WorldWideScience

Sample records for chemical potential equalization

  1. Improving intermolecular interactions in DFTB3 using extended polarization from chemical-potential equalization

    CERN Document Server

    Christensen, Anders S; Cui, Qiang

    2015-01-01

    Semi-empirical quantum mechanical methods traditionally expand the electron density in a minimal, valence-only electron basis set. The minimal-basis approximation causes molecular polarization to be underestimated, and hence intermolecular interaction energies are also underestimated, especially for intermolecular interactions involving charged species. In this work, the third-order self-consistent charge density functional tight-binding method (DFTB3) is augmented with an auxiliary response density using the chemical-potential equalization (CPE) method and an empirical dispersion correction (D3). The parameters in the CPE and D3 models are fitted to high-level CCSD(T) reference interaction energies for a broad range of chemical species, as well as dipole moments calculated at the DFT level; the impact of including polarizabilities of molecules in the parameterization is also considered. Parameters for the elements H, C, N, O and S are presented. The RMSD interaction energy is improved from 6.07 kcal/mol to 1...

  2. Relation between the equalized molecular chemical potential and the ionization potential of organic homologs

    Institute of Scientific and Technical Information of China (English)

    曹晨忠

    1995-01-01

    The ionization potential of organic homologs can be expressed as I_p=(∑X_i)/(a+bn).Here,X_i is the electronegativity(the average energy of valence electrons in a ground-state free atom)of the ith atomin an organic homologous molecule;n,the number of repeating units in the molecule;and(a+bn),the electronmoving range in the molecule orbit.The results of linear regression analysis show that the correlationcoefficients r are all "excellent"(r>0.990)for the 146 sets of photo electron spectroscopy data of 42 organichomologous series.

  3. Improving intermolecular interactions in DFTB3 using extended polarization from chemical-potential equalization

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, Anders S., E-mail: andersx@chem.wisc.edu, E-mail: cui@chem.wisc.edu; Cui, Qiang, E-mail: andersx@chem.wisc.edu, E-mail: cui@chem.wisc.edu [Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706 (United States); Elstner, Marcus [Theoretische Chemische Biologie, Universität Karlsruhe, Kaiserstr. 12, 76131 Karlsruhe (Germany)

    2015-08-28

    Semi-empirical quantum mechanical methods traditionally expand the electron density in a minimal, valence-only electron basis set. The minimal-basis approximation causes molecular polarization to be underestimated, and hence intermolecular interaction energies are also underestimated, especially for intermolecular interactions involving charged species. In this work, the third-order self-consistent charge density functional tight-binding method (DFTB3) is augmented with an auxiliary response density using the chemical-potential equalization (CPE) method and an empirical dispersion correction (D3). The parameters in the CPE and D3 models are fitted to high-level CCSD(T) reference interaction energies for a broad range of chemical species, as well as dipole moments calculated at the DFT level; the impact of including polarizabilities of molecules in the parameterization is also considered. Parameters for the elements H, C, N, O, and S are presented. The Root Mean Square Deviation (RMSD) interaction energy is improved from 6.07 kcal/mol to 1.49 kcal/mol for interactions with one charged species, whereas the RMSD is improved from 5.60 kcal/mol to 1.73 for a set of 9 salt bridges, compared to uncorrected DFTB3. For large water clusters and complexes that are dominated by dispersion interactions, the already satisfactory performance of the DFTB3-D3 model is retained; polarizabilities of neutral molecules are also notably improved. Overall, the CPE extension of DFTB3-D3 provides a more balanced description of different types of non-covalent interactions than Neglect of Diatomic Differential Overlap type of semi-empirical methods (e.g., PM6-D3H4) and PBE-D3 with modest basis sets.

  4. Potential Fluctuation Equality for Free Energy Evaluation

    CERN Document Server

    Ngo, Van

    2011-01-01

    Jarzynski's equality [1] allows us to investigate free energy landscapes (FELs) by constructing distributions of work performed on a system from an initial ensemble of states to final states. This work is experimentally measured by extension-versus-force (EVF) curves. We proposed a new approach that enables us to reconstruct such FELs without necessity of measuring EVF curves. We proved that any free energy changes could be computed by measuring the fluctuations of a harmonic external potential in final states. The main assumption of our proof is that one should probably treat a potential's minimum {\\lambda} (thought to be control parameter) and time in separate and independent manners. We recovered Jarzynski's equality from the introduction of a double Heaviside function. We then applied the approach in molecular dynamics (MD) simulations to compute the free energy barrier of breaking DNA base pairs (bps). The free energy barrier for breaking a CG bp in our simulations is identified as 1.7 +/- 0.2 kcal/mol t...

  5. Equal-potential interpretation of electrically induced resonances in metamaterials

    DEFF Research Database (Denmark)

    Peng, Liang; Mortensen, N. Asger

    2011-01-01

    We propose a general description of electrically induced resonances (EIR) in metamaterials (MMs) comprising subwavelength unit cells. Based on classical electrodynamics, we found that EIR is governed by an equal-potential effect. Our theory accounts for the EIR phenomena and can give a renewed...

  6. The Equal Rights Amendment: Its Potential Impact on Family Life

    Science.gov (United States)

    Myricks, Noel

    1977-01-01

    The potential impact of the proposed Equal Rights Amendment (ERA) can be measured in areas such as alimony, child support, child custody, property ownership, divorce and rights of consortium. Statutes which use sex as the sole criterion would be unconstitutional. (Author)

  7. Exact energy spectrum for models with equally spaced point potentials

    OpenAIRE

    Caudrelier, V.; Crampe, N.

    2006-01-01

    We describe a non-perturbative method for computing the energy band structures of one-dimensional models with general point potentials sitting at equally spaced sites. This is done thanks to a Bethe ansatz approach and the method is applicable even when periodicity is broken, that is when Bloch's theorem is not valid any more. We derive the general equation governing the energy spectrum and illustrate its use in various situations. In particular, we get exact results for boundary effects. We ...

  8. Exact energy spectrum for models with equally spaced point potentials

    Science.gov (United States)

    Caudrelier, V.; Crampé, N.

    2006-03-01

    We describe a non-perturbative method for computing the energy band structures of one-dimensional models with general point potentials sitting at equally spaced sites. This is done thanks to a Bethe ansatz approach and the method is applicable even when periodicity is broken, that is when Bloch's theorem is not valid any more. We derive the general equation governing the energy spectrum and illustrate its use in various situations. In particular, we get exact results for boundary effects. We also study non-perturbatively the effects of impurities in such systems. Finally, we discuss the possibility of including interactions between the particles of these systems.

  9. Bound States of the S-Wave Equation with Equal Scalar and Vector Standard Eckart Potential

    Institute of Scientific and Technical Information of China (English)

    Eser Ol(g)ar; Ramazan Ko(c); Hayriye Tütüncüler

    2006-01-01

    @@ A supersymmetric technique for the bound-state solutions of the s-wave Klein-Gordon equation with equal scalar and vector standard Eckart-type potential is proposed. Its exact solutions are obtained. Possible generalization of our approach is outlined.

  10. On the Chemical Potential of Dark Energy

    CERN Document Server

    Pereira, S H

    2008-01-01

    It is widely assumed that the observed universe is accelerating due to the existence of a new fluid component called dark energy. In this article, the thermodynamics consequences of a nonzero chemical potential on the dark energy component is discussed with special emphasis to the phantom fluid case. It is found that if the dark energy fluid is endowed with a negative chemical potential, the phantom field hypothesis becomes thermodynamically consistent with no need of negative temperatures as recently assumed in the literature.

  11. On the Chemical Potential of Dark Energy

    OpenAIRE

    Pereira, S. H.

    2008-01-01

    It is widely assumed that the observed universe is accelerating due to the existence of a new fluid component called dark energy. In this article, the thermodynamics consequences of a nonzero chemical potential on the dark energy component is discussed with special emphasis to the phantom fluid case. It is found that if the dark energy fluid is endowed with a negative chemical potential, the phantom field hypothesis becomes thermodynamically consistent with no need of negative temperatures as...

  12. Chemical Potential of Vacancies in Metal Crystals

    Institute of Scientific and Technical Information of China (English)

    SUN Jun; W.R.Tyson

    2000-01-01

    In this paper, a concept, the chemical potential of vacancies in metal crystals, has been derived from the partial mole free energy of vacancies based on a model of an atom-vacancy binary solution.For a pure metal crystal containing the mole concentration of vacancies, Cv and it's value in thermal equilibrium,C0, at temperature T the chemical potential can be expressed respectively as: μ v(Cv)=RT[1+1n(C√Co)]and μ v (Co)=RT The second term in μ v(Cv) is the chemical potential of the vacancies referred to the standardstate concentration given by J. P. Hirth [1] and first term is the standard-state one presented in this paper.

  13. Chemical-Sensing Cables Detect Potential Threats

    Science.gov (United States)

    2007-01-01

    Intelligent Optical Systems Inc. (IOS) completed Phase I and II Small Business Innovation Research (SBIR) contracts with NASA's Langley Research Center to develop moisture- and pH-sensitive sensors to detect corrosion or pre-corrosive conditions, warning of potentially dangerous conditions before significant structural damage occurs. This new type of sensor uses a specially manufactured optical fiber whose entire length is chemically sensitive, changing color in response to contact with its target, and demonstrated to detect potentially corrosive moisture incursions to within 2 cm. After completing the work with NASA, the company received a Defense Advanced Research Projects Agency (DARPA) Phase III SBIR to develop the sensors further for detecting chemical warfare agents, for which they proved just as successful. The company then worked with the U.S. Department of Defense (DoD) to fine tune the sensors for detecting potential threats, such as toxic industrial compounds and nerve agents. In addition to the work with government agencies, Intelligent Optical Systems has sold the chemically sensitive fiber optic cables to major automotive and aerospace companies, who are finding a variety of uses for the devices. Marketed under the brand name Distributed Intrinsic Chemical Agent Sensing and Transmission (DICAST), these unique continuous-cable fiber optic chemical sensors can serve in a variety of applications: Corrosive-condition monitoring, aiding experimentation with nontraditional power sources, as an economical means of detecting chemical release in large facilities, as an inexpensive "alarm" systems to alert the user to a change in the chemical environment anywhere along the cable, or in distance-resolved optical time domain reflectometry systems to provide detailed profiles of chemical concentration versus length.

