Chemical Fractionation and Abundances in Coronal Plasma
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.
Aqueous fractionation yields chemically stable lupin protein isolates
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
Chemical composition of material fractions in Danish household waste
DEFF Research Database (Denmark)
Riber, Christian; Petersen, Claus; Christensen, Thomas Højlund
2009-01-01
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......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...
Physico-chemical characterisation of material fractions in household waste
DEFF Research Database (Denmark)
Götze, Ramona; Boldrin, Alessio; Scheutz, Charlotte
2016-01-01
State-of-the-art environmental assessment of waste management systems rely on data for the physico-chemical composition of individual material fractions comprising the waste in question. To derive the necessary inventory data for different scopes and systems, literature data from different sources...... and backgrounds are consulted and combined. This study provides an overview of physico-chemical waste characterisation data for individual waste material fractions available in literature and thereby aims to support the selection of data fitting to a specific scope and the selection of uncertainty ranges related...... 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...
Method for fractional solid-waste sampling and chemical analysis
DEFF Research Database (Denmark)
Riber, Christian; Rodushkin, I.; Spliid, Henrik
2007-01-01
to repeated particle-size reduction, mixing, and mass reduction until a sufficiently small but representative sample was obtained for digestion prior to chemical analysis. The waste-fraction samples were digested according to their properties for maximum recognition of all the studied substances. By combining...... four subsampling methods and five digestion methods, paying attention to the heterogeneity and the material characteristics of the waste fractions, it was possible to determine 61 substances with low detection limits, reasonable variance, and high accuracy. For most of the substances of environmental...... concern, the waste-sample concentrations were above the detection limit (e.g. Cd gt; 0.001 mg kg-1, Cr gt; 0.01 mg kg-1, Hg gt; 0.002 mg kg-1, Pb gt; 0.005 mg kg-1). The variance was in the range of 5-100%, depending on material fraction and substance as documented by repeated sampling of two highly...
Yield and chemical composition of fractions from fermented shrimp biowaste.
Narayan, Bhaskar; Velappan, Suresh Puthanveetil; Zituji, Sakhare Patiram; Manjabhatta, Sachindra Nakkerike; Gowda, Lalitha Ramakrishna
2010-01-01
Chemical composition of chitinous residue and fermentation liquor fractions, obtained from fermented shrimp biowaste, was evaluated in order to explore their potential for further utilization. Lyophilization of the liquor fraction obtained after fermentation resulted in a powder rich in both protein (30%) and carotenoids (217.18 +/- 2.89 microg/g). The yield of chitinous residue was 44% (w/w) whereas the yield of lyophilized powder was >25% (w/v). About 69% of total carotenoids were recovered by fermentation. Fermentation resulted in the removal of both protein as well as ash content from the shrimp biowaste, as indicated by approximately 92% deproteination and >76% demineralization, respectively. Post fermentation, the residue had a chitin content of >90%. The lyophilized liquor fraction had all the essential amino acids (except threonine) in quantities comparable to Food & Agriculture Organization/World Health Organization reference protein. The composition of fermentation liquor is indicative of its potential for application as an amino acid supplement in aquaculture feed formulations.
Chemical fractionation of deuterium in the protosolar nebula
Kalvāns, J.; Shmeld, I.; Kalnin, J. R.; Hocuk, S.
2017-01-01
Understanding gas-grain chemistry of deuterium in star-forming objects may help to explain their history and present state. We aim to clarify how processes in ices affect the deuterium fractionation. In this regard, we investigate a Solar-mass protostellar envelope using an astrochemical rate-equation model that considers bulk-ice chemistry. The results show a general agreement with the molecular D/H abundance ratios observed in low-mass protostars. The simultaneous processes of ice accumulation and rapid synthesis of HD on grain surfaces in the prestellar core hampers the deuteration of icy species. The observed very high D/H ratios exceeding 10 per cent, i.e., super-deuteration, are reproduced for formaldehyde and dimethyl ether, but not for other species in the protostellar envelope phase. Chemical transformations in bulk ice lower D/H ratios of icy species and do not help explaining the super-deuteration. In the protostellar phase, the D2O/HDO abundance ratio was calculated to be higher than the HDO/H2O ratio owing to gas-phase chemistry. Species that undergo evaporation from ices have high molecular D/H ratio and a high gas-phase abundance.
Chemical Fractionation in the Silicate Vapor Atmosphere of the Earth
Pahlevan, Kaveh; Eiler, John; 10.1016/j.epsl.2010.10.03
2010-01-01
Despite its importance to questions of lunar origin, the chemical composition of the Moon is not precisely known. In recent years, however, the isotopic composition of lunar samples has been determined to high precision and found to be indistinguishable from the terrestrial mantle despite widespread isotopic heterogeneity in the Solar System. In the context of the giant-impact hypothesis, this level of isotopic homogeneity can evolve if the proto-lunar disk and post-impact Earth undergo turbulent mixing into a single uniform reservoir while the system is extensively molten and partially vaporized. In the absence of liquid-vapor separation, such a model leads to the lunar inheritance of the chemical composition of the terrestrial magma ocean. Hence, the turbulent mixing model raises the question of how chemical differences arose between the silicate Earth and Moon. Here we explore the consequences of liquid-vapor separation in one of the settings relevant to the lunar composition: the silicate vapor atmosphere...
Characterization and prediction of chemical functions and weight fractions in consumer products
Directory of Open Access Journals (Sweden)
Kristin K. Isaacs
2016-01-01
Full Text Available Assessing exposures from the thousands of chemicals in commerce requires quantitative information on the chemical constituents of consumer products. Unfortunately, gaps in available composition data prevent assessment of exposure to chemicals in many products. Here we propose filling these gaps via consideration of chemical functional role. We obtained function information for thousands of chemicals from public sources and used a clustering algorithm to assign chemicals into 35 harmonized function categories (e.g., plasticizers, antimicrobials, solvents. We combined these functions with weight fraction data for 4115 personal care products (PCPs to characterize the composition of 66 different product categories (e.g., shampoos. We analyzed the combined weight fraction/function dataset using machine learning techniques to develop quantitative structure property relationship (QSPR classifier models for 22 functions and for weight fraction, based on chemical-specific descriptors (including chemical properties. We applied these classifier models to a library of 10196 data-poor chemicals. Our predictions of chemical function and composition will inform exposure-based screening of chemicals in PCPs for combination with hazard data in risk-based evaluation frameworks. As new information becomes available, this approach can be applied to other classes of products and the chemicals they contain in order to provide essential consumer product data for use in exposure-based chemical prioritization.
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.
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
Assessment of heavy metal removal technologies for biowaste by physico-chemical fractionation
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
Metal fractionation of atmospheric aerosols via sequential chemical extraction: a review
Energy Technology Data Exchange (ETDEWEB)
Smichowski, Patricia; Gomez, Dario [Unidad de Actividad Quimica, Comision Nacional de Energia Atomica, San Martin (Argentina); Polla, Griselda [Unidad de Actividad Fisica, Comision Nacional de Energia Atomica, San Martin (Argentina)
2005-01-01
This review surveys schemes used to sequentially chemically fractionate metals and metalloids present in airborne particulate matter. It focuses mainly on sequential chemical fractionation schemes published over the last 15 years. These schemes have been classified into five main categories: (1) based on Tessier's procedure, (2) based on Chester's procedure, (3) based on Zatka's procedure, (4) based on BCR procedure, and (5) other procedures. The operational characteristics as well as the state of the art in metal fractionation of airborne particulate matter, fly ashes and workroom aerosols, in terms of applications, optimizations and innovations, are also described. Many references to other works in this area are provided. (orig.)
Quantification of chemical contaminants in the paper and board fractions of municipal solid waste.
Pivnenko, K; Olsson, M E; Götze, R; Eriksson, E; Astrup, T F
2016-05-01
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. However, a lack of quantitative data on the presence of chemicals in paper is evident in the literature. The aim of the present work is to quantify the presence of selected chemicals in waste paper derived from households. Samples of paper and board were collected from Danish households, including both 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, and selected toxic metals (Cd, Co, Cr, Cu, Ni, and Pb). The results suggest large variations in the concentration of chemicals depending on the waste paper fraction analysed. Research on the fate of chemicals in waste recycling and potential problem mitigation measures should be focused on in further studies.
Xiao, Jin; Liu, Yuan; Zuo, Yu Ling; Li, Ji Yao; Ye, Ling; Zhou, Xue Dong
2006-09-01
Nidus Vespae is the honeycomb of Polistes Olivaceous (De Geer), P. Japonicus Saussure, and Parapolybiavaria Fabricius. It is known to have a number of pharmacological effects, including antimicrobial, anti-inflammatory, anti-virus, anti-tumor and anesthetic properties. The present study evaluated the antimicrobial activity and acid inhibition properties of extracts and chemical fractions of Nidus Vespae. The raw material was first extracted using 95% ethanol/water. Subsequent fractions were prepared from this extract using cyclohexane/ethyl acetate, petroleum ether/ethyl acetate, and chloroform/methanol. For the antimicrobial activity assays, minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were determined using the microdilution method. The chloroform/methanol (Chl/MeOH) fraction showed the highest antibacterial activities with a MIC of 8-16mg/ml and an MBC of 16-32mg/ml. In addition, the extract and chemical fractions of Nidus Vespae showed a remarkable capacity for inhibiting the acid production of common oral bacteria at sub-MIC concentrations. Sub-MIC levels of the petroleum ether/ethyl acetate fraction significantly inhibited acid production by Streptococcus mutans ATCC 25175. The significant antiacidogenic activity demonstrated by Nidus Vespae shows it to be a promising source of novel anticariogenic agents.
Byers, J A
1992-09-01
Studies of chemical ecology of an organism are founded on the isolation and identification of a semiochemical, often comprised of two or more synergistic compounds (each Synergist alone has little activity, but presented together they are bioactive). Chromatographie fractionation and bioassay methods of binary splitting, additive combination, and subtractive combination are compared for efficiency in isolating synergists. Formulas are derived for the latter two methods that calculate the expected number of bioassay tests required for isolation of from two to five synergists from biological extracts with any number of compounds, depending on the number of initial (major) Chromatographic fractions. A computer program based on the formulas demonstrates the superiority of the subtractive-combination method. Simulations with the program were used to determine the optimal number of initial fractions for the additive- and subtractive-combination methods when isolating two to five synergists from extracts of from 25 to 1200 compounds. Methods of bioassay, isolation, identification, and field testing of semiochemicals are discussed.
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.
Occurrence of non extractable pesticide residues in physical and chemical fractions of two soils
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.
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
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.
Muhd Haffiz, J; Norhayati, I; Getha, K; Nor Azah, M A; Mohd Ilham, A; Lili Sahira, H; Roshan Jahn, M S; Muhd Syamil, A
2013-03-01
Essential oil from Cymbopogon nardus was evaluated for activity against Trypanosoma brucei brucei BS221 (IC50 = 0.31 ± 0.03 μg/mL) and cytotoxic effect on normal kidney (Vero) cells (IC50 = >100 μg/mL). The crude essential oil was subjected to various chromatography techniques afforded active sub fractions with antitrypanosomal activity; F4 (IC50 = 0.61 ± 0.06 μg/mL), F6 (IC50= 0.73 ± 0.33 μg/mL), F7 (IC50 = 1.15 ± 0 μg/mL) and F8 (IC50 = 1.11 ± 0.01 μg/mL). These active fractions did not exhibit any toxic effects against Vero cell lines and the chemical profiles investigation indicated presence of α-and γ-eudesmol, elemol, α-cadinol and eugenol by GC/MS analysis.
Yutong, Zong; Qing, Xiao; Shenggao, Lu
2016-12-01
Heavy metals in urban soils may pose risks to both urban environment and human health. However, only a fraction of heavy metals in soil is mobile and/or bioavailable for plant uptake and human ingestion. This study evaluates the chemical fraction and potential mobility and bioaccessibility of heavy metals (Cd, Cr, Cu, Pb, and Zn) in the contaminated urban topsoils from steel-industrial city (Anshan), Northeastern China. Chemical forms of heavy metals in soils are determined using Tessier sequential extraction technique. The toxicity characteristic leaching procedure (TCLP), ethylenediaminetetraacetic acid (EDTA), and US Pharmacopeia methodology (USPM) are used to determine the operationally defined potentially mobile and bioaccessible metal fractions, respectively. Sequential extraction results show that Cd has the highest percentage of exchangeable form, whereas Cr primarily exists in residual form. The non-residual fraction of heavy metals increases in the order of Cr metals evaluated by TCLP test indicates that Cd, Zn, Cu, and Pb have much higher mobile than Cr. The bioavailability of heavy metals determined by EDTA extraction decreases in the order of Pb > Cu ≅ Zn > Cd > Cr. The order of bioaccessibility determined by USPM extraction is Pb = Cu > Zn > Cd > Cr. The Cr exhibits the lowest leachability and bioaccessibility among the investigated metals. The Pb has the highest bioaccessibility, indicating higher potential hazard for the human health. There are significant relationships between the EDTA- and USPM-extractable metals (Cd, Cu, Pb, and Zn) and the sum of first three steps of sequential extraction. Highly significant correlation is found between amounts of EDTA-extractable Cd, Cu, Pb, and Zn and USPM-extractable metals. The result suggests that EDTA extraction can be helpful to estimate the bioaccessibility of heavy metals for human ingestion. Introduction of mobile and human bioaccessible concentrations into risk assessments can give more realistic
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.
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.
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.
Canellas, Luciano P; Piccolo, Alessandro; Dobbss, Leonardo B; Spaccini, Riccardo; Olivares, Fábio L; Zandonadi, Daniel B; Façanha, Arnoldo R
2010-01-01
Preparative high performance size-exclusion chromatography (HPSEC) was applied to humic acids (HA) extracted from vermicompost in order to separate humic matter of different molecular dimension and evaluate the relationship between chemical properties of size-fractions (SF) and their effects on plant root growth. Molecular dimensions of components in humic SF was further achieved by diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY-NMR) based on diffusion coefficients (D), while carbon distribution was evaluated by solid state (CP/MAS) (13)C NMR. Seedlings of maize and Arabidopsis were treated with different concentrations of SF to evaluate root growth. Six different SF were obtained and their carbohydrate-like content and alkyl chain length decreased with decreasing molecular size. Progressive reduction of aromatic carbon was also observed with decreasing molecular size of separated fractions. Diffusion-ordered spectroscopy (DOSY) spectra showed that SF were composed of complex mixtures of aliphatic, aromatic and carbohydrates constituents that could be separated on the basis of their diffusion. All SF promoted root growth in Arabidopsis and maize seedlings but the effects differed according to molecular size and plant species. In Arabidopsis seedlings, the bulk HA and its SF revealed a classical large auxin-like exogenous response, i.e.: shortened the principal root axis and induced lateral roots, while the effects in maize corresponded to low auxin-like levels, as suggested by enhanced principal axis length and induction of lateral roots. The reduction of humic heterogeneity obtained in HPSEC separated size-fractions suggested that their physiological influence on root growth and architecture was less an effect of their size than their content of specific bioactive molecules. However, these molecules may be dynamically released from humic superstructures and exert their bioactivity when weaker is the humic conformational stability as that obtained
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.
Chemical fractionation resulting from the hypervelocity impact process on metallic targets
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.
Isotopic fractionation of carbon, deuterium and nitrogen : a full chemical study
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...
Chemical fractionation of radionuclides and stable elements in aquatic plants of the Yenisei River.
Bolsunovsky, Alexander
2011-09-01
The Yenisei River is contaminated with artificial radionuclides released by one of the Russian nuclear plants. The aquatic plants growing in the radioactively contaminated parts of the river contain artificial radionuclides. The aim of the study was to investigate accumulation of artificial radionuclides and stable elements by submerged plants of the Yenisei River and estimate the strength of their binding to plant biomass by using a new sequential extraction scheme. The aquatic plants sampled were: Potamogeton lucens, Fontinalis antipyretica, and Batrachium kauffmanii. Gamma-spectrometric analysis of the samples of aquatic plants has revealed more than 20 radionuclides. We also investigated the chemical fractionation of radionuclides and stable elements in the biomass and rated radionuclides and stable elements based on their distribution in biomass. The greatest number of radionuclides strongly bound to biomass cell structures was found for Potamogeton lucens and the smallest for Batrachium kauffmanii. For Fontinalis antipyretica, the number of distribution patterns that were similar for both radioactive isotopes and their stable counterparts was greater than for the other studied species. The transuranic elements (239)Np and (241)Am were found in the intracellular fraction of the biomass, and this suggested their active accumulation by the plants.
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.
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.
Han, Junwon
The remarkable development of polymer synthesis techniques to make complex polymers with controlled chain architectures has inevitably demanded the advancement of polymer characterization tools to analyze the molecular dispersity in polymeric materials beyond size exclusion chromatography (SEC). In particular, man-made synthetic copolymers that consist of more than one monomer type are disperse mixtures of polymer chains that have distributions in terms of both chemical heterogeneity and chain length (molar mass). While the molecular weight distribution has been quite reliably estimated by the SEC, it is still challenging to properly characterize the chemical composition distribution in the copolymers. Here, I have developed and applied adsorption-based interaction chromatography (IC) techniques as a promising tool to characterize and fractionate polystyrene-based block, random and branched copolymers in terms of their chemical heterogeneity. The first part of this thesis is focused on the adsorption-desorption based purification of PS-b-PMMA diblock copolymers using nanoporous silica. The liquid chromatography analysis and large scale purification are discussed for the PS-b-PMMA block copolymers that have been synthesized by sequential anionic polymerization. SEC and IC are compared to critically analyze the contents of PS homopolymers in the as-synthesized block copolymers. In addition, I have developed an IC technique to provide faster and more reliable information on the chemical heterogeneity in the as-synthesized block copolymers. Finally, a large scale (multi-gram) separation technique is developed to obtain "homopolymer-free" block copolymers via a simple chromatographic filtration technique. By taking advantage of the large specific surface area of nanoporous silica (≈300m 2/g), large scale purification of neat PS-b-PMMA has successfully been achieved by controlling adsorption and desorption of the block copolymers on the silica gel surface using a
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.
Chemical characteristics and fractionation of proteins from Moringa oleifera Lam. leaves.
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.
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.
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.
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).
Modification of apparent fission yields by Chemical Fractionation following Fission (CFF)
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).
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.
Bueno, Kelly; Adorne, Marcia D; Jornada, Denise S; da Fonseca, Francisco Noé; Guterres, Sílvia S; Pohlmann, Adriana R
2013-01-01
In nanomedicine, different nanomaterials and nanoparticles have been proposed as therapeutic agents or adjuvants, as well as diagnosis devices. Considering that the principal cause of the ulcerations is the imbalance among the gastric juice secretion and the protection provided by the mucosal barrier and the neutralization of the gastric acid, as well as that nanoparticles are able to accumulate in the gastro-intestinal tissues, we proposed a 2(2) factorial design to evaluate the influence of the chemical composition and the volume fraction of the dispersed phase on the gastric protective effect against ulceration induced by ethanol. Cocoa-theospheres (CT) and lipid-core nanocapsules (LNC) (two different kinds of surfaces: lipid and polymeric, respectively) prepared at two different concentrations of soft materials: 4% and 12% (w/v) were produced by high pressure homogenization and solvent displacement methods, respectively. Laser diffraction showed volume-weighted mean diameters ranging from 133 to 207 nm, number median diameters lower than 100 nm and specific surfaces between 41.2 and 51.2 m(2) g(-1). The formulations had pH ranging from 4.7 to 6.3; and zeta potential close to -9 mV due to their coating with polysorbate 80. The ulcer indexes were 0.40 (LNC(4)) and 0.48 (CT(4)) for the lower total administered areas (3.3 and 4.1 m(2)g(-1), respectively), and 0.09 (LNC(12) and CT(12)) for the higher administered areas (10.0 and 12.0 m(2) g(-1), respectively). LNC(4), LNC(12) and CT(12) showed lower levels in the lipid peroxidation assay when compared either to the negative control (saline) or to CT(4). LNC(12) and CT(12) showed similar TBARS levels, as well as CT(4) was similar to the negative control. SEM analysis of the stomach mucosa showed coatings more homogenous and cohesive when LNC formulations were administered compared to the correspondent CT formulations. The higher total area of administered nanoparticles showed film formation. Moreover, LNC(12
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.)
Chemically fractionated fission-xenon in meteorites and on the earth
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.
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.
Kuiate, Jules-Roger; Bessière, Jean Marie; Zollo, Paul Henri Amvam; Kuate, Serge Philibert
2006-01-16
The chemical composition of five column fractions of hexanic leaf extract of Cupressus lusitanica were analysed by gas chromatography and gas chromatography-mass spectrometry and then tested for their antidermatophytic activities using the agar dilution method. The first fraction (F(1)) has only hydrocabon monoterpenes with alpha-pinene (80.0%) as major component. The main constituents of the second fraction (F(2)) were epi-bicyclosesquiphellandrene (35.3%), epi-zonarene (10.3%), 1S, cis-calamenene (13.1%) and beta-himachalene (10.4%). The third fraction (F(3)) was rich in hydrocarbon sesquiterpenes (45.4%) and a relatively high amount of diterpenes (29.8%) with epi-bicyclosesquiphellandrene (14.3%), pimaric acid (7.5%), kaurenoic acid (6.9%) and 8-beta-hydroxysandaracopimarane (3.5%) as main components. The last two fractions contain high molecular weight aliphatic hydrocarbons, their main constituents been eicosane (41.1%) and tricosane (37.3%) and heptacosane (22.1%). The agar dilution method was used to evaluate the antifungal properties of the crude extract and its fractions. These fractions showed several degrees of antidermatophytic activities against Microsporum audouinii, Microsporum Langeronii, Microsporum canis, Trichophyton rubrum and Trichophyton tonsurans. Fractions F(1) and F(3) exhibited the highest antidermatophytic activities with repective MICs of 250 and 125 mug/ml while the fractions F(4) and F(5) did not prevent the growth of the tested fungi up to dose 2,500 mug/ml.
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 ...
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
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......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....... However, a lack of quantitative data on the presence of chemicals in paper is evident in the literature. The aim of the present work is to quantify the presence of selected chemicals in waste paper derived from households. Samples of paper and board were collected from Danish households, including both...
Stewart, C. E.; Amatangelo, K.; Neff, J.
2007-12-01
Soil organic matter (SOM) inherits much of its chemical nature from the dominant vegetation, including phenolic (lignin-derived), aromatic, and aliphatic (cutin and wax-derived) compounds. However, relatively stable recalcitrant compounds may also be formed as a result of condensation and complexation reactions through decomposition and protected with association with mineral particles. The Hawaiian fern species Dicranopteris decomposes more slowly than the angiosperm, Cheirodendrom due to high concentrations of recalcitrant C compounds. These aliphatic fern leaf waxes are well-preserved and may comprise a large portion of the recalcitrant organic matter in these soils. Our objective was to determine the chemical composition of the SOM under the O- (litter-dominated) and the A- (mineral) horizons formed under fern and angiosperm vegetation. To determine the effect of mineral-association, we fractioned the soil into four size classes; 850-590 μm, 590-180 μm, 180-53 μm and cutin and leaf waxes (alkene and alkanes structures) occurred in the 180-53 μm fraction, which has been shown to be the most stable of the aggregate-size fractions. Soils developed under fern versus angiosperm vegetation have distinct chemical signatures, which likely determine the recalcitrance of the SOM.
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
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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
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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.
Chemical constituents in n-butanol fractions of Costus afer ker Gawl leaf and stem
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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
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Neerja Puri
2013-01-01
Full Text Available Introduction: Melasma is a commonly acquired hypermelanosis and a common dermatologic skin disease that occurs on sun-exposed areas of face. Aims: To assess the efficacy and safety of non-ablative 1,550 nm Erbium glass fractional laser therapy and compare results with those obtained with chemical peeling. Materials and Methods: We selected 30 patients of melasma aged between 20 years and 50 years for the study. The patients were divided into two groups of 15 patients each. Group I patients were subjected to four sessions of 1,550 nm Erbium glass non-ablative fractional laser at 3 weeks interval. In group II patients, four sessions of chemical peeling with 70% glycolic acid was performed. Results: After 12 weeks of treatment, percentage reduction in Melasma Area and Severity Index (MASI score was seen in 62.9% in the laser group and 58.7% in the peels group. Conclusion: It was observed that 1,550 nm fractional laser is as effective as 70% glycolic acid peel in reducing MASI score in patients with melasma.
Puri, Neerja
2013-01-01
Introduction: Melasma is a commonly acquired hypermelanosis and a common dermatologic skin disease that occurs on sun-exposed areas of face. Aims: To assess the efficacy and safety of non-ablative 1,550 nm Erbium glass fractional laser therapy and compare results with those obtained with chemical peeling. Materials and Methods: We selected 30 patients of melasma aged between 20 years and 50 years for the study. The patients were divided into two groups of 15 patients each. Group I patients were subjected to four sessions of 1,550 nm Erbium glass non-ablative fractional laser at 3 weeks interval. In group II patients, four sessions of chemical peeling with 70% glycolic acid was performed. Results: After 12 weeks of treatment, percentage reduction in Melasma Area and Severity Index (MASI) score was seen in 62.9% in the laser group and 58.7% in the peels group. Conclusion: It was observed that 1,550 nm fractional laser is as effective as 70% glycolic acid peel in reducing MASI score in patients with melasma. PMID:24163531
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.
