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Sample records for derivative methods applications

  1. Applications of Computational Methods for Dynamic Stability and Control Derivatives

    NASA Technical Reports Server (NTRS)

    Green, Lawrence L.; Spence, Angela M.

    2004-01-01

    Initial steps in the application o f a low-order panel method computational fluid dynamic (CFD) code to the calculation of aircraft dynamic stability and control (S&C) derivatives are documented. Several capabilities, unique to CFD but not unique to this particular demonstration, are identified and demonstrated in this paper. These unique capabilities complement conventional S&C techniques and they include the ability to: 1) perform maneuvers without the flow-kinematic restrictions and support interference commonly associated with experimental S&C facilities, 2) easily simulate advanced S&C testing techniques, 3) compute exact S&C derivatives with uncertainty propagation bounds, and 4) alter the flow physics associated with a particular testing technique from those observed in a wind or water tunnel test in order to isolate effects. Also presented are discussions about some computational issues associated with the simulation of S&C tests and selected results from numerous surface grid resolution studies performed during the course of the study.

  2. Application of the Bootstrap Statistical Method in Deriving Vibroacoustic Specifications

    NASA Technical Reports Server (NTRS)

    Hughes, William O.; Paez, Thomas L.

    2006-01-01

    This paper discusses the Bootstrap Method for specification of vibroacoustic test specifications. Vibroacoustic test specifications are necessary to properly accept or qualify a spacecraft and its components for the expected acoustic, random vibration and shock environments seen on an expendable launch vehicle. Traditionally, NASA and the U.S. Air Force have employed methods of Normal Tolerance Limits to derive these test levels based upon the amount of data available, and the probability and confidence levels desired. The Normal Tolerance Limit method contains inherent assumptions about the distribution of the data. The Bootstrap is a distribution-free statistical subsampling method which uses the measured data themselves to establish estimates of statistical measures of random sources. This is achieved through the computation of large numbers of Bootstrap replicates of a data measure of interest and the use of these replicates to derive test levels consistent with the probability and confidence desired. The comparison of the results of these two methods is illustrated via an example utilizing actual spacecraft vibroacoustic data.

  3. Generalized Derivation of the RRV Method and Its Application

    NASA Astrophysics Data System (ADS)

    Lin, F. R.; Peng, Q. Y.; Wang, N.; Peng, H. W.; Zhang, Q. F.; Li, Z.

    2016-12-01

    Very recently, Heinze & Metchev proposed a novel method for calculating precise distances to the main-belt asteroids using only two nights of data from a single observatory. In this paper, we re-derive the solution but use easily understood spherical astronomy. Our derivation is based on the premise that the geocentric angular velocity of an asteroid changes linearly with time, which is closer to the real situation. Therefore, a possible extra error of rotational reflex velocity, in some cases, is eliminated. A total of 193 frames of CCD images over four nights for 10 asteroids in a conventional stare mode taken with the 1 m telescope at Yunnan Observatory were used to test the improved solution and precise distances were evaluated.

  4. Application of a phosphazene derivative as a flame retardant for cotton fabric using conventional method and supercritical CO2

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conventional pad-dry-cure (non-scCO2) and supercritical carbon dioxide (scCO2) application methods were investigated to study the effectiveness of a phosphazene derivative as a flame retardant on cotton fabric. 1,1',4,5-tetrahydrotrispiro[1,3,2-diazaphosphole-2,2'-[1,3,5,2,4,6]triazatriphosphinine-4...

  5. Development, Implementation, and Application of an Analytic Second Derivative Formalism for the Normalized Elimination of the Small Component Method.

    PubMed

    Zou, Wenli; Filatov, Michael; Cremer, Dieter

    2012-08-14

    Analytical second derivatives for the normalized elimination of the small component (NESC) method are derived for the first time and implemented for the routine calculation of NESC vibrational frequencies and other second order molecular properties using the scalar relativistic form of NESC. Using response theory, the second derivatives of the transformation matrix U connecting the large and the pseudolarge components of the relativistic wave function are correctly derived. The 24 derivative terms involving the NESC Hamiltonian and the NESC renormalization matrix are individually tested, and their contributions to the energy Hessian are calculated. The influence of a finite nucleus model and that of the picture change is determined. Different ways of speeding up the calculation of the NESC second derivatives are tested. It is shown that second order properties can routinely be calculated in combination with Hartree-Fock, density functional theory, Moller-Plesset perturbation theory, and any other electron correlation corrected quantum chemical method provided analytic second derivatives are available in the nonrelativistic case. The general applicability of the analytic NESC Hessian is demonstrated by benchmark calculations for NESC/DFT calculations involving up to 1500 basis functions.

  6. Bayesian methods for uncertainty factor application for derivation of reference values.

    PubMed

    Simon, Ted W; Zhu, Yiliang; Dourson, Michael L; Beck, Nancy B

    2016-10-01

    In 2014, the National Research Council (NRC) published Review of EPA's Integrated Risk Information System (IRIS) Process that considers methods EPA uses for developing toxicity criteria for non-carcinogens. These criteria are the Reference Dose (RfD) for oral exposure and Reference Concentration (RfC) for inhalation exposure. The NRC Review suggested using Bayesian methods for application of uncertainty factors (UFs) to adjust the point of departure dose or concentration to a level considered to be without adverse effects for the human population. The NRC foresaw Bayesian methods would be potentially useful for combining toxicity data from disparate sources-high throughput assays, animal testing, and observational epidemiology. UFs represent five distinct areas for which both adjustment and consideration of uncertainty may be needed. NRC suggested UFs could be represented as Bayesian prior distributions, illustrated the use of a log-normal distribution to represent the composite UF, and combined this distribution with a log-normal distribution representing uncertainty in the point of departure (POD) to reflect the overall uncertainty. Here, we explore these suggestions and present a refinement of the methodology suggested by NRC that considers each individual UF as a distribution. From an examination of 24 evaluations from EPA's IRIS program, when individual UFs were represented using this approach, the geometric mean fold change in the value of the RfD or RfC increased from 3 to over 30, depending on the number of individual UFs used and the sophistication of the assessment. We present example calculations and recommendations for implementing the refined NRC methodology.

  7. Inter-laboratory verification of European pharmacopoeia monograph on derivative spectrophotometry method and its application for chitosan hydrochloride.

    PubMed

    Marković, Bojan; Ignjatović, Janko; Vujadinović, Mirjana; Savić, Vedrana; Vladimirov, Sote; Karljiković-Rajić, Katarina

    2015-01-01

    Inter-laboratory verification of European pharmacopoeia (EP) monograph on derivative spectrophotometry (DS) method and its application for chitosan hydrochloride was carried out on two generation of instruments (earlier GBC Cintra 20 and current technology TS Evolution 300). Instruments operate with different versions of Savitzky-Golay algorithm and modes of generating digital derivative spectra. For resolution power parameter, defined as the amplitude ratio A/B in DS method EP monograph, comparable results were obtained only with algorithm's parameters smoothing points (SP) 7 and the 2nd degree polynomial and those provided corresponding data with other two modes on TS Evolution 300 Medium digital indirect and Medium digital direct. Using quoted algorithm's parameters, the differences in percentages between the amplitude ratio A/B averages, were within accepted criteria (±3%) for assay of drug product for method transfer. The deviation of 1.76% for the degree of deacetylation assessment of chitosan hydrochloride, determined on two instruments, (amplitude (1)D202; the 2nd degree polynomial and SP 9 in Savitzky-Golay algorithm), was acceptable, since it was within allowed criteria (±2%) for assay deviation of drug substance, for method transfer in pharmaceutical analyses.

  8. Correction for dispersion and Coulombic interactions in molecular clusters with density functional derived methods: application to polycyclic aromatic hydrocarbon clusters.

    PubMed

    Rapacioli, Mathias; Spiegelman, Fernand; Talbi, Dahbia; Mineva, Tzonka; Goursot, Annick; Heine, Thomas; Seifert, Gotthard

    2009-06-28

    The density functional based tight binding (DFTB) is a semiempirical method derived from the density functional theory (DFT). It inherits therefore its problems in treating van der Waals clusters. A major error comes from dispersion forces, which are poorly described by commonly used DFT functionals, but which can be accounted for by an a posteriori treatment DFT-D. This correction is used for DFTB. The self-consistent charge (SCC) DFTB is built on Mulliken charges which are known to give a poor representation of Coulombic intermolecular potential. We propose to calculate this potential using the class IV/charge model 3 definition of atomic charges. The self-consistent calculation of these charges is introduced in the SCC procedure and corresponding nuclear forces are derived. Benzene dimer is then studied as a benchmark system with this corrected DFTB (c-DFTB-D) method, but also, for comparison, with the DFT-D. Both methods give similar results and are in agreement with references calculations (CCSD(T) and symmetry adapted perturbation theory) calculations. As a first application, pyrene dimer is studied with the c-DFTB-D and DFT-D methods. For coronene clusters, only the c-DFTB-D approach is used, which finds the sandwich configurations to be more stable than the T-shaped ones.

  9. Deriving brown carbon from multiwavelength absorption measurements: method and application to AERONET and Aethalometer observations

    NASA Astrophysics Data System (ADS)

    Wang, Xuan; Heald, Colette L.; Sedlacek, Arthur J.; de Sá, Suzane S.; Martin, Scot T.; Lizabeth Alexander, M.; Watson, Thomas B.; Aiken, Allison C.; Springston, Stephen R.; Artaxo, Paulo

    2016-10-01

    The radiative impact of organic aerosols (OA) is a large source of uncertainty in estimating the global direct radiative effect (DRE) of aerosols. This radiative impact includes not only light scattering but also light absorption from a subclass of OA referred to as brown carbon (BrC). However, the absorption properties of BrC are poorly understood, leading to large uncertainties in modeling studies. To obtain observational constraints from measurements, a simple absorption Ångström exponent (AAE) method is often used to separate the contribution of BrC absorption from that of black carbon (BC). However, this attribution method is based on assumptions regarding the spectral dependence of BC that are often violated in the ambient atmosphere. Here we develop a new AAE method which improves upon previous approaches by using the information from the wavelength-dependent measurements themselves and by allowing for an atmospherically relevant range of BC properties, rather than fixing these at a single assumed value. We note that constraints on BC optical properties and mixing state would help further improve this method. We apply this method to multiwavelength absorption aerosol optical depth (AAOD) measurements at AERONET sites worldwide and surface aerosol absorption measurements at multiple ambient sites. We estimate that BrC globally contributes up to 40 % of the seasonally averaged absorption at 440 nm. We find that the mass absorption coefficient of OA (OA-MAC) is positively correlated with the BC / OA mass ratio. Based on the variability in BC properties and BC / OA emission ratio, we estimate a range of 0.05-1.5 m2 g-1 for OA-MAC at 440 nm. Using the combination of AERONET and OMI UV absorption observations we estimate that the AAE388/440 nm for BrC is generally ˜ 4 worldwide, with a smaller value in Europe (< 2). Our analyses of observations at two surface sites (Cape Cod, to the southeast of Boston, and the GoAmazon2014/5 T3 site, to the west of

  10. Deriving brown carbon from multiwavelength absorption measurements: Method and application to AERONET and Aethalometer observations

    SciTech Connect

    Wang, X.; Heald, C. L.; Sedlacek, A.; de Sa, S. S.; Martin, S. T.; Alexander, M. L.; Watson, T. B.; Aiken, A. C.; Springston, S. R.; Artaxo, P.

    2016-10-13

    The radiative impact of organic aerosols (OA) is a large source of uncertainty in estimating the global direct radiative effect (DRE) of aerosols. This radiative impact includes not only light scattering but also light absorption from a subclass of OA referred to as brown carbon (BrC). However the absorption properties of BrC are poorly understood leading to large uncertainties in modelling studies. To obtain observational constraints from measurements, a simple Absorption Ångström Exponent (AAE) method is often used to separate the contribution of BrC absorption from that of black carbon (BC). However, this attribution method is based on assumptions regarding the spectral dependence of BC that are often violated in the ambient atmosphere. Here we develop a new method that decreases the uncertainties associated with estimating BrC absorption. By applying this method to multi-wavelength absorption aerosol optical depth (AAOD) measurements at AERONET sites worldwide and surface aerosol absorption measurements at multiple ambient sites, we estimate that BrC globally contributes 6-40% of the absorption at 440nm. We find that the mass absorption coefficient of OA (OA-MAC) is positively correlated with BC/OA mass ratio. Based on the variability of BC properties and BC/OA emission ratio, we estimate a range of 0.05-1.2 m2/g for OA-MAC at 440nm. Using the combination of AERONET and OMI UV absorption observations we estimate that the AAE388/440nm for BrC is generally ~4 world-wide, with a smaller value in Europe (< 2). Our analyses of two surface sites (Cape Cod, to the southeast of Boston, and the GoAmazon2014/5 T3 site, to the west of Manaus, Brazil) reveal no significant relationship between BrC absorptivity and photochemical aging in typical urban influenced conditions. However, the absorption of BrC measured during the biomass burning season near Manaus is found to decrease with photochemical aging with a lifetime of ~1 day. This lifetime is

  11. Deriving brown carbon from multiwavelength absorption measurements: Method and application to AERONET and Aethalometer observations

    DOE PAGES

    Wang, X.; Heald, C. L.; Sedlacek, A.; ...

    2016-10-13

    The radiative impact of organic aerosols (OA) is a large source of uncertainty in estimating the global direct radiative effect (DRE) of aerosols. This radiative impact includes not only light scattering but also light absorption from a subclass of OA referred to as brown carbon (BrC). However the absorption properties of BrC are poorly understood leading to large uncertainties in modelling studies. To obtain observational constraints from measurements, a simple Absorption Ångström Exponent (AAE) method is often used to separate the contribution of BrC absorption from that of black carbon (BC). However, this attribution method is based on assumptions regardingmore » the spectral dependence of BC that are often violated in the ambient atmosphere. Here we develop a new method that decreases the uncertainties associated with estimating BrC absorption. By applying this method to multi-wavelength absorption aerosol optical depth (AAOD) measurements at AERONET sites worldwide and surface aerosol absorption measurements at multiple ambient sites, we estimate that BrC globally contributes 6-40% of the absorption at 440nm. We find that the mass absorption coefficient of OA (OA-MAC) is positively correlated with BC/OA mass ratio. Based on the variability of BC properties and BC/OA emission ratio, we estimate a range of 0.05-1.2 m2/g for OA-MAC at 440nm. Using the combination of AERONET and OMI UV absorption observations we estimate that the AAE388/440nm for BrC is generally ~4 world-wide, with a smaller value in Europe (< 2). Our analyses of two surface sites (Cape Cod, to the southeast of Boston, and the GoAmazon2014/5 T3 site, to the west of Manaus, Brazil) reveal no significant relationship between BrC absorptivity and photochemical aging in typical urban influenced conditions. However, the absorption of BrC measured during the biomass burning season near Manaus is found to decrease with photochemical aging with a lifetime of ~1 day. This lifetime is comparable to

  12. Development and application of a selective detection method for genetically modified soy and soy-derived products.

    PubMed

    Hoef, A M; Kok, E J; Bouw, E; Kuiper, H A; Keijer, J

    1998-10-01

    A method has been developed to distinguish between traditional soy beans and transgenic Roundup Ready soy beans, i.e. the glyphosate ('Roundup') resistant soy bean variety developed by Monsanto Company. Glyphosate resistance results from the incorporation of an Agrobacterium-derived 5-enol-pyruvyl-shikimate-3-phosphatesynthase (EPSPS) gene. The detection method developed is based on a nested Polymerase Chain Reaction (PCR) procedure. Ten femtograms of soy bean DNA can be detected, while, starting from whole soy beans, Roundup Ready DNA can be detected at a level of 1 Roundup Ready soy bean in 5000 non-GM soy beans (0.02% Roundup Ready soy bean). The method has been applied to samples of soy bean, soy-meal pellets and soy bean flour, as well as a number of processed complex products such as infant formula based on soy, tofu, tempeh, soy-based desserts, bakery products and complex meat and meat-replacing products. The results obtained are discussed with respect to practical application of the detection method developed.

  13. Systematic method for deriving effective Hamiltonians

    NASA Astrophysics Data System (ADS)

    Swain, S.

    1994-04-01

    A systematic procedure for deriving effective Hamiltonians to any order is presented, which is applicable to any time-independent Hamiltonian. The method is based on a continued-fraction approach and avoids the singularities which may occur with perturbation theory. It is illustrated by deriving the effective Hamiltonian for the one-photon, dressed-state laser to second order.

  14. On the determination of atmospheric minor gases by the method of vanishing partial derivatives with application to CO2

    NASA Technical Reports Server (NTRS)

    Chahine, M.; Barnet, C.; Olsen, E. T.; Chen, L.; Maddy, E.

    2005-01-01

    We present a general method for the determination of minor gases in the troposphere from high spectral resolution observations. In this method, we make use of a general property of the total differential of multi-variable functions to separate the contributions of each individual minor gas. We have applied this method to derive the mixing ratio of carbon dioxide in the mid-troposphere using data from the Atmospheric Infrared Sounder (AIRS) currently flying on the NASA Aqua Mission. We compare our results to the aircraft flask CO2 measurements obtained by H. Matsueda et al. over the western Pacific and demonstrate skill in tracking the measured 5 ppmv seasonal variation with an accuracy of 0.43 +/- 1.20 ppmv.

  15. Coal liquefaction process streams characterization and evaluation. Topical report: Analytical methods for application to coal-derived resids, A literature survey

    SciTech Connect

    Brandes, S.D.

    1993-06-01

    This literature survey was conducted to address an important question: What are the methods available in the realm of analytical chemistry that may have potential usefulness to the development of coal liquefaction technology? In an attempt to answer to that question, the emphasis of this survey was directed at analytical techniques which would be applicable to the high molecular weight, non-distillable residue of coal-derived liquids. It is this material which is most problematic to the analytical investigator and the developer of direct coal liquefaction processes. A number of comprehensive analytical reviews of literature dealing with coal and other fossil fuels are available. This literature survey will (1) be limited to articles published between 1980--1991, with some exceptions; (2) be limited to the use of analytical methods for high molecular weight, primarily nondistillable, fossil fuel-derived materials, except where the application of an analytical method to coals or distillates may show promise for application to non-distillable coal-derived materials; and (3) demonstrate the potential usefulness of an analytical method by showing how the method has been applied to high molecular weight, non-distillable materials, if not specifically to coal liquids. The text is divided by type of methodology, i.e. spectroscopy, microscopy, etc. Each section will be essentially free-standing. An historical background is provided.

  16. Body burden of pesticides and wastewater-derived pollutants on freshwater invertebrates: Method development and application in the Danube River.

    PubMed

    Inostroza, Pedro A; Wicht, Anna-Jorina; Huber, Thomas; Nagy, Claudia; Brack, Werner; Krauss, Martin

    2016-07-01

    While environmental risk assessment is typically based on toxicant concentrations in water and/or sediment, awareness is increasing that internal concentrations or body burdens are the key to understand adverse effects in organisms. In order to link environmental micropollutants as causes of observed effects, there is an increasing demand for methods to analyse these chemicals in organisms. Here, a multi-target screening method based on pulverised liquid extraction (PuLE) and a modified QuEChERS approach with an additional hexane phase was developed. It is capable to extract and quantify organic micropollutants of diverse chemical classes in freshwater invertebrates. The method was tested on gammarids from the Danube River (within the Joint Danube Survey 3) and target compounds were analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Furthermore, a non-target screening using high resolution-tandem mass spectrometry (LC-HRMS/MS) was conducted. A total of 17 pollutants were detected and/or quantified in gammarids at low concentrations. Pesticide concentrations ranged from 0.1 to 6.52 ng g(-1) (wet weight), those of wastewater-derived pollutants from 0.1 to 2.83 ng g(-1) (wet weight). The presence of wastewater-derived pollutants was prominent at all spots sampled. Using non-target screening, we could successfully identify several chlorinated compounds. These results demonstrate for the first time the presence of pesticides and wastewater-derived pollutants in invertebrates of the Danube River.

  17. Application of HBOCs electrophoretic method to detect a new blood substitute derived from the giant extracellular haemoglobin of lugworm.

    PubMed

    Marchand, A; Crepin, N; Roulland, I; Semence, F; Domergue, V; Zal, F; Polard, V; Coquerel, A

    2016-10-27

    Manipulation of blood and blood components is prohibited in sports by the World Anti-Doping Agency (WADA). This includes the use of blood substitutes to increase oxygen transport, like haemoglobin-based oxygen carriers (HBOCs), which are compounds derived from haemoglobin. Despite their medical interest, the first generation of HBOCs had serious adverse effects and was abandoned. However, new studies are now exploiting the properties of marine worm haemoglobins, which circulate as giant extracellular complexes with high oxygen-binding capacities. HEMOXYCarrier® (HC), developed by Hemarina, is one of the most advanced and promising HBOCs, and HC may become a tempting doping tool for athletes in the future. Here, HC detection in plasma/serum was evaluated with the method used to detect the first HBOCs, based on electrophoresis and heme peroxidase properties. An HC-derived product was identified in human plasma up to 72 h after in vitro incubation at 37 °C. HC degradation also induced methemalbumin formation. After injecting HC at the effective dose of 200 mg/kg into mice, the HC-derived product was detected only for a few hours and no accumulation of methemalbumin was observed. Due to this limited detection window in vivo, measuring specific worm globin degradation products by mass spectrometry might be an alternative for future anti-doping analyses. Copyright © 2016 John Wiley & Sons, Ltd.

  18. A New Isolation and Evaluation Method for Marine-Derived Yeast spp. with Potential Applications in Industrial Biotechnology.

    PubMed

    Zaky, Abdelrahman Saleh; Greetham, Darren; Louis, Edward J; Tucker, Greg A; Du, Chenyu

    2016-11-28

    Yeasts that are present in marine environments have evolved to survive hostile environments that are characterized by high exogenous salt content, high concentrations of inhibitory compounds, and low soluble carbon and nitrogen levels. Therefore, yeasts isolated from marine environments could have interesting characteristics for industrial applications. However, the application of marine yeast in research or industry is currently very limited owing to the lack of a suitable isolation method. Current methods for isolation suffer from fungal interference and/or low number of yeast isolates. In this paper, an efficient and non-laborious isolation method has been developed and successfully isolated large numbers of yeasts without bacterial or fungal growth. The new method includes a three-cycle enrichment step followed by an isolation step and a confirmation step. Using this method, 116 marine yeast strains were isolated from 14 marine samples collected in the UK, Egypt, and the USA. These strains were further evaluated for the utilization of fermentable sugars (glucose, xylose, mannitol, and galactose) using a phenotypic microarray assay. Seventeen strains with higher sugar utilization capacity than the reference terrestrial yeast Saccharomyces cerevisiae NCYC 2592 were selected for identification by sequencing of the ITS and D1/D2 domains. These strains belonged to six species: S. cerevisiae, Candida tropicalis, Candida viswanathii, Wickerhamomyces anomalus, Candida glabrata, and Pichia kudriavzevii. The ability of these strains for improved sugar utilization using seawater-based media was confirmed and, therefore, they could potentially be utilized in fermentations using marine biomass in seawater media, particularly for the production of bioethanol and other biochemical products.

  19. Application of Synchrotron Methods to Assess the Uptake of Roadway-Derived Zn by Earthworms in an Urban Soil

    SciTech Connect

    Lev,S.; Landa, E.; Szlavecz, K.; Casey, R.; Snodgrass, J.

    2008-01-01

    The impact of human activities on biogeochemical cycles in terrestrial environments is nowhere more apparent than in urban landscapes. Trace metals, collected on roadways and transported by storm water, may contaminate soils and sediments associated with storm water management systems. These systems will accumulate metals and associated sediments may reach toxic levels for terrestrial and aquatic organisms using the retention basins as habitat. The fate and bioavailability of these metals once deposited is poorly understood. Here we present results from a dose-response experiment that examines the application of synchrotron X-ray fluorescence methods ({mu}-SXRF) to test the hypothesis that earthworms will bio-accumulate Zn in a roadway-dust contaminated soil system providing a potential pathway for roadway contaminants into the terrestrial food web, and that the storage and distribution of Zn will change with the level of exposure reflecting the micronutrient status of Zn. Lumbricus friendi was exposed to Zn-bearing roadway dust amended to a field soil at six target concentrations ranging from background levels (45 mg/kg Zn) to highly contaminated levels (460 mg/kg Zn) designed to replicate the observed concentration range in storm-water retention basin soils. After a 30 day exposure, Zn storage in the intestine is positively correlated with dose and there is a change in the pattern of Zn storage within the intestine. This relationship is only clear when {mu}-SXRF Zn map data is coupled with a traditional toxicological approach, and suggests that the gut concentration in L. friendi is a better indicator of Zn bioaccumulation and storage than the total body burden.

  20. Application of synchrotron methods to assess the uptake of roadway-derived Zn by earthworms in an urban soil

    USGS Publications Warehouse

    Lev, S.M.; Landa, E.R.; Szlavecz, K.; Casey, R.; Snodgrass, J.

    2008-01-01

    The impact of human activities on biogeochemical cycles in terrestrial environments is nowhere more apparent than in urban landscapes. Trace metals, collected on roadways and transported by storm water, may contaminate soils and sediments associated with storm water management systems. These systems will accumulate metals and associated sediments may reach toxic levels for terrestrial and aquatic organisms using the retention basins as habitat. The fate and bioavailability of these metals once deposited is poorly understood. Here we present results from a dose-response experiment that examines the application of synchrotron X-ray fluorescence methods (??-SXRF) to test the hypothesis that earthworms will bio-accumulate Zn in a roadway-dust contaminated soil system providing a potential pathway for roadway contaminants into the terrestrial food web, and that the storage and distribution of Zn will change with the level of exposure reflecting the micronutrient status of Zn. Lumbricus friendi was exposed to Zn-bearing roadway dust amended to a field soil at six target concentrations ranging from background levels (45 mg/kg Zn) to highly contaminated levels (460 mg/kg Zn) designed to replicate the observed concentration range in storm-water retention basin soils. After a 30 day exposure, Zn storage in the intestine is positively correlated with dose and there is a change in the pattern of Zn storage within the intestine. This relationship is only clear when ??-SXRF Zn map data is coupled with a traditional toxicological approach, and suggests that the gut concentration in L. friendi is a better indicator of Zn bioaccumulation and storage than the total body burden. ?? 2008 The Mineralogical Society.

  1. A numerical method to compute derivatives of functions of large complex matrices and its application to the overlap Dirac operator at finite chemical potential

    NASA Astrophysics Data System (ADS)

    Puhr, Matthias; Buividovich, Pavel

    2016-11-01

    We present a method for the numerical calculation of derivatives of functions of general complex matrices. The method can be used in combination with any algorithm that evaluates or approximates the desired matrix function, in particular with implicit Krylov-Ritz-type approximations. An important use case for the method is the evaluation of the overlap Dirac operator in lattice Quantum Chromodynamics (QCD) at finite chemical potential, which requires the application of the sign function of a non-Hermitian matrix to some source vector. While the sign function of non-Hermitian matrices in practice cannot be efficiently approximated with source-independent polynomials or rational functions, sufficiently good approximating polynomials can still be constructed for each particular source vector. Our method allows for an efficient calculation of the derivatives of such implicit approximations with respect to the gauge field or other external parameters, which is necessary for the calculation of conserved lattice currents or the fermionic force in Hybrid Monte-Carlo or Langevin simulations. We also give an explicit deflation prescription for the case when one knows several eigenvalues and eigenvectors of the matrix being the argument of the differentiated function. We test the method for the two-sided Lanczos approximation of the finite-density overlap Dirac operator on realistic SU(3) gauge field configurations on lattices with sizes as large as 14 ×143 and 6 ×183.

  2. An Empirical Method for Deriving Grade Equivalence for University Entrance Qualifications: An Application to A Levels and the International Baccalaureate

    ERIC Educational Resources Information Center

    Green, Francis; Vignoles, Anna

    2012-01-01

    We present a method to compare different qualifications for entry to higher education by studying students' subsequent performance. Using this method for students holding either the International Baccalaureate (IB) or A-levels gaining their degrees in 2010, we estimate an "empirical" equivalence scale between IB grade points and UCAS…

  3. Calculation of internal dose from ingested soil-derived uranium in humans: Application of a new method.

    PubMed

    Träber, S C; Li, W B; Höllriegl, V; Nebelung, K; Michalke, B; Rühm, W; Oeh, U

    2015-08-01

    The aim of the present study was to determine the internal dose in humans after the ingestion of soil highly contaminated with uranium. Therefore, an in vitro solubility assay was performed to estimate the bioaccessibility of uranium for two types of soil. Based on the results, the corresponding bioavailabilities were assessed by using a recently published method. Finally, these bioavailability data were used together with the biokinetic model of uranium to assess the internal doses for a hypothetical but realistic scenario characterized by a daily ingestion of 10 mg of soil over 1 year. The investigated soil samples were from two former uranium mining sites of Germany with (238)U concentrations of about 460 and 550 mg/kg. For these soils, the bioavailabilities of (238)U were quantified as 0.18 and 0.28 % (geometric mean) with 2.5th percentiles of 0.02 and 0.03 % and 97.5th percentiles of 1.48 and 2.34 %, respectively. The corresponding calculated annual committed effective doses for the assumed scenario were 0.4 and 0.6 µSv (GM) with 2.5th percentiles of 0.2 and 0.3 µSv and 97.5th percentiles of 1.6 and 3.0 µSv, respectively. These annual committed effective doses are similar to those from natural uranium intake by food and drinking water, which is estimated to be 0.5 µSv. Based on the present experimental data and the selected ingestion scenario, the investigated soils-although highly contaminated with uranium-are not expected to pose any major health risk to humans related to radiation.

  4. Truncated Gaussian and derived methods

    NASA Astrophysics Data System (ADS)

    Beucher, Hélène; Renard, Didier

    2016-09-01

    The interest of a digital model to represent the geological characteristics of the field is well established. However, the way to obtain it is not straightforward because this translation is necessarily a simplification of the actual field. This paper describes a stochastic model called truncated Gaussian simulations (TGS), which distributes a collection of facies or lithotypes over an area of interest. This method is based on facies proportions, spatial distribution and relationships, which can be easily tuned to produce numerous different textures. Initially developed for ordered facies, this model has been extended to complex organizations, where facies are not sequentially ordered. This method called pluri-Gaussian simulation (PGS) considers several Gaussian random functions, which can be correlated. PGS can produce a large variety of lithotype setups, as illustrated by several examples such as oriented deposits or high frequency layering.

  5. Spectrophotometric simultaneous determination of Tenofovir disoproxil fumarate and Emtricitabine in combined tablet dosage form by ratio derivative, first order derivative and absorbance corrected methods and its application to dissolution study.

    PubMed

    Choudhari, Vishnu P; Ingale, Snehal; Gite, Sacchidanand R; Tajane, Dipali D; Modak, Vikram G; Ambekar, Archana

    2011-01-01

    Three simple, economical, precise, and accurate methods are described for the simultaneous determination of Tenofovir disoproxil fumarate (TE) and Emtricitabine (EM) in combined tablet dosage form. The first method is ratio derivative spectra, second is first-order derivative spectrophotometry and third is absorption corrected method. The amplitudes at 271.07 and 302.17 nm in the ratio derivative method, 224.38 and 306.88 nm in the first order derivative method were selected to determine Tenofovir disoproxil fumarate (TE) and Emtricitabine (EM), respectively, in combined formulation. Beer's law is obeyed in the concentration range of 3-21 μg/ml for TE and 2-14 μg/ml for EM for first two methods and range for third method was 6-30 μg/ml of TE and 4-20 μg/ml of EM. The percent assay for commercial formulation was found to be in the range 98.91%-101.72% for both the analytes by the proposed three methods. Absorption corrected method was successfully applied to carry out dissolution study of commercial tablet formulation by using USP II dissolution test apparatus. The methods were validated with respect to linearity, precision, and accuracy. Recoveries by proposed methods were found in the range of 99.06 %-101.34 % for both the analytes.

  6. Plant-derived nanostructures: types and applications

    EPA Science Inventory

    Plant-derived nanostructures and nanoparticles (NPs) have functional applications in numerous disciplines such as health care, food and feed, cosmetics, biomedical science, energy science, drug-gene delivery, environmental health, and so on. Consequently, it is imperative for res...

  7. Structural sensitivity analysis: Methods, applications and needs

    NASA Technical Reports Server (NTRS)

    Adelman, H. M.; Haftka, R. T.; Camarda, C. J.; Walsh, J. L.

    1984-01-01

    Innovative techniques applicable to sensitivity analysis of discretized structural systems are reviewed. The techniques include a finite difference step size selection algorithm, a method for derivatives of iterative solutions, a Green's function technique for derivatives of transient response, simultaneous calculation of temperatures and their derivatives, derivatives with respect to shape, and derivatives of optimum designs with respect to problem parameters. Computerized implementations of sensitivity analysis and applications of sensitivity derivatives are also discussed. Some of the critical needs in the structural sensitivity area are indicated along with plans for dealing with some of those needs.

  8. Structural sensitivity analysis: Methods, applications, and needs

    NASA Technical Reports Server (NTRS)

    Adelman, H. M.; Haftka, R. T.; Camarda, C. J.; Walsh, J. L.

    1984-01-01

    Some innovative techniques applicable to sensitivity analysis of discretized structural systems are reviewed. These techniques include a finite-difference step-size selection algorithm, a method for derivatives of iterative solutions, a Green's function technique for derivatives of transient response, a simultaneous calculation of temperatures and their derivatives, derivatives with respect to shape, and derivatives of optimum designs with respect to problem parameters. Computerized implementations of sensitivity analysis and applications of sensitivity derivatives are also discussed. Finally, some of the critical needs in the structural sensitivity area are indicated along with Langley plans for dealing with some of these needs.

  9. Application of the N-point moving average method for brachial pressure waveform-derived estimation of central aortic systolic pressure.

    PubMed

    Shih, Yuan-Ta; Cheng, Hao-Min; Sung, Shih-Hsien; Hu, Wei-Chih; Chen, Chen-Huan

    2014-04-01

    The N-point moving average (NPMA) is a mathematical low-pass filter that can smooth peaked noninvasively acquired radial pressure waveforms to estimate central aortic systolic pressure using a common denominator of N/4 (where N=the acquisition sampling frequency). The present study investigated whether the NPMA method can be applied to brachial pressure waveforms. In the derivation group, simultaneously recorded invasive high-fidelity brachial and central aortic pressure waveforms from 40 subjects were analyzed to identify the best common denominator. In the validation group, the NPMA method with the obtained common denominator was applied on noninvasive brachial pressure waveforms of 100 subjects. Validity was tested by comparing the noninvasive with the simultaneously recorded invasive central aortic systolic pressure. Noninvasive brachial pressure waveforms were calibrated to the cuff systolic and diastolic blood pressures. In the derivation study, an optimal denominator of N/6 was identified for NPMA to derive central aortic systolic pressure. The mean difference between the invasively/noninvasively estimated (N/6) and invasively measured central aortic systolic pressure was 0.1±3.5 and -0.6±7.6 mm Hg in the derivation and validation study, respectively. It satisfied the Association for the Advancement of Medical Instrumentation standard of 5±8 mm Hg. In conclusion, this method for estimating central aortic systolic pressure using either invasive or noninvasive brachial pressure waves requires a common denominator of N/6. By integrating the NPMA method into the ordinary oscillometric blood pressure determining process, convenient noninvasive central aortic systolic pressure values could be obtained with acceptable accuracy.

  10. Selection and drift in subdivided populations: a straightforward method for deriving diffusion approximations and applications involving dominance, selfing and local extinctions.

    PubMed Central

    Roze, Denis; Rousset, François

    2003-01-01

    Population structure affects the relative influence of selection and drift on the change in allele frequencies. Several models have been proposed recently, using diffusion approximations to calculate fixation probabilities, fixation times, and equilibrium properties of subdivided populations. We propose here a simple method to construct diffusion approximations in structured populations; it relies on general expressions for the expectation and variance in allele frequency change over one generation, in terms of partial derivatives of a "fitness function" and probabilities of genetic identity evaluated in a neutral model. In the limit of a very large number of demes, these probabilities can be expressed as functions of average allele frequencies in the metapopulation, provided that coalescence occurs on two different timescales, which is the case in the island model. We then use the method to derive expressions for the probability of fixation of new mutations, as a function of their dominance coefficient, the rate of partial selfing, and the rate of deme extinction. We obtain more precise approximations than those derived by recent work, in particular (but not only) when deme sizes are small. Comparisons with simulations show that the method gives good results as long as migration is stronger than selection. PMID:14704194

  11. Computing Airplane Stopping Distance: Applications of Derivatives.

    ERIC Educational Resources Information Center

    Tylee, J. Louis

    1997-01-01

    Presents two real world applications that use derivatives and are related to computing the distance required to stop an airplane. Examines the curve-fitting techniques used to develop an equation for braking force and develops equations for the deceleration and speed. (DDR)

  12. A cGMP-applicable expansion method for aggregates of human neural stem and progenitor cells derived from pluripotent stem cells or fetal brain tissue.

    PubMed

    Shelley, Brandon C; Gowing, Geneviève; Svendsen, Clive N

    2014-06-15

    A cell expansion technique to amass large numbers of cells from a single specimen for research experiments and clinical trials would greatly benefit the stem cell community. Many current expansion methods are laborious and costly, and those involving complete dissociation may cause several stem and progenitor cell types to undergo differentiation or early senescence. To overcome these problems, we have developed an automated mechanical passaging method referred to as "chopping" that is simple and inexpensive. This technique avoids chemical or enzymatic dissociation into single cells and instead allows for the large-scale expansion of suspended, spheroid cultures that maintain constant cell/cell contact. The chopping method has primarily been used for fetal brain-derived neural progenitor cells or neurospheres, and has recently been published for use with neural stem cells derived from embryonic and induced pluripotent stem cells. The procedure involves seeding neurospheres onto a tissue culture Petri dish and subsequently passing a sharp, sterile blade through the cells effectively automating the tedious process of manually mechanically dissociating each sphere. Suspending cells in culture provides a favorable surface area-to-volume ratio; as over 500,000 cells can be grown within a single neurosphere of less than 0.5 mm in diameter. In one T175 flask, over 50 million cells can grow in suspension cultures compared to only 15 million in adherent cultures. Importantly, the chopping procedure has been used under current good manufacturing practice (cGMP), permitting mass quantity production of clinical-grade cell products.

  13. Method to screen for relevant yeast two-hybrid-derived clones by coimmunoprecipitation and colocalization of epitope-tagged fragments--application to Bcl-xL.

    PubMed

    Wong, C; Naumovski, L

    1997-10-01

    The yeast two-hybrid system is a powerful genetic method to screen cDNA libraries to identify protein-protein interactions. A screen with a typical bait may yield many clones, including ones that are not biologically relevant which need to be eliminated by evaluating each clone in an alternative assay to confirm the interaction with the bait protein. We have developed an efficient assay to quickly screen two-hybrid-derived clones for coimmunoprecipitation and colocalization with the bait protein in mammalian cells. Gene fragments derived from a two-hybrid screen are cloned into an epitope tagging vector that can generate high levels of epitope-tagged protein in mammalian cells. The vector expressing an epitope-tagged protein is then cotransfected into mammalian cells with an expression vector for the bait protein. Interaction between the bait protein and epitope-tagged protein is evaluated by coimmunoprecipitation and colocalization. We demonstrate the utility of this approach by applying it to clones isolated in a two-hybrid screen using Bcl-xL as bait, showing that two-hybrid-derived fragments of Bad and Bax, previously known to interact with Bcl-xL, both colocalize and coimmunoprecipitate with Bcl-xL.

  14. A comparison of computational methods for detecting bursts in neuronal spike trains and their application to human stem cell-derived neuronal networks.

    PubMed

    Cotterill, Ellese; Charlesworth, Paul; Thomas, Christopher W; Paulsen, Ole; Eglen, Stephen J

    2016-08-01

    Accurate identification of bursting activity is an essential element in the characterization of neuronal network activity. Despite this, no one technique for identifying bursts in spike trains has been widely adopted. Instead, many methods have been developed for the analysis of bursting activity, often on an ad hoc basis. Here we provide an unbiased assessment of the effectiveness of eight of these methods at detecting bursts in a range of spike trains. We suggest a list of features that an ideal burst detection technique should possess and use synthetic data to assess each method in regard to these properties. We further employ each of the methods to reanalyze microelectrode array (MEA) recordings from mouse retinal ganglion cells and examine their coherence with bursts detected by a human observer. We show that several common burst detection techniques perform poorly at analyzing spike trains with a variety of properties. We identify four promising burst detection techniques, which are then applied to MEA recordings of networks of human induced pluripotent stem cell-derived neurons and used to describe the ontogeny of bursting activity in these networks over several months of development. We conclude that no current method can provide "perfect" burst detection results across a range of spike trains; however, two burst detection techniques, the MaxInterval and logISI methods, outperform compared with others. We provide recommendations for the robust analysis of bursting activity in experimental recordings using current techniques.

  15. On the Exploitation of Sensitivity Derivatives for Improving Sampling Methods

    NASA Technical Reports Server (NTRS)

    Cao, Yanzhao; Hussaini, M. Yousuff; Zang, Thomas A.

    2003-01-01

    Many application codes, such as finite-element structural analyses and computational fluid dynamics codes, are capable of producing many sensitivity derivatives at a small fraction of the cost of the underlying analysis. This paper describes a simple variance reduction method that exploits such inexpensive sensitivity derivatives to increase the accuracy of sampling methods. Three examples, including a finite-element structural analysis of an aircraft wing, are provided that illustrate an order of magnitude improvement in accuracy for both Monte Carlo and stratified sampling schemes.

  16. Second-derivative synchronous fluorometric method for the simultaneous determination of cinnarizine and domperidone in pharmaceutical preparations. Application to biological fluids.

    PubMed

    Walash, M I; Belal, F; El-Enany, N; Abdelal, A A

    2008-01-01

    A rapid, simple and highly sensitive second derivative synchronous fluorometric method has been developed for the simultaneous analysis of binary mixture of cinnarizine (CN) and domperidone (DOM). The method is based upon measurement of the native fluorescence of these drugs at Deltalambda=80 nm in aqueous methanol (50% V/V). The different experimental parameters affecting the native fluorescence of the studied drugs were carefully studied and optimized. The fluorescence-concentration plots were rectilinear over the range of 0.1 to 1.3 microg mL(-1) and 0.1-3.0 microg mL(-1) for CN and DOM, respectively with lower detection limits of 0.017 and 5.77 x 10(-3) microg mL(-1) and quantification limits of 0.058 and 0.02 microg mL(-1) for CN and DOM. The proposed method was successfully applied for the determination of the studied compounds in synthetic mixtures and in commercial tablets. The results obtained were in good agreement with those obtained with reference methods. The high sensitivity attained by the synchronous fluorometric method allowed the determination of CN in real and spiked human plasma. The mean % recoveries in case of spiked human plasma (n=3) were 96.39+/-1.18 while that in real human plasma (n = 3) was 104.67+/-4.16.

  17. Phase diagrams, thermodynamic properties and sound velocities derived from a multiple Einstein method using vibrational densities of states: an application to MgO-SiO2

    NASA Astrophysics Data System (ADS)

    Jacobs, Michael H. G.; Schmid-Fetzer, Rainer; van den Berg, Arie P.

    2017-01-01

    In a previous paper, we showed a technique that simplifies Kieffer's lattice vibrational method by representing the vibrational density of states with multiple Einstein frequencies. Here, we show that this technique can be applied to construct a thermodynamic database that accurately represents thermodynamic properties and phase diagrams for substances in the system MgO-SiO2. We extended our technique to derive shear moduli of the relevant phases in this system in pressure-temperature space. For the construction of the database, we used recently measured calorimetric and volumetric data. We show that incorporating vibrational densities of states predicted from ab initio methods into our models enables discrimination between different experimental data sets for heat capacity. We show a general technique to optimize the number of Einstein frequencies in the VDoS, such that thermodynamic properties are affected insignificantly. This technique allows constructing clones of databases from which we demonstrate that the VDoS has a significant effect on heat capacity and entropy, and an insignificant effect on volume properties.

  18. Computational Methods for Dynamic Stability and Control Derivatives

    NASA Technical Reports Server (NTRS)

    Green, Lawrence L.; Spence, Angela M.; Murphy, Patrick C.

    2003-01-01

    Force and moment measurements from an F-16XL during forced pitch oscillation tests result in dynamic stability derivatives, which are measured in combinations. Initial computational simulations of the motions and combined derivatives are attempted via a low-order, time-dependent panel method computational fluid dynamics code. The code dynamics are shown to be highly questionable for this application and the chosen configuration. However, three methods to computationally separate such combined dynamic stability derivatives are proposed. One of the separation techniques is demonstrated on the measured forced pitch oscillation data. Extensions of the separation techniques to yawing and rolling motions are discussed. In addition, the possibility of considering the angles of attack and sideslip state vector elements as distributed quantities, rather than point quantities, is introduced.

  19. Computational Methods for Dynamic Stability and Control Derivatives

    NASA Technical Reports Server (NTRS)

    Green, Lawrence L.; Spence, Angela M.; Murphy, Patrick C.

    2004-01-01

    Force and moment measurements from an F-16XL during forced pitch oscillation tests result in dynamic stability derivatives, which are measured in combinations. Initial computational simulations of the motions and combined derivatives are attempted via a low-order, time-dependent panel method computational fluid dynamics code. The code dynamics are shown to be highly questionable for this application and the chosen configuration. However, three methods to computationally separate such combined dynamic stability derivatives are proposed. One of the separation techniques is demonstrated on the measured forced pitch oscillation data. Extensions of the separation techniques to yawing and rolling motions are discussed. In addition, the possibility of considering the angles of attack and sideslip state vector elements as distributed quantities, rather than point quantities, is introduced.

  20. 45 CFR 1630.12 - Applicability to derivative income.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 4 2011-10-01 2011-10-01 false Applicability to derivative income. 1630.12... CORPORATION COST STANDARDS AND PROCEDURES § 1630.12 Applicability to derivative income. (a) Derivative income... activity. (b) Derivative income which is allocated to the LSC fund in accordance with paragraph (a) of...

  1. 45 CFR 1630.12 - Applicability to derivative income.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 4 2013-10-01 2013-10-01 false Applicability to derivative income. 1630.12... CORPORATION COST STANDARDS AND PROCEDURES § 1630.12 Applicability to derivative income. (a) Derivative income... activity. (b) Derivative income which is allocated to the LSC fund in accordance with paragraph (a) of...

  2. 45 CFR 1630.12 - Applicability to derivative income.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 4 2014-10-01 2014-10-01 false Applicability to derivative income. 1630.12... CORPORATION COST STANDARDS AND PROCEDURES § 1630.12 Applicability to derivative income. (a) Derivative income... activity. (b) Derivative income which is allocated to the LSC fund in accordance with paragraph (a) of...

  3. 45 CFR 1630.12 - Applicability to derivative income.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Applicability to derivative income. 1630.12... CORPORATION COST STANDARDS AND PROCEDURES § 1630.12 Applicability to derivative income. (a) Derivative income... activity. (b) Derivative income which is allocated to the LSC fund in accordance with paragraph (a) of...

  4. 45 CFR 1630.12 - Applicability to derivative income.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 4 2012-10-01 2012-10-01 false Applicability to derivative income. 1630.12... CORPORATION COST STANDARDS AND PROCEDURES § 1630.12 Applicability to derivative income. (a) Derivative income... activity. (b) Derivative income which is allocated to the LSC fund in accordance with paragraph (a) of...

  5. System and method for deriving a process-based specification

    NASA Technical Reports Server (NTRS)

    Hinchey, Michael Gerard (Inventor); Rash, James Larry (Inventor); Rouff, Christopher A. (Inventor)

    2009-01-01

    A system and method for deriving a process-based specification for a system is disclosed. The process-based specification is mathematically inferred from a trace-based specification. The trace-based specification is derived from a non-empty set of traces or natural language scenarios. The process-based specification is mathematically equivalent to the trace-based specification. Code is generated, if applicable, from the process-based specification. A process, or phases of a process, using the features disclosed can be reversed and repeated to allow for an interactive development and modification of legacy systems. The process is applicable to any class of system, including, but not limited to, biological and physical systems, electrical and electro-mechanical systems in addition to software, hardware and hybrid hardware-software systems.

  6. Application of ZnO nanorods loaded on activated carbon for ultrasonic assisted dyes removal: Experimental design and derivative spectrophotometry method.

    PubMed

    Ansari, Fatemeh; Ghaedi, Mehrorang; Taghdiri, Mehdi; Asfaram, Arash

    2016-11-01

    A method based on application of ZnO nanorods loaded on activated carbon (ZnO-NRs-AC) for adsorption of Bromocresol Green (BCG) and Eosin Y (EY) accelerated by ultrasound was described. The present material was synthesized under ultrasound assisted wet-chemical method and subsequently was characterized by FE-SEM, TEM, BET and XRD analysis. The extent of contribution of conventional variables like pH (2.0-10.0), BCG concentration (4-20mgL(-1)), EY concentration (3-23mgL(-1)), adsorbent dosage (0.01-0.03g), sonication time (1-5min) and centrifuge time (2-6min) as main and interaction part were investigated by central composite design under response surface methodology. Analysis of variance (ANOVA) was adapted to experimental data and guide the best operational conditions mass by set at 6.0, 9mgL(-1), 10mgL(-1), 0.02g, 4 and 4min for pH, BCG concentration, EY concentration, adsorbent dosage, sonication and centrifuge time, respectively. At these specified conditions dye adsorption efficiency was higher than 99.5%. The suitability and well prediction of optimum point was tested by conducting five experiments and respective results revel that RSD% was lower than 3% and high quality of fitting was confirmed by t-test. The experimental data were best fitted in Langmuir isotherm equation and the removal followed pseudo second order kinetics. The experimentally obtained maximum adsorption capacities were estimated as 57.80 and 61.73mgg(-1) of ZnO-NRs-AC for BCG and EY respectively from binary dye solutions. The mechanism of removal was explained by boundary layer diffusion via intraparticle diffusion.

  7. Empirical Distributional Semantics: Methods and Biomedical Applications

    PubMed Central

    Cohen, Trevor; Widdows, Dominic

    2009-01-01

    Over the past fifteen years, a range of methods have been developed that are able to learn human-like estimates of the semantic relatedness between terms from the way in which these terms are distributed in a corpus of unannotated natural language text. These methods have also been evaluated in a number of applications in the cognitive science, computational linguistics and the information retrieval literatures. In this paper, we review the available methodologies for derivation of semantic relatedness from free text, as well as their evaluation in a variety of biomedical and other applications. Recent methodological developments, and their applicability to several existing applications are also discussed. PMID:19232399

  8. Advancing MODFLOW Applying the Derived Vector Space Method

    NASA Astrophysics Data System (ADS)

    Herrera, G. S.; Herrera, I.; Lemus-García, M.; Hernandez-Garcia, G. D.

    2015-12-01

    The most effective domain decomposition methods (DDM) are non-overlapping DDMs. Recently a new approach, the DVS-framework, based on an innovative discretization method that uses a non-overlapping system of nodes (the derived-nodes), was introduced and developed by I. Herrera et al. [1, 2]. Using the DVS-approach a group of four algorithms, referred to as the 'DVS-algorithms', which fulfill the DDM-paradigm (i.e. the solution of global problems is obtained by resolution of local problems exclusively) has been derived. Such procedures are applicable to any boundary-value problem, or system of such equations, for which a standard discretization method is available and then software with a high degree of parallelization can be constructed. In a parallel talk, in this AGU Fall Meeting, Ismael Herrera will introduce the general DVS methodology. The application of the DVS-algorithms has been demonstrated in the solution of several boundary values problems of interest in Geophysics. Numerical examples for a single-equation, for the cases of symmetric, non-symmetric and indefinite problems were demonstrated before [1,2]. For these problems DVS-algorithms exhibited significantly improved numerical performance with respect to standard versions of DDM algorithms. In view of these results our research group is in the process of applying the DVS method to a widely used simulator for the first time, here we present the advances of the application of this method for the parallelization of MODFLOW. Efficiency results for a group of tests will be presented. References [1] I. Herrera, L.M. de la Cruz and A. Rosas-Medina. Non overlapping discretization methods for partial differential equations, Numer Meth Part D E, (2013). [2] Herrera, I., & Contreras Iván "An Innovative Tool for Effectively Applying Highly Parallelized Software To Problems of Elasticity". Geofísica Internacional, 2015 (In press)

  9. Derivation and application of pluripotent stem cells for regenerative medicine.

    PubMed

    Wang, Jiaqiang; Zhou, Qi

    2016-06-01

    Pluripotent stem cells (PSCs) are cells that can differentiate into any type of cells in the body, therefore have valuable promise in regenerative medicine of cell replacement therapies and tissue/organ engineering. PSCs can be derived either from early embryos or directly from somatic cells by epigenetic reprogramming that result in customized cells from patients. Here we summarize the methods of deriving PSCs, the various types of PSCs generated with different status, and their versatile applications in both clinical and embryonic development studies. We also discuss an intriguing potential application of PSCs in constructing tissues/organs in large animals by interspecies chimerism. All these emerging findings are likely to contribute to the breakthroughs in biological research and the prosperous prospects of regenerative medicine.

  10. Time-derivative preconditioning method for multicomponent flow

    NASA Astrophysics Data System (ADS)

    Housman, Jeffrey Allen

    A time-derivative preconditioned system of equations suitable for the numerical simulation of single component and multicomponent inviscid flows at all speeds is formulated. The system is shown to be hyperbolic in time and remain well-posed at low Mach numbers, allowing an efficient time marching solution strategy to be utilized from transonic to incompressible flow speeds. For multicomponent flow at low speed, a preconditioned nonconservative discretization scheme is described which preserves pressure and velocity equilibrium across fluid interfaces, handles sharp liquid/gas interfaces with large density ratios, while remaining well-conditioned for time marching methods. The method is then extended to transonic and supersonic flows using a hybrid conservative/nonconservative formulation which retains the pressure/velocity equilibrium property and converges to the correct weak solution when shocks are present. In order to apply the proposed model to complex flow applications, the overset grid methodology is used where the equations are transformed to a nonorthogonal curvilinear coordinate system and discretized on structured body-fitted curvilinear grids. The multicomponent model and its extension to homogeneous multiphase mixtures is discussed and the hyperbolicity of the governing equations is demonstrated. Low Mach number perturbation analysis is then performed on the system of equations and a local time-derivative preconditioning matrix is derived allowing time marching numerical methods to remain efficient at low speeds. Next, a particular time marching numerical method is presented along with three discretization schemes for the convective terms. These include a conservative preconditioned Roe type method, a nonconservative preconditioned Split Coefficient Matrix (SCM) method, and hybrid formulation which combines the conservative and nonconservative schemes using a simple switching function. A characteristic boundary treatment which includes time-derivative

  11. Environmental applications of chitosan and its derivatives.

    PubMed

    Yong, Soon Kong; Shrivastava, Manoj; Srivastava, Prashant; Kunhikrishnan, Anitha; Bolan, Nanthi

    2015-01-01

    gels by using coagulating (e.g., alginate, phosphate) or crosslinking agents (e.g., GA, ECH). Such immobilization maintains the stability of sensing elements in the chitosan gel phase, and prevents inactivation and loss of the sensing agent. In this review, we have shown that chitosan, an efficient by-product of a waste biomaterial, has great potential for many environmental applications. With certain limitations, chitosan and its derivatives can be used for remediating contaminated soil and wastewater. Notwithstanding, further research is needed to enhance the physicochemical properties of chitosan and mitigate its deficiencies.

  12. Methods for synthesis of olefins and derivatives

    DOEpatents

    Burk, Mark J.; Pharkya, Priti; Van Dien, Stephen J.; Burgard, Anthony P.; Schilling, Christophe H.

    2016-06-14

    The invention provides a method of producing acrylic acid. The method includes contacting fumaric acid with a sufficient amount of ethylene in the presence of a cross-metathesis transformation catalyst to produce about two moles of acrylic acid per mole of fumaric acid. Also provided is an acrylate ester. The method includes contacting fumarate diester with a sufficient amount of ethylene in the presence of a cross-metathesis transformation catalyst to produce about two moles of acrylate ester per mole of fumarate diester. An integrated process for process for producing acrylic acid or acrylate ester is provided which couples bioproduction of fumaric acid with metathesis transformation. An acrylic acid and an acrylate ester production also is provided.

  13. Methods for deoxygenating biomass-derived pyrolysis oil

    DOEpatents

    Brandvold, Timothy A.

    2015-07-14

    Methods for deoxygenating a biomass-derived pyrolysis oil are provided. A method comprising the steps of diluting the biomass-derived pyrolysis oil with a phenolic-containing diluent to form a diluted pyoil-phenolic feed is provided. The diluted pyoil-phenolic feed is contacted with a deoxygenating catalyst in the presence of hydrogen at hydroprocessing conditions effective to form a low-oxygen biomass-derived pyrolysis oil effluent.

  14. Bacteriophages and phage-derived proteins--application approaches.

    PubMed

    Drulis-Kawa, Zuzanna; Majkowska-Skrobek, Grazyna; Maciejewska, Barbara

    2015-01-01

    Currently, the bacterial resistance, especially to most commonly used antibiotics has proved to be a severe therapeutic problem. Nosocomial and community-acquired infections are usually caused by multidrug resistant strains. Therefore, we are forced to develop an alternative or supportive treatment for successful cure of life-threatening infections. The idea of using natural bacterial pathogens such as bacteriophages is already well known. Many papers have been published proving the high antibacterial efficacy of lytic phages tested in animal models as well as in the clinic. Researchers have also investigated the application of non-lytic phages and temperate phages, with promising results. Moreover, the development of molecular biology and novel generation methods of sequencing has opened up new possibilities in the design of engineered phages and recombinant phage-derived proteins. Encouraging performances were noted especially for phage enzymes involved in the first step of viral infection responsible for bacterial envelope degradation, named depolymerases. There are at least five major groups of such enzymes - peptidoglycan hydrolases, endosialidases, endorhamnosidases, alginate lyases and hyaluronate lyases - that have application potential. There is also much interest in proteins encoded by lysis cassette genes (holins, endolysins, spanins) responsible for progeny release during the phage lytic cycle. In this review, we discuss several issues of phage and phage-derived protein application approaches in therapy, diagnostics and biotechnology in general.

  15. Bacteriophages and Phage-Derived Proteins – Application Approaches

    PubMed Central

    Drulis-Kawa, Zuzanna; Majkowska-Skrobek, Grazyna; Maciejewska, Barbara

    2015-01-01

    Currently, the bacterial resistance, especially to most commonly used antibiotics has proved to be a severe therapeutic problem. Nosocomial and community-acquired infections are usually caused by multidrug resistant strains. Therefore, we are forced to develop an alternative or supportive treatment for successful cure of life-threatening infections. The idea of using natural bacterial pathogens such as bacteriophages is already well known. Many papers have been published proving the high antibacterial efficacy of lytic phages tested in animal models as well as in the clinic. Researchers have also investigated the application of non-lytic phages and temperate phages, with promising results. Moreover, the development of molecular biology and novel generation methods of sequencing has opened up new possibilities in the design of engineered phages and recombinant phage-derived proteins. Encouraging performances were noted especially for phage enzymes involved in the first step of viral infection responsible for bacterial envelope degradation, named depolymerases. There are at least five major groups of such enzymes – peptidoglycan hydrolases, endosialidases, endorhamnosidases, alginate lyases and hyaluronate lyases – that have application potential. There is also much interest in proteins encoded by lysis cassette genes (holins, endolysins, spanins) responsible for progeny release during the phage lytic cycle. In this review, we discuss several issues of phage and phage-derived protein application approaches in therapy, diagnostics and biotechnology in general. PMID:25666799

  16. Methods for deoxygenating biomass-derived pyrolysis oil

    DOEpatents

    Baird, Lance Awender; Brandvold, Timothy A.

    2015-06-30

    Methods for deoxygenating a biomass-derived pyrolysis oil are provided. A method for deoxygenating a biomass-derived pyrolysis oil comprising the steps of combining a biomass-derived pyrolysis oil stream with a heated low-oxygen-pyoil diluent recycle stream to form a heated diluted pyoil feed stream is provided. The heated diluted pyoil feed stream has a feed temperature of about 150.degree. C. or greater. The heated diluted pyoil feed stream is contacted with a first deoxygenating catalyst in the presence of hydrogen at first hydroprocessing conditions effective to form a low-oxygen biomass-derived pyrolysis oil effluent.

  17. Trigonometrical fitting conditions for two derivative Runge Kutta methods

    NASA Astrophysics Data System (ADS)

    Monovasilis, Th.; Kalogiratou, Z.; Simos, T. E.

    2016-12-01

    Trigonometrically fitted two derivative explicit Runge-Kutta methods are considered in this work. We give order conditions for trigonometrically fitted methods that use several evaluations of the f and the g functions. We present modified methods based on methods with several f evaluations and one g evaluation.

  18. Deriving and applying generally applicable safety principles

    SciTech Connect

    Spray, S.D.

    1998-08-01

    The nuclear detonation safety of modern nuclear weapons depends on a coordinated safety theme incorporating three general safety principles: isolation, inoperability, and incompatibility. The success of this approach has encouraged them to study whether these and/or other principles might be useful in other applications. Not surprisingly, no additional first-principles (based on physical laws) have been identified. However, a more widely applicable definition and application of the principle-based approach has been developed, resulting in a selection of strategies that are basically subsets and varied combinations of the more general principles above. However, identification of principles to be relied on is only one step in providing a safe design. As one other important example, coordinating overall architecture and strategy is essential: the authors term this a safety theme.

  19. Logarithmic derivative method and system for capacitance measurement.

    PubMed

    Wu, Yichun; Wang, Lingzhi; Cai, Yuanfeng; Wu, Cunqiao

    2015-08-01

    A novel method based on logarithmic derivative is introduced to analyze multi-lifetime decay. As the discharge voltage signal of a RC circuit is a special kind of multi-lifetime exponential decay, the logarithmic derivative method can be used to measure single capacitance and multiple capacitances. With the logarithmic derivative method, a log(t) curve strongly peaked at precisely log(τ) is obtained, where the lifetime τ equals to RC. In a measurement system, if the resistance R is known, then the capacitance under test can be calculated. A logarithmic derivative curve fitting method is also presented, which has better anti-noise capability than the method that simply finds the maximum data on the peak. The curve fitting method can also be used for multiple capacitors measurement. To measure small capacitances, a large enough time window of the measuring instrument is required. Based on a field programmable gate array and a high speed analog-to-digital converter, a measurement system is developed. This system can provide the 16-bit resolution with sampling rate up to 250 MHz, which has a large enough time window for measuring lifetime shorter than 10(-8) s. To reduce the amount of data needed to be stored and the noise due to the derivative treatment of transient data, the interpolation and noise-filter algorithms are employed. Experiments indicate that the logarithmic derivative method and system are suitable for the measurement of capacitances discharge and other exponential decay processes.