  14. Intoxication by Intraperitoneal Injection or Oral Gavage Equally Potentiates Postburn Organ Damage and Inflammation

    Directory of Open Access Journals (Sweden)

    Michael M. Chen

    2013-01-01

    Full Text Available The increasing prevalence of binge drinking and its association with trauma necessitate accurate animal models to examine the impact of intoxication on the response and outcome to injuries such as burn. While much research has focused on the effect of alcohol dose and duration on the subsequent inflammatory parameters following burn, little evidence exists on the effect of the route of alcohol administration. We examined the degree to which intoxication before burn injury causes systemic inflammation when ethanol is given by intraperitoneal (i.p. injection or oral gavage. We found that intoxication potentiates postburn damage in the ileum, liver, and lungs of mice to an equivalent extent when either ethanol administration route is used. We also found a similar hematologic response and levels of circulating interleukin-6 (IL-6 when either ethanol paradigm achieved intoxication before burn. Furthermore, both i.p. and gavage resulted in similar blood alcohol concentrations at all time points tested. Overall, our data show an equal inflammatory response to burn injury when intoxication is achieved by either i.p. injection or oral gavage, suggesting that findings from studies using either ethanol paradigm are directly comparable.

  15. Computed potential energy surfaces for chemical reactions

    Science.gov (United States)

    Walch, Stephen P.

    1994-01-01

    Quantum mechanical methods have been used to compute potential energy surfaces for chemical reactions. The reactions studied were among those believed to be important to the NASP and HSR programs and included the recombination of two H atoms with several different third bodies; the reactions in the thermal Zeldovich mechanism; the reactions of H atom with O2, N2, and NO; reactions involved in the thermal De-NO(x) process; and the reaction of CH(squared Pi) with N2 (leading to 'prompt NO'). These potential energy surfaces have been used to compute reaction rate constants and rates of unimolecular decomposition. An additional application was the calculation of transport properties of gases using a semiclassical approximation (and in the case of interactions involving hydrogen inclusion of quantum mechanical effects).

  16. Correlation of the isosteric heat of adsorption of organic molecules over zeolites with equalized electronegativity and chemical hardness

    Indian Academy of Sciences (India)

    N V K Dutt; S J Kulkarni; Y V L Ravikumar; B S N Murthy

    2006-07-01

    Considering the direct correlation between charge transfer and heat of adsorption, we have equated the isosteric heat of adsorption () with Nalewajski's charge transfer equation involving equalized electronegativities and chemical hardness given in the literature. The equation is then tested and compared with the experimental heat of adsorption values of organic molecules over zeolites given in the literature with the average percentage deviation of 15.9. Other similar types of equations of charge transfer affinity are also tested. Various semi-empirical equations based on Barrer's approach of the determination of and neural network method have been proposed, tested and compared for the first time.

  17. Solutions of the Klein-Gordon equation with equal scalar and vector harmonic oscillator plus inverse quadratic potential

    Science.gov (United States)

    Ita, B. I.; Obong, H. P.; Ehi-Eromosele, C. O.; Edobor-Osoh, A.; Ikeuba, A. I.

    2014-11-01

    The solutions of the Klein-Gordon equation with equal scalar and vector harmonic oscillator plus inverse quadratic potential for S-waves have been presented using the Nikiforov-Uvarov method. The bound state energy eigenvalues and the corresponding un-normalized eigenfunctions are obtained in terms of the Laguerre polynomials.

  18. Deconfinement Transition at High Isospin Chemical Potential and Low Temperature

    CERN Document Server

    Cohen, Thomas D

    2015-01-01

    We consider QCD with two degenerate flavors of light quarks(up and down) at asymptotically high isospin and zero baryon chemical potential. In this regime and sufficiently low temperatures this theory becomes equivalent to a pure Yang-Mills theory and accordingly has a first order phase transition. This paper relates the parameters of this equivalent Yang-Mills theory to those of the underlying theory. Physically, the picture is that in this limit anti-up quarks and down quarks have Fermi surfaces with radii equal to half of the chemical potential. At high temperatures, the gluons are Debye-screened by quark quasi-particles around the Fermi surface. As the temperature is lowered, a Fermi liquid with Cooper pairing of pairs of anti-up and down quarks forms giving rise to U(1)em superconductivity. The condensate is parity odd and color neutral. The gluons do not pick up Meissner mass due to the color neutrality of the condensate. At temperatures much lower than the gap, Debye screening is absent too, as the fer...

  19. Finite density QCD via imaginary chemical potential

    CERN Document Server

    D'Elia, M

    2003-01-01

    We study QCD at nonzero temperature and baryon density in the framework of the analytic continuation from imaginary chemical potential. We carry out simulations of QCD with four flavor of staggered fermions, and reconstruct the phase diagram in the temperature-imaginary \\mu plane. We consider ans\\"atze for the analytic continuation of the critical line and other observables motivated both by theoretical considerations and mean field calculations in four fermion models and random matrix theory. We determine the critical line, and the analytic continuation of the chiral condensate, up to \\mu_B approx. 500 MeV. The results are in qualitative agreement with the predictions of model field theories, and consistent with a first order chiral transition. The correlation between the chiral transition and the deconfinement transition observed at \\mu=0 persists at nonzero density.

  20. Dual condensates at finite isospin chemical potential

    CERN Document Server

    Zhang, Zhao

    2015-01-01

    The dual observables as order parameters for center symmetry are tested at finite isospin chemical potential $\\mu_I$ in a Polyakov-loop enhanced chiral model of QCD with physical quark masses. As a counterpart of the dressed Polyakov-loop, the first Fourier moment of pion condensate is introduced for $\\mu_I>{m_\\pi}/{2}$ under the temporal twisted boundary conditions for quarks. We demonstrate that this dual condensate exhibits the similar temperature dependence as the conventional Polyakov-loop. We confirm that its rapid increase with $T$ is driven by the evaporating of pion condensation. On the other hand, the dressed Polyakov-loop shows abnormal thermal behavior, which even decreases with $T$ at low temperatures due to the influence of pion condensate. We thus argue that in QCD the critical temperature extracting from a dual observable may have nothing to do with the quark confinement-deconfinement transition if the quark mass is very small.

  1. Maximum work configurations of finite potential capacity reservoir chemical engines

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    An isothermal endoreversible chemical engine operating between the finite potential capacity high-chemical-potential reservoir and the infinite potential capacity low-chemical-potential reservoir has been studied in this work.Optimal control theory was applied to determine the optimal cycle configurations corresponding to the maximum work output per cycle for the fixed total cycle time and a universal mass transfer law.Analyses of special examples showed that the optimal cycle configuration with the mass transfer law g∝△μ,where△μis the chemical potential difference,is an isothermal endoreversible chemical engine cycle,in which the chemical potential(or the concentration) of the key component in the working substance of low-chemical-potential side is a constant,while the chemical potentials(or the concentrations) of the key component in the finite potential capacity high-chemical-potential reservoir and the corresponding side working substance change nonlinearly with time,and the difference of the chemical potentials(or the ratio of the concentrations) of the key component between the high-chemical-potential reservoir and the working substance is a constant.While the optimal cycle configuration with the mass transfer law g∝△μc,where △μc is the concentration difference,is different from that with the mass transfer law g∝△μ significantly.When the high-chemical-potential reservoir is also an infinite potential capacity chemical potential reservoir,the optimal cycle configuration of the isothermal endoreversible chemical engine consists of two constant chemical potential branches and two instantaneous constant mass-flux branches,which is independent of the mass transfer law.The object studied in this paper is general,and the results can provide some guidelines for optimal design and operation of real chemical engines.

  2. QCD Phase Transitions and Bag Constants at Finite Chemical Potential

    Institute of Scientific and Technical Information of China (English)

    YANG Shu; GUO Hua; ZHAO En-Guang; L(U) Xiao-Fu

    2007-01-01

    The global colour model at finite temperature is further extended to study the systems at finite chemical potential. The deconfinement and chiral phase transition at finite chemical potential and at temperature T=0K are studied simultaneously. Meanwhile the evolution of the bag constants at finite chemical potential is calculated. The dependences of results on the model parameters are discussed in detail.

  3. Dual condensates at finite isospin chemical potential

    Directory of Open Access Journals (Sweden)

    Zhao Zhang

    2016-02-01

    Full Text Available The dual observables as order parameters for center symmetry are tested at finite isospin chemical potential μI in a Polyakov-loop enhanced chiral model of QCD with physical quark masses. As a counterpart of the dressed Polyakov-loop, the first Fourier moment of pion condensate is introduced for μI>mπ/2 under the temporal twisted boundary conditions for quarks. We demonstrate that this dual condensate exhibits the similar temperature dependence as the conventional Polyakov-loop. We confirm that its rapid increase with T is driven by the evaporating of pion condensation. On the other hand, the dressed Polyakov-loop shows abnormal thermal behavior, which even decreases with T at low temperatures due to the influence of pion condensate. We also find that the dressed Polyakov-loop always rises most steeply at the chiral transition temperature, which is consistent with the previous results in Nambu–Jona-Lasinio (NJL model and its variants without considering the center symmetry. Since both quantities are strongly affected by the chiral symmetry and pion condensation, we conclude that it is difficult to clarify the deconfinement transition from the dual condensates in this situation within this model.

  4. Dual condensates at finite isospin chemical potential

    Science.gov (United States)

    Zhang, Zhao; Miao, Qing

    2016-02-01

    The dual observables as order parameters for center symmetry are tested at finite isospin chemical potential μI in a Polyakov-loop enhanced chiral model of QCD with physical quark masses. As a counterpart of the dressed Polyakov-loop, the first Fourier moment of pion condensate is introduced for μI >mπ / 2 under the temporal twisted boundary conditions for quarks. We demonstrate that this dual condensate exhibits the similar temperature dependence as the conventional Polyakov-loop. We confirm that its rapid increase with T is driven by the evaporating of pion condensation. On the other hand, the dressed Polyakov-loop shows abnormal thermal behavior, which even decreases with T at low temperatures due to the influence of pion condensate. We also find that the dressed Polyakov-loop always rises most steeply at the chiral transition temperature, which is consistent with the previous results in Nambu-Jona-Lasinio (NJL) model and its variants without considering the center symmetry. Since both quantities are strongly affected by the chiral symmetry and pion condensation, we conclude that it is difficult to clarify the deconfinement transition from the dual condensates in this situation within this model.