Simplifying Chemical Reactor Design by using Molar Quantities Instead of Fractional Conversion.
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)
[Effect of Nano Zeolite on Chemical Fractions of Cd in Soil and Its Uptake by Cabbage].
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 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 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 increased
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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.
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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.
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...
Liang, Peng; Wu, Sheng-Chun; Li, Yi-Chun; Li, Hong-Bo; Yu, Guang-bin; Yu, Shen; Wong, Ming H
2012-04-01
The aims of the present study were to investigate the effects of mariculture activities on inorganic mercury (Hg(2+)) adsorption/desorption on sediments and the distributions of newly adsorbed Hg(2+) on different chemical fractionations. The adsorption amount and binding energy of Hg(2+) on mariculture sediment (MS) were significantly higher (pHg(2+) and organic matter (OM), which derived from unconsumed fish feed and fish metabolites. The reducible Hg(2+) in MS was significantly lower (pHg(2+) bound to them. On the contrary, the residual Hg(2+) was significantly higher (pHg(2+) was more stable in MS than RS.
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 ...
O3, CO2 and chemical fractionation in ponderosa pine saplings
Environmental factors can affect plant tissue quality which is important for quality of organic matter inputs into soil food webs and decomposition of soil organic matter. Thus the effects of increases in CO2 and O3 and their interactions were determined for various chemical fra...
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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.
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.
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...... 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...... 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....
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W. T. Morgan
2009-12-01
Full Text Available The spatial distribution of aerosol chemical composition and the evolution of the Organic Aerosol (OA fraction is investigated based upon airborne measurements of aerosol chemical composition in the planetary boundary layer across Europe. Sub-micron aerosol chemical composition was measured using a compact Time-of-Flight Aerosol Mass Spectrometer (cToF-AMS. A range of sampling conditions were evaluated, including relatively clean background conditions, polluted conditions in North-Western Europe and the near-field to far-field outflow from such conditions. Ammonium nitrate and OA were found to be the dominant chemical components of the sub-micron aerosol burden, with mass fractions ranging from 20–50% each. Ammonium nitrate was found to dominate in North-Western Europe during episodes of high pollution, reflecting the enhanced NO_{x} and ammonia sources in this region. OA was ubiquitous across Europe and concentrations generally exceeded sulphate by 50–100%. A factor analysis of the OA burden was performed in order to probe the evolution across this large range of spatial and temporal scales. Two separate Oxygenated Organic Aerosol (OOA components were identified; one representing an aged-OOA, termed Low Volatility-OOA and another representing fresher-OOA, termed Semi Volatile-OOA on the basis of their mass spectral similarity to previous studies. The factors derived from different flights were not chemically the same but rather reflect the range of OA composition sampled during a particular flight. Significant chemical processing of the OA was observed downwind of major sources in North-Western Europe, with the LV-OOA component becoming increasingly dominant as the distance from source and photochemical processing increased. The measurements suggest that the aging of OA can be viewed as a continuum, with a progression from a less oxidised, semi-volatile component to a highly oxidised, less-volatile component. Substantial amounts of
Can a fractionally crystallized magma ocean explain the thermo-chemical evolution of Mars?
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...
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Gloria del Barrio
2011-10-01
Full Text Available The antiviral activity of extracts obtained from Ageratina havanensis (Kunth R.M.King & H.Rob., Asteraceae, against rabbit vesivirus (RaV (Caliciviridae and human herpes simplex viruses type 1 and 2 (HSV-1, HSV-2 (Herpesviridae were analyzed, and the main metabolites from the most active extract were isolated and characterized. The antiviral properties were investigated by measuring the inhibition of viral-induced cytopathic effect in Vero cells. The strongest inhibitory effects were found for ethyl acetate extract from leaves (SI=5 for RaV and SI=5.4 for HSV-1. The crude ethyl acetate extract was further fractionated by chromatographic methods and the structures of isolated compounds were established through comprehensive spectroscopic analyses, including IR, 2D NMR and MS. Four flavonoids were identified: 5,4'-dihydroxy-7-methoxyflavanone (sakuranetin, 3,5,4'-trihydroxy-7-methoxyflavanone (7-methoxyaromadendrin, 4'-O-β-D-glucosyl-5,3'-dihydroxy-7-methoxyflavanone (4'-O-β-D-glucosyl-7-methoxy-eriodictyol and 4'-O-β-D-glucosyl-5-hydroxy-7-methoxyflavanone (4'-O-β-D-glucosylsakuranetin. This is the first report on antiviral activity for Ageratina havanensis.
Choo, C Y; Chan, K L; Sam, T W; Hitotsuyanagi, Y; Takeya, K
2001-09-01
The plant, Typhonium flagelliforme (Araceae), commonly known as the "rodent tuber" in Malaysia, is often used as an essential ingredient of herbal remedies for alternative cancer therapies. The hexane extract of this plant was evaluated for cytotoxic activity against in vitro culture on P388 murine leukaemia cells and showed weak IC(50) of 15 microg/ml. The partial chemical constituents were identified as methyl esters of hexadecanoic acid, octadecanoic acid, 9-octadecenoic acid and 9,12-octadecadienoic acid. In addition, several common aliphatics were identified as dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane and eicosane. The unique methyl ester of 13-phenyltridecanoic acid was isolated and positively identified using spectroscopic methods. None of the identified compounds showed or are known to have cytotoxic behaviour.
Wen, Fang; Hou, Hong; Yao, Na; Yan, Zengguang; Bai, Liping; Li, Fasheng
2013-01-01
A laboratory repacked soil-leaching column experiment was conducted to study the effects of simulated acid rain or EDTA by themselves or in combination, on migration and chemical speciation distribution of Pb and its alternative rare metals including Ag, Bi, In, Sb, and Sn. Experimental results demonstrate that leaching with simulated acid rain promoted the migration of Bi, In and Pb, and their migration reached down to 8 cm in the soil profile, no enhancement of Sb, Ag or Sn migration was observed. Addition of EDTA significantly enhanced the migration of all six metals, especially Bi, In and Pb. The migration of metals was in the order Pb>Bi>In>Sb>Sn>Ag. The individual and combined effects of acid rain and EDTA increased the environmental risk of metals, by increasing the soluble content of metals in soil solutions and the relative distribution of the exchangeable fraction. Leaching risks of Bi, In and Pb were higher than other three metals.
Gokavi, Sumangala S; Malleshi, Nagappa G; Guo, Mingruo
2004-01-01
Garden cress (Lepidium sativum) belonging to the family Cruciferae grown in India, Europe and US is an underutilized crop. The edible whole seed is known to have health promoting properties. Hence, it was assumed that these seeds can be a functional food. A preliminary work on chemical composition of seeds was carried out and the possibility of using it as nutraceutical food ingredient in dietary fiber formulation was explored. Three fractions namely whole meal (WM), endosperm and bran were analyzed for chemical composition. The yield of the endosperm and the bran fraction were 72 and 28%, respectively. The WM, endosperm and bran had 22.5, 27.7 and 12.6% protein, 27.5, 33.1 and 6% fat, 30, 13.6 and 75% dietary fibre (DF), and 1193.00, 945.15 and 1934.57 mg% potassium respectively. The major protein on SDS-PAGE was of 29.5 kDa. The most abundant amino acid was glutamic acid (19.3%) and the essential amino acid, leucine was the highest (8.21 +/- 0.01%) and methionine the lowest (0.97 +/- 0.02%). The major fatty acid was linolenic acid (30.2%) and low amount of erucic acid (3.9%) was also present. Bran having high water holding capacity and high DF, its use as source of DF was explored. The product contained 12% protein, 4% fat and 74.3% DF and exhibited desirable functional properties such as dispersibility, gelling ability, stability, formed homogenous mild alkaline suspension and was comparable to proprietary DF.
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.
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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.
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
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E. T. Karageorgos
2007-06-01
Full Text Available The PM_{10} 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 PM_{10} 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-PM_{10} (PM_{10-2.5}+PM_{2.5} 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 PM_{10} 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, PM_{10} 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 Ca^{2+}, NO_{3}^{−}, Na
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.
DEFF Research Database (Denmark)
Glæsner, Nadia; Donner, Erica; Magid, Jakob;
2012-01-01
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...
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.
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
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.
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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.
Rocha, Otávio P; De Felício, Rafael; Rodrigues, Ana Helena B; Ambrósio, Daniela L; Cicarelli, Regina Maria B; De Albuquerque, Sérgio; Young, Maria Claudia M; Yokoya, Nair S; Debonsi, Hosana M
2011-08-19
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 IC(50) = 19.1 μg.mL-1 and trypomastigote IC(50) = 76.2 μg.mL-1). The hexanes and ethyl acetate fractions also displayed activity against both fungi species (200 μg) by TLC-bioautography.
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 (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.
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.
Sébastien, Gillet; Christophe, Blecker; Mario, Aguedo; Pascal, Laurent; Michel, Paquot; Aurore, Richel
2014-08-08
Crude locust bean gum (CLBG) was purified and fractionated into two parts: the first was obtained by solubilization in water at 25°C (GM25) and the second consisted in a further extraction at 80°C on the residual impoverished fraction (GM80). The complete structural characterization has shown that GM80 possessed relatively longer chain lengths than GM25, a slightly lower degree of galactose substitution and a somewhat sharper galactosyl distribution in substituted and unsubstituted regions. A physical behavior analysis was carried out on solubilization kinetics, viscosity, viscoelasticity and formation of associated gels with xanthan or carrageenan. The average structure of GM80 generated larger intra-chain, inter-chain and inter-molecular interactions, resulting in the appearance of a stronger network. Small structural differences therefore generated very different physical behaviors. This study thus allowed to establish, in a precise and complete manner, fractionation-purification-structure-function relationships of galactomannans extracted from carob.
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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.
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.
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.
Vavilin, V A
2012-04-01
A change in δ(13)CH(4) during mesophilic methanization of cellulosic waste (paper and cardboard) was described using a mathematical model based on stoichiometric chemical reactions, microbial dynamics and the equation for the (13)C isotope accumulation in products including isotope fractionation. In this study, experimental data, previously obtained by Qu et al. (2009), was used to model metabolic pathways of cellulose transformation. A significant change in δ(13)CH(4) occurred in time during cellulosic waste methanization which was in accordance with the model. It was explained by the change in input of acetoclastic and hydrogenotrophic methanogenesis as well as by fractionation of stable carbon isotopes (13)C and (12)C which was much higher for hydrogenotrophic methanogenesis when compared to acetoclastic methanogenesis.
Sklavounos, Evangelos; Iakovlev, Mikhail; Survase, Shrikant; Granström, Tom; van Heiningen, Adriaan
2013-11-01
A process has been developed for conversion of spent liquor produced by SO2-ethanol-water (SEW) fractionation of oil palm empty fruit bunch (OPEFB) fibers to biofuels by ABE fermentation. The fermentation process utilizes Clostridia bacteria that produce butanol, ethanol and acetone solvents at a total yield of 0.26 g/g sugars. A conditioning scheme is developed, which demonstrates that it is possible to utilize the hemicellulose sugars from this agricultural waste stream by traditional ABE fermentation. Fractionation as well as sugar hydrolysis in the spent liquor is hindered by the high cation content of OPEFB, which can be partly removed by acidic leaching suggesting that a better deashing method is necessary. Furthermore, it is inferred that better and more selective lignin removal is needed during conditioning to improve liquor fermentability.
M. Crippa; P. F. DeCarlo; Slowik, J. G.; Mohr, C; M. F. Heringa; R. Chirico; POULAIN L.; F. Freutel; Sciare, J.; Cozic, J.; Marco, C. F.; M. Elsasser; Nicolas, J.B.; N. Marchand; Abidi, E.
2013-01-01
The effect of a post-industrial megacity on local and regional air quality was assessed via a month-long field measurement campaign in the Paris metropolitan area during winter 2010. Here we present source apportionment results from three aerosol mass spectrometers and two aethalometers deployed at three measurement stations within the Paris region. Submicron aerosol composition is dominated by the organic fraction (30–36%) and nitrate (28–29%), with lower contributions from sulfate (14–16%),...
M. Crippa; P. F. DeCarlo; Slowik, J. G.; Mohr, C; M. F. Heringa; R. Chirico; POULAIN L.; F. Freutel; Sciare, J.; Cozic, J.; C. F. Di Marco; M. Elsasser; N. José; N. Marchand; Abidi, E.
2012-01-01
The effect of a post-industrial megacity on local and regional air quality was assessed via a month-long field measurement campaign in the Paris metropolitan area during winter 2010. Here we present source apportionment results from three aerosol mass spectrometers and two aethalometers deployed at three measurement stations within the Paris region. Submicron aerosol composition is dominated by the organic fraction (30–36%) and nitrate (28–29%), with lower contributions from sulfate (14–16%),...
Institute of Scientific and Technical Information of China (English)
冯冬冬; 张宇; 刘鹏; 郭洋洲; 黄玉东; 孙绍增; 吴江全; 赵义军
2015-01-01
化学分析分馏过程广泛应用于碱金属及碱土金属对生物质焦炭活性影响的研究。针对化学分析分馏过程对生物质热解焦炭物理化学结构产生的影响展开深入研究。通过压汞仪、扫描电子显微镜（SEM）对化学分析分馏过程中焦炭的孔径分布、孔隙率、比表面积及颗粒表面形貌等物理结构的变化进行了分析，结果表明该过程对焦炭的孔隙率影响显著，对比表面积影响不大，对热解焦炭多孔状表面形貌影响较为突出。利用X射线光电子光谱法（XPS）和拉曼光谱法（Raman）对焦炭表面碳氧活性官能团结构及焦炭芳香环结构等化学结构特征展开了研究，结果表明化学分析分馏过程对生物质焦炭表面碳氧活性官能团结构的破坏作用较小，化学分析分馏对焦炭的芳香环结构影响不大，水洗过程对焦炭内部的交联结构影响不明显，醋酸铵溶液、盐酸对焦炭内部的交联结构破坏明显。%Chemical fractionation analysis is widely used to study the effect of alkali and alkaline earth metal (AAEM) species on the reactivity of biomass char. The influence of chemical fractionation analysis on the physical and chemical structures of biomass char was investigated in this study. The physical structures of biomass char were studied by the mercury porosimetry and scanning electron microscopy (SEM). The results showed that the influence of chemical fractionation analysis on the porosity and surface morphology of the biomass char was apparent. However, the effect of chemical fractionation analysis on the specific surface area of biomass char could be ignored. X-ray photoelectron spectroscopy (XPS) and Raman were used to identify the O-containing functional groups and the aromatic ring structures in the biomass char, respectively. The results indicated that the changes of the oxygen containing functional groups were little during the chemical fractionation
Directory of Open Access Journals (Sweden)
Otávio dos Anjos Leal
2015-06-01
Full Text Available After open coal mining, soils are “constructed”, which usually contain low levels and quality of organic matter (OM. Therefore, the use of plant species for revegetation and reclamation of degraded areas is essential. This study evaluated the distribution of carbon (C in the chemical fractions as well as the chemical characteristics and humification degree of OM in a soil constructed after coal mining under cultivation of perennial grasses. The experiment was established in 2003 with the following treatments: Hemarthria altissima (T1, Paspalum notatum (T2, Cynodon dactilon (T3, Urochloa brizantha (T4, bare constructed soil (T5, and natural soil (T6. In 2009, soil samples were collected from the 0.00-0.03 m layer and the total organic carbon stock (TOC and C stock in the chemical fractions: acid extract (CHCl, fulvic acid (CFA, humic acid (CHA, and humin (CHU were determined. The humic acid (HA fraction was characterized by infrared spectroscopy and the laser-induced fluorescence index (ILIF of OM was also calculated. After six years, differences were only observed in the CHA stocks, which were highest in T1 (0.89 Mg ha-1 and T4 (1.06 Mg ha-1. The infrared spectra of HA in T1, T2 and T4 were similar to T6, with greater contribution of aliphatic organic compounds than in the other treatments. In this way, ILIF decreased in the sequence T5>T3>T4>T1>T2>T6, indicating higher OM humification in T3 and T5 and more labile OM in the other treatments. Consequently, the potential of OM quality recovery in the constructed soil was greatest in treatments T1 and T4.
Yokoyama, Tatsunori; Misawa, Keiji; Okano, Osamu; Shih, Chi-Yu; Nyquist, Laurence E.; Simon, Justin I.; Tappa, Michael J.; Yoneda, Shigekazu
2017-01-01
New K-Ca and Rb-Sr isotopic analyses have been performed on alkali-rich igneous rock fragments in the Yamato (Y)-74442 and Bhola LL-chondritic breccias to better understand the extent and timing of alkali enrichments in the early solar system. The Y-74442 fragments yield a K-Ca age of 4.41 ± 0.28 Ga for λ(40K) = 0.5543 Ga-1 with an initial 40Ca/44Ca ratio of 47.1618 ± 0.0032. Studying the same fragments with the Rb-Sr isotope system yields an age of 4.420 ± 0.031 Ga for λ(87Rb) = 0.01402 Ga-1 with an initial ratio of 87Sr/86Sr = 0.7203 ± 0.0044. An igneous rock fragment contained in Bhola shows a similar alkali fractionation pattern to those of Y-74442 fragments but does not plot on the K-Ca or Rb-Sr isochron of the Y-74442 fragments. Calcium isotopic compositions of whole-rock samples of angrite and chondrites are primordial, indistinguishable from mantle-derived terrestrial rocks, and here considered to represent the initial composition of bulk silicate Earth. The initial ε40Ca value determined for the source of the alkali clasts in Y-74442 that is ∼0.5 ε-units higher than the solar system value implies an early alkali enrichment. Multi-isotopic studies on these alkali-rich fragments reveal that the source material of Y-74442 fragments had elemental ratios of K/Ca = 0.43 ± 0.18, Rb/Sr = 3.45 ± 0.66 and K/Rb ∼ 170, that may have formed from mixtures of an alkali-rich component (possibly an alkali-enriched gaseous reservoir produced by fractionation of early nebular condensates) and chondritic components that were flash-heated during an impact event on the LL-chondrite parent body ∼4.42 Ga ago. Further enrichments of potassium and rubidium relative to calcium and strontium as well as a mutual alkali-fractionation (K/Rb ∼ 50 and heavier alkali-enrichment) would have likely occurred during subsequent cooling and differentiation of this melt. Alkali fragments in Bhola might have undergone similar solid-vapor fractionation processes to those of Y
Clauer, Norbert; Lewan, Michael D.; Dolan, Michael P.; Chaudhuri, Sambhudas; Curtis, John B.
2014-01-01
Progressive maturation of the Eocene Kreyenhagen Shale from the San Joaquin Basin of California was studied by combining mineralogical and chemical analyses with K–Ar dating of whole rocks and chemical organization of the K-bearing alumino-silicates with depth. No supply of K from outside of the rock volumes occurred, which indicates a closed-system behavior for it. Conversely, the content of the total organic carbon (TOC) content decreases significantly with burial, based on the progressive increasing Al/TOC ratio of the whole rocks. The initial varied mineralogy and chemistry of the rocks and their <2 μm fractions resulting from differences in detrital sources and depositional settings give scattered results that homogenize progressively during burial due to increased authigenesis, and concomitant increased alteration of the detrital material.
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.
Energy Technology Data Exchange (ETDEWEB)
Wright, C.W.; Later, D.W.; Dauble, D.D.; Wilson, B.W.
1985-07-01
This document reports and compares the results compiled from chemical analyses and biological testing of coal liquefaction process materials which were fractionally distilled, after production, into various comparable boiling-point range cuts. Comparative analyses were performed on solvent refined coal (SRC)-I, SRC-II, H-Coal, EDS an integrated two-stage liquefaction (ITSL) distillate materials. Mutagenicity and carcinogenicity assays were conducted in conjunction with chromatographic and mass spectrometric analyses to provide detailed, comparative, chemical and biological assessments. Where possible, results obtained from the distillate cuts are compared to those from coal liquefaction materials with limited boiling ranges. Work reported here was conducted by investigators in the Biology and Chemistry Department at the Pacific Northwest Laboratory (PNL), Richland, WA. 38 refs., 16 figs., 27 tabs.
DEFF Research Database (Denmark)
Götze, Ramona; Pivnenko, Kostyantyn; Boldrin, Alessio
2016-01-01
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 recy...
DEFF Research Database (Denmark)
Larsen, Simon Tylsgaard; Taboryski, Rafael Jozef
2009-01-01
We present experimental contact angle data for surfaces, which were surface-engineered with a hydrophobic micropattern of hexagonal geometry. The chemically heterogeneous surface of the same hexagonal pattern of defects resulted in faceted droplets of hexagonal shape. When measuring the advancing...
Buurman, P.; Roscob, R.
2011-01-01
To investigate both the effect of land-use systems on SOM characteristics and the effect of occlusion in aggregates on chemical composition of the occluded fraction, SOM fractions of soils under Cerrado, no-tillage and conventional tillage, were investigated. Free light, occluded light and extractab
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.
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.
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.
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.
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.
Avery, O T; Macleod, C M; McCarty, M
1944-02-01
1. From Type III pneumococci a biologically active fraction has been isolated in highly purified form which in exceedingly minute amounts is capable under appropriate cultural conditions of inducing the transformation of unencapsulated R variants of Pneumococcus Type II into fully encapsulated cells of the same specific type as that of the heat-killed microorganisms from which the inducing material was recovered. 2. Methods for the isolation and purification of the active transforming material are described. 3. The data obtained by chemical, enzymatic, and serological analyses together with the results of preliminary studies by electrophoresis, ultracentrifugation, and ultraviolet spectroscopy indicate that, within the limits of the methods, the active fraction contains no demonstrable protein, unbound lipid, or serologically reactive polysaccharide and consists principally, if not solely, of a highly polymerized, viscous form of desoxyribonucleic acid. 4. Evidence is presented that the chemically induced alterations in cellular structure and function are predictable, type-specific, and transmissible in series. The various hypotheses that have been advanced concerning the nature of these changes are reviewed.
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.
Joana Paula Lima de Castro
2014-01-01
The seaweed Gracilaria are important sources of agar sulfated polysaccharides that are commonly used in the food, pharmaceutical and biotechnology industries. For characterization of the media, the kelp was subjected to analysis of their chemical composition, which indicated their percentages of moisture, ash, protein and lipids. Extractions in which extraction by enzymatic digestion native extract (a seaweed is not subjected to pretreatments and obtaining the polysaccharides is by their boil...
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.
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.
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.
Energy Technology Data Exchange (ETDEWEB)
Montgomery, D.S.; Elbrink, C.
1983-03-31
A survey of the chemical types present in the polar fraction of Athabasca maltene revealed the presence of three prominent homologous series of sulfoxides, C/sub n/H sub 2n-2SO, C/sub n/H/sub 2n-4/SO and C/sub n/H/sub 2n-6/SO. The volatile members of these series have been studied to determine the chemical structure and stereochemistry of the leading members of the terpenoid sulfoxides to provide new series of biological markers for geothermal studies and compounds of more appropriate thermal stability to monitor new approaches to refining and upgrading. Of the three oxygen-containing homologous series found to be present, C/sub n/H/sub 2n-18/O, C/sub n/H/sub 2n-24/O and C/sub n/H/sub 2n-16/O, the volatile members belonging to the C/sub n/H/sub 2n-16/O were studied in detail and shown to consist of a series of fluorenols in which the substitutent in the 9 position extends out to C/sub 8/. Mass spectral evidence was also found for methyl substitution on the ring system. Of the various nitrogen- and oxygen-containing species, the elemental composition of the homologous series C/sub n/H/sub 2n-11/NO was confirmed by high resolution mass spectrometry and tentatively assigned to a series of quinolones. The concentration of these nitrogen compounds and the sulfoxides have been found to be extremely variable within the same oil sand quarry, reflecting subtle changes in the biological source material. No relation between the concentration of the acids and sulfoxides has been found which might be related to the oxygen potential of the water during the deposition of the bitumen. 9 refs., 76 figs., 3tabs.
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.
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
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
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.
