity of size-fractionated inorganic aerosols of 2013-14 winter haze in Shanghai and associated health risk of toxic elements

    Science.gov (United States)

    Behera, Sailesh N.; Cheng, Jinping; Huang, Xian; Zhu, Qiongyu; Liu, Ping; Balasubramanian, Rajasekhar

    2015-12-01

    The severe winter haze episode that occurred in Shanghai from December 2013 to January 2014, characterized by elevated levels of particulate matter (PM), received considerable international attention because of its impacts on public health and disruption of day-to-day activities. To examine the characteristics of PM during this haze episode and to assess the chemistry behind formation of secondary inorganic aerosols (SIA) and associated health impacts due to exposure of toxic elements, we characterized eight water soluble inorganic (WSI) ions and twenty four trace elements in twelve size-fractionated PM (10 nm-9.9 μm). The average mass concentrations of coarse (1.8 μm < Dp < 9.9 μm), fine (Dp < 2.5 μm), ultrafine (0.01 μm < Dp < 0.10 μm) and nano (0.01 μm < Dp < 0.056 μm) particles during hazy days were 2.8, 5.2, 5.3 and 5.1 times higher than those during non-hazy days, respectively. The in-situ pH (pHIS), as predicted by the Aerosol Inorganic Model (AIM-IV) in all sizes of PM, was observed to be lower during hazy days (average of -0.64) than that during non-hazy days (average of -0.29); there was an increased acidity in haze aerosols. Based on the measured concentrations of particulate-bound toxic elements, health risk assessment was conducted, which revealed that the excess lifetime carcinogenic risk to individuals exposed to fine particles under haze events increased significantly (P < 0.05) to 69 ± 18 × 10-6 compared to non-hazy days (34 ± 10 × 10-6). The qualitative source attribution analysis suggested that the occurrence of haze could be due to a combination of increased emissions of PM from multiple anthropogenic sources followed by its accumulation under unfavourable meteorological conditions with lower mixing heights and less wind speeds and the formation of secondary aerosols.

  14. Novel integrated mechanical biological chemical treatment (MBCT) systems for the production of levulinic acid from fraction of municipal solid waste: A comprehensive techno-economic analysis.

    Science.gov (United States)

    Sadhukhan, Jhuma; Ng, Kok Siew; Martinez-Hernandez, Elias

    2016-09-01

    This paper, for the first time, reports integrated conceptual MBCT/biorefinery systems for unlocking the value of organics in municipal solid waste (MSW) through the production of levulinic acid (LA by 5wt%) that increases the economic margin by 110-150%. After mechanical separation recovering recyclables, metals (iron, aluminium, copper) and refuse derived fuel (RDF), lignocelluloses from remaining MSW are extracted by supercritical-water for chemical valorisation, comprising hydrolysis in 2wt% dilute H2SO4 catalyst producing LA, furfural, formic acid (FA), via C5/C6 sugar extraction, in plug flow (210-230°C, 25bar, 12s) and continuous stirred tank (195-215°C, 14bar, 20min) reactors; char separation and LA extraction/purification by methyl isobutyl ketone solvent; acid/solvent and by-product recovery. The by-product and pulping effluents are anaerobically digested into biogas and fertiliser. Produced biogas (6.4MWh/t), RDF (5.4MWh/t), char (4.5MWh/t) are combusted, heat recovered into steam generation in boiler (efficiency: 80%); on-site heat/steam demand is met; balance of steam is expanded into electricity in steam turbines (efficiency: 35%).

  15. Composition and effects of inhalable size fractions of atmospheric aerosols in the polluted atmosphere: part I. PAHs, PCBs and OCPs and the matrix chemical composition.

    Science.gov (United States)

    Landlová, Linda; Cupr, Pavel; Franců, Juraj; Klánová, Jana; Lammel, Gerhard

    2014-05-01

    Atmospheric particulate matter (PM) abundance, mass size distribution (MSD) and chemical composition are parameters relevant for human health effects. The MSD and phase state of semivolatile organic pollutants were determined at various polluted sites in addition to the PM composition and MSD. The distribution pattern of pollutants varied from side to side in correspondence to main particle sources and PM composition. Levels of particle-associated polycyclic aromatic hydrocarbons (PAHs) were 1-30 ng m(-3) (corresponding to 15-35 % of the total, i.e., gas and particulate phase concentrations), of polychlorinated biphenyls (PCBs) were 2-11 pg m(-3) (4-26 % of the total) and of DDT compounds were 2-12 pg m(-3) (4-23 % of the total). The PM associated amounts of other organochlorine pesticides were too low for quantification. The organics were preferentially found associated with particles matrix composition, amount of contaminants and toxicological effects occur. Legislative regulation based on gravimetric determination of PM mass can clearly be insufficient for assessment.

  16. Novel integrated mechanical biological chemical treatment (MBCT) systems for the production of levulinic acid from fraction of municipal solid waste: A comprehensive techno-economic analysis.

    Science.gov (United States)

    Sadhukhan, Jhuma; Ng, Kok Siew; Martinez-Hernandez, Elias

    2016-09-01

    This paper, for the first time, reports integrated conceptual MBCT/biorefinery systems for unlocking the value of organics in municipal solid waste (MSW) through the production of levulinic acid (LA by 5wt%) that increases the economic margin by 110-150%. After mechanical separation recovering recyclables, metals (iron, aluminium, copper) and refuse derived fuel (RDF), lignocelluloses from remaining MSW are extracted by supercritical-water for chemical valorisation, comprising hydrolysis in 2wt% dilute H2SO4 catalyst producing LA, furfural, formic acid (FA), via C5/C6 sugar extraction, in plug flow (210-230°C, 25bar, 12s) and continuous stirred tank (195-215°C, 14bar, 20min) reactors; char separation and LA extraction/purification by methyl isobutyl ketone solvent; acid/solvent and by-product recovery. The by-product and pulping effluents are anaerobically digested into biogas and fertiliser. Produced biogas (6.4MWh/t), RDF (5.4MWh/t), char (4.5MWh/t) are combusted, heat recovered into steam generation in boiler (efficiency: 80%); on-site heat/steam demand is met; balance of steam is expanded into electricity in steam turbines (efficiency: 35%). PMID:27085988

  17. Composition and effects of inhalable size fractions of atmospheric aerosols in the polluted atmosphere: part I. PAHs, PCBs and OCPs and the matrix chemical composition.

    Science.gov (United States)

    Landlová, Linda; Cupr, Pavel; Franců, Juraj; Klánová, Jana; Lammel, Gerhard

    2014-05-01

    Atmospheric particulate matter (PM) abundance, mass size distribution (MSD) and chemical composition are parameters relevant for human health effects. The MSD and phase state of semivolatile organic pollutants were determined at various polluted sites in addition to the PM composition and MSD. The distribution pattern of pollutants varied from side to side in correspondence to main particle sources and PM composition. Levels of particle-associated polycyclic aromatic hydrocarbons (PAHs) were 1-30 ng m(-3) (corresponding to 15-35 % of the total, i.e., gas and particulate phase concentrations), of polychlorinated biphenyls (PCBs) were 2-11 pg m(-3) (4-26 % of the total) and of DDT compounds were 2-12 pg m(-3) (4-23 % of the total). The PM associated amounts of other organochlorine pesticides were too low for quantification. The organics were preferentially found associated with particles contaminants and toxicological effects occur. Legislative regulation based on gravimetric determination of PM mass can clearly be insufficient for assessment. PMID:24488522

  18. Fractional Chemotaxis Diffusion Equations

    CERN Document Server

    Langlands, T A M

    2010-01-01

    We introduce mesoscopic and macroscopic model equations of chemotaxis with anomalous subdiffusion for modelling chemically directed transport of biological organisms in changing chemical environments with diffusion hindered by traps or macro-molecular crowding. The mesoscopic models are formulated using Continuous Time Random Walk master equations and the macroscopic models are formulated with fractional order differential equations. Different models are proposed depending on the timing of the chemotactic forcing. Generalizations of the models to include linear reaction dynamics are also derived. Finally a Monte Carlo method for simulating anomalous subdiffusion with chemotaxis is introduced and simulation results are compared with numerical solutions of the model equations. The model equations developed here could be used to replace Keller-Segel type equations in biological systems with transport hindered by traps, macro-molecular crowding or other obstacles.

  19. Schinus terebinthifolius scale-up countercurrent chromatography (Part I): High performance countercurrent chromatography fractionation of triterpene acids with off-line detection using atmospheric pressure chemical ionization mass spectrometry.

    Science.gov (United States)

    Vieira, Mariana Neves; Costa, Fernanda das Neves; Leitão, Gilda Guimarães; Garrard, Ian; Hewitson, Peter; Ignatova, Svetlana; Winterhalter, Peter; Jerz, Gerold

    2015-04-10

    'Countercurrent chromatography' (CCC) is an ideal technique for the recovery, purification and isolation of bioactive natural products, due to the liquid nature of the stationary phase, process predictability and the possibility of scale-up from analytical to preparative scale. In this work, a method developed for the fractionation of Schinus terebinthifolius Raddi berries dichloromethane extract was thoroughly optimized to achieve maximal throughput with minimal solvent and time consumption per gram of processed crude extract, using analytical, semi-preparative and preparative 'high performance countercurrent chromatography' (HPCCC) instruments. The method using the biphasic solvent system composed of n-heptane-ethyl acetate-methanol-water (6:1:6:1, v/v/v/v) was volumetrically scaled up to increase sample throughput up to 120 times, while maintaining separation efficiency and time. As a fast and specific detection alternative, the fractions collected from the CCC-separations were injected to an 'atmospheric pressure chemical ionization mass-spectrometer' (APCI-MS/MS) and reconstituted molecular weight MS-chromatograms of the APCI-ionizable compounds from S. terebinthifolius were obtained. This procedure led to the direct isolation of tirucallane type triterpenes such as masticadienonic and 3β-masticadienolic acids. Also oleanonic and moronic acids have been identified for the first time in the species. In summary, this approach can be used for other CCC scale-up processes, enabling MS-target-guided isolation procedures. PMID:25757818

  20. Chemical nature of soil humified fractions and their bioactivity Natureza química do húmus do solo e sua bioatividade

    Directory of Open Access Journals (Sweden)

    Luciano Pasqualoto Canellas

    2004-03-01

    Full Text Available The aim of this work was to evaluate the humus composition from an Ultisol from Campos dos Goytacazes, RJ, Brazil. Soil samples of four depths (0-0.05, 0.05-0.10, 0.10-0.20 and 0.20-0.40 m and its chemical nature were analysed by elemental composition, E4/E6 ratios and Fourier transformed infrared spectroscopy. The bioactivity of these humified substances was evaluated through their action on maize root growth and H+-ATPase activity of roots microsomes. In topsoil, the content of high condensed alkaline soluble humic substances is greater than that found in the subsuperficial layers. The chemical nature of humic and fulvic acids also varied with the soil depth. The humic acids isolated from the soil samples exhibited higher bioactivity compared with the fulvic acids. Moreover, the results suggest that more condensed humic substances can promote highest stimulation of the microsomal H+-ATPases from maize roots. These data reinforce the concept that the activity of the H+ pumps can be used as a biochemical marker for evaluation of humic substances bioactivity.O objetivo deste trabalho foi avaliar a composição do húmus de um Argissolo Amarelo de Campos dos Goytacazes, RJ, Brasil. Amostras de solo de quatro profundidades (0-0,05, 0,05-0,10, 0,10-0,20 e 0,20-0,40 m foram analisados mediante o fracionamento químico da matéria orgânica. As frações ácidos húmicos e fúlvicos foram extraídas e sua natureza química avaliada por meio da composição elementar, relação E4/E6 e espectroscopia de infravermelho transformada de Fourier. A bioatividade das substâncias húmicas foi avaliada mediante sua ação sobre o crescimento radicular de plântulas de milho e atividade da H+-ATPase da fração microssomal das raízes. Os resultados mostraram que é maior o conteúdo de substâncias húmicas alcalino solúveis mais condensadas na camada superficial do solo. A natureza química dos ácidos húmicos e fúlvicos também variou com a profundidade

  1. Therapeutic effect of chemical fractions of Smilax china on Chronic pelvic inflammation disease in rats%菝葜各化学部位对大鼠慢性盆腔炎模型的治疗作用

    Institute of Scientific and Technical Information of China (English)

    马云; 罗艳琴; 宋路瑶; 龚恬; 侯连兵

    2013-01-01

    Objective To study the effects of the total ethanol extract and separated chemical fractions of Smilax China on hematological and pathomorphological alterations in rats with chronic pelvic inflammation disease (CPID),and to identify the active sites of Smilax China for treating CPID.Methods One hundred and sixty female Sprague-Dawley rats were randomly divided into 16 groups.Rat CPID model were constructed by intrauterine injection of phenol mucilage.Each of the four chemical fractions of Smilax China was administered to the model rats by gavage with three different doses (32.4,16.2 and 8.1 g/kg) for 10 consecutive days,once per day.Jingangteng capsule was administered in a dose of 16.2 g/kg as a positive control group.The rats of model control group,control group and sham-operated group were administered with the same amount of distilled water.Twenty-four hours after the last drug administration,the rats were killed and blood was collected from the abdominal aorta for hematological analysis,while the two uteri were removed for pathomorphological analysis.Results Compared with the model control group,the ethyl acetate fraction of Smilax significantly ameliorated the inflammatory response in uterus at its high and middle dose (P < 0.01).Pathological analysis indicated that the uterus swelling extent decreased in Smilax China ethyl acetate fraction group.The anti-inflammation effect of Smilax China ethyl acetate fraction was equal to that of the total Smilax China ethanol extract,and was much better than that of Smilax China n-butanol fraction group and water fraction group.Conclusion The ethyl acetate fraction of Smilax China is the main active fraction against CPID.%目的 研究菝葜乙醇总提取物及各化学部位对慢性盆腔炎疾病(chronic pelvic inflammatory diease,CPID)模型大鼠的血液学及病理形态学改变的影响,筛选出菝葜抗慢性盆腔炎的主要活性部位.方法 160只SD雌性大鼠按随机数字表法分为16个组,除

  2. Ethanol fractionation precipitation and soluble polysaccharides from physico-chemical properties of Prunella vulgaris Linn%夏枯草水溶性多糖乙醇分级纯化及其理化性质研究

    Institute of Scientific and Technical Information of China (English)

    张霞; 聂少平; 李昌; 谢明勇

    2012-01-01

    研究了夏枯草水溶性多糖的理化性质。采用水提醇沉法从夏枯草果穗中得到夏枯草多糖,将所得多糖复溶于水.依次在乙醇体积分数为20%、30%、40%、50%、60%和70%的条件下分级醇沉多糖,得到PVLP-1、PVLP-2、PVLP-3、PVLP-4、PVLP-5和PVLP-6等六个多糖组分。测定各组分的糖含量、糖醛酸含量及蛋白质含量等基本理化指标,并用气相色谱法测定它们的单糖组成,同时对其进行紫外和红外光谱扫描考察其光谱性质。结果表明,PVLP-1、PVLP-2、PVLP-3、PVLP-4、PVLP-5和PVLP-6均为酸性多糖,蛋白质含量较高。六个组分都含有鼠李糖、阿拉伯糖、木糖、甘露糖、葡萄糖和半乳糖,其中木糖和阿拉伯糖含量最高,甘露糖最低,不合核糖和岩藻糖,但各组分中单糖具体摩尔组成比例不同.%The physico-chemical properties of soluble polysaccharides from Prunella Vulgaris Linn were studied. Soluble polysaccharides extracted with hot water and subsequently precipitated with ethanol,were successively fractionated by different gradient concentrations of ethanol (20%, 30%,40%,50%, 60% and 70%) into six fractions, named as PVLP-1, PVLP -2, PVLP -3, PVLP-4,PVLP-5 and PVLP-6. Contents of sugar, uronic acid and protein in these fractions were determined, monosaccharide compositions of them were also analyzed by gas chromatography(GC), UV and I R spectra analysis were run simultaneously to determine their spectroscopy properties. The result showed that all six fractions were acidic polysaccharides, with high protein content. Each of these fractions all contain rhamnose, arabinose,xylose, mannose, glucose and galactose, and xylose and arabinose were the main monosaccharides in them,the content of mannose was Iowest,fucose and ribose were not found,but the mol ratios of these monosaccharides in six fractions were different.

  3. Fractional Vector Calculus and Fractional Special Function

    OpenAIRE

    Li, Ming-Fan; Ren, Ji-Rong; Zhu, Tao

    2010-01-01

    Fractional vector calculus is discussed in the spherical coordinate framework. A variation of the Legendre equation and fractional Bessel equation are solved by series expansion and numerically. Finally, we generalize the hypergeometric functions.

  4. Study of the argillaceous fraction of sedimentary sequences of Meuse and Gard. Reconstitution of the diagenetic history and of the physico-chemical characteristics of the targets. Mineralogical, geochemical and isotopic aspects

    International Nuclear Information System (INIS)

    Very low permeable argillaceous rocks like Callovo-Oxfordian clay-stones or Vraconian siltstones were chosen to host a research laboratory built to determine the physico-chemical properties of the host formations for a potential underground disposal of radioactive waste. Knowledge and understanding of post-sedimentary modifications are of prime importance for definition of these properties; evaluation and quantification of the post-sedimentary changes represent the aim of this study, focused specifically on the clay material of the sequences. Samples were taken from two drillings (HTM102 and MAR501). In the HTM102 core samples, illite and mixed-layers illite/smectite are the dominant clay components of most clay fractions. Systematic SEM and TEM observations and isotopic K-Ar and Rb-Sr analyses pointed to diagenetic neo-formations of carbonates (calcite, dolomite) and clays. For instance, veils and laths of authigenic clay particles around old detrital ones can distinctly be observed. The epoch, duration and extent of the diagenetic activity(ies) are difficult to evaluate because of an overall detrital contribution even in the finest granulometric fractions. However; analysis of a bentonite layer in the sequence provides a diagenetic reference for the authigenic clay material. Correlation between relative sea level and authigenesis of smectite-rich mineral has been outlined. Chemistry of diagenetic fluids also seems to be reliable with sea level variations. These observations argue in favour of diagenetic activities limited in restricted rock volumes. The case study of MAR501 is close to the HTM102 one: smectite-rich illite/smectite mixed-layers represent the major component of the clay fraction and K-Ar values argue ire the sense of a mixing between detrital and younger clay populations. Diagenetic glauconites in the sequence yield are age close to 93,7 ±0,3 Ma for Vraconian level, in agreement with stratigraphical data. The case study of a clay-filled fault

  5. COMPOSIÇÃO, PERFIL NITROGENADO E CARACTERÍSTICAS DO LEITE CAPRINO (SAANEN: REGIÃO SUDESTE, BRASIL COMPOSITION, NITROGEN FRACTIONS AND PHYSICO-CHEMICAL CHARACTERISTICS OF SAANEN GOAT’S MILK: SOUTHEASTERN REGION, BRAZIL

    Directory of Open Access Journals (Sweden)

    L.F. PRATA

    1998-10-01

    Full Text Available Durante um ano, trabalhou-se com o leite de conjunto produzido por três grupos distintos de cabras "Saanen", perfazendo um total variável entre 44 e 56 animais em lactação e um total de 179 amostras analisadas, nas quais determinou-se a composição química, o perfil nitrogenado e as principais características físico-químicas. Para a composição geral, os valores determinados foram: 3,27% para proteína total, 3,74% para gordura, 4,35% para lactose, 0,74% para cinzas e 88,49% para água. O perfil nitrogenado distribuiu-se em: 3,27% para proteína bruta (PB, 2,97% para proteína verdadeira (TP, 2,43% para a fração caseínas (C, e 0,84% para as proteínas do soro (PS, incluindo 0,30% para a fração nitrogenada não protéica (NNP. As características determinadas foram: 1,0324 para a densidade a 15ºC, 6,65 para o pH a 25ºC, 16,11ºD para a acidez, 0,172 g% para o teor de cloretos, -0,574ºH para o ponto de congelamento, 11,51% para sólidos totais (ST, 7,77% para sólidos desengordurados (SD, 12,45% para o extrato seco total (EST calculado e 8,90% para o extrato seco desengordurado (ESD, também calculado.During a year, were collected and analysed 179 samples of milk from three goat’s herds, having between 44 and 56 milking animals, determining their chemical composition, their mainly nitrogen fractions and their physico-chemical properties. The chemical composition was: 3,27% for total nitrogen content, 3,74% for fat, 4,35% for lactose, 0,74% for ashes and 88,49% for water content. Nitrogen fractions were: 2,97% for true protein (TP, 2,43% for casein and 0,84% for serum proteins including 0,30% for non protein nitrogen matter. The values for physico-chemical properties or milk characteristics were: 1,0324 for density at 15ºC, 6,65 for pH at 25ºC, 16,11ºD for acidity, 0,172g% for chloride content, -0,574ºH for freezing point, 11,51% for total solids and 7,77% solids not-fat.

  6. 三峡库区消落带沉积物重金属形态分布特征%Chemical fraction composition characteristics of heavy metals in sediments of water-level-fluctuating zone of Three Gorges Reservoir area

    Institute of Scientific and Technical Information of China (English)

    王图锦; 杨清伟; 潘瑾; 刘雪莲

    2012-01-01

    Objective To investigate the spatial distribution characteristics and chemical fraction composition characteristics of Cu, Pb, Cd and Cr in sediments of water-level-fluctuating zone of Three Gorges Reservoir area. Methods The sediment samples were collected at eleven typical sites in August, 2008. The concentrations and fraction composition characteristics of Cu, Pb, Cd and Cr were determined, and the environment quality evaluation of the sediment was carried out by the methods of geoaccumulation index and risk assessment code. Results The average contents of Cu, Pb, Cd and Cr in sediments were 84.0, S6.2, 0.S6 and 99.2 mg/kg respectively. The geoaccumulation index (Igro) analysis suggested "moderate pollution" of Cu and Cd, and "unpolluted to moderate pollution" of Pb and Cr. Fractionation studies indicated that Cd was predominantly associated with carbonate and Fe-Mn oxide fractions. Cd exhibited the greatest mobility and bioavailability, indicative of anthropogenic sources, while Cr was mainly found in the residual fraction, the average content of residual fraction of Cr reached 93.1%, and could be used as an indicator for the contribution from natural sources. Cu was predominantly associated with organic and residual fractions, and Pb with carbonate, Fe-Mn oxide and residual fractions. Risk assessment code(RAC) analysis indicated that Cd posed a high ecological risk to local environment, Cu was at low to medium risk level,Pb was at low to medium risk level,and Cr showed no to low risk level in sediments. The ecological risk ranked as Cd>Pb>Cu>Cr. Conclusion The pollution level of Cd in sediments from the investigated area is higher and the speciation of Cd exhibits high bioavailability and consequently this element posed a high ecological risk.%目的 了解三峡库区消落带沉积物中Cu、Pb、Cd、Cr四种重金属的形态含量及其分布特征.方法 于2008年8月汛期采集三峡库区消落带11个采样点的沉积物,测定Cu、Pb、Cd、Cr的

  7. Matrix fractional systems

    Science.gov (United States)

    Tenreiro Machado, J. A.

    2015-08-01

    This paper addresses the matrix representation of dynamical systems in the perspective of fractional calculus. Fractional elements and fractional systems are interpreted under the light of the classical Cole-Cole, Davidson-Cole, and Havriliak-Negami heuristic models. Numerical simulations for an electrical circuit enlighten the results for matrix based models and high fractional orders. The conclusions clarify the distinction between fractional elements and fractional systems.

  8. A new procedure for Uranium fractionation

    Energy Technology Data Exchange (ETDEWEB)

    Costas Costas, E.; Baselga Cervara, B.; Tarin garcia, F.

    2014-07-01

    Nowadays only few procedures are employed for uranium fractionation, all of them at physico-chemical level. Ideally, we would develop a procedure based in a von Neumann machines (a rapid self-replicating machine capable of perform the uranium fractionation). Microorganism behave as von Newmann machines and al l known enzymatic processes are able to isotopic fractionation, often enriching the living organism in the lighter isotope. (Author)

  9. Fractional vector calculus and fractional Maxwell's equations

    International Nuclear Information System (INIS)

    The theory of derivatives and integrals of non-integer order goes back to Leibniz, Liouville, Grunwald, Letnikov and Riemann. The history of fractional vector calculus (FVC) has only 10 years. The main approaches to formulate a FVC, which are used in the physics during the past few years, will be briefly described in this paper. We solve some problems of consistent formulations of FVC by using a fractional generalization of the Fundamental Theorem of Calculus. We define the differential and integral vector operations. The fractional Green's, Stokes' and Gauss's theorems are formulated. The proofs of these theorems are realized for simplest regions. A fractional generalization of exterior differential calculus of differential forms is discussed. Fractional nonlocal Maxwell's equations and the corresponding fractional wave equations are considered

  10. On Multiplicative Fractional Calculus

    OpenAIRE

    Abdeljawad, Thabet

    2015-01-01

    We set the main concepts for multiplicative fractional calculus. We define Caputo, Riemann and Letnikov multiplicative fractional derivatives and multiplicative fractional integrals and study some of their properties. Finally, the multiplicative analogue of the local conformable fractional derivative and integral is studied.

  11. Initialized Fractional Calculus

    Science.gov (United States)

    Lorenzo, Carl F.; Hartley, Tom T.

    2000-01-01

    This paper demonstrates the need for a nonconstant initialization for the fractional calculus and establishes a basic definition set for the initialized fractional differintegral. This definition set allows the formalization of an initialized fractional calculus. Two basis calculi are considered; the Riemann-Liouville and the Grunwald fractional calculi. Two forms of initialization, terminal and side are developed.

  12. Tempered fractional calculus

    International Nuclear Information System (INIS)

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered fractional difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series

  13. Tempered fractional calculus

    Energy Technology Data Exchange (ETDEWEB)

    Sabzikar, Farzad, E-mail: sabzika2@stt.msu.edu [Department of Statistics and Probability, Michigan State University, East Lansing, MI 48823 (United States); Meerschaert, Mark M., E-mail: mcubed@stt.msu.edu [Department of Statistics and Probability, Michigan State University, East Lansing, MI 48823 (United States); Chen, Jinghua, E-mail: cjhdzdz@163.com [School of Sciences, Jimei University, Xiamen, Fujian, 361021 (China)

    2015-07-15

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered fractional difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series.

  14. Study of the carbonaceous fraction of the atmospheric aerosol in Chamonix and St Jean de Maurienne: seasonal evolutions, source and chemical characteristics; Etude de la fraction carbonee de l'aerosol atmospherique a Chamonix et St Jean de Maurienne: evolutions saisonnieres, sources et caracteristiques chimiques

    Energy Technology Data Exchange (ETDEWEB)

    Aymoz, G.

    2005-03-15

    The atmospheric aerosols play an important role in the earth climatic system. They are also at the origin of air pollution problems in urban areas. However, their influence on the global climactic change, as well as their chemical properties in urban zone, is still very poorly known. One of the main reasons to that is the lack of information on one of the major components of aerosol, the carbonaceous matter. This work focuses on a better knowledge of this particulate carbonaceous matter. This study presents measurements of carbonaceous matter (OC and EC) in aerosol (PM10) performed within the framework of the program POVA, between February 2001 and June 2003 in Chamonix and St Jean de Maurienne (French Alps). This series represents one of the first of this type for basic sites of alpine valleys, characterized by emissions located in the bottom of the valleys and strong temperature inversions in winter, limiting the dispersion of pollutants. The POVA program, centred on the study of air pollution in these valleys, was proposed following the closing of the 'Tunnel du Mont Blanc', in 1999. One of the main objectives was to evaluate the sources of pollution by particles, in particular the share due to the international heavy duty traffic. We could establish that, on the two sites and while the international heavy duty traffic was not restored in the Chamonix Valley, this source represented approximately a third of the observed mass of particles, and was at the origin of a weaker fraction of the carbonaceous matter mass. The extremely primary character of the carbonaceous matter is a remarkable specificity of our sites. The source of carbonaceous matter represented by light vehicles emissions could not be studied. Then, it appears that combustion of biomass (probably from fireplaces) plays an important role, increased in the case of low temperatures, on the levels of pollution by particles. Lastly, the potential impact of the semi-volatile matter condensation

  15. 气质联用法分析香茶菜不同部位挥发油的化学成分%GC-MS Analysis on Chemical Constituents of Volatile Oils in Different Fractions of Isodon Amethystoides

    Institute of Scientific and Technical Information of China (English)

    许可; 朱冬青; 王贤亲; 林崇良

    2013-01-01

    Objective:To study the differences of chemical constituents of the volatile oils in different fractions from the Isodon amethystoides.Methods:The volatile oils of Isodon amethystoides were extracted by steam distillation and were identified by GC-MS.The percentage composition of the volatile oils were calculated according to Peak area normalization method.Results:The major constituents of the volatile oils were alkanes,alcohols,acids and esters.8 compounds were identified from the stems,24 from the leaves,17 from the inflorescences,8 from the roots,and 32 from the rhizomes.Conclusion:It provides a basis for further development and utilization of Isodon amethystoides.%目的:研究香茶菜不同部位挥发油化学成分的差异.方法:水蒸气蒸馏法提取挥发油,利用GC-MS计算机联用仪定性分析,按峰面积归一化法求出挥发油中化学成分的百分含量.结果:香茶菜挥发油主要成分以烷烃、醇、酸、酯为主,香茶菜茎鉴定出8个化合物,香茶菜叶鉴定出24个化合物,香荼菜花序鉴定出17个化合物,香茶菜根鉴定出8个化合物,香茶菜根茎挥发油中鉴定出32个化合物.结论:为进一步开发利用香茶菜提供依据.

  16. Comparison of brown and white adipose tissue fat fractions in ob, seipin, and Fsp27 gene knockout mice by chemical shift-selective imaging and (1)H-MR spectroscopy.

    Science.gov (United States)

    Peng, Xin-Gui; Ju, Shenghong; Fang, Fang; Wang, Yu; Fang, Ke; Cui, Xin; Liu, George; Li, Peng; Mao, Hui; Teng, Gao-Jun

    2013-01-15

    Brown adipose tissue (BAT) plays a key role in thermogenesis to protect the body from cold and obesity. White adipose tissue (WAT) stores excess energy in the form of triglycerides. To better understand the genetic effect on regulation of WAT and BAT, we investigated the fat fraction (FF) in two types of adipose tissues in ob/ob, human BSCL2/seipin gene knockout (SKO), Fsp27 gene knockout (Fsp27(-/-)), and wild-type (WT) mice in vivo using chemical shift selective imaging and (1)H-MR spectroscopy. We reported that the visceral fat volume in WAT was significantly larger in ob/ob mice, but visceral fat volumes were lower in SKO and Fsp27(-/-) mice compared with WT mice. BAT FF was significantly higher in ob/ob mice than the WT group and similar to that of WAT. In contrast, WAT FFs in SKO and Fsp27(-/-) mice were lower and similar to that of BAT. The adipocyte size of WAT in ob/ob mice and the BAT adipocyte size in ob/ob, SKO, and Fsp27 mice were significantly larger compared with WT mice. However, the WAT adipocyte size was significantly smaller in SKO mice than in WT mice. Positive correlations were observed between the adipocyte size and FFs of WAT and BAT. These results suggested that smaller adipocyte size correlates with lower FFs of WAT and BAT. In addition, the differences in FFs in WAT and BAT measured by MR methods in different mouse models were related to the different regulation effects of ob, seipin, or Fsp27 gene on developing WAT and BAT.

  17. Fractional Dynamical Systems

    CERN Document Server

    Edelman, Mark

    2014-01-01

    In this paper the author presents the results of the preliminary investigation of fractional dynamical systems based on the results of numerical simulations of fractional maps. Fractional maps are equivalent to fractional differential equations describing systems experiencing periodic kicks. Their properties depend on the value of two parameters: the non-linearity parameter, which arises from the corresponding regular dynamical systems; and the memory parameter which is the order of the fractional derivative in the corresponding non-linear fractional differential equations. The examples of the fractional Standard and Logistic maps demonstrate that phase space of non-linear fractional dynamical systems may contain periodic sinks, attracting slow diverging trajectories, attracting accelerator mode trajectories, chaotic attractors, and cascade of bifurcations type trajectories whose properties are different from properties of attractors in regular dynamical systems. The author argues that discovered properties s...

  18. Fractional Vector Calculus and Fractional Maxwell's Equations

    OpenAIRE

    Vasily E. Tarasov

    2009-01-01

    The theory of derivatives and integrals of non-integer order goes back to Leibniz, Liouville, Grunwald, Letnikov and Riemann. The history of fractional vector calculus (FVC) has only 10 years. The main approaches to formulate a FVC, which are used in the physics during the past few years, will be briefly described in this paper. We solve some problems of consistent formulations of FVC by using a fractional generalization of the Fundamental Theorem of Calculus. We define the differential and i...

  19. Fractional Differential Forms

    OpenAIRE

    Cotrill-Shepherd, Kathleen; NAber, Mark

    2003-01-01

    A generalization of exterior calculus is considered by allowing the partial derivatives in the exterior derivative to assume fractional orders. That is, a fractional exterior derivative is defined. This is found to generate new vector spaces of finite and infinite dimension, fractional differential form spaces. The definitions of closed and exact forms are extended to the new fractional form spaces with closure and integrability conditions worked out for a special case. Coordinate transformat...

  20. Fractional Poisson Bracket

    CERN Document Server

    Golmankhaneh, Alireza Khalili

    2008-01-01

    In the present paper fractional Hamilton-Jacobi equation has been derived for dynamical systems involving Caputo derivative. Fractional Poisson-bracket is introduced. Further Hamilton's canonical equations are formulated and quantum wave equation corresponds to the fractional Hamilton-Jacobi equation is suggested. Illustrative examples have been worked out to explain the formalism.

  1. DIY Fraction Pack.

    Science.gov (United States)

    Graham, Alan; Graham, Louise

    2003-01-01

    Describes a very successful attempt to teach fractions to year 5 pupils based on pupils making their own fraction pack. Children decided for themselves how to make the fractional slices used in the activity using colored cardboard sheets and templates of a paper circle consisting of 24 equal slices. (Author/NB)

  2. Fractional Differential Equations

    Directory of Open Access Journals (Sweden)

    Jianping Zhao

    2012-01-01

    Full Text Available An extended fractional subequation method is proposed for solving fractional differential equations by introducing a new general ansätz and Bäcklund transformation of the fractional Riccati equation with known solutions. Being concise and straightforward, this method is applied to the space-time fractional coupled Burgers’ equations and coupled MKdV equations. As a result, many exact solutions are obtained. It is shown that the considered method provides a very effective, convenient, and powerful mathematical tool for solving fractional differential equations.

  3. Fractional smith chart theory

    KAUST Repository

    Shamim, Atif

    2011-03-01

    For the first time, a generalized Smith chart is introduced here to represent fractional order circuit elements. It is shown that the standard Smith chart is a special case of the generalized fractional order Smith chart. With illustrations drawn for both the conventional integer based lumped elements and the fractional elements, a graphical technique supported by the analytical method is presented to plot impedances on the fractional Smith chart. The concept is then applied towards impedance matching networks, where the fractional approach proves to be much more versatile and results in a single element matching network for a complex load as compared to the two elements in the conventional approach. © 2010 IEEE.

  4. Foam Fractionation of Lycopene: An Undergraduate Chemistry Experiment

    Science.gov (United States)

    Wang, Yan; Zhang, Mingjie; Hu, Yongliang

    2010-01-01

    A novel experiment for the extraction of lycopene from tomato paste by foam fractionation is described. Foam fractionation is a process for separating and concentrating chemicals by utilizing differences in their surface activities. Extraction of lycopene by foam fractionation is a new method that has not been previously reported in the…

  5. Fractional Dynamics and Control

    CERN Document Server

    Machado, José; Luo, Albert

    2012-01-01

    Fractional Dynamics and Control provides a comprehensive overview of recent advances in the areas of nonlinear dynamics, vibration and control with analytical, numerical, and experimental results. This book provides an overview of recent discoveries in fractional control, delves into fractional variational principles and differential equations, and applies advanced techniques in fractional calculus to solving complicated mathematical and physical problems.Finally, this book also discusses the role that fractional order modeling can play in complex systems for engineering and science. Discusses how fractional dynamics and control can be used to solve nonlinear science and complexity issues Shows how fractional differential equations and models can be used to solve turbulence and wave equations in mechanics and gravity theories and Schrodinger’s equation  Presents factional relaxation modeling of dielectric materials and wave equations for dielectrics  Develops new methods for control and synchronization of...