  20. Certain implementative applications of Separate Node Ascending Derivatives Expansion (SNADE)

    NASA Astrophysics Data System (ADS)

    Bodur, Derya; Demiralp, Metin

    2017-01-01

    In this work we have focused on a very recently developed method called as Separate Node Ascending Derivatives Expansion (SNADE). SNADE can be considered as an infinite interpolation like Taylor Series Expansion. A Taylor Series is an infinite sum representation whose terms are calculated from the values of the functions derivatives at a single point. This newly proposed method involves denumerable infinitely many nodes in contrast to Taylor Series Expansion. SNADE is based on derivative integration formula for a univariate function. Integral of derivative identity is not only required to be used for the target function but repetitiously for its all derivatives. It may not be required to be used in the same interval. In addition to all these, each derivative value becomes evaluated at a different independent variable value. This work is designed to emphasize on the methods interpolatory nature. For this purpose certain implementation results are given and compared with well-known interpolation methods.

  1. Phosphorus Determination by Derivative Activation Analysis: A Multifaceted Radiochemical Application.

    ERIC Educational Resources Information Center

    Kleppinger, E. W.; And Others

    1984-01-01

    Although determination of phosphorus is important in biology, physiology, and environmental science, traditional gravimetric and colorimetric methods are cumbersome and lack the requisite sensitivity. Therefore, a derivative activation analysis method is suggested. Background information, procedures, and results are provided. (JN)

  2. The functions and clinical applications of tumor-derived exosomes

    PubMed Central

    Shao, Yingkuan; Shen, Yanwei; Chen, Ting; Xu, Fei; Chen, Xuewen; Zheng, Shu

    2016-01-01

    Exosomes are extracellular vesicles with diameters ranging from 30 to 150 nm. They can be secreted by all cell types and transfer information in the form of their contents, which include proteins, lipids and nucleic acids, to other cells throughout the body. They have roles in normal physiological processes as well as in disease development. Here, we review recent findings regarding tumor-derived exosomes, including methods for their extraction and preservation. We also describe the actions of exosomes in tumorigenesis. The exosomal antigen-presenting effect during antitumor immune responses and its suppressive function in immune tolerance are discussed. Finally, we describe the potential application of exosomes to cancer therapy and liquid biopsy. PMID:27517627

  3. Application of Statistically Derived CPAS Parachute Parameters

    NASA Technical Reports Server (NTRS)

    Romero, Leah M.; Ray, Eric S.

    2013-01-01

    The Capsule Parachute Assembly System (CPAS) Analysis Team is responsible for determining parachute inflation parameters and dispersions that are ultimately used in verifying system requirements. A model memo is internally released semi-annually documenting parachute inflation and other key parameters reconstructed from flight test data. Dispersion probability distributions published in previous versions of the model memo were uniform because insufficient data were available for determination of statistical based distributions. Uniform distributions do not accurately represent the expected distributions since extreme parameter values are just as likely to occur as the nominal value. CPAS has taken incremental steps to move away from uniform distributions. Model Memo version 9 (MMv9) made the first use of non-uniform dispersions, but only for the reefing cutter timing, for which a large number of sample was available. In order to maximize the utility of the available flight test data, clusters of parachutes were reconstructed individually starting with Model Memo version 10. This allowed for statistical assessment for steady-state drag area (CDS) and parachute inflation parameters such as the canopy fill distance (n), profile shape exponent (expopen), over-inflation factor (C(sub k)), and ramp-down time (t(sub k)) distributions. Built-in MATLAB distributions were applied to the histograms, and parameters such as scale (sigma) and location (mu) were output. Engineering judgment was used to determine the "best fit" distribution based on the test data. Results include normal, log normal, and uniform (where available data remains insufficient) fits of nominal and failure (loss of parachute and skipped stage) cases for all CPAS parachutes. This paper discusses the uniform methodology that was previously used, the process and result of the statistical assessment, how the dispersions were incorporated into Monte Carlo analyses, and the application of the distributions in

  4. Derivatives of optical path length: from mathematical formulation to applications.

    PubMed

    Lin, Psang Dain

    2015-05-01

    The optical path length (OPL) of an optical system is a highly important parameter since it determines the phase of the light passing through the system and governs the interference and diffraction of the rays as they propagate. The Jacobian and Hessian matrices of the OPL are of fundamental importance in tuning the performance of a system. However, the OPL varies as a recursive function of the incoming ray and the boundary variable vector, and hence computing the Jacobian and Hessian matrices is extremely challenging. In an earlier study by the present group, this problem was addressed by deriving the Jacobian matrix of the OPL with respect to all of the independent system variables of a nonaxially symmetric system. In the present study, the proposed method is extended to the Hessian matrix of a nonaxially symmetric optical system. The proposed method facilitates the cross-sensitivity analysis of the OPL with respect to arbitrary system variables and provides an ideal basis for automatic optical system design applications in which the merit function is defined in terms of wavefront aberrations. An illustrative example is given. It is shown that the proposed method requires fewer iterations than that based on the Jacobian matrix and yields a more reliable and precise optimization performance.

  5. A Definite Integration Method of Calculating Inclination Function and its Derivative

    NASA Astrophysics Data System (ADS)

    Wu, L. D.; Wang, H. B.

    2012-01-01

    The paper gives a definite integration method of calculating inclination function and its derivative. The expression is simple, but its accuracy is very well. It is about 10-15 and 10-13 for inclination function and its derivative, respectively. This level is comparable to the accuracy of Gooding's method. Through a lot of numerical simulations, it is proved that the method has good stability and wide-scope application of inclination. It takes very little time to calculate low-order function (less than 50), so the method can be directly used in calculating terrestrial and sun-moon gravitational perturbation.

  6. Definition and application of longitudinal stability derivatives for elastic airplanes

    NASA Technical Reports Server (NTRS)

    Kemp, W. B., Jr.

    1972-01-01

    A set of longitudinal stability derivatives for elastic airplanes is defined from fundamental principles allowing perturbations in forward speed. Application of these derivatives to longitudinal stability analysis by use of approximate expressions for static stability and control parameters as well as the dynamic equations of motion is illustrated. One commonly used alternative formulation for elastic airplanes is shown to yield significant inaccuracies because of inappropriate interpretation of inertial effects.

  7. Advanced composite applications for sub-micron biologically derived microstructures

    NASA Technical Reports Server (NTRS)

    Schnur, J. M.; Price, R. R.; Schoen, P. E.; Bonanventura, Joseph; Kirkpatrick, Douglas

    1991-01-01

    A major thrust of advanced material development is in the area of self-assembled ultra-fine particulate based composites (micro-composites). The application of biologically derived, self-assembled microstructures to form advanced composite materials is discussed. Hollow 0.5 micron diameter cylindrical shaped microcylinders self-assemble from diacetylenic lipids. These microstructures have a multiplicity of potential applications in the material sciences. Exploratory development is proceeding in application areas such as controlled release for drug delivery, wound repair, and biofouling as well as composites for electronic and magnetic applications, and high power microwave cathodes.

  8. A time-dependent neutron transport method of characteristics formulation with time derivative propagation

    NASA Astrophysics Data System (ADS)

    Hoffman, Adam J.; Lee, John C.

    2016-02-01

    A new time-dependent Method of Characteristics (MOC) formulation for nuclear reactor kinetics was developed utilizing angular flux time-derivative propagation. This method avoids the requirement of storing the angular flux at previous points in time to represent a discretized time derivative; instead, an equation for the angular flux time derivative along 1D spatial characteristics is derived and solved concurrently with the 1D transport characteristic equation. This approach allows the angular flux time derivative to be recast principally in terms of the neutron source time derivatives, which are approximated to high-order accuracy using the backward differentiation formula (BDF). This approach, called Source Derivative Propagation (SDP), drastically reduces the memory requirements of time-dependent MOC relative to methods that require storing the angular flux. An SDP method was developed for 2D and 3D applications and implemented in the computer code DeCART in 2D. DeCART was used to model two reactor transient benchmarks: a modified TWIGL problem and a C5G7 transient. The SDP method accurately and efficiently replicated the solution of the conventional time-dependent MOC method using two orders of magnitude less memory.

  9. A time-dependent neutron transport method of characteristics formulation with time derivative propagation

    SciTech Connect

    Hoffman, Adam J. Lee, John C.

    2016-02-15

    A new time-dependent Method of Characteristics (MOC) formulation for nuclear reactor kinetics was developed utilizing angular flux time-derivative propagation. This method avoids the requirement of storing the angular flux at previous points in time to represent a discretized time derivative; instead, an equation for the angular flux time derivative along 1D spatial characteristics is derived and solved concurrently with the 1D transport characteristic equation. This approach allows the angular flux time derivative to be recast principally in terms of the neutron source time derivatives, which are approximated to high-order accuracy using the backward differentiation formula (BDF). This approach, called Source Derivative Propagation (SDP), drastically reduces the memory requirements of time-dependent MOC relative to methods that require storing the angular flux. An SDP method was developed for 2D and 3D applications and implemented in the computer code DeCART in 2D. DeCART was used to model two reactor transient benchmarks: a modified TWIGL problem and a C5G7 transient. The SDP method accurately and efficiently replicated the solution of the conventional time-dependent MOC method using two orders of magnitude less memory.

  10. Methods and apparatuses for deoxygenating biomass-derived pyrolysis oil

    DOEpatents

    Baird, Lance Awender; Brandvold, Timothy A.

    2015-10-20

    Embodiments of methods and apparatuses for deoxygenating a biomass-derived pyrolysis oil are provided. In one example, a method comprises the steps of separating a low-oxygen biomass-derived pyrolysis oil effluent into a low-oxygen-pyoil organic phase stream and an aqueous phase stream. Phenolic compounds are removed from the aqueous phase stream to form a phenolic-rich diluent recycle stream. A biomass-derived pyrolysis oil stream is diluted and heated with the phenolic-rich diluent recycle stream to form a heated diluted pyoil feed stream. The heated diluted pyoil feed stream is contacted with a deoxygenating catalyst in the presence of hydrogen to deoxygenate the heated diluted pyoil feed stream.

  11. A Definite Integration Method for Calculating Inclination Function and Its Derivative

    NASA Astrophysics Data System (ADS)

    Wu, Lian-Da; Wang, Hong-Bo

    2012-07-01

    This paper gives a definite integration method for calculating the inclination function and its derivative, which has a very simple expression, and the accuracies as high as 10-15 for the inclination function, and 10-13 for its derivative, comparable with the accuracy of Gooding's method. By through a lot of numerical simulations, it is proved that this method has a good stability and an wide applicable range of inclinations, hence it can be used to calculate the inclination function to the maximum order of Lmax ≤ 50.

  12. A method for deriving leading causes of death.

    PubMed Central

    Becker, Roberto; Silvi, John; Ma Fat, Doris; L'Hours, André; Laurenti, Ruy

    2006-01-01

    OBJECTIVE: A standard list for ranking leading causes of death worldwide does not exist. WHO headquarters, regional offices and Member States all use different lists that have varying levels of detail. We sought to derive a standard list to enable countries to identify their leading causes of death and to permit comparison between countries. Our aim is to share the criteria and methodology we used to bring some order to the construction of such a list, to provide a consistent procedure that can be used by others, and to give researchers and data owners an opportunity to utilize the list at national and subnational levels. METHODS: Results were primarily data-driven. Data from individual countries representing different regions of the world were extracted from the WHO Mortality Database. Supplementary information from WHO estimates on mortality was used for regions where data were scarce. In addition, a set of criteria was used to group the candidate causes and to determine other causes that should be included on the list. FINDINGS: A ranking list of the leading causes of death that contains broad cause groupings (such as "all cancers", "all heart diseases" or "all accidents") is not effective and does not identify the leading individual causes within these broad groupings; thus it does not allow policy-makers to generate appropriate health advocacy and cost-effective interventions. Similarly, defining candidate causal groups too narrowly or including diseases that have a low frequency does not meet these objectives. CONCLUSION: For international comparisons, we recommend that countries use this list; it is based on extensive evidence and the application of public health disease-prevention criteria. It is not driven by political or financial motives. This list may be adapted for national statistical purposes. PMID:16628303

  13. Conjugate gradient method - Electromagnetism applications

    NASA Astrophysics Data System (ADS)

    Mosig, Juan R.

    1987-10-01

    This paper presents a brief but rigorous description of the conjugate gradient technique as applied to the solution of algebraic linear systems with complex coefficients. The relationships between conjugate gradient techniques and other commonly used methods are established. A normalized algorithm is introduced which optimally exploits the computer capabilities. Its performance is compared with that of Gaussian elimination by numerical tests on Hilbert matrices of more than a thousand unknowns. As a practical application, the problem of electrostatic screening by a finite ground plane has been solved with this technique.

  14. Initialization of the Primitive Equations by the Bounded Derivative Method.

    NASA Astrophysics Data System (ADS)

    Browning, G.; Kasahara, A.; Kreiss, H.-O.

    1980-07-01

    Large-amplitude high-frequency motions can appear in the solution of a hyperbolic system containing multiple time scales unless the initial conditions are suitably adjusted through a process called initialization. We observe that a solution of such a system which varies slowly with respect to time must have a number of time derivatives on the order of the slow time scale. Given a variable which is characteristic of low-frequency motions (e.g., vorticity), we can apply this observation at the initial time to find constraints which determine the rest of the initial data so that the amplitudes of the ensuing high-frequency motions remain small. Boundary conditions of the system must be taken into account in the derivation of the constraints. This procedure is referred to as the bounded derivative method.For a general linear version of the shallow-water equations, we prove that if the initial kth order time derivative is of the order of the slow time scale, then it will remain so for a fixed time interval. For the corresponding constant coefficient system, we compare the present initialization procedure with the normal mode approach. We then apply the new procedure to initialize the nonlinear shallow-water equations including the effect of orography for both the midlatitude and equatorial beta plane cases. In the midlatitude case, the initialization scheme based on quasi-geostrophic theory can be obtained from the bounded derivative method by certain simplifying assumptions. In the equatorial case, the bounded derivative method provides an effective initialization scheme and new insight into the nature of equatorial flows.

  15. Apparatuses and methods for deoxygenating biomass-derived pyrolysis oil

    SciTech Connect

    Kalnes, Tom N.

    2015-12-29

    Apparatuses and methods for deoxygenating a biomass-derived pyrolysis oil are provided herein. In one example, the method comprises of dividing a feedstock stream into first and second feedstock portions. The feedstock stream comprises the biomass-derived pyrolysis oil and has a temperature of about 60.degree. C. or less. The first feedstock portion is combined with a heated organic liquid stream to form a first heated diluted pyoil feed stream. The first heated diluted pyoil feed stream is contacted with a first deoxygenating catalyst in the presence of hydrogen to form an intermediate low-oxygen pyoil effluent. The second feedstock portion is combined with the intermediate low-oxygen pyoil effluent to form a second heated diluted pyoil feed stream. The second heated diluted pyoil feed stream is contacted with a second deoxygenating catalyst in the presence of hydrogen to form additional low-oxygen pyoil effluent.

  16. [Pharmacoepidemiology: definition, methods and applications].

    PubMed

    Montastruc, Jean-Louis; Sommet, Agnès; Montastruc, François; Moulis, Guillaume; Bagheri, Haleh; Damase-michel, Christine; Lapeyre-mestre, Maryse

    2015-01-01

    Clinical evaluation of drugs before approval is based on the experimental design of clinical trial with randomization of drug exposure. Unfortunately, conclusions of clinical trials are necessarily limited to patients enrolled in the trial. It is therefore necessary to compare these experimental data from clinical trials with the real use of drugs in clinical practice. Pharmacoepidemiology is defined as the study in real conditions and on large populations, of use, effectiveness and risk of drugs. The methods and fields of application of pharmacoepidemiology are described. They allow to characterize conditions of use, misuse, clinical effectiveness, adverse drug reactions and risks of drugs. The development of pharmacoepidemiology should allow optimization of "rational use" of drugs.

  17. METHOD FOR PRODUCING ISOTOPIC METHANES AND PARTIALLY HALOGENATED DERIVATIVES THEROF

    DOEpatents

    Frazer, J.W.

    1959-08-18

    A method is given for producing isotopic methanes and/ or partially halogenated derivatives. Lithium hydride, deuteride, or tritide is reacted with a halogenated methane or with a halogenated methane in combination with free halogen. The process is conveniently carried out by passing a halogenated methane preferably at low pressures or in an admixture with an inert gas through a fixed bed of finely divided lithium hydride heated initially to temperatures of 100 to 200 deg C depending upon the halogenated methane used.

  18. Derivative spectrophotometric method for simultaneous determination of clindamycin phosphate and tretinoin in pharmaceutical dosage forms.

    PubMed

    Barazandeh Tehrani, Maliheh; Namadchian, Melika; Fadaye Vatan, Sedigheh; Souri, Effat

    2013-04-10

    A derivative spectrophotometric method was proposed for the simultaneous determination of clindamycin and tretinoin in pharmaceutical dosage forms. The measurement was achieved using the first and second derivative signals of clindamycin at (1D) 251 nm and (2D) 239 nm and tretinoin at (1D) 364 nm and (2D) 387 nm.The proposed method showed excellent linearity at both first and second derivative order in the range of 60-1200 and 1.25-25 μg/ml for clindamycin phosphate and tretinoin respectively. The within-day and between-day precision and accuracy was in acceptable range (CV<3.81%, error<3.20%). Good agreement between the found andadded concentrations indicates successful application of the proposed method for simultaneous determination of clindamycin and tretinoin in synthetic mixtures and pharmaceutical dosage form.

  19. The Enterprise Derivative Application: Flexible Software for Optimizing Manufacturing Processes

    SciTech Connect

    Ward, Richard C; Allgood, Glenn O; Knox, John R

    2008-11-01

    The Enterprise Derivative Application (EDA) implements the enterprise-derivative analysis for optimization of an industrial process (Allgood and Manges, 2001). It is a tool to help industry planners choose the most productive way of manufacturing their products while minimizing their cost. Developed in MS Access, the application allows users to input initial data ranging from raw material to variable costs and enables the tracking of specific information as material is passed from one process to another. Energy-derivative analysis is based on calculation of sensitivity parameters. For the specific application to a steel production process these include: the cost to product sensitivity, the product to energy sensitivity, the energy to efficiency sensitivity, and the efficiency to cost sensitivity. Using the EDA, for all processes the user can display a particular sensitivity or all sensitivities can be compared for all processes. Although energy-derivative analysis was originally designed for use by the steel industry, it is flexible enough to be applied to many other industrial processes. Examples of processes where energy-derivative analysis would prove useful are wireless monitoring of processes in the petroleum cracking industry and wireless monitoring of motor failure for determining the optimum time to replace motor parts. One advantage of the MS Access-based application is its flexibility in defining the process flow and establishing the relationships between parent and child process and products resulting from a process. Due to the general design of the program, a process can be anything that occurs over time with resulting output (products). So the application can be easily modified to many different industrial and organizational environments. Another advantage is the flexibility of defining sensitivity parameters. Sensitivities can be determined between all possible variables in the process flow as a function of time. Thus the dynamic development of the

  20. Entrepreneur environment management behavior evaluation method derived from environmental economy.

    PubMed

    Zhang, Lili; Hou, Xilin; Xi, Fengru

    2013-12-01

    Evaluation system can encourage and guide entrepreneurs, and impel them to perform well in environment management. An evaluation method based on advantage structure is established. It is used to analyze entrepreneur environment management behavior in China. Entrepreneur environment management behavior evaluation index system is constructed based on empirical research. Evaluation method of entrepreneurs is put forward, from the point of objective programming-theory to alert entrepreneurs concerned to think much of it, which means to take minimized objective function as comprehensive evaluation result and identify disadvantage structure pattern. Application research shows that overall behavior of Chinese entrepreneurs environmental management are good, specially, environment strategic behavior are best, environmental management behavior are second, cultural behavior ranks last. Application results show the efficiency and feasibility of this method.

  1. Electropolymerized phenol derivatives as permselective polymers for biosensor applications.

    PubMed

    Calia, Giammario; Monti, Patrizia; Marceddu, Salvatore; Dettori, Maria A; Fabbri, Davide; Jaoua, Samir; O'Neill, Robert D; Serra, Pier A; Delogu, Giovanna; Migheli, Quirico

    2015-05-21

    Amperometric biosensors are often coated with a polymeric permselective film to avoid electroactive interference by reducing agents present in the target medium. Phenylenediamine and phenol monomers are commonly used to form these permselective films in the design of microsensors and biosensors. This paper aims to evaluate the permselectivity, stability and lifetime of polymers electrosynthesized using either constant potential amperometry (CPA) or cyclic voltammetry (CV) from naturally occurring phenylpropanoids in monomeric and dimeric forms (eugenol, isoeugenol, dehydrodieugenol and magnolol). Sensors were characterized by scanning electron microscopy and permselectivity analysis. Magnolol formed an electro-deposited polymer with a more defined three-dimensional texture in comparison with the other films. The phenol-derived films showed different permselectivity towards H2O2 over ascorbic acid and dopamine, likely to be related to the thickness and compactness of the polymer. The CV-derived films had a better permselectivity compared to the CPA-corresponding polymers. Based on these results, the permselectivity, stability and lifetime of a biosensor for glucose were studied when a magnolol coating was electro-deposited. The structural principles governing the permselectivity of the magnolol-derived film are suggested to be mainly related to the conformational flexibility of this monomer. Newly designed biosensors, coated with electropolymerized natural phenol derivatives, may represent promising analytical devices for different application fields.

  2. Incompressible spectral-element method: Derivation of equations

    NASA Technical Reports Server (NTRS)

    Deanna, Russell G.

    1993-01-01

    A fractional-step splitting scheme breaks the full Navier-Stokes equations into explicit and implicit portions amenable to the calculus of variations. Beginning with the functional forms of the Poisson and Helmholtz equations, we substitute finite expansion series for the dependent variables and derive the matrix equations for the unknown expansion coefficients. This method employs a new splitting scheme which differs from conventional three-step (nonlinear, pressure, viscous) schemes. The nonlinear step appears in the conventional, explicit manner, the difference occurs in the pressure step. Instead of solving for the pressure gradient using the nonlinear velocity, we add the viscous portion of the Navier-Stokes equation from the previous time step to the velocity before solving for the pressure gradient. By combining this 'predicted' pressure gradient with the nonlinear velocity in an explicit term, and the Crank-Nicholson method for the viscous terms, we develop a Helmholtz equation for the final velocity.

  3. Derivation of Instantaneous Wye and Zero-Phase Sequence Voltages from Line-Line Voltages in Unbalanced 3-Phase 3-Wire Systems and Application of This Method to 3-Phase PWM Converter Control

    NASA Astrophysics Data System (ADS)

    Yuzurihara, Itsuo; Kawamura, Atsuo

    In general, voltage imbalances in 3-phase AC power systems are inevitable. 3-Phase PWM (Pulse Width Modulation) converter used in 3-wire systems are generally designed for use under limited imbalances of input voltages, and problems such as input current distortion, deterioration of output properties, degradation of efficiency and failure may occur in some cases. These problems cause severe damages to industries in some cases, for example, semiconductor production machines: SEMI defined “SEMI F47-0200” and “SEMI F47-0706” standards that have to be satisfied to realize voltage sag immunity. In order to compensate the remained problems due to the unbalanced input voltages, particular storage devices are designed additionally for conventional converters. This paper proposes that the determination of both the instantaneous zero-phase sequence voltage and wye voltages is essential for 3-phase PWM converter control used for a 3-wire system to keep its output rated under occasional or long-term voltage imbalances in an AC system. This paper also describes a general new method to derive the components of the voltages of instantaneous wye and zero-phase sequence voltage from line-line voltages of a 3-wire system. This paper also describes a method to apply the voltages to control the converter. The results obtained on implementation verify that this new converter keeps its output rated under unbalanced conditions wider than those defined by SEMIs without particular storage devices as far as the AC voltages are remained live.

  4. Applications of Monte Carlo Methods in Calculus.

    ERIC Educational Resources Information Center

    Gordon, Sheldon P.; Gordon, Florence S.

    1990-01-01

    Discusses the application of probabilistic ideas, especially Monte Carlo simulation, to calculus. Describes some applications using the Monte Carlo method: Riemann sums; maximizing and minimizing a function; mean value theorems; and testing conjectures. (YP)

  5. Derivation of effectiveness-NTU method for heat exchangers with heat leak

    SciTech Connect

    William M. Soyars

    2001-11-01

    A powerful and useful method for heat exchanger analysis is the effectiveness-NTU method. The equations for this technique presented in textbooks, however, are limited to the case where all of the heat transfer occurs between the two fluid streams. In an application of interest to us, cryogenic heat exchangers, we wish to consider a heat leak term. Thus, we have derived equations for the {var_epsilon}-NTU method with heat leak involved. The cases to be studied include evaporators, condensers, and counter-flow, with heat leak both in and out.

  6. Acyl Meldrum's acid derivatives: application in organic synthesis

    NASA Astrophysics Data System (ADS)

    Janikowska, K.; Rachoń, J.; Makowiec, S.

    2014-07-01

    This review is focused on an important class of Meldrum's acid derivatives commonly known as acyl Meldrum's acids. The preparation methods of these compounds are considered including the recently proposed and rather rarely used ones. The chemical properties of acyl Meldrum's acids are described in detail, including thermal stability and reactions with various nucleophiles. The possible mechanisms of these transformations are analyzed. The bibliography includes 134 references.

  7. Numerical Method for Darcy Flow Derived Using Discrete Exterior Calculus

    NASA Astrophysics Data System (ADS)

    Hirani, A. N.; Nakshatrala, K. B.; Chaudhry, J. H.

    2015-05-01

    We derive a numerical method for Darcy flow, and also for Poisson's equation in mixed (first order) form, based on discrete exterior calculus (DEC). Exterior calculus is a generalization of vector calculus to smooth manifolds and DEC is one of its discretizations on simplicial complexes such as triangle and tetrahedral meshes. DEC is a coordinate invariant discretization, in that it does not depend on the embedding of the simplices or the whole mesh. We start by rewriting the governing equations of Darcy flow using the language of exterior calculus. This yields a formulation in terms of flux differential form and pressure. The numerical method is then derived by using the framework provided by DEC for discretizing differential forms and operators that act on forms. We also develop a discretization for a spatially dependent Hodge star that varies with the permeability of the medium. This also allows us to address discontinuous permeability. The matrix representation for our discrete non-homogeneous Hodge star is diagonal, with positive diagonal entries. The resulting linear system of equations for flux and pressure are saddle type, with a diagonal matrix as the top left block. The performance of the proposed numerical method is illustrated on many standard test problems. These include patch tests in two and three dimensions, comparison with analytically known solutions in two dimensions, layered medium with alternating permeability values, and a test with a change in permeability along the flow direction. We also show numerical evidence of convergence of the flux and the pressure. A convergence experiment is included for Darcy flow on a surface. A short introduction to the relevant parts of smooth and discrete exterior calculus is included in this article. We also include a discussion of the boundary condition in terms of exterior calculus.

  8. Naval applications of a TAE-derived executive

    NASA Technical Reports Server (NTRS)

    Guberek, Michael; Borders, Stephen; Masse, Serge

    1986-01-01

    Global Imaging introduced an interactive image processing system in 1985, featuring the Global Applications Executive (GAE) which is a modified Transportable Applications Executive (TAE) environment. The executive plus a large variety of image processing functions, known commercially as the System 9000, are designed to operate on the Hewlett-Packard as its standard desktop computer (NSDTC), the System 9000 has found easy acceptance for Naval image processing applications. The Department of Oceanography at the Naval Academy, Annapolis, Maryland, has installed an NSDTC with an image processing upgrade. This interactive digital image processing workstation is used by the midshipmen and staff for training and research in remote sensing oceanography. The turn-key system provides the capability to process imagery from commonly used Earth observation spacecraft, in conjunction with in situ data sets. The Acoustic Group at the Naval Research Laboratory, Washington, D.C. has acquired its first System 9000 to interactively process ocean acoustic data gathered by shipboard sensors. Finally, the Naval Oceanographic Facility in Bay St. Louis, Mississippi has acquired a System 9000 to provide a second generation Tactical Environmental Support System (TESS 2) prototype with image processing capabilities. This will permit merging of conventional data with polar orbiting spacecraft imagery. A brief description of these applications and the TAE-derived system is presented.

  9. Illustrated structural application of universal first-order reliability method

    NASA Technical Reports Server (NTRS)

    Verderaime, V.

    1994-01-01

    The general application of the proposed first-order reliability method was achieved through the universal normalization of engineering probability distribution data. The method superimposes prevailing deterministic techniques and practices on the first-order reliability method to surmount deficiencies of the deterministic method and provide benefits of reliability techniques and predictions. A reliability design factor is derived from the reliability criterion to satisfy a specified reliability and is analogous to the deterministic safety factor. Its application is numerically illustrated on several practical structural design and verification cases with interesting results and insights. Two concepts of reliability selection criteria are suggested. Though the method was developed to support affordable structures for access to space, the method should also be applicable for most high-performance air and surface transportation systems.

  10. Fast finite difference methods for space-fractional diffusion equations with fractional derivative boundary conditions

    NASA Astrophysics Data System (ADS)

    Jia, Jinhong; Wang, Hong

    2015-07-01

    Numerical methods for space-fractional diffusion equations often generate dense or even full stiffness matrices. Traditionally, these methods were solved via Gaussian type direct solvers, which requires O (N3) of computational work per time step and O (N2) of memory to store where N is the number of spatial grid points in the discretization. In this paper we develop a preconditioned fast Krylov subspace iterative method for the efficient and faithful solution of finite difference methods (both steady-state and time-dependent) space-fractional diffusion equations with fractional derivative boundary conditions in one space dimension. The method requires O (N) of memory and O (Nlog ⁡ N) of operations per iteration. Due to the application of effective preconditioners, significantly reduced numbers of iterations were achieved that further reduces the computational cost of the fast method. Numerical results are presented to show the utility of the method.

  11. A comparison of different methods to implement higher order derivatives of density functionals

    SciTech Connect

    van Dam, Hubertus J.J.

    2016-05-18

    Density functional theory is the dominant approach in electronic structure methods today. To calculate properties higher order derivatives of the density functionals are required. These derivatives might be implemented manually,by automatic differentiation, or by symbolic algebra programs. Different authors have cited different reasons for using the particular method of their choice. This paper presents work where all three approaches were used and the strengths and weaknesses of each approach are considered. It is found that all three methods produce code that is suffficiently performanted for practical applications, despite the fact that our symbolic algebra generated code and our automatic differentiation code still have scope for significant optimization. The automatic differentiation approach is the best option for producing readable and maintainable code.

  12. Directional microwave applicator and methods

    NASA Technical Reports Server (NTRS)

    Fink, Patrick W. (Inventor); Lin, Greg Y. (Inventor); Chu, Andrew W. (Inventor); Dobbins, Justin A. (Inventor); Arndt, G. Dickey (Inventor); Ngo, Phong H. (Inventor)

    2008-01-01

    A miniature microwave antenna is disclosed which may be utilized for biomedical applications such as, for example, radiation induced hyperthermia through catheter systems. One feature of the antenna is that it possesses azimuthal directionality despite its small size. This directionality permits targeting of certain tissues while limiting thermal exposure of adjacent tissue. One embodiment has an outer diameter of about 0.095'' (2.4 mm) but the design permits for smaller diameters.

  13. Sodium MRI: Methods and applications

    PubMed Central

    Madelin, Guillaume; Lee, Jae-Seung; Regatte, Ravinder R.; Jerschow, Alexej

    2014-01-01

    Sodium NMR spectroscopy and MRI have become popular in recent years through the increased availability of high-field MRI scanners, advanced scanner hardware and improved methodology. Sodium MRI is being evaluated for stroke and tumor detection, for breast cancer studies, and for the assessment of osteoarthritis and muscle and kidney functions, to name just a few. In this article, we aim to present an up-to-date review of the theoretical background, the methodology, the challenges and limitations, and current and potential new applications of sodium MRI. PMID:24815363

  14. A thermochemically derived global reaction mechanism for detonation application

    NASA Astrophysics Data System (ADS)

    Zhu, Y.; Yang, J.; Sun, M.

    2012-07-01

    A 4-species 4-step global reaction mechanism for detonation calculations is derived from detailed chemistry through thermochemical approach. Reaction species involved in the mechanism and their corresponding molecular weight and enthalpy data are derived from the real equilibrium properties. By substituting these global species into the results of constant volume explosion and examining the evolution process of these global species under varied conditions, reaction paths and corresponding rates are summarized and formulated. The proposed mechanism is first validated to the original chemistry through calculations of the CJ detonation wave, adiabatic constant volume explosion, and the steady reaction structure after a strong shock wave. Good agreement in both reaction scales and averaged thermodynamic properties has been achieved. Two sets of reaction rates based on different detailed chemistry are then examined and applied for numerical simulations of two-dimensional cellular detonations. Preliminary results and a brief comparison between the two mechanisms are presented. The proposed global mechanism is found to be economic in computation and also competent in description of the overall characteristics of detonation wave. Though only stoichiometric acetylene-oxygen mixture is investigated in this study, the method to derive such a global reaction mechanism possesses a certain generality for premixed reactions of most lean hydrocarbon mixtures.

  15. Biotechnological Applications Derived from Microorganisms of the Atacama Desert

    PubMed Central

    González-Silva, Carlos

    2014-01-01

    The Atacama Desert in Chile is well known for being the driest and oldest desert on Earth. For these same reasons, it is also considered a good analog model of the planet Mars. Only a few decades ago, it was thought that this was a sterile place, but in the past years fascinating adaptations have been reported in the members of the three domains of life: low water availability, high UV radiation, high salinity, and other environmental stresses. However, the biotechnological applications derived from the basic understanding and characterization of these species, with the notable exception of copper bioleaching, are still in its infancy, thus offering an immense potential for future development. PMID:25147824

  16. Derivatives of xanthic acid are novel antioxidants: application to synaptosomes.

    PubMed

    Lauderback, Christopher M; Drake, Jennifer; Zhou, Daohong; Hackett, Janna M; Castegna, Alessandra; Kanski, Jaroslaw; Tsoras, Maria; Varadarajan, Sridhar; Butterfield, D Allan

    2003-04-01

    Xanthic acids have long been known to act as reducing agents. Recently, D609, a tricyclodecanol derivative of xanthic acid, has been reported to have anti-apoptotic and anti-inflammatory properties that are attributed to specific inhibition of phosphatidyl choline phospholipase C (PC-PLC). However, because oxidative stress is involved in both of these cellular responses, the possibility that xanthates may act as antioxidants was investigated in the current study. Finding that xanthates efficiently scavenge hydroxyl radicals, the mechanism by which D609 and other xanthate derivatives may protect against oxidative damage was further examined. The xanthates studied, especially D609, mimic glutathione (GSH). Xanthates scavenge hydroxyl radicals and hydrogen peroxide, form disulfide bonds (dixanthogens), and react with electrophilic products of lipid oxidation (acrolein) in a manner similar to GSH. Further, upon disulfide formation, dixanthogens are reduced by glutathione reductase to a redox active xanthate. Supporting its role as an antioxidant, D609 significantly (p < 0.01) reduces free radical-induced changes in synaptosomal lipid peroxidation (TBARs), protein oxidation (protein carbonyls), and protein conformation. Thus, in addition to inhibitory effects on PC-PLC, D609 may prevent cellular apoptotic and inflammatory cascades by acting as antioxidants and novel GSH mimics. These results are discussed with reference to potential therapeutic application of D609 in oxidative stress conditions.

  17. APPLICATION OF RADON REDUCTION METHODS

    EPA Science Inventory

    The document is intended to aid homeowners and contractors in diagnosing and solving indoor radon problems. It will also be useful to State and Federal regulatory officials and many other persons who provide advice on the selection, design and operation of radon reduction methods...

  18. Refining a model electron-density map via the Phantom Derivative method.

    PubMed

    Burla, Maria Cristina; Carrozzini, Benedetta; Cascarano, Giovanni Luca; Giacovazzo, Carmelo; Polidori, Giampiero

    2015-09-01

    The Phantom Derivative (PhD) method [Giacovazzo (2015), Acta Cryst. A71, 483-512] has recently been described for ab initio and non-ab initio phasing. It is based on the random generation of structures with the same unit cell and the same space group as the target structure (called ancil structures), which are used to create derivatives devoid of experimental diffraction amplitudes. In this paper, the non-ab initio variant of the method was checked using phase sets obtained by molecular-replacement techniques as a starting point for phase extension and refinement. It has been shown that application of PhD is able to extend and refine phases in a way that is competitive with other electron-density modification techniques.

  19. Advanced Homomorphic Encryption its Applications and Derivatives (AHEAD)

    DTIC Science & Technology

    2013-09-01

    Cryptographic limitations on learning boolean formulae and finite automata. J. ACM, 41(1):67–95, 1994. Preliminary version in STOC 89. [Sch90] Robert E...ASdW09] Andris Ambainis, Robert Spalek, and Ronald de Wolf. A new quantum lower bound method, with applications to direct product theorems and time...space tradeoffs. Algo- rithmica, 55(3):422–461, 2009. [BBC+01] Robert Beals, Harry Buhrman, Richard Cleve, Michele Mosca, and Ronald de Wolf. Quantum

  20. Method for Implementing Subsurface Solid Derived Concentration Guideline Levels (DCGL) - 12331

    SciTech Connect

    Lively, J.W.

    2012-07-01

    The U.S. Nuclear Regulatory Commission (NRC) and other federal agencies currently approve the Multi-Agency Radiation Site Survey and Investigation Manual (MARSSIM) as guidance for licensees who are conducting final radiological status surveys in support of decommissioning. MARSSIM provides a method to demonstrate compliance with the applicable regulation by comparing residual radioactivity in surface soils with derived concentration guideline levels (DCGLs), but specifically discounts its applicability to subsurface soils. Many sites and facilities undergoing decommissioning contain subsurface soils that are potentially impacted by radiological constituents. In the absence of specific guidance designed to address the derivation of subsurface soil DCGLs and compliance demonstration, decommissioning facilities have attempted to apply DCGLs and final status survey techniques designed specifically for surface soils to subsurface soils. The decision to apply surface soil limits and surface soil compliance metrics to subsurface soils typically results in significant over-excavation with associated cost escalation. MACTEC, Inc. has developed the overarching concepts and principles found in recent NRC decommissioning guidance in NUREG 1757 to establish a functional method to derive dose-based subsurface soil DCGLs. The subsurface soil method developed by MACTEC also establishes a rigorous set of criterion-based data evaluation metrics (with analogs to the MARSSIM methodology) that can be used to demonstrate compliance with the developed subsurface soil DCGLs. The method establishes a continuum of volume factors that relate the size and depth of a volume of subsurface soil having elevated concentrations of residual radioactivity with its ability to produce dose. The method integrates the subsurface soil sampling regime with the derivation of the subsurface soil DCGL such that a self-regulating optimization is naturally sought by both the responsible party and regulator

  1. Hybrid codes: Methods and applications

    SciTech Connect

    Winske, D. ); Omidi, N. )

    1991-01-01

    In this chapter we discuss hybrid'' algorithms used in the study of low frequency electromagnetic phenomena, where one or more ion species are treated kinetically via standard PIC methods used in particle codes and the electrons are treated as a single charge neutralizing massless fluid. Other types of hybrid models are possible, as discussed in Winske and Quest, but hybrid codes with particle ions and massless fluid electrons have become the most common for simulating space plasma physics phenomena in the last decade, as we discuss in this paper.

  2. Diet history: Method and applications.

    PubMed

    Morán Fagúndez, Luis Juan; Rivera Torres, Alejandra; González Sánchez, María Eugenia; de Torres Aured, Mari Lourdes; Pérez Rodrigo, Carmen; Irles Rocamora, José Antonio

    2015-02-26

    The diet history is a traditional method of analysis of food intake. In its traditional structure consists of three components that provide an overall information of the usual food consumption pattern of the individual and also detailed information on certain foods. The information is collected in an interview and requires highly experienced qualified interviewers. The quality of information depends largely on the skills of the interviewer. It is mostly used in clinical practice. It has also been used in studies of diet and health relationship to investigate the usual diet in the past. The high cost and long duration of the interview limit their usefulness in large epidemiological studies.

  3. Quantum dots derived from two-dimensional materials and their applications for catalysis and energy.

    PubMed

    Wang, Xuewan; Sun, Gengzhi; Li, Nan; Chen, Peng

    2016-04-21

    Quantum dots (QDs) derived from the atomically-thin two-dimensional (2D) sheets (graphene, transition metal dichalcogenide, graphitic carbon nitride, hexagonal boron nitride, and phosphorene) are emerging extraordinary zero-dimensional materials. Covering a broad spectrum of interesting optical, catalytic, electronic, chemical and electrochemical properties, these 2D-QDs promise a wide range of novel applications including imaging, sensing, cancer therapy, optoelectronics, display, catalysis, and energy. In this article, we discuss the synthesis methods and the properties of these 2D-QDs and emphasize their applications in electrocatalysis, photocatalysis, supercapacitors, batteries, and photovoltaics.

  4. Adipose-Derived Stem Cells for Tissue Engineering and Regenerative Medicine Applications

    PubMed Central

    Dai, Ru; Wang, Zongjie; Samanipour, Roya; Koo, Kyo-in; Kim, Keekyoung

    2016-01-01

    Adipose-derived stem cells (ASCs) are a mesenchymal stem cell source with properties of self-renewal and multipotential differentiation. Compared to bone marrow-derived stem cells (BMSCs), ASCs can be derived from more sources and are harvested more easily. Three-dimensional (3D) tissue engineering scaffolds are better able to mimic the in vivo cellular microenvironment, which benefits the localization, attachment, proliferation, and differentiation of ASCs. Therefore, tissue-engineered ASCs are recognized as an attractive substitute for tissue and organ transplantation. In this paper, we review the characteristics of ASCs, as well as the biomaterials and tissue engineering methods used to proliferate and differentiate ASCs in a 3D environment. Clinical applications of tissue-engineered ASCs are also discussed to reveal the potential and feasibility of using tissue-engineered ASCs in regenerative medicine. PMID:27057174

  5. Application of 12S rRNA gene for the identification of animal-derived drugs.

    PubMed

    Luo, Jiaoyang; Yan, Dan; Zhang, Da; Han, Yumei; Dong, Xiaoping; Yang, Yong; Deng, Kejun; Xiao, Xiaohe

    2011-01-01

    PURPOSE. Animal-derived drugs are the major source of biological products and traditional medicine, but they are often difficult to identify, causing confusion in the clinical application. Among these medicinal animals, a number of animal species are endangered, leading to the destruction of biodiversity. The identification of animal-derived drugs and their alternatives would be a first step toward biodiversity conservation and safe medication. Until now, no effective method for identifying animal-derived drugs has been demonstrated; DNA-based species identification presents a brand-new technique. METHODS. We designed primers to amplify a 523-bp fragment of 12S rRNA and generated sequences for 13 individuals within six medicinal animal species. We examined the efficiency of species recognition based on this sequence, and we also tested the taxonomic affiliations against the GenBank database. RESULTS. All the tested drugs were identified successfully, and a visible gap was found between the inter-specific and intra-specific variation. We further demonstrated the importance of data exploration in DNA-based species identification practice by examining the sequence characteristics of relative genera in GenBank. This region of the 12S rRNA gene had a 100% success rate of species recognition within the six medicinal animal species. CONCLUSIONS. We propose that the 12S rRNA locus might be universal for identifying animal-derived drugs and their adulterants. The development of 12S rRNA for indentifying animal-derived drugs that share a common gene target would contribute significantly to the clinical application of animal-derived drugs and the conservation of medicinal animal species. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

  6. A review on mathematical methods of conventional and Islamic derivatives

    NASA Astrophysics Data System (ADS)

    Hisham, Azie Farhani Badrol; Jaffar, Maheran Mohd

    2014-12-01

    Despite the impressive growth of risk management tools in financial institutions, Islamic finance remains miles away behind the conventional institutions. Islamic finance products need to comply with the syariah law and prohibitions, therefore they can use fewer of the available risk management tools compared to conventional. Derivatives have proven to be the effective hedging technique and instrument that broadly being used in the conventional institutions to manage their risks. However, derivatives are not generally accepted as the legitimate products in Islamic finance and they remain controversial issues among the Islamic scholars. This paper reviews the evolution of derivatives such as forwards, futures and options and then explores the mathematical models that being used to solve derivatives such as random walk model, asset pricing model that follows Brownian motion and Black-Scholes model. Other than that, this paper also critically discuss the perspective of derivatives from Islamic point of view. In conclusion, this paper delivers the traditional Islamic products such as salam, urbun and istijrar that can be used to create building blocks of Islamic derivatives.

  7. Traceability of biotech-derived animals: application of DNA technology.

    PubMed

    Loftus, R

    2005-04-01

    Traceability is increasingly becoming standard across the agri-food industry, largely driven by recent food crises and the consequent demands for transparency within the food chain. This is leading to the development of a range of traceability concepts and technologies adapted to different industry needs. Experience with genetically modified plants has shown that traceability can play a role in increasing public confidence in biotechnology, and might similarly help allay concerns relating to the development of animal biotechnology. Traceability also forms an essential component of any risk management strategy and is a key requirement for post-marketing surveillance. Given the diversity of traceability concepts and technologies available, consideration needs to be given to the scope and precision of traceability systems for animal biotechnology. Experience to date has shown that conventional tagging and labelling systems can incorporate levels of error and may not have sufficient precision for biotech-derived animals. Deoxyribonucleic acid (DNA) technology can overcome these difficulties by tracing animals and animal by-products through their DNA code rather than an associated label. This offers the possibility of tracing some by-products of animal biotechnology through the supply chain back to source animals, offering unprecedented levels of traceability. Developments in both DNA sampling and analysis technology are making large-scale applications of DNA traceability increasingly cost effective and feasible, and are likely to lead to a broader uptake of DNA traceability concepts.

  8. Systems and Methods for Derivative-Free Adaptive Control

    NASA Technical Reports Server (NTRS)

    Yucelen, Tansel (Inventor); Kim, Kilsoo (Inventor); Calise, Anthony J. (Inventor)

    2015-01-01

    An adaptive control system is disclosed. The control system can control uncertain dynamic systems. The control system can employ one or more derivative-free adaptive control architectures. The control system can further employ one or more derivative-free weight update laws. The derivative-free weight update laws can comprise a time-varying estimate of an ideal vector of weights. The control system of the present invention can therefore quickly stabilize systems that undergo sudden changes in dynamics, caused by, for example, sudden changes in weight. Embodiments of the present invention can also provide a less complex control system than existing adaptive control systems. The control system can control aircraft and other dynamic systems, such as, for example, those with non-minimum phase dynamics.

  9. Methods for Assessing the Electromechanical Integration of Human Pluripotent Stem Cell-Derived Cardiomyocyte Grafts

    PubMed Central

    Zhu, Wei-Zhong; Filice, Dominic; Palpant, Nathan J.; Laflamme, Michael A.

    2014-01-01

    Cardiomyocytes derived from human pluripotent stem cells show tremendous promise for the replacement of myocardium and contractile function lost to infarction. However, until recently, no methods were available to directly determine whether these stem cell-derived grafts actually couple with host myocardium and fire synchronously following transplantation in either intact or injured hearts. To resolve this uncertainty, our group has developed techniques for the intravital imaging of hearts engrafted with stem cell-derived cardiomyocytes that have been modified to express the genetically encoded protein calcium sensor, GCaMP. When combined with the simultaneously recorded electrocardiogram, this protocol allows one to make quantitative assessments as to the presence and extent of host–graft electrical coupling as well as the timing and pattern of graft activation. As described here, this system has been employed to investigate the electromechanical integration of human embryonic stem cell-derived cardiomyocytes in a guinea pig model of cardiac injury, but analogous approaches should be applicable to other human graft cell types and animal models. PMID:25070341

  10. Methods for assessing the electromechanical integration of human pluripotent stem cell-derived cardiomyocyte grafts.

    PubMed

    Zhu, Wei-Zhong; Filice, Dominic; Palpant, Nathan J; Laflamme, Michael A

    2014-01-01

    Cardiomyocytes derived from human pluripotent stem cells show tremendous promise for the replacement of myocardium and contractile function lost to infarction. However, until recently, no methods were available to directly determine whether these stem cell-derived grafts actually couple with host myocardium and fire synchronously following transplantation in either intact or injured hearts. To resolve this uncertainty, our group has developed techniques for the intravital imaging of hearts engrafted with stem cell-derived cardiomyocytes that have been modified to express the genetically encoded protein calcium sensor, GCaMP. When combined with the simultaneously recorded electrocardiogram, this protocol allows one to make quantitative assessments as to the presence and extent of host-graft electrical coupling as well as the timing and pattern of graft activation. As described here, this system has been employed to investigate the electromechanical integration of human embryonic stem cell-derived cardiomyocytes in a guinea pig model of cardiac injury, but analogous approaches should be applicable to other human graft cell types and animal models.

  11. Discontinuous Galerkin Methods: Theory, Computation and Applications

    SciTech Connect

    Cockburn, B.; Karniadakis, G. E.; Shu, C-W

    2000-12-31

    This volume contains a survey article for Discontinuous Galerkin Methods (DGM) by the editors as well as 16 papers by invited speakers and 32 papers by contributed speakers of the First International Symposium on Discontinuous Galerkin Methods. It covers theory, applications, and implementation aspects of DGM.

  12. METHODS FOR THE ANALYSIS OF ALKYLPHENOL ETHOXYLATES AND DERIVATIVES

    EPA Science Inventory

    Alkylphenol ethoxylates and their derivatives are well known for their harmful impact in wildlife. These compounds are being phased-out and banned in most European Countries. Their use has increased in the U.S. resulting in their addition to the Priority Testing List, TSCA (1...

  13. Graphene doping methods and device applications.

    PubMed

    Oh, Jong Sik; Kim, Kyong Nam; Yeom, Geun Young

    2014-02-01

    Graphene has recently been studied as a promising material to replace and enhance conventional electronic materials in various fields such as electronics, photovoltaics, sensors, etc. However, for the electronic applications of graphene prepared by various techniques such as chemical vapor deposition, chemical exfoliation, mechanical exfoliation, etc., critical limitations are found due to the defects in the graphene in addition to the absence of a semiconducting band gap. For that, many researchers have investigated the doped graphene which is effective to tailor its electronic property and chemical reactivity. This work presents a review of the various graphene doping methods and their device applications. As doping methods, direct synthesis method and post treatment method could be categorized. Because the latter case has been widely investigated and used in various electronic applications, we will focus on the post treatment method. Post treatment method could be further classified into wet and dry doping methods. In the case of wet doping, acid treatment, metal chloride, and organic material coating are the methods used to functionalize graphene by using dip-coating, spin coating, etc. Electron charge transfer achieved from graphene to dopants or from dopants to graphene makes p-type or n-type graphenes, respectively, with sheet resistance reduction effect. In the case of dry doping, it can be further categorized into electrostatic field method, evaporation method, thermal treatment method, plasma treatment method, etc. These doping techniques modify Fermi energy level of graphene and functionalize the property of graphene. Finally, some perspectives and device applications of doped graphene are also briefly discussed.

  14. Application of derivative matrices of skew rays to design of compound dispersion prisms.

    PubMed

    Lin, Psang Dain

    2016-09-01

    Numerous optimization methods have been developed in recent decades for optical system design. However, these methods rely heavily on ray tracing and finite difference techniques to estimate the derivative matrices of the rays. Consequently, the accuracy of the results obtained from these methods is critically dependent on the incremental step size used in the tuning stage. To overcome this limitation, the present study proposes a comprehensive methodology for the design of compound dispersion prisms based on the first- and second-order derivative matrices of skew rays. The proposed method facilitates the analysis and design of prisms with respect to arbitrary system variables and provides an ideal basis for automatic prism design applications. Four illustrative examples are given. It is shown that the optical quantities required to evaluate the prism performance can be extracted directly from the proposed derivative matrices. In addition, it is shown in this study that the single-element 3D prism can have the same deviation angle and spectral dispersion as the 2D compound prism.

  15. Feynman path integral application on deriving black-scholes diffusion equation for european option pricing

    NASA Astrophysics Data System (ADS)

    Utama, Briandhika; Purqon, Acep

    2016-08-01

    Path Integral is a method to transform a function from its initial condition to final condition through multiplying its initial condition with the transition probability function, known as propagator. At the early development, several studies focused to apply this method for solving problems only in Quantum Mechanics. Nevertheless, Path Integral could also apply to other subjects with some modifications in the propagator function. In this study, we investigate the application of Path Integral method in financial derivatives, stock options. Black-Scholes Model (Nobel 1997) was a beginning anchor in Option Pricing study. Though this model did not successfully predict option price perfectly, especially because its sensitivity for the major changing on market, Black-Scholes Model still is a legitimate equation in pricing an option. The derivation of Black-Scholes has a high difficulty level because it is a stochastic partial differential equation. Black-Scholes equation has a similar principle with Path Integral, where in Black-Scholes the share's initial price is transformed to its final price. The Black-Scholes propagator function then derived by introducing a modified Lagrange based on Black-Scholes equation. Furthermore, we study the correlation between path integral analytical solution and Monte-Carlo numeric solution to find the similarity between this two methods.

  16. The Typicality Ranking Task: A New Method to Derive Typicality Judgments from Children

    PubMed Central

    Ameel, Eef; Storms, Gert

    2016-01-01

    An alternative method for deriving typicality judgments, applicable in young children that are not familiar with numerical values yet, is introduced, allowing researchers to study gradedness at younger ages in concept development. Contrary to the long tradition of using rating-based procedures to derive typicality judgments, we propose a method that is based on typicality ranking rather than rating, in which items are gradually sorted according to their typicality, and that requires a minimum of linguistic knowledge. The validity of the method is investigated and the method is compared to the traditional typicality rating measurement in a large empirical study with eight different semantic concepts. The results show that the typicality ranking task can be used to assess children’s category knowledge and to evaluate how this knowledge evolves over time. Contrary to earlier held assumptions in studies on typicality in young children, our results also show that preference is not so much a confounding variable to be avoided, but that both variables are often significantly correlated in older children and even in adults. PMID:27322371

  17. Electromagnetic imaging methods for nondestructive evaluation applications.

    PubMed

    Deng, Yiming; Liu, Xin

    2011-01-01

    Electromagnetic nondestructive tests are important and widely used within the field of nondestructive evaluation (NDE). The recent advances in sensing technology, hardware and software development dedicated to imaging and image processing, and material sciences have greatly expanded the application fields, sophisticated the systems design and made the potential of electromagnetic NDE imaging seemingly unlimited. This review provides a comprehensive summary of research works on electromagnetic imaging methods for NDE applications, followed by the summary and discussions on future directions.

  18. Electromagnetic Imaging Methods for Nondestructive Evaluation Applications

    PubMed Central

    Deng, Yiming; Liu, Xin

    2011-01-01

    Electromagnetic nondestructive tests are important and widely used within the field of nondestructive evaluation (NDE). The recent advances in sensing technology, hardware and software development dedicated to imaging and image processing, and material sciences have greatly expanded the application fields, sophisticated the systems design and made the potential of electromagnetic NDE imaging seemingly unlimited. This review provides a comprehensive summary of research works on electromagnetic imaging methods for NDE applications, followed by the summary and discussions on future directions. PMID:22247693

  19. Rapid and sensitive method for quantification of gestodene in human plasma as the oxime derivative by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and its application to bioequivalence study.

    PubMed

    Saxena, Ashish; Gupta, Arun; Kasibhatta, Ravisekhar; Bob, Manoj; Kumar, V Praveen; Purwar, Bipin

    2014-01-15

    A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the estimation of gestodene in human plasma. Gestodene was extracted from human plasma by using solid-phase extraction technique. Gestodene D6 was used as the internal standard. An Acquity HSS-T3 column provided chromatographic separation of analytes followed by detection with mass spectrometry. The mass transition ion-pair was followed as m/z 326.2→124.1 for gestodene and m/z 332.3→129.1 for gestodene D6. The method involves a solid phase extraction from plasma, rapid derivatization with hydroxylamine to form oxime, simple gradient chromatographic conditions and mass spectrometric detection that enables detection at sub-picogram levels. The proposed method has been validated for a linear range of 50-11957pg/ml with a correlation coefficient≥0.9994. The intra-run and inter-run precision and accuracy were within 10%. The overall recoveries for gestodene and gestodene D6 were 62.02% and 67.57% respectively. The total run time was 4.0min. The developed method was applied for the determination of the pharmacokinetic parameters of gestodene following a single oral administration of a 2×0.06mg gestodene tablets in 10 healthy female volunteers.

  20. Variational Methods in Sensitivity Analysis and Optimization for Aerodynamic Applications

    NASA Technical Reports Server (NTRS)

    Ibrahim, A. H.; Hou, G. J.-W.; Tiwari, S. N. (Principal Investigator)

    1996-01-01

    Variational methods (VM) sensitivity analysis, which is the continuous alternative to the discrete sensitivity analysis, is employed to derive the costate (adjoint) equations, the transversality conditions, and the functional sensitivity derivatives. In the derivation of the sensitivity equations, the variational methods use the generalized calculus of variations, in which the variable boundary is considered as the design function. The converged solution of the state equations together with the converged solution of the costate equations are integrated along the domain boundary to uniquely determine the functional sensitivity derivatives with respect to the design function. The determination of the sensitivity derivatives of the performance index or functional entails the coupled solutions of the state and costate equations. As the stable and converged numerical solution of the costate equations with their boundary conditions are a priori unknown, numerical stability analysis is performed on both the state and costate equations. Thereafter, based on the amplification factors obtained by solving the generalized eigenvalue equations, the stability behavior of the costate equations is discussed and compared with the state (Euler) equations. The stability analysis of the costate equations suggests that the converged and stable solution of the costate equation is possible only if the computational domain of the costate equations is transformed to take into account the reverse flow nature of the costate equations. The application of the variational methods to aerodynamic shape optimization problems is demonstrated for internal flow problems at supersonic Mach number range. The study shows, that while maintaining the accuracy of the functional sensitivity derivatives within the reasonable range for engineering prediction purposes, the variational methods show a substantial gain in computational efficiency, i.e., computer time and memory, when compared with the finite

  1. Error Bounds for Quadrature Methods Involving Lower Order Derivatives

    ERIC Educational Resources Information Center

    Engelbrecht, Johann; Fedotov, Igor; Fedotova, Tanya; Harding, Ansie

    2003-01-01

    Quadrature methods for approximating the definite integral of a function f(t) over an interval [a,b] are in common use. Examples of such methods are the Newton-Cotes formulas (midpoint, trapezoidal and Simpson methods etc.) and the Gauss-Legendre quadrature rules, to name two types of quadrature. Error bounds for these approximations involve…

  2. Extending the applicability of multigrid methods

    SciTech Connect

    Brannick, J; Brezina, M; Falgout, R; Manteuffel, T; McCormick, S; Ruge, J; Sheehan, B; Xu, J; Zikatanov, L

    2006-09-25

    Multigrid methods are ideal for solving the increasingly large-scale problems that arise in numerical simulations of physical phenomena because of their potential for computational costs and memory requirements that scale linearly with the degrees of freedom. Unfortunately, they have been historically limited by their applicability to elliptic-type problems and the need for special handling in their implementation. In this paper, we present an overview of several recent theoretical and algorithmic advances made by the TOPS multigrid partners and their collaborators in extending applicability of multigrid methods. Specific examples that are presented include quantum chromodynamics, radiation transport, and electromagnetics.

  3. Methods for studying the platelet-derived growth factor receptor

    SciTech Connect

    Bowen-Pope, D.F.; Ross, R.

    1985-01-01

    Platelet-derived growth factor (PDGF) is a basic 30,000-dalton protein circulating in normal blood sequestered within the platelet alpha granule. Radioiodinated PDGF shows saturable (e.g., 60,000-120,000 receptors per diploid human fibroblast) high affinity binding to culture PDGF-responsive cells. The apparent dissociation constant reported for this binding interaction has varied widely. This paper focuses on factors which affect (/sup 125/I)PGDF binding and on the development of a radioreceptor assay for PDGF.

  4. A domain derivative-based method for solving elastodynamic inverse obstacle scattering problems

    NASA Astrophysics Data System (ADS)

    Le Louër, Frédérique

    2015-11-01

    The present work is concerned with the shape reconstruction problem of isotropic elastic inclusions from far-field data obtained by the scattering of a finite number of time-harmonic incident plane waves. This paper aims at completing the theoretical framework which is necessary for the application of geometric optimization tools to the inverse transmission problem in elastodynamics. The forward problem is reduced to systems of boundary integral equations following the direct and indirect methods initially developed for solving acoustic transmission problems. We establish the Fréchet differentiability of the boundary to far-field operator and give a characterization of the first Fréchet derivative and its adjoint operator. Using these results we propose an inverse scattering algorithm based on the iteratively regularized Gauß-Newton method and show numerical experiments in the special case of star-shaped obstacles.

  5. Damage Based Analysis (DBA): Theory, Derivation and Practical Application - Using Both an Acceleration and Pseudo-Velocity Approach

    NASA Technical Reports Server (NTRS)

    Grillo, Vince

    2016-01-01

    The objective of this presentation is to give a brief overview of the theory behind the (DBA) method, an overview of the derivation and a practical application of the theory using the Python computer language. The Theory and Derivation will use both Acceleration and Pseudo Velocity methods to derive a series of equations for processing by Python. We will take the results and compare both Acceleration and Pseudo Velocity methods and discuss implementation of the Python functions. Also, we will discuss the efficiency of the methods and the amount of computer time required for the solution. In conclusion, (DBA) offers a powerful method to evaluate the amount of energy imparted into a system in the form of both Amplitude and Duration during qualification testing and flight environments. Many forms of steady state and transient vibratory motion can be characterized using this technique. (DBA) provides a more robust alternative to traditional methods such Power Spectral Density (PSD) using a Maximax approach.

  6. [Near infrared spectra (NIR) analysis of octane number by wavelet denoising-derivative method].

    PubMed

    Tian, Gao-you; Yuan, Hong-fu; Chu, Xiao-li; Liu, Hui-ying; Lu, Wan-zhen

    2005-04-01

    Derivative can correct baseline effects and also increase the level of noise. Wavelet transform has been proven an efficient tool for de-noising. This paper is directed to the application of wavelet transfer and derivative in the NIR analysis of octane number (RON). The derivative parameters, as well as their effects on the noise level and analytic accuracy of RON, have been studied in detail. The results show that derivative can correct the baseline effects and increase the analytic accuracy. Noise from the derivative spectra has great detriment to the analysis of RON. De-noising of wavelet transform can increase the S/N and improve the analytical accuracy.

  7. 17 CFR Appendix to Part 39 - Form DCO Derivatives Clearing Organization Application for Registrations

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 1 2012-04-01 2012-04-01 false Form DCO Derivatives Clearing... FUTURES TRADING COMMISSION DERIVATIVES CLEARING ORGANIZATIONS Pt. 39, App. Appendix to Part 39—Form DCO Derivatives Clearing Organization Application for Registrations ER08NO11.001 ER08NO11.002...