  5. Innovations Help Chemical Makers Improve Growing Potential

    Institute of Scientific and Technical Information of China (English)

    Zhong Weike

    2007-01-01

    @@ With overheated construction all over the country, China's GDP continued its fast growth in the first half. After suffering an explosion at a Jilin aniline facility, another explosion at Cangzhou TDI and a big outbreak of water pollution at Wuxi, the chemical raw materials and chemical manufacturing sectors are getting strict supervision from the central government.

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

    Indian Academy of Sciences (India)

    S Panda; B K Panda

    2010-09-01

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

  7. Chemical-potential-based Lattice Boltzmann Method for Nonideal Fluids

    CERN Document Server

    Wen, Binghai; He, Bing; Zhang, Chaoying; Fang, Haiping

    2016-01-01

    Chemical potential is an effective way to drive phase transition or express wettability. In this letter, we present a chemical-potential-based lattice Boltzmann model to simulate multiphase flows. The nonideal force is directly evaluated by a chemical potential. The model theoretically satisfies thermodynamics and Galilean invariance. The computational efficiency is improved owing to avoiding the calculation of pressure tensor. We have derived several chemical potentials of the popular equations of state from the free-energy density function. An effective chemical-potential boundary condition is implemented to investigate the wettability of a solid surface. Remarkably, the numerical results show that the contact angle can be linearly tuned by the surface chemical potential.

  8. Linear Chemical Potential Dependence of Two-Quark Condensate

    Institute of Scientific and Technical Information of China (English)

    ZONG Hong-Shi; SUN Wei-Min

    2006-01-01

    By differentiating the inverse dressed quark propagator at finite chemical potential μ with respect to μ, the linear response of the dressed quark propagator to the chemical potential can be obtained. From this we extract a modelindependent formula for the linear chemical potential dependence of the in-medium two-quark condensate and show by two independent methods (explicit calculation and Lorentz covariance arguments) that the first-order contribution in μto the in-medium two-quark condensate vanishes identically. Therefore if one wants to study the in-medium two-quark condensate one should expand to at least the second order in the chemical potential μ.

  9. Theory of the Kinetics of Chemical Potentials in Heterogeneous Catalysis

    OpenAIRE

    Cheng, Jun; Hu, P

    2011-01-01

    Simple and powerful: The reaction kinetics at surfaces of heterogeneous catalysts is reformulated in terms of the involved chemical potentials. Based on this formulism, an approach of searching for good catalysts is proposed without recourse to extensive calculations of reaction barriers and detailed kinetic analyses. (see picture; R=reactant, I=surface intermediate, P=product, and =standard chemical potential).

  10. Energy density for chiral lattice fermions with chemical potential

    CERN Document Server

    Gattringer, Christof

    2007-01-01

    We study a recently proposed formulation of overlap fermions at finite density. In particular we compute the energy density as a function of the chemical potential and the temperature. It is shown that overlap fermions with chemical potential reproduce the correct continuum behavior.

  11. Chemical Potential Dependence of Dressed-Quark Propagator

    Institute of Scientific and Technical Information of China (English)

    ZONGHong-Shi; HOUFeng-Yao; SUNWei-Min; WUXiao-Hua

    2004-01-01

    A method for obtaining the low chemical potential dependence of the dressed quark propagator from an effective quark-quark interaction model is developed.Of particular interest here is to give a general recipe to find without arbitrariness the solution representing the “Wigner”phase at non-zero chemical potential for the purpose of studying QCD phase structure.

  12. Chemical Potential Dependence of Dressed-Quark Propagator

    Institute of Scientific and Technical Information of China (English)

    ZONG Hong-Shi; HOU Feng-Yao; SUN Wei-Min; WU Xiao-Hua

    2004-01-01

    A method for obtaining the low chemical potential dependence of the dressed quark propagator from an effective quark-quark interaction model is developed. Of particular interest here is to give a generalrecipe to find without arbitrariness the solution representing the "Wigner" phase at non-zero chemical potential for the purpose of studying QCD phase structure.

  13. Understanding the temperature and the chemical potential using computer simulations

    CERN Document Server

    Tobochnik, J; Machta, J; Tobochnik, Jan; Gould, Harvey; Machta, Jonathan

    2004-01-01

    Several Monte Carlo algorithms and applications that are useful for understanding the concepts of temperature and chemical potential are discussed. We then introduce a generalization of the demon algorithm that measures the chemical potential and is suitable for simulating systems with variable particle number.

  14. ZnO nanoparticles and organic chemical UV-filters are equally well tolerated by human immune cells.

    Science.gov (United States)

    O'Keefe, Sean J; Feltis, Bryce N; Piva, Terrence J; Turney, Terence W; Wright, Paul F A

    2016-11-01

    An important part of assessing the toxic potential of nanoparticles for specific applications should be the direct comparison of biological activities with those of alternative materials for the same application. Nanoparticulate inorganic ultraviolet (UV) filters, such as zinc oxide (ZnO), are commonly incorporated into transparent sunscreen and cosmetic formulations. However, concerns have been raised about potential unwanted effects, despite their negligible skin penetration and inherent advantages over organic chemical UV-filters. To provide useful application-relevant assessments of their potential hazard with/without UVA co-exposure, we directly compared cytotoxic and immune response profiles of human THP-1 monocytic cells to ZnO nanoparticles (30 nm) with bulk ZnO particulates (200 nm) and five conventional organic chemical UV-filters - butylmethoxydibenzoylmethane (avobenzone), octylmethoxycinnamate, octylsalicylate, homosalate and 4-methylbenzylidene camphor. High exposure concentrations of both organic and particulate UV-filters were required to cause cytotoxicity in monocyte and macrophage cultures after 24 h. Co-exposure with UVA (6.7 J/cm(2)) did not alter cytotoxicity profiles. Particle surface area-based dose responses showed that ZnO NPs were better tolerated than bulk ZnO. Organic and particulate UV-filters increased apoptosis at similar doses. Only particulates increased the generation of reactive oxygen species. Interleukin-8 (IL-8) release was increased by all particulates, avobenzone, homosalate and octylsalicylate. IL-1β release was only increased in macrophages by exposure to avobenzone and homosalate. In conclusion, direct effects were caused in monocytes and macrophages at similar concentrations of both organic UV-filters and ZnO nanoparticulates - indicating that their intrinsic cytotoxicity is similar. With their lower skin penetration, ZnO nanoparticles are expected to have lower bioactivity when used in sunscreens. PMID:27345703

  15. Chemical Potential Jump during Evaporation of a Quantum Bose Gas

    CERN Document Server

    Bedrikova, E A

    2013-01-01

    The dependence of the chemical potential jump coefficient on the evaporation coefficient is analyzed for the case in which the evaporating component is a Bose gas. The concentration of the evaporating component is assumed to be much lower than the concentration of the carrier gas. The expression for the chemical potential jump is derived from the analytic solution of the problem for the case in which the collision frequency of molecules of the evaporating component is constant.

  16. Two-color QCD with chiral chemical potential

    Science.gov (United States)

    Braguta, V. V.; Goy, V. A.; Ilgenfritz, E.-M.; Kotov, A. Yu.; Molochkov, A. V.; Müller-Preussker, M.; Petersson, B.; Schreiber, A.

    2016-01-01

    The phase diagram of two-color QCD with a chiral chemical potential is studied on the lattice. The focus is on the confinement/deconfinement phase transition and the breaking/restoration of chiral symmetry. The simulations are carried out with dynamical staggered fermions without rooting. The dependence of the Polyakov loop, the chiral condensate and the corresponding susceptibilities on the chiral chemical potential and the temperature are presented.

  17. Equality = Inequality

    DEFF Research Database (Denmark)

    Khaled, Rilla

    2011-01-01

    A number of design and development methods, including participatory design and agile software development, are premised on an underlying assumption of equality amongst relevant stakeholders such as designers, developers, product owners, and end users. Equality, however, is not a straightforwardly...

  18. Chemical potential and reaction electronic flux in symmetry controlled reactions.

    Science.gov (United States)

    Vogt-Geisse, Stefan; Toro-Labbé, Alejandro

    2016-07-15

    In symmetry controlled reactions, orbital degeneracies among orbitals of different symmetries can occur along a reaction coordinate. In such case Koopmans' theorem and the finite difference approximation provide a chemical potential profile with nondifferentiable points. This results in an ill-defined reaction electronic flux (REF) profile, since it is defined as the derivative of the chemical potential with respect to the reaction coordinate. To overcome this deficiency, we propose a new way for the calculation of the chemical potential based on a many orbital approach, suitable for reactions in which symmetry is preserved. This new approach gives rise to a new descriptor: symmetry adapted chemical potential (SA-CP), which is the chemical potential corresponding to a given irreducible representation of a symmetry group. A corresponding symmetry adapted reaction electronic flux (SA-REF) is also obtained. Using this approach smooth chemical potential profiles and well defined REFs are achieved. An application of SA-CP and SA-REF is presented by studying the Cs enol-keto tautomerization of thioformic acid. Two SA-REFs are obtained, JA'(ξ) and JA'' (ξ). It is found that the tautomerization proceeds via an in-plane delocalized 3-center 4-electron O-H-S hypervalent bond which is predicted to exist only in the transition state (TS) region. © 2016 Wiley Periodicals, Inc.

  19. Relationship between Oxygen Chemical Potential and Steel Cleanliness

    Institute of Scientific and Technical Information of China (English)

    Mansour Soltanieh; Yousef Payandeh

    2005-01-01

    To investigate inclusion formation in each step during steel making process, several samples were taken in different steps of the production of steel at Mobarakeh Steel Co of Esfahan to measure the oxygen chemical potential of the molten steel in each stage. The chemical compositions of the inclusions in samples were investigated lby scanning electron microscope. The chemical composition of the slag was analyzed. With the use of thermodynamic calculations and chemical analysis of the melt, at the working temperature, the relationship between dissolved oxygen and other elements were determined. Finally, it was found that there is a close relationship between inclusions formed in each step with the oxygen partial pressure.