  6. Fractional factorial plans

    CERN Document Server

    Dey, Aloke

    2009-01-01

    A one-stop reference to fractional factorials and related orthogonal arrays.Presenting one of the most dynamic areas of statistical research, this book offers a systematic, rigorous, and up-to-date treatment of fractional factorial designs and related combinatorial mathematics. Leading statisticians Aloke Dey and Rahul Mukerjee consolidate vast amounts of material from the professional literature--expertly weaving fractional replication, orthogonal arrays, and optimality aspects. They develop the basic theory of fractional factorials using the calculus of factorial arrangements, thereby providing a unified approach to the study of fractional factorial plans. An indispensable guide for statisticians in research and industry as well as for graduate students, Fractional Factorial Plans features: * Construction procedures of symmetric and asymmetric orthogonal arrays. * Many up-to-date research results on nonexistence. * A chapter on optimal fractional factorials not based on orthogonal arrays. * Trend-free plans...

  7. Fractional vortex Hilbert's Hotel

    CERN Document Server

    Gbur, Greg

    2015-01-01

    We demonstrate how the unusual mathematics of transfinite numbers, in particular a nearly perfect realization of Hilbert's famous hotel paradox, manifests in the propagation of light through fractional vortex plates. It is shown how a fractional vortex plate can be used, in principle, to create any number of "open rooms," i.e. topological charges, simultaneously. Fractional vortex plates are therefore demonstrated to create a singularity of topological charge, in which the vortex state is completely undefined and in fact arbitrary.

  8. Fractional Derivative and Integral

    OpenAIRE

    Aygören, Aysel

    2014-01-01

    ABSTRACT: In this thesis we studied fractional order derivative and integral. In Chapter1, a brief history on the foundation of fractional derivative and integration has been given. In the second chapter, some definitions and theorems have been provided. Also some needed special functions such as Gamma, Beta, Mittag-Leffler and Wright function have taken place in this chapter. Properties of fractional derivative and integral are discussed in Chapter 3. We started to this chapter by the dis...

  9. Fractional Pure Birth Processes

    CERN Document Server

    Orsingher, Enzo; 10.3150/09-BEJ235

    2010-01-01

    We consider a fractional version of the classical non-linear birth process of which the Yule-Furry model is a particular case. Fractionality is obtained by replacing the first-order time derivative in the difference-differential equations which govern the probability law of the process, with the Dzherbashyan-Caputo fractional derivative. We derive the probability distribution of the number $ \\mathcal{N}_\

  10. Monomer Fraction in Real Gases

    Directory of Open Access Journals (Sweden)

    Boris Sedunov

    2008-03-01

    Full Text Available This work is aimed to attract attention to monomer fraction density (MFD, the variable that has not yet taken its place in the theory of real gases. The work shows that this variable can be calculated for monocomponent real gases from experimental isothermal dependences of their density on pressure and can be used for calculations of Gibbs energy, entropy and clusters equilibrium constants in real gases. The MFD-based joint series expansions method for density and pressure is suggested as an alternative to virial expansions. This method corresponds to the chemical equilibrium theory and provides new non-obvious results.

  11. Fractional Diffusion based on Riemann-Liouville Fractional Derivatives

    OpenAIRE

    Hilfer, R.

    2000-01-01

    A fractional diffusion equation based on Riemann-Liouville fractional derivatives is solved exactly. The initial values are given as fractional integrals. The solution is obtained in terms of $H$-functions. It differs from the known solution of fractional diffusion equations based on fractional integrals. The solution of fractional diffusion based on a Riemann-Liouville fractional time derivative does not admit a probabilistic interpretation in contrast with fractional diffusion based on frac...

  12. Social Trust and Fractionalization:

    DEFF Research Database (Denmark)

    Bjørnskov, Christian

    2008-01-01

    a much larger country sample than in previous literature confirms that fractionalization in the form of income inequality and political diversity adversely affects social trust while ethnic diversity does not. However, these effects differ systematically across countries, questioning standard......This paper takes a closer look at the importance of fractionalization for the creation of social trust. It first argues that the determinants of trust can be divided into two categories: those affecting individuals' trust radii and those affecting social polarization. A series of estimates using...... interpretations of the influence of fractionalization on trust....

  13. Active chemical fractions of stem bark extract of Khaya grandifoliola C.DC and Entada africana Guill. et Perr. synergistically protect primary rat hepatocytes against paracetamol-induced damage

    OpenAIRE

    Njayou, Frédéric Nico; Kouam, Arnaud Fondjo; Simo, Brice Fredy Nemg; Tchana, Angèle Nkouatchoua; Moundipa, Paul Fewou

    2016-01-01

    Background Khaya grandifoliola (Meliaceae) and Entada africana (Fabaceae) are traditionally used in Bamun (a western tribe of Cameroon) traditional medicine for the treatment of liver related diseases. In this study, the synergistic hepatoprotective effect of respective active fractions of the plants were investigated against paracetamol-induced toxicity in primary cultures of rat hepatocytes. Methods Paracetamol conferred hepatocyte toxicity, as determined by the 3-(4,5-dimethylthiazol-2-yl)...

  14. Atividade anticolinesterásica e perfil químico de uma fração cromatográfica ativa do extrato etanólico das flores Bellis perennis L. (Asteraceae Anticholinesterase activity and chemical profile of an active chromatographic fraction of ethanolic extract from Bellis perennis L. (Asteraceae flowers

    Directory of Open Access Journals (Sweden)

    Thiago Henrique Costa Marques

    2013-01-01

    Full Text Available This work describes the isolation of an active flavonoid fraction and identification of isorhamnetin 3-O-β-D-(6''-acetyl-galactopyranoside from flowers of B. perennis, and also the evaluation of anticholinesterase (AChE activity of ethanolic extract from flowers (EEF and the active fraction. The chemical structure of the flavonoid was defined on the basis of spectroscopic ¹H NMR, IR and UV data. EEF or flavonoid reduces AChE activity in vivo, while flavonoid also reduces AChE activity in vitro, showing a value of 1.49 mM for 50% inhibitory concentration (IC50, suggesting potential use as an insecticide or in the treatment of neurodegenerative diseases such as Alzheimer's disease.

  15. Chemical fractionation method for characterization of biomass-based bottom and fly ash fractions from large-sized power plant of an integrated pulp and paper mill complex%化学分离法分析大型纸浆发电厂废渣中生物质底灰和飞灰成分

    Institute of Scientific and Technical Information of China (English)

    Risto PÖYKIÖ; Hannu NURMESNIEMI; Olli DAHL; Mikko MÄKELÄ

    2014-01-01

    The aim of this study was to extract the biomass-based bottom and fly ash fractions by a three-stage fractionation method for water-soluble (H2O), ammonium-acetate (CH3COONH4) and hydrochloric acid (HCl) fractions in order to access the leaching behaviour of these residues. Except for Mo, S, Na and elements whose concentrations were lower than the detection limits, the extractable element concentrations in both ash fractions followed the order H2O

  16. Discrete fractional calculus

    CERN Document Server

    Goodrich, Christopher

    2015-01-01

    This text provides the first comprehensive treatment of the discrete fractional calculus. Experienced researchers will find the text useful as a reference for discrete fractional calculus and topics of current interest. Students who are interested in learning about discrete fractional calculus will find this text to provide a useful starting point. Several exercises are offered at the end of each chapter and select answers have been provided at the end of the book. The presentation of the content is designed to give ample flexibility for potential use in a myriad of courses and for independent study. The novel approach taken by the authors includes a simultaneous treatment of the fractional- and integer-order difference calculus (on a variety of time scales, including both the usual forward and backwards difference operators). The reader will acquire a solid foundation in the classical topics of the discrete calculus while being introduced to exciting recent developments, bringing them to the frontiers of the...

  17. Intracellular Cadmium Isotope Fractionation

    Science.gov (United States)

    Horner, T. J.; Lee, R. B.; Henderson, G. M.; Rickaby, R. E.

    2011-12-01

    Recent stable isotope studies into the biological utilization of transition metals (e.g. Cu, Fe, Zn, Cd) suggest several stepwise cellular processes can fractionate isotopes in both culture and nature. However, the determination of fractionation factors is often unsatisfactory, as significant variability can exist - even between different organisms with the same cellular functions. Thus, it has not been possible to adequately understand the source and mechanisms of metal isotopic fractionation. In order to address this problem, we investigated the biological fractionation of Cd isotopes within genetically-modified bacteria (E. coli). There is currently only one known biological use or requirement of Cd, a Cd/Zn carbonic anhydrase (CdCA, from the marine diatom T. weissfloggii), which we introduce into the E. coli genome. We have also developed a cleaning procedure that allows for the treating of bacteria so as to study the isotopic composition of different cellular components. We find that whole cells always exhibit a preference for uptake of the lighter isotopes of Cd. Notably, whole cells appear to have a similar Cd isotopic composition regardless of the expression of CdCA within the E. coli. However, isotopic fractionation can occur within the genetically modified E. coli during Cd use, such that Cd bound in CdCA can display a distinct isotopic composition compared to the cell as a whole. Thus, the externally observed fractionation is independent of the internal uses of Cd, with the largest Cd isotope fractionation occurring during cross-membrane transport. A general implication of these experiments is that trace metal isotopic fractionation most likely reflects metal transport into biological cells (either actively or passively), rather than relating to expression of specific physiological function and genetic expression of different metalloenzymes.

  18. Calculus of variations with fractional derivatives and fractional integrals

    OpenAIRE

    Almeida, Ricardo; Delfim F. M. Torres

    2009-01-01

    We prove Euler-Lagrange fractional equations and sufficient optimality conditions for problems of the calculus of variations with functionals containing both fractional derivatives and fractional integrals in the sense of Riemann-Liouville.

  19. Effects of Different Livestock Manures Combined with Chemical Fertilizers on Contents and Fractions of Zn in Black Soil%不同畜禽粪肥与化肥配施下黑土中Zn含量及形态变化特征

    Institute of Scientific and Technical Information of China (English)

    杨子仪; 吴景贵; 冯娜娜; 陈闯

    2014-01-01

    Applying livestock manures has resulted in accumulation of heavy metals in soils. Impacts of heavy metals on the eco-environ-ment are greatly dependent on their forms. Here a 3-year incubation experiment was conducted to study the effects of different livestock ma-nures combined with chemical fertilizers on the dynamics of contents and forms of Zn in black soil. Modified BCR sequential extraction pro-cedure was used to fractionate Zn forms. Combined applications of manures and chemical fertilizers increased the contents of total Zn and Zn fractions. Total Zn in the pig manure plus chemical fertilizer treatment was 1.69 times as much as that in the chemical fertilizers only, and each fraction of soil Zn was increased by an average of 238.9%. The combined application also led to a transformation of Zn from low bioavailability fractions(Organic matter fraction and Residual fraction)to high bioavailability fractions(Weak acid soluble and Reducible fractions). The degree of Zn transformation was in order of pig manures>chicken manure>cow manure/fertilizers only. No mater fertilization or not, soil pH and organic matter contents were significantly negatively correlated with weak acid soluble and reducible fractions, but posi-tively with organic and residual fractions of Zn. Combined applications enhanced the positive correlation between residual fraction and pH, but had no effects on the correlation between Zn fractions and organic matter contents. Therefore, the combined application of manures and chemical fertilizer caused accumulation of Zn and improved the bioavailability of Zn, thus increasing the risk of soil pollution, with pig ma-nure having the greatest impact on Zn pollution.%通过培养实验并采用改进的BCR连续提取法研究了不同畜禽粪肥与化肥配施作用下黑土中Zn含量及形态在3年内动态变化特征。研究结果显示:不同畜禽粪肥与化肥配施增加了土壤中Zn总量和土壤各形态Zn含量,其中猪粪与化

  20. Protein and Lipid Binding Parameters in Rainbow Trout (Oncorhynchus mykiss) Blood and Liver Fractions to Extrapolate from an in Vitro metabolic Degradation Assay to in Vivo Bioaccumulation Potential of Hydrophobic Organic Chemicals

    Science.gov (United States)

    Biotransformation reduces the extent to which environmental contaminants accumulate in fish and other aquatic biota. Unfortunately, the tendency for compounds to be metabolized is not easily predicted from physico-chemical properties (e.g., octanol:water partitioning) or an exam...

  1. Study of the argillaceous fraction of sedimentary sequences of Meuse and Gard. Reconstitution of the diagenetic history and of the physico-chemical characteristics of the targets. Mineralogical, geochemical and isotopic aspects; Etude de la fraction argileuse de sequences sedimentaires de la Meuse et du Gard. Reconstitution de l'histoire diagenetique et des caracteristiques physico-chimiques des cibles. Aspects mineralogiques, geochimiques et isotopiques

    Energy Technology Data Exchange (ETDEWEB)

    Rousset, D

    2002-01-01

    Very low permeable argillaceous rocks like Callovo-Oxfordian clay-stones or Vraconian siltstones were chosen to host a research laboratory built to determine the physico-chemical properties of the host formations for a potential underground disposal of radioactive waste. Knowledge and understanding of post-sedimentary modifications are of prime importance for definition of these properties; evaluation and quantification of the post-sedimentary changes represent the aim of this study, focused specifically on the clay material of the sequences. Samples were taken from two drillings (HTM102 and MAR501). In the HTM102 core samples, illite and mixed-layers illite/smectite are the dominant clay components of most clay fractions. Systematic SEM and TEM observations and isotopic K-Ar and Rb-Sr analyses pointed to diagenetic neo-formations of carbonates (calcite, dolomite) and clays. For instance, veils and laths of authigenic clay particles around old detrital ones can distinctly be observed. The epoch, duration and extent of the diagenetic activity(ies) are difficult to evaluate because of an overall detrital contribution even in the finest granulometric fractions. However; analysis of a bentonite layer in the sequence provides a diagenetic reference for the authigenic clay material. Correlation between relative sea level and authigenesis of smectite-rich mineral has been outlined. Chemistry of diagenetic fluids also seems to be reliable with sea level variations. These observations argue in favour of diagenetic activities limited in restricted rock volumes. The case study of MAR501 is close to the HTM102 one: smectite-rich illite/smectite mixed-layers represent the major component of the clay fraction and K-Ar values argue ire the sense of a mixing between detrital and younger clay populations. Diagenetic glauconites in the sequence yield are age close to 93,7 {+-}0,3 Ma for Vraconian level, in agreement with stratigraphical data. The case study of a clay-filled fault

  2. Fractional and noncommutative spacetimes

    Science.gov (United States)

    Arzano, Michele; Calcagni, Gianluca; Oriti, Daniele; Scalisi, Marco

    2011-12-01

    We establish a mapping between fractional and noncommutative spacetimes in configuration space. Depending on the scale at which the relation is considered, there arise two possibilities. For a fractional spacetime with log-oscillatory measure, the effective measure near the fundamental scale determining the log-period coincides with the nonrotation-invariant but cyclicity-preserving measure of κ-Minkowski spacetime. At scales larger than the log-period, the fractional measure is averaged and becomes a power law with real exponent. This can be also regarded as the cyclicity-inducing measure in a noncommutative spacetime defined by a certain nonlinear algebra of the coordinates, which interpolates between κ-Minkowski and canonical spacetime. These results are based upon a braiding formula valid for any nonlinear algebra which can be mapped onto the Heisenberg algebra.

  3. Fractional and noncommutative spacetimes

    CERN Document Server

    Arzano, Michele; Oriti, Daniele; Scalisi, Marco

    2011-01-01

    We establish a mapping between fractional and noncommutative spacetimes in configuration space. Depending on the scale at which the relation is considered, there arise two possibilities. For a fractional spacetime with log-oscillatory measure, the effective measure near the fundamental scale determining the log-period coincides with the non-rotation-invariant but cyclicity-preserving measure of \\kappa-Minkowski. At scales larger than the log-period, the fractional measure is averaged and becomes a power-law with real exponent. This can be also regarded as the cyclicity-inducing measure in a noncommutative spacetime defined by a certain nonlinear algebra of the coordinates, which interpolates between \\kappa-Minkowski and canonical spacetime. These results are based upon a braiding formula valid for any nonlinear algebra which can be mapped onto the Heisenberg algebra.

  4. Fractional Vortices and Lumps

    CERN Document Server

    Eto, Minoru; Gudnason, Sven Bjarke; Konishi, Kenichi; Nagashima, Takayuki; Nitta, Muneto; Ohashi, Keisuke; Vinci, Walter

    2009-01-01

    We study what might be called fractional vortices, vortex configurations with the minimum winding from the viewpoint of their topological stability, but which are characterized by various notable substructures in the transverse energy distribution. The fractional vortices occur in diverse Abelian or non-Abelian generalizations of the Higgs model. The global and local features characterizing these are studied, and we identify the two crucial ingredients for their occurrence - the vacuum degeneracy leading to non-trivial vacuum moduli M, and the BPS nature of the vortices. Fractional vortices are further classified into two kinds. The first type of such vortices appear when M has orbifold Z_n singularities; the second type occurs in systems in which the vacuum moduli space M possesses either a deformed geometry or some singularity. These general features are illustrated with several concrete models.

  5. Fracionamento químico e físico da matéria orgânica de um argissolo vermelho sob diferentes sistemas de uso Physical and chemical fractionation of organic matter of an alfisol under different use systems

    Directory of Open Access Journals (Sweden)

    Daiane Carvalho dos Santos

    2013-05-01

    Full Text Available Objetivou-se com este estudo avaliar o carbono orgânico total e as frações físicas e químicas da matéria orgânica (MO do solo em um Argissolo Vermelho Eutrófico arênico, submetido a diferentes sistemas de uso. Os sistemas de uso do solo avaliados foram: florestamento homogêneo de Eucalyptus grandis (EUC, sistema agrossilvipastoril na faixa (ASP e campo nativo (CN, nas camadas de 0,000-0,025m e de 0,025-0,075m. A fração grosseira (CFG e o carbono associado aos minerais (CAM foram obtidos por meio de fracionamento físico granulométrico. As frações leve livre (FLL, leve oclusa (FLO e pesada (FP foram obtidas por meio de fracionamento físico densimétrico. As frações não húmicas (NH, ácido fúlvico (AF, ácido húmico (AH e humina (HU foram obtidas por meio de fracionamento químico. O sistema EUC promoveu maiores estoques de carbono orgânico total, CFG, FLL e FLO e na fração AF nas camadas avaliadas. Na camada superficial, os mecanismos de proteção da MO por recalcitrância molecular e estabilização química estão sobrepondo a estabilidade decorrente da oclusão em agregados. Com a dificuldade de formar agregados, devido a matrizes arenosas desse solo, o carbono jovem que entra no sistema é decomposto pelos microrganismos, entrando em um estágio mais avançado de decomposição e, nesse caso, formando associações com as partículas silte e argila, mesmo em solos em que o percentual de argila é baixo. Através do fracionamento químico, observou-se que a maior parte da MO do solo encontra-se armazenada na forma de HU.The objective of this study was to evaluate the total organic carbon and the physical and chemical fractions of organic matter in an Alfisol under different use systems. The land use systems evaluated was homogeneous forestry of Eucalyptus grandis, agrosilvopastoral system and native grassland, in layers from 0.000-0.025 and 0.025-0.075m depth. The coarse fraction (CFG and the carbon associated

  6. Chemical and functional characterization of seed, pulp and skin powder from chilto (Solanum betaceum), an Argentine native fruit. Phenolic fractions affect key enzymes involved in metabolic syndrome and oxidative stress.

    Science.gov (United States)

    Orqueda, María Eugenia; Rivas, Marisa; Zampini, Iris Catiana; Alberto, María Rosa; Torres, Sebastian; Cuello, Soledad; Sayago, Jorge; Thomas-Valdes, Samanta; Jiménez-Aspee, Felipe; Schmeda-Hirschmann, Guillermo; Isla, María Inés

    2017-02-01

    The aim of this work was to assess the nutritional and functional components of powder obtained by lyophilization of whole fruits, seeds, pulp and skin from chilto (Solanum betaceum Cav) cultivated in the ecoregion of Yungas, Argentina. The powders have low carbohydrate and sodium content and are a source of vitamin C, carotenoid, phenolics, potassium and fiber. The HPLC-ESI-MS/MS analysis of the fractions enriched in phenolics allowed the identification of 12 caffeic acid derivatives and related phenolics, 10 rosmarinic acid derivatives and 7 flavonoids. The polyphenols enriched extracts before and after simulated gastroduodenal digestion inhibited enzymes associated with metabolic syndrome, including α-glucosidase, amylase and lipase and exhibited antioxidant activity by different mechanisms. None of the analyzed fruit powders showed acute toxicity or genotoxicity. The powders from the three parts of S. betaceum fruit may be a potential functional food and the polyphenol enriched extract of seed and skin may have nutraceutical properties. PMID:27596394

  7. Momentum fractionation on superstrata

    Science.gov (United States)

    Bena, Iosif; Martinec, Emil; Turton, David; Warner, Nicholas P.

    2016-05-01

    Superstrata are bound states in string theory that carry D1, D5, and momentum charges, and whose supergravity descriptions are parameterized by arbitrary functions of (at least) two variables. In the D1-D5 CFT, typical three-charge states reside in high-degree twisted sectors, and their momentum charge is carried by modes that individually have fractional momentum. Understanding this momentum fractionation holographically is crucial for understanding typical black-hole microstates in this system. We use solution-generating techniques to add momentum to a multi-wound supertube and thereby construct the first examples of asymptotically-flat superstrata. The resulting supergravity solutions are horizonless and smooth up to well-understood orbifold singularities. Upon taking the AdS3 decoupling limit, our solutions are dual to CFT states with momentum fractionation. We give a precise proposal for these dual CFT states. Our construction establishes the very nontrivial fact that large classes of CFT states with momentum fractionation can be realized in the bulk as smooth horizonless supergravity solutions.

  8. Vapor liquid fraction determination

    International Nuclear Information System (INIS)

    This invention describes a method of measuring liquid and vapor fractions in a non-homogeneous fluid flowing through an elongate conduit, such as may be required with boiling water, non-boiling turbulent flows, fluidized bed experiments, water-gas mixing analysis, and nuclear plant cooling. (UK)

  9. A Fractional Survival Model

    OpenAIRE

    Lee, Cheng K.; Lee, Jenq-Daw

    2006-01-01

    A survival model is derived from the exponential function using the concept of fractional differentiation. The hazard function of the proposed model generates various shapes of curves including increasing, increasing-constant-increasing, increasing-decreasing-increasing, and so-called bathtub hazard curve. The model also contains a parameter that is the maximum of the survival time.

  10. Avoidance of Fractions.

    Science.gov (United States)

    Hart, Kathleen; Kerslake, Daphne

    The Concepts in Secondary Mathematics and Science (CSMS) and Strategies and Errors in Secondary Mathematics (SESM) research projects based at Chelsa College, England, have shown the marked reluctance of secondary school students to use fractions when solving mathematical problems, even though they have been taught the topic for a number of years.…

  11. Fractional Differential Equation

    Directory of Open Access Journals (Sweden)

    Moustafa El-Shahed

    2007-01-01

    where 2<α<3 is a real number and D0+α is the standard Riemann-Liouville fractional derivative. Our analysis relies on Krasnoselskiis fixed point theorem of cone preserving operators. An example is also given to illustrate the main results.

  12. Understanding Fraction Multiplication.

    Science.gov (United States)

    Bezuk, Nadine S.; Armstrong, Barbara E.

    1992-01-01

    Presents five activities to help students construct meaning for multiplying fractions through real-world problem contexts, physical or pictorial models, the recognition of patterns, and the use of calculators. In the context of a garden plot, worksheets examine various aspects of parts of plots, patterns in plots, and a maximization problem.…

  13. Field-Flow Fractionation.

    Science.gov (United States)

    Caldwell, Karin D.

    1988-01-01

    Describes a technique for separating samples that range over 15 orders of magnitude in molecular weight. Discusses theory, apparatus, and sample preparation techniques. Lists several types of field-flow fractionation (FFF) and their uses: sedimentation FFF, thermal FFF, flow FFF, electrical FFF, and steric FFF. (ML)

  14. Fractional gradient and its application to the fractional advection equation

    OpenAIRE

    D'Ovidio, M; Garra, R.

    2013-01-01

    In this paper we provide a definition of fractional gradient operators, related to directional derivatives. We develop a fractional vector calculus, providing a probabilistic interpretation and mathematical tools to treat multidimensional fractional differential equations. A first application is discussed in relation to the d-dimensional fractional advection-dispersion equation. We also study the connection with multidimensional L\\'evy processes.

  15. From Complex Fractional Fourier Transform to Complex Fractional Radon Transform

    Institute of Scientific and Technical Information of China (English)

    FANHong-Yi; JIANGNian-Quan

    2004-01-01

    We show that for n-dimensional complex fractional Fourier transform the corresponding complex fractional Radon transform can also be derived, however, it is different from the direct product of two n-dimensional real fractional Radon transforms. The complex fractional Radon transform of two-mode Wigner operator is calculated.

  16. Parameter estimation for fractional birth and fractional death processes

    OpenAIRE

    Cahoy, Dexter O.; Polito, Federico

    2013-01-01

    The fractional birth and the fractional death processes are more desirable in practice than their classical counterparts as they naturally provide greater flexibility in modeling growing and decreasing systems. In this paper, we propose formal parameter estimation procedures for the fractional Yule, the fractional linear death, and the fractional sublinear death processes. The methods use all available data possible, are computationally simple and asymptotically unbiased. The procedures explo...

  17. Decontamination by fractional distillation of a radioactive mixture of perchlorethylene, bitumen, and sludges from chemical co-precipitations; Decontamination par distillation fractionnee d'un melange radioactif constitue par du perchlorethylene, du bitume et des boues de coprecipitation chimique

    Energy Technology Data Exchange (ETDEWEB)

    Lefillatre, G.; Hullo, R. [Commissariat a l' Energie Atomique, Chusclan (France). Centre de Production de Plutonium de Marcoule

    1969-07-01

    It is not possible to incinerate the contaminated organic waste containing chlorine, produced at the Marcoule Centre. The only valid method for these solvents of average activity is fractional distillation. This report presents a pilot fractional distillation plant designed for decontaminating the residual solvents produced by the Centre's Waste Processing Station. These contaminated solvents come from the decontamination of a screw extrusion apparatus with perchlorethylene; this equipment is used for coating the radioactive sludges with bitumen. The pilot plant operates discontinuously and is used to decontaminate the perchlorethylene, to separate the perchlorethylene from the water, and to process the distillation residue. The electrically heated boiler is fitted with a removable base in the form of a disposable container. The installations decontamination factor is 3.4 x 10{sup 6} when solvents with a specific activity of 0.23 Ci/m{sup 3} are used. The average flow-rate for a distillation run is 10 l/hr at atmospheric pressure, and 21 l/hr at a residual pressure of 40 torr. The decontamination factor for the installation is better at atmospheric pressure than in a vacuum. (authors) [French] Les effluents organiques contamines chlores du Centre de Marcoule ne peuvent etre incineres. Le seul mode de traitement qui s'impose pour ces solvants de moyenne activite s'avere etre la distillation fractionnee. Ce rapport presente une installation pilote de distillation fractionnee qui a ete concue pour decontaminer des solvants residuaires provenant de la Station de Traitement des Effluents du Centre. Ces solvants contamines resultent de la decontamination au moyen de perchlorethylene d'une extrudeuse a vis servant a l'enrobage par le bitume des boues radioactives de cette station. L'installation pilote fonctionne en discontinu et assure a la fois la decontamination du perchlorethylene, la separation du perchlorethylene et de l'eau et le

  18. Towards closing the gap between hygroscopic growth and CCN activation for secondary organic aerosols – Part 3: Influence of the chemical composition on the hygroscopic properties and volatile fractions of aerosols

    Directory of Open Access Journals (Sweden)

    L. Poulain

    2010-04-01

    Full Text Available The influence of varying levels of water mixing ratio, r, during the formation of secondary organic aerosol (SOA from the ozonolysis of α-pinene on the SOA hygroscopicity and volatility was investigated. The reaction proceeded and aerosols were generated in a mixing chamber and the hygroscopic characteristics of the SOA were determined with the Leipzig Aerosol Cloud Interaction Simulator (LACIS and a Cloud Condensation Nuclei counter (CCNc. In parallel, a High-Resolution Time-of-Flight Aerodyne Aerosol Mass Spectrometer (HR-ToF-AMS located downstream of a thermodenuder (TD sampling from the mixing chamber, to collect mass spectra of particles from the volatile and less-volatile fractions of the SOA. Results showed that both hygroscopic growth and the volatile fraction of the SOA increased with increases in r inside the mixing chamber during SOA generation. An effective density of 1.40 g cm−3 was observed for the generated SOA when the reaction proceeded with r>1 g kg−1. Changes in the concentrations of the fragment CO2+ and the sum of CxHyOz+ (short name CHO and CxHy+ (short name CH fragments as measured by the HR-ToF-AMS were used to estimate changes in the oxidation level of the SOA with reaction conditions, using the ratios CO2+ to CH and CHO to CH. Under humid conditions, both ratios increased, corresponding to the presence of more oxygenated functional groups (i.e., multifunctional carboxylic acids. This result is consistent with the α-pinene ozonolysis mechanisms which suggest that water interacts with the stabilized Criegee intermediate. The volatility and the hygroscopicity results show that SOA generation via ozonolysis of α-pinene in the presence of water vapour (r<16.9 g kg−1 leads to the formation of more highly oxygenated compounds that are more

  19. Towards closing the gap between hygroscopic growth and CCN activation for secondary organic aerosols – Part 3: Influence of the chemical composition on the hygroscopic properties and volatile fractions of aerosols

    Directory of Open Access Journals (Sweden)

    L. Poulain

    2009-08-01

    Full Text Available The influence of varying levels of water mixing ratio, r, during the formation of secondary organic aerosol (SOA from the ozonolysis of α-pinene on the SOA hygroscopicity and volatility was investigated. The reaction proceeded and aerosols were generated in a mixing chamber and the hygroscopic characteristics of the SOA were determined with LACIS (Leipzig Aerosol Cloud Interaction Simulator and a Cloud Condensation Nuclei counter (CCNc. In parallel, a High-Resolution Time-of-Flight Aerodyne Aerosol Mass Spectrometer (HR-ToF-AMS located downstream of a thermodenuder (TD sampling from the mixing chamber, to collect mass spectra of particles from the volatile and non-volatile fractions of the SOA. Results showed that both hygroscopic growth and the volatile fraction of the SOA increased with increases in r inside the mixing chamber during SOA generation. An effective density of 1.40 g cm−3 was observed for the generated SOA when the reaction proceeded with r>1 g kg−1. Changes in the concentrations of the fragment CO2+ and the sum of CxHyOz+ (short name CHO and CxHy+ (short name CH fragments as measured by the HR-ToF-AMS were used to estimate changes in the oxidation level of the SOA with reaction conditions, using the ratios CO2+ to CH and CHO to CH. Under humid conditions, both ratios increased, corresponding to the presence of more oxygenated functional groups (i.e., carboxylic groups. This result is consistent with the α-pinene ozonolysis mechanisms which suggest that water interacts with the stabilized Criegee intermediate. The volatility and the hygroscopicity results show that SOA generation via ozonolysis of α-pinene in the presence of water vapour (r<16.884 g kg−1 leads to the formation of more highly oxygenated compounds that are more hygroscopic and

  20. An Introduction to Continued Fractions.

    Science.gov (United States)

    Moore, Charles G.

    Provided is an introduction to the properties of continued fractions for the intellectually curious high school student. Among the topics included are (1) Expansion of Rational Numbers into Simple Continued Fractions, (2) Convergents, (3) Continued Fractions and Linear Diophantine Equations of the Type am + bn = c, (4) Continued Fractions and…

  1. Discrete fractional Calculus and Inequalities

    OpenAIRE

    Anastassiou, George A.

    2009-01-01

    Here we define a Caputo like discrete fractional difference and we compare it to the earlier defined Riemann-Liouville fractional discrete analog. Then we produce discrete fractional Taylor formulae for the first time, and we estimate their remainders. Finally, we derive related discrete fractional Ostrowski, Poincare and Sobolev type inequalities.

  2. -Dimensional Fractional Lagrange's Inversion Theorem

    Directory of Open Access Journals (Sweden)

    F. A. Abd El-Salam

    2013-01-01

    Full Text Available Using Riemann-Liouville fractional differential operator, a fractional extension of the Lagrange inversion theorem and related formulas are developed. The required basic definitions, lemmas, and theorems in the fractional calculus are presented. A fractional form of Lagrange's expansion for one implicitly defined independent variable is obtained. Then, a fractional version of Lagrange's expansion in more than one unknown function is generalized. For extending the treatment in higher dimensions, some relevant vectors and tensors definitions and notations are presented. A fractional Taylor expansion of a function of -dimensional polyadics is derived. A fractional -dimensional Lagrange inversion theorem is proved.

  3. Fracionamento químico e físico do carbono orgânico total em um solo de mata submetido a diferentes usos Chemical and physical fractions of soil organic carbon in a forest soil currently under different uses

    Directory of Open Access Journals (Sweden)

    Arlete Côrtes Barreto

    2008-08-01

    Full Text Available A matéria orgânica é um importante indicador da qualidade do solo, pois está relacionada com diversas propriedades químicas, físicas e biológicas, sendo importante o conhecimento do teor de C orgânico total (COT, bem como de suas frações. Com base nisso, realizou-se esta pesquisa objetivando caracterizar e quantificar os estoques de COT e suas frações como indicadores da qualidade de um solo, submetido a diferentes usos: (1 Mata Atlântica, (2 Cacau (Theobroma cacao e (3 Pastagem (Brachiaria decumbens, em uma microbacia no sul da Bahia. Para cada uso, coletaram-se amostras nas profundidades de 0-10 e 10-20 cm e procedeu-se à caracterização química e física do solo, à determinação do COT e ao seu fracionamento químico e físico. O teor de COT não diferiu entre os diferentes usos do solo nas duas profundidades estudadas. A percentagem de C humificado e nas frações de ácidos fúlvicos e humina foi maior na pastagem, na camada de 0-10 cm. Houve menor percentagem de C não-humificado nos sistemas cacau e pastagem, e maior relação C:N no sistema pastagem na camada de 10-20 cm. O sistema cacau promoveu aumento na quantidade de C orgânico na fração leve na camada de 10-20 cm. A substituição da mata pelo cultivo do cacau no sistema cabruca (sub-bosque ou pela pastagem não alterou os teores de COT e de suas frações na área estudada.Organic matter may be considered an important soil quality indicator, as it is related with many soil chemical, physical, and biological characteristics. The study of total organic carbon (TOC of the soil and its fractions is important. This study was conducted in a micro basin, with the purpose of: analyzing characteristics and quantify the stocks of total organic carbon (TOC and its fractions as evidence of soil quality after different forms of use: (1 Atlantic Forest, (2 Cocoa (Theobroma cacao, and (3 Pasture (Brachiaria decumbens. Samples were collected for each use type (at 0-10 and 10

  4. The Global Fractionation of Persistent Organic Pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Wania, F.; Mackay, D.

    1996-05-01

    As described in this report, the global distribution of persistent organic contaminants is controlled by (1) the point of discharge into the global environment, (2) the movements of atmosphere and oceans, (3) the rate of exchange processes between the atmosphere and the Earth`s surface and (4) the rate of chemical loss from various environmental phases. The strong temperature dependence of atmosphere-surface exchange favours evaporation from low and warmer latitudes and deposition in high and colder latitudes. As different chemicals have different volatilities this results in chemical fractionation along temperature, and thus latitudinal and climatic gradients. Relatively volatile chemicals with sub-cooled liquid vapour pressure P{sub L} at 25 {sup o}C from 0.01 to 1 Pa preferentially condense in polar climates, while less volatile chemicals with P{sub L} between 0.01 and 10{sup -4} Pa tend to accumulate in mid latitudes. Poleward atmospheric transport of these chemicals takes place in several steps facilitated by the seasonal fluctuation of temperature. Different chemicals will move with different meridional transport velocities depending on the capacity of the Earth`s surface to retain them. These large scale distribution processes are best understood by viewing the global environment as a complex chromatographic system. The interpretation of global distribution patterns is complicated by the large and often unknown changes in chemical emission that have occurred in time and space. 51 refs., 9 figs., 4 tabs.

  5. Testing Fractional Action Cosmology

    CERN Document Server

    Shchigolev, V K

    2015-01-01

    The present work deals with a combined test of the so-called Fractional Action Cosmology (FAC) on the example of a specific model obtained by the author earlier. In this model, the effective cosmological term is proportional to the Hubble parameter squared through the so-called kinematic induction. The reason of studying this cosmological model could be explained by its ability to describe two periods of accelerated expansion, that is in agreement with the recent observations and the cosmological inflation paradigm. First of all, we put our model through the theoretical tests that gives a general conception of the influence of the model parameters on its behavior. Then, we obtain some restrictions on the principal parameters of the model, including the fractional index, by means of the observational data. Finally, the cosmography parameters and the observational data compared to the theoretical predictions are presented both analytically and graphically.