  8. 17 CFR Appendix to Part 39 - Form DCO Derivatives Clearing Organization Application for Registrations

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 1 2013-04-01 2013-04-01 false Form DCO Derivatives Clearing... FUTURES TRADING COMMISSION DERIVATIVES CLEARING ORGANIZATIONS Pt. 39, App. Appendix to Part 39—Form DCO Derivatives Clearing Organization Application for Registrations ER08NO11.001 ER08NO11.002...

  9. New antimicrobial chitosan derivatives for wound dressing applications.

    PubMed

    Dragostin, Oana Maria; Samal, Sangram Keshari; Dash, Mamoni; Lupascu, Florentina; Pânzariu, Andreea; Tuchilus, Cristina; Ghetu, Nicolae; Danciu, Mihai; Dubruel, Peter; Pieptu, Dragos; Vasile, Cornelia; Tatia, Rodica; Profire, Lenuta

    2016-05-05

    Chitosan is a non-toxic, biocompatible, biodegradable natural cationic polymer known for its low imunogenicity, antimicrobial, antioxidant effects and wound-healing activity. To improve its therapeutic potential, new chitosan-sulfonamide derivatives have been designed to develop new wound dressing biomaterials. The structural, morphological and physico-chemical properties of synthesized chitosan derivatives were analyzed by FT-IR, (1)H NMR spectroscopy, scanning electron microscopy, swelling ability and porosity. Antimicrobial, in vivo testing and biodegradation behavior have been also performed. The chitosan derivative membranes showed improved swelling and biodegradation rate, which are important characteristics required for the wound healing process. The antimicrobial assay evidenced that chitosan-based sulfadiazine, sulfadimethoxine and sulfamethoxazole derivatives were the most active. The MTT assay showed that some of chitosan derivatives are nontoxic. Furthermore, the in vivo study on burn wound model induced in Wistar rats demonstrated an improved healing effect and enhanced epithelialization of chitosan-sulfonamide derivatives compared to neat chitosan. The obtained results strongly recommend the use of some of the newly developed chitosan derivatives as antimicrobial wound dressing biomaterials.

  10. Carcinogen derived biomarkers: applications in studies of human exposure to secondhand tobacco smoke

    PubMed Central

    Hecht, S

    2004-01-01

    Objective: To review the literature on carcinogen derived biomarkers of exposure to secondhand tobacco smoke (SHS). These biomarkers are specifically related to known carcinogens in tobacco smoke and include urinary metabolites, DNA adducts, and blood protein adducts. Method: Published reviews and the current literature were searched for relevant articles. Results: The most consistently elevated biomarker in people exposed to SHS was 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and its glucuronides (NNAL-Gluc), urinary metabolites of the tobacco specific lung carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). The tobacco specificity of this biomarker as well as its clear relation to an established lung carcinogen are particularly appropriate for its application in studies of SHS exposure. Conclusion: The results of the available carcinogen derived biomarker studies provide biochemical data which support the conclusion, based on epidemiologic investigations, that SHS causes lung cancer in non-smokers. PMID:14985617

  11. Matrix methods for determining the longitudinal-stability derivatives of an airplane from transient flight data

    NASA Technical Reports Server (NTRS)

    Donegan, James J

    1954-01-01

    Three matrice methods are developed and presented for determining the longitudinal-stability derivatives from transient flight data. In these methods the expressions for some of the stability derivatives are in the form generally used in stability calculations. The first method requires the combination of four measurements in time-history form, two of which must be incremental elevator deflection and incremental tail load and the other two measurements can be chosen from a possible three, namely incremental load factor, pitching velocity, and angle of attack. The method demonstrates the use of the tail load to separate the pitching-moment derivatives and to determine the downwash derivative. (author)

  12. Application of Derivative Spectrometry to the Analysis of Trace Gases

    NASA Technical Reports Server (NTRS)

    Hager, Robert N.

    1971-01-01

    A derivative spectrometer is sensitive to changes in spectral intensity over narrow wavelength internal. Specifically, a second derivative spectrometer senses the curvature of the incident spectral intensity, providing an output voltage signal proportional to the second derivative of intensity with respect to wavelength. When such an instrument is combined with multi-pass White cell, a unique trace gas analyzer results. The analyzer, operating within the middle ultraviolet spectral region, provides a highly amplified derivative spectrum of any molecular narrow band absorption which is used for trace gas identification. The intensity of any peak within a spectrum is proportional to the trace gas concentration. Such an analyzer, utilizing a 20 meter pathlength White cell, is presently being used to automatically monitor ambient air for SO2, NO, NO2, and O3 with minimum detectable concentration limits in the part per billion range.

  13. Hydroxylapatite nanoparticles: fabrication methods and medical applications

    PubMed Central

    Okada, Masahiro; Furuzono, Tsutomu

    2012-01-01

    Hydroxylapatite (or hydroxyapatite, HAp) exhibits excellent biocompatibility with various kinds of cells and tissues, making it an ideal candidate for tissue engineering, orthopedic and dental applications. Nanosized materials offer improved performances compared with conventional materials due to their large surface-to-volume ratios. This review summarizes existing knowledge and recent progress in fabrication methods of nanosized (or nanostructured) HAp particles, as well as their recent applications in medical and dental fields. In section 1, we provide a brief overview of HAp and nanoparticles. In section 2, fabrication methods of HAp nanoparticles are described based on the particle formation mechanisms. Recent applications of HAp nanoparticles are summarized in section 3. The future perspectives in this active research area are given in section 4. PMID:27877527

  14. Hydroxylapatite nanoparticles: fabrication methods and medical applications

    NASA Astrophysics Data System (ADS)

    Okada, Masahiro; Furuzono, Tsutomu

    2012-12-01

    Hydroxylapatite (or hydroxyapatite, HAp) exhibits excellent biocompatibility with various kinds of cells and tissues, making it an ideal candidate for tissue engineering, orthopedic and dental applications. Nanosized materials offer improved performances compared with conventional materials due to their large surface-to-volume ratios. This review summarizes existing knowledge and recent progress in fabrication methods of nanosized (or nanostructured) HAp particles, as well as their recent applications in medical and dental fields. In section 1, we provide a brief overview of HAp and nanoparticles. In section 2, fabrication methods of HAp nanoparticles are described based on the particle formation mechanisms. Recent applications of HAp nanoparticles are summarized in section 3. The future perspectives in this active research area are given in section 4.

  15. Application of L-cystein derivative to DNA microarray.

    PubMed

    Nakauchi, Gen; Inaki, Yoshiaki; Kitaoka, Shiho; Yokoyama, Chieko; Tanabe, Tadashi

    2002-01-01

    S-carboxymethyl-L-cystein derivatives of nucleic acid bases were prepared as DNA chip probe. These compounds in vitro have been found to form stable complex with oligo-DNA and RNA. This paper deals with preparing new DNA chip using L-cystein derivative synthetic nucleotides as probe and immobilized it to quartz plate by photosensitive PVA. Then the chip exposed with FITC labeled target DNA was observed by confocal fluorescence microscope.

  16. Engineering applications of heuristic multilevel optimization methods

    NASA Technical Reports Server (NTRS)

    Barthelemy, Jean-Francois M.

    1988-01-01

    Some engineering applications of heuristic multilevel optimization methods are presented and the discussion focuses on the dependency matrix that indicates the relationship between problem functions and variables. Coordination of the subproblem optimizations is shown to be typically achieved through the use of exact or approximate sensitivity analysis. Areas for further development are identified.

  17. Engineering applications of heuristic multilevel optimization methods

    NASA Technical Reports Server (NTRS)

    Barthelemy, Jean-Francois M.

    1989-01-01

    Some engineering applications of heuristic multilevel optimization methods are presented and the discussion focuses on the dependency matrix that indicates the relationship between problem functions and variables. Coordination of the subproblem optimizations is shown to be typically achieved through the use of exact or approximate sensitivity analysis. Areas for further development are identified.

  18. On Aims and Methods in the Neuroimaging of Derived Relations

    PubMed Central

    Dickins, David W

    2005-01-01

    Ingenious and seemingly powerful technologies have been developed recently that enable the visualization in some detail of events in the brain concomitant upon the ongoing behavioral performance of a human participant. Measurement of such brain events offers at the very least a new set of dependent variables in relation to which the independent variables familiarly manipulated in the operant laboratory may be explored. Two related paradigms in which a start has been made in such research concern the derivation of novel or emergent relations from a baseline set of trained relations, and include the phenomenon of transitive inference (TI), observed in studies of stimulus equivalence (SE) and serial learning (SL) or seriation. This paper reviews some published and forthcoming neuroimaging studies of these and related phenomena, and considers how this line of research both demands and represents a welcome synthesis between types of question and levels of explanation in behavioral science that often have been seen as antithetical. PMID:16596975

  19. Simultaneous iterative method for the derivatives of several eigenpairs of unsymmetric damped systems

    NASA Astrophysics Data System (ADS)

    Xie, Huiqing

    2015-12-01

    In this paper, a new iterative method is proposed to calculate a few eigenpair derivatives of damped systems. The proposed method simultaneously computes the derivatives of several simple eigenvalues and their corresponding eigenvectors. Eigenpair derivatives are directly determined in n-space. Moreover, our method does not require the left eigenvectors. Convergence theory of the proposed method is given. On these grounds, using vector ɛ-algorithm, acceleration techniques for our method are provided and analyzed. Finally some numerical experiments are reported to show the efficiency of the proposed methods.

  20. Highly accurate first-principles benchmark data sets for the parametrization and validation of density functional and other approximate methods. Derivation of a robust, generally applicable, double-hybrid functional for thermochemistry and thermochemical kinetics.

    PubMed

    Karton, Amir; Tarnopolsky, Alex; Lamère, Jean-François; Schatz, George C; Martin, Jan M L

    2008-12-18

    We present a number of near-exact, nonrelativistic, Born-Oppenheimer reference data sets for the parametrization of more approximate methods (such as DFT functionals). The data were obtained by means of the W4 ab initio computational thermochemistry protocol, which has a 95% confidence interval well below 1 kJ/mol. Our data sets include W4-08, which are total atomization energies of over 100 small molecules that cover varying degrees of nondynamical correlations, and DBH24-W4, which are W4 theory values for Truhlar's set of 24 representative barrier heights. The usual procedure of comparing calculated DFT values with experimental atomization energies is hampered by comparatively large experimental uncertainties in many experimental values and compounds errors due to deficiencies in the DFT functional with those resulting from neglect of relativity and finite nuclear mass. Comparison with accurate, explicitly nonrelativistic, ab initio data avoids these issues. We then proceed to explore the performance of B2x-PLYP-type double hybrid functionals for atomization energies and barrier heights. We find that the optimum hybrids for hydrogen-transfer reactions, heavy-atoms transfers, nucleophilic substitutions, and unimolecular and recombination reactions are quite different from one another: out of these subsets, the heavy-atom transfer reactions are by far the most sensitive to the percentages of Hartree-Fock-type exchange y and MP2-type correlation x in an (x, y) double hybrid. The (42,72) hybrid B2K-PLYP, as reported in a preliminary communication, represents the best compromise between thermochemistry and hydrogen-transfer barriers, while also yielding excellent performance for nucleophilic substitutions. By optimizing for best overall performance on both thermochemistry and the DBH24-W4 data set, however, we find a new (36,65) hybrid which we term B2GP-PLYP. At a slight expense in performance for hydrogen-transfer barrier heights and nucleophilic substitutions, we

  1. Microwave thermography: principles, methods and clinical applications.

    PubMed

    Myers, P C; Sadowsky, N L; Barrett, A H

    1979-06-01

    We review the physical principles, method of operation, measurement limitations, and potential medical applications of microwave thermography. We present detailed results of a study of breast cancer detection at 1.3 and 3.3 GHz, including the dependence of detection rates on microwave frequency, time, tumor depth, and tumor size. At 1.3 GHz, microwave thermography detects breast cancer as well as infrared thermography (true-positive rate = 0.76 when true-negative rate = 0.63). When the two methods are combined, the true-positive rate increases by about 0.1 over that of either method alone.

  2. Satellite Geodesy—Foundations, Methods, and Applications

    NASA Astrophysics Data System (ADS)

    Fell, Patrick

    This text is an updated English translation of Satellitengeodasie, a book that was published in German in 1989. The text is the first in many years that attempts to cover the broad spectrum of methods, applications, and systems, both classical and current, that have developed in the field of satellite geodesy.The material is presented in a structure that follows the major observational methods used in satellite geodesy: classical techniques, Doppler, GPS, laser, altimetry, and special methods including satellite-to-satellite tracking, satellite radiometry, and VLBI. Before introducing these observational techniques in detail, the author provides the fundamentals on reference frames, time signal propagation, orbital mechanics and basic applications of satellite geodesy in positioning, gravity field modeling, navigation, marine geodesy, kinematics, and geodynamics. An excellent reference list completes the text.

  3. A NEW METHOD FOR DERIVING THE STELLAR BIRTH FUNCTION OF RESOLVED STELLAR POPULATIONS

    SciTech Connect

    Gennaro, M.; Brown, T. M.; Gordon, K. D.; Tchernyshyov, K.

    2015-07-20

    We present a new method for deriving the stellar birth function (SBF) of resolved stellar populations. The SBF (stars born per unit mass, time, and metallicity) is the combination of the initial mass function (IMF), the star formation history (SFH), and the metallicity distribution function (MDF). The framework of our analysis is that of Poisson Point Processes (PPPs), a class of statistical models suitable when dealing with points (stars) in a multidimensional space (the measurement space of multiple photometric bands). The theory of PPPs easily accommodates the modeling of measurement errors as well as that of incompleteness. Our method avoids binning stars in the color–magnitude diagram and uses the whole likelihood function for each data point; combining the individual likelihoods allows the computation of the posterior probability for the population's SBF. Within the proposed framework it is possible to include nuisance parameters, such as distance and extinction, by specifying their prior distributions and marginalizing over them. The aim of this paper is to assess the validity of this new approach under a range of assumptions, using only simulated data. Forthcoming work will show applications to real data. Although it has a broad scope of possible applications, we have developed this method to study multi-band Hubble Space Telescope observations of the Milky Way Bulge. Therefore we will focus on simulations with characteristics similar to those of the Galactic Bulge.

  4. Inactivation of viruses in labile blood derivatives. II. Physical methods

    SciTech Connect

    Horowitz, B.; Wiebe, M.E.; Lippin, A.; Vandersande, J.; Stryker, M.H.

    1985-11-01

    The thermal inactivation of viruses in labile blood derivatives was evaluated by addition of marker viruses (VSV, Sindbis, Sendai, EMC) to anti-hemophilic factor (AHF) concentrates. The rate of virus inactivation at 60 degrees C was decreased by at least 100- to 700-fold by inclusion of 2.75 M glycine and 50 percent sucrose, or 3.0 M potassium citrate, additives which contribute to retention of protein biologic activity. Nonetheless, at least 10(4) infectious units of each virus was inactivated within 10 hours. Increasing the temperature from 60 to 70 or 80 degrees C caused a 90 percent or greater loss in AHF activity. An even greater decline in the rate of virus inactivation was observed on heating AHF in the lyophilized state, although no loss in AHF activity was observed after 72 hours of heating at 60 degrees C. Several of the proteins present in lyophilized AHF concentrates displayed an altered electrophoretic mobility as a result of exposure to 60 degrees C for 24 hours. Exposure of lyophilized AHF to irradiation from a cobalt 60 source resulted in an acceptable yield of AHF at 1.0, but not at 2.0, megarads. At 1 megarad, greater than or equal to 6.0 logs of VSV and 3.3 logs of Sindbis virus were inactivated.

  5. Signal processing using sparse derivatives with applications to chromatograms and ECG

    NASA Astrophysics Data System (ADS)

    Ning, Xiaoran

    In this thesis, we investigate the sparsity exist in the derivative domain. Particularly, we focus on the type of signals which posses up to Mth (M > 0) order sparse derivatives. Efforts are put on formulating proper penalty functions and optimization problems to capture properties related to sparse derivatives, searching for fast, computationally efficient solvers. Also the effectiveness of these algorithms are applied to two real world applications. In the first application, we provide an algorithm which jointly addresses the problems of chromatogram baseline correction and noise reduction. The series of chromatogram peaks are modeled as sparse with sparse derivatives, and the baseline is modeled as a low-pass signal. A convex optimization problem is formulated so as to encapsulate these non-parametric models. To account for the positivity of chromatogram peaks, an asymmetric penalty function is also utilized with symmetric penalty functions. A robust, computationally efficient, iterative algorithm is developed that is guaranteed to converge to the unique optimal solution. The approach, termed Baseline Estimation And Denoising with Sparsity (BEADS), is evaluated and compared with two state-of-the-art methods using both simulated and real chromatogram data. Promising result is obtained. In the second application, a novel Electrocardiography (ECG) enhancement algorithm is designed also based on sparse derivatives. In the real medical environment, ECG signals are often contaminated by various kinds of noise or artifacts, for example, morphological changes due to motion artifact, non-stationary noise due to muscular contraction (EMG), etc. Some of these contaminations severely affect the usefulness of ECG signals, especially when computer aided algorithms are utilized. By solving the proposed convex l1 optimization problem, artifacts are reduced by modeling the clean ECG signal as a sum of two signals whose second and third-order derivatives (differences) are sparse

  6. Methods for the synthesis of olefins and derivatives

    DOEpatents

    Burk, Mark J; Pharkya, Priti; Van Dien, Stephen J; Burgard, Anthony P; Schilling, Christophe H

    2013-06-04

    The invention provides a method of producing acrylic acid. The method includes contacting fumaric acid with a sufficient amount of ethylene in the presence of a cross-metathesis transformation catalyst to produce about two moles of acrylic acid per mole of fumaric acid. Also provided is an acrylate ester. The method includes contacting fumarate diester with a sufficient amount of ethylene in the presence of a cross-metathesis transformation catalyst to produce about two moles of acrylate ester per mole of fumarate diester. An integrated process for process for producing acrylic acid or acrylate ester is provided which couples bioproduction of fumaric acid with metathesis transformation. An acrylic acid and an acrylate ester production also is provided.

  7. Methods for the synthesis of olefins and derivatives

    DOEpatents

    Burk, Mark J.; Pharkya, Priti; Van Dien, Stephen J.; Burgard, Anthony P.; Schilling, Christophe H.

    2011-09-27

    The invention provides a method of producing acrylic acid. The method includes contacting fumaric acid with a sufficient amount of ethylene in the presence of a cross-metathesis transformation catalyst to produce about two moles of acrylic acid per mole of fumaric acid. Also provided is an acrylate ester. The method includes contacting fumarate diester with a sufficient amount of ethylene in the presence of a cross-metathesis transformation catalyst to produce about two moles of acrylate ester per mole of fumarate diester. An integrated process for process for producing acrylic acid or acrylate ester is provided which couples bioproduction of fumaric acid with metathesis transformation. An acrylic acid and an acrylate ester production also is provided.

  8. Method of producing solution-derived metal oxide thin films

    DOEpatents

    Boyle, Timothy J.; Ingersoll, David

    2000-01-01

    A method of preparing metal oxide thin films by a solution method. A .beta.-metal .beta.-diketonate or carboxylate compound, where the metal is selected from groups 8, 9, 10, 11, and 12 of the Periodic Table, is solubilized in a strong Lewis base to form a homogeneous solution. This precursor solution forms within minutes and can be deposited on a substrate in a single layer or a multiple layers to form a metal oxide thin film. The substrate with the deposited thin film is heated to change the film from an amorphous phase to a ceramic metal oxide and cooled.

  9. Method of producing solution-derived metal oxide thin films

    SciTech Connect

    Boyle, T.J.; Ingersoll, D.

    2000-07-11

    A method is described for preparing metal oxide thin films by a solution method. A {beta}-metal {beta}-diketonate or carboxylate compound, where the metal is selected from groups 8, 9, 10, 11, and 12 of the Periodic Table, is solubilized in a strong Lewis base to form a homogeneous solution. This precursor solution forms within minutes and can be deposited on a substrate in a single layer or a multiple layers to form a metal oxide thin film. The substrate with the deposited thin film is heated to change the film from an amorphous phase to a ceramic metal oxide and cooled.

  10. Application potential of mesenchymal stem cells derived from Wharton's jelly in liver tissue engineering.

    PubMed

    Zhang, Lei; Zhao, Yong-Hen; Guan, Zheng; Ye, Jun-Song; de Isla, Natalia; Stoltz, Jean-François

    2015-01-01

    The shortage of organ resource has been limiting the application of liver transplantation. Bioartificial liver construction is increasingly focused as a replacement treatment. To product a bioartificial liver, three elements must be considered: seeding cells, scaffold and bioreactor. Recent studies have shown that several methods can successfully differentiate MSC (mesenchymal stem cells) derived from Wharton's jelly into hepatocyte, such as stimulating MSC by cytokines and growth factors, direct and indirect co-culture MSC with hepatocytes, or promote MSC differentiation by 3-dimensional matrix. In some cases, differentiation of MSC into hepatocytes can also be an alternative approach for whole organ transplantation in treatment of acute and chronic liver diseases. In this review, the characterization of MSC from Wharton's jelly, their potential of application in liver tissue engineering on base of decellularized scaffold, their status of banking and their preclinical work performed will be discussed.

  11. Electrochemical study and analytical applications for new biologically active 2-nitrophenylbenzimidazole derivatives.

    PubMed

    Alvarez-Lueje, A; Zapata-Urzúa, C; Brain-Isasi, S; Pérez-Ortiz, M; Barros, L; Pessoa-Mahana, H; Kogan, M J

    2009-08-15

    The present study addresses the electrochemical behavior and the analytical applications of six 2-nitrophenylbenzimidazole derivatives with activity against Trypanosoma cruzi. When studied in a wide range of pH, by differential pulse polarography, tast polarography and cyclic voltammetry, these compounds exhibited two irreversible cathodic responses. With analytical purposes, the differential pulse polarography mode was selected, which exhibited adequate analytical parameters of repeatability, reproducibility and selectivity. The percentage of recovery was in all cases over 99%, and the detection and quantitation limits were at the level of 1 x 10(-7)mol L(-1) and 1 x 10(-6)mol L(-1), respectively. In addition, the differential pulse polarography method was successfully applied to study the hydrolytic degradation kinetic of one of the tested compounds. Activation energy, kinetic rate constants at different temperatures and half-life values of such application are reported.

  12. Sol-gel derived planar waveguides for sensor applications

    NASA Astrophysics Data System (ADS)

    Karasinski, Pawel; Zielonka, Iwona

    2003-09-01

    The paper presents investigation results on the application of sol-gel technology for the production of planar waveguides. These waveguides are produced in a two-component system SiO2:TiO2. We discussed application potentials of the produced layers and presented the results of theoretical analysis involving future structures.

  13. Extremal Optimization: Methods Derived from Co-Evolution

    SciTech Connect

    Boettcher, S.; Percus, A.G.

    1999-07-13

    We describe a general-purpose method for finding high-quality solutions to hard optimization problems, inspired by self-organized critical models of co-evolution such as the Bak-Sneppen model. The method, called Extremal Optimization, successively eliminates extremely undesirable components of sub-optimal solutions, rather than ''breeding'' better components. In contrast to Genetic Algorithms which operate on an entire ''gene-pool'' of possible solutions, Extremal Optimization improves on a single candidate solution by treating each of its components as species co-evolving according to Darwinian principles. Unlike Simulated Annealing, its non-equilibrium approach effects an algorithm requiring few parameters to tune. With only one adjustable parameter, its performance proves competitive with, and often superior to, more elaborate stochastic optimization procedures. We demonstrate it here on two classic hard optimization problems: graph partitioning and the traveling salesman problem.

  14. Gelatin Nanofiber Matrices Derived from Schiff Base Derivative for Tissue Engineering Applications.

    PubMed

    Jaiswal, Devina; James, Roshan; Shelke, Namdev B; Harmon, Matthew D; Brown, Justin L; Hussain, Fazle; Kumbar, Sangamesh G

    2015-11-01

    Electrospinning of water-soluble polymers and retaining their mechanical strength and bioactivity remain challenging. Volatile organic solvent soluble polymers and their derivatives are preferred for fabricating electrospun nanofibers. We report the synthesis and characterization of 2-nitrobenzyl-gelatin (N-Gelatin)--a novel gelatin Schiff base derivative--and the resulting electrospun nanofiber matrices. The 2-nitrobenzyl group is a photoactivatable-caged compound and can be cleaved from the gelatin nanofiber matrices following UV exposure. Such hydrophobic modification allowed the fabrication of gelatin and blend nanofibers with poly(caprolactone) (PCL) having significantly improved tensile properties. Neat gelatin and their PCL blend nanofiber matrices showed a modulus of 9.08 ± 1.5 MPa and 27.61 ± 4.3 MPa, respectively while the modified gelatin and their blends showed 15.63 ± 2.8 MPa and 24.47 ± 8.7 MPa, respectively. The characteristic infrared spectroscopy band for gelatin Schiff base derivative at 1560 cm(-1) disappeared following exposure to UV light indicating the regeneration of free NH2 group and gelatin. These nanofiber matrices supported cell attachment and proliferation with a well spread morphology as evidenced through cell proliferation assay and microscopic techniques. Modified gelatin fiber matrices showed a 73% enhanced cell attachment and proliferation rate compared to pure gelatin. This polymer modification methodology may offer a promising way to fabricate electrospun nanofiber matrices using a variety of proteins and peptides without loss of bioactivity and mechanical strength.

  15. Rosmarinic acid and its derivatives: biotechnology and applications.

    PubMed

    Bulgakov, Victor P; Inyushkina, Yuliya V; Fedoreyev, Sergey A

    2012-09-01

    Rosmarinic acid (RA) is one of the first secondary metabolites produced in plant cell cultures in extremely high yields, up to 19% of the cell dry weight. More complex derivatives of RA, such as rabdosiin and lithospermic acid B, later were also obtained in cell cultures at high yields. RA and its derivatives possess promising biological activities, such as improvement of cognitive performance, prevention of the development of Alzheimer's disease, cardioprotective effects, reduction of the severity of kidney diseases and cancer chemoprevention. The TNF-α-induced NF-κB signaling pathway has emerged as a central target for RA. Despite these impressive activities and high yields, the biotechnological production of these metabolites on an industrial scale has not progressed. We summarized data suggesting that external stimuli, the Ca(2+)-dependent NADPH oxidase pathway and processes of protein phosphorylation/dephosphorylation are involved in the regulation of biosynthesis of these substances in cultured plant cells. In spite of growing information about pathways regulating biosynthesis of RA and its derivatives in cultured plant cells, the exact mechanism of regulation remains unknown. We suggest that further progress in the biotechnology of RA and its derivatives can be achieved by using new high-throughput techniques.

  16. Marine-derived fungi: diversity of enzymes and biotechnological applications

    PubMed Central

    Bonugli-Santos, Rafaella C.; dos Santos Vasconcelos, Maria R.; Passarini, Michel R. Z.; Vieira, Gabriela A. L.; Lopes, Viviane C. P.; Mainardi, Pedro H.; dos Santos, Juliana A.; de Azevedo Duarte, Lidia; Otero, Igor V. R.; da Silva Yoshida, Aline M.; Feitosa, Valker A.; Pessoa, Adalberto; Sette, Lara D.

    2015-01-01

    The ocean is considered to be a great reservoir of biodiversity. Microbial communities in marine environments are ecologically relevant as intermediaries of energy, and play an important role in nutrient regeneration cycles as decomposers of dead and decaying organic matter. In this sense, marine-derived fungi can be considered as a source of enzymes of industrial and/or environmental interest. Fungal strains isolated from different substrates, such as invertebrates, decaying wood, seawater, sediments, and mangrove detritus, have been reported to be producers of hydrolytic and/or oxidative enzymes, with alginate lyase, amylase, cellulase, chitinase, glucosidase, inulinase, keratinase, ligninase, lipase, nuclease, phytase, protease, and xylanase being among the enzymes produced by fungi of marine origin. These enzymes present temperature and pH optima ranging from 35 to 70∘C, and 3.0 to 11.0, respectively. High-level production in bioreactors is mainly performed using submerged-state fermentation. Certain marine-derived fungal strains present enzymes with alkaline and cold-activity characteristics, and salinity is considered an important condition in screening and production processes. The adaptability of marine-derived fungi to oceanic conditions can be considered an attractive point in the field of fungal marine biotechnology. In this review, we focus on the advances in discovering enzymes from marine-derived fungi and their biotechnological relevance. PMID:25914680

  17. Marine-derived fungi: diversity of enzymes and biotechnological applications.

    PubMed

    Bonugli-Santos, Rafaella C; Dos Santos Vasconcelos, Maria R; Passarini, Michel R Z; Vieira, Gabriela A L; Lopes, Viviane C P; Mainardi, Pedro H; Dos Santos, Juliana A; de Azevedo Duarte, Lidia; Otero, Igor V R; da Silva Yoshida, Aline M; Feitosa, Valker A; Pessoa, Adalberto; Sette, Lara D

    2015-01-01

    The ocean is considered to be a great reservoir of biodiversity. Microbial communities in marine environments are ecologically relevant as intermediaries of energy, and play an important role in nutrient regeneration cycles as decomposers of dead and decaying organic matter. In this sense, marine-derived fungi can be considered as a source of enzymes of industrial and/or environmental interest. Fungal strains isolated from different substrates, such as invertebrates, decaying wood, seawater, sediments, and mangrove detritus, have been reported to be producers of hydrolytic and/or oxidative enzymes, with alginate lyase, amylase, cellulase, chitinase, glucosidase, inulinase, keratinase, ligninase, lipase, nuclease, phytase, protease, and xylanase being among the enzymes produced by fungi of marine origin. These enzymes present temperature and pH optima ranging from 35 to 70(∘)C, and 3.0 to 11.0, respectively. High-level production in bioreactors is mainly performed using submerged-state fermentation. Certain marine-derived fungal strains present enzymes with alkaline and cold-activity characteristics, and salinity is considered an important condition in screening and production processes. The adaptability of marine-derived fungi to oceanic conditions can be considered an attractive point in the field of fungal marine biotechnology. In this review, we focus on the advances in discovering enzymes from marine-derived fungi and their biotechnological relevance.

  18. Incompressible Spectral-Element Method-Derivation of Equations

    DTIC Science & Technology

    1993-04-01

    expansion functions. Not all orthogonal expansion functions provide high accuracy; however, the eigenfunctions of a singlar Sturm - Liouville operator allow...orthogonal functions p(x), q(x), w(x) = functions in Sturm - Liouville equation P = p/p + IV-V, dynamic pressure Pn = a system of orthogonal polynomials of...truncated series in approximating functions. 1.2 Sturm - Liouville Problems The importance of Sturm - Liouville problems for spectral methods lies in the fact

  19. Utilizing Computational Probabilistic Methods to Derive Shock Specifications in a Nondeterministic Environment

    SciTech Connect

    FIELD JR.,RICHARD V.; RED-HORSE,JOHN R.; PAEZ,THOMAS L.

    2000-10-25

    One of the key elements of the Stochastic Finite Element Method, namely the polynomial chaos expansion, has been utilized in a nonlinear shock and vibration application. As a result, the computed response was expressed as a random process, which is an approximation to the true solution process, and can be thought of as a generalization to solutions given as statistics only. This approximation to the response process was then used to derive an analytically-based design specification for component shock response that guarantees a balanced level of marginal reliability. Hence, this analytically-based reference SRS might lead to an improvement over the somewhat ad hoc test-based reference in the sense that it will not exhibit regions of conservativeness. nor lead to overtesting of the design.

  20. Stability Characterization of Quinazoline Derivative BG1188 by Optical Methods

    NASA Astrophysics Data System (ADS)

    Militaru, Andra; Smarandache, Adriana; Mahamoud, Abdallah; Damian, Victor; Ganea, Paul; Alibert, Sandrine; Pagès, Jean-Marie; Pascu, Mihail-Lucian

    2011-08-01

    3-[2-(dimethylamino)ethyl]-6-nitroquinazolin-4(3H)-one, labeled BG1188, is a new synthesized compound, out of a series of quinazoline derivatives developed to fight the multidrug resistance of antibiotics acquired by bacteria. A characterization of the BG1188 powder was made using FTIR spectra in order to evidence the functional groups in the medicine's molecule. The ultraviolet-visible (UV-Vis) absorption spectra were used to study the stability of the BG1188 solutions in two solvents and at different temperatures. BG1188 concentration in ultrapure water was varied between 2×10-3 M (stock solution) and 10-6 M. The concentration recommended by higher activity on bacteria was 10-3 M. For the same reason, this was the utilized concentration of BG1188 in dimethyl sulfoxide (DMSO). Time stability was characterized by comparing the time evolution of the UV-Vis absorption spectra of the BG1188 solutions in ultrapure de-ionized water or in DMSO. The spectra were recorded daily for about 4 months after the preparation for the BG1188 solutions in ultrapure water. Generally, samples are stable within the experimental errors at concentrations higher than 10-5 M, but the stability time interval may vary from 119 days at 10-4 M to 34 days at 10-5 M. Time evolution of the absorption spectra at 10-3 M in ultrapure water shows reproducibility within the measuring errors (±1.045%) for time intervals up to 1032 hours (more than 40 days) after preparation. On the other hand, BG1188 solutions in DMSO may be considered unstable because the absorption spectra modify in terms of peak shapes and intensities, indicating that the samples exhibit modifications immediately after preparation. Regardless the solvent used, some aggregation phenomena took place and wire-like aggregates were observed in all the solutions with the naked eye. These aggregates were analyzed, tentatively, using optical microscopy and FTIR.

  1. Establishment of mouse embryonic stem cells from isolated blastomeres and whole embryos using three derivation methods

    PubMed Central

    González, Sheyla; Ibáñez, Elena

    2010-01-01

    Purpose The aim of the present study is to compare three previously described mouse embryonic stem cell derivation methods to evaluate the influence of culture conditions, number of isolated blastomeres and embryonic stage in the derivation process. Methods Three embryonic stem cell derivation methods: standard, pre-adhesion and defined culture medium method, were compared in the derivation from isolated blastomeres and whole embryos at 4- and 8-cell stages. Results A total of 200 embryonic stem cell lines were obtained with an efficiency ranging from 1.9% to 72%. Conclusions Using either isolated blastomeres or whole embryos, the highest rates of mouse embryonic stem cell establishment were achieved with the defined culture medium method and efficiencies increased as development progressed. Using isolated blastomeres, efficiencies increased in parallel to the proportion of the embryo volume used to start the derivation process. PMID:20862536

  2. Extended applications of the vortex lattice method

    NASA Technical Reports Server (NTRS)

    Miranda, L. R.

    1976-01-01

    The application of the vortex lattice method to problems not usually dealt with by this technique is considered. It is shown that if the discrete vortex lattice is considered as an approximation to surface-distributed vorticity, then the concept of the generalized principal part of an integral yields a residual term to the vortex-induced velocity that renders the vortex lattice method valid for supersonic flow. Special schemes for simulating non-zero thickness lifting surfaces and fusiform bodies with vortex lattice elements are presented. Thickness effects of wing-like components are simulated by a double vortex lattice layer, and fusiform bodies are represented by a vortex grid arranged on a series of concentric cylindrical surfaces. Numerical considerations peculiar to the application of these techniques are briefly discussed.

  3. Simulating protein dynamics: Novel methods and applications

    NASA Astrophysics Data System (ADS)

    Vishal, V.

    This Ph.D dissertation describes several methodological advances in molecular dynamics (MD) simulations. Methods like Markov State Models can be used effectively in combination with distributed computing to obtain long time scale behavior from an ensemble of short simulations. Advanced computing architectures like Graphics Processors can be used to greatly extend the scope of MD. Applications of MD techniques to problems like Alzheimer's Disease and fundamental questions in protein dynamics are described.

  4. Nuclear data calculation methods for medical applications

    SciTech Connect

    Shubin, Yu.N.; Lunev, V.P.; Masterov, V.S.; Kurenkov, N.V.; Kulikov, E.V.

    1994-12-31

    Neutron deficient radionuclides play an important role in medicine, where they are used for diagnostic with Positron Emission Tomography (PET) and Single Photon Emission Tomography (SPET). Using some reactions connected with the producing most widely used radioisotopes {sup 123}I, {sup 201}Tl, {sup 99}Tc as example we calculated reaction cross sections and discuss the possibilities of the models and codes and recent progress in the methods to predict nuclear data for medical and other applications in medium energy region.

  5. Probabilistic structural analysis methods and applications

    NASA Technical Reports Server (NTRS)

    Cruse, T. A.; Wu, Y.-T.; Dias, B.; Rajagopal, K. R.

    1988-01-01

    An advanced algorithm for simulating the probabilistic distribution of structural responses due to statistical uncertainties in loads, geometry, material properties, and boundary conditions is reported. The method effectively combines an advanced algorithm for calculating probability levels for multivariate problems (fast probability integration) together with a general-purpose finite-element code for stress, vibration, and buckling analysis. Application is made to a space propulsion system turbine blade for which the geometry and material properties are treated as random variables.

  6. Analytical study to define a helicopter stability derivative extraction method, volume 1

    NASA Technical Reports Server (NTRS)

    Molusis, J. A.

    1973-01-01

    A method is developed for extracting six degree-of-freedom stability and control derivatives from helicopter flight data. Different combinations of filtering and derivative estimate are investigated and used with a Bayesian approach for derivative identification. The combination of filtering and estimate found to yield the most accurate time response match to flight test data is determined and applied to CH-53A and CH-54B flight data. The method found to be most accurate consists of (1) filtering flight test data with a digital filter, followed by an extended Kalman filter (2) identifying a derivative estimate with a least square estimator, and (3) obtaining derivatives with the Bayesian derivative extraction method.

  7. Harmony search method: theory and applications.

    PubMed

    Gao, X Z; Govindasamy, V; Xu, H; Wang, X; Zenger, K

    2015-01-01

    The Harmony Search (HS) method is an emerging metaheuristic optimization algorithm, which has been employed to cope with numerous challenging tasks during the past decade. In this paper, the essential theory and applications of the HS algorithm are first described and reviewed. Several typical variants of the original HS are next briefly explained. As an example of case study, a modified HS method inspired by the idea of Pareto-dominance-based ranking is also presented. It is further applied to handle a practical wind generator optimal design problem.

  8. Experimental design methods for bioengineering applications.

    PubMed

    Keskin Gündoğdu, Tuğba; Deniz, İrem; Çalışkan, Gülizar; Şahin, Erdem Sefa; Azbar, Nuri

    2016-01-01

    Experimental design is a form of process analysis in which certain factors are selected to obtain the desired responses of interest. It may also be used for the determination of the effects of various independent factors on a dependent factor. The bioengineering discipline includes many different areas of scientific interest, and each study area is affected and governed by many different factors. Briefly analyzing the important factors and selecting an experimental design for optimization are very effective tools for the design of any bioprocess under question. This review summarizes experimental design methods that can be used to investigate various factors relating to bioengineering processes. The experimental methods generally used in bioengineering are as follows: full factorial design, fractional factorial design, Plackett-Burman design, Taguchi design, Box-Behnken design and central composite design. These design methods are briefly introduced, and then the application of these design methods to study different bioengineering processes is analyzed.

  9. Skin Tissue Engineering: Application of Adipose-Derived Stem Cells

    PubMed Central

    Zimoch, Jakub; Biedermann, Thomas

    2017-01-01

    Perception of the adipose tissue has changed dramatically over the last few decades. Identification of adipose-derived stem cells (ASCs) ultimately transformed paradigm of this tissue from a passive energy depot into a promising stem cell source with properties of self-renewal and multipotential differentiation. As compared to bone marrow-derived stem cells (BMSCs), ASCs are more easily accessible and their isolation yields higher amount of stem cells. Therefore, the ASCs are of high interest for stem cell-based therapies and skin tissue engineering. Currently, freshly isolated stromal vascular fraction (SVF), which may be used directly without any expansion, was also assessed to be highly effective in treating skin radiation injuries, burns, or nonhealing wounds such as diabetic ulcers. In this paper, we review the characteristics of SVF and ASCs and the efficacy of their treatment for skin injuries and disorders. PMID:28337463

  10. Massive graviton on arbitrary background: derivation, syzygies, applications

    SciTech Connect

    Bernard, Laura; Deffayet, Cédric; Strauss, Mikael von E-mail: deffayet@iap.fr

    2015-06-01

    We give the detailed derivation of the fully covariant form of the quadratic action and the derived linear equations of motion for a massive graviton in an arbitrary background metric (which were presented in arXiv:1410.8302 [hep-th]). Our starting point is the de Rham-Gabadadze-Tolley (dRGT) family of ghost free massive gravities and using a simple model of this family, we are able to express this action and these equations of motion in terms of a single metric in which the graviton propagates, hence removing in particular the need for a ''reference metric' which is present in the non perturbative formulation. We show further how 5 covariant constraints can be obtained including one which leads to the tracelessness of the graviton on flat space-time and removes the Boulware-Deser ghost. This last constraint involves powers and combinations of the curvature of the background metric. The 5 constraints are obtained for a background metric which is unconstrained, i.e. which does not have to obey the background field equations. We then apply these results to the case of Einstein space-times, where we show that the 5 constraints become trivial, and Friedmann-Lemaître-Robertson-Walker space-times, for which we correct in particular some results that appeared elsewhere. To reach our results, we derive several non trivial identities, syzygies, involving the graviton fields, its derivatives and the background metric curvature. These identities have their own interest. We also discover that there exist backgrounds for which the dRGT equations cannot be unambiguously linearized.

  11. Massive graviton on arbitrary background: derivation, syzygies, applications

    SciTech Connect

    Bernard, Laura; Deffayet, Cédric; Strauss, Mikael von

    2015-06-23

    We give the detailed derivation of the fully covariant form of the quadratic action and the derived linear equations of motion for a massive graviton in an arbitrary background metric (which were presented in arXiv:1410.8302 [hep-th]). Our starting point is the de Rham-Gabadadze-Tolley (dRGT) family of ghost free massive gravities and using a simple model of this family, we are able to express this action and these equations of motion in terms of a single metric in which the graviton propagates, hence removing in particular the need for a “reference metric' which is present in the non perturbative formulation. We show further how 5 covariant constraints can be obtained including one which leads to the tracelessness of the graviton on flat space-time and removes the Boulware-Deser ghost. This last constraint involves powers and combinations of the curvature of the background metric. The 5 constraints are obtained for a background metric which is unconstrained, i.e. which does not have to obey the background field equations. We then apply these results to the case of Einstein space-times, where we show that the 5 constraints become trivial, and Friedmann-Lemaître-Robertson-Walker space-times, for which we correct in particular some results that appeared elsewhere. To reach our results, we derive several non trivial identities, syzygies, involving the graviton fields, its derivatives and the background metric curvature. These identities have their own interest. We also discover that there exist backgrounds for which the dRGT equations cannot be unambiguously linearized.

  12. Massive graviton on arbitrary background: derivation, syzygies, applications

    NASA Astrophysics Data System (ADS)

    Bernard, Laura; Deffayet, Cédric; von Strauss, Mikael

    2015-06-01

    We give the detailed derivation of the fully covariant form of the quadratic action and the derived linear equations of motion for a massive graviton in an arbitrary background metric (which were presented in arXiv:1410.8302 [hep-th]). Our starting point is the de Rham-Gabadadze-Tolley (dRGT) family of ghost free massive gravities and using a simple model of this family, we are able to express this action and these equations of motion in terms of a single metric in which the graviton propagates, hence removing in particular the need for a ``reference metric" which is present in the non perturbative formulation. We show further how 5 covariant constraints can be obtained including one which leads to the tracelessness of the graviton on flat space-time and removes the Boulware-Deser ghost. This last constraint involves powers and combinations of the curvature of the background metric. The 5 constraints are obtained for a background metric which is unconstrained, i.e. which does not have to obey the background field equations. We then apply these results to the case of Einstein space-times, where we show that the 5 constraints become trivial, and Friedmann-Lemaître-Robertson-Walker space-times, for which we correct in particular some results that appeared elsewhere. To reach our results, we derive several non trivial identities, syzygies, involving the graviton fields, its derivatives and the background metric curvature. These identities have their own interest. We also discover that there exist backgrounds for which the dRGT equations cannot be unambiguously linearized.

  13. Cationic porphyrin derivatives for application in photodynamic therapy of cancer

    NASA Astrophysics Data System (ADS)

    Prack McCormick, Bárbara P.; Florencia Pansa, M.; Milla Sanabria, Laura N.; Carvalho, Carla M. B.; Faustino, M. Amparo F.; Neves, Maria Graça P. M. S.; Cavaleiro, José A. S.; Rumie Vittar, Natalia B.; Rivarola, Viviana A.

    2014-04-01

    Current studies in photodynamic therapy (PDT) against cancer are focused on the development of new photosensitizers (PSs), with higher phototoxic action. The aim of this study was to compare the therapeutic efficiency of tri-cationic meso-substituted porphyrin derivatives (Tri-Py+-Me-PF, Tri-Py+-Me-Ph, Tri-Py+-Me-CO2Me and Tri-Py+-Me-CO2H) with the well-known tetra-cationic T4PM. The phototoxic action of these derivatives was assessed in human colon adenocarcinoma cells by cell viability, intracellular localization and nuclear morphology analysis. In the experimental conditions used we determined that after light activation -PF, -Ph and -CO2Me cause a more significant decline of cell viability compared to -CO2H and T4PM. These results suggest that the nature of the peripheral substituent influences the extent of cell photodamage. Moreover, we have demonstrated that PS concentration, physicochemical properties and further light activation determine the PDT response. All porphyrins were clearly localized as a punctuated pattern in the cytoplasm of the cells, and the PDT scheme resulted in apoptotic cell death after 3 h post-PDT. The tri-cationic porphyrin derivatives Tri-Py+-Me-PF, Tri-Py+-Me-Ph and Tri-Py+-Me-CO2Me showed a promising ability, making them good photosensitizer candidates for oncological PDT.

  14. Wood-Derived Materials for Green Electronics, Biological Devices, and Energy Applications.

    PubMed

    Zhu, Hongli; Luo, Wei; Ciesielski, Peter N; Fang, Zhiqiang; Zhu, J Y; Henriksson, Gunnar; Himmel, Michael E; Hu, Liangbing

    2016-08-24

    With the arising of global climate change and resource shortage, in recent years, increased attention has been paid to environmentally friendly materials. Trees are sustainable and renewable materials, which give us shelter and oxygen and remove carbon dioxide from the atmosphere. Trees are a primary resource that human society depends upon every day, for example, homes, heating, furniture, and aircraft. Wood from trees gives us paper, cardboard, and medical supplies, thus impacting our homes, school, work, and play. All of the above-mentioned applications have been well developed over the past thousands of years. However, trees and wood have much more to offer us as advanced materials, impacting emerging high-tech fields, such as bioengineering, flexible electronics, and clean energy. Wood naturally has a hierarchical structure, composed of well-oriented microfibers and tracheids for water, ion, and oxygen transportation during metabolism. At higher magnification, the walls of fiber cells have an interesting morphology-a distinctly mesoporous structure. Moreover, the walls of fiber cells are composed of thousands of fibers (or macrofibrils) oriented in a similar angle. Nanofibrils and nanocrystals can be further liberated from macrofibrils by mechanical, chemical, and enzymatic methods. The obtained nanocellulose has unique optical, mechanical, and barrier properties and is an excellent candidate for chemical modification and reconfiguration. Wood is naturally a composite material, comprised of cellulose, hemicellulose, and lignin. Wood is sustainable, earth abundant, strong, biodegradable, biocompatible, and chemically accessible for modification; more importantly, multiscale natural fibers from wood have unique optical properties applicable to different kinds of optoelectronics and photonic devices. Today, the materials derived from wood are ready to be explored for applications in new technology areas, such as electronics, biomedical devices, and energy. The

  15. Wood-Derived Materials for Green Electronics, Biological Devices, and Energy Applications

    SciTech Connect

    Zhu, Hongli; Luo, Wei; Ciesielski, Peter N.; Fang, Zhiqiang; Zhu, J. Y.; Henriksson, Gunnar; Himmel, Michael E.; Hu, Liangbing

    2016-08-24

    With the arising of global climate change and resource shortage, in recent years, increased attention has been paid to environmentally friendly materials. Trees are sustainable and renewable materials, which give us shelter and oxygen and remove carbon dioxide from the atmosphere. Trees are a primary resource that human society depends upon every day, for example, homes, heating, furniture, and aircraft. Wood from trees gives us paper, cardboard, and medical supplies, thus impacting our homes, school, work, and play. All of the above-mentioned applications have been well developed over the past thousands of years. However, trees and wood have much more to offer us as advanced materials, impacting emerging high-tech fields, such as bioengineering, flexible electronics, and clean energy. Wood naturally has a hierarchical structure, composed of well-oriented microfibers and tracheids for water, ion, and oxygen transportation during metabolism. At higher magnification, the walls of fiber cells have an interesting morphology--a distinctly mesoporous structure. Moreover, the walls of fiber cells are composed of thousands of fibers (or macrofibrils) oriented in a similar angle. Nanofibrils and nanocrystals can be further liberated from macrofibrils by mechanical, chemical, and enzymatic methods. The obtained nanocellulose has unique optical, mechanical, and barrier properties and is an excellent candidate for chemical modification and reconfiguration. Wood is naturally a composite material, comprised of cellulose, hemicellulose, and lignin. Wood is sustainable, earth abundant, strong, biodegradable, biocompatible, and chemically accessible for modification; more importantly, multiscale natural fibers from wood have unique optical properties applicable to different kinds of optoelectronics and photonic devices. Today, the materials derived from wood are ready to be explored for applications in new technology areas, such as electronics, biomedical devices, and energy. The

  16. A Comparison of the Bounded Derivative and the Normal Mode Initialization Methods Using Real Data

    NASA Technical Reports Server (NTRS)

    Semazzi, F. H. M.; Navon, I. M.

    1985-01-01

    Browning et al. (1980) proposed an initialization method called the bounded derivative method (BDI). They used analytical data to test the new method. Kasahara (1982) theoretically demonstrated the equivalence between BDI and the well known nonlinear normal mode initialization method (NMI). The purposes of this study are the extension of the application of BDI to real data and comparison with NMI. The unbalanced initial state (UBD) is data of January, 1979 OOZ which were interpolated from the adjacent sigma levels of the GLAS GCM to the 300 mb surface. The global barotropic model described by Takacs and Balgovind (1983) is used. Orographic forcing is explicitly included in the model. Many comparisons are performed between various quantities. However, we only present a comparison of the time evolution at two grid points A(50 S, 90 E) and B(10 S, 20 E) which represent low and middle latitude locations. To facilitate a more complete comparison an initialization experiment based on the classical balance equation (CBE) was also included.

  17. Prospect of Human Pluripotent Stem Cell-Derived Neural Crest Stem Cells in Clinical Application

    PubMed Central

    Zhu, Qian; Lu, Qiqi; Gao, Rong

    2016-01-01

    Neural crest stem cells (NCSCs) represent a transient and multipotent cell population that contributes to numerous anatomical structures such as peripheral nervous system, teeth, and cornea. NCSC maldevelopment is related to various human diseases including pigmentation abnormalities, disorders affecting autonomic nervous system, and malformations of teeth, eyes, and hearts. As human pluripotent stem cells including human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs) can serve as an unlimited cell source to generate NCSCs, hESC/hiPSC-derived NCSCs can be a valuable tool to study the underlying mechanisms of NCSC-associated diseases, which paves the way for future therapies for these abnormalities. In addition, hESC/hiPSC-derived NCSCs with the capability of differentiating to various cell types are highly promising for clinical organ repair and regeneration. In this review, we first discuss NCSC generation methods from human pluripotent stem cells and differentiation mechanism of NCSCs. Then we focus on the clinical application potential of hESC/hiPSC-derived NCSCs on peripheral nerve injuries, corneal blindness, tooth regeneration, pathological melanogenesis, Hirschsprung disease, and cardiac repair and regeneration. PMID:28090209

  18. A Series of Imidazole Derivatives: Synthesis, Two-Photon Absorption, and Application for Bioimaging

    PubMed Central

    Zhu, Yingzhong; Xiao, Lufei; Zhao, Meng; Zhou, Jiazheng; Zhang, Qiong; Wang, Hui; Li, Shengli; Zhou, Hongping; Wu, Jieying; Tian, Yupeng

    2015-01-01

    A new series of D-π-A type imidazole derivatives have been synthesized and characterized. Two corresponding imidazolium salts (iodine and hexafluorophosphate) were prepared from the imidazole compound. Their electron-withdrawing ability can be largely tunable by salt formation reaction or ion exchange. UV-vis absorption and single-photon fluorescence spectra have been systematically investigated in different solvents. The two-photon cross sections (δ2PA) of the imidazole derivatives are measured by two-photon excited fluorescence (2PEF) method. Compared with those of T-1 (107 GM) and T-3 (96 GM), T-2 (imidazolium iodine salt) has a large two-photon absorption (2PA) cross section value of 276 GM. Furthermore, the cytotoxicity and applications in bioimaging for the imidazole derivatives were carried out. The results showed that T-1 can be used as a lysosomal tracker with high stability and water solubility within pHs of 4–6, while T-2 and T-3 can be used as probes for cell cytoplasm. PMID:26579544

  19. Tissue-Derived Extracellular Matrix Bioscaffolds: Emerging Applications in Cartilage and Meniscus Repair.

    PubMed

    Monibi, Farrah A; Cook, James L

    2017-03-07

    Musculoskeletal injuries are a common problem in orthopedic practice. Given the long-term consequences of unaddressed cartilage and meniscal pathology, a number of treatments have been attempted to stimulate repair or to replace the injured tissue. Despite advances in orthopedic surgery, effective treatments for cartilage and meniscus injuries remain a significant clinical challenge. Tissue engineering is a developing field that aims to regenerate injured tissues with a combination of cells, scaffolds, and signals. Many natural and synthetic scaffold materials have been developed and tested for the repair and restoration of a number of musculoskeletal tissues. Among these, biological scaffolds derived from cell and tissue-derived extracellular matrix (ECM) have shown great promise in tissue engineering given the critical role of the ECM for maintaining the biological and biomechanical properties, structure, and function of native tissues. This review article presents emerging applications for tissue-derived ECM scaffolds in cartilage and meniscus repair. We examine normal ECM composition and the current and future methods for potential treatment of articular cartilage and meniscal defects with decellularized scaffolds.

  20. Welcome to Methods and Applications in Fluorescence

    NASA Astrophysics Data System (ADS)

    Birch, David; Mély, Yves; Wolfbeis, Otto S.

    2013-03-01

    On behalf of the Editorial Board of Methods and Applications in Fluorescence and IOP Publishing we are delighted to invite you to read the first articles in our new journal. Methods and Applications in Fluorescence is forged out of the renowned MAF conference series of the same name and we fully expect the natural synergy between the two to provide the ideal platform for moving the field of fluorescence forward. Our aim is for this new journal to reflect the truly global and diverse impact fluorescence is having across many disciplines and help fluorescence achieve its full potential. Just as MAF is the leading conference in fluorescence we are confident of the high impact of this new journal. Methods and Applications in Fluorescence has a distinguished Editorial Board that is drawn from the MAF conference Permanent Steering Committee. Together with the Editorial Board and the rest of the community, the journal will closely track the very latest developments in fluorescence while delivering a fair and constructive review process. We are very pleased that this journal is backed by the Institute of Physics, one of the world's premier learned societies. IOP Publishing has a wealth of experience in science publishing that dates back to 1874. It is a not-for-profit organization that publishes over 60 journals, many on multidisciplinary topics and many including seminal contributions from Nobel Laureates. Any funding surplus generated by IOP Publishing goes directly back into science through the Institute of Physics, thus helping to nurture science for future generations. We invite submissions as regular articles, review articles and technical notes within the scope of the journal, which includes all the major aspects of fluorescence. This covers both theory and experiment across spectroscopy, imaging, materials, labels, probes and sensors. The applications of fluorescence to emerging areas in bionanotechnology, nanotechnology and medicine are very much part of the

  1. Applicability and Limitations of Reliability Allocation Methods

    NASA Technical Reports Server (NTRS)

    Cruz, Jose A.

    2016-01-01

    Reliability allocation process may be described as the process of assigning reliability requirements to individual components within a system to attain the specified system reliability. For large systems, the allocation process is often performed at different stages of system design. The allocation process often begins at the conceptual stage. As the system design develops, more information about components and the operating environment becomes available, different allocation methods can be considered. Reliability allocation methods are usually divided into two categories: weighting factors and optimal reliability allocation. When properly applied, these methods can produce reasonable approximations. Reliability allocation techniques have limitations and implied assumptions that need to be understood by system engineers. Applying reliability allocation techniques without understanding their limitations and assumptions can produce unrealistic results. This report addresses weighting factors, optimal reliability allocation techniques, and identifies the applicability and limitations of each reliability allocation technique.

  2. Incorporation of salicylic acid derivatives to hydrophilic copolymer systems with biomedical applications.

    PubMed

    Elvira, C; Gallardo, A; Lacroix, N; Schacht, E; San Román, J

    2001-06-01

    Hydrogels based on polymeric derivatives of salicylic acid have been prepared for biomedical applications by free radical copolymerization of 2-hydroxy-4-methacrylamidobenzoic acid, 4HMA, and 2-hydroxy-5-methacrylamidobenzoic acid, 5HMA, with 2- hydroxyethylmethacrylate, HEMA, in a wide range of compositions. The reactivity ratios of 4HMA and 5HMA with HEMA in radical copolymerization processes have been determined from their 1H NMR spectra by applying linearization methods and non-linear least square treatments. Tgs of the corresponding copolymers were analyzed by DSC. The swelling behavior in water of the prepared copolymers was studied in comparison to poly-(HEMA), poly-(4HMA) and poly-(5HMA) hydration degrees, being in all cases superior to 35%. The hydrolytical behavior of the synthesized copolymers was studied at three different pHs (2, 7.4 and 10) determining the release percentage of the salicylic acid derivatives, 4-amino salicylic acid, 4ASA, and 5-amino salicylic acid, 5ASA, analyzed by high performance liquid chromatography (HPLC). The release analysis was followed during 230 days and a pH dependence was observed obtaining the highest release percentages at pH=10, whereas at physiological pH (7.4) the release percentages were in range from 2 to 5% at that time for all copolymer systems. The hydrolytical stability is enough for long-term applications like bone cements, ionomers, etc.

  3. Local Discontinuous Galerkin Methods for Partial Differential Equations with Higher Order Derivatives

    NASA Technical Reports Server (NTRS)

    Yan, Jue; Shu, Chi-Wang; Bushnell, Dennis M. (Technical Monitor)

    2002-01-01

    In this paper we review the existing and develop new continuous Galerkin methods for solving time dependent partial differential equations with higher order derivatives in one and multiple space dimensions. We review local discontinuous Galerkin methods for convection diffusion equations involving second derivatives and for KdV type equations involving third derivatives. We then develop new local discontinuous Galerkin methods for the time dependent bi-harmonic type equations involving fourth derivatives, and partial differential equations involving fifth derivatives. For these new methods we present correct interface numerical fluxes and prove L(exp 2) stability for general nonlinear problems. Preliminary numerical examples are shown to illustrate these methods. Finally, we present new results on a post-processing technique, originally designed for methods with good negative-order error estimates, on the local discontinuous Galerkin methods applied to equations with higher derivatives. Numerical experiments show that this technique works as well for the new higher derivative cases, in effectively doubling the rate of convergence with negligible additional computational cost, for linear as well as some nonlinear problems, with a local uniform mesh.

  4. Methods and applications of structure based pharmacophores in drug discovery.

    PubMed

    Pirhadi, Somayeh; Shiri, Fereshteh; Ghasemi, Jahan B

    2013-01-01

    A pharmacophore model does not describe a real molecule or a real association of functional groups but illustrates a molecular recognition of a biological target shared by a group of compounds. Pharmacophores also represent the spatial arrangement of essential interactions in a receptor-binding pocket. Structure based pharmacophores (SBPs) can work both with a free (apo) structure or a macromolecule-ligand complex (holo) structure. The SBP methods that derive pharmacophore from protein-ligand complexes use the potential interactions observed between ligand and protein, whereas, the SBP method that aims to derive pharmacophore from ligand free protein, uses only protein active site information. Therefore SBPs do not encounter to challenging problems such as ligand flexibility, molecular alignment as well as proper selection of training set compounds in ligand based pharmacophore modeling. The current review deals with Hot Spot' analysis of binding site to feature generation, several approaches to feature reduction, and considers shape and excluded volumes to SBP model building. This review continues to represent several applications of SBPs in virtual screening especially in parallel screening approach and multi-target drug design. Also it reports the applications of SBPs in QSAR. This review emphasizes that SBPs are valuable tools for hit to lead optimization, virtual screening, scaffold hopping, and multi-target drug design.

  5. Formulation and application of Russell's method

    NASA Technical Reports Server (NTRS)

    Hou, J. W.

    1985-01-01

    It is shown that the numerical technique of Russell's momentum approach can be derived by using Hamilton's principle and Vance's numerical scheme. It results in a set of first order differnce equations for solving the angular velocities. The numerical examples show that the method is reliable. The algorithm is modified next to perform the analysis of N-body systems with closed loop topology. To increase the formulation flexibility, the equations of motion are represented by using Cartesian coordinates and Lagrange multipliers. The algorithm consists of two parts, Vance's scheme and an unconstrained minimization. The Vance's scheme is used to find the angular velocities, and the unconstrained minimization is applied to provide the correct angular displacements. The proposed scheme is further extended to find the design sensitivity of an N-body system with closed loop configuration, and to carry out the design optimization as well. The numerical example of a small-scaled mechanical system is presented to verify the proposed formulation.

  6. Industrial applications of laser methods profilometry

    SciTech Connect

    Doyle, J.L.

    1995-12-31

    Laser-based profilometry has evolved rapidly over the past ten years. During that period, QUEST Integrated Inc. has been actively involved in the development of systems for a wide variety of NDE applications. The measurement method is based on the principle of optical triangulation. The sensor includes a diode laser which generates the collimated laser beam that is projected orthogonally onto a target surface. Receiving optics, positioned at an oblique angle to the beam, image the reflected light onto a lateral-effect photodetector. Depending on the packaging constraints and resolution requirements, probes use either a single or dual-axis lateral-effect photodetector. As the target surface moves toward or away from the laser source, the imaged light moves across the photodetector in a predictable and repeatable manner. Since the laser beam can be focused to a ``footprint`` as small as a few microns in diameter, this method provides unparalleled spatial resolution. In addition, lateral effect photodetectors are composed or a single silicon element that provides almost infinite lateral resolution. This method was applied to two applications in this paper. The first was to locate and identify flows caused by pitting corrosion in steam generator tubes at nuclear power plants. The second was for inspection of gun tubes by the US army.

  7. Evaluation of Existing Image Matching Methods for Deriving Glacier Surface Displacements Globally from Optical Satellite Imagery

    NASA Astrophysics Data System (ADS)

    Heid, T.; Kääb, A.

