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Sample records for bacteria-free solution derived

  1. Radiolysis of solutions in anthraquinone derivatives

    International Nuclear Information System (INIS)

    Kriminskaya, Z.K.

    1996-01-01

    Stationary radiolysis of anthraquinones in solutions of ethanol, propanol-2 and water by gamma-radiation (dose rate of 1.6 Gy/s) is studied. It is shown that anthraquinones are reduced in the above solutions up to anthrahydroquinones, whereby all reduction particles participate in the reduction process. The reverse process of the post-radiation oxidation of anthrahydroquinones up to anthraquinones is a radical process

  2. Quantifying risks with exact analytical solutions of derivative pricing distribution

    Science.gov (United States)

    Zhang, Kun; Liu, Jing; Wang, Erkang; Wang, Jin

    2017-04-01

    Derivative (i.e. option) pricing is essential for modern financial instrumentations. Despite of the previous efforts, the exact analytical forms of the derivative pricing distributions are still challenging to obtain. In this study, we established a quantitative framework using path integrals to obtain the exact analytical solutions of the statistical distribution for bond and bond option pricing for the Vasicek model. We discuss the importance of statistical fluctuations away from the expected option pricing characterized by the distribution tail and their associations to value at risk (VaR). The framework established here is general and can be applied to other financial derivatives for quantifying the underlying statistical distributions.

  3. Derivative spectrophotometry applied to solutions of complex composition

    International Nuclear Information System (INIS)

    Perfil'ev, V.A.

    1986-01-01

    The authors consider not only the basic principles of derivative spectrophotometry but also survey the data on its use in research on the properties of materials, the compositions of compounds, and the structures of complex chemical systems. Recording methods by which derivative spectra can be generated include descriptions of electronic differentiation, computer spectrum differentiation, wavelength modulation, and the two-way derivative method. A section on the advantages of derivative spectrophotometry presents a discussion on features enabling one to determine various substances from their characteristic absorption spectra without performing complicated operations to isolate or separate the components. Other topics include research on the structures of substances and metal-ion complexing in solutions, derivative spectrophotometry in gas analysis, gas determination, and determining organic and compounds

  4. Generalized Fokker-Planck equation: Derivation and exact solutions

    Science.gov (United States)

    Denisov, S. I.; Horsthemke, W.; Hänggi, P.

    2009-04-01

    We derive the generalized Fokker-Planck equation associated with the Langevin equation (in the Ito sense) for an overdamped particle in an external potential driven by multiplicative noise with an arbitrary distribution of the increments of the noise generating process. We explicitly consider this equation for various specific types of noises, including Poisson white noise and Lévy stable noise, and show that it reproduces all Fokker-Planck equations that are known for these noises. Exact analytical, time-dependent and stationary solutions of the generalized Fokker-Planck equation are derived and analyzed in detail for the cases of a linear, a quadratic, and a tailored potential.

  5. An unusual cosmological solution in the context of higher-derivative gravity

    International Nuclear Information System (INIS)

    Accioly, A.J.

    1988-01-01

    A general vacuum solution to the higher-derivative gravity field equations is presented in case of a model that exhibits symmetries of the Goedel-type. The solution possesses unusual properties. (author) [pt

  6. THE NEW SOLUTION OF TIME FRACTIONAL WAVE EQUATION WITH CONFORMABLE FRACTIONAL DERIVATIVE DEFINITION

    OpenAIRE

    Çenesiz, Yücel; Kurt, Ali

    2015-01-01

    – In this paper, we used new fractional derivative definition, the conformable fractional derivative, for solving two and three dimensional time fractional wave equation. This definition is simple and very effective in the solution procedures of the fractional differential equations that have complicated solutions with classical fractional derivative definitions like Caputo, Riemann-Liouville and etc. The results show that conformable fractional derivative definition is usable and convenient ...

  7. Solution of heat equation with variable coefficient using derive

    CSIR Research Space (South Africa)

    Lebelo, RS

    2008-09-01

    Full Text Available are considered. The first one involves quadratic approximation of the variable coefficient by direct integration. This case is studied using a conic domain. The second case approximates the variable coefficient quadratically and by step functions. The solution...

  8. Nodulin gene expression and ENOD2 localization in effective, nitrogen fixing and ineffective, bacteria-free nodules of alfalfa.

    NARCIS (Netherlands)

    Wiel, van de C.C.M.; Nurris, J.H.; Bocheneck, B.; Dickstein, R.; Bisseling, T.; Hirsch, A.M.

    1990-01-01

    Alfalfa plants form bacteria-free nodules in response to a number of agents, including Rhizobium meliloti exo mutants, Agrobacterium tumefaciens transconjugants carrying cloned R. meliloti nodulation genes, and compounds that function as auxin transport inhibitors, N-( 1-naphthyl)phthalamic acid or

  9. Modulation equations for spatially periodic systems: derivation and solutions

    NARCIS (Netherlands)

    Schielen, R.; Doelman, A.

    1996-01-01

    We study a class of partial dierential equations in one spatial dimension, which can be seen as model equations for the analysis of pattern formation in physical systems dened on unbounded, weakly oscillating domains. We perform a linear and weakly nonlinear stability analysis for solutions that

  10. Determination of a closed-form solution for the multidimensional transport equation using a fractional derivative

    Energy Technology Data Exchange (ETDEWEB)

    Zabadal, J. E-mail: jorge.zabadal@ufrgs.br; Vilhena, M.T. E-mail: vilhena@mat.ufrgs.br; Segatto, C.F. E-mail: cynthia@mat.ufrgs.br; Pazos, R.P.Ruben Panta. E-mail: rpp@mat.pucrgs.br

    2002-07-01

    In this work we construct a closed-form solution for the multidimensional transport equation rewritten in integral form which is expressed in terms of a fractional derivative of the angular flux. We determine the unknown order of the fractional derivative comparing the kernel of the integral equation with the one of the Riemann-Liouville definition of fractional derivative. We report numerical simulations.

  11. Solution derived ZnO:Al films with low resistivity

    International Nuclear Information System (INIS)

    Schellens, K.; Capon, B.; De Dobbelaere, C.; Detavernier, C.; Hardy, A.; Van Bael, M.K.

    2012-01-01

    ZnO:Al thin films were prepared via chemical solution deposition, using 2-butoxyethanol as an alternative for 2-methoxyethanol, which is more commonly used, but acutely toxic. The precursor solutions can be readily spin coated. The phase, morphology, electrical and optical properties of the deposited films are investigated, by XRD (X-ray diffraction), scanning electron microscopy, a two-point contact measurement and UV–vis spectrophotometry respectively. This way, the effect of this solvent is investigated. The films are deposited on borosilicate glass substrates and were found to be continuous and smooth. XRD measurements show a highly preferential c-axis orientation. The effects of the thermal treatment profile and Al dopant concentration are studied with respect to the obtained electrical properties. Optimally, the electrical resistivity was lowered to 6.5 × 10 −3 Ω cm after annealing at 450 °C in a 95% He/5% H 2 atmosphere. - Highlights: ► 2-Butoxyethanol as alternative for 2-methoxyethanol for precursor synthesis. ► Al:ZnO thin films with a strong preferential c-axis orientation are obtained. ► A forming gas anneal greatly improves the electrical properties. ► The addition of 1 at.% Al is found to improve the electrical properties.

  12. Mineral deposition in bacteria-filled and bacteria-free calcium bodies in the crustacean Hyloniscus riparius (Isopoda: Oniscidea.

    Directory of Open Access Journals (Sweden)

    Miloš Vittori

    Full Text Available Crustacean calcium bodies are epithelial sacs which contain a mineralized matrix. The objectives of this study were to describe the microscopic anatomy of calcium bodies in the terrestrial isopod Hyloniscus riparius and to establish whether they undergo molt-related structural changes. We performed 3D reconstruction of the calcium bodies from paraffin sections and analyzed their structure with light and electron microscopy. In addition, we analyzed the chemical composition of their mineralized matrices with micro-Raman spectroscopy. Two pairs of these organs are present in H. riparius. One pair is filled with bacteria while the other pair is not. In non-molting animals, the bacteria-filled calcium bodies contain apatite crystals and the bacteria-free calcium bodies enclose CaCO3-containing concretions with little organic matrix. During preparation for molt, an additional matrix layer is deposited in both pairs of calcium bodies. In the bacteria-filled calcium bodies it contains a mixture of calcium carbonate and calcium phosphate, whereas only calcium carbonate is present in bacteria-free calcium bodies. After ecdysis, all mineral components in bacteria-free calcium bodies and the additional matrix layer in bacteria-filled calcium bodies are completely resorbed. During calcium resorption, the apical surface of the calcium body epithelium is deeply folded and electron dense granules are present in spaces between epithelial cells. Our results indicate that the presence of bacteria might be linked to calcium phosphate mineralization. Calcium bodies likely provide a source of calcium and potentially phosphate for the mineralization of the new cuticle after molt. Unlike other terrestrial isopods, H. riparius does not form sternal CaCO3 deposits and the bacteria-free calcium bodies might functionally replace them in this species.

  13. High School Forum. The Solution: "Derivation of the Ideal Gas Law."

    Science.gov (United States)

    Herron, J. Dudley, Ed.

    1980-01-01

    Presents responses to an earlier report concerning a procedure for the derivation of the Ideal Gas Law from Charles', Boyle's, and other gas laws. Logic errors and solutions that work are discussed. (CS)

  14. Direct NMR Monitoring of Phase Separation Behavior of Highly Supersaturated Nifedipine Solution Stabilized with Hypromellose Derivatives.

    Science.gov (United States)

    Ueda, Keisuke; Higashi, Kenjirou; Moribe, Kunikazu

    2017-07-03

    We investigated the phase separation behavior and maintenance mechanism of the supersaturated state of poorly water-soluble nifedipine (NIF) in hypromellose (HPMC) derivative solutions. Highly supersaturated NIF formed NIF-rich nanodroplets through phase separation from aqueous solution containing HPMC derivative. Dissolvable NIF concentration in the bulk water phase was limited by the phase separation of NIF from the aqueous solution. HPMC derivatives stabilized the NIF-rich nanodroplets and maintained the NIF supersaturation with phase-separated NIF for several hours. The size of the NIF-rich phase was different depending on the HPMC derivatives dissolved in aqueous solution, although the droplet size had no correlation with the time for which NIF supersaturation was maintained without NIF crystallization. HPMC acetate and HPMC acetate succinate (HPMC-AS) effectively maintained the NIF supersaturation containing phase-separated NIF compared with HPMC. Furthermore, HPMC-AS stabilized NIF supersaturation more effectively in acidic conditions. Solution 1 H NMR measurements of NIF-supersaturated solution revealed that HPMC derivatives distributed into the NIF-rich phase during the phase separation of NIF from the aqueous solution. The hydrophobicity of HPMC derivative strongly affected its distribution into the NIF-rich phase. Moreover, the distribution of HPMC-AS into the NIF-rich phase was promoted at lower pH due to the lower aqueous solubility of HPMC-AS. The distribution of a large amount of HPMC derivatives into NIF-rich phase induced the strong inhibition of NIF crystallization from the NIF-rich phase. Polymer distribution into the drug-rich phase directly monitored by solution NMR technique can be a useful index for the stabilization efficiency of drug-supersaturated solution containing a drug-rich phase.

  15. Semi-analytical solution of land-derived solute transport under tidal fluctuation in a confined aquifer

    Science.gov (United States)

    Suk, Heejun

    2017-11-01

    A one-dimensional semi-analytical solution of land-derived solute transport, subject to tidal fluctuation in a coastal confined aquifer, was derived using the generalized integral-transform technique (GITT). To investigate the plume migration of land-derived contaminants within a tidally influenced aquifer, both spatially and temporally varying expressions of the Darcy velocity and dispersion coefficients obtained from the analytical solution of the groundwater head response, which were subject to sinusoidal boundary conditions due to tidal fluctuation, were considered. This new semi-analytical solution was verified against a numerical solution, as well as the peak location trajectory obtained using the Predictor-Corrector method. Sensitivity analyses of tidal amplitude, hydraulic conductivity, and storage coefficient using the proposed solution were performed to understand plume behavior with regard to plume shape, plume spatial moments, and macrodispersion coefficients to gain a better understanding of the transport mechanisms. As the tidal amplitude, hydraulic conductivity, and storage coefficient were increased, the peaks were travelled faster, and peak concentrations were decreased. In addition, an increase in tidal amplitude, hydraulic conductivity, and storage coefficient caused an increase in variance as well as the macrodispersion coefficient. It was observed that negative macrodispersion appeared when the storage coefficient was largest, as well as when the difference between landward-directed advective velocity at the leading and trailing edges of the plume was greatest. This newly developed semi-analytical solution provides a useful mathematical tool for validating numerical models and understanding the physical mechanism of the migration of plume discharge to the sea or estuaries within a tidally influenced aquifer.

  16. Interaction of derived polymers from pyrrole with biocompatible solutions

    International Nuclear Information System (INIS)

    Lopez G, O. G.

    2010-01-01

    This work presents a study about the synthesis by plasma, the electric properties and superficial interaction of polymers derived from pyrrole doped with Iodine with potential use as bio material. Poly-pyrrole is a semiconductor and biocompatible polymer with potential application in the development of artificial muscles and implants where the electric interaction between cells and material is an important variable. The syntheses were made at 13.5 MHz in a glass tubular reactor of 1500 cm 3 with electrodes of 6.5 cm diameter and stainless steel flanges. An electrode was connected to the RF terminal of the power supply that is combined with a matching coupling resistance. The monomer and dopant used in this work were pyrrole and Iodine respectively, in closed containers. They were vaporized and injected separately into the reactor at room temperature and 0.1 mbar. The vapors of the reagents mixed freely in the reactor. The synthesis time was 240 min at 40, 60, 80 and 100 W. The polymers were obtained as thin films adhered to the reactor walls. The films were washed and swollen with distilled water and removed from the reactor walls with a small spatula. The polymers were irradiated with gamma rays at 18 and 22 KGy. Due to the fact that the doses are cumulative, the final dose applied was 40 KGy. The polymers characterization was carried out by Fourier Transform Infrared Spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy, contact angle, electrical conductivity and X-ray diffraction. The analyses indicates that the polymers have very similar structure in almost the entire power range, showing C-O, C=C, C-H, O-H, N-H bonds with a predominantly amorphous structure. The TGA analyses showed that the material has 4 or 5 loses of material. The first one starts after that 115 C except for the material irradiated at 40 KGy, this one begins in 87 C, the second one is in the interval of 196 and 295 C, the third one between 311 and 500 C, and the last

  17. Computational solutions of unified fractional reaction-diffusion equations with composite fractional time derivative

    Science.gov (United States)

    Saxena, R. K.; Mathai, A. M.; Haubold, H. J.

    2015-10-01

    This paper deals with the investigation of the computational solutions of an unified fractional reaction-diffusion equation, which is obtained from the standard diffusion equation by replacing the time derivative of first order by the generalized fractional time-derivative defined by Hilfer (2000), the space derivative of second order by the Riesz-Feller fractional derivative and adding the function ϕ (x, t) which is a nonlinear function governing reaction. The solution is derived by the application of the Laplace and Fourier transforms in a compact and closed form in terms of the H-function. The main result obtained in this paper provides an elegant extension of the fundamental solution for the space-time fractional diffusion equation obtained earlier by Mainardi et al. (2001, 2005) and a result very recently given by Tomovski et al. (2011). Computational representation of the fundamental solution is also obtained explicitly. Fractional order moments of the distribution are deduced. At the end, mild extensions of the derived results associated with a finite number of Riesz-Feller space fractional derivatives are also discussed.

  18. Thermodynamic properties of ethanol solution of chiral camphors and its derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Takayoshi [Department of Chemistry, Kinki University, Kowakae, Higashi-Osaka 577-8502 (Japan)], E-mail: kimura@chem.kindai.ac.jp; Iwama, Sekai; Kido, Satoko; Khan, Mohammad Abdullah [Department of Chemistry, Kinki University, Kowakae, Higashi-Osaka 577-8502 (Japan)

    2009-10-15

    Enthalpies of mixing and the densities of ethanol solution of R- and S-enantiomers of camphor, 10-camphorsulfonamide, 10-camphorsulfonic acid, camphorquinone, and 10-camphorsulfonyl chloride have been measured for a wide range of mole fractions of heterochiral components at 298.15 K. Enthalpies of mixing were exothermic for all concentrations and heterochiral solutions were more stable than each of the homochiral solutions. Enthalpic stabilization of mixing of heterochiral solutions was increased with a decreasing concentration of all the camphor derivatives measured. The sequence of enthalpic stabilization on mixing was 10-camphorsulfonyl chloride, 10-camphorsulfonic acid, 10-camphorsulfonamide, camphor, and camphorquinone. Apparent molar volumes were determined and excess volumes of mixing of heterochiral solutions were small and negative. Enthalpic stabilizations were found to be dependent on dipole-dipole interaction between solutes and solvents.

  19. Electrochemiluminescence of coumarin derivatives induced by injection of hot electrons into aqueous electrolyte solution

    International Nuclear Information System (INIS)

    Helin, Mika; Jiang, Qinghong; Ketamo, Hanna; Hakansson, Markus; Spehar, Anna-Maria; Kulmala, Sakari; Ala-Kleme, Timo

    2005-01-01

    Hot electrons can be injected from conductor/insulator/electrolyte (C/I/E) junctions into an aqueous electrolyte solution by cathodic pulse-polarization of the electrode. Injected hot electrons induce electrogenerated chemiluminescence of various luminophores including coumarins in fully aqueous solutions. This is based on the tunnel emission of hot electrons into aqueous electrolyte solution, which can result in the generation of hydrated electrons as reducing mediators. These tunnel-emitted electrons allow also the production of highly oxidizing radicals from added precursors. This work shows that coumarin derivatives are suitable candidates as ECL labels for bioaffinity assays or other analytical applications in which detection is based on the ECL of pulse-polarized C/I/E tunnel-emission electrodes in fully aqueous solutions. The mechanisms of the ECL of coumarins are discussed and the analytical applicability of the ECL of three coumarin derivatives is studied

  20. Mild solutions for nonlocal fractional semilinear functional differential inclusions involving Caputo derivative

    Directory of Open Access Journals (Sweden)

    Ahmed G. Ibrahim

    2014-05-01

    Full Text Available In this paper, we prove various existence results of a mild solution for a fractional nonlocal functional semilinear differential inclusion involving Caputo derivative in Banach spaces. We consider the case when the values of the orient field are convex as well as nonconvex. Moreover, we study the topological structure of solution sets. Our results extend or generalize results proved in recent papers.

  1. Approximate analytical solution of diffusion equation with fractional time derivative using optimal homotopy analysis method

    Directory of Open Access Journals (Sweden)

    S. Das

    2013-12-01

    Full Text Available In this article, optimal homotopy-analysis method is used to obtain approximate analytic solution of the time-fractional diffusion equation with a given initial condition. The fractional derivatives are considered in the Caputo sense. Unlike usual Homotopy analysis method, this method contains at the most three convergence control parameters which describe the faster convergence of the solution. Effects of parameters on the convergence of the approximate series solution by minimizing the averaged residual error with the proper choices of parameters are calculated numerically and presented through graphs and tables for different particular cases.

  2. Analytical Solution for Fractional Derivative Gas-Flow Equation in Porous Media

    KAUST Repository

    El-Amin, Mohamed

    2017-07-06

    In this paper, we introduce an analytical solution of the fractional derivative gas transport equation using the power-series technique. We present a new universal transform, namely, generalized Boltzmann change of variable which depends on the fractional order, time and space. This universal transform is employed to transfer the partial differential equation into an ordinary differential equation. Moreover, the convergence of the solution has been investigated and found that solutions are unconditionally converged. Results are introduced and discussed for the universal variable and other physical parameters such as porosity and permeability of the reservoir; time and space.

  3. Enzyme stabilization by glass-derived silicates in glass-exposed aqueous solutions

    Science.gov (United States)

    Ives, J.A.; Moffett, J.R.; Arun, P.; Lam, D.; Todorov, T.I.; Brothers, A.B.; Anick, D.J.; Centeno, J.; Namboodiri, M.A.A.; Jonas, W.B.

    2010-01-01

    Objectives: To analyze the solutes leaching from glass containers into aqueous solutions, and to show that these solutes have enzyme activity stabilizing effects in very dilute solutions. Methods: Enzyme assays with acetylcholine esterase were used to analyze serially succussed and diluted (SSD) solutions prepared in glass and plastic containers. Aqueous SSD preparations starting with various solutes, or water alone, were prepared under several conditions, and tested for their solute content and their ability to affect enzyme stability in dilute solution. Results: We confirm that water acts to dissolve constituents from glass vials, and show that the solutes derived from the glass have effects on enzymes in the resultant solutions. Enzyme assays demonstrated that enzyme stability in purified and deionized water was enhanced in SSD solutions that were prepared in glass containers, but not those prepared in plastic. The increased enzyme stability could be mimicked in a dose-dependent manner by the addition of silicates to the purified, deionized water that enzymes were dissolved in. Elemental analyses of SSD water preparations made in glass vials showed that boron, silicon, and sodium were present at micromolar concentrations. Conclusions: These results show that silicates and other solutes are present at micromolar levels in all glass-exposed solutions, whether pharmaceutical or homeopathic in nature. Even though silicates are known to have biological activity at higher concentrations, the silicate concentrations we measured in homeopathic preparations were too low to account for any purported in vivo efficacy, but could potentially influence in vitro biological assays reporting homeopathic effects. ?? 2009 The Faculty of Homeopathy.

  4. Spectral Approach to Derive the Representation Formulae for Solutions of the Wave Equation

    Directory of Open Access Journals (Sweden)

    Gusein Sh. Guseinov

    2012-01-01

    Full Text Available Using spectral properties of the Laplace operator and some structural formula for rapidly decreasing functions of the Laplace operator, we offer a novel method to derive explicit formulae for solutions to the Cauchy problem for classical wave equation in arbitrary dimensions. Among them are the well-known d'Alembert, Poisson, and Kirchhoff representation formulae in low space dimensions.

  5. Classification of kink type solutions to the extended derivative nonlinear Schrödinger equation

    DEFF Research Database (Denmark)

    Wyller, J.; Fla, T.; Juul Rasmussen, J.

    1998-01-01

    The Raman Extended Derivative Non Linear Schrodinger (R-EDNLS) equation which models single mode propagation in optical fibers, is shown to possess travelling and stationary kink envelope solutions of monotonic and oscillatory type. These structures have been called optical shocks in analogy...

  6. A formal derivation for the Blasius similarity solution for flat-plate boundary layer

    Science.gov (United States)

    Lin, Hao

    2015-11-01

    The Blasius solution is a classical solution for a laminar boundary layer attached to a semi-infinite flat plate. The key of the solution strategy is to reduce the boundary layer equations, which are PDEs, to a set of ODEs, using a similarity variable transform. Conceptually, the similarity suggests that the velocity profile in each transverse cross-section appears ``self-similar''. In many classical text books and typical classroom lectures on fluid mechanics, the existence of the similarity solution is argued heuristically. The similarity variable is defined a priori so as to collapse the PDEs. It appears somewhat mystical that the PDEs can be perfectly reduced via such an approach. Here we present a rigorous derivation for the existence of a similarity solution, which naturally arises from the fact that there is no apparent streamwise length scale for a semi-infinite plate. Conversely, a similarity solution cannot exist if the plate size is finite. This derivation can be useful in fluids education, in topics including similarity, scaling arguments, and boundary layer theory.

  7. Evolution of castalagin and vescalagin in ethanol solutions. Identification of new derivatives.

    Science.gov (United States)

    Puech, J L; Mertz, C; Michon, V; Le Guernevé, C; Doco, T; Hervé Du Penhoat, C

    1999-05-01

    Brandies, cognac, armagnac, whiskeys, and rums are aged in oak barrels to improve their organoleptic properties. During this period, numerous compounds such as ellagitannins are extracted from the wood and can subsequently be transformed into new derivatives by chemical reactions. Model solutions of castalagin and vescalagin have been studied to determine the behavior of polyphenols in ethanol-water. Upon prolonged exposure to 40 and 70% (v/v) ethanol at room temperature, hemiketal derivatives containing ethoxy groups have been characterized by LC/MS and NMR. These compounds further evolve to afford the corresponding ketals. They have also been detected in the extracts of oak wood stored under similar conditions.

  8. Interactions of Lysozyme and Azobenzene Derivatives in the Solution and on a Surface

    Science.gov (United States)

    Wei, Tao; Shing, Katherine

    2015-03-01

    The reversible isomerization of the azobenzene and its derivatives can control protein structure in an aqueous environment with the alternation of visible and UV lights for very promising applications in drug delivery. However, an atomistic description of Azo-molecules and protein amino acid residues is still lacking. In this study we performed atomistic molecular dynamics simulation to study the interactions between a lysozyme molecule and the Azobenzene derivative (in the bulk solution and grafted on the Silica surfaces). Protein structural arrangements (i.e., the shape and secondary structures) and its mobility, as a function of tran/cis ratio in the bulk solution and on the self-assembling monolayer surface's density and morphology, are systematically investigated.

  9. Anomalous Advection-Dispersion Equations within General Fractional-Order Derivatives: Models and Series Solutions

    Directory of Open Access Journals (Sweden)

    Xin Liang

    2018-01-01

    Full Text Available In this paper, an anomalous advection-dispersion model involving a new general Liouville–Caputo fractional-order derivative is addressed for the first time. The series solutions of the general fractional advection-dispersion equations are obtained with the aid of the Laplace transform. The results are given to demonstrate the efficiency of the proposed formulations to describe the anomalous advection dispersion processes.

  10. Existence Theory for Pseudo-Symmetric Solution to -Laplacian Differential Equations Involving Derivative

    OpenAIRE

    Su, You-Hui; Wu, Weili; Yan, Xingjie

    2011-01-01

    We all-sidedly consider a three-point boundary value problem for $p$ -Laplacian differential equation with nonlinear term involving derivative. Some new sufficient conditions are obtained for the existence of at least one, triple, or arbitrary odd positive pseudosymmetric solutions by using pseudosymmetric technique and fixed-point theory in cone. As an application, two examples are given to illustrate the main results.

  11. THE STRUCTURE OF CONCENTRATED Li-AMMONIA SOLUTIONS AS DERIVED FROM MD SIMULATIONS

    Directory of Open Access Journals (Sweden)

    K.Heinzinger

    2003-01-01

    Full Text Available The results of Molecular Dynamics simulations of lithium-ammonia solutions over the whole concentration range from 0.5 to 19.6 MPM at 240 K are reported. The pseudopotential theory is employed at the higher concentrations and the direct contribution to the total potential which has been derived from ab initio calculations has been supplemented by three-body terms. The resulting partial structure and radial distribution functions are compared in detail with recent X-ray and neutron diffraction studies with isotopic substitution. There is an overall good agreement between simulation and experiment. Differences are discussed. The solvation number of the lithium ion is found to be six for the dilute solution and four for the higher concentrations in analogy to the hydration of Li+ found for various aqueous solutions.

  12. Global solutions to the initial-boundary value problem for the quasilinear viscoelastic equation with a derivative nonlinearity

    Directory of Open Access Journals (Sweden)

    Mitsuhiro Nakao

    2014-01-01

    Full Text Available We prove the existence and uniqueness of a global decaying solution to the initial boundary value problem for the quasilinear wave equation with Kelvin-Voigt dissipation and a derivative nonlinearity. To derive the required estimates of the solutions we employ a 'loan' method and use a difference inequality on the energy.

  13. Analytical study of exact solutions of the nonlinear Korteweg-de Vries equation with space-time fractional derivatives

    Science.gov (United States)

    Liu, Jiangen; Zhang, Yufeng

    2018-01-01

    This paper gives an analytical study of dynamic behavior of the exact solutions of nonlinear Korteweg-de Vries equation with space-time local fractional derivatives. By using the improved (G‧ G )-expansion method, the explicit traveling wave solutions including periodic solutions, dark soliton solutions, soliton solutions and soliton-like solutions, are obtained for the first time. They can better help us further understand the physical phenomena and provide a strong basis. Meanwhile, some solutions are presented through 3D-graphs.

  14. Furopyridine derivatives as host materials for solution processed blue phosphorescent organic light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Yook, Kyoung Soo; Lee, Jun Yeob, E-mail: leej17@dankook.ac.kr

    2014-07-01

    Soluble blue phosphorescent organic light-emitting diodes were developed using a pyridofuropyridine derivative, 3-(3-(carbazole-9-yl)phenyl) pyrido[3′,2′:4,5]furo[2,3-b]pyridine (CzPFP), and a benzofuropyridine derivative, 6-(3-(carbazole-9-yl)phenyl)benzofuro[2,3-b]pyridine (PCz-6BFP) as host materials. The CzPFP and PCz-6BFP hosts formed a smooth film morphology with a surface roughness less than 0.5 nm after spin coating. The PCz-6BFP host showed better quantum efficiency than the CzPFP host and a high quantum efficiency of 19.5% was achieved in solution processed blue phosphorescent organic light-emitting diodes using the PCz-6BFP host. - Highlights: • High quantum efficiency of 19.5% in blue phosphorescent organic light-emitting diodes • Stable film morphology using benzofuropyridine and pyridofuropyridine derivatives • High efficiency solution processed blue phosphorescent organic light-emitting diodes.

  15. Study of a Triazole Derivative as Corrosion Inhibitor for Mild Steel in Phosphoric Acid Solution

    Directory of Open Access Journals (Sweden)

    Lin Wang

    2012-01-01

    Full Text Available The corrosion inhibition by a triazole derivative (PAMT on mild steel in phosphoric acid (H3PO4 solution has been investigated by weight loss and polarization methods. The experimental results reveal that the compound has a significant inhibiting effect on the corrosion of steel in H3PO4 solution. It also shows good corrosion inhibition at higher concentration of H3PO4. Potentiodynamic polarization studies have shown that the compound acts as a mixed-type inhibitor retarding the anodic and cathodic corrosion reactions with predominant effect on the cathodic reaction. The values of inhibition efficiency obtained from weight loss and polarization measurements are in good agreement. The adsorption of this compound is found to obey the Langmuir adsorption isotherm. Some kinetic and thermodynamic parameters such as apparent activation energy, frequency factor, and adsorption free energy have been calculated and discussed.

  16. SANS structural characterization of fullerenol-derived star polymers in solutions

    CERN Document Server

    Jeng, U S; Wang, L Y; Chiang, L Y; Ho, D L; Han, C C

    2002-01-01

    We have studied the chain conformations of fullerenol-derived star polymers in two organic solvents using small-angle neutron scattering (SANS). The SANS results indicate that the six poly(urethane-ether) arms, chemically bonded on the fullerenol of the C sub 6 sub 0 -based star polymer, have a Gaussian chain conformation in toluene. However, these arms exhibit a pronounced excluded-volume effect in dimethylformamide solutions. We use a scattering model, with the polydispersity of the polymer taken into account, and a fractal model to extract the radius of gyration R sub g values and the persistence lengths of the C sub 6 sub 0 -star polymers in these two organic solutions. (orig.)

  17. Solution structure of the major fish allergen parvalbumin Sco j 1 derived from the Pacific mackerel.

    Science.gov (United States)

    Kumeta, Hiroyuki; Nakayama, Haruka; Ogura, Kenji

    2017-12-07

    Although fish is an important part of the human diet, it is also a common source of food allergy. The major allergen in fish is parvalbumin, a well-conserved Ca 2+ -binding protein found in the white muscle of many fish species. Here, we studied the solution structure of the parvalbumin Sco j 1, derived from the Pacific mackerel, using nuclear magnetic resonance spectroscopy. We mapped the IgE-binding epitope proposed in a recent study onto the present structure. Interestingly, three of four residues, which were elucidated as key residues of the IgE-binding epitope, were exposed to solvent, whereas one residue faced the inside of the molecule. We expect that this solution structure can be used in future studies attempting to analyze the various IgE-binding modes of these allergens.

  18. Thermodynamics of the interaction between antihistamines with native and hydroxypropyl-cyclodextrin derivatives in aqueous solutions

    International Nuclear Information System (INIS)

    Alvarez-Lopez, Enrique; Perez-Casas, Silvia

    2013-01-01

    Highlights: • The complexes formation between cyclodextrins and pheniramines were studied by ITC. • In all the cases, the process is enthalpy driven. • The interactions between cyclodextrins and pheniramines are discussed. -- Abstract: The interactions of native and hydroxypropyl-cyclodextrin derivatives with pheniramine, (±)-brompheniramine, (+)-brompheniramine, (±)-chlorpheniramine, (+)-chlorpheniramine, carbinoxamine maleate salts and doxylamine succinate salt have been studied by isothermal titration calorimetry at T = 298.15 K in aqueous solution. The enthalpies and association constants for the complex formation were obtained, from which the Gibbs energy and entropy changes were derived. The thermodynamic parameters corresponding to the transfer process of the guest from the native to the modified CD are also calculated. The results show that the hydrophobic interactions are important in this process, but the size of the guest and the nature of the substituent are also of some importance

  19. Solution structure of the major fish allergen parvalbumin Sco j 1 derived from the Pacific mackerel

    OpenAIRE

    Kumeta, Hiroyuki; Nakayama, Haruka; Ogura, Kenji

    2017-01-01

    Although fish is an important part of the human diet, it is also a common source of food allergy. The major allergen in fish is parvalbumin, a well-conserved Ca2+-binding protein found in the white muscle of many fish species. Here, we studied the solution structure of the parvalbumin Sco j 1, derived from the Pacific mackerel, using nuclear magnetic resonance spectroscopy. We mapped the IgE-binding epitope proposed in a recent study onto the present structure. Interestingly, three of four re...

  20. Metabolic Engineering of Yeast to Produce Fatty Acid-derived Biofuels: Bottlenecks and Solutions

    Directory of Open Access Journals (Sweden)

    Jiayuan eSheng

    2015-06-01

    Full Text Available Fatty acid-derived biofuels can be a better solution than bioethanol to replace petroleum fuel, since they have similar energy content and combustion properties as current transportation fuels. The environmentally friendly microbial fermentation process has been used to synthesize advanced biofuels from renewable feedstock. Due to their robustness as well as the high tolerance to fermentation inhibitors and phage contamination, yeast strains such as Saccharomyces cerevisiae and Yarrowia lipolytica have attracted tremendous attention in recent studies regarding the production of fatty acid-derived biofuels, including fatty acids, fatty acid ethyl esters, fatty alcohols, and fatty alkanes. However, the native yeast strains cannot produce fatty acids and fatty acid-derived biofuels in large quantities. To this end, we have summarized recent publications in this review on metabolic engineering of yeast strains to improve the production of fatty acid-derived biofuels, identified the bottlenecks that limit the productivity of biofuels, and categorized the appropriate approaches to overcome these obstacles.

  1. Optimization of regression equation for prediction of viscosity of aqueous solutions of the cellulose derivatives.

    Science.gov (United States)

    Sklubalova, Zdenka; Zatloukal, Zdenek

    2008-01-01

    Commercially, cellulose products are designated with viscosity grade measured at 2% w/v concentration in water at 20 degrees C using an Ubbelohde viscometer. To represent viscosity/concentration curves, linear function of the eighth root of dynamic viscosity and the concentration is generally used. In this work, the influence on viscosity of aqueous solutions of methylcellulose 400 and hypromellose 4000 by temperature and polymer concentration was modelled using an empirically proposed multiple linear regression in which the transformation of viscosity by logarithm, the reciprocal value of the absolute temperature, and the concentration by square root was recommended. Due to this, the viscosity of both cellulose derivatives investigated could be predicted simultaneously with the mean difference between the observed data and the ones estimated equal to 16.2%. Expanding the linear regression with the linear interaction between logarithm of the polymer viscosity grade and square root of the polymer concentration, the precision of the viscosity prediction increased to the acceptable level of 4.1%. Other interactions between the studied variables did not provide significantly better results. The optimized regression equation enabled the prediction of kinematic, dynamic, relative, and specific viscosity of the aqueous solutions of cellulose derivatives. The dimensionless relative viscosity could be recommended because it takes into account the water viscosity at the same experimental temperature. Selecting viscosity grade of the cellulose derivative and temperature of measurement, the partial regression equations were obtained from which the relative viscosity could be determined as the function of the polymer concentration with the precision in range of 1.3-4.7%.

  2. Technique for Calculating Solution Derivatives With Respect to Geometry Parameters in a CFD Code

    Science.gov (United States)

    Mathur, Sanjay

    2011-01-01

    A solution has been developed to the challenges of computation of derivatives with respect to geometry, which is not straightforward because these are not typically direct inputs to the computational fluid dynamics (CFD) solver. To overcome these issues, a procedure has been devised that can be used without having access to the mesh generator, while still being applicable to all types of meshes. The basic approach is inspired by the mesh motion algorithms used to deform the interior mesh nodes in a smooth manner when the surface nodes, for example, are in a fluid structure interaction problem. The general idea is to model the mesh edges and nodes as constituting a spring-mass system. Changes to boundary node locations are propagated to interior nodes by allowing them to assume their new equilibrium positions, for instance, one where the forces on each node are in balance. The main advantage of the technique is that it is independent of the volumetric mesh generator, and can be applied to structured, unstructured, single- and multi-block meshes. It essentially reduces the problem down to defining the surface mesh node derivatives with respect to the geometry parameters of interest. For analytical geometries, this is quite straightforward. In the more general case, one would need to be able to interrogate the underlying parametric CAD (computer aided design) model and to evaluate the derivatives either analytically, or by a finite difference technique. Because the technique is based on a partial differential equation (PDE), it is applicable not only to forward mode problems (where derivatives of all the output quantities are computed with respect to a single input), but it could also be extended to the adjoint problem, either by using an analytical adjoint of the PDE or a discrete analog.

  3. Anisotropic surface hole-transport property of triphenylamine-derivative single crystal prepared by solution method

    Energy Technology Data Exchange (ETDEWEB)

    Umeda, Minoru, E-mail: mumeda@vos.nagaokaut.ac.jp [Nagaoka University of Technology, Kamitomioka, Nagaoka, Niigata 940-2188 (Japan); Katagiri, Mitsuhiko; Shironita, Sayoko [Nagaoka University of Technology, Kamitomioka, Nagaoka, Niigata 940-2188 (Japan); Nagayama, Norio [Nagaoka University of Technology, Kamitomioka, Nagaoka, Niigata 940-2188 (Japan); Ricoh Company, Ltd., Nishisawada, Numazu, Shizuoka 410-0007 (Japan)

    2016-12-01

    Highlights: • A hole transport molecule was investigated based on its electrochemical redox characteristics. • The solubility and supersolubility curves of the molecule were measured in order to prepare a large crystal. • The polarization micrograph and XRD results revealed that a single crystal was obtained. • An anisotropic surface conduction, in which the long-axis direction exceeds that of the amorphous layer, was observed. • The anisotropic surface conduction was well explained by the molecular stacked structure. - Abstract: 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.

  4. Solute transport in shale and shale-derived soils at the Shale Hills CZO

    Science.gov (United States)

    Kuntz, B. W.; Singha, K.

    2009-12-01

    Interpreting the operation of parameters controlling solute transport is challenging in shales and shale-derived soils because of complex chemical and physical heterogeneity. Quantifying solute transport processes in the weathered shale and soils of the Shale Hills Critical Zone Observatory (SH-CZO) is important in interpreting the residence times of ions in the groundwater system, and consequently weathering rates and age of groundwater. In three 10-cm diameter undisturbed soil columns from the SH-CZO (spanning the intervals from 0-15, 20-35, and 40-50 cm) as well as consolidated shale cores, we are evaluating physical heterogeneity, as well as solute transport parameters such as (1) mobile/immobile porosity, (2) mass-transfer rate between domains, and (3) the behavior of exchangeable ions within the system as material properties shift from soil to consolidated rock. Soil samples change with respect to color and biogenic fabric or structure with depth, and the frequency of shale bedrock fragments within in the soil increases with depth. Constant flow experiments in the soil provide a hydraulic conductivity of 10-6 m/s at 0-15 cm depth. Field-scale hydraulic conductivities from slug and pumping tests of the fractured shale at depth are approximately the same: 10-5 to 10-6 m/s. A hydraulic test in a triaxial compression chamber places the hydraulic conductivity of the shale matrix, however, at less than 10-15 m/s, indicating that fractures control permeable pathways within the shale bedrock. Taken collectively, such observations indicate high physical heterogeneity within the subsurface material that could be controlling flow and transport behavior. Concentration histories from a conservative sodium bromide tracer test carried out on the uppermost soil column exhibit long tailing behavior, indicative of non-equilibrium transport. Numerical modeling with Comsol indicates that a mobile porosity of 0.3 and an immobile porosity of 0.35 coupled by a mass-transfer rate of

  5. Synthesis of an amphiphilic rhodamine derivative and characterization of its solution and thin film properties

    Energy Technology Data Exchange (ETDEWEB)

    Aviv, Hagit [Department of Chemistry, Bar-Ilan University, Ramat-Gan (Israel); Bar-Ilan University Institute for Nanotechnology and Advanced Materials, Ramat-Gan (Israel); Harazi, Sivan [Department of Chemistry, Bar-Ilan University, Ramat-Gan (Israel); Department of Physics, Bar-Ilan University, Ramat-Gan (Israel); Bar-Ilan University Institute for Nanotechnology and Advanced Materials, Ramat-Gan (Israel); Schiff, Dillon [Department of Chemistry, Bar-Ilan University, Ramat-Gan (Israel); Bar-Ilan University Institute for Nanotechnology and Advanced Materials, Ramat-Gan (Israel); Ramon, Yoni [Department of Chemistry, Bar-Ilan University, Ramat-Gan (Israel); Department of Physics, Bar-Ilan University, Ramat-Gan (Israel); Bar-Ilan University Institute for Nanotechnology and Advanced Materials, Ramat-Gan (Israel); Tischler, Yaakov R., E-mail: yrt@biu.ac.il [Department of Chemistry, Bar-Ilan University, Ramat-Gan (Israel); Bar-Ilan University Institute for Nanotechnology and Advanced Materials, Ramat-Gan (Israel)

    2014-08-01

    Here we present characterization of solution and thin film properties of Lissamine rhodamine B sulfonyl didodecyl amine (LRSD), an amphiphilic derivative of rhodamine. LRSD was synthesized by functionalizing Lissamine rhodamine B sulfonyl chloride (LRSC) with didodecylamine via a straightforward sulfonylation reaction. LRSD's long alkane chains make it highly soluble in chloroform, with a marked increase in brightness compared to the starting material. LRSD is shown to form well-defined robust micelles in water, without the addition of a co-surfactant and stable monolayers at the air–water interface. The greater lipophilicity of LRSD also enables doping into non-polar polymeric host matrices such as polystyrene with less aggregation and hence higher fluorescence quantum yield than LRSC or even rhodamine B. The monolayers of LRSD were prepared via Langmuir–Blodgett deposition and showed shifts in the photoluminescence peak from 575 nm to 595 nm, as the surface pressure is varied from 3 mN/m to 11 mN/m. - Highlights: • Lissamine rhodamine B sulfonyl didodecyl amine (LRSD) is soluble in chloroform. • LRSD shows robust quantum yield in solution and as a dopant in thin film. • LRSD is an amphiphilic rhodamine dye that forms compact fluorescent micelles. • LRSD forms a stable isotherm when spread at the air–water interface.

  6. Tratteggio retouch and its derivatives as an image reintegration solution in the process of restoration

    Directory of Open Access Journals (Sweden)

    Magdalena Grenda

    2010-11-01

    Full Text Available L’article traite du problème de retouche dans la conservation- restauration du papier, concernant en particulier la retouche tratteggio et ses derivatifs que peuvent être la solution de la réintegration de l’image, non si populaire parmi les restaurateurs du papier. C’était la partie du projet de Maîtrise de l’auteur d’examiner la possibilité de l’usage de retouches comme tratteggio dans la restauration de l’affiche de cinéma polonaise de Stefan Norblin, imprimée en lithographie en couleurs.The article describes issues concerning retouch in paper conservation- restoration with particular consideration of tratteggio retouch and its derivatives as an image reintegration solution, not very popular among paper conservators. It was a part of author’s MA project to examine the possibility of using tratteggio- like retouches during the restoration of 20th century Polish film poster by Stefan Norblin, printed in colour litograph.

  7. Cryopreservation of buffy-coat-derived platelet concentrates in dimethyl sulfoxide and platelet additive solution.

    Science.gov (United States)

    Johnson, L N; Winter, K M; Reid, S; Hartkopf-Theis, T; Marks, D C

    2011-04-01

    Platelets prepared in plasma can be frozen in 6% dimethyl sulfoxide (Me(2)SO) and stored for extended periods at -80°C. The aim of this study was to reduce the plasma present in the cryopreserved product, by substituting plasma with platelet additive solution (PAS; SSP+), whilst maintaining in vitro platelet quality. Buffy coat-derived pooled leukoreduced platelet concentrates were frozen in a mixture of SSP+, plasma and 6% Me(2)SO. The platelets were concentrated, to avoid post-thaw washing, and frozen at -80°C. The cryopreserved platelet units (n=9) were rapidly thawed at 37°C, reconstituted in 50% SSP+/plasma and stored at 22°C. Platelet recovery and quality were examined 1 and 24h post-thaw and compared to the pre-freeze samples. Upon thawing, platelet recovery ranged from 60% to 80%. However, there were differences between frozen and liquid-stored platelets, including a reduction in aggregation in response to ADP and collagen; increased CD62P expression; decreased viability; increased apoptosis and some loss of mitochondrial membrane integrity. Some recovery of these parameters was detected at 24h post-thaw, indicating an extended shelf-life may be possible. The data suggests that freezing platelets in 6% Me(2)SO and additive solution produces acceptable in vitro platelet quality. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Formation of passivating layers by 1,2,4-triazole derivatives on copper in aqueous solutions

    Science.gov (United States)

    Kuznetsov, Yu. I.; Shikhaliev, Kh. S.; Agafonkina, M. O.; Andreeva, N. P.; Semiletov, A. M.; Chirkunov, A. A.; Potapov, A. Yu.; Solov'ev, V. E.

    2017-12-01

    Ellipsometry and electrochemical measurements are used to study the adsorption of some substituted 1,2,4-triazoles on copper and their effect on dissolution of copper in aqueous buffer solutions at pH 7.4. It is found that the adsorption of triazole compounds on copper is polymolecular at potential E = 0.0 V, in relation to a normal hydrogen electrode. The first layer is described by the Temkin equation with free adsorption energy (-Δ G a 0) = 55.2-76.3 kJ/mol and an energy heterogeneity factor that varies from 0.91 to 2.5. The maximum value of -Δ G a 0 is found for an acid and a hydrogen sulfide corrosion inhibitor that is a mixture of triazole derivatives. The same inhibitor is the one least sensitive to the energy heterogeneity of the surface of a copper electrode, due to its high chemical reactivity and ability to be adsorbed on different active sites. This inhibitor is likely chemisorbed on copper and forms an ultrathin coating in an aqueous solution that is vastly superior to similar coatings produced by the familiar corrosion inhibitors of triazole group compounds in protecting against atmospheric corrosion.

  9. Efficient removal of lead from solution by celery-derived biochars rich in alkaline minerals.

    Science.gov (United States)

    Zhang, Tao; Zhu, Xiaoxiao; Shi, Lingna; Li, Jianfa; Li, Saijun; Lü, Jinhong; Li, Yimin

    2017-07-01

    Biochars were produced from celery biomass by slow pyrolysis at 350 and 500°C, and featured by high content of alkaline minerals namely salts of alkali and alkaline earth metals. The biochars' efficiency on removing Pb 2+ from solution was investigated, and two biochars derived from celery stalk (StC350 and StC500) showed higher Pb 2+ sorption capacity (288 and 304mg/g) than most biochars reported previously. The sorption mechanisms involving precipitation, cation exchange and surface complexation are related to three biochar fractions namely water-soluble matter, acid-soluble substances and insoluble organic carbon. The relative contributions of water-soluble matter and acid-soluble substances to the total Pb 2+ removal were 59.8% and 36.6% for the StC350 biochar, and 62.8% and 34.9% for the StC500 biochar, respectively. The results indicate that biochars derived from vegetable wastes are potential candidates for efficient sorption of heavy metals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Substituent Effects on the Photodeprotection Reactions of Selected Ketoprofen Derivatives in Phosphate Buffered Aqueous Solutions.

    Science.gov (United States)

    Liu, Mingyue; Li, Ming-De; Huang, Jinqing; Li, Tianlu; Liu, Han; Li, Xuechen; Phillips, David Lee

    2016-02-22

    Photodeprotection is an important reaction that has been attracting broad interest for use in a variety of applications. Recent advances in ultrafast and vibrational time-resolved spectroscopies can facilitate obtaining data to help unravel the reaction mechanisms involving in the photochemical reactions of interest. The kinetics and reaction mechanisms for the photodeprotection reactions of ketoprofen derivatives containing three different substituents (ibuprofen, Br and I) were investigated by femtosecond transient absorption (fs-TA) and nanosecond time-resolved resonance Raman (ns-TR(3)) spectroscopy methods in phosphate buffered solutions (PBS). Fs-TA allows us to detect the decay kinetics of the triplet species as the key precursor for formation of a carbanion species for three different substituents attached to ketoprofen. To characterize the structural and electronic properties of the corresponding carbanion and triplet intermediates, TR(3) spectroscopic experiments were conducted. The transient spectroscopy work reveals that the different substituents affect the photodecarboxylation reaction to produce carbon dioxide which in turn influences the generation of the carbanion species which determines the rate of the photorelease of the functional groups attached on the ketoprofen parent molecule. The fingerprint TR(3) spectroscopy results suggest that ketoprofen derivatives may be deactivated to produce a triplet carbanion when increasing the atom mass of the halogen atoms.

  11. Substituent effects on the photophysical properties of pterin derivatives in acidic and alkaline aqueous solutions.

    Science.gov (United States)

    Cabrerizo, Franco M; Petroselli, Gabriela; Lorente, Carolina; Capparelli, Alberto L; Thomas, Andrés H; Braun, André M; Oliveros, Esther

    2005-01-01

    Pterins are heterocyclic compounds with important biological functions, and most of them may exist in two acid-base forms in the pH range between 3 and 13 in aqueous solution. In this work, the photophysical properties of acid and basic forms of six compounds of the pterin family (6-hydroxymethylpterin [HPT], 6-methylpterin [MPT], 6,7-dimethylpterin [DPT], rhamnopterin [RPT], N-methylfolic acid [MFA], and pteroic acid [PA]) have been studied. The effects of the chemical nature of the substituents at position 6 of the pterin moiety and the effects of the pH on the absorption and emission properties are analyzed. The fluorescence characteristics (spectra, quantum yields, lifetimes) of these compounds have been investigated using the single-photon-counting technique. Results obtained for pterin derivatives containing small substituents with 1 carbon atom (HPT, MPT, DPT) and short hydrocarbon chain (4 carbon atoms) (RPT) are different from those found for pterin derivatives containing a p-aminobenzoic acid (PABA) moiety in the substituent (MFA and PA). Fluorescence quantum yields (Phi(F)) of the first group of compounds are relatively high (>/=0.4), whereas MFA and PA exhibit very small Phi(F) values (

  12. Stability analysis of the soliton solutions for the generalized quintic derivative nonlinear Schrödinger equation

    Science.gov (United States)

    Yue, Chen; Seadawy, Aly; Lu, Dianchen

    The propagation of hydrodynamic wave packets and media with negative refractive index is studied in a quintic derivative nonlinear Schrödinger (DNLS) equation. The quintic DNLS equation describe the wave propagation on a discrete electrical transmission line. We obtain a Lagrangian and the invariant variational principle for quintic DNLS equation. By using a class of ordinary differential equation, we found four types of exact solutions of the quintic DNLS equation, which are kink-type solitary wave solution, antikink-type solitary wave solution, sinusoidal solitary wave solution, bell-type solitary wave solution. By applying the modulation instability to discuss stability analysis of the obtained solutions. Modulation instabilities of continuous waves and localized solutions on a zero background have been investigated.

  13. Stability analysis of the soliton solutions for the generalized quintic derivative nonlinear Schrödinger equation

    Directory of Open Access Journals (Sweden)

    Chen Yue

    2016-01-01

    Full Text Available The propagation of hydrodynamic wave packets and media with negative refractive index is studied in a quintic derivative nonlinear Schrödinger (DNLS equation. The quintic DNLS equation describe the wave propagation on a discrete electrical transmission line. We obtain a Lagrangian and the invariant variational principle for quintic DNLS equation. By using a class of ordinary differential equation, we found four types of exact solutions of the quintic DNLS equation, which are kink-type solitary wave solution, antikink-type solitary wave solution, sinusoidal solitary wave solution, bell-type solitary wave solution. By applying the modulation instability to discuss stability analysis of the obtained solutions. Modulation instabilities of continuous waves and localized solutions on a zero background have been investigated.

  14. Soil solution phosphorus turnover: derivation, interpretation, and insights from a global compilation of isotope exchange kinetic studies

    Science.gov (United States)

    Helfenstein, Julian; Jegminat, Jannes; McLaren, Timothy I.; Frossard, Emmanuel

    2018-01-01

    The exchange rate of inorganic phosphorus (P) between the soil solution and solid phase, also known as soil solution P turnover, is essential for describing the kinetics of bioavailable P. While soil solution P turnover (Km) can be determined by tracing radioisotopes in a soil-solution system, few studies have done so. We believe that this is due to a lack of understanding on how to derive Km from isotopic exchange kinetic (IEK) experiments, a common form of radioisotope dilution study. Here, we provide a derivation of calculating Km using parameters obtained from IEK experiments. We then calculated Km for 217 soils from published IEK experiments in terrestrial ecosystems, and also that of 18 long-term P fertilizer field experiments. Analysis of the global compilation data set revealed a negative relationship between concentrations of soil solution P and Km. Furthermore, Km buffered isotopically exchangeable P in soils with low concentrations of soil solution P. This finding was supported by an analysis of long-term P fertilizer field experiments, which revealed a negative relationship between Km and phosphate-buffering capacity. Our study highlights the importance of calculating Km for understanding the kinetics of P between the soil solid and solution phases where it is bioavailable. We argue that our derivation can also be used to calculate soil solution turnover of other environmentally relevant and strongly sorbing elements that can be traced with radioisotopes, such as zinc, cadmium, nickel, arsenic, and uranium.

  15. Preparation of Cyano-Substituted Tetraphenylethylene Derivatives and Their Applications in Solution-Processable OLEDs

    Directory of Open Access Journals (Sweden)

    Xiaoyi Sun

    2018-01-01

    Full Text Available Creation of organic luminescent materials with high solid-state efficiency is of vital importance for their applications in optoelectronic fields. Here, a series of AIE luminogens (AIE gens, (Z-2,3-bis(4-(9,9-bis(6-(9H-carbazol-9-ylhexyl-9H-fluoren-2-ylphenyl-3-phenylacrylonitrile (SFC, and 2,3-bis(4-(9,9-bis(6-(9H-carbazol-9-ylhexyl-9H-fluoren-2-ylphenylfumaronitrile (DFC, utilizing 2,3,3-triphenylacrylonitrile and 2,3-diphenylfumaronitrile as respective centers, are designed and synthesized by Suzuki coupling reactions with high yields. The cis- and trans-isomers of DFC are also successfully obtained. All of them are thermally stable and show good solubility in common organic solvents. They all emit weakly in solution, but become strong emitters when fabricated into solid films. It is found introduction of one additional cyano group in DFC induced a big red-shift in solid-state emission, owing to its high electron-withdrawing ability. The cis- and trans-DFC show similar photophysical and Cyclic voltammogram (CV behaviors. Non-doped solution-processed organic light-emitting diodes (OLEDs using the three compounds as light-emitting layers are fabricated. SFC gives the best device performance with a maximum luminance of 5201 cd m−2, a maximum current efficiency of 3.67 cd A−1 and a maximum external quantum efficiencies (EQE of 1.37%. Red-shifted EL spectra are observed for cis- and trans-DFC-based device, and the OLED using trans-DFC as active layer exhibits better performance, which might derive from their different conformation in film state.

  16. Upper and lower solutions for BVPs on the half-line with variable coefficient and derivative depending nonlinearity

    Directory of Open Access Journals (Sweden)

    S. Djebali

    2011-02-01

    Full Text Available This paper is concerned with a second-order nonlinear boundary value problem with a derivative depending nonlinearity and posed on the positive half-line. The derivative operator is time dependent. Upon a priori estimates and under a Nagumo growth condition, the Schauder's fixed point theorem combined with the method of upper and lower solutions on unbounded domains are used to prove existence of solutions. A uniqueness theorem is also obtained and some examples of application illustrate the obtained results.

  17. Radiation-induced reduction of quinoxalin-2-one derivatives in aqueous solutions

    Science.gov (United States)

    Skotnicki, Konrad; De la Fuente, Julio R.; Cañete, Alvaro; Bobrowski, Krzysztof

    2016-07-01

    Quinoxaline-2-one derivatives have been proposed as potential drugs in treatments of various diseases since some of them showed a variety of pharmacological properties. The kinetics and spectral characteristics of the transients formed in the reactions of hydrated electrons (eaq-) with quinoxalin-2-(1H)-one (Q) and its methyl derivative, 3-methyl quinoxalin-2-(1H)-one (3-MeQ) were studied by pulse radiolysis in aqueous solutions at pH ranging from 5 to 14. The transient absorption spectra recorded in the reactions of (eaq-) with Q and 3-MeQ at pH 7 consisted of a broad, almost flat band in the range 390-450 nm and were assigned to the respective protonated radical anions (QH•/3-MeQH•) at N4 atom in a pyrazin-2-one ring. On the other hand, the transient absorption spectra recorded in the reactions of (eaq-) with Q and 3-MeQ at pH 13 are characterized by a broad band with a much better pronounced maximum at λmax=390 nm and higher intensity (in comparison to that at pH 7) and were assigned to the respective radical anions (Q•-/3-MeQ•-). Both forms are involved in the prototropic equilibrium with the pKa located at pH≥13.5. The rate constants of the reactions of (eaq-) with Q and 3-MeQ were found to be at pH 7 (2.6±0.1)×1010 M-1 s-1 and (2.1±0.1)×1010 M-1 s-1 and at pH 13 (1.6±0.1)×1010 M-1 s-1 and (1.3±0.1)×1010 M-1 s-1, respectively. Semi-empirical quantum mechanical calculations reproduce fairly well the spectral features of the experimental absorption spectra and show that protonated radical anions at nitrogen atom (N4) in both molecules are the most stable hydrogenated radicals.