  6. Testing fractional action cosmology

    Science.gov (United States)

    Shchigolev, V. K.

    2016-08-01

    The present work deals with a combined test of the so-called Fractional Action Cosmology (FAC) on the example of a specific model obtained by the author earlier. In this model, the effective cosmological term is proportional to the Hubble parameter squared through the so-called kinematic induction. The reason of studying this cosmological model could be explained by its ability to describe two periods of accelerated expansion, that is in agreement with the recent observations and the cosmological inflation paradigm. First of all, we put our model through the theoretical tests, which gives a general conception of the influence of the model parameters on its behavior. Then, we obtain some restrictions on the principal parameters of the model, including the fractional index, by means of the observational data. Finally, the cosmography parameters and the observational data compared to the theoretical predictions are presented both analytically and graphically.

  7. Fractions in elementary education

    CERN Document Server

    Quinn, Frank

    2013-01-01

    This paper is one of a series in which elementary-education practice is analyzed by comparison with the history of mathematics, mathematical structure, modern practice, and (occasionally) cognitive neuroscience. The primary concerns are: Why do so many children find elementary mathematics difficult? And, why are the ones who succeed still so poorly prepared for college material needed for technical careers? The answer provided by conventional wisdom is essentially that mathematics is difficult. Third-graders are not developmentally ready for the subtlety of fractions, for instance, and even high-performing students cannot be expected to develop the skills of experienced users. However we will see that this is far from the whole story and is probably wrong: elementary-education fractions are genuinely harder and less effective than the version employed by experienced users. Experts discard at least 90% of what is taught in schools. Our educational system is actually counterproductive for skill development, and...

  8. Nonlinear fractional relaxation

    Indian Academy of Sciences (India)

    A Tofighi

    2012-04-01

    We define a nonlinear model for fractional relaxation phenomena. We use -expansion method to analyse this model. By studying the fundamental solutions of this model we find that when → 0 the model exhibits a fast decay rate and when → ∞ the model exhibits a power-law decay. By analysing the frequency response we find a logarithmic enhancement for the relative ratio of susceptibility.

  9. Fractional Galilean symmetries

    Science.gov (United States)

    Hosseiny, Ali; Rouhani, Shahin

    2016-09-01

    We generalize the differential representation of the operators of the Galilean algebras to include fractional derivatives. As a result a whole new class of scale invariant Galilean algebras are obtained. The first member of this class has dynamical index z = 2 similar to the Schrödinger algebra. The second member of the class has dynamical index z = 3 / 2, which happens to be the dynamical index Kardar-Parisi-Zhang equation.

  10. New Dry Fractionation Methods

    Science.gov (United States)

    McKay, David S.; Cooper, Bonnie L.

    2010-01-01

    This slide presentation describes new fractionation methods that are used to create dust that is respirable for testing the effects of inhalation of lunar dust in preparation for future manned lunar exploration. Because lunar dust is a very limited commodity, a method that does not result in loss of the material had to be developed. The dust separation system that is described incorporates some traditional methods, while preventing the dust from being contaminated or changed in reactivity properties while also limiting losses.

  11. Momentum Fractionation on Superstrata

    CERN Document Server

    Bena, Iosif; Turton, David; Warner, Nicholas P

    2016-01-01

    Superstrata are bound states in string theory that carry D1, D5, and momentum charges, and whose supergravity descriptions are parameterized by arbitrary functions of (at least) two variables. In the D1-D5 CFT, typical three-charge states reside in high-degree twisted sectors, and their momentum charge is carried by modes that individually have fractional momentum. Understanding this momentum fractionation holographically is crucial for understanding typical black-hole microstates in this system. We use solution-generating techniques to add momentum to a multi-wound supertube and thereby construct the first examples of asymptotically-flat superstrata. The resulting supergravity solutions are horizonless and smooth up to well-understood orbifold singularities. Upon taking the AdS3 decoupling limit, our solutions are dual to CFT states with momentum fractionation. We give a precise proposal for these dual CFT states. Our construction establishes the very nontrivial fact that large classes of CFT states with mom...

  12. Model Fractional Chern Insulators

    Science.gov (United States)

    Behrmann, Jörg; Liu, Zhao; Bergholtz, Emil J.

    2016-05-01

    We devise local lattice models whose ground states are model fractional Chern insulators—Abelian and non-Abelian topologically ordered states characterized by exact ground state degeneracies at any finite size and infinite entanglement gaps. Most saliently, we construct exact parent Hamiltonians for two distinct families of bosonic lattice generalizations of the Zk parafermion quantum Hall states: (i) color-entangled fractional Chern insulators at band filling fractions ν =k /(C +1 ) and (ii) nematic states at ν =k /2 , where C is the Chern number of the lowest band. In spite of a fluctuating Berry curvature, our construction is partially frustration free: the ground states reside entirely within the lowest band and exactly minimize a local (k +1 ) body repulsion term by term. In addition to providing the first known models hosting intriguing states such as higher Chern number generalizations of the Fibonacci anyon quantum Hall states, the remarkable stability and finite-size properties make our models particularly well suited for the study of novel phenomena involving, e.g., twist defects and proximity induced superconductivity, as well as being a guide for designing experiments.

  13. Fractional Equations of Curie-von Schweidler and Gauss Laws

    CERN Document Server

    Tarasov, Vasily E

    2009-01-01

    The dielectric susceptibility of most materials follows a fractional power-law frequency dependence that is called the "universal" response. We prove that in the time domain this dependence gives differential equations with derivatives and integrals of noninteger order. We obtain equations that describe "universal" Curie-von Schweidler and Gauss laws for such dielectric materials. These laws are presented by fractional differential equations such that the electromagnetic fields in the materials demonstrate "universal" fractional damping. The suggested fractional equations are common (universal) to a wide class of materials, regardless of the type of physical structure, chemical composition or of the nature of the polarization.

  14. Antibacterial Activity and Chemical Constituents of Petroleum Ether Fraction in Aspergillus niger Mycelia%黑曲霉菌丝体抗菌活性及石油醚部分化学成分

    Institute of Scientific and Technical Information of China (English)

    刘吴娟; 陈青; 王嫱; 冯焕鹏; 李祝; 郭金; 龙云川

    2013-01-01

    Objective:In order to develop natural antibacterial agents, the antibacterial activity of Aspergillus niger xj was investigated. Method:The disc diffusion method was used to measure the antibacterial activity of petroleum ether (P. E) , ethyl acetate (EtOAc) and water extracts of Aspergillus niger mycelia. The P. E fraction with antibacterial activity was separated by silica gel column chromatography method, then separated and identified by GC-MS after being esterified with methanol. Result:Ten compounds were isolated and identified from the petroleum ether extract of mycelia which exhibited inhibitory effect against Staphylococcus aureus. Conclusion:The petroleum ether extract of Aspergillus niger xj mycelia contained natural substances with antibacterial activity in which fatty acids are the main constituents.%目的:对黑曲霉Aspergillus niger xj抗菌活性及化学成分进行研究以筛选天然抗菌药物.方法:采用滤纸片扩散法对黑曲霉菌丝体石油醚、醋酸乙酯和水提取物进行抗菌活性测定,并对石油醚部位活性部位进行硅胶柱色谱,甲酯化,通过气相色谱-质谱联用技术(GC-MS)对其化学成分进行分析.结果:菌丝体石油醚部分具有一定抗菌活性,从中鉴定出10个化合物.结论:黑曲霉菌丝体的石油醚部分存在抗菌活性物质,其化学成分以脂肪酸占较大比例.

  15. Fractional random walk lattice dynamics

    CERN Document Server

    Michelitsch, Thomas; Riascos, Alejandro Perez; Nowakowski, Andrzeij; Nicolleau, Franck

    2016-01-01

    We analyze time-discrete and continuous `fractional' random walks on undirected regular networks with special focus on cubic periodic lattices in $n=1,2,3,..$ dimensions.The fractional random walk dynamics is governed by a master equation involving {\\it fractional powers of Laplacian matrices $L^{\\frac{\\alpha}{2}}$}where $\\alpha=2$ recovers the normal walk.First we demonstrate thatthe interval $0\\textless{}\\alpha\\leq 2$ is admissible for the fractional random walk. We derive analytical expressions for fractional transition matrix and closely related the average return probabilities. We further obtain thefundamental matrix $Z^{(\\alpha)}$, and the mean relaxation time (Kemeny constant) for the fractional random walk.The representation for the fundamental matrix $Z^{(\\alpha)}$ relates fractional random walks with normal random walks.We show that the fractional transition matrix elements exihibit for large cubic $n$-dimensional lattices a power law decay of an $n$-dimensional infinite spaceRiesz fractional deriva...

  16. Fraccionamiento químico de carbono en Acrisoles con hori­zontes sómbricos del Sur de Brasil Chemical fractionation of carbon on Acrisols with sombric horizon from South Brazil

    Directory of Open Access Journals (Sweden)

    M. Velasco-Molina

    2010-01-01

    Full Text Available Los horizontes sómbricos (subsuperfi­ciales, oscuros y con mayor contenido de C tienen una génesis escasamente cono­cida, pudiendo funcionar como sumideros de C en condiciones subtropicales. En dos Acrisoles del Estado de Santa Catarina (S-Brasil se ha comprobado que la máxima acumulación de formas de C ligadas a Fe y Al extraíbles con pirofosfato y oxalato se presenta en horizontes sómbricos, pero que ésta no está relacionada con procesos de podsolización, andosolización, solodi­zación o acumulación de C por condicio­nes de hidromorfía subóxica. La mayor parte de su C se presenta en formas de oxidabilidad intermedia (oxidable con K2Cr2O7, en frío, pero no con KMnO4 0,2 M. Los porcentajes de C recalcitrante (no oxidable o díficilmente oxidable son sig­nificativos (20-45% pero variables a pe­queñas distancias. Procesos ligados a cambios de uso del suelo con diferente lo­calización del aporte de necromasa y efec­tos de incendios de la vegetación parecen ligados a su formación.Sombrics horizons (subsurface, dark and with a high content of C have a genesis poorly understood and can be conceived as a potential sink of C in subtropical envi­ronments. The maximum accumulation of C bound to Fe and Al extracted by pyrophos­phate and oxalate solution was observed in sombric horizons of two Acrisols of Santa Catarina State (S-Brazil, but this is not in­dicative of podzolisation, andosolisation or solodisation processes or accumulation of C due hydromorphy conditions. Most of its C was found at intermediate wet oxidisable fraction (oxidisable with K2Cr2O7, cold, but not by KMnO4. Recalcitrant C (non­oxidisable and difficult oxidisable was an important pool (20-45%, but variable into profile. Changes on land use with different input of necromass and vegetations fire ef­fects seem to be involved in its formation.

  17. Fractional Cointegration Rank Estimation

    OpenAIRE

    Lasak, K.A.; Velasco, C

    2014-01-01

    This discussion paper led to a publication in the Journal of Business & Economic Statistics , 2015, 33(2), 241-254. We consider cointegration rank estimation for a p-dimensional Fractional Vector Error Correction Model. We propose a new two-step procedure which allows testing for further long-run equilibrium relations with possibly different persistence levels. The first step consists in estimating the parameters of the model under the null hypothesis of the cointegration rank r=1,2,…,p-1. Th...

  18. Linear Network Fractional Routing

    Directory of Open Access Journals (Sweden)

    S.ASOKAN,

    2011-07-01

    Full Text Available A Network is a finite directed acyclic graph with source messages from a fixed alphabet and message demands at sink nodes. Linear Programming is an algorithm design method. It can be used whenthe solution to a problem can be viewed as the result of a sequence of decisions. The Linear Programming model for the network problem where in every variable has a value one or zero. The problem is todetermine a method of transmitting the messages through the network such that all sink demands are satisfied. We will prove fractional routing capacity for some solvable network using Linear Programmingmodel.

  19. Cosmological Models with Fractional Derivatives and Fractional Action Functional

    Institute of Scientific and Technical Information of China (English)

    V.K. Shchigolev

    2011-01-01

    Cosmological models of a scalar field with dynamical equations containing fractional derivatives or derived from the Einstein-Hilbert action of fractional order, are constructed. A number of exact solutions to those equations of fractional cosmological models in both eases is given.

  20. The Geminga Fraction

    CERN Document Server

    Harding, A K; Gonthier, P L; Harding, Alice K.; Grenier, Isabelle A.; Gonthier, Peter L.

    2007-01-01

    Radio-quiet gamma-ray pulsars like Geminga may account for a number of the unidentified EGRET sources in the Galaxy. The number of Geminga-like pulsars is very sensitive to the geometry of both the gamma-ray and radio beams. Recent studies of the shape and polarization of pulse profiles of young radio pulsars have provided evidence that their radio emission originates in wide cone beams at altitudes that are a significant fraction (1 -10%) of their light cylinder radius. Such wide radio emission beams will be visible at a much larger range of observer angles than the narrow core components thought to originate at lower altitude. Using 3D geometrical modeling that includes relativistic effects from pulsar rotation, we study the visibility of such radio cone beams as well as that of the gamma-ray beams predicted by slot gap and outer gap models. From the results of this study one can obtain revised predictions for the fraction of Geminga-like, radio quiet pulsars present in the gamma-ray pulsar population.

  1. BNCT and dose fractionation

    International Nuclear Information System (INIS)

    Some portion of the radiation dose received by a patient during BNCT consists of primary and secondary gammas. The biological effect of that portion of the dose will depend upon the time history of the delivered dose. The well-known models for relating time-dose effects to clinical experience, are of questionable value in understanding dose effects in the time regime of a few hours, and for doses of less than tolerance. In order to examine the time-dose effect in the regime of interest to BNCT a simple phenomenological model was developed and normalized to the accepted body of clinical experience. The model has been applied to the question of fractionation of BNCT and the results are presented. The model is simply a linear healing model with two time constants. In other words, a first hit of radiation is assumed to wound (or potentiate) a cell. Given time, the cell will fully repair itself. If a second hit occurs before the cell has healed, the cell is killed. Apparently, there are two kinds of healing, one which occurs in 30 to 60 minutes, the other in two to four days. A small fraction of the cells will die on the first hit

  2. Ejection Fraction Heart Failure Measurement

    Science.gov (United States)

    ... Tools & Resources Stroke More Ejection Fraction Heart Failure Measurement Updated:May 31,2016 The ejection fraction (EF) is an important measurement in determining how well your heart is pumping ...

  3. NESDIS VIIRS Green Vegetation Fraction

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains weekly Green Vegetation Fraction (GVF) derived from VIIRS. The Green Vegetation Fraction product is updated daily and is used as an input to...

  4. Advances in robust fractional control

    CERN Document Server

    Padula, Fabrizio

    2015-01-01

    This monograph presents design methodologies for (robust) fractional control systems. It shows the reader how to take advantage of the superior flexibility of fractional control systems compared with integer-order systems in achieving more challenging control requirements. There is a high degree of current interest in fractional systems and fractional control arising from both academia and industry and readers from both milieux are catered to in the text. Different design approaches having in common a trade-off between robustness and performance of the control system are considered explicitly. The text generalizes methodologies, techniques and theoretical results that have been successfully applied in classical (integer) control to the fractional case. The first part of Advances in Robust Fractional Control is the more industrially-oriented. It focuses on the design of fractional controllers for integer processes. In particular, it considers fractional-order proportional-integral-derivative controllers, becau...

  5. Positive fractional linear electrical circuits

    Science.gov (United States)

    Kaczorek, Tadeusz

    2013-10-01

    The positive fractional linear systems and electrical circuits are addressed. New classes of fractional asymptotically stable and unstable electrical circuits are introduced. The Caputo and Riemann-Liouville definitions of fractional derivatives are used to analysis of the positive electrical circuits composed of resistors, capacitors, coils and voltage (current) sources. The positive fractional electrical and specially unstable different types electrical circuits are analyzed. Some open problems are formulated.

  6. Experimental observation of fractional echoes

    Science.gov (United States)

    Karras, G.; Hertz, E.; Billard, F.; Lavorel, B.; Siour, G.; Hartmann, J.-M.; Faucher, O.; Gershnabel, Erez; Prior, Yehiam; Averbukh, Ilya Sh.

    2016-09-01

    We report the observation of fractional echoes in a double-pulse excited nonlinear system. Unlike standard echoes, which appear periodically at delays which are integer multiples of the delay between the two exciting pulses, the fractional echoes appear at rational fractions of this delay. We discuss the mechanism leading to this phenomenon, and provide experimental demonstration of fractional echoes by measuring third harmonic generation in a thermal gas of CO2 molecules excited by a pair of femtosecond laser pulses.

  7. Chemical Characterization of Cellulose-degrading Streptomyces and Its Alkaline Extraction Fraction During Cellulose Degradation%纤维素降解过程中链霉菌菌体及其碱提取物组分研究

    Institute of Scientific and Technical Information of China (English)

    张伟; 窦森

    2014-01-01

    as a unique carbon and energy source for the growth of strain Streptomyces sp. F. There was a significant increase in the production rate of harvested cells(α=0.05)during incubation. At the end of incubation(60 d), this production rate reached at 7.29%. Though the ele-mental composition was similar between the"mycelia"of harvested cells at different culture time and the humic acid(HA)of black soil, the mycelia showed different characteristics from these of the soil HA, with lower degree of crystallinity, greater thermal stability, weaker aro-maticity, and higher aliphatic carbon chain and oxygen-containing functional group content. Compared with HA from black soil, Strepto-myces had more"water-soluble component"groups and"alkali-soluble acid-insoluble groups(the equivalent of humic acid)"but less"al-kali- soluble component groups(the equivalent of humic and fulvic acid)". These results suggest that both the "water- soluble compo-nent" and"alkali-soluble acid-insoluble fraction"were related with the breakdown of sodium carboxymethyl cellulose and the biological synthesis in"mycelia", and that the“alkali-soluble acid-insoluble groups”characteristics of the"mycelia"was distinct from the humic acid of the real black soil(HA).

  8. Nonhomogeneous fractional Poisson processes

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xiaotian [School of Management, Tianjin University, Tianjin 300072 (China)]. E-mail: swa001@126.com; Zhang Shiying [School of Management, Tianjin University, Tianjin 300072 (China); Fan Shen [Computer and Information School, Zhejiang Wanli University, Ningbo 315100 (China)

    2007-01-15

    In this paper, we propose a class of non-Gaussian stationary increment processes, named nonhomogeneous fractional Poisson processes W{sub H}{sup (j)}(t), which permit the study of the effects of long-range dependance in a large number of fields including quantum physics and finance. The processes W{sub H}{sup (j)}(t) are self-similar in a wide sense, exhibit more fatter tail than Gaussian processes, and converge to the Gaussian processes in distribution in some cases. In addition, we also show that the intensity function {lambda}(t) strongly influences the existence of the highest finite moment of W{sub H}{sup (j)}(t) and the behaviour of the tail probability of W{sub H}{sup (j)}(t)

  9. Fractional cointegration rank estimation

    DEFF Research Database (Denmark)

    Lasak, Katarzyna; Velasco, Carlos

    We consider cointegration rank estimation for a p-dimensional Fractional Vector Error Correction Model. We propose a new two-step procedure which allows testing for further long-run equilibrium relations with possibly different persistence levels. The fi…rst step consists in estimating the...... parameters of the model under the null hypothesis of the cointegration rank r = 1, 2, ..., p-1. This step provides consistent estimates of the cointegration degree, the cointegration vectors, the speed of adjustment to the equilibrium parameters and the common trends. In the second step we carry out a sup......-likelihood ratio test of no-cointegration on the estimated p - r common trends that are not cointegrated under the null. The cointegration degree is re-estimated in the second step to allow for new cointegration relationships with different memory. We augment the error correction model in the second step to...

  10. Membrane Assisted Enzyme Fractionation

    DEFF Research Database (Denmark)

    Yuan, Linfeng

    . In this thesis, separations using crossflow elecro-membrane filtration (EMF) of amino acids, bovine serum albumin (BSA) and industrial enzymes from Novozymes were performed. The main objective of this study was to investigate the technological feasibility of EMF in the application of industrial enzyme...... fractionation, such as removal of a side activity from the main enzyme activity. As a proof-of-concept, amino acids were used as model solution to test the feasibility of EMF in the application of amphoteric molecule separation. A single amino acid was used to illustrate the effect of an electric field...... on the separation performance were very small in the investigated range. The mass transport of each enzyme can be well explained by the Extended-Nernst-Planck equation. Better separation was observed at lower feed concentration, higher solution pH in the investigated range and with a polysulfone (PS) MF membrane...

  11. Screening of Effective Chemical Fractions of Rhizoma Atractylodis Macrocephalae and Its Optimal Proportion in Combination with Cortex Mori and Their Effects on Nephrotic Syndrome%白术各化学拆分组分及其配伍对大鼠肾病综合征的影响

    Institute of Scientific and Technical Information of China (English)

    郑晓珂; 于洋; 周静; 吴广操; 王小兰; 牛艳; 黄岩杰; 匡海学; 冯卫生

    2016-01-01

    compatibility proportion for the treatment of the nephrotic syndrome.MethodsAdriamycin-induced nephrotic syndrome rat model was adopted. With 24 h urine protein,and the levels of serum albumin(Alb),triglycerides(TG),total cholesterol(TCH),serum creatinine(Cre-S)and bloodurea nitrogen(BUN)as the evaluation indexes,we screened the optimal effective fractions and the best compatibility ratio ofBaizhu. ELISA was applied to detect the serum levels of interleukin 6(IL-6),tumor necrosis factor alpha (TNF-α),superoxide dismutase(SOD),malondialdehyde(MDA)for the evaluation of the effects of the optimal effective fractions. Renal histology of rats in effective fraction groups was observed after HE staining. The therapeutic mechanism of the effective fractions was evaluated by examining the urine volume,arginine vasopressin(AVP)and serum levels of aquaporin 2(AQP2)and aquaporin 1(AQP1).ResultsAfter medication for 3 weeks,levels of 24 h urine protein,Cre-S,BUN,TG,TCH,and Alb of the low dose group(2.8 g·kg-1)were improved significantly(P< 0.05),indicating that 2.8 g·kg-1 was the optimal dose. The levels of 24 h urine protein,Cre-S,BUN,TG,and TCH of the polysaccharide fraction group were improved significantly(P< 0.05),IL-6 and TNF-αwere decreased, SOD was increased,and renal injury was relieved,indicating that polysaccharide fraction was optimal effective fraction. The optimal compatibility proportion ofBaizhutoSangbaipiwas 1∶1,and the combination of the two herbs had better effect on increasing rat urine volume and on decreasing AVP and AQP2 than the single herb ofSangbaipi (P< 0.05).ConclusionThe optimal effective chemical fractions ofBaizhuis polysaccharide fraction,which has anti-oxidative and anti-inflammation actions and can relieve renal injury. The optimal compatibility ratio ofBaizhuto Sangbaipiis 1∶1,and their combination at the ratio of 1∶1 can decrease the level of AVP and enhance the diuretic action.

  12. Iron isotopic fractionation during continental weathering

    Energy Technology Data Exchange (ETDEWEB)

    Fantle, Matthew S.; DePaolo, Donald J.

    2003-10-01

    The biological activity on continents and the oxygen content of the atmosphere determine the chemical pathways through which Fe is processed at the Earth's surface. Experiments have shown that the relevant chemical pathways fractionate Fe isotopes. Measurements of soils, streams, and deep-sea clay indicate that the {sup 56}Fe/{sup 54}Fe ratio ({delta}{sup 56}Fe relative to igneous rocks) varies from +1{per_thousand} for weathering residues like soils and clays, to -3{per_thousand} for dissolved Fe in streams. These measurements confirm that weathering processes produce substantial fractionation of Fe isotopes in the modern oxidizing Earth surface environment. The results imply that biologically-mediated processes, which preferentially mobilize light Fe isotopes, are critical to Fe chemistry in weathering environments, and that the {delta}{sup 56}Fe of marine dissolved Fe should be variable and negative. Diagenetic reduction of Fe in marine sediments may also be a significant component of the global Fe isotope cycle. Iron isotopes provide a tracer for the influence of biological activity and oxygen in weathering processes through Earth history. Iron isotopic fractionation during weathering may have been smaller or absent in an oxygen-poor environment such as that of the early Precambrian Earth.

  13. Toward lattice fractional vector calculus

    Science.gov (United States)

    Tarasov, Vasily E.

    2014-09-01

    An analog of fractional vector calculus for physical lattice models is suggested. We use an approach based on the models of three-dimensional lattices with long-range inter-particle interactions. The lattice analogs of fractional partial derivatives are represented by kernels of lattice long-range interactions, where the Fourier series transformations of these kernels have a power-law form with respect to wave vector components. In the continuum limit, these lattice partial derivatives give derivatives of non-integer order with respect to coordinates. In the three-dimensional description of the non-local continuum, the fractional differential operators have the form of fractional partial derivatives of the Riesz type. As examples of the applications of the suggested lattice fractional vector calculus, we give lattice models with long-range interactions for the fractional Maxwell equations of non-local continuous media and for the fractional generalization of the Mindlin and Aifantis continuum models of gradient elasticity.

  14. Copper isotope fractionation by desert shrubs

    Energy Technology Data Exchange (ETDEWEB)

    Navarrete, Jesica U., E-mail: jnavarrete2@miners.utep.edu [University of Texas at El Paso, Department of Geological Sciences, 500 W. University Ave, El Paso, TX 79968 (United States); Viveros, Marian; Ellzey, Joanne T. [University of Texas at El Paso, Department of Biological Sciences, El Paso, TX 79968 (United States); Borrok, David M. [University of Texas at El Paso, Department of Geological Sciences, 500 W. University Ave, El Paso, TX 79968 (United States)

    2011-06-15

    Copper has two naturally occurring stable isotopes of masses 63 and 65 which can undergo mass dependent fractionation during various biotic and abiotic chemical reactions. These interactions and their resulting Cu isotope fractionations can be used to determine the mechanisms involved in the cycling of Cu in natural systems. In this study, Cu isotope changes were investigated at the organismal level in the metal-accumulating desert plant, Prosopis pubescens. Initial results suggest that the lighter Cu isotope was preferentially incorporated into the leaves of the plant, which may suggest that Cu was actively transported via intracellular proteins. The roots and stems show a smaller degree of Cu isotope fractionation and the direction and magnitude of the fractionations was dependent upon the levels of Cu exposure. Based on this and previous work with bacteria and yeast, a trend is emerging that suggests the lighter Cu isotope is preferentially incorporated into biological components, while the heavier Cu isotope tends to become enriched in aqueous solutions. In bacteria, plants and animals, intracellular Cu concentrations are strictly regulated via dozens of enzymes that can bind, transport, and store Cu. Many of these enzymes reduce Cu(II) to Cu(I). These initial results seem to fit into a broader picture of Cu isotope cycling in natural systems where oxidation/reduction reactions are fundamental in controlling the distributions of Cu isotopes.

  15. Fractionally charged skyrmions in fractional quantum Hall effect

    Science.gov (United States)

    Balram, Ajit C.; Wurstbauer, U.; Wójs, A.; Pinczuk, A.; Jain, J. K.

    2015-11-01

    The fractional quantum Hall effect has inspired searches for exotic emergent topological particles, such as fractionally charged excitations, composite fermions, abelian and nonabelian anyons and Majorana fermions. Fractionally charged skyrmions, which support both topological charge and topological vortex-like spin structure, have also been predicted to occur in the vicinity of 1/3 filling of the lowest Landau level. The fractional skyrmions, however, are anticipated to be exceedingly fragile, suppressed by very small Zeeman energies. Here we show that, slightly away from 1/3 filling, the smallest manifestations of the fractional skyrmion exist in the excitation spectrum for a broad range of Zeeman energies, and appear in resonant inelastic light scattering experiments as well-defined resonances slightly below the long wavelength spin wave mode. The spectroscopy of these exotic bound states serves as a sensitive tool for investigating the residual interaction between composite fermions, responsible for delicate new fractional quantum Hall states in this filling factor region.

  16. Carbon and oxygen isotope fractionation in dense interstellar clouds

    Science.gov (United States)

    Langer, W. D.; Graedel, T. E.; Frerking, M. A.; Armentrout, P. B.

    1984-01-01

    It is pointed out that isotope fractionation as a result of chemical reactions is due to the small zero-point energy differences between reactants and products of isotopically distinct species. Only at temperatures near absolute zero does this energy difference become significant. Favorable conditions for isotope fractionation on the considered basis exist in space within dense interstellar clouds. Temperatures of approximately 10 K may occur in these clouds. Under such conditions, ion-molecule reactions have the potential to distribute isotopes of hydrogen, carbon, oxygen unequally among the interstellar molecules. The present investigation makes use of a detailed model of the time-dependent chemistry of dense interstellar clouds to study cosmological isotope fractionation. Attention is given to fractionation chemistry and the calculation of rate parameters, the isotope fractionation results, and a comparison of theoretical results with observational data.

  17. Rapid analysis of chemical compositions in the flavonoid fraction of Men-tha haplocalyx Briq.with LCMS-IT-TOF%LCMS-IT-TOF 法快速分析薄荷黄酮部位的主要化学成分

    Institute of Scientific and Technical Information of China (English)

    陈向阳; 张乐; 吴莹; 王卫华; 刘斌

    2015-01-01

    目的:快速分析鉴别薄荷黄酮部位的化学成分。方法采用高效液相色谱-离子阱-飞行时间质谱法(LCMS-IT-TOF)对薄荷黄酮部位化学成分进行分析,Sunfire C18色谱柱(4.6 mm ×150 mm,5μm),甲醇(A)-水(B)为流动相进行梯度洗脱,电喷雾离子源为质谱离子源,同时采用正、负离子检测模式,获得不同化合物的多级质谱数据。结果根据高分辨质谱结果和 MS /MS 碎片信息,结合对照品质谱信息及相关文献,共鉴定推断出12个黄酮类化合物,其中4个黄酮苷:芹菜素-7-O-芸香糖、香叶木苷、木犀草素-7-O-芸香糖、蒙花苷;6个黄酮苷元:5,6-二羟基-7,8,3′,4′-四甲氧基黄酮、栀子黄素 B、5,6-二羟基-7,8,4′-三甲氧基黄酮、刺槐素、5-羟基-6,7,8,3′,4′-五甲氧基黄酮、香叶木素;1个黄酮醇苷:芦丁;1个二氢黄酮苷:橙皮苷。结论LCMS-IT-TOF 能快速有效地分析薄荷黄酮部位的化学成分,为其进一步研究提供物质基础。%Objective To rapidly analyze chemical compositions in the flavonoid fraction of Mentha hap-localyx Briq.Methods The liquid chromatography-mass spectrometry-ion trap-time-of-flight (LCMS-IT-TOF)method was applied to analyze the flavonoid fraction of Mentha haplocalyx Briq.The chromato-graphic separation was performed on Sunfire C18 column(4.6 mm ×150 mm,5 μm)with gradient elution of methanol (A)-water (B).Multistage mass spectrometry data of different compounds was obtained by using electrospray ionization source and monitoring in positive and negative ion modes.Results Twelve flavonoids,including four flavonoid glycosides,six flavonoid aglycones,a flavonol glycoside and a flava-none glycoside,were identified based on the characteristic MS /MS fragment ions data with chemical standards and published literatures.These constituents are mainly hesperidin,rutin,apigenin-7-O

  18. Proton Fraction in Neutron Stars

    Institute of Scientific and Technical Information of China (English)

    张丰收; 陈列文

    2001-01-01

    The proton fraction in β-stable neutron stars is investigated within the framework of the Skyrme-Hartree-Fock theory using the extended Skyrme effective interaction for the first time. The calculated results show that the proton fraction disappears at high density, which implies that the pure neutron matter may exist in the interior of neutron stars. The incompressibility of the nuclear equation-of-state is shown to be more important to determine the proton fraction. Meanwhile, it is indicated that the addition of muons in neutron stars will change the proton fraction. It is also found that the higher-order terms of the nuclear symmetry energy have obvious effects on the proton fraction and the parabolic law of the nuclear symmetry energy is not enough to determine the proton fraction.

  19. The fractional symmetric rigid rotor

    OpenAIRE

    Herrmann, Richard

    2006-01-01

    Based on the Riemann fractional derivative the Casimir operators and multipletts for the fractional extension of the rotation group SO(n) are calculated algebraically. The spectrum of the corresponding fractional symmetric rigid rotor is discussed. It is shown, that the rotational, vibrational and $\\gamma$-unstable limits of the standard geometric collective models are particular limits of this spectrum. A comparison with the ground state band spectra of nuclei shows an agreement with experim...

  20. Chemical Emergencies

    Science.gov (United States)

    When a hazardous chemical has been released, it may harm people's health. Chemical releases can be unintentional, as in the case of an ... the case of a terrorist attack with a chemical weapon. Some hazardous chemicals have been developed by ...

  1. Composição química, fracionamento de carboidratos e proteínas e digestibilidade in vitro de forrageiras tropicais em diferentes idades de corte Chemical composition, fractionation of carbohydrates and crude protein and in vitro digestibility on tropical forages in the different cutting ages

    Directory of Open Access Journals (Sweden)

    Paula Andrea Toro Velásquez

    2010-06-01

    Full Text Available Objetivou-se avaliar o valor nutritivo de três espécies forrageiras tropicais: capim-tanzânia (Panicum maximum Jacq., capim-marandu (Brachiaria brizantha e capim-tifton 85 (Cynodon spp, em duas épocas do ano (janeiro-março e abril-junho e em três idades de rebrota (28, 35 e 42 dias, por meio da composição química, do fracionamento de proteínas e carboidratos e da digestibilidade in vitro da matéria seca (DIVMS e da matéria orgânica (DIVMO. O capim-marandu destacou-se no período de janeiro-março, com menores conteúdos de parede celular e fração B2 dos carboidratos e maiores valores de proteína bruta, fração A + B1, DIVMS e DIVMO, em comparação aos capins tanzânia e tifton 85, independentemente da idade de corte. O aumento da concentração de parede celular em detrimento ao conteúdo celular com o avanço da maturidade das plantas foi evidente no capim-marandu no período de janeiro-março, quando foram observados maior valor da fração B2, maior conteúdo de fibra em detergente neutro (FDN e menor concentração da fração carboidratos não-fibrosos. No período de abril-junho, a composição em parede celular não apresentou diferenças evidentes com aumento da idade, devido às condições ambientais observadas. O capim-tanzânia apresenta, de modo geral, baixos valores de parede celular e altos valores de carboidratos não-fibrosos, DIVMS e DIVMO nesse período, seguido pelos capins marandu e tifton 85, respectivamente.This trial was conducted with the objective of evaluating the nutritive value of three tropical forage species: tanzania grass (Panicum maximum Jacq., marandu grass (Brachiaria brizantha and Tifton 85 bermudagrass (Cynodon spp in two different periods of the year (January-March and April-June and in three cutting ages (28, 35 and 42 days, based on the chemical composition, protein and carbohydrate fractions, and in vitro digestibility of dry matter (DMD and organic matter (OMD. Marandu grass, in the

  2. Comment on "Fractional quantum mechanics" and "Fractional Schroedinger equation"

    CERN Document Server

    Wei, Yuchuan

    2016-01-01

    In this comment, we point out some shortcomings in two papers "Fractional quantum mechanics" [Phys. Rev. E 62, 3135 (2000)] and "Fractional Schroedinger equation" [Phys. Rev. E 66, 056108 (2002)]. We prove that the fractional uncertainty relation does not hold generally. The probability continuity equation in fractional quantum mechanics has a missing source term, which leads to particle teleportation, i.e., a particle can teleport from one place to another. Since the relativistic kinetic energy can be viewed as an approximate realization of the fractional kinetic energy, the particle teleportation should be an observable relativistic effect in quantum mechanics. With the help of this concept, superconductivity could be viewed as the teleportation of electrons from one side of a superconductor to another and superfluidity could be viewed as the teleportation of helium atoms from one end of a capillary tube to the other. We also point out how to teleport a particle to a destination.

  3. COMMERCIAL SNF ACCIDENT RELEASE FRACTIONS

    Energy Technology Data Exchange (ETDEWEB)

    S.O. Bader

    1999-10-18

    The purpose of this design analysis is to specify and document the total and respirable fractions for radioactive materials that are released from an accident event at the Monitored Geologic Repository (MGR) involving commercial spent nuclear fuel (CSNF) in a dry environment. The total and respirable release fractions will be used to support the preclosure licensing basis for the MGR. The total release fraction is defined as the fraction of total CSNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. The radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses. This subset of the total release fraction is referred to as the respirable release fraction. Potential accidents may involve waste forms that are characterized as either bare (unconfined) fuel assemblies or confined fuel assemblies. The confined CSNF assemblies at the MGR are contained in shipping casks, canisters, or disposal containers (waste packages). In contrast to the bare fuel assemblies, the container that confines the fuel assemblies has the potential of providing an additional barrier for diminishing the total release fraction should the fuel rod cladding breach during an accident. However, this analysis will not take credit for this additional bamer and will establish only the total release fractions for bare unconfined CSNF assemblies, which may however be

  4. Investigations on Multiplication of Fractions.

    Science.gov (United States)

    Sai, Khoo Phon; Inder, Walter R. D.