    2011-12-01

    Automatic matching of images from two different times is a method that is often used to derive glacier surface velocity. Nearly global repeat coverage of the Earth's surface by optical satellite sensors now opens the possibility for global-scale mapping and monitoring of glacier flow with a number of applications in, for example, glacier physics, glacier-related climate change and impact assessment, and glacier hazard management. The purpose of this study is to compare and evaluate different existing image matching methods for glacier flow determination over large scales. The study compares six different matching methods: normalized cross-correlation (NCC), the phase correlation algorithm used in the COSI-Corr software, and four other Fourier methods with different normalizations. We compare the methods over five regions of the world with different representative glacier characteristics: Karakoram, the European Alps, Alaska, Pine Island (Antarctica) and southwest Greenland. Landsat images are chosen for matching because they expand back to 1972, they cover large areas, and at the same time their spatial resolution is as good as 15 m for images after 1999 (ETM+ pan). Cross-correlation on orientation images (CCF-O) outperforms the three similar Fourier methods, both in areas with high and low visual contrast. NCC experiences problems in areas with low visual contrast, areas with thin clouds or changing snow conditions between the images. CCF-O has problems on narrow outlet glaciers where small window sizes (about 16 pixels by 16 pixels or smaller) are needed, and it also obtains fewer correct matches than COSI-Corr in areas with low visual contrast. COSI-Corr has problems on narrow outlet glaciers and it obtains fewer correct matches compared to CCF-O when thin clouds cover the surface, or if one of the images contains snow dunes. In total, we consider CCF-O and COSI-Corr to be the two most robust matching methods for global-scale mapping and monitoring of glacier

  8. On the applications of algebraic grid generation methods based on transfinite interpolation

    NASA Technical Reports Server (NTRS)

    Nguyen, Hung Lee

    1989-01-01

    Algebraic grid generation methods based on transfinite interpolation called the two-boundary and four-boundary methods are applied for generating grids with highly complex boundaries. These methods yield grid point distributions that allow for accurate application to regions of sharp gradients in the physical domain or time-dependent problems with small length scale phenomena. Algebraic grids are derived using the two-boundary and four-boundary methods for applications in both two- and three-dimensional domains. Grids are developed for distinctly different geometrical problems and the two-boundary and four-boundary methods are demonstrated to be applicable to a wide class of geometries.

  9. Utilizing Satellite-derived Precipitation Products in Hydrometeorological Applications

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Ostrenga, D.; Teng, W. L.; Kempler, S. J.; Huffman, G. J.

    2012-12-01

    Each year droughts and floods happen around the world and can cause severe property damages and human casualties. Accurate measurement and forecast are important for preparedness and mitigation efforts. Through multi-satellite blended techniques, significant progress has been made over the past decade in satellite-based precipitation product development, such as, products' spatial and temporal resolutions as well as timely availability. These new products are widely used in various research and applications. In particular, the TRMM Multi-satellite Precipitation Analysis (TMPA) products archived and distributed by the NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC) provide 3-hourly, daily and monthly near-global (50° N - 50° S) precipitation datasets for research and applications. Two versions of TMPA products are available, research (3B42, 3B43, rain gauge adjusted) and near-real-time (3B42RT). At GES DISC, we have developed precipitation data services to support hydrometeorological applications in order to maximize the TRMM mission's societal benefits. In this presentation, we will present examples of utilizing TMPA precipitation products in hydrometeorological applications including: 1) monitoring global floods and droughts; 2) providing data services to support the USDA Crop Explorer; 3) support hurricane monitoring activities and research; and 4) retrospective analog year analyses to improve USDA's world agricultural supply and demand estimates. We will also present precipitation data services that can be used to support hydrometeorological applications including: 1) User friendly TRMM Online Visualization and Analysis System (TOVAS; URL: http://disc2.nascom.nasa.gov/Giovanni/tovas/); 2) Mirador (http://mirador.gsfc.nasa.gov/), a simplified interface for searching, browsing, and ordering Earth science data at GES DISC; 3) Simple Subset Wizard (http://disc.sci.gsfc.nasa.gov/SSW/ ) for data subsetting and format conversion; 4) Data

  10. A New Method for Deriving the Stellar Birth Function of Resolved Stellar Populations.

    NASA Astrophysics Data System (ADS)

    Gennaro, M.; Tchernyshyov, K.; Brown, T. M.; Gordon, K. D.

    2015-07-01

    We present a new method for deriving the stellar birth function (SBF) of resolved stellar populations. The SBF (stars born per unit mass, time, and metallicity) is the combination of the initial mass function (IMF), the star formation history (SFH), and the metallicity distribution function (MDF). The framework of our analysis is that of Poisson Point Processes (PPPs), a class of statistical models suitable when dealing with points (stars) in a multidimensional space (the measurement space of multiple photometric bands). The theory of PPPs easily accommodates the modeling of measurement errors as well as that of incompleteness. Our method avoids binning stars in the color-magnitude diagram and uses the whole likelihood function for each data point; combining the individual likelihoods allows the computation of the posterior probability for the population's SBF. Within the proposed framework it is possible to include nuisance parameters, such as distance and extinction, by specifying their prior distributions and marginalizing over them. The aim of this paper is to assess the validity of this new approach under a range of assumptions, using only simulated data. Forthcoming work will show applications to real data. Although it has a broad scope of possible applications, we have developed this method to study multi-band Hubble Space Telescope observations of the Milky Way Bulge. Therefore we will focus on simulations with characteristics similar to those of the Galactic Bulge. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at STScI, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

  11. Global Precipitation Measurement: Methods, Datasets and Applications

    NASA Technical Reports Server (NTRS)

    Tapiador, Francisco; Turk, Francis J.; Petersen, Walt; Hou, Arthur Y.; Garcia-Ortega, Eduardo; Machado, Luiz, A. T.; Angelis, Carlos F.; Salio, Paola; Kidd, Chris; Huffman, George J.; De Castro, Manuel

    2011-01-01

    This paper reviews the many aspects of precipitation measurement that are relevant to providing an accurate global assessment of this important environmental parameter. Methods discussed include ground data, satellite estimates and numerical models. First, the methods for measuring, estimating, and modeling precipitation are discussed. Then, the most relevant datasets gathering precipitation information from those three sources are presented. The third part of the paper illustrates a number of the many applications of those measurements and databases. The aim of the paper is to organize the many links and feedbacks between precipitation measurement, estimation and modeling, indicating the uncertainties and limitations of each technique in order to identify areas requiring further attention, and to show the limits within which datasets can be used.

  12. New color segmentation method and its applications

    NASA Astrophysics Data System (ADS)

    Wang, Jian

    1999-01-01

    Segmentation is an important step in the early stage of image analysis. Color or multi-spectral image segmentation usually involves search and clustering techniques in a three or higher dimensional spectral space - an exercise which is considered computationally expensive. This paper presents a new color segmentation method for color image analysis with its application to plant leaf area measurement. A 3D histogram for an RGB color image is established basing on an octree data structure. The histogram represents the color distribution of the image in the RGB color space on which a 3D Gaussian filter is applied to smooth out small maxima of this distribution. The color space is then searched to find out al the major maxima. Around each maxima, a covering cube with a controlled side width is established. These maxima and covering cubes are considered to be potential color classes. Each cube may expand according to the value of surrounding neighbors. Once enough modes and their cover cubes have been found, a k-means clustering algorithm is used to classify these maxima into a predetermined number of classes. Then, the classified modes and the color covered by the cubes are used as training samples for a Bayes classifier which can be used to classify all the pixels in the image. A statistical relaxation method is then sued as a find segmentation. This method can either be supervised or unsupervised, depending on the different requirements of specific applications. The octree data structure significantly reduces the color space to be searched and consequently reduces computational cost. An extension of this method can also be applied to multi-spectral image analysis.

  13. Advances in Microalgae-Derived Phytosterols for Functional Food and Pharmaceutical Applications.

    PubMed

    Luo, Xuan; Su, Peng; Zhang, Wei

    2015-07-09

    Microalgae contain a variety of bioactive lipids with potential applications in aquaculture feed, biofuel, food and pharmaceutical industries. While microalgae-derived polyunsaturated fatty acid (PUFA) and their roles in promoting human health have been extensively studied, other lipid types from this resource, such as phytosterols, have been poorly explored. Phytosterols have been used as additives in many food products such as spread, dairy products and salad dressing. This review focuses on the recent advances in microalgae-derived phytosterols with functional bioactivities and their potential applications in functional food and pharmaceutical industries. It highlights the importance of microalgae-derived lipids other than PUFA for the development of an advanced microalgae industry.

  14. Thiourea derivatives, methods of their preparation and their use in neutron capture therapy of malignant melanoma

    DOEpatents

    Gabel, D.

    1991-06-04

    The present invention pertains to boron containing thiouracil derivatives, their method of preparations, and their use in the therapy of malignant melanoma using boron neutron capture therapy. No Drawings

  15. Development of Mass Spectrometric Ionization Methods for Fullerenes and Fullerene Derivatives

    EPA Science Inventory

    Currently investigations into the environmental behavior of fullerenes and fullerene derivatives is hampered by the lack of well characterized standards and by the lack of readily available quantitative analytical methods. Reported herein are investigations into the utility of ma...

  16. Medical Application of Spirulina platensis Derived C-Phycocyanin.

    PubMed

    Liu, Qian; Huang, Yinghong; Zhang, Ronghua; Cai, Tiange; Cai, Yu

    2016-01-01

    Along with the development of marine biological pharmaceutical research, high-effective and low-toxic drugs and functional foods isolated from marine organisms have become a new field of pharmacy and bromatology. The pharmacological actions, such as anti-inflammation, antioxidation, antitumor, immunological enhancement, and hepatorenal protection of C-phycocyanin (C-PC) from Spirulina platensis, have been reported, and C-PC has important value of development and utilization either as drug or as functional food. There are many researches about the various pharmacological actions and mechanisms of C-PC, but related reports are only to some extent integrated deeply and accurately enough, which put some limitations to the further application of C-PC in medicine. Particularly, with the improvement of living standards and attention to health issues, C-PC being a functional food is preferred by more and more people. C-PC is easy to get, safe, and nontoxic; thus, it has a great potential of research and development as a drug or functional food. Here, the separation and purification, physicochemical properties, physiological and pharmacological activities, safety, and some applications are reviewed to provide relevant basis for the development of natural medicine and applied products.

  17. Medical Application of Spirulina platensis Derived C-Phycocyanin

    PubMed Central

    Liu, Qian; Huang, Yinghong; Zhang, Ronghua; Cai, Tiange; Cai, Yu

    2016-01-01

    Along with the development of marine biological pharmaceutical research, high-effective and low-toxic drugs and functional foods isolated from marine organisms have become a new field of pharmacy and bromatology. The pharmacological actions, such as anti-inflammation, antioxidation, antitumor, immunological enhancement, and hepatorenal protection of C-phycocyanin (C-PC) from Spirulina platensis, have been reported, and C-PC has important value of development and utilization either as drug or as functional food. There are many researches about the various pharmacological actions and mechanisms of C-PC, but related reports are only to some extent integrated deeply and accurately enough, which put some limitations to the further application of C-PC in medicine. Particularly, with the improvement of living standards and attention to health issues, C-PC being a functional food is preferred by more and more people. C-PC is easy to get, safe, and nontoxic; thus, it has a great potential of research and development as a drug or functional food. Here, the separation and purification, physicochemical properties, physiological and pharmacological activities, safety, and some applications are reviewed to provide relevant basis for the development of natural medicine and applied products. PMID:27293463

  18. Customized PEG-derived copolymers for tissue-engineering applications.

    PubMed

    Tessmar, Joerg K; Göpferich, Achim M

    2007-01-05

    PEG-containing copolymers play a prominent role as biomaterials for different applications ranging from drug delivery to tissue engineering. These custom-designed materials offer enormous possibilities to change the overall characteristics of biomaterials by improving their biocompatibility and solubility, as well as their ability to crystallize in polymer blends and to resist protein adsorption. This article demonstrates various principles of PEG-based material design that are applied to fine tune the properties of biomaterials for different tissue engineering applications. More specifically, strategies are described to develop PEG copolymers with various block compositions and specific bulk properties, including low melting points and improved surface hydrophilicity. Highly hydrated polymer gel networks for promoting cellular growth or suppressing protein adsorption and cell adhesion are introduced. By incorporating selectively cleavable cross-links, these hydrophilic polymers can also serve as smart hydrogel scaffolds, mimicking the natural extracellular matrix for cell cultivation and tissue growth. Ultimately, these developments lead to the creation of biomimetic materials to immobilize bioactive compounds, allowing precise control of cellular adhesion and tissue growth. [image: see text

  19. Application of cow milk-derived carbon dots/Ag NPs composite as the antibacterial agent

    NASA Astrophysics Data System (ADS)

    Han, Shuai; Zhang, He; Xie, Yujie; Liu, Liangliang; Shan, Changfu; Li, Xiangkai; Liu, Weisheng; Tang, Yu

    2015-02-01

    Cow milk-derived carbon dots (CMCDs) were prepared by hydrothermal treatment of cow milk, and the as-prepared CMCDs were further extracted by ethyl acetate to obtain amphiphilic CMCDs (ACMCDs). Using the ACMCDs both as a reducing agent and a template, the ACMCDs-supported silver nanoparticles (ACMCD-Ag nanocomposites) were prepared, which showed good biocidal effect on both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacterias. After that, a novel ACMCD-Ag/polymethylmethacrylate nanocomposite antibacterial film was fabricated by solvent casting method. Due to the excellent antibacterial, light admitting, and flexible properties, the nanocomposite antibacterial film is considered to be of great potential in applications.

  20. Sol-gel derived antireflective structures for applications in silicon solar cells

    NASA Astrophysics Data System (ADS)

    Karasiński, Paweł; Skolik, Marcin

    2016-12-01

    This work presents theoretical and experimental results of antireflective coatings (ARCs) obtained for applications in silicon solar cells. ARCs were derived from sol-gel process and dip-coated using silica (SiO2) and titania (TiO2). Theoretical results were obtained using 2×2 transfer matrix calculation method. Technological process of SiO2 and TiO2 thin film fabrication as well as measurement techniques are described in this paper. Strong correlation between theoretical and experimental data is demonstrated. It is shown, that weighted average reflection from a substrate can be reduced ten times with the use of SiO2/TiO2/Si double layer ARCs, when compared to a bare silica substrate.

  1. Ligament-Derived Stem Cells: Identification, Characterisation, and Therapeutic Application

    PubMed Central

    Clegg, Peter David; Comerford, Eithne Josephine; Canty-Laird, Elizabeth Gail

    2017-01-01

    Ligament is prone to injury and degeneration and has poor healing potential and, with currently ineffective treatment strategies, stem cell therapies may provide an exciting new treatment option. Ligament-derived stem cell (LDSC) populations have been isolated from a number of different ligament types with the majority of studies focussing on periodontal ligament. To date, only a few studies have investigated LDSC populations in other types of ligament, for example, intra-articular ligaments; however, this now appears to be a developing field. This literature review aims to summarise the current information on nondental LDSCs including in vitro characteristics of LDSCs and their therapeutic potential. The stem cell niche has been shown to be vital for stem cell survival and function in a number of different physiological systems; therefore, the LDSC niche may have an impact on LDSC phenotype. The role of the LDSC niche on LDSC viability and function will be discussed as well as the therapeutic potential of LDSC niche modulation. PMID:28386284

  2. Ion mobility derived collision cross sections to support metabolomics applications.

    PubMed

    Paglia, Giuseppe; Williams, Jonathan P; Menikarachchi, Lochana; Thompson, J Will; Tyldesley-Worster, Richard; Halldórsson, Skarphédinn; Rolfsson, Ottar; Moseley, Arthur; Grant, David; Langridge, James; Palsson, Bernhard O; Astarita, Giuseppe

    2014-04-15

    Metabolomics is a rapidly evolving analytical approach in life and health sciences. The structural elucidation of the metabolites of interest remains a major analytical challenge in the metabolomics workflow. Here, we investigate the use of ion mobility as a tool to aid metabolite identification. Ion mobility allows for the measurement of the rotationally averaged collision cross-section (CCS), which gives information about the ionic shape of a molecule in the gas phase. We measured the CCSs of 125 common metabolites using traveling-wave ion mobility-mass spectrometry (TW-IM-MS). CCS measurements were highly reproducible on instruments located in three independent laboratories (RSD < 5% for 99%). We also determined the reproducibility of CCS measurements in various biological matrixes including urine, plasma, platelets, and red blood cells using ultra performance liquid chromatography (UPLC) coupled with TW-IM-MS. The mean RSD was < 2% for 97% of the CCS values, compared to 80% of retention times. Finally, as proof of concept, we used UPLC-TW-IM-MS to compare the cellular metabolome of epithelial and mesenchymal cells, an in vitro model used to study cancer development. Experimentally determined and computationally derived CCS values were used as orthogonal analytical parameters in combination with retention time and accurate mass information to confirm the identity of key metabolites potentially involved in cancer. Thus, our results indicate that adding CCS data to searchable databases and to routine metabolomics workflows will increase the identification confidence compared to traditional analytical approaches.

  3. Antimicrobial bacteriophage-derived proteins and therapeutic applications

    PubMed Central

    Roach, Dwayne R; Donovan, David M

    2015-01-01

    Antibiotics have the remarkable power to control bacterial infections. Unfortunately, widespread use, whether regarded as prudent or not, has favored the emergence and persistence of antibiotic resistant strains of human pathogenic bacteria, resulting in a global health threat. Bacteriophages (phages) are parasites that invade the cells of virtually all known bacteria. Phages reproduce by utilizing the host cell's machinery to replicate viral proteins and genomic material, generally damaging and killing the cell in the process. Thus, phage can be exploited therapeutically as bacteriolytic agents against bacteria. Furthermore, understanding of the molecular processes involved in the viral life cycle, particularly the entry and cell lysis steps, has led to the development of viral proteins as antibacterial agents. Here we review the current preclinical state of using phage-derived endolysins, virion-associated peptidoglycan hydrolases, polysaccharide depolymerases, and holins for the treatment of bacterial infection. The scope of this review is a focus on the viral proteins that have been assessed for protective effects against human pathogenic bacteria in animal models of infection and disease. PMID:26442196

  4. Applicability of tooth derived stem cells in neural regeneration

    PubMed Central

    Parisi, Ludovica; Manfredi, Edoardo

    2016-01-01

    Within the nervous system, regeneration is limited, and this is due to the small amount of neural stem cells, the inhibitory origin of the stem cell niche and often to the development of a scar which constitutes a mechanical barrier for the regeneration. Regarding these aspects, many efforts have been done in the research of a cell component that combined with scaffolds and growth factors could be suitable for nervous regeneration in regenerative medicine approaches. Autologous mesenchymal stem cells represent nowadays the ideal candidate for this aim, thank to their multipotency and to their amount inside adult tissues. However, issues in their harvesting, through the use of invasive techniques, and problems involved in their ageing, require the research of new autologous sources. To this purpose, the recent discovery of a stem cells component in teeth, and which derive from neural crest cells, has came to the light the possibility of using dental stem cells in nervous system regeneration. In this work, in order to give guidelines on the use of dental stem cells for neural regeneration, we briefly introduce the concepts of regeneration and regenerative medicine, we then focus the attention on odontogenesis, which involves the formation and the presence of a stem component in different parts of teeth, and finally we describe some experimental approaches which are exploiting dental stem cells for neural studies. PMID:28123398

  5. Boundary Value Technique for Initial Value Problems Based on Adams-Type Second Derivative Methods

    ERIC Educational Resources Information Center

    Jator, S. N.; Sahi, R. K.

    2010-01-01

    In this article, we propose a family of second derivative Adams-type methods (SDAMs) of order up to 2k + 2 ("k" is the step number) for initial value problems. The methods are constructed through a continuous approximation of the SDAM which is obtained by multistep collocation. The continuous approximation is used to obtain initial value methods,…

  6. A Multi-Modal Face Recognition Method Using Complete Local Derivative Patterns and Depth Maps

    PubMed Central

    Yin, Shouyi; Dai, Xu; Ouyang, Peng; Liu, Leibo; Wei, Shaojun

    2014-01-01

    In this paper, we propose a multi-modal 2D + 3D face recognition method for a smart city application based on a Wireless Sensor Network (WSN) and various kinds of sensors. Depth maps are exploited for the 3D face representation. As for feature extraction, we propose a new feature called Complete Local Derivative Pattern (CLDP). It adopts the idea of layering and has four layers. In the whole system, we apply CLDP separately on Gabor features extracted from a 2D image and depth map. Then, we obtain two features: CLDP-Gabor and CLDP-Depth. The two features weighted by the corresponding coefficients are combined together in the decision level to compute the total classification distance. At last, the probe face is assigned the identity with the smallest classification distance. Extensive experiments are conducted on three different databases. The results demonstrate the robustness and superiority of the new approach. The experimental results also prove that the proposed multi-modal 2D + 3D method is superior to other multi-modal ones and CLDP performs better than other Local Binary Pattern (LBP) based features. PMID:25333290

  7. An improved 3D MoF method based on analytical partial derivatives

    NASA Astrophysics Data System (ADS)

    Chen, Xiang; Zhang, Xiong

    2016-12-01

    MoF (Moment of Fluid) method is one of the most accurate approaches among various surface reconstruction algorithms. As other second order methods, MoF method needs to solve an implicit optimization problem to obtain the optimal approximate surface. Therefore, the partial derivatives of the objective function have to be involved during the iteration for efficiency and accuracy. However, to the best of our knowledge, the derivatives are currently estimated numerically by finite difference approximation because it is very difficult to obtain the analytical derivatives of the object function for an implicit optimization problem. Employing numerical derivatives in an iteration not only increase the computational cost, but also deteriorate the convergence rate and robustness of the iteration due to their numerical error. In this paper, the analytical first order partial derivatives of the objective function are deduced for 3D problems. The analytical derivatives can be calculated accurately, so they are incorporated into the MoF method to improve its accuracy, efficiency and robustness. Numerical studies show that by using the analytical derivatives the iterations are converged in all mixed cells with the efficiency improvement of 3 to 4 times.

  8. Inter-comparison of methods for deriving storage-discharge relation based on streamflow records

    NASA Astrophysics Data System (ADS)

    Chen, X.

    2015-12-01

    Storage-discharge relation is a fundamental characteristic of a watershed. Several methods have been presented in literature to derive the storage-discharge relation based on recession period streamflow data. However, the relative performance of these methods for capturing the storage-discharge relation, which can be used to reconstruct the streamflow time series is not known. Basso et al., [2015] made headway in this direction by comparing three methods for reconstructing streamflow probability distribution. In this study, we inter-compare the performance of four methods for deriving storage-discharge relation. All four methods were applied in more than 40 rain-dominated watersheds in the U.S., and their performances were evaluated by assessing the accuracy of reconstructed streamflow time series. Results indicate that two of the four methods generally outperform the others in the studied watersheds. In addition, the derived storage-discharge relationship is found to be very sensitive to the parameters used in each method, hence one needs to adjust parameters to optimize the performance of each method. Results also indicate that simulated streamflow time series using the derived storage-discharge relation generally captures the overall probability distribution of streamflow, even when the temporal distribution of streamflow magnitudes are not well captured. This suggests that derived storage-discharge relations based on recession periods can not always be used to reconstruct streamflow time series.

  9. Methods and applications in single molecule electronics

    NASA Astrophysics Data System (ADS)

    Hihath, Joshua

    In recent years it has become possible to measure charge transport in a single molecule contacted to two metal electrodes. However, a thorough understanding of how a molecule behaves while contacted to two electrodes and how it interacts with its environment is still lacking. This thesis demonstrates various experimental methods for understanding and controlling charge transport in a single molecule junction and the application of these methods to various molecular systems to help elucidate the conduction mechanisms invoked. First, the conductance of DNA is examined in a controlled environment while varying the length, sequence, base-pair matching, bias, temperature, and electrochemical gate of the molecule. These studies show that the conductance of DNA is extremely sensitive to changes in length, sequence, and base-matching, but not as sensitive to temperature and electrochemical gate. Despite the variety of experimental methods applied, the subtleties of the conduction mechanism remain uncertain, and as such necessitate the development of additional tools for understanding the behavior of a single molecule junction. Next, the Conductance Screening Tool for Molecules (CSTM) is described. This is a new tool capable of creating 1000's of single molecules junctions in a matter of minutes. This tool has been used to study the conductance of alkanedithiols, molecules in an array, and single amino acid residues. This system allows for greater speed and flexibility in determining the conductance of a single molecule junction, and provides a capability for performing large-scale systematic studies of molecular systems to determine the conduction mechanism. Finally, an additional experimental method capable of extracting information about the interaction between a molecule and its environment is developed. Here, electron-phonon interactions in a single molecule contacted to two electrodes are studied. This method allows one to obtain a specific, chemical signature of a

  10. Alternating direction implicit methods for parabolic equations with a mixed derivative

    NASA Technical Reports Server (NTRS)

    Beam, R. M.; Warming, R. F.

    1979-01-01

    Alternating direction implicit (ADI) schemes for two-dimensional parabolic equations with a mixed derivative are constructed by using the class of all A sub 0-stable linear two-step methods in conjunction with the method of approximation factorization. The mixed derivative is treated with an explicit two-step method which is compatible with an implicit A sub 0-stable method. The parameter space for which the resulting ADI schemes are second order accurate and unconditionally stable is determined. Some numerical examples are given.

  11. Solution-derived photocatalytic films for environmental cleaning applications

    NASA Astrophysics Data System (ADS)

    Lavrenčič Štangar, U.; Kete, M.; Šuligoj, A.; Tasbihi, M.

    2012-02-01

    When photocatalytic water treatment is concerned, suspended catalyst in the aqueous phase is usually more efficient than immobilized on an inert support, but in the former case an undesirable separation/recycling step is needed. We have therefore concentrated on the preparation of immobilized catalysts in the form of films on glass and aluminium supports. The low-temperature sol-gel processing route to obtain transparent thin TiO2/SiO2 films for self-cleaning purposes and thicker TiO2/SiO2 coatings for efficient removal of pollutants in water and air are presented. The synthesis is based on a production of a nanocrystalline titania sol with a silica binder that after deposition does not require thermal treatment at high temperatures. Depending on the target application, some specific synthesis parameters and photocatalytic activity testing conditions are illustrated. For water-cleaning coatings fast kinetics is required, which was achieved by addition of a highly active titania powder into the sol. The same preparation procedure was used to prepare efficient air-cleaning coatings. On the other hand, self-cleaning films were thinner and transparent to keep the original appearance of the substrate and they solidified at ambient conditions. Advanced methodologies to evaluate photocatalytic activity of the films were applied.

  12. Sol-gel derived electrode materials for supercapacitor applications

    NASA Astrophysics Data System (ADS)

    Lin, Chuan

    1998-12-01

    Electrochemical capacitors have been receiving increasing interest in recent years for use in energy storage systems because of their high energy and power density and long cycle lifes. Possible applications of electrochemical capacitors include high power pulsed lasers, hybrid power system for electric vehicles, etc. In this dissertation, the preparation of electrode materials for use as electrochemical capacitors has been studied using the sol-gel process. The high surface area electrode materials explored in this work include a synthetic carbon xerogel for use in a double-layer capacitor, a cobalt oxide xerogel for use in a pseudocapacitor, and a carbon-ruthenium xerogel composite, which utilizes both double-layer and faradaic capacitances. The preparation conditions of these materials were investigated in detail to maximize the surface area and optimize the pore size so that more energy could be stored while minimizing mass transfer limitations. The microstructures of the materials were also correlated with their performance as electrochemical capacitors to improve their energy and power densities. Finally, an idealistic mathematical model, including both double-layer and faradaic processes, was developed and solved numerically. This model can be used to perform the parametric studies of an electrochemical capacitor so as to gain a better understanding of how the capacitor works and also how to improve cell operations and electrode materials design.

  13. Engineering derivatives from biological systems for advanced aerospace applications

    NASA Technical Reports Server (NTRS)

    Winfield, Daniel L.; Hering, Dean H.; Cole, David

    1991-01-01

    The present study consisted of a literature survey, a survey of researchers, and a workshop on bionics. These tasks produced an extensive annotated bibliography of bionics research (282 citations), a directory of bionics researchers, and a workshop report on specific bionics research topics applicable to space technology. These deliverables are included as Appendix A, Appendix B, and Section 5.0, respectively. To provide organization to this highly interdisciplinary field and to serve as a guide for interested researchers, we have also prepared a taxonomy or classification of the various subelements of natural engineering systems. Finally, we have synthesized the results of the various components of this study into a discussion of the most promising opportunities for accelerated research, seeking solutions which apply engineering principles from natural systems to advanced aerospace problems. A discussion of opportunities within the areas of materials, structures, sensors, information processing, robotics, autonomous systems, life support systems, and aeronautics is given. Following the conclusions are six discipline summaries that highlight the potential benefits of research in these areas for NASA's space technology programs.

  14. A new second-derivative spectrophotometric method for the determination of permethrin in shampoo.

    PubMed

    Kazemipour, Maryam; Noroozian, Ebrahim; Saber Tehrani, Mohammad; Mahmoudian, Massoud

    2002-11-07

    Permethrin, a highly effective insecticide agent, has been widely used for the pest control in agriculture and the treatment of lice in human. A fast and reliable method for the determination of permethrin was highly desirable to support formulation screening and quality control. A second-derivative UV spectroscopic method was developed for the determination of permethrin in the shampoo dosage form after extraction. The second-derivative spectrum recorded between 250 and 310 nm, and a zero-crossing technique for second-derivative measurement at 279 nm was selected. It is found that the selectivity and sensitivity of the method to be in desirable range. In comparison with the direct UV method, second-derivative UV spectroscopy eliminates the interference from UV absorbing excipients. This method is also fast and economical in comparison with the more time-consuming GC method regularly used for formulation screening and quality control and can be used routinely by any laboratory possessing a spectrophotometer with a derivative accessory. The linear concentration ranges were 0.25-1.5 ppm (D2=0.00042Conc.+0.0018, r=0.9972, n=10). Between day of CV%method for determination in quality control.

  15. Applications of Langevin and Molecular Dynamics methods

    NASA Astrophysics Data System (ADS)

    Lomdahl, P. S.

    Computer simulation of complex nonlinear and disordered phenomena from materials science is rapidly becoming an active and new area serving as a guide for experiments and for testing of theoretical concepts. This is especially true when novel massively parallel computer systems and techniques are used on these problems. In particular the Langevin dynamics simulation technique has proven useful in situations where the time evolution of a system in contact with a heat bath is to be studied. The traditional way to study systems in contact with a heat bath has been via the Monte Carlo method. While this method has indeed been used successfully in many applications, it has difficulty addressing true dynamical questions. Large systems of coupled stochastic ODE's (or Langevin equations) are commonly the end result of a theoretical description of higher dimensional nonlinear systems in contact with a heat bath. The coupling is often local in nature, because it reflects local interactions formulated on a lattice, the lattice for example represents the underlying discreteness of a substrate of atoms or discrete k-values in Fourier space. The fundamental unit of parallelism thus has a direct analog in the physical system the authors are interested in. In these lecture notes the authors illustrate the use of Langevin stochastic simulation techniques on a number of nonlinear problems from materials science and condensed matter physics that have attracted attention in recent years. First, the authors review the idea behind the fluctuation-dissipation theorem which forms that basis for the numerical Langevin stochastic simulation scheme. The authors then show applications of the technique to various problems from condensed matter and materials science.

  16. Deriving welfare measures from discrete choice experiments: inconsistency between current methods and random utility and welfare theory.

    PubMed

    Lancsar, Emily; Savage, Elizabeth

    2004-09-01

    Discrete choice experiments (DCEs) are being used increasingly in health economics to elicit preferences for products and programs. The results of such experiments have been used to calculate measures of welfare or more specifically, respondents' 'willingness to pay' (WTP) for products and programs and their 'marginal willingness to pay' (MWTP) for the attributes that make up such products and programs. In this note we show that the methods currently used to derive measures of welfare from DCEs in the health economics literature are not consistent with random utility theory (RUT), or with microeconomic welfare theory more generally. The inconsistency with welfare theory is an important limitation on the use of such WTP estimates in cost-benefit analyses. We describe an alternative method of deriving measures of welfare (compensating variation) from DCEs that is consistent with RUT and is derived using welfare theory. We demonstrate its use in an empirical application to derive the WTP for asthma medication and compare it to the results elicited from the method currently used in the health economics literature.

  17. Graphene and its derivatives as versatile templates for materials synthesis and functional applications.

    PubMed

    Quan, Quan; Lin, Xin; Zhang, Nan; Xu, Yi-Jun

    2017-02-16

    The obvious incongruity between the increasing depletion of fossil fuel and the finite amount of resources has motivated us to seek means to maintain sustainability in our society. Developing renewable and highly efficient energy conversion and storage systems represents one of the most promising and viable methods. Although the efficiency of energy conversion and storage devices depends on various factors, their overall performances strongly rely on the structure and functional properties of materials. Graphene and its derivatives as versatile templates for materials synthesis have garnered widespread interest because of their flexible capability to tune the morphology and structure of functional materials. Herein, we have demonstrated recent progress on graphene and its derivatives as versatile templates for materials synthesis, particularly highlighting the basic fundamental roles of graphene in the materials preparation process. Then, a concise overview of the functional applications of materials obtained from graphene-templated approaches has been presented with a few selected examples to show the wide scope of potential in energy storage and conversion. Finally, a brief perspective and potential future challenges in this burgeoning research area have been discussed.

  18. Material derivatives of boundary integral operators in electromagnetism and application to inverse scattering problems

    NASA Astrophysics Data System (ADS)

    Ivanyshyn Yaman, Olha; Le Louër, Frédérique

    2016-09-01

    This paper deals with the material derivative analysis of the boundary integral operators arising from the scattering theory of time-harmonic electromagnetic waves and its application to inverse problems. We present new results using the Piola transform of the boundary parametrisation to transport the integral operators on a fixed reference boundary. The transported integral operators are infinitely differentiable with respect to the parametrisations and simplified expressions of the material derivatives are obtained. Using these results, we extend a nonlinear integral equations approach developed for solving acoustic inverse obstacle scattering problems to electromagnetism. The inverse problem is formulated as a pair of nonlinear and ill-posed integral equations for the unknown boundary representing the boundary condition and the measurements, for which the iteratively regularized Gauss-Newton method can be applied. The algorithm has the interesting feature that it avoids the numerous numerical solution of boundary value problems at each iteration step. Numerical experiments are presented in the special case of star-shaped obstacles.

  19. Potential biological applications of bio-based anacardic acids and their derivatives.

    PubMed

    Hamad, Fatma B; Mubofu, Egid B

    2015-04-16

    Cashew nut shells (CNS), which are agro wastes from cashew nut processing factories, have proven to be among the most versatile bio-based renewable materials in the search for functional materials and chemicals from renewable resources. CNS are produced in the cashew nut processing process as waste, but they contain cashew nut shell liquid (CNSL) up to about 30-35 wt. % of the nut shell weight depending on the method of extraction. CNSL is a mixture of anacardic acid, cardanol, cardol, and methyl cardol, and the structures of these phenols offer opportunities for the development of diverse products. For anacardic acid, the combination of phenolic, carboxylic, and a 15-carbon alkyl side chain functional group makes it attractive in biological applications or as a synthon for the synthesis of a multitude of bioactive compounds. Anacardic acid, which is about 65% of a CNSL mixture, can be extracted from the agro waste. This shows that CNS waste can be used to extract useful chemicals and thus provide alternative green sources of chemicals, apart from relying only on the otherwise declining petroleum based sources. This paper reviews the potential of anacardic acids and their semi-synthetic derivatives for antibacterial, antitumor, and antioxidant activities. The review focuses on natural anacardic acids from CNS and other plants and their semi-synthetic derivatives as possible lead compounds in medicine. In addition, the use of anacardic acid as a starting material for the synthesis of various biologically active compounds and complexes is reported.

  20. Potential Biological Applications of Bio-Based Anacardic Acids and Their Derivatives

    PubMed Central

    Hamad, Fatma B.; Mubofu, Egid B.

    2015-01-01

    Cashew nut shells (CNS), which are agro wastes from cashew nut processing factories, have proven to be among the most versatile bio-based renewable materials in the search for functional materials and chemicals from renewable resources. CNS are produced in the cashew nut processing process as waste, but they contain cashew nut shell liquid (CNSL) up to about 30–35 wt. % of the nut shell weight depending on the method of extraction. CNSL is a mixture of anacardic acid, cardanol, cardol, and methyl cardol, and the structures of these phenols offer opportunities for the development of diverse products. For anacardic acid, the combination of phenolic, carboxylic, and a 15-carbon alkyl side chain functional group makes it attractive in biological applications or as a synthon for the synthesis of a multitude of bioactive compounds. Anacardic acid, which is about 65% of a CNSL mixture, can be extracted from the agro waste. This shows that CNS waste can be used to extract useful chemicals and thus provide alternative green sources of chemicals, apart from relying only on the otherwise declining petroleum based sources. This paper reviews the potential of anacardic acids and their semi-synthetic derivatives for antibacterial, antitumor, and antioxidant activities. The review focuses on natural anacardic acids from CNS and other plants and their semi-synthetic derivatives as possible lead compounds in medicine. In addition, the use of anacardic acid as a starting material for the synthesis of various biologically active compounds and complexes is reported. PMID:25894225

  1. The ONIOM molecular dynamics method for biochemical applications: cytidine deaminase

    SciTech Connect

    Matsubara, Toshiaki; Dupuis, Michel; Aida, Misako

    2007-03-22

    Abstract We derived and implemented the ONIOM-molecular dynamics (MD) method for biochemical applications. The implementation allows the characterization of the functions of the real enzymes taking account of their thermal motion. In this method, the direct MD is performed by calculating the ONIOM energy and gradients of the system on the fly. We describe the first application of this ONOM-MD method to cytidine deaminase. The environmental effects on the substrate in the active site are examined. The ONIOM-MD simulations show that the product uridine is strongly perturbed by the thermal motion of the environment and dissociates easily from the active site. TM and MA were supported in part by grants from the Ministry of Education, Culture, Sports, Science and Technology of Japan. MD was supported by the Division of Chemical Sciences, Office of Basic Energy Sciences, and by the Office of Biological and Environmental Research of the U.S. Department of Energy DOE. Battelle operates Pacific Northwest National Laboratory for DOE.

  2. CSM research: Methods and application studies

    NASA Technical Reports Server (NTRS)

    Knight, Norman F., Jr.

    1989-01-01

    Computational mechanics is that discipline of applied science and engineering devoted to the study of physical phenomena by means of computational methods based on mathematical modeling and simulation, utilizing digital computers. The discipline combines theoretical and applied mechanics, approximation theory, numerical analysis, and computer science. Computational mechanics has had a major impact on engineering analysis and design. When applied to structural mechanics, the discipline is referred to herein as computational structural mechanics. Complex structures being considered by NASA for the 1990's include composite primary aircraft structures and the space station. These structures will be much more difficult to analyze than today's structures and necessitate a major upgrade in computerized structural analysis technology. NASA has initiated a research activity in structural analysis called Computational Structural Mechanics (CSM). The broad objective of the CSM activity is to develop advanced structural analysis technology that will exploit modern and emerging computers, such as those with vector and/or parallel processing capabilities. Here, the current research directions for the Methods and Application Studies Team of the Langley CSM activity are described.

  3. Application of numerical methods to elasticity imaging.

    PubMed

    Castaneda, Benjamin; Ormachea, Juvenal; Rodríguez, Paul; Parker, Kevin J

    2013-03-01

    Elasticity imaging can be understood as the intersection of the study of biomechanical properties, imaging sciences, and physics. It was mainly motivated by the fact that pathological tissue presents an increased stiffness when compared to surrounding normal tissue. In the last two decades, research on elasticity imaging has been an international and interdisciplinary pursuit aiming to map the viscoelastic properties of tissue in order to provide clinically useful information. As a result, several modalities of elasticity imaging, mostly based on ultrasound but also on magnetic resonance imaging and optical coherence tomography, have been proposed and applied to a number of clinical applications: cancer diagnosis (prostate, breast, liver), hepatic cirrhosis, renal disease, thyroiditis, arterial plaque evaluation, wall stiffness in arteries, evaluation of thrombosis in veins, and many others. In this context, numerical methods are applied to solve forward and inverse problems implicit in the algorithms in order to estimate viscoelastic linear and nonlinear parameters, especially for quantitative elasticity imaging modalities. In this work, an introduction to elasticity imaging modalities is presented. The working principle of qualitative modalities (sonoelasticity, strain elastography, acoustic radiation force impulse) and quantitative modalities (Crawling Waves Sonoelastography, Spatially Modulated Ultrasound Radiation Force (SMURF), Supersonic Imaging) will be explained. Subsequently, the areas in which numerical methods can be applied to elasticity imaging are highlighted and discussed. Finally, we present a detailed example of applying total variation and AM-FM techniques to the estimation of elasticity.

  4. Summary of methods for calculating dynamic lateral stability and response and for estimating aerodynamic stability derivatives

    NASA Technical Reports Server (NTRS)

    Campbell, John P; Mckinney, Marion O

    1952-01-01

    A summary of methods for making dynamic lateral stability and response calculations and for estimating the aerodynamic stability derivatives required for use in these calculations is presented. The processes of performing calculations of the time histories of lateral motions, of the period and damping of these motions, and of the lateral stability boundaries are presented as a series of simple straightforward steps. Existing methods for estimating the stability derivatives are summarized and, in some cases, simple new empirical formulas are presented. Detailed estimation methods are presented for low-subsonic-speed conditions but only a brief discussion and a list of references are given for transonic and supersonic speed conditions.

  5. Boiling Method-Based Zinc Oxide Nanorods for Enhancement of Adipose-Derived Stem Cell Proliferation.

    PubMed

    Jin, Su-Eon; Ahn, Hyo-Sun; Kim, Ji Hye; Arai, Yoshie; Lee, Soo-Hong; Yoon, Tae-Jong; Hwang, Sung-Joo; Sung, Jong-Hyuk

    2016-09-01

    Adipose-derived stem cells (ASCs) are typically expanded to acquire large numbers of cells for therapeutic applications. Diverse stimuli such as sphingosylphosphocholine and vitamin C have been used to increase the production yield and regenerative potential of ASCs. In the present study, we hypothesized that ZnO nanorods have promising potential for the enhancement of ASC proliferation. ZnO nanorods were prepared using three different methods: grinding and boiling at low temperature with and without surfactant. The physicochemical properties of the nanorods such as their crystallinity, morphology, size, and solvent compatibility were evaluated, and then, the ability of the synthesized ZnO nanorods to enhance ASC proliferation was investigated. Scanning electron microscopy images of all of the ZnO powders showed rod-shaped nanoflakes with lengths of 200-500 nm. Notably, although ZnO-G produced by the grinding method was well dispersed in ethanol, atomic force microscopy images of dispersions of both ZnO-B from boiling methods and ZnO-G indicated the presence of clusters of ZnO nanorods. In contrast, ZnO-B was freely dispersible in 5% dextrose of water and dimethyl sulfoxide, whereas ZnO-G and ZnO-M, produced by boiling with ethanolamine, were not. All three types of ZnO nanorods increased the proliferation of ASCs in a dose-dependent manner. These results collectively suggest that ZnO nanorods have promising potential for use as an agent for the enhancement of ASC proliferation.

  6. 40 CFR 425.03 - Sulfide analytical methods and applicability.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Provisions § 425.03 Sulfide analytical methods and applicability. (a) The potassium ferricyanide titration... the potassium ferricyanide titration method for the determination of sulfide in wastewaters...

  7. Methods of geodiversity assessment and theirs application

    NASA Astrophysics Data System (ADS)

    Zwoliński, Zbigniew; Najwer, Alicja; Giardino, Marco

    2016-04-01

    The concept of geodiversity has rapidly gained the approval of scientists around the world (Wiedenbein 1993, Sharples 1993, Kiernan 1995, 1996, Dixon 1996, Eberhard 1997, Kostrzewski 1998, 2011, Gray 2004, 2008, 2013, Zwoliński 2004, Serrano, Ruiz- Flano 2007, Gordon et al. 2012). However, the problem recognition is still at an early stage, and in effect not explicitly understood and defined (Najwer, Zwoliński 2014). Nevertheless, despite widespread use of the concept, little progress has been made in its assessment and mapping. Less than the last decade can be observing investigation of methods for geodiversity assessment and its visualisation. Though, many have acknowledged the importance of geodiversity evaluation (Kozłowski 2004, Gray 2004, Reynard, Panizza 2005, Zouros 2007, Pereira et al. 2007, Hjort et al. 2015). Hitherto, only a few authors have undertaken that kind of methodological issues. Geodiversity maps are being created for a variety of purposes and therefore their methods are quite manifold. In the literature exists some examples of the geodiversity maps applications for the geotourism purpose, basing mainly on the geological diversity, in order to point the scale of the area's tourist attractiveness (Zwoliński 2010, Serrano and Gonzalez Trueba 2011, Zwoliński and Stachowiak 2012). In some studies, geodiversity maps were created and applied to investigate the spatial or genetic relationships with the richness of particular natural environmental components (Burnett et al. 1998, Silva 2004, Jačková, Romportl 2008, Hjort et al. 2012, 2015, Mazurek et al. 2015, Najwer et al. 2014). There are also a few examples of geodiversity assessment in order to geoconservation and efficient management and planning of the natural protected areas (Serrano and Gonzalez Trueba 2011, Pellitero et al. 2011, 2014, Jaskulska et al. 2013, Melelli 2014, Martinez-Grana et al. 2015). The most popular method of assessing the diversity of abiotic components of the natural

  8. Fast Numerical Evaluation of Time-Derivative Nonadiabatic Couplings for Mixed Quantum-Classical Methods.

    PubMed

    Ryabinkin, Ilya G; Nagesh, Jayashree; Izmaylov, Artur F

    2015-11-05

    We have developed a numerical differentiation scheme that eliminates evaluation of overlap determinants in calculating the time-derivative nonadiabatic couplings (TDNACs). Evaluation of these determinants was the bottleneck in previous implementations of mixed quantum-classical methods using numerical differentiation of electronic wave functions in the Slater determinant representation. The central idea of our approach is, first, to reduce the analytic time derivatives of Slater determinants to time derivatives of molecular orbitals and then to apply a finite-difference formula. Benchmark calculations prove the efficiency of the proposed scheme showing impressive several-order-of-magnitude speedups of the TDNAC calculation step for midsize molecules.

  9. A simple method to engineer a protein-derived redox cofactor for catalysis.

    PubMed

    Shin, Sooim; Choi, Moonsung; Williamson, Heather R; Davidson, Victor L

    2014-10-01

    The 6×-Histidine tag which is commonly used for purification of recombinant proteins was converted to a catalytic redox-active center by incorporation of Co(2+). Two examples of the biological activity of this engineered protein-derived cofactor are presented. After inactivation of the natural diheme cofactor of MauG, it was shown that the Co(2+)-loaded 6×His-tag could substitute for the hemes in the H2O2-driven catalysis of tryptophan tryptophylquinone biosynthesis. To further demonstrate that the Co(2+)-loaded 6×His-tag could mediate long range electron transfer, it was shown that addition of H2O2 to the Co(2+)-loaded 6×His-tagged Cu(1+) amicyanin oxidizes the copper site which is 20Å away. These results provide proof of principle for this simple method by which to introduce a catalytic redox-active site into proteins for potential applications in research and biotechnology.

  10. A simple method to engineer a protein-derived redox cofactor for catalysis

    PubMed Central

    Shin, Sooim; Choi, Moonsung; Williamson, Heather R.; Davidson, Victor L.

    2014-01-01

    The 6x-Histidine tag which is commonly used for purification of recombinant proteins was converted to a catalytic redox-active center by incorporation of Co2+. Two examples of the biological activity of this engineered protein-derived cofactor are presented. After inactivation of the natural diheme cofactor of MauG, it was shown that the Co2+-loaded 6xHis-tag could substitute for the hemes in the H2O2-driven catalysis of tryptophan tryptophylquinone biosynthesis. To further demonstrate that the Co2+-loaded 6xHis-tag could mediate long range electron transfer, it was shown that addition of H2O2 to the Co2+-loaded 6xHis-tagged Cu1+ amicyanin oxidizes the copper site which is 20 Å away. These results provide proof of principle for this simple method by which to introduce a catalytic redox-active site into proteins for potential applications in research and biotechnology. PMID:24858537

  11. A rapid and economical method of preparing radioiodinated cyclic nucleotide derivatives for use in radioimmunoassays

    SciTech Connect

    Oehlenschlager, W.F.; Kubalak, S.W.; Currie, M.G. )

    1990-01-01

    2'-O-succinyladenosine 3':5'-cyclic monophosphate tyrosyl methyl ester (ScAMP-TME) and 2'-O-succinylguanosine 3':5'-cyclic monophosphate tyrosyl methyl ester (ScGMP-TME) were radioiodinated using chloramine T and Na125I. The resulting radiolabeled cyclic nucleotide derivatives, ScAMP-125I-TME and ScGMP-125I-TME, were subsequently purified by reverse-phase chromatography on Sep-Pak C18 cartridges (Waters Associates, Milford, MA) and tested as tracers in sensitive radioimmunoassays for cAMP and cGMP, respectively. Purified ScAMP-125I-TME and ScGMP-125I-TME functioned in the respective radioimmunoassays for up to 12 weeks when suspended in a 1:1 (v:v) mixture of n-propanol and 20 mM sodium acetate, pH 6.0. Thus, this purification method enables rapid and economical preparation of tracers for cyclic nucleotide radioimmunoassays. Furthermore, our findings suggest that reverse-phase chromatography may be applicable to the purification of other small polar molecules to which tyrosyl groups have been added for the purpose of radioiodination.

  12. Aggregative Learning Method and Its Application for Communication Quality Evaluation

    NASA Astrophysics Data System (ADS)

    Akhmetov, Dauren F.; Kotaki, Minoru

    2007-12-01

    In this paper, so-called Aggregative Learning Method (ALM) is proposed to improve and simplify the learning and classification abilities of different data processing systems. It provides a universal basis for design and analysis of mathematical models of wide class. A procedure was elaborated for time series model reconstruction and analysis for linear and nonlinear cases. Data approximation accuracy (during learning phase) and data classification quality (during recall phase) are estimated from introduced statistic parameters. The validity and efficiency of the proposed approach have been demonstrated through its application for monitoring of wireless communication quality, namely, for Fixed Wireless Access (FWA) system. Low memory and computation resources were shown to be needed for the procedure realization, especially for data classification (recall) stage. Characterized with high computational efficiency and simple decision making procedure, the derived approaches can be useful for simple and reliable real-time surveillance and control system design.

  13. Stem cell-derived kidney cells and organoids: Recent breakthroughs and emerging applications.

    PubMed

    Chuah, Jacqueline Kai Chin; Zink, Daniele

    The global rise in the numbers of kidney patients and the shortage in transplantable organs have led to an increasing interest in kidney-specific regenerative therapies, renal disease modelling and bioartificial kidneys. Sources for large quantities of high-quality renal cells and tissues would be required, also for applications in in vitro platforms for compound safety and efficacy screening. Stem cell-based approaches for the generation of renal-like cells and tissues would be most attractive, but such methods were not available until recently. This situation has drastically changed since 2013, and various protocols for the generation of renal-like cells and precursors from pluripotent stem cells (PSC) have been established. The most recent breakthroughs were related to the establishment of various protocols for the generation of PSC-derived kidney organoids. In combination with recent advances in genome editing, bioprinting and the establishment of predictive renal screening platforms this results in exciting new possibilities. This review will give a comprehensive overview over current PSC-based protocols for the generation of renal-like cells, precursors and organoids, and their current and potential applications in regenerative medicine, compound screening, disease modelling and bioartificial organs.

  14. Solution of the phase problem at non-atomic resolution by the phantom derivative method.

    PubMed

    Giacovazzo, Carmelo

    2015-09-01

    For a given unknown crystal structure (the target), n random structures, arbitrarily designed without any care for their chemical consistency and usually uncorrelated with the target, are sheltered in the same unit cell as the target structure and submitted to the same space-group symmetry. (These are called ancil structures.) The composite structures, whose electron densities are the sum of the target and of the ancil electron densities, are denoted derivatives. No observed diffraction amplitudes are available for them: in order to emphasize their unreal nature, the term phantom is added. The paper describes the theoretical basis by which the phantom derivative method may be used to phase the target structure. It may be guessed that 100-300 ancil structures may be sufficient for phasing a target structure, so that the phasing technique may be denoted as the multiple phantom derivative method. Ancil phases and amplitudes may be initially combined with observed target magnitudes to estimate amplitudes and phases of the corresponding phantom derivative. From them suitable algorithms allow one to obtain poor target phase estimates, which are often improved by combining the indications arising from each derivative. Probabilistic criteria are described to recognize the most reliable target phase estimates. The method is cyclic: the target phase estimates just obtained are used to improve amplitudes and phases of each derivative, which, in their turn, are employed to provide better target phase estimates. The method is a fully ab initio method, because it needs only the experimental data of the target structure. The term derivative is maintained with reference to SIR-MIR (single isomorphous replacement-multiple isomorphous replacement) techniques, even if its meaning is different: therefore the reader should think of the phantom derivative method more as a new method than as a variant of SIR-MIR techniques. The differences are much greater than the analogies. The paper

  15. Derivative Form of Off-axis Aberration Correction Surface and Its Application in Solar Energy Concentration

    NASA Astrophysics Data System (ADS)

    Li, Li; Chen, Ying-Tian; Hu, Sen

    2009-02-01

    By using the derivative method, we obtained the same result with that of the previous work of Chen et al. in 2006. Different from the integral form, the derivative form of the surface expression published in this paper is derived from differential equation and based on the theory of non-imaging focusing heliostat proposed by Chen et al. in 2001. The comparison of the derivative form of fixed aberration correction surface has been made with that of integral form surface as well as that of spherical surface in concentrating the solar ray.

  16. New anthracene-tetrathiafulvalene derivative-encapsulated SWNT nanocomposite and its application for biosensing.

    PubMed

    Song, Min; Wang, Xuemei; Liu, Wei; Zuo, Jinglin

    2010-03-01

    In this study, a novel anthracene-tetrathiafulvalene derivative has been synthesized and immobilized on single-walled carbon nanotubes through non-covalent sidewall functionalization. The new anthracene-tetrathiafulvalene (TTF) derivative-encapsulated SWNT nanocomposites were characterized using SEM, TEM, and Raman spectra and were utilized for biomolecular recognition. Our observations demonstrate that the new anthracene-TTF derivative-encapsulated SWNT nanocomposites can readily facilitate the biosensing and sensitive detection of DNA, which could be further explored for promising applications in bioelectronics and biosensors.

  17. Serum proteomics of glioma: methods and applications.

    PubMed

    Somasundaram, Kumaravel; Nijaguna, Mamatha B; Kumar, Durairaj Mohan

    2009-10-01

    The prognosis of patients with glioblastoma, the most malignant adult glial brain tumor, remains poor in spite of advances in treatment procedures, including surgical resection, irradiation and chemotherapy. Genetic heterogeneity of glioblastoma warrants extensive studies in order to gain a thorough understanding of the biology of this tumor. While there have been several studies of global transcript profiling of glioma with the identification of gene signatures for diagnosis and disease management, translation into clinics is yet to happen. Serum biomarkers have the potential to revolutionize the process of cancer diagnosis, grading, prognostication and treatment response monitoring. Besides having the advantage that serum can be obtained through a less invasive procedure, it contains molecules at an extraordinary dynamic range of ten orders of magnitude in terms of their concentrations. While the conventional methods, such as 2DE, have been in use for many years, the ability to identify the proteins through mass spectrometry techniques such as MALDI-TOF led to an explosion of interest in proteomics. Relatively new high-throughput proteomics methods such as SELDI-TOF and protein microarrays are expected to hasten the process of serum biomarker discovery. This review will highlight the recent advances in the proteomics platform in discovering serum biomarkers and the current status of glioma serum markers. We aim to provide the principles and potential of the latest proteomic approaches and their applications in the biomarker discovery process. Besides providing a comprehensive list of available serum biomarkers of glioma, we will also propose how these markers will revolutionize the clinical management of glioma patients.

  18. Phase derivative method for reconstruction of slightly off-axis digital holograms.

    PubMed

    Guo, Cheng-Shan; Wang, Ben-Yi; Sha, Bei; Lu, Yu-Jie; Xu, Ming-Yuan

    2014-12-15

    A phase derivative (PD) method is proposed for reconstruction of off-axis holograms. In this method, a phase distribution of the tested object wave constrained within 0 to pi radian is firstly worked out by a simple analytical formula; then it is corrected to its right range from -pi to pi according to the sign characteristics of its first-order derivative. A theoretical analysis indicates that this PD method is particularly suitable for reconstruction of slightly off-axis holograms because it only requires the spatial frequency of the reference beam larger than spatial frequency of the tested object wave in principle. In addition, because the PD method belongs to a pure local method with no need of any integral operation or phase shifting algorithm in process of the phase retrieval, it could have some advantages in reducing computer load and memory requirements to the image processing system. Some experimental results are given to demonstrate the feasibility of the method.

  19. Autologous adipose-derived stem cells: Basic science, technique, and rationale for application in ulcer and wound healing.

    PubMed

    Zollino, Ilaria; Zuolo, Michele; Gianesini, Sergio; Pedriali, Massimo; Sibilla, Maria Grazia; Tessari, Mirko; Carinci, Francesco; Occhionorelli, Savino; Zamboni, Paolo

    2017-04-01

    Objectives The present review represents a translational boundary between basic research and surgery, particularly focusing on the promising application of adipose-derived stem cells harvested intra-operatively during debridement of venous leg ulcers. Methods We reviewed 830 out of 5578 articles on MEDLINE starting from 1997 and sorted by the relevance option. Results The technique currently used for adipose-derived stem cells intra-operative harvesting is presented, including a safety evaluation on a cohort of 5089 revised patients who underwent plastic surgery and maxillo-facial surgical procedures. Complications were reported in 169 cases (3.3%). One hundred and forty-one (2.77%) patients were classified as having minor complications, specifically: nodularity/induration 93 (1.83%), dysesthesia 14 (0.26%), hematoma 12 (0.23%), superficial infection 11 (0.21%), pain 7 (0.13%), poor cosmesis 3 (0.06%), and abnormal breast secretion 1 (0.02%), while 28 patients (0.55%) were classified as having major complications, specifically: deep infection 22 (0.43%), sepsis 3 (0.06%), abdominal hematoma 2 (0.04%), and pneumothorax 1 (0.02%). Application of cell therapy in venous leg ulcer is currently used only for patients not responding to the standard treatment. The review shows the lack of randomized clinical trials for application of adipose-derived stem cells among treatments for venous leg ulcer. Finally, adipose-derived stem cells implantation at the wound site promotes a new tissue formation rich in vascular structures and remodeling collagen. Conclusion Adipose-derived stem cells strategy represents a great opportunity for the treatment of chronic wounds, due to the simplicity of the technique and the application of cell treatment in the operating room immediately following debridement. However, clinical studies and data from randomized trials are currently lacking.

  20. Using Selective Drainage Methods to Extract Continuous Surface Flow from 1-Meter Lidar-Derived Digital Elevation Data

    USGS Publications Warehouse

    Poppenga, Sandra K.; Worstell, Bruce B.; Stoker, Jason M.; Greenlee, Susan K.

    2010-01-01

    Digital elevation data commonly are used to extract surface flow features. One source for high-resolution elevation data is light detection and ranging (lidar). Lidar can capture a vast amount of topographic detail because of its fine-scale ability to digitally capture the surface of the earth. Because elevation is a key factor in extracting surface flow features, high-resolution lidar-derived digital elevation models (DEMs) provide the detail needed to consistently integrate hydrography with elevation, land cover, structures, and other geospatial features. The U.S. Geological Survey has developed selective drainage methods to extract continuous surface flow from high-resolution lidar-derived digital elevation data. The lidar-derived continuous surface flow network contains valuable information for water resource management involving flood hazard mapping, flood inundation, and coastal erosion. DEMs used in hydrologic applications typically are processed to remove depressions by filling them. High-resolution DEMs derived from lidar can capture much more detail of the land surface than courser elevation data. Therefore, high-resolution DEMs contain more depressions because of obstructions such as roads, railroads, and other elevated structures. The filling of these depressions can significantly affect the DEM-derived surface flow routing and terrain characteristics in an adverse way. In this report, selective draining methods that modify the elevation surface to drain a depression through an obstruction are presented. If such obstructions are not removed from the elevation data, the filling of depressions to create continuous surface flow can cause the flow to spill over an obstruction in the wrong location. Using this modified elevation surface improves the quality of derived surface flow and retains more of the true surface characteristics by correcting large filled depressions. A reliable flow surface is necessary for deriving a consistently connected drainage

  1. Antimicrobial applications of nanotechnology: methods and literature.

    PubMed

    Seil, Justin T; Webster, Thomas J

    2012-01-01

    The need for novel antibiotics comes from the relatively high incidence of bacterial infection and the growing resistance of bacteria to conventional antibiotics. Consequently, new methods for reducing bacteria activity (and associated infections) are badly needed. Nanotechnology, the use of materials with dimensions on the atomic or molecular scale, has become increasingly utilized for medical applications and is of great interest as an approach to killing or reducing the activity of numerous microorganisms. While some natural antibacterial materials, such as zinc and silver, possess greater antibacterial properties as particle size is reduced into the nanometer regime (due to the increased surface to volume ratio of a given mass of particles), the physical structure of a nanoparticle itself and the way in which it interacts with and penetrates into bacteria appears to also provide unique bactericidal mechanisms. A variety of techniques to evaluate bacteria viability, each with unique advantages and disadvantages, has been established and must be understood in order to determine the effectiveness of nanoparticles (diameter ≤ 100 nm) as antimicrobial agents. In addition to addressing those techniques, a review of select literature and a summary of bacteriostatic and bactericidal mechanisms are covered in this manuscript.

  2. Summary of Methods for Calculating Dynamic Lateral Stability and Response and for Estimating Lateral Stability Derivatives

    NASA Technical Reports Server (NTRS)

    Campbell, John P; Mckinney, Marion O

    1951-01-01

    A summary of methods for making dynamic lateral stability and response calculations and for estimating the aerodynamic stability derivatives required for use in these calculations is presented. The processes of performing calculations of the time histories of lateral motions, of the period and damping of these motions, and of the lateral stability boundaries are presented as a series of simple straightforward steps. Existing methods for estimating the stability derivatives are summarized and, in some cases, simple new empirical formulas are presented. Reference is also made to reports presenting experimental data that should be useful in making estimates of the derivatives. Detailed estimating methods are presented for low-subsonic-speed conditions but only a brief discussion and a list of references are given for transonic- and supersonic-speed conditions.