Hong, Seung-Phil; Han, Seung-Seog; Choi, Seok-Joo; Kim, Myoung-Shin; Won, Chong-Hyun; Lee, Mi-Woo; Choi, Jee-Ho; Moon, Kee-Chan; Kim, Youn Jin; Chang, Sung-Eun
2012-04-01
Fractional photothermolysis (FP) therapy and chemical peels have been reported to be effective in patients with recalcitrant melasma. However, there is little information to compare the efficacy of single treatment session in Asian women. The aim of this study was to examine the efficacy, long-lasting outcomes and safety of a single session of 1550-nm erbium-doped FP in Asian patients, compared with trichloroacetic acid (TCA) peel with a medium depth. Eighteen Korean women (Fitzpatrick skin type III or IV) with moderate-to-severe bilateral melasma were randomly treated with a single session of 1550-nm FP on one cheek, and with a 15% TCA peel on the other cheek. Outcome measures included an objective melasma area severity index and subjective patient-rated overall improvement at 4 and 12 weeks after treatment. Melasma lesions were significantly improved 4 weeks after either treatment, but melasma recurred at 12 weeks. Post-inflammatory hyperpigmentation developed in 28% of patients at 4 weeks but resolved in all but one patient by 12 weeks. There was no difference between FP treatment and TCA peeling with respect to any outcome measure. FP laser and TCA peel treatments were equally effective and safe when used to treat moderate-to-severe melasma, but neither treatment was long-lasting. We suggest that multiple or periodic maintenance treatments and/or supplemental procedures may be required for the successful treatment of melasma in Asian women.
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.
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.
Maria Klimikova
2010-01-01
Understanding the reasons of the present financial problems lies In understanding the substance of fractional reserve banking. The substance of fractional banking is in lending more money than the bankers have. Banking of partial reserves is an alternative form which links deposit banking and credit banking. Fractional banking is causing many unfavorable economic impacts in the worldwide system, specifically an inflation.
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.
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 ...
Kaufeld, Aurica M; Pertz, Heinz H; Kolodziej, Herbert
2014-07-25
Extracts of the bark of willow species (Salix spp.) are popular herbal remedies to relieve fever and inflammation. The effects are attributed to salicin and structurally related phenolic metabolites, while polyphenols including procyanidins are suggested to contribute to the overall effect of willow bark. This study aimed at investigating the relaxant response to a highly purified and chemically defined 2,3-trans procyanidin fraction in porcine coronary arteries. The procyanidin sample produced a concentration-dependent relaxation in U46619-precontracted tissues. Relaxation was predominantly mediated through the redox-sensitive activation of the endothelial phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathway, leading to the subsequent activation of endothelial nitric oxide synthase (eNOS) by phosphorylation, as evidenced by Western blotting using human umbilical vein endothelial cells (HUVECs). That the relaxant response to Salix procyanidins was reactive oxygen species (ROS)-dependent with O2(-) as the key species followed from densitometric analysis using 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA assay) and employment of various ROS inhibitors, respectively. The data also suggested the modification of intracellular Ca(2+) levels and KCa channel functions. In addition, our organ bath studies showed that Salix procyanidins reversed the abrogation of the relaxant response to bradykinin by oxidized low-density lipoproteins (oxLDL) in coronary arteries, suggesting a vasoprotective effect of willow bark against detrimental oxLDL in pathological conditions. Taken together, our findings suggest for the first time that 2,3-trans procyanidins may contribute not only to the beneficial effects of willow bark but also to health-promoting benefits of diverse natural products of plant origin.
Chemical Constituents in Ethyl Acetate Fraction of Abelmoschus esculentus%黄秋葵乙酸乙酯部位化学成分的研究
Institute of Scientific and Technical Information of China (English)
徐寅鹏; 石金敏; 郭明明; 敬林林; 贾陆
2013-01-01
采用硅胶柱色谱、Sephadex LH-20柱色谱、MCI、ODS和重结晶等多种分离纯化手段,对黄秋葵(Abelmoschus esculentus)乙酸乙酯部位的化学成分进行研究,从中分离得到了13个化合物,分别为β-谷甾醇(β-sitosterol) (1)β-胡萝卜苷(β-daucosterol) (2)、槲皮素(quercetin) (3)、东莨菪内酯(scopoletin) (4)、克利米可辛A(cleomiscosin A)(5)、克利米可辛C(cleomiscosin C) (6)、三十烷酸(triacontanoic acid)(7)、叶绿醇(phytol)(8)、十八碳二烯酸单甘油酯(glycerol-1-linoleate)(9)、亚油酸甘油三酯(trilinolein)(10)、熊果酸(ursolic acid) (11)、蕨内酰胺(pterolactarn) (12)、对羟基苯甲醛(p-hydroxy-benzaldehyde) (13).其中化合物4～12均为首次从黄秋葵中分离得到.%Thirteen compounds were obtained from EtoAc fraction of 95% ethanol extract of Abelmoschus esculentus L. by repeated column chromatography over silica gel.Sephadex LH-20,MCI,ODS,ete. By spectral analysis and physicochemi-cal properties,their chemical structures were identified as β-sitosterol (1) ,β-daucosterol (2) .quercetin (3) ,scopoletin (4) ,cleomiscosin A (5),cleomiscosin C (6) ,triacontanoic acid (7) , phytol (8) ,glycerol-1-linoleate (9) .trilinolein (10) ,ursolic acid (11) ,pterolactam (12) ,β-hydroxy-benzaldehyde (13). Compounds 4-12 were separated from A. esculentus for the first time.
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.
Institute of Scientific and Technical Information of China (English)
王艳宏; 王秋红; 夏永刚; 匡海学
2011-01-01
Objective; To study relationship between 'pungent dispersing bitter evacuant' antiasthmaticeffect and the chemical split fraction of Ephedrae Herba and to provide scientific evidence for the verification of the new assumption on the theory of properties and flavors of Chinese medicine ' one herbal contains X flavors and Y properties ( Y ≤X ) '. Method: Equal volume of acetylcholine chloride and histamine phosphate solution were used to induce abnormalism asthma in guinea, and water decoction(775 mg·kg-1 ) , alkaloids fraction(7. 8 mg·kg-1 ) , naphtha fraction(3. 87 × 10 -4 mg·kg-1), polysaccharide fraction(45. 6 mg·kg-1), phenolic acids fraction(36. 4 mg·kg-1) , alkaloids and polysaccharide fraction(7. 8 mg·kg-1 +45.6 mg·kg-1) were given The latent period of asthmatic convulsion was observed The effects of water decoction fraction, alkaloids fraction, naphtha fraction, polysaccharide fraction, phenolic acids fraction on spasm tracheal smooth muscle caused by histamine and acetylcholine in guinea was observed. Result; Compared with blank control group, water decoction, alkaloids fraction and polysaccharide fraction inhibited abnormalism asthma occurrence ( P < 0. 01 ) , Compared with water decoction, alkaloids fraction and polysaccharide fraction showed significant difference (P < 0. 05 ) . Compared with water decoction, alkaloids fraction compatibility with polysaccharide fraction according to the former proportion, there was no significant difference. Compared with blank control group, water decoction and alkaloids fraction take the effect to normal tracheal strips from guinea body showed significant difference ( P < 0. 05 ) ; water decoction, phenolic acids fraction, alkaloids fraction and naphtha fraction take the effect to spasticity tracheal strips caused by histamine showed significant difference ( P < 0. 01 , P < 0. 05 ) ; water decoction and alkaloids fraction showed significant difference(P <0. 01) to spasticity tracheal strips caused by acetyl
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.
Michallik, Radoslaw M.; Wagner, Thomas; Fusswinkel, Tobias; Heinonen, Jussi S.; Heikkilä, Pasi
2017-03-01
The 1928 Ma old Luumäki gem beryl pegmatite is hosted by rapakivi granites of the Wiborg batholith in southeast Finland. The moderately evolved niobium-yttrium-fluorine (NYF) pegmatite system belongs to the topaz-beryl type of the rare-element pegmatite class. It has a simple major mineral assemblage of K-feldspar + plagioclase + quartz + biotite ± fluorite throughout the main pegmatite zones (border, wall, intermediate, and core zone). It consists of at least two chemically related bodies (Luumäki N and Luumäki S), of which only Luumäki N contains gem beryl (heliodor) bearing miarolitic pockets. We characterize the geology, mineral assemblages, and the major and trace element chemistry of K-feldspar, plagioclase, biotite and quartz from the pegmatite. The mineral chemistry data show a progressive enrichment of Rb, Cs and Tl in K-feldspars, and depletion in Sr and Ba. The K-feldspar from the beryl-bearing pockets records the highest enrichment in incompatible elements, distinct from the data trend shown by K-feldspar from the main pegmatite zones. The REE data for plagioclase show a decrease of the positive Eu-anomaly and then a change to negative Eu-anomaly in the more evolved inner zones. This demonstrates an increase of the oxidation state of the pegmatite melt over time, consistent with the abundance of hematite in late-stage mineral assemblages including those of the miarolitic pockets. Fractional crystallization modeling is able to replicate the progressive enrichment of incompatible elements in K-feldspar, and to predict degrees of crystallization, which are in good agreement with volume estimates for the different pegmatite zones. The modeling results demonstrate that formation of the zoned pegmatite up to the quartz core can be well explained by an igneous crystallization process, leading up to considerable enrichment in incompatible elements. The melt reached saturation with an aqueous hydrothermal fluid only after more than 90% of the pegmatite melt
U.S. Environmental Protection Agency — The purpose of this study was to compare two in vitro systems, cryopreserved trout hepatocytes and trout liver S9 fractions, used to predict in vivo levels of...
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Eliazar, Iddo I., E-mail: eliazar@post.tau.ac.il [Holon Institute of Technology, P.O. Box 305, Holon 58102 (Israel); Shlesinger, Michael F., E-mail: mike.shlesinger@navy.mil [Office of Naval Research, Code 30, 875 N. Randolph St., Arlington, VA 22203 (United States)
2013-06-10
Brownian motion is the archetypal model for random transport processes in science and engineering. Brownian motion displays neither wild fluctuations (the “Noah effect”), nor long-range correlations (the “Joseph effect”). The quintessential model for processes displaying the Noah effect is Lévy motion, the quintessential model for processes displaying the Joseph effect is fractional Brownian motion, and the prototypical model for processes displaying both the Noah and Joseph effects is fractional Lévy motion. In this paper we review these four random-motion models–henceforth termed “fractional motions” –via a unified physical setting that is based on Langevin’s equation, the Einstein–Smoluchowski paradigm, and stochastic scaling limits. The unified setting explains the universal macroscopic emergence of fractional motions, and predicts–according to microscopic-level details–which of the four fractional motions will emerge on the macroscopic level. The statistical properties of fractional motions are classified and parametrized by two exponents—a “Noah exponent” governing their fluctuations, and a “Joseph exponent” governing their dispersions and correlations. This self-contained review provides a concise and cohesive introduction to fractional motions.
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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.
Allen, Gregory Harold
Chemical speciation and source apportionment of size fractionated atmospheric aerosols were investigated using laser desorption time-of-flight mass spectrometry (LD TOF-MS) and source apportionment was carried out using carbon-14 accelerator mass spectrometry (14C AMS). Sample collection was carried out using the Davis Rotating-drum Unit for Monitoring impact analyzer in Davis, Colfax, and Yosemite, CA. Ambient atmospheric aerosols collected during the winter of 2010/11 and 2011/12 showed a significant difference in the types of compounds found in the small and large sized particles. The difference was due to the increase number of oxidized carbon species that were found in the small particles size ranges, but not in the large particles size ranges. Overall, the ambient atmospheric aerosols collected during the winter in Davis, CA had and average fraction modern of F14C = 0.753 +/- 0.006, indicating that the majority of the size fractionated particles originated from biogenic sources. Samples collected during the King Fire in Colfax, CA were used to determine the contribution of biomass burning (wildfire) aerosols. Factor analysis was used to reduce the ions found in the LD TOF-MS analysis of the King Fire samples. The final factor analysis generated a total of four factors that explained an overall 83% of the variance in the data set. Two of the factors correlated heavily with increased smoke events during the sample period. The increased smoke events produced a large number of highly oxidized organic aerosols (OOA2) and aromatic compounds that are indicative of biomass burning organic aerosols (WBOA). The signal intensities of the factors generated in the King Fire data were investigated in samples collected in Yosemite and Davis, CA to look at the impact of biomass burning on ambient atmospheric aerosols. In both comparison sample collections the OOA2 and WBOA factors both increased during biomass burning events located near the sampling sites. The correlation
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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.
Institute of Scientific and Technical Information of China (English)
闫颖; 陈盈; 何红波; 解宏图; 白震; 李晓波; 田秋香; 张旭东
2012-01-01
The black soil fertilized with different chemical fertilizers for 21 years was sampled from Gongzhuling long-term located station. Fine clay （〈 0.2 p,m）, coarse clay （0.2 - 2 μm）, silt （2 - 53 μm）, fine sand （53 - 250 μm） and coarse sand （250 - 2000μm） fractions were obtained by ultrasonic dispersion, centrifugation and wet sieving separation. Carbohydrates were detected in bulk soil and particlesize fractions. The results showed that there was a large variation among the size separates in black soil carbohydrate pool. Clay plus silt fractions comprised major carbohydrates pool in the soils studied and contained about 70% of the total carbohydrate. In general the application of chemical fertilizers had no clear effect on either neueral sugar accumulation or distribution in size fractions. The decrease of the （Gal＋Man）： （Ara＋Xyl） ratio in coarse fraction after the application of chemical fertilizers indicated a higher contribution of plant sugars to the polysaccharide pool, suggesting that coarse sand fraction was more sensitive to fertilization than the other fractions.%本文采集公主岭市长期定位监测基地不施肥和施用不同化肥的黑土,通过超声波分散-离心分离得到细黏粒（〈0.2μm）、粗黏粒（0.2～2μm）、粉粒（2～53μm）、细砂粒（53～250μm）、粗砂粒（250～2000μm）5个颗粒级别,分析全土及不同粒级中土壤碳水化合物并进行含量与分布的比较。结果表明,黑土中不同粒级碳水化合物库的性质差异显著,碳水化合物多集中在粉＋黏粒中;长期施用化肥后,黑土全土及各粒级碳水化合物库大小和浓度基本上没有变化;粗砂粒级（Gal＋Man）（：Ara＋Xyl）下降,表明该粒级中植物来源碳水化合物所占比重有所增加,暗示出粗砂粒级对施肥措施更为敏感。
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Leandro Sampaio Oliveira Ribeiro
2014-06-01
Full Text Available The experiment was conducted to evaluate the concentrations of ammonia nitrogen, hydrogen potential, the losses of deriving the fermentative process, nutritional value, the fractioning of carbohydrates and protein the elephant grass silage wilted or not containing castor bean meal. The experimental design was completely randomized, with five treatments and with four replications: elephant grass wilted; elephant not wilted; elephant grass more castor bean meal (6%; elephant grass more castor bean meal (12% and elephant grass more castor bean meal (18%, the coproduct was added with base on natural matter. We adopted a specific mass of 600 kg/m3. The silage containing 18% castor bean meal showed higher (P0.05 among the silages with additives for fractions A+B1, B2 and C. For the protein fractioning, the fractions A and C decreased (P<0.05 with increase of the inclusion of castor bean meal, differently, of the fraction B1+B2 which increased. The castor bean stands out as a good additive in silage of elephant grass to reduce moisture and improve the fermentation characteristics of silages also was effective in increasing the protein value of silages, especially when using the dose 18%.
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...
Understanding Multiplication of Fractions.
Sweetland, Robert D.
1984-01-01
Discussed the use of Cuisenaire rods in teaching the multiplication of fractions. Considers whole number times proper fraction, proper fraction multiplied by proper fraction, mixed number times proper fraction, and mixed fraction multiplied by mixed fractions. (JN)
Sullivan, Amy P.; Weber, Rodney J.
2006-03-01
Group separation of the aqueous extract of fine particles bearing water-soluble organic carbon (WSOC) provides unique insights into the sources of organic carbon (OC). XAD-8 resin coupled with a Total Organic Carbon analyzer allows for direct quantification. We term the fraction of WSOC not retained by a XAD-8 resin column at pH 2 as hydrophilic WSOC (WSOCxp); this includes saccharides, amines, and carbonyls and aliphatic monocarboxylic/dicarboxylic/oxocarboxylic acids with less than 4 or 5 carbons. The fraction of WSOC retained by XAD-8, termed the hydrophobic fraction (WSOCxr), include aromatic acids, phenols, organic nitrates, cyclic acids, and carbonyls and monocarboxylic/dicarboxylic acids with greater than 3 or 4 carbons. However, only aromatic compounds (or aromatic-like compounds with similar properties) can subsequently be extracted from XAD-8 with high efficiency. By coupling a Particle-into-Liquid Sampler with this technique, online measurements of WSOC, WSOCxp, and WSOCxr are possible. Urban measurements from St. Louis and Atlanta, on a carbon mass basis, show an increase in the mean WSOC fraction from winter (51%) to summer (61%), due to increases in the WSOCxp/OC from 0.25 to 0.35. During a summer Atlanta PM event, WSOC to OC was 0.75, driven largely by increases in the WSOCxp. The results are consistent with the view that in the summer, there are increased amounts of oxygenated polar compounds, possibly from secondary organic aerosol production, and that these compounds account for an even larger fraction of OC during stagnation events. A companion paper describes a method to further group speciate these XAD-8 isolated fractions.
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.
Bhattacharyya, Sonalee; Namakshi, Nama; Zunker, Christina; Warshauer, Hiroko K.; Warshauer, Max
2016-01-01
Making math more engaging for students is a challenge that every teacher faces on a daily basis. These authors write that they are constantly searching for rich problem-solving tasks that cover the necessary content, develop critical-thinking skills, and engage student interest. The Mystery Fraction activity provided here focuses on a key number…
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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)
2008-09-19
DFO-B) complexes in aque - ous solution. In general, there was good agreement between the predicted properties of Fe(III)-DFO-B and previously... aque - ous Fe can lead to isotopic fractionation (Wiederhold et al., 2006). Thus, validation and interpretation of experi- mental findings would be...Holmen et al., 1997 ) used acetohydroxamic acid (aHa) as an analog for high molecular weight hydroxamate siderophores and per- formed Hartree–Fock
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.
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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.
Sun, Xiao-Feng; Sun, Run-Cang; Lu, Qi; Xu, Feng; Lin, Lu
2002-10-23
The cell wall material of Chinese shrubs Haloxylon ammodendron and Elaeagnus angustifolia was fractionated by successive extractions with ethanol/H(2)O (60:40, v/v) under acidic conditions (0.2 N HCl) at 70 degrees C for 4 h, and 2% H(2)O(2) at pH 11.5 for 16 h, respectively. The sequential two-step treatment resulted in the dissolution of 83.9% and 87.6% of the original hemicelluloses from dewaxed H. ammodendron and E. angustifolia, respectively. Xylose, glucose, and galactose were the major sugar constituents in the two acidic organosolv-soluble hemicellulosic preparations. The two alkaline peroxide-soluble hemicellulosic fractions were shown to be composed primarily of xylose, comprising over 80% of the total sugars. The results also showed that the two alkaline peroxide-soluble hemicellulosic fractions were more linear and acidic, and had higher molecular mass and thermal stability than the two acidic organosolv-soluble hemicellulosic preparations. The 2% H(2)O(2) posttreatment did not result in any significant changes in the macromolecular structure of the isolated hemicelluloses. It is probable that lignin protects hemicelluloses and cellulose from being attacked by peroxide.
Fraction Reduction through Continued Fractions
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.
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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.
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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.
Institute of Scientific and Technical Information of China (English)
万莉; 钱晓萍; 刘宝瑞
2012-01-01
延胡索在临床治疗中运用广泛,其主要成分为生物碱.现代研究表明延胡索生物碱中的延胡索碱、延胡索乙素、小檗碱、黄连碱巴马仃、d-海罂粟碱、d-异波尔定等成分具有一定的抗肿瘤作用.本文就近年来延胡索生物碱的化学成分及其抗肿瘤作用研究的进展情况作一综述.%Corydalis yanhusuo,the main chemical constituents of which are alkaloids, is widely used in the clinical treatment. Modem researches have showed that some constituents of the alkaloid fraction of Corydalis have anti - tumor activity, such as berberine, palmatine, glaucine, and boldine. The artical submitted the new progress of study in the chemical constituents and the anti - tumor activity of the alkaloid fraction of Corydalis yanhusuo.
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 exchange rate (p = 0.32). In summary, our study extends the conventional omega plot for quantitative analysis of DIACEST MRI.
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
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.
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K. Whitmore
2011-01-01
Full Text Available Secondary organic aerosol (SOA was produced from the aromatic precursors catechol and guaiacol by reaction with ozone in the presence and absence of simulated sunlight and humidity and investigated for its properties as a proxy for HUmic-LIke Substances (HULIS. Beside a small particle size, a relatively low molecular weight and typical optical features in the UV/VIS spectral range, HULIS contain a typical aromatic and/or olefinic chemical structure and highly oxidized functional groups within a high chemical diversity. Various methods were used to characterize the secondary organic aerosols obtained: Fourier transform infrared spectroscopy (FTIR demonstrated the formation of several carbonyl containing functional groups as well as structural and functional differences between aerosols formed at different environmental conditions. UV/VIS spectroscopy of filter samples showed that the particulate matter absorbs far into the visible range up to more than 500 nm. Ultrahigh resolved mass spectroscopy (ICR-FT/MS determined O/C-ratios between 0.3 and 1 and observed m/z ratios between 200 and 450 to be most abundant. Temperature-programmed-pyrolysis mass spectroscopy (TPP-MS identified carboxylic acids and lactones/esters as major functional groups. Particle sizing using a condensation-nucleus-counter and differential-mobility-particle-sizer (CNC/DMPS monitored the formation of small particles during the SOA formation process. Particle imaging, using field-emission-gun scanning electron microscopy (FEG-SEM, showed spherical particles, forming clusters and chains. We conclude that catechol and guaiacol are appropriate precursors for studies of the processing of aromatic SOA with atmospheric HULIS properties on the laboratory scale.
Chemical constituents in water fraction ofAbelmoschus esculentus%黄秋葵水溶性部位化学成分研究
Institute of Scientific and Technical Information of China (English)
贾陆; 钟丽君; 李焕芬; 敬林林
2011-01-01
目的 对黄秋葵Abelmoschus esculentu水溶性部位的化学成分进行研究.方法 利用MCI、ODS和硅胶等柱色谱分离纯化,根据波谱数据和理化性质鉴定结构.结果 分离得到12个化合物,分别鉴定为色氨酸(1)、鸟嘌呤脱氧核苷(2)、次黄嘌呤(3)、3,4-二羟基苯甲酸甲酯(4)、3'-脱氧次黄嘌呤核苷(5)、胸腺嘧啶脱氧核苷(6)、次黄苷(7)、胡萝卜苷(8)、金色酰胺醇酯(9)、黄嘌呤(10)、ethyl-β-D-xyloside(11)、ethyl-α-D-arabinofuranoside(12).结论 化合物2～12均为首次从黄秋葵中分离得到.%Objective To investigate the chemical constituents of Abelmoschus esculentus. Methods Compounds were isolated and purified by MCI, ODS, and silica gel column chromatography. Their chemical structures were elucidated on the basis of spectral data and physicochemical properties. Results Twelve compounds were isolated and identified as tryptophan (1), deoxyguanosine (2), hypoxanthine (3), 3, 4-dihydroxy benzoate (4), 3'-deoxyinosine (5), thymidine (6), inosine (7), β-daucosterol (8), aurantiamide acetate (9), xanthine (10), ethyl-β-D-xyloside (11), and ethyl-a-D-arabinofuranoside (12). Conclusion Except compound 1, other compounds are separated from A. Esculentus for the first time.
Institute of Scientific and Technical Information of China (English)
潘乔丹; 唐海燕; 黄元河; 韦贤; 李巨宝; 李雄富
2015-01-01
研究全缘栝楼多糖和提取物不同极性部位体外抗氧化活性。采用清除羟自由基（OH·）、[2，2＇-连氨-（3-乙基苯并噻唑林-6-磺酸）二氨盐]自由基（ABTS+·）、DPPH测定法以及Fe3+还原/抗氧化能力（FRAP）法，评价全缘栝楼多糖和提取物不同极性部位的抗氧化能力。全缘栝楼多糖和提取物不同极性部位清除DPPH·能力均强于抗坏血酸（IC50=1.22 mg/mL），且多糖（IC50=0.030 mg/mL）和乙酸乙酯层（IC50=0.082 mg/mL）比茶多酚强（IC50=0.118 mg/mL）；多糖（IC50=0.031 mg/mL）清除OH·能力比茶多酚（IC50=0.032 mg/mL）和抗坏血酸（IC50=0.044 mg/mL）强，而石油醚层（IC50=0.033 mg/mL）和乙酸乙酯层（IC50=0.038 mg/mL）强于抗坏血酸；清除ABTS+·能力均强于茶多酚（IC50=0.416 mg/mL），且多糖（IC50=0.008 mg/mL）强于抗坏血酸（IC50=0.011 mg/mL）；Fe3+还原/抗氧化能力均强于茶多酚（FRAP =1310.8μmol/g），但比抗坏血酸弱（FRAP=31469μmol/g）。全缘栝楼多糖和提取物不同极性部位有较强的抗氧化能力，为其生物活性的深入研究提供了参考依据。%To study the antioxidant activity of polysaccharides and different polarity chemical fractions of extract from Trichosanthes ovigera. The antioxidant activities of polysaccharides and different polarity chemical fractions of extract from Trichosanthes ovigera were evaluated by DPPH free radical scavening assay , and hydroxyl free radical (OH·) scavenging assay, and [2, 2'-Azino-bis (3-ethylbenzo thia zoline-6-sulfonic acid)]diammonium salt radical (ABTS+·)and ferric reducing antioxidant power (FRAP)assay. DPPH free radical scavening activity of polysaccharides and different polarity chemical fractions of extract from Trichosanthes ovigera were higher than VC (IC50 1.22 mg/mL) , and polysaccharides (IC50 0.030 mg/mL) and ethylacetate fraction(IC50 0.082 mg/mL) were higher than tea polyphenol(IC50 0.118 mg/mL). OH
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.