    1984-01-01

    Three different models with continuous materials, discontinuous materials, and number lines were used to study the operation concept in six investigations on multiplication with fractions with pupils aged 11-12 in a Penang International School. All approaches could be understood by pupils, but they preferred the area and fractional models. (MNS)

  5. The Fractional Quantum Hall Effect

    OpenAIRE

    Rao, Sumathi

    1999-01-01

    We give a brief introduction to the phenomenon of the Fractional Quantum Hall effect, whose discovery was awarded the Nobel prize in 1998. We also explain the composite fermion picture which describes the fractional quantum Hall effect as the integer quantum Hall effect of composite fermions.

  6. Financial Planning with Fractional Goals

    NARCIS (Netherlands)

    M.H. Goedhart; J. Spronk (Jaap)

    1995-01-01

    textabstractWhen solving financial planning problems with multiple goals by means of multiple objective programming, the presence of fractional goals leads to technical difficulties. In this paper we present a straightforward interactive approach for solving such linear fractional programs with mult

  7. Deterministic ratchets for suspension fractionation

    NARCIS (Netherlands)

    Kulrattanarak, T.

    2010-01-01

    Driven by the current insights in sustainability and technological development in biorefining natural renewable resources, the food industry has taken an interest in fractionation of agrofood materials, like milk and cereal crops. The purpose of fractionation is to split the raw material in sever

  8. Wavelet-fractional Fourier transforms

    Institute of Scientific and Technical Information of China (English)

    Yuan Lin

    2008-01-01

    This paper extends the definition of fractional Fourier transform (FRFT) proposed by Namias V by using other orthonormal bases for L2 (R) instead of Hermite-Ganssian functions.The new orthonormal basis is gained indirectly from multiresolution analysis and orthonormal wavelets. The so defined FRFT is called wavelets-fractional Fourier transform.

  9. Mechanical Analogies of Fractional Elements

    Institute of Scientific and Technical Information of China (English)

    HU Kai-Xin; ZHU Ke-Qin

    2009-01-01

    A Fractional element model describes a special kind of viscoelastic material.Its stress is proportional to the fractional-order derivative of strain. Physically the mechanical analogies of fractional elements can be represented by spring-dashpot fractal networks. We introduce a constitutive operator in the constitutive equations of viscoelastic materials.To derive constitutive operators for spring-dashpot fractal networks, we use Heaviside operational calculus, which provides explicit answers not otherwise obtainable simply.Then the series-parallel formulas for the constitutive operator are derived. Using these formulas, a constitutive equation of fractional element with 1/2-order derivative is obtained.Finally we find the way to derive the constitutive equations with other fractional-order derivatives and their mechanical analogies.

  10. Radiating subdispersive fractional optical solitons

    Energy Technology Data Exchange (ETDEWEB)

    Fujioka, J., E-mail: fujioka@fisica.unam.mx; Espinosa, A.; Rodríguez, R. F. [Departamento de Física Química, Instituto de Física, Universidad Nacional Autónoma de México, Mexico, DF 04510 (Mexico); Malomed, B. A. [Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel)

    2014-09-01

    It was recently found [Fujioka et al., Phys. Lett. A 374, 1126 (2010)] that the propagation of solitary waves can be described by a fractional extension of the nonlinear Schrödinger (NLS) equation which involves a temporal fractional derivative (TFD) of order α > 2. In the present paper, we show that there is also another fractional extension of the NLS equation which contains a TFD with α < 2, and in this case, the new equation describes the propagation of radiating solitons. We show that the emission of the radiation (when α < 2) is explained by resonances at various frequencies between the pulses and the linear modes of the system. It is found that the new fractional NLS equation can be derived from a suitable Lagrangian density, and a fractional Noether's theorem can be applied to it, thus predicting the conservation of the Hamiltonian, momentum and energy.

  11. Radiating subdispersive fractional optical solitons

    Science.gov (United States)

    Fujioka, J.; Espinosa, A.; Rodríguez, R. F.; Malomed, B. A.

    2014-09-01

    It was recently found [Fujioka et al., Phys. Lett. A 374, 1126 (2010)] that the propagation of solitary waves can be described by a fractional extension of the nonlinear Schrödinger (NLS) equation which involves a temporal fractional derivative (TFD) of order α > 2. In the present paper, we show that there is also another fractional extension of the NLS equation which contains a TFD with α < 2, and in this case, the new equation describes the propagation of radiating solitons. We show that the emission of the radiation (when α < 2) is explained by resonances at various frequencies between the pulses and the linear modes of the system. It is found that the new fractional NLS equation can be derived from a suitable Lagrangian density, and a fractional Noether's theorem can be applied to it, thus predicting the conservation of the Hamiltonian, momentum and energy.

  12. Chemical and isotopic fractionations of natural gases during their migration. Importance of methane solubilization and diffusion during geological times; Fractionnements chimiques et isotopiques des gaz naturels lors de leur migration. Importance de la solubilisation et de la diffusion du methane au cours des temps geologiques

    Energy Technology Data Exchange (ETDEWEB)

    Pernaton, E.

    1998-09-09

    Two experimental devices have been elaborated in the purpose of simulating in laboratory the solubilization of methane in water and the migration by solubilization/diffusion of some gas species (methane, ethane, propane and nitrogen) through porous media saturated with water. Significant shifts in isotopic ratios of diffused methane (carbon and hydrogen) have been observed. Those fractionations for carbon isotopes, which in most cases are characterised by a {sup 12}C-enriched diffused methane, have fundamental consequences about the interpretation of the origin of methane in sedimentary basins and, in a more general way, about the genetic characterisation of hydrocarbon gases in reservoirs. Indeed, this gives an ambiguous origin for any gas having {sup 12}C-enriched methane, two different interpretations are possible: mixing between thermogenic and bacterial hydrocarbon gases and a diffusive trend during migration. Using a diagram C2/C1 versus {delta}{sup 13}C1, we have shown that in some geological cases, these two processes, mixing and diffusion, exist and that it is possible to discern them.The chemical and isotopic compositions of natural gases do not only reflect genetic processes but are also an indication of their migration. Moreover, the experiments have shown that the gas transport by solubilization/diffusion is a potential operator of gas leakage from natural accumulations. In consequence, a numerical model of gas migration through cap rocks of reservoirs has been elaborated and will be integrated into sedimentary basin models. (author)

  13. Fractionation and business potential from sludge - Pafrak

    Energy Technology Data Exchange (ETDEWEB)

    Kylloenen, H.; Groenroos, A.; Pirkonen, P. (VTT Tecchnical Research Centre of Finland, Jyvaeskylae (Finland)), Email: hanna.kyllonen@vtt.fi; Maekinen, L.; Aemmaelae, A.; Niinimaeki, J. (Univ. of Oulu (Finland)), Email: liisa.makinen@oulu.fi

    2010-10-15

    Wastewater sludges contain valuable components which can be recycled and converted to secondary raw material. High water content of sludge can hinder the further processing. Dry solids content of waste activated sludge after dewatering can be as low as 12-20% and even lower for tertiary sludge. This research aimed with better knowledge of sludge and fractionation to generate potential business ideas, which could lead to new sludge based products and services in national and international markets already in this project or in separate development projects. Primary, waste activated, tertiary and deinking sludge from pulp and paper industry and municipal waste activated sludge were the suspensions to be studied. Basic properties of these sludges have been determined by large number of analysing methods. Wood based components and chemical elements have been determined to clarify the raw material potential for biorefineries. Conventional fractionation techniques (decanter centrifuge, hydrocyclone, belt filter press and sieve bend) have been used to see how the sludge can be fractionated. Correlations of wood based components and dewatering properties have been studied especially for the waste activated sludge. The effects of wood based filter aids were studied on the dewatering properties of waste activated sludge. State of the art has been drawn up about the current utilisation of wastewater sludge. (orig.)

  14. Isotopic fractionation of zinc in tektites

    Science.gov (United States)

    Moynier, Frederic; Beck, Pierre; Jourdan, Fred; Yin, Qing-Zhu; Reimold, Uwe; Koeberl, Christian

    2009-01-01

    Tektites are terrestrial natural glasses produced during a hypervelocity impact of an extraterrestrial projectile onto the Earth's surface. The similarity between the chemical and isotopic compositions of tektites and terrestrial upper continental crust implies that the tektites formed by fusion of such target rock. Tektites are among the driest rocks on Earth. Although volatilization at high temperature may have caused this extreme dryness, the exact mechanism of the water loss and the behavior of other volatile species during tektite formation are still debated. Volatilization can fractionate isotopes, therefore, comparing the isotope composition of volatile elements in tektites with that of their source rocks may help to understand the physical conditions during tektite formation. For this study, we have measured the Zn isotopic composition of 20 tektites from four different strewn fields. Almost all samples are enriched in heavy isotopes of Zn compared to the upper continental crust. On average, the different groups of tektites are isotopically distinct (listed from the isotopically lightest to the heaviest): Muong-Nong type indochinites ( δ66/64Zn = 0.61 ± 0.30‰); North American bediasites ( δ66/64Zn = 1.61 ± 0.49‰); Ivory Coast tektites ( δ66/64Zn = 1.66 ± 0.18‰); the Australasian tektites (others than the Muong Nong-type indochinites) ( δ66/64Zn = 1.84 ± 0.42‰); and Central European moldavites ( δ66/64Zn = 2.04 ± 0.19‰). These results are contrasted with a narrow range of δ66/64Zn = 0-0.7‰ for a diverse spectrum of upper continental crust materials. The elemental abundance of Zn is negatively correlated with δ66/64Zn, which may reflect that isotopic fractionation occurred by evaporation during the heating event upon tektite formation. Simple Rayleigh distillation predicts isotopic fractionations much larger than what is actually observed, therefore, such a model cannot account for the observed Zn isotope fractionation in tektites. We

  15. Chemical composition of atmospheric particulate matter soluble fraction and meteorological variables in São Paulo state, Brazil Composição química da fração solúvel do material particulado atmosférico e variáveis meteorológicas no estado de São Paulo, Brasil

    Directory of Open Access Journals (Sweden)

    Christine Laure Marie Bourotte

    2011-09-01

    Full Text Available The objective of this work was to characterize and compare the chemical composition of the PM10 soluble fraction in relation to meteorological variables such as wind direction and air masses backward trajectories. The PM10 was collected during winter of 1999 in two contrasting sites: the São Paulo city and the State Park of Serra do Mar (Cunha inside the Atlantic Forest Reserve. The aqueous extracts of PM10 were analyzed by Ion Chromatography for major ions (Na+, K+, Mg2+, Ca2+, NH4+, Cl-, NO3-, SO4(2- and by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS for trace elements (Al, Mn, Fe, Pb, Zn, etc.. In São Paulo, the dominant chemical species were SO4(2-, NO3-, NH4+, Zn, Fe, Al, Ba, Cu, Pb, Mn and Ni while in Cunha, Na+, K+, Cl-, SO4(2-, Zn and Ni were dominant. The chemical composition related to the wind direction during sampling reflected short-range influence due to soil occupation and anthropic activities.Este trabalho teve como objetivo a caracterização e a comparação da composição química da fração solúvel do PM10, com variáveis meteorológicas, tais como, direção do vento e trajetórias de massas de ar. O PM10 foi coletado durante o inverno de 1999 em dois locais contrastantes: na cidade de São Paulo e no Parque Estadual da Serra do Mar (Cunha, Reserva de Mata Atlântica. Os extratos aquosos do PM10 foram analisados por Cromatografia de Íons para quantificação dos íons maiores (Na+, K+, Mg2+, Ca2+, NH4+, Cl-, NO3-, SO4(2- e por ICP-MS para quantificação dos elementos traço (Al, Mn, Fe, Pb, Zn, etc.. As espécies químicas que predominaram foram SO4(2-, NO3-, NH4+, Zn, Fe, Al, Ba, Cu, Pb, Mn e Ni em São Paulo, e Na+, K+, Cl-, SO4(2-, Zn e Ni em Cunha. A composição química relacionada com a direção do vento que prevaleceu durante a amostragem, refletiu um transporte de curta escala influenciado pela ocupação do solo e as atividades antrópicas.

  16. Toward lattice fractional vector calculus

    International Nuclear Information System (INIS)

    An analog of fractional vector calculus for physical lattice models is suggested. We use an approach based on the models of three-dimensional lattices with long-range inter-particle interactions. The lattice analogs of fractional partial derivatives are represented by kernels of lattice long-range interactions, where the Fourier series transformations of these kernels have a power-law form with respect to wave vector components. In the continuum limit, these lattice partial derivatives give derivatives of non-integer order with respect to coordinates. In the three-dimensional description of the non-local continuum, the fractional differential operators have the form of fractional partial derivatives of the Riesz type. As examples of the applications of the suggested lattice fractional vector calculus, we give lattice models with long-range interactions for the fractional Maxwell equations of non-local continuous media and for the fractional generalization of the Mindlin and Aifantis continuum models of gradient elasticity. (papers)

  17. On Generalized Fractional Differentiator Signals

    Directory of Open Access Journals (Sweden)

    Hamid A. Jalab

    2013-01-01

    Full Text Available By employing the generalized fractional differential operator, we introduce a system of fractional order derivative for a uniformly sampled polynomial signal. The calculation of the bring in signal depends on the additive combination of the weighted bring-in of N cascaded digital differentiators. The weights are imposed in a closed formula containing the Stirling numbers of the first kind. The approach taken in this work is to consider that signal function in terms of Newton series. The convergence of the system to a fractional time differentiator is discussed.

  18. Fractional trajectories: Decorrelation versus friction

    Science.gov (United States)

    Svenkeson, A.; Beig, M. T.; Turalska, M.; West, B. J.; Grigolini, P.

    2013-11-01

    The fundamental connection between fractional calculus and subordination processes is explored and affords a physical interpretation of a fractional trajectory, that being an average over an ensemble of stochastic trajectories. Heretofore what has been interpreted as intrinsic friction, a form of non-Markovian dissipation that automatically arises from adopting the fractional calculus, is shown to be a manifestation of decorrelations between trajectories. We apply the general theory developed herein to the Lotka-Volterra ecological model, providing new insight into the final equilibrium state. The relaxation time to achieve this state is also considered.

  19. 40 CFR Table 34 to Subpart G of... - Fraction Measured (Fm) and Fraction Emitted (Fe) For HAP Compounds in Wastewater Streams

    Science.gov (United States)

    2010-07-01

    ... Emitted (Fe) For HAP Compounds in Wastewater Streams 34 Table 34 to Subpart G of Part 63 Protection of...—Fraction Measured (Fm) and Fraction Emitted (Fe) For HAP Compounds in Wastewater Streams Chemical name CAS... Acrolein 107028 1.00 0.43 Acrylonitrile 107131 1.00 0.43 Allyl chloride 107051 1.00 0.89 Benzene 71432...

  20. Observations of nitrogen isotope fractionation in deeply embedded protostars

    DEFF Research Database (Denmark)

    Wampfler, Susanne Franziska; Jørgensen, Jes Kristian; Bizzarro, Martin;

    2014-01-01

    Class~0 sources (14N/15N of 160-290) and the tentative trend toward a temperature-dependent 14N/15N ratio are consistent with the chemical fractionation scenario, but 14N/15N ratios from additional tracers are indispensable for testing the models. Spatially resolved observations are needed...

  1. Bioenergy II : Biomass Valorisation by a Hybrid Thermochemical Fractionation Approach

    NARCIS (Netherlands)

    de Wild, Paul J.; den Uil, Herman; Reith, Johannes H.; Lunshof, Anton; Hendriks, Carlijn; van Eck, Ernst R. H.; Heeres, Erik J.

    2009-01-01

    The need for green renewable sources is adamant because of the adverse effects of the increasing use of fossil fuels on our society. Biomass has been considered as a very attractive candidate for green energy carriers, chemicals and materials. The development of cheap and efficient fractionation tec

  2. SUMMARY OF EXPERIMENTAL RESEARCH OF GASOLINE AND OIL FRACTIONS

    Directory of Open Access Journals (Sweden)

    Kharchenko P. M.

    2014-05-01

    Full Text Available In the article we present the results of pilot studies of petrol and oil fractions; their main physical and chemical properties, density and DNP, a liquid phase, two-phase area, critical area and boundary curves are considered

  3. Australia's Next Top Fraction Model

    Science.gov (United States)

    Gould, Peter

    2013-01-01

    Peter Gould suggests Australia's next top fraction model should be a linear model rather than an area model. He provides a convincing argument and gives examples of ways to introduce a linear model in primary classrooms.

  4. Physcicists rewarded for 'fractional electrons'

    CERN Multimedia

    Ball, P

    1998-01-01

    The 1998 Nobel prize for physics has been awarded to Horst Stormer, Daniel Tsui and Robert Laughlin.Stormer and Tsui were the first to observe the fractional quantum Hall effect and Laughlin provided the theory shortly afterwards (1 page).

  5. Commercial SNF Accident Release Fractions

    Energy Technology Data Exchange (ETDEWEB)

    J. Schulz

    2004-11-05

    The purpose of this analysis is to specify and document the total and respirable fractions for radioactive materials that could be potentially released from an accident at the repository involving commercial spent nuclear fuel (SNF) in a dry environment. The total and respirable release fractions are used to support the preclosure licensing basis for the repository. The total release fraction is defined as the fraction of total commercial SNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. Radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses; this subset of the total release fraction is referred to as the respirable release fraction. Accidents may involve waste forms characterized as: (1) bare unconfined intact fuel assemblies, (2) confined intact fuel assemblies, or (3) canistered failed commercial SNF. Confined intact commercial SNF assemblies at the repository are contained in shipping casks, canisters, or waste packages. Four categories of failed commercial SNF are identified: (1) mechanically and cladding-penetration damaged commercial SNF, (2) consolidated/reconstituted assemblies, (3) fuel rods, pieces, and debris, and (4) nonfuel components. It is assumed that failed commercial SNF is placed into waste packages with a mesh screen at each end (CRWMS M&O 1999). In contrast to bare unconfined fuel assemblies, the

  6. Commercial SNF Accident Release Fractions

    International Nuclear Information System (INIS)

    The purpose of this analysis is to specify and document the total and respirable fractions for radioactive materials that could be potentially released from an accident at the repository involving commercial spent nuclear fuel (SNF) in a dry environment. The total and respirable release fractions are used to support the preclosure licensing basis for the repository. The total release fraction is defined as the fraction of total commercial SNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. Radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses; this subset of the total release fraction is referred to as the respirable release fraction. Accidents may involve waste forms characterized as: (1) bare unconfined intact fuel assemblies, (2) confined intact fuel assemblies, or (3) canistered failed commercial SNF. Confined intact commercial SNF assemblies at the repository are contained in shipping casks, canisters, or waste packages. Four categories of failed commercial SNF are identified: (1) mechanically and cladding-penetration damaged commercial SNF, (2) consolidated/reconstituted assemblies, (3) fuel rods, pieces, and debris, and (4) nonfuel components. It is assumed that failed commercial SNF is placed into waste packages with a mesh screen at each end (CRWMS M andO 1999). In contrast to bare unconfined fuel assemblies, the

  7. Fractionation of Stable Isotopes in Atmospheric Aerosol Reactions

    DEFF Research Database (Denmark)

    Meusinger, Carl

    reactions and undergo complex chemical and physical changes during their lifetimes. In order to assess processes that form and alter aerosols, information provided by stable isotopes can be used to help constrain estimates on the strength of aerosol sources and sinks. This thesis studies (mass......-independent) fractionation processes of stable isotopes of C, N, O and S in order to investigate three different systems related to aerosols: 1. Post-depositional processes of nitrate in snow that obscure nitrate ice core records 2. Formation and aging of secondary organic aerosol generated by ozonolysis of X...... as required. The kndings provide important results for the studies' respective felds, including a description of the isotopic fractionation and quantum yield of nitrate photolysis in snow, equilibrium fractionation in secondary organic aerosol and fractionation constants of different oxidation pathways of SO2....

  8. Fractional characteristic times and dissipated energy in fractional linear viscoelasticity

    Science.gov (United States)

    Colinas-Armijo, Natalia; Di Paola, Mario; Pinnola, Francesco P.

    2016-08-01

    In fractional viscoelasticity the stress-strain relation is a differential equation with non-integer operators (derivative or integral). Such constitutive law is able to describe the mechanical behavior of several materials, but when fractional operators appear, the elastic and the viscous contribution are inseparable and the characteristic times (relaxation and retardation time) cannot be defined. This paper aims to provide an approach to separate the elastic and the viscous phase in the fractional stress-strain relation with the aid of an equivalent classical model (Kelvin-Voigt or Maxwell). For such equivalent model the parameters are selected by an optimization procedure. Once the parameters of the equivalent model are defined, characteristic times of fractional viscoelasticity are readily defined as ratio between viscosity and stiffness. In the numerical applications, three kinds of different excitations are considered, that is, harmonic, periodic, and pseudo-stochastic. It is shown that, for any periodic excitation, the equivalent models have some important features: (i) the dissipated energy per cycle at steady-state coincides with the Staverman-Schwarzl formulation of the fractional model, (ii) the elastic and the viscous coefficients of the equivalent model are strictly related to the storage and the loss modulus, respectively.

  9. A method for isolating piperylenes from the C5 fraction of pyrolysis gasolines

    Energy Technology Data Exchange (ETDEWEB)

    Messinger, T.; Pop, G.; Purvutolu, T.

    1980-11-30

    A method is patented for separating piperylenes from the C5 fraction of pyrolysis benzine. The starting raw material is fractionated to remove the volatile C5 components (with a boiling point of less than 38 degrees), while the remainder is fractionated, removing the upper fraction which contains piperylenes (a boiling point of 38 to 45 degrees); this fraction is subjected to extractive distillation, distilling away the residues of the C5 components; the residual product is fractionated, producing in the distillate a mixture of piperylene, acetylenes and cyclopentadienes which is shifted to the zone of extractive distillation, producing in the distillate a piperylene concentrated which is then purified by known chemical means, producing a piperylene concentrate enriched with a transisomer. The residue from the fractionation is fractionated in another tower, from the top of which the piperylene concentrated, enriched with a cis isomer is distilled off.

  10. Study of Oil/Water Interfacial Tension of Vacuum Residual Fractions from Iranian Light Crude Oil

    Institute of Scientific and Technical Information of China (English)

    彭勃; 李明远; 赵锁奇; 吴肇亮; JohanSjoblom; HaraldHoiland

    2003-01-01

    The vacuum residual from Iranian Light crude oil are separated into a series of 16 narrow fractions according to the molecular weight by the supercritical fluid extraction and fractional (SFEF) technology. The chemical element and the UV spectrum of each fraction are analyzed. The effects of several factors on the interfacial tension are investigated, which are the fraction concentration in oil phase, the ratio of oil component, the salts dissolved in the water phase and the pH value. The interfacial tension decreases rapidly as the concentration of the residual fraction in the oil increases, showing a higher interfacial activity of the fraction. The interfacial tension changes, as the amount of absorption or the state of the fractions in the interface changes resulting from different ratios of oil, different kinds or concentrations of salts in water, and different pH values. It is concluded that the intrfacial tension changes regularly, corresponding to the regular molecular parameters of the vacuum residual fractions.

  11. GENERALIZED FRACTIONAL TRACE VARIATIONAL IDENTITY AND A NEW FRACTIONAL INTEGRABLE COUPLINGS OF SOLITON HIERARCHY

    Institute of Scientific and Technical Information of China (English)

    Hanyu WEI; Tiecheng XIA

    2014-01-01

    Based on fractional isospectral problems and general bilinear forms, the gener-alized fractional trace identity is presented. Then, a new explicit Lie algebra is introduced for which the new fractional integrable couplings of a fractional soliton hierarchy are derived from a fractional zero-curvature equation. Finally, we obtain the fractional Hamiltonian structures of the fractional integrable couplings of the soliton hierarchy.

  12. Conformable Fractional Bessel Equation and Bessel Functions

    OpenAIRE

    Gökdoğan, Ahmet; Ünal, Emrah; Çelik, Ercan

    2015-01-01

    In this work, we study the fractional power series solutions around regular singular point x=0 of conformable fractional Bessel differential equation and fractional Bessel functions. Then, we compare fractional solutions with ordinary solutions. In addition, we present certain property of fractional Bessel functions.

  13. Trihalomethane formation potential of organic fractions in secondary effluent

    Institute of Scientific and Technical Information of China (English)

    XUE Shuang; ZHAO Qingliang; WEI Liangliang; JIA Ting

    2008-01-01

    Organic matter is known to be the precursor of numerous chlorination by-products. Organic matter in the secondary effluent from the Wenchang Wastewater Treatment Plant(Harbin. China)was physically separated into the following fractions: particulate organic carbon(1. 2-0. 45un), colloidal organic carbon(0. 45-0. 1um), fine colloidal organic carbon(0. 1-0. 025um), and dissolved organic carbon(DOC)(<0. 025um). Moreover, <0. 45 um fraction was chemically separated into hydrophobic acid(HPO-A), hydrophobic neutral(HPO-N), transphilic acid(TPI-A), transphilic neutral(TPI-N), and hydrophilic fraction(HPI). The chlorine reactivity of these organic fractions obtained from both size and XAD fractionations were evaluated. The structural and chemical compositions of the HPO-A. HPO-N. TPI-A. and TPI-N isolates were characterized using elemental analysis(C, H, 0, and N), Fourier trailsform infrared spectroscopy(FT-IR), and proton nuclear magnetic resonance spectroscopy(1H-NMR). Results showed that Doe was dominant in terms of total concentration and trihalomethane formation potential(THMFP). and there was no statistical difference in both specific THMFP(STHMFP)and specific ultraviolet light absorbance among the 0. 45, 0. 1, and 0. 025 um filtrates. HPO-A had the highest STHMFP compared to other chemical fractions. HPO-A, HPO-N, TPI-A, and TPI-N contained 3. 02%-3. 52%of nitrogen. The molar Ratio of H/C increased in the order of HPO. Afractions. 1H-NMR analysis of the four fractions indicated that the relative content of aromatic protons in HPO-A was significantly higher than those in the others. The ratio of aliphatic to aromatic protons increased in the order of HPO-Afractions showed that HPO-A had greater aromatic C=C content whereas HPO-N, TPI-A, and TPI-N had greater aliphatic C-H content. TPI-N contained more oxygen

  14. From fractional Fourier transformation to quantum mechanical fractional squeezing transformation

    Institute of Scientific and Technical Information of China (English)

    吕翠红; 范洪义; 李东韡

    2015-01-01

    By converting the triangular functions in the integration kernel of the fractional Fourier transformation to the hy-perbolic function, i.e., tanα→tanhα, sinα→sinhα, we find quantum mechanical fractional squeezing transformation (FrST) which satisfies additivity. By virtue of the integration technique within ordered product of operators (IWOP) wederive the unitary operator responsible for the FrST, which is composite and is made of eiπa†a/2 and exp[ iα2 (a2+a†2)]. The FrST may be implemented in combinations of quadratic nonlinear crystals with different phase mismatches.

  15. Chemical conditioning of sludge.

    Science.gov (United States)

    Novak, J T; Park, C

    2004-01-01

    With all the advances made in understanding the structure and composition of sewage sludges, chemical conditioning remains a trial and error process, both with regard to the type and dose of conditioner needed. Recent studies at Virginia Tech have found that biological floc consists of two types of biopolymer, material associated with iron and aluminium and material associated with calcium and magnesium. These materials behave differently when sludges undergo digestion. This results in very different material being released into solution during digestion and very different conditioning requirements. This study shows that the primary materials released during anaerobic digestion are proteins and coagulation of the colloidal protein fraction in solution is the primary mechanism for conditioning. For aerobically digested sludges, both proteins and polysaccharides make up the colloid fraction, which interferes with dewatering. This research also shows that the effectiveness of the digestion process as characterized by volatile solids destruction is directly related to the chemical dose required for conditioning. That is, as the solids destruction increases, the conditioning chemical requirement also increases. Well digested sludges dewater more poorly and require more conditioning chemical than those with less volatile solids destruction. PMID:15259940

  16. Identification of sitosteryl glucoside palmitate in a chloroform-derived fraction of Phyllanthus niruri with antiplasmodial and peripheral antinociceptive properties

    Institute of Scientific and Technical Information of China (English)

    Ezenyi Ifeoma Chinwude; Kulkarni Roshan; Joshi Swati; Salawu Oluwakanyinsola Adeola; Emeje Martins

    2014-01-01

    Objective: To evaluate the antiplasmodial properties of fractions of chloroform portion of Phyllanthus niruri (P. niruri) methanol extract and identify a suitable chemical marker present therein. Methods: Chloroform portion of P. niruri methanol extract was separated from silica gel using gradient systems of hexane, ethylacetate and methanol. The fractions were screened for antiplasmodial activity against Plasmodium falciparum HB3 and FcM29. Fractions with IC50 Results:Fractions 12-14 were very active (IC50 Conclusions:Our findings illustrate antiplasmodial column fractions of P. niruri with analgesic activity and identify sitosteryl glucoside palmitate as a chemical marker of activity.

  17. REFractions: The Representing Equivalent Fractions Game

    Science.gov (United States)

    Tucker, Stephen I.

    2014-01-01

    Stephen Tucker presents a fractions game that addresses a range of fraction concepts including equivalence and computation. The REFractions game also improves students' fluency with representing, comparing and adding fractions.

  18. Purity assessment of condensed tannin fractions by nuclear magnetic resonance (NMR) spectroscopy

    Science.gov (United States)

    Unambiguous investigation of condensed tannin (CT) structure-activity relationships in biological systems requires the use of highly enriched CT fractions of defined chemical purity. Purification of CTs from Sorghum bicolor, Trifolium repens, Theobroma cacao, Lespedeza cuneata, Lotus pedunculatus, a...

  19. Fractional Derivatives in Dengue Epidemics

    Science.gov (United States)

    Pooseh, Shakoor; Rodrigues, Helena Sofia; Torres, Delfim F. M.

    2011-09-01

    We introduce the use of fractional calculus, i.e., the use of integrals and derivatives of non-integer (arbitrary) order, in epidemiology. The proposed approach is illustrated with an outbreak of dengue disease, which is motivated by the first dengue epidemic ever recorded in the Cape Verde islands off the coast of west Africa, in 2009. Numerical simulations show that in some cases the fractional models fit better the reality when compared with the standard differential models. The classical results are obtained as particular cases by considering the order of the derivatives to take an integer value.

  20. Fractional derivatives in Dengue epidemics

    CERN Document Server

    Pooseh, Shakoor; Torres, Delfim F M

    2011-01-01

    We introduce the use of fractional calculus, i.e., the use of integrals and derivatives of non-integer (arbitrary) order, in epidemiology. The proposed approach is illustrated with an outbreak of dengue disease, which is motivated by the first dengue epidemic ever recorded in the Cape Verde islands off the coast of west Africa, in 2009. Numerical simulations show that in some cases the fractional models fit better the reality when compared with the standard differential models. The classical results are obtained as particular cases by considering the order of the derivatives to take an integer value.

  1. Fractional differences and sums with binomial coefficients

    OpenAIRE

    Abdeljawad, Thabet; Baleanu, Dumitru; Jarad, Fahd; Agarwal, Ravi

    2012-01-01

    In fractional calculus there are two approaches to obtain fractional derivatives. The first approach is by iterating the integral and then defining a fractional order by using Cauchy formula to obtain Riemann fractional integrals and derivatives. The second approach is by iterating the derivative and then defining a fractional order by making use of the binomial theorem to obtain Gr\\"{u}nwald-Litnikov fractional derivatives. In this article we formulate the delta and nabla discrete versions f...

  2. Optical encryption with cascaded fractional wavelet transforms

    Institute of Scientific and Technical Information of China (English)

    BAO Liang-hua; CHEN Lin-fei; ZHAO Dao-mu

    2006-01-01

    On the basis of fractional wavelet transform, we propose a new method called cascaded fractional wavelet transform to encrypt images. It has the virtues of fractional Fourier transform and wavelet transform. Fractional orders, standard focal lengths and scaling factors are its keys. Multistage fractional Fourier transforms can add the keys easily and strengthen information security. This method can also realize partial encryption just as wavelet transform and fractional wavelet transform. Optical realization of encryption and decryption is proposed. Computer simulations confirmed its possibility.

  3. Fractionation and business potential from sludge - Pafrak

    Energy Technology Data Exchange (ETDEWEB)

    Kylloenen, H.; Groenroos, A.; Pirkonen, P. (VTT Technical Research Centre of Finland, Jyvaeskylae (Finland)), email: hanna.kyllonen@vtt.fi; Maekinen, L.; Suopajaervi, T.; Niinimaeki, J. (Univ. of Oulu (Finland)), email: liisa.makinen@oulu.fi

    2009-10-15

    Wastewater sludge contains valuable components which can be recycled and converted to secondary raw material. High water content of sludge can hinder the further processing. Dry solids content of waste activated sludge after dewatering can be as low as 12-20% and even lower for tertiary sludge. This research aims with better knowledge of sludge and fractination to generate potential business ideas, which could lead to new sludge based products and services in national and international markets already in this project or in separate development projects. Primary, waste activated, tertiary and deinking sludge from pulp and paper industry and municipal waste activated sludge have been the suspensions to be studied. Basic properties of these sludges have been determined by large number of analysing methods. Wood based components and chemical elements have been determined to clarify the raw material potential for biorefineries. Correlations of wood based components and dewatering properties, which is one of the key topics, have been studied especially for the waste activated sludge. Conventional fractionation techniques (decanter centrifuge, hydro cyclone, belt filter press and sieve bend) have been used to see how the sludge can be fractionated. State of the art has been drawn up about the current utilisation of wastewater sludge. (orig.)

  4. Development and Application of Heat-integrated Aromatics Fractionation Process

    Institute of Scientific and Technical Information of China (English)

    Yang Weisheng; Kong Dejin; Tan Yongzhong

    2009-01-01

    The PRO/Ⅱ process simulation software was applied to carry out simulated calculation of the aromatics frac-tionation unit and the heat integrated rectification process was proposed for the aromatics fractionation section of the 1.0 Mt/a toluene disproportionation unit at the Zhenhai Refining and Chemical Company. The optimized operating parameters were obtained through the energy utilization analysis, process simulation, heat exchanger calculations and comparisons of utility consumption. The operation of commercialized unit has revealed that the design parameters of each rectification column were consistent with the operation results, and the utility consumption was about 47% lower than the waditional heat integrated process.

  5. Fractional Schrödinger equation.

    Science.gov (United States)

    Laskin, Nick

    2002-11-01

    Some properties of the fractional Schrödinger equation are studied. We prove the Hermiticity of the fractional Hamilton operator and establish the parity conservation law for fractional quantum mechanics. As physical applications of the fractional Schrödinger equation we find the energy spectra of a hydrogenlike atom (fractional "Bohr atom") and of a fractional oscillator in the semiclassical approximation. An equation for the fractional probability current density is developed and discussed. We also discuss the relationships between the fractional and standard Schrödinger equations. PMID:12513557

  6. Experimental Test of Condensate-Excitation Theories of the Fractional Quantum Hall Effect

    OpenAIRE

    Brueckner, Reinhold

    2000-01-01

    It is shown that the description of the FQHE as condensation of the electron system into a ground state with fractionally charged excitations is incompatible with experimental observations. The nature of the Hall voltage in fractional plateaux as a chemical potential difference eliminates the condensate as current carrier and the temperature dependence of longitudinal conductance eliminates the excitation picture of charge carriers.

  7. RELATIONSHIPS BETWEEN FRACTIONATIONS OF Pb, Cd, Cu, Zn AND Ni AND SOIL PROPERTIES IN URBAN SOILS OF CHANGCHUN, CHINA

    Institute of Scientific and Technical Information of China (English)

    GUO Ping; XIE Zhong-lei; LI Jun; KANG Chun-li; LIU Jian-hua

    2005-01-01

    An extensive soil investigation was conducted in different domains of Changchun to disclose the fractionations of Pb, Cu, Cd, Zn and Ni in urban soils. Meanwhile correlation analysis and multiple stepwise regressions were used to define relationships between soil properties and metal fractions and the chief factors influencingthe fractionation of heavy metals in the soils. The results showed that Pb, Ni and Cu were mainly associated with the residual and organic forms; most of Cd was concentrated in the residual and exchangeable fractions. Zn in residual and carbonate fraction was the highest. The activities of the heavy metals probably declined in the following order: Cd, Zn,Pb, CuandNi. The chemical fractions of heavy metals in different domains in Changchun City were of significantly spatial heterogeneity. Soil properties had different influences on the chemical fractions of heavy metals to some extent and the main factors influencing Cd, Zn, Pb, Cu and Ni fractionation and transformation were apparently different.