  3. Culture bag systems for clinical applications of adult human neural crest-derived stem cells

    PubMed Central

    2014-01-01

    Introduction Facing the challenging treatment of neurodegenerative diseases as well as complex craniofacial injuries such as those common after cancer therapy, the field of regenerative medicine increasingly relies on stem cell transplantation strategies. Here, neural crest-derived stem cells (NCSCs) offer many promising applications, although scale up of clinical-grade processes prior to potential transplantations is currently limiting. In this study, we aimed to establish a clinical-grade, cost-reducing cultivation system for NCSCs isolated from the adult human nose using cGMP-grade Afc-FEP bags. Methods We cultivated human neural crest-derived stem cells from inferior turbinate (ITSCs) in a cell culture bag system using Afc-FEP bags in human blood plasma-supplemented medium. Investigations of viability, proliferation and expression profile of bag-cultured ITSCs were followed by DNA-content and telomerase activity determination. Cultivated ITSCs were introduced to directed in vitro differentiation assays to assess their potential for mesodermal and ectodermal differentiation. Mesodermal differentiation was determined using an enzyme activity assay (alkaline phosphatase, ALP), respective stainings (Alizarin Red S, Von Kossa and Oil Red O), and RT-PCR, while immunocytochemistry and synaptic vesicle recycling were applied to assay neuroectodermal differentiation of ITSCs. Results When cultivated within Afc-FEP bags, ITSCs grew three-dimensionally in a human blood plasma-derived matrix, thereby showing unchanged morphology, proliferation capability, viability and expression profile in comparison to three dimensionally-cultured ITSCs growing in standard cell culture plastics. Genetic stability of bag-cultured ITSCs was further accompanied by unchanged telomerase activity. Importantly, ITSCs retained their potential to differentiate into mesodermal cell types, particularly including ALP-active, Alizarin Red S-, and Von Kossa-positive osteogenic cell types, as well as

  4. Space-time adaptive numerical methods for geophysical applications.

    PubMed

    Castro, C E; Käser, M; Toro, E F

    2009-11-28

    In this paper we present high-order formulations of the finite volume and discontinuous Galerkin finite-element methods for wave propagation problems with a space-time adaptation technique using unstructured meshes in order to reduce computational cost without reducing accuracy. Both methods can be derived in a similar mathematical framework and are identical in their first-order version. In their extension to higher order accuracy in space and time, both methods use spatial polynomials of higher degree inside each element, a high-order solution of the generalized Riemann problem and a high-order time integration method based on the Taylor series expansion. The static adaptation strategy uses locally refined high-resolution meshes in areas with low wave speeds to improve the approximation quality. Furthermore, the time step length is chosen locally adaptive such that the solution is evolved explicitly in time by an optimal time step determined by a local stability criterion. After validating the numerical approach, both schemes are applied to geophysical wave propagation problems such as tsunami waves and seismic waves comparing the new approach with the classical global time-stepping technique. The problem of mesh partitioning for large-scale applications on multi-processor architectures is discussed and a new mesh partition approach is proposed and tested to further reduce computational cost.

  5. Convergent integration of two self-labor domino sequences: a novel method for the synthesis of oxazole derivatives from methyl ketones and benzoins.

    PubMed

    Xue, Wei-Jian; Li, Qi; Zhu, Yan-Ping; Wang, Jun-Gang; Wu, An-Xin

    2012-04-11

    A highly efficient method for the synthesis of oxazole derivatives from methyl ketones, benzoins and ammonium acetate has been established via a novel strategy-convergent integration of two self-labor domino sequences. Owing to the simple and readily available starting materials, mild reaction conditions, facile operation, and the high bioactivity of oxazole derivatives, this reaction promises diverse applications in medical chemistry. Additionally, this reaction could provide an efficient example for self-labor synthesis strategy of organic compounds.

  6. Method and apparatus for collaborative use of application program

    DOEpatents

    Dean, Craig D.

    1994-01-01

    Method and apparatus permitting the collaborative use of a computer application program simultaneously by multiple users at different stations. The method is useful with communication protocols having client/server control structures. The method of the invention requires only a sole executing copy of the application program and a sole executing copy of software comprising the invention. Users may collaboratively use a set of application programs by invoking for each desired application program one copy of software comprising the invention.

  7. Regenerative Applications Using Tooth Derived Stem Cells in Other Than Tooth Regeneration: A Literature Review

    PubMed Central

    Park, Yun-Jong; Cha, Seunghee; Park, Young-Seok

    2016-01-01

    Tooth derived stem cells or dental stem cells are categorized according to the location from which they are isolated and represent a promising source of cells for regenerative medicine. Originally, as one kind of mesenchymal stem cells, they are considered an alternative of bone marrow stromal cells. They share many commonalties but maintain differences. Considering their original function in development and the homeostasis of tooth structures, many applications of these cells in dentistry have aimed at tooth structure regeneration; however, the application in other than tooth structures has been attempted extensively. The availability from discarded or removed teeth can be an innate benefit as a source of autologous cells. Their origin from the neural crest results in exploitation of neurological and numerous other applications. This review briefly highlights current and future perspectives of the regenerative applications of tooth derived stem cells in areas beyond tooth regeneration. PMID:26798366

  8. Comparison of three embryo culture methods for derivation of human embryonic stem cells from discarded embryos.

    PubMed

    Liu, Ying; Li, Yang; Hwang, Andrew; Wang, Shu-yu; Jia, Chan-wei; Yu, Lan; Li, Jian

    2011-06-01

    Human embryonic stem cells (hESC) are self-renewing and pluripotent cells that hold great promise. Our objective was to compare the effect of three different embryo culture methods for derivation of human embryonic stem cells from discarded embryos. A prospective and randomized trial was conducted using 381 discarded human embryos at days 2-3 postfertilization in Beijing Obstetrics and Gynecology Hospital IVF center. After removal of the zona pellucida, discarded human embryos were cultured by three different methods as multiple embryo aggregates, single embryo, and blastomeres. Outgrowth of embryos and hESC derivation were observed. The outgrowth rate of embryos cultured as multiple embryo aggregates was higher than that of those cultured as single embryos or blastomeres (p < 0.05). Three propagating hESC lines were derived from poor quality day 2-3 postfertilization nonblastocyst embryos cultured as multiple embryo aggregates. Derived hESC lines expressed hESC-specific markers of pluripotency and had normal diploid karyotype. The cells were able to form derivatives of all three germ layers in vivo as teratomas. Our results demonstrate that culturing these discarded embryos as multiple embryo aggregates was more profitable for outgrowth and derivation of ESC line than culturing these as single embryo or blastomeres.

  9. Applicability of optical scanner method for fine root dynamics

    NASA Astrophysics Data System (ADS)

    Kume, Tomonori; Ohashi, Mizue; Makita, Naoki; Khoon Kho, Lip; Katayama, Ayumi; Matsumoto, Kazuho; Ikeno, Hidetoshi

    2016-04-01

    Fine root dynamics is one of the important components in forest carbon cycling, as ~60 % of tree photosynthetic production can be allocated to root growth and metabolic activities. Various techniques have been developed for monitoring fine root biomass, production, mortality in order to understand carbon pools and fluxes resulting from fine roots dynamics. The minirhizotron method is now a widely used technique, in which a transparent tube is inserted into the soil and researchers count an increase and decrease of roots along the tube using images taken by a minirhizotron camera or minirhizotron video camera inside the tube. This method allows us to observe root behavior directly without destruction, but has several weaknesses; e.g., the difficulty of scaling up the results to stand level because of the small observation windows. Also, most of the image analysis are performed manually, which may yield insufficient quantitative and objective data. Recently, scanner method has been proposed, which can produce much bigger-size images (A4-size) with lower cost than those of the minirhizotron methods. However, laborious and time-consuming image analysis still limits the applicability of this method. In this study, therefore, we aimed to develop a new protocol for scanner image analysis to extract root behavior in soil. We evaluated applicability of this method in two ways; 1) the impact of different observers including root-study professionals, semi- and non-professionals on the detected results of root dynamics such as abundance, growth, and decomposition, and 2) the impact of window size on the results using a random sampling basis exercise. We applied our new protocol to analyze temporal changes of root behavior from sequential scanner images derived from a Bornean tropical forests. The results detected by the six observers showed considerable concordance in temporal changes in the abundance and the growth of fine roots but less in the decomposition. We also examined

  10. Cell-Derived Extracellular Matrix: Basic Characteristics and Current Applications in Orthopedic Tissue Engineering.

    PubMed

    Zhang, Weixiang; Zhu, Yun; Li, Jia; Guo, Quanyi; Peng, Jiang; Liu, Shichen; Yang, Jianhua; Wang, Yu

    2016-06-01

    The extracellular matrix (ECM) is a dynamic and intricate microenvironment with excellent biophysical, biomechanical, and biochemical properties, which can directly or indirectly regulate cell proliferation, adhesion, migration, and differentiation, as well as plays key roles in homeostasis and regeneration of tissues and organs. The ECM has attracted a great deal of attention with the rapid development of tissue engineering in the field of regenerative medicine. Tissue-derived ECM scaffolds (also referred to as decellularized tissues and whole organs) are considered a promising therapy for the repair of musculoskeletal defects, including those that are widely used in orthopedics, although there are a few shortcomings. Similar to tissue-derived ECM scaffolds, cell-derived ECM scaffolds also have highly advantageous biophysical and biochemical properties, in particular their ability to be produced in vitro from a number of different cell types. Furthermore, cell-derived ECM scaffolds more closely resemble native ECM microenvironments. The products of cell-derived ECM have a wide range of biomedical applications; these include reagents for cell culture substrates and biomaterials for scaffolds, hybrid scaffolds, and living cell sheet coculture systems. Although cell-derived ECM has only just begun to be investigated, it has great potential as a novel approach for cell-based tissue repair in orthopedic tissue engineering. This review summarizes and analyzes the various types of cell-derived ECM products applied in cartilage, bone, and nerve tissue engineering in vitro or in vivo and discusses future directions for investigation of cell-derived ECM.

  11. Three dimethoxy-substituted luminol derivatives: A comparative study using theoretical method

    NASA Astrophysics Data System (ADS)

    Xue, Bingchun; Liu, Cuilan; Liu, Yanhong; Liu, Erbao

    2015-02-01

    In this research, geometrical optimisation, Mulliken charge, molecular electrostatic potential, and the frontier molecular orbitals of three dimethoxy-substituted luminol derivatives were investigated by ab initio, density functional, and Møller-Plesset perturbation theory with a 6-311G (d, p) basis set in gas phase, water, and dimethylsulphoxide solution. The UV-vis spectra were calculated by time dependent density functional theory method. The properties of derivatives were compared with luminol at a molecular level to investigate the change induced by the methoxy group. The three derivatives were also compared with the aim of predicting the order of chemiluminescent efficiency. The results showed that methoxy substitution significantly changed the electronic and spectral properties of luminol. Among three derivatives, structure 2 was suggested to have the highest chemiluminescent efficiency. The results may shed some light on the design and selection of chemiluminescent reagents.

  12. On Applicability of Formal Methods and Tools to Dependable Services

    NASA Astrophysics Data System (ADS)

    Ishikawa, Fuyuki; Honiden, Shinichi

    As a variety of digital services are provided through networks, more and more efforts are made to ensure dependability of software behavior implementing services. Formal methods and tools have been considered as promising means to support dependability in complex software systems during the development. On the other hand, there have been serious doubts on practical applicability of formal methods. This paper overviews the present state of formal methods and discusses their applicability, especially focusing on two representative methods (SPIN and B Method) and their recent industrial applications. This paper also discusses applications of formal methods to dependable networked software.

  13. An integer order approximation method based on stability boundary locus for fractional order derivative/integrator operators.

    PubMed

    Deniz, Furkan Nur; Alagoz, Baris Baykant; Tan, Nusret; Atherton, Derek P

    2016-05-01

    This paper introduces an integer order approximation method for numerical implementation of fractional order derivative/integrator operators in control systems. The proposed method is based on fitting the stability boundary locus (SBL) of fractional order derivative/integrator operators and SBL of integer order transfer functions. SBL defines a boundary in the parametric design plane of controller, which separates stable and unstable regions of a feedback control system and SBL analysis is mainly employed to graphically indicate the choice of controller parameters which result in stable operation of the feedback systems. This study reveals that the SBL curves of fractional order operators can be matched with integer order models in a limited frequency range. SBL fitting method provides straightforward solutions to obtain an integer order model approximation of fractional order operators and systems according to matching points from SBL of fractional order systems in desired frequency ranges. Thus, the proposed method can effectively deal with stability preservation problems of approximate models. Illustrative examples are given to show performance of the proposed method and results are compared with the well-known approximation methods developed for fractional order systems. The integer-order approximate modeling of fractional order PID controllers is also illustrated for control applications.

  14. Application of indicators derived by remote sensing for mapping of landslide hazard and vulnerability

    NASA Astrophysics Data System (ADS)

    Eidsvig, Unni; Vidar Vangelsten, Bjørn; Geiss, Christian; Klotz, Martin; Ekseth, Kristine; Taubenböck, Hannes

    2014-05-01

    The choice and the development of methods for risk assessment of landslides depends on several factors. Important factors are the type of landslide and the elements at risk, the choice of spatial and temporal scale, the purpose of the analysis and the needs of the end-users. In addition, data availability is a major constraint, which greatly affects the type of methods and models that can be developed. Remote sensing is a promising tool for an economical and up-to-date data collection, which also could be applied to monitor the dynamic development of risk. The spatial and temporal distribution of the risk for landslides can be assessed by monitoring hazard indicators (e.g. slope height and slope angle), exposure indicators (e.g. number of houses and the total population) and vulnerability indicators (e.g. population density, settlement structures or indicators related to structural vulnerability). Several of the indicators applicable for landslide risk and vulnerability can be obtained by remote sensing techniques. However, for better results, indicators from remote sensing should be combined with other type of data. In this work, a review on the application of indicators for landslide risk assessment in explicit models as well as an assessment of end user needs was conducted in order to determine the most relevant indicators for landslide hazard and vulnerability. Lists of recommended indicators, mainly derivable from remote sensing, have been developed. These indicators are supposed to be used in risk assessment, e.g. by combining hazard, vulnerability and exposure indicators to produce risk indices. Moreover schemes for ranking, weighting and aggregation of the indicators into hazard- and vulnerability indices are provided. The research leading to these results has received funding from the European Community's Seventh Framework Programme [FP7-SPACE-2012-1] under Grant agreement No 312972 Framework to integrate Space-based and in-situ sENSing for dynamic v

  15. A comparative study of four change detection methods for aerial photography applications

    NASA Astrophysics Data System (ADS)

    Abramovich, Gil; Brooksby, Glen; Bush, Stephen F.; Manickam, Swaminathan; Ozcanli, Ozge; Garrett, Benjamin D.

    2010-04-01

    We present four new change detection methods that create an automated change map from a probability map. In this case, the probability map was derived from a 3D model. The primary application of interest is aerial photographic applications, where the appearance, disappearance or change in position of small objects of a selectable class (e.g., cars) must be detected at a high success rate in spite of variations in magnification, lighting and background across the image. The methods rely on an earlier derivation of a probability map. We describe the theory of the four methods, namely Bernoulli variables, Markov Random Fields, connected change, and relaxation-based segmentation, evaluate and compare their performance experimentally on a set probability maps derived from aerial photographs.

  16. Analysis of the methods for the derivation of binary kinetic equations in the theory of fluorescence concentration quenching

    SciTech Connect

    Doktorov, A. B.

    2014-09-14

    In the framework of unified many-particle approach the familiar problem of fluorescence concentration quenching in the presence of pumping (light pulse) of arbitrary intensity is considered. This process is a vivid and the simplest example of multistage bulk reaction including bimolecular irreversible quenching reaction and reversible monomolecular transformation as elementary stages. General relation between the kinetics of multistage bulk reaction and that of the elementary stage of quenching has been established. This allows one to derive general kinetic equations (of two types) for the multistage reaction in question on the basis of general kinetic equations (differential and integro-differential) of elementary stage of quenching. Relying on the same unified many-particle approach we have developed binary approximations with the use of two (frequently employed in the literature) many-particle methods (such as simple superposition approximation and the method of extracting pair channels in three-particle correlation evolution) to the derivation of non-Markovian binary kinetic equations. The possibility of reducing the obtained binary equations to the Markovian equations of formal chemical kinetics has been considered. As an example the exact solution of the problem (for the specific case) is examined, and the applicability of two many particle methods of derivation of binary equations is analyzed.

  17. Analysis of the methods for the derivation of binary kinetic equations in the theory of fluorescence concentration quenching.

    PubMed

    Doktorov, A B

    2014-09-14

    In the framework of unified many-particle approach the familiar problem of fluorescence concentration quenching in the presence of pumping (light pulse) of arbitrary intensity is considered. This process is a vivid and the simplest example of multistage bulk reaction including bimolecular irreversible quenching reaction and reversible monomolecular transformation as elementary stages. General relation between the kinetics of multistage bulk reaction and that of the elementary stage of quenching has been established. This allows one to derive general kinetic equations (of two types) for the multistage reaction in question on the basis of general kinetic equations (differential and integro-differential) of elementary stage of quenching. Relying on the same unified many-particle approach we have developed binary approximations with the use of two (frequently employed in the literature) many-particle methods (such as simple superposition approximation and the method of extracting pair channels in three-particle correlation evolution) to the derivation of non-Markovian binary kinetic equations. The possibility of reducing the obtained binary equations to the Markovian equations of formal chemical kinetics has been considered. As an example the exact solution of the problem (for the specific case) is examined, and the applicability of two many particle methods of derivation of binary equations is analyzed.

  18. Calculation Methods and Conversions for Pesticide Application.

    ERIC Educational Resources Information Center

    Cole, Herbert, Jr.

    This agriculture extension service publication from Pennsylvania State University consists of conversion tables and formulas for determining concentration and rate of application of pesticides. Contents include: (1) Area and volume conversions; (2) Important conversion formulae; (3) Conversions for rates of application; (4) Quantities of pesticide…

  19. 40 CFR 18.6 - Method of Application.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... RESEARCH FELLOWSHIPS AND SPECIAL RESEARCH CONSULTANTS FOR ENVIRONMENTAL PROTECTION § 18.6 Method of Application. Application for an Environmental Protection Research fellowship shall be made in accordance with... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Method of Application. 18.6 Section...

  20. 42 CFR 61.6 - Method of application.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Method of application. 61.6 Section 61.6 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.6 Method of application. Application for a regular fellowship shall...

  1. 42 CFR 61.35 - Method of application.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Method of application. 61.35 Section 61.35 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Service Fellowships § 61.35 Method of application. Application for a service fellowship shall...

  2. 42 CFR 61.6 - Method of application.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Method of application. 61.6 Section 61.6 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.6 Method of application. Application for a regular fellowship shall...

  3. 42 CFR 61.35 - Method of application.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Method of application. 61.35 Section 61.35 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Service Fellowships § 61.35 Method of application. Application for a service fellowship shall...

  4. 42 CFR 61.35 - Method of application.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Method of application. 61.35 Section 61.35 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Service Fellowships § 61.35 Method of application. Application for a service fellowship shall...

  5. 42 CFR 61.35 - Method of application.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Method of application. 61.35 Section 61.35 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Service Fellowships § 61.35 Method of application. Application for a service fellowship shall...

  6. 42 CFR 61.35 - Method of application.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Method of application. 61.35 Section 61.35 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Service Fellowships § 61.35 Method of application. Application for a service fellowship shall...

  7. 42 CFR 61.6 - Method of application.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Method of application. 61.6 Section 61.6 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.6 Method of application. Application for a regular fellowship shall...

  8. 42 CFR 61.6 - Method of application.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Method of application. 61.6 Section 61.6 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.6 Method of application. Application for a regular fellowship shall...

  9. 42 CFR 61.6 - Method of application.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Method of application. 61.6 Section 61.6 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.6 Method of application. Application for a regular fellowship shall...

  10. An efficient method for systems of variable coefficient coupled Burgers' equation with time-fractional derivative.

    PubMed

    Aminikhah, Hossein; Malekzadeh, Nasrin

    2013-01-01

    A new homotopy perturbation method (NHPM) is applied to system of variable coefficient coupled Burgers' equation with time-fractional derivative. The fractional derivatives are described in the Caputo fractional derivative sense. The concept of new algorithm is introduced briefly, and NHPM is examined for two systems of nonlinear Burgers' equation. In this approach, the solution is considered as a power series expansion that converges rapidly to the nonlinear problem. The new approximate analytical procedure depends on two iteratives. The modified algorithm provides approximate solutions in the form of convergent series with easily computable components. Results indicate that the introduced method is promising for solving other types of systems of nonlinear fractional-order partial differential equations.

  11. Nanobody-derived nanobiotechnology tool kits for diverse biomedical and biotechnology applications.

    PubMed

    Wang, Yongzhong; Fan, Zhen; Shao, Lei; Kong, Xiaowei; Hou, Xianjuan; Tian, Dongrui; Sun, Ying; Xiao, Yazhong; Yu, Li

    2016-01-01

    Owing to peculiar properties of nanobody, including nanoscale size, robust structure, stable and soluble behaviors in aqueous solution, reversible refolding, high affinity and specificity for only one cognate target, superior cryptic cleft accessibility, and deep tissue penetration, as well as a sustainable source, it has been an ideal research tool for the development of sophisticated nanobiotechnologies. Currently, the nanobody has been evolved into versatile research and application tool kits for diverse biomedical and biotechnology applications. Various nanobody-derived formats, including the nanobody itself, the radionuclide or fluorescent-labeled nanobodies, nanobody homo- or heteromultimers, nanobody-coated nanoparticles, and nanobody-displayed bacteriophages, have been successfully demonstrated as powerful nanobiotechnological tool kits for basic biomedical research, targeting drug delivery and therapy, disease diagnosis, bioimaging, and agricultural and plant protection. These applications indicate a special advantage of these nanobody-derived technologies, already surpassing the "me-too" products of other equivalent binders, such as the full-length antibodies, single-chain variable fragments, antigen-binding fragments, targeting peptides, and DNA-based aptamers. In this review, we summarize the current state of the art in nanobody research, focusing on the nanobody structural features, nanobody production approach, nanobody-derived nanobiotechnology tool kits, and the potentially diverse applications in biomedicine and biotechnology. The future trends, challenges, and limitations of the nanobody-derived nanobiotechnology tool kits are also discussed.

  12. Nanobody-derived nanobiotechnology tool kits for diverse biomedical and biotechnology applications

    PubMed Central

    Wang, Yongzhong; Fan, Zhen; Shao, Lei; Kong, Xiaowei; Hou, Xianjuan; Tian, Dongrui; Sun, Ying; Xiao, Yazhong; Yu, Li

    2016-01-01

    Owing to peculiar properties of nanobody, including nanoscale size, robust structure, stable and soluble behaviors in aqueous solution, reversible refolding, high affinity and specificity for only one cognate target, superior cryptic cleft accessibility, and deep tissue penetration, as well as a sustainable source, it has been an ideal research tool for the development of sophisticated nanobiotechnologies. Currently, the nanobody has been evolved into versatile research and application tool kits for diverse biomedical and biotechnology applications. Various nanobody-derived formats, including the nanobody itself, the radionuclide or fluorescent-labeled nanobodies, nanobody homo- or heteromultimers, nanobody-coated nanoparticles, and nanobody-displayed bacteriophages, have been successfully demonstrated as powerful nanobiotechnological tool kits for basic biomedical research, targeting drug delivery and therapy, disease diagnosis, bioimaging, and agricultural and plant protection. These applications indicate a special advantage of these nanobody-derived technologies, already surpassing the “me-too” products of other equivalent binders, such as the full-length antibodies, single-chain variable fragments, antigen-binding fragments, targeting peptides, and DNA-based aptamers. In this review, we summarize the current state of the art in nanobody research, focusing on the nanobody structural features, nanobody production approach, nanobody-derived nanobiotechnology tool kits, and the potentially diverse applications in biomedicine and biotechnology. The future trends, challenges, and limitations of the nanobody-derived nanobiotechnology tool kits are also discussed. PMID:27499623

  13. An Application of Trimethylsilyl Derivatives with Temperature Programmed Gas Chromatography to the Senior Analytical Laboratory.

    ERIC Educational Resources Information Center

    Kelter, Paul B.; Carr, James D.

    1983-01-01

    Describes an experiment designed to teach temperature programed gas chromatography (TPGC) techniques and importance of derivatizing many classes of substrated to be separated. Includes equipment needed, procedures for making trimethylsilyl derivatives, applications, sample calculations, and typical results. Procedure required one, three-hour…

  14. 40 CFR 454.60 - Applicability; description of manufacture of rosin-based derivatives subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Applicability; description of manufacture of rosin-based derivatives subcategory. 454.60 Section 454.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GUM AND WOOD...

  15. 40 CFR 454.60 - Applicability; description of manufacture of rosin-based derivatives subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 31 2012-07-01 2012-07-01 false Applicability; description of manufacture of rosin-based derivatives subcategory. 454.60 Section 454.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GUM AND WOOD...

  16. 40 CFR 454.60 - Applicability; description of manufacture of rosin-based derivatives subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Applicability; description of manufacture of rosin-based derivatives subcategory. 454.60 Section 454.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GUM AND WOOD...

  17. 40 CFR 454.60 - Applicability; description of manufacture of rosin-based derivatives subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Applicability; description of manufacture of rosin-based derivatives subcategory. 454.60 Section 454.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GUM AND WOOD...

  18. 40 CFR 454.60 - Applicability; description of manufacture of rosin-based derivatives subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of manufacture of rosin-based derivatives subcategory. 454.60 Section 454.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GUM AND WOOD...

  19. A unified convergence theory of a numerical method, and applications to the replenishment policies.

    PubMed

    Mi, Xiang-jiang; Wang, Xing-hua

    2004-01-01

    In determining the replenishment policy for an inventory system, some researchers advocated that the iterative method of Newton could be applied to the derivative of the total cost function in order to get the optimal solution. But this approach requires calculation of the second derivative of the function. Avoiding this complex computation we use another iterative method presented by the second author. One of the goals of this paper is to present a unified convergence theory of this method. Then we give a numerical example to show the application of our theory.

  20. Advances in Microalgae-Derived Phytosterols for Functional Food and Pharmaceutical Applications

    PubMed Central

    Luo, Xuan; Su, Peng; Zhang, Wei

    2015-01-01

    Microalgae contain a variety of bioactive lipids with potential applications in aquaculture feed, biofuel, food and pharmaceutical industries. While microalgae-derived polyunsaturated fatty acid (PUFA) and their roles in promoting human health have been extensively studied, other lipid types from this resource, such as phytosterols, have been poorly explored. Phytosterols have been used as additives in many food products such as spread, dairy products and salad dressing. This review focuses on the recent advances in microalgae-derived phytosterols with functional bioactivities and their potential applications in functional food and pharmaceutical industries. It highlights the importance of microalgae-derived lipids other than PUFA for the development of an advanced microalgae industry. PMID:26184233

  1. Application of throughfall methods to estimate dry deposition of mercury

    SciTech Connect

    Lindberg, S.E.; Owens, J.G.; Stratton, W.

    1992-12-31

    Several dry deposition methods for Mercury (Hg) are being developed and tested in our laboratory. These include big-leaf and multilayer resistance models, micrometeorological methods such as Bowen ratio gradient approaches, laboratory controlled plant chambers, and throughfall. We have previously described our initial results using modeling and gradient methods. Throughfall may be used to estimate Hg dry deposition if some simplifying assumptions are met. We describe here the application and initial results of throughfull studies at the Walker Branch Watershed forest, and discuss the influence of certain assumptions on interpretation of the data. Throughfall appears useful in that it can place a lower bound to dry deposition under field conditions. Our preliminary throughfall data indicate net dry deposition rates to a pine canopy which increase significantly from winter to summer, as previously predicted by our resistance model. Atmospheric data suggest that rainfall washoff of fine aerosol dry deposition at this site is not sufficient to account for all of the Hg in net throughfall. Potential additional sources include dry deposited gas-phase compounds, soil-derived coarse aerosols, and oxidation reactions at the leaf surface.

  2. Validated derivative and ratio derivative spectrophotometric methods for the simultaneous determination of levocetirizine dihydrochloride and ambroxol hydrochloride in pharmaceutical dosage form

    NASA Astrophysics Data System (ADS)

    Ali, Omnia I. M.; Ismail, Nahla S.; Elgohary, Rasha M.

    2016-01-01

    Three simple, precise, accurate and validated derivative spectrophotometric methods have been developed for the simultaneous determination of levocetirizine dihydrochloride (LCD) and ambroxol hydrochloride (ABH) in bulk powder and in pharmaceutical formulations. The first method is a first derivative spectrophotometric method (1D) using a zero-crossing technique of measurement at 210.4 nm for LCD and at 220.0 nm for ABH. The second method employs a second derivative spectrophotometry (2D) where the measurements were carried out at 242.0 and 224.4 nm for LCD and ABH, respectively. In the third method, the first derivative of the ratio spectra was calculated and the first derivative of the ratio amplitudes at 222.8 and 247.2 nm was selected for the determination of LCD and ABH, respectively. Calibration graphs were established in the ranges of 1.0-20.0 μg mL- 1 for LCD and 4.0-20.0 μg mL- 1 for ABH using derivative and ratio first derivative spectrophotometric methods with good correlation coefficients. The developed methods have been successfully applied to the simultaneous determination of both drugs in commercial tablet dosage form.

  3. Validated derivative and ratio derivative spectrophotometric methods for the simultaneous determination of levocetirizine dihydrochloride and ambroxol hydrochloride in pharmaceutical dosage form.

    PubMed

    Ali, Omnia I M; Ismail, Nahla S; Elgohary, Rasha M

    2016-01-15

    Three simple, precise, accurate and validated derivative spectrophotometric methods have been developed for the simultaneous determination of levocetirizine dihydrochloride (LCD) and ambroxol hydrochloride (ABH) in bulk powder and in pharmaceutical formulations. The first method is a first derivative spectrophotometric method ((1)D) using a zero-crossing technique of measurement at 210.4 nm for LCD and at 220.0 nm for ABH. The second method employs a second derivative spectrophotometry ((2)D) where the measurements were carried out at 242.0 and 224.4 nm for LCD and ABH, respectively. In the third method, the first derivative of the ratio spectra was calculated and the first derivative of the ratio amplitudes at 222.8 and 247.2 nm was selected for the determination of LCD and ABH, respectively. Calibration graphs were established in the ranges of 1.0-20.0 μg mL(-1) for LCD and 4.0-20.0 μg mL(-1) for ABH using derivative and ratio first derivative spectrophotometric methods with good correlation coefficients. The developed methods have been successfully applied to the simultaneous determination of both drugs in commercial tablet dosage form.

  4. 12 CFR Appendix A to Subpart A of... - Method to Derive Pricing Multipliers and Uniform Amount

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Uniform Amount A Appendix A to Subpart A of Part 327 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION REGULATIONS AND STATEMENTS OF GENERAL POLICY ASSESSMENTS In General Pt. 327, Subpt. A, App. A Appendix A to Subpart A of Part 327—Method to Derive Pricing Multipliers and Uniform Amount I....

  5. 12 CFR Appendix A to Subpart A of... - Method to Derive Pricing Multipliers and Uniform Amount

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Uniform Amount A Appendix A to Subpart A of Part 327 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION REGULATIONS AND STATEMENTS OF GENERAL POLICY ASSESSMENTS In General Pt. 327, Subpt. A, App. A Appendix A to Subpart A of Part 327—Method to Derive Pricing Multipliers and Uniform Amount I....

  6. 12 CFR Appendix A to Subpart A of... - Method to Derive Pricing Multipliers and Uniform Amount

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Uniform Amount A Appendix A to Subpart A of Part 327 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION REGULATIONS AND STATEMENTS OF GENERAL POLICY ASSESSMENTS In General Pt. 327, Subpt. A, App. A Appendix A to Subpart A of Part 327—Method to Derive Pricing Multipliers and Uniform Amount I....

  7. Monoterpene-based chiral β-amino acid derivatives prepared from natural sources: syntheses and applications.

    PubMed

    Szakonyi, Zsolt; Fülöp, Ferenc

    2011-08-01

    Natural monoterpenes have proved to be good starting materials for the synthesis of β-amino acid derivatives. In the past decade, a number of well-known synthetic procedures have been applied for the preparation of monoterpene-based β-amino acid derivatives, e.g. from β-lactams via the 1,2-dipolar cycloaddition of chlorosulfonyl isocyanate to commercial or readily available monoterpenes [e.g. (+)- and (-)-α- or δ-pinene, (+)-3- and 2-carene, (+)- and (-)-apopinene], the conjugate addition of amides to monoterpene-based α,β-unsaturated esters or the transformations of (-)-cis-pinonoic acid prepared by the oxidative cleavage of (+)- and (-)-verbenone. β-Amino acid derivatives are excellent building blocks for versatile transformations, e.g. multicomponent reactions resulting in β-lactams, syntheses of 1,3-heterocycles and diaminopyrimidine derivatives or the formation of peptides containing an H12 helix. 1,3-Amino alcohol derivatives prepared from β-amino esters have been applied as chiral catalysts in enantioselective transformations. Several of these compounds are of noteworthy pharmacological importance, such as tyrosine kinase Axl inhibitor diaminopyrimidine-coupled β-aminocarboxamides, MDR inhibitor thiourea derivatives of β-amino esters or 2-imino-1,3-oxazines, which exhibit marked growth inhibitory activity on multiple cancer cell lines. The present review summarizes recent developments relating to the syntheses, applications and pharmaceutical importance of monoterpene-based β-amino acids and their derivatives.

  8. Physiochemical, optical and biological activity of chitosan-chromone derivative for biomedical applications.

    PubMed

    Kumar, Santosh; Koh, Joonseok

    2012-01-01

    This paper describes the physiochemical, optical and biological activity of chitosan-chromone derivative. The chitosan-chromone derivative gels were prepared by reacting chitosan with chromone-3-carbaldehyde, followed by solvent exchange, filtration and drying by evaporation. The identity of Schiff base was confirmed by UV-Vis absorption spectroscopy and Fourier-transform infrared (FTIR) spectroscopy. The chitosan-chromone derivative was evaluated by X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), photoluminescence (PL) and circular dichroism (CD). The CD spectrum showed the chitosan-chromone derivative had a secondary helical structure. Microbiological screening results demonstrated the chitosan-chromone derivative had antimicrobial activity against Escherichia coli bacteria. The chitosan-chromone derivative did not have any adverse effect on the cellular proliferation of mouse embryonic fibroblasts (MEF) and did not lead to cellular toxicity in MEFs. These results suggest that the chitosan-chromone derivative gels may open a new perspective in biomedical applications.

  9. 40 CFR 18.6 - Method of Application.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ....6 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL ENVIRONMENTAL PROTECTION RESEARCH FELLOWSHIPS AND SPECIAL RESEARCH CONSULTANTS FOR ENVIRONMENTAL PROTECTION § 18.6 Method of Application. Application for an Environmental Protection Research fellowship shall be made in accordance...

  10. 40 CFR 18.6 - Method of Application.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ....6 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL ENVIRONMENTAL PROTECTION RESEARCH FELLOWSHIPS AND SPECIAL RESEARCH CONSULTANTS FOR ENVIRONMENTAL PROTECTION § 18.6 Method of Application. Application for an Environmental Protection Research fellowship shall be made in accordance...

  11. 40 CFR 18.6 - Method of Application.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ....6 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL ENVIRONMENTAL PROTECTION RESEARCH FELLOWSHIPS AND SPECIAL RESEARCH CONSULTANTS FOR ENVIRONMENTAL PROTECTION § 18.6 Method of Application. Application for an Environmental Protection Research fellowship shall be made in accordance...

  12. 40 CFR 18.6 - Method of Application.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ....6 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL ENVIRONMENTAL PROTECTION RESEARCH FELLOWSHIPS AND SPECIAL RESEARCH CONSULTANTS FOR ENVIRONMENTAL PROTECTION § 18.6 Method of Application. Application for an Environmental Protection Research fellowship shall be made in accordance...

  13. Fourth-order derivative spectrophotometric method for simultaneous determination of pseudoephedrine and naproxen in pharmaceutical dosage forms

    PubMed Central

    Souri, Effat; Mosafer, Amir; Tehrani, Maliheh Barazandeh

    2016-01-01

    Combination dosage forms of naproxen sodium and pseudoephedrine hydrochloride are used for symptomatic treatment of cold and sinus disorders. In this study, fourth-order derivative spectrophotometric method was used for simultaneous determination of naproxen sodium and pseudoephedrine hydrochloride. The method was linear over the range of 2-28 μg/ml for pseudoephedrine hydrochloride and 4-200 μg/ml for naproxen sodium. The within-day and between-day coefficient of variation values were less than 5.8% and 2.5% for pseudoephedrine hydrochloride and naproxen sodium, respectively. The application of the proposed method for simultaneous determination of naproxen and pseudoephedrine in dosage forms was demonstrated without any special pretreatment. PMID:27168748

  14. Fourth-order derivative spectrophotometric method for simultaneous determination of pseudoephedrine and naproxen in pharmaceutical dosage forms.

    PubMed

    Souri, Effat; Mosafer, Amir; Tehrani, Maliheh Barazandeh

    2016-01-01

    Combination dosage forms of naproxen sodium and pseudoephedrine hydrochloride are used for symptomatic treatment of cold and sinus disorders. In this study, fourth-order derivative spectrophotometric method was used for simultaneous determination of naproxen sodium and pseudoephedrine hydrochloride. The method was linear over the range of 2-28 μg/ml for pseudoephedrine hydrochloride and 4-200 μg/ml for naproxen sodium. The within-day and between-day coefficient of variation values were less than 5.8% and 2.5% for pseudoephedrine hydrochloride and naproxen sodium, respectively. The application of the proposed method for simultaneous determination of naproxen and pseudoephedrine in dosage forms was demonstrated without any special pretreatment.

  15. Follow-up: Prospective compound design using the 'SAR Matrix' method and matrix-derived conditional probabilities of activity.

    PubMed

    Gupta-Ostermann, Disha; Hirose, Yoichiro; Odagami, Takenao; Kouji, Hiroyuki; Bajorath, Jürgen

    2015-01-01

    In a previous Method Article, we have presented the 'Structure-Activity Relationship (SAR) Matrix' (SARM) approach. The SARM methodology is designed to systematically extract structurally related compound series from screening or chemical optimization data and organize these series and associated SAR information in matrices reminiscent of R-group tables. SARM calculations also yield many virtual candidate compounds that form a "chemical space envelope" around related series. To further extend the SARM approach, different methods are developed to predict the activity of virtual compounds. In this follow-up contribution, we describe an activity prediction method that derives conditional probabilities of activity from SARMs and report representative results of first prospective applications of this approach.

  16. Biomedical Application of Dental Tissue-Derived Induced Pluripotent Stem Cells.

    PubMed

    Lee, Jung-Hwan; Seo, Seog-Jin

    2016-01-01

    The academic researches and clinical applications in recent years found interest in induced pluripotent stem cells (iPSCs-) based regenerative medicine due to their pluripotency able to differentiate into any cell types in the body without using embryo. However, it is limited in generating iPSCs from adult somatic cells and use of these cells due to the low stem cell potency and donor site morbidity. In biomedical applications, particularly, dental tissue-derived iPSCs have been getting attention as a type of alternative sources for regenerating damaged tissues due to high potential of stem cell characteristics, easy accessibility and attainment, and their ectomesenchymal origin, which allow them to have potential for nerve, vessel, and dental tissue regeneration. This paper will cover the overview of dental tissue-derived iPSCs and their application with their advantages and drawbacks.

  17. Biomedical Application of Dental Tissue-Derived Induced Pluripotent Stem Cells

    PubMed Central

    Lee, Jung-Hwan; Seo, Seog-Jin

    2016-01-01

    The academic researches and clinical applications in recent years found interest in induced pluripotent stem cells (iPSCs-) based regenerative medicine due to their pluripotency able to differentiate into any cell types in the body without using embryo. However, it is limited in generating iPSCs from adult somatic cells and use of these cells due to the low stem cell potency and donor site morbidity. In biomedical applications, particularly, dental tissue-derived iPSCs have been getting attention as a type of alternative sources for regenerating damaged tissues due to high potential of stem cell characteristics, easy accessibility and attainment, and their ectomesenchymal origin, which allow them to have potential for nerve, vessel, and dental tissue regeneration. This paper will cover the overview of dental tissue-derived iPSCs and their application with their advantages and drawbacks. PMID:26989423

  18. Ejection time by ear densitogram and its derivative - Clinical and physiologic applications.

    NASA Technical Reports Server (NTRS)

    Quarry-Pigott, V.; Chirife, R.; Spodick, D. H.

    1973-01-01

    Ear densitographic ejection times (EDET) and first derivative ear densitogram ejection times (dEDET) were studied to determine whether their reliability and validity justify their substitution for ejection times derived from the far less stable carotid pulse tracing. Inter- and intra-subject comparisons were made on thirty individuals under a wide variety of disease and challenge states. Statistical analysis of the data - which had been obtained through a blinded procedure - showed an overall correlation (r) of .98 for carotid vs EDET and .99 for carotid vs dEDET. The t-test demonstrated no significant differences among ejection times derived from the three methods. Moreover, the close tracking at rest and during challenges of ejection times derived from these curves with those from the carotid indicate that either method may be substituted for standard carotid curves without sacrificing reliability or validity of the measure.

  19. Fuzzy Set Methods for Object Recognition in Space Applications

    NASA Technical Reports Server (NTRS)

    Keller, James M. (Editor)

    1992-01-01

    Progress on the following four tasks is described: (1) fuzzy set based decision methodologies; (2) membership calculation; (3) clustering methods (including derivation of pose estimation parameters), and (4) acquisition of images and testing of algorithms.

  20. Low oxygen biomass-derived pyrolysis oils and methods for producing the same

    DOEpatents

    Marinangeli, Richard; Brandvold, Timothy A; Kocal, Joseph A

    2013-08-27

    Low oxygen biomass-derived pyrolysis oils and methods for producing them from carbonaceous biomass feedstock are provided. The carbonaceous biomass feedstock is pyrolyzed in the presence of a catalyst comprising base metal-based catalysts, noble metal-based catalysts, treated zeolitic catalysts, or combinations thereof to produce pyrolysis gases. During pyrolysis, the catalyst catalyzes a deoxygenation reaction whereby at least a portion of the oxygenated hydrocarbons in the pyrolysis gases are converted into hydrocarbons. The oxygen is removed as carbon oxides and water. A condensable portion (the vapors) of the pyrolysis gases is condensed to low oxygen biomass-derived pyrolysis oil.

  1. Application of chromatography technology in the separation of active components from nature derived drugs.

    PubMed

    Zhao, H-Y; Jiang, J-G

    2010-11-01

    Chromatography technology has been widely applied in various aspects of the pharmacy research on traditional Chinese medicine (TCM). This paper reviews literatures, published in the past decades, on the separation of active component from TCM using chromatography technology. Ultra-performance liquid chromatography (UPLC), high-speed counter-current chromatography (HSCCC), rapid resolution liquid chromatography (RRLC), supercritical fluid chromatography (SFC), affinity chromatography (AC), and bio-chromatography (BC) are introduced in detail. Compared to high performance of high-performance liquid chromatography (HPLC), analysis time and solvent loss are significantly reduced by UPLC with increase in resolution and sensitivity. Some ingredients from nature derived drugs can be separated more completely by HSCCC, which has remarkable characteristics such as low cost, simple operation and no pollution. Trace components from complex systems can be selectively and efficiently separated and purified by AC, This feature makes it effective in isolation and identification of active components of Chinese herbs. Interference of some impurities could be excluded by BC. Active ingredients that are difficult to be separated by normal method can be acquired by SFC. Currently, application of novel chromatography techniques in TCM is still in the exploratory stage and many problems, such as preparation of stationary phase and detection, need to be solved.

  2. Monosodium glutamate derived tricolor fluorescent carbon nanoparticles for cell-imaging application.

    PubMed

    Zheng, Nannan; Ding, Sha; Zhou, Xingping

    2016-06-01

    Fluorescent carbon nanoparticle (FCN) is a new type of carbon-based materials. Because of its wide raw material sources, excellent optical properties and good biocompatibility, FCN is getting more and more attentions. However, its synthesis from resources at low cost under mild conditions is still a challenge. Here we report a novel and simple method derived from monosodium glutamate carbonization to make tricolor fluorescent carbon nanoparticles with an average size below 10nm, a high yield up to 35.2% based on the carbon content in the resource, a long life-time of 3.71ns, and a high fluorescence quantum yield up to 51.5% by using quinine sulfate as the standard substance. We discovered that the fluorescent stability of the FCNs was very excellent under UV irradiation for hours in aqueous solutions of pH ranged from 2.0 to 9.0. The cell viability tested under a pretty high concentration of FCNs indicated their safety for biological applications. Based on their high fluorescence quantum efficiency and the advantages mentioned above, these FCNs were then used for cell imaging and exhibited a perfect performance under 3 kinds of excitation bands (UV, blue, and green lights). Thus, they can be practically applied to immune labeling and imaging in vivo in the near future.

  3. A Fast Method of Deriving the Kirchhoff Formula for Moving Surfaces

    NASA Technical Reports Server (NTRS)

    Farassat, F.; Posey, Joe W.

    2007-01-01

    The Kirchhoff formula for a moving surface is very useful in many wave propagation problems, particularly in the prediction of noise from rotating machinery. Several publications in the last two decades have presented derivations of the Kirchhoff formula for moving surfaces in both time and frequency domains. Here we present a method originally developed by Farassat and Myers in time domain that is both simple and direct. It is based on generalized function theory and the useful concept of imbedding the problem in the unbounded three-dimensional space. We derive an inhomogeneous wave equation with the source terms that involve Dirac delta functions with their supports on the moving data surface. This wave equation is then solved using the simple free space Green's function of the wave equation resulting in the Kirchhoff formula. The algebraic manipulations are minimal and simple. We do not need the Green's theorem in four dimensions and there is no ambiguity in the interpretation of any terms in the final formulas. Furthermore, this method also gives the simplest derivation of the classical Kirchhoff formula which has a fairly lengthy derivation in physics and applied mathematics books. The Farassat-Myers method can be used easily in frequency domain.

  4. Influence of DNA extraction methods, PCR inhibitors and quantification methods on real-time PCR assay of biotechnology-derived traits.

    PubMed

    Demeke, Tigst; Jenkins, G Ronald

    2010-03-01

    Biotechnology-derived varieties of canola, cotton, corn and soybean are being grown in the USA, Canada and other predominantly grain exporting countries. Although the amount of farmland devoted to production of biotechnology-derived crops continues to increase, lingering concerns that unintended consequences may occur provide the EU and most grain-importing countries with justification to regulate these crops. Legislation in the EU requires traceability of grains/oilseeds, food and feed products, and labelling, when a threshold level of 0.9% w/w of genetically engineered trait is demonstrated to be present in an analytical sample. The GE content is routinely determined by quantitative PCR (qPCR) and plant genomic DNA provides the template for the initial steps in this process. A plethora of DNA extraction methods exist for qPCR applications. Implementing standardized methods for detection of genetically engineered traits is necessary to facilitate grain marketing. The International Organization for Standardization draft standard 21571 identifies detergent-based methods and commercially available kits that are widely used for DNA extraction, but also indicates that adaptations may be necessary depending upon the sample matrix. This review assesses advantages and disadvantages of various commercially available DNA extraction kits, as well as modifications to published cetyltrimethylammonium bromide methods. Inhibitors are a major obstacle for efficient amplification in qPCR. The types of PCR inhibitors and techniques to minimize inhibition are discussed. Finally, accurate quantification of DNA for applications in qPCR is not trivial. Many confounders contribute to differences in analytical measurements when a particular DNA quantification method is applied and different methods do not always provide concordant results on the same DNA sample. How these differences impact measurement uncertainty in qPCR is considered.

  5. Derivation of many-body potential among charged particles in the S-matrix method

    NASA Astrophysics Data System (ADS)

    Ohta, Tadayuki; Kimura, Toshiei

    1992-06-01

    A general method of deriving a classical potential from the S-matrix element of particle scattering in the theory of quantized fields is applied to electrodynamics to the post-post-Coulombian approximation. To obtain the many-body potential, a consistent prescription is implemented in subtracting the contributions of the repetition of lower-order potential from the S-matrix elements of the higher-order diagrams. The result shows that the four-body potential between charged particles has a characteristic feature at a large distance and the two-body potential is identical with that given in the reduced Hamiltonian of Wheeler-Feynman electrodynamics. The advantage of the S-matrix method over the canonical formalism is to give the potential directly, without complicated treatment of the interaction with higher derivatives by a method of constrained dynamics.

  6. A Method for Sectioning and Immunohistochemical Analysis of Stem Cell-Derived 3-D Organoids.

    PubMed

    Wiley, Luke A; Beebe, David C; Mullins, Robert F; Stone, Edwin M; Tucker, Budd A

    2016-05-12

    This unit describes a protocol for embedding, sectioning, and immunocytochemical analysis of pluripotent stem cell-derived 3-D organoids. Specifically, we describe a method to embed iPSC-derived retinal cups in low-melt agarose, acquire thick sections using a vibratome tissue slicer, and perform immunohistochemical analysis. This method includes an approach for antibody labeling that minimizes the amount of antibody needed for individual experiments and that utilizes large-volume washing to increase the signal-to-noise ratio, allowing for clean, high-resolution imaging of developing cell types. The universal methods described can be employed regardless of the type of pluripotent stem cell used and 3-D organoid generated. © 2016 by John Wiley & Sons, Inc.

  7. Wide-field TCSPC: methods and applications

    NASA Astrophysics Data System (ADS)

    Hirvonen, Liisa M.; Suhling, Klaus

    2017-01-01

    Time-correlated single photon counting (TCSPC) is a widely used, robust and mature technique to measure the photon arrival time in applications such as fluorescence spectroscopy and microscopy, LIDAR and optical tomography. In the past few years there have been significant developments with wide-field TCSPC detectors, which can record the position as well as the arrival time of the photon simultaneously. In this review, we summarise different approaches used in wide-field TCSPC detection, and discuss their merits for different applications, with emphasis on fluorescence lifetime imaging.

  8. [Application of Delphi method in traditional Chinese medicine clinical research].

    PubMed

    Bi, Ying-fei; Mao, Jing-yuan

    2012-03-01

    In recent years, Delphi method has been widely applied in traditional Chinese medicine (TCM) clinical research. This article analyzed the present application situation of Delphi method in TCM clinical research, and discussed some problems presented in the choice of evaluation method, classification of observation indexes and selection of survey items. On the basis of present application of Delphi method, the author analyzed the method on questionnaire making, selection of experts, evaluation of observation indexes and selection of survey items. Furthermore, the author summarized the steps of application of Delphi method in TCM clinical research.

  9. Methods for human embryonic stem cells derived cardiomyocytes cultivation, genetic manipulation, and transplantation.

    PubMed

    Arbel, Gil; Caspi, Oren; Huber, Irit; Gepstein, Amira; Weiler-Sagie, Michal; Gepstein, Lior

    2010-01-01

    A decade has passed since the initial derivation of human embryonic stem cells (hESC). The ensuing years have witnessed a significant progress in the development of methodologies allowing cell cultivation, differentiation, genetic manipulation, and in vivo transplantation. Specifically, the potential to derive human cardiomyocytes from the hESC lines, which can be used for several basic and applied cardiovascular research areas including in the emerging field of cardiac regenerative medicine, attracted significant attention from the scientific community. This resulted in the development of protocols for the cultivation of hESC and their successful differentiation toward the cardiomyocyte lineage fate. In this chapter, we will describe in detail methods related to the cultivation, genetic manipulation, selection, and in vivo transplantation of hESC-derived cardiomyocytes.

  10. A simple method to derive bounds on the size and to train multilayer neural networks

    NASA Technical Reports Server (NTRS)

    Sartori, Michael A.; Antsaklis, Panos J.

    1991-01-01

    A new derivation is presented for the bounds on the size of a multilayer neural network to exactly implement an arbitrary training set; namely, the training set can be implemented with zero error with two layers and with the number of the hidden-layer neurons equal to no.1 is greater than p - 1. The derivation does not require the separation of the input space by particular hyperplanes, as in previous derivations. The weights for the hidden layer can be chosen almost arbitrarily, and the weights for the output layer can be found by solving no.1 + 1 linear equations. The method presented exactly solves (M), the multilayer neural network training problem, for any arbitrary training set.

  11. Higher-order numerical methods derived from three-point polynomial interpolation

    NASA Technical Reports Server (NTRS)

    Rubin, S. G.; Khosla, P. K.

    1976-01-01

    Higher-order collocation procedures resulting in tridiagonal matrix systems are derived from polynomial spline interpolation and Hermitian finite-difference discretization. The equations generally apply for both uniform and variable meshes. Hybrid schemes resulting from different polynomial approximations for first and second derivatives lead to the nonuniform mesh extension of the so-called compact or Pade difference techniques. A variety of fourth-order methods are described and this concept is extended to sixth-order. Solutions with these procedures are presented for the similar and non-similar boundary layer equations with and without mass transfer, the Burgers equation, and the incompressible viscous flow in a driven cavity. Finally, the interpolation procedure is used to derive higher-order temporal integration schemes and results are shown for the diffusion equation.

  12. Problems of applicability of statistical methods in cosmology

    SciTech Connect

    Levin, S. F.

    2015-12-15

    The problems arising from the incorrect formulation of measuring problems of identification for cosmological models and violations of conditions of applicability of statistical methods are considered.

  13. Two non-parametric methods for derivation of constraints from radiotherapy dose-histogram data

    NASA Astrophysics Data System (ADS)

    Ebert, M. A.; Gulliford, S. L.; Buettner, F.; Foo, K.; Haworth, A.; Kennedy, A.; Joseph, D. J.; Denham, J. W.

    2014-07-01

    Dose constraints based on histograms provide a convenient and widely-used method for informing and guiding radiotherapy treatment planning. Methods of derivation of such constraints are often poorly described. Two non-parametric methods for derivation of constraints are described and investigated in the context of determination of dose-specific cut-points—values of the free parameter (e.g., percentage volume of the irradiated organ) which best reflect resulting changes in complication incidence. A method based on receiver operating characteristic (ROC) analysis and one based on a maximally-selected standardized rank sum are described and compared using rectal toxicity data from a prostate radiotherapy trial. Multiple test corrections are applied using a free step-down resampling algorithm, which accounts for the large number of tests undertaken to search for optimal cut-points and the inherent correlation between dose-histogram points. Both methods provide consistent significant cut-point values, with the rank sum method displaying some sensitivity to the underlying data. The ROC method is simple to implement and can utilize a complication atlas, though an advantage of the rank sum method is the ability to incorporate all complication grades without the need for grade dichotomization.

  14. Optimization of complex slater-type functions with analytic derivative methods for describing photoionization differential cross sections.

    PubMed

    Matsuzaki, Rei; Yabushita, Satoshi

    2017-05-05

    The complex basis function (CBF) method applied to various atomic and molecular photoionization problems can be interpreted as an L2 method to solve the driven-type (inhomogeneous) Schrödinger equation, whose driven term being dipole operator times the initial state wave function. However, efficient basis functions for representing the solution have not fully been studied. Moreover, the relation between their solution and that of the ordinary Schrödinger equation has been unclear. For these reasons, most previous applications have been limited to total cross sections. To examine the applicability of the CBF method to differential cross sections and asymmetry parameters, we show that the complex valued solution to the driven-type Schrödinger equation can be variationally obtained by optimizing the complex trial functions for the frequency dependent polarizability. In the test calculations made for the hydrogen photoionization problem with five or six complex Slater-type orbitals (cSTOs), their complex valued expansion coefficients and the orbital exponents have been optimized with the analytic derivative method. Both the real and imaginary parts of the solution have been obtained accurately in a wide region covering typical molecular regions. Their phase shifts and asymmetry parameters are successfully obtained by extrapolating the CBF solution from the inner matching region to the asymptotic region using WKB method. The distribution of the optimized orbital exponents in the complex plane is explained based on the close connection between the CBF method and the driven-type equation method. The obtained information is essential to constructing the appropriate basis sets in future molecular applications. © 2017 Wiley Periodicals, Inc.

  15. Monte Carlo method based QSAR modeling of maleimide derivatives as glycogen synthase kinase-3β inhibitors.

    PubMed

    Živković, Jelena V; Trutić, Nataša V; Veselinović, Jovana B; Nikolić, Goran M; Veselinović, Aleksandar M

    2015-09-01

    The Monte Carlo method was used for QSAR modeling of maleimide derivatives as glycogen synthase kinase-3β inhibitors. The first QSAR model was developed for a series of 74 3-anilino-4-arylmaleimide derivatives. The second QSAR model was developed for a series of 177 maleimide derivatives. QSAR models were calculated with the representation of the molecular structure by the simplified molecular input-line entry system. Two splits have been examined: one split into the training and test set for the first QSAR model, and one split into the training, test and validation set for the second. The statistical quality of the developed model is very good. The calculated model for 3-anilino-4-arylmaleimide derivatives had following statistical parameters: r(2)=0.8617 for the training set; r(2)=0.8659, and r(m)(2)=0.7361 for the test set. The calculated model for maleimide derivatives had following statistical parameters: r(2)=0.9435, for the training, r(2)=0.9262 and r(m)(2)=0.8199 for the test and r(2)=0.8418, r(av)(m)(2)=0.7469 and ∆r(m)(2)=0.1476 for the validation set. Structural indicators considered as molecular fragments responsible for the increase and decrease in the inhibition activity have been defined. The computer-aided design of new potential glycogen synthase kinase-3β inhibitors has been presented by using defined structural alerts.

  16. Low-derivative operators of the Standard Model effective field theory via Hilbert series methods

    NASA Astrophysics Data System (ADS)

    Lehman, Landon; Martin, Adam

    2016-02-01

    In this work, we explore an extension of Hilbert series techniques to count operators that include derivatives. For sufficiently low-derivative operators, we conjecture an algorithm that gives the number of invariant operators, properly accounting for redundancies due to the equations of motion and integration by parts. Specifically, the conjectured technique can be applied whenever there is only one Lorentz invariant for a given partitioning of derivatives among the fields. At higher numbers of derivatives, equation of motion redundancies can be removed, but the increased number of Lorentz contractions spoils the subtraction of integration by parts redundancies. While restricted, this technique is sufficient to automatically recreate the complete set of invariant operators of the Standard Model effective field theory for dimensions 6 and 7 (for arbitrary numbers of flavors). At dimension 8, the algorithm does not automatically generate the complete operator set; however, it suffices for all but five classes of operators. For these remaining classes, there is a well defined procedure to manually determine the number of invariants. Assuming our method is correct, we derive a set of 535 dimension-8 N f = 1 operators.

  17. A multi-wavelength spectrophotometric method for the simultaneous determination of five haemoglobin derivatives.

    PubMed

    Zwart, A; Buursma, A; van Kampen, E J; Oeseburg, B; van der Ploeg, P H; Zijlstra, W G

    1981-07-01

    A method is described by which the concentration of deoxyhaemoglobin, oxyhaemoglobin, carboxyhaemoglobin, haemoglobin and sulfhaemoglobin in a human blood sample is determined by passing the haemolysate without air contact through a coarse filter and subsequently measuring the absorbance at lambda = 500, 569, 577, 620 and 760 nm. The ensuing set of equations is solved by matrix calculation with the aid of a simple computer program. The method has been tested by comparing it with conventional methods for the determination of the various haemoglobin derivatives separately.

  18. The Meshfree Finite Volume Method with application to multi-phase porous media models

    NASA Astrophysics Data System (ADS)

    Foy, Brody H.; Perré, Patrick; Turner, Ian

    2017-03-01

    Numerical methods form a cornerstone of the analysis and investigation of mathematical models for physical processes. Many classical numerical schemes rely on the application of strict meshing structures to generate accurate solutions, which in some applications are an infeasible constraint. Within this paper we outline a new meshfree numerical scheme, which we call the Meshfree Finite Volume Method (MFVM). The MFVM uses interpolants to approximate fluxes in a disjoint finite volume scheme, allowing for the accurate solution of strong-form PDEs. We present a derivation of the MFVM, and give error bounds on the spatial and temporal approximations used within the scheme. We present a wide variety of applications of the method, showing key features, and advantages over traditional meshed techniques. We close with an application of the method to a non-linear multi-phase wood drying model, showing the potential for solving numerically challenging problems.

  19. Ground water modeling applications using the analytic element method.

    PubMed

    Hunt, Randall J

    2006-01-01

    Though powerful and easy to use, applications of the analytic element method are not as widespread as finite-difference or finite-element models due in part to their relative youth. Although reviews that focus primarily on the mathematical development of the method have appeared in the literature, a systematic review of applications of the method is not available. An overview of the general types of applications of analytic elements in ground water modeling is provided in this paper. While not fully encompassing, the applications described here cover areas where the method has been historically applied (regional, two-dimensional steady-state models, analyses of ground water-surface water interaction, quick analyses and screening models, wellhead protection studies) as well as more recent applications (grid sensitivity analyses, estimating effective conductivity and dispersion in highly heterogeneous systems). The review of applications also illustrates areas where more method development is needed (three-dimensional and transient simulations).

  20. Non-singular acoustic cloak derived by the ray tracing method with rotationally symmetric transformations

    PubMed Central

    Wu, Linzhi

    2016-01-01

    Recently, the ray tracing method has been used to derive the non-singular cylindrical invisibility cloaks for out-of-plane shear waves, which is impossible via the transformation method directly owing to the singular push-forward mapping. In this paper, the method is adopted to design a kind of non-singular acoustic cloak. Based on Hamilton's equations of motion, eikonal equation and pre-designed ray equations, we derive several constraint equations for bulk modulus and density tensor. On the premise that the perfect matching conditions are satisfied, a series of non-singular physical profiles can be obtained by arranging the singular terms reasonably. The physical profiles derived by the ray tracing method will degenerate to the transformation-based solutions when taking the transport equation into consideration. This illuminates the essence of the newly designed cloaks that they are actually the so-called eikonal cloaks that can accurately control the paths of energy flux but with small disturbance in energy distribution along the paths. The near-perfect invisible performance has been demonstrated by the numerical ray tracing results and the pressure distribution snapshots. Finally, a kind of reduced cloak is conceived, and the good invisible performance has been measured quantitatively by the normalized scattering width. PMID:27118884

  1. Non-singular acoustic cloak derived by the ray tracing method with rotationally symmetric transformations.

    PubMed

    Gao, Penglin; Wu, Linzhi

    2016-02-01

    Recently, the ray tracing method has been used to derive the non-singular cylindrical invisibility cloaks for out-of-plane shear waves, which is impossible via the transformation method directly owing to the singular push-forward mapping. In this paper, the method is adopted to design a kind of non-singular acoustic cloak. Based on Hamilton's equations of motion, eikonal equation and pre-designed ray equations, we derive several constraint equations for bulk modulus and density tensor. On the premise that the perfect matching conditions are satisfied, a series of non-singular physical profiles can be obtained by arranging the singular terms reasonably. The physical profiles derived by the ray tracing method will degenerate to the transformation-based solutions when taking the transport equation into consideration. This illuminates the essence of the newly designed cloaks that they are actually the so-called eikonal cloaks that can accurately control the paths of energy flux but with small disturbance in energy distribution along the paths. The near-perfect invisible performance has been demonstrated by the numerical ray tracing results and the pressure distribution snapshots. Finally, a kind of reduced cloak is conceived, and the good invisible performance has been measured quantitatively by the normalized scattering width.