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.
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Anton Rahmadi
2015-12-01
Full Text Available This study aimed to produce functional food products with the main ingredient of pumpkin and olein fraction of red palm oil (OF-RPO. This research was conducted in two stages. The first was to analyze consumer acceptance where a Completely Randomized Design was used with one factor. The factor was the composition of pumpkin and OF-RPO levelled as follow: 100:0, 95:5, 90:10, 85:15, 80:20, and 0:100 (v/v. In the second stage, analyses of carotenoids using HPLC, FFA, pH, vitamin C, and peroxide values were carried out on selected formula (mixture of pumpkin and OF-RPO, formula with 100 mL of pumpkin, formula with 100 mL of OF-RPO, and negative control (without pumpkin and OF-RPO, before and after the storage period of two months, except for HPLC analysis. The best formula based on acceptance test was a composition of 90 mL pumpkin and 10 mL OF-RPO was further diluted 1:4 (v/v. Characteristics of the product were sweet, sour, not bitter, not grassy, and not rancid. The emulsion product contains trans-β-carotene at 141.65±0.47 mg/L, equivalent to 237 UI activity of vitamin A/mL. The content of trans-β-carotene was found at the highest (341.83 mg/L from the pumpkin juice, while the OF-RPO had the lowest trans-β-carotene content (41.2 mg/L. Product was acidic with a pH of 3.6±0.1 and with vitamin C content of 13.2±1.2 mg/100 g of product. Acidity and vitamin C levels tended to remain stable during the storage period for two months. Peroxide value of the emulsion product was at 0.8 mEq oxygen/kg. The FFAs were in the range of 1.59 to 1.73% and they also did not change significantly after storage for two months.
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.
Bressi, Michael; Cavalli, Fabrizia; Belis, Claudio A.; Putaud, Jean-Philippe; Fröhlich, Roman; Martins dos Santos, Sebastiao; Petralia, Ettore; Prévôt, André S. H.; Berico, Massimo; Malaguti, Antonella; Canonaco, Francesco
2016-10-01
Fine particulate matter (PM) levels and resulting impacts on human health are in the Po Valley (Italy) among the highest in Europe. To build effective PM abatement strategies, it is necessary to characterize fine PM chemical composition, sources and atmospheric processes on long timescales (> months), with short time resolution (fossil fuel combustion (11 %). Significant contributions of aged secondary organic aerosol (OOA) are observed throughout the year. The unexpectedly high degree of oxygenation estimated during wintertime is probably due to the contribution of secondary BBOA and the enhancement of aqueous-phase production of OOA during cold months. BBOA and nitrate are the only components of which contributions increase with the NR-PM1 levels. Therefore, biomass burning and NOx emission reductions would be particularly efficient in limiting submicron aerosol pollution events. Abatement strategies conducted during cold seasons appear to be more efficient than annual-based policies. In a broader context, further studies using high-time-resolution analytical techniques on a long-term basis for the characterization of fine aerosol should help better shape our future air quality policies, which constantly need refinement.
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%).
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
Fractional Chemotaxis Diffusion Equations
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.
Bergstra, Jan A.
2015-01-01
In the context of an involutive meadow a precise definition of fractions is formulated and on that basis formal definitions of various classes of fractions are given. The definitions follow the fractions as terms paradigm. That paradigm is compared with two competing paradigms for storytelling on fractions: fractions as values and fractions as pairs.
Institute of Scientific and Technical Information of China (English)
杨云; 匡海学; 冯卫生; 郑晓珂; 赫金丽; 孙亚萍; 张国顺; 张娜; 袁培培; 李玲玲; 杨梦; 王小兰
2015-01-01
目的:探讨葶苈子的化学拆分组分的止咳祛痰及平喘作用.方法:分别采用氨水引咳法、气管酚红排泌法、组胺与乙酰胆碱致喘法、离体气管法观察葶苈子各化学拆分组分的止咳、祛痰、平喘作用.结果:葶苈子水煎液低、中、高剂量均能显著减少小鼠咳嗽次数、增加小鼠呼吸道的酚红排泌量,同时能延长豚鼠哮喘潜伏期,并且提高解痉率,与空白对照组比较,中剂量效果最好.与空白组相比,葶苈子20%乙醇组分、脂肪油组分、水部位组分均能显著减少浓氨水引起小鼠咳嗽的次数,并延长咳嗽潜伏期、增加酚红排泌量、延长豚鼠发生哮喘的潜伏期(P<0.01,P<0.05),此外,20%乙醇组分、水部位组分能使气管收缩幅度明显降低(P<0.01, P<0.05),具有一定的解痉挛作用.结论:葶苈子水煎液具有较好的止咳、祛痰、平喘作用,其有效部位为20%乙醇组分、脂肪油及水部位组分,其止咳祛痰和平喘作用最为显著,与水煎液中剂量作用相当.%This study was aimed to investigate the antitussive, expectorant and antiasthmatic effects of chemical split fractions of Descurinia sophia (L.) Webb. ex Prantl. The ammonia water induced cough model, phenol red induced expectoration model, histamine and acetylcholine mixture induced antiasthmatic model were established, respectively. The isolated trachea method was used to observe the antitussive, expectorant and antiasthmatic effects of chemical split fractions of D. sophia (L.) Webb. ex Prantl. The results showed that the low, medium and high doses of aqueous extracts of D. sophia (L.) Webb. ex Prantl. can obviously decrease the frequency of cough, increase phenol red output of trachea in mice, prolong the latent period of asthma in guinea pigs, increase the antispasmodic rate. Compared with the control group, the medium dose group had the best effect. Compared to the control group, 20% ethanol fraction, fatty oil fraction
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.
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)
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.
Initialized Fractional Calculus
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.
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.
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.
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
Fraction Sense: Foundational Understandings.
Fennell, Francis Skip; Karp, Karen
2016-08-09
The intent of this commentary is to identify elements of fraction sense and note how the research studies provided in this special issue, in related but somewhat different ways, validate the importance of such understandings. Proficiency with fractions serves as a prerequisite for student success in higher level mathematics, as well as serving as a gateway to many occupations and varied contexts beyond the mathematics classroom. Fraction sense is developed through instructional opportunities involving fraction equivalence and magnitude, comparing and ordering fractions, using fraction benchmarks, and computational estimation. Such foundations are then extended to operations involving fractions and decimals and applications involving proportional reasoning. These components of fraction sense are all addressed in the studies provided in this issue, with particular consideration devoted to the significant importance of the use of the number line as a central representational tool for conceptually understanding fraction magnitude.
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...
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)
On continued fraction algorithms
Smeets, Ionica
2010-01-01
Is there a good continued fraction approximation between every two bad ones? What is the entropy of the natural extension for alpha-Rosen fractions? How do you find multi-dimensional continued fractions with a guaranteed quality in polynomial time? These, and many more, questions are answered in thi
Foam Fractionation of Lycopene: An Undergraduate Chemistry Experiment
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…
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.
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.
Fractional Dynamics and Control
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...
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...
Dividing Fractions: A Pedagogical Technique
Lewis, Robert
2016-01-01
When dividing one fraction by a second fraction, invert, that is, flip the second fraction, then multiply it by the first fraction. To multiply fractions, simply multiply across the denominators, and multiply across the numerators to get the resultant fraction. So by inverting the division of fractions it is turned into an easy multiplication of…
Fractional Pure Birth Processes
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}_\
Fractional Electromagnetic Waves
Gómez, J F; Bernal, J J; Tkach, V I; Guía, M
2011-01-01
In the present work we consider the electromagnetic wave equation in terms of the fractional derivative of the Caputo type. The order of the derivative being considered is 0 <\\gamma<1. A new parameter \\sigma, is introduced which characterizes the existence of the fractional components in the system. We analyze the fractional derivative with respect to time and space, for \\gamma = 1 and \\gamma = 1/2 cases.
Fractional vortex Hilbert's Hotel
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.
Fractional and noncommutative spacetimes
Arzano, M.; Calcagni, M.; Oriti, D.; Scalisi, M.
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 determi
Can Kindergartners Do Fractions?
Cwikla, Julie
2014-01-01
Mathematics professor Julie Cwikla decided that she needed to investigate young children's understandings and see what precurricular partitioning notions young minds bring to the fraction table. Cwikla realized that only a handful of studies have examined how preschool-age and early elementary school-age students solve fraction problems (Empson…
Wilkerson, Trena L.; Bryan, Tommy; Curry, Jane
2012-01-01
This article describes how using candy bars as models gives sixth-grade students a taste for learning to represent fractions whose denominators are factors of twelve. Using paper models of the candy bars, students explored and compared fractions. They noticed fewer different representations for one-third than for one-half. The authors conclude…
Categories of Fractions Revisited
Fritz, Tobias
2008-01-01
The theory of categories of fractions as originally developed by Gabriel and Zisman is reviewed in a pedagogical manner giving detailed proofs of all statements. A weakening of the category of fractions axioms used by Higson is discussed and shown to be equivalent to the original axioms.
Energy Technology Data Exchange (ETDEWEB)
Bajona-Xandri, C.; Martinez-Legaz, J.E.
1994-12-31
This paper studies the minimax fractional programming problem, assuming quasiconvexity of the objective function, under the lower subdifferentiability viewpoint. Necessary and sufficient optimality conditions and dual properties are found. We present applications of this theory to find the Pareto efficient solutions of a multiobjective fractional problem and to solve several economic models.
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.
Social Trust and Fractionalization:
DEFF Research Database (Denmark)
Bjørnskov, Christian
2008-01-01
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...... 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...... interpretations of the influence of fractionalization on trust....
Yang, Weitao; Mori-Sánchez, Paula; Cohen, Aron J
2013-09-14
The exact conditions for density functionals and density matrix functionals in terms of fractional charges and fractional spins are known, and their violation in commonly used functionals has been shown to be the root of many major failures in practical applications. However, approximate functionals are designed for physical systems with integer charges and spins, not in terms of the fractional variables. Here we develop a general framework for extending approximate density functionals and many-electron theory to fractional-charge and fractional-spin systems. Our development allows for the fractional extension of any approximate theory that is a functional of G(0), the one-electron Green's function of the non-interacting reference system. The extension to fractional charge and fractional spin systems is based on the ensemble average of the basic variable, G(0). We demonstrate the fractional extension for the following theories: (1) any explicit functional of the one-electron density, such as the local density approximation and generalized gradient approximations; (2) any explicit functional of the one-electron density matrix of the non-interacting reference system, such as the exact exchange functional (or Hartree-Fock theory) and hybrid functionals; (3) many-body perturbation theory; and (4) random-phase approximations. A general rule for such an extension has also been derived through scaling the orbitals and should be useful for functionals where the link to the Green's function is not obvious. The development thus enables the examination of approximate theories against known exact conditions on the fractional variables and the analysis of their failures in chemical and physical applications in terms of violations of exact conditions of the energy functionals. The present work should facilitate the calculation of chemical potentials and fundamental bandgaps with approximate functionals and many-electron theories through the energy derivatives with respect to the
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
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...
Fractional Derivative Cosmology
Roberts, Mark D
2009-01-01
The degree by which a function can be differentiated need not be restricted to integer values. Usually most of the field equations of physics are taken to be second order, curiosity asks what happens if this is only approximately the case and the field equations are nearly second order. For Robertson-Walker cosmology there is a simple fractional modification of the Friedman and conservation equations. In general fractional gravitational equations similar to Einstein's are hard to define as this requires fractional derivative geometry. What fractional derivative geometry might entail is briefly looked at and it turns out that even asking very simple questions in two dimensions leads to ambiguous or intractable results. A two dimensional line element which depends on the Gamma-function is looked at.
Intracellular Cadmium Isotope Fractionation
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.
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...
Institute of Scientific and Technical Information of China (English)
祝鹤鸣; 吴艳玲; 李雪; 姚大雷; 张昌浩; 崔炯谟; 李镐
2013-01-01
[Objective] To study the effects of chemical fractions from Chroogomphus rutilus fruiting body on the proliferation of human hepatic stellate cells LX-2 and human liver carcinoma Hep G2 cells,and to screen the active fractions with anti-hepatic fibrosis and anti-tumor activity from C.rutilus fruiting body.[Method] The polysaccharide,petroleum ether,dichloromethane,ethyl acetate,n-butanol and aqueous fractions from C.rutilus fruiting body were obtained by the methods of nature products chemistry.MTT assay was used to determine the effects of above fractions on the proliferation of human hepatic stellate cells LX-2 and human liver carcinoma Hep G2 cells.Morphological changes were observed through invert microscope.[Result] The petroleum ether fraction,dichloromethane fraction and ethyl acetate fraction showed inhibitory activities on human hepatic stellate cells LX-2 with IC50 values at 519.6,526,675.7 μg/ml,respectively,and human liver carcinoma Hep G2 cells with IC50 values at 727.6,610.1,618.1 μg/ml,respectively.Morphological change of apoptosis body formation was observed by invert microscope.[Conclusion] Among polysaccharide and solvent fractions from C.rutilus fruiting body,the petroleum ether fraction,dichloromethane fraction and ethyl acetate fraction have anti-hepatic fibrosis and anti-tumor activities as the main active parts.%[目的]探讨血红铆钉菇子实体对人肝癌细胞HepG2和人肝星状细胞LX-2增殖的影响,筛选出血红铆钉菇子实体抗肝纤维化和抗肿瘤作用的活性部位.[方法]利用天然药物化学方法提取得到血红铆钉菇子实体的石油醚、二氯甲烷、乙酸乙酯、正丁醇、水和粗多糖提取物,应用MTT法观察血红铆钉菇子实体不同溶剂提取物对体外培养的人肝星状细胞LX-2和人肝癌细胞Hep G2增殖的抑制作用,通过倒置显微镜观察细胞的形态学变化.[结果]血红铆钉菇子实体石油醚、二氯甲烷和乙酸乙酯提
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
Fractional and noncommutative spacetimes
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.
Fractional and noncommutative spacetimes
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.
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.
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
Energy Technology Data Exchange (ETDEWEB)
Edelman, Mark, E-mail: edelman@cims.nyu.ed [Courant Institute of Mathematical Sciences, New York University, 251 Mercer St., New York, NY 10012 (United States)] [Department of Physics, Stern College at Yeshiva University, 245 Lexington Avenue, New York, NY 10016 (United States); Tarasov, Vasily E. [Courant Institute of Mathematical Sciences, New York University, 251 Mercer St., New York, NY 10012 (United States)] [Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow 119991 (Russian Federation)
2009-12-28
Properties of the phase space of the standard map with memory are investigated. This map was obtained from a kicked fractional differential equation. Depending on the value of the map parameter and the fractional order of the derivative in the original differential equation, this nonlinear dynamical system demonstrates attractors (fixed points, stable periodic trajectories, slow converging and slow diverging trajectories, ballistic trajectories, and fractal-like structures) and/or chaotic trajectories. At least one type of fractal-like sticky attractors in the chaotic sea was observed.
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.
From Complex Fractional Fourier Transform to Complex Fractional Radon Transform
Institute of Scientific and Technical Information of China (English)
FAN Hong-Yi; JIANG Nian-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.
Fractional statistics and confinement
Gaete, P; Gaete, Patricio; Wotzasek, Clovis
2004-01-01
It is shown that a pointlike composite having charge and magnetic moment displays a confining potential for the static interaction while simultaneously obeying fractional statistics in a pure gauge theory in three dimensions, without a Chern-Simons term. This result is distinct from the Maxwell-Chern-Simons theory that shows a screening nature for the potential.
Momentum fractionation on superstrata
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.
Vinogradova, Natalya; Blaine, Larry
2013-01-01
Almost everyone loves chocolate. However, the same cannot be said about fractions, which are loved by markedly fewer. Middle school students tend to view them with wary respect, but little affection. The authors attempt to sweeten the subject by describing a type of game involving division of chocolate bars. The activity they describe provides a…
Stephens, Ana C.; Bottge, Brian A.; Rueda, Enrique
2009-01-01
This article describes a technology-based and hands-on instructional intervention designed to advance middle school students' understandings of fractions. This problem-solving experience is based on the principles of Enhanced Anchored Instruction (EAI) and proved instructionally worthwhile and motivating to teachers and students in both inclusive …
Brewing with fractionated barley
Donkelaar, van L.H.G.
2016-01-01
Brewing with fractionated barley Beer is a globally consumed beverage, which is produced from malted barley, water, hops and yeast. In recent years, the use of unmalted barley and exogenous enzymes have become more popular because they enable simpler processing and reduced environmental impact. Raw
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.…
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.
Clauer, N.; Lewan, M. D.; Dolan, M. P.; Chaudhuri, S.; Curtis, J. B.
2014-04-01
Progressive maturation of the Eocene Kreyenhagen Shale from the San Joaquin Basin of California was studied by combining mineralogical and chemical analyses with K-Ar dating of whole rocks and bearing minerals of the rocks. The Al/K ratio of the naturally matured rocks is essentially constant for the entire depth sequence, indicating that there is no detectable variation in the crystallo-chemical organization of the K-bearing alumino-silicates with depth. No supply of K from outside of the rock volumes occurred, which indicates a closed-system behavior for it. Conversely, the content of the total organic carbon (TOC) content decreases significantly with burial, based on the progressive increasing Al/TOC ratio of the whole rocks. The initial varied mineralogy and chemistry of the rocks and their sources and depositional settings give scattered results that homogenize progressively during burial due to increased authigenesis, and concomitant increased alteration of the detrital material. Hydrous pyrolysis was intended to alleviate the problem of mineral and chemical variations in initially deposited rocks of naturally matured sequences. However, experiments on aliquots from thermally immature Kreyenhagen Shale outcrop sample did not mimic the results from naturally buried samples. Experiments conducted for 72 h at temperatures from 270 to 365 °C did not induce significant changes at temperatures above 310 °C in the mineralogical composition and K-Ar ages of the rock and heated the most at 365 °C for 216 h. This slight decrease in age outlines some loss of radiogenic 40Ar, together with losses of organic matter as oil, gas, and aqueous organic species. Large amounts of smectite layers in the illite-smectite mixed layers of the pyrolyzed outcrop source rock, the pore system is no longer wetted by water and smectite to illite conversion ceases. Experimental attempts to evaluate the smectite conversion to illite should preferentially use low-TOC rocks to avoid
Institute of Scientific and Technical Information of China (English)
秦菲; 崔洪友; 王传波; 王丽红; 易维明
2014-01-01
Upgrading the oil-soluble fraction, which was obtained by water extraction of bio-oil from fast pyrolysis of rice husk, was investigated with simultaneous esterification and acetalation in butanol with online solvent extraction ( SEAWOSE) . The results show that almost all of the acids, aldehydes and ketones in the oil-soluble fraction can be converted to the corresponding esters, hemiacetals and acetals by SEAWOSE. In comparing with direct esterification and acetalation without extraction, the char formation is significantly suppressed. Meanwhile, the upgraded oil has very low acidity and moisture content, but high heating value andgood volatility. The effect of oxidation and reduction pretreatment of the oil-soluble fraction before SEAWOSE was also investigated. By hydrogen peroxide oxidation, the aldehydes are firstly converted into acids and subsequently esterified to esters, consequently without char formation. The upgraded oil is high quality, less than% in moisture higher than MJ/kg in heating value and less than KOH mg/g in acidity.%采用萃取耦合化学转化技术对生物油油溶相进行了提质研究。将稻壳快速裂解油加入适宜水使其自然分为水溶相和油溶相。以正丁醇为萃取剂和转化剂,通过在线萃取将油溶相中的酸、醛、酮等可萃物不断萃取出来,再经酯化、缩醛化反应,转化为相应正丁醇的酯、缩醛和半缩醛等。与生物油直接酯化提质相比,萃取耦合化学转化法可以显著抑制提质过程中的结焦问题,降低了提质油相的含水量和酸值,提高了其热值和可挥发性。此外,还考察了油溶相预氧化和预还原对萃取耦合化学转化提质的影响。结果表明,预氧化后可将油溶相中的醛类转化为酸,再经酯化转化为稳定性好的酯类,提质后的油品水含量低于4%,热值高于30 MJ/ kg,酸值低于2 KOH mg/ g,并且结焦率为零。
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 CO_{2}^{+} and the sum of C_{x}H_{y}O_{z}^{+} (short name CHO and C_{x}H_{y}^{+} (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 CO_{2}^{+} 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
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 CO_{2}^{+} and the sum of C_{x}H_{y}O_{z}^{+} (short name CHO and C_{x}H_{y}^{+} (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 CO_{2}^{+} 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
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
Creating, Naming, and Justifying Fractions
Siebert, Daniel; Gaskin, Nicole
2006-01-01
For students to develop meaningful conceptions of fractions and fraction operations, they need to think of fractions in terms other than as just whole-number combinations. In this article, we suggest two powerful images for thinking about fractions that move beyond whole-number reasoning. (Contains 5 figures.)
-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.
Testing Fractional Action Cosmology
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.
Testing fractional action cosmology
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.
Fractions in elementary education
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...
Fractional lattice charge transport
Flach, Sergej; Khomeriki, Ramaz
2017-01-01
We consider the dynamics of noninteracting quantum particles on a square lattice in the presence of a magnetic flux α and a dc electric field E oriented along the lattice diagonal. In general, the adiabatic dynamics will be characterized by Bloch oscillations in the electrical field direction and dispersive ballistic transport in the perpendicular direction. For rational values of α and a corresponding discrete set of values of E(α) vanishing gaps in the spectrum induce a fractionalization of the charge in the perpendicular direction - while left movers are still performing dispersive ballistic transport, the complementary fraction of right movers is propagating in a dispersionless relativistic manner in the opposite direction. Generalizations and the possible probing of the effect with atomic Bose-Einstein condensates and photonic networks are discussed. Zak phase of respective band associated with gap closing regime has been computed and it is found converging to π/2 value. PMID:28102302
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.
Brewing with fractionated barley
Donkelaar, van, CC René
2016-01-01
Brewing with fractionated barley Beer is a globally consumed beverage, which is produced from malted barley, water, hops and yeast. In recent years, the use of unmalted barley and exogenous enzymes have become more popular because they enable simpler processing and reduced environmental impact. Raw barley, however, contains less endogenous enzymes and more undesired components for the use of beer brewing, compared to malted barley. The overall aim of this thesis is to investigate how ba...
Momentum Fractionation on Superstrata
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...
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.
Fractional random walk lattice dynamics
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...
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.
Gauge Invariant Fractional Electromagnetic Fields
Lazo, Matheus Jatkoske
2011-01-01
Fractional derivatives and integrations of non-integers orders was introduced more than three centuries ago but only recently gained more attention due to its application on nonlocal phenomenas. In this context, several formulations of fractional electromagnetic fields was proposed, but all these theories suffer from the absence of an effective fractional vector calculus, and in general are non-causal or spatially asymmetric. In order to deal with these difficulties, we propose a spatially symmetric and causal gauge invariant fractional electromagnetic field from a Lagrangian formulation. From our fractional Maxwell's fields arose a definition for the fractional gradient, divergent and curl operators.
Fractional Langevin equation and Riemann-Liouville fractional derivative.
Sau Fa, Kwok
2007-10-01
In this present work we consider a fractional Langevin equation with Riemann-Liouville fractional time derivative which modifies the classical Newtonian force, nonlocal dissipative force, and long-time correlation. We investigate the first two moments, variances and position and velocity correlation functions of this system. We also compare them with the results obtained from the same fractional Langevin equation which uses the Caputo fractional derivative.
Andreasen, Niels; Bjerregaard, Mads; Lund, Jonas; Olsen, Ove Bitsch; Rasmussen, Andreas Dalgas
2012-01-01
Projektet er bygget op omkring kritisk realisme, som er det gennemgående videnskabelige fundament til undersøgelsen af hvilke strukturelle grunde der er til finansiel ustabilitet i Danmark. Projektet går i dybden med Fractional Reserve Banking og incitamentsstrukturen i banksystemet. Vi bevæger os både på det makro- og mikroøkonomiske niveau i analysen. På makro niveau bruger vi den østrigske skole om konjunktur teori (The Positive Theory of the Cycle). På mikro niveau arbejder vi med princip...
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......-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...