  8. Influências físicas sobre características químicas na compostagem da fracção sólida de chorume de bovinos leiteiros Influence of dairy cattle slurry solid fraction physical characteristics on chemical characteristics of composts

    Directory of Open Access Journals (Sweden)

    L. M. Brito

    2007-07-01

    covered and with 15 m³ outside the greenhouse, covered with a polyethylene film or with a geotextile film which allowed gas exchange but not rain infiltration. The piles covered with the geotextile film or uncovered reached higher temperatures compared with those covered with the polyethylene film because the oxygen could be exchanged from outside. When covered with polyethylene the temperatures were lower inside the piles with initial lower dry matter content. The physical characteristics such as temperature, moisture and aeration inside the piles were periodically related to chemical characteristics such as pH, electrical conductivity, organic matter, Kjeldahl N and C/N ratio. Organic matter losses were compared with N content throughout the composting period and it was concluded that the solid fraction from slurry can be composted with minimum N losses in static piles with a reduced number of turnings.

  9. Fractional Laplace Transforms - A Perspective

    CERN Document Server

    Treumann, R A

    2014-01-01

    A form of the Laplace transform is reviewed as a paradigm for an entire class of fractional functional transforms. Various of its properties are discussed. Such transformations should be useful in application to differential/integral equations or problems in non-extensive statistical mechanics.

  10. Optimization in fractional aircraft ownership

    Science.gov (United States)

    Septiani, R. D.; Pasaribu, H. M.; Soewono, E.; Fayalita, R. A.

    2012-05-01

    Fractional Aircraft Ownership is a new concept in flight ownership management system where each individual or corporation may own a fraction of an aircraft. In this system, the owners have privilege to schedule their flight according to their needs. Fractional management companies (FMC) manages all aspects of aircraft operations, including utilization of FMC's aircraft in combination of outsourced aircrafts. This gives the owners the right to enjoy the benefits of private aviations. However, FMC may have complicated business requirements that neither commercial airlines nor charter airlines faces. Here, optimization models are constructed to minimize the number of aircrafts in order to maximize the profit and to minimize the daily operating cost. In this paper, three kinds of demand scenarios are made to represent different flight operations from different types of fractional owners. The problems are formulated as an optimization of profit and a daily operational cost to find the optimum flight assignments satisfying the weekly and daily demand respectively from the owners. Numerical results are obtained by Genetic Algorithm method.

  11. Fun with Fractions and Algebra.

    Science.gov (United States)

    Chandler, Jane

    1997-01-01

    Presents two games that provide practice with equivalent fractions, that were produced at three levels of difficulty, Level 1 being the simplest. Also describes another game for practice in solving simple linear equations. Appendices contain examples of materials used in the games. (ASK)

  12. A Fast Fractional Difference Algorithm

    DEFF Research Database (Denmark)

    Jensen, Andreas Noack; Nielsen, Morten Ørregaard

    We provide a fast algorithm for calculating the fractional difference of a time series. In standard implementations, the calculation speed (number of arithmetic operations) is of order T 2, where T is the length of the time series. Our algorithm allows calculation speed of order T log...

  13. What next in fractionated radiotherapy

    International Nuclear Information System (INIS)

    Trends in models for predicting the total dose required to produce tolerable normal-tissue injury can be seen by the progression from the ''cube root law'', through Strandqvist's slope of 0.22, to NSD, TDF and CRE which have separate time and fraction number exponents, to even better approximations now available. The dose-response formulae that can be used to define the effect of fraction size (and number) include (1) the linear quadratic (LQ) model (2) the two-component (TC) multi-target model and (3) repair-misrepair models. The LQ model offers considerable convenience, requires only two parameters to be determined, and emphasizes the difference between late and early normal-tissue dependence on dose per fraction first shown by exponents greater than the NSD slope of 0.24. Exponents of overall time, e.g. Tsup(0.11), yield the wrong shape of time curve, suggesting that most proliferating occurs early, although it really occurs after a delay depending on the turnover time of the tissue. Improved clinical results are being sought by hyperfractionation, accelerated fractionation, or continuous low dose rate irradiation as in interstitial implants. (U.K.)

  14. Staircase and Fractional Part Functions

    Science.gov (United States)

    Amram, Meirav; Dagan, Miriam; Ioshpe, Michael; Satianov, Pavel

    2016-01-01

    The staircase and fractional part functions are basic examples of real functions. They can be applied in several parts of mathematics, such as analysis, number theory, formulas for primes, and so on; in computer programming, the floor and ceiling functions are provided by a significant number of programming languages--they have some basic uses in…

  15. Riesz potential versus fractional Laplacian

    KAUST Repository

    Ortigueira, Manuel Duarte

    2014-09-01

    This paper starts by introducing the Grünwald-Letnikov derivative, the Riesz potential and the problem of generalizing the Laplacian. Based on these ideas, the generalizations of the Laplacian for 1D and 2D cases are studied. It is presented as a fractional version of the Cauchy-Riemann conditions and, finally, it is discussed with the n-dimensional Laplacian.

  16. Isotopic Fractionation in Interstellar Chemistry

    Science.gov (United States)

    Charnley, Steven

    2009-01-01

    Isotopically fractionated material is found in many solar system objects, including meteorites and comets. It is thought, in some cases, to trace interstellar material that was incorporated into the solar sys tem without undergoing significant processing. In this poster, we sho w the results of several models of the nitrogen, oxygen, and carbon f ractionation in proto-stellar cores.

  17. A fast fractional difference algorithm

    DEFF Research Database (Denmark)

    Jensen, Andreas Noack; Nielsen, Morten Ørregaard

    2014-01-01

    We provide a fast algorithm for calculating the fractional difference of a time series. In standard implementations, the calculation speed (number of arithmetic operations) is of order T 2, where T is the length of the time series. Our algorithm allows calculation speed of order T logT . For...

  18. Chemical use

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a summary of research and activities related to chemical use on Neal Smith National Wildlife Refuge between 1992 and 2009. The chemicals used on the Refuge...

  19. Chemical Reactors.

    Science.gov (United States)

    Kenney, C. N.

    1980-01-01

    Describes a course, including content, reading list, and presentation on chemical reactors at Cambridge University, England. A brief comparison of chemical engineering education between the United States and England is also given. (JN)

  20. Fractional Processes and Fractional-Order Signal Processing Techniques and Applications

    CERN Document Server

    Sheng, Hu; Qiu, TianShuang

    2012-01-01

    Fractional processes are widely found in science, technology and engineering systems. In Fractional Processes and Fractional-order Signal Processing, some complex random signals, characterized by the presence of a heavy-tailed distribution or non-negligible dependence between distant observations (local and long memory), are introduced and examined from the ‘fractional’ perspective using simulation, fractional-order modeling and filtering and realization of fractional-order systems. These fractional-order signal processing (FOSP) techniques are based on fractional calculus, the fractional Fourier transform and fractional lower-order moments. Fractional Processes and Fractional-order Signal Processing: • presents fractional processes of fixed, variable and distributed order studied as the output of fractional-order differential systems; • introduces FOSP techniques and the fractional signals and fractional systems point of view; • details real-world-application examples of FOSP techniques to demonstr...

  1. Chemical sensor

    Science.gov (United States)

    Rauh, R. David (Inventor)

    1990-01-01

    A sensor for detecting a chemical substance includes an insertion element having a structure which enables insertion of the chemical substance with a resulting change in the bulk electrical characteristics of the insertion element under conditions sufficient to permit effective insertion; the change in the bulk electrical characteristics of the insertion element is detected as an indication of the presence of the chemical substance.

  2. Galaxy cluster baryon fractions revisited

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Anthony H. [Department of Astronomy, University of Florida, Gainesville, FL 32611-2055 (United States); Sivanandam, Suresh; Zabludoff, Ann I.; Zaritsky, Dennis [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)

    2013-11-20

    We measure the baryons contained in both the stellar and hot-gas components for 12 galaxy clusters and groups at z ∼ 0.1 with M = 1-5 × 10{sup 14} M {sub ☉}. This paper improves upon our previous work through the addition of XMM-Newton X-ray data, enabling measurements of the total mass and masses of each major baryonic component—intracluster medium, intracluster stars, and stars in galaxies—for each system. We recover a mean relation for the stellar mass versus halo mass, M{sub ⋆}∝M{sub 500}{sup −0.52±0.04}, that is 1σ shallower than in our previous result. We confirm that the partitioning of baryons between the stellar and hot-gas components is a strong function of M {sub 500}; the fractions of total mass in stars and X-ray gas within a sphere of radius r {sub 500} scale as f{sub ⋆}∝M{sub 500}{sup −0.45±0.04} and f{sub gas}∝M{sub 500}{sup 0.26±0.03}, respectively. We also confirm that the combination of the brightest cluster galaxy and intracluster stars is an increasingly important contributor to the stellar baryon budget in lower halo masses. Studies that fail to fully account for intracluster stars typically underestimate the normalization of the stellar baryon fraction versus M {sub 500} relation by ∼25%. Our derived stellar baryon fractions are also higher, and the trend with halo mass weaker, than those derived from recent halo occupation distribution and abundance matching analyses. One difference from our previous work is the weak, but statistically significant, dependence here of the total baryon fraction upon halo mass: f{sub bary}∝M{sub 500}{sup 0.16±0.04}. For M {sub 500} ≳ 2 × 10{sup 14}, the total baryon fractions within r {sub 500} are on average 18% below the universal value from the seven year Wilkinson Microwave Anisotropy Probe (WMAP) analysis, or 7% below for the cosmological parameters from the Planck analysis. In the latter case, the difference between the universal value and cluster baryon fractions is

  3. Antibacterial, Antibiofilm Effect of Burdock (Arctium lappa L.) Leaf Fraction and Its Efficiency in Meat Preservation.

    Science.gov (United States)

    Lou, Zaixiang; Li, Cheng; Kou, Xingran; Yu, Fuhao; Wang, Hongxin; Smith, Gary M; Zhu, Song

    2016-08-01

    First, the antibacterial, antibiofilm effect and chemical composition of burdock (Arctium lappa L.) leaf fractions were studied. Then, the efficiency of burdock leaf fractions in pork preservation was evaluated. The results showed that burdock leaf fraction significantly inhibited the growth and biofilm development of Escherichia coli and Salmonella Typhimurium. MICs of burdock leaf fractions on E. coli and Salmonella Typhimurium were both 2 mg/ml. At a concentration of 2.0 mg/ml, the inhibition rates of the fraction on growth and development of E. coli and Salmonella Typhimurium biofilms were 78.7 and 69.9%, respectively. During storage, the log CFU per gram of meat samples treated with burdock leaf fractions decreased 2.15, compared with the samples without treatment. The shelf life of pork treated with burdock leaf fractions was extended 6 days compared with the pork without treatment, and the sensory property was obviously improved. Compared with the control group, burdock leaf fraction treatment significantly decreased the total volatile basic nitrogen value and pH of the meat samples. Chemical composition analysis showed that the burdock leaf fraction consisted of chlorogenic acid, caffeic acid, p-coumaric acid, rutin, cynarin, crocin, luteolin, arctiin, and quercetin. As a vegetable with an abundant source, burdock leaf is safe, affordable, and efficient in meat preservation, indicating that burdock leaf fraction is a promising natural preservative for pork.

  4. Antibacterial, Antibiofilm Effect of Burdock (Arctium lappa L.) Leaf Fraction and Its Efficiency in Meat Preservation.

    Science.gov (United States)

    Lou, Zaixiang; Li, Cheng; Kou, Xingran; Yu, Fuhao; Wang, Hongxin; Smith, Gary M; Zhu, Song

    2016-08-01

    First, the antibacterial, antibiofilm effect and chemical composition of burdock (Arctium lappa L.) leaf fractions were studied. Then, the efficiency of burdock leaf fractions in pork preservation was evaluated. The results showed that burdock leaf fraction significantly inhibited the growth and biofilm development of Escherichia coli and Salmonella Typhimurium. MICs of burdock leaf fractions on E. coli and Salmonella Typhimurium were both 2 mg/ml. At a concentration of 2.0 mg/ml, the inhibition rates of the fraction on growth and development of E. coli and Salmonella Typhimurium biofilms were 78.7 and 69.9%, respectively. During storage, the log CFU per gram of meat samples treated with burdock leaf fractions decreased 2.15, compared with the samples without treatment. The shelf life of pork treated with burdock leaf fractions was extended 6 days compared with the pork without treatment, and the sensory property was obviously improved. Compared with the control group, burdock leaf fraction treatment significantly decreased the total volatile basic nitrogen value and pH of the meat samples. Chemical composition analysis showed that the burdock leaf fraction consisted of chlorogenic acid, caffeic acid, p-coumaric acid, rutin, cynarin, crocin, luteolin, arctiin, and quercetin. As a vegetable with an abundant source, burdock leaf is safe, affordable, and efficient in meat preservation, indicating that burdock leaf fraction is a promising natural preservative for pork. PMID:27497128

  5. Evaluating fractionated space systems - Status

    Science.gov (United States)

    Cornford, S.; Jenkins, S.; Wall, S.; Cole, B.; Bairstow, B.; Rouquette, N.; Dubos, G.; Ryan, T.; Zarifian, P.; Boutwell, J.

    DARPA has funded a number of teams to further refine its Fractionated Spacecraft vision. Several teams, including this team led by JPL, have been tasked to develop a tool for the evaluation of the Business case for a fractionated system architecture. This evaluation is to understand under what conditions and constraints the fractionated architecture make more sense (in a cost/benefit sense) than the traditional monolithic paradigm. Our approach to this evaluation is to generate and evaluate a variety of trade space options. These options include various sets of stimuli, various degrees of fractionation and various subsystem element properties. The stimuli include many not normally modeled such as technology obsolescence, funding profile changes and changes in mission objectives during the mission itself. The degrees of fractionation enable various traditional subsystem elements to be distributed across different free flyers which then act in concert as needed. This will enable key technologies to be updated as need dictates and availability allows. We have described our approach in a previous IEEE Aerospace conference paper but will briefly summarize here. Our approach to generate the Business Case evaluation is to explicitly model both the implementation and operation phases for the life cycle of a fractionated constellation. A variety of models are integrated into the Phoenix ModelCenter framework and are used to generate various intermediate data which is aggregated into the Present Strategic Value (PSV). The PSV is essentially the value (including the value of the embedded real options) minus the cost. These PSVs are calculated for a variety of configurations and scenarios including variations of various stimuli or uncertainties (e.g. supply chain delays, launch vehicle failures and orbital debris events). There are various decision options (e.g. delay, accelerate, cancel) which can now be exercised for each stimulus. We can compute the PSV for the various comb

  6. Green's Theorem for Generalized Fractional Derivatives

    OpenAIRE

    Odzijewicz, Tatiana; Malinowska, Agnieszka B.; Delfim F. M. Torres

    2012-01-01

    We study three types of generalized partial fractional operators. An extension of Green's theorem, by considering partial fractional derivatives with more general kernels, is proved. New results are obtained, even in the particular case when the generalized operators are reduced to the standard partial fractional derivatives and fractional integrals in the sense of Riemann-Liouville or Caputo.

  7. Using Number Sense to Compare Fractions

    Science.gov (United States)

    Bray, Wendy S.; Abreu-Sanchez, Laura

    2010-01-01

    One mathematical focus for third graders is to develop deep understanding of fractions and fraction equivalence, including comparing fractions through use of models and reasoning strategies. Before reading further, consider how you might solve the following problem: Which fraction is greater, 14/24 or 17/36? The initial impulse of many adults is…

  8. STOCHASTIC INTEGRATION FOR TEMPERED FRACTIONAL BROWNIAN MOTION.

    Science.gov (United States)

    Meerschaert, Mark M; Sabzikar, Farzad

    2014-07-01

    Tempered fractional Brownian motion is obtained when the power law kernel in the moving average representation of a fractional Brownian motion is multiplied by an exponential tempering factor. This paper develops the theory of stochastic integrals for tempered fractional Brownian motion. Along the way, we develop some basic results on tempered fractional calculus. PMID:24872598

  9. Expanding the bovine milk proteome through extensive fractionation

    DEFF Research Database (Denmark)

    Nissen, Asger; Bendixen, Emøke; Ingvartsen, Klaus Lønne;

    2013-01-01

    of low abundant proteins. Further, the general health and udder health of the dairy cows delivering the milk may influence the composition of the milk proteome. To gain a more exhaustive and true picture of the milk proteome, we performed an extensive preanalysis fractionation of raw composite milk...... collected from documented healthy cows in early lactation. Four simple and industrially applicable techniques exploring the physical and chemical properties of milk, including acidification, filtration, and centrifugation, were used for separation of the proteins. This resulted in 5 different fractions...... sensitivity limit of the 2-dimensional liquid chromatography tandem mass spectrometry analysis. Each fractionation technique resulted in identification of a unique subset of proteins. However, high-speed centrifugation of milk to whey was by far the best method to achieve high and repeatable proteome coverage...

  10. Defining Product Intake Fraction to Quantify and Compare Exposure to Consumer Products.

    Science.gov (United States)

    Jolliet, Olivier; Ernstoff, Alexi S; Csiszar, Susan A; Fantke, Peter

    2015-08-01

    There is a growing consciousness that exposure studies need to better cover near-field exposure associated with products use. To consistently and quantitatively compare human exposure to chemicals in consumer products, we introduce the concept of product intake fraction, as the fraction of a chemical within a product that is eventually taken in by the human population. This metric enables consistent comparison of exposures during consumer product use for different product-chemical combinations, exposure duration, exposure routes and pathways and for other life cycle stages. We present example applications of the product intake fraction concept, for two chemicals in two personal care products and two chemicals encapsulated in two articles, showing how intakes of these chemicals can primarily occur during product use. We demonstrate the utility of the product intake fraction and its application modalities within life cycle assessment and risk assessment contexts. The product intake fraction helps to provide a clear interface between the life cycle inventory and impact assessment phases, to identify best suited sentinel products and to calculate overall exposure to chemicals in consumer products, or back-calculate maximum allowable concentrations of substances inside products.

  11. Chemical Leukoderma.

    Science.gov (United States)

    Bonamonte, Domenico; Vestita, Michelangelo; Romita, Paolo; Filoni, Angela; Foti, Caterina; Angelini, Gianni

    2016-01-01

    Chemical leukoderma, often clinically mimicking idiopathic vitiligo and other congenital and acquired hypopigmentation, is an acquired form of cutaneous pigment loss caused by exposure to a variety of chemicals that act through selective melanocytotoxicity. Most of these chemicals are phenols and aromatic or aliphatic catechols derivatives. These chemicals, however, are harmful for melanocytes in individuals with an individual susceptibility. Nowadays, chemical leukoderma is fairly common, caused by common domestic products. The presence of numerous acquired confetti- or pea-sized macules is clinically characteristic of chemical leukoderma, albeit not diagnostic. Other relevant diagnostic elements are a history of repeated exposure to a known or suspected depigmenting agent at the sites of onset and a macules distribution corresponding to sites of chemical exposure. Spontaneous repigmentation has been reported when the causative agent is avoided; the repigmentation process is perifollicular and gradual, taking place for a variable period of weeks to months. PMID:27172302

  12. Optimal fractionation from radiobiological view

    International Nuclear Information System (INIS)

    Not only in animal experiments but also from analyses of clinical data important knowledge could be obtained in recent years, that deal with the course of biological processes in tumor and normal tissue during fractionated irradiation. Relevant are differences in the capacity for recovery from sublethal radiation injury and in repopulation. Chronically reacting normal tissues show a clearly higher repair capacity than tumors, that can be used for hyperfractionation with reduced single dosis. However, strong attention must be given to repairing time, that the selective benefit is not endangered by incomplete recovery. On the other side clinical analyses have confirmed that the stem cell repopulation - going on in several tumor types, so e.g. in squamous cell carcinomas, during the time of conventional treatment - can make a considerable contribution to radioresistance. The actual level of knowledge justifies further clinical experiments with unconventional fractionation, especially with accelerated hyperfractionation. (author)

  13. Astrophysical Applications of Fractional Calculus

    Science.gov (United States)

    Stanislavsky, Aleksander A.

    The paradigm of fractional calculus occupies an important place for the macroscopic description of subdiffusion. Its advance in theoretical astrophysics is expected to be very attractive too. In this report we discuss a recent development of the idea to some astrophysical problems. One of them is connected with a random migration of bright points associated with magnetic fields at the solar photosphere. The transport of the bright points has subdiffusive features that require the fractional generalization of the Leighton's model. Another problem is related to the angular distribution of radio beams, being propagated through a medium with random inhomogeneities. The peculiarity of this medium is that radio beams are trapped because of random wave localization. This idea can be useful for the diagnostics of interplanetary and interstellar turbulent media.

  14. Nitrogen fractionation in Titan's aerosols

    Science.gov (United States)

    Carrasco, Nathalie; Kuga, Maia; Marty, Bernard; Fleury, Benjamin; Marrocchi, Yves

    2016-06-01

    A strong nitrogen fractionation is found by Cassini in Titan's atmosphere with the detection of 15N-rich HCN relative to N2. Photodissociation of N2 associated or not to self-shielding might involve 15N-rich radicals prone to incorporation into forming organics. However the isotopic composition is only available for very simple gaseous N-bearing compounds, and the propagation and conservation of such a large N-isotopic fractionation upon polymerization is actually out of reach with the instruments onboard Cassini. We will therefore present a first laboratory investigation of the possible enrichment in the solid organic aerosols. We will also discuss the space instrumention required in the future to answer this pending issue on Titan.

  15. Fractional Authorship in Nuclear Physics

    CERN Document Server

    Pritychenko, B

    2015-01-01

    Large, multi-institutional groups or collaborations of scientists are engaged in nuclear physics research projects, and the number of research facilities is dwindling. These collaborations have their own authorship rules, and they produce a large number of highly-cited papers. Multiple authorship of nuclear physics publications creates a problem with the assessment of an individual author's productivity relative to his/her colleagues and renders ineffective a performance metrics solely based on annual publication and citation counts. Many institutions are increasingly relying on the total number of first-author papers; however, this approach becomes counterproductive for large research collaborations with an alphabetical order of authors. A concept of fractional authorship (the claiming of credit for authorship by more than one individual) helps to clarify this issue by providing a more complete picture of research activities. In the present work, nuclear physics fractional and total authorships have been inv...

  16. Fractionated radiation therapy after Strandqvist

    International Nuclear Information System (INIS)

    Models for predicting the total dose required to produce tolerable normal-tissue damage in radiation therapy are becoming less empirical, more realistic, and more specific for different tissue reactions. The progression is described from the 'cube root law', through STRANDQVIST'S well known graph to NSD, TDF and CRE and more recently to biologically based time factors and linear-quadratic dose-response curves. New applications of the recent approach are reviewed together with their implications for non-standard fractionation in radiation therapy. It is concluded that accelerated fractionation is an important method to be investigated, as well as hyperfractionation; and that more data are required about the proliferation rates of clonogenic cells in human tumours. (orig.)

  17. Electrochemically controlled iron isotope fractionation

    Science.gov (United States)

    Black, Jay R.; Young, Edward D.; Kavner, Abby

    2010-02-01

    Variations in the stable isotope abundances of transition metals have been observed in the geologic record and trying to understand and reconstruct the physical/environmental conditions that produced these signatures is an area of active research. It is clear that changes in oxidation state lead to large fractionations of the stable isotopes of many transition metals such as iron, suggesting that transition metal stable isotope signatures could be used as a paleo-redox proxy. However, the factors contributing to these observed stable isotope variations are poorly understood. Here we investigate how the kinetics of iron redox electrochemistry generates isotope fractionation. Through a combination of electrodeposition experiments and modeling of electrochemical processes including mass-transport, we show that electron transfer reactions are the cause of a large isotope separation, while mass transport-limited supply of reactant to the electrode attenuates the observed isotopic fractionation. Furthermore, the stable isotope composition of electroplated transition metals can be tuned in the laboratory by controlling parameters such as solution chemistry, reaction overpotential, and solution convection. These methods are potentially useful for generating isotopically-marked metal surfaces for tracking and forensic purposes. In addition, our studies will help interpret stable isotope data in terms of identifying underlying electron transfer processes in laboratory and natural samples.

  18. Geometrical explanation of the fractional complex transform and derivative chain rule for fractional calculus

    International Nuclear Information System (INIS)

    The fractional complex transform is suggested to convert a fractional differential equation with Jumarie's modification of Riemann–Liouville derivative into its classical differential partner. Understanding the fractional complex transform and the chain rule for fractional calculus are elucidated geometrically. -- Highlights: ► The chain rule for fractional calculus is invalid, a counter example is given. ► The fractional complex transform is explained geometrically. ► Fractional equations can be converted into differential equations.

  19. Geometrical explanation of the fractional complex transform and derivative chain rule for fractional calculus

    Energy Technology Data Exchange (ETDEWEB)

    He, Ji-Huan, E-mail: hejihuan@suda.edu.cn [National Engineering Laboratory for Modern Silk, College of Textile and Engineering, Soochow University, 199 Ren-ai Road, Suzhou 215123 (China); Elagan, S.K., E-mail: sayed_khalil2000@yahoo.com [Mathematics and Statistics Department, Faculty of Science, Taif University, P.O. 888 (Saudi Arabia); Department of Mathematics, Faculty of Science, Menofiya University, Shebin Elkom (Egypt); Li, Z.B., E-mail: zhengbiaoli@l26.com [College of Mathematics and Information Science, Qujing Normal University, Qujing, Yunnan 655011 (China)

    2012-01-09

    The fractional complex transform is suggested to convert a fractional differential equation with Jumarie's modification of Riemann–Liouville derivative into its classical differential partner. Understanding the fractional complex transform and the chain rule for fractional calculus are elucidated geometrically. -- Highlights: ► The chain rule for fractional calculus is invalid, a counter example is given. ► The fractional complex transform is explained geometrically. ► Fractional equations can be converted into differential equations.

  20. Removal of Mercury by Foam Fractionation Using Surfactin, a Biosurfactant

    OpenAIRE

    Atla, Shashi B.; Jyoti Prakash Maity; Wei Pan; Hung-Tsan Liu; Min-Jen Tseng; Wun Rong Li; Chien-Yen Chen; A. Satyanarayana Reddy; Chien-Cheng Chen; Hau-Ren Chen

    2011-01-01

    The separation of mercury ions from artificially contaminated water by the foam fractionation process using a biosurfactant (surfactin) and chemical surfactants (SDS and Tween-80) was investigated in this study. Parameters such as surfactant and mercury concentration, pH, foam volume, and digestion time were varied and their effects on the efficiency of mercury removal were investigated. The recovery efficiency of mercury ions was highly sensitive to the concentration of the surfactant. The h...

  1. Temperature sensitivity of decomposition of soil organic carbon fractions

    Science.gov (United States)

    Hilasvuori, Emmi; Järvenpää, Marko; Akujärvi, Anu; Arppe, Laura; Christensen, Bent T.; Fritze, Hannu; Kaasalainen, Mikko; Karhu, Kristiina; Oinonen, Markku; Palonen, Vesa; Pitkänen, Juha-Matti; Repo, Anna; Vanhala, Pekka; Liski, Jari

    2015-04-01

    Knowing the temperature sensitivity of soil organic matter (SOM) decomposition is important for estimating the release of carbon from soil to the atmosphere in response to global warming. This temperature sensitivity is known relatively well for the most labile SOM fractions but still quite poorly for more recalcitrant fractions that represent the great majority of SOM. We report results for the temperature sensitivity of various SOM fractions in two different experiments in which we utilized natural abundances of carbon isotopes 13C and 14C combined with Bayesian mathematical modelling. In one experiment, the different age fractions were distinguished based on depth in a peat profile. In the other experiment, the age fractions were separated based on a time series of conversion from C3 vegetation to C4 vegetation. In both experiments, the temperature sensitivity of the SOM fractions was estimated by measuring the carbon isotope composition of heterotrophic soil respiration at different temperatures in laboratory. The results from these experiments suggest that the temperature sensitivity of unprotected SOM fractions increases with age, but if an environmental factor, such as bonding to soil minerals, limits decomposition of a SOM fraction, the temperature sensitivity is reduced. Our results are in agreement with the theory that suggests that in soil without environmental, physical or chemical protection, temperature sensitivity of carbon compounds is mainly determined by its chemical structure. The more complex the structure is the higher activation energy is needed and the higher its temperature sensitivity. Since SOM enriches with more complicated carbon compounds with time, this leads to increase in temperature sensitivity as SOM ages. However, our results also indicate that if the soil carbon is associated with minerals it might exhibit lower temperature sensitivities than when the carbon is "free" in the soil. Since the mineral associated carbon can have high

  2. Antihyperglycemic activity of various fractions of Cassia auriculata linn. in alloxan diabetic rats

    Directory of Open Access Journals (Sweden)

    Surana S

    2008-01-01

    Full Text Available Present work describes the potent antidiabetic fraction from flowers of Cassia auriculata Linn. Hydromethanolic extract along with its ethyl acetate and n-butanol fractions were evaluated for antidiabetic activity in alloxan-induced diabetes in rats. The n-butanol fraction exhibited significant reduction (p< 0.001 in blood glucose levels and was also found effective in restoring the blood lipids and proteins to normal level. The activity was found comparable with standard drug phenformin. The hydromethanolic extract and its fractions were subjected to preliminary qualitative chemical investigations which indicated the presence of phenolic compounds, carbohydrates, tannins, steroids and amino acids.

  3. The preparation of low electroendosmosis agarose and its physico-chemical property

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Studies on Gelidium amansii agar fractionations were carried out in this paper. Gelidium amansii agar was fractionated on DEAE-Cellulose, and four fractions were obtained sequentially. The fractions were analyzed on physical and chemical properties, and IR and 13C-NMR spectroscopy applied for elucidating the chemical structure. Among the four fractions obtained, water fraction measured up to the standard of low EEO agarose. The sulfate content, ash content, electroendosmosis and gel strength(1%) of water fraction were 0.16%, 0.34%, 0.12 and 1 130g/cm2 respectively, similar to those of the Sigma products.

  4. Fractionation of extracts from paper and board food contact materials forin vitroscreening of toxicity

    DEFF Research Database (Denmark)

    Bengtström, Linda; Trier, Xenia; Granby, Kit;

    2014-01-01

    Paper and board used as food contact materials (FCMs) are chemically complex matrices, partly due to the naturally occurring substances in paper and board, but also due to the chemical treatment of the paper used to make it suitable for food contact. In order to assure the safety of packaging......% after extraction and fractionation. The fractionation both reduces the number of compounds to be identified and works as a sample clean-up by reducing matrix effects. Raw extracts and fractions from two paper and board FCMs were furthermore tested in the aryl hydrocarbon receptor (AhR) reporter gene...... assay. Both raw extracts and two of the fractions of the raw extracts gave a positive response in the AhR assay. The strategy of extraction followed by fractionation offers a powerful tool in order to make the workflow for screening FCMs for potentially adverse effects more efficient....

  5. Chemical networks*

    OpenAIRE

    Thi Wing-Fai

    2015-01-01

    This chapter discusses the fundamental ideas of how chemical networks are build, their strengths and limitations. The chemical reactions that occur in disks combine the cold phase reactions used to model cold molecular clouds with the hot chemistry applied to planetary atmosphere models. With a general understanding of the different types of reactions that can occur, one can proceed in building a network of chemical reactions and use it to explain the abundance of species seen in disks. One o...

  6. Fractional Sums and Differences with Binomial Coefficients

    Directory of Open Access Journals (Sweden)

    Thabet Abdeljawad

    2013-01-01

    Full Text Available In fractional calculus, there are two approaches to obtain fractional derivatives. The first approach is by iterating the integral and then defining a fractional order by using Cauchy formula to obtain Riemann fractional integrals and derivatives. The second approach is by iterating the derivative and then defining a fractional order by making use of the binomial theorem to obtain Grünwald-Letnikov fractional derivatives. In this paper we formulate the delta and nabla discrete versions for left and right fractional integrals and derivatives representing the second approach. Then, we use the discrete version of the Q-operator and some discrete fractional dual identities to prove that the presented fractional differences and sums coincide with the discrete Riemann ones describing the first approach.

  7. Theory of fractional-ordered thermoelastic diffusion

    Science.gov (United States)

    Shaw, Soumen; Mukhopadhyay, Basudeb

    2016-06-01

    In this note, the traditional theory of thermoelastic diffusion is replaced by fractional ordered thermoelasticity based on fractional conservation of mass, fractional Taylor series and fractional divergence theorem. We replace the integer-order Taylor series approximation for flux with the fractional-order Taylor series approximation which can remove the restriction that the flux has to be linear, or piece-wise linear and the restriction that the control volume must be infinitesimal. There are two important distinctions between the traditional thermoelastic diffusion, and its fractional equivalent. The first is that the divergence term in the heat conduction and mass diffusion equations are the fractional divergence, and the second is the appearance of strain tensor term in the fractional equation is in the form of "incomplete fractional-strain measures".

  8. Influence of Organic Manure on Organic Phosphorus Fraction in Soils

    Institute of Scientific and Technical Information of China (English)

    ZHANGYONG-SONG; NIWU-ZHONG; 等

    1993-01-01

    The transformation of organic P(Po) from organic manures in two types of soils (ultisol and entisol) and the influences of external addition of organic substance or inorganic P(Pi) on Po under the condition of the 60% maximum water capacity were investigated.The results obtained from Po fractionation experiments indicated that all the Po fractions except for the highly resistant Po fraction decreased during incubation.Application of pig feces and cow feces could largely increase each fraction of Po in the soils.Immediately after application of organic manure into the soils a large part of labile and moderately labile Po from organic manure was transferred into moderately resistant Po,which might be due to the fact that Ca-or Mg-inositol P was precipitated into Fe-inositol P.However,the availability of Po from organic manure in the soils would increase again after incubation because of the transformation of moderately labile and resistant Po fractions into labile Po fractions.Addition of cellulose or Pi into the soils showed a good effect on increasing all the Po fractions except for the highly resistant Po,and this effect was much more pronounced when cellulose was applied in combination with Pi.Therefore,in view of the effect of organic manure on improving P nutrition to plant,attention should be paid to both the Po and the organic substances from organic manure,It is suggested that application of Pi fertilizer combined with organic manure may be referred to as an effective means of protecting Pi from chemical fixation in soil.

  9. Sorption of 1-naphthol by plant cuticular fractions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment, but sorption mechanism is still not fully understood. In this study,sorption of 1-naphthol by plant cuticular fractions was examined to better understand the contributions of respective fraction. Toward this end, cuticular materials were isolated from the fruits of tomato by chemical method. The tomato cuticle sheet consisted of waxes(6.5 wt%), cuticular monomer (69.5 wt%), and polysaccharide (24.0 wt%). Isotherms of 1-naphthol to the cuticular fractions were nonlinear (N value (0.82 - 0.90)) at the whole tested concentration ranges. The Koc/Kow ratios for bulk cuticle (TC1), dewaxed cuticle(TC2), cutin (TC4), and desugared cuticle (TC5) were larger than unity, suggested that tomato bulk cuticle and cutin are much powerful sorption medium. Sorption capability of cutin (TC4) was 2.4 times higher than the nonsaponifiable fraction (TC3). The 1-naphthol interactions with tomato cuticular materials were governed by both hydrophobic-type interactions and polar (H-bonding) interactions.Removal of the wax and polysaccharide materials from the bulk tomato cuticle caused a significant increase in the sorption ability of the cuticular material. There was a linear negative trend between Koc values and the amount of polysaccharides or fraction's polarities((N+O)/C); while a linear positive relationship between Koc values and the content of cutin monomer (linear R2 = 0.993) was observed for present in the cuticular fractions. Predominant sorbent of the hydrophobic organic compounds (HOCs) in the plant cuticular fraction was the cutin monomer, contributing to 91.7% of the total sorption of tomato bulk cuticle.