  20. Persistence and transport potential of chemicals in a multimedia environment

    Energy Technology Data Exchange (ETDEWEB)

    van de Meent, D.; McKone, T.E.; Parkerton, T.; Matthies, M.; Scheringer, M.; Wania, F.; Purdy, R.; Bennett, D.H.

    2000-02-01

    Persistence in the environment and potential for long-range transport are related since time in the environment is required for transport. A persistent chemical will travel longer distances than a reactive chemical that shares similar chemical properties. Scheringer (1997) has demonstrated the correlation between persistence and transport distance for different organic chemicals. However, this correlation is not sufficiently robust to predict one property from the other. Specific chemicals that are persistent mayor may not exhibit long-range transport potential. Persistence and long-range transport also present different societal concerns. Persistence concerns relate to the undesired possibility that chemicals produced and used now may somehow negatively affect future generations. Long-range transport concerns relate to the undesired presence of chemicals in areas where these compounds have not been used. Environmental policy decisions can be based on either or both considerations depending on the aim of the regulatory program. In this chapter, definitions and methods for quantifying persistence and transport potential of organic chemicals are proposed which will assist in the development of sound regulatory frameworks.

  1. Secondary metabolites as potential cancer therapeutic leads : : synthesis and chemical biology of Englerin A and Fusarisetin A

    OpenAIRE

    Caro-Diaz, Eduardo J.E.

    2014-01-01

    Secondary metabolites generated from natural sources such as microbes, fungi, marine fauna and other microorganism have proven to represent a microcosm of chemical diversity and therefore a great source of novel phamacophoric structures. It is without question that nature in its long biological and chemical evolution has gifted us with beautiful molecular architectures with equally important biological function to provide leads into new and potentially useful biologically active molecules. As...

  2. Revisiting the definition of the electronic chemical potential, chemical hardness, and softness at finite temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Franco-Pérez, Marco, E-mail: qimfranco@hotmail.com, E-mail: jlgm@xanum.uam.mx [Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, México D. F. 09340 (Mexico); Department of Chemistry, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Gázquez, José L., E-mail: qimfranco@hotmail.com, E-mail: jlgm@xanum.uam.mx [Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, México D. F. 09340 (Mexico); Ayers, Paul W. [Department of Chemistry, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Vela, Alberto [Departamento de Química, Centro de Investigación y de Estudios Avanzados (Cinvestav), Av. Instituto Politécnico Nacional 2508, México D. F. 07360 (Mexico)

    2015-10-21

    We extend the definition of the electronic chemical potential (μ{sub e}) and chemical hardness (η{sub e}) to finite temperatures by considering a reactive chemical species as a true open system to the exchange of electrons, working exclusively within the framework of the grand canonical ensemble. As in the zero temperature derivation of these descriptors, the response of a chemical reagent to electron-transfer is determined by the response of the (average) electronic energy of the system, and not by intrinsic thermodynamic properties like the chemical potential of the electron-reservoir which is, in general, different from the electronic chemical potential, μ{sub e}. Although the dependence of the electronic energy on electron number qualitatively resembles the piecewise-continuous straight-line profile for low electronic temperatures (up to ca. 5000 K), the introduction of the temperature as a free variable smoothens this profile, so that derivatives (of all orders) of the average electronic energy with respect to the average electron number exist and can be evaluated analytically. Assuming a three-state ensemble, well-known results for the electronic chemical potential at negative (−I), positive (−A), and zero values of the fractional charge (−(I + A)/2) are recovered. Similarly, in the zero temperature limit, the chemical hardness is formally expressed as a Dirac delta function in the particle number and satisfies the well-known reciprocity relation with the global softness.

  3. Revisiting the definition of the electronic chemical potential, chemical hardness, and softness at finite temperatures

    International Nuclear Information System (INIS)

    We extend the definition of the electronic chemical potential (μe) and chemical hardness (ηe) to finite temperatures by considering a reactive chemical species as a true open system to the exchange of electrons, working exclusively within the framework of the grand canonical ensemble. As in the zero temperature derivation of these descriptors, the response of a chemical reagent to electron-transfer is determined by the response of the (average) electronic energy of the system, and not by intrinsic thermodynamic properties like the chemical potential of the electron-reservoir which is, in general, different from the electronic chemical potential, μe. Although the dependence of the electronic energy on electron number qualitatively resembles the piecewise-continuous straight-line profile for low electronic temperatures (up to ca. 5000 K), the introduction of the temperature as a free variable smoothens this profile, so that derivatives (of all orders) of the average electronic energy with respect to the average electron number exist and can be evaluated analytically. Assuming a three-state ensemble, well-known results for the electronic chemical potential at negative (−I), positive (−A), and zero values of the fractional charge (−(I + A)/2) are recovered. Similarly, in the zero temperature limit, the chemical hardness is formally expressed as a Dirac delta function in the particle number and satisfies the well-known reciprocity relation with the global softness

  4. Skyrmions in the presence of isospin chemical potential

    CERN Document Server

    Ponciano, J A

    2008-01-01

    We analyze the existence of localized finite energy topological excitations on top of the perturbative pion vacuum within the Skyrme model at finite isospin chemical potential and finite pion mass. We show that there is a critical isospin chemical potential $\\mu_I^c$ above which such solutions cease to exist. We find that $\\mu_I^c$ is closely related to the value of the pion mass. In particular for vanishing pion mass we obtain $\\mu_I^c=0$ in contradiction with some results recently reported in the literature. We also find that below $\\mui^c$ the skyrmion mass and baryon radius show, at least for the case of the hedgehog ansatz, only a mild dependence on the isospin chemical potential.

  5. Catalysis of Dynamical Chiral Symmetry Breaking by Chiral Chemical Potential

    CERN Document Server

    Braguta, V V

    2016-01-01

    In this paper we study the properties of media with chiral imbalance parameterized by chiral chemical potential. It is shown that depending on the strength of interaction between constituents in the media the chiral chemical potential either creates or enhances dynamical chiral symmetry breaking. Thus the chiral chemical potential plays a role of the catalyst of dynamical chiral symmetry breaking. Physically this effect results from the appearance of the Fermi surface and additional fermion states on this surface which take part in dynamical chiral symmetry breaking. An interesting conclusion which can be drawn is that at sufficiently small temperature chiral plasma is unstable with respect to condensation of Cooper pairs and dynamical chiral symmetry breaking even for vanishingly small interactions between constituents.

  6. Thermalization with chemical potentials, and higher spin black holes

    CERN Document Server

    Mandal, Gautam; Sorokhaibam, Nilakash

    2015-01-01

    We study the long time behaviour of local observables following a quantum quench in 1+1 dimensional conformal field theories possessing additional conserved charges besides the energy. We show that the expectation value of an arbitrary string of {\\it local} observables supported on a finite interval exponentially approaches an equilibrium value. The equilibrium is characterized by a temperature and chemical potentials defined in terms of the quenched state. For an infinite number of commuting conserved charges, the equilibrium ensemble is a generalized Gibbs ensemble (GGE). We compute the thermalization rate in a systematic perturbation in the chemical potentials, using a new technique to sum over an infinite number of Feynman diagrams. The above technique also allows us to compute relaxation times for thermal Green's functions in the presence of an arbitrary number of chemical potentials. In the context of a higher spin (hs[\\lambda]) holography, the partition function of the final equilibrium GGE is known to...

  7. QCD in One Dimension at Nonzero Chemical Potential

    CERN Document Server

    Ravagli, L

    2007-01-01

    Using an integration formula recently derived by Conrey, Farmer and Zirnbauer, we calculate the expectation value of the phase factor of the fermion determinant for the staggered lattice QCD action in one dimension. We show that the chemical potential can be absorbed into the quark masses; the theory is in the same chiral symmetry class as QCD in three dimensions at zero chemical potential. In the limit of a large number of colors and fixed number of lattice points, chiral symmetry is broken spontaneously, and our results are in agreement with expressions based on a chiral Lagrangian. In this limit, the eigenvalues of the Dirac operator are correlated according to random matrix theory for QCD in three dimensions. The discontinuity of the chiral condensate is due to an alternative to the Banks-Casher formula recently discovered for QCD in four dimensions at nonzero chemical potential. The effect of temperature on the average phase factor is discussed in a schematic random matrix model.

  8. Chemical Potential Calculations In Dense Liquids Using Metadynamics

    CERN Document Server

    Perego, Claudio; Parrinello, Michele

    2016-01-01

    The calculation of chemical potential has traditionally been a challenge in atomistic simulations. One of the most used approaches is Widom's insertion method in which the chemical potential is calculated by periodically attempting to insert an extra particle in the system. In dense systems this method fails since the insertion probability is very low. In this paper we show that in a homogeneous fluid the insertion probability can be increased using metadynamics. We test our method on a supercooled high density binary Lennard-Jones fluid. We find that we can obtain efficiently converged results even when Widom's method fails.

  9. Modulation of mechanical resonance by chemical potential oscillation in graphene

    Science.gov (United States)

    Chen, Changyao; Deshpande, Vikram V.; Koshino, Mikito; Lee, Sunwoo; Gondarenko, Alexander; MacDonald, Allan H.; Kim, Philip; Hone, James

    2016-03-01

    The classical picture of the force on a capacitor assumes a large density of electronic states, such that the electrochemical potential of charges added to the capacitor is given by the external electrostatic potential and the capacitance is determined purely by geometry. Here we consider capacitively driven motion of a nano-mechanical resonator with a low density of states, in which these assumptions can break down. We find three leading-order corrections to the classical picture: the first of which is a modulation in the static force due to variation in the internal chemical potential; the second and third are changes in the static force and dynamic spring constant due to the rate of change of chemical potential, expressed as the quantum (density of states) capacitance. As a demonstration, we study capacitively driven graphene mechanical resonators, where the chemical potential is modulated independently of the gate voltage using an applied magnetic field to manipulate the energy of electrons residing in discrete Landau levels. In these devices, we observe large periodic frequency shifts consistent with the three corrections to the classical picture. In devices with extremely low strain and disorder, the first correction term dominates and the resonant frequency closely follows the chemical potential. The theoretical model fits the data with only one adjustable parameter representing disorder-broadening of the Landau levels. The underlying electromechanical coupling mechanism is not limited by the particular choice of material, geometry, or mechanism for variation in the chemical potential, and can thus be extended to other low-dimensional systems.