Preheating with fractional powers
Moghaddam, Hossein Bazrafshan; Brandenberger, Robert
2016-11-01
We consider preheating in models in which the potential for the inflaton is given by a fractional power, as is the case in axion monodromy inflation. We assume a standard coupling between the inflaton field and a scalar matter field. We find that in spite of the fact that the oscillation of the inflaton about the field value which minimizes the potential is anharmonic, there is nevertheless a parametric resonance instability, and we determine the Floquet exponent which describes this instability as a function of the parameters of the inflaton potential.
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.
Fractional Integral Inequalities via Hadamard’s Fractional Integral
2014-01-01
We establish new fractional integral inequalities, via Hadamard’s fractional integral. Several new integral inequalities are obtained, including a Grüss type Hadamard fractional integral inequality, by using Young and weighted AM-GM inequalities. Many special cases are also discussed.
Body Fractions: A Physical Approach to Fraction Learning
Mills, Judith
2011-01-01
Many students experience great difficulty understanding the meaning of fractions. For many students who have spent their early mathematics lessons focusing on counting (whole) numbers, recognising that there are many numbers between those whole numbers called fractional numbers, is quite revolutionary. The foundation of understanding fractions is…
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.
Advances in robust fractional control
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...
NESDIS VIIRS Green Vegetation Fraction
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...
Fractional Reserve in Banking System
Valkonen, Maria
2016-01-01
This thesis is aimed to provide understanding of the role of the fractional reserve in the mod-ern banking system worldwide and particularly in Finland. The fractional reserve banking is used worldwide, but the benefits of this system are very disputable. On the one hand, experts say that the fractional reserve is a necessary instrument for the normal business and profit making. On the other hand, sceptics openly criticize the fractional reserve system and blame it for fiat money (money n...
Experimental observation of fractional echoes
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.
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).
Fractional Hopfield Neural Networks: Fractional Dynamic Associative Recurrent Neural Networks.
Pu, Yi-Fei; Yi, Zhang; Zhou, Ji-Liu
2016-07-14
This paper mainly discusses a novel conceptual framework: fractional Hopfield neural networks (FHNN). As is commonly known, fractional calculus has been incorporated into artificial neural networks, mainly because of its long-term memory and nonlocality. Some researchers have made interesting attempts at fractional neural networks and gained competitive advantages over integer-order neural networks. Therefore, it is naturally makes one ponder how to generalize the first-order Hopfield neural networks to the fractional-order ones, and how to implement FHNN by means of fractional calculus. We propose to introduce a novel mathematical method: fractional calculus to implement FHNN. First, we implement fractor in the form of an analog circuit. Second, we implement FHNN by utilizing fractor and the fractional steepest descent approach, construct its Lyapunov function, and further analyze its attractors. Third, we perform experiments to analyze the stability and convergence of FHNN, and further discuss its applications to the defense against chip cloning attacks for anticounterfeiting. The main contribution of our work is to propose FHNN in the form of an analog circuit by utilizing a fractor and the fractional steepest descent approach, construct its Lyapunov function, prove its Lyapunov stability, analyze its attractors, and apply FHNN to the defense against chip cloning attacks for anticounterfeiting. A significant advantage of FHNN is that its attractors essentially relate to the neuron's fractional order. FHNN possesses the fractional-order-stability and fractional-order-sensitivity characteristics.
Institute of Scientific and Technical Information of China (English)
李振宇; 杨炳友; 舒尊鹏; 王秋红; 肖洪彬; 匡海学
2011-01-01
目的:建立洋金花性味物质基础的拆分方法,阐明洋金花性味辛温的物质基础,进而为“中药一味一性,一药X味Y性(Y≤X)”的中药性味理论新假说的客观性和中药性味的可拆分、可组合性研究方法提供科学依据.方法:根据洋金花的化学成分,组合应用多种色谱法及溶剂法等,建立洋金花性味物质基础的拆分方法；采用与洋金花性味功效相关的止咳、平喘、镇痛、解痉复合药理学指标作为洋金花性味辛温评价系统,对洋金花及其不同化学拆分组分的性味归属进行研究.结果:将洋金花中的化学成分拆分为生物碱组分和非生物碱组分；各给药组同空白对照组比较证明,洋金花水煎液和生物碱组分具有止咳、平喘、镇痛、解痉的作用,非生物碱组分不具有此类作用.结论:本文建立的洋金花性味物质基础拆分方法可行,工艺稳定、重现性好；洋金花性味辛温的物质基础为生物碱组分,即生物碱组分具有辛温的药性；非生物碱组分的性味与洋金花的传统药性不同,其性味的确定有待于进一步研究.%Objective: This paper establishes the exact splitting method of the Flos Datura chemical composition and clarify on chemical composition of acrid - group and warm - group of the Flos Datura property and flavor, then provides scientific basis for the the hypothesis of" one medicine has one property and flavor & X properties and Y flavors (Y ≤ X) " and the idea of resolvability and combinability for property and flavor of traditional Chinese medicine. Methods; According to the chemistry composition of the Flos Daturae and connecting the modern chromatography and extraction methods, we established the splitting method of property and flavor material basis of the Flos Datura and select the pharmaceutical efficacy index includeding relieving a cough, relieving asthma, analgesia and spasmolysis. Finally we determined the evaluation
Nonholonomic constraints with fractional derivatives
Energy Technology Data Exchange (ETDEWEB)
Tarasov, Vasily E [Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow 119992 (Russian Federation); Zaslavsky, George M [Courant Institute of Mathematical Sciences, New York University, 251 Mercer St, New York, NY 10012 (United States)
2006-08-04
We consider the fractional generalization of nonholonomic constraints defined by equations with fractional derivatives and provide some examples. The corresponding equations of motion are derived using variational principle. We prove that fractional constraints can be used to describe the evolution of dynamical systems in which some coordinates and velocities are related to velocities through a power-law memory function.
How Weird Are Weird Fractions?
Stuffelbeam, Ryan
2013-01-01
A positive rational is a weird fraction if its value is unchanged by an illegitimate, digit-based reduction. In this article, we prove that each weird fraction is uniquely weird and initiate a discussion of the prevalence of weird fractions.
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.
Elemental composition and functional groups in soil labile organic matter fractions
Labile organic matter fractions are major components involved in nutrient cycle in soil. In this chapter, we examine three labile organic matter fraction: light fraction (LF), humic acid (HA) and fulvic acid (HA) in Alabama cotton soils (ultisol) amended with chemical fertilizer (NH4NO3) and poult...
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.
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)
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...
Fractional condensation of pyrolysis vapors produced from Nordic feedstocks in cyclone pyrolysis
Energy Technology Data Exchange (ETDEWEB)
Johansson, Ann-Christine; Iisa, Kristiina; Sandström, Linda; Ben, Haoxi; Pilath, Heidi; Deutch, Steve; Wiinikka, Henrik; Öhrman, Olov G. W.
2017-01-01
Pyrolysis oil is a complex mixture of different chemical compounds with a wide range of molecular weights and boiling points. Due to its complexity, an efficient fractionation of the oil may be a more promising approach of producing liquid fuels and chemicals than treating the whole oil. In this work a sampling system based on fractional condensation was attached to a cyclone pyrolysis pilot plant to enable separation of the produced pyrolysis vapors into five oil fractions. The sampling system was composed of cyclonic condensers and coalescing filters arranged in series. The objective was to characterize the oil fractions produced from three different Nordic feedstocks and suggest possible applications. The oil fractions were thoroughly characterized using several analytical techniques including water content; elemental composition; heating value, and chemical compound group analysis using solvent fractionation, quantitative 13C NMR and 1H NMR and GC x GC - TOFMS. The results show that the oil fractions significantly differ from each other both in chemical and physical properties. The first fractions and the fraction composed of aerosols were highly viscous and contained larger energy-rich compounds of mainly lignin-derived material. The middle fraction contained medium-size compounds with relatively high concentration of water, sugars, alcohols, hydrocarbonyls and acids and finally the last fraction contained smaller molecules such as water, aldehydes, ketones and acids. However, the properties of the respective fractions seem independent on the studied feedstock types, i.e. the respective fractions produced from different feedstock are rather similar. This promotes the possibility to vary the feedstock depending on availability while retaining the oil properties. Possible applications of the five fractions vary from oil for combustion and extraction of the pyrolytic lignin in the early fractions to extraction of sugars from the early and middle fractions, and
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.
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 ...
Fractional Calculus: Integral and Differential Equations of Fractional Order
Gorenflo, Rudolf
2008-01-01
We introduce the linear operators of fractional integration and fractional differentiation in the framework of the Riemann-Liouville fractional calculus. Particular attention is devoted to the technique of Laplace transforms for treating these operators in a way accessible to applied scientists, avoiding unproductive generalities and excessive mathematical rigor. By applying this technique we shall derive the analytical solutions of the most simple linear integral and differential equations of fractional order. We show the fundamental role of the Mittag-Leffler function, whose properties are reported in an ad hoc Appendix. The topics discussed here will be: (a) essentials of Riemann-Liouville fractional calculus with basic formulas of Laplace transforms, (b) Abel type integral equations of first and second kind, (c) relaxation and oscillation type differential equations of fractional order.
Directory of Open Access Journals (Sweden)
Cristiane Vieira Helm
2004-12-01
Full Text Available Even though hulless barley is widely known due to its nutritional potential, in Brazil it is only grown at a few agricultural experimental stations. There is no published data about the chemical composition of Brazilian hulless barley varieties; however, research laboratories have studied their agronomical characteristics. The objectives of this study were to present the chemical characterization and effect of flour fractionation on protein concentration of six Brazilian hulless barley varieties, namely IAC IBON 214/82, IAC 8612/421, IAC 8501/31, IAC 8501/12, IAPAR 39-Acumaí, and IAC 8501/22. The analyses included: ash, ether extract, total protein, starch, total insoluble and soluble dietary fiber, and beta-glucans. Flour fractionation was carried out by sieving. The flour fractions were evaluated for crude protein, protein, and protein and non-protein nitrogen. Chemical composition varied (P Apesar de a cevada nua ser amplamente conhecida por seu potencial nutricional, no Brasil é apenas cultivada em poucas estações experimentais agronômicas. Em relação as variedades brasileiras de cevada nua, não se têm dados sobre a composição química, entretanto instituições de pesquisa têm estudado suas características agronômicas. Os objetivos deste estudo foram apresentar a caracterização química e o efeito no fracionamento da farinha obtida visando à concentração de proteína de seis variedades brasileiras de cevada nua: IAC IBON 214/82, IAC 8612/421, IAC 8501/31, IAC 8501/12, IAPAR 39-Acumaí, e IAC 8501/22. Foram realizadas análises de: cinzas, extrato etéreo, proteína total, amido, fibra alimentar total, solúvel e insolúvel e beta-glucanas. As frações das farinhas foram obtidas por peneiramento e avaliadas quanto aos teores de proteína bruta, proteína, nitrogênio protéico e não protéico. Houve variação entre as variedades testadas (P < 0,05. As variedades IAC 8501/22, IAC 8501/31 e IAC 8501/12 apresentaram o
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
Institute of Scientific and Technical Information of China (English)
王小兰; 匡海学; 郑晓珂; 赫金丽; 张国顺; 孙亚萍; 曹彦刚; 张娜; 李玲玲; 袁培培; 王绅
2014-01-01
This study was aimed to investigate the antitussive, expectorant and antiasthmatic effects of aqueous extracts and the chemical split fractions ofMori Cortex. Cough mice models induced by ammonia water were used to observe the effect on arresting cough. The phenol red expectoration method in mice was used to observe the effect on expelling phlegm. Histamine and acetylcholine mixture induced asthma model was used to observe the effect on relieving asthma. Isolated trachea model was used to observe the effect on relieving spasm. Compared with the control group, the low, medium and high doses of aqueous extracts ofM. Cortex can obviously decrease the frequency of cough, increase phenol red output of trachea in mice, prolong the latent period of asthma in guinea pigs, and increase the antispasmodic rate. The medium dose had the best effect. The comparison between different chemical split fractions ofM. Cortex and the control group showed that the 30% and 50% ethanol fraction ofM. Cortex can obviously decrease the frequency of cough and prolong the latent period of cough induced by ammonia water in mice, increase phenol red output of trachea in mice (P<0.05 orP<0.01); and 30% ethanol fraction and fatty oil fraction can prolong the latent period of asthma in guinea pigs (P< 0.05 orP<0.01). In addition, 30% ethanol fraction can obviously reduce the degree of tracheal contraction. It had certain effect of relieving spasm. It was concluded that aqueous extracts ofM. Cortex had better effects on relieving cough, expectorant and antiasthma. The effective part was the 30% ethanol fraction, which was the dose equivalent of 1/3 of the medium dose. It had significant effect on relieving cough, expectorant and antiasthma. The effect was equivalent to the medium dose of aqueous extracts of M. Cortex.%目的：研究桑白皮水煎液及化学拆分组分的止咳祛痰平喘作用。方法：采用氨水诱咳法观察止咳作用；小鼠酚红排泌法观察祛痰作用；组胺
Accessible solitons of fractional dimension
Energy Technology Data Exchange (ETDEWEB)
Zhong, Wei-Ping, E-mail: zhongwp6@126.com [Department of Electronic and Information Engineering, Shunde Polytechnic, Guangdong Province, Shunde 528300 (China); Texas A& M University at Qatar, P.O. Box 23874, Doha (Qatar); Belić, Milivoj [Texas A& M University at Qatar, P.O. Box 23874, Doha (Qatar); Zhang, Yiqi [Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, Xi’an Jiaotong University, Xi’an 710049 (China)
2016-05-15
We demonstrate that accessible solitons described by an extended Schrödinger equation with the Laplacian of fractional dimension can exist in strongly nonlocal nonlinear media. The soliton solutions of the model are constructed by two special functions, the associated Legendre polynomials and the Laguerre polynomials in the fraction-dimensional space. Our results show that these fractional accessible solitons form a soliton family which includes crescent solitons, and asymmetric single-layer and multi-layer necklace solitons. -- Highlights: •Analytic solutions of a fractional Schrödinger equation are obtained. •The solutions are produced by means of self-similar method applied to the fractional Schrödinger equation with parabolic potential. •The fractional accessible solitons form crescent, asymmetric single-layer and multilayer necklace profiles. •The model applies to the propagation of optical pulses in strongly nonlocal nonlinear media.
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.
Incompressible Stars and Fractional Derivatives
Bayin, S S
2014-01-01
Fractional calculus is an effective tool in incorporating the effects of non-locality and memory into physical models. In this regard, successful applications exist rang- ing from signal processing to anomalous diffusion and quantum mechanics. In this paper we investigate the fractional versions of the stellar structure equations for non radiating spherical objects. Using incompressible fluids as a comparison, we develop models for constant density Newtonian objects with fractional mass distributions or stress conditions. To better understand the fractional effects, we discuss effective values for the density, gravitational field and equation of state. The fractional ob- jects are smaller and less massive than integer models. The fractional parameters are related to a polytropic index for the models considered.
Number line representations of fractions
Behr, Merlyn J.; Bright, George W.; Wachsmuth, Ipke; Wagner, Sigrid
1982-01-01
The study explored students' interpretations of representations of fractions on number lines and the effect of instruction on those interpretations. Subjects were five fourth-graders, and instruction was a four-day unit on the use of number lines. A 16-item, multiple-choice pre- and posttest was used along with videotaped interviews. Performance improved except when students had to associate a reduced fraction symbol with an equivalent, unreduced fraction representation on a number line. The ...
Characterization of Particulate Emissions: Size Fractionation and Chemical Speciation
2003-10-01
J. Schauer, G.R. Cass, Application of a Combustion Source Study to Ambient Freeway Data Using Aerosol Time-of-Flight Mass Spectrometry...Combustion Source Study to Ambient Freeway Data Using Aerosol Time-of-Flight Mass Spectrometry. Department of Chemistry Seminar, University of
Comment on "Fractional quantum mechanics" and "Fractional Schroedinger equation"
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.
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
Particle related fractionation and characterisation of municipal wastewater.
van Nieuwenhuijzen, A F; van der Graaf, J H J M; Kampschreur, M J; Mels, A R
2004-01-01
Several studies show that a more detailed characterisation of the particulate matter in municipal wastewater gives a better understanding and prediction of removal efficiencies of physical-chemical treatment techniques and the application of optimal chemical dosages. Such a characterisation should include the distribution of contaminants over various particle sizes. This article describes a method and results of experimental and full-scale investigations, conducted to determine how contaminants in wastewater are distributed over different particle sizes. For this purpose, particle size fractionations of wastewater influents originating from more than thirteen WWTP were carried out. One of these fractionations (WWTP Venray) is shown and interpreted in this article. First, the wastewaters were fractionated into 5 to 6 particle fractions (45, 5.0, 1.0/1.2, 0.45 and 0.1 microm) after which the fractions were analyzed for various water quality parameters like organic components, nutrients, salts, solids and turbidity. Based on the results the effects of removal of the different size fractions on design of the biological treatment and energy balance of a wastewater treatment plant can be assessed. The method also indicates whether a certain wastewater is efficiently treatable with physical-chemical pre-treatment methods. It is concluded wastewater fractionation on particle size is very useful, but that wastewater characteristics and particle size distributions should not be generalised, but have to be interpreted as indications for a certain average wastewater composition. To give more insight into the distribution of contaminants over particle size and the particle removal potential, a specific wastewater fractionation has to be carried out per WWTP.
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)
Understanding Magnitudes to Understand Fractions
Gabriel, Florence
2016-01-01
Fractions are known to be difficult to learn and difficult to teach, yet they are vital for students to have access to further mathematical concepts. This article uses evidence to support teachers employing teaching methods that focus on the conceptual understanding of the magnitude of fractions.
Investigations on Multiplication of Fractions.
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)
Ejection Fraction Heart Failure Measurement
... Disease Venous Thromboembolism Aortic Aneurysm More Ejection Fraction Heart Failure Measurement Updated:Feb 15,2017 The ejection fraction ( ... failure This content was last reviewed April 2015. Heart Failure • Home • About Heart Failure • Causes and Risks for ...
Financial Planning with Fractional Goals
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
Financial Planning with Fractional Goals
Goedhart, M.H.; 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 multiple goal variables. The approach is illustrated by means of an example in financial planning.
Fractional Trajectories: Decorrelation Versus Friction
2013-07-27
E. Scalas, Fractional calculus and continuous-time finance II: the waiting-time distribution, Physica A 287 (2000) 468–481. [3] R.V. Mendes, A...Physics of Fractal Operators, Springer, New York, 2003. [20] R. Metzler, E. Barkai, J. Klafter, Deriving fractional Fokker–Planck equations from a
Deterministic ratchets for suspension fractionation
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
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.
Unwrapping Students' Ideas about Fractions
Lewis, Rebecca M.; Gibbons, Lynsey K.; Kazemi, Elham; Lind, Teresa
2015-01-01
Supporting students to develop an understanding of the meaning of fractions is an important goal of elementary school mathematics. This involves developing partitioning strategies, creating representations, naming fractional quantities, and using symbolic notation. This article describes how teachers can use a formative assessment problem to…
Rational Exponentials and Continued Fractions
Denny, J. K.
2012-01-01
Using continued fraction expansions, we can approximate constants, such as pi and e, using an appropriate integer n raised to the power x[superscript 1/x], x a suitable rational. We review continued fractions and give an algorithm for producing these approximations.
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.
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.
Fractional active disturbance rejection control.
Li, Dazi; Ding, Pan; Gao, Zhiqiang
2016-05-01
A fractional active disturbance rejection control (FADRC) scheme is proposed to improve the performance of commensurate linear fractional order systems (FOS) and the robust analysis shows that the controller is also applicable to incommensurate linear FOS control. In FADRC, the traditional extended states observer (ESO) is generalized to a fractional order extended states observer (FESO) by using the fractional calculus, and the tracking differentiator plus nonlinear state error feedback are replaced by a fractional proportional-derivative controller. To simplify controller tuning, the linear bandwidth-parameterization method has been adopted. The impacts of the observer bandwidth ωo and controller bandwidth ωc on system performance are then analyzed. Finally, the FADRC stability and frequency-domain characteristics for linear single-input single-output FOS are analyzed. Simulation results by FADRC and ADRC on typical FOS are compared to demonstrate the superiority and effectiveness of the proposed scheme.
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.
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.)
The ionization fraction in dense clouds
De Boisanger, C B; Van Dishoeck, E F
1995-01-01
We present submillimeter observations of various molecular ions toward two dense clouds, NGC 2264 IRS1 and W 3 IRS5, in order to investigate their ionization fraction. Analysis of the line intensity ratios by the way of statistical equilibrium calculations allows determination of the physical parameters: n(H2)~(1-2)e6 cm-3 and T(kin)~50-100 K. Column densities and abundances are also derived. Together, the abundances of the observed ions provide a lower limit to the ionization fraction, which is (2-3)e-9 in both clouds. In order to better constrain the electron abundance, a simple chemical model is built which calculates the steady state abundances of the major positive ions, using the observed abundances wherever available. With reasonable assumptions, good agreement within a factor of two with the observations can be achieved. The calculated electron fraction is x(e)= (1.0-3.3)e-8 in the case of NGC 2264 and x(e)=(0.5-1.1)e-8 for W 3 IRS5. In the first case, the high abundance of N2H+ requires a rather high...
Dobson, Christopher M
2004-12-16
Chemical space--which encompasses all possible small organic molecules, including those present in biological systems--is vast. So vast, in fact, that so far only a tiny fraction of it has been explored. Nevertheless, these explorations have greatly enhanced our understanding of biology, and have led to the development of many of today's drugs. The discovery of new bioactive molecules, facilitated by a deeper understanding of the nature of the regions of chemical space that are relevant to biology, will advance our knowledge of biological processes and lead to new strategies to treat disease.
Permutation entropy of fractional Brownian motion and fractional Gaussian noise
Energy Technology Data Exchange (ETDEWEB)
Zunino, L. [Centro de Investigaciones Opticas, C.C. 124 Correo Central, 1900 La Plata (Argentina); Departamento de Ciencias Basicas, Facultad de Ingenieria, Universidad Nacional de La Plata (UNLP), 1900 La Plata (Argentina); Departamento de Fisica, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, 1900 La Plata (Argentina)], E-mail: lucianoz@ciop.unlp.edu.ar; Perez, D.G. [Instituto de Fisica, Pontificia Universidad Catolica de Valparaiso (PUCV), 23-40025 Valparaiso (Chile)], E-mail: dario.perez@ucv.cl; Martin, M.T. [Instituto de Fisica (IFLP), Facultad de Ciencias Exactas, Universidad Nacional de La Plata and Argentina' s National Council (CCT-CONICET), C.C. 727, 1900 La Plata (Argentina)], E-mail: mtmartin@fisica.unlp.edu.ar; Garavaglia, M. [Centro de Investigaciones Opticas, C.C. 124 Correo Central, 1900 La Plata (Argentina); Departamento de Fisica, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, 1900 La Plata (Argentina)], E-mail: garavagliam@ciop.unlp.edu.ar; Plastino, A. [Instituto de Fisica (IFLP), Facultad de Ciencias Exactas, Universidad Nacional de La Plata and Argentina' s National Council (CCT-CONICET), C.C. 727, 1900 La Plata (Argentina)], E-mail: plastino@fisica.unlp.edu.ar; Rosso, O.A. [Centre for Bioinformatics, Biomarker Discovery and Information-Based Medicine, School of Electrical Engineering and Computer Science, The University of Newcastle, University Drive, Callaghan NSW 2308 (Australia); Chaos and Biology Group, Instituto de Calculo, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellon II, Ciudad Universitaria, 1428 Ciudad de Buenos Aires (Argentina)], E-mail: oarosso@fibertel.com.ar
2008-06-30
We have worked out theoretical curves for the permutation entropy of the fractional Brownian motion and fractional Gaussian noise by using the Bandt and Shiha [C. Bandt, F. Shiha, J. Time Ser. Anal. 28 (2007) 646] theoretical predictions for their corresponding relative frequencies. Comparisons with numerical simulations show an excellent agreement. Furthermore, the entropy-gap in the transition between these processes, observed previously via numerical results, has been here theoretically validated. Also, we have analyzed the behaviour of the permutation entropy of the fractional Gaussian noise for different time delays.
2010-07-01
... Emitted (Fe) For HAP Compounds in Wastewater Streams 34 Table 34 to Subpart G of Part 63 Protection of... Vessels, Transfer Operations, and Wastewater Pt. 63, Subpt. G, Table 34 Table 34 to Subpart G of Part 63—Fraction Measured (Fm) and Fraction Emitted (Fe) For HAP Compounds in Wastewater Streams Chemical name...
Bioenergy II : Biomass Valorisation by a Hybrid Thermochemical Fractionation Approach
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
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.
Fractional trajectories: Decorrelation versus friction
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.