  10. Extractable Fractions of Metals in Sewage Sludges from Five Typical Urban Wastewater Treatment Plants of China

    Institute of Scientific and Technical Information of China (English)

    WANG Chao; LI Xiao-Chen; WANG Pei-Fang; ZOU Li-Min; MA Hai-Tao

    2006-01-01

    Metal content and bioavailability are often the limiting factors for application of sewage sludge in agricultural fields.Sewage sludge samples were collected from five typical urban wastewater treatment plants in China to investigate their contents and distribution of various chemical fractions of Cu, Zn, Ni, Cr, Pb and Mo by using the BCR (Community Bureau of Reference) sequential extraction procedure. The sludges contained considerable amounts of organic matter (31.8%-48.0%), total N (16.3-26.4 g kg-1) and total P (15.1-23.9 g kg-1), indicating high potential agricultural benefits of their practical applications. However, total Zn and Ni contents in the sludge exceeded the values permitted in China's control standards for pollutants in sludges from agricultural use (GB 4284-1984). The residual fraction was the predominant fraction for Mo, Ni and Cr, the oxidizable fraction was the primary fraction for Cu and Pb, and the exchangeable and reducible fractions were principal for Zn. The distribution of different chemical fractions among the sludge samples reflected differences in their physicochemical properties, especially pH. The sludge pH was negatively correlated with the percentages of reducible fraction of Cu and exchangeable fraction of Zn. The sludges from these plants might not be suitable for agricultural applications due to their high contents of Zn, Ni and Cr, as well as high potential of mobility and bioavailability of Zn.

  11. Conformable Fractional Nikiforov—Uvarov Method

    Science.gov (United States)

    Karayer, H.; Demirhan, D.; Büyükkılıç, F.

    2016-07-01

    We introduce conformable fractional Nikiforov—Uvarov (NU) method by means of conformable fractional derivative which is the most natural definition in non-integer calculus. Since, NU method gives exact eigenstate solutions of Schrödinger equation (SE) for certain potentials in quantum mechanics, this method is carried into the domain of fractional calculus to obtain the solutions of fractional SE. In order to demonstrate the applicability of the conformable fractional NU method, we solve fractional SE for harmonic oscillator potential, Woods—Saxon potential, and Hulthen potential.

  12. Natural fractionation of uranium isotopes

    International Nuclear Information System (INIS)

    The topic of this thesis was the investigation of U (n(238U) / n(235U)) isotope variations in nature with a focus on samples (1) that represent the continental crust and its weathering products (i.e. granites, shales and river water) (2) that represent products of hydrothermal alteration on mid-ocean ridges (i.e. altered basalts, carbonate veins and hydrothermal water) and (3) from restricted euxinic basins (i.e. from the water column and respective sediments). The overall goal was to explore the environmental conditions and unravel the mechanisms that fractionate the two most abundant U isotopes, n(238U) and n(235U), on Earth.

  13. Composição química do óleo essencial e avaliação da atividade antimicrobiana do óleo essencial, extrato etanólico bruto e frações das folhas de Spiranthera odoratissima A. St.-Hil Chemical composition of the essential oil and evaluation of the antimicrobial activity of essential oil, crude ethanol extract and fractions of Spiranthera odoratissima A. St.-Hil. leaves

    Directory of Open Access Journals (Sweden)

    B.A. Chaibub

    2013-01-01

    Full Text Available A Spiranthera odoratissima A. St.-Hil (manacá é utilizada popularmente como depurativo do sangue, nas afecções renais e hepáticas (chá das folhas para dores musculares, de estômago, de cabeça, e disfunções hepáticas (chá das raízes. O objetivo desse trabalho foi avaliar a composição química do óleo essencial e a atividade antimicrobiana do óleo essencial, do extrato etanólico bruto e frações obtidos das folhas de S. odoratissima contra bactérias Gram positivas e negativas, e Candida albicans. O extrato bruto das folhas foi obtido por maceração seguido de concentração em rotaevaporador e as frações por partição em coluna filtrante. O pó das folhas foi submetido à hidrodestilação em aparelho de Clevenger e o óleo essencial obtido foi analisado por CG/EM. A atividade antimicrobiana foi avaliada pelo método da diluição em ágar para determinar a concentração inibitória mínima (CIM. Os constituintes majoritários do óleo essencial foram β-cariofileno (20,64%, γ-muuroleno (17,70%, biciclogermacreno (14,73%, e δ-cadineno (13,40%. No estudo da atividade antimicrobiana de S. odoratissima, os principais resultados foram obtidos contra Staphylococus epidermidis (extrato etanólico bruto, CIM de 0,098 mg/mL, C. albicans (fração hexano, CIM de 0,049 mg/mL, Bacillus cereus (diclorometano, CIM de 0,098 mg/mL, Micrococcus roseus (fração acetato de etila, CIM 0,049 mg/mL, e M. roseus, Micrococus luteus, B. cereus e C. albicans (fração metanol, CIM de 0,391 mg/mL.Spiranthera odoratissima ("manacá" has been popularly used as a blood cleanser, for liver and kidney diseases (tea from the leaves, as well as for muscle and stomach pains, headache and liver disorders (tea from the roots. The aim of this study was to evaluate the chemical composition of the essential oil and the antimicrobial activity of essential oil, crude ethanol extract and fractions of S. odoratissima leaves against Gram-positive and negative

  14. Soluble/insoluble (dilute-HCl-extractable fractionation of Cd, Pb and Cu in Antarctic snow and its relationship with metal fractionations in the aerosol

    Directory of Open Access Journals (Sweden)

    Annibaldi A.

    2013-04-01

    Full Text Available A chemical fractionation methodology for determination of the (water soluble and the insoluble (dilute-HCl-extractable fractions of Cd, Pb and Cu in Antarctic snow was set-up and verified for the additivity of the two fractions detected. Molten samples were filtrated and the water-insoluble fraction was extracted by dilute ultrapure HCl (pH ~1.5. Metal determinations were carried out in the two fractions by square wave anodic stripping voltammetry. The total metal concentrations in samples collected in the 2000–2001 austral summer in a clean area (Faraglione Camp in the neighbourhood of the Mario Zucchelli Italian Station were of the order of Cd 10-20 pg g−1, Pb 20–40 pg g−1, Cu 60–120 pg g−1 with an approximate equidistribution between soluble and insoluble fractions. These fractionations compare well (and show a quite consistent temporal trend with those observed in the aerosol samples collected in the same area/period and confirm the close relationship between metal distributions in snow/ice and in the aerosol. At the station metal concentrations increase due to anthropic contribution and the distribution changes with Cd predominantly present in the soluble fraction (~80%, while Pb and Cu are more concentrated in the insoluble fraction, 70–80% and ~70%, respectively.

  15. Chemical sensors

    Science.gov (United States)

    Lowell, J.R. Jr.; Edlund, D.J.; Friesen, D.T.; Rayfield, G.W.

    1991-07-02

    Sensors responsive to small changes in the concentration of chemical species are disclosed. The sensors comprise a mechanochemically responsive polymeric film capable of expansion or contraction in response to a change in its chemical environment. They are operatively coupled to a transducer capable of directly converting the expansion or contraction to a measurable electrical response. 9 figures.

  16. Purification and Structural Analysis of a Selective Toxin Fraction Produced by the Plant Pathogen Setosphaeria turcica

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li-hui; DONG Jin-gao; WANG Chao-hua; LI Zheng-ping

    2007-01-01

    Thirteen fractions from the pathogenic plant fungus Setosphaeria turcica race 1 were separated and collected using high performance liquid chromatography (HPLC). Their toxic activities were assayed through leaf puncturing on corn differentials (OH43, OH43Htl, OH43Ht2, and OH43HtN), and the results revealed that eight fractions were toxic and fraction 6 was specifically toxic to OH43Htl, which could be taken as a gene-selective toxin fraction. Fraction 6 was finely purified via HPLC and condensed by freeze desiccation. Its chemical structure was analyzed with EI-MS, IR, HMBC, 1H-NMR, and two-dimensional NMR. The results suggested that fraction 6 contained an unsaturated double bond, carbonyl and methylene groups with molecular weight of 142.

  17. Chemical Radioprotectors

    Directory of Open Access Journals (Sweden)

    S. N. Upadhyay

    2005-10-01

    Full Text Available Protection of biological systems against radiation damage is of paramount importance during accidental and unavoidable exposure to radiation. Several physico-chemical and biological factors collectively contribute to the damage caused by radiation and are, therefore, targets for developing radioprotectors. Work on the development of chemicals capable of protecting biological systemsfrom radiation damage was initiated nearly six decades ago with cysteine being the first molecule to be reported. Chemicals capable of scavenging free radicals, inducing oxygen depletion,antioxidants and modulators of immune response have been some of the radioprotectors extensively investigated with limited success. Mechanism of action of some chemical radioprotectors and their combinations have been elucidated, while further understanding is required in many instances. The present review elaborates on structure-activity relationship of some of the chemical radioprotectors, their evaluation, and assessment, limitation, and future prospects.

  18. Staircase and fractional part functions

    Science.gov (United States)

    Amram, Meirav; Dagan, Miriam; Ioshpe, Michael; Satianov, Pavel

    2016-10-01

    The staircase and fractional part functions are basic examples of real functions. They can be applied in several parts of mathematics, such as analysis, number theory, formulas for primes, and so on; in computer programming, the floor and ceiling functions are provided by a significant number of programming languages - they have some basic uses in various programming tasks. In this paper, we view the staircase and fractional part functions as a classical example of non-continuous real functions. We introduce some of their basic properties, present some interesting constructions concerning them, and explore some intriguing interpretations of such functions. Throughout the paper, we use these functions in order to explain basic concepts in a first calculus course, such as domain of definition, discontinuity, and oddness of functions. We also explain in detail how, after researching the properties of such functions, one can draw their graph; this is a crucial part in the process of understanding their nature. In the paper, we present some subjects that the first-year student in the exact sciences may not encounter. We try to clarify those subjects and show that such ideas are important in the understanding of non-continuous functions, as a part of studying analysis in general.

  19. Microfluidic Devices for Blood Fractionation

    Directory of Open Access Journals (Sweden)

    Chwee Teck Lim

    2011-07-01

    Full Text Available Blood, a complex biological fluid, comprises 45% cellular components suspended in protein rich plasma. These different hematologic components perform distinct functions in vivo and thus the ability to efficiently fractionate blood into its individual components has innumerable applications in both clinical diagnosis and biological research. Yet, processing blood is not trivial. In the past decade, a flurry of new microfluidic based technologies has emerged to address this compelling problem. Microfluidics is an attractive solution for this application leveraging its numerous advantages to process clinical blood samples. This paper reviews the various microfluidic approaches realized to successfully fractionate one or more blood components. Techniques to separate plasma from hematologic cellular components as well as isolating blood cells of interest including certain rare cells are discussed. Comparisons based on common separation metrics including efficiency (sensitivity, purity (selectivity, and throughput will be presented. Finally, we will provide insights into the challenges associated with blood-based separation systems towards realizing true point-of-care (POC devices and provide future perspectives.

  20. Dean flow fractionation of chromosomes

    Science.gov (United States)

    Hockin, Matt; Sant, Himanshu J.; Capecchi, Mario; Gale, Bruce K.

    2016-03-01

    Efforts to transfer intact mammalian chromosomes between cells have been attempted for more than 50 years with the consistent result being transfer of sub unit length pieces regardless of method. Inertial microfluidics is a new field that has shown much promise in addressing the fractionation of particles in the 2-20 μm size range (with unknown limits) and separations are based upon particles being carried by curving confined flows (within a spiral shaped, often rectangular flow chamber) and migrating to stable "equilibrium" positions of varying distance from a chamber wall depending on the balance of dean and lift forces. We fabricated spiral channels for inertial microfluidic separations using a standard soft lithography process. The concentration of chromosomes, small contaminant DNA and large cell debris in each outlets were evaluated using microscope (60X) and a flow cytometer. Using Dean Flow Fractionation, we were able to focus 4.5 times more chromosomes in outlet 2 compared to outlet 4 where most of the large debris is found. We recover 16% of the chromosomes in outlet #1- 50% in 2, 23% in 3 and 11% in 4. It should be noted that these estimates of recovery do not capture one piece of information- it actually may be that the chromosomes at each outlet are physically different and work needs to be done to verify this potential.

  1. Oxygen isotope fractionation in synthetic magnesian calcite

    Science.gov (United States)

    Jiménez-López, Concepción; Romanek, Christopher S.; Huertas, F. Javier; Ohmoto, Hiroshi; Caballero, Emilia

    2004-08-01

    Mg-bearing calcite was precipitated at 25°C in closed system free-drift experiments from solutions containing NaHCO 3, CaCl 2 and MgCl 2. The chemical and isotope composition of the solution and precipitate were investigated during time course experiments of 24-h duration. Monohydrocalcite and calcite precipitated early in the experiments (95%) thereafter. Solid collected at the end of the experiments displayed compositional zoning from pure calcite in crystal cores to up to 23 mol% MgCO 3 in the rims. Smaller excursions in Mg were superimposed on this chemical record, which is characteristic of oscillatory zoning observed in synthetic and natural solid-solution carbonates of differing solubility. Magnesium also altered the predominant morphology of crystals over time from the {104} to {100} and {110} growth forms. The oxygen isotope fractionation factor for the magnesian-calcite-water system (as 10 3lnα Mg-cl-H 2O ) displayed a strong dependence on the mol% MgCO 3 in the solid phase, but quantification of the relationship was difficult due to the heterogeneous nature of the precipitate. Considering only the Mg-content and δ 18O values for the bulk solid, 10 3lnα Mg-cl-H 2O increased at a rate of 0.17 ± 0.02 per mol% MgCO 3; this value is a factor of three higher than the single previous estimate (Tarutani T., Clayton R.N., and Mayeda T. K. (1969) The effect of polymorphims and magnesium substitution on oxygen isotope fractionation between calcium carbonate and water. Geochim. Cosmochim. Acta 33, 987-996). Nevertheless, extrapolation of our relationship to the pure calcite end member yielded a value of 27.9 ± 0.02, which is similar in magnitude to published values for the calcite-water system. Although no kinetic effect was observed on 10 3lnα Mg-cl-H 2O for precipitation rates that ranged from 10 3.21 to 10 4.60 μmol · m -2 · h -1, it was impossible to disentangle the potential effect(s) of precipitation rate and Mg-content on 10 3lnα Mg-cl-H 2O due to

  2. Size fraction characterization of highly-calcareous fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Itskos, Grigorios; Koukouzas, Nikolaos [Institute for Solid Fuels Technology and Applications, Centre for Research and Technology Hellas, 357-359 Mesogeion Avenue, GR-152 31, Halandri, Athens (Greece); Itskos, Socrates [Department of Chemical Technology and the Environment, Steam Electric Station of Amynteon-Filotas, Public Power Corporation of Greece, GR-532 00, Amynteon (Greece)

    2010-11-15

    The chemical and mineralogical composition of lignite fly ash (FA) varies as a function of the prevalent conditions in both the processes of power production and lignite mining. The differentiation of the qualitative and quantitative composition of the highly-calcareous lignite fly ash, as a function of its particle size distribution, is verified in this paper. According to the results of the conducted research, a fine-grained fraction of considerable amount presents properties that obstruct the sustainable exploitation of calcareous lignite fly ash in cement industry applications. On the other hand, the same grain fraction (because of its hydraulic properties) can be utilized in other sort of applications, based on different criteria, i.e. in road constructions. The coarse-grained fraction (which reflects a low proportion to the total fly ash output) presents the same undesired characteristics as well. Rather, the intermediate grain fraction (75-150 {mu}m) presents the highly desirable properties when fly ash is utilized as a pozzolanic additive. In addition, the mechanism of the formation of the intermediate grain fraction strongly prevents the factors that cause the variation of fly ash-quality. It is therefore the optimum part of the whole amount of lignite FA, to be utilized as additive in cement manufacturing. The outcomes of this paper will hopefully contribute towards the crucial goal of the expansion of the utilization of calcareous lignite fly ash by proposing a more effective way of using this material, basically by taking advantage of its fundamental chemical and mineralogical properties. (author)

  3. Isotope Fractionation Studies in Prestellar Cores: The Case of Nitrogen

    Science.gov (United States)

    Milam, Stefanie N.; Charnley, Steven B.

    2011-01-01

    Isotopically fractionated material is found in many solar system objects, including meteorites and comets. It is considered, in some cases, to trace interstellar material that was incorporated into the solar system without undergoing significant processing, thus preserving the fractionation. In interstellar molecular clouds, ion-molecule chemistry continually cycles nitrogen between the two main reservoirs - N and N2 - leading to only minor N-15 enrichments. Charnley and Rodgers showed that depletion of CO removes oxygen from the gas and weakens this cycle such that significant N-15 fractionation can occur for N2 and other N-bearing species in such cores. Observations are being conducted at millimeter and submillimeter wavelengths employing various facilities in order to both spatially and spectrally, resolve emission from these cores. A preliminary study to obtain the N-14/N-15 ratio in nitriles (HCN and HNC) was conducted at the Arizona Radio Observatory's 12m telescope on Kitt Peak, AZ. Spectra were obtained at high resolution (0.08 km/s) in order to resolve dynamic properties of each source as well as to resolve hyperfine structure present in certain isotopologues. This study included four dark cloud cores, observed to have varying levels of molecular depletion: L1521E, L1498, L1544, and L1521F. Previous studies of the N-14/N-15 ratio towards LI544 were obtained with N2H+ and NIH3, yielding ratios of 446 and >700, respectively. The discrepancy observed in these two measurements suggests a strong chemical dependence on the fractionation of nitrogen. Ratios (C,N, and D) obtained from isotopologues for a particular molecule are likely tracing the same chemical heritage and are directly comparable within a given source. Results and comparisons between the protostellar evolutionary state and isomer isotope fractionation as well as between other N-bearing species will be presented.

  4. Observations of Nitrogen Isotope Fractionation in Prestellar Cores

    Science.gov (United States)

    Milam, Stefanie N.; Charnley, Steven B.

    2011-01-01

    Isotopically fractionated material is found in many solar system objects, including meteorites and comets [1]. It is considered, in some cases, to trace interstellar material that was incorporated into the solar system without undergoing significant processing, thus preserving the fractionation. In interstellar molecular clouds, ion-molecule chemistry continually cycles nitrogen between the two main reservoirs - Nand N2 - leading to only minor N-15 enrichments [2]. Charnley and Rodgers [3,4] showed that depletion of CO removes oxygen from the gas and weakens this cycle such that significant N-15 fractionation can occur for N2 and other N-bearing species in such cores. Observations are being conducted at millimeter and submillimeter wavelengths employing various facilities in order to both spatially and spectrally, resolve emission from these cores. A preliminary study to obtain the N-14/N-15 ratio in nitriles was conducted at the Arizona Radio Observatory's 12m telescope on Kitt Peak, AZ. Spectra were obtained at high resolution (0.08 km/s) in order to resolve dynamic properties of each source as well as to resolve hyperfine structure present in certain isotopologues. This study included four dark cloud cores, observed to have varying levels of molecular depletion: Ll521E, Ll498, Ll544, and Ll521F. Previous studies of the N-14/N-15 ratio towards Ll544 were obtained with N2H(+) and NH3 yielding ratios of 446 and greater than 700, respectively [5,6]. The discrepancy observed in these two measurements suggests a strong chemical dependence on the fractionation of nitrogen. Ratios (C,N, and D) obtained from isotopologues for a particular molecule are likely tracing the same chemical heritage and are directly comparable within a given source. Results and comparisons between the protostellar evolutionary state and isomer isotope fractionation as well as between other N-bearing species will be presented.

  5. Fractional-differential equations of motion

    OpenAIRE

    Olemskoi, Alexander I.

    1999-01-01

    An elementary system leading to the notions of fractional integrals and derivatives is considered. Various physical situations whose description is associated with fractional differential equations of motion are discussed.

  6. Boundary Controllability of Nonlinear Fractional Integrodifferential Systems

    Directory of Open Access Journals (Sweden)

    Ahmed HamdyM

    2010-01-01

    Full Text Available Sufficient conditions for boundary controllability of nonlinear fractional integrodifferential systems in Banach space are established. The results are obtained by using fixed point theorems. We also give an application for integropartial differential equations of fractional order.

  7. Multiple Interactive Representations for Fractions Learning

    NARCIS (Netherlands)

    Feenstra, Laurens; Aleven, Vincent; Rummel, Nikol; Taatgen, Niels; Aleven,; Kay, J; Mostow, J

    2010-01-01

    Multiple External Representations (MERs) have been used successfully in instructional activities, including fractions However, students often have difficulties making the connections between the MERs spontaneously We argue that interactive fraction representations may help students in discovering re

  8. Fractional Order Element Based Impedance Matching

    KAUST Repository

    Radwan, Ahmed Gomaa

    2014-06-24

    Disclosed are various embodiments of methods and systems related to fractional order element based impedance matching. In one embodiment, a method includes aligning a traditional Smith chart (|.alpha.|=1) with a fractional order Smith chart (|.alpha.|.noteq.1). A load impedance is located on the traditional Smith chart and projected onto the fractional order Smith chart. A fractional order matching element is determined by transitioning along a matching circle of the fractional order Smith chart based at least in part upon characteristic line impedance. In another embodiment, a system includes a fractional order impedance matching application executed in a computing device. The fractional order impedance matching application includes logic that obtains a first set of Smith chart coordinates at a first order, determines a second set of Smith chart coordinates at a second order, and determines a fractional order matching element from the second set of Smith chart coordinates.

  9. A fractional model for dye removal

    OpenAIRE

    Ji-Huan He; Zheng-Biao Li

    2016-01-01

    The adsorption process has a fractional property, and a fractional model is suggested to study a transport model of direct textile industry wastewater. An approximate solution of the concentration is obtained by the variational iteration method.

  10. The multiple-parameter fractional Fourier transform

    Institute of Scientific and Technical Information of China (English)

    LANG Jun; TAO Ran; RAN QiWen; WANG Yue

    2008-01-01

    The fractional Fourier transform (FRFT) has multiplicity, which is intrinsic in frac-tional operator. A new source for the multiplicity of the weight-type fractional Fou-rier transform (WFRFT) is proposed, which can generalize the weight coefficients of WFRFT to contain two vector parameters MN,∈ZM. Therefore a generalized frac-tional Fourier transform can be defined, which is denoted by the multiple-parameter fractional Fourier transform (MPFRFT). It enlarges the multiplicity of the FRFT, which not only includes the conventional FRFT and general multi-fractional Fourier transform as special cases, but also introduces new fractional Fourier transforms. It provides a unified framework for the FRFT, and the method is also available for fractionalizing other linear operators. In addition, numerical simulations of the MPFRFT on the Hermite-Gaussian and rectangular functions have been performed as a simple application of MPFRFT to signal processing.

  11. Fractional Smoothness of Some Stochastic Integrals

    Institute of Scientific and Technical Information of China (English)

    Peng XIE; Xi Cheng ZHANG

    2007-01-01

    We study the fractional smoothness in the sense of Malliavin calculus of stochastic integralsof the form ∫10 φ(Xs)d Xs,where Xs is a semimartingale and φ belongs to some fractional Sobolev spaceover R.

  12. A fractional model for dye removal

    Directory of Open Access Journals (Sweden)

    Ji-Huan He

    2016-01-01

    Full Text Available The adsorption process has a fractional property, and a fractional model is suggested to study a transport model of direct textile industry wastewater. An approximate solution of the concentration is obtained by the variational iteration method.

  13. BOUNDEDNESS OF GENERALIZED FRACTIONAL INTEGRAL OPERATORS

    Institute of Scientific and Technical Information of China (English)

    Tang Canqin; Yang Dachun; Zhang Pu

    2002-01-01

    The authors introduce a new kind of fractional integral operators, namely, the so called (θ,N)-type fractional integral operators, and discuss their boundedness on the Hardy spaces, the weak Hardy spaces and the Herz-type Hardy spaces.

  14. Accelerator dynamics of a fractional kicked rotor

    OpenAIRE

    Iomin, A.

    2006-01-01

    It is shown that the Weyl fractional derivative can quantize an open system. A fractional kicked rotor is studied in the framework of the fractional Schrodinger equation. The system is described by the non-Hermitian Hamiltonian by virtue of the Weyl fractional derivative. Violation of space symmetry leads to acceleration of the orbital momentum. Quantum localization saturates this acceleration, such that the average value of the orbital momentum can be a direct current and the system behaves ...

  15. Langevin equation with two fractional orders

    Energy Technology Data Exchange (ETDEWEB)

    Lim, S.C. [Faculty of Engineering, Multimedia University, Jalan Multimedia, Cyberjaya 63100, Selangor Darul Ehsan (Malaysia)], E-mail: sclim@mmu.edu.my; Li Ming [School of Information Science and Technology, East China Normal University, No. 500, Dong-Chuan Road, Shanghai 200241 (China)], E-mail: mli@ee.ecnu.edu.cn; Teo, L.P. [Faculty of Information Technology, Multimedia University, Jalan Multimedia, Cyberjaya 63100, Selangor Darul Ehsan (Malaysia)], E-mail: lpteo@mmu.edu.my

    2008-10-13

    A new type of fractional Langevin equation of two different orders is introduced. The solutions for this equation, known as the fractional Ornstein-Uhlenbeck processes, based on Weyl and Riemann-Liouville fractional derivatives are obtained. The basic properties of these processes are studied. An example of the spectral density of ocean wind speed which has similar spectral density as that of Weyl fractional Ornstein-Uhlenbeck process is given.

  16. Fractional Order Modelling Using State Space Theory

    Directory of Open Access Journals (Sweden)

    Pritesh Shah

    2013-06-01

    Full Text Available There are various fractional order systems existing. This paper deals with the modelling of fractional order systems using an old and unique model structure i.e. state space model. The fractional order process system can be mathematically modelled by state space model. Simulation results validated that the fractional order model using state space is better as compared to other models such as first order with delay.

  17. On tumor development: fractional transport approach

    CERN Document Server

    Iomin, A; Dorfman, L

    2004-01-01

    A growth of malignant neoplasm is considered as a fractional transport approach. We suggested that the main process of the tumor development through a lymphatic net is fractional transport of cells. In the framework of this fractional kinetics we were able to show that the mean size of main growth is due to subdiffusion, while the appearance of metaphases is determined by superdiffusion.

  18. Early Predictors of Middle School Fraction Knowledge

    Science.gov (United States)

    Bailey, Drew H.; Siegler, Robert S.; Geary, David C.

    2014-01-01

    Recent findings that earlier fraction knowledge predicts later mathematics achievement raise the question of what predicts later fraction knowledge. Analyses of longitudinal data indicated that whole number magnitude knowledge in first grade predicted knowledge of fraction magnitudes in middle school, controlling for whole number arithmetic…

  19. Identifying Fractions on a Number Line

    Science.gov (United States)

    Wong, Monica

    2013-01-01

    Fractions are generally introduced to students using the part--whole model. Yet the number line is another important representation which can be used to build fraction concepts (Australian Curriculum Assessment and Reporting Authority [ACARA], 2012). Number lines are recognised as key in students' number development not only of fractions, but…

  20. Stretching Student Teachers' Understanding of Fractions

    Science.gov (United States)

    Harvey, Roger

    2012-01-01

    The teaching of fractions in elementary school is known to be challenging. Literature indicates that teachers' and prospective teachers' lack of depth of fraction content knowledge and associated pedagogical knowledge is of concern. This study investigated the fraction content knowledge of prospective teachers and their ability to use that…

  1. Take a Bite out of Fraction Division

    Science.gov (United States)

    Cengiz, Nesrin; Rathouz, Margaret

    2011-01-01

    Division of fractions is often considered the most mechanical and least understood topic in elementary school. Enacting fraction division tasks in meaningful ways requires that teachers know not only "how" fraction division works but also "why" it works. The authors have created materials to help preservice teachers develop that knowledge. To…

  2. Lyapunov functions for fractional order systems

    Science.gov (United States)

    Aguila-Camacho, Norelys; Duarte-Mermoud, Manuel A.; Gallegos, Javier A.

    2014-09-01

    A new lemma for the Caputo fractional derivatives, when 0<α<1, is proposed in this paper. This result has proved to be useful in order to apply the fractional-order extension of Lyapunov direct method, to demonstrate the stability of many fractional order systems, which can be nonlinear and time varying.

  3. Hazardous Chemicals

    Centers for Disease Control (CDC) Podcasts

    2007-04-10

    Chemicals are a part of our daily lives, providing many products and modern conveniences. With more than three decades of experience, The Centers for Disease Control and Prevention (CDC) has been in the forefront of efforts to protect and assess people's exposure to environmental and hazardous chemicals. This report provides information about hazardous chemicals and useful tips on how to protect you and your family from harmful exposure.  Created: 4/10/2007 by CDC National Center for Environmental Health.   Date Released: 4/13/2007.

  4. Distribution of Soil Zinc.Iron,Copper and Manganese Fractions and Its Relationship with Plant Availability

    Institute of Scientific and Technical Information of China (English)

    ZOUBANG-JI; MORUN-CANG

    1995-01-01

    The distribution of various fractions of Zn,Fe,Cu and Mn in 15 types of soils in China and its relationship with plant availability were studied.Fractions of various elements were found to have some similar characterstic distribution regularities in various types of soils,but various soil types differed to varying degrees in the distribution of each fraction.Soil physico-chemical properties,such as pH,CEC and the contents of OM,CaCO3,free Fe,free Mn and P2O5,were significantly correlated with the distribution of elemental fractions,and a significant correlation also existed between the distribution and plant availability of elemental fractions.Various fractions of each element were divided into two groups based on their plant availability.The correlation between the distribution of combination fractions and plat availability indicated a significantly or an extremely significantly positive correlation for Group I but a significantly or an extremely significantly negative correlation for Group II.Therefore,the fractions in Goup I were primary pools of available nutrients,while those in Group II could hardly provide available nutrients for plants.Decreasing the transformation of corresponding elements into fractions of Group II and increasing the storage capacity of various fractions of Group I were an important direction for regulation and controlling of soil nutrients.However,some Particular soils with too high contents of Zn,Fe,Cu and Mn should be regulated and controlled adversely.

  5. Natural fractionation of uranium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Noordmann, Janine

    2015-01-24

    The topic of this thesis was the investigation of U (n({sup 238}U) / n({sup 235}U)) isotope variations in nature with a focus on samples (1) that represent the continental crust and its weathering products (i.e. granites, shales and river water) (2) that represent products of hydrothermal alteration on mid-ocean ridges (i.e. altered basalts, carbonate veins and hydrothermal water) and (3) from restricted euxinic basins (i.e. from the water column and respective sediments). The overall goal was to explore the environmental conditions and unravel the mechanisms that fractionate the two most abundant U isotopes, n({sup 238}U) and n({sup 235}U), on Earth.

  6. Chemical Peels

    Science.gov (United States)

    ... pills, who subsequently become pregnant or have a history of brownish facial discoloration. Scarring Reactivation of cold sores What can I expect after having a chemical peel? All peels require some follow-up care: ...

  7. Unnecessary Chemicals

    Science.gov (United States)

    Johnson, Anita

    1978-01-01

    Discusses the health hazards resulting from chemical additions of many common products such as cough syrups, food dyes, and cosmetics. Steps being taken to protect consumers from these health hazards are included. (MDR)

  8. Phase—Controlled and Gas—Washing Fractionations During the Formation of Petroleum Reservoirs

    Institute of Scientific and Technical Information of China (English)

    苏爱国; 向龙斌; 等

    2001-01-01

    By PVT fractionation experiments to model phase-controlled and gaw-washing fractionations during the formation of petroleum reservoirs,the authors measured the physical and chemical properties of products formed in different fractionation staes and made a correlative analysis of the influence of depressurization and gas washing on oil/gas molecular composition and the rule of fractionation.The analytical results showed that gas washing is an important factor affecting the physical properties of crude oils.and also can be regarded as a good genetic interpretation of marine wax-high oils in the Tarim region,Xinjiang,China.Phase-controlled and gaw-washing fractionations can lead to the formation of condensates and their differences in chemical composition from crude oils are a direct reflection of evaporating fractionation.Phasecontrolled and gaw-washing fractionations have a great influence on the composition of molecular compounds and relevant parameters.So phase-controlled and gas-washing fractionations during the formation of petroleum reservoirs are not only favorable to identifying different processes of formation of petroleum reservoirs,but also to the scientific application of routine geochemical parameters.

  9. Phase-Controlled and Gas-Washing Fractionations During the Formation of Petroleum Reservoirs

    Institute of Scientific and Technical Information of China (English)

    苏爱国; 张水昌; 向龙斌; 曾凡刚

    2001-01-01

    By PVT fractionation experiments to model phase-controlled and gas-washing fractionations during the formation of petroleum reservoirs, the authors measured the physical and chemical properties of products formed in different fractionation stages and made a correlative analysis of the influence of depressurization and gas washing on oil/gas molecular composition and the rule of fractionation. The analytical results showed that gas washing is an important factor affecting the physical properties of crude oils, and also can be regarded as a good genetic interpretation of marine wax-high oils in the Tarim region, Xinjiang, China. Phase-controlled and gas-washing fractionations can lead to the formation of condensates and their differences in chemical composition from crude oils are a direct reflection of evaporating fractionation. Phasecontrolled and gas-washing fractionations have a great influence on the composition of molecular compounds and relevant parameters. So phase-controlled and gas-washing fractionations during the formation of petroleum reservoirs are not only favorable to identifying different processes of formation of petroleum reservoirs, but also to the scientific application of routine geochemical parameters.

  10. Predictive Functional Control for Fractional Order System

    Directory of Open Access Journals (Sweden)

    Morteza Abdolhosseini

    2014-01-01

    Full Text Available The fractional calculus is the area of mathematics that handles derivatives and integrals of any arbitrary order (fractional or integer, real or complex order. Predictive Functional Control (PFC is one of the most popular methods of model predictive control. The implementation of the predictive functional controller (PFC on the fractional order systems has been presented in this paper. The effect of various approximations, sensitivity analysis, tuning of predictive functional controller parameters, the effect of delay and noise analysis of the fractional-order system has been considered. It has been shown that, in fractional order system, predictive functional control gives acceptable results

  11. Second Study of Hyper-Fractionated Radiotherapy

    Directory of Open Access Journals (Sweden)

    R. Jacob

    1999-01-01

    Full Text Available Purpose and Method. Hyper-fractionated radiotherapy for treatment of soft tissue sarcomas is designed to deliver a higher total dose of radiation without an increase in late normal tissue damage. In a previous study at the Royal Marsden Hospital, a total dose of 75 Gy using twice daily 1.25 Gy fractions resulted in a higher incidence of late damage than conventional radiotherapy using 2 Gy daily fractions treating to a total of 60 Gy. The current trial therefore used a lower dose per fraction of 1.2 Gy and lower total dose of 72 Gy, with 60 fractions given over a period of 6 weeks.

  12. Deuterium Fractionation and Ion-Molecule Reactions at Low Temperatures

    Science.gov (United States)

    Schlemmer, Stephan; Asvany, Oskar; Hugo, Edouard; Gerlich, Dieter

    2005-08-01

    Understanding deuterium fractionation is currently one of the greatest challenges in astrochemistry. In this contribution deuteration experiments of the series CH_n^+, n=2-5, in a low temperature 22-pole ion trap are used to systematically test a simple chemical rule predicting which molecular ion undergoes deuterium exchange in collisions with HD. CH_4^+ turns out to be a problem case, where prediction fails. The method of laser induced reaction (LIR) is used to determine the population ratio of the lowest ortho-to-para states of H_2D^+ relaxed in collisions with H_2. Preliminary results indicate that the ortho-to-para ratio of H_2D^+ is substantially reduced in para-H_2. This points at the important role of nuclear spin in deuterium fractionation, in particular at the destruction of ortho-H_2D^+ in collisions with ortho-H_2. More systematic LIR experiments are needed for a chemical model of deuterium fractionation including state-to-state modifications of the species involved.

  13. Fractional linear systems and electrical circuits

    CERN Document Server

    Kaczorek, Tadeusz

    2015-01-01

    This monograph covers some selected problems of positive and fractional electrical circuits composed of resistors, coils, capacitors and voltage (current) sources. The book consists of 8 chapters, 4 appendices and a list of references. Chapter 1 is devoted to fractional standard and positive continuous-time and discrete-time linear systems without and with delays. In chapter 2 the standard and positive fractional electrical circuits are considered and the fractional electrical circuits in transient states are analyzed.  Descriptor linear electrical circuits and their properties are investigated in chapter 3,  while chapter 4 is devoted to the stability of fractional standard and positive linear electrical circuits. The reachability, observability and reconstructability of fractional positive electrical circuits and their decoupling zeros are analyzed in chapter 5. The fractional linear electrical circuits with feedbacks are considered in chapter 6. In chapter 7 solutions of minimum energy control for standa...