  10. Molecular Dynamics Simulations of Solutions at Constant Chemical Potential

    CERN Document Server

    Perego, Claudio; Parrinello, Michele

    2015-01-01

    Molecular Dynamics studies of chemical processes in solution are of great value in a wide spectrum of applications, that range from nano-technology to pharmaceutical chemistry. However, these calculations are affected by severe finite-size effects, such as the solution being depleted as the chemical process proceeds, that influence the outcome of the simulations. To overcome these limitations, one must allow the system to exchange molecules with a macroscopic reservoir, thus sampling a Grand-Canonical ensemble. Despite the fact that different remedies have been proposed, this still represents a key challenge in molecular simulations. In the present work we propose the C$\\mu$MD method, which introduces an external force that controls the environment of the chemical process of interest. This external force, drawing molecules from a finite reservoir, maintains the chemical potential constant in the region where the process takes place. We have applied the C$\\mu$MD method to the paradigmatic case of urea crystall...

  11. Estimation of Radiative Efficiency of Chemicals with Potentially Significant Global Warming Potential

    Data.gov (United States)

    U.S. Environmental Protection Agency — The set of commercially available chemical substances in commerce that may have significant global warming potential (GWP) is not well defined. Although there are...

  12. Potts Flux Tube Model at Nonzero Chemical Potential

    CERN Document Server

    Condella, J; Condella, Jac; Tar, Carleton De

    2000-01-01

    We model the deconfinement phase transition in quantum chromodynamics at nonzero baryon number density and large quark mass by extending the flux tube model (three-state, three-dimensional Potts model) to nonzero chemical potential. In a direct numerical simulation we confirm mean-field-theory predictions that the deconfinement transition does not occur in a baryon-rich environment.

  13. Jet Quenching and Holographic Thermalization with a Chemical Potential

    CERN Document Server

    Caceres, Elena; Yang, Di-Lun

    2012-01-01

    We investigate jet quenching of virtual gluons and thermalization of a strongly-coupled plasma with a non-zero chemical potential via the gauge/gravity duality. By tracking a charged shell falling in an asymptotic AdS$_{d+1}$ background for $d=3$ and $d=4$, which is characterized by the AdS-Reissner-Nordstr\\"om-Vaidya (AdS-RN-Vaidya) geometry, we extract a thermalization time of the medium with a non-zero chemical potential. In addition, we study the falling string as the holographic dual of a virtual gluon in the AdS-RN-Vaidya spacetime. The stopping distance of the massless particle representing the tip of the falling string in such a spacetime could reveal the jet quenching of an energetic light probe traversing the medium in the presence of a chemical potential. We find that the stopping distance decreases when the chemical potential is increased in both AdS-RN and AdS-RN-Vaidya spacetimes, which correspond to the thermalized and thermalizing media respectively. Moreover, we find that the soft gluon with ...

  14. Jet quenching and holographic thermalization with a chemical potential

    Energy Technology Data Exchange (ETDEWEB)

    Caceres, Elena [Facultad de Ciencias, Universidad de Colima,Bernal Diaz del Castillo 340, Colima (Mexico); Theory Group, Department of Physics,University of Texas at Austin, Austin, TX 78712 (United States); Kundu, Arnab [Theory Group, Department of Physics,University of Texas at Austin, Austin, TX 78712 (United States); Yang, Di-Lun [Department of Physics, Duke University,Durham, North Carolina 27708 (United States)

    2014-03-17

    We investigate jet quenching of virtual gluons and thermalization of a strongly-coupled plasma with a non-zero chemical potential via the gauge/gravity duality. By tracking a charged shell falling in an asymptotic AdS{sub d+1} background for d=3 and d=4, which is characterized by the AdS-Reissner-Nordström-Vaidya (AdS-RN-Vaidya) geometry, we extract a thermalization time of the medium with a non-zero chemical potential. In addition, we study the falling string as the holographic dual of a virtual gluon in the AdS-RN-Vaidya spacetime. The stopping distance of the massless particle representing the tip of the falling string in such a spacetime could reveal the jet quenching of an energetic light probe traversing the medium in the presence of a chemical potential. We find that the stopping distance decreases when the chemical potential is increased in both AdS-RN and AdS-RN-Vaidya spacetimes, which correspond to the thermalized and thermalizing media respectively. Moreover, we find that the soft gluon with an energy comparable to the thermalization temperature and chemical potential in the medium travels further in the non-equilibrium plasma. The thermalization time obtained here by tracking a falling charged shell does not exhibit, generically, the same qualitative features as the one obtained studying non-local observables. This indicates that — holographically — the definition of thermalization time is observer dependent and there is no unambiguos definition.

  15. Phase transition of strongly interacting matter with a chemical potential dependent Polyakov loop potential

    Science.gov (United States)

    Shao, Guo-yun; Tang, Zhan-duo; Di Toro, Massimo; Colonna, Maria; Gao, Xue-yan; Gao, Ning

    2016-07-01

    We construct a hadron-quark two-phase model based on the Walecka-quantum hadrodynamics and the improved Polyakov-Nambu-Jona-Lasinio (PNJL) model with an explicit chemical potential dependence of Polyakov loop potential (μ PNJL model). With respect to the original PNJL model, the confined-deconfined phase transition is largely affected at low temperature and large chemical potential. Using the two-phase model, we investigate the equilibrium transition between hadronic and quark matter at finite chemical potentials and temperatures. The numerical results show that the transition boundaries from nuclear to quark matter move towards smaller chemical potential (lower density) when the μ -dependent Polyakov loop potential is taken. In particular, for charge asymmetric matter, we compute the local asymmetry of u , d quarks in the hadron-quark coexisting phase, and analyze the isospin-relevant observables possibly measurable in heavy-ion collision (HIC) experiments. In general new HIC data on the location and properties of the mixed phase would bring relevant information on the expected chemical potential dependence of the Polyakov loop contribution.

  16. Chemical and preclinical studies on Hedyotis diffusa with anticancer potential.

    Science.gov (United States)

    Niu, Yu; Meng, Qiu-Xia

    2013-01-01

    This paper presents the chemical and preclinical anticancer research on Hedyotis diffusa Willd. in detail, one of the most renowned herbs often prescribed in the polyherbal formulas for cancer treatment in traditional Chinese medicine. Anthraquinones, flavonoids, and terpenoids constitute the majority of the 69 compounds that have been isolated and identified from H. diffusa. The anticancer effects of the methanolic, ethanolic, and aqueous extracts in various preclinical cancer models have been described. This review also summarized the anticancer activity of constituents of the herb and the mechanisms of action. All the studies suggest that H. diffusa has enormous potential in the therapy of cancer and warrants further chemical and pharmacological investigation. PMID:23600735

  17. Higher spin entanglement entropy at finite temperature with chemical potential

    CERN Document Server

    Chen, Bin

    2016-01-01

    It is generally believed that the semiclassical AdS$_3$ higher spin gravity could be described by a two dimensional conformal field theory with ${\\cal{W}}$-algebra symmetry in the large central charge limit. In this paper, we study the single interval entanglement entropy on the torus in the CFT with a ${\\cW}_3$ deformation. More generally we develop the monodromy analysis to compute the two-point function of the light operators under a thermal density matrix with a ${\\cW}_3$ chemical potential to the leading order. Holographically we compute the probe action of the Wilson line in the background of the spin-3 black hole with a chemical potential. We find exact agreement.

  18. The pressure of QCD at finite temperatures and chemical potentials

    CERN Document Server

    Vuorinen, Aleksi R

    2003-01-01

    The perturbative expansion of the pressure of hot QCD is computed here to order g^6ln(g) in the presence of finite quark chemical potentials. In this process all two- and three-loop one-particle irreducible vacuum diagrams of the theory are evaluated at arbitrary T and mu, and these results are then used to analytically verify the outcome of an old order g^4 calculation of Freedman and McLerran for the zero-temperature pressure. The results for the pressure and the different quark number susceptibilities at high T are compared with recent lattice simulations showing excellent agreement especially for the chemical potential dependent part of the pressure.

  19. Implications of imaginary chemical potential for model building of QCD

    CERN Document Server

    Kashiwa, Kouji

    2016-01-01

    Properties of QCD at finite imaginary chemical potential are revisited to utilize for the model building of QCD in low energy regimes. For example, the electric holonomy which is closely related to the Polyakov-loop drastically affects thermodynamic quantities beside the Roberge-Weiss transition line. To incorporate several properties at finite imaginary chemical potential, it is important to introduce the holonomy effects to the coupling constant of effective models. This extension is possible by considering the entanglement vertex. We show justifications of the entanglement vertex based on the derivation of the effective four-fermi interaction in the Nambu--Jona-Lasinio model and present its general form with the local approximation. To discuss how to remove model ambiguities in the entanglement vertex, we calculate the chiral condensate with different $\\mathbb{Z}_3$ sectors and the dual quark condensate.

  20. Relativistic second-order dissipative hydrodynamics at finite chemical potential

    Directory of Open Access Journals (Sweden)

    Amaresh Jaiswal

    2015-12-01

    Full Text Available Starting from the Boltzmann equation in the relaxation time approximation and employing a Chapman–Enskog like expansion for the distribution function close to equilibrium, we derive second-order evolution equations for the shear stress tensor and the dissipative charge current for a system of massless quarks and gluons. The transport coefficients are obtained exactly using quantum statistics for the phase space distribution functions at non-zero chemical potential. We show that, within the relaxation time approximation, the second-order evolution equations for the shear stress tensor and the dissipative charge current can be decoupled. We find that, for large values of the ratio of chemical potential to temperature, the charge conductivity is small compared to the coefficient of shear viscosity. Moreover, we show that in the relaxation-time approximation, the limiting behaviour of the ratio of heat conductivity to shear viscosity is qualitatively similar to that obtained for a strongly coupled conformal plasma.