  18. Derivation and solution of a time-dependent, nonlinear, Schrodinger-like equation for the superconductivity order parameter

    International Nuclear Information System (INIS)

    Esrick, M.A.

    1981-01-01

    A time-dependent, nonlinear, Schrodinger-like equation for the superconductivity order parameter is derived from the Gor'kov equations. Three types of traveling wave solutions of the equation are discussed. The phases and amplitudes of these solutions propagate at different speeds. The first type of solution has an amplitude that propagates as a soliton and it is suggested that this solution might correspond to the recently observed propagating collective modes of the order parameter. The amplitude of the second type of solution propagates as a periodic disturbance in space and time. It is suggested that this type of solution might explain the recently observed multiple values of the superconductor energy gap as well as the spatially inhomogenous superconducting state. The third type of solution, which is of a more general character, might provide some insight into non-periodic, inhomogeneous states occuring in superconductors. It is also proposed that quasiparticle injection and microwave irradiation might generate soliton-like disturbances in superconductors

  19. Application of A Second Derivative Multi-Step Method to Numerical Solution of Volterra Integral Equation of Second Kind

    Directory of Open Access Journals (Sweden)

    Mehriban Imanova Natiq

    2012-03-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE As is known, many problems of natural science are reduced mainly to the solution of nonlinear Volterra integral equations. The method of quadratures that was first applied by Volterra to solving variable boundary integral equations is popular among numerical methods for the solution of such equations. At present, there are different modifications of the method of quadratures that have bounded accuracies. Here we suggest a second derivative multistep method for constructing more exact methods.

  20. Deriving the New Traveling Wave Solutions for the Nonlinear Dispersive Equation, KdV-ZK Equation and Complex Coupled KdV System Using Extended Simplest Equation Method

    Science.gov (United States)

    Mohammed, K. Elboree

    2015-10-01

    In this paper, we investigate the traveling wave solutions for the nonlinear dispersive equation, Korteweg-de Vries Zakharov-Kuznetsov (KdV-ZK) equation and complex coupled KdV system by using extended simplest equation method, and then derive the hyperbolic function solutions include soliton solutions, trigonometric function solutions include periodic solutions with special values for double parameters and rational solutions. The properties of such solutions are shown by figures. The results show that this method is an effective and a powerful tool for handling the solutions of nonlinear partial differential equations (NLEEs) in mathematical physics.

  1. Physical Property Modeling of Concentrated Cesium Eluate Solutions, Part I - Derivation of Models

    Energy Technology Data Exchange (ETDEWEB)

    Choi, A.S.; Pierce, R. A.; Edwards, T. B.; Calloway, T. B.

    2005-09-15

    Major analytes projected to be present in the Hanford Waste Treatment Plant cesium ion-exchange eluate solutions were identified from the available analytical data collected during radioactive bench-scale runs, and a test matrix of cesium eluate solutions was designed within the bounding concentrations of those analytes. A computer model simulating the semi-batch evaporation of cesium eluate solutions was run in conjunction with a multi-electrolyte aqueous system database to calculate the physical properties of each test matrix solution concentrated to the target endpoints of 80% and 100% saturation. The calculated physical properties were analyzed statistically and fitted into mathematical expressions for the bulk solubility, density, viscosity, heat capacity and volume reduction factor as a function of temperature and concentration of each major analyte in the eluate feed. The R{sup 2} of the resulting physical property models ranged from 0.89 to 0.99.

  2. Existence Theory for Pseudo-Symmetric Solution to -Laplacian Differential Equations Involving Derivative

    Directory of Open Access Journals (Sweden)

    You-Hui Su

    2011-01-01

    are obtained for the existence of at least one, triple, or arbitrary odd positive pseudosymmetric solutions by using pseudosymmetric technique and fixed-point theory in cone. As an application, two examples are given to illustrate the main results.

  3. Reactions of oxidation of methyl derivatives of aniline and diaminodurene by Ce(4) in perchloric acid aqueous solutions

    International Nuclear Information System (INIS)

    Ignachak, M.; Dzegets, Yu.; Leshchinski, L.

    1988-01-01

    Method of potentiometric titration was used to study the effect of reagent concentration on oxidation rate of methyl derivatives of aniline and diaminodurene by cerium (4) in aqueous solutions of perchloric acid at 50 deg C. Approximate stoichiometry of the reaction was established and some intermediate products were isolated. It was shown that oxidation process included series-parallel reactions, differing considerably from one onother with respect to rates

  4. Numerical simulation for solution of space-time fractional telegraphs equations with local fractional derivatives via HAFSTM

    Science.gov (United States)

    Pandey, Rishi Kumar; Mishra, Hradyesh Kumar

    2017-11-01

    In this paper, the semi-analytic numerical technique for the solution of time-space fractional telegraph equation is applied. This numerical technique is based on coupling of the homotopy analysis method and sumudu transform. It shows the clear advantage with mess methods like finite difference method and also with polynomial methods similar to perturbation and Adomian decomposition methods. It is easily transform the complex fractional order derivatives in simple time domain and interpret the results in same meaning.

  5. Application of adsorption process by activated carbon derived from scrap tires for Pb+2 removal from aqueous solutions

    OpenAIRE

    Edris Hoseinzadeh; Ali Reza Rahmani; Ghorban Asgari; Mohamad Taghi Samadi; Ghodratollah Roshanaei; Mohammad Reza Zare

    2013-01-01

    Background and Aim: Heavy metals have been recognized as very poisonous elements and their discharge into water sources can cause damaging effects on human and environmental health. The present study aimed at producing activated carbon from scrap tires and using it in removing Pb+2 from synthetic aqueous solutions. Materials and Methods: In this experimental study, activated carbon powder was derived from scrap tires under laboratory conditions. The effect of Pb (II) ions wi...

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

    Science.gov (United States)

    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

  7. Solutions for the Cell Cycle in Cell Lines Derived from Human Tumors

    Directory of Open Access Journals (Sweden)

    B. Zubik-Kowal

    2006-01-01

    Full Text Available The goal of the paper is to compute efficiently solutions for model equations that have the potential to describe the growth of human tumor cells and their responses to radiotherapy or chemotherapy. The mathematical model involves four unknown functions of two independent variables: the time variable t and dimensionless relative DNA content x. The unknown functions can be thought of as the number density of cells and are solutions of a system of four partial differential equations. We construct solutions of the system, which allow us to observe the number density of cells for different t and x values. We present results of our experiments which simulate population kinetics of human cancer cells in vitro. Our results show a correspondence between predicted and experimental data.

  8. Solution-derived sodalite made with Si- and Ge-ethoxide precursors for immobilizing electrorefiner salt

    International Nuclear Information System (INIS)

    Riley, Brian J.; Lepry, William C.; Crum, Jarrod V.

    2016-01-01

    Chlorosodalite has the general form of Na 8 (AlSiO 4 ) 6 Cl 2 and this paper describes experiments conducted to synthesize sodalite with a solution-based approach to immobilize a simulated spent electrorefiner salt solution containing a mixture of alkali, alkaline earth, and lanthanide chlorides. The reactants used were the salt solution, NaAlO 2 , and either Si(OC 2 H 5 ) 4 or Ge(OC 2 H 5 ) 4 . Additionally, seven different glass sintering aids (at loadings of 5 mass%) were evaluated as sintering aids for consolidating the as-made powders using a cold-press-and-sinter technique. This process of using alkoxide additives for the Group IV component can be used to produce large quantities of sodalite at near-room temperature as compared to a method where colloidal silica was used as the silica source. However, the small particle sizes inhibited densification during heat treatments.

  9. Numerical solution to the oblique derivative boundary value problem on non-uniform grids above the Earth topography

    Science.gov (United States)

    Medl'a, Matej; Mikula, Karol; Čunderlík, Róbert; Macák, Marek

    2018-01-01

    The paper presents a numerical solution of the oblique derivative boundary value problem on and above the Earth's topography using the finite volume method (FVM). It introduces a novel method for constructing non-uniform hexahedron 3D grids above the Earth's surface. It is based on an evolution of a surface, which approximates the Earth's topography, by mean curvature. To obtain optimal shapes of non-uniform 3D grid, the proposed evolution is accompanied by a tangential redistribution of grid nodes. Afterwards, the Laplace equation is discretized using FVM developed for such a non-uniform grid. The oblique derivative boundary condition is treated as a stationary advection equation, and we derive a new upwind type discretization suitable for non-uniform 3D grids. The discretization of the Laplace equation together with the discretization of the oblique derivative boundary condition leads to a linear system of equations. The solution of this system gives the disturbing potential in the whole computational domain including the Earth's surface. Numerical experiments aim to show properties and demonstrate efficiency of the developed FVM approach. The first experiments study an experimental order of convergence of the method. Then, a reconstruction of the harmonic function on the Earth's topography, which is generated from the EGM2008 or EIGEN-6C4 global geopotential model, is presented. The obtained FVM solutions show that refining of the computational grid leads to more precise results. The last experiment deals with local gravity field modelling in Slovakia using terrestrial gravity data. The GNSS-levelling test shows accuracy of the obtained local quasigeoid model.

  10. Radiolytic degradation of gallic acid and its derivatives in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Melo, R. [Instituto Tecnologico e Nuclear, UCQR, Estrada Nacional No. 10, Apartado 21, 2686-953, Sacavem (Portugal); Leal, J.P. [Instituto Tecnologico e Nuclear, UCQR, Estrada Nacional No. 10, Apartado 21, 2686-953, Sacavem (Portugal); Centro Quimica e Bioquimica, Faculdade de Ciencias da Universidade de Lisboa, 1749-016 Lisboa (Portugal); Takacs, E., E-mail: takacs@iki.kfki.hu [Institute of Isotopes, Hungarian Academy of Sciences, P.O. Box 77, H-1525 Budapest (Hungary); Wojnarovits, L. [Institute of Isotopes, Hungarian Academy of Sciences, P.O. Box 77, H-1525 Budapest (Hungary)

    2009-12-30

    Polyphenols, like gallic acid (GA) released in the environment in larger amount, by inducing some unwanted oxidations, may constitute environmental hazard: their concentration in wastewater should be controlled. Radiolytic degradation of GA was investigated by pulse radiolysis and final product techniques in dilute aqueous solution. Subsidiary measurements were made with 3,4,5-trimethoxybenzoic acid (TMBA) and 3,4,5-trihydroxy methylbenzoate (MGA). The hydroxyl radical and hydrogen atom intermediates of water radiolysis react with the solute molecules yielding cyclohexadienyl radicals. The radicals formed in GA and MGA solutions in acid/base catalyzed water elimination decay to phenoxyl radicals. This reaction is not observed in TMBA solution. The hydrated electron intermediate of water decomposition adds to the carbonyl oxygen, the anion thus formed protonates on the ring forming cyclohexadienyl radical or on the carbonyl group forming carbonyl centred radical. The GA intermediates formed during reaction with primary water radicals in presence of oxygen transform to non-aromatic molecules, e.g., to aliphatic carboxylic acids.

  11. Stability and square integrability of derivatives of solutions of nonlinear fourth order differential equations with delay

    Directory of Open Access Journals (Sweden)

    Erdal Korkmaz

    2017-06-01

    Full Text Available Abstract In this paper, we give sufficient conditions for the boundedness, uniform asymptotic stability and square integrability of the solutions to a certain fourth order non-autonomous differential equations with delay by using Lyapunov’s second method. The results obtained essentially improve, include and complement the results in the literature.

  12. Stability and square integrability of derivatives of solutions of nonlinear fourth order differential equations with delay.

    Science.gov (United States)

    Korkmaz, Erdal

    2017-01-01

    In this paper, we give sufficient conditions for the boundedness, uniform asymptotic stability and square integrability of the solutions to a certain fourth order non-autonomous differential equations with delay by using Lyapunov's second method. The results obtained essentially improve, include and complement the results in the literature.

  13. The Removal of Phenol and Its Derivatives from Aqueous Solutions by Adsorption on Petroleum Asphaltene

    Directory of Open Access Journals (Sweden)

    Omer El-Amin Ahmed Adam

    2013-01-01

    Full Text Available This research describes the adsorption of phenol and o-substituted phenols and xylenol isomers on petroleum asphaltenes from aqueous solution. The results revealed that the adsorption equilibrium data were best fitted with the generalized and Freundlich isotherms. For o-substituted phenols, it was found that electron-withdrawing groups increase the adsorption capacity. The uptake of these phenols decreases in the order: o-nitrophenol > o-chlorophenol > o-aminophenol > o-cresol > phenol, while the adsorption of xylenol isomers decreases in the order: 2,6-xylenol > 2,5-xylenol > 3,5-xylenol > 3,4-xylenol. Batch equilibrium results at different temperatures suggest that the adsorption of 2,6-xylenol and 3,5-xylenol onto asphaltene is an endothermic process, values obtained were positive indicating a nonspontaneous process with increasing randomness at the solid-solution interface. The influence of solution pH on the adsorption of 3,5-xylenol on asphaltenes was also investigated. The adsorption process was found to be independent on the solution pH. The adsorption capacity of 3,5-xylenol was found to increase with the decrease in particle size of the adsorbent.

  14. Deriving robust and globalized robust solutions of uncertain linear programs having general convex uncertainty sets

    NARCIS (Netherlands)

    Gorissen, B.L.; Blanc, J.P.C.; den Hertog, D.; Ben-Tal, A.

    We propose a new way to derive tractable robust counterparts of a linear program based on the duality between the robust (“pessimistic”) primal problem and its “optimistic” dual. First we obtain a new convex reformulation of the dual problem of a robust linear program, and then show how to construct

  15. Studies on triazole derivatives as inhibitors for the corrosion of muntz metal in acidic and neutral solutions

    International Nuclear Information System (INIS)

    Berchmans, L. John; Sivan, V.; Iyer, S. Venkata Krishna

    2006-01-01

    The influence of few triazole derivatives namely, 4-amino-5-mercapto-3-methyl 1,2,4 triazole (AMMT), 4-amino-5-mercapto-3-methyl 1,2,4 triazole (AMET) and 4-amino-5-mercapto-3-propyl 1,2,4 triazole (AMPT) on the corrosion behavior of muntz metal (60Cu-40Zn) in acidic and neutral solutions has been studied using weight loss measurements and potentiodynamic polarization methods. Surface morphological examinations such as UV spectral analysis, XRD and SEM have also been carried out to understand the mechanism of inhibition of corrosion. All the triazoles derivatives are found to inhibit the corrosion of muntz metal very effectively in both the acidic and neutral solutions. Polarization measurements clearly show that the inhibitors behave as mixed type in neutral medium and are predominantly cathodic nature in acidic solutions. UV spectra, XRD and Scanning Electron Microscopic studies clearly reveal the formation of a strongly adsorbed film on the metal surface, which is responsible for the inhibition of corrosion in both the media. From the above studies, it can be concluded that the inhibition of corrosion by these compounds is due to a chmisorption process. Among these compounds, AMPT is found to offer better corrosion inhibition than the other compounds

  16. Bioreversible Derivatives of Phenol. 2. Reactivity of Carbonate Esters with Fatty Acid-like Structures Towards Hydrolysis in Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Claus Larsen

    2007-10-01

    Full Text Available A series of model phenol carbonate ester prodrugs encompassing derivatives with fatty acid-like structures were synthesized and their stability as a function of pH (range 0.4 – 12.5 at 37°C in aqueous buffer solutions investigated. The hydrolysis rates in aqueous solutions differed widely, depending on the selected pro-moieties (alkyl and aryl substituents. The observed reactivity differences could be rationalized by the inductive and steric properties of the substituent groups when taking into account that the mechanism of hydrolysis may change when the type of pro-moiety is altered, e.g. n-alkyl vs. t-butyl. Hydrolysis of the phenolic carbonate ester 2-(phenoxycarbonyloxy-acetic acid was increased due to intramolecular catalysis, as compared to the derivatives synthesized from ω-hydroxy carboxylic acids with longer alkyl chains. The carbonate esters appear to be less reactive towards specific acid and base catalyzed hydrolysis than phenyl acetate. The results underline that it is unrealistic to expect that phenolic carbonate ester prodrugs can be utilized in ready to use aqueous formulations. The stability of the carbonate ester derivatives with fatty acid-like structures, expected to interact with the plasma protein human serum albumin, proved sufficient for further in vitro and in vivo evaluation of the potential of utilizing HSA binding in combination with the prodrug approach for optimization of drug pharmacokinetics.

  17. On-design solutions of hypersonic flows past elliptic-cone derived waveriders

    International Nuclear Information System (INIS)

    Yoon, Bok Hyun

    1992-01-01

    The hypersonic flows past a class of elliptic-conederived waverider at the on-design condition are analyzed. A CFD(Computational Fluid Dynamics) algorithm due to Lawrence is utilized to numerically integrate the steady Euler equations. The singular behavior at the sharp leading-edge of a waverider where a bow shock is to be attached for the ideal situation makes the computation extremely difficult for convergence of numerical solution. Various types of grids are generated and tested for converged solutions. A new formula for more accurate waverider shape is established and by means of this new waverider configuration the reason for the shock stand-off which was detected in previous investigations is clarified in this paper. (Author)

  18. Corrosion inhibition of iron in acidic solution by a green formulation derived from Nigella sativa L

    International Nuclear Information System (INIS)

    Chellouli, M.; Chebabe, D.; Dermaj, A.; Erramli, H.; Bettach, N.; Hajjaji, N.; Casaletto, M.P.; Cirrincione, C.; Privitera, A.; Srhiri, A.

    2016-01-01

    In this work the corrosion inhibition of iron in acidic solution by a formulation based on the oil extracted from the seeds of Nigella Sativa L. (labeled as FBN) was investigated by means of potentiodynamic polarization, electrochemical impedance spectroscopy and weight loss measurements. Results showed that the formulation acts as a good mixed type (cathodic/anodic) inhibitor. The dissolution rate decreased with the increase of the FBN concentration and the immersion time. An inhibition efficiency of 99% was reached for FBN concentration at 2500 ppm. Surface analysis of the samples was performed by Scanning Electron Microscopy coupled with chemical analysis (SEM-EDS) and X-ray Photoemission Spectroscopy (XPS). Results confirmed a good protective action of the FBN film on the iron substrate in acidic solution. The FBN formulation is a not toxic and environmentally safe product, as determined by acute toxicity tests, and can be fruitfully used for a sustainable conservation of iron-based artifacts.

  19. Cationic flocculants derived from native cellulose: Preparation, biodegradability, and removal of dyes in aqueous solution

    OpenAIRE

    Hiroyuki Kono

    2017-01-01

    Water-soluble quaternized celluloses with various substitution degrees were prepared. The polymers showed excellent flocculation ability against anionic dyes; this ability was strongly dependent on the substituent degree and not affected by the temperature and pH of the dye solution. The flocculation ability was accurately fitted by a pseudo-second order kinetic model, which enabled reliable predictions of the flocculation behavior. In addition, the flocculation behavior of the anionic dyes f...

  20. Host-guest chemistry of cyclodextrin carbamates and cellulose derivatives in aqueous solution.

    Science.gov (United States)

    Guo, Xin; Jia, Xiangxiang; Du, Jiaojiao; Xiao, Longqiang; Li, Feifei; Liao, Liqiong; Liu, Lijian

    2013-10-15

    Supramolecular polymer micelles were prepared on basis of the inclusion complexation between cyclodextrin carbamates and cellulose derivatives in aqueous media. Cyclodextrin carbamates were synthesized by microwave-assisted method from cyclodextrin and urea. The urea modified cyclodextrin shows the higher yield than the physical mixture of urea/cyclodextrin in the micellization with cellulose derivatives. The supramolecular structure of the core-shell micelles was demonstrated by (1)H NMR spectra, TEM images, and fluorescence spectra. The drug release behavior of the supramolecular polymer micelles was evaluated using prednisone acetate as a model drug. The drug loaded micelles showed steady and long time drug release behavior. With these properties, the supramolecular polymer micelles are attractive as drug carriers for pharmaceutical applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Solution Processable Organic Solar Cell Based on Bulk Heterojunction Utilizing Phthalocyanine Derivative

    Science.gov (United States)

    Hori, Tetsuro; Miyake, Yasuo; Yamasaki, Naoyuki; Yoshida, Hiroyuki; Fujii, Akihiko; Shimizu, Yo; Ozaki, Masanori

    2010-10-01

    Organic thin-film solar cells based on a bulk heterojunction utilizing the phthalocyanine derivative 1,4,8,11,15,18,22,25-octahexylphthalocyanine (C6PcH2) have been studied. C6PcH2 is soluble in common organic solvents such as chloroform, and the blend uniform thin film with the fullerene derivative 1-(3-methoxy-carbonyl)-propyl-1-1-phenyl-(6,6)C61 (PCBM) could be fabricated by a spin-coating method. Solar cells with an indium-tin-oxide/polymer hole transport layer/C6PcH2:PCBM/Al structure, the active layer of which was prepared by a wet process using a low-weighted molecular system, have demonstrated a high external quantum efficiency of more than 70% in the Q-band absorption region of C6PcH2 and a high energy conversion efficiency of 3.1%.

  2. Chloramphenicol Derivatives as Antibacterial and Anticancer Agents: Historic Problems and Current Solutions

    Directory of Open Access Journals (Sweden)

    George P. Dinos

    2016-06-01

    Full Text Available Chloramphenicol (CAM is the D-threo isomer of a small molecule, consisting of a p-nitrobenzene ring connected to a dichloroacetyl tail through a 2-amino-1,3-propanediol moiety. CAM displays a broad-spectrum bacteriostatic activity by specifically inhibiting the bacterial protein synthesis. In certain but important cases, it also exhibits bactericidal activity, namely against the three most common causes of meningitis, Haemophilus influenzae, Streptococcus pneumoniae and Neisseria meningitidis. Resistance to CAM has been frequently reported and ascribed to a variety of mechanisms. However, the most important concerns that limit its clinical utility relate to side effects such as neurotoxicity and hematologic disorders. In this review, we present previous and current efforts to synthesize CAM derivatives with improved pharmacological properties. In addition, we highlight potentially broader roles of these derivatives in investigating the plasticity of the ribosomal catalytic center, the main target of CAM.

  3. Use of the Fox derivatives in the solution of the word problem for groups

    International Nuclear Information System (INIS)

    Majumdar, S.

    1988-09-01

    Applying Fox's free partial derivative, the word problem of a finitely presented group has been reduced to the problem of finding an algorithm for determining the existence of a root of a system of linear equations over the integral group ring. The solubility of the word problem for torsion-free one-relator groups and torsion-free polycyclic-by-finite groups has been deduced. (author). 10 refs

  4. Evidence for the Formation of Benzacridine Derivatives in Alkaline-Treated Sunflower Meal and Model Solutions

    Directory of Open Access Journals (Sweden)

    Verena Bongartz

    2016-01-01

    Full Text Available Sunflower extraction meal (SEM is an economically interesting protein source. During alkaline extraction of proteins, the presence of chlorogenic acid (CQA in the meal gives rise to the formation of o-quinones. Reactions with nucleophiles present in proteins can lead to green discoloration. Although such reactions have been known for a long time, there is a lack of information on the chemical nature of the reaction products. SEM and model systems consisting of amino acids and CQA were subjected to alkaline treatment and, for comparison, to oxidation of CQA by polyphenoloxidase (PPO. Several green trihydroxy benzacridine (TBA derivatives were tentatively identified in all samples by UHPLC-DAD-MS/MS. Surprisingly, in alkaline-treated samples of particular amino acids as well as in SEM, the same six TBA isomers were detected. In contrast, the enzymatically oxidized samples resulted in only three TBA derivatives. Contrary to previous findings, neither peptide nor amino acid residues were attached to the resultant benzacridine core. The results indicate that the formation of TBA derivatives is caused by the reaction between CQA quinones and free NH2 groups. Further research is necessary to elucidate the structure of the addition products for a comprehensive evaluation of food and feed safety aspects.

  5. Investigation on Adsorption and the Corrosion Inhibition Effect of Some Novel Hydrazide Derivatives for Mild Steel in HCl Solution

    Science.gov (United States)

    Singh, Dharmendra Kumar; Behera, Debasis; Singh, Mantu Kumar; Udayabhanu, G.; John, Rohith P.

    2017-10-01

    Two hydrazide derivatives, namely, N'-(thiophene-2-ylmethylene)nicotinic hydrazone (TNH) and N'-(pyrrol-2-ylmethylene)nicotinic hydrazone (PNH), have been synthesized and investigated as corrosion inhibitors for mild steel in 1 M HCl solution by electrochemical, weight loss, field emission-scanning electron microscope (FE-SEM), atomic force microscope (AFM), and quantum chemical calculation methods. The experimental results show that both the compounds are good inhibitors for mild steel in 1 M HCl. They act as mixed type inhibitors with predominating cathodic character. The adsorption of inhibitors obeys the Langmuir adsorption isotherm. Correlation between quantum chemical parameters and experimental results is discussed.

  6. A Novel Operational Matrix of Caputo Fractional Derivatives of Fibonacci Polynomials: Spectral Solutions of Fractional Differential Equations

    Directory of Open Access Journals (Sweden)

    Waleed M. Abd-Elhameed

    2016-09-01

    Full Text Available Herein, two numerical algorithms for solving some linear and nonlinear fractional-order differential equations are presented and analyzed. For this purpose, a novel operational matrix of fractional-order derivatives of Fibonacci polynomials was constructed and employed along with the application of the tau and collocation spectral methods. The convergence and error analysis of the suggested Fibonacci expansion were carefully investigated. Some numerical examples with comparisons are presented to ensure the efficiency, applicability and high accuracy of the proposed algorithms. Two accurate semi-analytic polynomial solutions for linear and nonlinear fractional differential equations are the result.

  7. Experimental and theoretical investigations of spectroscopic properties of azobenzene derivatives in solution.

    Science.gov (United States)

    Zaleśny, Robert; Matczyszyn, Katarzyna; Kaczmarek, Anna; Bartkowiak, Wojciech; Cysewski, Piotr

    2007-07-01

    The UV-Vis spectra of series of polymethylmethacrylate (PMMA) copolymers with attached trans-azobenzene derivatives were measured in 1,1,2-trichloroethane. In order to gain some insight into the recorded spectra, the quantum chemical calculations were performed for the substituted azobenzenes using both configuration interaction with single excitations method (CIS) as well as density functional theory (DFT) with B3LYP and PBE0 functionals. The calculations were performed in solvent. In particular, we found that the PBE0 excitation energies are in very good agreement with the experimental data.

  8. Potential Biosorbent Derived from Calligonum polygonoides for Removal of Methylene Blue Dye from Aqueous Solution

    Science.gov (United States)

    Nasrullah, Asma; Khan, Hizbullah; Khan, Amir Sada; Man, Zakaria; Muhammad, Nawshad; Khan, Muhammad Irfan; Abd El-Salam, Naser M.

    2015-01-01

    The ash of C. polygonoides (locally called balanza) was collected from Lakki Marwat, Khyber Pakhtunkhwa, Pakistan, and was utilized as biosorbent for methylene blue (MB) removal from aqueous solution. The ash was used as biosorbent without any physical or chemical treatment. The biosorbent was characterized by using various techniques such as Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The particle size and surface area were measured using particle size analyzer and Brunauer-Emmett-Teller equation (BET), respectively. The SEM and BET results expressed that the adsorbent has porous nature. Effects of various conditions such as initial concentration of methylene blue (MB), initial pH, contact time, dosage of biosorbent, and stirring rate were also investigated for the adsorption process. The rate of the adsorption of MB on biomass sample was fast, and equilibrium has been achieved within 1 hour. The kinetics of MB adsorption on biosorbent was studied by pseudo-first- and pseudo-second-order kinetic models and the pseudo-second-order has better mathematical fit with correlation coefficient value (R 2) of 0.999. The study revealed that C. polygonoides ash proved to be an effective, alternative, inexpensive, and environmentally benign biosorbent for MB removal from aqueous solution. PMID:25705714

  9. Lead and copper removal from aqueous solutions using carbon foam derived from phenol resin.

    Science.gov (United States)

    Lee, Chang-Gu; Jeon, Jun-Woo; Hwang, Min-Jin; Ahn, Kyu-Hong; Park, Chanhyuk; Choi, Jae-Woo; Lee, Sang-Hyup

    2015-07-01

    Phenolic resin-based carbon foam was prepared as an adsorbent for removing heavy metals from aqueous solutions. The surface of the produced carbon foam had a well-developed open cell structure and the specific surface area according to the BET model was 458.59m(2)g(-1). Batch experiments showed that removal ratio increased in the order of copper (19.83%), zinc (34.35%), cadmium (59.82%), and lead (73.99%) in mixed solutions with the same initial concentration (50mgL(-1)). The results indicated that the Sips isotherm model was the most suitable for describing the experimental data of lead and copper. The maximum adsorption capacity of lead and copper determined to Sips model were 491mgg(-1) and 247mgg(-1). The obtained pore diffusion coefficients for lead and copper were found to be 1.02×10(-6) and 2.42×10(-7)m(2)s(-1), respectively. Post-sorption characteristics indicated that surface precipitation was the primary mechanism of lead and copper removal by the carbon foam, while the functional groups on the surface of the foam did not affect metal adsorption. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Efficient OLEDs Fabricated by Solution Process Based on Carbazole and Thienopyrrolediones Derivatives

    Directory of Open Access Journals (Sweden)

    Luis-Abraham Lozano-Hernández

    2018-01-01

    Full Text Available Four low molecular weight compounds—three of them new, two of them with carbazole (Cz as functional group and the other two with thienopyrroledione (TPD group—were used as emitting materials in organic light emitting diodes (OLEDs. Devices were fabricated with the configuration ITO/PEDOT:PSS/emitting material/LiF/Al. The hole injector layer (HIL and the emitting sheet were deposited by spin coating; LiF and Al were thermally evaporated. OLEDs based on carbazole derivatives show luminances up to 4130 cd/m2, large current efficiencies about 20 cd/A and, cautiously, a very impressive External Quantum Efficiency (EQE up to 9.5%, with electroluminescence peaks located around 490 nm (greenish blue region. Whereas, devices manufactured with TPD derivatives, present luminance up to 1729 cd/m2, current efficiencies about 4.5 cd/A and EQE of 1.5%. These results are very competitive regarding previous reported materials/devices.

  11. SOLUTIONING

    Directory of Open Access Journals (Sweden)

    Maria de Hoyos Guajardo, Ph.D. Candidate, M.Sc., B.Eng.

    2004-11-01

    Full Text Available The theory that is presented below aims to conceptualise how a group of undergraduate students tackle non-routine mathematical problems during a problem-solving course. The aim of the course is to allow students to experience mathematics as a creative process and to reflect on their own experience. During the course, students are required to produce a written ‘rubric’ of their work, i.e., to document their thoughts as they occur as well as their emotionsduring the process. These ‘rubrics’ were used as the main source of data.Students’ problem-solving processes can be explained as a three-stage process that has been called ‘solutioning’. This process is presented in the six sections below. The first three refer to a common area of concern that can be called‘generating knowledge’. In this way, generating knowledge also includes issues related to ‘key ideas’ and ‘gaining understanding’. The third and the fourth sections refer to ‘generating’ and ‘validating a solution’, respectively. Finally, once solutions are generated and validated, students usually try to improve them further before presenting them as final results. Thus, the last section deals with‘improving a solution’. Although not all students go through all of the stages, it may be said that ‘solutioning’ considers students’ main concerns as they tackle non-routine mathematical problems.

  12. Lignocellulosic-derived modified agricultural waste: development, characterisation and implementation in sequestering pyridine from aqueous solutions.

    Science.gov (United States)

    Ahmed, Md Juned K; Ahmaruzzaman, M; Reza, Ruhul A

    2014-08-15

    The development and characterisation of modified agricultural waste (MAW) by H3PO4 activation is addressed in this study for sequestering pyridine from aqueous solutions. The adsorbent is characterised by carbon, hydrogen and nitrogen content of 55.53%, 3.28% and 0.98% respectively. The adsorbent also shows acidic (carboxylic, lactonic, phenolic groups) and basic carbon surface functionalities, functional groups viz. hydroxyl, carboxylic acid and bounded water molecules, BET surface area of 1254.67 m(2) g(-1), heterogeneous surface morphology and graphite like XRD patterns. Adsorption of pyridine is executed to evaluate the adsorptive uptake in batch (q(e)=107.18 mg g(-1)) as well as in column system (q(e)=140.94 mg g(-1)). The adsorption process followed the pseudo-second-order kinetics with the Langmuir isotherm best representing the equilibrium adsorption data. The thermodynamic parameters (ΔH(o)=9.39 kJ mol(-1), ΔG(o)=-5.99 kJ mol(-1), ΔS(o)=50.76 J K(-1) mol(-1)) confirm the endothermic and spontaneous nature of the adsorption process with increase in randomness at solid/solution interface. The adsorption mechanism is governed by electrostatic and π-π dispersive interactions as well as by a two stage diffusion phenomena. Thermally regenerated spent MAW exhibited better adsorption efficiency for five adsorption-desorption cycles than chemically regenerated. The low-cost of MAW (USD 10.714 per kg) and favourable adsorption parameters justifies its use in the adsorptive removal of pyridine. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Halogen and Hydrogen Bonding between (N-Halogeno)-succinimides and Pyridine Derivatives in Solution, the Solid State and In Silico.

    Science.gov (United States)

    Stilinović, Vladimir; Horvat, Gordan; Hrenar, Tomica; Nemec, Vinko; Cinčić, Dominik

    2017-04-19

    A study of strong halogen bonding within three series of halogen-bonded complexes, derived from seven para-substituted pyridine derivatives and three N-halosuccinimides (iodo, bromo and chloro), has been undertaken with the aid of single-crystal diffraction, solution complexation and computational methods. The halogen bond was compared with the hydrogen bond in an equivalent series based on succinimide. The halogen-bond energies are in the range -60 to -20 kJ mol -1 and change regularly with pyridine basicity and the Lewis acidity of the halogen. The halogen-bond energies correlate linearly with the product of charges on the contact atoms, which indicates a predominantly electrostatic interaction. The binding enthalpies in solution are around 19 kJ mol -1 less negative due to solvation effects. The optimised geometries of the complexes in the gas phase are comparable to those of the solid-state structures, and the effects of the supramolecular surroundings in the latter are discussed. The bond energies for the hydrogen-bonded series are intermediate between the halogen-bond energies of iodine and bromine, although there are specific differences in the geometries of the halogen- and hydrogen-bonded complexes. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Removal of Congo Red and Methylene Blue from Aqueous Solutions by Vermicompost-Derived Biochars

    Science.gov (United States)

    Yang, Gang; Wu, Lin; Xian, Qiming; Shen, Fei; Wu, Jun; Zhang, Yanzong

    2016-01-01

    Biochars, produced by pyrolyzing vermicompost at 300, 500, and 700°C were characterized and their ability to adsorb the dyes Congo red (CR) and Methylene blue (MB) in an aqueous solution was investigated. The physical and chemical properties of biochars varied significantly based on the pyrolysis temperatures. Analysis of the data revealed that the aromaticity, polarity, specific surface area, pH, and ash content of the biochars increased gradually with the increase in pyrolysis temperature, while the cation exchange capacity, and carbon, hydrogen, nitrogen and oxygen contents decreased. The adsorption kinetics of CR and MB were described by pseudo-second-order kinetic models. Both of Langmuir and Temkin model could be employed to describe the adsorption behaviors of CR and MB by these biochars. The biochars generated at higher pyrolysis temperature displayed higher CR adsorption capacities and lower MB adsorption capacities than those compared with the biochars generated at lower pyrolysis temperatures. The biochar generated at the higher pyrolytic temperature displayed the higher ability to adsorb CR owing to its promoted aromaticity, and the cation exchange is the key factor that positively affects adsorption of MB. PMID:27144922

  15. Removal of Congo Red and Methylene Blue from Aqueous Solutions by Vermicompost-Derived Biochars.

    Science.gov (United States)

    Yang, Gang; Wu, Lin; Xian, Qiming; Shen, Fei; Wu, Jun; Zhang, Yanzong

    2016-01-01

    Biochars, produced by pyrolyzing vermicompost at 300, 500, and 700°C were characterized and their ability to adsorb the dyes Congo red (CR) and Methylene blue (MB) in an aqueous solution was investigated. The physical and chemical properties of biochars varied significantly based on the pyrolysis temperatures. Analysis of the data revealed that the aromaticity, polarity, specific surface area, pH, and ash content of the biochars increased gradually with the increase in pyrolysis temperature, while the cation exchange capacity, and carbon, hydrogen, nitrogen and oxygen contents decreased. The adsorption kinetics of CR and MB were described by pseudo-second-order kinetic models. Both of Langmuir and Temkin model could be employed to describe the adsorption behaviors of CR and MB by these biochars. The biochars generated at higher pyrolysis temperature displayed higher CR adsorption capacities and lower MB adsorption capacities than those compared with the biochars generated at lower pyrolysis temperatures. The biochar generated at the higher pyrolytic temperature displayed the higher ability to adsorb CR owing to its promoted aromaticity, and the cation exchange is the key factor that positively affects adsorption of MB.

  16. Hygroscopic growth of common organic aerosol solutes, including humic substances, as derived from water activity measurements

    Science.gov (United States)

    Zamora, Idania R.; Tabazadeh, Azadeh; Golden, David M.; Jacobson, Mark Z.

    2011-12-01

    Studies have shown that organic matter often constitutes up to 50% by mass of tropospheric aerosols. These organics may considerably affect the water uptake properties of these aerosols, impacting Earth's climate and atmosphere. However, considerable uncertainties still exist about hygroscopic properties of organic carbon (OC) in particles. In this study, we have assembled an apparatus to measure equilibrium water vapor pressure over bulk solutions. We used these results to calculate the hygroscopic growth curve and deliquescence relative humidity (DRH) of representative compounds in three OC categories: saccharides, mono/dicarboxylic acids, and HULIS (Humic-Like Substances). To our knowledge, this is the first study to examine the hygroscopic growth of HULIS by means of a bulk method on representative compounds such as fulvic and humic acids. We also explored the temperature effect on hygroscopic growth within the 0°C-30°C temperature range and found no effect. The DRH and hygroscopic growth obtained were in excellent agreement with published tandem differential mobility analyzer (TDMA), electrodynamic balance, and bulk data for sodium chloride, ammonium sulfate, d-glucose, levoglucosan, succinic acid, and glutaric acid. However, we found a hygroscopic growth factor of 1.0 at a relative humidity of 90% for phthalic, oxalic, humic, and two fulvic acids; these results disagree with various TDMA studies. The TDMA is used widely to study water uptake of organic particles but can be affected by particle microstructural arrangements before the DRH and by the inability to fully dry particles. Thus, in the future it will be important to confirm TDMA data for nondeliquescent organic particles with alternate methods.

  17. Protonation and Solvation Thermodynamics of Some Naphthol Derivatives in KCl Aqueous Solution of Different Ionic Strengths

    Directory of Open Access Journals (Sweden)

    Farid I. El-Dossoki

    2016-01-01

    Full Text Available The acid-base properties of naphthalen-1-ol (L1, naphthalene-1,5-diol (L2, and 4-amino-3-hydroxynaphthalene-1-sulphonic acid (L3 were characterized from pH-metric measurements in pure water and in different concentrations (0–4 mol kg−1 of aqueous KCl solutions at the temperature range of T = (293.15 to 213.15 K at 5 K intervals. The results reveal that naphthalen-1-ol and naphthalene-1,5-diol molecules have two ionisable protons (of the hydroxyl groups while 4-amino-3-hydroxynaphthalene-1-sulphonic acid has three ionisable protons (hydrogen ion of the hydroxyl group, SO3H, and NH3+. Modeling of the data was done by applying Debye-Hückel model. The protonation and the solvation processes of all studied ligands are spontaneous and endothermic processes. Also the solubilities of naphthalen-1-ol, naphthalene-1,5-diol, and 4-amino-3-hydroxynaphthalene-1-sulphonic acid were determined. The data were analyzed using Setschenow equation and the values of Setschenow coefficients (km were determined. From the solubility data, the activity coefficients were obtained. The values of the total solubilities (ST for naphthalen-1-ol and naphthalene-1,5-diol were found equal to the values of their neutral species (S0. On the other hand, the total solubility for 4-amino-3-hydroxynaphthalene-1-sulphonic acid is different from that of its neutral species. The results also indicate solubility decrease in pure water from L1-L2-L3.

  18. Potential mechanisms of cadmium removal from aqueous solution by Canna indica derived biochar

    International Nuclear Information System (INIS)

    Cui, Xiaoqiang; Fang, Siyu; Yao, Yiqiang; Li, Tingqiang; Ni, Qijun; Yang, Xiaoe; He, Zhenli

    2016-01-01

    The objective of this study was to investigate the mechanisms of cadmium (Cd) sorption on biochars produced at different temperature (300–600 °C) and their quantitative contribution. The sorption isotherms and kinetics of Cd 2+ sorption on biochars were determined and fitted to different models. The Cd 2+ sorption data could be well described by a simple Langmuir model, and the pseudo second order kinetic model best fitted the kinetic data. The maximum sorption capacity (Q m ) obtained from the Langmuir model for CIB500 was 188.8 mg g −1 , which was greater than that of biochars produced at other temperature. Precipitation with minerals, ion exchange, complexation with surface oxygen-containing functional groups, and coordination with π electrons were the possible mechanisms of Cd 2+ sorption on the biochars. The contribution of each mechanism varied with the pyrolysis temperature. With increasing pyrolysis temperature, the contribution of surface complexation and metal ion exchange decreased from 24.5% and 43.3% to 0.7% and 4.7%, while the contribution of precipitation and Cd 2+ -π interaction significantly increased from 29.7% and 2.5% to 89.5% and 5.1%, respectively. Overall, the precipitation with minerals and metal ion exchange dominated Cd 2+ sorption on the biochars (accounted for 73.0–94.1%), and precipitation with minerals was the primary mechanism of Cd 2+ sorption on the high-temperature biochars (≥ 500 °C) (accounted for 86.1–89.5%). - Highlights: • Sorption capacity of metal on biochars is affected by pyrolysis temperature. • Biochar derived from Canna indica at 500 °C has a high sorption capacity for Cd 2+ . • Cd 2+ sorption on the biochars fits a pseudo second order and Langmuir model. • Precipitation and ion exchange mechanisms dominated Cd 2+ sorption on the biochars.

  19. Nonlinear Dynamics and Exact Traveling Wave Solutions of the Higher-Order Nonlinear Schrödinger Equation with Derivative Non-Kerr Nonlinear Terms

    Directory of Open Access Journals (Sweden)

    Heng Wang

    2016-01-01

    Full Text Available By using the method of dynamical system, the exact travelling wave solutions of the higher-order nonlinear Schrödinger equation with derivative non-Kerr nonlinear terms are studied. Based on this method, all phase portraits of the system in the parametric space are given with the aid of the Maple software. All possible bounded travelling wave solutions, such as solitary wave solutions, kink and anti-kink wave solutions, and periodic travelling wave solutions, are obtained, respectively. The results presented in this paper improve the related previous conclusions.

  20. Potential mechanisms of cadmium removal from aqueous solution by Canna indica derived biochar

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Xiaoqiang; Fang, Siyu; Yao, Yiqiang; Li, Tingqiang [Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Ni, Qijun [The 702 Research Institute of China Shipbuilding Industry Corporation, Wuxi 214082 (China); Yang, Xiaoe, E-mail: xyang@zju.edu.cn [Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); He, Zhenli [Indian River Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Fort Pierce, FL 34951 (United States)

    2016-08-15

    The objective of this study was to investigate the mechanisms of cadmium (Cd) sorption on biochars produced at different temperature (300–600 °C) and their quantitative contribution. The sorption isotherms and kinetics of Cd{sup 2+} sorption on biochars were determined and fitted to different models. The Cd{sup 2+} sorption data could be well described by a simple Langmuir model, and the pseudo second order kinetic model best fitted the kinetic data. The maximum sorption capacity (Q{sub m}) obtained from the Langmuir model for CIB500 was 188.8 mg g{sup −1}, which was greater than that of biochars produced at other temperature. Precipitation with minerals, ion exchange, complexation with surface oxygen-containing functional groups, and coordination with π electrons were the possible mechanisms of Cd{sup 2+} sorption on the biochars. The contribution of each mechanism varied with the pyrolysis temperature. With increasing pyrolysis temperature, the contribution of surface complexation and metal ion exchange decreased from 24.5% and 43.3% to 0.7% and 4.7%, while the contribution of precipitation and Cd{sup 2+}-π interaction significantly increased from 29.7% and 2.5% to 89.5% and 5.1%, respectively. Overall, the precipitation with minerals and metal ion exchange dominated Cd{sup 2+} sorption on the biochars (accounted for 73.0–94.1%), and precipitation with minerals was the primary mechanism of Cd{sup 2+} sorption on the high-temperature biochars (≥ 500 °C) (accounted for 86.1–89.5%). - Highlights: • Sorption capacity of metal on biochars is affected by pyrolysis temperature. • Biochar derived from Canna indica at 500 °C has a high sorption capacity for Cd{sup 2+}. • Cd{sup 2+} sorption on the biochars fits a pseudo second order and Langmuir model. • Precipitation and ion exchange mechanisms dominated Cd{sup 2+} sorption on the biochars.

  1. Dimethylaminodiethylenetriamine Derivatives of Fluorescence Chemosenso for Detection of Zn2+ In Aqueous Solution

    Science.gov (United States)

    Adnan, S. N. A. M.; Hasan, S.; Zakaria, S.; Yusof, Y. M.

    2017-02-01

    Fluorescent chemosensors for the detection and measurement of metal ions, especially for cations environmental interest such as Fe3+, Co2+, Mn2+, Cu2+, and Zn2+ are actively investigated because it shows simplicity, high sensitivity and fast response. New benzenyl derivative bearing pyridine group has been synthesized and studied as fluorescent chemosensor for Zn2+ ion. Chemosensor N-{2-[(4-Dimethylamino-benzylidene)-amino]-ethyl}-N’-pyridin-2-ylmethylene-ethane-1,2-diamine was synthesized by condensation of p-dimethylaminobenzaldehyde, diethylenetriamine and o-pyridinecarbaldehyde and characterized by FT-IR, 1H-NMR and elemental analysis (CHN). FT-IR showed the appearance of peak azomethine (C=NH) at 1639.46 cm-1, pyridine (C-N) at 1591 cm-1and disappearance of NH2 peak at 3278.78 cm-1 after the condensation reaction in between aldehyde and amine. 1H-NMR signal at 8.19 ppm, 3.12 ppm and 8.08 ppm was assigned to C=NH, N(CH3)2 and C-N respectively, confirmed the formation of N-{2-[(4-Dimethylamino-benzylidene)-amino]-ethyl}-N’-pyridin-2-ylmethylene-ethane-1,2-diamine. The elemental analysis was found closed to the theoretical value and the percent composition of A is 91.82%. Sensor A exhibits high selectivity and sensitivity towards Zn2+. Other metal ions such Cu2+, Fe3+, Co2+ and Ni2+ had no such significant effect on the fluorescence. The detection limit of N-{2-[(4-Dimethylamino-benzylidene)-amino]-ethyl}-N’-pyridin-2-ylmethylene-ethane-1,2-diamine for Zn2+ was 3.5 x 10-5 M. M. This sensor exhibits a very good fluorescence sensing ability to Zn2+ over a wide range of pH. Therefore it is capable of being a practical system for the monitoring of Zn2+ concentrations in real water sample.

  2. Theoretical Derivation of Simplified Evaluation Models for the First Peak of a Criticality Accident in Nuclear Fuel Solution

    International Nuclear Information System (INIS)

    Nomura, Yasushi

    2000-01-01

    In a reprocessing facility where nuclear fuel solutions are processed, one could observe a series of power peaks, with the highest peak right after a criticality accident. The criticality alarm system (CAS) is designed to detect the first power peak and warn workers near the reacting material by sounding alarms immediately. Consequently, exposure of the workers would be minimized by an immediate and effective evacuation. Therefore, in the design and installation of a CAS, it is necessary to estimate the magnitude of the first power peak and to set up the threshold point where the CAS initiates the alarm. Furthermore, it is necessary to estimate the level of potential exposure of workers in the case of accidents so as to decide the appropriateness of installing a CAS for a given compartment.A simplified evaluation model to estimate the minimum scale of the first power peak during a criticality accident is derived by theoretical considerations only for use in the design of a CAS to set up the threshold point triggering the alarm signal. Another simplified evaluation model is derived in the same way to estimate the maximum scale of the first power peak for use in judging the appropriateness for installing a CAS. Both models are shown to have adequate margin in predicting the minimum and maximum scale of criticality accidents by comparing their results with French CRiticality occurring ACcidentally (CRAC) experimental data

  3. Photochemical coupling of 5-bromouracil to tryptophan, tyrosine and histidine, peptide-like derivatives in aqueous fluid solution

    International Nuclear Information System (INIS)

    Dietz, T.M.; Koch, T.H.

    1987-01-01

    Direct irradiation of 5-bromouracil (BU) in aqueous fluid solution in the presence of tryptophan (trp), tyrosine (tyr) or histidine (his) derivatives using a XeCl excimer laser at 308 nm yielded photocoupling of BU to the aromatic ring of each amino acid. Irradiation of BU at 308 nm most likely results in excitation of the n-π* transition, intersystem crossing to the triplet manifold, and coupling via electron transfer from the aromatic amino acid. The coupling observed was regiospecific between the 5-position of uracil (U) and the 2-position of the indole and phenol rings and the 5-position of the imidazole ring of the respective amino acids. Quantum yields of photocoupling to BU ranged from 1 x 10 -3 to 7 x 10 -3 and paralleled known rates of electron transfer and ionization potentials of the aromatic rings. The photocoupling between BU and some of the aromatic amino acid peptide-like derivatives possibly mimics photocrosslinking of BU-DNA to associated proteins, a potentially useful photoreaction for studying nucleic acid-protein interactions. Formation of crosslinks of the type proposed here might be detected by the characteristic fluorescence emission of the uracil amino acid adducts. (author)

  4. Competitive removal of hazardous dyes from aqueous solution by MIL-68(Al): Derivative spectrophotometric method and response surface methodology approach

    Science.gov (United States)

    Tehrani, Mahnaz Saghanejhad; Zare-Dorabei, Rouholah

    2016-05-01

    MIL-68(Al) as a metal-organic framework (MOF) was synthesized and characterized by different techniques such as SEM, BET, FTIR, and XRD analysis. This material was then applied for simulations removal of malachite green (MG) and methylene blue (MB) dyes from aqueous solutions using second order derivative spectrophotometric method (SODS) which was applied to resolve the overlap between the spectra of these dyes. The dependency of dyes removal efficiency in binary solutions was examined and optimized toward various parameters including initial dye concentration, pH of the solution, adsorbent dosage and ultrasonic contact time using central composite design (CCD) under response surface methodology (RSM) approach. The optimized experimental conditions were set as pH 7.78, contact time 5 min, initial MB concentration 22 mg L- 1, initial MG concentration 12 mg L- 1 and adsorbent dosage 0.0055 g. The equilibrium data was fitted to isotherm models such as Langmuir, Freundlich and Tempkin and the results revealed the suitability of the Langmuir model. The maximum adsorption capacity of 666.67 and 153.85 mg g- 1 was obtained for MB and MG removal respectively. Kinetics data fitting to pseudo-first order, pseudo-second order and Elovich models confirmed the applicability of pseudo-second order kinetic model for description of the mechanism and adsorption rate. Dye-loaded MIL-68(Al) can be easily regenerated using methanol and applied for three frequent sorption/desorption cycles with high performance. The impact of ionic strength on removal percentage of both dyes in binary mixture was studied by using NaCl and KCl soluble salts at different concentrations. According to our findings, only small dosage of the proposed MOF is considerably capable to remove large amounts of dyes at room temperature and in very short time that is a big advantage of MIL-68(Al) as a promising adsorbent for adsorptive removal processes.

  5. Removal of Copper ions from aqueous solutions using polymer derivations of poly (styrene-alt-maleic anhydride

    Directory of Open Access Journals (Sweden)

    Naser Samadi

    2017-06-01

    Full Text Available In this study chelating resins have been considered to be suitable materials for the recovery of Copper (II ions in water treatments. Furthermore, these modified resins were reacted with 1,2-diaminoethane in the presence of ultrasonic irradiation for the preparation of a tridimensional chelating resin on the Nano scale for the recovery of Copper (II ions from aqueous solutions. This method which is used for removing and determining Copper (II ions using copolymers derived resins of poly (styrene-alternative-maleic anhydride (SMA and atomic absorption spectroscopy. The method is simple, sensitive, inexpensive and fast. The various parameters such as pH, contact time, concentrations of metal ions, mass of resin, and agitation speed were investigated on adsorption effect. The adsorption behavior of Copper (II ions were investigated by the synthesis of chelating resins at various pHs. The prepared resins showed a good tendency for removing the selected metal ions from aqueous solution, even at an acidic pH. Also, the prepared resins were examined for the removal of Copper (II ions from real samples such as industrial wastewater and were shown to be very efficient at adsorption in the cases of Copper (II ions. The pseudo-first-order, pseudo-second-order, and intra-particle diffusion kinetics equations were used for modeling of adsorption data and it was shown that pseudo-second-order kinetic equation could best describe the adsorption kinetics. The intra-particle diffusion study revealed that external diffusion might be involved in this case. The resins were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction analysis.

  6. Electrochemical and DFT studies of quinoline derivatives on corrosion inhibition of AA5052 aluminium alloy in NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dapeng; Yang, Dong [Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, School of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Zhang, Daquan, E-mail: zhangdaquan@shiep.edu.cn [Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, School of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Li, Kang; Gao, Lixin [Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, School of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Lin, Tong [Institute for Frontier Materials, Deakin University, Geelong, VIC 3216 (Australia)

    2015-12-01

    Graphical abstract: - Highlights: • 8-AQ and 8-NQ have a good anti-corrosion effect acting as anodic inhibitor. • The inhibition mechanism is dominated by geometric covering effect. • The p-orbital of reactive site of inhibitor and sp-orbital of Al are hybridizing. - Abstract: Two quinoline derivatives, 8-aminoquinoline (8-AQ) and 8-nitroquinoline (8-NQ), have been used as inhibitors to examine their corrosion protection effect on AA5052 aluminium alloy in 3% NaCl solution. The weight-loss and electrochemical measurement have indicated that 8-AQ and 8-NQ play as anodic inhibitor to retard the anodic electrochemical process. SEM/EDS analysis clearly shows that 8-AQ and 8-NQ form a protective film on the AA5052 alloy surface. Density functional theory (DFT) calculation confirmed the formation of strong hybridization between the p-orbital of reactive sites in the inhibitor molecules and the sp-orbital of the Al atom. 8-aminoquinoline and 8-nitroquinoline may be useful as effective corrosion inhibitors for aluminium alloys.

  7. Decolorisation of Basic Textile Dye from Aqueous Solutions using a Biosorbent derived from Thespesia populnea used Biomass

    Science.gov (United States)

    Gunturu, Bhargavi; Rao Palukuri, Nageswara; Sahadevan, Renganathan

    2018-03-01

    In the present study, the efficiency of a biosorbent derived from seeds of Thespesia populnea was investigated towards the removal of basic textile dye Methylene Blue from an aqueous solution. Adsorption studies were carried out in batch system. Influence of experimental parameters such as adsorbent dosage (0.1g/L-0.3g/L), PH (2-10) and initial dye concentration (50-130mg/L) on adsorption of dye onto biosorbent was investigated. Maximum uptake of dye was observed with 0.1g/L adsorbent dosage at PH 8.0. Equilibrium uptake of methylene blue dye by the adsorbent was analyzed by Langmuir and Freundlich isotherm models. The data fitted best with Freundlich model, suggesting that adsorption of the dye was by multilayer model on the surface of the adsorbent. Experimental results obtained support that the biosorbent used in the present study can be a suitable low cost alternate for the removal of basic textile dyes.

  8. Computer programme for the derivation of transfer functions for multivariable systems (solutions of determinants with polynomial elements)

    International Nuclear Information System (INIS)

    Guppy, C.B.

    1962-03-01

    In the methods adopted in this report transfer functions in the form of the ratio of two polynomials of the complex variable s are derived from sets of laplace transformed simultaneous differential equations. The set of algebraic simultaneous equations are solved using Cramer's Rule and this gives rise to determinants having polynomial elements. It is shown how the determinants are formed when transfer functions are specified. The procedure for finding the polynomial coefficients from a given determinant is fully described. The first method adopted is a direct one and reduces a determinant with first degree polynomial elements to secular form and follows this by an application of the similarity transformation to reduce the determinant to a form from which the polynomial coefficients can be read out directly. The programme is able to solve a single determinant with polynomial elements and this can be used to reduce an eigenvalue problem in the form of a secular determinant to polynomial form if the need arises. A description is given of the way in which the data is to be set out for solution by the programme. A description is also given of a method used in an earlier programme for solving polynomial determinants by curve fitting techniques using Chebyshev Polynomials. In this method determinants with polynomial elements of any degree can be solved. (author)

  9. sym-Trisubstituted 1,3,5-Triazine Derivatives as Promising Organic Corrosion Inhibitors for Steel in Acidic Solution.

    Science.gov (United States)

    El-Faham, Ayman; Dahlous, Kholood A; Al Othman, Zeid A; Al-Lohedan, Hamad A; El-Mahdy, Gamal A

    2016-03-31

    Triazine derivatives, namely, 2,4,6-tris(quinolin-8-yloxy)-1,3,5-triazine (T3Q), N²,N⁴,N⁶-tris(pyridin-2-ylmethyl)-1,3,5-triazine-2,4,6-triamine (T3AMPy) and 2,2',2''-[(1,3,5-triazine-2,4,6-triyl)tris(azanediyl)] tris(ethan-1-ol) (T3EA) were synthesized and their inhibition of steel corrosion in hydrochloric acid solution was investigated using electrochemical techniques. The corrosion protection of the prepared compounds increased with increasing concentration and reached up to 98% at 250 ppm. The adsorption of T3Q, T3AMPy, and T3EA on the steel surface was in accordance with the Langmuir adsorption isotherm. The electrochemical results revealed that T3Q, T3AMPy and T3EA act as excellent organic inhibitors and can labeled as mixed type inhibitors. The efficiencies of the tested compounds were affected by the nature of the side chain present in the triazine ring, where T3EA gave the least inhibition while T3Q and T3AMPy gave higher and almost the same inhibition effects. The inhibition efficiencies obtained from the different electrochemical techniques were in good agreement.