  14. Heavy metals fractionation in Ganga River sediments, India.

    Science.gov (United States)

    Purushothaman, P; Chakrapani, G J

    2007-09-01

    The Ganga River is the largest river in India which, originates in the Himalayas and along with the Brahmaputra River, another Himalayan river, transports enormous amounts of sediments from the Indian sub-continent to the Bay of Bengal. Because of the important role of river sediments in the biogeochemical cycling of elements, the Ganga river sediments, collected from its origin to the down stretches, were studied in the present context, to assess the heavy metals associated with different chemical fractions of sediments. The fractionation of metals were studied in the sediments using SM&T protocol for the extraction of heavy metals and geo-accumulation index (GAI) (Muller, Schwermetalle in den sedimenten des rheins - Veranderungen seit. Umschau, 79, 778-783, 1979) and Metal Enrichment Factor (MEF) in different fractions were calculated. As with many river systems, residual fractions constitute more than 60% of total metals, except Zn, Cu and Cr. However, the reducible and organic and sulfide components also act as major sinks for metals in the down stretches of the river, which is supported by the high GAI and MEF values. The GAI values range between 4 and 5 and MEF exceed more than 20 for almost all the locations in the downstream locations indicating to the addition of metals through urban and industrial effluents, as compared to the low metals concentrations with less GAI and MEF in the pristine river sediments from the rivers in Himalayas.

  15. Heavy metals fractionation in Ganga River sediments, India.

    Science.gov (United States)

    Purushothaman, P; Chakrapani, G J

    2007-09-01

    The Ganga River is the largest river in India which, originates in the Himalayas and along with the Brahmaputra River, another Himalayan river, transports enormous amounts of sediments from the Indian sub-continent to the Bay of Bengal. Because of the important role of river sediments in the biogeochemical cycling of elements, the Ganga river sediments, collected from its origin to the down stretches, were studied in the present context, to assess the heavy metals associated with different chemical fractions of sediments. The fractionation of metals were studied in the sediments using SM&T protocol for the extraction of heavy metals and geo-accumulation index (GAI) (Muller, Schwermetalle in den sedimenten des rheins - Veranderungen seit. Umschau, 79, 778-783, 1979) and Metal Enrichment Factor (MEF) in different fractions were calculated. As with many river systems, residual fractions constitute more than 60% of total metals, except Zn, Cu and Cr. However, the reducible and organic and sulfide components also act as major sinks for metals in the down stretches of the river, which is supported by the high GAI and MEF values. The GAI values range between 4 and 5 and MEF exceed more than 20 for almost all the locations in the downstream locations indicating to the addition of metals through urban and industrial effluents, as compared to the low metals concentrations with less GAI and MEF in the pristine river sediments from the rivers in Himalayas. PMID:17295113

  16. Modeling of turbulent chemical reaction

    Science.gov (United States)

    Chen, J.-Y.

    1995-01-01

    Viewgraphs are presented on modeling turbulent reacting flows, regimes of turbulent combustion, regimes of premixed and regimes of non-premixed turbulent combustion, chemical closure models, flamelet model, conditional moment closure (CMC), NO(x) emissions from turbulent H2 jet flames, probability density function (PDF), departures from chemical equilibrium, mixing models for PDF methods, comparison of predicted and measured H2O mass fractions in turbulent nonpremixed jet flames, experimental evidence of preferential diffusion in turbulent jet flames, and computation of turbulent reacting flows.

  17. Chemical Evolution of the Galaxy

    OpenAIRE

    Tosi, M.

    1994-01-01

    Standard models for the chemical evolution of the Galaxy are reviewed with particular emphasis on the history of the abundance gradients in the disk. The effects on the disk structure and metallicity of gas accretion are discussed, showing that a significant fraction of the current disk mass has been accreted in the last Gyrs and that the chemical abundances of the infalling gas can be non primordial but should not exceed 0.3 Z(sun). The distributions with time and with galactocentric distanc...

  18. Composition and thermal characteristics of Madhuca longifolia seed fat and its solid and liquid fractions.

    Science.gov (United States)

    Marikkar, J M N; Ghazali, H M; Long, K

    2010-01-01

    This study was to characterize the seed fat from Madhuca longifolia known as Mee fat and its solid and liquid fractions with the objective of distinguishing them. A sample of Mee fat was partitioned into solid and liquid fractions using acetone as the solvent medium. The isolated fractions were compared to the native Mee fat sample with respect to various physico-chemical parameters using standard chemical methods as well as instrumental techniques such as, gas liquid chromatography (GLC), reversed-phase high performance liquid chromatography (RP-HPLC), and differential scanning calorimetry (DSC). Basic analyses indicated that there were wide variations between the native sample and its fractions with respect to iodine value (IV), and slip melting point (SMP). The cloud point (CP) of the liquid fraction was found to be 10.5 degrees C. Fatty acid compositional analyses showed that the proportion of saturated fatty acids (SFA) such as palmitic and stearic went up in the high-melting fraction (HMF) while in low-melting fraction (LMF) the proportion of unsaturated fatty acid (USFA) such as oleic and lenoleic increased. According to the HPLC analyses, Mee fat had a tiacyl glycerol (TAG) sequence similar to that of palm oil. After fractionation, the solid and liquid fractions obtained were found to have TAG profiles very much different from the native sample. Thermal analyses by DSC showed that Mee fat had two-widely separated high and low melting thermal transitions, a feature which was beneficial for the effective separation of solid and liquid fractions. The thermal profiles displayed by the fractions were clearly distinguishable from that of the native sample. PMID:20032594

  19. Composition and thermal characteristics of Madhuca longifolia seed fat and its solid and liquid fractions.

    Science.gov (United States)

    Marikkar, J M N; Ghazali, H M; Long, K

    2010-01-01

    This study was to characterize the seed fat from Madhuca longifolia known as Mee fat and its solid and liquid fractions with the objective of distinguishing them. A sample of Mee fat was partitioned into solid and liquid fractions using acetone as the solvent medium. The isolated fractions were compared to the native Mee fat sample with respect to various physico-chemical parameters using standard chemical methods as well as instrumental techniques such as, gas liquid chromatography (GLC), reversed-phase high performance liquid chromatography (RP-HPLC), and differential scanning calorimetry (DSC). Basic analyses indicated that there were wide variations between the native sample and its fractions with respect to iodine value (IV), and slip melting point (SMP). The cloud point (CP) of the liquid fraction was found to be 10.5 degrees C. Fatty acid compositional analyses showed that the proportion of saturated fatty acids (SFA) such as palmitic and stearic went up in the high-melting fraction (HMF) while in low-melting fraction (LMF) the proportion of unsaturated fatty acid (USFA) such as oleic and lenoleic increased. According to the HPLC analyses, Mee fat had a tiacyl glycerol (TAG) sequence similar to that of palm oil. After fractionation, the solid and liquid fractions obtained were found to have TAG profiles very much different from the native sample. Thermal analyses by DSC showed that Mee fat had two-widely separated high and low melting thermal transitions, a feature which was beneficial for the effective separation of solid and liquid fractions. The thermal profiles displayed by the fractions were clearly distinguishable from that of the native sample.

  20. On Coupled Systems of Time-Fractional Differential Problems by Using a New Fractional Derivative

    Directory of Open Access Journals (Sweden)

    Ahmed Alsaedi

    2016-01-01

    Full Text Available The existence of solutions for a coupled system of time-fractional differential equations including continuous functions and the Caputo-Fabrizio fractional derivative is examined. After that we investigated a coupled system of time-fractional differential inclusions including compact- and convex-valued L1-Caratheodory multifunctions and the Caputo-Fabrizio fractional derivative.

  1. Fractional Calculus of Variations in Terms of a Generalized Fractional Integral with Applications to Physics

    CERN Document Server

    Odzijewicz, Tatiana; Torres, Delfim F M

    2012-01-01

    We study fractional variational problems in terms of a generalized fractional integral with Lagrangians depending on classical derivatives, generalized fractional integrals and derivatives. We obtain necessary optimality conditions for the basic and isoperimetric problems, as well as natural boundary conditions for free boundary value problems. The fractional action-like variational approach (FALVA) is extended and some applications to Physics discussed.

  2. Biomass pyrolysis for chemicals

    Energy Technology Data Exchange (ETDEWEB)

    De Wild, P.

    2011-07-15

    The problems associated with the use of fossil fuels demand a transition to renewable sources (sun, wind, water, geothermal, biomass) for materials and energy where biomass provides the only renewable source for chemicals. In a biorefinery, biomass is converted via different technologies into heat, power and various products. Here, pyrolysis (thermal degradation without added oxygen) of lignocellulosic biomass can play an important role, because it leads to an array of useful chemicals. Examples are furfural and acetic acid from hemicellulose, levoglucosan from cellulose and phenols and biochar from lignin. Since the three major biomass polymers hemicellulose, cellulose and lignin possess dissimilar thermal stabilities and reactivities, type and amount of degradation products are tunable by proper selection of the pyrolysis conditions. To determine if step-wise pyrolysis would be suitable for the production of chemicals, staged degasification of lignocellulosic biomass was studied. Due to limited yields, a hot pressurized water pre-treatment (aquathermolysis) followed by pyrolysis was subsequently developed as an improved version of a staged approach to produce furfural and levoglucosan from the carbohydrate fraction of the biomass. Lignin is the only renewable source for aromatic chemicals. Lignocellulosic biorefineries for bio-ethanol produce lignin as major by-product. The pyrolysis of side-streams into valuable chemicals is of prime importance for a profitable biorefinery. To determine the added-value of lignin side-streams other than their use as fuel for power, application research including techno-economic analysis is required. In this thesis, the pyrolytic valorisation of lignin into phenols and biochar was investigated and proven possible.

  3. Different approaches to tailoring chemical pulp fibres

    OpenAIRE

    El-Sharkawy, Khalil

    2008-01-01

    The objective of this thesis work was to examine different approaches to tailor chemical fibres of different raw materials. The focus in searching for new approaches was on pressure screen fractionation, selective treatment of each fraction, mechanical pre-treatment before refining, refiner loadability and its link to fibre properties and filling design, and on-line quality control of fibre properties. The evaluation is based on the impacts on fibre properties, filtration, refining and the re...

  4. Solution of nonlinear space time fractional differential equations via the fractional projective Riccati expansion method

    CERN Document Server

    Abdel-Salam, Emad A-B; Hassan, Gmal F

    2015-01-01

    In this paper, the fractional projective Riccati expansion method is proposed to solve fractional differential equations. To illustrate the effectiveness of the method, we discuss the space-time fractional Burgers equation, the space-time fractional mKdV equation and time fractional biological population model. The solutions are expressed in terms of fractional hyperbolic functions. These solutions are useful to understand the mechanisms of the complicated nonlinear physical phenomena and fractional differential equations. Among these solutions, some are found for the first time. The fractal index for the obtained results is equal to one. Counter examples to compute the fractal index are introduced in appendix.

  5. Tungsten-molybdenum fractionation in estuarine environments

    Science.gov (United States)

    Mohajerin, T. Jade; Helz, George R.; Johannesson, Karen H.

    2016-03-01

    Dissolved tungsten (W) and molybdenum (Mo) concentrations were measured in surface waters and sediment pore waters of Terrebonne Bay, a shallow estuary in the Mississippi River delta, to investigate the biogeochemical processes that fractionate these Group 6 elements relative to one another during transit from weathering to sedimentary environments. Although many of the chemical properties of W and Mo are similar, the two elements behave autonomously, and the fractionation mechanisms are only partly understood. In sulfidic pore waters, dissolved Mo is depleted relative to river water-seawater mixtures, whereas dissolved W is >10-fold enriched. Reductive dissolution of poorly crystalline phases like ferrihydrite, which is a preferential host of W relative to Mo in grain coatings on river-borne particles, can explain the dissolved W enrichment. Dissolved W becomes increasingly enriched as H2S(aq) rises above about 60 μM due to transformation of WO42- to thiotungstates as well as to additional reductive dissolution of phases that host W. In contrast, as rising sulfide transforms MoO42- to thiomolybdates in pore waters, dissolved Mo is suppressed, probably owing to equilibration with an Fe-Mo-S phase. This putative phase appears to control the aqueous ion product, Q = [Fe2+][MoS42-]0.6 [H2S0]0.4/[H+]0.8, at a value of 10-7.78. Concentrations of dissolved W and Mo in pore waters bear no relation to concentrations in surface waters of the same salinity. In surface waters, dissolved Mo is nearly conserved in the estuarine mixing zone. Dissolved W appears also to be conserved except for several cases where W may have been enhanced by exchange with underlying, W-rich pore waters. With increasing salinity, the molar Mo/W ratio rises from about 10 to about 1000 in surface waters whereas it is mostly sediments, whereas the second explains tungsten's proportionately greater sequestration on river-borne particles and its subsequent release to sulfidic pore waters after the

  6. Fractionation of metal stable isotopes by higher plants

    Science.gov (United States)

    Von Blanckenburg, F.; Von Wiren, N.; Guelke, M.; Weiss, D.J.; Bullen, T.D.

    2009-01-01

    Higher plants induce chemical reactions in the rhizosphere, facilitating metal uptake by roots. Fractionation of the isotopes in nutrients such as calcium, iron, magnesium, and zinc produces a stable isotope composition in the plants that generally differs from that of the growth medium. Isotope fractionation also occurs during transport of the metals within most plants, but its extent depends on plant species and on the metal, in particular, on the metal's redox state and what ligand it is bound to. The metal stable isotope variations observed in plants create an isotope signature of life at the Earth's surface, contributing substantially to our understanding of metal cycling processes in the environment and in individual organisms.

  7. Zinc fractionation in the rhizosphere of wheat (Triticum aestivum L.) plant in soils treated with sewage sludge

    OpenAIRE

    Hosseinpur A. R.; Motaghian H. R.

    2013-01-01

    Rhizosphere is a microbiosphere and has quite different chemical, physical and biological properties from bulk soils. A greenhouse experiment was performed to compare fractionation of Zinc (Zn) between rhizosphere and bulk soils amended with sewage sludge (1% w/w of sewage sludge to soil). Fractions of Zn were determined in two subsamples (rhizosphere and bulk soils). The results indicated concentration of Zn-fractions (except carbonates-associated) in the rhizosphere soils were significantly (p

  8. Wright functions governed by fractional directional derivatives and fractional advection diffusion equations

    CERN Document Server

    D'Ovidio, Mirko

    2012-01-01

    We consider fractional directional derivatives and establish some connection with stable densities. Solutions to advection equations involving fractional directional derivatives are presented and some properties investigated. In particular we obtain solutions written in terms of Wright functions by exploiting operational rules involving the shift operator. We also consider fractional advection diffusion equations involving fractional powers of the negative Laplace operator and directional derivatives of fractional order and discuss the probabilistic interpretations of solutions.

  9. Exact Solutions of Fractional Burgers and Cahn-Hilliard Equations Using Extended Fractional Riccati Expansion Method

    Directory of Open Access Journals (Sweden)

    Wei Li

    2014-01-01

    Full Text Available Based on a general fractional Riccati equation and with Jumarie’s modified Riemann-Liouville derivative to an extended fractional Riccati expansion method for solving the time fractional Burgers equation and the space-time fractional Cahn-Hilliard equation, the exact solutions expressed by the hyperbolic functions and trigonometric functions are obtained. The obtained results show that the presented method is effective and appropriate for solving nonlinear fractional differential equations.

  10. Hamiltonian chaos and fractional dynamics

    CERN Document Server

    Zaslavsky, George M

    2008-01-01

    The dynamics of realistic Hamiltonian systems has unusual microscopic features that are direct consequences of its fractional space-time structure and its phase space topology. The book deals with the fractality of the chaotic dynamics and kinetics, and also includes material on non-ergodic and non-well-mixing Hamiltonian dynamics. The book does not follow the traditional scheme of most of today's literature on chaos. The intention of the author has been to put together some of the most complex and yet open problems on the general theory of chaotic systems. The importance of the discussed issues and an understanding of their origin should inspire students and researchers to touch upon some of the deepest aspects of nonlinear dynamics. The book considers the basic principles of the Hamiltonian theory of chaos and some applications including for example, the cooling of particles and signals, control and erasing of chaos, polynomial complexity, Maxwell's Demon, and others. It presents a new and realistic image ...

  11. Fractional ablative erbium YAG laser

    DEFF Research Database (Denmark)

    Taudorf, Elisabeth H; Haak, Christina S; Erlendsson, Andrés M;

    2014-01-01

    BACKGROUND AND OBJECTIVES: Treatment of a variety of skin disorders with ablative fractional lasers (AFXL) is driving the development of portable AFXLs. This study measures micropore dimensions produced by a small 2,940 nm AFXL using a variety of stacked pulses, and determines a model correlating...... laser parameters with tissue effects. MATERIALS AND METHODS: Ex vivo pig skin was exposed to a miniaturized 2,940 nm AFXL, spot size 225 µm, density 5%, power levels 1.15-2.22 W, pulse durations 50-225 microseconds, pulse repetition rates 100-500 Hz, and 2, 20, or 50 stacked pulses, resulting in pulse...... 190 to 347 µm. CONCLUSIONS: Pulse stacking with a small, low power 2,940 nm AFXL created reproducible shallow to deep micropores, and influenced micropore configuration. Mathematical modeling established relations between laser settings and micropore dimensions, which assists in choosing laser...

  12. The Initial Conditions of Fractional Calculus

    International Nuclear Information System (INIS)

    During the past fifty years , Fractional Calculus has become an original and renowned mathematical tool for the modelling of diffusion Partial Differential Equations and the design of robust control algorithms. However, in spite of these celebrated results, some theoretical problems have not yet received a satisfying solution. The mastery of initial conditions, either for Fractional Differential Equations (FDEs) or for the Caputo and Riemann-Liouville fractional derivatives, remains an open research domain. The solution of this fundamental problem, also related to the long range memory property, is certainly the necessary prerequisite for a satisfying approach to modelling and control applications. The fractional integrator and its continuously frequency distributed differential model is a valuable tool for the simulation of fractional systems and the solution of initial condition problems. Indeed, the infinite dimensional state vector of fractional integrators allows the direct generalization to fractional calculus of the theoretical results of integer order systems. After a reminder of definitions and properties related to fractional derivatives and systems, this presentation is intended to show, based on the results of two recent publications [1,2], how the fractional integrator provides the solution of the initial condition problem of FDEs and of Caputo and Riemann-Liouville fractional derivatives. Numerical simulation examples illustrate and validate these new theoretical concepts.

  13. Evaluation of Microneedling Fractional Radiofrequency Device for Treatment of Acne Scars

    OpenAIRE

    Byalekere Shivanna Chandrashekar; Rashmi Sriram; Rajdeep Mysore; Sapnashree Bhaskar; Abhishek Shetty

    2014-01-01

    Background: Various treatment modalities including non-invasive methods such as chemical peels, topical retinoids, microdermabrasion, minimally invasive techniques such as microneedling, fractional lasers, microneedling radiofrequency devices and invasive procedures such as acne scar surgeries and ablative lasers are used for acne scars, each with its own unique advantages and disadvantages. This study is a retrospective assessment of efficacy and safety of microneedling fractional radiofrequ...

  14. Determination of Bioactive Components of Ethyl Acetate Fraction of Punica granatum Rind Extract

    OpenAIRE

    J. Sangeetha; Vijayalakshmi, K.

    2011-01-01

    Punica granatum belongs to a Punicaceae family. The Punica granatum is valued as a powerful medicinal plant and used in folk medicines. Hence the present investigation was carried out to determine the possible chemical components from ethyl acetate fraction of Punica granatum rind extract by GC-MS Technique. This analysis revealed that ethyl acetate fraction of Punica granatum rind extract contain Pyrogallol (41.88%), 5-Hydroxymethylfurfural (14.10%), D-Allose (9.17%), 2-Methoxy-1, 4-Benzened...

  15. Bioenergy II. Biomass Valorisation by a Hybrid Thermochemical Fractionation Approach

    Energy Technology Data Exchange (ETDEWEB)

    De Wild, P.J.; Den Uil, H.; Reith, J.H. [ECN Biomass, Coal and Environmental Research, Petten (Netherlands); Lunshof, A.; Hendriks, C.; Van Eck, E. [Radboud University, Nijmegen (Netherlands); Heeres, E. [University of Groningen, Groningen (Netherlands)

    2009-11-15

    The need for green renewable sources is adamant because of the adverse effects of the increasing use of fossil fuels on our society. Biomass has been considered as a very attractive candidate for green energy carriers, chemicals and materials. The development of cheap and efficient fractionation technology to separate biomass into its main constituents is highly desirable. It enables treatment of each constituent separately, using dedicated conversion technologies to get specific target chemicals. The synergistic combination of aquathermolysis (hot pressurised water treatment) and pyrolysis (thermal degradation in the absence of oxygen) is a promising thermolysis option, integrating fractionation of biomass with production of valuable chemicals. Batch aquathermolysis in an autoclave and subsequent pyrolysis using bubbling fluidised bed reactor technology with beech, poplar, spruce and straw indicate the potential of this hybrid concept to valorise lignocellulosic biomass. Hemicellulose-derived furfural was obtained in yields that ranged from 2 wt% for spruce to 8 wt% for straw. Hydroxymethylfurfural from hemicellulose was obtained in yields from 0.3 wt% for poplar to 3 wt% for spruce. Pyrolysis of the aquathermolised biomass types resulted in 8 wt% (straw) to 11 wt% (spruce) of cellulose-derived levoglucosan. Next to the furfurals and levoglucosan, appreciable amounts of acetic acid were obtained as well from the aquathermolysis step, ranging from 1 wt% for spruce to 5 wt% for straw. To elucidate relations between the chemical changes occurring in the biomass during the integrated process and type and amount of the chemical products formed, a 13C-solid state NMR study has been conducted. Main conclusions are that aquathermolysis results in hemicellulose degradation to lower molecular weight components. Lignin ether bonds are broken, but apart from that, lignin is hardly affected by the aquathermolysis. Cellulose is also retained, although it seems to become more

  16. 40 CFR 721.10178 - Distillates (Fischer-Tropsch), hydroisomerized middle, C10-13-branched alkane fraction.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Distillates (Fischer-Tropsch), hydroisomerized middle, C10-13-branched alkane fraction. 721.10178 Section 721.10178 Protection of Environment...), hydroisomerized middle, C10-13-branched alkane fraction. (a) Chemical substance and significant new uses...

  17. Insights on the Phytochemical Profile (Cyclopeptides and Biological Activities of Calotropis procera Latex Organic Fractions

    Directory of Open Access Journals (Sweden)

    Thiago Lustosa Jucá

    2013-01-01

    Full Text Available Calotropis procera is a medicinal plant whose pharmacological properties are associated with its latex. Here, the Calotropis procera latex fractions were investigated in an attempt to trace its phytochemical profile and measure its anti-inflammatory and toxicity activity. The crude latex was partitioned, yielding five fractions (49.4% hexane, 5.2% dichloromethane, 2.0% ethyl acetate, 2.1% n-butanol, and 41.1% aqueous. Phytochemical screening and spectroscopy analysis revealed that dichloromethane is the most chemically diverse fraction. Triterpenes were detected in both the hexane and dichloromethane fractions, while flavonoids were detected in the dichloromethane and ethyl acetate fractions. These fractions were cytotoxic to cancer cell lines (LD50 0.05 to 3.9 μg/mL and lethal to brine shrimp (LD50 10.9 to 65.7 μg/mL. Reduced neutrophil migration in rats was observed in carrageenan-induced peritonitis for the dichloromethane (67%, ethyl acetate (56%, and aqueous (72% fractions. A positive reaction with tolidine and ninhydrin suggested that cyclopeptides are in the ethyl acetate fraction. It is therefore concluded that Calotropis procera latex dichloromethane and ethyl acetate fractions exhibit both in vitro and in vivo activities as well as anti-inflammatory properties. Cyclopeptide detection is especially interesting because previous attempts to investigate these low-molecular cyclic amino acid sequences in C. procera have failed.

  18. Review of Some Promising Fractional Physical Models

    CERN Document Server

    Tarasov, Vasily E

    2015-01-01

    Fractional dynamics is a field of study in physics and mechanics investigating the behavior of objects and systems that are characterized by power-law non-locality, power-law long-term memory or fractal properties by using integrations and differentiation of non-integer orders, i.e., by methods of the fractional calculus. This paper is a review of physical models that look very promising for future development of fractional dynamics. We suggest a short introduction to fractional calculus as a theory of integration and differentiation of non-integer order. Some applications of integro-differentiations of fractional orders in physics are discussed. Models of discrete systems with memory, lattice with long-range inter-particle interaction, dynamics of fractal media are presented. Quantum analogs of fractional derivatives and model of open nano-system systems with memory are also discussed.

  19. Oversampling analysis in fractional Fourier domain

    Institute of Scientific and Technical Information of China (English)

    ZHANG Feng; TAO Ran; WANG Yue

    2009-01-01

    Oversampling is widely used in practical applications of digital signal processing. As the fractional Fourier transform has been developed and applied in signal processing fields, it is necessary to consider the oversampling theorem in the fractional Fourier domain. In this paper, the oversampling theorem in the fractional Fourier domain is analyzed. The fractional Fourier spectral relation between the original oversampled sequence and its subsequences is derived first, and then the expression for exact reconstruction of the missing samples in terms of the subsequences is obtained. Moreover, by taking a chirp signal as an example, it is shown that, reconstruction of the missing samples in the oversampled signal Is suitable in the fractional Fourier domain for the signal whose time-frequency distribution has the minimum support in the fractional Fourier domain.

  20. Fractional RC and LC Electrical Circuits

    Directory of Open Access Journals (Sweden)

    Gómez-Aguilar José Francisco

    2014-04-01

    Full Text Available In this paper we propose a fractional differential equation for the electrical RC and LC circuit in terms of the fractional time derivatives of the Caputo type. The order of the derivative being considered is 0 < ɣ ≤1. To keep the dimensionality of the physical parameters R, L, C the new parameter σ is introduced. This parameter characterizes the existence of fractional structures in the system. A relation between the fractional order time derivative ɣ and the new parameter σ is found. The numeric Laplace transform method was used for the simulation of the equations results. The results show that the fractional differential equations generalize the behavior of the charge, voltage and current depending of the values of ɣ. The classical cases are recovered by taking the limit when ɣ = 1. An analysis in the frequency domain of an RC circuit shows the application and use of fractional order differential equations.

  1. The fractional oscillator process with two indices

    Energy Technology Data Exchange (ETDEWEB)

    Lim, S C [Faculty of Engineering, Multimedia University, Jalan Multimedia, Cyberjaya 63100, Selangor Darul Ehsan (Malaysia); Teo, L P [Faculty of Information Technology, Multimedia University, Jalan Multimedia, Cyberjaya 63100, Selangor Darul Ehsan (Malaysia)], E-mail: sclim@mmu.edu.my, E-mail: lpteo@mmu.edu.my

    2009-02-13

    We introduce a new fractional oscillator process which can be obtained as a solution of a stochastic differential equation with two fractional orders. Basic properties such as fractal dimension and short-range dependence of the process are studied by considering the asymptotic properties of its covariance function. By considering the fractional oscillator process as the velocity of a diffusion process, we derive the corresponding diffusion constant, fluctuation-dissipation relation and mean-square displacement. The fractional oscillator process can also be regarded as a one-dimensional fractional Euclidean Klein-Gordon field, which can be obtained by applying the Parisi-Wu stochastic quantization method to a nonlocal Euclidean action. The Casimir energy associated with the fractional field at positive temperature is calculated by using the zeta function regularization technique.

  2. Silicon Isotopic Fractionation of CAI-like Vacuum Evaporation Residues

    Energy Technology Data Exchange (ETDEWEB)

    Knight, K; Kita, N; Mendybaev, R; Richter, F; Davis, A; Valley, J

    2009-06-18

    Calcium-, aluminum-rich inclusions (CAIs) are often enriched in the heavy isotopes of magnesium and silicon relative to bulk solar system materials. It is likely that these isotopic enrichments resulted from evaporative mass loss of magnesium and silicon from early solar system condensates while they were molten during one or more high-temperature reheating events. Quantitative interpretation of these enrichments requires laboratory determinations of the evaporation kinetics and associated isotopic fractionation effects for these elements. The experimental data for the kinetics of evaporation of magnesium and silicon and the evaporative isotopic fractionation of magnesium is reasonably complete for Type B CAI liquids (Richter et al., 2002, 2007a). However, the isotopic fractionation factor for silicon evaporating from such liquids has not been as extensively studied. Here we report new ion microprobe silicon isotopic measurements of residual glass from partial evaporation of Type B CAI liquids into vacuum. The silicon isotopic fractionation is reported as a kinetic fractionation factor, {alpha}{sub Si}, corresponding to the ratio of the silicon isotopic composition of the evaporation flux to that of the residual silicate liquid. For CAI-like melts, we find that {alpha}{sub Si} = 0.98985 {+-} 0.00044 (2{sigma}) for {sup 29}Si/{sup 28}Si with no resolvable variation with temperature over the temperature range of the experiments, 1600-1900 C. This value is different from what has been reported for evaporation of liquid Mg{sub 2}SiO{sub 4} (Davis et al., 1990) and of a melt with CI chondritic proportions of the major elements (Wang et al., 2001). There appears to be some compositional control on {alpha}{sub Si}, whereas no compositional effects have been reported for {alpha}{sub Mg}. We use the values of {alpha}Si and {alpha}Mg, to calculate the chemical compositions of the unevaporated precursors of a number of isotopically fractionated CAIs from CV chondrites whose

  3. New Approach To A Generalized Fractional Integral

    OpenAIRE

    Katugampola, Udita N.

    2010-01-01

    The paper presents a new formula for the fractional integration, which generalizes the Riemann-Liouville and Hadamard fractional integrals into a single form, which when a parameter fixed at different values, produces the above integrals as special cases. Conditions are given for such a generalized fractional integration operator to be bounded in an extended Lebesgue measurable space. Semigroup property for the above operator is also proved. Finally, we give a general definition of the Fracti...

  4. Fractional Bateman—Feshbach Tikochinsky Oscillator

    International Nuclear Information System (INIS)

    In the last few years the numerical methods for solving the fractional differential equations started to be applied intensively to real world phenomena. Having these things in mind in this manuscript we focus on the fractional Lagrangian and Hamiltonian of the complex Bateman—Feshbach Tikochinsky oscillator. The numerical analysis of the corresponding fractional Euler-Lagrange equations is given within the Grünwald—Letnikov approach, which is power series expansion of the generating function. (physics of elementary particles and fields)

  5. Operator Fractional Brownian Motion and Martingale Differences

    Directory of Open Access Journals (Sweden)

    Hongshuai Dai

    2014-01-01

    Full Text Available It is well known that martingale difference sequences are very useful in applications and theory. On the other hand, the operator fractional Brownian motion as an extension of the well-known fractional Brownian motion also plays an important role in both applications and theory. In this paper, we study the relation between them. We construct an approximation sequence of operator fractional Brownian motion based on a martingale difference sequence.

  6. The Fractional Orthogonal Difference with Applications

    OpenAIRE

    Enno Diekema

    2015-01-01

    This paper is a follow-up of a previous paper of the author published in Mathematics journal in 2015, which treats the so-called continuous fractional orthogonal derivative. In this paper, we treat the discrete case using the fractional orthogonal difference. The theory is illustrated with an application of a fractional differentiating filter. In particular, graphs are presented of the absolutel value of the modulus of the frequency response. These make clear that for a good insight into the ...

  7. Linear and nonlinear fractional Voigt models

    OpenAIRE

    Chidouh, Amar; Guezane-Lakoud, Assia; Bebbouchi, Rachid; Bouaricha, Amor; Torres, Delfim F. M.

    2016-01-01

    We consider fractional generalizations of the ordinary differential equation that governs the creep phenomenon. Precisely, two Caputo fractional Voigt models are considered: a rheological linear model and a nonlinear one. In the linear case, an explicit Volterra representation of the solution is found, involving the generalized Mittag-Leffler function in the kernel. For the nonlinear fractional Voigt model, an existence result is obtained through a fixed point theorem. A nonlinear example, il...

  8. Fractional constant elasticity of variance model

    OpenAIRE

    Ngai Hang Chan; Chi Tim Ng

    2007-01-01

    This paper develops a European option pricing formula for fractional market models. Although there exist option pricing results for a fractional Black-Scholes model, they are established without accounting for stochastic volatility. In this paper, a fractional version of the Constant Elasticity of Variance (CEV) model is developed. European option pricing formula similar to that of the classical CEV model is obtained and a volatility skew pattern is revealed.

  9. Effects of Chemical Stabilization on Soil Cd Fractions and Water Spinach Cd Contents After Amendment with Dredged River Sediments%稳定化处理对底泥利用后土壤Cd形态及空心菜Cd含量的影响

    Institute of Scientific and Technical Information of China (English)

    李翔; 刘永兵; 程言君; 罗楠; 臧振远; 吴军; 洪文良; 沈来新

    2015-01-01

    In situ stabilization is a low—cost, simple—operation and fast—effectiveness technique for remediating heavy metals—contaminated soils. In this study, a field trial was carried out to investigate the stabilization effects of three different amendment treatments(lime+calcium magnesium phosphate fertilizer, sepiolite+calcium dihydrogen phosphate, and calcium magnesium phosphate fertilizer alone)on soil Cd forms and bioavailability. The effectiveness of the treatments was evaluated by soil Cd fractions and Cd contents in water spinach. Results showed that amendments changed Cd fractions in treated soil. Compared with the control, the maximum reduction of acid extractable Cd fraction was 54.43%, while the increase percentages were as high as 81.90% for reducible fraction, 107.43% for oxidizable fraction, and 74.15%for residual fraction. Water spinach Cd contents were 38.61%to 85.69%lower in the stabilization treatments than in control, meet—ing the safety requirements for non—pollution vegetables. For all Cd levels, the reducing effect of stabilizers on water spinach Cd content was lime+calcium magnesium phosphate fertilizer>calcium magnesium phosphate fertilizer>sepiolite+calcium dihydrogen phosphate, which was consistent with acid extractable Cd in soil. In conclusion, soil amendments could effectively control the Cd pollution caused by sediment ap—plications, ensuring the food safety of water spinach produce.%采用大田试验,研究了石灰+钙镁磷肥、海泡石+磷酸二氢钙、单独使用钙镁磷肥3种不同的稳定剂组合对底泥土地利用后造成污染的农田土壤中Cd的稳定化处理效果以及对空心菜吸收Cd的影响。结果表明,3种稳定剂组合均能有效改变土壤中Cd的形态分布,弱酸提取态含量最大减少率54.43%,可还原态含量最大增加率81.90%,可氧化态含量最大增加率107.43%,残渣态含量最大增加率74.15%,稳定化效果明显。稳定化处理组的空心

  10. Chemical Mahjong

    Science.gov (United States)

    Cossairt, Travis J.; Grubbs, W. Tandy

    2011-01-01

    An open-access, Web-based mnemonic game is described whereby introductory chemistry knowledge is tested using mahjong solitaire game play. Several tile sets and board layouts are included that are themed upon different chemical topics. Introductory tile sets can be selected that prompt the player to match element names to symbols and metric…

  11. Chemical Peels

    Science.gov (United States)

    ... resources Meet our partners Español Donate Diseases and treatments Acne and rosacea Bumps and growths Color problems Contagious skin diseases ... Chemical peels public SPOT Skin Cancer™ Diseases and treatments Acne and rosacea Bumps and growths Color problems Contagious skin diseases ...

  12. Chemical pressure

    OpenAIRE

    Hauser, Andreas; Amstutz, Nahid; Delahaye, Sandra; Sadki, Asmaâ; Schenker, Sabine; Sieber, Regula; Zerara, Mohamed

    2002-01-01

    The physical and photophysical properties of three classic transition metal complexes, namely [Fe(bpy)3]2+, [Ru(bpy)3]2+, and [Co(bpy)3]2+, can be tuned by doping them into a variety of inert crystalline host lattices. The underlying guest-host interactions are discussed in terms of a chemical pressure.

  13. Chemical dispersants

    NARCIS (Netherlands)

    Rahsepar, Shokouhalsadat; Smit, Martijn P.J.; Murk, Albertinka J.; Rijnaarts, Huub H.M.; Langenhoff, Alette A.M.

    2016-01-01

    Chemical dispersants were used in response to the Deepwater Horizon oil spill in the Gulf of Mexico, both at the sea surface and the wellhead. Their effect on oil biodegradation is unclear, as studies showed both inhibition and enhancement. This study addresses the effect of Corexit on oil biodeg

  14. Resistant starch: an indigestible fraction of foods

    Directory of Open Access Journals (Sweden)

    Saura Calixto, F.

    1991-06-01

    Full Text Available Resistant starch (RS, the dietary starch that scape digestion in the small intestine, can yields up to 20% of the starch in cereal and legume products. Several fractions contribute to the total RS of foods: retrograded amylose, starch inaccessible to digestive enzymes because of mechanical barriers, chemically modified starch fragments, undigested starch due to α-amylase inhibitors and starch complexed with other food components. RS is formed in products processed following heat treatments (baking, extrusion, autoclaving, etc.. RS produces significant fecal bulking and is partially fermentable by anaerobic bacteria of the colon. On the other hand, the relation of resistant starch with the glucose and insulin response in human subjects is an important nutritional effect. RS analytical methods are reported.