  2. Interlaminar Stresses by Refined Beam Theories and the Sinc Method Based on Interpolation of Highest Derivative

    NASA Technical Reports Server (NTRS)

    Slemp, Wesley C. H.; Kapania, Rakesh K.; Tessler, Alexander

    2010-01-01

    Computation of interlaminar stresses from the higher-order shear and normal deformable beam theory and the refined zigzag theory was performed using the Sinc method based on Interpolation of Highest Derivative. The Sinc method based on Interpolation of Highest Derivative was proposed as an efficient method for determining through-the-thickness variations of interlaminar stresses from one- and two-dimensional analysis by integration of the equilibrium equations of three-dimensional elasticity. However, the use of traditional equivalent single layer theories often results in inaccuracies near the boundaries and when the lamina have extremely large differences in material properties. Interlaminar stresses in symmetric cross-ply laminated beams were obtained by solving the higher-order shear and normal deformable beam theory and the refined zigzag theory with the Sinc method based on Interpolation of Highest Derivative. Interlaminar stresses and bending stresses from the present approach were compared with a detailed finite element solution obtained by ABAQUS/Standard. The results illustrate the ease with which the Sinc method based on Interpolation of Highest Derivative can be used to obtain the through-the-thickness distributions of interlaminar stresses from the beam theories. Moreover, the results indicate that the refined zigzag theory is a substantial improvement over the Timoshenko beam theory due to the piecewise continuous displacement field which more accurately represents interlaminar discontinuities in the strain field. The higher-order shear and normal deformable beam theory more accurately captures the interlaminar stresses at the ends of the beam because it allows transverse normal strain. However, the continuous nature of the displacement field requires a large number of monomial terms before the interlaminar stresses are computed as accurately as the refined zigzag theory.

  3. Power Measurement Methods for Energy Efficient Applications

    PubMed Central

    Calandrini, Guilherme; Gardel, Alfredo; Bravo, Ignacio; Revenga, Pedro; Lázaro, José L.; Toledo-Moreo, F. Javier

    2013-01-01

    Energy consumption constraints on computing systems are more important than ever. Maintenance costs for high performance systems are limiting the applicability of processing devices with large dissipation power. New solutions are needed to increase both the computation capability and the power efficiency. Moreover, energy efficient applications should balance performance vs. consumption. Therefore power data of components are important. This work presents the most remarkable alternatives to measure the power consumption of different types of computing systems, describing the advantages and limitations of available power measurement systems. Finally, a methodology is proposed to select the right power consumption measurement system taking into account precision of the measure, scalability and controllability of the acquisition system. PMID:23778191

  4. Enabling consistency in pluripotent stem cell-derived products for research and development and clinical applications through material standards.

    PubMed

    French, Anna; Bravery, Christopher; Smith, James; Chandra, Amit; Archibald, Peter; Gold, Joseph D; Artzi, Natalie; Kim, Hae-Won; Barker, Richard W; Meissner, Alexander; Wu, Joseph C; Knowles, Jonathan C; Williams, David; García-Cardeña, Guillermo; Sipp, Doug; Oh, Steve; Loring, Jeanne F; Rao, Mahendra S; Reeve, Brock; Wall, Ivan; Carr, Andrew J; Bure, Kim; Stacey, Glyn; Karp, Jeffrey M; Snyder, Evan Y; Brindley, David A

    2015-03-01

    There is a need for physical standards (reference materials) to ensure both reproducibility and consistency in the production of somatic cell types from human pluripotent stem cell (hPSC) sources. We have outlined the need for reference materials (RMs) in relation to the unique properties and concerns surrounding hPSC-derived products and suggest in-house approaches to RM generation relevant to basic research, drug screening, and therapeutic applications. hPSCs have an unparalleled potential as a source of somatic cells for drug screening, disease modeling, and therapeutic application. Undefined variation and product variability after differentiation to the lineage or cell type of interest impede efficient translation and can obscure the evaluation of clinical safety and efficacy. Moreover, in the absence of a consistent population, data generated from in vitro studies could be unreliable and irreproducible. Efforts to devise approaches and tools that facilitate improved consistency of hPSC-derived products, both as development tools and therapeutic products, will aid translation. Standards exist in both written and physical form; however, because many unknown factors persist in the field, premature written standards could inhibit rather than promote innovation and translation. We focused on the derivation of physical standard RMs. We outline the need for RMs and assess the approaches to in-house RM generation for hPSC-derived products, a critical tool for the analysis and control of product variation that can be applied by researchers and developers. We then explore potential routes for the generation of RMs, including both cellular and noncellular materials and novel methods that might provide valuable tools to measure and account for variation. Multiparametric techniques to identify "signatures" for therapeutically relevant cell types, such as neurons and cardiomyocytes that can be derived from hPSCs, would be of significant utility, although physical RMs will

  5. 7 CFR 1430.503 - Time and method for application.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS DAIRY PRODUCTS Dairy Market Loss Assistance Program § 1430.503 Time and method for application. (a) Dairy operations may obtain an application, Form CCC-1040 (Dairy Market Loss Assistance Program Payment Application), in person, by mail,...

  6. Indirect methods of determination of the asymptotic normalization coefficients and their application for nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Yarmukhamedov, R.

    2014-05-01

    The basic methods of the determination of asymptotic normalization coefficient for A+a→B of astrophysical interest are briefly presented. The results of the application of the specific asymptotic normalization coefficients derived within these methods for the extrapolation of the astrophysical S factors to experimentally inaccessible energy regions (E ≤ 25 keV) for the some specific radiative capture A(a,γ)B reactions of the pp-chain and the CNO cycle are presented.

  7. Nonlinear parameter identification: Ballistic range experience applicable to flight testing. [using Gauss-Newton method

    NASA Technical Reports Server (NTRS)

    Chapman, G.; Kirk, D.

    1974-01-01

    The parameter identification scheme being used is a differential correction least squares procedure (Gauss-Newton method). The position, orientation, and derivatives of these quantities with respect to the parameters of interest (i.e., sensitivity coefficients) are determined by digital integration of the equations of motion and the parametric differential equations. The application of this technique to three vastly different sets of data is used to illustrate the versatility of the method and to indicate some of the problems that still remain.

  8. A General Symbolic Method with Physical Applications

    NASA Astrophysics Data System (ADS)

    Smith, Gregory M.

    2000-06-01

    A solution to the problem of unifying the General Relativistic and Quantum Theoretical formalisms is given which introduces a new non-axiomatic symbolic method and an algebraic generalization of the Calculus to non-finite symbolisms without reference to the concept of a limit. An essential feature of the non-axiomatic method is the inadequacy of any (finite) statements: Identifying this aspect of the theory with the "existence of an external physical reality" both allows for the consistency of the method with the results of experiments and avoids the so-called "measurement problem" of quantum theory.

  9. Production and biomedical applications of virus-like particles derived from polyomaviruses.

    PubMed

    Teunissen, Erik A; de Raad, Markus; Mastrobattista, Enrico

    2013-11-28

    Virus-like particles (VLPs), aggregates of capsid proteins devoid of viral genetic material, show great promise in the fields of vaccine development and gene therapy. These particles spontaneously self-assemble after heterologous expression of viral structural proteins. This review will focus on the use of virus-like particles derived from polyomavirus capsid proteins. Since their first recombinant production 27 years ago these particles have been investigated for a myriad of biomedical applications. These virus-like particles are safe, easy to produce, can be loaded with a broad range of diverse cargoes and can be tailored for specific delivery or epitope presentation. We will highlight the structural characteristics of polyomavirus-derived VLPs and give an overview of their applications in diagnostics, vaccine development and gene delivery.

  10. Application of bioethanol derived lignin for improving physico-mechanical properties of thermoset biocomposites.

    PubMed

    Bajwa, Dilpreet S; Wang, Xinnan; Sitz, Evan; Loll, Tyler; Bhattacharjee, Sujal

    2016-08-01

    Lignin is the most abundant of renewable polymers next to cellulose with a global annual production of 70million tons, largely produced from pulping and second generation biofuel industries. Low value of industrial lignin makes it an attractive biomaterial for wide range of applications. The study investigated the application of wheat straw and corn stover based lignin derived from ethanol production for use in thermoset biocomposites. The biocomposite matrix constituted a two component low viscosity Araldite(®)LY 8601/Aradur(®) 8602 epoxy resin system and the lignin content varied from 0 to 25% by weight fraction. The analysis of the physical and mechanical properties of the biocomposites show bioethanol derived lignin can improve selective properties such as impact strength, and thermal stability without compromising the modulus and strength attributes.

  11. Krylov subspace methods - Theory, algorithms, and applications

    NASA Technical Reports Server (NTRS)

    Sad, Youcef

    1990-01-01

    Projection methods based on Krylov subspaces for solving various types of scientific problems are reviewed. The main idea of this class of methods when applied to a linear system Ax = b, is to generate in some manner an approximate solution to the original problem from the so-called Krylov subspace span. Thus, the original problem of size N is approximated by one of dimension m, typically much smaller than N. Krylov subspace methods have been very successful in solving linear systems and eigenvalue problems and are now becoming popular for solving nonlinear equations. The main ideas in Krylov subspace methods are shown and their use in solving linear systems, eigenvalue problems, parabolic partial differential equations, Liapunov matrix equations, and nonlinear system of equations are discussed.

  12. Application of geophysical methods for fracture characterization

    SciTech Connect

    Lee, K.H.; Majer, E.L.; McEvilly, T.V. |; Morrison, H.F. |

    1990-01-01

    One of the most crucial needs in the design and implementation of an underground waste isolation facility is a reliable method for the detection and characterization of fractures in zones away from boreholes or subsurface workings. Geophysical methods may represent a solution to this problem. If fractures represent anomalies in the elastic properties or conductive properties of the rocks, then the seismic and electrical techniques may be useful in detecting and characterizing fracture properties. 7 refs., 3 figs.

  13. Silver nanoparticles: Synthesis methods, bio-applications and properties.

    PubMed

    Abbasi, Elham; Milani, Morteza; Fekri Aval, Sedigheh; Kouhi, Mohammad; Akbarzadeh, Abolfazl; Tayefi Nasrabadi, Hamid; Nikasa, Parisa; Joo, San Woo; Hanifehpour, Younes; Nejati-Koshki, Kazem; Samiei, Mohammad

    2016-01-01

    Silver nanoparticles size makes wide range of new applications in various fields of industry. Synthesis of noble metal nanoparticles for applications such as catalysis, electronics, optics, environmental and biotechnology is an area of constant interest. Two main methods for Silver nanoparticles are the physical and chemical methods. The problem with these methods is absorption of toxic substances onto them. Green synthesis approaches overcome this limitation. Silver nanoparticles size makes wide range of new applications in various fields of industry. This article summarizes exclusively scalable techniques and focuses on strengths, respectively, limitations with respect to the biomedical applicability and regulatory requirements concerning silver nanoparticles.

  14. A pointwise estimate for fractionary derivatives with applications to partial differential equations.

    PubMed

    Cordoba, Antonio; Cordoba, Diego

    2003-12-23

    This article emphasizes the role played by a remarkable pointwise inequality satisfied by fractionary derivatives in order to obtain maximum principles and Lp-decay of solutions of several interesting partial differential equations. In particular, there are applications to quasigeostrophic flows, in two space variables with critical viscosity, that model the Eckman pumping [see Baroud, Ch. N., Plapp, B. B., She, Z. S. & Swinney, H. L. (2002) Phys. Rev. Lett. 88, 114501 and Constantin, P. (2002) Phys. Rev. Lett. 89, 184501].

  15. Kernel-Correlated Levy Field Driven Forward Rate and Application to Derivative Pricing

    SciTech Connect

    Bo Lijun; Wang Yongjin; Yang Xuewei

    2013-08-01

    We propose a term structure of forward rates driven by a kernel-correlated Levy random field under the HJM framework. The kernel-correlated Levy random field is composed of a kernel-correlated Gaussian random field and a centered Poisson random measure. We shall give a criterion to preclude arbitrage under the risk-neutral pricing measure. As applications, an interest rate derivative with general payoff functional is priced under this pricing measure.

  16. Multigrid methods with applications to reservoir simulation

    SciTech Connect

    Xiao, Shengyou

    1994-05-01

    Multigrid methods are studied for solving elliptic partial differential equations. Focus is on parallel multigrid methods and their use for reservoir simulation. Multicolor Fourier analysis is used to analyze the behavior of standard multigrid methods for problems in one and two dimensions. Relation between multicolor and standard Fourier analysis is established. Multiple coarse grid methods for solving model problems in 1 and 2 dimensions are considered; at each coarse grid level we use more than one coarse grid to improve convergence. For a given Dirichlet problem, a related extended problem is first constructed; a purification procedure can be used to obtain Moore-Penrose solutions of the singular systems encountered. For solving anisotropic equations, semicoarsening and line smoothing techniques are used with multiple coarse grid methods to improve convergence. Two-level convergence factors are estimated using multicolor. In the case where each operator has the same stencil on each grid point on one level, exact multilevel convergence factors can be obtained. For solving partial differential equations with discontinuous coefficients, interpolation and restriction operators should include information about the equation coefficients. Matrix-dependent interpolation and restriction operators based on the Schur complement can be used in nonsymmetric cases. A semicoarsening multigrid solver with these operators is used in UTCOMP, a 3-D, multiphase, multicomponent, compositional reservoir simulator. The numerical experiments are carried out on different computing systems. Results indicate that the multigrid methods are promising.

  17. Development of a rapid HRM genotyping method for detection of dog-derived Giardia lamblia.

    PubMed

    Tan, Liping; Yu, Xingang; Abdullahi, Auwalu Yusuf; Wu, Sheng; Zheng, Guochao; Hu, Wei; Song, Meiran; Wang, Zhen; Jiang, Biao; Li, Guoqing

    2015-11-01

    Giardia lamblia is a zoonotic flagellate protozoan in the intestine of human and many mammals including dogs. To assess a threat of dog-derived G. lamblia to humans, the common dog-derived G. lamblia assemblages A, C, and D were genotyped by high-resolution melting (HRM) technology. According to β-giardin gene sequence, the qPCR-HRM primers BG5 and BG7 were designed. A series of experiments on the stability, sensitivity, and accuracy of the HRM method were also tested. Results showed that the primers BG5 and BG7 could distinguish among three assemblages A, C, and D, which Tm value differences were about 1 °C to each other. The melting curves of intra-assay reproducibility were almost coincided, and those of inter-assay reproducibility were much the same shape. The lowest detection concentration was about 5 × 10(-6)-ng/μL sample. The genotyping results from 21 G. lamblia samples by the HRM method were in complete accordance with sequencing results. It is concluded that the HRM genotyping method is rapid, stable, specific, highly sensitive, and suitable for clinical detection and molecular epidemiological survey of dog-derived G. lamblia.

  18. Solvent-free method for the determination of lignin-derived phenols in sediments.

    PubMed

    Pinto, Mayara; Frena, Morgana; Dos Santos Madureira, Luiz Augusto

    2017-03-03

    A solvent-free method that uses headspace solid-phase microextraction and gas chromatography with flame ionization detection is proposed for the determination of lignin-derived phenols in sediments. The extraction and derivatization conditions for the simultaneous analysis of acetosyringone, acetovanillone, syringaldehyde, vanillin, ferulic acid, syringic acid, vanillic acid, p-hydroxybenzoic acid and p-coumaric acid were optimized using a central composite design. After optimization, the best results were obtained with the following conditions: exposure of the polyacrylate fiber to the headspace with 60 μL of N,O-bis(trimethylsilyl)trifluoroacetamide as a derivatizing agent for 15 min and then extraction in the headspace of 100 mg of sediment (previously spiked with lignin-derived phenols) for 35 min. The accuracy of the method was estimated based on recovery tests at two concentration levels and by comparison with a high- performance liquid chromatography method reported in the literature. Based on the t-test with a confidence level of 95%, no statistical differences were observed. The detection and quantification limits for the target compounds varied according to their characteristics: values at the μg g(-1) level for non-acid compounds and mg g(-1) level for phenolic acids, due to the lower volatility of the derivatives. This article is protected by copyright. All rights reserved.

  19. Precision cleaning methods for spacecraft applications

    NASA Technical Reports Server (NTRS)

    Ryan, L. E.; Lindewall, H.

    1988-01-01

    A small CO2 snow cleaning apparatus to clean both molecular films and particles from small and large components and surfaces was constructed. Various types of surfaces were cleaned using the CO2 technique. Vacuum deposited and sputtered metallic coatings such as germanium, aluminum, and silver and silicon wafers, and polished copper conical mirrors were purposely contaminated with everyday aerospace contaminants, including particle fallout and fingerprints. Precleaning characterization by Bidirectional Reflectance Distribution Function (BRDF), ellipsometry, nonvolatile residue, and microscopic particle evaluation served as evaluation of cleaning efficiency. Good results were obtained in trial application.

  20. Potential application of extracellular vesicles of human adipose tissue-derived mesenchymal stem cells in Alzheimer's disease therapeutics.

    PubMed

    Katsuda, Takeshi; Oki, Katsuyuki; Ochiya, Takahiro

    2015-01-01

    In the last 20 years, extracellular vesicles (EVs) have attracted attention as a versatile cell-cell communication mediator. The biological significance of EVs remains to be fully elucidated, but many reports have suggested that the functions of EVs mirror, at least in part, those of the cells from which they originate. Mesenchymal stem cells (MSCs) are a type of adult stem cell that can be isolated from connective tissue including bone marrow and adipose tissue and have emerged as an attractive candidate for cell therapy applications. Accordingly, an increasing number of reports have shown that EVs derived from MSCs have therapeutic potential in multiple diseases. We recently reported a novel therapeutic potential of EVs secreted from human adipose tissue-derived MSCs (hADSCs) (also known as adipose tissue-derived stem cells; ASCs) against Alzheimer's disease (AD). We found that hADSCs secrete exosomes carrying enzymatically active neprilysin, the most important β-amyloid peptide (Aβ)-degrading enzyme in the brain. In this chapter, we describe a method by which to evaluate the therapeutic potential of hADSC-derived EVs against AD from the point of view of their Aβ-degrading capacity.

  1. Applications of a transonic wing design method

    NASA Technical Reports Server (NTRS)

    Campbell, Richard L.; Smith, Leigh A.

    1989-01-01

    A method for designing wings and airfoils at transonic speeds using a predictor/corrector approach was developed. The procedure iterates between an aerodynamic code, which predicts the flow about a given geometry, and the design module, which compares the calculated and target pressure distributions and modifies the geometry using an algorithm that relates differences in pressure to a change in surface curvature. The modular nature of the design method makes it relatively simple to couple it to any analysis method. The iterative approach allows the design process and aerodynamic analysis to converge in parallel, significantly reducing the time required to reach a final design. Viscous and static aeroelastic effects can also be accounted for during the design or as a post-design correction. Results from several pilot design codes indicated that the method accurately reproduced pressure distributions as well as the coordinates of a given airfoil or wing by modifying an initial contour. The codes were applied to supercritical as well as conventional airfoils, forward- and aft-swept transport wings, and moderate-to-highly swept fighter wings. The design method was found to be robust and efficient, even for cases having fairly strong shocks.

  2. A theoretical analysis of the free vibrations of ring- and/or stringer-stiffened elliptical cylinders with arbitrary end conditions. Volume 1: Analytical derivation and applications

    NASA Technical Reports Server (NTRS)

    Boyd, D. E.; Rao, C. K. P.

    1973-01-01

    The derivation and application of a Rayleigh-Ritz modal vibration analysis are presented for ring and/or stringer stiffened noncircular cylindrical shells with arbitrary end conditions. Comparisons with previous results from experimental and analytical studies showed this method of analysis to be accurate for a variety of end conditions. Results indicate a greater effect of rings on natural frequencies than of stringers.

  3. Sigmoid function based integral-derivative observer and application to autopilot design

    NASA Astrophysics Data System (ADS)

    Shao, Xingling; Wang, Honglun; Liu, Jun; Tang, Jun; Li, Jie; Zhang, Xiaoming; Shen, Chong

    2017-02-01

    To handle problems of accurate signal reconstruction and controller implementation with integral and derivative components in the presence of noisy measurement, motivated by the design principle of sigmoid function based tracking differentiator and nonlinear continuous integral-derivative observer, a novel integral-derivative observer (SIDO) using sigmoid function is developed. The key merit of the proposed SIDO is that it can simultaneously provide continuous integral and differential estimates with almost no drift phenomena and chattering effect, as well as acceptable noise-tolerance performance from output measurement, and the stability is established based on exponential stability and singular perturbation theory. In addition, the effectiveness of SIDO in suppressing drift phenomena and high frequency noises is firstly revealed using describing function and confirmed through simulation comparisons. Finally, the theoretical results on SIDO are demonstrated with application to autopilot design: 1) the integral and tracking estimates are extracted from the sensed pitch angular rate contaminated by nonwhite noises in feedback loop, 2) the PID(proportional-integral-derivative) based attitude controller is realized by adopting the error estimates offered by SIDO instead of using the ideal integral and derivative operator to achieve satisfactory tracking performance under control constraint.

  4. A vortex-lattice method for calculating longitudinal dynamic stability derivatives of oscillating delta wings

    NASA Technical Reports Server (NTRS)

    Levin, D.

    1981-01-01

    A nonsteady vortex-lattice method is introduced for predicting the dynamic stability derivatives of a delta wing undergoing an oscillatory motion. The analysis is applied to several types of small oscillations in pitch. The angle of attack varied between + or - 1 deg, with the mean held at 0 deg when the flow was assumed to be attached and between + or - 1 deg and the mean held at 15 deg when both leading-edge separation and wake roll-up were included. The computed results for damping in pitch are compared with several other methods and with experiments, and are found to be consistent and in good agreement.

  5. New Formulae for the High-Order Derivatives of Some Jacobi Polynomials: An Application to Some High-Order Boundary Value Problems

    PubMed Central

    Abd-Elhameed, W. M.

    2014-01-01

    This paper is concerned with deriving some new formulae expressing explicitly the high-order derivatives of Jacobi polynomials whose parameters difference is one or two of any degree and of any order in terms of their corresponding Jacobi polynomials. The derivatives formulae for Chebyshev polynomials of third and fourth kinds of any degree and of any order in terms of their corresponding Chebyshev polynomials are deduced as special cases. Some new reduction formulae for summing some terminating hypergeometric functions of unit argument are also deduced. As an application, and with the aid of the new introduced derivatives formulae, an algorithm for solving special sixth-order boundary value problems are implemented with the aid of applying Galerkin method. A numerical example is presented hoping to ascertain the validity and the applicability of the proposed algorithms. PMID:25386599

  6. Numerical methods for time-domain and frequency-domain analysis: applications in engineering

    NASA Astrophysics Data System (ADS)

    Tamas, R. D.

    2015-11-01

    Numerical methods are widely used for modeling different physical phenomena in engineering, especially when an analytic approach is not possible. Time-domain or frequency- domain type variations are generally investigated, depending on the nature of the process under consideration. Some methods originate from mechanics, although most of their applications belong to other fields, such as electromagnetism. Conversely, other methods were firstly developed for electromagnetism, but their field of application was extended to other fields. This paper presents some results that we have obtained by using a general purpose method for solving linear equations, i.e., the method of moments (MoM), and a time-domain method derived for electromagnetism, i.e., the Transmission Line Matrix method (TLM).

  7. Computational methods in the pricing and risk management of modern financial derivatives

    NASA Astrophysics Data System (ADS)

    Deutsch, Hans-Peter

    1999-09-01

    In the last 20 years modern finance has developed into a complex mathematically challenging field. Very complicated risks exist in financial markets which need very advanced methods to measure and/or model them. The financial instruments invented by the market participants to trade these risk, the so called derivatives are usually even more complicated than the risks themselves and also sometimes generate new riks. Topics like random walks, stochastic differential equations, martingale measures, time series analysis, implied correlations, etc. are of common use in the field. This is why more and more people with a science background, such as physicists, mathematicians, or computer scientists, are entering the field of finance. The measurement and management of all theses risks is the key to the continuing success of banks. This talk gives insight into today's common methods of modern market risk management such as variance-covariance, historical simulation, Monte Carlo, “Greek” ratios, etc., including the statistical concepts on which they are based. Derivatives are at the same time the main reason for and the most effective means of conducting risk management. As such, they stand at the beginning and end of risk management. The valuation of derivatives and structured financial instruments is therefore the prerequisite, the condition sine qua non, for all risk management. This talk introduces some of the important valuation methods used in modern derivatives pricing such as present value, Black-Scholes, binomial trees, Monte Carlo, etc. In summary this talk highlights an area outside physics where there is a lot of interesting work to do, especially for physicists. Or as one of our consultants said: The fascinating thing about this job is that Arthur Andersen hired me not ALTHOUGH I am a physicist but BECAUSE I am a physicist.

  8. Intercomparison of diffusion coefficient derived from the through-diffusion experiment using different numerical methods.

    PubMed

    Chen, Chih-Lung; Wang, Tsing-Hai; Lee, Ching-Hor; Teng, Shi-Ping

    Diffusion is a dominant mechanism regulating the transport of released nuclides. The through-diffusion method is typically applied to determine the diffusion coefficients (D). Depending on the design of the experiment, the concentrations in the source term [i.e., inlet reservoir (IR)] or the end term [i.e., outlet reservoir (OR)] can be fixed or vary. The combinations involve four distinct models (i.e., the CC-CC model, CC-VC model, VC-CC model, and the VC-VC model). Studies discussing the VC-CC model are scant. An analytical method considering the decay effect is required to accurately interpret the radioactive nuclide diffusion experiment results. Therefore, we developed a CC-CC model and a CC-VC model with a decay effect and the simplified formulas of these two models to determine the diffusion coefficient (i.e., the CC-CC method and CC-VC method). We also proposed two simplified methods using the VC-VC model to determine the diffusion coefficient straightforwardly based upon the concentration variation in IR and OR. More importantly, the best advantage of proposed method over others is that one can derive three diffusion coefficients based on one run of experiment. In addition, applying our CC-VC method to those data reported from Radiochemica Acta 96:111-117, 2008; and J Contam Hydrol 35:55-65, 1998, derived comparable diffusion coefficient lying in the identical order of magnitude. Furthermore, we proposed a formula to determine the conceptual critical time (Tc), which is particularly beneficial for the selection of using CC-VC or VC-VC method. Based on our proposed method, it becomes possible to calculate diffusion coefficient from a through-diffusion experiment in a shorter period of time.

  9. Optical Element, Device, Method, and Applications

    DTIC Science & Technology

    2011-04-14

    optical element is a phase-only element; and h) repeating steps ( c -f). 28. The method of claim 26, further comprising: c1) in step (c), setting...jl(l;, 11) to 0, wherein the optical element is an amplitude-only element; and h) repeating steps ( c -f). * * * * *

  10. Translational bioinformatics in psychoneuroimmunology: methods and applications.

    PubMed

    Yan, Qing

    2012-01-01

    Translational bioinformatics plays an indispensable role in transforming psychoneuroimmunology (PNI) into personalized medicine. It provides a powerful method to bridge the gaps between various knowledge domains in PNI and systems biology. Translational bioinformatics methods at various systems levels can facilitate pattern recognition, and expedite and validate the discovery of systemic biomarkers to allow their incorporation into clinical trials and outcome assessments. Analysis of the correlations between genotypes and phenotypes including the behavioral-based profiles will contribute to the transition from the disease-based medicine to human-centered medicine. Translational bioinformatics would also enable the establishment of predictive models for patient responses to diseases, vaccines, and drugs. In PNI research, the development of systems biology models such as those of the neurons would play a critical role. Methods based on data integration, data mining, and knowledge representation are essential elements in building health information systems such as electronic health records and computerized decision support systems. Data integration of genes, pathophysiology, and behaviors are needed for a broad range of PNI studies. Knowledge discovery approaches such as network-based systems biology methods are valuable in studying the cross-talks among pathways in various brain regions involved in disorders such as Alzheimer's disease.

  11. Gas sensing method applicable to real conditions

    NASA Astrophysics Data System (ADS)

    Szczurek, A.; Maciejewska, M.

    2013-04-01

    In this work, we tested the influence of various sampling techniques and modes of operation on the response of sensor systems under real conditions. The first system was based on diffusive sampling. The second one used a dynamic method of sampling. In the third system, a stop flow mode of operation was applied. A considerable error of target gas concentration assessment was obtained in the first two cases. The error resulted from sensor signal fluctuations encountered during their exposure either to the air at the measurement point (diffusive sampling) or to the air drawn from the measurement point (dynamic sampling). The fluctuations could be attributed to the temporal variation of physical and chemical parameters of air. The main merit of the third method consists in utilizing sensor exposure under the conditions of stopped flow for the purpose of pollutant concentration assessment. While using this method, the accuracy of target gas quantification under real conditions was comparable to the one achieved when measuring standard gases. We think that the proposed method is a valuable contribution, which addresses the increasing demand for sensor systems that perform quantitative pollution assessment in workplace air, under real conditions. This paper was presented at the Conference on Optoelectronic and Electronic Sensors held in Karpacz, Poland, on 24-27 June 2012.

  12. Symmetries in nuclei: New methods and applications

    NASA Astrophysics Data System (ADS)

    Caprio, Mark A.

    2011-04-01

    When a symmetry is a ``good'' symmetry of the nuclear system, as in the dynamical symmetries of the shell model and interacting boson model, this symmetry can directly give the spectroscopic properties of the nucleus, without the need for involved calculations. However, even if a symmetry is strongly broken, it nonetheless provides a calculational tool, classifying the basis states used in a full computational treatment of the many-body problem and greatly simplifying the underlying computational machinery. The symmetry then serves as the foundation for a physically meaningful truncation scheme for the calculation. This talk will provide an introduction to new applications of symmetry approaches to the nuclear problem, including the required mathematical developments. Supported by the US DOE under grant DE-FG02-95ER-40934 and by the Research Corporation for Science Advancement under a Cottrell Scholar Award.

  13. Rapid analytical method for the determination of aflatoxins in plant-derived dietary supplement and cosmetic oils.

    PubMed

    Mahoney, Noreen; Molyneux, Russell J

    2010-04-14

    Consumption of edible oils derived from conventional crop plants is increasing because they are generally regarded as healthier alternatives to animal-based fats and oils. More recently, there has been increased interest in the use of alternative specialty plant-derived oils, including those from tree nuts (almonds, pistachios, and walnuts) and botanicals (borage, evening primrose, and perilla) both for direct human consumption (e.g., as salad dressings) and for the preparation of cosmetics, soaps, and fragrance oils. This has raised the issue as to whether or not exposure to aflatoxins can result from such oils. Although most crops are subject to analysis and control, it has generally been assumed that plant oils do not retain aflatoxins due to the high polarity and lipophobicity of these compounds. There is virtually no scientific evidence to support this supposition, and available information is conflicting. To improve the safety and consistency of botanicals and dietary supplements, research is needed to establish whether or not oils used directly, or in the formulation of products, contain aflatoxins. A validated analytical method for the analysis of aflatoxins in plant-derived oils is essential to establish the safety of dietary supplements for consumption or cosmetic use that contain such oils. The aim of this research was therefore to develop an HPLC method applicable to a wide variety of oils from different plant sources spiked with aflatoxins, thereby providing a basis for a comprehensive project to establish an intra- and interlaboratory validated analytical method for the analysis of aflatoxins in dietary supplements and cosmetics formulated with plant oils.

  14. A Rapid Analytical Method for Determination of Aflatoxins in Plant-Derived Dietary Supplement and Cosmetic Oils

    PubMed Central

    Mahoney, Noreen; Molyneux, Russell J.

    2010-01-01

    Consumption of edible oils derived from conventional crop plants is increasing because they are generally regarded as more healthy alternatives to animal based fats and oils. More recently there has been increased interest in the use of alternative specialty plant-derived oils, including those from tree nuts (almonds, pistachios and walnuts) and botanicals (borage, evening primrose and perilla) both for direct human consumption (e.g. as salad dressings) but also for preparation of cosmetics, soaps, and fragrance oils. This has raised the issue as to whether or not exposure to aflatoxins can result from such oils. Although most crops are subject to analysis and control, it has generally been assumed that plant oils do not retain aflatoxins due to their high polarity and lipophobicity of these compounds. There is virtually no scientific evidence to support this supposition and available information is conflicting. To improve the safety and consistency of botanicals and dietary supplements, research is needed to establish whether or not oils used directly, or in the formulation of products, contain aflatoxins. A validated analytical method for the analysis of aflatoxins in plant-derived oils is essential, in order to establish the safety of dietary supplements for consumption or cosmetic use that contain such oils. The aim of this research was therefore to develop an HPLC method applicable to a wide variety of oils from different plant sources spiked with aflatoxins, thereby providing a basis for a comprehensive project to establish an intra- and inter-laboratory validated analytical method for analysis of aflatoxins in dietary supplements and cosmetics formulated with plant oils. PMID:20235534

  15. A method to derive vegetation distribution maps for pollen dispersion models using birch as an example.

    PubMed

    Pauling, A; Rotach, M W; Gehrig, R; Clot, B

    2012-09-01

    Detailed knowledge of the spatial distribution of sources is a crucial prerequisite for the application of pollen dispersion models such as, for example, COSMO-ART (COnsortium for Small-scale MOdeling-Aerosols and Reactive Trace gases). However, this input is not available for the allergy-relevant species such as hazel, alder, birch, grass or ragweed. Hence, plant distribution datasets need to be derived from suitable sources. We present an approach to produce such a dataset from existing sources using birch as an example. The basic idea is to construct a birch dataset using a region with good data coverage for calibration and then to extrapolate this relationship to a larger area by using land use classes. We use the Swiss forest inventory (1 km resolution) in combination with a 74-category land use dataset that covers the non-forested areas of Switzerland as well (resolution 100 m). Then we assign birch density categories of 0%, 0.1%, 0.5% and 2.5% to each of the 74 land use categories. The combination of this derived dataset with the birch distribution from the forest inventory yields a fairly accurate birch distribution encompassing entire Switzerland. The land use categories of the Global Land Cover 2000 (GLC2000; Global Land Cover 2000 database, 2003, European Commission, Joint Research Centre; resolution 1 km) are then calibrated with the Swiss dataset in order to derive a Europe-wide birch distribution dataset and aggregated onto the 7 km COSMO-ART grid. This procedure thus assumes that a certain GLC2000 land use category has the same birch density wherever it may occur in Europe. In order to reduce the strict application of this crucial assumption, the birch density distribution as obtained from the previous steps is weighted using the mean Seasonal Pollen Index (SPI; yearly sums of daily pollen concentrations). For future improvement, region-specific birch densities for the GLC2000 categories could be integrated into the mapping procedure.

  16. A method to derive vegetation distribution maps for pollen dispersion models using birch as an example

    NASA Astrophysics Data System (ADS)

    Pauling, A.; Rotach, M. W.; Gehrig, R.; Clot, B.

    2012-09-01

    Detailed knowledge of the spatial distribution of sources is a crucial prerequisite for the application of pollen dispersion models such as, for example, COSMO-ART (COnsortium for Small-scale MOdeling - Aerosols and Reactive Trace gases). However, this input is not available for the allergy-relevant species such as hazel, alder, birch, grass or ragweed. Hence, plant distribution datasets need to be derived from suitable sources. We present an approach to produce such a dataset from existing sources using birch as an example. The basic idea is to construct a birch dataset using a region with good data coverage for calibration and then to extrapolate this relationship to a larger area by using land use classes. We use the Swiss forest inventory (1 km resolution) in combination with a 74-category land use dataset that covers the non-forested areas of Switzerland as well (resolution 100 m). Then we assign birch density categories of 0%, 0.1%, 0.5% and 2.5% to each of the 74 land use categories. The combination of this derived dataset with the birch distribution from the forest inventory yields a fairly accurate birch distribution encompassing entire Switzerland. The land use categories of the Global Land Cover 2000 (GLC2000; Global Land Cover 2000 database, 2003, European Commission, Joint Research Centre; resolution 1 km) are then calibrated with the Swiss dataset in order to derive a Europe-wide birch distribution dataset and aggregated onto the 7 km COSMO-ART grid. This procedure thus assumes that a certain GLC2000 land use category has the same birch density wherever it may occur in Europe. In order to reduce the strict application of this crucial assumption, the birch density distribution as obtained from the previous steps is weighted using the mean Seasonal Pollen Index (SPI; yearly sums of daily pollen concentrations). For future improvement, region-specific birch densities for the GLC2000 categories could be integrated into the mapping procedure.

  17. Advanced method to derive the IMF direction near Mars from cycloidal proton distributions

    NASA Astrophysics Data System (ADS)

    Yamauchi, M.; Futaana, Y.; Fedorov, A.; Kallio, E.; Frahm, R. A.; Lundin, R.; Sauvaud, J.-A.; Winningham, J. D.; Barabash, S.; Holmström, M.

    2008-06-01

    In a previous paper, we showed a method for deriving the interplanetary magnetic field (IMF) orientation from the velocity distribution of ring-like distributed ions as measured by the Ion Mass Analyser (IMA) on board Mars Express (MEX). This method has been improved so that one can derive the IMF orientation from a very limited portion of the ring distributions, i.e., only the highest energy portion of the ring distribution. This method uses the maximum variance direction L instead of the minimum variance direction N, which are derived from manually selected ring data. Because IMA's count rate for a semi-persistent ring distribution is nearly proportional to energy squire, L is most likely aligned to the tangential direction of the ring distribution at its highest energy, and this tangential direction is parallel or anti-parallel to the electric field. A vector product of L and the solar wind direction ( X) gives the IMF orientation projected to the Y- Z plane. The tilt angle of IMF toward the X direction from the Y- Z plane is the same as the angle between the X direction and the ring plane, and is obtained from two methods when the initial speed of the ring ions is estimated to be much smaller than the solar wind speed: (1) angle between the velocity of ring's maximum energy portion and the solar wind vector, and (2) energy ratio between the solar wind and the maximum energy of the ring. The present method is applied to the IMA data from 3 June 2005 (0605-0640 UT) when the Mars Global Surveyor (MGS) magnetometer data are available. Using these data, we also tried to determine the sign of the IMF direction by estimating the evolution direction of the ring ions.

  18. Validated stability-indicating derivative and derivative ratio methods for the determination of some drugs used to alleviate respiratory tract disorders and their degradation products.

    PubMed

    Hassib, Sonia T; El-Zaher, Asmaa A; Fouad, Marwa A

    2011-05-01

    Derivative and derivative ratio methods are presented for the determination of butamirate citrate, formoterol fumarate, montelukast sodium, and sodium cromoglycate. Using the second derivative ultraviolet (UV) spectrophotometry, butamirate citrate and formoterol fumarate were determined by measuring the peak amplitude at 260.4 and 261.8 nm, respectively, without any interference of their degradation products. Butamirate citrate degradation product, 2-phenyl butyric acid, was determined by the measurement of its second derivative amplitude at 246.7 nm where butamirate citrate displays zero crossing. Formoterol fumarate degradation product, desformyl derivative, could be evaluated through the use of the first derivative at peak amplitude of 264.8 nm where interference of formoterol fumarate is negligible. In the first mode, the zero-crossing technique was applied at 305 nm for the determination of montelukast sodium in the presence of its photodegradation product, cis-isomer. The derivative of ratio spectra of montelukast sodium and its cis- isomer were used to determine both isomers using the first derivative of the ratio spectra by measuring the amplitudes of the trough at 305 nm and the peak at 308 nm, respectively. The later technique was also used for the determination of a ternary mixture of sodium cromoglycate and its two degradation products using zero-crossing method. In the derivative ratio spectra of the ternary mixture, trough depths were measured at 271.6, 302.8 and 302.2 nm, using the second, the first, and the second mode to evaluate sodium cromoglycate, degradation product (1) and degradation product (2), respectively. All the methods were applied successfully to the pharmaceutical preparation and were validated according to ICH guidelines.

  19. Application of the Conditioned Reverse Path Method

    NASA Astrophysics Data System (ADS)

    Garibaldi, L.

    2003-01-01

    The conditioned reverse path (CRP) method has been applied to identify the non-linear behaviour of a beam-like structure, both ends clamped, one with a non-linear stiffness characteristic. The same method was already successfully applied to the identification of another COST benchmark, known as the VTT non-linear suspension. This benchmark shows the enhancements of the technique, now applied to a real multi-degree-of-freedom (mdof) system, with single-point excitation subject to bending modes; the non-linearity is acting on one end of the beam in terms of displacements. The CRP technique is based on the construction of a hierarchy of uncorrelated response components in the frequency domain, allowing the estimation of the coefficients of the non-linearities away from the location of the applied excitation and also the identification of the linear dynamic compliance matrix when the number of excitations is smaller than the number of response locations.

  20. The generalized log-derivative method for evaluation of second-order transition amplitudes

    NASA Astrophysics Data System (ADS)

    Mrugała, Felicja

    1989-07-01

    The log-derivative method of Johnson is generalized to calculate matrix elements of multichannel Green's functions—second-order transition amplitudes—which arise from description of a variety of physical processes involving weak interactions of initial and final (bound) states with a set of strongly coupled continuum and/or bound intermediate states. A purely approximate-solution algorithm and two hybrid approximate-solution approximate-potential versions, based on the use of piecewise constant reference potentials, are presented and tested on problems concerning investigations of nonadiabatic effects in the spectroscopy of H2. A comparison with the renormalized Numerov method, extended to calculation of considered transition amplitudes, is made and superior efficiency of the hybrid log-derivative algorithms is demonstrated. It is shown both practically and theoretically that discretization errors of the hybrid algorithms grow linearly with increasing energy in calculations, whereas cubic growth of errors with energy is characteristic for the purely approximate-solution log-derivative and Numerov algorithms.

  1. In vivo 1H MR spectra analysis by means of second derivative method.

    PubMed

    Sokół, M

    2001-05-01

    Short echo time (TE) in vivo PRESS 1H MR spectra (2 T, TE=35 ms) of normal brain were fitted in the frequency domain using the second derivative method. In this approach, local maxima and hidden peaks are found as local minima of spectrum second derivative. The Lorentzian robust minimisation procedure (referred to as maximum likelihood or m-estimate fitting) using Levenburg-Marquardt non-linear fitting engine was applied. Spectral lines were approximated under the assumption of the mixed Lorentzian/Gaussian lineshapes. The same procedure was applied to 18 proton spectra. The number of peaks found within the range of 0.74/4.2 parts per million (ppm) was 52+/-3 and their positions were almost the same. The fitted lines were assigned on the basis of the J-pattern recalculated for the field strength of 2 T and by comparing the chemical shifts with the shifts in the single compound spectra. The ratios of main metabolites, such as NAA/Cr, Cho/Cr, Cho/NAA and mI/Cr, are in accord with those obtained earlier using the software supplied with the MR imager and the absolute concentrations of N-acetylaspartate (NAA), choline containing compounds (Cho), myoInositol (mI), glucose (Glc) and glutamate (Glu) obtained from the fit agree with those reported in literature, which confirms the usefulness of the second derivative method in routine analyses of 1H MR brain spectra.

  2. Identification of Baribis fault - West Java using second vertical derivative method of gravity

    NASA Astrophysics Data System (ADS)

    Sari, Endah Puspita; Subakti, Hendri

    2015-04-01

    Baribis fault is one of West Java fault zones which is an active fault. In modern era, the existence of fault zone can be observed by gravity anomaly. Baribis fault zone has not yet been measured by gravity directly. Based on this reason, satellite data supported this research. Data used on this research are GPS satellite data downloaded from TOPEX. The purpose of this research is to determine the type and strike of Baribis fault. The scope of this research is Baribis fault zone which lies on 6.50o - 7.50o S and 107.50o - 108.80o E. It consists of 5146 points which one point to another is separated by 1 minute meridian. The method used in this research is the Second Vertical Derivative (SVD) of gravity anomaly. The Second Vertical Derivative of gravity anomaly show as the amplitude of gravity anomaly caused by fault structure which appears as residual anomaly. The zero value of residual gravity anomaly indicates that the contact boundary of fault plane. Second Vertical Derivative method of gravity was applied for identifying Baribis fault. The result of this research shows that Baribis fault has a thrust mechanism. It has a lineament strike varies from 107o to 127o. This result agrees with focal mechanism data of earthquakes occurring on this region based on Global CMT catalogue.

  3. Domain adaptive boosting method and its applications

    NASA Astrophysics Data System (ADS)

    Geng, Jie; Miao, Zhenjiang

    2015-03-01

    Differences of data distributions widely exist among datasets, i.e., domains. For many pattern recognition, nature language processing, and content-based analysis systems, a decrease in performance caused by the domain differences between the training and testing datasets is still a notable problem. We propose a domain adaptation method called domain adaptive boosting (DAB). It is based on the AdaBoost approach with extensions to cover the domain differences between the source and target domains. Two main stages are contained in this approach: source-domain clustering and source-domain sample selection. By iteratively adding the selected training samples from the source domain, the discrimination model is able to achieve better domain adaptation performance based on a small validation set. The DAB algorithm is suitable for the domains with large scale samples and easy to extend for multisource adaptation. We implement this method on three computer vision systems: the skin detection model in single images, the video concept detection model, and the object classification model. In the experiments, we compare the performances of several commonly used methods and the proposed DAB. Under most situations, the DAB is superior.

  4. Field calibration of blowfly-derived DNA against traditional methods for assessing mammal diversity in tropical forests.

    PubMed

    Lee, Ping-Shin; Gan, Han Ming; Clements, Gopalasamy Reuben; Wilson, John-James

    2016-11-01

    Mammal diversity assessments based on DNA derived from invertebrates have been suggested as alternatives to assessments based on traditional methods; however, no study has field-tested both approaches simultaneously. In Peninsular Malaysia, we calibrated the performance of mammal DNA derived from blowflies (Diptera: Calliphoridae) against traditional methods used to detect species. We first compared five methods (cage trapping, mist netting, hair trapping, scat collection, and blowfly-derived DNA) in a forest reserve with no recent reports of megafauna. Blowfly-derived DNA and mist netting detected the joint highest number of species (n = 6). Only one species was detected by multiple methods. Compared to the other methods, blowfly-derived DNA detected both volant and non-volant species. In another forest reserve, rich in megafauna, we calibrated blowfly-derived DNA against camera traps. Blowfly-derived DNA detected more species (n = 11) than camera traps (n = 9), with only one species detected by both methods. The rarefaction curve indicated that blowfly-derived DNA would continue to detect more species with greater sampling effort. With further calibration, blowfly-derived DNA may join the list of traditional field methods. Areas for further investigation include blowfly feeding and dispersal biology, primer biases, and the assembly of a comprehensive and taxonomically-consistent DNA barcode reference library.

  5. An empirical method for deriving RBE values associated with electrons, photons and radionuclides.

    PubMed

    Bellamy, M; Puskin, J; Hertel, N; Eckerman, K

    2015-12-01

    There is substantial evidence to justify using relative biological effectiveness (RBE) values of >1 for low-energy electrons and photons. But, in the field of radiation protection, radiation associated with low linear energy transfer has been assigned a radiation weighting factor wR of 1. This value may be suitable for radiation protection but, for risk considerations, it is important to evaluate the potential elevated biological effectiveness of radiation to improve the quality of risk estimates. RBE values between 2 and 3 for tritium are implied by several experimental measurements. Additionally, elevated RBE values have been found for other similar low-energy radiation sources. In this work, RBE values are derived for electrons based upon the fractional deposition of absorbed dose of energies less than a few kiloelectron volts. Using this empirical method, RBE values were also derived for monoenergetic photons and 1070 radionuclides from ICRP Publication 107 for which photons and electrons are the primary emissions.

  6. Analytic second derivatives of the energy in the fragment molecular orbital method

    NASA Astrophysics Data System (ADS)

    Nakata, Hiroya; Nagata, Takeshi; Fedorov, Dmitri G.; Yokojima, Satoshi; Kitaura, Kazuo; Nakamura, Shinichiro

    2013-04-01

    We developed the analytic second derivatives of the energy for the fragment molecular orbital (FMO) method. First we derived the analytic expressions and then introduced some approximations related to the first and second order coupled perturbed Hartree-Fock equations. We developed a parallel program for the FMO Hessian with approximations in GAMESS and used it to calculate infrared (IR) spectra and Gibbs free energies and to locate the transition states in SN2 reactions. The accuracy of the Hessian is demonstrated in comparison to ab initio results for polypeptides and a water cluster. By using the two residues per fragment division, we achieved the accuracy of 3 cm-1 in the reduced mean square deviation of vibrational frequencies from ab initio for all three polyalanine isomers, while the zero point energy had the error not exceeding 0.3 kcal/mol. The role of the secondary structure on IR spectra, zero point energies, and Gibbs free energies is discussed.

  7. Analytic second derivatives of the energy in the fragment molecular orbital method.

    PubMed

    Nakata, Hiroya; Nagata, Takeshi; Fedorov, Dmitri G; Yokojima, Satoshi; Kitaura, Kazuo; Nakamura, Shinichiro

    2013-04-28

    We developed the analytic second derivatives of the energy for the fragment molecular orbital (FMO) method. First we derived the analytic expressions and then introduced some approximations related to the first and second order coupled perturbed Hartree-Fock equations. We developed a parallel program for the FMO Hessian with approximations in GAMESS and used it to calculate infrared (IR) spectra and Gibbs free energies and to locate the transition states in SN2 reactions. The accuracy of the Hessian is demonstrated in comparison to ab initio results for polypeptides and a water cluster. By using the two residues per fragment division, we achieved the accuracy of 3 cm(-1) in the reduced mean square deviation of vibrational frequencies from ab initio for all three polyalanine isomers, while the zero point energy had the error not exceeding 0.3 kcal/mol. The role of the secondary structure on IR spectra, zero point energies, and Gibbs free energies is discussed.

  8. Evaluation of potential factors affecting deriving conductivity benchmark by utilizing weighting methods in Hun-Tai River Basin, Northeastern China.

    PubMed

    Jia, Xiaobo; Zhao, Qian; Guo, Fen; Ma, Shuqin; Zhang, Yuan; Zang, Xiaomiao

    2017-03-01

    Specific conductivity is an increasingly important stressor for freshwater ecosystems. Interacting with other environmental factors, it may lead to habitat degradation and biodiversity loss. However, it is still poorly understood how the effect of specific conductivity on freshwater organisms is confounded by other environmental factors. In this study, a weight-of-evidence method was applied to evaluate the potential environmental factors that may confound the effect of specific conductivity on macroinvertebrate structure communities and identify the confounders affecting deriving conductivity benchmark in Hun-Tai River Basin, China. A total of seven potential environmental factors were assessed by six types of evidence (i.e., correlation of cause and confounder, correlation of effect and confounder, the contingency of high level cause and confounder, the removal of confounder, levels of confounder known to cause effects, and multivariate statistics for confounding). Results showed that effects of dissolved oxygen (DO), fecal coliform, habitat score, total phosphorus (TP), pH, and temperature on the relationship between sensitive genera loss and specific conductivity were minimal and manageable. NH3-N was identified as a confounder affecting deriving conductivity benchmark for macroinvertebrate. The potential confounding by high NH3-N was minimized by removing sites with NH3-N > 2.0 mg/L from the data set. Our study tailored the weighting method previously developed by USEPA to use field data to develop causal relationships for basin-scale applications and may provide useful information for pollution remediation and natural resource management.

  9. COMPLEX VARIABLE BOUNDARY ELEMENT METHOD: APPLICATIONS.

    USGS Publications Warehouse

    Hromadka, T.V.; Yen, C.C.; Guymon, G.L.

    1985-01-01

    The complex variable boundary element method (CVBEM) is used to approximate several potential problems where analytical solutions are known. A modeling result produced from the CVBEM is a measure of relative error in matching the known boundary condition values of the problem. A CVBEM error-reduction algorithm is used to reduce the relative error of the approximation by adding nodal points in boundary regions where error is large. From the test problems, overall error is reduced significantly by utilizing the adaptive integration algorithm.

  10. DERIVING STELLAR EFFECTIVE TEMPERATURES OF METAL-POOR STARS WITH THE EXCITATION POTENTIAL METHOD

    SciTech Connect

    Frebel, Anna; Casey, Andrew R.; Jacobson, Heather R.; Yu Qinsi

    2013-05-20

    It is well established that stellar effective temperatures determined from photometry and spectroscopy yield systematically different results. We describe a new, simple method to correct spectroscopically derived temperatures (''excitation temperatures'') of metal-poor stars based on a literature sample with -3.3 < [Fe/H] < -2.5. Excitation temperatures were determined from Fe I line abundances in high-resolution optical spectra in the wavelength range of {approx}3700-{approx}7000 A, although shorter wavelength ranges, up to 4750-6800 A, can also be employed, and compared with photometric literature temperatures. Our adjustment scheme increases the temperatures up to several hundred degrees for cool red giants, while leaving the near-main-sequence stars mostly unchanged. Hence, it brings the excitation temperatures in good agreement with photometrically derived values. The modified temperature also influences other stellar parameters, as the Fe I-Fe II ionization balance is simultaneously used to determine the surface gravity, while also forcing no abundance trend on the absorption line strengths to obtain the microturbulent velocity. As a result of increasing the temperature, the often too low gravities and too high microturbulent velocities in red giants become higher and lower, respectively. Our adjustment scheme thus continues to build on the advantage of deriving temperatures from spectroscopy alone, independent of reddening, while at the same time producing stellar chemical abundances that are more straightforwardly comparable to studies based on photometrically derived temperatures. Hence, our method may prove beneficial for comparing different studies in the literature as well as the many high-resolution stellar spectroscopic surveys that are or will be carried out in the next few years.

  11. A review of droplet resonators: Operation method and application

    NASA Astrophysics Data System (ADS)

    Wang, Yan; Li, Hanyang; Zhao, Liyuan; Wu, Bing; Liu, Shuangqiang; Liu, Yongjun; Yang, Jun

    2016-12-01

    Droplet resonators hold promise as a special class of optical cavities for numerous applications in micro-optical. Owing to liquid surface tension, droplet resonators possess nearly perfect spherical geometry and exceptionally smooth surfaces that prompt more and more meritorious applications to be exploit. Herein, we survey two typical operation methods of the droplet resonators, passive and active droplet resonator. Besides, droplet applications as high-performance lasers and sensors have been discussed. Although these applications have brought us tremendous value, the research for droplet resonators are still in its infancy, added potential application and intrinsic investigation of the droplet resonators should be developed in the future work.

  12. Production and applications of carbohydrate-derived sugar acids as generic biobased chemicals.

    PubMed

    Mehtiö, Tuomas; Toivari, Mervi; Wiebe, Marilyn G; Harlin, Ali; Penttilä, Merja; Koivula, Anu

    2016-10-01

    This review considers the chemical and biotechnological synthesis of acids that are obtained by direct oxidation of mono- or oligosaccharide, referred to as sugar acids. It focuses on sugar acids which can be readily derived from plant biomass sources and their current and future applications. The three main classes of sugar acids are aldonic, aldaric and uronic acids. Interest in organic acids derived from sugars has recently increased, as part of the interest to develop biorefineries which produce not only biofuels, but also chemicals to replace those currently derived from petroleum. More than half of the most desirable biologically produced platform chemicals are organic acids. Currently, the only sugar acid with high commercial production is d-gluconic acid. However, other sugar acids such as d-glucaric and meso-galactaric acids are being produced at a lower scale. The sugar acids have application as sequestering agents and binders, corrosion inhibitors, biodegradable chelators for pharmaceuticals and pH regulators. There is also considerable interest in the use of these molecules in the production of synthetic polymers, including polyamides, polyesters and hydrogels. Further development of these sugar acids will lead to higher volume production of the appropriate sugar acids and will help support the next generation of biorefineries.

  13. Endothelial cell micropatterning: Methods, effects, and applications

    PubMed Central

    Anderson, Deirdre E.J.; Hinds, Monica T.

    2012-01-01

    The effects of flow on endothelial cells have been widely examined for the ability of fluid shear stress to alter cell morphology and function; however, the effects of endothelial cell morphology without flow have only recently been observed. An increase in lithographic techniques in cell culture spurred a corresponding increase in research aiming to confine cell morphology. These studies lead to a better understanding of how morphology and cytoskeletal configuration affect the structure and function of the cells. This review examines endothelial cell micropatterning research by exploring both the many alternative methods used to alter endothelial cell morphology and the resulting changes in cellular shape and phenotype. Micropatterning induced changes in endothelial cell proliferation, apoptosis, cytoskeletal organization, mechanical properties, and cell functionality. Finally, the ways these cellular manipulation techniques have been applied to biomedical engineering research, including angiogenesis, cell migration, and tissue engineering, is discussed. PMID:21761242

  14. Applications of geophysical methods to volcano monitoring

    USGS Publications Warehouse

    Wynn, Jeff; Dzurisin, Daniel; Finn, Carol A.; Kauahikaua, James P.; Lahusen, Richard G.

    2006-01-01

    The array of geophysical technologies used in volcano hazards studies - some developed originally only for volcano monitoring - ranges from satellite remote sensing including InSAR to leveling and EDM surveys, campaign and telemetered GPS networks, electronic tiltmeters and strainmeters, airborne magnetic and electromagnetic surveys, short-period and broadband seismic monitoring, even microphones tuned for infrasound. They include virtually every method used in resource exploration except large-scale seismic reflection. By “geophysical ” we include both active and passive methods as well as geodetic technologies. Volcano monitoring incorporates telemetry to handle high-bandwith cameras and broadband seismometers. Critical geophysical targets include the flux of magma in shallow reservoir and lava-tube systems, changes in active hydrothermal systems, volcanic edifice stability, and lahars. Since the eruption of Mount St. Helens in Washington State in 1980, and the eruption at Pu’u O’o in Hawai’i beginning in 1983 and still continuing, dramatic advances have occurred in monitoring technology such as “crisis GIS” and lahar modeling, InSAR interferograms, as well as gas emission geochemistry sampling, and hazards mapping and eruption predictions. The on-going eruption of Mount St. Helens has led to new monitoring technologies, including advances in broadband Wi-Fi and satellite telemetry as well as new instrumentation. Assessment of the gap between adequate monitoring and threat at the 169 potentially dangerous Holocene volcanoes shows where populations are dangerously exposed to volcanic catastrophes in the United States and its territories . This paper focuses primarily on Hawai’ian volcanoes and the northern Pacific and Cascades volcanoes. The US Geological Survey, the US National Park System, and the University of Utah cooperate in a program to monitor the huge Yellowstone volcanic system, and a separate observatory monitors the restive Long Valley

  15. Scheduled Relaxation Jacobi method: Improvements and applications

    NASA Astrophysics Data System (ADS)

    Adsuara, J. E.; Cordero-Carrión, I.; Cerdá-Durán, P.; Aloy, M. A.

    2016-09-01

    Elliptic partial differential equations (ePDEs) appear in a wide variety of areas of mathematics, physics and engineering. Typically, ePDEs must be solved numerically, which sets an ever growing demand for efficient and highly parallel algorithms to tackle their computational solution. The Scheduled Relaxation Jacobi (SRJ) is a promising class of methods, atypical for combining simplicity and efficiency, that has been recently introduced for solving linear Poisson-like ePDEs. The SRJ methodology relies on computing the appropriate parameters of a multilevel approach with the goal of minimizing the number of iterations needed to cut down the residuals below specified tolerances. The efficiency in the reduction of the residual increases with the number of levels employed in the algorithm. Applying the original methodology to compute the algorithm parameters with more than 5 levels notably hinders obtaining optimal SRJ schemes, as the mixed (non-linear) algebraic-differential system of equations from which they result becomes notably stiff. Here we present a new methodology for obtaining the parameters of SRJ schemes that overcomes the limitations of the original algorithm and provide parameters for SRJ schemes with up to 15 levels and resolutions of up to 215 points per dimension, allowing for acceleration factors larger than several hundreds with respect to the Jacobi method for typical resolutions and, in some high resolution cases, close to 1000. Most of the success in finding SRJ optimal schemes with more than 10 levels is based on an analytic reduction of the complexity of the previously mentioned system of equations. Furthermore, we extend the original algorithm to apply it to certain systems of non-linear ePDEs.

  16. Development of T m -shift genotyping method for detection of cat-derived Giardia lamblia.

    PubMed

    Pan, Weida; Fu, Yeqi; Abdullahi, Auwalu Yusuf; Wang, Mingwei; Shi, Xianli; Yang, Fang; Yu, Xingang; Yan, Xinxin; Zhang, Pan; Hang, Jianxiong; Li, Guoqing

    2017-04-01

    To develop T m -shift genotyping method for detection of cat-derived Giardia lamblia, two sets of primers with two GC-rich tails of unequal length attached to their 5'-end were designed according to two SNPs (BG434 and BG170) of β-giardin (bg) gene, and specific PCR products were identified by inspection of a melting curve on real-time PCR thermocycler. A series of experiments on the stability, sensitivity, and accuracy of T m -shift method was tested, and clinical samples were also detected. The results showed that two sets of primers based on SNP could distinguish accurately between assemblages A and F. Coefficient of variation of T m values of assemblage A and F was 0.14 and 0.07% in BG434 and 0.10 and 0.11% in BG170, respectively. The lowest detection concentration was 4.52 × 10(-5) and 4.88 × 10(-5) ng/μL samples of assemblage A and F standard plasmids. The T m -shift genotyping results of ten DNA samples from the cat-derived G. lamblia were consistent with their known genotypes. The detection rate of clinical samples by T m -shift was higher than that by microscopy, and their genotyping results were in complete accordance with sequencing results. It is concluded that the T m -shift genotyping method is rapid, specific, and sensitive and may provide a new technological mean for molecular detection and epidemiological investigation of the cat-derived G. lamblia.

  17. Formal Methods Applications in Air Transportation

    NASA Technical Reports Server (NTRS)

    Farley, Todd

    2009-01-01

    The U.S. air transportation system is the most productive in the world, moving far more people and goods than any other. It is also the safest system in the world, thanks in part to its venerable air traffic control system. But as demand for air travel continues to grow, the air traffic control system s aging infrastructure and labor-intensive procedures are impinging on its ability to keep pace with demand. And that impinges on the growth of our economy. Air traffic control modernization has long held the promise of a more efficient air transportation system. Part of NASA s current mission is to develop advanced automation and operational concepts that will expand the capacity of our national airspace system while still maintaining its excellent record for safety. It is a challenging mission, as efforts to modernize have, for decades, been hamstrung by the inability to assure safety to the satisfaction of system operators, system regulators, and/or the traveling public. In this talk, we ll provide a brief history of air traffic control, focusing on the tension between efficiency and safety assurance, and the promise of formal methods going forward.