  10. Adsorption of Cu(2+) and methyl orange from aqueous solutions by activated carbons of corncob-derived char wastes.

    Science.gov (United States)

    Hou, Xiao-Xu; Deng, Qing-Fang; Ren, Tie-Zhen; Yuan, Zhong-Yong

    2013-12-01

    Corncob-derived char wastes (CCW) obtained from biomass conversion to syngas production through corncob steam gasification, which were often discarded, were utilized for preparation of activated carbon by calcination, and KOH and HNO3 activation treatments, on the view of environment protection and waste recycling. Their adsorption performance in the removal of heavy metal ions and dye molecules from wastewater was evaluated by using Cu(2+) and methyl orange (MO) as the model pollutant. The surface and structure characteristics of the CCW-based activated carbons (CACs) were investigated by N2 adsorption, CO2 adsorption, FT-IR, and He-TPD. The adsorption capacity varied with the activation methods of CACs and different initial solution concentrations, indicating that the adsorption behavior was influenced by not only the surface area and porosity but also the oxygen functional groups on the surface of the CACs. The equilibrium adsorption data were analyzed with the Langmuir, Freundlich, and Temkin isotherm models, and the adsorption kinetics was evaluated by the pseudo-first-order and pseudo-second-order models.

  11. Fluorinated antimony(v) derivatives: strong Lewis acidic properties and application to the complexation of formaldehyde in aqueous solutions.

    Science.gov (United States)

    Tofan, Daniel; Gabbaï, François P

    2016-11-01

    As part of our ongoing studies of water tolerant Lewis acids, we have synthesized and investigated the properties of Sb(C 6 F 5 ) 3 (O 2 C 6 Cl 4 ), a fluorinated stiborane whose Lewis acidity approaches that of B(C 6 F 5 ) 3 . While chloroform solutions of this Lewis acid can be kept open to air or exposed to water for extended periods of time, this new Lewis acid reacts with P t Bu 3 and paraformaldehyde to form the corresponding formaldehyde adduct t Bu 3 P-CH 2 -O-Sb(C 6 F 5 ) 3 (O 2 C 6 Cl 4 ). To test if this reactivity can also be observed with systems that combine the phosphine and the stiborane within the same molecule, we have also prepared o -C 6 H 4 (PPh 2 )(SbAr 2 (O 2 C 6 Cl 4 )) (Ar = Ph, C 6 F 5 ). These yellow compounds, which possess an intramolecular P→Sb interaction, are remarkably inert to water but do, nonetheless, react with and accomodate formaldehyde into the P/Sb pocket. In the case of the fluorinated derivative o -C 6 H 4 (PPh 2 )(Sb(C 6 F 5 ) 2 (O 2 C 6 Cl 4 )), formaldehyde complexation, which occurs in water/dichloromethane biphasic mixtures, is accompanied by a colourimetric turn-off response thus highlighting the potential that this chemistry holds in the domain of molecular sensing.

  12. Mechanisms of oxidation reactions of alkyl and aryl derivatives of aniline and p-phenylenediamine by cerium (4) in perchloric acid aqueous solutions

    International Nuclear Information System (INIS)

    Ignachak, M.; Dzegets, Yu.

    1989-01-01

    The mechanisms of oxidation reactions of alkyl, N-alkyl and N-aryl derivatives of aniline and p-phenylenediamine by cerium (4) in perchloric acid aqueous solutions are studied. The possible mechanisms of the above reactions are presented; the possibility of preparation of some intermediate products of these reactions using Ce(4) as an oxidant is pointed out

  13. On existence of solution in $\\mathbb{R}^n$ of stochastic differential inclusions with current velocities in the presence of approximations with uniformly bounded first partial derivatives

    Directory of Open Access Journals (Sweden)

    Alla V. Makarova

    2017-05-01

    Full Text Available Notion of mean derivatives was introduced by Edward Nelson for the needs of stochastic mechanics (a version of quantum mechanics. Nelson introduced forward and backward mean derivatives while only their half-sum, symmetric mean derivative called current velocity, is a direct analog of ordinary velocity for deterministic processes. Another mean derivative called quadratic, was introduced by Yuri E. Gliklikh and Svetlana V. Azarina. It gives information on the diffusion coefficient of the process and using Nelson's and quadratic mean derivatives together, one can in principle recover the process from its mean derivatives. Since the current velocities are natural analogs of ordinary velocities of deterministic processes, investigation of equations and especially inclusions with current velocities is very much important for applications since there are a lot of models of various physical, economical etc. processes based on such equations and inclusions. Existence of solution theorems are obtained for stochastic differential inclusions given in terms of the so-called current velocities (symmetric mean derivatives, a direct analogs of ordinary velocity of deterministic systems and quadratic mean derivatives (giving information on the diffusion coefficient on $\\mathbb{R}^n$. Right-hand sides in both the current velocity part and the quadratic part are set-valued but satisfy some natural conditions.

  14. Synthesis and characterization of a J-aggregating TDBC derivative in solution and in Langmuir–Blodgett films

    Energy Technology Data Exchange (ETDEWEB)

    Aviv, Hagit [Department of Chemistry, Bar-Ilan University (Israel); Institute for Nanotechnology and Advanced Materials, Bar-Ilan University (Israel); Tischler, Yaakov R., E-mail: yrt@biu.ac.il [Department of Chemistry, Bar-Ilan University (Israel); Institute for Nanotechnology and Advanced Materials, Bar-Ilan University (Israel)

    2015-02-15

    Here we present the synthesis and optical characterization of a new amphiphilic cyanine dye, 1,1′-dioctadecane-3,3′-di(4-sulfobutyl)-5,5′,6,6′-tetrachloro -benzimidazolocarbo-cyanine (C18S4). C18S4 is a derivative of the heavily studied J-aggregating cyanine dye TDBC that was designed specifically for creating stable amphiphilic monolayers when spread at an air–water interface. Unlike TDBC, which readily J-aggregates in water, we show that C18S4 introduced into water tends to produce micelles with monomeric spectral properties and only exhibits strong J-aggregation after an emulsification procedure and a week of dye reorganization. When deposited on a Langmuir Blodgett (LB) trough, C18S4 forms a stable monolayer with a repeatable isotherm. Layers transferred via LB deposition to a functionalized glass substrate show pronounced J-aggregation, depending on the surface transfer pressure. Layers transferred at 35 mN/m present an intense narrow absorption spectrum peaked at λ=589 nm with FWHM=523 cm{sup −1} (18 nm). The accompanying fluorescence shows a narrow spectrum with FWHM=332 cm{sup −1} (11.5 nm) and a Stokes shift less than 1 nm. The ability to create J-aggregates of C18S4 via LB deposition provides control over the J-aggregation process of TDBC-like molecules and can ultimately lead to tuning the J-aggregate coupling for specific experiments and applications. - Highlights: • C18S4 is an amphiphilic J-aggregating cyanine dye. • C18S4 J-aggregates in aqueous solution. • C18S4 forms a stable isotherm when spread at the air–water interface. • C18S4 J-aggregates at an air–water interface upon compression. • Langmuir–Blodgett J-aggregated films have narrow absorption and emission spectra.

  15. Synthesis of magnetite derivatives nanoparticles and their application for the removal of chromium (VI) from aqueous solutions.

    Science.gov (United States)

    Tahar, Lotfi Ben; Oueslati, Mohamed Habid; Abualreish, Mustafa Jaipallah Abdelmageed

    2018-02-15

    Nowadays there is a continuously increasing worldwide concern for the development of efficient wastewaters treatment technologies. Among the heavy metal ions, chromium holds a distinct position due to its high toxic nature to biological systems. This study aims to assess magnetite derivatives nanoparticles for the removal of Cr(VI) species. Crystalline magnetite-rich (Magn) and pure maghemite (Magh) nanoparticles were produced by the polyol method and by subsequent heat treatment of Magn, respectively. The XRD analysis confirmed the formation of nanosized single phase cubic spinels with a cell parameter of 8.3710(2)Å for Magn and 8.3401(2)Å for Magh, consistent with those of a magnetite-rich ferrite and maghemite, respectively. TEM analysis showed that the two nanoferrites possessed comparable mean particle size of ∼15nm. Magn and Magh showed superparamagnetic behavior at room temperature and reasonable saturation magnetizations at 300K of 69 and 67emu.g -1 , respectively. The Curie temperature of both nanoferrites exceeded 350°C allowing the materials to work in severe conditions. Room temperature, batch adsorption experiments of Cr(VI) onto maghemite nanoparticles were carried out at pH 2.0. Adsorption efficiency increased rapidly was the increase of the nanoparticles dose. For a 20mg.L -1 Cr(VI) solution a 100% removal was found with ∼3g.L -1 dose. Additionally, for a given dose (4.0g.L -1 ), the adsorption rate measured as a function of time for different Cr(VI) concentrations was very rapid; ∼90% of removable Cr(VI) species was achieved within 10min. The high rate of Cr(VI) uptake takes advantages of the high active surface chemistry of the nanoparticles. The adsorption of Cr(VI) onto Magh nanoparticles followed a pseudo-second order kinetics indicating a chemisorption process. Further, the Langmuir isotherm model was found to best describe the equilibrium data with a maximum adsorption capacity of 12.5mg.g -1 for an adsorbent dosage of 4.0g.L -1

  16. A liquid chromatography – tandem mass spectrometry method to measure a selected panel of uremic retention solutes derived from endogenous and colonic microbial metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Loor, Henriette de; Poesen, Ruben [KU Leuven – University of Leuven, Department of Microbiology and Immunology, Laboratory of Nephrology, B-3000 Leuven (Belgium); De Leger, Wout; Dehaen, Wim [KU Leuven – University of Leuven, Department of Chemistry, Division of Molecular Design and Synthesis, B-3000 Leuven (Belgium); Augustijns, Patrick [KU Leuven – University of Leuven, Department of Pharmaceutical and Pharmacological Sciences, Drug Delivery and Disposition, B-3000 Leuven (Belgium); Evenepoel, Pieter [KU Leuven – University of Leuven, Department of Microbiology and Immunology, Laboratory of Nephrology, B-3000 Leuven (Belgium); University Hospitals Leuven, Department of Nephrology and Renal Transplantation, B-3000 Leuven (Belgium); Meijers, Björn, E-mail: bjorn.meijers@uzleuven.be [KU Leuven – University of Leuven, Department of Microbiology and Immunology, Laboratory of Nephrology, B-3000 Leuven (Belgium); University Hospitals Leuven, Department of Nephrology and Renal Transplantation, B-3000 Leuven (Belgium)

    2016-09-14

    Chronic kidney disease (CKD) is associated with an increased risk of mortality and cardiovascular disease, which is, at least partly, mediated by the accumulation of so-called uremic retention solutes. Although there has been an increasing interest in the behavior of these solutes, derived from both the endogenous and colonic microbial metabolism, methods to simultaneously and accurately measure a broad panel of relevant uremic retention solutes remain scarce. We developed a highly sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. A high throughput sample preparation was used with extraction of analytes from 50 μl serum using Ostro plate technology. For most solutes, stable isotopes labelled metabolites were used as internal standards. Chromatography was achieved using an Acquity UPLC CSH Fluoro Phenyl column. The total run time was 8 min, the mobile phase was a gradient of 0.1% formic acid in Milli-Q water and pure methanol at a flow rate of 0.5 ml min{sup −1}. Detection was performed using a tandem mass spectrometer with alternated positive and negative electrospray ionization. Calibration curves were linear for all solutes. Precision was assessed according to the NCCLS EP5-T guideline, being below 15% for all metabolites. Mean recoveries were between 83 and 104% for all metabolites. The validated method was successfully applied in a cohort of 488 patients with CKD. We developed and validated a sensitive and robust UPLC-MS/MS method for quantification of 15 uremic retention solutes derived from endogenous and colonic microbial metabolism. This method allows for studying the behavior and relevance of these solutes in patients with CKD. - Highlights: • Simultaneous quantification of fifteen relevant uremic retention solutes. • Comprehensive validation, highly sensitive and high through-put LC-MSMS method. • Comparison of different blood tubes. • Freeze-thaw stability. • Successful implementation in a

  17. Solutions of Cattaneo-Hristov model of elastic heat diffusion with Caputo-Fabrizio and Atangana-Baleanu fractional derivatives

    Directory of Open Access Journals (Sweden)

    Koca Ilknur

    2017-01-01

    Full Text Available Recently Hristov using the concept of a relaxation kernel with no singularity developed a new model of elastic heat diffusion equation based on the Caputo-Fabrizio fractional derivative as an extended version of Cattaneo model of heat diffusion equation. In the present article, we solve exactly the Cattaneo-Hristov model and extend it by the concept of a derivative with non-local and non-singular kernel by using the new Atangana-Baleanu derivative. The Cattaneo-Hristov model with the extended derivative is solved analytically with the Laplace transform, and numerically using the Crank-Nicholson scheme.

  18. Properties of cationic monosubstituted tetraalkylammonium cyclodextrin derivatives – their stability, complexation ability in solution or when deposited on solid anionic surface

    Directory of Open Access Journals (Sweden)

    Martin Popr

    2015-02-01

    Full Text Available The thermal stability of the monosubstituted cationic cyclodextrin (CD derivatives PEMEDA-β-CD and PEMPDA-β-CD, which differ in their substituent linker length (ethylene and propylene, respectively, was studied via 1H NMR experiments. PEMPDA-β-CD exhibited higher resistance towards the Hofmann degradation and was chosen as a more suitable host molecule for further studies. Inclusion properties of PEMPDA-β-CD in solution with a series of simple aromatic guests (salicylic acid, p-methoxyphenol and p-nitroaniline were determined by isothermal titration calorimetry (ITC and compared to the native β-CD. Permanently charged cationic CD derivatives were successfully deposited on the anionic solid surface of polymeric Nafion® 117 membrane via electrostatic interactions. Deposition kinetics and coverage of the surface were determined by ELSD. Finally, the ability of the CD derivatives bound to the solid surface to encapsulate aromatic compounds from aqueous solution was measured by UV–vis spectroscopy. The obtained results are promising for future industrial applications of the monosubstituted β-CD derivatives, because the preparation of cationic CD derivatives is applicable in large scale, without the need of chromatographic purification. Their ionic deposition on a solid surface is simple, yet robust and a straightforward process as well.

  19. The crystal structure of paarite, the newly discovered 56 Å derivative of the bismuthinite-aikinite solid-solution series

    DEFF Research Database (Denmark)

    Makovicky, Emil; Topa, Dan; Balic-Zunic, Tonci

    2001-01-01

    geologi, paarite, Cu1.7Pb1.7Bi6.3S12, bismuthinite-aikinite derivative, crystal structure, sulfosalt, Felbertal, scheelite deposit, Austria......geologi, paarite, Cu1.7Pb1.7Bi6.3S12, bismuthinite-aikinite derivative, crystal structure, sulfosalt, Felbertal, scheelite deposit, Austria...

  20. Solution of the two-dimensional transient heat conduction equation using the finite element method and the Saul'ev ADE method for time derivation

    International Nuclear Information System (INIS)

    Haner, A.; Fremd, R.; Schmidt, F.

    1979-12-01

    The finite element method (FEM) is used for the solution of the twodimensional transient heat conduction equation. The time derivation is approximated by use of Saul'ev ADE method, which is modified for the FEM. This method will be improved in such way that the use of any triangular element is possible. The realisation of the method is based on a modified version of the program DIFGEN which solves the neutron diffusion equation. (orig.) 891 RW/orig. 892 MKO [de

  1. Role of intrinsic hydrogen bonds in the assembly of perylene imide derivatives in solution and at the liquid-solid interface.

    Science.gov (United States)

    Guo, Zongxia; Wang, Kun; Yu, Ping; Zhang, Shengyue; Sun, Kai; Li, Zhibo

    2017-08-30

    The impact of hydrogen bond formation on the supramolecular assembly of two perylene imide derivatives (PMAMI and PDINH) was systematically investigated in solution and at the liquid-solid interface. PDINH has intrinsic hydrogen bond sites, but this is not the case for PMAMI. The solution assembly was explored by morphological methods (SEM, AFM, TEM and cryo-TEM) and spectral characterization (UV-vis, FL, XRD, and FTIR spectra). The surface assembly at the liquid-solid interface was detected by scanning tunneling microscopy (STM). It was found that in a mixed solution (THF/MeOH, 10 v%/90 v%), PMAMI formed nanofibers together with large sheet structures and PDINH assembled into uniform nanosheets, suggesting different molecular packing routes. The assembled structures could be adjusted by varying the solvent polarity for both molecules. At the liquid-solid interface, clearly distinguished surface nanostructures from PMAMI and PDINH were easily observed. Based on all spectral and morphological characterizations, it was suggested that in solution the assembly of PMAMI was mainly derived by π-π stacking interactions; on the other hand, the synergetic interaction of hydrogen bonds and π-π stacking was the reason for the hierarchical assembly of PDINH. Hydrogen bonds could be formed both for PMAMI and PDINH and stabilized nanostructures at the liquid-solid interface. This investigation could be useful in designing perylene imide-based building blocks for fabricating supramolecular assemblies with predetermined nanostructures and properties.

  2. Calorimetric investigations of hydrogen bonding in binary mixtures containing pyridine and its methyl-substituted derivatives. II. The dilute solutions of methanol and 2-methyl-2-propanol

    International Nuclear Information System (INIS)

    Marczak, Wojciech; Heintz, Andreas; Bucek, Monika

    2004-01-01

    Enthalpies of solution of methanol and 2-methyl-2-propanol (tert-butanol) in pyridine and its methyl derivatives were investigated in the range of mole fractions of alcohol x≤0.02 at temperature 298.15 K by a titration calorimeter. Dissolution of methanol is an exothermic process, with heat effects very close to those for water reported in part I of this study. The negative enthalpy of solution increases in the following order: pyridine < 3-methylpyridine < 4-methylpyridine < 2-methylpyridine < 2,6-dimethylpyridine < 2,4,6-trimethylpyridine. Positive enthalpies of solution of 2-methyl-2-propanol increase as follows: 2-methylpyridine < 2,4,6-trimethylpyridine < 4-methylpyridine < 2,6-dimethylpyridine < 3-methylpyridine < pyridine. The propensity of pyridine derivatives to hydrogen bonding is enhanced by the ortho effect. Methyl groups are probably too small to prevent the nitrogen atom in the pyridine ring from hydrogen bonding. However, spacious hydrocarbon group in 2-methyl-2-propanol molecule makes the bonding difficult for 2,6-dimethylpyridine and 2,4,6-trimethylpyridine, thus the number of O-H···N bonds is smaller than that in the solutions of methanol or water. The two latter seem to be very close to each other

  3. Temperature field due to time-dependent heat sources in a large rectangular grid - Derivation of analytical solution

    Energy Technology Data Exchange (ETDEWEB)

    Claesson, J.; Probert, T. [Lund Univ. (Sweden). Dept. of Building Physics and Mathematical Physics

    1996-01-01

    The temperature field in rock due to a large rectangular grid of heat releasing canisters containing nuclear waste is studied. The solution is by superposition divided into different parts. There is a global temperature field due to the large rectangular canister area, while a local field accounts for the remaining heat source problem. The global field is reduced to a single integral. The local field is also solved analytically using solutions for a finite line heat source and for an infinite grid of point sources. The local solution is reduced to three parts, each of which depends on two spatial coordinates only. The temperatures at the envelope of a canister are given by a single thermal resistance, which is given by an explicit formula. The results are illustrated by a few numerical examples dealing with the KBS-3 concept for storage of nuclear waste. 8 refs.

  4. X-ray CT-derived soil characteristics explain varying air, water, and solute transport properties across a loamy field

    DEFF Research Database (Denmark)

    Paradelo Pérez, Marcos; Katuwal, Sheela; Møldrup, Per

    2016-01-01

    to explain water, air, and solute transport through soil. Forty-five soil columns (20 by 20 cm) were collected from an agricultural field in Estrup, Denmark, and subsequently scanned using a medical CT scanner. Nonreactive tracer leaching experiments were performed in the laboratory along with measurements...... when the limiting macroporosity (the minimum macroporosity for every 0.6-mm layer along the soil column) was used, suggesting that soil layers with the narrowest macropore section restricted the flow through the whole soil column. Water, air, and solute transport were related with the CT...

  5. Derivation and application of an analytical rock displacement solution on rectangular cavern wall using the inverse mapping method.

    Directory of Open Access Journals (Sweden)

    Mingzhong Gao

    Full Text Available Rectangular caverns are increasingly used in underground engineering projects, the failure mechanism of rectangular cavern wall rock is significantly different as a result of the cross-sectional shape and variations in wall stress distributions. However, the conventional computational method always results in a long-winded computational process and multiple displacement solutions of internal rectangular wall rock. This paper uses a Laurent series complex method to obtain a mapping function expression based on complex variable function theory and conformal transformation. This method is combined with the Schwarz-Christoffel method to calculate the mapping function coefficient and to determine the rectangular cavern wall rock deformation. With regard to the inverse mapping concept, the mapping relation between the polar coordinate system within plane ς and a corresponding unique plane coordinate point inside the cavern wall rock is discussed. The disadvantage of multiple solutions when mapping from the plane to the polar coordinate system is addressed. This theoretical formula is used to calculate wall rock boundary deformation and displacement field nephograms inside the wall rock for a given cavern height and width. A comparison with ANSYS numerical software results suggests that the theoretical solution and numerical solution exhibit identical trends, thereby demonstrating the method's validity. This method greatly improves the computing accuracy and reduces the difficulty in solving for cavern boundary and internal wall rock displacements. The proposed method provides a theoretical guide for controlling cavern wall rock deformation failure.

  6. Thermodynamic functions of hydrogen bonding of amines in methanol derived from solution calorimetry data and headspace analysis

    International Nuclear Information System (INIS)

    Zaitseva, Ksenia V.; Varfolomeev, Mikhail A.; Solomonov, Boris N.

    2012-01-01

    Highlights: ► Solution enthalpies and activity coefficients of amines in methanol were measured. ► Thermodynamic functions of H-bonding of amines with methanol were determined. ► Specific interaction entropy of amines in methanol can be about zero or positive. ► Cooperativity of H-bonds in methanol media is smaller than in water solutions. ► A new view on analysis of specific interaction of solute with methanol is presented. - Abstract: Reactivity and equilibrium properties of organic molecules in self-associated liquids greatly depend on the hydrogen bonding with solvent. This work contains comprehensive thermodynamic analysis of hydrogen bonding of aliphatic and aromatic amines in self-associated solvent methanol. Enthalpies of solution at infinite dilution and limiting activity coefficients for the studied systems were measured experimentally. Enthalpies and Gibbs energies of hydrogen bonding of amines with neat methanol were determined. These values were found to be decreased compared with hydrogen bond energy in equimolar complexes “methanol–amine” determined in inert solvent or base media. A linear dependence between enthalpies and Gibbs energies of hydrogen bonding of amines with neat methanol was observed. It was firstly revealed that the entropy of specific interactions of amines with neat methanol can be about zero or positive. Disruption of solvent–solvent hydrogen bonds can be regarded as the most important step during dissolution of amine in methanol. It was found that the cooperative effect influences on the Gibbs energies of hydrogen bonding of amines in methanol, but in a lesser extent than in aqueous solutions. The new results show that the hydrogen bonding process in the self-associated solvents differs significantly from equimolar complexation in aprotic media.

  7. Physicochemical characteristics of the sorption of 4-aminoquinoline derivatives from water-acetonitrile solutions on nonpolar sorbents

    Science.gov (United States)

    Paramonova, A. S.; Kurbatova, S. B.; Zemtsova, M. N.

    2014-02-01

    Regularities of the retention of certain 4-aminoquinoline derivatives in the conditions of the reversed phase type of high performance liquid chromatography (HPLC) on octadecyl silica (ODS) and hypercrosslinked polystyrene (HCLPS) are studied. The correlation between the structure of aminoquinolines and their chromatographic retention is demonstrated.

  8. The comparative photodegradation activities of pentachlorophenol (PCP and polychlorinated biphenyls (PCBs using UV alone and TiO2-derived photocatalysts in methanol soil washing solution.

    Directory of Open Access Journals (Sweden)

    Zeyu Zhou

    Full Text Available Photochemical treatment is increasingly being applied to remedy environmental problems. TiO2-derived catalysts are efficiently and widely used in photodegradation applications. The efficiency of various photochemical treatments, namely, the use of UV irradiation without catalyst or with TiO2/graphene-TiO2 photodegradation methods was determined by comparing the photodegadation of two main types of hydrophobic chlorinated aromatic pollutants, namely, pentachlorophenol (PCP and polychlorinated biphenyls (PCBs. Results show that photodegradation in methanol solution under pure UV irradiation was more efficient than that with either one of the catalysts tested, contrary to previous results in which photodegradation rates were enhanced using TiO2-derived catalysts. The effects of various factors, such as UV light illumination, addition of methanol to the solution, catalyst dosage, and the pH of the reaction mixture, were examined. The degradation pathway was deduced. The photochemical treatment in methanol soil washing solution did not benefit from the use of the catalysts tested. Pure UV irradiation was sufficient for the dechlorination and degradation of the PCP and PCBs.

  9. Experimental data of biomaterial derived from Malva sylvestris and charcoal tablet powder for Hg2+ removal from aqueous solutions

    Directory of Open Access Journals (Sweden)

    Alireza Rahbar

    2016-09-01

    Full Text Available In this experimental data article, a novel biomaterial was provided from Malva sylvestris and characterized its properties using various instrumental techniques. The operating parameters consisted of pH and adsorbent dose on Hg2+ adsorption from aqueous solution using M. sylvestris powder (MSP were compared with charcoal tablet powder (CTP, a medicinal drug. The data acquired showed that M. sylvestris is a viable and very promising alternative adsorbent for Hg2+ removal from aqueous solutions. The experimental data suggest that the MSP is a potential adsorbent to use in medicine for treatment of poisoning with heavy metals; however, the application in animal models is a necessary step before the eventual application of MSP in situations involving humans.

  10. Orientation symmetry breaking in self-assembled Ce1-xGdxO2-y nanowires derived from chemical solutions

    OpenAIRE

    Queraltó, Albert; Mata, Maria de la; Martínez, L.; Magén, César; Gibert, M; Arbiol, Jordi; Hühne, R; Obradors Berenguer, Xavier; Puig Molina, Teresa

    2016-01-01

    Understanding the growth mechanisms of nanostructures obtained from chemical solutions, a high-throughput production methodology, is essential to correlate precisely the growth conditions with the nanostructures' morphology, dimensions and orientation. It is shown that self-organized (011)-oriented CeGdO (CGO) nanowires having a single in-plane orientation are achieved when an anisotropic (011)-LaAlO (LAO) substrate is chosen. STEM and AFM images of the epitaxial nanowires reveal the (001)CGO...

  11. Enhanced corrosion resistance of mild steel in hydrochloric acid solution by new thiadiazole derivatives: Electrochemical, theoretical and XPS studies

    Energy Technology Data Exchange (ETDEWEB)

    Bentiss, Fouad; Lebrini, Mounim; Lagrenee, Michel [Laboratoire de Cristallochimie et Physicochimie du Solide, CNRS UMR 8012, ENSCL, BP. 108, F-59652 Villeneuve d' Ascq Cedex (France); Herve, Vezin [Laboratoire de Chimie Organique et Macromoleculaire, CNRS UMR 8009, USTL Bat C3, F-59655 Villeneuve d' Ascq Cedex (France)

    2004-07-01

    In this work, a new class of thiadiazole derivatives, namely 3,5-bis(2-thienyl)-1,3,4-thiadiazole (2-TTH) and 3,5-bis(3-thienyl)-1,3,4-thiadiazole (3-TTH), have been studied as possible corrosion inhibitors for mild steel in molar hydrochloric acid (1M HCl). Polarisation curves and AC impedance methods have been used. These studies have shown that the thiadiazole derivatives were very good inhibitors for mild steel in 1M HCl. Comparison of results showed that 3-TTH was the best inhibitor. The potential of zero charge (PZC) of mild steel was studied by ac impedance method, and the mechanism of adsorption has been predicted. X-ray photoelectron spectroscopy surface analysis with thiadiazole derivatives shows that it chemisorbed at the mild steel/HCl interface. The adsorption of these inhibitors followed Langmuir's adsorption isotherm. The electronic properties of 2-TTH and 3-TTH, obtained using the AM1 semi-empirical quantum chemical approach, were correlated with their experimental efficiencies using the linear resistance model (LR). (authors)

  12. An alternative integral-balance solutions to transient diffusion of heat (mass by time-fractional semi-derivatives and semi-integrals: Fixed boundary conditions

    Directory of Open Access Journals (Sweden)

    Hristov Jordan

    2016-01-01

    Full Text Available A new approach to integral-balance solutions of the diffusion equation of heat (mass with constant transport properties by applying time-fractional semi-derivatives and semi-integrals of Riemann-Liouville sense has been developed. The time-fractional semiderivatives and semiintegrals replace the surface gradient (temperature which in the classical Heat-balance integral method (HBIM of Goodman and the Double-integration method (DIM should be expressed through the assumed profile. The application of semiderivatives and semiintegrals reduces the approximation errors to levels less than the ones exhibited by the classical HBIM and DIM. The method is exemplified by solutions of Dirichlet and Neumann boundary condition problems.

  13. A novel colorimetric receptor responding AcO- anions based on an azo derivative in DMSO and DMSO/water solution

    International Nuclear Information System (INIS)

    Li Yaping; Li Jianwei; Lin Hai; Shao Jie; Cai Zunsheng; Lin Huakuan

    2010-01-01

    A novel and efficient receptor based on the phenylhydrazone derivatives is successfully developed and applied to the acetate anion recognition, indicating that the origin of special preference for acetate (AcO - ) anion maybe the structure well matching between the host and the guest. The sensor changes its color so obviously on addition of the acetate ions and that may make the naked-eye recognition in DMSO and even in DMSO/H 2 O (95/5) solution come true. Also, the anion binding ability determinations were performed by UV-vis titration and 1 H NMR titration experiments with different anions in the solutions mentioned. The fluorescence enhancement can also be observed after the host is coordinated with the AcO - anion and excited by light wavelength at 280 nm.

  14. Monitoring of praseodymium(III) ions in aqueous solutions, soil and sediment samples by a PVC membrane sensor based on a furan-triazole derivative

    Energy Technology Data Exchange (ETDEWEB)

    Pourjavid, Mohammad Reza [Islamic Azad University, Tehran (Iran, Islamic Republic of). Dept. of Medicinal Chemistry. Nuclear Science and Technology Research Institute; Rezaee, Mohammad; Hosseini, Majid Haji [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of); Razavi, Taherehsadat, E-mail: pourjavid@gmail.com [Research Institute of Petroleum Industry, Tehran (Iran, Islamic Republic of). Instrumental Analysis Dept.

    2012-07-01

    A furan-triazole derivative has been explored as an ionophore for preparation of a highly selective Pr(III) membrane sensor. The proposed sensor exhibits a Nernstian response for Pr(III) activity over a wide concentration range with a detection limit of 5.2 x 10{sup -8}M. Its response is independent of pH of the solution in the range 3.0-8.8 and offers the advantages of fast response time. To investigate the analytical applicability of the sensor, it was applied successfully as an indicator electrode in potentiometric titration of Pr(III) solution and also in the direct and indirect determination of trace Pr(III) ions in some samples. (author)

  15. Electrical properties of (1 0 0)-predominant BaTiO3 films derived from alkoxide solutions of two concentrations

    International Nuclear Information System (INIS)

    Guo Yiping; Suzuki, Kazuyuki; Nishizawa, Kaori; Miki, Takeshi; Kato, Kazumi

    2006-01-01

    Lead-free piezoelectric films with thickness larger than 1 μm integrated on silicon substrates have been receiving considerable attention because of environmental concerns and their potential applications in microelectromechanical systems. We demonstrate that, by chemical solution deposition, it is possible to process (1 0 0)-predominant 1 μm BaTiO 3 films on LaNiO 3 /Pt/TiO x /SiO 2 /Si substrates using thinner high-crystallinity columnar BaTiO 3 films as buffer layers. We point out that this kind of buffer layer prepared with a lower concentration solution on the surface of an LaNiO 3 /Pt electrode is effective in enhancing the crystallinity and orientation degree of final BaTiO 3 films prepared with a higher concentration solution. The 1 μm BaTiO 3 films show good dielectric and insulating characteristics against an applied field, and the conduction current shows Schottky emission behavior at modest voltage and space-charge-limited behavior at higher voltage. We also demonstrate that the (1 0 0)-predominant 1 μm BaTiO 3 films have excellent piezoelectric properties: piezoelectric coefficients d 33 higher than 50 pm/V have been determined for the bare films using atomic force microscopy, which are comparable to those of Pb(Zr,Ti)O 3 films. These results indicate that the (1 0 0)-predominant BaTiO 3 films should be promising candidates for microelectromechanical systems applications

  16. A spectroscopic study of the optical properties of a nitrobenzoxadiazole derivative in solution: The role of specific interactions

    Science.gov (United States)

    Quarti, Claudio; Villafiorita-Monteoleone, Francesca; Botta, Chiara; Daita, Valentina; Perdicchia, Dario; Del Buttero, Paola; Del Zoppo, Mirella

    2014-08-01

    The role of specific interactions on the optical properties of organic dyes is an important issue when designing optimized organic chromophores to be used in optoelectronic applications. The role of quantum chemical modeling of environmental effects can be of relevance in this respect but it is a very delicate issue to be tackled with different approaches. In this Letter we show that a simple dimer approach (one solvent + one solute molecule) is enough to reproduce the correct solvatochromic behavior of 4-hexylamino-7-nitro-2,1,3-benzoxadiazoles, which belongs to a class of molecules well known for their fluorogenic properties.

  17. Induced alignment of a solution-cast discotic hexabenzocoronene derivative for electronic devices investigated by surface X-ray diffraction

    DEFF Research Database (Denmark)

    Bunk, Oliver; Nielsen, Martin Meedom; Sølling, Theis Ivan

    2003-01-01

    A surface X-ray diffraction study is presented showing that highly ordered and uniaxially aligned hexa(3,7-dimethyl-octanyl)hexa-peri-hexabenzocoronene (HBC-C8,2) films can be fabricated by crystallization from solution onto friction-transferred poly(tetrafluoroethylene) (PTFE) layers. Three...... crystalline HBC-C8,2 majority phases result. In all three phases, the HBC-C8,2 molecules self-organize into columns which are uniaxially aligned along the direction defined by the PTFE macromolecules of the substrate. The three phases are quite similar, the major difference being their orientation...

  18. Transforming the promise of pluripotent stem cell-derived cardiomyocytes to a therapy: challenges and solutions for clinical trials.

    Science.gov (United States)

    Prowse, Andrew B J; Timmins, Nicholas E; Yau, Terrence M; Li, Ren-Ke; Weisel, Richard D; Keller, Gordon; Zandstra, Peter W

    2014-11-01

    Despite advances in coronary artery disease treatment and prevention, myocardial damage due to acute myocardial infarction (MI) remains a major cause of morbidity and mortality in the population. Cell-based clinical trials to treat MI have focused on cells derived from the bone marrow or those potentially possessing functional similarities such as skeletal myoblasts or cardiac progenitors isolated from heart biopsies. Any benefits provided by these cells in improving heart function, left ventricular ejection fraction, or extending life expectancy after MI have been credited mostly to paracrine effects. Functional restoration of damaged myocardium will require a functional cell type with similar phenotype and characteristics of the damaged tissue that can also integrate, survive, and electrically couple to the host. Human pluripotent stem cells (hPSCs) have the ability to differentiate into multiple cell types of the adult body. hPSC-derived cardiomyocytes represent a promising target population for cell-based therapies for MI because they are scalable and the product can be defined with a specific set of release criteria. The purpose of this article is to review the rationale for cell therapy in heart disease, discuss the properties of hPSC cardiomyocytes that define their usefulness for regenerative therapy, consider manufacturing issues and preclinical investigation, and finally examine the steps required to establish effective clinical implementation. Pluripotent stem cell-derived cardiomyocyte-based therapies have enormous potential to revolutionize the management of heart disease; expedient but careful development is needed to ensure that this potential is fully realized. Copyright © 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  19. Derivation of an Analytical Solution to a Reaction-Diffusion Model for Autocatalytic Degradation and Erosion in Polymer Microspheres.

    Science.gov (United States)

    Ford Versypt, Ashlee N; Arendt, Paul D; Pack, Daniel W; Braatz, Richard D

    2015-01-01

    A mathematical reaction-diffusion model is defined to describe the gradual decomposition of polymer microspheres composed of poly(D,L-lactic-co-glycolic acid) (PLGA) that are used for pharmaceutical drug delivery over extended periods of time. The partial differential equation (PDE) model treats simultaneous first-order generation due to chemical reaction and diffusion of reaction products in spherical geometry to capture the microsphere-size-dependent effects of autocatalysis on PLGA erosion that occurs when the microspheres are exposed to aqueous media such as biological fluids. The model is solved analytically for the concentration of the autocatalytic carboxylic acid end groups of the polymer chains that comprise the microspheres as a function of radial position and time. The analytical solution for the reaction and transport of the autocatalytic chemical species is useful for predicting the conditions under which drug release from PLGA microspheres transitions from diffusion-controlled to erosion-controlled release, for understanding the dynamic coupling between the PLGA degradation and erosion mechanisms, and for designing drug release particles. The model is the first to provide an analytical prediction for the dynamics and spatial heterogeneities of PLGA degradation and erosion within a spherical particle. The analytical solution is applicable to other spherical systems with simultaneous diffusive transport and first-order generation by reaction.

  20. DNA derived fluorescent bio-dots for sensitive detection of mercury and silver ions in aqueous solution

    Science.gov (United States)

    Song, Ting; Zhu, Xuefeng; Zhou, Shenghai; Yang, Guang; Gan, Wei; Yuan, Qunhui

    2015-08-01

    Inspired by the high affinity between heavy metal ions and bio-molecules as well as the low toxicity of carbon-based quantum dots, we demonstrated the first application of a DNA derived carbonaceous quantum dots, namely bio-dots, in metal ion sensing. The present DNA-derived bio-dots contain graphitic carbon layers with 0.242 nm lattice fringes, exhibit excellent fluorescence property and can be obtained via a facile hydrothermal preparation procedure. Hg(II) and Ag(I) are prone to be captured by the bio-dots due to the existence of residual thymine (T) and cytosine (C) groups, resulting in a quenched fluorescence while other heavy metal ions would cause negligible changes on the fluorescent signals of the bio-dots. The bio-dots could be used as highly selective toxic-free biosensors, with two detecting linear ranges of 0-0.5 μM and 0.5-6 μM for Hg(II) and one linear range of 0-10 μM for Ag(I). The detection limits (at a signal-to-noise ratio of 3) were estimated to be 48 nM for Hg(II) and 0.31 μM for Ag(I), respectively. The detection of Hg(II) and Ag(I) could also be realized in the real water sample analyses, with satisfying recoveries ranging from 87% to 100%.

  1. Hydrazino-methoxy-1,3,5-triazine Derivatives' Excellent Corrosion Organic Inhibitors of Steel in Acidic Chloride Solution.

    Science.gov (United States)

    El-Faham, Ayman; Osman, Sameh M; Al-Lohedan, Hamad A; El-Mahdy, Gamal A

    2016-06-01

    The corrosion inhibition performance of 2-hydrazino-4,6-dimethoxy-1,3,5-tirazine (DMeHT), 2,4-dihydrazino-6-methoxy-1,3,5-triaizine (DHMeT), and 2,4,6-tridydrazino-1,3,5-triaizne (TH₃) on steel corrosion in acidic media was examined using electrochemical techniques. The results showed 2,4-Ddihydrazino-6-methoxy-1,3,5-triaizine (DHMeT) gave the best corrosion protection performance among the other hydrazino derivatives even at a low concentration of 25 ppm (95%). The number of hydrazino groups play an important role in the corrosion inhibition, where the two hydrazine groups increased the electrostatic interactions between the protonated tested compounds, the negatively charged steel surface resulted from the adsorption of the chloride anions, and the presence of the methoxy group made the compound more reliable for formation of film protection on the surface of steel through the lone pair of oxygen atoms. Electrochemical Impedance Spectroscopy (EIS) measurements suggested that the corrosion process of steel in presence of the hydrazino-s-triazine derivatives (TH₃, DMeHT and DHMeT) were being controlled by the charge transfer reaction. Polarization curves indicated that the examined TH₃, DMeHT and DHMeT behaved as mixed type inhibitors.

  2. Self-aggregation behavior of hydrophobic sodium alginate derivatives in aqueous solution and their application in the nanoencapsulation of acetamiprid.

    Science.gov (United States)

    Zhao, Xinyu; Li, Jiacheng; Feng, Yuhong; Yu, Gaobo; Zhou, Qingfeng; He, Furui; Xiao, Dunchao; Chen, Kai; Zhang, Lei

    2018-01-01

    In this study, cholesteryl-grafted sodium alginate derivatives (CSAD) with different molecular weights were synthesized by esterification. The structure of CSAD was confirmed by FT-IR and 1 H NMR spectrometers. The effects of pH and CSAD polymer concentration on the self-assembled behavior and particle size of CSAD were investigated by fluorescence measurement (FM) and dynamic light scattering (DLS). In the presence of Ca 2+ , the cholesteryl-grafted sodium alginate derivative was used for fabricating self-assembled nanoparticles that can effectively encapsulate the drug acetamiprid. The drug-loaded nanoparticles were characterized by transmission electron microscopy (TEM). The encapsulation efficiency (EE) and acetamiprid drug release behavior from the nanoparticles were also studied. The results reveal that CSAD self-assembled nanoparticles had a diameter of 100nm and were nonaggregated in aqueous media; Moreover, the encapsulation efficiency and the release behavior of nanoparticles were influenced by the MW of CSAD. The mechanism of acetamiprid release was found to vary from non-Fickian (anomalous) to Fickian transport with a decrease in the molecular weight of CSAD. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. High-performance semiconductors based on oligocarbazole–thiophene derivatives for solution-fabricated organic field-effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Gung-Pei; Hsieh, Kuo-Huang, E-mail: khhsieh@ntu.edu.tw

    2013-01-01

    A series of oligocarbazole–thiophenes based on a constant conjugate backbone (carbazole–bithiophene–carbazole) with various n-alkyl chain lengths was prepared for application to organic field-effect transistors (OFETs). The lengths of the n-alkyl substitutions attached on 9-position of carbazole moieties were methyl (CCzT2), hexyl (C6CzT2), dodecyl (C12CzT2), and octadecyl (C18CzT2), called CxCzT2. Variations of n-alkyl chain lengths are proposed to figure out the optimization of OFET performance via solution fabrication of the active layer. Before fabricating OFET devices, the thermal, optical, and electrochemical properties of CxCzT2 were fully characterized with thermogravimetric analysis, differential scanning calorimetry, ultraviolet–visible spectroscopy, and cyclic voltammetry to realize the relationships of the structure to the properties. After fabricating CxCzT2 on Si/SiO{sub 2} substrates via solution casting, the thin film morphologies were also studied with polarizing optical microscopy, atomic force microscopy, and X-ray diffraction to investigate the structural relationship to OFET performance. A higher hole mobility was observed with C12CzT2 (3.6 × 10{sup −2} cm{sup 2} V{sup −1} s{sup −1}) due to its liquid crystal properties, and the hole mobility could be further improved to 1.2 × 10{sup −1} cm{sup 2} V{sup −1} s{sup −1} by the introduction of a phenyl-self-assembled monolayer on the Si/SiO{sub 2} substrates. The excellent OFET performances of C12CzT2 by solution–fabrication could be considered as a promising candidate for high-end OFET application. - Highlights: ► These oligomeric semiconductors were synthesized rapidly. ► The thermal, optical, and electrochemical properties were fully investigated. ► The liquid crystal properties can be obtained via alkyl chain length adjustment. ► These oligomeric semiconductors can be solution-fabricated. ► One of these oligomeric semiconductors yields high field-effect hole

  4. The mobile order theory versus UNIFAC and regular solution theory-derived models for predicting the solubility of solid substances.

    Science.gov (United States)

    Ruelle, P; Buchmann, M; Hô, N T; Kesselring, U W

    1992-06-01

    The theory of mobile order of Huyskens is tested against the UNIFAC model, the regular solution model, and the extended Hildebrand or Hansen solubility approaches in predicting the solubility of naphthalene in both polar and nonpolar solvents at 40 degrees C. While all models correctly predict the solubility in nonpolar and moderately polar solvents, a substantial improvement is achieved by Huyskens' model, particularly in alcohols. This improvement originates from the correct description of the entropy effects as well as of the hydrophobic effects in the particular case of the alcohols. The model necessitates the knowledge of only one parameter not known a priori, i.e., the naphthalene modified nonspecific solubility parameter, the value of which is deduced from its solubility in hexane.

  5. Simple and mixed complexes of copper(II) with 8-hydroxyquinoline derivatives and amino acids: Characterization in solution and potential biological implications.

    Science.gov (United States)

    Sgarlata, Carmelo; Arena, Giuseppe; Bonomo, Raffaele P; Giuffrida, Alessandro; Tabbì, Giovanni

    2018-03-01

    Copper(II) complexes with 8-hydroxyquinoline (8-HQ) and two 8-HQ derivatives, namely clioquinol (CQ) and 5,7-dichloro-2-[(dimethylamino)methyl]quinolin-8-ol (PBT2), were investigated in organic and, where feasible, in aqueous solutions. This class of compounds is of particular interest in neurological disorders since they may act as metal-protein attenuating compounds and may help redistributing metal ions and restoring intracellular metal reserves, which are often perturbed in neurological patients. Several techniques, like potentiometry, UV-Vis absorption, electron paramagnetic resonance (EPR), cyclic voltammetry and electrospray ionisation-mass spectrometry (ESI-MS), were used to obtain information on both the formation of copper(II) complexes in solution as well as on the structure of their species. Multi-wavelength treatment of UV-Vis data clearly indicated the formation of both [Cu(PBT2)] + and [Cu(PBT2) 2 ] species; the speciation was also supported by ESI-MS data. The EPR results showed that the mono- and bis-copper(II) complexes with PBT2 have square-based pyramidal structures while the bis-copper (II) complexes with CQ or 8-HQ have square-planar o pseudo-octahedral geometries. The formation of copper(II) ternary complexes with 8-HQ, CQ and PBT2 and some selected neurotransmitters (glycine, glutamate and histidine) is also reported. Except for the copper(II) ternary complex with PBT2 and His, almost all ternary complexes have molecular geometries, which are not different from those of the bis-complexes. Interestingly the ternary copper(II) complexes, containing CQ, 8-HQ and PBT2 and glycine, glutamate or histidine turned out to be more soluble in aqueous solution than their binary complexes with parent 8-HQ derivatives; the copper(II) complexes can also be reduced more easily than their parent bis-complexes. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. A family of four stages embedded explicit six-step methods with eliminated phase-lag and its derivatives for the numerical solution of the second order problems

    Science.gov (United States)

    Simos, T. E.

    2017-11-01

    A family of four stages high algebraic order embedded explicit six-step methods, for the numerical solution of second order initial or boundary-value problems with periodical and/or oscillating solutions, are studied in this paper. The free parameters of the new proposed methods are calculated solving the linear system of equations which is produced by requesting the vanishing of the phase-lag of the methods and the vanishing of the phase-lag's derivatives of the schemes. For the new obtained methods we investigate: • Its local truncation error (LTE) of the methods.• The asymptotic form of the LTE obtained using as model problem the radial Schrödinger equation.• The comparison of the asymptotic forms of LTEs for several methods of the same family. This comparison leads to conclusions on the efficiency of each method of the family.• The stability and the interval of periodicity of the obtained methods of the new family of embedded finite difference pairs.• The applications of the new obtained family of embedded finite difference pairs to the numerical solution of several second order problems like the radial Schrödinger equation, astronomical problems etc. The above applications lead to conclusion on the efficiency of the methods of the new family of embedded finite difference pairs.

  7. Adsorption of Zn(2+) and Ni(2+) in a binary aqueous solution by biosorbents derived from sawdust and water hyacinth (Eichhornia crassipes).

    Science.gov (United States)

    Gwenzi, Willis; Musarurwa, Tinashe; Nyamugafata, Phillip; Chaukura, Nhamo; Chaparadza, Allen; Mbera, Sharron

    2014-01-01

    The Zn(2+) and Ni(2+) adsorption capacities of six biosorbents derived from water hyacinth (Eichhornia crassipes) (WH) and sawdust (SD) were investigated, with activated carbon as the control. The biosorbents were raw biomass (WH, SD), charred WH (BWH) and SD and sulphonated bio-chars of WH and SD. The effect of the initial solution pH and Zn(2+) and Ni(2+) concentrations on adsorption capacity was studied, and adsorption isotherms for Zn(2+) and Ni(2+) evaluated. The initial solution pH significantly influenced adsorption (p adsorption on all biosorbents. The adsorption capacities of the biosorbents were statistically (p ≤ 0.05) similar to or higher than that of activated carbon. The effects of pyrolysis and bio-char sulphonation on adsorption were inconsistent and dependent on biomass type; in most cases bio-char was a better biosorbent than the original biomass, while sulphonation resulted in less or comparable adsorption. Adsorption data obeyed at least one of three isotherms (linear, Langmuir and Freundlich) (r(2) = 0.90-0.995, p < 0.05). The study revealed that low-cost biosorbents may be used as alternatives to activated carbon in applications including selective separation of Zn(2+) from multi-metal ion solutions containing Ni(2+), and water and wastewater treatment.

  8. Adsorption of Cd(II) from aqueous solutions by rape straw biochar derived from different modification processes.

    Science.gov (United States)

    Li, Bing; Yang, Lan; Wang, Chang-Quan; Zhang, Qing-Pei; Liu, Qing-Cheng; Li, Yi-Ding; Xiao, Rui

    2017-05-01

    In order to deal with cadmium (Cd(II)) pollution, three modified biochar materials: alkaline treatment of biochar (BC-NaOH), KMnO 4 impregnation of biochar (BC-MnO x ) and FeCl 3 magnetic treatment of biochar (BC-FeO x ), were investigated. Nitrogen adsorption-desorption isotherms, Fourier transform infrared spectroscopy (FTIR), Boehm titration, and scanning electron microscopy (SEM) were used to determine the characteristics of adsorbents and explore the main adsorption mechanism. The results show that manganese oxide particles are carried successfully within the biochar, contributing to micropore creation, boosting specific surface area and forming innersphere complexes with oxygen-containing groups, while also increasing the number of oxygen-containing groups. The adsorption sites created by the loaded manganese oxide, rather than specific surface areas, play the most important roles in cadmium adsorption. Batch adsorption experiments demonstrate a Langmuir model fit for Cd(II), and BC-MnO x provided the highest sorption capacity (81.10 mg g -1 ). The sorption kinetics of Cd(II) on adsorbents follows pseudo-second-order kinetics and the adsorption rate of the BC-MnO x material was the highest (14.46 g (mg·h) -1 ). Therefore, biochar modification methods involving KMnO 4 impregnation may provide effective ways of enhancing Cd(II) removal from aqueous solutions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Stability of the Stevia-Derived Sweetener Rebaudioside A in Solution as Affected by Ultraviolet Light Exposure.

    Science.gov (United States)

    Zhang, Jiewen; Bell, Leonard N

    2017-04-01

    Rebaudioside A is a natural noncaloric high-potency sweetener extracted from the leaves of Stevia rebaudiana. With rebaudioside A use increasing in foods, understanding the factors affecting its stability is necessary. This project evaluated the degradation rate constants of rebaudioside A in water, 0.1 M phosphate buffer, and 0.1 M citrate buffer at pH 3 and 7 as a function of ultraviolet (UV) light intensity (365 nm, 0 μW/cm 2 for dark conditions, 27 μW/cm 2 for low intensity, and 190 μW/cm 2 for high intensity) at 32.5 °C. Rebaudioside A stability was adversely affected by light exposure. The pseudo-1st-order degradation rate constants increased significantly (P < 0.05) with increasing light intensity in all solutions. Under dark conditions, rebaudioside A in phosphate buffers was more susceptible to breakdown than in water and citrate buffers at both pH levels. However, exposure to UV light resulted in rebaudioside A degradation occurring approximately 10 times faster in citrate than in phosphate buffers at both pH levels. The sensitivity of rebaudioside A to UV light was greater in citrate buffers than in water or phosphate buffers. The use of light-protective packaging for beverages containing rebaudioside A will improve its stability. © 2017 Institute of Food Technologists®.

  10. Technology-derived storage solutions for stabilizing insulin in extreme weather conditions I: the ViViCap-1 device.

    Science.gov (United States)

    Pfützner, Andreas; Pesach, Gidi; Nagar, Ron

    2017-06-01

    Injectable life-saving drugs should not be exposed to temperatures 30°C/86°F. Frequently, weather conditions exceed these temperature thresholds in many countries. Insulin is to be kept at 4-8°C/~ 39-47°F until use and once opened, is supposed to be stable for up to 31 days at room temperature (exception: 42 days for insulin levemir). Extremely hot or cold external temperature can lead to insulin degradation in a very short time with loss of its glucose-lowering efficacy. Combined chemical and engineering solutions for heat protection are employed in ViViCap-1 for disposable insulin pens. The device works based on vacuum insulation and heat consumption by phase-change material. Laboratory studies with exposure of ViViCap-1 to hot outside conditions were performed to evaluate the device performance. ViViCap-1 keeps insulin at an internal temperature phase-change process and 'recharges' the device for further use. ViViCap-1 performed within its specifications. The small and convenient device maintains the efficacy and safety of using insulin even when carried under hot weather conditions.

  11. Decontamination of Hg(II) from aqueous solution using polyamine-co-thiourea inarched chitosan gel derivatives.

    Science.gov (United States)

    Liang, Wen; Li, Manlin; Zhang, Zengqiang; Jiang, Yahui; Awasthi, Mukesh Kumar; Jiang, Shuncheng; Li, Ronghua

    2018-07-01

    Ethylenediamine (EDA), triethylenetetramine (TETA) and tetraethylenepentamine (TEPA) had been successfully introduced into the structure of thiourea (TC) modified chitosan (CS) by using formaldehyde as linkage, respectively. The resulted materials, TC-CS, TC-EDA-CS, TC-TETA-CS, and TC-TEPA-CS were characterized and employed as adsorbents in batch experiment for the Hg(II) removal. We have found the modification enhanced the Hg(II) adsorption significantly in comparison with raw CS. Hg(II) adsorption amounts for all adsorbents increased gradually and reached maxima at pH≥4.0. The adsorption of Hg(II) achieved an equilibrium state within 12h with the process drove by the pseudo-second-order model. The ionic strength had no remarkable inhibition effect on Hg(II) adsorption. While the Hg(II) adsorption capacities of the adsorbents were strongly related with the modifier types and the length of the incorporating amino ligands. Langmuir model described Hg(II) adsorption well with the maximum adsorption capacities of prepared adsorbents in order of TC-EDA-CS (217.1mg/g)>TC-CS (164.8mg/g)>TC-TETA-CS (149.7mg/g)>TC-TEPA-CS (140.6mg/g) at room temperature. The FT-IR and XPS investigations implied that Hg(II) ion adsorption mechanism was characterized by a complexation reaction process. Adsorbents could be readily regenerated and had great reusability potential in Hg(II) ions capture from aqueous solution. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Interaction of derived polymers from pyrrole with biocompatible solutions; Interaccion de polimeros derivados de pirrol con soluciones biocompatibles

    Energy Technology Data Exchange (ETDEWEB)

    Lopez G, O. G.

    2010-07-01

    This work presents a study about the synthesis by plasma, the electric properties and superficial interaction of polymers derived from pyrrole doped with Iodine with potential use as bio material. Poly-pyrrole is a semiconductor and biocompatible polymer with potential application in the development of artificial muscles and implants where the electric interaction between cells and material is an important variable. The syntheses were made at 13.5 MHz in a glass tubular reactor of 1500 cm{sup 3} with electrodes of 6.5 cm diameter and stainless steel flanges. An electrode was connected to the RF terminal of the power supply that is combined with a matching coupling resistance. The monomer and dopant used in this work were pyrrole and Iodine respectively, in closed containers. They were vaporized and injected separately into the reactor at room temperature and 0.1 mbar. The vapors of the reagents mixed freely in the reactor. The synthesis time was 240 min at 40, 60, 80 and 100 W. The polymers were obtained as thin films adhered to the reactor walls. The films were washed and swollen with distilled water and removed from the reactor walls with a small spatula. The polymers were irradiated with gamma rays at 18 and 22 KGy. Due to the fact that the doses are cumulative, the final dose applied was 40 KGy. The polymers characterization was carried out by Fourier Transform Infrared Spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy, contact angle, electrical conductivity and X-ray diffraction. The analyses indicates that the polymers have very similar structure in almost the entire power range, showing C-O, C=C, C-H, O-H, N-H bonds with a predominantly amorphous structure. The TGA analyses showed that the material has 4 or 5 loses of material. The first one starts after that 115 C except for the material irradiated at 40 KGy, this one begins in 87 C, the second one is in the interval of 196 and 295 C, the third one between 311 and 500 C, and the

  13. A numerical solution for a variable-order reaction-diffusion model by using fractional derivatives with non-local and non-singular kernel

    Science.gov (United States)

    Coronel-Escamilla, A.; Gómez-Aguilar, J. F.; Torres, L.; Escobar-Jiménez, R. F.