    El almidón resistente (RS, fracción de almidón de la dieta que no es digerido en el intestino delgado, puede alcanzar hasta un 20% del almidón en productos derivados de cereales y legumbres. Varias fracciones contribuyen al contenido total de almidón resistente: amilosa retrogradada, almidón inaccesible físicamente a los enzimas digestivos, almidón indigestible debido a inhibición de α-amilasas y almidón complejado con otros constituyentes de los alimentos. El almidón resistente se forma en productos que han sufrido tratamientos térmicos (panificación, extrusión, autoclave, etc. El RS aumenta el volumen de heces y es fermentado parcialmente en el colon por bacterias anaeróbicas. Igualmente, está relacionado con los niveles de glucosa en sangre y la respuesta de insulina en humanos. Se describen los métodos analíticos para su determinación.

  15. Subcritical water extraction to isolate kinetically different soil nitrogen fractions

    Directory of Open Access Journals (Sweden)

    S. Sleutel

    2013-06-01

    Full Text Available Soil organic N is largely composed of inherently biologically labile proteinaceous N and its persistence in soil is mainly explained by stabilization through binding to minerals and other soil organic matter (SOM components at varying strengths. In order to separate kinetically different soil N fractions we hypothesize that an approach, which isolates soil N fractions on the basis of bonding strength is required, rather than employing chemical agents or physical methods. We developed a sequential subcritical water extraction (SCWE procedure at 100 °C, 150 °C and 200°C to isolate SOM fractions. We assessed these SCWE N fractions as predictors for aerobic and anaerobic N mineralization measured from 25 paddy soil cores in incubations. SCWE organic carbon (SCWE OC and N (SCWE N increased exponentially with the increase of temperature and N was extracted preferentially over OC. The efficiency of SCWE and the selectivity towards N were both lower in soils with increasingly reactive clay mineralogy. The 100–150 °C SCWE N and the 100 °C + 100–150 °C SCWE N correlated slightly better with the aerobic N mineralization than soil N content. The resulting explained percentages (46–49% are, however, too small to allow accurate fertilizer recommendations. No correlations were found between the SCWE fractions and anaerobic N mineralization rate and consequently alternative driving factors should be looked for. Nonetheless, perhaps SCWE does, still hold potential to separate kinetically different SOM pools from upland soils, in which the bio-availability of N is more likely to be a key constraint in the N mineralization process. This in contrast to the studied paddy soils, in which N mineralization appeared to be largely decoupled from SOM quantity and quality or its availability, perhaps due to an overriding control of abiotic factors on the anaerobic N mineralization process.

  16. A Fractional Micro-Macro Model for Crowds of Pedestrians based on Fractional Mean Field Games

    CERN Document Server

    Cao, Ke-cai; Stuart, Dan

    2016-01-01

    Modeling of crowds of pedestrians has been considered in this paper from different aspects. Based on fractional microscopic model that may be much more close to reality, a fractional macroscopic model has been proposed using conservation law of mass. Then in order to characterize the competitive and cooperative interactions among pedestrians, fractional mean field games are utilized in the modeling problem when the number of pedestrians goes to infinity and fractional dynamic model composed of fractional backward and fractional forward equations are constructed in macro scale. Fractional micro-macro model for crowds of pedestrians are obtained in the end. Simulation results are also included to illustrate the proposed fractional microscopic model and fractional macroscopic model respectively.

  17. Chaos in discrete fractional difference equations

    Indian Academy of Sciences (India)

    AMEY DESHPANDE; VARSHA DAFTARDAR-GEJJI

    2016-10-01

    Recently, the discrete fractional calculus (DFC) is receiving attention due to its potential applications in the mathematical modelling of real-world phenomena with memory effects. In the present paper, the chaotic behaviour of fractional difference equations for the tent map, Gauss map and 2x(mod 1) map are studied numerically. We analyse the chaotic behaviour of these fractional difference equations and compare them with their integer counterparts. It is observed that fractional difference equations for the Gauss and tent maps are more stable compared to their integer-order version.

  18. RHEOLOGICAL BEHAVIOUR OF PSYLLIUM GUM FRACTIONS

    Directory of Open Access Journals (Sweden)

    Mohammad Hojjatoleslamyi

    2013-10-01

    Full Text Available Psyllium (Plantago psyllium is a native plant that grows widely in India, Iran and Pinjab. Studies showed psyllium gum has good rheological properties for using in wide range of food products. In this study, different fractions of psyllium gum extracted by water and alkali treatment. Rheological properties of these fractions determined by Brookfield rheometer (RV DVIII. Obtained data fitted in three temperatures 30, 60 and 80°C by Herschel-bulkly rheological model. Results showed that fractions have different behaviour during heating treatment. The most difference observed in AEG0.5 fraction.

  19. Fractional Dynamics of Computer Virus Propagation

    Directory of Open Access Journals (Sweden)

    Carla M. A. Pinto

    2014-01-01

    Full Text Available We propose a fractional model for computer virus propagation. The model includes the interaction between computers and removable devices. We simulate numerically the model for distinct values of the order of the fractional derivative and for two sets of initial conditions adopted in the literature. We conclude that fractional order systems reveal richer dynamics than the classical integer order counterpart. Therefore, fractional dynamics leads to time responses with super-fast transients and super-slow evolutions towards the steady-state, effects not easily captured by the integer order models.

  20. Numerical Solutions of Fractional Boussinesq Equation

    Institute of Scientific and Technical Information of China (English)

    WANG Qi

    2007-01-01

    Based upon the Adomian decomposition method,a scheme is developed to obtain numerical solutions of a fractional Boussinesq equation with initial condition,which is introduced by replacing some order time and space derivatives by fractional derivatives.The fractional derivatives are described in the Caputo sense.So the traditional Adomian decomposition method for differential equations of integer order is directly extended to derive explicit and numerical solutions of the fractional differential equations.The solutions of our model equation are calculated in the form of convergent series with easily computable components.

  1. Fractional Partial Differential Equation: Fractional Total Variation and Fractional Steepest Descent Approach-Based Multiscale Denoising Model for Texture Image

    Directory of Open Access Journals (Sweden)

    Yi-Fei Pu

    2013-01-01

    Full Text Available The traditional integer-order partial differential equation-based image denoising approaches often blur the edge and complex texture detail; thus, their denoising effects for texture image are not very good. To solve the problem, a fractional partial differential equation-based denoising model for texture image is proposed, which applies a novel mathematical method—fractional calculus to image processing from the view of system evolution. We know from previous studies that fractional-order calculus has some unique properties comparing to integer-order differential calculus that it can nonlinearly enhance complex texture detail during the digital image processing. The goal of the proposed model is to overcome the problems mentioned above by using the properties of fractional differential calculus. It extended traditional integer-order equation to a fractional order and proposed the fractional Green’s formula and the fractional Euler-Lagrange formula for two-dimensional image processing, and then a fractional partial differential equation based denoising model was proposed. The experimental results prove that the abilities of the proposed denoising model to preserve the high-frequency edge and complex texture information are obviously superior to those of traditional integral based algorithms, especially for texture detail rich images.

  2. Evaluation of Anti-hyperglycaemic Action of Different Fractions and Sub-fractions from Aqueous Extract of Aloe vera Linn. Leaf on Alloxan Induced Type 2 Diabetic Rats

    Institute of Scientific and Technical Information of China (English)

    Alok Maithani; Versha Parcha; Geeta Pant; Deepak Kumar; Ishan Dhulia

    2012-01-01

    Objective: To evaluate the fasting serum glucose (FSG) lowering potential of different fractions (C & D) and subfraction (D1 & D2) from aqueous extract of Aloe vera leaf on normal and alloxan induced type 2 diabetic rats. Methods: Two fractions (C & D) obtained by common chemical treatment of the aqueous extract of Aleo vera leaf and subfraction (D1 & D2) from fraction D were administered to the alloxan induced (150mg/kg i.p.) diabetic rats. The FSG lowering capacity, of different fractions and subfractions, was then evaluated in terms of percentage reduction in blood glucose level. Results: Oral administration of fractions C & D and subfraction D1 & D2 for 15 days led significant (P<0.05) reduction to the elevated FSG level of alloxan induced diabetic rats. Percentage reduction in blood glucose level and comparison with standard drug glibenclamide suggest the superiority of fraction D and subfraction D1 in hypoglycaemic potential. Conclusions:The results suggest that fraction D and subfraction D1 from aqueous extracts of Aloe vera leaf possesses the maximum FSG lowering capacity and further investigation is required for determination of anti-diabetic principal(s) and exact mechanism of their hypoglycaemic action.

  3. Fractional-order adaptive fault estimation for a class of nonlinear fractional-order systems

    KAUST Repository

    N'Doye, Ibrahima

    2015-07-01

    This paper studies the problem of fractional-order adaptive fault estimation for a class of fractional-order Lipschitz nonlinear systems using fractional-order adaptive fault observer. Sufficient conditions for the asymptotical convergence of the fractional-order state estimation error, the conventional integer-order and the fractional-order faults estimation error are derived in terms of linear matrix inequalities (LMIs) formulation by introducing a continuous frequency distributed equivalent model and using an indirect Lyapunov approach where the fractional-order α belongs to 0 < α < 1. A numerical example is given to demonstrate the validity of the proposed approach.

  4. A Fractional Variational Approach to the Fractional Basset-Type Equation

    Science.gov (United States)

    Baleanu, Dumitru; Garra, Roberto; Petras, Ivo

    2013-08-01

    In this paper we discuss an application of fractional variational calculus to the Basset-type fractional equations. It is well known that the unsteady motion of a sphere immersed in a Stokes fluid is described by an integro-differential equation involving derivative of real order. Here we study the inverse problem, i.e. we consider the problem from a Lagrangian point of view in the framework of fractional variational calculus. In this way we find an application of fractional variational methods to a classical physical model, finding a Basset-type fractional equation starting from a Lagrangian depending on derivatives of fractional order.

  5. Fractional distillation as a strategy for reducing the genotoxic potential of SRC-II coal liquids: a status report

    Energy Technology Data Exchange (ETDEWEB)

    Pelroy, R.A.; Wilson, B.W.

    1981-09-01

    This report presents results of studies on the effects of fractional distillation on the genotoxic potential of Solvent Refined Coal (SRC-II) liquids. SRC-II source materials and distilled liquids were provided by Pittsburg and Midway Coal Mining Co. Fractional distillations were conducted on products from the P-99 process development unit operating under conditions approximating those anticipated at the SRC-II demonstration facility. Distillation cuts were subjected to chemical fractionation, in vitro bioassay and initial chemical analysis. Findings are discussed as they relate to the temperature at which various distillate cuts were produced. This document is the first of two status reports scheduled for 1981 describing these studies.

  6. PROPERTIES OF FRACTIONAL κ-FACTORS OF GRAPHS

    Institute of Scientific and Technical Information of China (English)

    Liu Guizhen; Zhang Lanju

    2005-01-01

    In this paper the properties of some maximum fractional [0, κ]-factors of graphs are presented. And consequently some results on fractional matchings and fractional 1-factors are generalized and a characterization of fractional κ-factors is obtained.

  7. Stability of Fractional Order Switching Systems

    CERN Document Server

    HosseinNia, S Hassan; Vinagre, Blas M

    2012-01-01

    This paper addresses the stabilization issue for fractional order switching systems. Common Lyapunov method is generalized for fractional order systems and frequency domain stability equivalent to this method is proposed to prove the quadratic stability. Some examples are given to show the applicability and effectiveness of the proposed theory.

  8. Cell fractionation of parasitic protozoa: a review

    Directory of Open Access Journals (Sweden)

    Souza Wanderley de

    2003-01-01

    Full Text Available Cell fractionation, a methodological strategy for obtaining purified organelle preparations, has been applied successfully to parasitic protozoa by a number of investigators. Here we present and discuss the work of several groups that have obtained highly purified subcellular fractions from trypanosomatids, Apicomplexa and trichomonads, and whose work have added substantially to our knowledge of the cell biology of these parasites.

  9. Fractional Exact Solutions and Solitons in Gravity

    OpenAIRE

    Baleanu, Dumitru; Vacaru, Sergiu I.

    2010-01-01

    We survay our recent results on fractional gravity theory. It is also provided the Main Theorem on encoding of geometric data (metrics and connections in gravity and geometric mechanics) into solitonic hierarchies. Our approach is based on Caputo fractional derivative and nonlinear connection formalism.

  10. Search for fractional charges in water

    International Nuclear Information System (INIS)

    Results are presented from a search for fractional charges in water from a variety of natural sources. About 30 000 water drops have been measured, comprising 51 μg of water and dissolved materials. No evidence for fractional charge was seen

  11. A new definition of the fractional Laplacian

    OpenAIRE

    Chen, W.

    2002-01-01

    It is noted that the standard definition of the fractional Laplacian leads to a hyper-singular convolution integral and is also obscure about how to implement the boundary conditions. This purpose of this note is to introduce a new definition of the fractional Laplacian to overcome these major drawbacks.

  12. Safety of protein hydrolysates, fractions thereof and

    NARCIS (Netherlands)

    Schaafsma, Gertjan

    2009-01-01

    This paper evaluates the safety for humans with regard to consumption of protein hydrolysates and fractions thereof, including bioactive peptides. The available literature on the safety of protein, protein hydrolysates, fractions thereof and free amino acids on relevant food legislation is reviewed

  13. Void Fraction Instrument operation and maintenance manual

    International Nuclear Information System (INIS)

    This Operations and Maintenance Manual (O ampersand MM) addresses riser installation, equipment and personnel hazards, operating instructions, calibration, maintenance, removal, and other pertinent information necessary to safely operate and store the Void Fraction Instrument. Final decontamination and decommissioning of the Void Fraction Instrument are not covered in this document

  14. Protein-contg. fraction from mussel feet

    NARCIS (Netherlands)

    Van der Leeden, M.C.; Groen, B.W.

    1997-01-01

    Abstract of NL 1000732 (C1) A protein-contg. fraction suitable for use as an adhesive that can provide an adhesive bond with a strength of more than 15 N/cm2 is claimed. The fraction comprises one or more proteins contg. 3,4-dihydroxyphenylalanine (Dopa) and is obtd. by a process comprising trea

  15. FRACTIONAL (g, f)-FACTORS OF GRAPHS

    Institute of Scientific and Technical Information of China (English)

    刘桂真; 张兰菊

    2001-01-01

    This paper presents a new proof of a charaterization of fractional (g, f)-factors of a graph in which multiple edges are allowed. From the proof a polynomial algorithm for finding the fractional (g, f)-factor can be induced.

  16. Symmetric, discrete fractional splines and Gabor systems

    DEFF Research Database (Denmark)

    Søndergaard, Peter Lempel

    2006-01-01

    In this paper we consider fractional splines as windows for Gabor frames. We introduce two new types of symmetric, fractional splines in addition to one found by Unser and Blu. For the finite, discrete case we present two families of splines: One is created by sampling and periodizing the...

  17. Bioassay-Directed Fractionation and Sub-fractionation for Mutagenicity and Chemical Analysis of Diesel Exhaust Particles

    Science.gov (United States)

    Several types of diesel exhaust particles (DEPs) have been used for toxicology studies, including a high-organic automobile DEP (A-DEP) from Japan, and a low-organic forklift DEP developed by the National Institute of Standards and Technology (N-DEP). However, these DEPs were no...

  18. Fractional flux and non-normal diffusion

    Directory of Open Access Journals (Sweden)

    Ali Abdennadher

    2007-05-01

    Full Text Available Fractional diffusion equations are widely used for mass spreading in heterogeneous media. The correspondence between fractional equations and random walks based upon stable Levy laws, keeps in analogy with that between heat equation and Brownian motion. Several definitions of fractional derivatives yield operators, which coincide on a wide domain and can be used in fractional partial differential equations. Then, the various definitions are useful in different purposes: they may be very close to some physics, or to numerical schemes, or be based upon important mathematical properties. Here we present a definition, which enables us to describe the flux of particles, performing a random walk. We show that it is a left inverse to fractional integrals. Hence it coincides with Riemann-Liouville and Marchaud's derivatives when applied to functions, belonging to suitable domains.

  19. Volume Fraction Effects in Electroacoustic Measurements.

    Science.gov (United States)

    Rasmusson, Mikael

    2001-08-15

    We measured the dynamic mobility of a polystyrene latex at 1 MHz as a function of volume fraction using the ESA-8000. The volume fraction dependence is compared with a semiempirical equation as well as with some theoretical predictions. It turns out that our polystyrene latex exhibits a volume fraction dependence much weaker than that predicted by any of the theories. This suggests that (polystyrene) latices may not be the ideal model system and that the centrifugation process may influence the surface structure of the particles. We also measured the dynamic mobility spectrum of a silica sol as a function of volume fraction using the Acoustosizer. The experimental spectrum of the silica sol was found to agree reasonably well with the semiempirical and theoretical spectra, especially below φ=0.144. At higher volume fractions we observed positive phase angles that were not predicted by the semiempirical method nor the cell model. Copyright 2001 Academic Press. PMID:11482951

  20. On a new class of Hardy-type inequalities with fractional integrals and fractional derivatives

    OpenAIRE

    Iqbal, Sajid; Krulić Himmelreich, Kristina; Pečarić, Josip

    2014-01-01

    This paper is devoted to a new class of general weighted Hardy-type inequalities for arbitrary convex functions with some applications to different type of fractional integrals and fractional derivatives.

  1. Research on inter-fraction and intra-fraction motion of crystalline lens in radiotherapy

    Directory of Open Access Journals (Sweden)

    Shu-ming YANG

    2013-03-01

    Full Text Available Objective  To investigate the range of inter-fraction and intra-fraction motion of crystalline lens in radiotherapy. Methods  The CT and MRI images of 17 patients were registered, and the profile of crystalline lens was delineated to determine the respective center coordinates, thus simulating and analyzing inter-fraction and intra-fraction motion of lens in radiotherapy. Results  Both left and right lens moved in different degree during both inter-or intra-fraction phase. The range of lens movement was larger in inter-fraction than in intra-fraction phase in all directions. Conclusion  When radiotherapy is given in the free state, considering the distance of lens movement alone in inter-and intra-fraction and without considering the setup error, the lens planning organs at risk should increase 1.5mm outside the lens boundary.

  2. Reply to "Comment on `Fractional quantum mechanics' and `Fractional Schrödinger equation' "

    Science.gov (United States)

    Laskin, Nick

    2016-06-01

    The fractional uncertainty relation is a mathematical formulation of Heisenberg's uncertainty principle in the framework of fractional quantum mechanics. Two mistaken statements presented in the Comment have been revealed. The origin of each mistaken statement has been clarified and corrected statements have been made. A map between standard quantum mechanics and fractional quantum mechanics has been presented to emphasize the features of fractional quantum mechanics and to avoid misinterpretations of the fractional uncertainty relation. It has been shown that the fractional probability current equation is correct in the area of its applicability. Further studies have to be done to find meaningful quantum physics problems with involvement of the fractional probability current density vector and the extra term emerging in the framework of fractional quantum mechanics.

  3. Reply to "Comment on 'Fractional quantum mechanics' and 'Fractional Schrödinger equation' ".

    Science.gov (United States)

    Laskin, Nick

    2016-06-01

    The fractional uncertainty relation is a mathematical formulation of Heisenberg's uncertainty principle in the framework of fractional quantum mechanics. Two mistaken statements presented in the Comment have been revealed. The origin of each mistaken statement has been clarified and corrected statements have been made. A map between standard quantum mechanics and fractional quantum mechanics has been presented to emphasize the features of fractional quantum mechanics and to avoid misinterpretations of the fractional uncertainty relation. It has been shown that the fractional probability current equation is correct in the area of its applicability. Further studies have to be done to find meaningful quantum physics problems with involvement of the fractional probability current density vector and the extra term emerging in the framework of fractional quantum mechanics.

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

    International Nuclear Information System (INIS)

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

  5. Effect of organic fractions on sorption properties of organic pollutants in sediments

    Institute of Scientific and Technical Information of China (English)

    CHEN Hua-lin; ZHOU Jiang-min; CHEN Ying-xu; XU Yun-tai

    2005-01-01

    Humic substrates are a major fraction of sediment organic matters, and the sorption of hydrophobic organic chemicals by humic substrates influences their behavior and fate in sediment. In this paper, organic matters were divided into non-humic substrates and humic substrates. Non-humic substrates include acid leaching fraction, acid extracted fraction, and lipid; humic substrates were fractionated into Ca-binding-FA(fulvic acid), Ca-binding-HA (humic acid), oxide-FA, oxide-HA, and humin. To study the effect of organic fractions on sorption properties, sorption kinetic and equilibrium sorption experiments of phenanthrene and pentachlorophenol(PCP) in five sediments were carried out. The results showed that the contents of acid leaching fraction and oxide-binding-HA were the main fractions to affect the sorption rate constant, and for the sorption capacity of phenanthrene, humin was the major fraction, followed by oxide-binding-HA, oxidebinding-FA, and so on. While for PCP, the factors of influence on sorption capacity were mainly CEC, Ca-binding-FA, and Ca-bindingHA.

  6. Fractional kinetics in multi-compartmental systems.

    Science.gov (United States)

    Dokoumetzidis, Aristides; Magin, Richard; Macheras, Panos

    2010-10-01

    Fractional calculus, the branch of calculus dealing with derivatives of non-integer order (e.g., the half-derivative) allows the formulation of fractional differential equations (FDEs), which have recently been applied to pharmacokinetics (PK) for one-compartment models. In this work we extend that theory to multi-compartmental models. Unlike systems defined by a single ordinary differential equation (ODE), considering fractional multi-compartmental models is not as simple as changing the order of the ordinary derivatives of the left-hand side of the ODEs to fractional orders. The latter may produce inconsistent systems which violate mass balance. We present a rationale for fractionalization of ODEs, which produces consistent systems and allows processes of different fractional orders in the same system. We also apply a method of solving such systems based on a numerical inverse Laplace transform algorithm, which we demonstrate that is consistent with analytical solutions when these are available. As examples of our approach, we consider two cases of a basic two-compartment PK model with a single IV dose and multiple oral dosing, where the transfer from the peripheral to the central compartment is of fractional order α < 1, accounting for anomalous kinetics and deep tissue trapping, while all other processes are of the usual order 1. Simulations with the studied systems are performed using the numerical inverse Laplace transform method. It is shown that the presence of a transfer rate of fractional order produces a non-exponential terminal phase, while multiple dose and constant infusion systems never reach steady state and drug accumulation carries on indefinitely. The IV fractional system is also fitted to PK data and parameter values are estimated. In conclusion, our approach allows the formulation of systems of FDEs, mixing different fractional orders, in a consistent manner and also provides a method for the numerical solution of these systems. PMID

  7. Fractional Brownian Motion Approximation Based on Fractional Integration of a White Noise

    OpenAIRE

    Chechkin, A. V.; Gonchar, V. Yu.

    1999-01-01

    We study simple approximations to fractional Gaussian noise and fractional Brownian motion. The approximations are based on spectral properties of the noise. They allow one to consider the noise as the result of fractional integration/differentiation of a white Gaussian noise. We study correlation properties of the approximation to fractional Gaussian noise and point to the peculiarities of persistent and anti-persistent behaviors. We also investigate self-similar properties of the approximat...

  8. The Deuterium Fractionation Timescale in Dense Cloud Cores: A Parameter Space Exploration

    OpenAIRE

    Kong, Shuo; Caselli, Paola; Tan, Jonathan C.; Wakelam, Valentine; Sipilä, Olli

    2013-01-01

    The deuterium fraction [N$_2$D$^+$]/[N$_2$H$^+$], may provide information about the ages of dense, cold gas structures, important to compare with dynamical models of cloud core formation and evolution. Here we introduce a complete chemical network with species containing up to three atoms, with the exception of the Oxygen chemistry, where reactions involving H$_3$O$^+$ and its deuterated forms have been added, significantly improving the consistency with comprehensive chemical networks. Deute...

  9. CHARACTERIZATION OF FRACTIONATED LIGNINS POLYMERIZED BY FUNGAL LACCASES

    Directory of Open Access Journals (Sweden)

    Daniel van de Pas

    2011-04-01

    Full Text Available Lignins are important biopolymers that can be converted into value-added materials by enzymatic treatments. However, the heterogeneity of the lignin polymer makes it a challenging material to modify. Thus, chemical fractionation was used to obtain lignins with high homogeneity in order to assess their biotechnological utilization. Commercial Alcell, birch organosolv lignins, and steam-exploded pine and eucalypt lignins were sequentially fractionated by ether, ether/acetone 4:1 (v:v, and acetone. All fractions were structurally characterized prior to treatments with Thielavia arenaria, Trametes hirsuta, and Melanocarpus albomyces laccases. The reactivities of the enzymes towards the lignins were determined by oxygen consumption measurements, and the degree of polymerization was confirmed by size exclusion chromatography. Field emission scanning electron microscopy revealed that the surfaces of the lignin nanoparticles were dispersed in the enzyme treatment, suggesting an increase in hydrophilicity of the surfaces detected as loosened morphology. Hence, it was concluded that enzyme-aided valorization is an attractive means for lignin modification, provided that optimum reaction conditions are employed.

  10. Clay fraction mineralogy of a Cambisol in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Anastacio, A. S.; Fabris, J. D., E-mail: jdfabris@ufmg.br [Federal University of Minas Gerais, Campus - Pampulha, Department of Chemistry (Brazil); Stucki, J. W. [Department of Natural Resources and Environmental Sciences (United States); Coelho, F. S.; Pinto, I. V. [Federal University of Minas Gerais, Campus - Pampulha, Department of Chemistry (Brazil); Viana, J. H. M. [Embrapa Milho e Sorgo (Brazil)

    2005-11-15

    Clay minerals having a 2:1 (tetrahedral:octahedral sheet) structure may be found in strongly weathering soils only if the local pedo-climatic environment prevents them from further weathering to other minerals such as iron oxides. The clay minerals impart important chemical properties to soils, in part by virtue of changes in the redox state of iron in their crystal structures. Knowing the chemical nature of soil clays is a first step in evaluating their potential reactivity with other soil constituents and processes, such as the chemical decomposition of organic substrates to be potentially used in environmental remediation. The purpose of this work was to characterize the iron oxides and iron-bearing clay minerals from a B horizon of a Cambisol developed on tuffite in the State of Minas Gerais, Brazil, using chemical analysis, powder X-ray diffraction, Moessbauer spectroscopy, and thermal analysis. The iron oxides of this NaOH-treated clay-fraction were found to contain mainly maghemite ({gamma}Fe{sub 2}O{sub 3}) and superparamagnetic goethite ({alpha}FeOOH). Kaolinite (Al{sub 2}Si{sub 2}O{sub 5}(OH){sub 4}), smectite, and minor portions of anatase (TiO{sub 2}) were identified in the CBD-treated sample.

  11. Fractional Representation Formulae Under Initial Conditions and Fractional Ostrowski Type Inequalities

    Directory of Open Access Journals (Sweden)

    Anastassiou George A.

    2015-09-01

    Full Text Available Here we present very general fractional representation formulae for a function in terms of the fractional Riemann-Liouville integrals of different orders of the function and its ordinary derivatives under initial conditions. Based on these, we derive general fractional Ostrowski type inequalities with respect to all basic norms.

  12. Fractional differential approach to detecting textural features of digital image and its fractional differential filter implementation

    Institute of Scientific and Technical Information of China (English)

    PU YiFei; WANG WeiXing; ZHOU diLiu; WANG YiYang; JIA HuaDing

    2008-01-01

    This paper mainly discusses fractional differential approach to detecting textural features of digital image and its fractional differential filter. Firstly, both the geometric meaning and the kinetic physical meaning of fractional differential are clearly explained in view of information theory and kinetics, respectively. Secondly, it puts forward and discusses the definitions and theories of fractional stationary point, fractional equilibrium coefficient, fractional stable coefficient, and fractional grayscale co-occurrence matrix. At the same time, it particularly discusses frac-tional grayscale co-occurrence matrix approach to detecting textural features of digital image. Thirdly, it discusses in detail the structures and parameters of nxn any order fractional differential mask on negative x-coordinate, positive x-coordi-nate, negative y-coordinate, positive y-coordinate, left downward diagonal, left upward diagonal, right downward diagonal, and right upward diagonal, respectively. Furthermore, it discusses the numerical implementation algorithms of fractional differential mask for digital image. Lastly, based on the above-mentioned discus-sion, it puts forward and discusses the theory and implementation of fractional differential filter for digital image. Experiments show that the fractional differen-tial-based image operator has excellent feedback for enhancing the textural details of rich-grained digital images.

  13. The Fractionation of Adipose Tissue (FAT) procedure to obtain stromal vascular fractions for regenerative purposes

    NARCIS (Netherlands)

    van Dongen, Joris A; Stevens, Hieronymus P; Parvizi, Mojtaba; van der Lei, Berend; Harmsen, Martin C

    2016-01-01

    Autologous adipose tissue transplantation is clinically used to reduce dermal scarring and to restore volume loss. The therapeutic benefit on tissue damage more likely depends on the stromal vascular fraction of adipose tissue than on the adipocyte fraction. This stromal vascular fraction can be obt

  14. Single fraction versus multiple fraction radiotherapy for palliation of painful vertebral bone metastases: A prospective study

    Directory of Open Access Journals (Sweden)

    Dipanjan Majumder

    2012-01-01

    Conclusions: Different fractionation of radiation has same response and toxicity in treatment of vertebral bone metastasis. Single fraction RT may be safely used to treat these cases as this is more cost effective and less time consuming. Studies may be conducted to find out particular subgroup of patients to be benefitted more by either fractionation schedule; however, our study cannot comment on that issue.

  15. The relative roles of boundary layer fractionation and homogeneous fractionation in cooling basaltic magma chambers

    Science.gov (United States)

    Kuritani, Takeshi

    2009-06-01

    In a cooling magma chamber, magmatic differentiation can proceed both by fractionation of crystals from the main molten part of the magma body (homogeneous fractionation) and by mixing of the main magma with fractionated melt derived from low-temperature mush zones (boundary layer fractionation). In this study, the relative roles of boundary layer fractionation and homogeneous fractionation in basaltic magma bodies were examined using a thermodynamics-based mass balance model. Model calculations show that boundary layer fractionation cannot be a dominant fractionation mechanism when magma chambers are located at low pressures (magmatic evolution. On the other hand, boundary layer fractionation can occur effectively when magmas are hydrous (> ~ 2 wt.%), such as arc basalt, and the magma chambers are located at depth (> ~ 100 MPa). Because the melt derived from mush zones is enriched in alkalis and H 2O, crystallization from the main magma is suppressed by mixing with the mush melt as a consequence of depression of the liquidus temperature. Therefore, homogeneous fractionation is more effectively suppressed in magma chambers in which boundary layer fractionation is more active. If magmatic differentiation proceeds primarily by boundary layer fractionation, magmas can remain free of crystals for long periods during magmatic evolution.

  16. Cr stable isotope fractionation and reaction kinetics in aqueous milieu

    Science.gov (United States)

    Zink, S.; Schoenberg, R.; Staubwasser, M.

    2009-12-01

    using H2O2 as reducing agent. The observed, small Cr isotope fractionation can not be explained by one, unidirectional oxidation process. The high energy needed to oxidise Cr(III) to Cr(VI), potential Cr(III) oligomerisation and the formation of Cr(IV) and/or Cr(V) intermediates make the oxidation of Cr(III) to Cr(VI) a very complex fractionation mechanism. Our best-fit modelling points to an overall isotope fractionation Δ(53,52Cr)Cr(VI)-Cr(III) of +0.15 ‰ during the different oxidation steps, which is overprinted by a much larger isotope fractionation Δ(53,52Cr)Cr(III)-Cr(VI) of -3.4 ‰ during the back reduction of approximately 15 % of the chromium. No isotope exchange between soluble Cr(VI) and Cr(III) species at pH values of 5.5 and 7 was revealed by our experiments over a timescale of 120 hours. This observation is in good agreement with the lack of isotope exchange between oxygen bound in dissolved chromate CrO42- and that of the surrounding water [3]. [1] Schoenberg, R. et al. (2008) Chemical Geology, 249, 294ff. [2] Ellis, A. et al. (2002) Science, 295, 2060ff. [3] Bullen, T. et al. (2009) Geochim. Cosmochim. Acta, 73 (13), Suppl. 1, A173

  17. Toxic chemical considerations for tank farm releases

    Energy Technology Data Exchange (ETDEWEB)

    Van Keuren, J.C.; Davis, J.S., Westinghouse Hanford

    1996-08-01

    This topical report contains technical information used to determine the accident consequences of releases of toxic chemical and gases for the Tank Farm Final Safety Analysis report (FSAR).It does not provide results for specific accident scenarios but does provide information for use in those calculations including chemicals to be considered, chemical concentrations, chemical limits and a method of summing the fractional contributions of each chemical. Tank farm composites evaluated were liquids and solids for double shell tanks, single shell tanks, all solids,all liquids, headspace gases, and 241-C-106 solids. Emergency response planning guidelines (ERPGs) were used as the limits.Where ERPGs were not available for the chemicals of interest, surrogate ERPGs were developed. Revision 2 includes updated sample data, an executive summary, and some editorial revisions.

  18. Chemical carcinogenesis

    Directory of Open Access Journals (Sweden)

    Paula A. Oliveira

    2007-12-01

    Full Text Available The use of chemical compounds benefits society in a number of ways. Pesticides, for instance, enable foodstuffs to be produced in sufficient quantities to satisfy the needs of millions of people, a condition that has led to an increase in levels of life expectancy. Yet, at times, these benefits are offset by certain disadvantages, notably the toxic side effects of the chemical compounds used. Exposure to these compounds can have varying effects, ranging from instant death to a gradual process of chemical carcinogenesis. There are three stages involved in chemical carcinogenesis. These are defined as initiation, promotion and progression. Each of these stages is characterised by morphological and biochemical modifications and result from genetic and/or epigenetic alterations. These genetic modifications include: mutations in genes that control cell proliferation, cell death and DNA repair - i.e. mutations in proto-oncogenes and tumour suppressing genes. The epigenetic factors, also considered as being non-genetic in character, can also contribute to carcinogenesis via epigenetic mechanisms which silence gene expression. The control of responses to carcinogenesis through the application of several chemical, biochemical and biological techniques facilitates the identification of those basic mechanisms involved in neoplasic development. Experimental assays with laboratory animals, epidemiological studies and quick tests enable the identification of carcinogenic compounds, the dissection of many aspects of carcinogenesis, and the establishment of effective strategies to prevent the cancer which results from exposure to chemicals.A sociedade obtém numerosos benefícios da utilização de compostos químicos. A aplicação dos pesticidas, por exemplo, permitiu obter alimento em quantidade suficiente para satisfazer as necessidades alimentares de milhões de pessoas, condição relacionada com o aumento da esperança de vida. Os benefícios estão, por

  19. Chemical cosmology

    CERN Document Server

    Boeyens, Jan CA

    2010-01-01

    The composition of the most remote objects brought into view by the Hubble telescope can no longer be reconciled with the nucleogenesis of standard cosmology and the alternative explanation, in terms of the LAMBDA-Cold-Dark-Matter model, has no recognizable chemical basis. A more rational scheme, based on the chemistry and periodicity of atomic matter, opens up an exciting new interpretation of the cosmos in terms of projective geometry and general relativity. The response of atomic structure to environmental pressure predicts non-Doppler cosmical redshifts and equilibrium nucleogenesis by alp

  20. The effect of composting on the organic colloidal fraction from domestic sewage sludge

    Science.gov (United States)

    Almendros, Gonzalo; Leal, Juan A.; Martin, Francisco; Gonzalez-Vila, Francisco J.

    Due to the frequent use of domestic sewage sludges as organic additives to soils with low humus content, the chemical characteristics of the extractable polymers from composted and uncomposted sludges were described. The alkali-soluble, acid-insoluble sludge fraction (humic-like) was isolated after exhaustive lipid extraction, and analyzed by chemical degradation followed by combined gas chromatography mass spectrometry. It was observed that this sludge fraction contained an important amount of lipid compounds (more than 40% by weight). Most of this lipid material can be physically removed, but the residual polymer fractions were also found to be highly aliphatic in nature. The high yields upon degradation of several types of alkanoic acids and the relatively high proportion of polypeptides (30% by weight), as well as carbohydrates, suggested that the humic-like fractions from both the composted and uncomposted sludges consisted of slightly altered microbial and residual biopolymers. The effects of composting sludge mainly concern the selective biodegradation of the less resistant moieties. The great differences between the chemical nature of the humic-like fraction of the composted sludge and that of the soil humic acids are considered to reflect the low proportion of lignified materials in the original sludge.