Penger, Jörn; Conrad, Ralf; Blaser, Martin
2014-09-01
Temperature is the major driving force for many biological as well as chemical reactions and may impact the fractionation of stable carbon isotopes. Thus, a good correlation between temperature and fractionation is observed in many chemical systems that are controlled by an equilibrium isotope effect. In contrast, biological systems that are usually controlled by a kinetic isotope effect are less well studied with respect to temperature effects and have shown contrasting results. We studied three different biological pathways (methylotrophic methanogenesis, hydrogenotrophic methanogenesis, acetogenesis by the acetyl-CoA pathway) which are characterized by very strong carbon isotope enrichment factors (-50‰ to -83‰). The microorganisms (Methanosarcina barkeri, Methanosarcina acetivorans, Methanolobus zinderi, Methanothermobacter marburgensis, Methanothermobacter thermoautotrophicus, Thermoanaerobacter kivui) exhibiting these pathways were grown at different temperatures ranging between 25 and 68 °C, and the fractionation factors were determined from 13C/12C isotope discrimination during substrate depletion and product formation. Our experiments showed that the fractionation factors were different for the different metabolic pathways but were not much affected by the different growth temperatures. Slight variations were well within the standard errors of replication and regression analysis. Our results showed that temperature had no significant effect on the fractionation of stable carbon isotopes during anaerobic microbial metabolism with relatively strong isotope fractionation.
Physcicists rewarded for 'fractional electrons'
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).
Solutions of fractional diffusion problems
Directory of Open Access Journals (Sweden)
Rabha W. Ibrahim
2010-10-01
Full Text Available Using the concept of majorant functions, we prove the existence and uniqueness of holomorphic solutions to nonlinear fractional diffusion problems. The analytic continuation of these solutions is studied and the singularity for two cases are posed.
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
The Periodogram of fractional processes
Velasco, Carlos
2007-01-01
We analyse asymptotic properties of the discrete Fourier transform and the periodogram of time series obtained through (truncated) linear filtering of stationary processes. The class of filters contains the fractional differencing operator and its coefficients decay at an algebraic rate, implying long-range-dependent properties for the filtered processes when the degree of integration α is positive. These include fractional time series which are nonstationary for any value of the memory param...
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.
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.
Xin, Donglin; Yang, Zhong; Liu, Feng; Xu, Xueru; Zhang, Junhua
2015-01-01
The effect of two pretreatments methods, aqueous ammonia (SAA) and dilute acid (DA), on the chemical compositions, cellulose crystallinity, morphologic change, and enzymatic hydrolysis of bamboo fractions (bamboo yellow, timber, green, and knot) was compared. Bamboo fractions with SAA pretreatment had better hydrolysability than those with DA pretreatment. High crystallinity index resulted in low hydrolysis yield in the conversion of SAA pretreated bamboo fractions, not DA pretreated fractions. The increase of cellulase loading had modestly positive effect in the hydrolysis of both SAA and DA pretreated bamboo fractions, while supplement of xylanase significantly increased the hydrolysis of the pretreated bamboo fractions, especially after SAA pretreatment. The results indicated that SAA pretreatment was more effective than DA pretreatment in conversion of bamboo fractions, and supplementation of xylanase was necessary in effective conversion of the SAA pretreated fractions into fermentable sugars.
Phosphorus fractions in sandy soils of vineyards in southern Brazil
Directory of Open Access Journals (Sweden)
Djalma Eugênio Schmitt
2013-04-01
Full Text Available Phosphorus (P applications to vineyards can cause P accumulation in the soil and maximize pollution risks. This study was carried out to quantify the accumulation of P fractions in sandy soils of vineyards in southern Brazil. Soil samples (layers 0-5, 6-10 and 11-20 cm were collected from a native grassland area and two vineyards, after 14 years (vineyard 1 and 30 years (vineyard 2 of cultivation, in Santana do Livramento, southern Brazil, and subjected to chemical fractionation of P. Phosphorus application, especially to the 30-year-old vineyard 2, increased the inorganic P content down to a depth of 20 cm, mainly in the labile fractions extracted by anion-exchange resin and NaHCO3, in the moderately labile fraction extracted by 0.1 and 0.5 mol L-1 NaOH, and in the non-labile fraction extracted by 1 mol L-1 HCl, indicating the possibility of water eutrophication. Phosphorus application and grapevine cultivation time increased the P content in the organic fraction extracted by NaHCO3 from the 0-5 cm layer, and especially in the moderately labile fraction extracted by 0.1 mol L-1 NaOH, down to a depth of 20 cm.
Xenon fractionation in porous planetesimals.
Zahnle, K; Pollack, J B; Kasting, J F
1990-01-01
The distinctively fractionated Xe on Mars and Earth may have its root in a common source from which both planets accreted. We begin with Ozima and Nakazawa's hypothesis that terrestrial Xe fractionation was caused by gravitational separation of adsorbed solar nebular gases inside large porous planetesimals. We point out that Xe would have been trapped as the planetesimal grew and pores were squeezed shut by lithostatic pressure. We show that enough fractionated Xe to supply the Earth could have been trapped this way. The degree of fractionation is controlled by the lithostatic pressure at the pore-closing front and so would have been roughly the same for all large planetesimals. The predicted degree of fractionation agrees well with that preserved in terrestrial and martian Xe. Relative to Xe, this source is strongly depleted in other noble gases. In contrast to the original Ozima and Nakazawa hypothesis, our hypothesis predicts the observed fractionation, and it allows planetary accretion to occur after the dissipation of the solar nebula. The required planetesimals are large, representing a class of object now extinct in the solar system.
Fractional characteristic times and dissipated energy in fractional linear viscoelasticity
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.
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. A
Yamamoto, I; Nagumo, T; Fujihara, M; Takahashi, M; Ando, Y
1977-06-01
An almost purified antitumor polysaccharide fraction (SFPP) was obtained by fractional precipitation with ethanol from hot-water extract of Sargassum fulvellum. The fraction showed remarkable tumor-inhibiting effect against sarcoma-180 implanted subcutaneously in mice. The results of chemical and physical analyses suggested that the active substance may be either a sulphated peptidoglycuronoglycan or a sulphated glycuronoglycan.
2010-07-01
...), 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 subject... middle, C10-13-branched alkane fraction (PMN P-04-319; CAS No. 642928-30-1) is subject to reporting...
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.
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.
FRACTIONAL TRANSPORT OF SEDIMENT MIXTURES
Institute of Scientific and Technical Information of China (English)
Baosheng WU; Albert MOLINAS; Anping SHU
2003-01-01
A new method based on the Transport Capacity Fraction (TCF) concept is proposed to compute the fractional transport rates for nonuniform sediment mixtures in sand-bed channels. The TCF concept is derived from the understanding that the measurements and predictions of bed-material load are more accurate and reliable than the measurements and predictions of fractional loads. First the bed-material load is computed using an appropriate equation, then the fractional transport rates are determined by distributing the bed-material load into size groups through a transport capacity distribution function. For the computation of bed-material loads, the Aekers and White, Engelund and Hansen, and Yang equations are used in this study. Two new transport capacity distribution functions are developed for flows in sand-bed channels. The new expressions presented in this paper account for the sheltering and exposure effects that exist in mixtures. Comparisons with measured data show that the proposed method can significantly improve the predictions of fractional transport rates for nonuniform sediment mixtures.
Determination of thoracic and inhalable fraction of sulfuric acid(VI) in workplace air
Małgorzata Szewczyńska; Małgorzata Pośniak; Emilia Pągowska
2016-01-01
Background: The article presents the results of the determination of the inhalable and thoracic fraction of sulfuric acid(VI) in 3 workplaces producing or processing this chemical. Material and Methods: To collect thoracic fractions of sulfuric acid(VI) Parallel Particle Impactor (PPI) was used. To isolate inhalable fraction of sulfuric acid(VI) from the air we used a sampler developed at the Institute of Occupational Medicine (IOM), United Kingdom. Parallel Particle Impactor and IOM samplers...
Search for fractional charges in water
Joyce, D. C.; Abrams, P. C.; Bland, R. W.; Johnson, R. T.; Lindgren, M. A.; Savage, M. H.; Scholz, M. H.; Young, B. A.; Hodges, C. L.
1983-08-01
The results of a search for quarks in water, using a modified Millikan-oil-drop experiment, are presented. A total of 51 micrograms of water from different fresh and salt sources were investigated in a computer-controlled device comprising a piezoelectric drop injector, a series of 90 optical timing slits, and a chamber with an electric field that is reversed as the drop reaches split 39 and again at slit 74. Only drops with a charge between -12 and +12 e were accepted. A typical drift-velocity plot and the residual-charge frequency distribution for all the observations are shown. No fractional charges were detected in the samples, corresponding to an upper limit of quark concentration per nucleon of 9.8 x 10 to the -20th. This negative finding is discussed in terms of the presumed chemical properties of quarked atoms and compared with the results of other quark searches.
REFractions: The Representing Equivalent Fractions Game
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.
Analysis of Fractionated Fly Ash and Slag at Kemerovo State District Power Plant
Directory of Open Access Journals (Sweden)
Sysolyatin Andrey S.
2016-01-01
Full Text Available Experimental results of the separation of fly ash into microspheres, magnetic and non-magnetic fractions and analysis of chemical composition of slag and magnetic and non-magnetic fractions of fly ash from Kemerovo SDPS (Russia, Kuzbass are presented.
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.
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.
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...
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)
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.)
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.
On a fractional difference operator
Directory of Open Access Journals (Sweden)
P. Baliarsingh
2016-06-01
Full Text Available In the present article, a set of new difference sequence spaces of fractional order has been introduced and subsequently, an application of these spaces, the notion of the derivatives and the integrals of a function to the case of non-integer order have been generalized. Certain results involving the unusual and non-uniform behavior of the corresponding difference operator have been investigated and also been verified by using some counter examples. We also verify these unusual and non-uniform behaviors by studying the geometry of fractional calculus.
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 logT . For mode......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...
Fractional Derivatives in Dengue Epidemics
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.
Fractional derivatives in Dengue epidemics
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.
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.
CATALYSED ALKALINE OXIDATION AS A WOOD FRACTIONATION TECHNIQUE
Directory of Open Access Journals (Sweden)
Stella Rovio,
2012-01-01
Full Text Available Alkaline oxidation (AlkOx is an effective fractionation technique for lignocellulosic raw materials. The efficiency of the AlkOx treatment can further be enhanced by using a catalyst (CatOx. Both CatOx and AlkOx provide a fiber fraction containing readily hydrolysable carbohydrates that can be utilized in biotechnical processes and a liquid fraction containing solubilized lignin and reaction products from various biomass components. The effects of different fractionation conditions on yields and chemical composition of solubilized and insoluble fractions were investigated. Two temperatures and two reaction times were studied with and without a catalyst. The composition and content of carbohydrates in the fiber and liquid fractions were examined. The generation of aliphatic carboxylic acids as oxidation products was also investigated. The catalytically assisted oxidation was more efficient than the alkaline counterpart in dissolution of wood components under a four-hour treatment period resulting in higher dissolution of hemicelluloses. A longer reaction time of 20 hours leveled out the differences between the oxidation processes. Comparison of different bases showed that similar solubilisation of dry matter was obtained with NaOH, KOH, and Na2CO3. Oxidation in Na2CO3 caused higher dissolution of glucomannan and greater acid production. The dissolution of hemicellulose and lignin, and their oxidation to acids was most efficient in the first 4 hours of oxidation.
Fractional Laplace Transforms - A Perspective
Directory of Open Access Journals (Sweden)
Rudolf A. Treumann
2014-06-01
Full Text Available A new 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.
A note on fractional supersolutions
Directory of Open Access Journals (Sweden)
Janne Korvenpaa
2016-09-01
Full Text Available We study a class of equations driven by nonlocal, possibly degenerate, integro-differential operators of differentiability order $s\\in (0,1$ and summability growth $p>1$, whose model is the fractional $p$-Laplacian with measurable coefficients. We prove that the minimum of the corresponding weak supersolutions is a weak supersolution as well.
Fractional Laplace Transforms - A Perspective
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.
Subcellular fractionation of rough microsomes.
Sabatini, David D
2014-09-02
When eukaryotic cells are homogenized, the rough endoplasmic reticula are converted into small vesicles, called rough microsomes. Strategies for the isolation of rough microsomes are introduced here, as are methods for evaluating the purity and intactness of an isolated rough microsomal fraction.
Complexity and the Fractional Calculus
2013-01-01
developed in a number of signif- icant ways in the recent past. Sokolov et al. [1] maintain that this calculus was restricted to the field of mathematics... Sokolov , J. Klafter, and A. Blumen, “Fractional kinetics,” Physics Today, vol. 55, no. 11, pp. 48–54, 2002. [2] V. Seshadri and B. J. West, “Fractal
Staircase and Fractional Part Functions
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…
Pythagorean Approximations and Continued Fractions
Peralta, Javier
2008-01-01
In this article, we will show that the Pythagorean approximations of [the square root of] 2 coincide with those achieved in the 16th century by means of continued fractions. Assuming this fact and the known relation that connects the Fibonacci sequence with the golden section, we shall establish a procedure to obtain sequences of rational numbers…
Riesz potential versus fractional Laplacian
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.
Mokashi, Neelima A.
2009-01-01
This article depicts the rewarding experience of creating mathematical environments for kindergarten and elementary students by focusing on one of the most important and often difficult-to-grasp concepts (fractions) through play methods incorporated into a math fair. The basic concept of a math fair is threefold: (1) to create preplanned,…
Fractional diffusion: recovering the distributed fractional derivative from overposed data
Rundell, W.; Zhang, Z.
2017-03-01
There has been considerable recent study in ‘subdiffusion’ models that replace the standard parabolic equation model by a one with a fractional derivative in the time variable. There are many ways to look at this newer approach and one such is to realize that the order of the fractional derivative is related to the time scales of the underlying diffusion process. This raises the question of what order α of derivative should be taken and if a single value actually suffices. This has led to models that combine a finite number of these derivatives each with a different fractional exponent {αk} and different weighting value c k to better model a greater possible range of time scales. Ultimately, one wants to look at a situation that combines derivatives in a continuous way—the so-called distributional model with parameter μ ≤ft(α \\right) . However all of this begs the question of how one determines this ‘order’ of differentiation. Recovering a single fractional value has been an active part of the process from the beginning of fractional diffusion modeling and if this is the only unknown then the markers left by the fractional order derivative are relatively straightforward to determine. In the case of a finite combination of derivatives this becomes much more complex due to the more limited analytic tools available for such equations, but recent progress in this direction has been made, (Li et al 2015 Appl. Math. Comput. 257 381–97, Li and Yamamoto 2015 Appl. Anal. 94 570–9). This paper considers the full distributional model where the order is viewed as a function μ ≤ft(α \\right) on the interval (0, 1]. We show existence, uniqueness and regularity for an initial-boundary value problem including an important representation theorem in the case of a single spatial variable. This is then used in the inverse problem of recovering the distributional coefficient μ ≤ft(α \\right) from a time trace of the solution and a uniqueness result is
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.
Fractional Processes and Fractional-Order Signal Processing Techniques and Applications
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...
Defining Product Intake Fraction to Quantify and Compare Exposure to Consumer Products.
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.
The preparation of low electroendosmosis agarose and its physico-chemical property
Institute of Scientific and Technical Information of China (English)
无
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.
Improving Children's Knowledge of Fraction Magnitudes
Fazio, Lisa K.; Kennedy, Casey A.; Siegler, Robert S.
2016-01-01
We examined whether playing a computerized fraction game, based on the integrated theory of numerical development and on the Common Core State Standards' suggestions for teaching fractions, would improve children's fraction magnitude understanding. Fourth and fifth-graders were given brief instruction about unit fractions and played "Catch…
Green's Theorem for Generalized Fractional Derivatives
Odzijewicz, Tatiana; Torres, Delfim F M
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.
Using Number Sense to Compare Fractions
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…
'The mother of all continued fractions'
Dajani, K.; Kraaikamp, C.
2001-01-01
In this paper we give the relationship between the regular continued fraction and the Lehner fractions using a procedure known as insertion Starting from the regular continued fraction expansion of any real irrational x when the maximal number of insertions is applied one obtains the Lehner fraction
9 CFR 113.7 - Multiple fractions.
2010-01-01
... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Multiple fractions. 113.7 Section 113... § 113.7 Multiple fractions. (a) When a biological product contains more than one immunogenic fraction, the completed product shall be evaluated by tests applicable to each fraction. (b) When...
Evaluating fractionated space systems - Status
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
Philip Ye, X; Liu, Lu; Hayes, Douglas; Womac, Alvin; Hong, Kunlun; Sokhansanj, Shahab
2008-10-01
The objectives of this research were to determine the variation of chemical composition across botanical fractions of cornstover, and to probe the potential of Fourier transform near-infrared (FT-NIR) techniques in qualitatively classifying separated cornstover fractions and in quantitatively analyzing chemical compositions of cornstover by developing calibration models to predict chemical compositions of cornstover based on FT-NIR spectra. Large variations of cornstover chemical composition for wide calibration ranges, which is required by a reliable calibration model, were achieved by manually separating the cornstover samples into six botanical fractions, and their chemical compositions were determined by conventional wet chemical analyses, which proved that chemical composition varies significantly among different botanical fractions of cornstover. Different botanic fractions, having total saccharide content in descending order, are husk, sheath, pith, rind, leaf, and node. Based on FT-NIR spectra acquired on the biomass, classification by Soft Independent Modeling of Class Analogy (SIMCA) was employed to conduct qualitative classification of cornstover fractions, and partial least square (PLS) regression was used for quantitative chemical composition analysis. SIMCA was successfully demonstrated in classifying botanical fractions of cornstover. The developed PLS model yielded root mean square error of prediction (RMSEP %w/w) of 0.92, 1.03, 0.17, 0.27, 0.21, 1.12, and 0.57 for glucan, xylan, galactan, arabinan, mannan, lignin, and ash, respectively. The results showed the potential of FT-NIR techniques in combination with multivariate analysis to be utilized by biomass feedstock suppliers, bioethanol manufacturers, and bio-power producers in order to better manage bioenergy feedstocks and enhance bioconversion.
Fractional conservation laws in optimal control theory
Frederico, Gastao S F
2007-01-01
Using the recent formulation of Noether's theorem for the problems of the calculus of variations with fractional derivatives, the Lagrange multiplier technique, and the fractional Euler-Lagrange equations, we prove a Noether-like theorem to the more general context of the fractional optimal control. As a corollary, it follows that in the fractional case the autonomous Hamiltonian does not define anymore a conservation law. Instead, it is proved that the fractional conservation law adds to the Hamiltonian a new term which depends on the fractional-order of differentiation, the generalized momentum, and the fractional derivative of the state variable.
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.
Nitrogen fractionation in Titan's aerosols
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.
Fractional Authorship in Nuclear Physics
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...
Astrophysical Applications of Fractional Calculus
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.
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....
Fractional-calculus diffusion equation
Ajlouni, Abdul-Wali MS; Al-Rabai'ah, Hussam A
2010-01-01
Background Sequel to the work on the quantization of nonconservative systems using fractional calculus and quantization of a system with Brownian motion, which aims to consider the dissipation effects in quantum-mechanical description of microscale systems. Results The canonical quantization of a system represented classically by one-dimensional Fick's law, and the diffusion equation is carried out according to the Dirac method. A suitable Lagrangian, and Hamiltonian, describing the diffusive...
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.
Fractional statistical potential in graphene
Ardenghi, J. S.
2017-03-01
In this work the fractional statistics is applied to an anyon gas in graphene to obtain the special features that the arbitrary phase interchange of the particle coordinates introduce in the thermodynamic properties. The electron gas is constituted by N anyons in the long wavelength approximation obeying fractional exclusion statistics and the partition function is analyzed in terms of a perturbation expansion up to first order in the dimensionless constant λ / L being L the length of the graphene sheet and λ = βℏvF the thermal wavelength. By considering the correct permutation expansion of the many-anyons wavefunction, taking into account that the phase changes with the number of inversions in each permutation, the statistical fermionic/bosonic potential is obtained and the intermediate statistical behavior is found. It is shown that "extra" fermonic and bosonic particles states appears and this "statistical particle" distribution depends on N. Entropy and specific heat is obtained up to first order in λ / L showing that the results obtained differs from those obtained in different approximation to the fractional exclusion statistics.
Symmetry fractionalization and twist defects
Tarantino, Nicolas; Lindner, Netanel H.; Fidkowski, Lukasz
2016-03-01
Topological order in two-dimensions can be described in terms of deconfined quasiparticle excitations—anyons—and their braiding statistics. However, it has recently been realized that this data does not completely describe the situation in the presence of an unbroken global symmetry. In this case, there can be multiple distinct quantum phases with the same anyons and statistics, but with different patterns of symmetry fractionalization—termed symmetry enriched topological order. When the global symmetry group G, which we take to be discrete, does not change topological superselection sectors—i.e. does not change one type of anyon into a different type of anyon—one can imagine a local version of the action of G around each anyon. This leads to projective representations and a group cohomology description of symmetry fractionalization, with the second cohomology group {H}2(G,{{ A }}{{abelian}}) being the relevant group. In this paper, we treat the general case of a symmetry group G possibly permuting anyon types. We show that despite the lack of a local action of G, one can still make sense of a so-called twisted group cohomology description of symmetry fractionalization, and show how this data is encoded in the associativity of fusion rules of the extrinsic ‘twist’ defects of the symmetry. Furthermore, building on work of Hermele (2014 Phys. Rev. B 90 184418), we construct a wide class of exactly-solvable models which exhibit this twisted symmetry fractionalization, and connect them to our formal framework.
Release to the gas phase of metals, S and Cl during combustion of dedicated waste fractions
DEFF Research Database (Denmark)
Pedersen, Anne Juul; van Lith, Simone Cornelia; Frandsen, Flemming
2010-01-01
wood, shoes, automotive shredder waste and PVC (poly-vinyl-chloride). The waste fractions were characterized by use of wet chemical analysis, and, based on the chemical composition of the initial fuel sample and the ash residue after the experiments; the release of inorganic elements was quantified...
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.
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.
Sorption of 1-naphthol by plant cuticular fractions
Institute of Scientific and Technical Information of China (English)
无
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.
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.
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
On fractional Langevin equation involving two fractional orders
Baghani, Omid
2017-01-01
In numerical analysis, it is frequently needed to examine how far a numerical solution is from the exact one. To investigate this issue quantitatively, we need a tool to measure the difference between them and obviously this task is accomplished by the aid of an appropriate norm on a certain space of functions. For example, Sobolev spaces are indispensable part of theoretical analysis of partial differential equations and boundary integral equations, as well as are necessary for the analysis of some numerical methods for the solving of such equations. But most of articles that appear in this field usually use ‖.‖∞ in the space of C[a, b] which is very restrictive. In this paper, we introduce a new norm that is convenient for the fractional and singular differential equations. Using this norm, the existence and uniqueness of initial value problems for nonlinear Langevin equation with two different fractional orders are studied. In fact, the obtained results could be used for the classical cases. Finally, by two examples we show that we cannot always speak about the existence and uniqueness of solutions just by using the previous methods.
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.
Conformable Fractional Nikiforov—Uvarov Method
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.
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.
Fractional Moments on Bandit Problems
B, Ananda Narayanan
2012-01-01
Reinforcement learning addresses the dilemma between exploration to find profitable actions and exploitation to act according to the best observations already made. Bandit problems are one such class of problems in stateless environments that represent this explore/exploit situation. We propose a learning algorithm for bandit problems based on fractional expectation of rewards acquired. The algorithm is theoretically shown to converge on an eta-optimal arm and achieve O(n) sample complexity. Experimental results show the algorithm incurs substantially lower regrets than parameter-optimized eta-greedy and SoftMax approaches and other low sample complexity state-of-the-art techniques.
Fractional vortex dipole phase filter
Sharma, Manoj Kumar; Joseph, Joby; Senthilkumaran, Paramasivam
2014-10-01
In spatial filtering experiments, the use of vortex phase filters plays an important role in realizing isotropic edge enhancement. In this paper, we report the use of a vortex dipole phase filter in spatial filtering. A dipole made of fractional vortices is used, and its filtering characteristics are studied. It is observed that the filter performance can be tuned by varying the distance of separation between the vortices of the dipole to achieve better contrast and output noise suppression, and when this distance tends to infinity, the filter performs like a 1-D Hilbert mask. Experimental and simulation results are presented.
Reconstructing past fractional record values
Directory of Open Access Journals (Sweden)
Magdy E. El-Adll
2016-10-01
Full Text Available In this paper, reconstructing past fractional upper (lower records from any absolutely continuous distribution is proposed. For this purpose, two pivotal quantities are given and their exact distributions are derived. More detailed results, including the case of unknown parameters, are given for the exponential and Fre´chet distributions. Moreover, the exact mean square reconstructor errors are obtained and some comparisons between the pivotal quantities are performed. To explore the efficiency of the obtained results, a simulation study is conducted and two real data sets are analyzed.
DEFF Research Database (Denmark)
Dantoft, Thomas Meinertz; Andersson, Linus; Nordin, Steven;
2015-01-01
Chemical intolerance (CI) is a term used to describe a condition in which the sufferer experiences a complex array of recurrent unspecific symptoms attributed to low-level chemical exposure that most people regard as unproblematic. Severe CI constitutes the distinguishing feature of multiple...... chemical sensitivity (MCS). The symptoms reported by CI subjects are manifold, involving symptoms from multiple organs systems. In severe cases of CI, the condition can cause considerable life-style limitations with severe social, occupational and economic consequences. As no diagnostic tools for CI...