    2018-02-01

    A reaction-diffusion system can be represented by the Gray-Scott model. The reaction-diffusion dynamic is described by a pair of time and space dependent Partial Differential Equations (PDEs). In this paper, a generalization of the Gray-Scott model by using variable-order fractional differential equations is proposed. The variable-orders were set as smooth functions bounded in (0 , 1 ] and, specifically, the Liouville-Caputo and the Atangana-Baleanu-Caputo fractional derivatives were used to express the time differentiation. In order to find a numerical solution of the proposed model, the finite difference method together with the Adams method were applied. The simulations results showed the chaotic behavior of the proposed model when different variable-orders are applied.

  14. Environmental Informatics and Soft Computing Paradigm: Processing of Cocos Nucifera Shell Derived Activated Carbon for Treatment of Distillery Spent Wash—A Solution to Environmental Issue

    Directory of Open Access Journals (Sweden)

    N. B. Raut

    2014-01-01

    Full Text Available Soft computing techniques are very much needed to design the environmental related systems these days. Soft computing (SC is a set of computational methods that attempt to determine satisfactory approximate solutions to find a model for real-world problems. Techniques such as artificial neural networks, fuzzy logic, and genetic algorithms can be used in solving complex environmental problems. Self-organizing feature map (SOFM model is proposed in monitoring and collecting of the data that are real time and static datasets acquired through pollution monitoring sensors and stations in the distilleries. In the environmental monitoring systems the ultimate requirement is to establish controls for the sensor based data acquisition systems and needs interactive and dynamic reporting services. SOFM techniques are used for data analysis and processing. The processed data is used for control system which even feeds to the treatment systems. Cocos nucifera activated carbon commonly known as coconut shell activated carbon (CSC was utilized for the treatment of distillery spent wash. Batch and column studies were done to investigate the kinetics and effect of operating parameter on the rate of adsorption. Since the quantum of spent water generated from the sugar industry allied distillery units is huge, this low cost adsorbent is found to be an attractive economic option. Equilibrium adsorption date was generated to plot Langmuir and Tempkin adsorption isotherm. The investigation reveals that though with lower adsorption capacities CSC seems to be technically feasible solution for treating sugar distillery spent. Efforts are made in this paper to build informatics for derived activated carbon for solving the problem of treatment of distillery spent wash. Capsule. Coconut shell derived activated carbon was synthesized, characterized, and successfully employed as a low cost adsorbent for treatment of distillery spent wash.

  15. Aromatic hydrazones derived from nicotinic acid hydrazide as fluorimetric pH sensing molecules: Structural analysis by computational and spectroscopic methods in solid phase and in solution

    Science.gov (United States)

    Benković, T.; Kenđel, A.; Parlov-Vuković, J.; Kontrec, D.; Chiş, V.; Miljanić, S.; Galić, N.

    2018-02-01

    Structural analyses of aroylhydrazones were performed by computational and spectroscopic methods (solid state NMR, 1 and 2D NMR spectroscopy, FT-IR (ATR) spectroscopy, Raman spectroscopy, UV-Vis spectrometry and spectrofluorimetry) in solid state and in solution. The studied compounds were N‧-(2,3-dihydroxyphenylmethylidene)-3-pyridinecarbohydrazide (1), N‧-(2,5-dihydroxyphenylmethylidene)-3-pyridinecarbohydrazide (2), N‧-(3-chloro-2-hydroxy-phenylmethylidene)-3-pyridinecarbohydrazide (3), and N‧-(2-hydroxy-4-methoxyphenyl-methylidene)-3-pyridinecarbohydrazide (4). Both in solid state and in solution, all compounds were in ketoamine form (form I, sbnd COsbnd NHsbnd Ndbnd Csbnd), stabilized by intramolecular H-bond between hydroxyl proton and nitrogen atom of the Cdbnd N group. In solid state, the Cdbnd O group of 1-4 were involved in additional intermolecular H-bond between closely packed molecules. Among hydrazones studied, the chloro- and methoxy-derivatives have shown pH dependent and reversible fluorescence emission connected to deprotonation/protonation of salicylidene part of the molecules. All findings acquired by experimental methods (NMR, IR, Raman, and UV-Vis spectra) were in excellent agreement with those obtained by computational methods.

  16. Aromatic hydrazones derived from nicotinic acid hydrazide as fluorimetric pH sensing molecules: Structural analysis by computational and spectroscopic methods in solid phase and in solution.

    Science.gov (United States)

    Benković, T; Kenđel, A; Parlov-Vuković, J; Kontrec, D; Chiş, V; Miljanić, S; Galić, N

    2018-02-05

    Structural analyses of aroylhydrazones were performed by computational and spectroscopic methods (solid state NMR, 1 and 2D NMR spectroscopy, FT-IR (ATR) spectroscopy, Raman spectroscopy, UV-Vis spectrometry and spectrofluorimetry) in solid state and in solution. The studied compounds were N'-(2,3-dihydroxyphenylmethylidene)-3-pyridinecarbohydrazide (1), N'-(2,5-dihydroxyphenylmethylidene)-3-pyridinecarbohydrazide (2), N'-(3-chloro-2-hydroxy-phenylmethylidene)-3-pyridinecarbohydrazide (3), and N'-(2-hydroxy-4-methoxyphenyl-methylidene)-3-pyridinecarbohydrazide (4). Both in solid state and in solution, all compounds were in ketoamine form (form I, CONHNC), stabilized by intramolecular H-bond between hydroxyl proton and nitrogen atom of the CN group. In solid state, the CO group of 1-4 were involved in additional intermolecular H-bond between closely packed molecules. Among hydrazones studied, the chloro- and methoxy-derivatives have shown pH dependent and reversible fluorescence emission connected to deprotonation/protonation of salicylidene part of the molecules. All findings acquired by experimental methods (NMR, IR, Raman, and UV-Vis spectra) were in excellent agreement with those obtained by computational methods. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. ZIF-67 derived porous Co3O4 hollow nanopolyhedron functionalized solution-gated graphene transistors for simultaneous detection of glucose and uric acid in tears.

    Science.gov (United States)

    Xiong, Can; Zhang, Tengfei; Kong, Weiyu; Zhang, Zhixiang; Qu, Hao; Chen, Wei; Wang, Yanbo; Luo, Linbao; Zheng, Lei

    2018-03-15

    Biomarkers in tears have attracted much attention in daily healthcare sensing and monitoring. Here, highly sensitive sensors for simultaneous detection of glucose and uric acid are successfully constructed based on solution-gated graphene transistors (SGGTs) with two separate Au gate electrodes, modified with GOx-CHIT and BSA-CHIT respectively. The sensitivity of the SGGT is dramatically improved by co-modifying the Au gate with ZIF-67 derived porous Co 3 O 4 hollow nanopolyhedrons. The sensing mechanism for glucose sensor is attributed to the reaction of H 2 O 2 generated by the oxidation of glucose near the gate, while the sensing mechanism for uric acid is due to the direct electro-oxidation of uric acid molecules on the gate. The optimized glucose and uric acid sensors show the detection limits both down to 100nM, far beyond the sensitivity required for non-invasive detection of glucose and uric acid in tears. The glucose and uric acid in real tear samples was quantitatively detected at 323.2 ± 16.1μM and 98.5 ± 16.3μM by using the functionalized SGGT device. Due to the low-cost, high-biocompatibility and easy-fabrication features of the ZIF-67 derived porous Co 3 O 4 hollow nanopolyhedron, they provide excellent electrocatalytic nanomaterials for enhancing sensitivity of SGGTs for a broad range of disease-related biomarkers. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Synthesis, electrochemical, spectrophotometric and potentiometric studies of two azo-compounds derived from 4-amino-2-methylquinoline in ethanolic-aqueous buffered solutions

    Energy Technology Data Exchange (ETDEWEB)

    El-Attar, Mona A.; Ghoneim, Mohamed M. [Analytical Chemistry Research Unit, Chemistry Department, Tanta University (Egypt); Ismail, Iqbal M., E-mail: maema.2011@yahoo.com [Chemistry Department, Faculty of Science, King Abdul Aziz University, Jeddah (Saudi Arabia)

    2012-08-15

    Two azo-compounds, 2-methyl-4-(5-amino-2-hydroxy-phenylazo)-quinoline (2) and 2-methyl-4-(2-hydroxy-5-nitrophenylazo)-quinoline, derived from 4-amino-2-methylquinoline were synthesized. Their chemical structures were characterized and confirmed by means of elemental chemical analysis, infrared (IR) spectroscopy, {sup 1}H nuclear magnetic resonance (NMR) and mass spectrometry (MS). The electrochemical behavior of the starting compound (4-amino-2-methylquinoline) and of the two synthesized azo-derivatives was studied at the mercury electrode in the B-R universal buffer at various pH values (2-11.5) containing 40% (v/v) ethanol using dc-polarography, cyclic voltammetry and controlled-potential coulometry. Their electrode reaction pathways were elucidated and discussed. The dissociation constants (pKa) of the examined compounds, stability constants and stoichiometry of their complexes in solution with some transition metal ions (Co(II), Ni(II), Cu(II), La(III) and UO{sup 2+}{sub 2}) were determined. (author)

  19. Thermodynamics and kinetics of adsorption of Cu(II) from aqueous solutions onto a new cation exchanger derived from tamarind fruit shell

    Energy Technology Data Exchange (ETDEWEB)

    Anirudhan, T.S. [Department of Chemistry, University of Kerala, Kariavattom, Trivandrum 695 581 (India)], E-mail: tsani@rediffmail.com; Radhakrishnan, P.G. [Department of Chemistry, University of Kerala, Kariavattom, Trivandrum 695 581 (India)

    2008-04-15

    A novel cation exchanger (TFS-CE) having carboxylate functionality was prepared through graft copolymerization of hydroxyethylmethacrylate onto tamarind fruit shell (TFS) in the presence of N,N'-methylenebisacrylamide as a cross-linking agent using K{sub 2}S{sub 2}O{sub 8}/Na{sub 2}S{sub 2}O{sub 3} initiator system, followed by functionalisation. The TFS-CE was used for the removal of Cu(II) from aqueous solutions. At fixed solid/solution ratio the various factors affecting adsorption such as pH, initial concentration, contact time, and temperature were investigated. Kinetic experiments showed that the amount of Cu(II) adsorbed increased with increase in Cu(II) concentration and equilibrium was attained at 1 h. The kinetics of adsorption follows pseudo-second-order model and the rate constant increases with increase in temperature indicating endothermic nature of adsorption. The Arrhenius and Eyring equations were used to obtain the kinetic parameters such as activation energy (E{sub a}) and enthalpy ({delta}H'), entropy ({delta}S') and free energy ({delta}G') of activation for the adsorption process. The value of E{sub a} for adsorption was found to be 10.84 kJ . mol{sup -1} and the adsorption involves diffusion controlled process. The equilibrium data were well fitted to the Langmuir isotherm. The maximum adsorption capacity for Cu(II) was 64 . 10 mg . g{sup -1} at T = 303 K. The thermodynamic parameters such as changes in free energy ({delta}G{sup 0}), enthalpy ({delta}H{sup 0}), and entropy ({delta}S{sup 0}) were derived to predict the nature of adsorption process. The isosteric heat of adsorption increases with increase in surface loading indicating some lateral interactions between the adsorbed metal ions.

  20. ⁹⁹mTc pyrene derivative complex causes double-strand breaks in dsDNA mainly through cluster-mediated indirect effect in aqueous solution.

    Directory of Open Access Journals (Sweden)

    Wei-Ju Chung

    Full Text Available Radiation therapy for cancer patients works by ionizing damage to nuclear DNA, primarily by creating double-strand breaks (DSB. A major shortcoming of traditional radiation therapy is the set of side effect associated with its long-range interaction with nearby tissues. Low-energy Auger electrons have the advantage of an extremely short effective range, minimizing damage to healthy tissue. Consequently, the isotope ⁹⁹mTc, an Auger electron source, is currently being studied for its beneficial potential in cancer treatment. We examined the dose effect of a pyrene derivative ⁹⁹mTc complex on plasmid DNA by using gel electrophoresis in both aqueous and methanol solutions. In aqueous solutions, the average yield per decay for double-strand breaks is 0.011±0.005 at low dose range, decreasing to 0.0005±0.0003 in the presence of 1 M dimethyl sulfoxide (DMSO. The apparent yield per decay for single-strand breaks (SSB is 0.04±0.02, decreasing to approximately a fifth with 1 M DMSO. In methanol, the average yield per decay of DSB is 0.54±0.06 and drops to undetectable levels in 2 M DMSO. The SSB yield per decay is 7.2±0.2, changing to 0.4±0.2 in the presence of 2 M DMSO. The 95% decrease in the yield of DSB in DMSO indicates that the main mechanism for DSB formation is through indirect effect, possibly by cooperative binding or clustering of intercalators. In the presence of non-radioactive ligands at a near saturation concentration, where radioactive Tc compounds do not form large clusters, the yield of SSB stays the same while the yield of DSB decreases to the value in DMSO. DSBs generated by ⁹⁹mTc conjugated to intercalators are primarily caused by indirect effects through clustering.

  1. NH+-F hydrogen bonding in a fluorinated "proton sponge" derivative: integration of solution, solid-state, gas-phase, and computational studies.

    Science.gov (United States)

    Scerba, Michael T; Leavitt, Christopher M; Diener, Matthew E; DeBlase, Andrew F; Guasco, Timothy L; Siegler, Maxime A; Bair, Nathaniel; Johnson, Mark A; Lectka, Thomas

    2011-10-07

    We report detailed studies on the characterization of an intramolecular NH-F hydrogen bond formed within a fluorinated "proton sponge" derivative. An ammonium ion, generated from 8-fluoro-N,N-dimethylnaphthalen-1-amine, serves as a charged hydrogen bond donor to a covalently bound fluorine appropriately positioned on the naphthalene skeleton. Potentiometric titrations of various N,N-dimethylnaphthalen-1-amines demonstrate a significant increase in basicity when hydrogen bonding is possible. X-ray crystallography reveals that NH-F hydrogen bonding in protonated 8-fluoro-N,N-dimethylnaphthalen-1-amine is heavily influenced by ion pairing in the solid state; bifurcated and trifurcated hydrogen bonds are formed depending on the counterion utilized. Compelling evidence of hydrogen bonding in the 8-fluoro-N,N-dimethylnaphthyl-1-ammonium cation is provided by gas-phase cryogenic vibrational photodissociation spectroscopy. Solution-phase infrared spectroscopy provides complementary results, and the frequencies of the N-H stretching mode in both phases are in excellent agreement with the computed vibrational spectra. NMR analysis of protonated 8-fluoro-N,N-dimethylnaphthalen-1-amine demonstrates significant H-F coupling between the N-H hydrogen and fluorine that cannot be attributed to long-range, through-bond interactions; the couplings correlate favorably with calculated values. The results obtained from these experiments are congruent with the formation of an NH-F hydrogen bond upon protonation of 8-fluoro-N,N-dimethylnaphthalen-1-amine.

  2. Novel magnetic porous carbon spheres derived from chelating resin as a heterogeneous Fenton catalyst for the removal of methylene blue from aqueous solution.

    Science.gov (United States)

    Ma, Junjun; Zhou, Lincheng; Dan, Wenfeng; Zhang, He; Shao, Yanming; Bao, Chao; Jing, Lingyun

    2015-05-15

    Porous magnetic carbon spheres (MCS) were prepared from carbonized chelating resin composites derived from ethylenediaminetetraacetic acid-modified macroporous polystyrene (PS-EDTA) resin, and then loaded with iron composites via ion exchange. The resulting composites were characterized for this study using X-ray diffraction, MÖssbauer spectroscopy, and Raman spectroscopy, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller surface area method, scanning electron microscopy, and vibrating sample magnetometry. The porous magnetic carbon spheres were then used, in the existence of H2O2 and NH2OH, with a view to remove methylene blue from the aqueous solution by catalyze a heterogeneous Fenton reaction. Results indicated excellent removal rates and removal efficiency for this catalytic system. Optimal degradation was achieved (nearly 100% within 10 min) using initial concentrations of 5 mmol H2O2 L(-1), 2.5 mmol L(-1) NH2OH and 40 mg L(-1) methylene blue. The catalyst retained its activity after six reuses, indicating strong stability and reusability. Porosity of the catalyst contributed to its high activity, suggesting its potential application for the industrial treatment of wastewater. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Nucleation and mesostrain influence on percolating critical currents of solution derived YBa{sub 2}Cu{sub 3}O{sub 7} superconducting thin films

    Energy Technology Data Exchange (ETDEWEB)

    Obradors, X., E-mail: Xavier.obradors@icmab.es [Institut de Ciencia de Materials de Barcelona (ICMAB-CSIC), Campus Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Martinez-Julian, F.; Zalamova, K.; Vlad, V.R.; Pomar, A.; Palau, A.; Llordes, A.; Chen, H.; Coll, M.; Ricart, S.; Mestres, N.; Granados, X.; Puig, T. [Institut de Ciencia de Materials de Barcelona (ICMAB-CSIC), Campus Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Rikel, M. [Nexans Superconductors, 50354 Huerth (Germany)

    2012-11-20

    After briefly reviewing the present understanding of the nucleation process of YBCO films, a new approach is presented to enhance the stability of c-axis nucleation in epitaxial chemical solution deposited YBCO thin films derived from TFA precursors. We show that with silver addition to the TFA precursor c-axis nucleation can be reached in a wide range of temperature thus keeping high percolating J{sub c}. We argue that silver reduces supersaturation and makes more stable the c-axis nuclei without modifying T{sub c}. Additional advantages of silver addition are an enhanced surface smootheness and a reduced porosity of the YBCO films. The second reported topic relates to the discovery of an adverse relationship between percolating J{sub c} and YBCO films mesostrain, as determined through X-ray diffraction line broadening. We show that mesostrain is enhanced in processes leading to inefficient strain healing at grain boundaries, for instance annealing times too short or growth temperatures too low. It is suggested that the strained regions at the low angle grain boundaries lead to a weak link behavior which can be microscopically understood on the basis of pair formation prevention, as proposed by the bond contraction pairing model.

  4. Investigation of the luminescent properties of terbium-anthranilate complexes and application to the determination of anthranilic acid derivatives in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Arnaud, N.; Georges, J

    2003-01-10

    The luminescent properties of terbium complexes with furosemide (FR), flufenamic (FF) acid, tolfenamic (TF) acid and mefenamic (MF) acid have been investigated in aqueous solutions. For all four compounds, complexation occurs when the carboxylic acid of the aminobenzoic group is dissociated and is greatly favoured in the presence of trioctylphosphine oxide as co-ligand and Triton X-100 as surfactant. Under optimum conditions, luminescence of the lanthanide ion is efficiently sensitised and the lifetime of the {sup 5}D{sub 4} resonance level of terbium in the complex is ranging between 1 and 1.9 ms, against 0.4 ms for the aqua ion. The sensitivity of the method for the determination of anthranilic acid derivatives is improved by one to two orders of magnitude with respect to that achieved using native fluorescence or terbium-sensitised luminescence in methanol. The limits of detection are 2x10{sup -10}, 5x10{sup -10} and 2x10{sup -9} mol l{sup -1} for flufenamic acid, furosemide and tolfenamic acid, and mefenamic acid, respectively, with within-run RSD values of less than 1%. The method has been applied to the determination of flufenamic acid in spiked calf sera with and without sample pretreatment. Depending on the method and the analyte concentration, the recovery was ranging between 83 and 113% and the lowest concentration attainable in serum samples was close to 1x10{sup -7} mol l{sup -1}.

  5. The Influence of Prebiotic Arabinoxylan Oligosaccharides on Microbiota Derived Uremic Retention Solutes in Patients with Chronic Kidney Disease: A Randomized Controlled Trial

    Science.gov (United States)

    Evenepoel, Pieter; de Loor, Henriette; Delcour, Jan A.; Courtin, Christophe M.; Kuypers, Dirk; Augustijns, Patrick; Verbeke, Kristin; Meijers, Björn

    2016-01-01

    The colonic microbial metabolism is a key contributor to uremic retention solutes accumulating in patients with CKD, relating to adverse outcomes and insulin resistance. Whether prebiotics can reduce intestinal generation of these microbial metabolites and improve insulin resistance in CKD patients not yet on dialysis remains unknown. We performed a randomized, placebo-controlled, double-blind, cross-over study in 40 patients with eGFR between 15 and 45 ml/min/1.73 m2. Patients were randomized to sequential treatment with prebiotic arabinoxylan oligosaccharides (AXOS) (10 g twice daily) and maltodextrin for 4 weeks, or vice versa, with a 4-week wash-out period between both intervention periods. Serum levels and 24h urinary excretion of p-cresyl sulfate, p-cresyl glucuronide, indoxyl sulfate, trimethylamine N-oxide and phenylacetylglutamine were determined at each time point using liquid chromatography—tandem mass spectrometry. In addition, insulin resistance was estimated by the homeostatic model assessment (HOMA-IR). A total of 39 patients completed the study. We observed no significant effect of AXOS on serum p-cresyl sulfate (P 0.42), p-cresyl glucuronide (P 0.59), indoxyl sulfate (P 0.70) and phenylacetylglutamine (P 0.41) and a small, albeit significant decreasing effect on serum trimethylamine N-oxide (P 0.04). There were neither effect of AXOS on 24h urinary excretion of p-cresyl sulfate (P 0.31), p-cresyl glucuronide (P 0.23), indoxyl sulfate (P 0.87) and phenylacetylglutamine (P 0.43), nor on 24h urinary excretion of trimethylamine N-oxide (P 0.97). In addition, we observed no significant change in HOMA-IR (P 0.93). In conclusion, we could not demonstrate an influence of prebiotic AXOS on microbiota derived uremic retention solutes and insulin resistance in patients with CKD not yet on dialysis. Further study is necessary to elucidate whether prebiotic therapy with other characteristics, higher cumulative exposure or in different patient populations may

  6. Formation, spectroscopic characterization, and solution stability of an [Fe4S4]2+ cluster derived from β-cyclodextrin dithiolate.

    Science.gov (United States)

    Lo, Wayne; Zhang, Ping; Ling, Chang-Chun; Huang, Shaw; Holm, R H

    2012-09-17

    The formation and solution properties, including stability in mixed aqueous-Me(2)SO media, have been investigated for an [Fe(4)S(4)](2+) cluster derived from β-cyclodextrin (CD) dithiolate. Clusters of the type [Fe(4)S(4)(SAr)(4)](2-) (Ar = Ph, C(6)H(4)-3-F) are generated in Me(2)SO by redox reactions of [Fe(4)S(4)(SEt)(4)](2-) with 2 equiv of ArSSAr. An analogous reaction with the intramolecular disulfide of 6(A),6(D)-(3-NHCOC(6)H(4)-1-SH)(2)-6(A),6(D)-dideoxy-β-cyclodextrin (14), whose synthesis is described, affords a completely substituted cluster formulated as [Fe(4)S(4){β-CD-(1,3-NHCOC(6)H(4)S)(2)}(2)](2-) (15). Ligand binding is indicated by a circular dichroism spectrum and also by UV-visible and isotropically shifted (1)H NMR spectra and redox behavior convincingly similar to [Fe(4)S(4)(SPh)(4)](2-). One formulation of 15 is a single cluster to which two dithiolates are bound, each in bidentate coordination. With there being no proven precedent for this binding mode, we show that the cluster [Fe(4)S(4)(S(2)-m-xyl)(2)](2-) is a single cubane whose m-xylyldithiolate ligands are bound in a bidentate arrangement. This same structure type was proposed for a cluster formulated as [Fe(4)S(4){β-CD-(1,3-SC(6)H(4)S)(2)}(2)](2-) (16; Kuroda et al. J. Am. Chem. Soc.1988, 110, 4049-4050) and reported to be water-stable. Clusters 15 and 16 are derived from similar ligands differing only in the spacer group between the thiolate binding site and the CD platform. In our search for clusters stable in aqueous or organic-aqueous mixed solvents that are potential candidates for the reconstitution of scaffold proteins implicated in cluster biogenesis, 15 is the most stable cluster that we have thus far encountered under anaerobic conditions in the absence of added ligand.

  7. Application of experimental design and derivative spectrophotometry methods in optimization and analysis of biosorption of binary mixtures of basic dyes from aqueous solutions.

    Science.gov (United States)

    Asfaram, Arash; Ghaedi, Mehrorang; Ghezelbash, Gholam Reza; Pepe, Francesco

    2017-05-01

    Simultaneous biosorption of malachite green (MG) and crystal violet (CV) on biosorbent Yarrowia lipolytica ISF7 was studied. An appropriate derivative spectrophotometry technique was used to evaluate the concentration of each dye in binary solutions, despite significant interferences in visible light absorbances. The effects of pH, temperature, growth time, initial MG and CV concentration in batch experiments were assessed using Design of Experiment (DOE) according to central composite second order response surface methodology (RSM). The analysis showed that the greatest biosorption efficiency (>99% for both dyes) can be obtained at pH 7.0, T=28°C, 24h mixing and 20mgL -1 initial concentrations for both MG and CV dyes. The quadratic constructed equation ability for fitting experimental data is judged based on criterions like R 2 values, significant p and lack-of-fit value strongly confirm its high adequacy and applicability for prediction of revel behavior of the system under study. The proposed model showed very high correlation coefficients (R 2 =0.9997 for CV and R 2 =0.9989 for MG), while supported by closeness of predicted and experimental value. A kinetic analysis was carried out, showing that for both dyes a pseudo-second order kinetic model adequately describes the available data. The Langmuir isotherm model in single and binary components has better performance for description of dyes biosorption with maximum monolayer biosorption capacity of 59.4 and 62.7mgg -1 in single component and 46.4 and 50.0mgg -1 for CV and MB in binary components, respectively. The surface structure of biosorbents and the possible biosorbents-dyes interactions between were also evaluated by Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The values of thermodynamic parameters including ΔG° and ΔH° strongly confirm which method is spontaneous and endothermic. Copyright © 2017. Published by Elsevier Inc.

  8. Biochars derived from wasted marine macro-algae (Saccharina japonica and Sargassum fusiforme) and their potential for heavy metal removal in aqueous solution.

    Science.gov (United States)

    Poo, Kyung-Min; Son, Eun-Bi; Chang, Jae-Soo; Ren, Xianghao; Choi, Yun-Jung; Chae, Kyu-Jung

    2018-01-15

    For the purpose of reusing wasted marine macro-algae generated during cultivation, harvesting, processing and selling processes, biochars derived from Saccharina japonica (known as kelp) and Sargassum fusiforme (known as hijikia) were characterized and their removal capacities for Cu, Cd, and Zn in aqueous solution were assessed. Feedstocks, S. japonica, S. fusiforme, and also pinewood sawdust as a control, were pyrolyzed at 250, 400, 500, 600 and 700 °C. In evaluating heavy metal removal capacities, SJB (S. japonica biochar) showed the best performance, with removal efficiencies of more than 98% for the three heavy metals when pyrolyzed at over 400 °C. SFB (S. fusiforme biochar) also showed good potential as an adsorbent, with removal efficiencies for the three heavy metals of more than 86% when pyrolyzed at over 500 °C. On the contrary, the maximum removal efficiencies of PSB (pinewood sawdust biochar) were 81%, 46%, and 47% for Cu, Cd, and Zn, respectively, even at 700 °C, the highest pyrolysis temperature. This demonstrates that marine macro-algae were advantageous in terms of production energy for removing heavy metals even at relatively low pyrolysis temperatures, compared with PSB. The excellent heavy metal adsorption capacities of marine macro-algae biochars were considered due to their higher pH and more oxygen-containing functional groups, although the specific surface areas of SJB and SFB were significantly lower than that of PSB. This research confirmed that the use of marine macro-algae as a heavy metal adsorbent was suitable not only in the removal of heavy metals, but also in terms of resource recycling and energy efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Evaluation of Amnion-derived Multipotent Progenitor (AMP) Cells and Amnion-derived Cellular Cytokine Solution (ST266) in Promoting Craniomaxillofacial Regenerative Bone Healing in Critical Size Calvarial Defects

    Science.gov (United States)

    2017-10-10

    NAVAL MEDICAL RESEARCH UNIT SAN ANTONIO EVALUATION OF AMNION-DERIVED MULTIPOTENT PROGENITOR ( AMP ) CELLS AND AMNION-DERIVED...Care International AMP Amnion-derived multipotent progenitor BCA Bicinchoninic acid BS/BV Bone surface/bone volume BV/TV Bone volume/tissue... AMP ) cells release ST266, a secretome of biomolecules identified as integral to the process of bone regeneration and angiogenesis. The AMP cells

  10. Bioreversible Derivatives of Phenol. 1. The Role of Human Serum Albumin as Related to the Stability and Binding Properties of Carbonate Esters with Fatty Acid-like Structures in Aqueous Solution and Biological Media

    Directory of Open Access Journals (Sweden)

    Claus Larsen

    2007-10-01

    Full Text Available With the overall objective of assessing the potential of utilizing plasma protein binding interactions in combination with the prodrug approach for improving the pharmacokinetics of drug substances, a series of model carbonate ester prodrugs of phenol, encompassing derivatives with fatty acid-like structures, were characterized in vitro. Stability of the derivatives was studied in aqueous solution, human serum albumin solution, human plasma, and rat liver homogenate at 37°C. Stability of the derivatives in aqueous solution varied widely, with half-lives ranging from 31 to 1.7 × 104 min at pH 7.4 and 37°C. The carbonate esters were subject to catalysis by plasma esterases except for the t-butyl and acetic acid derivatives, which were stabilized in both human plasma and human serum albumin solutions relative to buffer. In most cases, however, hydrolysis was accelerated in the presence of human serum albumin indicating that the derivatives interacted with the protein, a finding which was confirmed using the p-nitrophenyl acetate kinetic assay. Different human serum albumin binding properties of the phenol model prodrugs with fatty acid-like structure and neutral carbonate esters were observed. In the context of utilizing plasma protein binding in combination with the prodrug approach for optimizing drug pharmacokinetics, the esterase-like properties of human serum albumin towards the carbonate esters potentially allowing the protein to act as a catalyst of parent compound regenerations is interesting.

  11. In situ synthesis, electrochemical and quantum chemical analysis of an amino acid-derived ionic liquid inhibitor for corrosion protection of mild steel in 1M HCl solution

    International Nuclear Information System (INIS)

    Kowsari, E.; Arman, S.Y.; Shahini, M.H.; Zandi, H.; Ehsani, A.; Naderi, R.; PourghasemiHanza, A.; Mehdipour, M.

    2016-01-01

    Highlights: • Electrochemical analysis of effectiveness of an amino acid-derived ionic liquid inhibitor. • Quantum chemical analysis of effectiveness of an amino acid-derived ionic liquid inhibitor. • Finding correlation between electrochemical analysis and quantum chemical analysis. - Abstract: In this study, an amino acid-derived ionic liquid inhibitor, namely tetra-n-butyl ammonium methioninate, was synthesized and the role this inhibitor for corrosion protection of mild steel exposed to 1.0 M HCl was investigated using electrochemical, quantum and surface analysis. By taking advantage of potentiodynamic polarization, the inhibitory action of tetra-n-butyl ammonium methioninate was found to be mainly mixed-type with dominant anodic inhibition. The effectiveness of the inhibitor was also indicated using electrochemical impedance spectroscopy (EIS). Moreover, to provide further insight into the mechanism of inhibition, electrochemical noise (EN) and quantum chemical calculations of the inhibitor were performed.

  12. Thermodynamics of the sorption of 1,3,4-oxadiazole and 1,2,4,5-tetrazine derivatives from solutions on hypercrosslinked polystyrene

    Science.gov (United States)

    Saifutdinov, B. R.; Davankov, V. A.; Il'in, M. M.

    2014-03-01

    The sorption of a series of aromatic heterocycles on neutral hypercrosslinked polystyrene from maximally dilute acetonitrile and water.acetonitrile solutions of them is investigated by high-performance liquid chromatography in a range of column temperatures from 308 to 348 K at 5 K intervals. It is found that for all heterocycles, the logarithm of the retention factor versus the reciprocal of the temperature dependences can be approximated by linear functions with r 2 ≥ 0.999. It is established that the true compensation effect (which does not result from the correlation between enthalpy and entropy determination errors) occurs during the sorption of heterocycles on hypercrosslinked polystyrene from both acetonitrile and water-acetonitrile solutions. It is shown that in the compensation diagram, the points corresponding to sorbates are grouped together according to the type of sorbate-sorbent interactions. It is found that changes in the Gibbs energy, enthalpy, and entropy of sorption from acetonitrile solutions and for sorption from water-acetonitrile solutions are related to one another by linear dependences.

  13. Thiazol-4-one derivatives from the reaction of monosubstituted thioureas with maleimides: structures and factors determining the selectivity and tautomeric equilibrium in solution

    Directory of Open Access Journals (Sweden)

    Alena S. Pankova

    2016-11-01

    Full Text Available 2-(Alkyl(arylaminothiazol-4(5H-ones can regioselectively be prepared from monoalkyl(arylthioureas and maleimides. In solution, the former heterocycles exist in a tautomeric equilibrium with 2-(alkyl(aryliminothiazolidin-4-ones and the substituent on the exocyclic nitrogen atom governs the ratio of these tautomers. Isomers with the alkyl group in the endocyclic position can be obtained from N-methyl(ethylthioureas. 2D NMR spectroscopy and DFT calculations rationalize experimental results.

  14. Photoreversible switching of the lower critical solution temperature in a photoresponsive host-guest system of pillar[6]arene with triethylene oxide substituents and an azobenzene derivative.

    Science.gov (United States)

    Ogoshi, Tomoki; Kida, Kanako; Yamagishi, Tada-aki

    2012-12-12

    A new water-soluble thermoresponsive pillar[6]arene with triethylene oxide groups was synthesized. The pillar[6]arene showed lower critical solution temperature behavior in aqueous solution. Its clouding point was photoreversibly switched based on a photoresponsive host-guest system. The trans form of an azobenzene guest formed a stable 1:1 complex with the pillar[6]arene. Complexation increased the clouding point. Irradiation with UV light induced a conformation change for the azobenzene guest from the trans to cis form, and dethreading occurred because of a size mismatch between the cis form and the pillar[6]arene cavity. This dethreading decreased the clouding point. The photoresponsive host-guest system was reversible, and the clouding point could be switched by alternating irradiation with UV or visible light. We demonstrated photoresponsive reversible clear-to-turbid and turbid-to-clear transitions for the solution based on the reversible switching of the clouding point using the photosensitive host-guest system.

  15. Removal of Pb2+,Cd2+, Fe3+ and Sr2+ from Aqueous Solution by Selected Activated Carbons Derived from Date Pits

    International Nuclear Information System (INIS)

    Awwad, N.S.; Daifuallah, A.A.M.; Ali, M.M.S.

    2008-01-01

    Date pits (DP) as a huge solid waste in Egypt is of little or no economic value and in fact present a disposal problem. The quantity of DP has been estimated to million tons per year. DP was used for preparation of physically and chemically activated carbons. The raw materials were physically activated with pure steam, steam with flow of nitrogen gas or steam with current of air, while the chemically activated samples were prepared by impregnation of 10% ferric chloride or 10% calcium acetate. The effect of various factors, e.g., carbon type, carbon dosage, ph, initial concentration, temperature, and various inorganic ions on the adsorption capacity, were quantitatively determined. The two-parameters equilibrium models Langmuir and Freundlich equations were discussed. In this work, analyses and batch adsorption experiments have been carried out to characterize and to understand adsorption mechanism by modeling the adsorption kinetics. The present study deals with the factors affecting the uptake of Pb 2+ , Cd 2+ , Fe 3+ , and Sr 2+ ions from aqueous solution using activated carbon developed from locally available material DP, by one-step steam pyrolysis in a batch mode. Concurrently removal of these cations from aqueous medium are affected by the presence of other ions e.g. NO 3 - , CO 3 - , SO 4 - and masking agents e.g. oxalic acid and EDTA in solution. Uptake values are decreased with increasing the concentration of these ions in solution heavy metals

  16. Derivative chameleons

    International Nuclear Information System (INIS)

    Noller, Johannes

    2012-01-01

    We consider generalized chameleon models where the conformal coupling between matter and gravitational geometries is not only a function of the chameleon field φ, but also of its derivatives via higher order co-ordinate invariants (such as ∂ μ φ∂ μ φ,□φ,...). Specifically we consider the first such non-trivial conformal factor A(φ,∂ μ φ∂ μ φ). The associated phenomenology is investigated and we show that such theories have a new generic mass-altering mechanism, potentially assisting the generation of a sufficiently large chameleon mass in dense environments. The most general effective potential is derived for such derivative chameleon setups and explicit examples are given. Interestingly this points us to the existence of a purely derivative chameleon protected by a shift symmetry for φ → φ+c. We also discuss potential ghost-like instabilities associated with mass-lifting mechanisms and find another, mass-lowering and instability-free, branch of solutions. This suggests that, barring fine-tuning, stable derivative models are in fact typically anti-chameleons that suppress the field's mass in dense environments. Furthermore we investigate modifications to the thin-shell regime and prove a no-go theorem for chameleon effects in non-conformal geometries of the disformal type

  17. The Influence of pH and Temperature on the Stability of N-[(Piperidinemethylene]daunorubicin Hydrochloride and a Comparison of the Stability of Daunorubicin and Its Four New Amidine Derivatives in Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Mikołaj Piekarski

    2014-01-01

    Full Text Available The influence of pH and temperature on the stability of N-[(piperidinemethylene]daunorubicin hydrochloride (PPD was investigated. Degradation was studied using an HPLC method. Specific acid-base catalysis of PPD involves hydrolysis of protonated molecules of PPD catalyzed by hydrogen ions and spontaneous hydrolysis under the influence of water zwitterions, unprotonated molecules, and monoanions of PPD. The thermodynamic parameters of these reactions, energy, enthalpy, and entropy, were calculated. Also, the stability of daunorubicin and its new amidine derivatives (piperidine, morpholine, pyrrolidine, and hexahydroazepin-1-yl in aqueous solutions was compared and discussed.

  18. Photo-degradation of basic green 1 and basic red 46 dyes in their binary solution by La2O3-Al2O3nanocomposite using first-order derivative spectra and experimental design methodology

    Science.gov (United States)

    Fahimirad, Bahareh; Asghari, Alireza; Rajabi, Maryam

    2017-05-01

    In this work, the lanthanum oxide-aluminum oxide (La2O3-Al2O3) nanocomposite is introduced as an efficient photocatalyst for the photo-degradation of the dyes basic green 1 (BG1) and basic red 46 (BR46) in their binary aqueous solution under the UV light irradiation. The properties of this catalyst are determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Brunauer-Emmett-Teller (BET), and UV-visible spectrophotometry. The first-order derivative spectra are used for the simultaneous analysis of the dyes in their binary solution. The screening investigations indicate that five parameters including the catalyst dosage, concentration of the dyes, irradiation time, and solution pH have significant effects on the photo-degradation of the dyes. The effects of these variables together with their interactions in the photo-degradation of the dyes are studied using the Box-Behnken design (BBD). Under the optimum experimental conditions, obtained via the desirability function, the photo-catalytic activities of La2O3-Al2O3 and pure Al2O3 are also investigated. The results obtained show an enhancement in the photo-catalytic activity when La2O3 nanoparticles are loaded on the surface of Al2O3 nanoparticles. The La2O3-Al2O3nanocomposite was synthesized as new photo-catalyst for the degradation of binary dyes. The photo-catalytic effect on the binary dyes solution was followed by the first-order derivative spectrophotometric method. Simultaneous dyes photodegradation methodology was presented by using experimental design.

  19. Modification of bio-char derived from fast pyrolysis of biomass and its application in removal of tetracycline from aqueous solution.

    Science.gov (United States)

    Liu, Pei; Liu, Wu-Jun; Jiang, Hong; Chen, Jie-Jie; Li, Wen-Wei; Yu, Han-Qing

    2012-10-01

    In this work, bio-char, a mass productive by-product of biomass fast pyrolysis, was adopted as an adsorbent to remove tetracycline (TC) from aqueous solution. To enhance the adsorption capacity, a simple modification of bio-char with acid and alkali was carried out. Bio-char samples were characterized by Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption-desorption isotherm. The results show that the alkali treated bio-char possesses larger surface area than those of raw and acid treated bio-chars, and accordingly exhibits a more excellent adsorption performance (58.8 mg/g) than the other two bio-chars and other adsorbents reported previously. The graphite-like structure of bio-char facilitates the formation of π-π interactions between ring structure in tetracycline molecule and graphite-like sheets. The surface area showed significant effects on TC adsorption as well as O-containing functional groups, whereas the initial pH of solution has small effects on TC adsorption under the experimental conditions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Temperature control of functionally graded plates using a feedforward-feedback controller based on the inverse solution and proportional-derivative controller

    International Nuclear Information System (INIS)

    Golbahar Haghighi, M.R.; Eghtesad, M.; Necsulescu, D.S.; Malekzadeh, P.

    2010-01-01

    As a first endeavor, an approach for the two- and three-dimensional temperature control of functionally graded (FG) plates by using the inverse solution and the proportional-differential (PD) controller is provided. For this purpose, firstly, having the desired temperatures at different locations and times, heat fluxes at the boundaries of the plates are estimated by inverse solution techniques offline. Then, the estimated heat fluxes as feedforward control inputs are combined with a PD controller to introduce a hybrid feedforward-feedback control input to the FG domain in the presence of disturbance and noise. In order to show the efficiency and accuracy of the proposed (inverse + PD) controller in two- and three-dimensional domains, different distinct examples, which include different boundary conditions, material properties and disturbance sources are presented. It is shown that the presented approach can adjust heat fluxes for control of the temperature accurately; also, the PD controller gains do not need to be re-adjusted for different problems.

  1. Challenges in the Application of Fractional Derivative Models in Capturing Solute Transport in Porous Media: Darcy-Scale Fractional Dispersion and the Influence of Medium Properties

    Directory of Open Access Journals (Sweden)

    Yong Zhang

    2013-01-01

    Full Text Available Heterogeneous media consisting of segregated flow regions are fractional-order systems, where the regional-scale anomalous diffusion can be described by the fractional derivative model (FDM. The standard FDM, however, first, cannot characterize the Darcy-scale dispersion through repacked sand columns, and second, the link between medium properties and model parameters remains unknown. To fill these two knowledge gaps, this study applies a tempered fractional derivative model (TFDM to capture bromide transport through laboratory repacked sand. Column transport experiments are conducted first, where glass beads and silica sand with different diameters are repacked individually. Late-time tails are observed in the breakthrough curves (BTC of bromide even in relatively homogeneous glass beads. The TFDM can capture the observed subdiffusion, especially the late-time BTC with a transient declining rate. Results also show that both the size distribution of repacked sand and the magnitude of fluid velocity can affect subdiffusion. In particular, a wider sand size distribution or a smaller flow rate can enhance the subdiffusion, leading to a smaller time index and a higher truncation parameter in the TFDM. Therefore, the Darcy-scale dispersion follows the tempered stable law, and the model parameters might be related to the soil size and flow conditions.

  2. Co-pigmentation of pelargonidin derivatives in strawberry and red radish model solutions by the addition of phenolic fractions from mango peels.

    Science.gov (United States)

    Müller-Maatsch, Judith; Bechtold, Lena; Schweiggert, Ralf M; Carle, Reinhold

    2016-12-15

    Pelargonidin-based colors suffer from notorious instability. A phenolic mango peel extract and defined phenolic fractions thereof were shown to effectively modulate the visible absorption of anthocyanins from strawberry (Fragaria x ananassa Duch.) and red radish (Raphanus sativus L.) by intermolecular co-pigmentation. Consistently, non-acylated pelargonidin derivatives from strawberry exerted significantly greater hyper- and bathochromic spectral shifts than their acylated counterparts from red radish. The addition of low molecular-weight co-pigments such as gallic acid and monogalloyl glucoses to strawberry anthocyanins led to strong hyperchromic shifts from 30% to 48%, while gallotannins (>six galloyl units) exerted smaller co-pigmentation effects (36±2%; Δλmax 13nm), possibly due to steric hindrances. In contrast, penta- and hexa-O-galloyl-glucose induced greatest and most stable co-pigmentation effects (53±2%; Δλmax 13nm). Irrespective of the underlying mechanisms and the responsible compounds, phenolic mango peel extracts might represent suitable color enhancers for coloring foodstuff, particularly for those containing non-acylated pelargonidin derivatives. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Removal of manganese(II ions from aqueous solutions by adsorption on activated carbon derived a new precursor: Ziziphus spina-christi seeds

    Directory of Open Access Journals (Sweden)

    Abdessalem Omri

    2012-12-01

    Full Text Available In this paper, activated carbon was prepared from Ziziphus spina-christi seeds (ZSAC to remove Mn(II from aqueous solutions. To characterize the adsorptive characteristics of the produced active carbon, surface area was calculated using the standard Brunauer–Emmet–Teller method. The microstructures of the resultant activated carbon were observed by with scanning electron micrographs. Chemical characterization of the surface resultant activated carbon was studied by Fourier Transform Infrared Spectroscopy. The effects of pH, initial metal ion concentration and temperature on the adsorption performance of ZSAC for Mn(II ions were examined by batch method. The adsorption equilibrium data were analyzed by Langmuir, Freundlich and Temkin isotherm models. We concluded that maximum adsorption capacity of manganese calculated from Langmuir isotherm was around 172 mg/g.

  4. Alternative Donor--Acceptor Stacks from Crown Ethers and Naphthalene Diimide Derivatives: Rapid, Selective Formation from Solution and Solid State Grinding

    Energy Technology Data Exchange (ETDEWEB)

    Advanced Light Source; Liu, Yi; Klivansky, Liana; Cao, Dennis; Snauko, Marian; Teat, Simon J.; Struppe, Jochem O.; Koshkakaryan, Gayane

    2009-01-22

    Self assembling {pi}-conjugated molecules into ordered structures are of increasing interest in the field of organic electronics. One particular example is charge transfer complexes containing columnar alternative donor-acceptor (ADA) stacks, where neutral and ionic ground states can be readily tuned to modulate electrical, optical, and ferroelectrical properties. Aromatic-aromatic and charge transfer interactions have been the leading driving forces in assisting the self-assembly of ADA stacks. Various folding structures containing ADA stacks were assembled in solution with the aid of solvophobic or ion-binding interactions. Meanwhile, examples of solid ADA stacks, which are more appealing for practical use in devices, were obtained from cocrystalization of binary components or mesophase assembly of liquid crystals in bulk blends. Regardless of these examples, faster and more controllable approaches towards precise supramolecular order in the solid state are still highly desirable.

  5. Photo-degradation of basic green 1 and basic red 46 dyes in their binary solution by La2O3-Al2O3nanocomposite using first-order derivative spectra and experimental design methodology.

    Science.gov (United States)

    Fahimirad, Bahareh; Asghari, Alireza; Rajabi, Maryam

    2017-05-15

    In this work, the lanthanum oxide-aluminum oxide (La 2 O 3 -Al 2 O 3 ) nanocomposite is introduced as an efficient photocatalyst for the photo-degradation of the dyes basic green 1 (BG1) and basic red 46 (BR46) in their binary aqueous solution under the UV light irradiation. The properties of this catalyst are determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Brunauer-Emmett-Teller (BET), and UV-visible spectrophotometry. The first-order derivative spectra are used for the simultaneous analysis of the dyes in their binary solution. The screening investigations indicate that five parameters including the catalyst dosage, concentration of the dyes, irradiation time, and solution pH have significant effects on the photo-degradation of the dyes. The effects of these variables together with their interactions in the photo-degradation of the dyes are studied using the Box-Behnken design (BBD). Under the optimum experimental conditions, obtained via the desirability function, the photo-catalytic activities of La 2 O 3 -Al 2 O 3 and pure Al 2 O 3 are also investigated. The results obtained show an enhancement in the photo-catalytic activity when La 2 O 3 nanoparticles are loaded on the surface of Al 2 O 3 nanoparticles. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Inhibition Effects of a Synthesized Novel 4-Aminoantipyrine Derivative on the Corrosion of Mild Steel in Hydrochloric Acid Solution together with Quantum Chemical Studies

    Directory of Open Access Journals (Sweden)

    Abu Bakar Mohamad

    2013-06-01

    Full Text Available 1,5-Dimethyl-4-((2-methylbenzylideneamino-2-phenyl-1H-pyrazol-3(2H-one (DMPO was synthesized to be evaluated as a corrosion inhibitor. The corrosion inhibitory effects of DMPO on mild steel in 1.0 M HCl were investigated using electrochemical impedance spectroscopy (EIS, potentiodynamic polarization, open circuit potential (OCP and electrochemical frequency modulation (EFM. The results showed that DMPO inhibited mild steel corrosion in acid solution and indicated that the inhibition efficiency increased with increasing inhibitor concentration. Changes in the impedance parameters suggested an adsorption of DMPO onto the mild steel surface, leading to the formation of protective films. The novel synthesized corrosion inhibitor was characterized using UV-Vis, FT-IR and NMR spectral analyses. Electronic properties such as highest occupied molecular orbital energy, lowest unoccupied molecular orbital energy (EHOMO and ELUMO, respectively and dipole moment (μ were calculated and discussed. The results showed that the corrosion inhibition efficiency increased with an increase in the EHOMO values but with a decrease in the ELUMO value.

  7. Magnetoelectric coupling effect in lead-free Bi4Ti3O12/CoFe2O4 composite films derived from chemistry solution deposition

    Science.gov (United States)

    Tang, Zhehong; Chen, Jieyu; Bai, Yulong; Zhao, Shifeng

    2016-08-01

    Lead-free magnetoelectric composite films combining Bi4Ti3O12 and CoFe2O4 were synthesized by chemical solution deposition on Pt (100)/Ti/SiO2/Si substrate. Morphological and electrical domain structure, ferroelectric, leakage, dielectric, piezoelectric, magnetic and magnetoelectric properties were investigated for Bi4Ti3O12/CoFe2O4 composite films. Well-defined interfaces between Bi4Ti3O12 and CoFe2O4 film layers and electrical domain structure were observed. The composite films show the coexistence of ferroelectric and ferromagnetic orders at room temperature. Larger piezoelectric coefficient and magnetization are obtained for the composite films, which is contributed to the magnetoelectric effect since it originates from the interface coupling through mechanical strain transfer. This work presents a feasible way to modulate the magnetoelectric coupling in ferromagnetic/ferroelectric composite films for developing lead-free micro-electro-mechanical system and information storage devices.

  8. Synthesis of Copper-Chelates Derived from Amino Acids and Evaluation of Their Efficacy as Copper Source and Growth Stimulator for Lactuca sativa in Nutrient Solution Culture.

    Science.gov (United States)

    Kaewchangwat, Narongpol; Dueansawang, Sattawat; Tumcharern, Gamolwan; Suttisintong, Khomson

    2017-11-15

    Five tetradentate ligands were synthesized from l-amino acids and utilized for the synthesis of Cu(II)-chelates 1-5. The efficacy of Cu(II)-chelates as copper (Cu) source and growth stimulator in hydroponic cultivation was evaluated with Lactuca sativa. Their stability test was performed at pH 4-10. The results suggested that Cu(II)-chelate 3 is the most pH tolerant complex. Levels of Cu, Zn, and Fe accumulated in plants supplied with Cu(II)-chelates were compared with those supplied with CuSO 4 at the same Cu concentration of 8.0 μM. The results showed that Cu(II)-chelate 3 significantly enhanced Cu, Zn, and Fe content in shoot by 35, 15, and 48%, respectively. Application of Cu(II)-chelate 3 also improved plant dry matter yield by 54%. According to the results, Cu(II)-chelate 3 demonstrated the highest stimulating effect on plant growth and plant mineral accumulation so that it can be used as an alternative to CuSO 4 for supplying Cu in nutrient solutions and enhancing the plant growth.

  9. Treatment of a non-azo dye aqueous solution by CWAO in continuous reactor using a Ni catalyst derived from hydrotalcite-like precursor

    Energy Technology Data Exchange (ETDEWEB)

    Vallet, Ana, E-mail: avallet@quim.ucm.es [Grupo de Catalisis y Procesos de Separacion (CyPS), Departamento de Ingenieria Quimica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain); Besson, Michele, E-mail: michele.besson@ircelyon.univ-lyon1.fr [IRCELYON, Institut de recherches sur la catalyse et l' environnement de Lyon, UMR5256 CNRS-Universite Lyon1, 2 Avenue Albert Einstein, F-69626 Villeurbanne Cedex (France); Ovejero, Gabriel; Garcia, Juan [Grupo de Catalisis y Procesos de Separacion (CyPS), Departamento de Ingenieria Quimica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer Ni supported over hydrotalcite calcined precursors as catalyst. Black-Right-Pointing-Pointer Catalytic wet air oxidation in trickle bed reactor for Basic Yellow 11 removal. Black-Right-Pointing-Pointer Dye removal depends on temperature, initial dye concentration and flow rate. Black-Right-Pointing-Pointer The catalyst proved to be stable and efficient for the dye degradation. - Abstract: Catalytic wet air oxidation (CWAO) of a Basic Yellow 11 (BY11) aqueous solution, chosen as a model of a hardly biodegradable non-azo dye was carried out in a continuous-flow trickle-bed reactor, using nickel supported over hydrotalcite precursor calcined at 550 Degree-Sign C. An increase in the reaction temperature (120-180 Degree-Sign C), and a decrease in dye concentration (1000-3000 ppm) or liquid flow rate (0.1-0.7 mL min{sup -1}) enhanced the CWAO performance in a 30 and 19% for the variation of the temperature and concentration respectively. After a small leaching observed within the first hours, the catalyst proved to be very stable during the 65-day reaction. The CWAO process was found to be very efficient, achieving BY11 conversion up to 95% and TOC conversion up to 85% at 0.1 mL min{sup -1} and 180 Degree-Sign C under 5 MPa air.

  10. Mechanistic Study on the Solution-Phase n-Doping of 1,3-Dimethyl-2-aryl-2,3-dihydro-1H-benzoimidazole Derivatives

    Science.gov (United States)

    Naab, Benjamin D.; Guo, Song; Olthof, Selina; Evans, Eric G. B.; Wei, Peng; Millhauser, Glenn L.; Kahn, Antoine; Barlow, Stephen; Marder, Seth R.; Bao, Zhenan

    2014-01-01

    The discovery of air-stable n-dopants for organic semiconductor materials has been hindered by the necessity of high-energy HOMOs and the air sensitivity of compounds that satisfy this requirement. One strategy for circumventing this problem is to utilize stable precursor molecules that form the active doping complex in situ during the doping process or in a postdeposition thermal- or photo-activation step. Some of us have reported on the use of 1H-benzimidazole (DMBI) and benzimidazolium (DMBI-I) salts as solution- and vacuum-processable n-type dopant precursors, respectively. It was initially suggested that DMBI dopants function as single-electron radical donors wherein the active doping species, the imidazoline radical, is generated in a postdeposition thermal annealing step. Herein we report the results of extensive mechanistic studies on DMBI-doped fullerenes, the results of which suggest a more complicated doping mechanism is operative. Specifically, a reaction between the dopant and host that begins with either hydride or hydrogen atom transfer and which ultimately leads to the formation of host radical anions is responsible for the doping effect. The results of this research will be useful for identifying applications of current organic n-doping technology and will drive the design of next-generation n-type dopants that are air stable and capable of doping low-electron-affinity host materials in organic devices. PMID:24011269

  11. Activities of lectins and their immobilized derivatives in detergent solutions. Implications on the use of lectin affinity chromatography for the purification of membrane glycoproteins.

    Science.gov (United States)

    Lotan, R; Beattie, G; Hubbell, W; Nicolson, G L

    1977-05-03

    The effects of several commonly used detergents on the saccharide-binding activities of lectins were investigated using lectin-mediated agglutination of formalin-fixed erythrocytes and affinity chromatography of glycoproteins on columns of lectins immobilized on polyacrylic hydrazide-Sepharose. In the hemagglutination assays, Ricinus communis I (RCA1) and II (RCAII), concanavalin A (Con A), and the agglutinins from peanut (PNA), soybean (SBA), wheat germ (WGA), and Limulus polyphemus (LPA) were tested with several concentrations of switterionic, cationic, anionic, and nonionic detergents. It was found that increasing detergent concentrations eventually affected hemagglutination titers in both test and control samples, and the highest detergent concentrations not affecting lectin hemagglutinating activities were determined. The effects of detergents on specific binding of [3H]fetuin and asialo[3H]fetuin to and elution from columns of immobilized lectins were less severe when compared with lectins in solution, suggesting that the lectins are stabilized by covalent attachment to agarose beads. Nonionic detergents did not affect the binding efficiency of the immobilized lectins tested at concentrations used for membrane solubilization while cationic and zwitterionic detergents caused significant inhibition of Con A- and SBA-Sepharose activities. In sodium deoxycholate (greater than 1%) only RCAI-Sepharose retained its activity, whereas the activities of the other lectins were reduced dramatically. Low concentrations of sodium dodecyl sulfate (0.05%) inhibited only the activity of immobilized SBA, but at higher concentration (0.1%) and prolonged periods of incubation (16 h, 23 degrees C) most of the lectins were inactivated. These data are compared with previous reports on the use of detergents in lectin affinity chromatography, and the conditions for the optimal use of detergents are detailed.

  12. [Improvement of the recruitment of surgery interns derived from the Epreuves Nationales Classantes (National-Ranking Exam): practical solution applied to urology].

    Science.gov (United States)

    Beley, Sébastien; Dubosq, Francis; Simon, Pascal; Larré, Stéphane; Battisti, Simon; Ballereau, Charles; Boublil, Véronique; Richard, François; Rouprêt, Morgan

    2005-12-01

    To analyse the value of an urology initiation session proposed to young interns to improve recruitment of the discipline since the introduction of the new National-Ranking Exam (NRE). In October 2004, the 77 interns appointed to surgery in Paris on the basis of the ENC participated in a one-day urology initiation session organized by the AFUF, at the AP-HP School of Surgery. All interns were given a questionnaire at the beginning of the session to record the following data: age, gender, teaching hospital, a student attachment in urology and desired specialization as a function of the surgical training programmes proposed by the ENC. Items concerning the desired specialization were resubmitted to the interns at the end of the session. Population. 77 interns, 48 females (62.3%) and 29 males (37.7%) with a mean age of 25.2 +/- 5 years (range: 23-31). 55 interns had trained at a Parisian teaching hospital (67%) and 22 (28.6%) had trained at a provincial teaching hospital. 16 interns (20.8%) had completed at least one urology attachment during their medical training. Desired specialization. Orthopaedics was the discipline most frequently cited (n = 20; 26%). Urology was chosen by 8 interns (10.40%), who had all completed an urology attachment during their medical training. At the end of the urology initiation session, another 8 interns expressed the desire to specialize in urology. Of the 16 potential urology interns, 9 (56.2%) confirmed that their decision was final. Urology occupies a special place and remains a popular surgical speciality among students. Organization of practical sessions constitutes a solution to inform, create an emulation and motivate surgery interns to choose urology.