  1. Relativistic second-order dissipative hydrodynamics at finite chemical potential

    Science.gov (United States)

    Jaiswal, Amaresh; Friman, Bengt; Redlich, Krzysztof

    2015-12-01

    Starting from the Boltzmann equation in the relaxation time approximation and employing a Chapman-Enskog like expansion for the distribution function close to equilibrium, we derive second-order evolution equations for the shear stress tensor and the dissipative charge current for a system of massless quarks and gluons. The transport coefficients are obtained exactly using quantum statistics for the phase space distribution functions at non-zero chemical potential. We show that, within the relaxation time approximation, the second-order evolution equations for the shear stress tensor and the dissipative charge current can be decoupled. We find that, for large values of the ratio of chemical potential to temperature, the charge conductivity is small compared to the coefficient of shear viscosity. Moreover, we show that in the relaxation-time approximation, the limiting behaviour of the ratio of heat conductivity to shear viscosity is qualitatively similar to that obtained for a strongly coupled conformal plasma.

  2. Relativistic second-order dissipative hydrodynamics at finite chemical potential

    CERN Document Server

    Jaiswal, Amaresh; Redlich, Krzysztof

    2015-01-01

    Starting from the Boltzmann equation in the relaxation time approximation and employing Chapman-Enskog like expansion for the distribution function close to equilibrium, we derive second-order evolution equations for shear stress tensor and dissipative charge current for a system of massless quarks and gluons. The transport coefficients are obtained exactly using quantum statistics for the phase space distribution functions at non-zero chemical potential. We show that, within the relaxation time approximation, the evolution equations for shear stress tensor and dissipative charge current could be decoupled. We find that, for large values of the ratio of chemical potential to temperature, the charge conductivity is small compared to the coefficient of shear viscosity.

  3. Higher spin entanglement entropy at finite temperature with chemical potential

    Science.gov (United States)

    Chen, Bin; Wu, Jie-qiang

    2016-07-01

    It is generally believed that the semiclassical AdS3 higher spin gravity could be described by a two dimensional conformal field theory with W -algebra symmetry in the large central charge limit. In this paper, we study the single interval entanglement entropy on the torus in the CFT with a W_{3} deformation. More generally we develop the monodromy analysis to compute the two-point function of the light operators under a thermal density matrix with a W_{3} chemical potential to the leading order. Holographically we compute the probe action of the Wilson line in the background of the spin-3 black hole with a chemical potential. We find exact agreement.

  4. Chemically induced electric field: flat band potential engineering

    Science.gov (United States)

    Bak, T.; Guo, Z.; Li, W.; Atanacio, A. J.; Nowotny, J.

    2012-10-01

    The present work considers engineering of the flat band potential, FBP, of metal oxides in a controlled manner. The aim is to minimise the energy losses related to recombination. The related experimental approaches include imposition of a chemically-induced electric field using the phenomena of segregation, diffusion and the formation of multilayer systems. This paper considers several basic phenomena that allow the modification of the surface charge and the space charge at the gas/solid and solid/liquid interfaces.

  5. Rapidity-dependent chemical potentials in a statistical approach

    Science.gov (United States)

    Broniowski, Wojciech; Biedroń, Bartłomiej

    2008-04-01

    We present a single-freeze-out model with thermal and geometric parameters dependent on the position within the fireball and use it to describe the rapidity distribution and transverse-momentum spectra of pions, kaons, protons and antiprotons measured at RHIC at \\sqrt{s_NN}=200\\,\\, GeV by BRAHMS. THERMINATOR is used to perform the necessary simulation, which includes all resonance decays. The result of the fit to the data is the expected growth of the baryon and strange chemical potentials with the spatial rapidity αpar. The value of the baryon chemical potential at αpar ~ 3 is about 200 MeV, i.e. it lies in the range of the highest SPS energies. The chosen geometry of the fireball has a decreasing transverse size as the magnitude of αpar is increased, which also corresponds to decreasing transverse flow. The strange chemical potential obtained from the fit to the K+/K- ratio is such that the local strangeness density in the fireball is compatible with zero. The resulting rapidity distribution of net protons are described qualitatively within the statistical approach. As a result of our study, the knowledge of the 'topography' of the fireball is acquired, allowing for other analyses and predictions. Research supported by the Polish Ministry of Education and Science, grants N202 034 32/0918 and 2 P03B 02828.

  6. Granting Equality

    Institute of Scientific and Technical Information of China (English)

    YIN PUMIN

    2010-01-01

    @@ An amendment to the Electoral Law of the National People's Congress and Local People's Congresses of the People's Republic of China granting equal representation in legislative bodies to rural and urban people was ratified by the National People's Congress(NPC),China's top legislature,on March 14.

  7. Unjust Equalities

    DEFF Research Database (Denmark)

    Albertsen, Andreas; Midtgaard, Søren Flinch

    2014-01-01

    In the luck egalitarian literature, one influential formulation of luck egalitarianism does not specify whether equalities that do not reflect people’s equivalent exercises of responsibility are bad with regard to inequality. This equivocation gives rise to two competing versions of luck egalitar...

  8. Phase transition of strongly interacting matter with a chemical potential dependent Polyakov loop potential

    CERN Document Server

    Shao, Guo-yun; Di Toro, Massimo; Colonna, Maria; Gao, Xue-yan; Gao, Ning

    2016-01-01

    We construct a hadron-quark two-phase model based on the Walecka-quantum hadrodynamics and the improved Polyakov-Nambu--Jona-Lasinio model with an explicit chemical potential dependence of Polyakov-loop potential ($\\mu$PNJL model). With respect to the original PNJL model, the confined-deconfined phase transition is largely affected at low temperature and large chemical potential. Using the two-phase model, we investigate the equilibrium transition between hadronic and quark matter at finite chemical potentials and temperatures. The numerical results show that the transition boundaries from nuclear to quark matter move towards smaller chemical potential (lower density) when the $\\mu$-dependent Polyakov loop potential is taken. In particular, for charge asymmetric matter, we compute the local asymmetry of $u, d$ quarks in the hadron-quark coexisting phase, and analyse the isospin-relevant observables possibly measurable in heavy-ion collision (HIC) experiments. In general new HIC data on the location and proper...

  9. Swift chemical sputtering and potential development for fusion reactor materials

    Energy Technology Data Exchange (ETDEWEB)

    Bjoerkas, C.; Juslin, N.; Nordlund, K.; Keinonen, J. (Univ. of Helsinki, Dept. of Physics (Finland)); Traeskelin, P. (Univ. of California at Davis, Dept. of Chemical Engineering and Materials Science, CA (United States)); Salonen, E. (Helsinki Univ. of Technology, Lab. of Physics (Finland)); Krasheninnikov, A.V.

    2008-10-15

    occurs on femtosecond time scales, whence we call it swift chemical sputtering. Sputtering and redeposition will unavoidably lead to formation of surfaces which are made up of a mixture of the three PFMs. The properties of these mixed materials can differ strongly from those of their constituents, hence, an understanding of their effects is considered to be crucial for the reactor operation. The understanding of the retention and recycling of hydrogen isotopes in Be is also of particular interest, since this will give insight into the undesired trapping of tritium and also into the plasma cooling effect by the release of the isotopes. When exploring the consequences of mixed materials and the influence of H isotopes on PFMs, realistic experiments with ITER relevant conditions are preferred, but not yet feasible. An excellent tool is, however, computer simulations and especially the sub-part of this field, the simulation technique based on Molecular Dynamics (MD), which allows for modelling of tens of millions atoms. The reliability of MD is proportional to the accuracy of the interatomic potentials used in the simulations, hence, great efforts must be made in developing proper potentials. We have developed interatomic potentials to be used in MD simulations to study the interplay between the fusion reactor materials beryllium, carbon and hydrogen. These potentials are so called analytical bond-order potentials (ABOP), which were initially developed by Tersoff (1988) to describe covalent solids and extended to metals by Brenner (1990). They are able to describe variations of the local chemical environment, such as bond-breaking, yet at the same time they are computationally efficient. In this contribution, we will present the swift chemical sputtering and show how this mechanism can explain many of the observed features of carbon erosion in fusion reactors. We will also present the development and performance of the recent Be-C-H potentials. (au)

  10. Critical endpoint in the presence of a chiral chemical potential

    CERN Document Server

    Cui, Zhu-Fang; Lu, Ya; Roberts, Craig D; Schmidt, Sebastian M; Xu, Shu-Sheng; Zong, Hong-Shi

    2016-01-01

    A class of Polyakov-loop-modified Nambu--Jona-Lasinio (PNJL) models have been used to support a conjecture that numerical simulations of lattice-regularized quantum chromodynamics (QCD) defined with a chiral chemical potential can provide information about the existence and location of a critical endpoint in the QCD phase diagram drawn in the plane spanned by baryon chemical potential and temperature. That conjecture is challenged by conflicts between the model results and analyses of the same problem using simulations of lattice-regularized QCD (lQCD) and well-constrained Dyson-Schwinger equation (DSE) studies. We find the conflict is resolved in favor of the lQCD and DSE predictions when both a physically-motivated regularization is employed to suppress the contribution of high-momentum quark modes in the definition of the effective potential connected with the PNJL models and the four-fermion coupling in those models does not react strongly to changes in the mean-field that is assumed to mock-up Polyakov l...

  11. Holographic black hole engineering at finite baryon chemical potential

    CERN Document Server

    Rougemont, Romulo

    2016-01-01

    This is a contribution for the Proceedings of the Conference Hot Quarks 2016, held at South Padre Island, Texas, USA, 12-17 September 2016. I briefly review some thermodynamic and baryon transport results obtained from a bottom-up Einstein-Maxwell-Dilaton holographic model engineered to describe the physics of the quark-gluon plasma at finite temperature and baryon density. The results for the equation of state, baryon susceptibilities, and the curvature of the crossover band are in quantitative agreement with the corresponding lattice QCD results with $2+1$ flavors and physical quark masses. Baryon diffusion is predicted to be suppressed by increasing the baryon chemical potential.