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.
Directory of Open Access Journals (Sweden)
Yong-Ju Yang
2013-01-01
Full Text Available The local fractional variational iteration method for local fractional Laplace equation is investigated in this paper. The operators are described in the sense of local fractional operators. The obtained results reveal that the method is very effective.
Isotope Fractionation Studies in Prestellar Cores: The Case of Nitrogen
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.
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)
Stability of Soil Carbon Fractions - from molecules to aggregates
Mueller, C. W.; Mueller, K. E.; Freeman, K. H.; Eissenstat, D.; Kögel-Knabner, I.
2009-12-01
The turnover of soil organic matter (SOM) is controlled both by its chemical composition, its spatial bioavailability and the association with the mineral phase. Separation by physical fractionation of bulk soils and subsequent chemical analysis of these fractions should give insights to how compositional differences in SOM drive turnover rates of different size-defined carbon pools. The main objective of the study was to elucidate the relative abundance and recalcitrance of lignin and plant lipids (e.g. cutin and suberin) in the course of SOM decomposition within aggregated bulk soils and SOM fractions. By the parallel incubation of physically-separated size fractions and bulk soils of the Ah horizon from a forested soil (Picea abies L.Karst) over a period of 400 days, a unique set of samples was created to study SOM dynamics. We used solid-state 13C-CPMAS NMR spectroscopy and GC-MS (after copper oxide oxidation and solvent extraction) to analyze the composition of the incubated samples. The abundance and isotopic composition (including 13C and 14C) of respired CO2 further enabled us to monitor the dynamics of SOM mineralization. This approach allowed for differentiating between C stabilization of soil fractions due to accessibility/aggregation and to recalcitrance at different scales of resolution (GC-MS, NMR). A relative enrichment of alkyl C and decreasing lignin contents in the order of sand cutin, and suberin monomers measured by GC-MS before and after the incubation indicate selective degradation and preservation patterns at the molecular scale that are rarely observed and are unresolved by NMR analyses. We suggest that the monomer-specific patterns of lignin, cutin, and suberin decomposition facilitate better understanding and modelling of SOM dynamics by providing a tool to potentially separate the influence of input rates from selective preservation on the abundance of these bipolymers in soil.
Staircase and fractional part functions
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.
Dean flow fractionation of chromosomes
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.
Continued fractions and heavy sequences
Boshernitzan, Michael
2009-01-01
We initiate the study of the sets $H(c)$, $0=x-[x]$ stands for the fractional part of $x\\in \\mathbb R$. We prove that, for rational $c$, the sets $H(c)$ are of positive Hausdorff dimension and, in particular, are uncountable. For integers $m\\geq1$, we obtain a surprising characterization of the numbers $\\alpha\\in H_m= H(\\frac1m)$ in terms of their continued fraction expansions: The odd entries (partial quotients) of these expansions are divisible by $m$. The characterization implies that $x\\in H_m$ if and only if $\\frac 1{mx} \\in H_m$, for $x>0$. We are unaware of a direct proof of this equivalence, without making a use of the mentioned characterization of the sets $H_m$. We also introduce the dual sets $\\hat H_m$ of reals $y$ for which the sequence of integers $\\big([ky]\\big)_{k\\geq1}$ consistently hits the set $m\\mathbb Z$ with the at least expected frequency $\\frac1m$ and establish the connection with the sets $H_m$: {2mm} If $xy=m$ for $x,y>0$, then $x\\in H_m$ if and only if $y\\in \\hat H_m$. The motivatio...
Directory of Open Access Journals (Sweden)
J. Vierinen
2011-06-01
Full Text Available We present a novel approach for modulating radar transmissions in order to improve target range and Doppler estimation accuracy. This is achieved by using non-uniform baud lengths. With this method it is possible to increase sub-baud range-resolution of phase coded radar measurements while maintaining a narrow transmission bandwidth. We first derive target backscatter amplitude estimation error covariance matrix for arbitrary targets when estimating backscatter in amplitude domain. We define target optimality and discuss different search strategies that can be used to find well performing transmission envelopes. We give several simulated examples of the method showing that fractional baud-length coding results in smaller estimation errors than conventional uniform baud length transmission codes when estimating the target backscatter amplitude at sub-baud range resolution. We also demonstrate the method in practice by analyzing the range resolved power of a low-altitude meteor trail echo that was measured using a fractional baud-length experiment with the EISCAT UHF system.
Galaxy Cluster Baryon Fractions Revisited
Gonzalez, Anthony H; Zabludoff, Ann I; Zaritsky, Dennis
2013-01-01
We measure the baryons contained in both the stellar and hot gas components for twelve galaxy clusters and groups at z~0.1 with M=1-5e14 Msun. This paper improves upon our previous work through the addition of XMM data, enabling measurements of the total mass and masses of each major baryonic component --- ICM, intracluster stars, and stars in galaxies --- for each system. We recover a relation for the stellar mass versus halo mass consistent with our previous result. We confirm that the partitioning of baryons between the stellar and hot gas components is a strong function of M500; the fractions of total mass in stars and X-ray gas within r500 scale as M500^-0.45 and M500^0.26, respectively. We also confirm that the combination of the BCG and intracluster stars is an increasingly important contributor to the stellar baryon budget in lower halo masses. We find a weak, but statistically significant, dependence of the total baryon fraction upon halo mass, scaling as M500^0.16. For M500>2e14, the total baryon fr...
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.
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.
Fractional Order Element Based Impedance Matching
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.
Multiple Interactive Representations for Fractions Learning
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
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.
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.
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.
Spectroscopic study of humic acids fractionated by means of tangential ultrafiltration
Francioso, O.; Sánchez-Cortés, S.; Casarini, D.; Garcia-Ramos, J. V.; Ciavatta, C.; Gessa, C.
2002-05-01
Different chemical and spectroscopic techniques—diffuse reflectance infrared Fourier transform (DRIFT), surface-enhanced Raman spectroscopy (SERS), and 1H, 13C nuclear magnetic resonance (NMR) have been applied to investigate a peat humic acid (HA) separated by tangential ultrafiltration into different nominal molecular weight (NMW) fractions. Each fraction analyzed showed a characteristic DRIFT and NMR pattern. High nominal molecular weight fractions were mainly characterized by long chains of methyl and methylene groups and poorly substituted aromatic rings, while in low nominal molecular weight fractions (L-NMW), phenolic and oxygen-containing groups were predominant. A comparative study on fractions before and after treatment with 0.5 M HCl was carried out. Purified fractions showed either an increase in the carboxylate and phenolic OH groups or an improvement in signal-to-noise ratio of their NMR spectra. The SERS study of NMW fractions allowed significative information on structure and conformation of these fractions. In particular, L-NMW fractions showed a great structural modification, when different alkaline extractants or treatment with HCl were used. Humic-like substances obtained by catechol and gallic acid polymerization on metal surface were investigated using SERS. The SERS spectra of these polymers were compared and discussed with those of NMW HA fractions.
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.
Transcendental $p$-adic continued fractions
Ooto, Tomohiro
2014-01-01
We establish a new transcendence criterion of $p$-adic continued fractions which are called Ruban continued fractions. By this result, we give explicit transcendental Ruban continued fractions with bounded $p$-adic absolute value of partial quotients. This is $p$-adic analogy of Baker's result. We also prove that $p$-adic analogy of Lagrange Theorem for Ruban continued fractions is not true.
Stretching Student Teachers' Understanding of Fractions
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…
Take a Bite out of Fraction Division
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…
An Alternative Starting Point for Fraction Instruction
Cortina, José Luis; Višnovská, Jana; Zúñiga, Claudia
2015-01-01
We analyze the results of a study conducted for the purpose of assessing the viability of an alternative starting point for teaching fractions. The alternative is based on Freudenthal's insights about fraction as comparison. It involves portraying the entities that unit fractions quantify as always being apart from the reference unit, instead of…
Lyapunov functions for fractional order systems
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.
Mathematical modelling of fractional order circuits
Moreles, Miguel Angel
2016-01-01
In this work a classical derivation of fractional order circuits models is presented. Generalized constitutive equations in terms of fractional Riemann-Liouville derivatives are introduced in the Maxwell's equations. Next the Kirchhoff voltage law is applied in a RCL circuit configuration. A fractional differential equation model is obtained with Caputo derivatives. Thus standard initial conditions apply.
Early Predictors of Middle School Fraction Knowledge
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…
Preparing for Algebra by Building Fraction Sense
Rodrigues, Jessica; Dyson, Nancy I.; Hansen, Nicole; Jordan, Nancy C.
2016-01-01
Fractions are troublesome for many children, especially students with learning difficulties and disabilities in mathematics. To address this serious educational concern, this article recommends the use of number lines to build fraction sense. Math activities that center on the number line build fraction concepts as early as third grade. A number…
The Richness of Children's Fraction Strategies
Kent, Laura B.; Empson, Susan B.; Nielsen, Lynne
2015-01-01
In this article, the authors discuss a special type of multiplication-and-division-of-fractions problem that elementary school teachers can use to promote children's understanding of fractional quantities and their relationships. These problems are accessible to students working at different levels of fraction understanding, and they can be solved…
Continued fractions and the second Kepler law
Karpenkov, Oleg
2009-01-01
In this paper we introduce a link between geometry of ordinary continued fractions and trajectories of points that moves according to the second Kepler law. We expand geometric interpretation of ordinary continued fractions to the case of continued fractions with arbitrary elements.
Identifying Fractions on a Number Line
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…
2010-01-01
... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Fractions. 500.17 Section 500.17 Commercial... LABELING ACT § 500.17 Fractions. (a) SI metric declarations of net quantity of contents of any consumer commodity may contain only decimal fractions. Other declarations of net quantity of contents may...
Locating Fractions on a Number Line
Wong, Monica
2013-01-01
Understanding fractions remains problematic for many students. The use of the number line aids in this understanding, but requires students to recognise that a fraction represents the distance from zero to a dot or arrow marked on a number line which is a linear scale. This article continues the discussion from "Identifying Fractions on a…
Teaching Fractions. Educational Practices Series-22
Fazio, Lisa; Siegler, Robert
2011-01-01
Students around the world have difficulties in learning about fractions. In many countries, the average student never gains a conceptual knowledge of fractions. This research guide provides suggestions for teachers and administrators looking to improve fraction instruction in their classrooms or schools. The recommendations are based on a…
Modeling of turbulent chemical reaction
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.
Assessing transport susceptibility of rapeseed meal fractionation products
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Milena Bojanowska
2016-09-01
Full Text Available Background: Having considered increasing production of liquid and solid biofuels from rapeseed and bearing in mind its stable and unquestionable position in the food and animal feed industries, a rational approach towards technologically and logistically efficient utilization of by-products from rapeseed processing is required. The aim of the research presented in the article is to assess the transport susceptibility of rapeseed meal fractions, varying according to particle size and chemical composition. Methods: Resistance to changes stimulating self-heating has been assumed as the main criterion of transport susceptibility. The following diagnostic variables have been experimentally determined: total protein, crude fat and crude fiber content, porosity, and water activity in the fraction of examined meal. In order to organize a set of particles and to indicate their optimal applications according to criteria chosen with regard to both utilization and transportation, two aggregate indicators have been calculated. Results: It has been proved that medium-sized particle fractions (0.075-0.4 mm exhibit the lowest transport susceptibility, whereas the those with the largest granulations (>3 mm -have the highest. One significant relationship is the decline of feeding value and concurrent increase in the transport susceptibility of meal fractions, which in practice means that those fractions least-favoured by the animal feed industry can be least cumbersome to transport. Conclusions: It has been suggested that there should be a division of rapeseed meal into two products with different applications and different transport susceptibility. The fractioning of meal can bring numerous, measurable benefits for the meal industry and logistics processes for solid biofuels, where storage and transport properties have considerable importance, alongside commodity price and transport costs.
Method for Attaining Caraway Seed Oil Fractions with Different Composition.
Shiwakoti, Santosh; Poudyal, Shital; Saleh, Osama; Astatkie, Tess; Zheljazkov, Valtcho D
2016-06-01
Caraway (Carum carvi L.) is a medicinal and aromatic plant; its seeds (fruits) are used as spice and they contain essential oils. We hypothesized that by collecting caraway oil at different time points during the extraction process, we could obtain oil fractions with distinct chemical composition. A hydrodistillation time (HDT) study was conducted to test the hypothesis. The caraway seed oil fractions were collected at eight different HDT (at 0 - 2, 2 - 7, 7 - 15, 15 - 30, 30 - 45, 45 - 75, 75 - 105, and 105 - 135 min). Additionally, a non-stop HD for 135 min was conducted as a control. Most of the oil was eluted early in the HD process. The non-stop HDT treatment yielded 2.76% oil by weight. Of the 24 essential oil constituents, limonene (77 - 19% of the total oil) and carvone (20 - 79%) were the major ones. Other constituents included myrcene (0.72 - 0.16%), trans-carveol (0.07 - 0.39%), and β-caryophyllene (0.07 - 0.24%). Caraway seed oil with higher concentration of limonene can be obtained by sampling oil fractions early in HD process; conversely, oil with high concentration of carvone can be obtained by excluding the fractions eluted early in the HD process. We demonstrated a method of obtaining caraway seed oil fractions with various and unique composition. These novel oil fractions with unique composition are not commercially available and could have much wider potential uses, and also target different markets compared to the typical caraway essential oil.
Toxicity assessment of unrefined crude oil fractions in soil ecosystems
Energy Technology Data Exchange (ETDEWEB)
Goudey, J.S.; Wilson, J.J. [HydroQual Lab. Ltd., Calgary, AB (Canada); Chu, A. [Calgary Univ., AB (Canada)
2001-07-01
The chemical and physical differences amongst crude oils and bioavailability (toxicity) of crude oil constituents are not addressed with existing numerical criteria for remediation of hydrocarbon contaminated soils. The constituents of crude oil include short chain hydrocarbons, such as light ends or gasoline, and long chain hydrocarbons (saturates), aromatic and polar compounds and heavier asphaltenes. Natural weathering and biodegradation take care of the lighter compounds. Less biodegradable are the heavier compounds which tend to be immobile. A range of questions concerning these immobile substances need to be answered to determine their effect on the bioavailability, hence toxicity, when solutes become solvents, etc. In this study, different crude oils and crude oil fractions were assessed as to their effect on the bioavailability (as toxicity) to microbes, plants and invertebrates. Five fractions with boiling point distillation were obtained from the separation of each of three base crude oils for a total of fifteen fractions. This practical approach to fractionating hydrocarbon represents the standard method for crude characterization. Ecological relevance, volume requirements, and availability of standard methods formed the basis for the selection of the tests and test species. The relative amounts of the different compounds (aromatics, saturates, polars, and asphaltenes) were different for each crude. Worm survival and lettuce seeding emergence tests were conducted on the spiked soils, and the extracts were tested with bacterial luminescence and lettuce root elongation. The results obtained for the three crude oils were similar. It was found that the heavier fractions were not toxic. Aging decreased the toxicity of aqueous extracts of spiked soils. Methanol extracts showed no loss of toxicity. The toxicity of whole crude was compared to the toxicity recovered in the fractions. The aqueous extracts of the naphthenic crude and the methanol extract of the
Deuterium Fractionation and Ion-Molecule Reactions at Low Temperatures
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.
Subordination Pathways to Fractional Diffusion
Gorenflo, Rudolf; 10.1140/epjst/e2011-01386-2
2011-01-01
The uncoupled Continuous Time Random Walk (CTRW) in one space-dimension and under power law regime is splitted into three distinct random walks: (rw_1), a random walk along the line of natural time, happening in operational time; (rw_2), a random walk along the line of space, happening in operational time;(rw_3), the inversion of (rw_1), namely a random walk along the line of operational time, happening in natural time. Via the general integral equation of CTRW and appropriate rescaling, the transition to the diffusion limit is carried out for each of these three random walks. Combining the limits of (rw_1) and (rw_2) we get the method of parametric subordination for generating particle paths, whereas combination of (rw_2) and (rw_3) yields the subordination integral for the sojourn probability density in space-time fractional diffusion.
Superconducting wires and fractional flux
Sá de Melo, C. A. R.
1996-05-01
The quantization of flux quanta in superconductors is revisited and analyzed in a new geometry. The system analyzed is a superconducting wire. The geometry is such that the superconducting wire winds N times around an insulating cylinder and that the wire has its end connected back to its beginning, thus producing an N-loop short circuited solenoid. The winding number N acts as a topological index that controls flux quantization. In this case, fractional flux quanta can be measured through the center of the insulating cylinder, provided that the cylinder radius is small enough. The Little-Parks experiment for an identical geometry is discussed. The period of oscillation of the transition temperature of the wire is found to vary as 1/N in units of flux Φ relative to the flux quantum Φ0. When a SQUID is made in such a geometry the maximal current through the SQUID varies with period Φ0/N.
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.
Directory of Open Access Journals (Sweden)
Sabrina Marcantonio Coneglian
2012-04-01
Full Text Available The objective of this study work was to assess crude protein fractions in structural components (leaves, stem and dead material of Coastcross grass (Cynodon dactylon (L. Pers under grazing, on winter, spring and summer seasons, in the Northwestern of Paraná, South of Brazil. Were determined CP, NDF, ADF contents and protein fractions, A, B1, B2, B3 and C. The analysis of CP showed great differences among months, but there was no difference among seasons. NDF and ADF in the stem were lower (p 0.05 protein fractions A, B1, B2, B3 and C of leaves. However, it was observed that the highest proportions of CP were B3 and A fractions. For the stem, the most important crude protein fraction is A, and it was observed that B1 fraction was lowest (p O objetivo deste estudo foi determinar as frações da proteína bruta dos componentes estruturais (lâmina verde, colmo e material morto, da gramínea Coastcross (Cynodon dactylon (L. Pers, nas estações do inverno, primavera e verão, no Noroeste do Estado do Paraná, Sul do Brasil. Foram determinados os teores de PB, FDN, FDA e a frações proteicas A, B1, B2, B3 e C. A análise de PB mostrou grande variabilidade entre os meses, porém, não houve diferença entre as estações. Os teores de FDN e FDA no colmo foram menores (p 0,05. Porém, foi observado que as frações mais representativas foram a B3 e a A em sua ordem. No colmo, a fração da proteina bruta de maior importância é a A e foi observado que a fração B1 foi menor (p < 0,05 na primavera. Considerando as frações da proteina bruta da gramínea Coastcross, nas condições deste estudo, pode-se concluir que essa apresenta valor proteico adequado para produção de bovinos de corte em pastagem.
Second Study of Hyper-Fractionated Radiotherapy
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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.
Correlation Structure of Fractional Pearson Diffusions.
Leonenko, Nikolai N; Meerschaert, Mark M; Sikorskii, Alla
2013-09-01
The stochastic solution to a diffusion equations with polynomial coefficients is called a Pearson diffusion. If the first time derivative is replaced by a Caputo fractional derivative of order less than one, the stochastic solution is called a fractional Pearson diffusion. This paper develops an explicit formula for the covariance function of a fractional Pearson diffusion in steady state, in terms of Mittag-Leffler functions. That formula shows that fractional Pearson diffusions are long range dependent, with a correlation that falls off like a power law, whose exponent equals the order of the fractional derivative.
On the Definitions of Nabla Fractional Operators
Directory of Open Access Journals (Sweden)
Thabet Abdeljawad
2012-01-01
properties of the one operator by using the known properties of the other. We illustrate this idea with proving power rule and commutative property of discrete fractional sum operators. We also introduce and prove summation by parts formulas for the right and left fractional sum and difference operators, where we employ the Riemann-Liouville definition of the fractional difference. We formalize initial value problems for nonlinear fractional difference equations as an application of our findings. An alternative definition for the nabla right fractional difference operator is also introduced.
Fractional Action Cosmology with Variable Order Parameter
El-Nabulsi, Rami Ahmad
2017-01-01
Fractional action cosmology with variable order parameter was constructed in this paper. Starting from a fractional weighted action which generalizes the fractional actionlike variational approach, a large number of cosmological dynamical equations are obtained depending on the mathematical type of the fractional order parameter. Through this paper, we selected two independent types which result on a number of cosmological scenarios and we discussed their dynamical consequences. It was observed that the present fractional cosmological formalism holds a large family of solutions and offers new features not found in the standard formalism and in many fundamental research papers.
Fractional Action Cosmology with Variable Order Parameter
El-Nabulsi, Rami Ahmad
2017-04-01
Fractional action cosmology with variable order parameter was constructed in this paper. Starting from a fractional weighted action which generalizes the fractional actionlike variational approach, a large number of cosmological dynamical equations are obtained depending on the mathematical type of the fractional order parameter. Through this paper, we selected two independent types which result on a number of cosmological scenarios and we discussed their dynamical consequences. It was observed that the present fractional cosmological formalism holds a large family of solutions and offers new features not found in the standard formalism and in many fundamental research papers.
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.
Utilization of Different Corn Fractions by Broilers
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SIFR Costa
2015-09-01
Full Text Available ABSTRACTThis study was conducted to evaluate the nutritional values of fractions of damaged corn. One hundred and eighty 22-d-old Cobb 500 male broilers were distributed in batteries according to a completely randomized design with six treatments of six replicates each. The treatments consisted of diets containing five corn fractions, classified as sound, fermented, insect-damaged, mold-damaged, or reference corn. The test diets consisted of 60% of reference diet + 40% of each corn fraction. Only the reference corn fraction included all the fractions at different proportions (0.8% fermented, 0.05% insect-damaged, 3.3% mold-damaged, and 95.85% sound grains. The method of total excreta collection was used to determine AMEn values and metabolizability coefficients of dry matter (MDM, crude protein (MCP, ether extract (MEE, and gross energy (MGE of the reference corn and its fractions. The density values of the corn fractions were used to calculate the correlations among the evaluated parameters. The evaluated corn fractions presented different compositions values. The insect-damaged and mold-damaged grains presented higher CP level, lower density, and MDM and MCP coefficients compared with the other fractions. However, calculated AMEn values were not significantly different (p>0.05 among corn fractions. A low correlation between density and AMEn content (r0.8 were calculated. Although the evaluated corn fractions presented different nutritional values, there were no marked differences in their utilization by broilers.
Fractional linear systems and electrical circuits
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...
Marcelo Franchin; Marcos Guilherme da Cunha; Carina Denny; Marcelo Henrique Napimoga; Thiago Mattar Cunha; Bruno Bueno-Silva; Severino Matias de Alencar; Masaharu Ikegaki; Pedro Luiz Rosalen
2013-01-01
The aim of this study was to evaluate the activity of the ethanolic extract of geopropolis (EEGP) from Melipona scutellaris and its fractions on the modulation of neutrophil migration in the inflammatory process, and the participation of nitric oxide (NO) pathway, as well as to check the chemical profile of the bioactive fraction. EEGP and its aqueous fraction decreased neutrophil migration in the peritoneal cavity and also the interaction of leukocytes (rolling and adhesion) with endothelial...
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.
Determination of Bioactive Components of Ethyl Acetate Fraction of Punica granatum Rind Extract
J. Sangeetha; K. Vijayalakshmi
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...
Chromium stable isotope fractionation in modern biogeochemical cycling
DEFF Research Database (Denmark)
Paulukat, Cora Stefanie
oxygen in the Earth’s atmosphere. Oxidative rock weathering on land induces oxidation of immobile Cr(III) to mobile Cr(VI). Isotopically relatively heavy Cr(VI) is released to runoff, and transported by rivers to the oceans, where it is incorporated into chemical sediments and carbonate shells...... laterite soils from India, formed on ultramafic rocks, indicates extensive leaching of isotopically heavy Cr(VI). Transferring this knowledge to ancient weathering profiles, negatively fractionated Cr is clear evidence for the presence of free oxygen in the atmosphere. The second part demonstrates...... that the positively fractionated Cr from the catchment area is preserved during its riverine transport to the sea. A global compilation of surface seawater Cr-isotope compositions shows a heterogeneous Cr-isotope distribution in the oceans, indicating that the signal is influenced by local factors as reduction...
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.
Ping Zhou; Rui Ding
2012-01-01
The unstable equilibrium points of the fractional-order Lorenz chaotic system can be controlled via fractional-order derivative, and chaos synchronization for the fractional-order Lorenz chaotic system can be achieved via fractional-order derivative. The control and synchronization technique, based on stability theory of fractional-order systems, is simple and theoretically rigorous. The numerical simulations demonstrate the validity and feasibility of the proposed method.
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.
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.
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…
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
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...
Hamiltonian chaos and fractional dynamics
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 ...