  13. Experimental determination of enthalpies of solution of tetraphenyl porphyrin (TPP) and some metal derivatives, in chloroform: interpretation of the solvation processes at a molecular level.

    Science.gov (United States)

    Gamboa, Minerva; Campos, Myriam; Torres, Luis Alfonso

    2010-01-18

    The enthalpies of solution, Delta(sol)H(m), for 5,10,15,20-tetraphenylporphine (CA registry number 917-23-7, TPP), 5,10,15,20-tetraphenylporphine of Co(II), Ni(II), Cu(II), and Zn(II) (to be written as CoTPP, NiTPP, CuTPP, and ZnTPP) in chloroform, were calorimetrically measured at T = 298 K in the concentration ranging from 3.5 x 10(-5) to 2.8 x 10(-4) mol.kg(-1). Through the linear extrapolation of the experimental data, corresponding values at infinite dilution were determined as: Delta(sol)H(m) (ZnTPP) = (55.5 +/- 0.2) kJ x mol(-1), Delta(sol)H(m) (CoTPP) = (36.9 +/- 0.2) kJ x mol(-1), Delta(sol)H(m) (TPP) = (25.7 +/- 0.6) kJ x mol(-1), Delta(sol)H(m) (NiTPP) = (15.6 +/- 0.1) kJ x mol(-1), and Delta(sol)H(m) (CuTPP) = (15.6 +/- 0.1) kJ x mol(-1). The enthalpies of solvation for the five compounds were also determined using the previously published values for the enthalpy of sublimation, as well as complementary data from the literature. The values obtained are as follows: Delta(solv)H(m)(TPP) = -(158.3 +/- 2.1) kJ x mol(-1), Delta(solv)H(m)(CoTPP) = -(154.1 +/- 2.0) kJ x mol(-1), Delta(solv)H(m)(CuTPP) = -(149.4 +/- 5.0) kJ x mol(-1) Delta(solv)H(m)(NiTPP) = -(141.4 +/- 4.0) kJ x mol(-1), and Delta(solv)H(m)(ZnTPP) = -(140.5 +/- 3.0) kJ x mol(-1). The results are analyzed in relation to several molecular properties such as ionic radius, electronic spectra, and Connolly surface. An explanation of the observed trends for solvation enthalpies is proposed.

  14. Surface-enhanced Raman scattering studies on the interaction of phosphonate derivatives of imidazole, thiazole, and pyridine with a silver electrode in aqueous solution.

    Science.gov (United States)

    Podstawka, Edyta; Kudelski, Andrzej; Olszewski, Tomasz K; Boduszek, Bogdan

    2009-07-23

    Surface-enhanced Raman scattering (SERS) spectra from phosphonate derivatives of N-heterocyclic aromatic compounds immobilized on an electrochemically roughened silver electrode surface are reported and compared to Raman spectra of the corresponding solid species. The tested compounds contain imidazole [ImMeP ([hydroxy-(1H-imidazol-5-yl)-methyl]-phosphonic acid) and (ImMe)2P (bis[hydroxy-(1H-imidazol-4-yl)-methyl]-phosphinic acid)]; thiazole [BAThMeP ((butylamino-thiazol-2-yl-methyl)-phosphonic acid) and BzAThMeP ((benzylamino-thiazol-2-yl-methyl)-phosphonic acid)]; and pyridine ((PyMe)2P (bis[(hydroxy-pyridin-3-yl-methyl)]-phosphinic acid) aromatic rings. Changes in wavenumber, broadness, and the enhancement of N-heterocyclic aromatic ring bands upon adsorption are consistent with the adsorption primarily occurring through the N lone pair of electrons with the ring arranged in a largely edge-on manner for ImMeP and BzAThMeP or in a slightly inclined orientation to the silver electrode surface at an intermediate angle from the surface normal for (ImMe)2P, BAThMeP, and (PyMe)2P. A strong enhancement of a roughly 1500 cm(-1) SERS signal for ImMeP and (PyMe)2P is also observed. This phenomenon is attributed to the formation of a localized C=C bond, which is accompanied by a decrease in the ring-surface pi-electrons' overlap. In addition, more intense SERS bands due to the benzene ring in BzAThMeP are observed than those observed for the thiazole ring, which suggests a preferential adsorption of benzene. Some interaction of a phosphonate unit is also suggested but with moderate strength between biomolecules. The strength of the P=O coordination to the silver electrode is highest for ImMeP but lowest for BzAThMeP. For all studied biomolecules, the contribution of the structural components to their ability to interact with their receptors was correlated with the SERS patterns.

  15. Solid state structure and solution thermodynamics of three-centered hydrogen bonds (O∙∙∙H∙∙∙O) using N-(2-benzoyl-phenyl) oxalyl derivatives as model compounds.

    Science.gov (United States)

    Gómez-Castro, Carlos Z; Padilla-Martínez, Itzia I; García-Báez, Efrén V; Castrejón-Flores, José L; Peraza-Campos, Ana L; Martínez-Martínez, Francisco J

    2014-09-12

    Intramolecular hydrogen bond (HB) formation was analyzed in the model compounds N-(2-benzoylphenyl)acetamide, N-(2-benzoylphenyl)oxalamate and N1,N2-bis(2-benzoylphenyl)oxalamide. The formation of three-center hydrogen bonds in oxalyl derivatives was demonstrated in the solid state by the X-ray diffraction analysis of the geometric parameters associated with the molecular structures. The solvent effect on the chemical shift of H6 [δH6(DMSO-d6)-δH6(CDCl3)] and Δδ(ΝΗ)/ΔT measurements, in DMSO-d6 as solvent, have been used to establish the energetics associated with intramolecular hydrogen bonding. Two center intramolecular HB is not allowed in N-(2-benzoylphenyl)acetamide either in the solid state or in DMSO-d6 solution because of the unfavorable steric effects of the o-benzoyl group. The estimated ΔHº and ΔSº values for the hydrogen bonding disruption by DMSO-d6 of 28.3(0.1) kJ·mol-1 and 69.1(0.4) J·mol-1·K-1 for oxalamide, are in agreement with intramolecular three-center hydrogen bonding in solution. In the solid, the benzoyl group contributes to develop 1-D and 2-D crystal networks, through C-H∙∙∙A (A = O, π) and dipolar C=O∙∙∙A (A = CO, π) interactions, in oxalyl derivatives. To the best of our knowledge, this is the first example where three-center hydrogen bond is claimed to overcome steric constraints.

  16. A Mathematica program for the two-step twelfth-order method with multi-derivative for the numerical solution of a one-dimensional Schrödinger equation

    Science.gov (United States)

    Wang, Zhongcheng; Ge, Yonghua; Dai, Yongming; Zhao, Deyin

    2004-06-01

    In this paper, we present the detailed Mathematica symbolic derivation and the program which is used to integrate a one-dimensional Schrödinger equation by a new two-step numerical method. We add the fourth- and sixth-order derivatives to raise the precision of the traditional Numerov's method from fourth order to twelfth order, and to expand the interval of periodicity from (0,6) to the one of (0,9.7954) and (9.94792,55.6062). In the program we use an efficient algorithm to calculate the first-order derivative and avoid unnecessarily repeated calculation resulting from the multi-derivatives. We use the well-known Woods-Saxon's potential to test our method. The numerical test shows that the new method is not only superior to the previous lower order ones in accuracy, but also in the efficiency. This program is specially applied to the problem where a high accuracy or a larger step size is required. Program summaryTitle of program: ShdEq.nb Catalogue number: ADTT Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADTT Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Licensing provisions: none Computer for which the program is designed and others on which it has been tested: The program has been designed for the microcomputer and been tested on the microcomputer. Computers: IBM PC Operating systems under which the program has been tested: Windows XP Programming language used: Mathematica 4.2 Memory required to execute with typical data: 51 712 bytes No. of bytes in distributed program, including test data, etc.: 45 381 No. of lines in distributed program, including test data, etc.: 7311 Distribution format: tar gzip file CPC Program Library subprograms used: no Nature of physical problem: Numerical integration of one-dimensional or radial Schrödinger equation to find the eigenvalues for a bound states and phase shift for a continuum state. Method of solution: Using a two-step method twelfth-order method to integrate a Schr

  17. Numerical derivation in optimization

    International Nuclear Information System (INIS)

    Abadie, J.; Salhi, Y.

    1988-01-01

    Newton's method for function minimization possesses an outstanding property. Its final quadratic convergence under very weak hypothesis, but also some drawbacks, among which (i) the possibility of non convergence when starting far from the solution sought and (ii) the necessity of computing (and then programming) the first and second partial derivatives. We show in this paper how to avoid both difficulties, assuming however that the first partial derivatives are computed by exact formulae. The second partial derivatives are computed by central differences of first derivatives. The difference step h is calculated so as to establish a trade-off between accuracy and computation speed. Encouraging numerical experiments support the proposed method [fr

  18. Solution-Processed Blue/Deep Blue and White Phosphorescent Organic Light-Emitting Diodes (PhOLEDs) Hosted by a Polysiloxane Derivative with Pendant mCP (1,3-bis(9-carbazolyl)benzene).

    Science.gov (United States)

    Sun, Dianming; Zhou, Xiaokang; Liu, Junteng; Sun, Xiaoli; Li, Huihui; Ren, Zhongjie; Ma, Dongge; Bryce, Martin R; Yan, Shouke

    2015-12-30

    The synthesis and characterization is reported of an efficient polysiloxane derivative containing the 1,3-bis(9-carbazolyl)benzene (mCP) moiety as a pendant unit on the polysiloxane backbone. In comparison with mCP, the mCP-polysiloxane hybrid (PmCPSi) has significantly improved thermal and morphological stabilities with a high decomposition temperature (Td = 523 °C) and glass transition temperature (Tg = 194 °C). The silicon-oxygen linkage of PmCPSi prevents intermolecular π-stacking and ensures a high triplet energy level (ET = 3.0 eV). Using PmCPSi as a host, blue phosphorescent organic light emitting devices (PhOLEDs) effectively confine triplet excitons, with efficient energy transfer to the guest emitter and a relatively low turn-on voltage of 5.8 V. A maximum external quantum efficiency of 9.24% and maximum current efficiency of 18.93 cd/A are obtained. These values are higher than for directly analogous poly(vinylcarbazole) (PVK) based devices (6.76%, 12.29 cd/A). Good color stability over a range of operating voltages is observed. A two-component "warm-white" device with a maximum current efficiency of 10.4 cd/A is obtained using a blend of blue and orange phosphorescent emitters as dopants in PmCPSi host. These results demonstrate that well-designed polysiloxane derivatives are highly efficient hosts suitable for low-cost solution-processed PhOLEDs.

  19. One-soliton solutions from Laplace's seed

    Indian Academy of Sciences (India)

    One-soliton solutions of axially symmetric vacuum Einstein field equations are presented in this paper. Two sets of Laplace's solutions are used as seed and it is shown that the derived solutions reduce to some already known solutions when the constants are properly adjusted. An analysis of the solutions in terms of the ...

  20. One-soliton solutions from Laplace's seed

    Indian Academy of Sciences (India)

    Abstract. One-soliton solutions of axially symmetric vacuum Einstein field equations are pre- sented in this paper. Two sets of Laplace's solutions are used as seed and it is shown that the derived solutions reduce to some already known solutions when the constants are properly adjusted. An analysis of the solutions in ...

  1. Solutions to horava gravity.

    Science.gov (United States)

    Lü, H; Mei, Jianwei; Pope, C N

    2009-08-28

    Recently Horava proposed a nonrelativistic renormalizable theory of gravitation, which reduces to Einstein's general relativity at large distances, and that may provide a candidate for a UV completion of Einstein's theory. In this Letter, we derive the full set of equations of motion, and then we obtain spherically symmetric solutions and discuss their properties. We also obtain solutions for the Friedmann-Lemaître-Robertson-Walker cosmological metric.

  2. Growth of ferroelectric Ba{sub 0.8}Sr{sub 0.2}TiO{sub 3} epitaxial films by ultraviolet pulsed laser irradiation of chemical solution derived precursor layers

    Energy Technology Data Exchange (ETDEWEB)

    Queraltó, A.; Pérez del Pino, A., E-mail: aperez@icmab.es; Mata, M. de la; Tristany, M.; Gómez, A.; Obradors, X.; Puig, T. [Institut de Ciència de Materials de Barcelona, Consejo Superior de Investigaciones Científicas (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Catalonia (Spain); Arbiol, J. [Institut de Ciència de Materials de Barcelona, Consejo Superior de Investigaciones Científicas (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Catalonia (Spain); Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys, 23, 08010 Barcelona, Catalonia (Spain)

    2015-06-29

    Highly crystalline epitaxial Ba{sub 0.8}Sr{sub 0.2}TiO{sub 3} (BST) thin-films are grown on (001)-oriented LaNiO{sub 3}-buffered LaAlO{sub 3} substrates by pulsed laser irradiation of solution derived barium-zirconium-titanium precursor layers using a UV Nd:YAG laser source at atmospheric conditions. The structural analyses of the obtained films, studied by X-ray diffractometry and transmission electron microscopy, demonstrate that laser processing allows the growth of tens of nm-thick BST epitaxial films with crystalline structure similar to that of films obtained through conventional thermal annealing methods. However, the fast pulsed nature of the laser employed leads to crystallization kinetic evolution orders of magnitude faster than in thermal treatments. The combination of specific photothermal and photochemical mechanisms is the main responsible for the ultrafast epitaxial laser-induced crystallization. Piezoresponse microscopy measurements demonstrate equivalent ferroelectric behavior in laser and thermally annealed films, being the piezoelectric constant ∼25 pm V{sup −1}.

  3. Facilitative capture of As(V), Pb(II) and methylene blue from aqueous solutions with MgO hybrid sponge-like carbonaceous composite derived from sugarcane leafy trash.

    Science.gov (United States)

    Li, Ronghua; Liang, Wen; Wang, Jim J; Gaston, Lewis A; Huang, Di; Huang, Hui; Lei, Shuang; Awasthi, Mukesh Kumar; Zhou, Baoyue; Xiao, Ran; Zhang, Zengqiang

    2018-04-15

    Enhancing the contaminant adsorption capacity is a key factor affecting utilization of carbon-based adsorbents in wastewater treatment and encouraging development of biomass thermo-disposal. In this study, a novel MgO hybrid sponge-like carbonaceous composite (HSC) derived from sugarcane leafy trash was prepared through an integrated adsorption-pyrolysis method. The resulted HSC composite was characterized and employed as adsorbent for the removal of negatively charged arsenate (As(V)), positively charged Pb(II), and the organic pollutant methylene blue (MB) from aqueous solutions in batch experiments. The effects of solution pH, contact time, initial concentration, temperature, and ionic strength on As(V), Pb(II) and MB adsorption were investigated. HSC was composed of nano-size MgO flakes and nanotube-like carbon sponge. Hybridization significantly improved As(V), Pb(II) and methylene blue (MB) adsorption when compared with the material without hybridization. The maximum As(V), Pb(II) and MB adsorption capacities obtained from Langmuir model were 157 mg/g, 103 mg/g and 297 mg/g, respectively. As(V) adsorption onto HSC was best fit by the pseudo-second-order model, and Pb(II) and MB with the intraparticle diffusion model. Increased temperature and ionic strength decreased Pb(II) and MB adsorption onto HSC more than As(V). Further FT-IR, XRD and XPS analysis demonstrated that the removal of As(V) by HSC was mainly dominated by surface deposition of MgHAsO 4 and Mg(H 2 AsO 4 ) 2 crystals on the HSC composite, while carbon π-π* transition and carbon π-electron played key roles in Pb(II) and MB adsorption. The interaction of Pb(II) with carbon matrix carboxylate was also evident. Overall, MgO hybridization improves the preparation of the nanotube-like carbon sponge composite and provides a potential agricultual residue-based adsorbent for As(V), Pb(II) and MB removal. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Viscosity Solution

    OpenAIRE

    Camilli, Fabio; Prados, Emmanuel

    2011-01-01

    International audience; Viscosity solution is a notion of weak solution for a class of partial differential equations of Hamilton-Jacobi type. The range of applications of the notions of viscosity solution and Hamilton-Jacobi equations is enormous, including common class of partial differential equations such as evolutive problems and problems with boundary conditions, equations arising in optimal control theory, differential games, second-order equations arising in stochastic optimal control...

  5. Hemoglobin derivatives

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003371.htm Hemoglobin derivatives To use the sharing features on this page, please enable JavaScript. Hemoglobin derivatives are altered forms of hemoglobin . Hemoglobin is ...

  6. Nuclear magnetic resonance studies of an N2-guanine adduct derived from the tumorigen dibenzo[a,l]pyrene in DNA: impact of adduct stereochemistry, size, and local DNA sequence on solution conformations.

    Science.gov (United States)

    Rodríguez, Fabián A; Liu, Zhi; Lin, Chin H; Ding, Shuang; Cai, Yuqin; Kolbanovskiy, Alexander; Kolbanovskiy, Marina; Amin, Shantu; Broyde, Suse; Geacintov, Nicholas E

    2014-03-25

    The dimensions and arrangements of aromatic rings (topology) in adducts derived from the reactions of polycyclic aromatic hydrocarbon (PAH) diol epoxide metabolites with DNA influence the distortions and stabilities of double-stranded DNA, and hence their recognition and processing by the human nucleotide excision repair (NER) system. Dibenzo[a,l]pyrene (DB[a,l]P) is a highly tumorigenic six-ring PAH, which contains a nonplanar and aromatic fjord region that is absent in the structurally related bay region five-ring PAH benzo[a]pyrene (B[a]P). The PAH diol epoxide-DNA adducts formed include the stereoisomeric 14S and 14R trans-anti-DB[a,l]P-N(2)-dG and the stereochemically analogous 10S- and 10R-B[a]P-N(2)-dG (B[a]P-dG) guanine adducts. However, nuclear magnetic resonance (NMR) solution studies of the 14S-DB[a,l]P-N(2)-dG adduct in DNA have not yet been presented. Here we have investigated the 14S-DB[a,l]P-N(2)-dG adduct in two different sequence contexts using NMR methods with distance-restrained molecular dynamics simulations. In duplexes with dC opposite the adduct deleted, a well-resolved base-displaced intercalative adduct conformation can be observed. In full duplexes, in contrast to the intercalated 14R stereoisomeric adduct, the bulky DB[a,l]P residue in the 14S adduct is positioned in a greatly widened and distorted minor groove, with significant disruptions and distortions of base pairing at the lesion site and two 5'-side adjacent base pairs. These unique structural features are significantly different from those of the stereochemically analogous but smaller B[a]P-dG adduct. The greater size and different topology of the DB[a,l]P aromatic ring system lead to greater structurally destabilizing DNA distortions that are partially compensated by stabilizing DB[a,l]P-DNA van der Waals interactions, whose combined effects impact the NER response to the adduct. These structural results broaden our understanding of the structure-function relationship in NER.

  7. Solution preparation

    International Nuclear Information System (INIS)

    Seitz, M.G.

    1982-01-01

    Reviewed in this statement are methods of preparing solutions to be used in laboratory experiments to examine technical issues related to the safe disposal of nuclear waste from power generation. Each approach currently used to prepare solutions has advantages and any one approach may be preferred over the others in particular situations, depending upon the goals of the experimental program. These advantages are highlighted herein for three approaches to solution preparation that are currently used most in studies of nuclear waste disposal. Discussion of the disadvantages of each approach is presented to help a user select a preparation method for his particular studies. Also presented in this statement are general observations regarding solution preparation. These observations are used as examples of the types of concerns that need to be addressed regarding solution preparation. As shown by these examples, prior to experimentation or chemical analyses, laboratory techniques based on scientific knowledge of solutions can be applied to solutions, often resulting in great improvement in the usefulness of results

  8. The crystal structure of emilite, Cu10.7Pb10.7Bi21.3S48, the second 45 Å derivative of the bismuthinite-aikinite solid-solution series

    DEFF Research Database (Denmark)

    Balic-Zunic, Tonci; Topa, Dan; Makovicky, Emil

    2002-01-01

    geology, emilite, Cu10.7Pb10.7Bi21.3S48, aikinite-bismuthinite derivative, crystal structure, Felbertal, scheelite deposit, Austria......geology, emilite, Cu10.7Pb10.7Bi21.3S48, aikinite-bismuthinite derivative, crystal structure, Felbertal, scheelite deposit, Austria...

  9. The crystal structure of Cu1.6Pb1.6Bi6.4S12, a new 44.8 Å derivative of the bismuthinite-aikinite solid-solution series

    DEFF Research Database (Denmark)

    Topa, Dan; Balic-Zunic, Tonci; Makovicky, Emil

    2000-01-01

    Cu1.6Pb1.6Bi6.4S12, aikinite-bismuthinite derivative, crystal structure, Felbertal, scheelite deposit, Austria......Cu1.6Pb1.6Bi6.4S12, aikinite-bismuthinite derivative, crystal structure, Felbertal, scheelite deposit, Austria...

  10. Financial derivatives

    OpenAIRE

    Koutný, Ondřej

    2012-01-01

    1 Abstract/ Financial derivatives The purpose of this thesis is to provide an introduction to financial derivatives which has been, from the legal perspective, described in a not satisfactory manner as quite little literature that can be found about this topic. The main objectives of this thesis are to define the term "financial derivatives" and its particular types and to analyse legal nature of these financial instruments. The last objective is to try to draft future law regulation of finan...

  11. Financial Derivatives

    DEFF Research Database (Denmark)

    Wigan, Duncan

    2013-01-01

    Contemporary derivatives mark the development of capital and constitute a novel form of ownership. By reconfiguring the temporal, spatial and legal character of ownership derivatives present a substantive challenge to the tax collecting state. While fiscal systems are nationally bounded and inheren......Contemporary derivatives mark the development of capital and constitute a novel form of ownership. By reconfiguring the temporal, spatial and legal character of ownership derivatives present a substantive challenge to the tax collecting state. While fiscal systems are nationally bounded...

  12. Multipolar Solutions

    OpenAIRE

    Quevedo, Hernando

    2012-01-01

    A class of exact solutions of the Einstein-Maxwell equations is presented which contains infinite sets of gravitoelectric, gravitomagnetic and electromagnetic multipole moments. The multipolar structure of the solutions indicates that they can be used to describe the exterior gravitational field of an arbitrarily rotating mass distribution endowed with an electromagnetic field. The presence of gravitational multipoles completely changes the structure of the spacetime because of the appearance...

  13. An Iteration Method Generating Analytical Solutions for Blasius Problem

    OpenAIRE

    Yun, Beong In

    2011-01-01

    We derive a new iteration method for finding solution of the generalized Blasius problem. This method results in the analytical series solutions which are consistent with the existing series solutions for some special cases.

  14. Perturbation Solutions of the Quintic Duffing Equation with Strong Nonlinearities

    Directory of Open Access Journals (Sweden)

    Mehmet Pakdemirli

    Full Text Available The quintic Duffing equation with strong nonlinearities is considered. Perturbation solutions are constructed using two different techniques: The classical multiple scales method (MS and the newly developed multiple scales Lindstedt Poincare method (MSLP. The validity criteria for admissible solutions are derived. Both approximate solutions are contrasted with the numerical solutions. It is found that MSLP provides compatible solution with the numerical solution for strong nonlinearities whereas MS solution fail to produce physically acceptable solution for large perturbation parameters.

  15. Global Derivatives

    DEFF Research Database (Denmark)

    Andersen, Torben Juul

    ." - Steen Parsholt, Chairman and CEO, Aon Nordic Region. "Andersen has done a wonderful job of developing a comprehensive text that deals with risk management in global markets. I would recommend this book to any student or businessman who has a need to better understand the risks and risk management......""In Global Derivatives: A Strategic Risk Management Perspective", Torben Juul Andersen has succeeded to gather in one book a complete and thorough summary and an easy-to-read explanation of all types of derivative instruments and their background, and their use in modern management of risk...... approaches to dealing in the global business environment." - Sharon Brown-Hruska, Commissioner, Commodity Futures Trading Commission, USA. "This comprehensive survey of modern risk management using derivative securities is a fine demonstration of the practical relevance of modern derivatives theory to risk...

  16. Polymer solutions

    Science.gov (United States)

    Krawczyk, Gerhard Erich [Bremen, DE; Miller, Kevin Michael [West Dundee, IL

    2011-07-26

    There is provided a method of making a polymer solution comprising polymerizing one or more monomer in a solvent, wherein said monomer comprises one or more ethylenically unsaturated monomer that is a multi-functional Michael donor, and wherein said solvent comprises 40% or more by weight, based on the weight of said solvent, one or more multi-functional Michael donor.

  17. Solution Prototype

    DEFF Research Database (Denmark)

    Efeoglu, Arkin; Møller, Charles; Serie, Michel

    2013-01-01

    environment. The solution prototype that is composed from blending product and service prototype has particular impacts on the dualism of DSR’s “Build” and “Evaluate”. Since the mix between product and service prototyping can be varied, there is a demand for a more agile and iterative framework. Van de Ven...

  18. Podcast solutions

    CERN Document Server

    Geoghegan, Michael W

    2005-01-01

    Podcasting is the art of recording radio show style audio tracks, then distributing them to listeners on the Web via podcasting software such as iPodder. From downloading podcasts to producing a track for fun or profit, ""Podcast Solutions"" covers the entire world of podcasting with insight, humor, and the unmatched wisdom of experience.

  19. Homotopy Shear Band Solutions in Gradient Plasticity

    Science.gov (United States)

    Raees, Ammarah; Xu, Hang; Aifantis, Elias C.

    2017-05-01

    Analytical shear band type solutions for finite domains are derived within the framework of gradient plasticity theory by employing the homotopy analysis method (HAM). Such types of solutions were available in the literature only for infinite domains in the nonlinear material softening regime and steady-state conditions, as well as for finite domains in the material hardening regime. HAM allows for solutions to be obtained for both hardening and softening material models, as well as for unsteady conditions periodic solutions are also derived. The HAM results are verified with numerical simulations, which show excellent agreement. Moreover, an error analysis is provided which guarantees the convergence of our series solution.

  20. Hyperscaling violating solutions in generalised EMD theory

    Directory of Open Access Journals (Sweden)

    Li Li

    2017-04-01

    Full Text Available This short note is devoted to deriving scaling but hyperscaling violating solutions in a generalised Einstein–Maxwell-Dilaton theory with an arbitrary number of scalars and vectors. We obtain analytic solutions in some special case and discuss the physical constraints on the allowed parameter range in order to have a well-defined holographic ground-state solution.

  1. Hyperscaling violating solutions in generalised EMD theory

    Energy Technology Data Exchange (ETDEWEB)

    Li, Li, E-mail: lil416@lehigh.edu [Crete Center for Theoretical Physics, Institute for Theoretical and Computational Physics, Department of Physics, University of Crete, 71003 Heraklion (Greece); Crete Center for Quantum Complexity and Nanotechnology, Department of Physics, University of Crete, 71003 Heraklion (Greece); Department of Physics, Lehigh University, Bethlehem, PA, 18018 (United States)

    2017-04-10

    This short note is devoted to deriving scaling but hyperscaling violating solutions in a generalised Einstein–Maxwell-Dilaton theory with an arbitrary number of scalars and vectors. We obtain analytic solutions in some special case and discuss the physical constraints on the allowed parameter range in order to have a well-defined holographic ground-state solution.

  2. Transfer functions for solid-solution partitioning of cadmium, copper, nickel, lead and zinc in soils: derivation of relationships for free metal ion activities and validation with independent data

    NARCIS (Netherlands)

    Groenenberg, J.E.; Römkens, P.F.A.M.; Comans, R.N.J.; Luster, J.; Pampura, T.; Shotbolt, L.; Tipping, E.; Vries, de W.

    2010-01-01

    Models to predict the solid-solution partitioning of trace metals are important tools in risk assessment, providing information on the biological availability of metals and their leaching. Empirically based models, or transfer functions, published to date differ with respect to the mathematical

  3. Semianalytic Solution of Space-Time Fractional Diffusion Equation

    Directory of Open Access Journals (Sweden)

    A. Elsaid

    2016-01-01

    Full Text Available We study the space-time fractional diffusion equation with spatial Riesz-Feller fractional derivative and Caputo fractional time derivative. The continuation of the solution of this fractional equation to the solution of the corresponding integer order equation is proved. The series solution of this problem is obtained via the optimal homotopy analysis method (OHAM. Numerical simulations are presented to validate the method and to show the effect of changing the fractional derivative parameters on the solution behavior.

  4. Global Derivatives

    DEFF Research Database (Denmark)

    Andersen, Torben Juul

    , postgraduate qualification or MBA programme. This book also caters for practicing managers and executives who need to understand current developments in global derivatives markets and require cutting-edge insight on strategic risk management issues. Dr Torben Juul Andersen is currently Associate Professor...... approaches to dealing in the global business environment." - Sharon Brown-Hruska, Commissioner, Commodity Futures Trading Commission, USA. "This comprehensive survey of modern risk management using derivative securities is a fine demonstration of the practical relevance of modern derivatives theory to risk...... management practice. Of particular note is the global and integrated approach chosen in this book which should be of special interest to aspiring managers active in global and international markets." - Dr Jean-Pierre Zigrand, Lecturer in Finance, London School of Economics, UK. More than 90 per cent...

  5. Electricity derivatives

    CERN Document Server

    Aïd, René

    2015-01-01

    Offering a concise but complete survey of the common features of the microstructure of electricity markets, this book describes the state of the art in the different proposed electricity price models for pricing derivatives and in the numerical methods used to price and hedge the most prominent derivatives in electricity markets, namely power plants and swings. The mathematical content of the book has intentionally been made light in order to concentrate on the main subject matter, avoiding fastidious computations. Wherever possible, the models are illustrated by diagrams. The book should allow prospective researchers in the field of electricity derivatives to focus on the actual difficulties associated with the subject. It should also offer a brief but exhaustive overview of the latest techniques used by financial engineers in energy utilities and energy trading desks.

  6. A study on preparation of new core [99mTc (CO)2 (NO)]2+ and its derivatives [99mTc (CO)2 (NO)-L] (L=DTPA/DETA/EHIDA) in aqueous solution

    International Nuclear Information System (INIS)

    Liu Jingying; Yang Yang; Qiao Jinping; Zhu Lin

    2008-01-01

    Two different procedures for preparation of [ 99m Tc(CO) 2 (NO)-L] (L=DTPA/EDTA/EHIDA) complexes was developed in aqueous solution: one is formation of the metal-tricarbonyl-ligand complex and subsequent nitrosylation; another is nitrosylation of the metal-tricarbonyl precursor followed by reaction with the ligand. Results of TLC and HPLC indicate that the radiochemical yield of all radiolabeled compounds is more than 90%. It's a easier new way to prepare [ 99m Tc(CO) 2 (NO)-L] complexes in aqueous solution with high efficiency. The lipophility and net charge of [ 99m Tc(CO) 2 (NO)-L] complexes also change. It provides a new method for designing radiopharmaceuticals. (authors)

  7. Electricity derivatives

    OpenAIRE

    Barone-Adesi, Giovanni; Gigli, Andrea

    2006-01-01

    In this paper we propose an algorithm for pricing derivatives written on electricity in an incomplete market setting. A discrete time model for price dynamics which embodies the main features of electricity price revealed by simple time series analysis is considered. We use jointly Binomial and Monte Carlo methods for pricing under a risk-neutral measure of which we prove the existence.

  8. dione derivatives

    Indian Academy of Sciences (India)

    dione derivatives via de-Boc and cyclization reaction in modest yield. Spectroscopic (1H, 13C NMR, and Mass) and analytical techniques have been used to identify and confirm the structure of the products. Keywords. Triflic anhydride; Boc anhydride; Negishi coupling; acid-amine coupling; cyclization reaction; cytotoxicity ...

  9. Association of Chernobyl-derived 239+240Pu, 241Am, 90Sr and 137Cs with different molecular size fractions of organic matter in the soil solution of two grassland soils

    International Nuclear Information System (INIS)

    Bunzl, K.; Kracke, W.; Agapkina, G.I.; Tikhomirov, A.; Shcheglov, A.I.

    1998-01-01

    Radiocesium is normally bound only rather weakly and unspecifically by humic substances, in contrast to the actinides Pu and Am. Recently, however, it was observed that fallout 137 Cs in the soil solution from an Of-horizon of a podzol forest soil (slightly decomposed plant material) was associated essentially only with one single size fraction of the humic substances. In deeper soil layers with well humified material (AOh-horizon), radiocesium was associated with all size fractions of the dissolved organic matter (DOM). To examine whether this unexpected behaviour is also observable for DOM isolated from other soils, we determined the association of fallout 137 Cs, 90 Sr, 238 Pu, 239+240 Pu and 241 Am with various size fractions of DOM from in situ soil solutions isolated from two layers (0-2 cm and 2-5 cm) of two grassland soils (a soddy podzolic soil and a peat soil) within the 10 km zone of the nuclear reactor at Chernobyl (Ukraine). The four size fractions of DOM as obtained by gel filtration of the soil solution were (mean nominal molecular weight in daltons): fraction I: ≥2000, fraction II: 1300; fraction III: 560, fraction IV: inorganic compounds. The results for the well humified DOM (humus accumulation horizon of podzol, deeper layer of peat soil) showed that Pu and Am are essentially associated with the high molecular weight fractions, while Sr is present only in the 'inorganic' fraction. Radiocesium is found in all the size fractions separated. A quite similar pattern was also found for Pu, Am, and Sr in the soil solution from only slightly decomposed plant material (0-2 cm of peat soil), but not for radiocesium. This radionuclide was again essentially only observable in one single low molecular weight fraction of DOM. The above results thus support our recent observations in the different horizons of a forest podzol mentioned above, even though no reason for the different binding of radiocesium by well humified soil organic matter and by only

  10. Solution Leaching

    Science.gov (United States)

    Chun, Tiejun; Zhu, Deqing; Pan, Jian; He, Zhen

    2014-06-01

    Recovery of alumina from magnetic separation tailings of red mud has been investigated by Na2CO3 solution leaching. X-ray diffraction (XRD) results show that most of the alumina is present as 12CaO·7Al2O3 and CaO·Al2O3 in the magnetic separation tailings. The shrinking core model was employed to describe the leaching kinetics. The results show that the calculated activation energy of 8.31 kJ/mol is characteristic for an internal diffusion-controlled process. The kinetic equation can be used to describe the leaching process. The effects of Na2CO3 concentration, liquid-to-solid ratio, and particle size on recovery of Al2O3 were examined.

  11. Co-seismic Displacement of the 25 April 2015 Nepal Ms8.1 Earthquake Effects on the China's Mount Everest Area Derived from GNSS Data Using the PPP Network Solution by UPD Ambiguity Fixed Technology

    Directory of Open Access Journals (Sweden)

    WANG Hu

    2017-05-01

    Full Text Available Co-seismic displacement of the GNSS stations in areas surrounding the earthquake are accurately obtained using UPD (uncalibrated phase delay ambiguity fixed technology without having to consider the effects of earthquake on the GNSS baseline calculating. During the 25 April 2015 Nepal Ms8.1 seismological GNSS data from the National Datum Engineering of China, the Crustal Movement Observation Network of China and the Mount Everest GNSS stations are calculated using UPD ambiguity fixed technology, then co-seismic displacement field of the China's Mount Everest and surrounding areas are derived and analyzed. Firstly, the UPD of wide-lane and narrow lane are estimated using the uniform distribution National GNSS and the surrounding IGS stability stations away from the seismic zones. Secondly, the float carrier phase ambiguities from each GNSS station in the seismic zones are fixed using the UPD of wide-lane and narrow until all the GNSS station are completed. Then whole network GNSS station coordinates are just only estimated using the accurately phase observations without ambiguity form all the GNSS stations. The GNSS data from IGS stations are used to verify the precision of the above method. Finally, Co-seismic displacement field of the China's Mount Everest are derived and particularly analyzed. From 2005 to 2015 year the displacement of China's Mount Everest are showed. Meanwhlile, this paper provides a precise and reliable method to monitor earthquake.

  12. The development of the architectural form of a tower derived from a traditional and philosophical symbol, realized by solutions of high-class technologies. The case of the Bitexco Financial Tower

    Science.gov (United States)

    Van Khai, Tran

    2018-03-01

    The Bitexco Financial Tower, majestically standing tall in the heart of Ho Chi Minh City, Vietnam, rejects the box-shaped, abstract forms of modernism, incorporating an innovative idea of contemporary architecture. Based on the inspiration from the Bitexco Group, a renowned architect designedthe tower that became an iconic landmark of the city in the form of a lotus bud, one of the most iconic symbols of Vietnamese culture since ancient times. High class structural system solution designed by top international professional teams enable the building to rise high with its graceful, statuesque design of the lotus flower shape. CNNGo recently ranked the Bitexco Financial Tower fifth in their listing of the world's 20 most-iconic skyscrapers.

  13. Complexability of o-bisguanidinobenzenes with arsenic and phosphoric acids in solution and solid states, and the potential use of their immobilized derivatives as solid base ligands for metal salts and arsenic acid.

    Science.gov (United States)

    Ito, Tomoya; Suda, Koji; Kumamoto, Takuya; Nakanishi, Waka; Watanabe, Toshiko; Ishikawa, Tsutomu; Seki, Hiroko; Kawahata, Masatoshi; Yamaguchi, Kentaro; Ogura, Yasumitsu; Suzuki, Kazuo T

    2010-02-01

    The role of o-bisguanidinobenzenes (BGBs) as new Brønsted base ligands for arsenic and phosphoric acids was examined. In solution state, complexation was evaluated by Job's plot in (1)H NMR experiment, indicating a 1:1 complex formation, whereas in solid state crystalline structures of complexes obtained were addressed by X-ray crystallographic analysis and/or solid state (13)C NMR experiment, in which 1:2 complexes between the BGB and the acid components were normally formed. Based on these results, Merrifield and Hypogel resin-anchored BGBs were designed and prepared as the corresponding polymer-supported host ligands. Evaluation of their coordination ability with metal salts (ZnCl(2) and CoCl(2)) and arsenic acid in aqueous media by ICP-MS showed that the latter Hypogel resin-anchored BGBs acted as effective immobilized base ligands.

  14. Accurate estimates of solutions of second order recursions

    NARCIS (Netherlands)

    Mattheij, R.M.M.

    1975-01-01

    Two important types of two dimensional matrix-vector and second order scalar recursions are studied. Both types possess two kinds of solutions (to be called forward and backward dominant solutions). For the directions of these solutions sharp estimates are derived, from which the solutions

  15. Traveling Wave Solutions in a Reaction-Diffusion Epidemic Model

    OpenAIRE

    Wang, Sheng; Liu, Wenbin; Guo, Zhengguang; Wang, Weiming

    2013-01-01

    We investigate the traveling wave solutions in a reaction-diffusion epidemic model. The existence of the wave solutions is derived through monotone iteration of a pair of classical upper and lower solutions. The traveling wave solutions are shown to be unique and strictly monotonic. Furthermore, we determine the critical minimal wave speed.

  16. Cationic metallocene polymerization catalysts based on tetrakis(pentafluorophenyl)borate and its derivatives. Probing the limits of anion `noncoordination` via a synthetic, solution dynamic, structural, and catalytic olefin polymerization study

    Energy Technology Data Exchange (ETDEWEB)

    Jia, L.; Yang, X.; Stern, C.L.; Marks, T.J. [Northwestern Univ., Evanston, IL (United States)

    1997-03-04

    The silyl-functionalized/protected derivatives of the tetrakis(perfluoroaryl)borate anions, B(C{sub 6}F{sub 4}TBS){sub 4}{sup -} and B(C{sub 6}F{sub 4}TIPS){sub 4}{sup -} (TBS = tert-butyldimethylsilyl and TIPS = triisopropylsilyl) have been synthesized, and a series of stable, highly reactive Zr and Th ion-paired methyl and hydride catalysts have been isolated using these anions. In contrast, the analogous B(C{sub 6}F{sub 5}){sub 4}{sup -}-based zirconocene methyl complexes are not stable at room temperature; however, B(C{sub 6}F{sub 5}){sub 4}{sup -}-based zirconocene hydride complexes can be isolated. The relative coordinative ability of the series of fluoroarylborates with respect to metallocene cations has been evaluated on the basis of spectroscopic and reactivity data. The polymerization activity of the zirconocene catalysts reaches a maximum when B(C{sub 6}F{sub 4}TBS){sub 4}{sup -} and B(C{sub 6}F{sub 4}TIPS){sub 4}{sup -} are counteranions, and the polymerization activity of the Zr constrained geometry catalyst reaches a maximum in aromatic solvents due to arene coordination when B(C{sub 6}F{sub 5}){sub 4}{sup -} is the counteranion. 37 refs., 5 figs., 7 tabs.

  17. Strongly nonlinear oscillators analytical solutions

    CERN Document Server

    Cveticanin, Livija

    2014-01-01

    This book provides the presentation of the motion of pure nonlinear oscillatory systems and various solution procedures which give the approximate solutions of the strong nonlinear oscillator equations. The book presents the original author’s method for the analytical solution procedure of the pure nonlinear oscillator system. After an introduction, the physical explanation of the pure nonlinearity and of the pure nonlinear oscillator is given. The analytical solution for free and forced vibrations of the one-degree-of-freedom strong nonlinear system with constant and time variable parameter is considered. Special attention is given to the one and two mass oscillatory systems with two-degrees-of-freedom. The criteria for the deterministic chaos in ideal and non-ideal pure nonlinear oscillators are derived analytically. The method for suppressing chaos is developed. Important problems are discussed in didactic exercises. The book is self-consistent and suitable as a textbook for students and also for profess...

  18. Periodic Solutions and S-Asymptotically Periodic Solutions to Fractional Evolution Equations

    Directory of Open Access Journals (Sweden)

    Jia Mu

    2017-01-01

    Full Text Available This paper deals with the existence and uniqueness of periodic solutions, S-asymptotically periodic solutions, and other types of bounded solutions for some fractional evolution equations with the Weyl-Liouville fractional derivative defined for periodic functions. Applying Fourier transform we give reasonable definitions of mild solutions. Then we accurately estimate the spectral radius of resolvent operator and obtain some existence and uniqueness results.

  19. Static and stationary multiple soliton solutions to the Einstein equations

    International Nuclear Information System (INIS)

    Letelier, P.S.

    1985-01-01

    The application of the Belinsky--Zakharov solution-generating technique, i.e., the inverse scattering method, to generate stationary axially symmetric solutions to the vacuum Einstein equations is reduced to a single quadrature when the seed solution is diagonal. The possibility of having real odd-number soliton solutions is investigated. These solutions represent solitonic perturbations of Euclidean metrics. The possibility of using instantons as seed solutions is also investigated. The one- and two-soliton solutions generated from a diagonal seed solution are studied. As an application, a unified derivation of some well-known static solutions, like the Schwarzschild metric and the Chazy--Curzon metric, as well as other new metrics is presented. By using these metrics as seed solutions, some known stationary solutions, like the Kerr-NUT metric, the double Kerr metric, and the rotating Weyl C-metric, as well as other new metrics are also derived in a unified way

  20. Boundary Value Problems and Approximate Solutions ...

    African Journals Online (AJOL)

    In this paper, we discuss about some basic things of boundary value problems. Secondly, we study boundary conditions involving derivatives and obtain finite difference approximations of partial derivatives of boundary value problems. The last section is devoted to determine an approximate solution for boundary value ...

  1. Substrate-dependent ferroelectric and dielectric properties of Mn doped Na{sub 0.5}Bi{sub 0.5}TiO{sub 3} thin films derived by chemical solution decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Feng, C. [School of Materials Science and Engineering, University of Jinan, Jinan, 250022 (China); Yang, C.H., E-mail: fengchao901008@163.com [School of Materials Science and Engineering, University of Jinan, Jinan, 250022 (China); Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan, 250022 (China); Zhou, Y.Y.; Geng, F.J.; Lv, P.P.; Yao, Q. [School of Materials Science and Engineering, University of Jinan, Jinan, 250022 (China)

    2016-09-15

    Na{sub 0.5}Bi{sub 0.5}(Ti{sub 0.98}Mn{sub 0.02})O{sub 3} (NBTMn) thin films have been fabricated on Pt/TiO{sub 2}/SiO{sub 2}/Si and LaNiO{sub 3} (LNO)/Si substrates via chemical solution decomposition. The microstructure, ferroelectric and dielectric properties were investigated. Both films on different substrates can be crystallized into the phase-pure perovskite structures. The NBTMn thin film deposited on Pt/TiO{sub 2}/SiO{sub 2}/Si substrate shows random orientation with (l00) and (110) diffraction peaks, while the sample on LNO/Si exhibits preferred orientation with strong diffraction peaks of (l00). The NBTMn thin film deposited on LNO/Si substrate exhibits a denser and smoother microstructure. Compared with the round shaped polarization-electric field hysteresis loops of NBTMn on Pt/TiO{sub 2}/SiO{sub 2}/Si substrate, the enhanced ferroelectric property can be observed in NBTMn thin film fabricated on LNO/Si with a remanent polarization (P{sub r}) of 10.2 μC/cm{sup 2} due to the reduced leakage current. The dielectric tunabilities of two films increase gradually with the increasing of applied voltage, and the sample on LNO/Si substrate has a relatively larger dielectric tunability with 20% at 14 V and 1 MHz. - Graphical abstract: Na{sub 0.5}Bi{sub 0.5}(Ti{sub 0.98}Mn{sub 0.02})O{sub 3} (NBTMn) thin films have been fabricated on Pt/Si and LaNiO{sub 3} (LNO)/Si substrates. Compared with the NBTMn thin film deposited on Pt/Si substrate which shows poor P-E loops with a round shaped feature because of the high leakage current, the NBTMn thin film on LNO/Si substrate exhibits much improved P-E loops with a slim shaped feature and a remanent polarization of 10.2 μC/cm{sup 2}. - Highlights: • The phase-pure perovskite can be obtained with both adopted substrates. • Obviously reduced leakage current can be obtained in thin film on LNO/Si substrate. • A well-defined P-E loop is achieved in NBTMn thin film on LNO/Si substrate. • The dielectric properties of

  2. Higher-derivative massive actions from dimensional reduction

    Science.gov (United States)

    Joung, Euihun; Mkrtchyan, Karapet

    2013-02-01

    A procedure to obtain higher-derivative free massive actions is proposed. It consists in dimensional reduction of conventional two-derivative massless actions, where solutions to constraints bring in higher derivatives. We apply this procedure to derive the arbitrary dimensional generalizations of (linearized) New Massive Gravity and New Topologically Massive Gravity.

  3. New Similarity Reduction Solutions for the (2+1)-Dimensional Nizhnik—Novikov—Veselov Equation

    Science.gov (United States)

    Zhi, Hong-Yan

    2013-03-01

    In this paper, some new formal similarity reduction solutions for the (2+1)-dimensional Nizhnik-Novikov-Veselov equation are derived. Firstly, we derive the similarity reduction of the NNV equation with the optimal system of the admitted one-dimensional subalgebras. Secondly, by analyzing the reduced equation, three types of similarity solutions are derived, such as multi-soliton like solutions, variable separations solutions, and KdV type solutions.

  4. An Analytical Method of Auxiliary Sources Solution for Plane Wave Scattering by Impedance Cylinders

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2004-01-01

    Analytical Method of Auxiliary Sources solutions for plane wave scattering by circular impedance cylinders are derived by transformation of the exact eigenfunction series solutions employing the Hankel function wave transformation. The analytical Method of Auxiliary Sources solution thus obtained...

  5. New exact solutions of the (2 + 1)-dimensional breaking soliton system via an extended mapping method

    International Nuclear Information System (INIS)

    Ma Songhua; Fang Jianping; Zheng Chunlong

    2009-01-01

    By means of an extended mapping method and a variable separation method, a series of solitary wave solutions, periodic wave solutions and variable separation solutions to the (2 + 1)-dimensional breaking soliton system is derived.

  6. Synthesis of 2-phosphaadamantane derivatives

    International Nuclear Information System (INIS)

    Zemlyanoi, V.N.; Aleksandrov, A.M.; Kukhar', V.P.

    1986-01-01

    The authors describe the synthesis and properties of 2-phosphadamantane derivatives. For the synthesis of 2-phosphaadamantane derivatives they decided to use the methodology of the synthesis of 2-thiaadamantane. The IR spectra were determined on CHCl 3 solutions with a Specord 711R spectrometer, the PMR spectra were determined on Tesla BS-467 (60 MHz) and Bruker WP-200 (200 MHz) spectrometers, external standard hexamethyldisiloxane, the 31 P NMR spectra were determined on Tesla BS-487 C (30 MHz) and Bruker WP-200 (81 MHz) spectrometers, external standard 85% phosphoric acid, and the mass spectra were determined on an MS-1302 spectrometer

  7. Dimension and deriving manner for derived quantities

    International Nuclear Information System (INIS)

    Zhao Zhixiang

    1993-01-01

    Most physical quantities we are interested in are derived from some directly measured physical quantities. To obtain correct least-square result in derived quantity space, one must pay attention to inconsistencies problem to avoid ppp phenomenon in generating derived quantities and their covariance matrix. The situation is complicated by the problems of dimension and deriving manner for derived quantities. Some more general problems, which are independent of ppp, are discussed

  8. Ineffective higher derivative black hole hair

    Science.gov (United States)

    Goldstein, Kevin; Mashiyane, James Junior

    2018-01-01

    Inspired by the possibility that the Schwarzschild black hole may not be the unique spherically symmetric vacuum solution to generalizations of general relativity, we consider black holes in pure fourth order higher derivative gravity treated as an effective theory. Such solutions may be of interest in addressing the issue of higher derivative hair or during the later stages of black hole evaporation. Non-Schwarzschild solutions have been studied but we have put earlier results on a firmer footing by finding a systematic asymptotic expansion for the black holes and matching them with known numerical solutions obtained by integrating out from the near-horizon region. These asymptotic expansions can be cast in the form of trans-series expansions which we conjecture will be a generic feature of non-Schwarzschild higher derivative black holes. Excitingly we find a new branch of solutions with lower free energy than the Schwarzschild solution, but as found in earlier work, solutions only seem to exist for black holes with large curvatures, meaning that one should not generically neglect even higher derivative corrections. This suggests that one effectively recovers the nonhair theorems in this context.

  9. Analytical solution of groundwater waves in unconfined aquifers with ...

    Indian Academy of Sciences (India)

    A new analytical solution is derived for tide-driven groundwater waves in coastal aquifers using higher-order Boussinesq equation. The homotopy perturbation solution is derived using a virtual perturbation approach without any pre-defined physical parameters. The secular term removal is performed using a combinationof ...

  10. A Dual Egalitarian Solution

    NARCIS (Netherlands)

    Klijn, F.; Slikker, M.; Tijs, S.H.

    2000-01-01

    In this note we introduce an egalitarian solution, called the dual egalitarian solution, that is the natural counterpart of the egalitarian solution of Dutta and Ray (1989).We prove, among others, that for a convex game the egalitarian solution coincides with the dual egalitarian solution for its

  11. New Exact Solutions for the (3+1-Dimensional Generalized BKP Equation

    Directory of Open Access Journals (Sweden)

    Jun Su

    2016-01-01

    Full Text Available The Wronskian technique is used to investigate a (3+1-dimensional generalized BKP equation. Based on Hirota’s bilinear form, new exact solutions including rational solutions, soliton solutions, positon solutions, negaton solutions, and their interaction solutions are formally derived. Moreover we analyze the strangely mechanical behavior of the Wronskian determinant solutions. The study of these solutions will enrich the variety of the dynamics of the nonlinear evolution equations.

  12. Infinite derivative gravity : non-singular cosmology & blackhole solutions

    NARCIS (Netherlands)

    Mazumdar, Anupam

    2017-01-01

    Both Einstein's theory of General Relativity and Newton's theory of gravity possess a short dis- tance and small time scale catastrophe. The blackhole singularity and cosmological Big Bang singularity problems highlight that current theories of gravity are incomplete description at early times and

  13. Solution-derived photocatalytic films for environmental cleaning applications

    International Nuclear Information System (INIS)

    Štangar, U Lavrencic; Kete, M; Šuligoj, A; Tasbihi, M

    2012-01-01

    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 TiO 2 /SiO 2 films for self-cleaning purposes and thicker TiO 2 /SiO 2 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.

  14. Sol-gel derived sorbents

    Science.gov (United States)

    Sigman, Michael E.; Dindal, Amy B.

    2003-11-11

    Described is a method for producing copolymerized sol-gel derived sorbent particles for the production of copolymerized sol-gel derived sorbent material. The method for producing copolymerized sol-gel derived sorbent particles comprises adding a basic solution to an aqueous metal alkoxide mixture for a pH.ltoreq.8 to hydrolyze the metal alkoxides. Then, allowing the mixture to react at room temperature for a precalculated period of time for the mixture to undergo an increased in viscosity to obtain a desired pore size and surface area. The copolymerized mixture is then added to an immiscible, nonpolar solvent that has been heated to a sufficient temperature wherein the copolymerized mixture forms a solid upon the addition. The solid is recovered from the mixture, and is ready for use in an active sampling trap or activated for use in a passive sampling trap.

  15. Static Solutions of Einstein's Equations with Cylindrical Symmetry

    Science.gov (United States)

    Trendafilova, C. S.; Fulling, S. A.

    2011-01-01

    In analogy with the standard derivation of the Schwarzschild solution, we find all static, cylindrically symmetric solutions of the Einstein field equations for vacuum. These include not only the well-known cone solution, which is locally flat, but others in which the metric coefficients are powers of the radial coordinate and the spacetime is…

  16. Exact solution of the hidden Markov processes

    Science.gov (United States)

    Saakian, David B.

    2017-11-01

    We write a master equation for the distributions related to hidden Markov processes (HMPs) and solve it using a functional equation. Thus the solution of HMPs is mapped exactly to the solution of the functional equation. For a general case the latter can be solved only numerically. We derive an exact expression for the entropy of HMPs. Our expression for the entropy is an alternative to the ones given before by the solution of integral equations. The exact solution is possible because actually the model can be considered as a generalized random walk on a one-dimensional strip. While we give the solution for the two second-order matrices, our solution can be easily generalized for the L values of the Markov process and M values of observables: We should be able to solve a system of L functional equations in the space of dimension M -1 .

  17. Analytic computation of energy derivatives - Relationships among partial derivatives of a variationally determined function

    Science.gov (United States)

    King, H. F.; Komornicki, A.

    1986-01-01

    Formulas are presented relating Taylor series expansion coefficients of three functions of several variables, the energy of the trial wave function (W), the energy computed using the optimized variational wave function (E), and the response function (lambda), under certain conditions. Partial derivatives of lambda are obtained through solution of a recursive system of linear equations, and solution through order n yields derivatives of E through order 2n + 1, extending Puley's application of Wigner's 2n + 1 rule to partial derivatives in couple perturbation theory. An examination of numerical accuracy shows that the usual two-term second derivative formula is less stable than an alternative four-term formula, and that previous claims that energy derivatives are stationary properties of the wave function are fallacious. The results have application to quantum theoretical methods for the computation of derivative properties such as infrared frequencies and intensities.

  18. Cancer treatment model with the Caputo-Fabrizio fractional derivative

    Science.gov (United States)

    Ali Dokuyucu, Mustafa; Celik, Ercan; Bulut, Hasan; Mehmet Baskonus, Haci

    2018-03-01

    In this article, a model for cancer treatment is examined. The model is integrated into the Caputo-Fabrizio fractional derivative first, to examine the existence of the solution. Then, the uniqueness of the solution is investigated and we identified under which conditions the model provides a unique solution.

  19. Microscopic treatment of solute trapping and drag

    Science.gov (United States)

    Humadi, Harith; Hoyt, J. J.; Provatas, Nikolas

    2016-01-01

    The long wavelength limit of a recent microscopic phase-field crystal (PFC) theory of a binary alloy mixture is used to derive an analytical approximation for the segregation coefficient as a function of the interface velocity, and relate it to the two-point correlation function of the liquid and the thermodynamic properties of solid and liquid phases. Our results offer the first analytical derivation of solute segregation from a microscopic model, and support recent molecular dynamics and numerical PFC simulations. Our results also provide an independent framework, motivated from classical density functional theory, from which to elucidate the fundamental nature of solute drag, which is still highly contested in the literature.

  20. On new solutions of fuzzy differential equations

    International Nuclear Information System (INIS)

    Chalco-Cano, Y.; Roman-Flores, H.

    2008-01-01

    We study fuzzy differential equations (FDE) using the concept of generalized H-differentiability. This concept is based in the enlargement of the class of differentiable fuzzy mappings and, for this, we consider the lateral Hukuhara derivatives. We will see that both derivatives are different and they lead us to different solutions from a FDE. Also, some illustrative examples are given and some comparisons with other methods for solving FDE are made

  1. Multi loop soliton solutions and their interactions in the Degasperis-Procesi equation

    OpenAIRE

    Stalin, S.; Senthilvelan, M.

    2012-01-01

    In this article, we construct loop soliton solutions and mixed soliton - loop soliton solution for the Degasperis-Procesi equation. To explore these solutions we adopt the procedure given by Matsuno. By appropriately modifying the $\\tau$-function given in the above paper we derive these solutions. We present the explicit form of one and two loop soliton solutions and mixed soliton - loop soliton solutions and investigate the interaction between (i) two loop soliton solutions in different para...