  12. Hot Quark Matter with an Axial Chemical Potential

    CERN Document Server

    Gatto, Raoul

    2011-01-01

    We analyze the phase diagram of hot quark matter in presence of an axial chemical potential, $\\mu_5$. The latter is introduced to mimic the chirality transitions induced, in hot Quantum Chromodynamics, by the strong sphaleron configurations. In particular, we study the curvature of the critical line at small $\\mu_5$, the effects of a finite quark mass and of a vector interaction. Moreover, we build the mixed phase at the first order phase transition line, and draw the phase diagram in the chiral density and temperature plane. We finally compute the full topological susceptibility in presence of a background of topological charge.

  13. Bosonic Partition Functions at Nonzero (Imaginary) Chemical Potential

    CERN Document Server

    Kellerstein, M

    2016-01-01

    We consider bosonic random matrix partition functions at nonzero chemical potential and compare the chiral condensate, the baryon number density and the baryon number susceptibility to the result of the corresponding fermionic partition function. We find that as long as results are finite, the phase transition of the fermionic theory persists in the bosonic theory. However, in case that bosonic partition function diverges and has to be regularized, the phase transition of the fermionic theory does not occur in the bosonic theory, and the bosonic theory is always in the broken phase.

  14. The Instanton-Dyon Liquid Model III: Finite Chemical Potential

    CERN Document Server

    Liu, Yizhuang; Zahed, Ismail

    2016-01-01

    We discuss an extension of the instanton-dyon liquid model that includes light quarks at finite chemical potential in the center symmetric phase. We develop the model in details for the case of SU_c(2)\\times SU_f(2) by mapping the theory on a 3-dimensional quantum effective theory. We analyze the different phases in the mean-field approximation. We extend this analysis to the general case of SU_c(N_c)\\times SU_f(N_f) and note that the chiral and diquark pairings are always comparable.

  15. Pionic BEC--BCS crossover at finite isospin chemical potential

    CERN Document Server

    Matsuzaki, Masayuki

    2009-01-01

    We study the character change of the pionic condensation at finite isospin chemical potential \\mu_\\mathrm{I} by adopting the linear sigma model as a non-local interaction between quarks. At low |\\mu_\\mathrm{I}| the condensation is purely bosonic, then the Cooper pairing around the Fermi surface grows gradually as |\\mu_\\mathrm{I}| increases. This q-\\bar q pairing is weakly coupled in comparison with the case of the q-q pairing that leads to color superconductivity.

  16. The equation of state of QCD at finite chemical potential

    CERN Document Server

    Gupta, Sourendu; Majumdar, Pushan

    2014-01-01

    We obtain the baryon number density, n, and the excess contribution to the pressure, Delta P, at finite chemical potential, mu_B, and temperature, T, by resumming the Taylor series expansion in a lattice computation with lattice spacing of 1/(4T) and two flavours of quarks at three different quark masses. The method proceeds by giving a critical mu_B and limits on the critical exponent, and permits reliable estimations of the errors in resummed quantities. We find that n and Delta P are insensitive to the quark mass. We also report the bulk isothermal compressibility, kappa, over a range of T and mu_B.

  17. Composite reweighting with Imaginary Chemical Potentials in SU(3)

    CERN Document Server

    Crompton, P R

    2002-01-01

    We review the overlap pathology of the Glasgow reweighting method for finite density QCD, and discuss the sampling bias that effects the determination of the ensemble-averaged fugacity polynomial expansion coefficients that form the Grand Canonical Partition function. The expectation of the difference in free energies between canonical partition functions generated with different measures is presented as an indicator of a systematic quark number dependent biasing in the reweighting approach. The advantages of building up an unbiased polynomial expansion for the Grand Canonical Partition function through a series of parallel ensembles generated by reweighting with imaginary chemical potentials are then contrasted with addressing the overlap pathology through a secondary reweighting.

  18. Chemicals from biomass: an assessment of the potential for production of chemical feedstocks from renewable resources

    Energy Technology Data Exchange (ETDEWEB)

    Donaldson, T.L.; Culberson, O.L.

    1983-06-01

    This assessment of the potential for production of commodity chemicals from renewable biomass resources is based on (1) a Delphi study with 50 recognized authorities to identify key technical issues relevant to production of chemicals from biomass, and (2) a systems model based on linear programming for a commodity chemicals industry using renewable resources and coal as well as gas and petroleum-derived resources. Results from both parts of the assessment indicate that, in the absence of gas and petroleum, coal undoubtedly would be a major source of chemicals first, followed by biomass. The most attractive biomass resources are wood, agricultural residues, and sugar and starch crops. A reasonable approximation to the current product slate for the petrochemical industry could be manufactured using only renewable resources for feedstocks. Approximately 2.5 quads (10/sup 15/ Btu (1.055 x 10/sup 18/ joules)) per year of oil and gas would be released. Further use of biomass fuels in the industry could release up to an additional 1.5 quads. however, such an industry would be unprofitable under current economic conditions with existing or near-commercial technology. As fossil resources become more expensive and biotechnology becomes more efficient, the economics will be more favorable. Use of the chemicals industry model to evaluate process technologies is demonstrated. Processes are identified which have potential for significant added value to the system if process improvements can be made to improve the economics. Guidelines and recommendations for research and development programs to improve the attractiveness of chemicals from biomass are discussed.

  19. Chemical potential and compressibility of quantum Hall bilayer excitons,.

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, Brian

    2016-02-25

    I consider a system of two parallel quantum Hall layers with total filling factor 0 or 1. When the distance between the layers is small enough, electrons and holes in opposite layers can form inter-layer excitons, which have a finite effective mass and interact via a dipole-dipole potential. I present results for the chemical potential u of the resulting bosonic system as a function of the exciton concentration n and the interlayer separation d. I show that both u and the interlayer capacitance have an unusual nonmonotonic dependence on d, owing to the interplay between an increasing dipole moment and an increasing effective mass with increasing d. Finally, I discuss the transition between the superfluid and Wigner crystal phases, which is shown to occur at d x n-1/10. Results are derived first via simple intuitive arguments, and then verified with more careful analytic derivations and numeric calculations.

  20. Semi-infinite jellium: Thermodynamic potential, chemical potential, and surface energy

    Science.gov (United States)

    Kostrobij, P. P.; Markovych, B. M.

    2015-08-01

    A general expression for the thermodynamic potential of the model of semi-infinite jellium is obtained. By using this expression, the surface energy for the infinite barrier model is calculated. The behavior of the surface energy and of the chemical potential as functions of the Wigner-Seitz radius and the influence of the Coulomb interaction between electrons on the calculated values is studied. It is shown that taking into account the Coulomb interaction between electrons leads to growth of the surface energy. The surface energy is positive in the entire area of the Wigner-Seitz radius. It is shown that taking into account the Coulomb interaction between electrons leads to a decrease of the chemical potential.

  1. Electric charge catalysis by magnetic fields and isospin chemical potential

    CERN Document Server

    Bruckmann, F; Sulejmanpasic, T

    2013-01-01

    We describe a generic mechanism by which a system of Dirac fermions which carry an additional quantum number (isospin) acquires electric charge when the system is subject to an isospin chemical potential and a superposition of a normal magnetic field and a magnetic field which distinguishes the isospin. A nontrivial feature of fermions in the background of such gauge fields is that the electric charge appears due to nonzero isospin chemical potential and vice versa. The charge is accumulated since the degeneracies of occupied lowest Landau levels for particles of positive isospin and anti-particles of negative isospin are different. We discuss two physical systems where this phenomenon can be realized. One is monolayer graphene where the isospin is associated with two valleys in the Brillouin zone and the strain-induced pseudo-magnetic field acts differently on charge carriers in different valleys. Another is hot QCD, for which the role of isospin is played by the color of quarks. In the latter case the descr...

  2. Holographic thermalization with a chemical potential from Born-Infeld electrodynamics

    CERN Document Server

    Camilo, Giancarlo; Abdalla, Elcio

    2014-01-01

    The problem of holographic thermalization in the framework of Einstein gravity coupled to Born-Infeld nonlinear electrodynamics is investigated. We use equal time twopoint correlation functions and expectation values of Wilson loop operators in the boundary quantum field theory as probes of thermalization, which have dual gravity descriptions in terms of geodesic lengths and minimal area surfaces in the bulk spacetime. The full range of values of the chemical potential per temperature ratio on the boundary is explored. The numerical results show that the effect of the charge on the thermalization time is similar to the one obtained with Maxwell electrodynamics, namely the larger the charge the later thermalization occurs. The inverse Born-Infeld parameter, on the other hand, has the opposite effect: the more nonlinear the theory is, the sooner it thermalizes. We also study the thermalization velocity and how the parameters affect the phase transition point separating the thermalization process into an acceler...

  3. Estimation of Radiative Efficiency of Chemicals with Potentially Significant Global Warming Potential.

    Science.gov (United States)

    Betowski, Don; Bevington, Charles; Allison, Thomas C

    2016-01-19

    Halogenated chemical substances are used in a broad array of applications, and new chemical substances are continually being developed and introduced into commerce. While recent research has considerably increased our understanding of the global warming potentials (GWPs) of multiple individual chemical substances, this research inevitably lags behind the development of new chemical substances. There are currently over 200 substances known to have high GWP. Evaluation of schemes to estimate radiative efficiency (RE) based on computational chemistry are useful where no measured IR spectrum is available. This study assesses the reliability of values of RE calculated using computational chemistry techniques for 235 chemical substances against the best available values. Computed vibrational frequency data is used to estimate RE values using several Pinnock-type models, and reasonable agreement with reported values is found. Significant improvement is obtained through scaling of both vibrational frequencies and intensities. The effect of varying the computational method and basis set used to calculate the frequency data is discussed. It is found that the vibrational intensities have a strong dependence on basis set and are largely responsible for differences in computed RE values.

  4. $3d$ fermion-boson map with imaginary chemical potential

    CERN Document Server

    Filothodoros, E G; Vlachos, N D

    2016-01-01

    We study the three-dimensional $U(N)$ Gross-Neveu and CP$^{N-1}$ models in the canonical formalism with fixed $U(1)$ charge. For large-$N$ this is closely related to coupling the models to abelian Chern-Simons in a monopole background. We show that the presence of the imaginary chemical potential for the $U(1)$ charge makes the phase structure of the models remarkably similar. We calculate their respective large-$N$ free energy densities and show that they are mapped into each other in a precise way. Intriguingly, the free energy map involves the Bloch-Wigner function and its generalizations introduced by Zagier. We expect that our results are connected to the recently discussed $3d$ bosonization.