Water Fractions in Extrasolar Planetesimals
Jura, M
2011-01-01
With the goal of using externally-polluted white dwarfs to investigate the water fractions of extrasolar planetesimals, we assemble from the literature a sample that we estimate to be more than 60% complete of DB white dwarfs warmer than 13,000 K, more luminous than 3 ${\\times}$ 10$^{-3}$ L$_{\\odot}$ and within 80 pc of the Sun. When considering all the stars together, we find the summed mass accretion rate of heavy atoms exceeds that of hydrogen by over a factor of 1000. If so, this sub-population of extrasolar asteroids treated as an ensemble has little water and is at least a factor of 20 drier than CI chondrites, the most primitive meteorites. In contrast, while an apparent "excess" of oxygen in a single DB can be interpreted as evidence that the accreted material originated in a water-rich parent body, we show that at least in some cases, there can be sufficient uncertainties in the time history of the accretion rate that such an argument may be ambiguous. Regardless of the difficulty associated with int...
Analysis of Fractional Flow for Transient Two-Phase Flow in Fractal Porous Medium
Lu, Ting; Duan, Yonggang; Fang, Quantang; Dai, Xiaolu; Wu, Jinsui
2016-03-01
Prediction of fractional flow in fractal porous medium is important for reservoir engineering and chemical engineering as well as hydrology. A physical conceptual fractional flow model of transient two-phase flow is developed in fractal porous medium based on the fractal characteristics of pore-size distribution and on the approximation that porous medium consist of a bundle of tortuous capillaries. The analytical expression for fractional flow for wetting phase is presented, and the proposed expression is the function of structural parameters (such as tortuosity fractal dimension, pore fractal dimension, maximum and minimum diameters of capillaries) and fluid properties (such as contact angle, viscosity and interfacial tension) in fractal porous medium. The sensitive parameters that influence fractional flow and its derivative are formulated, and their impacts on fractional flow are discussed.
Alvarado-Lassman, A; Méndez-Contreras, J M; Martínez-Sibaja, A; Rosas-Mendoza, E S; Vallejo-Cantú, N A
2016-09-13
The high liquid content in fruit and vegetable wastes makes it convenient to mechanically separate these wastes into mostly liquid and solid fractions by means of pretreatment. Then, the liquid fraction can be treated using a high-rate anaerobic biofilm reactor to produce biogas, simultaneously reducing the amount of solids that must be landfilled. In this work, the specific composition of municipal solid waste (MSW) in a public market was determined; then, the sorted organic fraction of municipal solid waste was treated mechanically to separate and characterize the mostly liquid and solid fractions. Then, the mesophilic anaerobic digestion for biogas production of the first fraction was evaluated. The anaerobic digestion resulted in a reduced hydraulic retention time of two days with high removal of chemical oxygen demand, that is, 88% on average, with the additional benefit of reducing the mass of the solids that had to be landfilled by about 80%.
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
Zhang, Mei; Zhu, Lin; Cui, Steve W; Wang, Qi; Zhou, Ting; Shen, Hengsheng
2011-01-01
Fractionation and purification of mushroom polysaccharides is a critical process for mushroom clinical application. After a hot-water treatment, the crude Pleurotus geesteranus (PG) was further fractionated into four fractions (PG-1, -2, -3, -4) using gradient precipitation with water and ammonia sulphate. By controlling the initial polymer concentration and ratio of solvents, this process produced PG fractions with high chemical uniformity and narrow Mw distribution without free proteins. Structurally, PG-1 and PG-2 are pure homopolysaccharide mainly composed of glucose; and PG-3 and PG-4 are heteropolysaccharide-protein complexes. PG-2, a high M(w) fraction mainly composed of glucose presented significant cytotoxicity at the concentration of 200 and 100 μg/ml to human breast cancer cells. Here, we report a new mushroom polysaccharides extraction and fractionation method, with which we produced four fractions of PG with PG-2 appearing effective anti-tumour activity.
Role of unsaponifiable fraction on the preference for beef tallow in C57Black/6 mice.
Sasaki, Keisuke; Mitsumoto, Mitsuru
2004-06-01
We examined the contribution of unsaponifiable fraction, a model for minor substances in food fat, on the preference for beef tallow in C57Black/6NCrj mice. First, we tested the difference in preference among three kinds of beef tallow in mice by a two-bottle choice test. The beef tallow samples were preferred in the order 'premium' food-use, food-use, and chemical grades. The amount of unsaponifiable fraction was the highest in the premium and the lowest in the chemical-grade beef tallow sample. Fatty acid and triacylglycerol profiles, however, were similar in the three samples. Subsequently, we examined the effects and role of unsaponifiable fraction in the preference for triacylglycerol. Unsaponifiable fraction prepared from premium beef tallow sample alone did not affect the preference in mice, but a preference was observed when triolein and unsaponifiable fraction coexisted. These results indicated that the unsaponifiable fraction in beef tallow contributed to the preference in mice. In addition, it was suggested that the unsaponifiable fraction acted as an enhancer in the preference for triacylglycerol in C57Black/6NCrj mice.
Review of Some Promising Fractional Physical Models
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.
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.
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.
Dynamics with Low-Level Fractionality
Tarasov, V E; Tarasov, Vasily E.; Zaslavsky, George M.
2005-01-01
The notion of fractional dynamics is related to equations of motion with one or a few terms with derivatives of a fractional order. This type of equation appears in the description of chaotic dynamics, wave propagation in fractal media, and field theory. For the fractional linear oscillator the physical meaning of the derivative of order $\\alpha<2$ is dissipation. In systems with many spacially coupled elements (oscillators) the fractional derivative, along the space coordinate, corresponds to a long range interaction. We discuss a method of constructing a solution using an expansion in $\\epsilon=n-\\alpha$ with small $\\epsilon$ and positive integer $n$. The method is applied to the fractional linear and nonlinear oscillators and to fractional Ginzburg-Landau or parabolic equations.
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.
Coupled near-field and far-field exposure assessment framework for chemicals in consumer products
DEFF Research Database (Denmark)
Fantke, Peter; Ernstoff, Alexi; Huang, Lei;
2016-01-01
Humans can be exposed to chemicals in consumer products through product use and environmental emissions over the product life cycle. Exposure pathways are often complex, where chemicals can transfer directly from products to humans during use or exchange between various indoor and outdoor...... compartments until sub-fractions reach humans. To consistently evaluate exposure pathways along product life cycles, a flexible mass balance-based assessment framework is presented structuring multimedia chemical transfers in a matrix of direct inter-compartmental transfer fractions. By matrix inversion, we...... quantify cumulative multimedia transfer fractions and exposure pathway-specific product intake fractions defined as chemical mass taken in by humans per unit mass of chemical in a product. Combining product intake fractions with chemical mass in the product yields intake estimates for use in life cycle...
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.
Fractional Order Models of Industrial Pneumatic Controllers
Directory of Open Access Journals (Sweden)
Abolhassan Razminia
2014-01-01
Full Text Available This paper addresses a new approach for modeling of versatile controllers in industrial automation and process control systems such as pneumatic controllers. Some fractional order dynamical models are developed for pressure and pneumatic systems with bellows-nozzle-flapper configuration. In the light of fractional calculus, a fractional order derivative-derivative (FrDD controller and integral-derivative (FrID are remodeled. Numerical simulations illustrate the application of the obtained theoretical results in simple examples.
Early Predictors of Middle School Fraction Knowledge
Drew H. Bailey; Siegler, Robert S.; David C Geary
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 proficiency, domain general cognitive abilities, parental income and education, race, and gender. Similarly, knowledge of whole number arithmetic in first...
Wavelet Analysis of Fractionally Integrated Processes
Mark J. Jensen
1994-01-01
In this paper we apply wavelet analysis to the class of fractionally integrated processes to show that this class is a member of the $1/f$ family of processes as defined by Wornell (1993) and to produce an alternative method of estimating the fractional differencing parameter. Currently the method by Geweke and Porter-Hudak (1983) is used most often to estimate and test the fractional differencing parameter. The GPH approach, however, has been shown to have poor statistical properties and suf...
Time-delay and fractional derivatives
Tenreiro Machado JA
2011-01-01
This paper proposes the calculation of fractional algorithms based on time-delay systems. The study starts by analyzing the memory properties of fractional operators and their relation with time delay. Based on the Fourier analysis an approximation of fractional derivatives through time-delayed samples is developed. Furthermore, the parameters of the proposed approximation are estimated by means of genetic algorithms. The results demonstrate the feasibility of the new perspective.
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.
Unpacking the Division Interpretation of a Fraction
Poon, Rebecca C.; Lewis, Priscilla Eide
2015-01-01
One of the challenges in learning fractions is understanding how and why a fraction can have multiple interpretations. As presented in one textbook, a fraction is "a symbol, such as 2/3, 5/1, or 8/5, used to name a part of a whole, a part of a set, a location on a number line, or a division of whole numbers" (Charles et al. 2012, p.…
Fractional constant elasticity of variance model
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.
A Fractional Micro-Macro Model for Crowds of Pedestrians based on Fractional Mean Field Games
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.
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.
Easy characterization of petroleum fractions: Part 1
Energy Technology Data Exchange (ETDEWEB)
Miquel, J. (Univ. Politecnica de Catalunya (Spain)); Castells, F. (Univ. Rovira i Virgili, Catalunya (Spain))
1993-12-01
A new method for characterizing petroleum fractions, based on pseudocomponent breakdown using the integral method has been developed. It requires only that one has an atmospheric true boiling point (tbp) distillation curve and known the entire fraction density. The proposed characterization procedure is valid for representing any oil fraction (light or heavy) with a boiling point range smaller than 300 K. It is based on the hypothesis of constant Watson's characterization factor, K[sub w], for all the pseudocomponents. Outside this range, it is less accurate (greater errors in material and molar balances). Therefore, a method considering the variable K[sub w] is best to treat these fractions.
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.
Mesoscopic Fractional Quantum in Soft Matter
Chen, W
2005-01-01
Soft matter (e.g., biomaterials, polymers, sediments, oil, emulsions) has become an important bridge between physics and diverse disciplines. Its fundamental physical mechanism, however, is largely obscure. This study made the first attempt to connect fractional Schrodinger equation and soft matter physics under a consistent framework from empirical power scaling to phenomenological kinetics and macromechanics to mesoscopic quantum mechanics. The original contributions are the fractional quantum relationships, which show Levy statistics and fractional Brownian motion are essentially related to momentum and energy, respectively. The fractional quantum underlies fractal mesostructures and many-body interactions of macromolecules in soft matter and is experimentally testable.
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.
Sáenz-Navajas, María-Pilar; Ferreira, Vicente; Dizy, Marta; Fernández-Zurbano, Purificación
2010-07-19
Five Tempranillo wines exhibiting marked differences in taste and/or astringency were selected for the study. In each wine the non-volatile extract was obtained by freeze-drying and further liquid extraction in order to eliminate remaining volatile compounds. This extract was fractionated by semipreparative C18-reverse phase-high performance liquid chromatography (C18-RP-HPLC) into nine fractions which were freeze-dried, reconstituted with water and sensory assessed for taste attributes and astringency by a specifically trained sensory panel. Results have shown that wine bitterness and astringency cannot be easily related to the bitter and astringent character of the HPLC fractions, what can be due to the existence of perceptual and physicochemical interactions. While the bitter character of the bitterest fractions may be attributed to some flavonols (myricetin, quercetin and their glycosides) the development of a sensitive UPLC-MS method to quantify astringent compounds present in wines has made it possible to demonstrate that proanthocyanidins monomers, dimers, trimers and tetramers, both galloylated or non-galloylated are not relevant compounds for the perceived astringency of the fractions, while cis-aconitic acid, and secondarily vainillic, and syringic acids and ethyl syringate, are the most important molecules driving astringency in two of the fractions (F5 and F6). The identity of the chemicals responsible for the astringency of the third fraction could be assigned to some proanthocyanidins (higher than the tetramer) capable to precipitate with ovalbumin.
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.
Fractionation of Stable Isotopes in Atmospheric Aerosol Reactions
DEFF Research Database (Denmark)
Meusinger, Carl
-pinene - an abundant precursor to biogenic aerosol 3. Oxidation of SO2 to sulfuric acid - one of the key species in aerosol formation Laboratory experiments were designed and conducted as part of this thesis to investigate these processes. In addition, advanced data treatment and chemical modeling were performed...... 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...
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.
Fractional-order adaptive fault estimation for a class of nonlinear fractional-order systems
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.
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.
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...
Directory of Open Access Journals (Sweden)
Pâmela S. Silva
2010-12-01
Full Text Available A comparison between two extraction approaches of volatiles compounds from six species of Verbenaceae collected at Serra do Cipó, Minas Gerais, Brazil was done. The essential oil and hexanic fraction of leaves from two Lantana and four Lippia species collected in two different seasons were analyzed by GC/MS. Among various identified compounds from both extraction methods the majority of species showed major amounts of β-caryophyllene followed by germacrene D, bicyclogermacrene and α-pinene. Few differences were observed between the composition of essential oil and the hexanic fraction regarding the two studied genera. These results suggest that the analysis of hexanic fraction can be used, as an alternative way, to analyze the volatile compounds of the essential oil.Foi realizada a comparação entre dois métodos de extração dos compostos voláteis obtidos de seis espécies de Verbenaceae, coletadas na Serra do Cipó, Minas Gerais, Brasil. Os óleos essenciais e as frações hexanica obtidos das folhas de duas espécies de Lantana e quatro espécies de Lippia, coletadas em duas diferentes estações do ano, foram analisados por CG/EM. Grande número de constituintes foi identificado nas amostras oriundas dos dois métodos de extração e o componente majoritário para a maior parte das espécies foi o β-cariofileno, seguido pelo germacreno D, biciclogermacreno e α-pineno. Para os dois gêneros estudados, foram observadas pequenas diferenças na composição do óleo essencial e fração hexânica. Esses resultados sugerem que a análise da fração hexânica pode ser usada para identificar os componentes voláteis majoritários dessas espécies, além de ser uma técnica alternativa para a análise dos compostos voláteis presentes no óleo essencial, uma vez que ambos mostraram composição similar.
Effect of size-fractionation dissolved organic matter on the mobility of prometryne in soil.
Chen, Guang; Lin, Chao; Chen, Liang; Yang, Hong
2010-05-01
Import of organic materials in the form of compost, sludge or plant residues introduces large amounts of dissolved organic matter (DOM) into soils. DOM as a dynamic soil component affects the behaviors of organic pollutants. Different DOM constituents may affect herbicide action in a different way. However, the process of interaction between the distinct DOM-fractions and herbicides is largely unknown. In this study, DOM was separated by size-fractionation into three molecular size groups: MW14000 Da. Effects of DOM-fractions on prometryne sorption/desorption and mobility were analyzed using approaches of batch experiments, soil column and soil thin-layer chromatography. Application of varied DOM-fractions at 50mg DOCL(-1) to the soil reduced the sorption and increased desorption of prometryne. DOM-fraction with MW>14000 Da appeared most effective in prometryne mobilization in the soil than any other fractions. Finally, DOM-fractions were characterized by chemical analyses, fourier transformed infrared spectroscopy (FT-IR) and excitation-emission matrices (EEMs) fluorescence spectroscopy. Our studies revealed that the high-molecular weight fraction contained more aromatic framework and unsaturated structure that was most likely the dominant factor modulating the behavior of prometryne in soils.
Numerical simulation of the fractional Langevin equation
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Guo Peng
2012-01-01
Full Text Available In this paper, we study the fractional Langevin equation, whose derivative is in Caputo sense. By using the derived numerical algorithm, we obtain the displacement and the mean square displacement which describe the dynamic behaviors of the fractional Langevin equation.
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.
Continued fractions constructed from prime numbers
Wolf, Marek
2010-01-01
We give 50 digits values of the simple continued fractions whose denominators are formed from a) prime numbers, b) twin primes, c) primes of the form m^2+1 and Mersenne primes. All these continued fractions belong to the set of measure zero of exceptions to the Khinchin Theorem.
Safety of protein hydrolysates, fractions thereof and
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
Stability of Fractional Order Switching Systems
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.
Potentials of Arbitrary Forces with Fractional Derivatives
Rabei, Eqab M.; Alhalholy, Tareq S.; Rousan, Akram
The Laplace transform of fractional integrals and fractional derivatives is used to develop a general formula for determining the potentials of arbitrary forces: conservative and nonconservative in order to introduce dissipative effects (such as friction) into Lagrangian and Hamiltonian mechanics. The results are found to be in exact agreement with Riewe's results of special cases. Illustrative examples are given.
Cell fractionation of parasitic protozoa: a review
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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.
Approximating fractional derivatives through the generalized mean
Tenreiro Machado, J. A.; Galhano, Alexandra M.; Oliveira, Anabela M.; Tar, József K.
2009-11-01
This paper addresses the calculation of fractional order expressions through rational fractions. The article starts by analyzing the techniques adopted in the continuous to discrete time conversion. The problem is re-evaluated in an optimization perspective by tacking advantage of the degree of freedom provided by the generalized mean formula. The results demonstrate the superior performance of the new algorithm.
Likelihood based testing for no fractional cointegration
DEFF Research Database (Denmark)
Lasak, Katarzyna
We consider two likelihood ratio tests, so-called maximum eigenvalue and trace tests, for the null of no cointegration when fractional cointegration is allowed under the alternative, which is a first step to generalize the so-called Johansen's procedure to the fractional cointegration case. The s...
Maximum likelihood estimation of fractionally cointegrated systems
DEFF Research Database (Denmark)
Lasak, Katarzyna
In this paper we consider a fractionally cointegrated error correction model and investigate asymptotic properties of the maximum likelihood (ML) estimators of the matrix of the cointe- gration relations, the degree of fractional cointegration, the matrix of the speed of adjustment...
Paper Plate Fractions: The Counting Connection
McCoy, Ann; Barnett, Joann; Stine, Tammy
2016-01-01
Without a doubt, fractions prove to be a stumbling block for many children. Researchers have suggested a variety of explanations for why this is the case. The introduction of symbolization and operations before the development of conceptual understanding of fractions, a lack of understanding of the role of the numerator and denominator, and an…
Assessing Students' Understanding of Fraction Multiplication
Rumsey, Chepina; Guarino, Jody; Beltramini, Jennie; Cole, Shelbi; Farmer, Alicia; Gray, Kristin; Saxby, Morgan
2016-01-01
In this article the authors describe a project during which they unpacked fraction standards, created rigorous tasks and lesson plans, and developed formative and summative assessments to analyze students' thinking about fraction multiplication. The purpose of this article is to (1) illustrate a process that can be replicated by educators…
In Search of the Prototypical Fraction
Wright, Vince
2013-01-01
Vince Wright makes a convincing argument for presenting children with a different "prototype" of a fraction to the typical one-half. Consider how the prototype that Wright mentions may be applied to a variety of fraction concepts. We are sure that you will never look at a doughnut in quite the same way.
Engaging Students with Multiple Models of Fractions
Zhang, Xiaofen; Clements, M. A.; Ellerton, Nerida F.
2015-01-01
An understanding of unit fractions, and especially of one-half, one-third, and one-fourth, is crucially important for elementary school children's development of number sense (CCSSI 2010). We describe multimodal activities designed to assist elementary school students in gaining a rich understanding of unit fractions. Research has shown (Zhang,…
Fractions Instruction: Linking Concepts and Procedures
Pitsolantis, Nicole; Osana, Helena P.
2013-01-01
It is not surprising, as research has shown, that fractions are one of the most difficult of the elementary school math topics to teach and learn in ways that are meaningful. The authors reference a work by James Hiebert, "Mathematical, Cognitive, and Instructional Analyses of Decimal Fractions" (1992), that mathematical concepts should…
Making Sense of Fractions and Percentages
Whitin, David J.; Whitin, Phyllis
2012-01-01
Because fractions and percentages can be difficult for children to grasp, connecting them whenever possible is beneficial. Linking them can foster representational fluency as children simultaneously see the part-whole relationship expressed numerically (as a fraction and as a percentage) and visually (as a pie chart). NCTM advocates these…
Unpacking Referent Units in Fraction Operations
Philipp, Randolph A.; Hawthorne, Casey
2015-01-01
Although fraction operations are procedurally straightforward, they are complex, because they require learners to conceptualize different units and view quantities in multiple ways. Prospective secondary school teachers sometimes provide an algebraic explanation for inverting and multiplying when dividing fractions. That authors of this article…
Fractions Learning in Children with Mathematics Difficulties
Tian, Jing; Siegler, Robert S.
2016-01-01
Learning of fractions is difficult for children in general and especially difficult for children with mathematics difficulties (MD). Recent research on developmental and individual differences in fraction knowledge of MD and typically achieving (TA) children has demonstrated that U.S. children with MD start middle school behind TA peers in…
Estimation's Role in Calculations with Fractions
Johanning, Debra I.
2011-01-01
Estimation is more than a skill or an isolated topic. It is a thinking tool that needs to be emphasized during instruction so that students will learn to develop algorithmic procedures and meaning for fraction operations. For students to realize when fractions should be added, subtracted, multiplied, or divided, they need to develop a sense of…
On Fractional Order Hybrid Differential Equations
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Mohamed A. E. Herzallah
2014-01-01
Full Text Available We develop the theory of fractional hybrid differential equations with linear and nonlinear perturbations involving the Caputo fractional derivative of order 0<α<1. Using some fixed point theorems we prove the existence of mild solutions for two types of hybrid equations. Examples are given to illustrate the obtained results.
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
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
Reply to "Comment on `Fractional quantum mechanics' and `Fractional Schrödinger equation' "
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.
Research on inter-fraction and intra-fraction motion of crystalline lens in radiotherapy
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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.
Reply to "Comment on 'Fractional quantum mechanics' and 'Fractional Schrödinger equation' ".
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.
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.
Fractional flux and non-normal diffusion
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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.
Neutron Imaging Calibration to Measure Void Fraction
Energy Technology Data Exchange (ETDEWEB)
Geoghegan, Patrick J [ORNL; Bilheux, Hassina Z [ORNL; Sharma, Vishaldeep [ORNL; Fricke, Brian A [ORNL
2015-01-01
Void fraction is an intuitive parameter that describes the fraction of vapor in a two-phase flow. It appears as a key variable in most heat transfer and pressure drop correlations used to design evaporating and condensing heat exchangers, as well as determining charge inventory in refrigeration systems. Void fraction measurement is not straightforward, however, and assumptions on the invasiveness of the measuring technique must be made. Neutron radiography or neutron imaging has the potential to be a truly non-invasive void fraction measuring technique but has until recently only offered qualitative descriptions of two-phase flow, in terms of flow maldistributions, for example. This paper describes the calibration approach necessary to employ neutron imaging to measure steady-state void fraction. Experiments were conducted at the High Flux Isotope Reactor (HFIR) Cold Guide 1D neutron imaging facility at Oak Ridge National Laboratory (ORNL), Oak Ridge, TN, USA.
Variable-order fuzzy fractional PID controller.
Liu, Lu; Pan, Feng; Xue, Dingyu
2015-03-01
In this paper, a new tuning method of variable-order fractional fuzzy PID controller (VOFFLC) is proposed for a class of fractional-order and integer-order control plants. Fuzzy logic control (FLC) could easily deal with parameter variations of control system, but the fractional-order parameters are unable to change through this way and it has confined the effectiveness of FLC. Therefore, an attempt is made in this paper to allow all the five parameters of fractional-order PID controller vary along with the transformation of system structure as the outputs of FLC, and the influence of fractional orders λ and μ on control systems has been investigated to make the fuzzy rules for VOFFLC. Four simulation results of different plants are shown to verify the availability of the proposed control strategy.
Generalized Fractional Derivative Anisotropic Viscoelastic Characterization
Directory of Open Access Journals (Sweden)
Harry H. Hilton
2012-01-01
Full Text Available Isotropic linear and nonlinear fractional derivative constitutive relations are formulated and examined in terms of many parameter generalized Kelvin models and are analytically extended to cover general anisotropic homogeneous or non-homogeneous as well as functionally graded viscoelastic material behavior. Equivalent integral constitutive relations, which are computationally more powerful, are derived from fractional differential ones and the associated anisotropic temperature-moisture-degree-of-cure shift functions and reduced times are established. Approximate Fourier transform inversions for fractional derivative relations are formulated and their accuracy is evaluated. The efficacy of integer and fractional derivative constitutive relations is compared and the preferential use of either characterization in analyzing isotropic and anisotropic real materials must be examined on a case-by-case basis. Approximate protocols for curve fitting analytical fractional derivative results to experimental data are formulated and evaluated.
Representations of the magnitudes of fractions.
Schneider, Michael; Siegler, Robert S
2010-10-01
We tested whether adults can use integrated, analog, magnitude representations to compare the values of fractions. The only previous study on this question concluded that even college students cannot form such representations and instead compare fraction magnitudes by representing numerators and denominators as separate whole numbers. However, atypical characteristics of the presented fractions might have provoked the use of atypical comparison strategies in that study. In our 3 experiments, university and community college students compared more balanced sets of single-digit and multi-digit fractions and consistently exhibited a logarithmic distance effect. Thus, adults used integrated, analog representations, akin to a mental number line, to compare fraction magnitudes. We interpret differences between the past and present findings in terms of different stimuli eliciting different solution strategies.