  2. Fundamental solutions of singular SPDEs

    Energy Technology Data Exchange (ETDEWEB)

    Selesi, Dora, E-mail: dora@dmi.uns.ac.rs [Department of Mathematics and Informatics, University of Novi Sad (Serbia)

    2011-07-15

    Highlights: > Fundamental solutions of linear SPDEs are constructed. > Wick-convolution product is introduced for the first time. > Fourier transformation maps Wick-convolution into Wick product. > Solutions of linear SPDEs are expressed via Wick-convolution with fundamental solutions. > Stochastic Helmholtz equation is solved. - Abstract: This paper deals with some models of mathematical physics, where random fluctuations are modeled by white noise or other singular Gaussian generalized processes. White noise, as the distributional derivative od Brownian motion, which is the most important case of a Levy process, is defined in the framework of Hida distribution spaces. The Fourier transformation in the framework of singular generalized stochastic processes is introduced and its applications to solving stochastic differential equations involving Wick products and singularities such as the Dirac delta distribution are presented. Explicit solutions are obtained in form of a chaos expansion in the Kondratiev white noise space, while the coefficients of the expansion are tempered distributions. Stochastic differential equations of the form P({omega}, D) Lozenge u(x, {omega}) = A(x, {omega}) are considered, where A is a singular generalized stochastic process and P({omega}, D) is a partial differential operator with random coefficients. We introduce the Wick-convolution operator * which enables us to express the solution as u = s*A Lozenge I{sup Lozenge (-1)}, where s denotes the fundamental solution and I is the unit random variable. In particular, the stochastic Helmholtz equation is solved, which in physical interpretation describes waves propagating with a random speed from randomly appearing point sources.

  3. Fundamental solutions of singular SPDEs

    International Nuclear Information System (INIS)

    Selesi, Dora

    2011-01-01

    Highlights: → Fundamental solutions of linear SPDEs are constructed. → Wick-convolution product is introduced for the first time. → Fourier transformation maps Wick-convolution into Wick product. → Solutions of linear SPDEs are expressed via Wick-convolution with fundamental solutions. → Stochastic Helmholtz equation is solved. - Abstract: This paper deals with some models of mathematical physics, where random fluctuations are modeled by white noise or other singular Gaussian generalized processes. White noise, as the distributional derivative od Brownian motion, which is the most important case of a Levy process, is defined in the framework of Hida distribution spaces. The Fourier transformation in the framework of singular generalized stochastic processes is introduced and its applications to solving stochastic differential equations involving Wick products and singularities such as the Dirac delta distribution are presented. Explicit solutions are obtained in form of a chaos expansion in the Kondratiev white noise space, while the coefficients of the expansion are tempered distributions. Stochastic differential equations of the form P(ω, D) ◊ u(x, ω) = A(x, ω) are considered, where A is a singular generalized stochastic process and P(ω, D) is a partial differential operator with random coefficients. We introduce the Wick-convolution operator * which enables us to express the solution as u = s*A ◊ I ◊(-1) , where s denotes the fundamental solution and I is the unit random variable. In particular, the stochastic Helmholtz equation is solved, which in physical interpretation describes waves propagating with a random speed from randomly appearing point sources.

  4. Conformable derivative approach to anomalous diffusion

    Science.gov (United States)

    Zhou, H. W.; Yang, S.; Zhang, S. Q.

    2018-02-01

    By using a new derivative with fractional order, referred to conformable derivative, an alternative representation of the diffusion equation is proposed to improve the modeling of anomalous diffusion. The analytical solutions of the conformable derivative model in terms of Gauss kernel and Error function are presented. The power law of the mean square displacement for the conformable diffusion model is studied invoking the time-dependent Gauss kernel. The parameters related to the conformable derivative model are determined by Levenberg-Marquardt method on the basis of the experimental data of chloride ions transportation in reinforced concrete. The data fitting results showed that the conformable derivative model agrees better with the experimental data than the normal diffusion equation. Furthermore, the potential application of the proposed conformable derivative model of water flow in low-permeability media is discussed.

  5. Solutions of fractional diffusion equations by variation of parameters method

    Directory of Open Access Journals (Sweden)

    Mohyud-Din Syed Tauseef

    2015-01-01

    Full Text Available This article is devoted to establish a novel analytical solution scheme for the fractional diffusion equations. Caputo’s formulation followed by the variation of parameters method has been employed to obtain the analytical solutions. Following the derived analytical scheme, solution of the fractional diffusion equation for several initial functions has been obtained. Graphs are plotted to see the physical behavior of obtained solutions.

  6. Electronic absorption spectra of antiviral aminophenol derivatives

    Science.gov (United States)

    Belkov, M. V.; Ksendzova, G. A.; Raichyonok, T. F.; Skornyakov, I. V.; Sorokin, V. L.; Tolstorozhev, G. B.; Shadyro, O. I.

    2011-03-01

    Electronic absorption spectra of aminophenol derivatives in solutions have been studied. A general property of the absorption spectra of these compounds, the dependence of the maximum of a long-wavelength absorption band on the solvent polarity, is revealed. As a rule, the absorption band maximum of compounds possessing pharmacological properties shows a greater shift to short wavelength with an increase in the medium polarity than that of inactive compounds. Absorption measurements of solutions of aminophenol derivatives can be used for a tentative estimation of their antiviral activity.

  7. Interest rate derivatives

    DEFF Research Database (Denmark)

    Svenstrup, Mikkel

    This Ph.D. thesis consists of four self-contained essays on valuation of interest rate derivatives. In particular derivatives related to management of interest rate risk care are considered.......This Ph.D. thesis consists of four self-contained essays on valuation of interest rate derivatives. In particular derivatives related to management of interest rate risk care are considered....

  8. Colliding black hole solution

    International Nuclear Information System (INIS)

    Ahmed, Mainuddin

    2005-01-01

    A new solution of Einstein equation in general relativity is found. This solution solves an outstanding problem of thermodynamics and black hole physics. Also this work appears to conclude the interpretation of NUT spacetime. (author)

  9. Generalized Riemann derivative

    Directory of Open Access Journals (Sweden)

    Sorin Radulescu

    2013-03-01

    Full Text Available Initiated by Marshall Ash in 1966, the study of generalized Riemann derivative draw significant attention of the mathematical community and numerous studies where carried out since then. One of the major areas that benefits from these developments is the numerical analysis, as the use of generalized Riemann derivatives leads to solving a wider class of problems that are not solvable with the classical tools. This article studies the generalized Riemann derivative and its properties and establishes relationships between Riemann generalized derivative and the classical one. The existence of classical derivative implies the existence of the Riemann generalized derivative, and we study conditions necessary for the generalized Riemann derivative to imply the existence of the classical derivative. Furthermore, we provide conditions on the generalized Riemann derivative that are sufficient for the existence of the classical derivative.

  10. PFP solution stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Aftanas, B.L.

    1996-04-30

    This Functional Design Criteria (FDC) addresses remediation of the plutonium-bearing solutions currently in inventory at the Plutonium Finishing Plant (PFP). The recommendation from the Environmental Impact Statement (EIS) is that the solutions be treated thermally and stabilized as a solid for long term storage. For solutions which are not discardable, the baseline plan is to utilize a denitration process to stabilize the solutions prior to packaging for storage.

  11. Liquid scintillation solution

    International Nuclear Information System (INIS)

    Long, E.C.

    1977-01-01

    A liquid scintillation solution is described which includes (1) a scintillation solvent (toluene and xylene), (2) a primary scintillation solute (PPO and Butyl PBD), (3) a secondary scintillation solute (POPOP and Dimethyl POPOP), (4) a plurality of substantially different surfactants and (5) a filter dissolving and/or transparentizing agent. 8 claims

  12. Metric solution of a spinning mass

    International Nuclear Information System (INIS)

    Sato, H.

    1982-01-01

    Studies on a particular class of asymptotically flat and stationary metric solutions called the Kerr-Tomimatsu-Sato class are reviewed about its derivation and properties. For a further study, an almost complete list of the papers worked on the Tomimatsu-Sato metrics is given. (Auth.)

  13. Scaling solutions for dilaton quantum gravity

    Directory of Open Access Journals (Sweden)

    T. Henz

    2017-06-01

    The field equations derived from this effective action can be used directly for cosmology. Scale symmetry is spontaneously broken by a non-vanishing cosmological value of the scalar field. For the cosmology corresponding to our scaling solutions, inflation arises naturally. The effective cosmological constant becomes dynamical and vanishes asymptotically as time goes to infinity.

  14. Black holes in higher derivative gravity.

    Science.gov (United States)

    Lü, H; Perkins, A; Pope, C N; Stelle, K S

    2015-05-01

    Extensions of Einstein gravity with higher-order derivative terms arise in string theory and other effective theories, as well as being of interest in their own right. In this Letter we study static black-hole solutions in the example of Einstein gravity with additional quadratic curvature terms. A Lichnerowicz-type theorem simplifies the analysis by establishing that they must have vanishing Ricci scalar curvature. By numerical methods we then demonstrate the existence of further black-hole solutions over and above the Schwarzschild solution. We discuss some of their thermodynamic properties, and show that they obey the first law of thermodynamics.

  15. Radioiodination of C60 derivative

    International Nuclear Information System (INIS)

    Li Yuguo; Zhang Xiaodong; Li Qingnuan; Li Wenxin

    2001-01-01

    The water-soluble C 60 derivative was iodo-labelled radioactively with Iodogen method. The labelled yield was measured by Silica GF254 TLC. The effects of pH value, time, temperature and the amount of Iodogen on the labelled yield were studied. 125 I-C 60 (OH) x O y was purified by Sephadex G-25 column chromatography and then the stability of 125 I-C 60 (OH) x O y was examined. The results showed that the radiochemical purity of 125 I-C 60 (OH) x O y solution with 2% benzylalcohol remained 82.7% after 43h

  16. Family of electrovac colliding wave solutions of Einstein's equations

    International Nuclear Information System (INIS)

    Li, W.; Ernst, F.J.

    1989-01-01

    Beginning with any colliding wave solution of the vacuum Einstein equations, a corresponding electrified colliding wave solution can be generated through the use of a transformation due to Harrison [J. Math. Phys. 9, 1744 (1968)]. The method, long employed in the context of stationary axisymmetric fields, is equally applicable to colliding wave solutions. Here it is applied to a large family of vacuum metrics derived by applying a generalized Ehlers transformation to solutions published recently by Ernst, Garcia, and Hauser (EGH) [J. Math. Phys. 28, 2155, 2951 (1987); 29, 681 (1988)]. Those EGH solutions were themselves a generalization of solutions first derived by Ferrari, Ibanez, and Bruni [Phys. Rev. D 36, 1053 (1987)]. Among the electrovac solutions that are obtained is a charged version of the Nutku--Halil [Phys. Rev. Lett. 39, 1379 (1977)] metric that possesses an arbitrary complex charge parameter

  17. Radiological protection optimization using derivatives

    International Nuclear Information System (INIS)

    Freitas Acosta Perez, C. de; Sordi, G.M.A.A.

    2006-01-01

    The aim of this paper is to provide a different approach related to the integral cost-benefit and extended cost-benefit analysis used in the decision-aiding techniques. In the ICRP publication 55 the annual protection cost is envisaged as a set of points, each of them representing an option, linked by a straight line. The detriment cost function is considered a linear function whose angular coefficient is determined by the alpha value. In this paper the uranium mine example considered in the ICRP publication 55 was used. But the potential curve was introduced both in the integral cost benefit analysis and in the extended cost-benefit analysis, which the individual dose distribution attribute is added. The result was obtained using derivatives. The detriment cost, Y, is not necessary because the alpha value is known. The Y derivative dS/dY is the alpha value itself and so, the attention is directed to the derivative -dX/dS on the points that, along with the alpha value, present the optimum option. The results makes clear that the prevailing factor in the optimum option selection is the alpha value imputed, and those a single alpha value, as suggested now, probably as little efficiency on the optimization process. Obtaining a curve for the alpha value and using the derivative technique introduced in this paper, the analytical solution is more convenient and reliable compared to the one used now. (authors)

  18. Ten-dimensional supersymmetric Janus solutions

    Energy Technology Data Exchange (ETDEWEB)

    D' Hoker, Eric [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Estes, John [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Gutperle, Michael [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States)]. E-mail: gutperle@physics.ucla.edu

    2006-11-20

    The reduced field equations and BPS conditions are derived in Type IIB supergravity for configurations of the Janus type, characterized by an AdS{sub 4}-slicing of AdS{sub 5}, and various degrees of internal symmetry and supersymmetry. A generalization of the Janus solution, which includes a varying axion along with a varying dilaton, and has SO(6) internal symmetry, but completely broken supersymmetry, is obtained analytically in terms of elliptic functions. A two-parameter family of solutions with 4 real supersymmetries, SU(3) internal symmetry, a varying axion along with a varying dilaton, and non-trivial B{sub (2)} field, is derived analytically in terms of genus 3 hyper-elliptic integrals. This supersymmetric solution is the 10-dimensional Type IIB dual to the N=1 interface super-Yang-Mills theory with SU(3) internal symmetry previously found in the literature.

  19. On the solution of fractional evolution equations

    International Nuclear Information System (INIS)

    Kilbas, Anatoly A; Pierantozzi, Teresa; Trujillo, Juan J; Vazquez, Luis

    2004-01-01

    This paper is devoted to the solution of the bi-fractional differential equation ( C D α t u)(t, x) = λ( L D β x u)(t, x) (t>0, -∞ 0 and λ ≠ 0, with the initial conditions lim x→±∞ u(t,x) = 0 u(0+,x)=g(x). Here ( C D α t u)(t, x) is the partial derivative coinciding with the Caputo fractional derivative for 0 L D β x u)(t, x)) is the Liouville partial fractional derivative ( L D β t u)(t, x)) of order β > 0. The Laplace and Fourier transforms are applied to solve the above problem in closed form. The fundamental solution of these problems is established and its moments are calculated. The special case α = 1/2 and β = 1 is presented, and its application is given to obtain the Dirac-type decomposition for the ordinary diffusion equation

  20. Davey-Stewartson equation with fractional coordinate derivatives.

    Science.gov (United States)

    Jafari, H; Sayevand, K; Khan, Yasir; Nazari, M

    2013-01-01

    We have used the homotopy analysis method (HAM) to obtain solution of Davey-Stewartson equations of fractional order. The fractional derivative is described in the Caputo sense. The results obtained by this method have been compared with the exact solutions. Stability and convergence of the proposed approach is investigated. The effects of fractional derivatives for the systems under consideration are discussed. Furthermore, comparisons indicate that there is a very good agreement between the solutions of homotopy analysis method and the exact solutions in terms of accuracy.

  1. Proteins in solution: Fractal surfaces in solutions

    Directory of Open Access Journals (Sweden)

    R. Tscheliessnig

    2016-02-01

    Full Text Available The concept of the surface of a protein in solution, as well of the interface between protein and 'bulk solution', is introduced. The experimental technique of small angle X-ray and neutron scattering is introduced and described briefly. Molecular dynamics simulation, as an appropriate computational tool for studying the hydration shell of proteins, is also discussed. The concept of protein surfaces with fractal dimensions is elaborated. We finish by exposing an experimental (using small angle X-ray scattering and a computer simulation case study, which are meant as demonstrations of the possibilities we have at hand for investigating the delicate interfaces that connect (and divide protein molecules and the neighboring electrolyte solution.

  2. Hydration of urea and alkylated urea derivatives

    Science.gov (United States)

    Kaatze, Udo

    2018-01-01

    Compressibility data and broadband dielectric spectra of aqueous solutions of urea and some of its alkylated derivatives have been evaluated to yield their numbers Nh of hydration water molecules per molecule of solute. Nh values in a broad range of solute concentrations are discussed and are compared to hydration numbers of other relevant molecules and organic ions. Consistent with previous results, it is found that urea differs from other solutes in its unusually small hydration number, corresponding to just one third of the estimated number of nearest neighbor molecules. This remarkable hydration behavior is explained by the large density φH of hydrogen bonding abilities offered by the urea molecule. In terms of currently discussed models of reorientational motions and allied dynamics in water and related associating liquids, the large density φH causes a relaxation time close to that of undisturbed water with most parts of water encircling the solute. Therefore only a small part of disturbed ("hydration") water is left around each urea molecule. Adding alkyl groups to the basic molecule leads to Nh values which, within the series of n-alkylurea derivatives, progressively increase with the number of methyl groups per solute. With n-butylurea, Nh from dielectric spectra, in conformity with many other organic solutes, slightly exceeds the number of nearest neighbors. Compared to such Nh values, hydration numbers from compressibility data are substantially smaller, disclosing incorrect assumptions in the formula commonly used to interpret the experimental compressibilities. Similar to other series of organic solutes, effects of isomerization have been found with alkylated urea derivatives, indicating that factors other than the predominating density φH of hydrogen bond abilities contribute also to the hydration properties.

  3. reaction-diffusion system with fractional derivatives

    Directory of Open Access Journals (Sweden)

    Kamel Haouam

    2006-01-01

    Full Text Available We give some necessary conditions for local and global existence of a solution to reaction-diffusion system of type (FDS with temporal and spacial fractional derivatives. As in the case of single equation of type (STFE studied by M. Kirane et al. (2005, we prove that these conditions depend on the behavior of initial conditions for large |x|.

  4. Orbits 2nd order singularity-free solutions

    CERN Document Server

    Xu, Guochang

    2014-01-01

    In its 2nd edition, this book covers the theory of satellite orbits, derives the complete solutions of orbital disturbances, describes the algorithms of orbits determination and the applications of the theory to the phenomenon of physical satellite formation.

  5. Existence and uniqueness of solutions to impulsive fractional differential equations

    Directory of Open Access Journals (Sweden)

    Boualem Attou Slimani

    2009-01-01

    Full Text Available In this article, we establish sufficient conditions for the existence of solutions for a class of initial value problem for impulsive fractional differential equations involving the Caputo fractional derivative.

  6. Solution mining process

    International Nuclear Information System (INIS)

    Showalter, W.E.

    1984-01-01

    A solution mining process which may be used for uranium, thorium, vanadium, copper, nickel, molybdenum, rhenium, and selenium is claimed. During a first injection-and-production phase of between 6 months and 5 years, a leaching solution is injected through at least one well into the formation to solubilize the mineral values and form a pregnant liquor. This liquor is recovered through another well. The leaching solution contains sulfuric acid, nitric acid, hydrochloric acid, carbonic acid, an alkali metal carbonate, an alkali metal bicarbonate, ammonium carbonate or ammonium bicarbonate. Subsequently during a first production-only phase of between about 2 weeks and one year, injection of the leaching solution is suspended but pregnant liquor is still recovered. This stage is followed by a second injection-and-production phase of between 6 months and 5 years and a second production-only phase. The mineral values are separated from the pregnant liquor to form a barren liquor. The leaching agent is introduced into this liquor, and the solution is recycled. In a second claim for the solution mining of uranium, dilute carbonic acid is used as the leaching solution. The solution has a pH less than 7 and a bicarbonate ion concentration between about 380 ppm and 1000 ppm. The injection-and-production phase lasts between one and two years and the production only phase takes between one and four months. Carbon dioxide is introduced into the barren liquor to form a dilute carbonic acid solution and the solution is recycled

  7. Solution-grown crystals for neutron radiation detectors, and methods of solution growth

    Science.gov (United States)

    Zaitseva, Natalia; Carman, M Leslie; Payne, Steve

    2014-10-28

    An organic crystal according to one embodiment includes an organic crystal comprising diphenylacetylene and stilbene or a stilbene derivative, the crystal having physical characteristics of formation from solution, the organic crystal exhibiting a signal response signature for neutrons from a radioactive source. A system according to one embodiment includes an organic crystal comprising diphenylacetylene and stilbene or a stilbene derivative, the crystal having physical characteristics of formation from solution, the organic crystal exhibiting a signal response signature for neutrons from a radioactive source; and a photodetector for detecting the signal response of the organic crystal. Methods of making such crystals are also provided.

  8. Higher-order numerical solutions using cubic splines

    Science.gov (United States)

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

    1976-01-01

    A cubic spline collocation procedure was developed for the numerical solution of partial differential equations. This spline procedure is reformulated so that the accuracy of the second-derivative approximation is improved and parallels that previously obtained for lower derivative terms. The final result is a numerical procedure having overall third-order accuracy of a nonuniform mesh. Solutions using both spline procedures, as well as three-point finite difference methods, are presented for several model problems.

  9. Derivative Kernels: Numerics and Applications.

    Science.gov (United States)

    Hosseini, Mahdi S; Plataniotis, Konstantinos N

    2017-10-01

    A generalized framework for numerical differentiation (ND) is proposed for constructing a finite impulse response (FIR) filter in closed form. The framework regulates the frequency response of ND filters for arbitrary derivative-order and cutoff frequency selected parameters relying on interpolating power polynomials and maximally flat design techniques. Compared with the state-of-the-art solutions, such as Gaussian kernels, the proposed ND filter is sharply localized in the Fourier domain with ripple-free artifacts. Here, we construct 2D MaxFlat kernels for image directional differentiation to calculate image differentials for arbitrary derivative order, cutoff level and steering angle. The resulted kernel library renders a new solution capable of delivering discrete approximation of gradients, Hessian, and higher-order tensors in numerous applications. We tested the utility of this library on three different imaging applications with main focus on the unsharp masking. The reported results highlight the high efficiency of the 2D MaxFlat kernel and its versatility with respect to robustness and parameter control accuracy.

  10. Derivatives in emerging markets

    OpenAIRE

    Dubravko Mihaljek; Frank Packer

    2010-01-01

    Turnover of derivatives has grown more rapidly in emerging markets than in developed countries. Foreign exchange derivatives are the most commonly traded of all risk categories, with increasingly frequent turnover in emerging market currencies and a growing share of cross-border transactions. As the global reach of the financial centres in emerging Asia has expanded, the offshore trading of many emerging market currency derivatives has risen as well. Growth in derivatives turnover is positive...

  11. Solutions to Organizational Paradox

    DEFF Research Database (Denmark)

    Li, Xin; Worm, Verner; Peihong, Xie

    Organizations face all kinds of paradoxical problems. There exist various solutions to organizational paradoxes. We develop a typology that lists nine possible logical approaches to understanding the relationship between paradoxical opposites, out of which we identify five types of solutions...... to organizational paradox. Four of the five solutions are explicitly associated with four prominent philosophies. We show the relevance of the five solutions to the real world by applying our scheme to understand different solutions to the generic strategy paradox. Finally, we address the question whether...... there is a superior solution and point out the paradox of paradox resolving, namely, paradoxes cannot be resolved once for all and we have to live with them....

  12. Solution deposition assembly

    Science.gov (United States)

    Roussillon, Yann; Scholz, Jeremy H; Shelton, Addison; Green, Geoff T; Utthachoo, Piyaphant

    2014-01-21

    Methods and devices are provided for improved deposition systems. In one embodiment of the present invention, a deposition system is provided for use with a solution and a substrate. The system comprises of a solution deposition apparatus; at least one heating chamber, at least one assembly for holding a solution over the substrate; and a substrate curling apparatus for curling at least one edge of the substrate to define a zone capable of containing a volume of the solution over the substrate. In another embodiment of the present invention, a deposition system for use with a substrate, the system comprising a solution deposition apparatus; at heating chamber; and at least assembly for holding solution over the substrate to allow for a depth of at least about 0.5 microns to 10 mm.

  13. On the solution of the space-time fractional cubic nonlinear Schrödinger equation

    Science.gov (United States)

    Yousif, E. A.; Abdel-Salam, E. A.-B.; El-Aasser, M. A.

    2018-03-01

    The space-time fractional nonlinear Schrödinger equation is studied based on the modified Riemann-Liouville derivative. The fractional mapping expansion method is used to find analytical solution of this model. We discuss the effects of the fractional differential order on the W-soliton and bright soliton solutions. The derived solutions show direct proportionality between soliton intensities and the value of the fractional order derivative.

  14. Stability and square integrability of solutions of nonlinear fourth order differential equations

    Directory of Open Access Journals (Sweden)

    Moussadek Remili

    2016-05-01

    Full Text Available The aim of the present paper is to establish a new result, which guarantees the asymptotic stability of zero solution and square integrability of solutions and their derivatives to nonlinear differential equations of fourth order.

  15. Qualitative Observations Concerning Packing Densities for Liquids, Solutions, and Random Assemblies of Spheres

    Science.gov (United States)

    Duer, W. C.; And Others

    1977-01-01

    Discusses comparisons of packing densities derived from known molar volume data of liquids and solutions. Suggests further studies for using assemblies of spheres as models for simple liquids and solutions. (MLH)

  16. The Ungraded Derived Category

    OpenAIRE

    Stai, Torkil Utvik

    2012-01-01

    By means of the ungraded derived category we prove that the orbit category of the bounded derived category of an iterated tilted algebra with respect to translation is triangulated in such a way that the canonical functor from the bounded derived category to the orbit category becomes a triangle functor.

  17. Liquid scintillation solution

    International Nuclear Information System (INIS)

    Long, E.C.

    1976-01-01

    The invention deals with a liquid scintillation solution which contains 1) a scintillation solvent (toluol), 2) a primary scintillation solute (PPO), 3) a secondary scintillation solute (dimethyl POPOP), 4) several surfactants (iso-octyl-phenol polyethoxy-ethanol and sodium di-hexyl sulfosuccinate) essentially different from one another and 5) a filter resolution and/or transparent-making agent (cyclic ether, especially tetrahydrofuran). (HP) [de

  18. PERVASIVE BUSINESS INTELLIGENCE SOLUTIONS

    Directory of Open Access Journals (Sweden)

    Rocsana Tonis (Bucea-Manea

    2011-03-01

    Full Text Available The utility of BI solutions is accepted all over the world in the modern organizations. However, the BI solutions do not offer a constant feedback in line with the organizational activities. In this context, there have been developed pervasive BI solutions which are present at different levels of the organization, so that employees can observe only what is most relevant to their day-to-day tasks. They are organized in vertical silos, with clearly identified performance and expectations. The paper emphasizes the role of pervasive BI solutions in reaching the key performance indicators of the modern organizations, more important in the context of crisis.

  19. Adsorption of heavy metals by agroforestry waste derived activated ...

    African Journals Online (AJOL)

    Adsorption of heavy metals by agroforestry waste derived activated carbons applied to aqueous solutions. Jane M Misihairabgwi, Abisha Kasiyamhuru, Peter Anderson, Colin J Cunningham, Tanya A Peshkur, Ignatious Ncube ...

  20. Exact solutions for nonlinear foam drainage equation

    Science.gov (United States)

    Zayed, E. M. E.; Al-Nowehy, Abdul-Ghani

    2017-02-01

    In this paper, the modified simple equation method, the exp-function method, the soliton ansatz method, the Riccati equation expansion method and the ( G^' }/G)-expansion method are used to construct exact solutions with parameters of the nonlinear foam drainage equation. When these parameters are taken to be special values, the solitary wave solutions and the trigonometric function solutions are derived from the exact solutions. The obtained results confirm that the proposed methods are efficient techniques for analytic treatments of a wide variety of nonlinear partial differential equations in mathematical physics. We compare our results together with each other yielding from these integration tools. Also, our results have been compared with the well-known results of others.

  1. International young physicists' tournament problems & solutions 2014

    CERN Document Server

    Gao, Wenli

    2016-01-01

    International Young Physicists' Tournament (Iypt), is one of the most prestigious international physics contests among high school students. This book is based on the solutions of 2014 Iypt problems. The authors are undergraduate students who participated in the Cupt (Chinese Undergraduate Physics Tournament). It is intended as a college level solution to the challenging open-ended problems. It provides original, quantitative solutions in fulfilling seemingly impossible tasks. This book is not limited to the tasks required by the problems and it is not confined to the models and methods in present literatures. Many of the articles include modification and extension to existing models in references, or derivation and computation based on fundamental physics. This book provides quantitative solutions to practical problems in everyday life. This is a good reference book for undergraduates, advanced high-school students, physics educators and curious public interested in the intriguing phenomena in daily life.

  2. The Median Solution of the Newsvendor Problem and Some Observations

    Directory of Open Access Journals (Sweden)

    Sinha Pritibhushan

    2015-09-01

    Full Text Available We consider the median solution of the Newsvendor Problem. Some properties of such a solution are shown through a theoretical analysis and a numerical experiment. Sometimes, though not often, median solution may be better than solutions maximizing expected profit, or maximizing minimum possible, over distribution with the same average and standard deviation, expected profit, according to some criteria. We discuss the practical suitability of the objective function set and the solution derived, for the Newsvendor Problem, and other such random optimization problems.

  3. The Exact Solutions for a Point Mass Moving along a Stretched String on a Winkler Foundation

    Directory of Open Access Journals (Sweden)

    Q. Gao

    2014-01-01

    Full Text Available This paper derives the exact solutions for a point mass moving along a stretched infinite string on a Winkler foundation at a constant velocity. The solutions for the contact force between the string and the mass are derived and then the displacement responses of the string can be obtained easily. The solutions cover infinite string subjected to a moving mass at subsonic, sonic, or supersonic velocities. When time tends to infinity, the asymptotical solutions for the contact force between the mass and the string and for the displacement of the contact point are derived. The formulas derived are shown to be correct by comparison with the semianalytical method.

  4. Removal of hexavalent chromium from aqueous solution using ...

    African Journals Online (AJOL)

    Removal of hexavalent chromium from aqueous solution using activated carbon derived from palmyra palm fruit seed. A. Kannan, S. Thambidurai. Abstract. In this study, removal of chromium(VI) from aqueous solutions by Palmyra palm fruit seed carbon (PPFSC) and commercial activated carbon (CAC) was investigated.

  5. On the solution of the Liouville equation over a rectangle

    Directory of Open Access Journals (Sweden)

    A. M. Arthurs

    1996-01-01

    Full Text Available Methods for integral equations are used to derive pointwise bounds for the solution of a boundary value problem for the nonlinear Liouville partial differential equation over a rectangle. Several test calculations are performed and the resulting solutions are more accurate than those obtained previously by other methods.

  6. Initial value formulation for the spherically symmetric dust solution

    International Nuclear Information System (INIS)

    Liu, H.

    1990-01-01

    An initial value formulation for the dust solution with spherical symmetry is given explicitly in which the initial distributions of dust and its velocity on an initial surface are chosen to be the initial data. As special cases, the Friedmann universe, the Schwarzschild solution in comoving coordinates, and a spherically symmetric and radially inhomogeneous cosmological model are derived

  7. The functional variable method for finding exact solutions of some ...

    Indian Academy of Sciences (India)

    Abstract. In this paper, we implemented the functional variable method and the modified. Riemann–Liouville derivative for the exact solitary wave solutions and periodic wave solutions of the time-fractional Klein–Gordon equation, and the time-fractional Hirota–Satsuma coupled. KdV system. This method is extremely simple ...

  8. Solute-solute interactions in intermetallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Debashis; Murray, Ryan; Collins, Gary S., E-mail: collins@wsu.edu [Washington State University, Department of Physics and Astronomy (United States); Zacate, Matthew O. [Northern Kentucky University, Department of Physics and Geology (United States)

    2017-11-15

    Experiments were carried out on highly ordered GdAl{sub 2} samples containing extremely dilute mole fractions of{sup 111}In/Cd probe-atom solutes (about 10{sup −11}), intrinsic antisite atoms Al{sub Gd} having mole fractions of order 0-10{sup −2}, and doped with Ag solutes at mole fractions of order 10{sup −2}. Three types of defect interactions were investigated. (1) Quadrupole interactions caused by Ag-solute atoms neighboring{sup 111}In/Cd solute probe atoms were detected using the method of perturbed angular correlation of gamma rays (PAC). Three complexes of pairs of In-probes and Ag-solutes occupying neighboring positions on Gd- and Al-sublattices were identified by comparing site fractions in Gd-poor and Gd-rich GdAl{sub 2}(Ag) samples and from the symmetry of the quadrupole interactions. Interaction enthalpies between solute-atom pairs were determined from temperature dependences of observed site fractions. Repulsive interactions were observed for close-neighbor complexes In{sub Gd}+Ag{sub Gd} and In{sub Gd}+Ag{sub Al} pairs, whereas a slightly attractive interaction was observed for In{sub Al}+Ag{sub Al}. Interaction enthalpies were all small, in the range ±0.15 eV. (2) Quadrupole interactions caused by intrinsic antisite atoms Al{sub Gd} neighboring In{sub Gd} probes were also detected and site fractions measured as a function of temperature, as in previous work on samples not doped with Ag-solutes [Temperature- and composition-driven changes in site occupation of solutes in Gd{sub 1+3x}Al{sub 2−3x}, Zacate and Collins (Phys. Rev. B69, 174202 (1))]. However, the effective binding enthalpy between In{sub Gd} probe and Al{sub Gd} antisite was found to change sign from -0.12 eV (attractive interaction) in undoped samples to + 0.24 eV (repulsive) in Ag-doped samples. This may be attributed to an attractive interaction between Al{sub Gd} antisite atoms and Ag-dopants that competes with the attractive interaction between In{sub Gd} and Al{sub Gd

  9. Cromolyn Sodium Nasal Solution

    Science.gov (United States)

    Cromolyn comes as a solution to use with a special nasal applicator. It usually is inhaled three to six times a day to prevent allergy ... first time, read the instructions provided with the solution. Ask your doctor, pharmacist, or respiratory therapist to ...

  10. The procedural egalitarian solution

    NARCIS (Netherlands)

    Dietzenbacher, Bas; Borm, Peter; Hendrickx, Ruud

    2017-01-01

    In this paper we introduce and analyze the procedural egalitarian solution for transferable utility games. This new concept is based on the result of a coalitional bargaining procedure in which egalitarian considerations play a central role. The procedural egalitarian solution is the first

  11. The Procedural Egalitarian Solution

    NARCIS (Netherlands)

    Dietzenbacher, Bas; Borm, Peter; Hendrickx, Ruud

    2016-01-01

    In this paper we introduce and analyze the procedural egalitarian solution for transferable utility games. This new concept is based on the result of a coalitional bargaining procedure in which egalitarian considerations play a central role. The procedural egalitarian solution is the first

  12. On the Sensitivity Matrix of the Nash Bargaining Solution

    NARCIS (Netherlands)

    Engwerda, J.C.; Douven, R.C.M.H.

    2005-01-01

    In this note we derive the sensitivity matrix of the Nash bargaining solution w.r.t. the disagreement point d.This first order derivative is completely specified in terms of the Pareto frontier function.We show that whenever one player increases his threatpoint always at least one player will loose

  13. Local derivative post-processing : Challenges for a non-uniform mesh

    NARCIS (Netherlands)

    Ryan, J.K.

    2010-01-01

    Previous investigations into accuracy enhancement for the derivatives of a discontinuous Galerkin solution demonstrated that there are many ways to approach obtaining higher order accuracy in the derivatives, each with different advantageous properties. For the discontinuous Galerkin method, the

  14. An Analytical Method of Auxiliary Sources Solution for Plane Wave Scattering by Impedance Cylinders - A Reference Solution for the Numerical Method of Auxiliary Sources

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2004-01-01

    To facilitate the validation of the numerical Method of Auxiliary Sources an analytical Method of Auxiliary Sources solution is derived in this paper. The Analytical solution is valid for transverse magnetic, and electric, plane wave scattering by circular impedance Cylinders, and it is derived b...

  15. Bolting multicenter solutions

    Energy Technology Data Exchange (ETDEWEB)

    Bena, Iosif [Institut de Physique Théorique, Université Paris Saclay, CEA, CNRS, 91191 Gif-sur-Yvette Cedex (France); Bossard, Guillaume [Centre de Physique Théorique, Ecole Polytechnique, CNRS, Université Paris-Saclay, 91128 Palaiseau Cedex (France); Katmadas, Stefanos; Turton, David [Institut de Physique Théorique, Université Paris Saclay, CEA, CNRS, 91191 Gif-sur-Yvette Cedex (France)

    2017-01-30

    We introduce a solvable system of equations that describes non-extremal multicenter solutions to six-dimensional ungauged supergravity coupled to tensor multiplets. The system involves a set of functions on a three-dimensional base metric. We obtain a family of non-extremal axisymmetric solutions that generalize the known multicenter extremal solutions, using a particular base metric that introduces a bolt. We analyze the conditions for regularity, and in doing so we show that this family does not include solutions that contain an extremal black hole and a smooth bolt. We determine the constraints that are necessary to obtain smooth horizonless solutions involving a bolt and an arbitrary number of Gibbons-Hawking centers.

  16. Regular and conformal regular cores for static and rotating solutions

    International Nuclear Information System (INIS)

    Azreg-Aïnou, Mustapha

    2014-01-01

    Using a new metric for generating rotating solutions, we derive in a general fashion the solution of an imperfect fluid and that of its conformal homolog. We discuss the conditions that the stress–energy tensors and invariant scalars be regular. On classical physical grounds, it is stressed that conformal fluids used as cores for static or rotating solutions are exempt from any malicious behavior in that they are finite and defined everywhere.

  17. Regular and conformal regular cores for static and rotating solutions

    Energy Technology Data Exchange (ETDEWEB)

    Azreg-Aïnou, Mustapha

    2014-03-07

    Using a new metric for generating rotating solutions, we derive in a general fashion the solution of an imperfect fluid and that of its conformal homolog. We discuss the conditions that the stress–energy tensors and invariant scalars be regular. On classical physical grounds, it is stressed that conformal fluids used as cores for static or rotating solutions are exempt from any malicious behavior in that they are finite and defined everywhere.

  18. Uniqueness of singular solution of semilinear elliptic equation

    Indian Academy of Sciences (India)

    Nonhomogeneous semilinear elliptic equation; positive solutions; asymptotic behavior; singular ... a removable singular point of a solution of equation (1.1), the existence of the derivatives of the solution depends on the 'blow up' ..... On the other hand, for 0 <ε

  19. Multivariate statistics exercises and solutions

    CERN Document Server

    Härdle, Wolfgang Karl

    2015-01-01

    The authors present tools and concepts of multivariate data analysis by means of exercises and their solutions. The first part is devoted to graphical techniques. The second part deals with multivariate random variables and presents the derivation of estimators and tests for various practical situations. The last part introduces a wide variety of exercises in applied multivariate data analysis. The book demonstrates the application of simple calculus and basic multivariate methods in real life situations. It contains altogether more than 250 solved exercises which can assist a university teacher in setting up a modern multivariate analysis course. All computer-based exercises are available in the R language. All R codes and data sets may be downloaded via the quantlet download center  www.quantlet.org or via the Springer webpage. For interactive display of low-dimensional projections of a multivariate data set, we recommend GGobi.

  20. Langmuir-Blodgett Films of Graphene Derivatives

    DEFF Research Database (Denmark)

    Petersen, Søren Vermehren

    The work presented in this PhD thesis can be divided into two main categories: 1) Syn-thesis and Langmuir-Blodgett assembly of graphene derivatives and 2) Application and characterization of graphene derivatives as an interface material in molecular electron-ics. While the first category could...... be divided further, the synthesis and Langmuir-Blodgett results are intertwined in such a way that it would be more confusing to pre-sent them separately. The Langmuir-Blodgett deposition also played a crucial, but more isolated, part in the investigation of graphene derivatives as interface material....... Solution processable graphene in the form of chemically derived graphene has been synthesized through the modified Hummers method with subsequent reduction into reduced graphene oxide with hydrazine. The completeness of oxidation, the effect of the refinement steps and the reduction of the graphene oxide...

  1. Higher derivative mimetic gravity

    Science.gov (United States)

    Gorji, Mohammad Ali; Mansoori, Seyed Ali Hosseini; Firouzjahi, Hassan

    2018-01-01

    We study cosmological perturbations in mimetic gravity in the presence of classified higher derivative terms which can make the mimetic perturbations stable. We show that the quadratic higher derivative terms which are independent of curvature and the cubic higher derivative terms which come from curvature corrections are sufficient to remove instabilities in mimetic perturbations. The classified higher derivative terms have the same dimensions but they contribute differently in the background and perturbed equations. Therefore, we can control both the background and the perturbation equations allowing us to construct the higher derivative extension of mimetic dark matter and the mimetic nonsingular bouncing scenarios. The latter can be thought as a new higher derivative effective action for the loop quantum cosmology scenario in which the equations of motion coincide with those suggested by loop quantum cosmology. We investigate a possible connection between the mimetic cosmology and the Randall-Sundrum cosmology.

  2. Taxation of Derivatives

    DEFF Research Database (Denmark)

    Dyppel, Katja Joo

    2013-01-01

    are known as futures, forwards, options and swaps. Derivatives are traded for the purpose of hedging financial or business risk, speculating in future spot prices and taking advantage of arbitrage opportunities. This market has increased tremendously in recent years. The term derivative is not used......The main objective for this thesis is to analyse and systematise the Danish legislation on taxation of derivatives. According to financial terminology, a derivative is a financial instrument. Its value is derived from changes in the value of one or more underlying assets.The most common derivatives...... in the Danish tax legislation. However, contracts known as forwards (terminskontrakter) and options (aftaler om køberetter og salgsretter) are generally included in the term financials contracts covered by the Danish Act on Taxation of Gains and Losses on Claims and Debt. The main part of the analysis deals...

  3. Derivation of Orthometric Heights from GPS Measured Heights ...

    African Journals Online (AJOL)

    In this study, geometric technique of deriving orthometric height from GPS survey along a profile and the use of EGM 96 geoid model for deriving orthometric height from GPS data (using GNSS solution software) are discussed. The main focus of the research is to critically examine the potentials of these methods with a view ...

  4. Some Stiffly Stable Second Derivative Continuous Linear Multistep ...

    African Journals Online (AJOL)

    Dr Grace Nwachukwu

    Based on Gear's fixed step size backward differentiation methods, Gear (1968), second derivative continuous ... whose solution is stiff, let us consider the family of hybrid second derivative continuous linear multistep methods. ( ) ...... The Numerical Integration of stiff Systems of ODEs using Stiffly Stable Continuous Second.

  5. Global Derivatives Market

    Directory of Open Access Journals (Sweden)

    Stankovska Aleksandra

    2017-06-01

    Full Text Available Globalization of financial markets led to the enormous growth of volume and diversification of financial transactions. Financial derivatives were the basic elements of this growth. Derivatives play a useful and important role in hedging and risk management, but they also pose several dangers to the stability of financial markets and thereby the overall economy. Derivatives are used to hedge and speculate the risk associated with commerce and finance.

  6. Professional Hadoop solutions

    CERN Document Server

    Lublinsky, Boris; Yakubovich, Alexey

    2013-01-01

    The go-to guidebook for deploying Big Data solutions with Hadoop Today's enterprise architects need to understand how the Hadoop frameworks and APIs fit together, and how they can be integrated to deliver real-world solutions. This book is a practical, detailed guide to building and implementing those solutions, with code-level instruction in the popular Wrox tradition. It covers storing data with HDFS and Hbase, processing data with MapReduce, and automating data processing with Oozie. Hadoop security, running Hadoop with Amazon Web Services, best practices, and automating Hadoop processes i

  7. The crystal structure of emilite, Cu10.7Pb10.7Bi21.3S48, the second 45 Å derivative of the bismuthinite-aikinite solid-solution series

    DEFF Research Database (Denmark)

    Balic-Zunic, Tonci; Topa, Dan; Makovicky, Emil

    2002-01-01

    geology, emilite, Cu10.7Pb10.7Bi21.3S48, aikinite-bismuthinite derivative, crystal structure, Felbertal, scheelite deposit, Austria......geology, emilite, Cu10.7Pb10.7Bi21.3S48, aikinite-bismuthinite derivative, crystal structure, Felbertal, scheelite deposit, Austria...

  8. The crystal structure of Cu1.6Pb1.6Bi6.4S12, a new 44.8 Å derivative of the bismuthinite-aikinite solid-solution series

    DEFF Research Database (Denmark)

    Topa, Dan; Balic-Zunic, Tonci; Makovicky, Emil

    2000-01-01

    Cu1.6Pb1.6Bi6.4S12, aikinite-bismuthinite derivative, crystal structure, Felbertal, scheelite deposit, Austria......Cu1.6Pb1.6Bi6.4S12, aikinite-bismuthinite derivative, crystal structure, Felbertal, scheelite deposit, Austria...

  9. Comment on the Exterior Solutions and Their Geometry in Scalar-Tensor Theories of Gravity

    Science.gov (United States)

    Tsuchida, T.; Watanabe, K.

    1999-01-01

    We study series of stationary solutions with asymptotic flatness properties in the Einstein-Maxwell-free scalar system because they are locally equivalent to the exterior solutions in some class of scalar-tensor theories of gravity. First, we classify spherical exterior solutions into two types of solutions, an apparently black hole type solution and an apparently worm hole type solution. The solutions contain three parameters, and we clarify their physical significance. Second, we reduce the field equations for the axisymmetric exterior solutions. We find that the reduced equations are partially the same as the Ernst equations. As simple examples, we derive new series of static, axisymmetric exterior solutions, which correspond to Voorhees's solutions. We then establish a non-trivial relation between the spherical exterior solutions and our new solutions. Finally, since null geodesics have conformally invariant properties, we study the local geometry of the exterior solutions by using the optical scalar equations and find some anomalous behavior of the null geodesics.

  10. Time—periodic weak solutions

    Directory of Open Access Journals (Sweden)

    Eliana Henriques de Brito

    1990-01-01

    Full Text Available In continuing from previous papers, where we studied the existence and uniqueness of the global solution and its asymptotic behavior as time t goes to infinity, we now search for a time-periodic weak solution u(t for the equation whose weak formulation in a Hilbert space H isddt(u′,v+δ(u′,v+αb(u,v+βa(u,v+(G(u,v=(h,vwhere: ′=d/dt; (′ is the inner product in H; b(u,v, a(u,v are given forms on subspaces U⊂W, respectively, of H; δ>0, α≥0, β≥0 are constants and α+β>0; G is the Gateaux derivative of a convex functional J:V⊂H→[0,∞ for V=U, when α>0 and V=W when α=0, hence β>0; v is a test function in V; h is a given function of t with values in H.

  11. Relative oral bioavailability of morphine and naltrexone derived from crushed morphine sulfate and naltrexone hydrochloride extended-release capsules versus intact product and versus naltrexone solution: a single-dose, randomized-sequence, open-label, three-way crossover trial in healthy volunteers.

    Science.gov (United States)

    Johnson, Franklin K; Stark, Jeffrey G; Bieberdorf, Frederick A; Stauffer, Joe

    2010-06-01

    Morphine sulfate/sequestered naltrexone hydrochloride (HCl) (MS-sNT) extended-release fixed-dose combination capsules, approved by the US Food and Drug Administration (FDA) in August 2009 for chronic moderate to severe pain, contain extended-release morphine pellets with a sequestered core of the opioid antagonist naltrexone. MS-sNT was designed so that if the product is tampered with by crushing, the naltrexone becomes bioavailable to mitigate morphine-induced subjective effects, rendering the product less attractive for tampering. The primary aim of this study was to compare the oral bioavailability of naltrexone and its metabolite 6-beta-naltrexol, derived from crushed pellets from MS-sNT capsules, to naltrexone solution. This study also assessed the relative bioavailability of morphine from crushed pellets from MS-sNT capsules and that from the whole, intact product. This single-dose, randomized-sequence, open-label, 3-period, 3-treatment crossover trial was conducted in healthy volunteers. Adults admitted to the study center underwent a 10-hour overnight fast before study drug administration. Each subject received all 3 of the following treatments, 1 per session, separated by a 14-day washout: tampered pellets (crushed for >or=2 minutes with a mortar and pestle) from a 60-mg MS-sNT capsule (60 mg morphine/2.4 mg naltrexone); 60-mg whole, intact MS-sNT capsule; and oral naltrexone HCl (2.4 mg) solution. Plasma concentrations of naltrexone and 6-beta-naltrexol were measured 0 to 168 hours after administration. Morphine pharmaco-kinetics of crushed and whole pellets were determined 0 to 72 hours after administration. The analysis of relative bioavailability was based on conventional FDA criteria for assuming bioequivalence; that is, 90% CIs for ratios of geometric means (natural logarithm [In]-transformed C(max) and AUC) fell within the range of 80% to 125%. Subjects underwent physical examinations, clinical laboratory tests, and ECG at screening and study

  12. OIL SOLUTIONS POWDER

    Science.gov (United States)

    Technical product bulletin: aka OIL SOLUTIONS POWDER, SPILL GREEN LS, this miscellaneous oil spill control agent used in cleanups initially behaves like a synthetic sorbent, then as a solidifier as the molecular microencapsulating process occurs.

  13. Convergent Aeronautics Solutions Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Convergent Aeronautics Solutions (CAS) Project uses short-duration activities to establish early-stage concept and technology feasibility for high-potential...

  14. ERP SOLUTIONS FOR SMEs

    Directory of Open Access Journals (Sweden)

    TUTUNEA MIHAELA FILOFTEIA

    2012-09-01

    Full Text Available The integration of activities, the business processes as well as their optimization, bring the perspective of profitable growth and create significant and competitive advantages in any company. The adoption of some ERP integrated software solutions, from SMEs’ perspective, must be considered as a very important management decision in medium and long term. ERP solutions, along with the transparent and optimized management of all internal processes, also offer an intra and inter companies collaborative platform, which allows a rapid expansion of activities towards e- business and mobile-business environments. This material introduces ERP solutions for SMEs from commercial offer and open source perspective; the results of comparative analysis of the solutions on the specific market, can be an useful aid to the management of the companies, in making the decision to integrate business processes, using ERP as a support.

  15. Piezoelectric Energy Harvesting Solutions

    Science.gov (United States)

    Caliò, Renato; Rongala, Udaya Bhaskar; Camboni, Domenico; Milazzo, Mario; Stefanini, Cesare; de Petris, Gianluca; Oddo, Calogero Maria

    2014-01-01

    This paper reviews the state of the art in piezoelectric energy harvesting. It presents the basics of piezoelectricity and discusses materials choice. The work places emphasis on material operating modes and device configurations, from resonant to non-resonant devices and also to rotational solutions. The reviewed literature is compared based on power density and bandwidth. Lastly, the question of power conversion is addressed by reviewing various circuit solutions. PMID:24618725

  16. Upscaling nonreactive solute transport

    OpenAIRE

    LLERAR MEZA, GERÓNIMO

    2011-01-01

    This thesis focuses on solute transport upscaling. Upscaling of solute transport is usually required to obtain computationally efficient numerical models in many field applications such as, remediation of aquifers, environmental risk to groundwater resources or the design of underground repositories of nuclear waste. The non-Fickian behavior observed in the field, and manifested by peaked concentration profiles with pronounced tailing, has questioned the use of the classical advection-dispers...

  17. ERP SOLUTIONS FOR SMEs

    OpenAIRE

    TUTUNEA MIHAELA FILOFTEIA

    2012-01-01

    The integration of activities, the business processes as well as their optimization, bring the perspective of profitable growth and create significant and competitive advantages in any company. The adoption of some ERP integrated software solutions, from SMEs’ perspective, must be considered as a very important management decision in medium and long term. ERP solutions, along with the transparent and optimized management of all internal processes, also offer an...

  18. Brainmining emotive lateral solutions

    Directory of Open Access Journals (Sweden)

    Theodore Scaltsas

    2016-07-01

    Full Text Available BrainMining is a theory of creative thinking that shows how we should exploit the mind’s spontaneous natural disposition to use old solutions to address new problems – our Anchoring Cognitive Bias. BrainMining develops a simple and straightforward method to transform recalcitrant problems into types of problems which we have solved before, and then apply an old type of solution to them. The transformation makes the thinking lateral by matching up disparate types of problem and solution. It emphasises the role of emotive judgements that the agent makes, when she discerns whether a change of the values or the emotions and feelings in a situation, which would expand the space of solutions available for the problem at hand, would be acceptable or appropriate in the situation. A lateral solution for an intractable problem is thus spontaneously brainmined from the agent’s old solutions, to solve a transformed version of the intractable problem, possibly involving changes in the value system or the emotional profile of the situation, which the agent judges, emotively, will be acceptable, and even appropriate in the circumstances.

  19. Scale up of proteoliposome derived Cochleate production.

    Science.gov (United States)

    Zayas, Caridad; Bracho, Gustavo; Lastre, Miriam; González, Domingo; Gil, Danay; Acevedo, Reinaldo; del Campo, Judith; Taboada, Carlos; Solís, Rosa L; Barberá, Ramón; Pérez, Oliver

    2006-04-12

    Cochleate are highly stable structures with promising immunological features. Cochleate structures are usually obtaining from commercial lipids. Proteoliposome derived Cochleate are derived from an outer membrane vesicles of Neisseria meningitidis B. Previously, we obtained Cochleates using dialysis procedures. In order to increase the production process, we used a crossflow system (CFS) that allows easy scale up to obtain large batches in an aseptic environment. The raw material and solutions used in the production process are already approved for human application. This work demonstrates that CFS is very efficient process to obtain Cochleate structures with a yield of more than 80% and the immunogenicity comparable to that obtained by dialysis membrane.

  20. 4-Aminoquinoline derivatives

    DEFF Research Database (Denmark)

    Singh, Shailja; Agarwal, Drishti; Sharma, Kumkum

    2016-01-01

    Synthetic quinoline derivatives continue to be considered as candidates for new drug discovery if they act against CQ-resistant strains of malaria even after the widespread emergence of resistance to CQ. In this study, we explored the activities of two series of new 4-aminoquinoline derivatives a...

  1. The Dangers of Derivatives.

    Science.gov (United States)

    Blumenstyk, Goldie

    1994-01-01

    Heavy investment in derivatives, whose value derives from the price movement of some underlying security, has meant heavy losses for some colleges and universities despite the fact that institutional investors are required to assure that they understand the risks of such investment. (MSE)

  2. Vitamin D derivatives

    International Nuclear Information System (INIS)

    Deluca, H.F.; Schnoes, H.K.; Napoli, J.L.; Fivizzani, M.A.

    1982-01-01

    The chemical preparation of 26,27-isotopically labelled vitamin D 3 derivatives of high specific activity is described. These labelled vitamin D derivatives are useful in the determination of vitamin D metabolite levels in the blood and tissues of man and animals. (U.K.)

  3. LCCT-derived three-level three-phase inverters

    DEFF Research Database (Denmark)

    Shults, Tatiana; Husev, Oleksandr; Blaabjerg, Frede

    2017-01-01

    Solutions for a family of the novel three-level neutral-point-clamped (NPC) inductor-capacitor-capacitor-transformer (LCCT)-derived three-phase inverters are described and compared. Component design guidelines and steady state analysis, current and voltage waveforms are given. The authors......' simulation results confirm the theoretical predictions. It was found that an asymmetrical three-level NPC LCCT-derived inverter with a single diode in the impedance source network is the most promising solution. Experimental results for an asymmetrical three-level NPC LCCT-derived inverter with a single...

  4. Solution of IVP of Second Order ODE with Oscillatory Solutions ...

    African Journals Online (AJOL)

    Solution of IVP of Second Order ODE with Oscillatory Solutions using Variational Iterative Method (VIM) ... Abstract. A Numerical method for solution of IVP of second order with oscillatory solutions using VIM is developed. The method ... Keywords: Variational Iteration Method, Lagrange multiplier, oscillatory solutions, ODE.

  5. A New Truncated M-Fractional Derivative Type Unifying Some Fractional Derivative Types with Classical Properties

    Directory of Open Access Journals (Sweden)

    J. Vanterler da C. Sousa

    2018-01-01

    Full Text Available We introduce a truncated $M$-fractional derivative type for $\\alpha$-differentiable functions that generalizes four other fractional derivatives types recently introduced by Khalil et al., Katugampola and Sousa et al., the so-called conformable fractional derivative, alternative fractional derivative, generalized alternative fractional derivative and $M$-fractional derivative, respectively. We denote this new differential operator by $_{i}\\mathscr{D}_{M}^{\\alpha,\\beta }$, where the parameter $\\alpha$, associated with the order of the derivative is such that $ 0 <\\alpha<1 $, $\\beta>0$ and $ M $ is the notation to designate that the function to be derived involves the truncated Mittag-Leffler function with one parameter.The definition of this truncated $M$-fractional derivative type satisfies the properties of the integer-order calculus. We also present, the respective fractional integral from which emerges, as a natural consequence, the result, which can be interpreted as an inverse property. Finally, we obtain the analytical solution of the $M$-fractional heat equation and present a graphical analysis.

  6. Passive House Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Strom, I.; Joosten, L.; Boonstra, C. [DHV Sustainability Consultants, Eindhoiven (Netherlands)

    2006-05-15

    PEP stands for 'Promotion of European Passive Houses' and is a consortium of European partners, supported by the European Commission, Directorate General for Energy and Transport. In this working paper an overview is given of Passive House solutions. An inventory has been made of Passive House solutions for new build residences applied in each country. Based on this, the most common basic solutions have been identified and described in further detail, including the extent to which solutions are applied in common and best practice and expected barriers for the implementation in each country. An inventory per country is included in the appendix. The analysis of Passive House solutions in partner countries shows high priority with regard to the performance of the thermal envelope, such as high insulation of walls, roofs, floors and windows/ doors, thermal bridge-free construction and air tightness. Due to the required air tightness, special attention must be paid to indoor air quality through proper ventilation. Finally, efficient ((semi-)solar) heating systems for combined space and DHW heating still require a significant amount of attention in most partner countries. Other basic Passive House solutions show a smaller discrepancy with common practice and fewer barriers have been encountered in partner countries. In the next section, the general barriers in partner countries have been inventoried. For each type of barrier a suggested approach has been given. Most frequently encountered barriers in partner countries are: limited know-how; limited contractor skills; and acceptation of Passive Houses in the market. Based on the suggested approaches to overcoming barriers, this means that a great deal of attention must be paid to providing practical information and solutions to building professionals, providing practical training to installers and contractors and communication about the Passive House concept to the market.

  7. Inverse solutions for tilting orthogonal double prisms.

    Science.gov (United States)

    Li, Anhu; Ding, Ye; Bian, Yongming; Liu, Liren

    2014-06-10

    An analytical reverse solution and actual examples are given to show how to direct a laser beam from a pair of orthogonal prisms to given targets in free space. Considering the influences of double-prism structural parameters, a lookup table method to seek the numerical reverse solution of each prism's tilting angle is also proposed for steering the double-prism orientation to track a target position located in the near field. Some case studies, as well as a specified elliptical target trajectory scanned by the cam-based driving double prisms, exhibit the significant application values of the theoretical derivation. The analytic reverse and numerical solutions can be generalized to investigate the synthesis of scanning patterns and the controlling strategy of double-prism tilting motion, the potentials of which can be explored to perform the orientation and position tracking functions in applications of precision engineering fields.

  8. Stationary Cylindrically Symmetric Solution Approaching Einstein's Cosmological Solution

    OpenAIRE

    Iftime, M. D.