  18. Platelet activation of platelet concentrates derived from buffy coat and apheresis methods.

    PubMed

    Ali, Soleimany Ferizhandy

    2011-02-01

    Preparation for storage may cause platelet activation. The quality of platelet concentrates plays an important role in transfusion therapy. Platelet concentrates are produced by different centrifugation methods; buffy coat (buffy coat-derived platelet concentrates-BC) and plateletpheresis (apheresis-derived platelet concentrates-APC). Their quality was assessed using the following parameters: platelet, WBC and RBC counts pH, volume, platelet factor 4 (PF4) and Annexin V. The present paper compares the quality of both platelet preparations in vitro. In this experimental study, 30 platelet concentrates were harvested with the Haemonetics MCS plus and 30 units via the buffy coat (BC) method. The percentages of Annexin V expression, PF4 levels, platelet, WBC and RBC counts, pH and volume were measure immediately after collection and after 3 days of storage. During storage for up to 3 days, BC units displayed, no significant pH or RBC, difference in comparison with apheresis preparations (p>0.05). During storage for up to 3 days, BC units displayed a significant increase in the PF4 and Annexin V expression, compared to the apheresis preparations on day three (p<0.05). The kinetics of PF4 and Annexin V levels are influenced by the method used to prepare platelets for storage. The different levels of PF4 and Annexin V in BCs and APCs clearly demonstrates a progressive activation of BC platelets exceeding that of APC. However, in vivo studies should be performed to confirm these findings.

  19. Concise reviews: Characteristics and potential applications of human dental tissue-derived mesenchymal stem cells.

    PubMed

    Liu, Junjun; Yu, Fang; Sun, Yao; Jiang, Beizhan; Zhang, Wenjun; Yang, Jianhua; Xu, Guo-Tong; Liang, Aibin; Liu, Shangfeng

    2015-03-01

    Recently, numerous types of human dental tissue-derived mesenchymal stem cells (MSCs) have been isolated and characterized, including dental pulp stem cells, stem cells from exfoliated deciduous teeth, periodontal ligament stem cells, dental follicle progenitor cells, alveolar bone-derived MSCs, stem cells from apical papilla, tooth germ progenitor cells, and gingival MSCs. All these MSC-like cells exhibit self-renewal, multilineage differentiation potential, and immunomodulatory properties. Several studies have demonstrated the potential advantages of dental stem cell-based approaches for regenerative treatments and immunotherapies. This review outlines the properties of various dental MSC-like populations and the progress toward their use in regenerative therapy. Several dental stem cell banks worldwide are also introduced, with a view toward future clinical application.

  20. Quinoxaline, its derivatives and applications: A State of the Art review.

    PubMed

    Pereira, Joana A; Pessoa, Ana M; Cordeiro, M Natália D S; Fernandes, Rúben; Prudêncio, Cristina; Noronha, João Paulo; Vieira, Mónica

    2015-06-05

    Quinoxaline derivatives are an important class of heterocycle compounds, where N replaces some carbon atoms in the ring of naphthalene. Its molecular formula is C8H6N2, formed by the fusion of two aromatic rings, benzene and pyrazine. It is rare in natural state, but their synthesis is easy to perform. In this review the State of the Art will be presented, which includes a summary of the progress made over the past years in the knowledge of the structure and mechanism of the quinoxaline and quinoxaline derivatives, associated medical and biomedical value as well as industrial value. Modifying quinoxaline structure it is possible to obtain a wide variety of biomedical applications, namely antimicrobial activities and chronic and metabolic diseases treatment.

  1. Determining quasidiabatic coupled electronic state Hamiltonians using derivative couplings: A normal equations based method.

    PubMed

    Papas, Brian N; Schuurman, Michael S; Yarkony, David R

    2008-09-28

    A self-consistent procedure for constructing a quasidiabatic Hamiltonian representing N(state) coupled electronic states in the vicinity of an arbitrary point in nuclear coordinate space is described. The matrix elements of the Hamiltonian are polynomials of arbitrary order. Employing a crude adiabatic basis, the coefficients of the linear terms are determined exactly using analytic gradient techniques. The remaining polynomial coefficients are determined from the normal form of a system of pseudolinear equations, which uses energy gradient and derivative coupling information obtained from reliable multireference configuration interaction wave functions. In a previous implementation energy gradient and derivative coupling information were employed to limit the number of nuclear configurations at which ab initio data were required to determine the unknown coefficients. Conversely, the key aspect of the current approach is the use of ab initio data over an extended range of nuclear configurations. The normal form of the system of pseudolinear equations is introduced here to obtain a least-squares fit to what would have been an (intractable) overcomplete set of data in the previous approach. This method provides a quasidiabatic representation that minimizes the residual derivative coupling in a least-squares sense, a means to extend the domain of accuracy of the diabatic Hamiltonian or refine its accuracy within a given domain, and a way to impose point group symmetry and hermiticity. These attributes are illustrated using the 1 (2)A(1) and 1 (2)E states of the 1-propynyl radical, CH(3)CC.

  2. Continuous refractive index dispersion measurement based on derivative total reflection method

    NASA Astrophysics Data System (ADS)

    Deng, Zhichao; Wang, Jin; Ye, Qing; Sun, Tengqian; Zhou, Wenyuan; Mei, Jianchun; Zhang, Chunping; Tian, Jianguo

    2015-04-01

    Traditionally, continuous refractive index dispersion (CRID) measurement of materials with scattering is hard to realize. In this paper, CRID measurement based on the derivative total reflection method (CRIDM-DTRM) is proposed to measure the CRID of both absorption and scattering materials. It effectively determined the CRID of K9 glass, concentrated milk, and 0.5% methyl red solution in the 400-750 nm range with the spectral resolution of about 0.259 nm. For the first time, CRID of a scattering material is measured. CRIDM-DTRM is a useful technique in the field of RID measurement, especially for biotissues and anomalous dispersion materials.

  3. Comparison of function approximation, heuristic, and derivative-based methods for automatic calibration of computationally expensive groundwater bioremediation models

    NASA Astrophysics Data System (ADS)

    Mugunthan, Pradeep; Shoemaker, Christine A.; Regis, Rommel G.

    2005-11-01

    The performance of function approximation (FA) methods is compared to heuristic and derivative-based nonlinear optimization methods for automatic calibration of biokinetic parameters of a groundwater bioremediation model of chlorinated ethenes on a hypothetical and a real field case. For the hypothetical case, on the basis of 10 trials on two different objective functions, the FA methods had the lowest mean and smaller deviation of the objective function among all algorithms for a combined Nash-Sutcliffe objective and among all but the derivative-based algorithm for a total squared error objective. The best algorithms in the hypothetical case were applied to calibrate eight parameters to data obtained from a site in California. In three trials the FA methods outperformed heuristic and derivative-based methods for both objective functions. This study indicates that function approximation methods could be a more efficient alternative to heuristic and derivative-based methods for automatic calibration of computationally expensive bioremediation models.

  4. NEOCHIM: An electrochemical method for environmental application

    USGS Publications Warehouse

    Leinz, R.W.; Hoover, D.B.; Meier, A.L.

    1999-01-01

    Ion migration and electroosmosis are the principal processes underlying electrokinetic remediation of hazardous wastes from soils. These processes are a response of charged species to an applied electrical current and they are accompanied by electrolysis of water at the electrodes through which the current is applied. Electrolysis results in the formation of OH- at the cathode and H+ at the anode. The current drives the OH- and H+ thus formed from the electrodes, through the soil and to the electrode of opposite charge. Introduction of OH- and H+ into the soil being treated modifies soil chemistry and can interfere with either the collection or immobilization of hazardous waste ions. The introduction of either OH- or H+ to the soil can be problematic to electrokinetic remediation but the problem caused by OH- has been the focus of most researchers. The problem has been addressed by flushing the OH- from the soil near the cathode or treating the soil with buffers. These treatments would apply as well to soils affected by H+. With the NEOCHIM technology, developed by the U.S. Geological Survey (USGS) for use as a sampling technique in exploration for buried ore deposits, OH- and H+ are retained in the inner compartment of two-compartment electrodes and are thus prevented from reaching the soil. This enables the extraction of cations and anions, including anionic forms of toxic metals such as HAsO42-. One of the principal attributes of NEOCHIM is the large volume of soil from which ions can be extracted. It is mathematically demonstrable that NEOCHIM extraction volumes can be orders of magnitude greater than volumes typically sampled in more conventional geochemical exploration methods or for environmental sampling. The technology may also be used to introduce selected ions into the soil that affect the solubility of ceratin ions present in the soil. Although field tests for mineral exploration have shown NEOCHIM extraction efficiencies of about 25-35%, laboratory

  5. Pathogen inactivation and removal methods for plasma-derived clotting factor concentrates.

    PubMed

    Klamroth, Robert; Gröner, Albrecht; Simon, Toby L

    2014-05-01

    Pathogen safety is crucial for plasma-derived clotting factor concentrates used in the treatment of bleeding disorders. Plasma, the starting material for these products, is collected by plasmapheresis (source plasma) or derived from whole blood donations (recovered plasma). The primary measures regarding pathogen safety are selection of healthy donors donating in centers with appropriate epidemiologic data for the main blood-transmissible viruses, screening donations for the absence of relevant infectious blood-borne viruses, and release of plasma pools for further processing only if they are nonreactive for serologic markers and nucleic acids for these viruses. Despite this testing, pathogen inactivation and/or removal during the manufacturing process of plasma-derived clotting factor concentrates is required to ensure prevention of transmission of infectious agents. Historically, hepatitis viruses and human immunodeficiency virus have posed the greatest threat to patients receiving plasma-derived therapy for treatment of hemophilia or von Willebrand disease. Over the past 30 years, dedicated virus inactivation and removal steps have been integrated into factor concentrate production processes, essentially eliminating transmission of these viruses. Manufacturing steps used in the purification of factor concentrates have also proved to be successful in reducing potential prion infectivity. In this review, current techniques for inactivation and removal of pathogens from factor concentrates are discussed. Ideally, production processes should involve a combination of complementary steps for pathogen inactivation and/or removal to ensure product safety. Finally, potential batch-to-batch contamination is avoided by stringent cleaning and sanitization methods as part of the manufacturing process.

  6. 7 CFR 786.103 - Time and method of application.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ....103 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS DAIRY DISASTER ASSISTANCE PAYMENT PROGRAM (DDAP-III) § 786.103 Time and method of application. (a) Dairy producers may obtain an application, in person, by mail,...

  7. 7 CFR 786.103 - Time and method of application.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ....103 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS DAIRY DISASTER ASSISTANCE PAYMENT PROGRAM (DDAP-III) § 786.103 Time and method of application. (a) Dairy producers may obtain an application, in person, by mail,...

  8. 7 CFR 786.103 - Time and method of application.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ....103 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS DAIRY DISASTER ASSISTANCE PAYMENT PROGRAM (DDAP-III) § 786.103 Time and method of application. (a) Dairy producers may obtain an application, in person, by mail,...

  9. 7 CFR 786.103 - Time and method of application.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ....103 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS DAIRY DISASTER ASSISTANCE PAYMENT PROGRAM (DDAP-III) § 786.103 Time and method of application. (a) Dairy producers may obtain an application, in person, by mail,...

  10. 7 CFR 786.103 - Time and method of application.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ....103 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS DAIRY DISASTER ASSISTANCE PAYMENT PROGRAM (DDAP-III) § 786.103 Time and method of application. (a) Dairy producers may obtain an application, in person, by mail,...

  11. [Application of morpheme translation method in english translation of TCM].

    PubMed

    Diao, Xiang; Hu, You-Ping

    2006-03-01

    In this paper, application of morpheme translation method in English translation of TCM was introduced, and its superiorities and limitations were analyzed in order to promote the standardization and improve the confused current status of the English translation of TCM.

  12. Modern industrial and pharmacological applications of indigo dye and its derivatives--a review.

    PubMed

    Stasiak, Natalia; Kukuła-Koch, Wirginia; Głowniak, Kazimierz

    2014-01-01

    Plant sources, chemical properties, bioactivities, as well as the synthesis of indigo dye and its derivatives, are reviewed in this paper. These compounds were chosen because of their significant benefits and scope of application as both coloring agents in the textile industry and as pharmacologically active natural products. Their use in traditional chinese medicine (TCM) has directed the attention of European researchers and medical doctors alike. The preparation of indigoferous plants--Indigo naturalis is currently about to be introduced into the European Pharmacopoeia.

  13. Derive and conquer: sourcing and differentiating stem cells for therapeutic applications.

    PubMed

    Klimanskaya, Irina; Rosenthal, Nadia; Lanza, Robert

    2008-02-01

    Although great progress has been made in the isolation and culture of stem cells, the future of stem-cell-based therapies and their productive use in drug discovery and regenerative medicine depends on two key factors: finding reliable sources of multipotent and pluripotent cells and the ability to control their differentiation to generate desired derivatives. It is essential for clinical applications to establish reliable sources of pathogen-free human embryonic stem cells (ESCs) and develop suitable differentiation techniques. Here, we address some of the problems associated with the sourcing of human ESCs and discuss the current status of stem-cell differentiation technology.

  14. A new generation of bio-derived ceramic materials for medical applications.

    PubMed

    González, P; Borrajo, J P; Serra, J; Chiussi, S; León, B; Martínez-Fernández, J; Varela-Feria, F M; de Arellano-López, A R; de Carlos, A; Muñoz, F M; López, M; Singh, M

    2009-03-01

    A new generation of bio-derived ceramics can be developed as a base material for medical implants. Specific plant species are used as templates on which innovative transformation processes can modify the chemical composition maintaining the original biostructure. Building on the outstanding mechanical properties of the starting lignocellulosic templates, it is possible to develop lightweight and high-strength scaffolds for bone substitution. In vitro and in vivo experiments demonstrate the excellent biocompatibility of this new silicon carbide material (bioSiC) and how it gets colonized by the hosting bone tissue because of its unique interconnected hierarchic porosity, which opens the door to new biomedical applications.

  15. Quantitative analysis of chlorpheniramine maleate and phenylephrine hydrochloride in nasal drops by differential-derivative spectrophotometric, zero-crossing first derivative UV spectrophotometric and absorbance ratio methods.

    PubMed

    Erk, N

    2000-11-01

    Three simple, rapid and accurate methods are described for the simultaneous determination of chlorpheniramine maleate and phenylephrine hydrochloride in two component mixtures. The first method comprised of measurement of difference absorptivities derivatized in first order of a nasal drops in 0.1 N NaOH relative to that of an equimolar solution in methanol at wavelengths of 271.6 and 250.2 nm, respectively. The second method, zero-crossing derivative spectrophotometry, is based on recording the first derivative curves and determining each component using the zero-crossing technique. Using first derivative spectrophotometry, the amplitudes in the first derivative spectra at 246.5 and 238.6 nm were selected to simultaneously determine chlorpheniramine maleate and phenylephrine hydrochloride in the mixture. The presence of identical zero-crossing points for pure drugs and nasal drop solutions established the non-interference of the excipients in the absorption at these wavelengths. Absorbance ratio method was also developed for a comparison method. The proposed procedures were successfully applied to the determination of chlorpheniramine maleate and phenylephrine hydrochloride in nasal drops, with a high percentage of recovery, good accuracy and precision.

  16. Application of ligand- and receptor-based approaches for prediction of the HIV-RT inhibitory activity of fullerene derivatives

    NASA Astrophysics Data System (ADS)

    Yilmaz, Hayriye; Ahmed, Lucky; Rasulev, Bakhtiyor; Leszczynski, Jerzy

    2016-05-01

    Fullerene and its derivatives have potential to be utilized in many biomedical applications. In the present study, we investigated the role of fullerene derivatives as inhibitors of HIV-RT by combined protein-ligand docking approach and QSAR methods. The study shows the best predictive QSAR model that represents a two-variable model. It has a good ratio of the number of descriptors and predictive ability. The main contributions to the inhibitory activity are provided by signal JhetZ descriptor and μ (dipole moment, as a measure of the polarity of a compound). The developed GA-MLRA-based model demonstrates a good performance, confirmed by statistics ( {R2_{{training}} = 0.867,Q2 = 0.788,R2_{{test}} = 0.902} ). The structure-activity analysis of these fullerene analogues allowed us to design and suggest for synthesis a set of new potentially active fullerenes. Finally, the molecular docking analysis was carried out to understand the details of interactions between HIV-RT and fullerene-C60 derivatives.

  17. Antibody humanization methods for development of therapeutic applications.

    PubMed

    Ahmadzadeh, Vahideh; Farajnia, Safar; Feizi, Mohammad Ali Hosseinpour; Nejad, Ramezan Ali Khavari

    2014-04-01

    Recombinant antibody technologies are rapidly becoming available and showing considerable clinical success. However, the immunogenicity of murine-derived monoclonal antibodies is restrictive in cancer immunotherapy. Humanized antibodies can overcome these problems and are considered to be a promising alternative therapeutic agent. There are several approaches for antibody humanization. In this article we review various methods used in the antibody humanization process.

  18. Diaminoacid derivatives of protoporphyrine used as photosensitizers in photodynamic method of tumor diagnosis and treatment

    NASA Astrophysics Data System (ADS)

    Graczyk, Alfreda; Kwasny, Miroslaw; Ye, Shu; Milosz, Ewa; Kowalska, Agnieszka; Podhajska, Anna

    2003-10-01

    Observation and selective destruction of biological tissues, due to use of photochemical reaction sensitised with photosensitive dyes, are applied in modern method of tumor diagnosis and treatment as well as destruction of atheromatous plaques and restenosis prevention. This method, called photodynamic method (PDT), has been developed for recent 30 years in USA, Canada, Japan, and China and in majority of European countries. It has many advantages that distinguish it from among other currently used diagnostic and therapeutic methods. Both, the applied photosensitizers and photodynamic effect influence on active biological compounds present in an organism, mainly on enzymatic proteins, hormones, and particular elements of immunological system. The PDT method can be used not only for in situ tumor treatment but also for the treatment in metastasis state. It was thought previously that direct activity of cytotoxic radicals and singlet oxygen causes tissues necrosis. At present, additional investigations are performed on destruction mechanisms, i.e., occlusion of blood vessels and lymphatic vessels and PDT influence on immunological system revealing in cytokines release. In Poland, the technology of new class of photosensitizer - diaminoacid derivatives of protoporphyrin PP(AA)2Arg2 as well as the basic half-product - hemis of very high purity has been developed and activities for their industrial production have been performed. In vitro investigations on quantum luminescence yield and singlet oxygen quantum yield of the obtained preparations were made. These compounds do not show toxic properties and they are neither mutagenic nor teratogenic. Three aminoacid protoporphyrine derivatives were chosen for industrial scale production, i.e., PP(Ala)2Arg2, PP(Ser)2Arg2, PP(Plu)2Arg2 that were efficient for the largest number of tumors investigated on cell lines. A preparation being the mixture of these derivatives is called Sensyphyrine. In the first stage of Sensyphyrine

  19. Anisotropic surface hole-transport property of triphenylamine-derivative single crystal prepared by solution method

    NASA Astrophysics Data System (ADS)

    Umeda, Minoru; Katagiri, Mitsuhiko; Shironita, Sayoko; Nagayama, Norio

    2016-12-01

    This paper reports the anisotropic hole transport at the triphenylamine-derivative single crystal surface prepared by a solution method. Triphenylamine derivatives are commonly used in a hole-transport material for organic photoconductors of laser-beam printers, in which the materials are used as an amorphous form. For developing organic photovoltaics using the photoconductor's technology, preparation of a single crystal seems to be a specific way by realizing the high mobility of an organic semiconductor. In this study, a single crystal of 4-(2,2-diphenylethenyl)-N,N-bis(4-methylphenyl)-benzenamine (TPA) was prepared and its anisotropic hole-transport property measured. First, the hole-transport property of the TPA was investigated based on its chemical structure and electrochemical redox characteristics. Next, a large-scale single crystal formation at a high rate was developed by employing a solution method based on its solubility and supersolubility curves. The grown TPA was found to be a single crystal based on the polarization micrograph observation and crystallographic analysis. For the TPA single crystal, an anisotropic surface conduction was found, which was well explained by its molecular stack structure. The measured current in the long-axis direction is one order of magnitude greater than that of amorphous TPA.

  20. Pharmacophore identification and bioactivity prediction for triaminotriazine derivatives by electron conformational-genetic algorithm QSAR method.

    PubMed

    Saripinar, Emin; Geçen, Nazmiye; Sahin, Kader; Yanmaz, Ersin

    2010-09-01

    The electron conformational-genetic algorithm (EC-GA) method has been employed as a 4D-QSAR approach to reveal the pharmacophore (Pha) and to predict anticancer activity in the N-morpholino triaminotriazine derivatives. The electron conformational matrices of congruity (ECMCs) identified by electronic and structural parameters are constructed from data of conformational analysis and electronic structure calculation of molecules. Comparing the matrices, electron conformational submatrix of activity (ECSA, Pha) are revealed that are common for these compounds within a minimum tolerance. To predict the theoretical activity of training and test set and to select important variables for describing the activities, genetic algorithm and non-linear least square regression methods were applied. Regression coefficients were found 0.9708 for training and 0.9520 for test set.

  1. Using a derivative-free optimization method for multiple solutions of inverse transport problems

    SciTech Connect

    Armstrong, Jerawan C.; Favorite, Jeffrey A.

    2016-01-14

    Identifying unknown components of an object that emits radiation is an important problem for national and global security. Radiation signatures measured from an object of interest can be used to infer object parameter values that are not known. This problem is called an inverse transport problem. An inverse transport problem may have multiple solutions and the most widely used approach for its solution is an iterative optimization method. This paper proposes a stochastic derivative-free global optimization algorithm to find multiple solutions of inverse transport problems. The algorithm is an extension of a multilevel single linkage (MLSL) method where a mesh adaptive direct search (MADS) algorithm is incorporated into the local phase. Furthermore, numerical test cases using uncollided fluxes of discrete gamma-ray lines are presented to show the performance of this new algorithm.

  2. Using a derivative-free optimization method for multiple solutions of inverse transport problems

    DOE PAGES

    Armstrong, Jerawan C.; Favorite, Jeffrey A.

    2016-01-14

    Identifying unknown components of an object that emits radiation is an important problem for national and global security. Radiation signatures measured from an object of interest can be used to infer object parameter values that are not known. This problem is called an inverse transport problem. An inverse transport problem may have multiple solutions and the most widely used approach for its solution is an iterative optimization method. This paper proposes a stochastic derivative-free global optimization algorithm to find multiple solutions of inverse transport problems. The algorithm is an extension of a multilevel single linkage (MLSL) method where a meshmore » adaptive direct search (MADS) algorithm is incorporated into the local phase. Furthermore, numerical test cases using uncollided fluxes of discrete gamma-ray lines are presented to show the performance of this new algorithm.« less

  3. Perturbative method for the derivation of quantum kinetic theory based on closed-time-path formalism.

    PubMed

    Koide, Jun

    2002-02-01

    Within the closed-time-path formalism, a perturbative method is presented, which reduces the microscopic field theory to the quantum kinetic theory. In order to make this reduction, the expectation value of a physical quantity must be calculated under the condition that the Wigner distribution function is fixed, because it is the independent dynamical variable in the quantum kinetic theory. It is shown that when a nonequilibrium Green function in the form of the generalized Kadanoff-Baym ansatz is utilized, this condition appears as a cancellation of a certain part of contributions in the diagrammatic expression of the expectation value. Together with the quantum kinetic equation, which can be derived in the closed-time-path formalism, this method provides a basis for the kinetic-theoretical description.

  4. A method for evaluating models that use galaxy rotation curves to derive the density profiles

    NASA Astrophysics Data System (ADS)

    de Almeida, Álefe O. F.; Piattella, Oliver F.; Rodrigues, Davi C.

    2016-11-01

    There are some approaches, either based on General Relativity (GR) or modified gravity, that use galaxy rotation curves to derive the matter density of the corresponding galaxy, and this procedure would either indicate a partial or a complete elimination of dark matter in galaxies. Here we review these approaches, clarify the difficulties on this inverted procedure, present a method for evaluating them, and use it to test two specific approaches that are based on GR: the Cooperstock-Tieu (CT) and the Balasin-Grumiller (BG) approaches. Using this new method, we find that neither of the tested approaches can satisfactorily fit the observational data without dark matter. The CT approach results can be significantly improved if some dark matter is considered, while for the BG approach no usual dark matter halo can improve its results.

  5. ATLID beam steering mechanism and derived new piezoelectric-based devices for optical applications

    NASA Astrophysics Data System (ADS)

    Bourgain, F.; Barillot, F.; Belly, C.; Claeyssen, F.

    2015-09-01

    In Space & Defence (as well as in many others fields), there is a trend for miniaturisation in active optics requiring new actuators. Applications also often require the ability to withstand high vibrations and shocks levels, as well as vacuum compatibility for space applications. A new generation of small and smart actuators such as piezoelectric (piezo) actuators, are resolving this trend, thanks to their capacity to offer high energy density and to support both extreme and various requirements. This paper first presents the BSM mechanism and its requirements, the technologies involved in the design and the validation campaign results. Secondly, a derived XY piezoelectric positioning stage based on the same APA® and associated Strain Gage sensing technology is presented with its associated performances. Finally, a new piezoelectric motor based on the APA® technology, which allows the combination of long stroke while maintaining high resolution positioning of optical elements, is presented with experimental performances.

  6. Application research on enhancing near-infrared micro-imaging quality by 2nd derivative

    NASA Astrophysics Data System (ADS)

    Wang, Dong; Ma, Zhi-hong; Zhao, Liu; Wang, Bei-hong; Han, Ping; Pan, Li-gang; Wang, Ji-hua

    2013-08-01

    Near-infrared micro-imaging will not only provide the sample's spatial distribution information, but also the spectroscopic information of each pixel. In this thesis, it took the artificial sample of wheat flour and formaldehyde sodium sulfoxylate distribution given for example to research the data processing method for enhancing the quality of near-infrared micro-imaging. Near-infrared spectroscopic feature of wheat flour and formaldehyde sodium sulfoxylate being studied on, compare correlation imaging and 2nd derivative imaging were applied in the imaging processing of the near-infrared micro-image of the artificial sample. Furthermore, the two methods were combined, i.e. 2nd derivative compare correlation imaging was acquired. The result indicated that the difference of the correlation coefficients between the two substances, i.e. wheat flour and formaldehyde sodium sulfoxylate, and the reference spectrum has been increased from 0.001 in compare correlation image to 0.796 in 2nd derivative compare correlation image respectively, which enhances the imaging quality efficiently. This study will, to some extent, be of important reference significance to near-infrared micro-imaging method research of agricultural products and foods.

  7. Derivative spectrophotometric method for simultaneous determination of zofenopril and fluvastatin in mixtures and pharmaceutical dosage forms

    NASA Astrophysics Data System (ADS)

    Stolarczyk, Mariusz; Maślanka, Anna; Apola, Anna; Rybak, Wojciech; Krzek, Jan

    2015-09-01

    Fast, accurate and precise method for the determination of zofenopril and fluvastatin was developed using spectrophotometry of the first (D1), second (D2), and third (D3) order derivatives in two-component mixtures and in pharmaceutical preparations. It was shown, that the developed method allows for the determination of the tested components in a direct manner, despite the apparent interference of the absorption spectra in the UV range. For quantitative determinations, "zero-crossing" method was chosen, appropriate wavelengths for zofenopril were: D1 λ = 270.85 nm, D2 λ = 286.38 nm, D3 λ = 253.90 nm. Fluvastatin was determined at wavelengths: D1 λ = 339.03 nm, D2 λ = 252.57 nm, D3 λ = 258.50 nm, respectively. The method was characterized by high sensitivity and accuracy, for zofenopril LOD was in the range of 0.19-0.87 μg mL-1, for fluvastatin 0.51-1.18 μg mL-1, depending on the class of derivative, and for zofenopril and fluvastatin LOQ was 0.57-2.64 μg mL-1 and 1.56-3.57 μg mL-1, respectively. The recovery of individual components was within the range of 100 ± 5%. For zofenopril, the linearity range was estimated between 7.65 μg mL-1 and 22.94 μg mL-1, and for fluvastatin between 5.60 μg mL-1 and 28.00 μg mL-1.

  8. Derivative spectrophotometric method for simultaneous determination of zofenopril and fluvastatin in mixtures and pharmaceutical dosage forms.

    PubMed

    Stolarczyk, Mariusz; Maślanka, Anna; Apola, Anna; Rybak, Wojciech; Krzek, Jan

    2015-09-05

    Fast, accurate and precise method for the determination of zofenopril and fluvastatin was developed using spectrophotometry of the first (D1), second (D2), and third (D3) order derivatives in two-component mixtures and in pharmaceutical preparations. It was shown, that the developed method allows for the determination of the tested components in a direct manner, despite the apparent interference of the absorption spectra in the UV range. For quantitative determinations, "zero-crossing" method was chosen, appropriate wavelengths for zofenopril were: D1 λ=270.85 nm, D2 λ=286.38 nm, D3 λ=253.90 nm. Fluvastatin was determined at wavelengths: D1 λ=339.03 nm, D2 λ=252.57 nm, D3 λ=258.50 nm, respectively. The method was characterized by high sensitivity and accuracy, for zofenopril LOD was in the range of 0.19-0.87 μg mL(-1), for fluvastatin 0.51-1.18 μg mL(-1), depending on the class of derivative, and for zofenopril and fluvastatin LOQ was 0.57-2.64 μg mL(-1) and 1.56-3.57 μg mL(-1), respectively. The recovery of individual components was within the range of 100±5%. For zofenopril, the linearity range was estimated between 7.65 μg mL(-1) and 22.94 μg mL(-1), and for fluvastatin between 5.60 μg mL(-1) and 28.00 μg mL(-1).

  9. Comparison of Response Surface Construction Methods for Derivative Estimation Using Moving Least Squares, Kriging and Radial Basis Functions

    NASA Technical Reports Server (NTRS)

    Krishnamurthy, Thiagarajan

    2005-01-01

    Response construction methods using Moving Least Squares (MLS), Kriging and Radial Basis Functions (RBF) are compared with the Global Least Squares (GLS) method in three numerical examples for derivative generation capability. Also, a new Interpolating Moving Least Squares (IMLS) method adopted from the meshless method is presented. It is found that the response surface construction methods using the Kriging and RBF interpolation yields more accurate results compared with MLS and GLS methods. Several computational aspects of the response surface construction methods also discussed.

  10. The applications of buckminsterfullerene C60 and derivatives in orthopaedic research

    PubMed Central

    Liu, Qihai; Cui, Quanjun; Li, Xudong Joshua; Jin, Li

    2014-01-01

    Buckminsterfullerene C60 and derivatives have been extensively explored in biomedical research due to their unique structure and unparalleled physicochemical properties. C60 is characterized as a “free radical sponge” with an anti-oxidant efficacy several hundred-fold higher than conventional anti-oxidants. Also, the C60 core has a strong electron-attracting ability and numerous functional compounds with widely different properties can be added to this fullerene cage. This review focused on the applications of C60 and derivatives in orthopaedic research, such as the treatment of cartilage degeneration, bone destruction, intervertebral disc degeneration (IVDD), vertebral bone marrow disorder, radiculopathy, etc., as well as their toxicity in vitro and in vivo. We suggest that C60 and derivatives, especially the C60 cores coupled with functional groups presenting new biological and pharmacological activities, are advantageous in orthopaedic research and will be promising in clinical performance for musculoskeletal disorders treatment; however, the pharmacokinetics and toxicology of these agents as local/systemic administration need to be carefully determined. PMID:24409811

  11. Cytotoxicity evaluation of polymer-derived ceramics for pacemaker electrode applications.

    PubMed

    Grossenbacher, Jonas; Gullo, Maurizio R; Dalcanale, Federico; Blugan, Gurdial; Kuebler, Jakob; Lecaudé, Stéphanie; Tevaearai Stahel, Hendrik; Brugger, Juergen

    2015-11-01

    Ceramics are known to be chemically stable, and the possibility to electrically dope polymer-derived ceramics makes it a material of interest for implantable electrode applications. We investigated cytotoxic characteristics of four polymer-derived ceramic candidates with either electrically conductive or insulating properties. Cytotoxicity was assessed by culturing C2C12 myoblast cells under two conditions: by exposing them to material extracts and by putting them directly in contact with material samples. Cell spreading was optically evaluated by comparing microscope observations immediately after the materials insertion and after 24 h culturing. Cell viability (MTT) and mortality (LDH) were quantified after 24-h incubation in contact with the materials. Comparison was made with biocompatible positive references (alumina, platinum, biocompatible stainless steel 1.4435), negative references (latex, stainless steel 1.4301) and controls (no material present in the culture wells). We found that the cytotoxic properties of tested ceramics are comparable to established reference materials. These ceramics, which are reported to be very stable, can be microstructured and electrically doped to a wide range of conductivity and are thus excellent candidates for implantable electrode applications including pacemakers.

  12. Synthesis and Characterization of a Chitosan Derivative for Electro-Optical Applications

    NASA Technical Reports Server (NTRS)

    Prastofer, Thomas

    1996-01-01

    Chitin is a naturally occurring polymer of alpha(1-4) poly N-acetylglucosamine found primarily in the shells of crustaceans and insects. This polymer is chemically and thermally stable and physically durable as a consequence of hydrogen bonding which causes the alignment and ordering of the polymer chains into microcrystals which aggregate into sheets with chiral nematic order. Industry has attempted to take advantage of chitin's properties and low cost (chitin is a waste product of the shellfish industry) to produce durable fibers and other products. This has been largely unsuccessful because of chitin's non reactivity and insolubility. Chitosan is the deacetylation product of chitin and retains many of the structural properties of chitin. Unlike chitin, chitosan is soluble in aqueous solution at reduced pH making it easier to be processed into fibers and films than chitin. Chitosan and its derivatives are now used in such commercial applications as wound dressings, waste water treatment, and in pharmaceuticals. In this study, we have synthesized a chitosan derivative, N-para-nitrophenyl chitosan (NPNPC), as a model material with potential applications in electro optics.

  13. The Application of Graphene and Its Derivatives to Energy Conversion, Storage, and Environmental and Biosensing Devices.

    PubMed

    Ali Tahir, Asif; Ullah, Habib; Sudhagar, Pitchaimuthu; Asri Mat Teridi, Mohd; Devadoss, Anitha; Sundaram, Senthilarasu

    2016-06-01

    Graphene (GR) and its derivatives are promising materials on the horizon of nanotechnology and material science and have attracted a tremendous amount of research interest in recent years. The unique atom-thick 2D structure with sp(2) hybridization and large specific surface area, high thermal conductivity, superior electron mobility, and chemical stability have made GR and its derivatives extremely attractive components for composite materials for solar energy conversion, energy storage, environmental purification, and biosensor applications. This review gives a brief introduction of GR's unique structure, band structure engineering, physical and chemical properties, and recent energy-related progress of GR-based materials in the fields of energy conversion (e.g., photocatalysis, photoelectrochemical water splitting, CO2 reduction, dye-sensitized and organic solar cells, and photosensitizers in photovoltaic devices) and energy storage (batteries, fuel cells, and supercapacitors). The vast coverage of advancements in environmental applications of GR-based materials for photocatalytic degradation of organic pollutants, gas sensing, and removal of heavy-metal ions is presented. Additionally, the use of graphene composites in the biosensing field is discussed. We conclude the review with remarks on the challenges, prospects, and further development of GR-based materials in the exciting fields of energy, environment, and bioscience.

  14. Biomedical applications of polymers derived by reversible addition - fragmentation chain-transfer (RAFT).

    PubMed

    Fairbanks, Benjamin D; Gunatillake, Pathiraja A; Meagher, Laurence

    2015-08-30

    RAFT- mediated polymerization, providing control over polymer length and architecture as well as facilitating post polymerization modification of end groups, has been applied to virtually every facet of biomedical materials research. RAFT polymers have seen particularly extensive use in drug delivery research. Facile generation of functional and telechelic polymers permits straightforward conjugation to many therapeutic compounds while synthesis of amphiphilic block copolymers via RAFT allows for the generation of self-assembled structures capable of carrying therapeutic payloads. With the large and growing body of literature employing RAFT polymers as drug delivery aids and vehicles, concern over the potential toxicity of RAFT derived polymers has been raised. While literature exploring this complication is relatively limited, the emerging consensus may be summed up in three parts: toxicity of polymers generated with dithiobenzoate RAFT agents is observed at high concentrations but not with polymers generated with trithiocarbonate RAFT agents; even for polymers generated with dithiobenzoate RAFT agents, most reported applications call for concentrations well below the toxicity threshold; and RAFT end-groups may be easily removed via any of a variety of techniques that leave the polymer with no intrinsic toxicity attributable to the mechanism of polymerization. The low toxicity of RAFT-derived polymers and the ability to remove end groups via straightforward and scalable processes make RAFT technology a valuable tool for practically any application in which a polymer of defined molecular weight and architecture is desired.

  15. Rice Husk Silica-Derived Nanomaterials for Battery Applications: A Literature Review.

    PubMed

    Shen, Yafei

    2017-02-08

    Silica-rich rice husk (RH) is an abundant and sustainable agricultural waste. The recovery of value-added products from RH or its ash to explore an economic way for the valorization of agricultural wastes has attracted wide attention. For instance, RH can be converted to biofuels and biochars simultaneously via thermochemical processes. In general, the applications of RH biochars include soil remediation, pollutant removal, silicon battery materials, and so forth. This review concludes recent progress in the synthesis of RH-derived silicon materials for lithium-ion battery (LIB) applications. Silica nanomaterials produced from RH are initially discussed. RH amorphous silica can also be fabricated to crystal silicon used for battery materials via widely used magnesiothermic reduction. However, the RH-derived Si nanoparticles suffer from a low Coulombic efficiency in the initial charge/discharge and limited cycle life as anode materials due to high surface reactions and low thermodynamic stability. The synthesis of Si materials with nano/microhierarchical structure would be an ideal way to improve their electrochemical performances. Embedding nano-Si into 3D conductive matrix is an effective way to improve the structural stability. Among the Si/carbon composite materials, carbon nanotubdes (CNTs) are a promising matrix due to the wired morphology, high electronic conductivity, and robust structure. Additionally, CNTs can easily form 3D cross-linked conducting networks, ensuring effective electron transportation among active particles. Si nanomaterials with microhierarchical structures in which CNTs are tightly intertwined between the RH-derived Si nanoparticles have been proven to be ideal LIB anode materials.

  16. Applications of Genetic Methods to NASA Design and Operations Problems

    NASA Technical Reports Server (NTRS)

    Laird, Philip D.

    1996-01-01

    We review four recent NASA-funded applications in which evolutionary/genetic methods are important. In the process we survey: the kinds of problems being solved today with these methods; techniques and tools used; problems encountered; and areas where research is needed. The presentation slides are annotated briefly at the top of each page.

  17. Host-Derived Artificial MicroRNA as an Alternative Method to Improve Soybean Resistance to Soybean Cyst Nematode

    PubMed Central

    Tian, Bin; Li, Jiarui; Oakley, Thomas R.; Todd, Timothy C.; Trick, Harold N.

    2016-01-01

    The soybean cyst nematode (SCN), Heterodera glycines, is one of the most important pests limiting soybean production worldwide. Novel approaches to managing this pest have focused on gene silencing of target nematode sequences using RNA interference (RNAi). With the discovery of endogenous microRNAs as a mode of gene regulation in plants, artificial microRNA (amiRNA) methods have become an alternative method for gene silencing, with the advantage that they can lead to more specific silencing of target genes than traditional RNAi vectors. To explore the application of amiRNAs for improving soybean resistance to SCN, three nematode genes (designated as J15, J20, and J23) were targeted using amiRNA vectors. The transgenic soybean hairy roots, transformed independently with these three amiRNA vectors, showed significant reductions in SCN population densities in bioassays. Expression of the targeted genes within SCN eggs were downregulated in populations feeding on transgenic hairy roots. Our results provide evidence that host-derived amiRNA methods have great potential to improve soybean resistance to SCN. This approach should also limit undesirable phenotypes associated with off-target effects, which is an important consideration for commercialization of transgenic crops. PMID:27941644

  18. Interatomic methods for the dispersion energy derived from the adiabatic connection fluctuation-dissipation theorem.

    PubMed

    Tkatchenko, Alexandre; Ambrosetti, Alberto; DiStasio, Robert A

    2013-02-21

    Interatomic pairwise methods are currently among the most popular and accurate ways to include dispersion energy in density functional theory calculations. However, when applied to more than two atoms, these methods are still frequently perceived to be based on ad hoc assumptions, rather than a rigorous derivation from quantum mechanics. Starting from the adiabatic connection fluctuation-dissipation (ACFD) theorem, an exact expression for the electronic exchange-correlation energy, we demonstrate that the pairwise interatomic dispersion energy for an arbitrary collection of isotropic polarizable dipoles emerges from the second-order expansion of the ACFD formula upon invoking the random-phase approximation (RPA) or the full-potential approximation. Moreover, for a system of quantum harmonic oscillators coupled through a dipole-dipole potential, we prove the equivalence between the full interaction energy obtained from the Hamiltonian diagonalization and the ACFD-RPA correlation energy. This property makes the Hamiltonian diagonalization an efficient method for the calculation of the many-body dispersion energy. In addition, we show that the switching function used to damp the dispersion interaction at short distances arises from a short-range screened Coulomb potential, whose role is to account for the spatial spread of the individual atomic dipole moments. By using the ACFD formula, we gain a deeper understanding of the approximations made in the interatomic pairwise approaches, providing a powerful formalism for further development of accurate and efficient methods for the calculation of the dispersion energy.

  19. Graphical method for deriving an effective interaction with a new vertex function

    SciTech Connect

    Suzuki, K.; Okamoto, R.; Kumagai, H.; Fujii, S.

    2011-02-15

    Introducing a new vertex function, Z(E), of an energy variable E, we derive a new equation for the effective interaction. The equation is obtained by replacing the Q box in the Krenciglowa-Kuo (KK) method with Z(E). This new approach can be viewed as an extension of the KK method. We show that this equation can be solved both in iterative and noniterative ways. We observe that the iteration procedure with Z(E) brings about fast convergence compared to the usual KK method. It is shown that, as in the KK approach, the procedure of calculating the effective interaction can be reduced to determining the true eigenvalues of the original Hamiltonian H and they can be obtained as the positions of intersections of graphs generated from Z(E). We find that this graphical method yields always precise results and reproduces any of the true eigenvalues of H. The calculation in the present approach can be made regardless of overlaps with the model space and energy differences between unperturbed energies and the eigenvalues of H. We find also that Z(E) is a well-behaved function of E and has no singularity. These characteristics of the present approach ensure stability in actual calculations and would be helpful to resolve some difficulties due to the presence of poles in the Q box. Performing test calculations, we verify numerically theoretical predictions made in the present approach.

  20. Advanced Applications of Adifor 3.0 for Efficient Calculation of First-and Second-Order CFD Sensitivity Derivatives

    NASA Technical Reports Server (NTRS)

    Taylor, Arthur C., III

    2004-01-01

    This final report will document the accomplishments of the work of this project. 1) The incremental-iterative (II) form of the reverse-mode (adjoint) method for computing first-order (FO) aerodynamic sensitivity derivatives (SDs) has been successfully implemented and tested in a 2D CFD code (called ANSERS) using the reverse-mode capability of ADIFOR 3.0. These preceding results compared very well with similar SDS computed via a black-box (BB) application of the reverse-mode capability of ADIFOR 3.0, and also with similar SDs calculated via the method of finite differences. 2) Second-order (SO) SDs have been implemented in the 2D ASNWERS code using the very efficient strategy that was originally proposed (but not previously tested) of Reference 3, Appendix A. Furthermore, these SO SOs have been validated for accuracy and computational efficiency. 3) Studies were conducted in Quasi-1D and 2D concerning the smoothness (or lack of smoothness) of the FO and SO SD's for flows with shock waves. The phenomenon is documented in the publications of this study (listed subsequently), however, the specific numerical mechanism which is responsible for this unsmoothness phenomenon was not discovered. 4) The FO and SO derivatives for Quasi-1D and 2D flows were applied to predict aerodynamic design uncertainties, and were also applied in robust design optimization studies.

  1. An efficient and scalable extraction and quantification method for algal derived biofuel.

    PubMed

    Lohman, Egan J; Gardner, Robert D; Halverson, Luke; Macur, Richard E; Peyton, Brent M; Gerlach, Robin

    2013-09-01

    Microalgae are capable of synthesizing a multitude of compounds including biofuel precursors and other high value products such as omega-3-fatty acids. However, accurate analysis of the specific compounds produced by microalgae is important since slight variations in saturation and carbon chain length can affect the quality, and thus the value, of the end product. We present a method that allows for fast and reliable extraction of lipids and similar compounds from a range of algae, followed by their characterization using gas chromatographic analysis with a focus on biodiesel-relevant compounds. This method determines which range of biologically synthesized compounds is likely responsible for each fatty acid methyl ester (FAME) produced; information that is fundamental for identifying preferred microalgae candidates as a biodiesel source. Traditional methods of analyzing these precursor molecules are time intensive and prone to high degrees of variation between species and experimental conditions. Here we detail a new method which uses microwave energy as a reliable, single-step cell disruption technique to extract lipids from live cultures of microalgae. After extractable lipid characterization (including lipid type (free fatty acids, mono-, di- or tri-acylglycerides) and carbon chain length determination) by GC-FID, the same lipid extracts are transesterified into FAMEs and directly compared to total biodiesel potential by GC-MS. This approach provides insight into the fraction of total FAMEs derived from extractable lipids compared to FAMEs derived from the residual fraction (i.e. membrane bound phospholipids, sterols, etc.). This approach can also indicate which extractable lipid compound, based on chain length and relative abundance, is responsible for each FAME. This method was tested on three species of microalgae; the marine diatom Phaeodactylum tricornutum, the model Chlorophyte Chlamydomonas reinhardtii, and the freshwater green alga Chlorella vulgaris

  2. Probabilistic logic methods and some applications to biology and medicine.

    PubMed

    Sakhanenko, Nikita A; Galas, David J

    2012-03-01

    For the computational analysis of biological problems-analyzing data, inferring networks and complex models, and estimating model parameters-it is common to use a range of methods based on probabilistic logic constructions, sometimes collectively called machine learning methods. Probabilistic modeling methods such as Bayesian Networks (BN) fall into this class, as do Hierarchical Bayesian Networks (HBN), Probabilistic Boolean Networks (PBN), Hidden Markov Models (HMM), and Markov Logic Networks (MLN). In this review, we describe the most general of these (MLN), and show how the above-mentioned methods are related to MLN and one another by the imposition of constraints and restrictions. This approach allows us to illustrate a broad landscape of constructions and methods, and describe some of the attendant strengths, weaknesses, and constraints of many of these methods. We then provide some examples of their applications to problems in biology and medicine, with an emphasis on genetics. The key concepts needed to picture this landscape of methods are the ideas of probabilistic graphical models, the structures of the graphs, and the scope of the logical language repertoire used (from First-Order Logic [FOL] to Boolean logic.) These concepts are interlinked and together define the nature of each of the probabilistic logic methods. Finally, we discuss the initial applications of MLN to genetics, show the relationship to less general methods like BN, and then mention several examples where such methods could be effective in new applications to specific biological and medical problems.

  3. Multichannel spectroreflectometry: a noninvasive method for assessment of on-line hemoglobin derivatives.

    PubMed

    Diaconu, Vasile

    2009-04-01

    The goal of the current study was to introduce a mathematical method to derive hemoglobin, oxyhemoglobin and carboxyl-hemoglobin absorption factors from full spectrum reflectometry measurements of retinal microcapillaries. The mathematical equation that describes the spectral reflectometry function was expressed as a linear combination of several terms of S(i)(lambda) representing the spectral signature functions of hemoglobin, oxyhemoglobin, carboxyl-hemoglobin, ocular media, melanin, and a scattering factor. Contrary to the classical model, where the reflectometry function was expressed as an absorbance Ab(lambda)=log?(incident light(lambda)/reflected light(lambda)), in this model and system, it is proposed to express the reflectometry function from the eye structures as an absorption factor A(lambda)%=incident light(lambda)/reflected light(lambda). To increase confidence in the estimation of hemoglobin derivatives, the mathematical model was applied to only a part of the spectral function of reflectometry, while the results of the model were used to explain the other part of the reflectometry function. The results demonstrate that for the visible spectral field, the model that explains the absorption of the light by the blood contained in the microcapillaries of biological structures is not compatible with the Beer-Lambert law.

  4. New method for deriving the topside ionospheric Vary-Chap scale height

    NASA Astrophysics Data System (ADS)

    Wang, Sicheng; Huang, Sixun; Fang, Hanxian

    2015-09-01

    An α-Chapman function with a continuously varying scale height H(h) can be used to describe the topside ionosphere electron density profile that seamlessly connects the ionosphere with the plasmasphere. Huang and Reinisch have derived the analytic expression of the scale height from the Vary-Chap function, which can be applied to the topside F2 region. However, the H(h) is still difficult to obtain because H(h) is a function of the unknown value H(h) at hmF2. In this paper, the maximum entropy method is introduced to solve this ill-posed problem, and the Vary-Chap scale height for each electron density profile is derived. Then the average percentage errors that defined as the differences between the measured electron density profiles and the Vary-Chap profiles obtained from the Vary-Chap scale heights are calculated with the Alouette/ISIS satellites topside sounder database. The results reveal that the average percentage errors are generally less than 5% and the Vary-Chap profiles can well represent the topside electron density profiles. What is more, the local time, seasonal, solar cycle, and latitudinal variations of the Vary-Chap scale height are preliminarily analyzed.

  5. An Empirical Method for deriving RBE values associated with Electrons, Photons and Radionuclides

    DOE PAGES

    Bellamy, Michael B; Puskin, J.; Eckerman, Keith F.; ...

    2015-01-01

    There is substantial evidence to justify using relative biological effectiveness (RBE) values greater than one for low-energy electrons and photons. But, in the field of radiation protection, radiation associated with low linear energy transfer (LET) has been assigned a radiation weighting factor wR of one. This value may be suitable for radiation protection but, for risk considerations, it is important to evaluate the potential elevated biological effectiveness of radiation to improve the quality of risk estimates. RBE values between 2 and 3 for tritium are implied by several experimental measurements. Additionally, elevated RBE values have been found for other similarmore » low-energy radiation sources. In this work, RBE values are derived for electrons based upon the fractional deposition of absorbed dose of energies less than a few keV. Using this empirical method, RBE values were also derived for monoenergetic photons and 1070 radionuclides from ICRP Publication 107 for which photons and electrons are the primary emissions.« less

  6. An Empirical Method for deriving RBE values associated with Electrons, Photons and Radionuclides

    SciTech Connect

    Bellamy, Michael B; Puskin, J.; Eckerman, Keith F.; Hertel, Nolan

    2015-01-01

    There is substantial evidence to justify using relative biological effectiveness (RBE) values greater than one for low-energy electrons and photons. But, in the field of radiation protection, radiation associated with low linear energy transfer (LET) has been assigned a radiation weighting factor wR of one. This value may be suitable for radiation protection but, for risk considerations, it is important to evaluate the potential elevated biological effectiveness of radiation to improve the quality of risk estimates. RBE values between 2 and 3 for tritium are implied by several experimental measurements. Additionally, elevated RBE values have been found for other similar low-energy radiation sources. In this work, RBE values are derived for electrons based upon the fractional deposition of absorbed dose of energies less than a few keV. Using this empirical method, RBE values were also derived for monoenergetic photons and 1070 radionuclides from ICRP Publication 107 for which photons and electrons are the primary emissions.

  7. Fitting FFT-derived spectra: Theory, tool, and application to solar radio spike decomposition

    SciTech Connect

    Nita, Gelu M.; Fleishman, Gregory D.; Gary, Dale E.; Marin, William; Boone, Kristine

    2014-07-10

    Spectra derived from fast Fourier transform (FFT) analysis of time-domain data intrinsically contain statistical fluctuations whose distribution depends on the number of accumulated spectra contributing to a measurement. The tail of this distribution, which is essential for separating the true signal from the statistical fluctuations, deviates noticeably from the normal distribution for a finite number of accumulations. In this paper, we develop a theory to properly account for the statistical fluctuations when fitting a model to a given accumulated spectrum. The method is implemented in software for the purpose of automatically fitting a large body of such FFT-derived spectra. We apply this tool to analyze a portion of a dense cluster of spikes recorded by our FASR Subsystem Testbed instrument during a record-breaking event that occurred on 2006 December 6. The outcome of this analysis is briefly discussed.

  8. Advanced stress analysis methods applicable to turbine engine structures

    NASA Technical Reports Server (NTRS)

    Pian, T. H. H.

    1985-01-01

    Advanced stress analysis methods applicable to turbine engine structures are investigated. Constructions of special elements which containing traction-free circular boundaries are investigated. New versions of mixed variational principle and version of hybrid stress elements are formulated. A method is established for suppression of kinematic deformation modes. semiLoof plate and shell elements are constructed by assumed stress hybrid method. An elastic-plastic analysis is conducted by viscoplasticity theory using the mechanical subelement model.

  9. Prospective Mathematics Teachers' Opinions about Mathematical Modeling Method and Applicability of This Method

    ERIC Educational Resources Information Center

    Akgün, Levent

    2015-01-01

    The aim of this study is to identify prospective secondary mathematics teachers' opinions about the mathematical modeling method and the applicability of this method in high schools. The case study design, which is among the qualitative research methods, was used in the study. The study was conducted with six prospective secondary mathematics…

  10. Generation of stoichiometric ethylene and isotopic derivatives and application in transition-metal-catalyzed vinylation and enyne metathesis.

    PubMed

    Min, Geanna K; Bjerglund, Klaus; Kramer, Søren; Gøgsig, Thomas M; Lindhardt, Anders T; Skrydstrup, Troels

    2013-12-16

    Ethylene is one of the most important building blocks in industry for the production of polymers and commodity chemicals. (13)C- and D-isotope-labeled ethylenes are also valuable reagents with applications ranging from polymer-structure determination, reaction-mechanism elucidation to the preparation of more complex isotopically labeled compounds. However, these isotopic derivatives are expensive, and are flammable gases, which are difficult to handle. We have developed a method for the controlled generation of ethylene and its isotopic variants including, for the first time, fully isotopically labeled ethylene, from simple alkene precursors by using Ru catalysis. Applying a two-chamber reactor allows both the synthesis of ethylene and its immediate consumption in a chemical transformation permitting reactions to be performed with only stoichiometric amounts of this two carbon olefin. This was demonstrated in the Ni-catalyzed Heck reaction with aryl triflates and benzyl chlorides, as well as Ru-mediated enyne metathesis.

  11. Preparation, characterization, and potential application of chitosan, chitosan derivatives, and chitosan metal nanoparticles in pharmaceutical drug delivery

    PubMed Central

    Ahmed, Tarek A; Aljaeid, Bader M

    2016-01-01

    Naturally occurring polymers, particularly of the polysaccharide type, have been used pharmaceutically for the delivery of a wide variety of therapeutic agents. Chitosan, the second abundant naturally occurring polysaccharide next to cellulose, is a biocompatible and biodegradable mucoadhesive polymer that has been extensively used in the preparation of micro-as well as nanoparticles. The prepared particles have been exploited as a potential carrier for different therapeutic agents such as peptides, proteins, vaccines, DNA, and drugs for parenteral and nonparenteral administration. Therapeutic agent-loaded chitosan micro- or nanoparticles were found to be more stable, permeable, and bioactive. In this review, we are highlighting the different methods of preparation and characterization of chitosan micro- and nanoparticles, while reviewing the pharmaceutical applications of these particles in drug delivery. Moreover, the roles of chitosan derivatives and chitosan metal nanoparticles in drug delivery have been illustrated. PMID:26869768

  12. HPLC method for identification and quantification of benzimidazole derivatives in antiparasitic drugs.

    PubMed

    Kulik, Anna; Białecka, Wanda; Podolska, Marzena; Kwiatkowska-Puchniarz, Barbara; Mazurek, Aleksander

    2011-01-01

    The subject of the study was to develop a versatile HPLC system for identification and determination of four benzimidazole derivatives in the antiparasitic drugs. The tests covered: Zentel, Panacur, Vermox tablets and Systamex suspension. A satisfactory separation was obtained using the Nucleosil C8 column in the gradient system composed of mobile phase A: 85% orthophosphoric acid / water / acetonitrile in 0.05:75:25, v/v/v ratio, and mobile phase B: 85% orthophosphoric acid / water / acetonitrile in 0.05:50:50, v/v/v ratio. Both phases were adjusted to pH = 4.5 with 15% sodium hydroxide solution. A detection at 288 nm for oxfendazole and 254 nm for albendazole, fenbendazole and mebendazole was applied. The correlation coefficients in the range 0,9997 - 0,9999 proved that the calibration curves were linear. The method was validated in terms of selectivity, accuracy and precision.

  13. An electrochemical method for fluoride analysis based on a naphthalene urea derivative as a selective receptor.

    PubMed

    Quintana, Carmen; Suárez, Patricia; Hernández, Lucas

    2008-09-01

    The use of a naphthalene urea derivative as a host molecule for selective fluoride binding allows us to develop a highly selective and sensitive electrochemical method for fluoride analysis without the interference of other halogen atoms. All the parameters affecting the differential pulse voltammetric response of the host molecule used as a fluoride receptor have been optimized and the mechanisms of the electrochemical behavior have been elucidated. The inhibition in the electrochemical signal of the anionic receptor due to the increase of the fluoride amounts allows the determination of F-with an LOD of 3.16 x 10(-6) M with an RSD (%) value lower than 4.8% and an Er (%) value lower than 3.8%.

  14. Conformational and NMR study of some furan derivatives by DFT methods.

    PubMed

    Santos-Carballal, David; Suardíaz, Reynier; Crespo-Otero, Rachel; González, Leandro; Pérez, Carlos S

    2013-10-01

    4'-substituted neutral/protonated furfurylidenanilines and trans-styrylfurans are able to exist in two different conformations related to the rotation around the furan ring-bridge double bond. In this work, the equilibrium geometry and the corresponding rotational barrier of the benzene ring for each furan derivative conformation were calculated by DFT methods. The trend and shape of the rotational barrier are rationalized within natural bond orbitals as well as atoms-in-molecules approach. For the corresponding equilibrium geometries, (1)H and (13)C substituent induced shifts (SIS) were calculated and compared with experimental values. Calculated shielding constants are shown to be sensitive to the substituent effect through a linear fit with substituent's Hammett constants. An alternative approach was followed for assessing the effect of substituents over SIS through comparing the differences in isotropic shielding constants with NBO charges as well as with (1)H and (13)C experimental chemical shifts.

  15. Processing methods, characteristics and adsorption behavior of tire derived carbons: a review.

    PubMed

    Saleh, Tawfik A; Gupta, Vinod Kumar

    2014-09-01

    The remarkable increase in the number of vehicles worldwide; and the lack of both technical and economical mechanisms of disposal make waste tires to be a serious source of pollution. One potential recycling process is pyrolysis followed by chemical activation process to produce porous activated carbons. Many researchers have recently proved the capability of such carbons as adsorbents to remove various types of pollutants including organic and inorganic species. This review attempts to compile relevant knowledge about the production methods of carbon from waste rubber tires. The effects of various process parameters including temperature and heating rate, on the pyrolysis stage; activation temperature and time, activation agent and activating gas are reviewed. This review highlights the use of waste-tires derived carbon to remove various types of pollutants like heavy metals, dye, pesticides and others from aqueous media.

  16. Peptide-derived Method to Transport Genes and Proteins Across Cellular and Organellar Barriers in Plants

    PubMed Central

    Chuah, Jo-Ann; Horii, Yoko; Numata, Keiji

    2016-01-01

    The capacity to introduce exogenous proteins and express (or down-regulate) specific genes in plants provides a powerful tool for fundamental research as well as new applications in the field of plant biotechnology. Viable methods that currently exist for protein or gene transfer into plant cells, namely Agrobacterium and microprojectile bombardment, have disadvantages of low transformation frequency, limited host range, or a high cost of equipment and microcarriers. The following protocol outlines a simple and versatile method, which employs rationally-designed peptides as delivery agents for a variety of nucleic acid- and protein-based cargoes into plants. Peptides are selected as tools for development of the system due to their biodegradability, reduced size, diverse and tunable properties as well as the ability to gain intracellular/organellar access. The preparation, characterization and application of optimized formulations for each type of the wide range of delivered cargoes (plasmid DNA, double-stranded DNA or RNA, and protein) are described. Critical steps within the protocol, possible modifications and existing limitations of the method are also discussed. PMID:28060264

  17. Application of Spectroscopic Methods for Structural Analysis of Chitin and Chitosan

    PubMed Central

    Kumirska, Jolanta; Czerwicka, Małgorzata; Kaczyński, Zbigniew; Bychowska, Anna; Brzozowski, Krzysztof; Thöming, Jorg; Stepnowski, Piotr

    2010-01-01

    Chitin, the second most important natural polymer in the world, and its N-deacetylated derivative chitosan, have been identified as versatile biopolymers for a broad range of applications in medicine, agriculture and the food industry. Two of the main reasons for this are firstly the unique chemical, physicochemical and biological properties of chitin and chitosan, and secondly the unlimited supply of raw materials for their production. These polymers exhibit widely differing physicochemical properties depending on the chitin source and the conditions of chitosan production. The presence of reactive functional groups as well as the polysaccharide nature of these biopolymers enables them to undergo diverse chemical modifications. A complete chemical and physicochemical characterization of chitin, chitosan and their derivatives is not possible without using spectroscopic techniques. This review focuses on the application of spectroscopic methods for the structural analysis of these compounds. PMID:20559489

  18. Deriving Shape-Based Features for C. elegans Locomotion Using Dimensionality Reduction Methods.

    PubMed

    Gyenes, Bertalan; Brown, André E X

    2016-01-01

    High-throughput analysis of animal behavior is increasingly common following the advances of recording technology, leading to large high-dimensional data sets. This dimensionality can sometimes be reduced while still retaining relevant information. In the case of the nematode worm Caenorhabditis elegans, more than 90% of the shape variance can be captured using just four principal components. However, it remains unclear if other methods can achieve a more compact representation or contribute further biological insight to worm locomotion. Here we take a data-driven approach to worm shape analysis using independent component analysis (ICA), non-negative matrix factorization (NMF), a cosine series, and jPCA (a dynamic variant of principal component analysis [PCA]) and confirm that the dimensionality of worm shape space is close to four. Projecting worm shapes onto the bases derived using each method gives interpretable features ranging from head movements to tail oscillation. We use these as a comparison method to find differences between the wild type N2 worms and various mutants. For example, we find that the neuropeptide mutant nlp-1(ok1469) has an exaggerated head movement suggesting a mode of action for the previously described increased turning rate. The different bases provide complementary views of worm behavior and we expect that closer examination of the time series of projected amplitudes will lead to new results in the future.

  19. A rapid derivative spectrophotometric method for simultaneous determination of naphazoline and antazoline in eye drops.

    PubMed

    Souri, Effat; Amanlou, Massoud; Farsam, Hassan; Afshari, Alma

    2006-01-01

    A zero-crossing first-derivative spectrophotometric method is applied for the simultaneous determination of naphazoline hydrochloride and antazoline phosphate in eye drops. The measurements were carried out at wavelengths of 225 and 252 nm for naphazoline hydrochloride and antazoline phosphate, respectively. The method was found to be linear (r2>0.999) in the range of 0.2-1 microg/ml for naphazoline hydrochloride in the presence of 5 microg/ml antazoline phosphate at 225 nm. The same linear correlation (r2>0.999) was obtained in the range of 1-10 microg/ml of antazoline phosphate in the presence of 0.5 microg/ml of naphazoline hydrochloride at 252 nm. The limit of determination was 0.2 microg/ml and 1 microg/ml for naphazoline hydrochloride and antazoline phosphate, respectively. The method was successfully used for simultaneous analysis of naphazoline hydrochloride and antazoline phosphate in eye drops without any interference from excipients and prior separation before analysis.