    2001-01-01

    Here we describe a stationary cylindrically symmetric solution of Einstein's equation with matter consisting of a positive cosmological and rotating dust term. The solution approaches Einstein static universe solution.

  9. Exact bidirectional X -wave solutions in fiber Bragg gratings

    Science.gov (United States)

    Efremidis, Nikolaos K.; Nye, Nicholas S.; Christodoulides, Demetrios N.

    2017-10-01

    We find exact solutions describing bidirectional pulses propagating in fiber Bragg gratings. They are derived by solving the coupled-mode theory equations and are expressed in terms of products of modified Bessel functions with algebraic functions. Depending on the values of the two free parameters, the general bidirectional X -wave solution can also take the form of a unidirectional pulse. We analyze the symmetries and the asymptotic properties of the solutions and also discuss additional waveforms that are obtained by interference of more than one solution. Depending on their parameters, such pulses can create a sharp focus with high contrast.

  10. Towards combined global monthly gravity field solutions

    Science.gov (United States)

    Jaeggi, Adrian; Meyer, Ulrich; Beutler, Gerhard; Weigelt, Matthias; van Dam, Tonie; Mayer-Gürr, Torsten; Flury, Jakob; Flechtner, Frank; Dahle, Christoph; Lemoine, Jean-Michel; Bruinsma, Sean

    2014-05-01

    Currently, official GRACE Science Data System (SDS) monthly gravity field solutions are generated independently by the Centre for Space Research (CSR) and the German Research Centre for Geosciences (GFZ). Additional GRACE SDS monthly fields are provided by the Jet Propulsion Laboratory (JPL) for validation and outside the SDS by a number of other institutions worldwide. Although the adopted background models and processing standards have been harmonized more and more by the various processing centers during the past years, notable differences still exist and the users are more or less left alone with a decision which model to choose for their individual applications. This procedure seriously limits the accessibility of these valuable data. Combinations are well established in the area of other space geodetic techniques, such as the Global Navigation Satellite Systems (GNSS), Satellite Laser Ranging (SLR), and Very Long Baseline Interferometry (VLBI). Regularly comparing and combining space-geodetic products has tremendously increased the usefulness of the products in a wide range of disciplines and scientific applications. Therefore, we propose in a first step to mutually compare the large variety of available monthly GRACE gravity field solutions, e.g., by assessing the signal content over selected regions, by estimating the noise over the oceans, and by performing significance tests. We make the attempt to assign different solution characteristics to different processing strategies in order to identify subsets of solutions, which are based on similar processing strategies. Using these subsets we will in a second step explore ways to generate combined solutions, e.g., based on a weighted average of the individual solutions using empirical weights derived from pair-wise comparisons. We will also assess the quality of such a combined solution and discuss the potential benefits for the GRACE and GRACE-FO user community, but also address minimum processing

  11. Siemens IT solutions for power sector. PROFIT solutions

    International Nuclear Information System (INIS)

    Lunter, P.

    2004-01-01

    The cost reduction, flexibility and revenue increase, potential exploitation, productivity increase, and business opportunities exploitation - that is all what can be required in the races for the promonent positioning on the electricity power market. These requirements can be realized by the sophisticated IT solutions hand-tailored to the special requirements of the electric power producers and tradesmen. This approach makes it possible to achieve greater profit. Our solutions 'PROFIT Solutions', that are symbiosis of the most progressive information technologies and the power plant techniques of the company Siemens, satisfy submitted specifications in substantial measure. The system solutions 'PROFIT Solutions' comprise three solution groups: process, operation a business. The solutions of the group 'IT Process Solutions' increase flexibility and manoeuvrability of equipment, improve the efficiency and contribute to more economical operation of the power generation. Solutions 'IT Process Solutions' simplify and shorten the period of power cycles and conduce to higher labour productivity. Solutions group 'IT Process Solutions' approaches equipment to the market - supports the profit strategies, helps quickly and expertly to determine and predict hazards. The extension PROFIT Cockpit means the nuance to the solutions world 'PROFIT Solutions'. The survey about the whole installation is within reach at the simple touch of a button. It is possible to compile the total system part by part from single solutions 'PROFIT Solutions'. As a matter of fact all single parts can be interconnected with already existing solutions. Routines 'PROFIT Solutions' cooperate with all modern control systems. (author)

  12. Intravenous fluids: balancing solutions.

    Science.gov (United States)

    Hoorn, Ewout J

    2017-08-01

    The topic of intravenous (IV) fluids may be regarded as "reverse nephrology", because nephrologists usually treat to remove fluids rather than to infuse them. However, because nephrology is deeply rooted in fluid, electrolyte, and acid-base balance, IV fluids belong in the realm of our specialty. The field of IV fluid therapy is in motion due to the increasing use of balanced crystalloids, partly fueled by the advent of new solutions. This review aims to capture these recent developments by critically evaluating the current evidence base. It will review both indications and complications of IV fluid therapy, including the characteristics of the currently available solutions. It will also cover the use of IV fluids in specific settings such as kidney transplantation and pediatrics. Finally, this review will address the pathogenesis of saline-induced hyperchloremic acidosis, its potential effect on outcomes, and the question if this should lead to a definitive switch to balanced solutions.

  13. Solute segregation during irradiation

    International Nuclear Information System (INIS)

    Wiedersich, H.; Okamoto, P.R.; Lam, N.Q.

    1977-01-01

    Irradiation at elevated temperature induces redistribution of the elements in alloys on a microstructural level. This phenomenon is caused by differences in the coupling of the various alloy constituents to the radiation-induced defect fluxes. A simple model of the segregation process based on coupled reaction-rate and diffusion equations is discussed. The model gives a good description of the experimentally observed consequences of radiation-induced segregation, including enrichment or depletion of solute elements near defect sinks such as surfaces, voids and dislocations; precipitation of second phases in solid solutions; precipitate redistribution in two-phase alloys; and effects of defect-production rates on void-swelling rates in alloys with minor solute additions

  14. Superstrings fermionic solutions

    International Nuclear Information System (INIS)

    Rausch de Traubenberg, M.

    1990-06-01

    The solutions proposed by the superstring theory are classified and compared. In order to obtain some of the equivalences, the demonstration is based on the coincidence of the excitation spectrum and the quantum numbers from different states. The fermionic representation of the heterotical strings is discussed. The conformal invariance and the supersymmetric results extended to two dimensions are investigated. Concerning the fermionic strings, the formalism and a phenomenological solution involving three families of quarks, chiral leptons and leptons from the E 6 gauge group are presented. The equivalence between real and complex fermions is discussed. The similarity between some of the solutions of the Wess-Zumino-Witten model and the orbifolds is considered. The formal calculation program developed for reproducing the theory's low energy spectra, in the fermionic string formalism is given [fr

  15. On the solution of the space-time fractional cubic nonlinear Schrödinger equation

    Directory of Open Access Journals (Sweden)

    E.A. Yousif

    2018-03-01

    Full Text Available The space–time fractional nonlinear Schrödinger equation is studied based on the modified Riemann–Liouville derivative. The fractional mapping expansion method is used to find analytical solution of this model. We discuss the effects of the fractional differential order on the W-soliton and bright soliton solutions. The derived solutions show direct proportionality between soliton intensities and the value of the fractional order derivative. Keywords: Fractional mapping expansion method, Nonlinear fractional differential equation, Modified Riemann–Liouville derivative, Space-time fractional nonlinear Schrödinger equation

  16. Business Intelligence Integrated Solutions

    Directory of Open Access Journals (Sweden)

    Cristescu Marian Pompiliu

    2017-12-01

    Full Text Available A Business Intelligence solution concerns the simple, real-time access to complete information about the business shown in a relevant format of the report, graphic or dashboard type in order help the taking of strategic decisions regarding the direction in which the company goes. Business Intelligence does not produce data, but uses the data produced by the company’s applications. BI solutions extract their data from ERP (Enterprise Resource Planning, CRM (Customer Relationship Management, HCM (Human Capital Management, and Retail, eCommerce or other databases used in the company.

  17. Decontamination solution development studies

    International Nuclear Information System (INIS)

    Allen, R.P.; Fetrow, L.K.; Kjarmo, H.E.; Pool, K.H.

    1993-09-01

    This study was conducted for the Westinghouse Hanford Company (WHC) by Pacific Northwest Laboratory (PNL) as part of the Hanford Grout Technology Program (HGTP). The objective of this study was to identify decontamination solutions capable of removing radioactive contaminants and grout from the Grout Treatment Facility (GTF) process equipment and to determine the impact of these solutions on equipment components and disposal options. The reference grout used in this study was prepared with simulated double-shell slurry feed (DSSF) and a dry blend consisting of 40 wt % limestone flour, 28 wt % blast furnace slag, 28 wt % fly ash, and 4 wt % type I/II Portland cement

  18. Calculus problems and solutions

    CERN Document Server

    Ginzburg, Abraham

    2011-01-01

    Ideal for self-instruction as well as for classroom use, this text helps students improve their understanding and problem-solving skills in analysis, analytic geometry, and higher algebra. More than 1,200 problems appear in the text, with concise explanations of the basic notions and theorems to be used in their solution. Many are followed by complete answers; solutions for the others appear at the end of the book. Topics include sequences, functions of a single variable, limit of a function, differential calculus for functions of a single variable, fundamental theorems and applications of dif

  19. Microsoft big data solutions

    CERN Document Server

    Jorgensen, Adam; Welch, John; Clark, Dan; Price, Christopher; Mitchell, Brian

    2014-01-01

    Tap the power of Big Data with Microsoft technologies Big Data is here, and Microsoft's new Big Data platform is a valuable tool to help your company get the very most out of it. This timely book shows you how to use HDInsight along with HortonWorks Data Platform for Windows to store, manage, analyze, and share Big Data throughout the enterprise. Focusing primarily on Microsoft and HortonWorks technologies but also covering open source tools, Microsoft Big Data Solutions explains best practices, covers on-premises and cloud-based solutions, and features valuable case studies. Best of all,

  20. The azobenzene derivatives

    Science.gov (United States)

    Ionita, Ionica; Radulescu, Cristiana; Poinescu, Aurora Anca; Anghelina, Florina Violeta; Bunghez, Raluca; Ion, Rodica-Mariana

    2015-02-01

    Azobenzene derivatives constitute a group of dyes which have photochromic properties and have been investigated as promising systems for diverse applications in the unconventional optic area, their properties can be moulded with help of light.

  1. ASTEROID LIGHTCURVE DERIVED DATA

    Data.gov (United States)

    National Aeronautics and Space Administration — This is a compilation of published rotational parameters derived from lightcurve data for asteroids, based on the Warner et al. (2009) Asteroid Lightcurve Database....

  2. Investigation - Derived Waste Program

    International Nuclear Information System (INIS)

    Beardsley, C.; Anderson, R.

    1998-06-01

    The Investigation-Derived Waste Program is a software application that was developed to identify the groundwater monitoring wells at the Savannah River Site that require containerization and treatment for purge water generated during sampling

  3. Granin-derived peptides.

    Science.gov (United States)

    Troger, Josef; Theurl, Markus; Kirchmair, Rudolf; Pasqua, Teresa; Tota, Bruno; Angelone, Tommaso; Cerra, Maria C; Nowosielski, Yvonne; Mätzler, Raphaela; Troger, Jasmin; Gayen, Jaur R; Trudeau, Vance; Corti, Angelo; Helle, Karen B

    2017-07-01

    The granin family comprises altogether 7 different proteins originating from the diffuse neuroendocrine system and elements of the central and peripheral nervous systems. The family is dominated by three uniquely acidic members, namely chromogranin A (CgA), chromogranin B (CgB) and secretogranin II (SgII). Since the late 1980s it has become evident that these proteins are proteolytically processed, intragranularly and/or extracellularly into a range of biologically active peptides; a number of them with regulatory properties of physiological and/or pathophysiological significance. The aim of this comprehensive overview is to provide an up-to-date insight into the distribution and properties of the well established granin-derived peptides and their putative roles in homeostatic regulations. Hence, focus is directed to peptides derived from the three main granins, e.g. to the chromogranin A derived vasostatins, betagranins, pancreastatin and catestatins, the chromogranin B-derived secretolytin and the secretogranin II-derived secretoneurin (SN). In addition, the distribution and properties of the chromogranin A-derived peptides prochromacin, chromofungin, WE14, parastatin, GE-25 and serpinins, the CgB-peptide PE-11 and the SgII-peptides EM66 and manserin will also be commented on. Finally, the opposing effects of the CgA-derived vasostatin-I and catestatin and the SgII-derived peptide SN on the integrity of the vasculature, myocardial contractility, angiogenesis in wound healing, inflammatory conditions and tumors will be discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Brain derived neurotrophic factor

    DEFF Research Database (Denmark)

    Mitchelmore, Cathy; Gede, Lene

    2014-01-01

    Brain Derived Neurotrophic Factor (BDNF) is a neurotrophin with important functions in neuronal development and neuroplasticity. Accumulating evidence suggests that alterations in BDNF expression levels underlie a variety of psychiatric and neurological disorders. Indeed, BDNF therapies are curre......Brain Derived Neurotrophic Factor (BDNF) is a neurotrophin with important functions in neuronal development and neuroplasticity. Accumulating evidence suggests that alterations in BDNF expression levels underlie a variety of psychiatric and neurological disorders. Indeed, BDNF therapies...

  5. Phenomenology of polymer solution dynamics

    National Research Council Canada - National Science Library

    Phillies, George D. J

    2011-01-01

    ... solutions, not dilute solutions or polymer melts. From centrifugation and solvent dynamics to viscosity and diffusion, experimental measurements and their quantitative representations are the core of the discussion...

  6. Langmuir-Blodgett Films of Graphene Derivatives

    DEFF Research Database (Denmark)

    Petersen, Søren Vermehren

    The work presented in this PhD thesis can be divided into two main categories: 1) Syn-thesis and Langmuir-Blodgett assembly of graphene derivatives and 2) Application and characterization of graphene derivatives as an interface material in molecular electron-ics. While the first category could....... Solution processable graphene in the form of chemically derived graphene has been synthesized through the modified Hummers method with subsequent reduction into reduced graphene oxide with hydrazine. The completeness of oxidation, the effect of the refinement steps and the reduction of the graphene oxide...... immobilization of the monolayered graphene oxide via the Langmuir-Blodgett deposition technique prior to a three step reduction scheme involving hydrazine reduc-tion, sulfuric acid de-oxygenation, and thermal annealing. This method resulted in wrin-kle-free reduced graphene oxide with a negligible oxygen content...

  7. A NEET Solution?

    OpenAIRE

    Simmons, Robin; Lambert, Stephen

    2013-01-01

    YOUTH unemployment across the country rose by 20,000 last\\ud month and almost one million 18 to 24-year-olds are classified as\\ud NEET – not in education, employment or training. PROFESSOR\\ud ROBIN SIMMONS and NEWCASTLE COUNCILLOR STEPHEN\\ud LAMBERT argue we need radical solutions to youth unemployment.

  8. Antisocial Personalities, Antidemocractic Solutions.

    Science.gov (United States)

    Schneiderman, Howard G.

    1996-01-01

    Provides critical analysis of David T. Lykken's article "Psychopathy, Sociopathy, and Crime" (1996) and its correlation between unstable families and sociopathy and the use of parental licensing as a solution. Discusses reasons for the appeal of parental licensing as well as the issue of state control replacing social control. (GR)

  9. Investing in solutions

    International Development Research Centre (IDRC) Digital Library (Canada)

    2016-03-31

    Mar 31, 2016 ... Improving food security through research is just one of our key activities. the Canadian International Food. Security Research Fund ..... Ministry and the American Chamber of Commerce signed an agreement to implement solutions .... Court with first-ever conviction of two former military members for wartime ...

  10. An Inexpensive Solution Calorimeter

    Science.gov (United States)

    Kavanagh, Emma; Mindel, Sam; Robertson, Giles; Hughes, D. E. Peter

    2008-01-01

    We describe the construction of a simple solution calorimeter, using a miniature bead thermistor as a temperature-sensing element. This has a response time of a few seconds and made it possible to carry out a thermometric reaction in under a minute, which led to minimal heat losses. Small temperature changes of 1 K associated with enthalpies of…

  11. Aliteracy : causes and solutions

    NARCIS (Netherlands)

    Nielen, Thijs Martinus Johannes

    2016-01-01

    The reading motivation of the majority of students declines in the upper half of primary school, which implies a risk for aliteracy: Students can read but, due to lack of practice, their skills remain underdeveloped (Chapter 2). In this thesis we have explored causes and solutions for this important

  12. School Solutions for Cyberbullying

    Science.gov (United States)

    Sutton, Susan

    2009-01-01

    This article offers solutions and steps to prevent cyberbullying. Schools can improve their ability to handle cyberbullying by educating staff members, students, and parents and by implementing rules and procedures for how to handle possible incidents. Among the steps is to include a section about cyberbullying and expectations in the student…

  13. Exact solutions of space-time fractional EW and modified EW equations

    International Nuclear Information System (INIS)

    Korkmaz, Alper

    2017-01-01

    The bright soliton solutions and singular solutions are constructed for the space-time fractional EW and the space-time fractional modified EW (MEW) equations. Both equations are reduced to ordinary differential equations by the use of fractional complex transform (FCT) and properties of modified Riemann–Liouville derivative. Then, various ansatz method are implemented to construct the solutions for both equations.

  14. Exact solutions of space-time fractional EW and modified EW equations

    Science.gov (United States)

    Korkmaz, Alper

    2017-03-01

    The bright soliton solutions and singular solutions are constructed for space-time fractional EW and modified EW equations. Both equations are reduced to ordinary differential equations by the use of fractional complex transform and properties of modified Riemann-Liouville derivative. Then, implementation of ansatz method the solutions are constructed.

  15. Exact Solutions of Space-time Fractional EW and modified EW equations

    OpenAIRE

    Korkmaz, Alper

    2016-01-01

    The bright soliton solutions and singular solutions are constructed for space-time fractional EW and modified EW equations. Both equations are reduced to ordinary differential equations by the use of fractional complex transform and properties of modified Riemann-Liouville derivative. Then, implementation of ansatz method the solutions are constructed.

  16. Self-aggregation of liquids from biomass in aqueous solution

    International Nuclear Information System (INIS)

    Lomba, Laura; Giner, Beatriz; Zuriaga, Estefanía; Moya, Juana; Lafuente, Carlos

    2013-01-01

    Highlights: • Aggregation behaviour of liquids from biomass in aqueous solution has been studied. • Standard Gibbs free energies of aggregation have been calculated. • Solubility in water of these compounds has been determined. • Critical aggregation concentration decreases as the solubility in water does. -- Abstract: Aggregation of several chemicals from biomass: furfural derived compounds (furfural, 5-methylfurfural, furfuryl alcohol and tetrahydrofurfuryl alcohol), lactate derived compounds (methyl lactate, ethyl lactate and butyl lactate), acrylate derived compound (methyl acrylate) and levulinate compounds (methyl levulinate, ethyl levulinate and butyl levulinate) in aqueous solution has been characterised at T = 298.15 K through density, ρ, speed of sound, u, and isentropic compressibilities, κ S , measurements. In addition the standard Gibbs free energies of aggregation have been also calculated. Furthermore, in order to deepen insight the behaviour of these chemicals in aqueous solution, the solubility of these compounds has been measured at T = 298.15 K

  17. Stiff fluid spike solutions from Bianchi type V seed solutions

    Science.gov (United States)

    Gregoris, D.; Lim, W. C.; Coley, A. A.

    2017-12-01

    In this paper we expand upon our previous work Coley et al (2016 Class. Quantum Grav. 33 215010) by using the entire family of Bianchi type V stiff fluid solutions as seed solutions of the Stephani transformation. Among the new exact solutions generated, we observe a number of important physical phenomena. The most interesting phenomenon is exact solutions with intersecting spikes. Other interesting phenomena are solutions with saddle states and a close-to-FL epoch.

  18. Analytic Solution to Shell Boundary – Value Problems

    Directory of Open Access Journals (Sweden)

    Yu. I. Vinogradov

    2015-01-01

    Full Text Available Object of research is to find analytical solution to the shell boundary – value problems, i.e. to consider the solution for a class of problems concerning the mechanics of hoop closed shells strain.The objective of work is to create an analytical method to define a stress – strain state of shells under non-axisymmetric loading. Thus, a main goal is to derive the formulas – solutions of the linear ordinary differential equations with variable continuous coefficients.The partial derivative differential equations of mechanics of shells strain by Fourier's method of variables division are reduced to the system of the differential equations with ordinary derivatives. The paper presents the obtained formulas to define solutions of the uniform differential equations and received on their basis formulas to define a particular solution depending on a type of the right parts of the differential equations.The analytical algorithm of the solution of a boundary task uses an approach to transfer the boundary conditions to the randomly chosen point of an interval of changing independent variable through the solution of the canonical matrix ordinary differential equation with the subsequent solution of system of algebraic equations for compatibility of boundary conditions at this point. Efficiency of algorithm is based on the fact that the solution of the ordinary differential equations is defined as the values of Cauchy – Krylova functions, which meet initial arbitrary conditions.The results of researches presented in work are useful to experts in the field of calculus mathematics, dealing with solution of systems of linear ordinary differential equations and creation of effective analytical computing methods to solve shell boundary – value problems.

  19. Asia Pacific energy derivatives

    International Nuclear Information System (INIS)

    Fusaro, P.C.

    1997-09-01

    Asia Pacific Energy Derivatives, from FT Energy, is the first report of its kind to examine the growth of energy derivatives within Asia Pacific and their increasing importance within this region. It provides a comprehensive overview of the subject, including analysis of: deregulation as a market driver; the impact of privatisation; the future for energy risk management tools; the unique characteristics of the Asia Pacific energy market; the role of futures exchanges in Asia; existing indexes and their performance; the differences between the Asia Pacific markets and their more mature counterparts in London and New York; non-oil derivatives, project finance and cross commodity arbitrage; the thriving Pacific Rim Over the Counter (OTC) markets. (author)

  20. Essays on Derivatives Pricing

    DEFF Research Database (Denmark)

    Kokholm, Thomas

    . With the existence of a liquid market for derivatives with variance as underlying, such as VIX options, VIX futures and a well-developed over-the-counter market for options on variance swaps, it is important to consider models that are able to fit these markets while consistently pricing vanilla options...... financial models, and most importantly, to be aware of their limitations. Following that belief, this thesis consists of three independent and self-contained papers, all dealing with topics in derivatives pricing. The first paper considers the pricing of traffic light options, which are appropriate...... the market for multivariate credit instruments, we take a step back and focus on single-name default modeling and introduce two new model classes for modeling of the default time of a company. Finally, in the third paper we propose a consistent pricing model for index and volatility derivatives...

  1. Earnest Rutherford, the solution

    CERN Multimedia

    2003-01-01

    If you did not make it to the Science & Society talk by John Campbell last week and are still wondering about the spelling of "Earnest", here is the solution: Two months after the birth of his fourth child on 30 August 1871 in Spring Grove, New Zealand, James Rutherford registered his son, who was recorded as "Earnest" in the Birth Register. Presumably the Registrar wrote the name down as it sounded and the father failed to notice the mistake when signing the Register.

  2. Severe service sealing solutions

    International Nuclear Information System (INIS)

    Metcalfe, R.; Wensel, R.

    1994-09-01

    Successful sealing usually requires much more than initial leak-tightness. Friction and wear must also be acceptable, requiring a good understanding of tribology at the sealing interface. This paper describes various sealing solutions for severe service conditions. The CAN2A and CAN8 rotary face seals use tungsten carbide against carbon-graphite to achieve low leakage and long lifetime in nuclear main coolant pumps. The smaller CAN6 seal successfully uses tungsten carbide against silicon carbide in reactor water cleanup pump service. Where friction in CANDU fuelling machine rams must be essentially zero, a hydrostatic seal using two silicon carbide faces is the solution. In the NRU reactor moderator pumps, where pressure is much lower, eccentric seals that prevent boiling at the seal faces are giving excellent service. All these rotary face seals rely on supplementary elastomer seals between their parts. An integrated engineering approach to high performance sealing with O-rings is described. This is epitomized in critical Space Shuttle applications, but is increasingly being applied in CANDU plants. It includes gland design, selection and qualification of material, quality assurance, detection of defects and the effects of lubrication, surface finish, squeeze, stretch and volume constraints. In conclusion, for the severe service applications described, customized solutions have more than paid for themselves by higher reliability, lower maintenance requirements and reduced outage time. (author)

  3. Three-dimensional stationary cyclic symmetric Einstein-Maxwell solutions; black holes

    International Nuclear Information System (INIS)

    Garcia, Alberto A.

    2009-01-01

    From a general metric for stationary cyclic symmetric gravitational fields coupled to Maxwell electromagnetic fields within the (2 + 1)-dimensional gravity the uniqueness of wide families of exact solutions is established. Among them, all uniform electromagnetic solutions possessing electromagnetic fields with vanishing covariant derivatives, all fields having constant electromagnetic invariants F μν F μν and T μν T μν , the whole classes of hybrid electromagnetic solutions, and also wide classes of stationary solutions are derived for a third-order nonlinear key equation. Certain of these families can be thought of as black hole solutions. For the most general set of Einstein-Maxwell equations, reducible to three nonlinear equations for the three unknown functions, two new classes of solutions - having anti-de Sitter spinning metric limit - are derived. The relationship of various families with those reported by different authors' solutions has been established. Among the classes of solutions with cosmological constant a relevant place is occupied by the electrostatic and magnetostatic Peldan solutions, the stationary uniform and spinning Clement classes, the constant electromagnetic invariant branches with the particular Kamata-Koikawa solution, the hybrid cyclic symmetric stationary black hole fields, and the non-less important solutions generated via SL(2,R)-transformations where the Clement spinning charged solution, the Martinez-Teitelboim-Zanelli black hole solution, and Dias-Lemos metric merit mention.

  4. Regularity of large solutions for the compressible magnetohydrodynamic equations

    Directory of Open Access Journals (Sweden)

    Qin Yuming

    2011-01-01

    Full Text Available Abstract In this paper, we consider the initial-boundary value problem of one-dimensional compressible magnetohydrodynamics flows. The existence and continuous dependence of global solutions in H 1 have been established in Chen and Wang (Z Angew Math Phys 54, 608-632, 2003. We will obtain the regularity of global solutions under certain assumptions on the initial data by deriving some new a priori estimates.

  5. Symmetries and exact solutions of fractional filtration equations

    Science.gov (United States)

    Gazizov, Rafail K.; Kasatkin, Alexey A.; Lukashchuk, Stanislav Yu.

    2017-11-01

    Few fractional differential models of fluid flow through porous medium are considered. We use several modifications of Darcy's law that contain time-and space-fractional derivatives corresponding to memory or non-local effects in filtration. Symmetry properties of the resulting nonlinear anomalous diffusion-type equations are analyzed and new group-invariant solutions are constructed. In particular, we obtain fractional analogues of so-called blow-up solutions.

  6. Similarity Solutions for Multiterm Time-Fractional Diffusion Equation

    OpenAIRE

    Elsaid, A.; Abdel Latif, M. S.; Maneea, M.

    2016-01-01

    Similarity method is employed to solve multiterm time-fractional diffusion equation. The orders of the fractional derivatives belong to the interval (0,1] and are defined in the Caputo sense. We illustrate how the problem is reduced from a multiterm two-variable fractional partial differential equation to a multiterm ordinary fractional differential equation. Power series solution is obtained for the resulting ordinary problem and the convergence of the series solution is discussed. Based on ...

  7. Gorenstein derived functions

    DEFF Research Database (Denmark)

    Holm, Henrik Granau

    2004-01-01

    Over any associative ring R it is standard to derive HomR(􀀀;􀀀) using projective resolutions in the rst variable, or injective resolutions in the second variable, and doing this, one obtains Extn R(􀀀;􀀀) in both cases. We examine the situation where projective an...

  8. Original and Derived Judgment

    DEFF Research Database (Denmark)

    Foss, Kirsten; Foss, Nicolai Juul; Klein, Peter G.

    2007-01-01

    to subordinates, who exercise derived judgment. We call these employees `proxy-entrepreneurs', and ask how the firm's organizational structure - its formal and informal systems of rewards and punishments, rules for settling disputes and renegotiating agreements, means of evaluating performance and so on - can...

  9. 78 FR 32191 - Derivatives

    Science.gov (United States)

    2013-05-29

    ...] Counterparty exposure management. [cir] Evaluating liquidity risk. Conduct: [cir] Collateral [cir] Accounting... rate risk. This proposed rule applies to federal credit unions and any federally insured, state... derivatives transactions \\1\\ for the purpose of mitigating interest rate risk (IRR). This proposed authority...

  10. Contribution of the GOCE gradiometer components to regional gravity solutions

    Science.gov (United States)

    Naeimi, Majid; Bouman, Johannes

    2017-05-01

    The contribution of the GOCE gravity gradients to regional gravity field solutions is investigated in this study. We employ radial basis functions to recover the gravity field on regional scales over Amazon and Himalayas as our test regions. In the first step, four individual solutions based on the more accurate gravity gradient components Txx, Tyy, Tzz and Txz are derived. The Tzz component gives better solution than the other single-component solutions despite the less accuracy of Tzz compared to Txx and Tyy. Furthermore, we determine five more solutions based on several selected combinations of the gravity gradient components including a combined solution using the four gradient components. The Tzz and Tyy components are shown to be the main contributors in all combined solutions whereas the Txz adds the least value to the regional gravity solutions. We also investigate the contribution of the regularization term. We show that the contribution of the regularization significantly decreases as more gravity gradients are included. For the solution using all gravity gradients, regularization term contributes to about 5 per cent of the total solution. Finally, we demonstrate that in our test areas, regional gravity modelling based on GOCE data provide more reliable gravity signal in medium wavelengths as compared to pre-GOCE global gravity field models such as the EGM2008.

  11. Electrospinning chitosan/poly(ethylene oxide) solutions with essential oils: Correlating solution rheology to nanofiber formation.

    Science.gov (United States)

    Rieger, Katrina A; Birch, Nathan P; Schiffman, Jessica D

    2016-03-30

    Electrospinning hydrophilic nanofiber mats that deliver hydrophobic agents would enable the development of new therapeutic wound dressings. However, the correlation between precursor solution properties and nanofiber morphology for polymer solutions electrospun with or without hydrophobic oils has not yet been demonstrated. Here, cinnamaldehyde (CIN) and hydrocinnamic alcohol (H-CIN) were electrospun in chitosan (CS)/poly(ethylene oxide) (PEO) nanofiber mats as a function of CS molecular weight and degree of acetylation (DA). Viscosity stress sweeps determined how the oils affected solution viscosity and chain entanglement (Ce) concentration. Experimentally, the maximum polymer:oil mass ratio electrospun was 1:3 and 1:6 for CS/PEO:CIN and:H-CIN, respectively; a higher chitosan DA increased the incorporation of H-CIN only. The correlations determined for electrospinning plant-derived oils could potentially be applied to other hydrophobic molecules, thus broadening the delivery of therapeutics from electrospun nanofiber mats. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. A finite element solution of transonic flow

    Science.gov (United States)

    Tatum, K. E.

    1978-01-01

    The use of finite elements is explored in a field in which its use has previously not been deemed very feasible, that of transonic flow. The specific problem chosen is that of steady small-disturbance transonic flow. The nonlinear equations are formulated with an artificial viscosity term added to yield the proper domain of dependence and directional bias in supersonic regions and across imbedded shock waves. Justification is given for the problem and means of solution chosen, and the potential advantages of the finite element procedure over standard finite difference procedures are discussed. Several possible improvements on the method as presently derived are stated. Computational mesh requirements and certain mesh variations are described. Some results equivalent to finite difference calculations are given as a sample solution.

  13. Generalization of the Randall–Sundrum solution

    Directory of Open Access Journals (Sweden)

    A.V. Kisselev

    2016-08-01

    Full Text Available The generalization of the Randall–Sundrum solution for the warp factor exp⁡[σ(y] in the scenario with one extra coordinate y, non-factorizable space–time geometry and two branes is obtained. It is shown that the function obtained σ(y is symmetric with respect to an interchange of two branes. It also obeys the orbifold symmetry y→−y and explicitly reproduces jumps of its derivative on both branes. This solution is defined by the Einstein–Hilbert's equations up to a constant C. It is demonstrated that different values of C result in theories with quite different spectra of the Kaluza–Klein gravitons.

  14. Intestinal solute carriers

    DEFF Research Database (Denmark)

    Steffansen, Bente; Nielsen, Carsten Uhd; Brodin, Birger

    2004-01-01

    A large amount of absorptive intestinal membrane transporters play an important part in absorption and distribution of several nutrients, drugs and prodrugs. The present paper gives a general overview on intestinal solute carriers as well as on trends and strategies for targeting drugs and...... membrane transporters in the small intestine in order to increase oral bioavailabilities of drug or prodrug, the major influence on in vivo pharmacokinetics is suggested to be dose-dependent increase in bioavailability as well as prolonged blood circulation due to large capacity facilitated absorption...

  15. From Goods to Solutions

    DEFF Research Database (Denmark)

    Chakkol, Mehmet; Johnson, Mark; Raja, Jawwad

    2014-01-01

    Purpose – This paper aims to adopt service-dominant logic (SDL) to empirically explore network configurations resulting from the provision of goods, goods and services, and solutions. Design/methodology/approach – This paper uses a single, in-depth, exploratory case study in a truck manufacturer......: dyadic, triadic and tetradic. The extent to which different network actors contribute to value co-creation varies across the offerings. Research limitations/implications – This paper is based on a single, in-depth case study developed in one industrial context. Whilst this represents an appropriate...

  16. Shuttle Wastewater Solution Characterization

    Science.gov (United States)

    Adam, Niklas; Pham, Chau

    2011-01-01

    During the 31st shuttle mission to the International Space Station, STS-129, there was a clogging event in the shuttle wastewater tank. A routine wastewater dump was performed during the mission and before the dump was completed, degraded flow was observed. In order to complete the wastewater dump, flow had to be rerouted around the dump filter. As a result, a basic chemical and microbial investigation was performed to understand the shuttle wastewater system and perform mitigation tasks to prevent another blockage. Testing continued on the remaining shuttle flights wastewater and wastewater tank cleaning solutions. The results of the analyses and the effect of the mitigation steps are detailed in this paper.

  17. Intestinal solute carriers

    DEFF Research Database (Denmark)

    Steffansen, Bente; Nielsen, Carsten Uhd; Brodin, Birger

    2004-01-01

    membrane transporters in the small intestine in order to increase oral bioavailabilities of drug or prodrug, the major influence on in vivo pharmacokinetics is suggested to be dose-dependent increase in bioavailability as well as prolonged blood circulation due to large capacity facilitated absorption......A large amount of absorptive intestinal membrane transporters play an important part in absorption and distribution of several nutrients, drugs and prodrugs. The present paper gives a general overview on intestinal solute carriers as well as on trends and strategies for targeting drugs and...

  18. Total Logistic Plant Solutions

    Directory of Open Access Journals (Sweden)

    Dusan Dorcak

    2016-02-01

    Full Text Available The Total Logistics Plant Solutions, plant logistics system - TLPS, based on the philosophy of advanced control processes enables complex coordination of business processes and flows and the management and scheduling of production in the appropriate production plans and planning periods. Main attributes of TLPS is to create a comprehensive, multi-level, enterprise logistics information system, with a certain degree of intelligence, which accepts the latest science and research results in the field of production technology and logistics. Logistic model of company understands as a system of mutually transforming flows of materials, energy, information, finance, which is realized by chain activities and operations

  19. Coarse-Grained Modeling of Polyelectrolyte Solutions

    Science.gov (United States)

    Denton, Alan R.; May, Sylvio

    2014-03-01

    Ionic mixtures, such as electrolyte and polyelectrolyte solutions, have attracted much attention recently for their rich and challenging combination of electrostatic and non-electrostatic interparticle forces and their practical importance, from battery technologies to biological systems. Hydration of ions in aqueous solutions is known to entail ion-specific effects, including variable solubility of organic molecules, as manifested in the classic Hofmeister series for salting-in and salting-out of proteins. The physical mechanism by which the solvent (water) mediates effective interactions between ions, however, is still poorly understood. Starting from a microscopic model of a polyelectrolyte solution, we apply a perturbation theory to derive a coarse-grained model of ions interacting through both long-range electrostatic and short-range solvent-induced pair potentials. Taking these effective interactions as input to molecular dynamics simulations, we calculate structural and thermodynamic properties of aqueous ionic solutions. This work was supported by the National Science Foundation under Grant No. DMR-1106331.

  20. Distributed order reaction-diffusion systems associated with Caputo derivatives

    Science.gov (United States)

    Saxena, R. K.; Mathai, A. M.; Haubold, H. J.

    2014-08-01

    This paper deals with the investigation of the solution of an unified fractional reaction-diffusion equation of distributed order associated with the Caputo derivatives as the time-derivative and Riesz-Feller fractional derivative as the space-derivative. The solution is derived by the application of the joint Laplace and Fourier transforms in compact and closed form in terms of the H-function. The results derived are of general nature and include the results investigated earlier by other authors, notably by Mainardi et al. ["The fundamental solution of the space-time fractional diffusion equation," Fractional Calculus Appl. Anal. 4, 153-202 (2001); Mainardi et al. "Fox H-functions in fractional diffusion," J. Comput. Appl. Math. 178, 321-331 (2005)] for the fundamental solution of the space-time fractional equation, including Haubold et al. ["Solutions of reaction-diffusion equations in terms of the H-function," Bull. Astron. Soc. India 35, 681-689 (2007)] and Saxena et al. ["Fractional reaction-diffusion equations," Astrophys. Space Sci. 305, 289-296 (2006a)] for fractional reaction-diffusion equations. The advantage of using the Riesz-Feller derivative lies in the fact that the solution of the fractional reaction-diffusion equation, containing this derivative, includes the fundamental solution for space-time fractional diffusion, which itself is a generalization of fractional diffusion, space-time fraction diffusion, and time-fractional diffusion, see Schneider and Wyss ["Fractional diffusion and wave equations," J. Math. Phys. 30, 134-144 (1989)]. These specialized types of diffusion can be interpreted as spatial probability density functions evolving in time and are expressible in terms of the H-function in compact forms. The convergence conditions for the double series occurring in the solutions are investigated. It is interesting to observe that the double series comes out to be a special case of the Srivastava-Daoust hypergeometric function of two variables

  1. Quantum Difference Langevin System with Nonlocal q-Derivative Conditions

    Directory of Open Access Journals (Sweden)

    Surang Sitho

    2016-01-01

    Full Text Available We introduce a new class of boundary value problems for Langevin quantum difference systems. Some new existence and uniqueness results for coupled systems are obtained by using fixed point theorems. The existence and uniqueness of solutions are established by Banach’s contraction mapping principle, while the existence of solutions is derived by using Leray-Schauder’s alternative. The obtained results are well illustrated with the aid of examples.

  2. Numerical solutions of the Vlasov equation

    International Nuclear Information System (INIS)

    Satofuka, Nobuyuki; Morinishi, Koji; Nishida, Hidetoshi

    1985-01-01

    A numerical procedure is derived for the solutions of the one- and two-dimensional Vlasov-Poisson system equations. This numerical procedure consists of the phase space discretization and the integration of the resulting set of ordinary differential equations. In the phase space discretization, derivatives with respect to the phase space variable are approximated by a weighted sum of the values of the distribution function at properly chosen neighboring points. Then, the resulting set of ordinary differential equations is solved by using an appropriate time integration scheme. The results for linear Landau damping, nonlinear Landau damping and counter-streaming plasmas are investigated and compared with those of the splitting scheme. The proposed method is found to be very accurate and efficient. (author)

  3. Lump Solutions and Resonance Stripe Solitons to the (2+1-Dimensional Sawada-Kotera Equation

    Directory of Open Access Journals (Sweden)

    Xian Li

    2017-01-01

    Full Text Available Based on the symbolic computation, a class of lump solutions to the (2+1-dimensional Sawada-Kotera (2DSK equation is obtained through making use of its Hirota bilinear form and one positive quadratic function. These solutions contain six parameters, four of which satisfy two determinant conditions to guarantee the analyticity and rational localization of the solutions, while the others are free. Then by adding an exponential function into the original positive quadratic function, the interaction solutions between lump solutions and one stripe soliton are derived. Furthermore, by extending this method to a general combination of positive quadratic function and hyperbolic function, the interaction solutions between lump solutions and a pair of resonance stripe solitons are provided. Some figures are given to demonstrate the dynamical properties of the lump solutions, interaction solutions between lump solutions, and stripe solitons by choosing some special parameters.

  4. Exact half-BPS type IIB interface solutions II: flux solutions and multi-Janus

    Energy Technology Data Exchange (ETDEWEB)

    D' Hoker, Eric; Estes, John; Gutperle, Michael [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States)

    2007-06-15

    Regularity and topology conditions are imposed on the exact Type IIB solutions on AdS{sub 4} x S{sup 2} x S{sup 2} x {sigma} with 16 supersymmetries, which were derived in a companion paper [1]. We construct an infinite class of regular solutions with varying dilaton, and non-zero 3-form fluxes. Our solutions may be viewed as the fully back-reacted geometries of AdS{sub 5} x S{sup 5} (or more generally, Janus) doped with D5 and/or NS5 branes. The solutions are parametrized by the choice of an arbitrary genus g hyper-elliptic Riemann surface {sigma} with boundary, all of whose branch points are restricted to lie on a line. For genus 0, the Janus solution with 16 supersymmetries and 6 real parameters is recovered; its topology coincides with that of AdS{sub 5} x S{sup 5}. The genus g {>=} 1 solutions are parametrized by a total of 4g + 6 real numbers, 2g-1 of which are the real moduli of {sigma}. The solutions have 2g + 2 asymptotic AdS{sub 5} x S{sup 5} regions, g three-spheres with RR 3-form charge, and another g with NSNS 3-form charge. Collapse of consecutive branch points of {sigma} yields singularities which correspond to D5 and NS5 branes in the probe limit. It is argued that the AdS/CFT dual gauge theory to each of our solutions consists of a 2+1-dimensional planar interface on which terminate 2g + 2 half-Minkowski 3+1-dimensional space-time N = 4 super-Yang-Mills theories. Generally, the N = 4 theory in each Minkowski half-space-time may have an independent value of the gauge coupling, and the interface may support various operators, whose interface couplings are further free parameters of the dual gauge theory.

  5. Numerical solution of non-linear diffusion problems

    International Nuclear Information System (INIS)

    Carmen, A. del; Ferreri, J.C.

    1998-01-01

    This paper presents a method for the numerical solution of non-linear diffusion problems using finite-differences in moving grids. Due to the presence of steep fronts in the solution domain and to the presence of advective terms originating in the grid movement, an implicit TVD scheme, first order in time and second order in space has been developed. Some algebraic details of the derivation are given. Results are shown for the pure advection of a scalar as a test case and an example dealing with the slow spreading of viscous fluids over plane surfaces. The agreement between numerical and analytical solutions is excellent. (author). 8 refs., 3 figs

  6. Fast multigrid solution of the advection problem with closed characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Yavneh, I. [Israel Inst. of Technology, Haifa (Israel); Venner, C.H. [Univ. of Twente, Enschede (Netherlands); Brandt, A. [Weizmann Inst. of Science, Rehovot (Israel)

    1996-12-31

    The numerical solution of the advection-diffusion problem in the inviscid limit with closed characteristics is studied as a prelude to an efficient high Reynolds-number flow solver. It is demonstrated by a heuristic analysis and numerical calculations that using upstream discretization with downstream relaxation-ordering and appropriate residual weighting in a simple multigrid V cycle produces an efficient solution process. We also derive upstream finite-difference approximations to the advection operator, whose truncation terms approximate {open_quotes}physical{close_quotes} (Laplacian) viscosity, thus avoiding spurious solutions to the homogeneous problem when the artificial diffusivity dominates the physical viscosity.

  7. Multi-cut solutions in Chern-Simons matrix models

    Science.gov (United States)

    Morita, Takeshi; Sugiyama, Kento

    2018-04-01

    We elaborate the Chern-Simons (CS) matrix models at large N. The saddle point equations of these matrix models have a curious structure which cannot be seen in the ordinary one matrix models. Thanks to this structure, an infinite number of multi-cut solutions exist in the CS matrix models. Particularly we exactly derive the two-cut solutions at finite 't Hooft coupling in the pure CS matrix model. In the ABJM matrix model, we argue that some of multi-cut solutions might be interpreted as a condensation of the D2-brane instantons.

  8. Adjoint P1 equations solution for neutron slowing down

    International Nuclear Information System (INIS)

    Cardoso, Carlos Eduardo Santos; Martinez, Aquilino Senra; Silva, Fernando Carvalho da

    2002-01-01

    In some applications of perturbation theory, it is necessary know the adjoint neutron flux, which is obtained by the solution of adjoint neutron diffusion equation. However, the multigroup constants used for this are weighted in only the direct neutron flux, from the solution of direct P1 equations. In this work, the adjoint P1 equations are derived by the neutron transport equation, the reversion operators rules and analogies between direct and adjoint parameters. The direct and adjoint neutron fluxes resulting from the solution of P 1 equations were used to three different weighting processes, to obtain the macrogroup macroscopic cross sections. It was found out noticeable differences among them. (author)

  9. Studies on derivative fluorimetry

    International Nuclear Information System (INIS)

    Gao Jinzhang; He Jiang; Wang Xiwen; Wang Zheming; Bai Guangbi

    1987-01-01

    A method is described for the derivative spectrofluorimetric determination of trace amounts of Sm, Eu and Tb as their ternary complexes with 2-thenoyltrifluoroacetone and diphenylguanidine. These ternary complexes show excitation bands at 345 nm for Sm and Eu and 350 nm for Tb, and fluorescence bands at 645 nm for Sm, 614 nm for Eu and 545 nm for Tb. A mixture of Sm, Eu and Tb can be determined by second-derivative spectrofluorimetry. The calibration graphs are linear over the range 10-100 p.p.m. for Sm, 0.5-50 p.p.m. for Eu and 100-1000 p.p.m. for Tb. (author)

  10. Insulin-derived amyloidosis

    Directory of Open Access Journals (Sweden)

    Yashdeep Gupta

    2015-01-01

    Full Text Available Amyloidosis is the term for diseases caused by the extracellular deposition of insoluble polymeric protein fibrils in tissues and organs. Insulin-derived amyloidosis is a rare, yet significant complication of insulin therapy. Insulin-derived amyloidosis at injection site can cause poor glycemic control and increased insulin dose requirements because of the impairment in insulin absorption, which reverse on change of injection site and/or excision of the mass. This entity should be considered and assessed by histopathology and immunohistochemistry, in patients with firm/hard local site reactions, which do not regress after cessation of insulin injection at the affected site. Search strategy: PubMed was searched with terms "insulin amyloidosis". Full text of articles available in English was reviewed. Relevant cross references were also reviewed. Last search was made on October 15, 2014.

  11. Multifunctional Cinnamic Acid Derivatives

    Directory of Open Access Journals (Sweden)

    Aikaterini Peperidou

    2017-07-01

    Full Text Available Our research to discover potential new multitarget agents led to the synthesis of 10 novel derivatives of cinnamic acids and propranolol, atenolol, 1-adamantanol, naphth-1-ol, and (benzylamino ethan-1-ol. The synthesized molecules were evaluated as trypsin, lipoxygenase and lipid peroxidation inhibitors and for their cytotoxicity. Compound 2b derived from phenoxyphenyl cinnamic acid and propranolol showed the highest lipoxygenase (LOX inhibition (IC50 = 6 μΜ and antiproteolytic activity (IC50 = 0.425 μΜ. The conjugate 1a of simple cinnamic acid with propranolol showed the higher antiproteolytic activity (IC50 = 0.315 μΜ and good LOX inhibitory activity (IC50 = 66 μΜ. Compounds 3a and 3b, derived from methoxylated caffeic acid present a promising combination of in vitro inhibitory and antioxidative activities. The S isomer of 2b also presented an interesting multitarget biological profile in vitro. Molecular docking studies point to the fact that the theoretical results for LOX-inhibitor binding are identical to those from preliminary in vitro study.

  12. Computation of Mie derivatives.

    Science.gov (United States)

    Li, Yang; Bowler, Nicola

    2013-07-10

    Analytical expressions are obtained for the derivatives of Mie scattering coefficients with respect to the electrical radius of the spherical scattering particle, and to the relative permittivity and permeability of both the particle and the surrounding medium. Their corresponding approximate expressions are developed to avoid numerical overflow based on the logarithmic derivative of Riccati-Bessel functions. The analytical expressions have been verified by comparing their results with those calculated by analytical expressions developed by Mathematica. Compared with the numerical derivative, the analytical expressions and approximate expressions show a higher accuracy and are 2.0 and 2.8 times, respectively, faster in the case of a single magnetodielectric sphere. Generally, for spheres with an electrical radius in a large range, the approximate expressions can yield acceptable accuracy and computation time up to a high order. This work can be used in the design of nonmetallic metamaterials, and in the retrieval of aerosol properties from remote sensing data. An example calculation is given for the design of an optical, all-dielectric, mu-negative metamaterial consisting of a simple cubic array of tellurium nanoparticles.

  13. On classical de Sitter and Minkowski solutions with intersecting branes

    Science.gov (United States)

    Andriot, David

    2018-03-01

    Motivated by the connection of string theory to cosmology or particle physics, we study solutions of type II supergravities having a four-dimensional de Sitter or Minkowski space-time, with intersecting D p -branes and orientifold O p -planes. Only few such solutions are known, and we aim at a better characterisation. Modulo a few restrictions, we prove that there exists no classical de Sitter solution for any combination of D 3/ O 3 and D 7/ O 7, while we derive interesting constraints for intersecting D 5/ O 5 or D 6/ O 6, or combinations of D 4/ O 4 and D 8/ O 8. Concerning classical Minkowski solutions, we understand some typical features, and propose a solution ansatz. Overall, a central information appears to be the way intersecting D p / O p overlap each other, a point we focus on.

  14. Analytical solution for soil water redistribution during evaporation process.

    Science.gov (United States)

    Teng, Jidong; Yasufuku, Noriyuki; Liu, Qiang; Liu, Shiyu

    2013-01-01

    Simulating the dynamics of soil water content and modeling soil water evaporation are critical for many environmental and agricultural strategies. The present study aims to develop an analytical solution to simulate soil water redistribution during the evaporation process. This analytical solution was derived utilizing an exponential function to describe the relation of hydraulic conductivity and water content on pressure head. The solution was obtained based on the initial condition of saturation and an exponential function to model the change of surface water content. Also, the evaporation experiments were conducted under a climate control apparatus to validate the theoretical development. Comparisons between the proposed analytical solution and experimental result are presented from the aspects of soil water redistribution, evaporative rate and cumulative evaporation. Their good agreement indicates that this analytical solution provides a reliable way to investigate the interaction of evaporation and soil water profile.

  15. Credit derivatives and risk management

    OpenAIRE

    Michael S. Gibson

    2007-01-01

    The striking growth of credit derivatives suggests that market participants find them to be useful tools for risk management. I illustrate the value of credit derivatives with three examples. A commercial bank can use credit derivatives to manage the risk of its loan portfolio. An investment bank can use credit derivatives to manage the risks it incurs when underwriting securities. An investor, such as an insurance company, asset manager, or hedge fund, can use credit derivatives to align its...

  16. Time-periodic solutions of the Benjamin-Ono equation

    Energy Technology Data Exchange (ETDEWEB)

    Ambrose , D.M.; Wilkening, Jon

    2008-04-01

    We present a spectrally accurate numerical method for finding non-trivial time-periodic solutions of non-linear partial differential equations. The method is based on minimizing a functional (of the initial condition and the period) that is positive unless the solution is periodic, in which case it is zero. We solve an adjoint PDE to compute the gradient of this functional with respect to the initial condition. We include additional terms in the functional to specify the free parameters, which, in the case of the Benjamin-Ono equation, are the mean, a spatial phase, a temporal phase and the real part of one of the Fourier modes at t = 0. We use our method to study global paths of non-trivial time-periodic solutions connecting stationary and traveling waves of the Benjamin-Ono equation. As a starting guess for each path, we compute periodic solutions of the linearized problem by solving an infinite dimensional eigenvalue problem in closed form. We then use our numerical method to continue these solutions beyond the realm of linear theory until another traveling wave is reached (or until the solution blows up). By experimentation with data fitting, we identify the analytical form of the solutions on the path connecting the one-hump stationary solution to the two-hump traveling wave. We then derive exact formulas for these solutions by explicitly solving the system of ODE's governing the evolution of solitons using the ansatz suggested by the numerical simulations.

  17. The stability of bubbles formed from supersaturated solutions, and homogeneous nucleation of gas bubbles from solution, both revisited.

    Science.gov (United States)

    Goldman, Saul

    2008-12-25

    The solution of the problem of the relative stability of all possible equilibrium bubble states that can form from a closed, finite, supersaturated gas-liquid solution, maintained at a fixed temperature and a fixed external pressure is given. The supersaturated solution may contain any number of dissolved volatile solutes. The full solution to this problem has remained elusive for decades, because of the complication of pressure inequalities between the bubbles and the constant external (or reservoir) pressure. The method of solution is one that had been used previously to solve the related problem of the stability of a liquid droplet in a supersaturated vapor, where the same complication occurred. The derived equations were found to reduce correctly when simplified; they were consistent with experiment, and the system Gibbs free energy appropriately obeyed the Law of Corresponding States. The expressions were used in the context of transition state theory to provide semiempirical predictions of the rate of homogeneous bubble formation from a supersaturated solution, and the "critical pressure for homogeneous nucleation (P(crit))". The nucleation Gibbs free energy expression derived here had a lower barrier height and resulted in a reduction of P(crit) values, relative to what was obtained from the basis of a pre-existing approximate expression taken from the literature. Applications to chemical engineering and human decompression modeling are briefly described.

  18. 2010 Water & Aqueous Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Dor Ben-Amotz

    2010-08-13

    Water covers more than two thirds of the surface of the Earth and about the same fraction of water forms the total mass of a human body. Since the early days of our civilization water has also been in the focus of technological developments, starting from converting it to wine to more modern achievements. The meeting will focus on recent advances in experimental, theoretical, and computational understanding of the behavior of the most important and fascinating liquid in a variety of situations and applications. The emphasis will be less on water properties per se than on water as a medium in which fundamental dynamic and reactive processes take place. In the following sessions, speakers will discuss the latest breakthroughs in unraveling these processes at the molecular level: Water in Solutions; Water in Motion I and II; Water in Biology I and II; Water in the Environment I and II; Water in Confined Geometries and Water in Discussion (keynote lecture and poster winners presentations).

  19. Internet Business Solutions

    Science.gov (United States)

    1997-01-01

    Cogent Software, Inc. was formed in January 1995 by David Atkinson and Irene Woerner, both former employees of the Jet Propulsion Laboratory (JPL). Several other Cogent employees also worked at JPL. Atkinson headed JPL's Information Systems Technology section and Woerner lead the Advanced User Interfaces Group. Cogent's mission is to help companies organize and manage their online content by developing advanced software for the next generation of online directories and information catalogs. The company offers a complete range of Internet solutions, including Internet access, Web site design, local and wide-area networks, and custom software for online commerce applications. Cogent also offers DesignSphere Online, an electronic community for the communications arts industry. Customers range from small offices to manufacturers with thousands of employees, including Chemi-Con, one of the largest manufacturers of capacitors in the world.

  20. Fundamentals and advanced techniques in derivatives hedging

    CERN Document Server

    Bouchard, Bruno

    2016-01-01

    This book covers the theory of derivatives pricing and hedging as well as techniques used in mathematical finance. The authors use a top-down approach, starting with fundamentals before moving to applications, and present theoretical developments alongside various exercises, providing many examples of practical interest. A large spectrum of concepts and mathematical tools that are usually found in separate monographs are presented here. In addition to the no-arbitrage theory in full generality, this book also explores models and practical hedging and pricing issues. Fundamentals and Advanced Techniques in Derivatives Hedging further introduces advanced methods in probability and analysis, including Malliavin calculus and the theory of viscosity solutions, as well as the recent theory of stochastic targets and its use in risk management, making it the first textbook covering this topic. Graduate students in applied mathematics with an understanding of probability theory and stochastic calculus will find this b...

  1. Solution of Finite Element Equations

    DEFF Research Database (Denmark)

    Krenk, Steen

    An important step in solving any problem by the finite element method is the solution of the global equations. Numerical solution of linear equations is a subject covered in most courses in numerical analysis. However, the equations encountered in most finite element applications have some special...... features that justify the development of specialized solution algorithms....

  2. Location Intelligence Solutions

    International Nuclear Information System (INIS)

    Schmidt, D.

    2015-01-01

    Location Intelligence (LI) means using the spatial dimension of information as a key to support business processes. This spatial dimension has to be defined by geographic coordinates. Storing these spatial objects in a database allows for attaching a 'meaning' to them, like 'current position', 'border', 'building' or 'room'. Now the coordinates represent real-world objects, which can be relevant for the measurement, documentation, control or optimization of (parameters of) business processes aiming at different business objectives. But LI can only be applied, if the locations can be determined with an accuracy (in space and time) appropriate for the business process in consideration. Therefore the first step in any development of a LI solution is the analysis of the business process itself regarding its requirements for spatial and time resolution and accuracy. The next step is the detailed analysis of the surrounding conditions of the process: Does the process happen indoor and/or outdoor? Are there moving objects? If yes, how fast are they? How does the relevant environment look like? Is technical infrastructure available? Is the process restricted by regulations? As a result, a proper Location Detection Technology (LDT) has to be chosen in order to get reliable and accurate positions of the relevant objects. At the highly challenging conditions of the business processes IAEA inspectors are working with, the chosen LDTs have to deliver reliable positioning on ''room-level'' accuracy, even if there is no location enabling infrastructure in place, the objects (people) mostly are indoors and have to work under strong regulations. The presentation will give insights into innovative LI solutions based on technologies of different LDT providers. Pros and cons of combinations of different LDT (like multi- GNSS, IMU, camera, and human interaction based positioning) will be discussed from the

  3. Natural climate solutions

    Science.gov (United States)

    Griscom, Bronson W.; Adams, Justin; Ellis, Peter W.; Houghton, Richard A.; Lomax, Guy; Miteva, Daniela A.; Schlesinger, William H.; Shoch, David; Siikamäki, Juha V.; Smith, Pete; Woodbury, Peter; Zganjar, Chris; Blackman, Allen; Campari, João; Conant, Richard T.; Delgado, Christopher; Elias, Patricia; Gopalakrishna, Trisha; Hamsik, Marisa R.; Herrero, Mario; Kiesecker, Joseph; Landis, Emily; Laestadius, Lars; Leavitt, Sara M.; Minnemeyer, Susan; Polasky, Stephen; Potapov, Peter; Putz, Francis E.; Sanderman, Jonathan; Silvius, Marcel; Wollenberg, Eva; Fargione, Joseph

    2017-10-01

    Better stewardship of land is needed to achieve the Paris Climate Agreement goal of holding warming to below 2 °C; however, confusion persists about the specific set of land stewardship options available and their mitigation potential. To address this, we identify and quantify “natural climate solutions” (NCS): 20 conservation, restoration, and improved land management actions that increase carbon storage and/or avoid greenhouse gas emissions across global forests, wetlands, grasslands, and agricultural lands. We find that the maximum potential of NCS—when constrained by food security, fiber security, and biodiversity conservation—is 23.8 petagrams of CO2 equivalent (PgCO2e) y‑1 (95% CI 20.3–37.4). This is ≥30% higher than prior estimates, which did not include the full range of options and safeguards considered here. About half of this maximum (11.3 PgCO2e y‑1) represents cost-effective climate mitigation, assuming the social cost of CO2 pollution is ≥100 USD MgCO2e‑1 by 2030. Natural climate solutions can provide 37% of cost-effective CO2 mitigation needed through 2030 for a >66% chance of holding warming to below 2 °C. One-third of this cost-effective NCS mitigation can be delivered at or below 10 USD MgCO2‑1. Most NCS actions—if effectively implemented—also offer water filtration, flood buffering, soil health, biodiversity habitat, and enhanced climate resilience. Work remains to better constrain uncertainty of NCS mitigation estimates. Nevertheless, existing knowledge reported here provides a robust basis for immediate global action to improve ecosystem stewardship as a major solution to climate change.

  4. An Ionic Liquid Solution of Chitosan as Organocatalyst

    Directory of Open Access Journals (Sweden)

    René Wilhelm

    2013-11-01

    Full Text Available Chitosan, which is derived from the biopolymer chitin, can be readily dissolved in different ionic liquids. The resulting homogeneous solutions were applied in an asymmetric Aldol reaction. Depending on the type of ionic liquid used, high asymmetric inductions were found. The influence of different additives was also studied. The best results were obtained in [BMIM][Br] without an additive.

  5. Solitary wave solution to a singularly perturbed generalized Gardner ...

    Indian Academy of Sciences (India)

    2017-03-24

    Mar 24, 2017 ... which is one model in plasma physics and solid physics. [3]. Hamdi et al [4] obtained an exact solitary wave solution to eq. (1.2). They also derived three conserva- tion laws and three invariants of motion for eq. (1.2). [5]. Antonova and Biswas [6] exploited the soliton perturbation theory to eq. (1.2) with γ = 1.

  6. Finite element approach to solution of multidimensional quasi ...

    African Journals Online (AJOL)

    problems whose function can be expressed as derivatives and integrated functional or on solution of quasi-harmonic functions whose physical behaviors are governed by a general quasi-harmonic differential equation that can be treated as a quadratic functional that can be minimized over a region. The functional of a ...

  7. Path integral solution for some time-dependent potential

    International Nuclear Information System (INIS)

    Storchak, S.N.

    1989-12-01

    The quantum-mechanical problem with a time-dependent potential is solved by the path integral method. The solution is obtained by the application of the previously derived general formula for rheonomic homogeneous point transformation and reparametrization in the path integral. (author). 4 refs

  8. Global weak solution for a equations in plasma

    International Nuclear Information System (INIS)

    Guo Boling; Huang Daiwen

    2010-01-01

    The existence of global weak solutions of the initial boundary value problem to a simplified equations, derived from the equations of two fluid system in plasma, is proven by using energy method and some embedding theorems in Sobolev-Orlicz space.

  9. Graphical Solution of the Monic Quadratic Equation with Complex Coefficients

    Science.gov (United States)

    Laine, A. D.

    2015-01-01

    There are many geometrical approaches to the solution of the quadratic equation with real coefficients. In this article it is shown that the monic quadratic equation with complex coefficients can also be solved graphically, by the intersection of two hyperbolas; one hyperbola being derived from the real part of the quadratic equation and one from…

  10. A generic travelling wave solution in dissipative laser cavity

    Indian Academy of Sciences (India)

    2016-09-09

    Sep 9, 2016 ... Abstract. A large family of cosh-Gaussian travelling wave solution of a complex Ginzburg–Landau equation. (CGLE), that describes dissipative semiconductor laser cavity is derived. Using perturbation method, the stabil- ity region is identified. Bifurcation analysis is done by smoothly varying the cavity loss ...

  11. Exact solutions of a nonconservative system in elastodynamics

    OpenAIRE

    Kayyunnapara Thomas Joseph

    2015-01-01

    In this article we find an explicit formula for solutions of a nonconservative system when the initial data lies in the level set of one of the Riemann invariants. Also for nonconservative shock waves in the sense of Volpert we derive an explicit formula for the viscous shock profile.

  12. Solitary wave solutions of selective nonlinear diffusion-reaction ...

    Indian Academy of Sciences (India)

    An auto-Bäcklund transformation derived in the homogeneous balance method is employed to obtain several new exact solutions of certain kinds of nonlinear diffusion-reaction (D-R) equations. These equations arise in a variety of problems in physical, chemical, biological, social and ecological sciences.

  13. Solitary wave solutions to nonlinear evolution equations in ...

    Indian Academy of Sciences (India)

    where u(x,y,t) is a travelling wave solution of nonlinear partial differential equation. We use the ... The ordinary differential equation (9) is then integrated as long as all terms contain derivatives, where we neglect ...... In addition to deterministic perturbation terms, stochastic perturbation terms will also be taken into account.

  14. Analytical solutions of one-dimensional advection– diffusion ...

    Indian Academy of Sciences (India)

    Advection–diffusion equation describes the solute transport due to combined effect of diffusion and convection in a medium. It is a partial differen- tial equation of parabolic type, derived on the principle of conservation of mass using Fick's law. Due to the growing surface and subsurface hydro- environment degradation and ...

  15. Solitary wave solutions of selective nonlinear diffusion-reaction ...

    Indian Academy of Sciences (India)

    An auto-Bäcklund transformation derived in the homogeneous balance method is employed to obtain several new exact solutions of certain kinds of nonlin- ear diffusion-reaction (D-R) equations. These equations arise in a variety of problems in physical, chemical, biological, social and ecological sciences. Keywords.

  16. Radial solutions to semilinear elliptic equations via linearized operators

    Directory of Open Access Journals (Sweden)

    Phuong Le

    2017-04-01

    Full Text Available Let $u$ be a classical solution of semilinear elliptic equations in a ball or an annulus in $\\mathbb{R}^N$ with zero Dirichlet boundary condition where the nonlinearity has a convex first derivative. In this note, we prove that if the $N$-th eigenvalue of the linearized operator at $u$ is positive, then $u$ must be radially symmetric.

  17. Continuous rearrangement and symmetry of solutions of elliptic ...

    Indian Academy of Sciences (India)

    nonnegative solutions of some semilinear elliptic problems in symmetric domains satisfy a weak, `local' kind .... This type of continuous rearrangement can be used to prove the symmetry of local minimizers for certain .... of functions u P LpЕΩЖ having generalized partial derivatives uxi P LpЕΩЖ, i И 1Y ... Y n, and we write.

  18. Higher-Derivative Supergravity and Moduli Stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Ciupke, David; Westphal, Alexander [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Louis, Jan [Hamburg Univ. (Germany). Fachberich Physik; Hamburg Univ. (Germany). Zentrum fuer Mathematische Physik

    2015-05-15

    We review the ghost-free four-derivative terms for chiral superfields in N=1 supersymmetry and supergravity. These terms induce cubic polynomial equations of motion for the chiral auxiliary fields and correct the scalar potential. We discuss the different solutions and argue that only one of them is consistent with the principles of effective field theory. Special attention is paid to the corrections along flat directions which can be stabilized or destabilized by the higher-derivative terms. We then compute these higher-derivative terms explicitly for the type IIB string compactified on a Calabi-Yau orientifold with fluxes via Kaluza-Klein reducing the (α'){sup 3}R{sup 4} corrections in ten dimensions for the respective N=1 Kaehler moduli sector. We prove that together with flux and the known (α'){sup 3}-corrections the higher-derivative term stabilizes all Calabi-Yau manifolds with positive Euler number, provided the sign of the new correction is negative.

  19. Analysis of the Keller–Segel Model with a Fractional Derivative without Singular Kernel

    Directory of Open Access Journals (Sweden)

    Abdon Atangana

    2015-06-01

    Full Text Available Using some investigations based on information theory, the model proposed by Keller and Segel was extended to the concept of fractional derivative using the derivative with fractional order without singular kernel recently proposed by Caputo and Fabrizio. We present in detail the existence of the coupled-solutions using the fixed-point theorem. A detailed analysis of the uniqueness of the coupled-solutions is also presented. Using an iterative approach, we derive special coupled-solutions of the modified system and we present some numerical simulations to see the effect of the fractional order.

  20. Synthesis of 5'-deoxy-5'-nucleosideacetic acid derivatives

    Science.gov (United States)

    Harada, Kazuo; Orgel, Leslie E.

    1990-01-01

    Several new 5'-deoxy-5'-nucleosideacetic acid derivatives have been synthesized by the reactions of alkoxycarbonylmethylene triphenylphosphoranes with nucleoside 5'-aldehydes. The oligomerization of adenine derivatives IIa, IIIa, IV, V and guanine derivatives IIc and IIIc in aqueous solution was studied using a water-soluble carbodiimide as a condensing agent. It is found that the saturated acid (IV) tends to cyclize to the lactone, while IIa and unsaturated acids (IIIa and V) oligomerized efficiently, especially in the presence of poly (U) as a template.

  1. Orbital Resonances in the Vinti Solution

    Science.gov (United States)

    Zurita, L. D.

    As space becomes more congested, contested, and competitive, high-accuracy orbital predictions become critical for space operations. Current orbit propagators use the two-body solution with perturbations added, which have significant error growth when numerically integrated for long time periods. The Vinti Solution is a more accurate model than the two-body problem because it also accounts for the equatorial bulge of the Earth. Unfortunately, the Vinti solution contains small divisors near orbital resonances in the perturbative terms of the Hamiltonian, which lead to inaccurate orbital predictions. One approach to avoid the small divisors is to apply transformation theory, which is presented in this research. The methodology of this research is to identify the perturbative terms of the Vinti Solution, perform a coordinate transformation, and derive the new equations of motion for the Vinti system near orbital resonances. An analysis of these equations of motion offers insight into the dynamics found near orbital resonances. The analysis in this research focuses on the 2:1 resonance, which includes the Global Positioning System. The phase portrait of a nominal Global Positioning System satellite orbit is found to contain a libration region and a chaotic region. Further analysis shows that the dynamics of the 2:1 resonance affects orbits with semi-major axes ranging from -5.0 to +5.4 kilometers from an exactly 2:1 resonant orbit. Truth orbits of seven Global Positioning System satellites are produced for 10 years. Two of the satellites are found to be outside of the resonance region and three are found to be influenced by the libration dynamics of the resonance. The final satellite is found to be influenced by the chaotic dynamics of the resonance. This research provides a method of avoiding the small divisors found in the perturbative terms of the Vinti Solution near orbital resonances.

  2. Enthalpy of solution of biuret in various aqueous electrolyte solutions and in an urea solution

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Hisashi; Murakami, Sachio (Osaka City Univ. (Japan))

    1989-06-30

    Enthalpies of biuret which is simplest amido acid and does not have hydrophobic group, in various aqueous solutions and in urea solution were measured at 298.15K to clarify the influence of salt on polymer conformal changes of organism or structure and functions of membrane. The isoperibol calorimeter where the quartz thermometer was used as the thermal sensor, was used in the measurement. The performance of this calorimeter was tested by comparing measurements with values in references. From the analysis of enthalpies of biuret solutions, following results of solute-solute-solvent interactions could be obtained: the rate where biuret destroys water structure is smaller in salt solutions than in aqueous solutions and the tendency depends on the ion size; ion-water interaction weakens owing to the ion-biuret interaction in salt solution of biuret; and water molecules are made free. 25 refs., 4 figs., 5 tabs.

  3. Free Energy and Equilibrium: The Basis of Change in G Degrees = -RT In K for Reactions in Solution.

    Science.gov (United States)

    Barrow, Gordon M.

    1983-01-01

    Discusses the derivation of a thermodynamic relation. The relation is derived, for reactants in solution, from a treatment of the free energy of the reducing system as a function of the degree of advancement of the solution. Includes microcomputer figures/diagrams produced by programs developed to simulate this study. (JN)

  4. Original and Derived Judgment

    DEFF Research Database (Denmark)

    Foss, Kirsten; Foss, Nicolai Juul; Klein, Peter G.

    may delegate a wide range of decision rights to subordinates, who exercise derived judgment. We call these employees "proxy-entrepreneurs," and ask how the firm's or-ganizational structure — its formal and informal systems of rewards and punishments, rules for settling disputes and renegotiating...... agreements, means of evaluating perform-ance, and so on — can be designed to encourage forms of proxy-entrepreneurship that increase firm value while discouraging actions that destroy value. Building on key ideas from the entrepreneurship literature, Austrian economics, and the economic theory of the firm we...

  5. Elastic interaction of partially debonded circular inclusions. I. Theoretical solution

    DEFF Research Database (Denmark)

    Kushch, V.I.; Shmegera, S.V.; Mishnaevsky, Leon

    2010-01-01

    derived by combining the complex potentials technique with the newly derived series expansions. This solution is valid for any non-uniform far load and is finite and exact in the case of polynomial far field. Applying the superposition principle expands this theory to the multiple inclusion problem......A complete solution has been obtained of the elasticity problem for a plane containing a finite array of partially debonded circular inclusions, regarded as the open-crack model of fibrous composite with interface damage. A general displacement solution of the single-inclusion problem has been...... and provides a simple and rapidly convergent iterative algorithm. The presented numerical data show an accuracy and numerical efficiency of the proposed method and discover the way and extent to which the elastic interaction between the partially debonded inclusions affects the local fields, stress intensity...

  6. Certain legal aspects of derivatives.

    Science.gov (United States)

    Cloney, T J

    1994-01-01

    This article discusses legal characteristics of derivatives that a not-for-profit health care company may use in a conduit financing in which a governmental issuer issues bonds for the benefit of a health care company. This article also presents the Master Agreement promulgated by the International Swaps and Derivatives Association; discusses how to get out of a derivative; discusses the status of a derivative after insolvency of a counterparty; presents disclosure issues relating to documents prepared in connection with an issue of bonds; and describes the treatment of derivatives under commodities regulations. It concludes with a presentation of possible new regulations applying to derivatives.

  7. In defense of derivations

    Science.gov (United States)

    Mungan, Carl E.

    2016-05-01

    At the 2015 AAPT Summer Meeting, I presented four derivations of the formula for motional emf. Such physics derivations involve the construction of explanatory frameworks involving diagrams and mathematical models. Although textbooks devote considerable space to such explanations, many teachers and students spend their time on worksheets, end-of-chapter problems, and the like. The book is reduced to a bank of solved (i.e., example) and unsolved (i.e., homework) questions, along with equations in colored boxes that presumably are to be used to answer those questions. Such an approach encourages fragmentation of knowledge, the view that there is only one right answer to a problem with the goal of physics being to find that answer (neatly boxed of course), and the inability to reason about even a slightly different (much less a novel) situation. If we are to develop scientific literacy, significant course time must be devoted to explaining the structure of and support for the models and equations we use.

  8. Quinazolin-4-one derivatives

    DEFF Research Database (Denmark)

    Mosley, Cara A; Acker, Timothy M; Hansen, Kasper Bø

    2010-01-01

    We describe a new class of subunit-selective antagonists of N-methyl D-aspartate (NMDA)-selective ionotropic glutamate receptors that contain the (E)-3-phenyl-2-styrylquinazolin-4(3H)-one backbone. The inhibition of recombinant NMDA receptor function induced by these quinazolin-4-one derivatives ...... were identified with 50-fold selectivity for recombinant NR2C/D-containing receptors over NR2A/B containing receptors. These compounds represent a new class of noncompetitive subunit-selective NMDA receptor antagonists.......We describe a new class of subunit-selective antagonists of N-methyl D-aspartate (NMDA)-selective ionotropic glutamate receptors that contain the (E)-3-phenyl-2-styrylquinazolin-4(3H)-one backbone. The inhibition of recombinant NMDA receptor function induced by these quinazolin-4-one derivatives...... is noncompetitive and voltage-independent, suggesting that this family of compounds does not exert action on the agonist binding site of the receptor or block the channel pore. The compounds described here resemble CP-465,022 ((S)-3-(2-chlorophenyl)-2-[2-(6-diethylaminomethyl-pyridin-2-yl)-vinyl]-6-fluoro-3H...

  9. catalyzed oxidation of formamidine derivative by hexacyanoferrate(III)

    Indian Academy of Sciences (India)

    coordinated with these metal ions such as 1,2,4-tria- zole derivatives which ... bly distilled water. A solution of hexacyanoferrate(III) was prepared by dissolving potassium hexacyanofer- rate(III) (BDH) in water and its concentration was ascertained by ... by measuring the decay of HCF absorbance as a func- tion of time at its ...

  10. Sulfonamide Derivatives of 2-Amino-1-phenylethane as Suitable ...

    African Journals Online (AJOL)

    Methods: A series of sulfamoyl derivatives, 3a-l, of 1-amino-2-phenylethane (1) were synthesized by reacting with various aryl sulfonyl chlorides, 2a-l, in the presence of aqueous Na2CO3 solution under definite pH control. All the synthesized molecules were screened against three enzymes, acetyl cholinesterase (AChE), ...

  11. LCCT-derived three-level three-phase inverters

    DEFF Research Database (Denmark)

    Shults, Tatiana; Husev, Oleksandr; Blaabjerg, Frede

    2017-01-01

    Solutions for a family of the novel three-level neutral-point-clamped (NPC) inductor-capacitor-capacitor-transformer (LCCT)-derived three-phase inverters are described and compared. Component design guidelines and steady state analysis, current and voltage waveforms are given. The authors...... input voltage source and continuous input current are presented. The main advantages and design requirements are discussed...

  12. Application of Weather Derivatives in Multi-Period Risk Management

    OpenAIRE

    Vedenov, Dmitry V.; Sanchez, Leonardo

    2011-01-01

    This work is a first attempt to analyze the effect of weather derivative availability on the risk management strategies in a multi-period setting, when crop activities take place twice a year. Rice production in Ecuador is used as a case study. Numerical solutions show farmers improve their well-being by reducing their risk exposure.

  13. Thermodynamics of association of water soluble fullerene derivatives

    Indian Academy of Sciences (India)

    SONANKI KESHRI

    2017-08-31

    Aug 31, 2017 ... Abstract. The thermodynamics of association of fullerene [C60] and water-soluble fullerene derivatives, i.e., fullerols [C60(OH)n, where, n = 2, 4, 8, 12] in aqueous solutions have been studied using molecular dynamics simulations. The potentials of mean force (PMFs) bring out the tendency of aggregation ...

  14. Long-time asymptotics for the derivative nonlinear Schrödinger equation on the half-line

    Science.gov (United States)

    Arruda, Lynnyngs Kelly; Lenells, Jonatan

    2017-11-01

    We derive asymptotic formulas for the solution of the derivative nonlinear Schrödinger equation on the half-line under the assumption that the initial and boundary values lie in the Schwartz class. The formulas clearly show the effect of the boundary on the solution. The approach is based on a nonlinear steepest descent analysis of an associated Riemann–Hilbert problem.

  15. Acquiring Knowledge of Derived Nominals and Derived Adjectives in Context

    Science.gov (United States)

    Marinellie, Sally A.; Kneile, Lynn A.

    2012-01-01

    Purpose: This research investigated children's ability to acquire semantic and syntactic knowledge of derived nominals and derived adjectives in the context of short passages. The study also investigated the relation of morphological awareness and the ability to acquire knowledge of derived words in context. Method: A total of 106 children in…

  16. Experts' Understanding of Partial Derivatives Using the Partial Derivative Machine

    Science.gov (United States)

    Roundy, David; Weber, Eric; Dray, Tevian; Bajracharya, Rabindra R.; Dorko, Allison; Smith, Emily M.; Manogue, Corinne A.

    2015-01-01

    Partial derivatives are used in a variety of different ways within physics. Thermodynamics, in particular, uses partial derivatives in ways that students often find especially confusing. We are at the beginning of a study of the teaching of partial derivatives, with a goal of better aligning the teaching of multivariable calculus with the needs of…

  17. Insight solutions are correct more often than analytic solutions

    Science.gov (United States)

    Salvi, Carola; Bricolo, Emanuela; Kounios, John; Bowden, Edward; Beeman, Mark

    2016-01-01

    How accurate are insights compared to analytical solutions? In four experiments, we investigated how participants’ solving strategies influenced their solution accuracies across different types of problems, including one that was linguistic, one that was visual and two that were mixed visual-linguistic. In each experiment, participants’ self-judged insight solutions were, on average, more accurate than their analytic ones. We hypothesised that insight solutions have superior accuracy because they emerge into consciousness in an all-or-nothing fashion when the unconscious solving process is complete, whereas analytic solutions can be guesses based on conscious, prematurely terminated, processing. This hypothesis is supported by the finding that participants’ analytic solutions included relatively more incorrect responses (i.e., errors of commission) than timeouts (i.e., errors of omission) compared to their insight responses. PMID:27667960

  18. Simple de Sitter solutions

    International Nuclear Information System (INIS)

    Silverstein, Eva

    2008-01-01

    We present a framework for de Sitter model building in type IIA string theory, illustrated with specific examples. We find metastable de Sitter (dS) minima of the potential for moduli obtained from a compactification on a product of two nil three-manifolds (which have negative scalar curvature) combined with orientifolds, branes, fractional Chern-Simons forms, and fluxes. As a discrete quantum number is taken large, the curvature, field strengths, inverse volume, and four-dimensional string coupling become parametrically small, and the de Sitter Hubble scale can be tuned parametrically smaller than the scales of the moduli, Kaluza Klein (KK), and winding mode masses. A subtle point in the construction is that although the curvature remains consistently weak, the circle fibers of the nilmanifolds become very small in this limit (though this is avoided in illustrative solutions at modest values of the parameters). In the simplest version of the construction, the heaviest moduli masses are parametrically of the same order as the lightest KK and winding masses. However, we provide a method for separating these marginally overlapping scales, and more generally the underlying supersymmetry of the model protects against large corrections to the low-energy moduli potential

  19. Plutonium solution analyzer

    International Nuclear Information System (INIS)

    Burns, D.A.

    1994-09-01

    A fully automated analyzer has been developed for plutonium solutions. It was assembled from several commercially available modules, is based upon segmented flow analysis, and exhibits precision about an order of magnitude better than commercial units (0.5%-O.05% RSD). The system was designed to accept unmeasured, untreated liquid samples in the concentration range 40-240 g/L and produce a report with sample identification, sample concentrations, and an abundance of statistics. Optional hydraulics can accommodate samples in the concentration range 0.4-4.0 g/L. Operating at a typical rate of 30 to 40 samples per hour, it consumes only 0.074 mL of each sample and standard, and generates waste at the rate of about 1.5 mL per minute. No radioactive material passes through its multichannel peristaltic pump (which remains outside the glovebox, uncontaminated) but rather is handled by a 6-port, 2-position chromatography-type loop valve. An accompanying computer is programmed in QuickBASIC 4.5 to provide both instrument control and data reduction. The program is truly user-friendly and communication between operator and instrument is via computer screen displays and keyboard. Two important issues which have been addressed are waste minimization and operator safety (the analyzer can run in the absence of an operator, once its autosampler has been loaded)

  20. Future climate. Engineering solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ferdinand, J.F.; Hagedorn-Rasmussen, P.; Fonnesbech, B.

    2009-09-15

    Future Climate Engineering Solutions - Joint Report is the common output and a documentation of more than 1 year's effort by 13 engineering associations - in 12 countries - to demonstrate how technologies can combat climate change. The report consists of three parts: Summaries of 10 national climate plans and technology prospects, 5 Key Common Findings, and a Climate Call from Engineers to create a new global climate treaty. The basic assumption of the project is recognition that GHG emissions, and their concentration in the atmosphere, must be reduced to a sustainable level. The project definition of a sustainable level is equivalent to the best-case stabilisation scenario which was presented in the 4th Assessment Report (AR4) by the UN Intergovernmental Panel on Climate Change (IPCC), whereby the global mean temperature is most likely to stabilise at 2.0-2.4 deg. C. The Future Climate website www.futureclimate.info holds more information about the project, including possibility to download project material, including the full national climate plans.

  1. Plutonium solution analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Burns, D.A.

    1994-09-01

    A fully automated analyzer has been developed for plutonium solutions. It was assembled from several commercially available modules, is based upon segmented flow analysis, and exhibits precision about an order of magnitude better than commercial units (0.5%-O.05% RSD). The system was designed to accept unmeasured, untreated liquid samples in the concentration range 40-240 g/L and produce a report with sample identification, sample concentrations, and an abundance of statistics. Optional hydraulics can accommodate samples in the concentration range 0.4-4.0 g/L. Operating at a typical rate of 30 to 40 samples per hour, it consumes only 0.074 mL of each sample and standard, and generates waste at the rate of about 1.5 mL per minute. No radioactive material passes through its multichannel peristaltic pump (which remains outside the glovebox, uncontaminated) but rather is handled by a 6-port, 2-position chromatography-type loop valve. An accompanying computer is programmed in QuickBASIC 4.5 to provide both instrument control and data reduction. The program is truly user-friendly and communication between operator and instrument is via computer screen displays and keyboard. Two important issues which have been addressed are waste minimization and operator safety (the analyzer can run in the absence of an operator, once its autosampler has been loaded).

  2. On the Partial Analytical Solution of the Kirchhoff Equation

    KAUST Repository

    Michels, Dominik L.

    2015-09-01

    We derive a combined analytical and numerical scheme to solve the (1+1)-dimensional differential Kirchhoff system. Here the object is to obtain an accurate as well as an efficient solution process. Purely numerical algorithms typically have the disadvantage that the quality of solutions decreases enormously with increasing temporal step sizes, which results from the numerical stiffness of the underlying partial differential equations. To prevent that, we apply a differential Thomas decomposition and a Lie symmetry analysis to derive explicit analytical solutions to specific parts of the Kirchhoff system. These solutions are general and depend on arbitrary functions, which we set up according to the numerical solution of the remaining parts. In contrast to a purely numerical handling, this reduces the numerical solution space and prevents the system from becoming unstable. The differential Kirchhoff equation describes the dynamic equilibrium of one-dimensional continua, i.e. slender structures like fibers. We evaluate the advantage of our method by simulating a cilia carpet.

  3. An Analytical Method of Auxiliary Sources Solution for Plane Wave Scattering by Impedance Cylinders - A Reference Solution for the Numerical Method of Auxiliary Sources

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2004-01-01

    To facilitate the validation of the numerical Method of Auxiliary Sources an analytical Method of Auxiliary Sources solution is derived in this paper. The Analytical solution is valid for transverse magnetic, and electric, plane wave scattering by circular impedance Cylinders, and it is derived...... of the numerical Method of Auxiliary Sources for a range of scattering configurations....... with their singularities at different positions away from the origin. The transformation necessitates a truncation of the wave transformation but the inaccuracy introduced hereby is shown to be negligible. The analytical Method of Auxiliary Sources solution is employed as a reference to investigate the accuracy...

  4. Sharp asymptotic estimates for vorticity solutions of the 2D Navier-Stokes equation

    Directory of Open Access Journals (Sweden)

    Yuncheng You

    2008-12-01

    Full Text Available The asymptotic dynamics of high-order temporal-spatial derivatives of the two-dimensional vorticity and velocity of an incompressible, viscous fluid flow in $mathbb{R}^2$ are studied, which is equivalent to the 2D Navier-Stokes equation. It is known that for any integrable initial vorticity, the 2D vorticity solution converges to the Oseen vortex. In this paper, sharp exterior decay estimates of the temporal-spatial derivatives of the vorticity solution are established. These estimates are then used and combined with similarity and $L^p$ compactness to show the asymptotical attraction rates of temporal-spatial derivatives of generic 2D vorticity and velocity solutions by the Oseen vortices and velocity solutions respectively. The asymptotic estimates and the asymptotic attraction rates of all the derivatives obtained in this paper are independent of low or high Reynolds numbers.

  5. Topics on dimensional reduction: Solutions and consistency

    Science.gov (United States)

    Martinez Acosta, Rene R.

    2000-10-01

    We exploit the dimensional reduction ideas to interpret several solutions of low dimensional effective theories from the viewpoint of string theory and M-theory. We report that a rectangular three-dimensional lattice of intersecting domain walls in D = 4 dimensions, with arbitrary spacing, emerges naturally as a classical solution of M-theory. We also construct the non-linear Kaluza-Klein ansätze describing the embeddings of the U(1)3, U(1)4 and U(1)2 truncations of D = 5, D = 4 and D = 7 gauged supergravities into the type IIB string and M-theory. We use these general ansätze to embed and interpret the charged AdS5, AdS4 and AdS7 black hole solutions in ten and eleven dimensions. We then elaborate on the consistent truncation of Kaluza- Klein theories to their massless sector while retaining the full gauge symmetry associated with the isometry group G of the internal manifold M. We derive and test in general a consistency condition for Kaluza-Klein dimensional reduction for any Einstein space M̂ that is constructed as a U(1) bundle over a product of complex projective base spaces.

  6. Brane Inflation, Solitons and Cosmological Solutions: I

    Energy Technology Data Exchange (ETDEWEB)

    Chen, P.

    2005-01-25

    In this paper we study various cosmological solutions for a D3/D7 system directly from M-theory with fluxes and M2-branes. In M-theory, these solutions exist only if we incorporate higher derivative corrections from the curvatures as well as G-fluxes. We take these corrections into account and study a number of toy cosmologies, including one with a novel background for the D3/D7 system whose supergravity solution can be completely determined. Our new background preserves all the good properties of the original model and opens up avenues to investigate cosmological effects from wrapped branes and brane-antibrane annihilation, to name a few. We also discuss in some detail semilocal defects with higher global symmetries, for example exceptional ones, that occur in a slightly different regime of our D3/D7 model. We show that the D3/D7 system does have the required ingredients to realize these configurations as non-topological solitons of the theory. These constructions also allow us to give a physical meaning to the existence of certain underlying homogeneous quaternionic Kahler manifolds.

  7. Laplace transform solutions for solute transport in fissured aquifers

    Science.gov (United States)

    Barker, J. A.

    The main processes affecting the migration of a solute in a fissured aquifer will be advection and dispersion in the fissures, diffusion into the porous matrix; and adsorption. This paper considers solute transport in an idealized fissured aquifer consisting of slabs of saturated rock-matrix separated by equally spaced, planar fissures. The solution of the transport equations is developed as far as Laplace transforms of the solute concentrations in the fissure and matrix water. Numerical inversion of the transforms is used to investigate characteristic behaviour of the model for a number of special cases.

  8. Exact solutions of a nonpolynomially nonlinear Schrodinger equation

    International Nuclear Information System (INIS)

    Parwani, R.; Tan, H.S.

    2007-01-01

    A nonlinear generalisation of Schrodinger's equation had previously been obtained using information-theoretic arguments. The nonlinearities in that equation were of a nonpolynomial form, equivalent to the occurrence of higher-derivative nonlinear terms at all orders. Here we construct some exact solutions to that equation in 1+1 dimensions. On the half-line, the solutions resemble (exponentially damped) Bloch waves even though no external periodic potential is included. The solutions are nonperturbative as they do not reduce to solutions of the linear theory in the limit that the nonlinearity parameter vanishes. An intriguing feature of the solutions is their infinite degeneracy: for a given energy, there exists a very large arbitrariness in the normalisable wavefunctions. We also consider solutions to a q-deformed version of the nonlinear equation and discuss a natural discretisation implied by the nonpolynomiality. Finally, we contrast the properties of our solutions with other solutions of nonlinear Schrodinger equations in the literature and suggest some possible applications of our results in the domains of low-energy and high-energy physics

  9. Variable coefficient nonlinear systems derived from an atmospheric dynamical system

    International Nuclear Information System (INIS)

    Xiao-Yan, Tang; Yuan, Gao; Sen-Yue, Lou; Fei, Huang

    2009-01-01

    Variable coefficient nonlinear systems, the Korteweg de Vries (KdV), the modified KdV (mKdV) and the nonlinear Schrödinger (NLS) type equations, are derived from the nonlinear inviscid barotropic nondivergent vorticity equation in a beta-plane by means of the multi-scale expansion method in two different ways, with and without the so-called y-average trick. The non-auto-Bäcklund transformations are found to transform the derived variable coefficient equations to the corresponding standard KdV, mKdV and NLS equations. Thus, many possible exact solutions can be obtained by taking advantage of the known solutions of these standard equations. Further, many approximate solutions of the original model are ready to be yielded which might be applied to explain some real atmospheric phenomena, such as atmospheric blocking episodes. (general)

  10. Algae Derived Biofuel

    Energy Technology Data Exchange (ETDEWEB)

    Jahan, Kauser [Rowan Univ., Glassboro, NJ (United States)

    2015-03-31

    One of the most promising fuel alternatives is algae biodiesel. Algae reproduce quickly, produce oils more efficiently than crop plants, and require relatively few nutrients for growth. These nutrients can potentially be derived from inexpensive waste sources such as flue gas and wastewater, providing a mutual benefit of helping to mitigate carbon dioxide waste. Algae can also be grown on land unsuitable for agricultural purposes, eliminating competition with food sources. This project focused on cultivating select algae species under various environmental conditions to optimize oil yield. Membrane studies were also conducted to transfer carbon di-oxide more efficiently. An LCA study was also conducted to investigate the energy intensive steps in algae cultivation.

  11. Metal borohydrides and derivatives

    DEFF Research Database (Denmark)

    Paskevicius, Mark; Haarh Jepsen, Lars; Schouwink, Pascal

    2017-01-01

    review new synthetic strategies along with structural, physical and chemical properties for metal borohydrides, revealing a number of new trends correlating composition, structure, bonding and thermal properties. These new trends provide general knowledge and may contribute to the design and discovery......A wide variety of metal borohydrides, MBH4, have been discovered and characterized during the past decade, revealing an extremely rich chemistry including fascinating structural flexibility and a wide range of compositions and physical properties. Metal borohydrides receive increasing interest...... major classes of metal borohydride derivatives have also been discovered: anion-substituted compounds where the complex borohydride anion, BH4 -, is replaced by another anion, i.e. a halide or amide ion; and metal borohydrides modified with neutral molecules, such as NH3, NH3BH3, N2H4, etc. Here, we...

  12. SEMANTIC DERIVATION OF BORROWINGS

    Directory of Open Access Journals (Sweden)

    Shigapova, F.F.

    2017-09-01

    Full Text Available The author carried out the contrastive analysis of the word спикер borrowed into Russian from English and the English word speaker. The findings of the analysis include confirm (1 different derivational abilities and functions of the borrowed word and the native word; (2 distinctive features in the definitions, i.e. semantic structures, registered in monolingual non-abridged dictionaries; (3 heterogeneous parameters of frequencies recorded in the National Corpus of the Russian language and the British National Corpus; (4 absence of bilingual equivalent collocations with words спикер and speaker. The collocations with words studied revealed new lexical and connotative senses in the meaning of the word. Relevance of the study conducted is justified by the new facts revealed about the semantic adaptation of the borrowed word in the system of the Russian language and its paradigmatic and syntagmatic connections in the system of the recipient language.

  13. 6-Bromocholesterol derivatives

    International Nuclear Information System (INIS)

    Flanagan, R.J.

    1984-01-01

    Novel 6-bromo derivatives of cholesterol have the formula 3-(R-O-),6-BR,17-((H3C-)2-HC-H2C-H2C-H2C-HC(-CH3)-)-ESTR-5-ENE Such compounds are prepared from the known 6-iodocholesterol by treatment with cuprous bromide. These compounds, labelled with radioisotopes of Br-82 or Br-77, are localized in the adrenal, mammary and ovary tissue of female mammals and in the adrenal or prostate tissue of males when administered to such individuals. This provides a method for imaging adrenal, ovary or prostate tissue which is superior to use of the prior art 6-iodo-cholesterol

  14. Development of credit derivatives trading

    OpenAIRE

    Kunovjánek, Robert

    2015-01-01

    The bachelor thesis is focused on the structure and development of credit derivatives market. The thesis provides a basic summary for insight into credit derivatives market. The first part deals with general specifications of derivatives, their structure, functions and relevant categorization. The main chapter is dedicated to the most frequently used variants of credit derivatives, namely, credit default swap, total return swap and credit-linked note. Predominantly traded credit default swap ...

  15. Properties of scintillator solutes

    International Nuclear Information System (INIS)

    Fluornoy, J.M.

    1998-06-01

    This special report summarizes measurements of the spectroscopic and other properties of the solutes that were used in the preparation of several new liquid scintillators developed at EG and G/Energy Measurements/Santa Barbara Operations (the precursor to Bechtel Nevada/Special Technologies Laboratory) on the radiation-to-light converter program. The data on the individual compounds are presented in a form similar to that used by Prof. Isadore Berlman in his classic handbook of fluorescence spectra. The temporal properties and relative efficiencies of the new scintillators are presented in Table 1, and the efficiencies as a function of wavelength are presented graphically in Figure 1. In addition, there is a descriptive glossary of the abbreviations used herein. Figure 2 illustrates the basic structures of some of the compounds and of the four solvents reported in this summary. The emission spectra generally exhibit more structure than the absorption spectra, with the result that the peak emission wavelength for a given compound may lie several nm away from the wavelength, λ avg , at the geometric center of the emission spectrum. Therefore, the author has chosen to list absorption peaks, λ max , and emission λ avg values in Figures 3--30, as being most illustrative of the differences between the compounds. The compounds, BHTP, BTPB, ADBT, and DPTPB were all developed on this program. P-terphenyl, PBD, and TPB are commercially available blue emitters. C-480 and the other longer-wavelength emitters are laser dyes available commercially from Exciton Corporation. 1 ref., 30 figs

  16. State-Space Modelling of Loudspeakers using Fractional Derivatives

    DEFF Research Database (Denmark)

    King, Alexander Weider; Agerkvist, Finn T.

    2015-01-01

    This work investigates the use of fractional order derivatives in modeling moving-coil loudspeakers. A fractional order state-space solution is developed, leading the way towards incorporating nonlinearities into a fractional order system. The method is used to calculate the response of a fractio......This work investigates the use of fractional order derivatives in modeling moving-coil loudspeakers. A fractional order state-space solution is developed, leading the way towards incorporating nonlinearities into a fractional order system. The method is used to calculate the response...... of a fractional harmonic oscillator, representing the mechanical part of a loudspeaker, showing the effect of the fractional derivative and its relationship to viscoelasticity. Finally, a loudspeaker model with a fractional order viscoelastic suspension and fractional order voice coil is fit to measurement data...

  17. Asymptotic Solutions of Time-Space Fractional Coupled Systems by Residual Power Series Method

    Directory of Open Access Journals (Sweden)

    Wenjin Li

    2017-01-01

    Full Text Available This paper focuses on the asymptotic solutions to time-space fractional coupled systems, where the fractional derivative and integral are described in the sense of Caputo derivative and Riemann-Liouville integral. We introduce the Residual Power Series (for short RPS method to construct the desired asymptotic solutions. Furthermore, we apply this method to some time-space fractional coupled systems. The simplicity and efficiency of RPS method are shown by the application.

  18. Solutions of Riccati-Abel equation in terms of characteristics of general complex algebra

    International Nuclear Information System (INIS)

    Yamaleev, R.M.

    2012-01-01

    The Riccati-Abel differential equation defined as an equation between the first order derivative and the cubic polynomial is explored. In the case of constant coefficients this equation is reduced into an algebraic equation. A method of derivation of a summation formula for solutions of the Riccati-Abel equation is elaborated. The solutions of the Riccati-Abel equation are expressed in terms of the characteristic functions of general complex algebra of the third order

  19. Synthesis of Glucose Spiropiperazinone Derivatives

    OpenAIRE

    Vasiļjevs, D

    2013-01-01

    Piperazinone derivatives аге noticeable peptidometics; therefore, they сап replace peptides, such as RGD and Leu-enkephalin in different biological processes. Some piperazinone derivatives are anticoagulants, others act like neurotransmitters. Herein, we report an approach for the synthesis of поуеl piperazinone ring containing spiro-derivatives of glucose.

  20. Protein diffusion in polyelectrolyte solutions

    Science.gov (United States)

    Khandai, Santripti; Jena, Sidhartha S.

    2012-06-01

    The diffusion of green fluorescent protein (GFP) in non-dilute polyelectrolyte solutions of Poly-L-lysine was studied using fluorescence recovery after photobleaching (FRAP) technique. The effect of background charges on probe diffusion of GFP was studied with varying ionic strength of the solution. With increase in polyelectrolyte concentration, increase in solution viscosity and decrease in probe diffusion coefficient was observed. At the same time, we observed the diffusion coefficient increased with increase in salt concentration, while solution viscosity decreased, indicating a competition between electrostatic force between background and probe and viscosity drag. When the probe diffusion coefficient was compared with the predicted Stokes-Einstein (S-E) relation, strong positive deviations were observed for all the solutions with highest deviation observed for solution with zero salt concentration.

  1. On the perturbation estimates of the maximal solution for the matrix equation X+ATX−1A=P

    Directory of Open Access Journals (Sweden)

    Naglaa M. El-Shazly

    2016-10-01

    Full Text Available In this paper we investigate the nonlinear matrix equation X+ATX−1A=P, for the existence of positive definite solutions. Bounds for ∥XL−1∥ and ∥X−1∥ are derived where XL is the maximal solution and X is any other positive definite solution of this matrix equation. A perturbation estimate for the maximal solution and an error bound for approximate solutions are derived. A numerical example is given to illustrate the reliability of the obtained results.

  2. Colligative properties of simple solutions.

    Science.gov (United States)

    Andrews, F C

    1976-11-05

    Vapor pressure lowering, osmotic pressure, boiling point elevation, and freezing point depression are all related quantitatively to the decrease in micro(1)(soln) upon the addition of solute in forming a solution. In any equilibrium system, regardless of whether it is in a gravitational field or whether it contains walls, semipermeable membranes, phase transitions, or solutes, all equilibria are maintained locally, in the small region of the equilibrium, by the equality of micro(1)(soln). If there are several subsystems in a gravitational field, at any fixed height, microi will have the same value in each subsystem into which substance i can get, and microi + M(i)gh is constant throughout the entire system. In a solution, there is no mechanism by which solvent and solute molecules could sustain different pressures. Both the solvent and solute are always under identical pressures in a region of solution, namely, the pressure of the solution in that region. Since nature does not know which component we call the solvent and which the solute, equations should be symmetric in the two (acknowledging that the nonvolatile component, if any, is commonly chosen to be solute). Simple molecular pictures illustrate what is happening to cause pressure (positive or negative) in liquids, vapor pressure of liquids, and the various colligative properties of solutions. The only effect of solute involved in these properties is that it dilutes the solvent, with the resulting increase in S and decrease in micro(1)(soln). Water can be driven passively up a tree to enormous heights by the difference between its chemical potential in the roots and the ambient air. There is nothing mysterious about the molecular bases for any of these phenomena. Biologists can use the well-understood pictures of these phenomena with confidence to study what is happening in the complicated living systems they consider.

  3. Initial value problems for fractional functional differential inclusions with Hadamard type derivatives in Banach spaces

    Directory of Open Access Journals (Sweden)

    John R. Graef

    2018-02-01

    Full Text Available The authors establish sufficient conditions for the existence of solutions to boundary value problems for fractional differential inclusions involving the Hadamard type derivatives of order α ∈ (0,1] in Banach spaces.

  4. The Yang-Laplace Transform for Solving the IVPs with Local Fractional Derivative

    Directory of Open Access Journals (Sweden)

    Chun-Guang Zhao

    2014-01-01

    Full Text Available The IVPs with local fractional derivative are considered in this paper. Analytical solutions for the homogeneous and nonhomogeneous local fractional differential equations are discussed by using the Yang-Laplace transform.

  5. Enhanced safeguards via solution monitoring

    International Nuclear Information System (INIS)

    Burr, T.; Wangen, L.

    1996-09-01

    Solution monitoring is defined as the essentially continuous monitoring of solution level, density, and temperature in all tanks in the process that contain, or could contain, safeguards-significant quantities of nuclear material. This report describes some of the enhancements that solution monitoring could make to international safeguards. The focus is on the quantifiable benefits of solution monitoring, but qualitatively, solution monitoring can be viewed as a form of surveillance. Quantitatively, solution monitoring can in some cases improve diversion detection probability. For example, the authors show that under certain assumptions, solution monitoring can be used to reduce the standard deviation of the annual material balance, σ MB , from approximately 17 kg to approximately 4 kg. Such reduction in σ MB will not always be possible, as they discuss. However, in all cases, solution monitoring would provide assurance that the measurement error models are adequate so that one has confidence in his estimate of σ MB . Some of the results in this report were generated using data that were simulated with prototype solution monitoring software that they are developing. An accompanying document describes that software

  6. The double-dust solution

    CERN Document Server

    Krämer, Dietrich

    2002-01-01

    An exact solution describing the static gravitational field produced by the superposition of two dust beams of equal mass density but opposite propagation direction is given in a closed form. In particular, the cylindrically symmetric situation is considered in which the two dust components move on trajectories screwing around the axis. In this case, the solution can be matched to the Levi-Civita external vacuum solution at any value of the radial coordinate. The axis is regular and the mass density is positive everywhere in the interior region of the global solution. The dominant energy condition is satisfied.

  7. Structure and dynamics of solutions

    CERN Document Server

    Ohtaki, H

    2013-01-01

    Recent advances in the study of structural and dynamic properties of solutions have provided a molecular picture of solute-solvent interactions. Although the study of thermodynamic as well as electronic properties of solutions have played a role in the development of research on the rate and mechanism of chemical reactions, such macroscopic and microscopic properties are insufficient for a deeper understanding of fast chemical and biological reactions. In order to fill the gap between the two extremes, it is necessary to know how molecules are arranged in solution and how they change their pos

  8. Explicit Solutions for One-Dimensional Mean-Field Games

    KAUST Repository

    Prazeres, Mariana

    2017-04-05

    In this thesis, we consider stationary one-dimensional mean-field games (MFGs) with or without congestion. Our aim is to understand the qualitative features of these games through the analysis of explicit solutions. We are particularly interested in MFGs with a nonmonotonic behavior, which corresponds to situations where agents tend to aggregate. First, we derive the MFG equations from control theory. Then, we compute explicit solutions using the current formulation and examine their behavior. Finally, we represent the solutions and analyze the results. This thesis main contributions are the following: First, we develop the current method to solve MFG explicitly. Second, we analyze in detail non-monotonic MFGs and discover new phenomena: non-uniqueness, discontinuous solutions, empty regions and unhappiness traps. Finally, we address several regularization procedures and examine the stability of MFGs.

  9. Exact supersymmetric string solutions in curved gravitational backgrounds

    CERN Document Server

    Antoniadis, Ignatios; Kounnas, Costas

    1994-01-01

    We construct a new class of exact and stable superstring solutions based on $N=4$ superconformal world-sheet symmetry. In a subclass of these, the full spectrum of string excitations is derived in a modular-invariant way. In the weak curvature limit, our solutions describe a target space with non-trivial metric and topology, and generalize the previously known (semi) wormhole. The effective field theory limit is identified in certain cases, with solutions of the $N=4$ and $N=8$ extended gauged supergravities, in which the number of space-time supersymmetries is reduced by a factor of 2 because of the presence of non-trivial dilaton, gravitational and/or gauge backgrounds. In the context of string theory, our solutions correspond to stable non-critical superstrings in the strong coupling region; the super-Liouville field couples to a unitary matter system with central charge $5\\le{\\hat c}_M\\le 9$.

  10. Particular solution of the discrete-ordinate method.

    Science.gov (United States)

    Qin, Yi; Box, Michael A; Jupp, David L

    2004-06-20

    We present two methods that can be used to derive the particular solution of the discrete-ordinate method (DOM) for an arbitrary source in a plane-parallel atmosphere, which allows us to solve the transfer equation 12-18% faster in the case of a single beam source and is even faster for the atmosphere thermal emission source. We also remove the divide by zero problem that occurs when a beam source coincides with a Gaussian quadrature point. In our implementation, solution for multiple sources can be obtained simultaneously. For each extra source, it costs only 1.3-3.6% CPU time required for a full solution. The GDOM code that we developed previously has been revised to integrate with the DOM. Therefore we are now able to compute the Green's function and DOM solutions simultaneously.

  11. Quantitative relationship between adsorbed amount of solute and solvent composition

    International Nuclear Information System (INIS)

    Wang Yan; Geng Xindu; Zebolsky, Don M.

    2003-01-01

    A new adsorption isotherm that relates the amount of solute adsorbed to the solvent concentration is proposed. The new equation is derived from Geng and Shi's stoichiometric displacement model for adsorption (SDM-A). The obtained equation may be simplified to an expression containing two parameters. The equation with two parameters, valid for low concentrations of solute, is a logarithmically linear relationship. The intercept contains a thermodynamic equilibrium constant of the solute displacing solvent from the adsorbent. The slope is the negative value of the stoichiometric displacement parameter (Z), the average total number of solvent molecules displaced from an active site on the adsorbent and from the solute. Tests with a homologous series of aromatic alcohols by frontal analysis in reversed phase liquid chromatography demonstrate that experimental results fit the equation well

  12. Self-Gravitating Spherically Symmetric Solutions in Scalar-Torsion Theories

    CERN Document Server

    Kofinas, Georgios; Saridakis, Emmanuel N

    2015-01-01

    We studied spherically symmetric solutions in scalar-torsion gravity theories in which a scalar field is coupled to torsion with a derivative coupling. We obtained the general field equations from which we extracted a decoupled master equation, the solution of which leads to the specification of all other unknown functions. We first obtained an exact solution which represents a new wormhole-like solution dressed with a regular scalar field. Then, we found large distance linearized spherically symmetric solutions in which the space asymptotically is AdS.

  13. Exact solutions to nonlinear symmetron theory: One- and two-mirror systems

    Science.gov (United States)

    Brax, Philippe; Pitschmann, Mario

    2018-03-01

    We derive the exact analytical solutions to the symmetron field theory equations in the presence of a one- or two-mirror system. The one-dimensional equations of motion are integrated exactly for both systems and their solutions can be expressed in terms of Jacobi elliptic functions. Surprisingly, in the case of two parallel mirrors, the equations of motion generically provide not a unique solution but a discrete set of solutions with increasing number of nodes and energies. The solutions obtained herein can be applied to q BOUNCE experiments, neutron interferometry and for the calculation of the symmetron-field-induced "Casimir force" in the CANNEX experiment.

  14. Viscosity Control of Protein Solution by Small Solutes: A Review.

    Science.gov (United States)

    Hong, Taehun; Iwashita, Kazuki; Shiraki, Kentaro

    2017-12-12

    Viscosity of protein solution is one of the most troublesome issues for the high-concentration formulation of protein drugs. In this review, we summarize the practical methods that suppress the viscosity of protein solution using small molecular additives. The small amount of salts decreases the viscosity that results from electrostatic repulsion and attraction. The chaotrope suppresses the hydrophobic attraction and cluster formation, which can lower the solution viscosity. Arginine hydrochloride (ArgHCl) also suppresses the solution viscosity due to the hydrophobic and aromatic interactions between protein molecules. The small molecular additives are the simplest resolution of the high viscosity of protein solution as well as understanding of the primary cause in complex phenomena of protein interactions. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  15. Studies in higher-derivative gravitation

    International Nuclear Information System (INIS)

    Dutt, S.K.

    1987-01-01

    In this work two formulations of gravitation in which the action includes the second-derivatives of the metric in a non-trivial fashion are investigated. In the first part, the gauge theory of gravitation proposed by Yang in 1974 is investigated. The implications of coupling the pure space equations to matter sources via the action principle proposed by Yang is studied. It is shown that this action principle does not couple to matter sources in a satisfactory fashion. An earlier study by Fairchild along similar lines is critically examined. It is argued that Fairchild's action functional, and his objections to Yang's gauge approach to gravitation, arise from a not very meaningful analogy with the case of a general gauge field. Also, a conjecture originated in that work is refuted. A modification of Yang's action functional is provided which leads to both the Einstein and Yang field-equations. This system is shown to have non-trivial solutions in the presence of matter. An additional advantage is that the unphysical solutions of the pure space equations can be ruled out. It is shown that the joint system of Einstein and Yang field-equations leads to a physically viable cosmological model based on the Robertson-Walker metric, which satisfies both sets of field-equations. In the second part of this work, the Hamiltonian for pure gravity in Einstein's theory is obtained directly from the Hilbert Lagrangian. Since the Lagrangian depends upon the second-derivatives of the metric tensor, first the Hamiltonian formulation for a Lagrangian which may, in general depend upon the Nth-order time derivatives of the dynamical variables is developed

  16. ADIFOR–Generating Derivative Codes from Fortran Programs

    Directory of Open Access Journals (Sweden)

    Christian Bischof

    1992-01-01

    Full Text Available The numerical methods employed in the solution of many scientific computing problems require the computation of derivatives of a function f Rn→Rm. Both the accuracy and the computational requirements of the derivative computation are usually of critical importance for the robustness and speed of the numerical solution. Automatic Differentiation of FORtran (ADIFOR is a source transformation tool that accepts Fortran 77 code for the computation of a function and writes portable Fortran 77 code for the computation of the derivatives. In contrast to previous approaches, ADIFOR views automatic differentiation as a source transformation problem. ADIFOR employs the data analysis capabilities of the ParaScope Parallel Programming Environment, which enable us to handle arbitrary Fortran 77 codes and to exploit the computational context in the computation of derivatives. Experimental results show that ADIFOR can handle real-life codes and that ADIFOR-generated codes are competitive with divided-difference approximations of derivatives. In addition, studies suggest that the source transformation approach to automatic differentiation may improve the time to compute derivatives by orders of magnitude.

  17. Can the causal pathologies of Goedel-type universes be avoided in higher-derivative gravity

    International Nuclear Information System (INIS)

    Accioly, A.J.; Goncalves, A.T.

    1986-10-01

    A completely causal rotating Goedel-type universe is obtained in the context of higher-derivative gravity. The solution is such that it has no similar in the framework of standard general relativity. The aforementioned solution presents the interesting feature of relating the mass of the nontachyonic spin-O particle, concerning the linearized higher-derivative theory, with the velocity of rigid rotation of matter. (Author) [pt

  18. Dissipative motion perturbation theory and exact solutions

    International Nuclear Information System (INIS)

    Lodder, J.J.

    1976-06-01

    Dissipative motion of classical and quantum systems is described. In particular, attention is paid to systems coupled to the radiation field. A dissipative equation of motion for a particle in an arbitrary potential coupled to the radiation field is derived by means of perturbation theory. The usual divrgencies associated with the radiation field are eliminated by the application of a theory of generalized functions. This theory is developed as a subject in its own right and is presented independently. The introduction of classical zero-point energy makes the classical equa tion of motion for the phase density formally the same as its quantum counterpart. In particular, it is shown that the classical zero-point energy prevents the collapse of a classical H-atom and gives rise to a classical ground state. For systems with a quadratic Hamiltoian, the equation of motion can be solved exactly, even in the continuum limit for the radiation field, by means of the new generalized functions. Classically, the Fokker-Planck equation is found without any approximations, and quantum mechanically, the only approximation is the neglect of the change in the ground state caused by the interaction. The derivation is valid even for strong damping and arbitrarily short times. There is no transient time. For harmonic oscillators complete equivalence is shown to exist between quantum mechanics and classical mechanics with zero-point energy. A discussion of the derivation of the Pauli equation is given and perturbation theory is compared with the exact derivation. The exactly solvable models are used to calculate the Langevin force of the radiation field. The result is that the classical Langevin force is exactly delta-correlated, while the quantum Langevin force is not delta-correlated at all. The fluctuation-dissipation theorem is shown to be an exact consequence of the solution to the equations of motion

  19. Self-interacting scalar field cosmologies: unified exact solutions and symmetries

    Energy Technology Data Exchange (ETDEWEB)

    Charters, T. [Departamento de Engenharia Mecânica/Área Científica de Matemática, Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emídio Navarro, 1, P-1949-014 Lisbon (Portugal); Mimoso, J.P., E-mail: tca@cii.fc.ul.pt, E-mail: jpmimoso@cii.fc.ul.pt [Departamento de Física, Faculdade de Ciências da Universidade de Lisboa, Avenida Professor Gama Pinto 2, P-1649-003 Lisbon (Portugal)

    2010-08-01

    We investigate a mechanism that generates exact solutions of scalar field cosmologies in a unified way. The procedure investigated here permits to recover almost all known solutions, and allows one to derive new solutions as well. In particular, we derive and discuss one novel solution defined in terms of the Lambert function. The solutions are organised in a classification which depends on the choice of a generating function which we have denoted by x(φ) that reflects the underlying thermodynamics of the model. We also analyse and discuss the existence of form-invariance dualities between solutions. A general way of defining the latter in an appropriate fashion for scalar fields is put forward.

  20. Application of the Kirkwood–Buff theory of solutions to acetonitrile + ...

    Indian Academy of Sciences (India)

    Administrator

    terize it. 11,12. Kirkwood and Buff. 13 theory of solutions relates the radial distribution functions of various molecular species in a mixture to the derivatives of the thermo- dynamic properties of the species. This is a general statistical mechanical theory of solutions which is applicable to all types of intermolecular interactions.