  20. Deriving Shape-Based Features for C. elegans Locomotion Using Dimensionality Reduction Methods

    PubMed Central

    Gyenes, Bertalan; Brown, André E. X.

    2016-01-01

    High-throughput analysis of animal behavior is increasingly common following the advances of recording technology, leading to large high-dimensional data sets. This dimensionality can sometimes be reduced while still retaining relevant information. In the case of the nematode worm Caenorhabditis elegans, more than 90% of the shape variance can be captured using just four principal components. However, it remains unclear if other methods can achieve a more compact representation or contribute further biological insight to worm locomotion. Here we take a data-driven approach to worm shape analysis using independent component analysis (ICA), non-negative matrix factorization (NMF), a cosine series, and jPCA (a dynamic variant of principal component analysis [PCA]) and confirm that the dimensionality of worm shape space is close to four. Projecting worm shapes onto the bases derived using each method gives interpretable features ranging from head movements to tail oscillation. We use these as a comparison method to find differences between the wild type N2 worms and various mutants. For example, we find that the neuropeptide mutant nlp-1(ok1469) has an exaggerated head movement suggesting a mode of action for the previously described increased turning rate. The different bases provide complementary views of worm behavior and we expect that closer examination of the time series of projected amplitudes will lead to new results in the future. PMID:27582697

  1. A Fréchet derivative-free cubically convergent method for set-valued maps

    NASA Astrophysics Data System (ADS)

    Argyros, Ioannis; Hilout, Saïd

    2008-08-01

    We introduce a new iterative method in order to approximate a locally unique solution of variational inclusions in Banach spaces. The method uses only divided differences operators of order one. An existence-convergence theorem and a radius of convergence are given under some conditions on divided difference operator and Lipschitz-like continuity property of set-valued mappings. Our method extends the recent work related to the resolution of nonlinear equation in Argyros (J Math Anal Appl 332:97-108, 2007) and has the following advantages: faster convergence to the solution than all the previous known ones in Argyros and Hilout (Appl Math Comput, 2008 in press), Hilout (J Math Anal Appl 339:53-761, 2008, Positivity 10:673-700, 2006), and we do not need to evaluate any Fréchet derivative. We provide also an improvement of the ratio of our algorithm under some center-conditions and less computational cost. Numerical examples are also provided.

  2. Simultaneous Determination and Stability Studies on Diminazene Diaceturate and Phenazone Using Developed Derivative Spectrophotometric Method

    PubMed Central

    Ahmed Gadkariem, Elrasheed; Awadalla Mohamed, Magdi

    2017-01-01

    This work presents UV first derivative spectrophotometry as a precise, accurate, and feasible method for simultaneous determination of diminazene diaceturate and phenazone in bulk and dosage forms. The absorbance values of diminazene diaceturate and phenazone aqueous mixture were obtained at 398 nm and 273 nm, respectively. The developed method was proved to be linear over the concentration ranges (2–10) μg/mL and (2.496–12.48) μg/mL for diminazene diaceturate and phenazone, respectively, with good correlation coefficients (not less than 0.997). The detection and quantitation limits were found to be (LOD = 0.63 and 0.48 μg/mL; LOQ = 1.92 and 1.47 μg/mL, resp.). The developed method was employed for stability studies of both drugs under different stress conditions. Diminazene diaceturate was prone to degrade at acidic pH via first-order kinetics. The degradation process was found to be temperature dependent with an activation energy of 7.48 kcal/mole. Photo-stability was also investigated for this drug. PMID:28246529

  3. Evaluation of methods to derive green-up dates based on daily NDVI satellite observations

    NASA Astrophysics Data System (ADS)

    Doktor, Daniel

    2010-05-01

    Bridging the gap between satellite derived green-up dates and in situ phenological observations has been the purpose of many studies over the last decades. Despite substantial advancements in satellite technology and data quality checks there is as yet no universally accepted method for extracting phenological metrics based on satellite derived vegetation indices. Dependent on the respective method derived green-up dates can vary up to serveral weeks using identical data sets. Consequently, it is difficult to compare various studies and to accurately determine an increased vegetation length due to changing temperature patterns as observed by ground phenological networks. Here, I compared how the characteristic NDVI increase over temperate deciduous forests in Germany in spring relates to respective budburst events observed on the ground. MODIS Terra daily surface reflectances with a 250 m resolution (2000-2008) were gathered to compute daily NDVI values. As ground truth, observations of the extensive phenological network of the German Weather Service were used. About 1500 observations per year and species (Beech, Oak and Birch) were available evenly distributed all over Germany. Two filtering methods were tested to reduce the noisy raw data. The first method only keeps NDVI values which are classified as ‚ideal global quality' and applies on those a temporal moving window where values are removed which differ more than 20% of the mean. The second method uses an adaptation of the BISE (Best Index Slope Extraction) algorithm. Subsequently, three functions were fitted to the selected observations: a simple linear interpolation, a sigmoidal function and a double logistic sigmoidal function allowing to approximate two temporally separated green-up signals. The green-up date was then determined at halfway between minimum and maximum (linear interpolation) or at the inflexion point of the sigmoidal curve. A number of global threshold values (NDVI 0.4,0.5,0.6) and

  4. Nutrient conservation during spent mushroom compost application using spent mushroom substrate derived biochar.

    PubMed

    Lou, Zimo; Sun, Yue; Bian, Shuping; Ali Baig, Shams; Hu, Baolan; Xu, Xinhua

    2017-02-01

    Spent mushroom compost (SMC), a spent mushroom substrate (SMS) derived compost, is always applied to agriculture land to enhance soil organic matter and nutrient contents. However, nitrogen, phosphate and organic matter contained in SMC can leach out and contaminate ground water during its application. In this study, biochars prepared under different pyrolytic temperatures (550 °C, 650 °C or 750 °C) from SMS were applied to soil as a nutrient conservation strategy. The resultant biochars were characterized for physical and mineralogical properties. Surface area and pore volume of biochars increased as temperature increased, while pore size decreased with increasing temperature. Calcite and quartz were evidenced by X-ray diffraction analysis in all biochars produced. Results of column leaching test suggested that mixed treatment of SMC and SMS-750-800 (prepared with the temperature for pyrolysis and activation was chosen as 750 °C and 800 °C, respectively) could reduce 43% of TN and 66% of CODCr in leachate as compared to chemical fertilizers and SMC, respectively. Furthermore, increasing dosage of SMS-750-800 from 1% to 5% would lead to 54% CODCr reduction in leachate, which confirmed its nutrient retention capability. Findings from this study suggested that combined application of SMC and SMS-based biochar was an applicable strategy for reducing TN and CODCr leaching.

  5. Mucoadhesive cellulosic derivative sponges as drug delivery system for vaginal application.

    PubMed

    Furst, Tania; Piette, Marie; Lechanteur, Anna; Evrard, Brigitte; Piel, Géraldine

    2015-09-01

    Vaginal delivery of active drugs has been largely studied for local and systemic applications. It is well known that vagina is a complex route, due to physiological and non-physiological changes. Therefore, in order to achieve a prolonged local effect, these variations have to be considered. The aim of this study was to formulate and to characterize a solid system, called sponges, obtained by lyophilization of cellulosic derivative (HEC 250M) hydrogels. These sponges have to meet particular criteria to be adapted for vaginal application: they have to adhere to the vaginal cavity and to be rehydrated by the small amount of vaginal fluids. Moreover, they have to be easily manipulated and to be stable. Three freezing temperatures have been tested to prepare sponges (-15°C, -25°C, -35°C). By SEM analyzes, it was observed that the pores into the sponges were smaller and numerous as the freezing temperature decreases. However, this temperature did not have any influence on the rehydration speed that was rather influenced by the HEC concentration. Viscosity and mucoadhesive strength of hydrogels and corresponding sponges were also measured. It appeared that these parameters are mainly dependent on the HEC concentration. These mucoadhesive sponges can be considered as potential drug delivery systems intended for vaginal application.

  6. The current landscape of adipose-derived stem cells in clinical applications.

    PubMed

    Lim, Ming Hui; Ong, Wee Kiat; Sugii, Shigeki

    2014-05-07

    Adipose-derived stem cells (ASCs) are considered a great alternative source of mesenchymal stem cells (MSCs). Unlike bone marrow stem cells (BMSCs), ASCs can be retrieved in high numbers from lipoaspirate, a by-product of liposuction procedures. Given that ASCs represent an easily accessible and abundant source of multipotent cells, ASCs have garnered attention and curiosity from both scientific and clinical communities for their potential in clinical applications. Furthermore, their unique immunobiology and secretome are attractive therapeutic properties. A decade since the discovery of a stem cell reservoir residing within adipose tissue, ASC-based clinical trials have grown over the years around the world along with assessments made on their safety and efficacy. With the progress of ASCs into clinical applications, the aim towards producing clinical-grade ASCs becomes increasingly important. Several countries have recognised the growing industry of cell therapies and have developed regulatory frameworks to assure their safety. With more research efforts made to understand their effects in both scientific and clinical settings, ASCs hold great promise as a future therapeutic strategy in treating a wide variety of diseases. Therefore, this review seeks to highlight the clinical applicability of ASCs as well as their progress in clinical trials across various medical disciplines.

  7. Application of geo-information science methods in ecotourism exploitation

    NASA Astrophysics Data System (ADS)

    Dong, Suocheng; Hou, Xiaoli

    2004-11-01

    Application of geo-information science methods in ecotourism development was discussed in the article. Since 1990s, geo-information science methods, which take the 3S (Geographic Information System, Global Positioning System, and Remote Sensing) as core techniques, has played an important role in resources reconnaissance, data management, environment monitoring, and regional planning. Geo-information science methods can easily analyze and convert geographic spatial data. The application of 3S methods is helpful to sustainable development in tourism. Various assignments are involved in the development of ecotourism, such as reconnaissance of ecotourism resources, drawing of tourism maps, dealing with mass data, and also tourism information inquire, employee management, quality management of products. The utilization of geo-information methods in ecotourism can make the development more efficient by promoting the sustainable development of tourism and the protection of eco-environment.

  8. Application of linear gauss pseudospectral method in model predictive control

    NASA Astrophysics Data System (ADS)

    Yang, Liang; Zhou, Hao; Chen, Wanchun

    2014-03-01

    This paper presents a model predictive control(MPC) method aimed at solving the nonlinear optimal control problem with hard terminal constraints and quadratic performance index. The method combines the philosophies of the nonlinear approximation model predictive control, linear quadrature optimal control and Gauss Pseudospectral method. The current control is obtained by successively solving linear algebraic equations transferred from the original problem via linearization and the Gauss Pseudospectral method. It is not only of high computational efficiency since it does not need to solve nonlinear programming problem, but also of high accuracy though there are a few discrete points. Therefore, this method is suitable for on-board applications. A design of terminal impact with a specified direction is carried out to evaluate the performance of this method. Augmented PN guidance law in the three-dimensional coordinate system is applied to produce the initial guess. And various cases for target with straight-line movements are employed to demonstrate the applicability in different impact angles. Moreover, performance of the proposed method is also assessed by comparison with other guidance laws. Simulation results indicate that this method is not only of high computational efficiency and accuracy, but also applicable in the framework of guidance design.

  9. Local Derivative-Free Parallel Computing Method for Solving the Inverse Problem in Groundwater Modeling

    NASA Astrophysics Data System (ADS)

    Pham, H. V.; Elshall, A. S.; Tsai, F. T.; Yan, L.

    2012-12-01

    The inverse problem in groundwater modeling deals with a rugged (i.e. ill-conditioned and multimodal), nonseparable and noisy function since it involves solving second order nonlinear partial deferential equations with forcing terms. Derivative-based optimization algorithms may fail to reach a near global solution due to their stagnation at a local minimum solution. To avoid entrapment in a local optimum and enhance search efficiency, this study introduces the covariance matrix adaptation-evolution strategy (CMA-ES) as a local derivative-free optimization method. In the first part of the study, we compare CMA-ES with five commonly used heuristic methods and the traditional derivative-based Gauss-Newton method on a hypothetical problem. This problem involves four different cases to allow a rigorous assessment against ten criterions: ruggedness in terms of nonsmooth and multimodal, ruggedness in terms of ill-conditioning and high nonlinearity, nonseparablity, high dimensionality, noise, algorithm adaptation, algorithm tuning, performance, consistency, parallelization (scaling with number of cores) and invariance (solution vector and function values). The CMA-ES adapts a covariance matrix representing the pair-wise dependency between decision variables, which approximates the inverse of the Hessian matrix up to a certain factor. The solution is updated with the covariance matrix and an adaptable step size, which are adapted through two conjugates that implement heuristic control terms. The covariance matrix adaptation uses information from the current population of solutions and from the previous search path. Since such an elaborate search mechanism is not common in the other heuristic methods, CMA-ES proves to be more robust than other population-based heuristic methods in terms of reaching a near-optimal solution for a rugged, nonseparable and noisy inverse problem. Other favorable properties that the CMA-ES exhibits are the consistency of the solution for repeated

  10. Photometric method for the quantification of chlorophylls and their derivatives in complex mixtures: fitting with Gauss-peak spectra.

    PubMed

    Küpper, H; Spiller, M; Küpper, F C

    2000-11-15

    Accurate quantification of pigments in mixtures is essential in all cases in which separation of pigments by chromatography is impracticable for one reason or another. An example is the analysis of in vivo formation of heavy metal-substituted chlorophylls in heavy metal-stressed plants. We describe here a novel, accurate UV/VIS spectrophotometric method for the quantification of individual chlorophyll derivatives in complex mixtures, which has the potential for universal applicability for mixtures difficult to separate. The method is based on the description of each pigment spectrum by a series of Gaussian peaks. A sample spectrum is then fitted by a linear combination of these "Gauss-peak spectra" including an automatic correction of wavelength inaccuracy and baseline instability of the spectrometer as well as a correction of the widening of absorbance peaks in more concentrated pigment solutions. The automatic correction of peak shifts can also partially correct shifts caused by processes like allomerization. In this paper, we present the Gauss-peak spectra for Mg-chlorophyll a, b, c, pheophytin a, b, c, Cu-chlorophyll a, b, c, and Zn-chlorophyll a in acetone; Mg-chlorophyll a, b, pheophytin a, b, Cu-chlorophyll a, b, allomerized Cu-chlorophyll a, b, and Zn-chlorophyll a, b in cyclohexane; Mg-chlorophyll a, b, pheophytin a, b, and Cu-chlorophyll a, b in diethyl ether.

  11. The application of mixed methods designs to trauma research.

    PubMed

    Creswell, John W; Zhang, Wanqing

    2009-12-01

    Despite the use of quantitative and qualitative data in trauma research and therapy, mixed methods studies in this field have not been analyzed to help researchers designing investigations. This discussion begins by reviewing four core characteristics of mixed methods research in the social and human sciences. Combining these characteristics, the authors focus on four select mixed methods designs that are applicable in trauma research. These designs are defined and their essential elements noted. Applying these designs to trauma research, a search was conducted to locate mixed methods trauma studies. From this search, one sample study was selected, and its characteristics of mixed methods procedures noted. Finally, drawing on other mixed methods designs available, several follow-up mixed methods studies were described for this sample study, enabling trauma researchers to view design options for applying mixed methods research in trauma investigations.

  12. Antibacterial Derivatives of Marine Algae: An Overview of Pharmacological Mechanisms and Applications.

    PubMed

    Shannon, Emer; Abu-Ghannam, Nissreen

    2016-04-22

    The marine environment is home to a taxonomically diverse ecosystem. Organisms such as algae, molluscs, sponges, corals, and tunicates have evolved to survive the high concentrations of infectious and surface-fouling bacteria that are indigenous to ocean waters. Both macroalgae (seaweeds) and microalgae (diatoms) contain pharmacologically active compounds such as phlorotannins, fatty acids, polysaccharides, peptides, and terpenes which combat bacterial invasion. The resistance of pathogenic bacteria to existing antibiotics has become a global epidemic. Marine algae derivatives have shown promise as candidates in novel, antibacterial drug discovery. The efficacy of these compounds, their mechanism of action, applications as antibiotics, disinfectants, and inhibitors of foodborne pathogenic and spoilage bacteria are reviewed in this article.

  13. Preparation and application of abietic acid-derived optically active helical polymers and their chiral hydrogels.

    PubMed

    Yao, Fei; Zhang, Dongyue; Zhang, Chaohong; Yang, Wantai; Deng, Jianping

    2013-02-01

    A novel chiral monomer N-propargyl abietamide, M1, was synthesized from abietic acid and catalytically polymerized with (nbd)Rh+B-(C6H5)4 (nbd=norbornadiene), providing polymer [poly(1)] with a molecular weight of 13,000-36,000 at a yield of 59-84%. Poly(1) did not form stable helices in tetrahydrofuran at room temperature whereas copolymerization of M1 and the achiral N-propargylamide monomer, M2, led to the formation of helical optically active copolymers as indicated by circular dichroism studies, UV-vis spectroscopy, and specific optical rotation measurements. Hydrogels were prepared based on an optically active helical copolymer, poly(M1(0.32)-co-M2(0.68)) that exhibited enantioselective recognition toward l-alanine. The novel chiral polymers derived from abietic acid are expected to find applications in such areas as chiral recognition, chiral resolution, and chiral catalysis.

  14. Antibacterial Derivatives of Marine Algae: An Overview of Pharmacological Mechanisms and Applications

    PubMed Central

    Shannon, Emer; Abu-Ghannam, Nissreen

    2016-01-01

    The marine environment is home to a taxonomically diverse ecosystem. Organisms such as algae, molluscs, sponges, corals, and tunicates have evolved to survive the high concentrations of infectious and surface-fouling bacteria that are indigenous to ocean waters. Both macroalgae (seaweeds) and microalgae (diatoms) contain pharmacologically active compounds such as phlorotannins, fatty acids, polysaccharides, peptides, and terpenes which combat bacterial invasion. The resistance of pathogenic bacteria to existing antibiotics has become a global epidemic. Marine algae derivatives have shown promise as candidates in novel, antibacterial drug discovery. The efficacy of these compounds, their mechanism of action, applications as antibiotics, disinfectants, and inhibitors of foodborne pathogenic and spoilage bacteria are reviewed in this article. PMID:27110798

  15. Nano Metal-Organic Framework-Derived Inorganic Hybrid Nanomaterials: Synthetic Strategies and Applications.

    PubMed

    Mai, Hien Duy; Rafiq, Khezina; Yoo, Hyojong

    2016-11-11

    Nano- (or micro-scale) metal-organic frameworks (NMOFs), also known as coordination polymer particles (CPPs), have received much attention because of their structural diversities and tunable properties. Besides the direct use, NMOFs can be alternatively used as sacrificial templates/precursors for the preparation of a wide range of hybrid inorganic nanomaterials in straightforward and controllable manners. Distinct advantages of using NMOF templates are correlated to their structural and functional tailorability at molecular levels that is rarely acquired in any other conventional template/precursor. In addition, NMOF-derived inorganic nanomaterials with distinct chemical and physical properties are inferred to dramatically expand the scope of their utilization in many fields. In this review, we aim to provide readers with a comprehensive summary of recent progress in terms of synthetic approaches for the production of diverse inorganic hybrid nanostructures from as-synthesized NMOFs and their promising applications.

  16. Derivation and application of the energy dissipation factor in the design of fishways

    USGS Publications Warehouse

    Towler, Brett; Mulligan, Kevin; Haro, Alexander J.

    2015-01-01

    Reducing turbulence and associated air entrainment is generally considered advantageous in the engineering design of fish passage facilities. The well-known energy dissipation factor, or EDF, correlates with observations of the phenomena. However, inconsistencies in EDF forms exist and the bases for volumetric energy dissipation rate criteria are often misunderstood. A comprehensive survey of EDF criteria is presented. Clarity in the application of the EDF and resolutions to these inconsistencies are provided through formal derivations; it is demonstrated that kinetic energy represents only 1/3 of the total energy input for the special case of a broad-crested weir. Specific errors in published design manuals are identified and resolved. New, fundamentally sound, design equations for culvert outlet pools and standard Denil Fishway resting pools are developed. The findings underscore the utility of EDF equations, demonstrate the transferability of volumetric energy dissipation rates, and provide a foundation for future refinement of component-, species-, and life-stage-specific EDF criteria.

  17. Study on iron oxide nanoparticles coated with glucose-derived polymers for biomedical applications

    NASA Astrophysics Data System (ADS)

    Herea, D. D.; Chiriac, H.; Lupu, N.; Grigoras, M.; Stoian, G.; Stoica, B. A.; Petreus, T.

    2015-10-01

    This study reports an approach for a facile one-step synthesis of magnetic nanoparticles (MNPs) coated with glucose-derived polymers (GDP) through a mechanochemical hydrothermal process for biomedical applications. Polymer-coated magnetic nanoparticles (Fe2O3/Fe3O4), with sizes below 10 nm, exhibited superparamagnetic behavior, with a specific magnetization saturation value of about 40 emu/g, and a maximum specific absorption rate (SAR) of 30 W/g in AC magnetic fields. Depending on the intensity of the applied AC magnetic field, a temperature of 42 °C can be achieved in 4-17 min. The surface polymerized layer affords functional hydroxyl groups for binding to biomolecules containing carboxyl, thiol, or amino groups, thereby making the coated nanoparticles feasible for bio-conjugation. In vitro cytotoxicity evaluation pointed out that a relatively high concentration of polymer-coated magnetic nanoparticles (GDP-MNPs) did not induce severe cell alteration, suggesting a good biocompatibility.

  18. On the Yakhot-Orszag renormalization group method for deriving turbulence statistics and models

    NASA Technical Reports Server (NTRS)

    Smith, L. M.; Reynolds, W. C.

    1992-01-01

    An independent, comprehensive, critical review of the 'renormalization group' (RNG) theory of turbulence developed by Yakhot and Orszag (1986) is provided. Their basic theory for the Navier-Stokes equations is confirmed, and approximations in the scale removal procedure are discussed. The YO derivations of the velocity-derivative skewness and the transport equation for the energy dissipation rate are examined. An algebraic error in the derivation of the skewness is corrected. The corrected RNG skewness value of -0.59 is in agreement with experiments at moderate Reynolds numbers. Several problems are identified in the derivation of the energy dissipation rate equations which suggest that the derivation should be reformulated.

  19. Adipose-derived adult stem cells: available technologies for potential clinical regenerative applications in dentistry.

    PubMed

    Catalano, Enrico; Cochis, Andrea; Varoni, Elena; Rimondini, Lia; Carrassi, Antonio; Azzimonti, Barbara

    2013-01-01

    Tissue homeostasis depends closely on the activity and welfare of adult stem cells. These cells represent a promising tool for biomedical research since they can aid in treatment and promote the regeneration of damaged organs in many human disorders. Adult stem cells indefinitely preserve their ability to self-renew and differentiate into various phenotypes; this capacity could be promoted in vitro by particular culture conditions (differentiation media) or spontaneously induced in vivo by exploiting the biochemical and mechanical properties of the tissue in which the stem cells are implanted. Among the different sources of adult stem cells, adipose tissue is an attractive possibility thanks to its ready availability and the standard extraction techniques at our disposal today. This review discusses the isolation, characterization, and differentiation of human adipose-derived adult stem cells, as well as regeneration strategies, therapeutic uses, and adverse effects of their delivery. In particular, since oral disorders (e.g., trauma, erosion, and chronic periodontitis) often cause the loss of dental tissue along with functional, phonetic, and aesthetic impairment, this review focuses on the application of human adipose-derived adult stem cells, alone or in combination with biomaterials, in treating oral diseases.

  20. Characterization of chlorophyll derivatives in micelles of polymeric surfactants aiming photodynamic applications

    NASA Astrophysics Data System (ADS)

    Gerola, Adriana Passarella; de Morais, Flavia Amanda Pedroso; Costa, Paulo Fernando A.; Kimura, Elza; Caetano, Wilker; Hioka, Noboru

    2017-02-01

    The spectrophotometric properties of chlorophylls' derivatives (Chls) formulated in the Pluronics® F-127 and P-123 were evaluated and the results have shown that the Chls were efficiently solubilized in these drug delivery systems as monomers. The relative location of the Chls in the Pluronics® was estimated from the Stokes shift and micropolarity of the micellar environment. Chls with phytyl chain were located in the micellar core, where the micropolarity is similar to ethanol, while phorbides' derivatives (without phytyl chain) were located in the outer shell of the micelle, i.e., more polar environment. In addition, the thermal stability of the micellar formulations was evaluated through electronic absorption, fluorescence emission and resonance light scattering with lowering the temperature. The Chls promote the stability of the micelles at temperatures below the Critical Micellar Temperature (CMT) of these surfactants. For F-127 formulations, the water molecules drive through inside the nano-structure at temperatures below the CMT, which increased the polarity of this microenvironment and directly affected the spectrophotometric properties of the Chls with phytyl chain. The properties of the micellar microenvironment of P-123, with more hydrophobic core due to the small PEO/PPO fraction, were less affected by lowering the temperature than for F-127. These results enable us to better understand the Chls behavior in micellar copolymers and allowed us to design new drug delivery system that maintains the photosensitizer's properties for photodynamic applications.

  1. Activated carbons derived from oil palm empty-fruit bunches: application to environmental problems.

    PubMed

    Alam, Md Zahangir; Muyibi, Suleyman A; Mansor, Mariatul F; Wahid, Radziah

    2007-01-01

    Activated carbons derived from oil palm empty fruit bunches (EFB) were investigated to find the suitability of its application for removal of phenol in aqueous solution through adsorption process. Two types of activation namely; thermal activation at 300, 500 and 800 degrees C and physical activation at 150 degrees C (boiling treatment) were used for the production of the activated carbons. A control (untreated EFB) was used to compare the adsorption capacity of the activated carbons produced from these processes. The results indicated that the activated carbon derived at the temperature of 800 degrees C showed maximum absorption capacity in the aqueous solution of phenol. Batch adsorption studies showed an equilibrium time of 6 h for the activated carbon at 800 degrees C. It was observed that the adsorption capacity was higher at lower values of pH (2-3) and higher value of initial concentration of phenol (200-300 mg/L). The equilibrium data fitted better with the Freundlich adsorption isotherm compared to the Langmuir. Kinetic studies of phenol adsorption onto activated carbons were also studied to evaluate the adsorption rate. The estimated cost for production of activated carbon from EFB was shown in lower price (USD 0.50/kg of activated carbon) compared the activated carbon from other sources and processes.

  2. A new method to derive electronegativity from resonant inelastic x-ray scattering

    SciTech Connect

    Carniato, S.; Journel, L.; Guillemin, R.; Piancastelli, M. N.; Simon, M.; Stolte, W. C.; Lindle, D. W.

    2012-10-14

    Electronegativity is a well-known property of atoms and substituent groups. Because there is no direct way to measure it, establishing a useful scale for electronegativity often entails correlating it to another chemical parameter; a wide variety of methods have been proposed over the past 80 years to do just that. This work reports a new approach that connects electronegativity to a spectroscopic parameter derived from resonant inelastic x-ray scattering. The new method is demonstrated using a series of chlorine-containing compounds, focusing on the Cl 2p{sup -1}LUMO{sup 1} electronic states reached after Cl 1s{yields} LUMO core excitation and subsequent KL radiative decay. Based on an electron-density analysis of the LUMOs, the relative weights of the Cl 2p{sub z} atomic orbital contributing to the Cl 2p{sub 3/2} molecular spin-orbit components are shown to yield a linear electronegativity scale consistent with previous approaches.

  3. Analytical method for the determination and a survey of parabens and their derivatives in pharmaceuticals.

    PubMed

    Moreta, Cristina; Tena, María-Teresa; Kannan, Kurunthachalam

    2015-10-01

    Exposure of humans to parabens is a concern due to the estrogenic activity of these compounds. Parabens are widely used as preservatives in some personal care products, foodstuffs and pharmaceuticals owing to their low cost, high water solubility and broad spectrum antimicrobial properties. Despite this, little is known on the occurrence of parabens in pharmaceutical products. In this study, a method based on solid-liquid or liquid-liquid extraction (SLE or LLE), and high performance liquid chromatography (HPLC) coupled with triple quadrupole tandem mass spectrometry (QqQ or MS/MS) was developed for the determination of six most frequently used parabens and four paraben derivatives (methyl- and ethyl-protocatechuates, and mono- and di-hydroxybenzoic acids) in pharmaceuticals. A sample-purification step involving solid phase extraction (SPE) was optimized for the analysis of solid and lipid-rich pharmaceuticals. To our knowledge, this is the first comprehensive report on the occurrence of parabens in pharmaceuticals. The developed method was applied for the analysis of 128 liquid/syrup, cream, solid, prescription or over-the counter (OTC) drugs collected from the USA and a few other countries in Europe and Asia. Although majority of the drugs analyzed in the study did not contain parabens, concentrations as high as 2 mg/g were found in some drugs. Methyl- and propyl- parabens were the frequently detected compounds. 4-Hydroxybenzoic acid was the major metabolite found in pharmaceutical products.

  4. Mouse Mammary Intraductal (MIND) Method for Transplantation of Patient Derived Primary DCIS Cells and Cell Lines

    PubMed Central

    Kittrell, Frances; Valdez, Kelli; Elsarraj, Hanan; Hong, Yan; Medina, Daniel; Behbod, Fariba

    2016-01-01

    The MIND method involves intraductal injection of patient derived ductal carcinoma in situ (DCIS) cells and DCIS cell lines (MCF10DCIS.COM and SUM225) inside the mouse mammary ducts [Video 1 and Figure 1 in Behbod et al. (2009)]. This method mimics the normal environment of DCIS and facilitates study of the natural progression of human DCIS, i.e., their initial growth as carcinoma in situ within the ducts, followed by invasion into the stroma through the myoepithelial cell layer and basement membrane (Behbod et al., 2009; Valdez et al., 2011). In order to demonstrate that transplantation procedure is successful, the transplanted mammary glands may be excised as early as two weeks following intraductal injection of cells followed by Hematoxylin and Eosin (H&E) staining and/or immunofluorescence staining using human specific cytokeratin 5 and/or 19 [please see Figures 2–4 in Behbod et al. (2009)]. Additionally, the presence of trypan blue inside the mouse mammary ducts immediately following intraductal injection is the best indicator that the injection was successful (Video 1 starting at 4:33 sec). PMID:27446983

  5. Application of Vacuum Deposition Methods to Solid Oxide Fuel Cells

    SciTech Connect

    Pederson, Larry R.; Singh, Prabhakar; Zhou, Xiao Dong

    2006-07-01

    The application of vacuum deposition techniques to the fabrication of solid oxide fuel cell materials and structures are reviewed, focusing on magnetron sputtering, vacuum plasma methods, laser ablation, and electrochemical vapor deposition. A description of each method and examples of use to produce electrolyte, electrode, and/or electrical interconnects are given. Generally high equipment costs and relatively low deposition rates have limited the use of vacuum deposition methods in solid oxide fuel cell manufacture, with a few notable exceptions. Vacuum methods are particularly promising in the fabrication of micro fuel cells, where thin films of high quality and unusual configuration are desired.

  6. Analytical and numerical schemes for a derivative with filtering property and no singular kernel with applications to diffusion

    NASA Astrophysics Data System (ADS)

    Doungmo Goufo, Emile Franc; Atangana, Abdon

    2016-08-01

    There have been numbers of conflicting and confusing situations, but also uniformity, in the application of the two most popular fractional derivatives, namely the classic Riemann-Liouville and Caputo fractional derivatives. The range of these issues is wide, including the initialization with the Caputo derivative and its observed difficulties compared to the Riemann-Liouville initialization conditions. In this paper, being aware of these issues and reacting to the newly introduced Caputo-Fabrizio fractional derivative (CFFD) without singular kernel, we introduce a new definition of fractional derivative called the new Riemann-Liouville fractional derivative (NRLFD) without singular kernel. The filtering property of the NRLFD is pointed out by showing it as the derivative of a convolution and contrary to the CFFD, it matches with the function when the order is zero. We also explore various scientific situations that may be conflicting and confusing in the applicability of both new derivatives. In particular, we show that both definitions still have some basic similarities, like not obeying the traditional chain rule. Furthermore, we provide the explicit formula for the Laplace transform of the NRLFD and we prove that, contrary to the CFFD, the NRLFD requires non-constant initial conditions and does not require the function f to be continuous or differentiable. Some simulations for the NRLFD are presented for different values of the derivative order. In the second part of this work, numerical approximations for the first- and second-order NRLFD are developped followed by a concrete application to diffusion. The stability of the numerical scheme is proved and numerical simulations are performed for different values of the derivative order α. They exhibit similar behavior for closed values of α.

  7. A new method to quantify the application thickness of sunscreen on skin.

    PubMed

    Bauer, Ulrike; O'Brien, Dominique S; Kimlin, Michael G

    2010-01-01

    Proper application of sunscreen is essential as an effective public health strategy for skin cancer prevention. Insufficient application is common among sunbathers, results in decreased sun protection and may therefore lead to increased UV damage of the skin. However, no objective measure of sunscreen application thickness (SAT) is currently available for field-based use. We present a method to detect SAT on human skin for determining the amount of sunscreen applied and thus enabling comparisons to manufacturer recommendations. Using a skin swabbing method and subsequent spectrophotometric analysis, we were able to determine SAT on human skin. A swabbing method was used to derive SAT on skin (in mg sunscreen per cm(2) of skin area) through the concentration-absorption relationship of sunscreen determined in laboratory experiments. Analysis differentiated SATs between 0.25 and 4 mg cm(-2) and showed a small but significant decrease in concentration over time postapplication. A field study was performed, in which the heterogeneity of sunscreen application could be investigated. The proposed method is a low cost, noninvasive method for the determination of SAT on skin and it can be used as a valid tool in field- and population-based studies.

  8. Application of the {gamma}SF method to palladium

    SciTech Connect

    Utsunomiya, H.; Akimune, H.; Yamagata, T.; Kondo, T.; Iwamoto, C.; Kamata, M.; Itoh, O.; Goriely, S.; Daoutidis, I.; Arteaga, D. P.; Harada, H.; Kitatani, F.; Goko, S.; Toyokawa, H.; Yamada, K.; Lui, Y.-W.; Hilaire, S.; Koning, A. J.

    2011-10-28

    Photoneutron cross sections were measured for {sup 108}Pd, {sup 106}Pd, and {sup 105}Pd with laser-Compton scattering {gamma}-ray beams in an application of the {gamma}SF method to a radioactive nucleus {sup 107}Pd. We present radiative neutron cross sections for {sup 107}Pd[6.5x10{sup 6} y] obtained with the {gamma}SF method.

  9. Application of the Discontinuous Galerkin Method to Acoustic Scatter Problems

    NASA Technical Reports Server (NTRS)

    Atkins, H. L.

    1997-01-01

    The application of the quadrature-free form of the discontinuous Galerkin method to two problems from Category 1 of the Second Computational Aeroacoustics Workshop on Benchmark problems is presented. The method and boundary conditions relevant to this work are described followed by two test problems, both of which involve the scattering of an acoustic wave off a cylinder. The numerical test performed to evaluate mesh-resolution requirements and boundary-condition effectiveness are also described.

  10. Monte Carlo methods and applications in nuclear physics

    SciTech Connect

    Carlson, J.

    1990-01-01

    Monte Carlo methods for studying few- and many-body quantum systems are introduced, with special emphasis given to their applications in nuclear physics. Variational and Green's function Monte Carlo methods are presented in some detail. The status of calculations of light nuclei is reviewed, including discussions of the three-nucleon-interaction, charge and magnetic form factors, the coulomb sum rule, and studies of low-energy radiative transitions. 58 refs., 12 figs.

  11. A rhenium tris-carbonyl derivative as a model molecule for incorporation into phospholipid assemblies for skin applications.

    PubMed

    Fernández, Estibalitz; Rodríguez, Gelen; Hostachy, Sarah; Clède, Sylvain; Cócera, Mercedes; Sandt, Christophe; Lambert, François; de la Maza, Alfonso; Policar, Clotilde; López, Olga

    2015-07-01

    A rhenium tris-carbonyl derivative (fac-[Re(CO)3Cl(2-(1-dodecyl-1H-1,2,3,triazol-4-yl)-pyridine)]) was incorporated into phospholipid assemblies, called bicosomes, and the penetration of this molecule into skin was monitored using Fourier-transform infrared microspectroscopy (FTIR). To evaluate the capacity of bicosomes to promote the penetration of this derivative, the skin penetration of the Re(CO)3 derivative dissolved in dimethyl sulfoxide (DMSO), a typical enhancer, was also studied. Dynamic light scattering results (DLS) showed an increase in the size of the bicosomes with the incorporation of the Re(CO)3 derivative, and the FTIR microspectroscopy showed that the Re(CO)3 derivative incorporated in bicosomes penetrated deeper into the skin than when dissolved in DMSO. When this molecule was applied on the skin using the bicosomes, 60% of the Re(CO)3 derivative was retained in the stratum corneum (SC) and 40% reached the epidermis (Epi). Otherwise, the application of this molecule via DMSO resulted in 95% of the Re(CO)3 derivative being in the SC and only 5% reaching the Epi. Using a Re(CO)3 derivative with a dodecyl-chain as a model molecule, it was possible to determine the distribution of molecules with similar physicochemical characteristics in the skin using bicosomes. This fact makes these nanostructures promising vehicles for the application of lipophilic molecules inside the skin.

  12. Improved methods for GRACE-derived groundwater storage change estimation in large-scale agroecosystems

    NASA Astrophysics Data System (ADS)

    Brena, A.; Kendall, A. D.; Hyndman, D. W.

    2013-12-01

    Large-scale agroecosystems are major providers of agricultural commodities and an important component of the world's food supply. In agroecosystems that depend mainly in groundwater, it is well known that their long-term sustainability can be at risk because of water management strategies and climatic trends. The water balance of groundwater-dependent agroecosystems such as the High Plains aquifer (HPA) are often dominated by pumping and irrigation, which enhance hydrological processes such as evapotranspiration, return flow and recharge in cropland areas. This work provides and validates new quantitative groundwater estimation methods for the HPA that combine satellite-based estimates of terrestrial water storage (GRACE), hydrological data assimilation products (NLDAS-2) and in situ measurements of groundwater levels and irrigation rates. The combined data can be used to elucidate the controls of irrigation on the water balance components of agroecosystems, such as crop evapotranspiration, soil moisture deficit and recharge. Our work covers a decade of continuous observations and model estimates from 2003 to 2013, which includes a significant drought since 2011. This study aims to: (1) test the sensitivity of groundwater storage to soil moisture and irrigation, (2) improve estimates of irrigation and soil moisture deficits (3) infer mean values of groundwater recharge across the HPA. The results show (1) significant improvements in GRACE-derived aquifer storage changes using methods that incorporate irrigation and soil moisture deficit data, (2) an acceptable correlation between the observed and estimated aquifer storage time series for the analyzed period, and (3) empirically-estimated annual rates of groundwater recharge that are consistent with previous geochemical and modeling studies. We suggest testing these correction methods in other large-scale agroecosystems with intensive groundwater pumping and irrigation rates.

  13. Manufacturing methods and applications of membranes in microfluidics.

    PubMed

    Chen, Xueye; Shen, Jienan; Hu, Zengliang; Huo, Xuyao

    2016-12-01

    Applications of membranes in microfluidics solved many thorny problems for analytical chemistry and bioscience, so that the use of membranes in microfluidics has been a topic of growing interest. Many different examples have been reported, demonstrating the versatile use of membranes. This work reviews a lot of applications of membranes in microfluidics. Membranes in microfluidics for applications including chemical reagents detection, gas detection, drug screening, cell, protein, microreactor, electrokinetical fluid, pump and valve and fluid transport control and so on, have been analyzed and discussed. In addition, the definition and basic concepts of membranes are summed up. And the methods of manufacturing membranes in microfluidics are discussed. This paper will provide a helpful reference to researchers who want to study applications of membranes in microfluidics.

  14. Biogenesis, Function, and Applications of Virus-Derived Small RNAs in Plants

    PubMed Central

    Zhang, Chao; Wu, Zujian; Li, Yi; Wu, Jianguo

    2015-01-01

    RNA silencing, an evolutionarily conserved and sequence-specific gene-inactivation system, has a pivotal role in antiviral defense in most eukaryotic organisms. In plants, a class of exogenous small RNAs (sRNAs) originating from the infecting virus called virus-derived small interfering RNAs (vsiRNAs) are predominantly responsible for RNA silencing-mediated antiviral immunity. Nowadays, the process of vsiRNA formation and the role of vsiRNAs in plant viral defense have been revealed through deep sequencing of sRNAs and diverse genetic analysis. The biogenesis of vsiRNAs is analogous to that of endogenous sRNAs, which require diverse essential components including dicer-like (DCL), argonaute (AGO), and RNA-dependent RNA polymerase (RDR) proteins. vsiRNAs trigger antiviral defense through post-transcriptional gene silencing (PTGS) or transcriptional gene silencing (TGS) of viral RNA, and they hijack the host RNA silencing system to target complementary host transcripts. Additionally, several applications that take advantage of the current knowledge of vsiRNAs research are being used, such as breeding antiviral plants through genetic engineering technology, reconstructing of viral genomes, and surveying viral ecology and populations. Here, we will provide an overview of vsiRNA pathways, with a primary focus on the advances in vsiRNA biogenesis and function, and discuss their potential applications as well as the future challenges in vsiRNAs research. PMID:26617580

  15. Boundary layer drag reduction research hypotheses derived from bio-inspired surface and recent advanced applications.

    PubMed

    Luo, Yuehao; Yuan, Lu; Li, Jianhua; Wang, Jianshe

    2015-12-01

    Nature has supplied the inexhaustible resources for mankind, and at the same time, it has also progressively developed into the school for scientists and engineers. Through more than four billions years of rigorous and stringent evolution, different creatures in nature gradually exhibit their own special and fascinating biological functional surfaces. For example, sharkskin has the potential drag-reducing effect in turbulence, lotus leaf possesses the self-cleaning and anti-foiling function, gecko feet have the controllable super-adhesion surfaces, the flexible skin of dolphin can accelerate its swimming velocity. Great profits of applying biological functional surfaces in daily life, industry, transportation and agriculture have been achieved so far, and much attention from all over the world has been attracted and focused on this field. In this overview, the bio-inspired drag-reducing mechanism derived from sharkskin is explained and explored comprehensively from different aspects, and then the main applications in different fluid engineering are demonstrated in brief. This overview will inevitably improve the comprehension of the drag reduction mechanism of sharkskin surface and better understand the recent applications in fluid engineering.

  16. How to save water by choice of irrigation application method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is known that irrigation application method can impact crop water use and water use efficiency, but the mechanisms involved are incompletely understood, particularly in terms of the water and energy balances during the growing season from pre-irrigation through planting, early growth and yield de...

  17. Click Reaction: An Applicable Radiolabeling Method for Molecular Imaging.

    PubMed

    Choi, Ji Young; Lee, Byung Chul

    2015-12-01

    In recent years, the click reaction has found rapidly growing applications in the field of radiochemistry, ranging from a practical labeling method to molecular imaging of biomacromolecules. This present review details the development of highly reliable, powerful and selective click chemistry reactions for the rapid synthesis of new radiotracers for molecular imaging.

  18. Application of geophysical methods to agriculture: An overview

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Geophysical methods are becoming an increasingly valuable tool for agricultural applications. Agricultural geophysics investigations are commonly (although certainly not always) focused on delineating small- and/or large-scale objects/features within the soil profile (~ 0 to 2 m depth) over very lar...

  19. An Overview of the Monte Carlo Methods, Codes, & Applications Group

    SciTech Connect

    Trahan, Travis John

    2016-08-30

    This report sketches the work of the Group to deliver first-principle Monte Carlo methods, production quality codes, and radiation transport-based computational and experimental assessments using the codes MCNP and MCATK for such applications as criticality safety, non-proliferation, nuclear energy, nuclear threat reduction and response, radiation detection and measurement, radiation health protection, and stockpile stewardship.

  20. 7 CFR 1430.303 - Time and method of application.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS DAIRY PRODUCTS 2004 Dairy Disaster Assistance Payment Program § 1430.303 Time and method of application. (a) Dairy producers may obtain an... where the dairy operation is located but, in any case, must be received by the FSA county office by...

  1. 7 CFR 784.4 - Time and method of application.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AGRICULTURE SPECIAL PROGRAMS 2004 EWE LAMB REPLACEMENT AND RETENTION PAYMENT PROGRAM § 784.4 Time and method of application. (a) A request for benefits under this part must be submitted on the Ewe Lamb... documents that prove the eligibility of the qualifying ewe lambs and the sheep and lamb operation....

  2. The ReaxFF method - new applications and developments

    NASA Astrophysics Data System (ADS)

    van Duin, Adri

    The ReaxFF method provides a highly transferable simulation method for atomistic scale simulations on chemical reactions at the nanosecond and nanometer scale. It combines concepts of bond-order based potentials with a polarizable charge distribution. Since it initial development for hydrocarbons in 2001, we have found that this concept is transferable to applications to elements all across the periodic table, including all first row elements, metals, ceramics and ionic materials. For all these elements and associated materials we have demonstrated that ReaxFF can reproduce quantum mechanics-based structures, reaction energies and reaction barriers with reasonable accuracy, enabling the method to predict reaction kinetics in complicated, multi-material environments at a relatively modest computational expense. This presentation will describe the current concepts of the ReaxFF method, the current status of the various ReaxFF codes, including parallel implementations and recently developed hybrid Grand Canonical Monte Carlo options - which significantly increase its application areas. Also, we will present and overview of recent applications to a range of materials of increasing complexity, with a focus on applications to combustion, biomaterials, batteries, tribology and catalysis.

  3. Method for deriving information regarding stress from a stressed ferromagnetic material

    DOEpatents

    Jiles, D.C.

    1991-04-30

    A nondestructive evaluation technique is disclosed for deriving stress in ferromagnetic materials including deriving anhysteretic and hysteresis magnetization curves for the material in both unstressed and stressed states. The anhysteretic curve is expressed as a Langevin function. The stress is expressed as an equivalent magnetic field dependent on stress and change of magnetostriction with magnetization. By measurement of these bulk magnetic properties, stress can be derived.

  4. Method for deriving information regarding stress from a stressed ferromagnetic material

    DOEpatents

    Jiles, David C.

    1991-04-30

    A non-destructive evaluation technique for deriving stress in ferromagnetic materials including deriving anhysteretic and hysteresis magnetization curves for the material in both unstressed and stressed states. The anhysteretic curve is expressed as a Langevin function. The stress is expressed as an equivalent magnetic field dependent on stress and change of magnetostriction with magnetization. By measurement of these bulk magnetic properties, stress can be derived.

  5. Calculation of Frequency-Dependent Polarizabilities and Hyperpolarizabilities Based on the Quasienergy Derivative Method (Is the Numerical Approach Impossible?)

    SciTech Connect

    Sasagane, Kotoku

    2008-09-17

    The essence of the quasienergy derivative (QED) method and calculations of the frequency-dependent hyperpolarizabilities based on the QED method will be presented in the first half. Our recent and up-to-date development and some possibilities concerning the QED method will be explained later. At the end of the lecture whether the extension of the QED method to the numerical approach is possible or not will be investigated.

  6. The ADI-FDTD method for high accuracy electrophysics applications

    NASA Astrophysics Data System (ADS)

    Haeri Kermani, Mohammad

    The Finite-Difference Time-Domain (FDTD) is a dependable method to simulate a wide range of problems from acoustics, to electromagnetics, and to photonics, amongst others. The execution time of an FDTD simulation is inversely proportional to the time-step size. Since the FDTD method is explicit, its time-step size is limited by the well-known Courant-Friedrich-Levy (CFL) stability limit. The CFL stability limit can render the simulation inefficient for very fine structures. The Alternating Direction Implicit FDTD (ADI-FDTD) method has been introduced as an unconditionally stable implicit method. Numerous works have shown that the ADI-FDTD method is stable even when the CFL stability limit is exceeded. Therefore, the ADI-FDTD method can be considered an efficient method for special classes of problems with very fine structures or high gradient fields. Whenever the ADI-FDTD method is used to simulate open-region radiation or scattering problems, the implementation of a mesh-truncation scheme or absorbing boundary condition becomes an integral part of the simulation. These truncation techniques represent, in essence, differential operators that are discretized using a distinct differencing scheme which can potentially affect the stability of the scheme used for the interior region. In this work, we show that the ADI-FDTD method can be rendered unstable when higher-order mesh truncation techniques such as Higdon's Absorbing Boundary Condition (ABC) or Complementary Derivatives Method (COM) are used. When having large field gradients within a limited volume, a non-uniform grid can reduce the computational domain and, therefore, it decreases the computational cost of the FDTD method. However, for high-accuracy problems, different grid sizes increase the truncation error at the boundary of domains having different grid sizes. To address this problem, we introduce the Complementary Derivatives Method (CDM), a second-order accurate interpolation scheme. The CDM theory is

  7. Histotripsy Methods in Mechanical Disintegration of Tissue: Toward Clinical Applications

    PubMed Central

    Khokhlova, VA; Fowlkes, JB; Roberts, WW; Schade, GR; Xu, Z; Khokhlova, TD; Hall, TL; Maxwell, AD; Wang, YN; Cain, CA

    2015-01-01

    Purpose In high intensity focused ultrasound (HIFU) therapy, an ultrasound beam is focused within the body to locally affect the targeted site without damaging intervening tissues. The most common HIFU regime is thermal ablation. Recently, there has been increasing interest in generating purely mechanical lesions in tissue (histotripsy). This paper provides an overview of several studies on the development of histotripsy methods toward clinical applications. Material and Methods Two histotripsy approaches and examples of their applications are presented. In one approach, sequences of high-amplitude, short (microsecond-long), focused ultrasound pulses periodically produce dense, energetic bubble clouds that mechanically disintegrate tissue. In an alternative approach, longer (millisecond-long) pulses with shock fronts generate boiling bubbles and the interaction of shock fronts with the resulting vapor cavity causes tissue disintegration. Results Recent pre-clinical studies on histotripsy are reviewed for treating benign prostatic hyperplasia (BPH), liver and kidney tumors, kidney stone fragmentation, enhancing antitumor immune response, and tissue decellularization for regenerative medicine applications. Potential clinical advantages of the histotripsy methods are discussed. Conclusions Histotripsy methods can be used to mechanically ablate a wide variety of tissues, whilst selectivity sparing structures such as large vessels. Both ultrasound and MR imaging can be used for targeting and monitoring the treatment in real time. Although the two approaches utilize different mechanisms for tissue disintegration, both have many of the same advantages and offer a promising alternative method of noninvasive surgery. PMID:25707817

  8. Review of SMS design methods and real-world applications

    NASA Astrophysics Data System (ADS)

    Dross, Oliver; Mohedano, Ruben; Benitez, Pablo; Minano, Juan Carlos; Chaves, Julio; Blen, Jose; Hernandez, Maikel; Munoz, Fernando

    2004-09-01

    The Simultaneous Multiple Surfaces design method (SMS), proprietary technology of Light Prescription Innovators (LPI), was developed in the early 1990's as a two dimensional method. The first embodiments had either linear or rotational symmetry and found applications in photovoltaic concentrators, illumination optics and optical communications. SMS designed devices perform close to the thermodynamic limit and are compact and simple; features that are especially beneficial in applications with today's high brightness LEDs. The method was extended to 3D "free form" geometries in 1999 that perfectly couple two incoming with two outgoing wavefronts. SMS 3D controls the light emitted by an extended light source much better than single free form surface designs, while reaching very high efficiencies. This has enabled the SMS method to be applied to automotive head lamps, one of the toughest lighting tasks in any application, where high efficiency and small size are required. This article will briefly review the characteristics of both the 2D and 3D methods and will present novel optical solutions that have been developed and manufactured to meet real world problems. These include various ultra compact LED collimators, solar concentrators and highly efficient LED low and high beam headlamp designs.

  9. ROS evaluation for a series of CNTs and their derivatives using an ESR method with DMPO

    PubMed Central

    Tsuruoka, S; Takeuchi, K; Koyama, K; Noguchi, T; Endo, M; Tristan, F; Terrones, M; Matsumoto, H; Saito, N; Usui, Y; Porter, D W; Castranova, V

    2015-01-01

    Carbon nanotubes (CNTs) are important materials in advanced industries. It is a concern that pulmonary exposure to CNTs may induce carcinogenic responses. It has been recently reported that CNTs scavenge ROS though non-carbon fibers generate ROS. A comprehensive evaluation of ROS scavenging using various kinds of CNTs has not been demonstrated well. The present work specifically investigates ROS scavenging capabilities with a series of CNTs and their derivatives that were physically treated, and with the number of commercially available CNTs. CNT concentrations were controlled at 0.2 through 0.6 wt%. The ROS scavenging rate was measured by ESR with DMPO. Interestingly, the ROS scavenging rate was not only influenced by physical treatments, but was also dependent on individual manufacturing methods. Ratio of CNTs to DMPO/ hydrogen peroxide is a key parameter to obtain appropriate ROS quenching results for comparison of CNTs. The present results suggest that dangling bonds are not a sole factor for scavenging, and electron transfer on the CNT surface is not clearly determined to be the sole mechanism to explain ROS scavenging. PMID:26300949

  10. Application of integrated fluid-thermal-structural analysis methods

    NASA Technical Reports Server (NTRS)

    Wieting, Allan R.; Dechaumphai, Pramote; Bey, Kim S.; Thornton, Earl A.; Morgan, Ken

    1988-01-01

    Hypersonic vehicles operate in a hostile aerothermal environment which has a significant impact on their aerothermostructural performance. Significant coupling occurs between the aerodynamic flow field, structural heat transfer, and structural response creating a multidisciplinary interaction. Interfacing state-of-the-art disciplinary analysis methods is not efficient, hence interdisciplinary analysis methods integrated into a single aerothermostructural analyzer are needed. The NASA Langley Research Center is developing such methods in an analyzer called LIFTS (Langley Integrated Fluid-Thermal-Structural) analyzer. The evolution and status of LIFTS is reviewed and illustrated through applications.

  11. Control of chaos: methods and applications in mechanics.

    PubMed

    Fradkov, Alexander L; Evans, Robin J; Andrievsky, Boris R

    2006-09-15

    A survey of the field related to control of chaotic systems is presented. Several major branches of research that are discussed are feed-forward ('non-feedback') control (based on periodic excitation of the system), the 'Ott-Grebogi-Yorke method' (based on the linearization of the Poincaré map), the 'Pyragas method' (based on a time-delayed feedback), traditional for control-engineering methods including linear, nonlinear and adaptive control. Other areas of research such as control of distributed (spatio-temporal and delayed) systems, chaotic mixing are outlined. Applications to control of chaotic mechanical systems are discussed.

  12. Applications of alignment-free methods in epigenomics

    PubMed Central

    Pinello, Luca

    2014-01-01

    Epigenetic mechanisms play an important role in the regulation of cell type-specific gene activities, yet how epigenetic patterns are established and maintained remains poorly understood. Recent studies have supported a role of DNA sequences in recruitment of epigenetic regulators. Alignment-free methods have been applied to identify distinct sequence features that are associated with epigenetic patterns and to predict epigenomic profiles. Here, we review recent advances in such applications, including the methods to map DNA sequence to feature space, sequence comparison and prediction models. Computational studies using these methods have provided important insights into the epigenetic regulatory mechanisms. PMID:24197932

  13. Applications of alignment-free methods in epigenomics.

    PubMed

    Pinello, Luca; Lo Bosco, Giosuè; Yuan, Guo-Cheng

    2014-05-01

    Epigenetic mechanisms play an important role in the regulation of cell type-specific gene activities, yet how epigenetic patterns are established and maintained remains poorly understood. Recent studies have supported a role of DNA sequences in recruitment of epigenetic regulators. Alignment-free methods have been applied to identify distinct sequence features that are associated with epigenetic patterns and to predict epigenomic profiles. Here, we review recent advances in such applications, including the methods to map DNA sequence to feature space, sequence comparison and prediction models. Computational studies using these methods have provided important insights into the epigenetic regulatory mechanisms.

  14. Advanced stress analysis methods applicable to turbine engine structures

    NASA Technical Reports Server (NTRS)

    Pian, Theodore H. H.

    1991-01-01

    The following tasks on the study of advanced stress analysis methods applicable to turbine engine structures are described: (1) constructions of special elements which contain traction-free circular boundaries; (2) formulation of new version of mixed variational principles and new version of hybrid stress elements; (3) establishment of methods for suppression of kinematic deformation modes; (4) construction of semiLoof plate and shell elements by assumed stress hybrid method; and (5) elastic-plastic analysis by viscoplasticity theory using the mechanical subelement model.

  15. Applications of nuclear analytical methods to materials analysis

    SciTech Connect

    Jones, K.W.; Hanson, A.L.; Kraner, H.W.

    1982-01-01

    Nuclear analytical methods have now become important in the characterization of many types of materials and have been shown to be an extremely important extension of many more common methods. To illustrate the breadth of their use, some recent Brookhaven experiments are described that deal with the depth distribution of hydrogen in Nb-H alloys, the diffusion of Mo in graphite at high temperatures, and the measurement of Al and Si concentrations in zeolite catalysts. It is hoped that the presentation of these illustrative examples will serve as a stimulus and encouragement for the further application of nuclear analytical methods.

  16. Derivative-ratio spectrophotometric method for the determination of ternary mixture of aspirin, paracetamol and salicylic acid

    NASA Astrophysics Data System (ADS)

    El-Yazbi, Fawzi A.; Hammud, Hassan H.; Assi, Sulaf A.

    2007-10-01

    A derivative spectrophotometric method was developed for the assay of a ternary mixture of aspirin (ASP), paracetamol (PAR) and salicylic acid (SAL). The method is based on the use of the first and second derivatives of the ratio spectra and measurement at zero-crossing wavelengths. The ratio spectra were obtained by dividing the absorption spectrum of the mixture by that of one of the components. The concentration of the other components are then determined from their respective calibration curves treated similarly. The described method was applied for the determination of these combinations in synthetic mixtures and dosage forms. The results obtained were accurate and precise.

  17. Derivative-ratio spectrophotometric method for the determination of ternary mixture of aspirin, paracetamol and salicylic acid.

    PubMed

    El-Yazbi, Fawzi A; Hammud, Hassan H; Assi, Sulaf A

    2007-10-01

    A derivative spectrophotometric method was developed for the assay of a ternary mixture of aspirin (ASP), paracetamol (PAR) and salicylic acid (SAL). The method is based on the use of the first and second derivatives of the ratio spectra and measurement at zero-crossing wavelengths. The ratio spectra were obtained by dividing the absorption spectrum of the mixture by that of one of the components. The concentration of the other components are then determined from their respective calibration curves treated similarly. The described method was applied for the determination of these combinations in synthetic mixtures and dosage forms. The results obtained were accurate and precise.

  18. Three-dimensional surface deformation derived from airborne interferometric UAVSAR: Application to the Slumgullion Landslide

    NASA Astrophysics Data System (ADS)

    Delbridge, Brent G.; Bürgmann, Roland; Fielding, Eric; Hensley, Scott; Schulz, William H.

    2016-05-01

    In order to provide surface geodetic measurements with "landslide-wide" spatial coverage, we develop and validate a method for the characterization of 3-D surface deformation using the unique capabilities of the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) airborne repeat-pass radar interferometry system. We apply our method at the well-studied Slumgullion Landslide, which is 3.9 km long and moves persistently at rates up to ˜2 cm/day. A comparison with concurrent GPS measurements validates this method and shows that it provides reliable and accurate 3-D surface deformation measurements. The UAVSAR-derived vector velocity field measurements accurately capture the sharp boundaries defining previously identified kinematic units and geomorphic domains within the landslide. We acquired data across the landslide during spring and summer and identify that the landslide moves more slowly during summer except at its head, presumably in response to spatiotemporal variations in snowmelt infiltration. In order to constrain the mechanics controlling landslide motion from surface velocity measurements, we present an inversion framework for the extraction of slide thickness and basal geometry from dense 3-D surface velocity fields. We find that the average depth of the Slumgullion Landslide is 7.5 m, several meters less than previous depth estimates. We show that by considering a viscoplastic rheology, we can derive tighter theoretical bounds on the rheological parameter relating mean horizontal flow rate to surface velocity. Using inclinometer data for slow-moving, clay-rich landslides across the globe, we find a consistent value for the rheological parameter of 0.85 ± 0.08.

  19. Cellulosome-based, Clostridium-derived multi-functional enzyme complexes for advanced biotechnology tool development: advances and applications.

    PubMed

    Hyeon, Jeong Eun; Jeon, Sang Duck; Han, Sung Ok

    2013-11-01

    The cellulosome is one of nature's most elegant and elaborate nanomachines and a key biological and biotechnological macromolecule that can be used as a multi-functional protein complex tool. Each protein module in the cellulosome system is potentially useful in an advanced biotechnology application. The high-affinity interactions between the cohesin and dockerin domains can be used in protein-based biosensors to improve both sensitivity and selectivity. The scaffolding protein includes a carbohydrate-binding module (CBM) that attaches strongly to cellulose substrates and facilitates the purification of proteins fused with the dockerin module through a one-step CBM purification method. Although the surface layer homology (SLH) domain of CbpA is not present in other strains, replacement of the cell surface anchoring domain allows a foreign protein to be displayed on the surface of other strains. The development of a hydrolysis enzyme complex is a useful strategy for consolidated bioprocessing (CBP), enabling microorganisms with biomass hydrolysis activity. Thus, the development of various configurations of multi-functional protein complexes for use as tools in whole-cell biocatalyst systems has drawn considerable attention as an attractive strategy for bioprocess applications. This review provides a detailed summary of the current achievements in Clostridium-derived multi-functional complex development and the impact of these complexes in various areas of biotechnology.

  20. Determination of hemoglobin derivatives with IL 282 CO-oximeter as compared with a manual spectrophotometric five-wavelength method.

    PubMed

    Zwart, A; Buursma, A; Oeseburg, B; Zijlstra, W G

    1981-11-01

    Hemoglobin derivatives as determined with the IL 282 CO-Oximeter correlated well with results by a manual five-wavelength method, which in turn had been checked against established methods for one or two derivatives. Measurement of total hemoglobin yielded almost identical results with both methods. As for oxyhemoglobin, carboxyhemoglobin, and hemiglobin, agreement between the two methods was fair. Although the IL 282 CO-Oximeter has not been constructed for the determination of sulfhemoglobin, it appeared that the instrument can still give a strong indication as to the presence of this hemoglobin derivative. Results from the IL 282 for fetal human blood should be used with caution, especially because of the possibility of falsely high HbCO readings.