  5. Density versus chemical potential in holographic field theories

    CERN Document Server

    Nogueira, Fernando

    2011-01-01

    We study the relationship between charge density ({\\rho}) and chemical potential ({\\mu}) for an array of Lorentz invariant 3 + 1 dimensional holographic field theories with the minimal structure of a conserved charge. The systems considered include Dp-Dq probe brane constructions and probe and backreacted 'bottom-up' models with gauge and scalar fields. In all cases, at large density, the relationship is well modelled by a power law behaviour of the form {\\rho} $\\propto$ {\\mu}^{\\alpha}. A variety of powers {\\alpha} are found in the brane systems while in most of the bottom-up models {\\alpha} is determined by the underlying conformal symmetry. Further, it is demonstrated that basic thermodynamical and causality constraints demand {\\alpha} \\geq 1, a condition that was realized in each system considered.

  6. Aspects of Holographic Entanglement at Finite Temperature and Chemical Potential

    CERN Document Server

    Kundu, Sandipan

    2016-01-01

    We investigate the behavior of entanglement entropy at finite temperature and chemical potential for strongly coupled large-N gauge theories in $d$-dimensions ($d\\ge 3$) that are dual to Anti-de Sitter-Reissner-Nordstrom geometries in $(d+1)-$dimensions, in the context of gauge-gravity duality. We develop systematic expansions based on the Ryu-Takayanagi prescription that enable us to derive analytic expressions for entanglement entropy and mutual information in different regimes of interest. Consequently, we identify the specific regions of the bulk geometry that contribute most significantly to the entanglement entropy of the boundary theory at different limits. We define a scale, dubbed as the effective temperature, which determines the behavior of entanglement in different regimes. At high effective temperature, entanglement entropy is dominated by the thermodynamic entropy, however, mutual information subtracts out this contribution and measures the actual quantum entanglement. Finally, we study the enta...

  7. Determination of Reference Chemical Potential Using Molecular Dynamics Simulations

    Directory of Open Access Journals (Sweden)

    Krishnadeo Jatkar

    2010-01-01

    Full Text Available A new method implementing molecular dynamics (MD simulations for calculating the reference properties of simple gas hydrates has been proposed. The guest molecules affect interaction between adjacent water molecules distorting the hydrate lattice, which requires diverse values of reference properties for different gas hydrates. We performed simulations to validate the experimental data for determining Δ0, the chemical potential difference between water and theoretical empty cavity at the reference state, for structure II type gas hydrates. Simulations have also been used to observe the variation of the hydrate unit cell volume with temperature. All simulations were performed using TIP4P water molecules at the reference temperature and pressure conditions. The values were close to the experimental values obtained by the Lee-Holder model, considering lattice distortion.

  8. Phase diagram of the Dirac spectrum at nonzero chemical potential

    International Nuclear Information System (INIS)

    The Dirac spectrum of QCD with dynamical fermions at nonzero chemical potential is characterized by three regions: a region with a constant eigenvalue density, a region where the eigenvalue density shows oscillations that grow exponentially with the volume and the remainder of the complex plane where the eigenvalue density is zero. In this paper we derive the phase diagram of the Dirac spectrum from a chiral Lagrangian. We show that the constant eigenvalue density corresponds to a pion condensed phase while the strongly oscillating region is given by a kaon condensed phase. The normal phase with nonzero chiral condensate but vanishing Bose condensates coincides with the region of the complex plane where there are no eigenvalues.

  9. Plant Growth Promotion Potential Is Equally Represented in Diverse Grapevine Root-Associated Bacterial Communities from Different Biopedoclimatic Environments

    Directory of Open Access Journals (Sweden)

    Ramona Marasco

    2013-01-01

    Full Text Available Plant-associated bacteria provide important services to host plants. Environmental factors such as cultivar type and pedoclimatic conditions contribute to shape their diversity. However, whether these environmental factors may influence the plant growth promoting (PGP potential of the root-associated bacteria is not widely understood. To address this issue, the diversity and PGP potential of the bacterial assemblage associated with the grapevine root system of different cultivars in three Mediterranean environments along a macrotransect identifying an aridity gradient were assessed by culture-dependent and independent approaches. According to 16S rRNA gene PCR-DGGE, the structure of endosphere and rhizosphere bacterial communities was highly diverse (P=0.03 and was associated with a cultivar/latitudinal/climatic effect. Despite being diverse, the bacterial communities associated with Egyptian grapevines shared a higher similarity with the Tunisian grapevines than those cultivated in North Italy. A similar distribution, according to the cultivar/latitude/aridity gradients, was observed for the cultivable bacteria. Many isolates (23% presented in vitro multiple stress resistance capabilities and PGP activities, the most frequent being auxin synthesis (82%, insoluble phosphate solubilisation (61%, and ammonia production (70%. The comparable numbers and types of potential PGP traits among the three different environmental settings indicate a strong functional homeostasis of beneficial bacteria associated with grape root.

  10. Not all sperm are equal: functional mitochondria characterize a subpopulation of human sperm with better fertilization potential.

    Directory of Open Access Journals (Sweden)

    Ana Paula Sousa

    Full Text Available Human sperm samples are very heterogeneous and include a low amount of truly functional gametes. Distinct strategies have been developed to characterize and isolate this specific subpopulation. In this study we have used fluorescence microscopy and fluorescence-activated cell sorting to determine if mitochondrial function, as assessed using mitochondrial-sensitive probes, could be employed as a criterion to obtain more functional sperm from a given ejaculate. We first determined that mitochondrial activity correlated with the quality of distinct human samples, from healthy donors to patients with decreased semen quality. Furthermore, using fluorescence-activated cell sorting to separate sperm with active and inactive mitochondria we found that this was also true within samples. Indeed, sperm with active mitochondria defined a more functional subpopulation, which contained more capacitated and acrosome intact cells, sperm with lower chromatin damage, and, crucially, sperm more able to decondense and participate in early development using both chemical induction and injection into mature bovine oocytes. Furthermore, cell sorting using mitochondrial activity produced a more functional sperm subpopulation than classic swim-up, both in terms of improvement in a variety of functional sperm parameters and in statistical significance. In conclusion, whatever the true biological role of sperm mitochondria in fertilization, mitochondrial activity is a clear hallmark of human sperm functionality.

  11. Not all sperm are equal: functional mitochondria characterize a subpopulation of human sperm with better fertilization potential.

    Science.gov (United States)

    Sousa, Ana Paula; Amaral, Alexandra; Baptista, Marta; Tavares, Renata; Caballero Campo, Pedro; Caballero Peregrín, Pedro; Freitas, Albertina; Paiva, Artur; Almeida-Santos, Teresa; Ramalho-Santos, João

    2011-03-23

    Human sperm samples are very heterogeneous and include a low amount of truly functional gametes. Distinct strategies have been developed to characterize and isolate this specific subpopulation. In this study we have used fluorescence microscopy and fluorescence-activated cell sorting to determine if mitochondrial function, as assessed using mitochondrial-sensitive probes, could be employed as a criterion to obtain more functional sperm from a given ejaculate. We first determined that mitochondrial activity correlated with the quality of distinct human samples, from healthy donors to patients with decreased semen quality. Furthermore, using fluorescence-activated cell sorting to separate sperm with active and inactive mitochondria we found that this was also true within samples. Indeed, sperm with active mitochondria defined a more functional subpopulation, which contained more capacitated and acrosome intact cells, sperm with lower chromatin damage, and, crucially, sperm more able to decondense and participate in early development using both chemical induction and injection into mature bovine oocytes. Furthermore, cell sorting using mitochondrial activity produced a more functional sperm subpopulation than classic swim-up, both in terms of improvement in a variety of functional sperm parameters and in statistical significance. In conclusion, whatever the true biological role of sperm mitochondria in fertilization, mitochondrial activity is a clear hallmark of human sperm functionality.

  12. Chemical composition, therapeutic potential and perspectives of Foeniculum vulgare

    Directory of Open Access Journals (Sweden)

    Chanchal Garga

    2009-01-01

    Full Text Available Foeniculum vulgare is a widely distributed plant in most tropical and subtropical countries and have long been used in folk medicines to treat obstruction of the liver, spleen and gall bladder and for digestive complaints such as colic, indigestion, nausea and flatulence. In recent years the interest in this plant has increased considerably with substantial progress on its chemical and pharmacological properties. This review discusses the current knowledge of its chemistry, the various compounds isolated and pharamcological studies conducted. These studies carried out with the extracts and volatile oil support most of the reports of using this plant in folk medicines. However, well controlled, double-binding clinical trials are lacking. Several compounds including trans-anethole, estragole, fenchone and polyphenolics were isolated from this plant and some of these interact with potential mechanisms of the body. Together this data strongly supports the view that this plant has potential beneficial therapeutic actions in the management of bacterial and fungal infections, colic pain and lipid peroxidation.

  13. Yield and depth Estimation of Selected NTS Nuclear and SPE Chemical Explosions Using Source Equalization by modeling Local and Regional Seismograms (Invited)

    Science.gov (United States)

    Saikia, C. K.; Roman-nieves, J. I.; Woods, M. T.

    2013-12-01

    Source parameters of nuclear and chemical explosions are often estimated by matching either the corner frequency and spectral level of a single event or the spectral ratio when spectra from two events are available with known source parameters for one. In this study, we propose an alternative method in which waveforms from two or more events can be simultaneously equalized by setting the differential of the processed seismograms at one station from any two individual events to zero. The method involves convolving the equivalent Mueller-Murphy displacement source time function (MMDSTF) of one event with the seismogram of the second event and vice-versa, and then computing their difference seismogram. MMDSTF is computed at the elastic radius including both near and far-field terms. For this method to yield accurate source parameters, an inherent assumption is that green's functions for the any paired events from the source to a receiver are same. In the frequency limit of the seismic data, this is a reasonable assumption and is concluded based on the comparison of green's functions computed for flat-earth models at various source depths ranging from 100m to 1Km. Frequency domain analysis of the initial P wave is, however, sensitive to the depth phase interaction, and if tracked meticulously can help estimating the event depth. We applied this method to the local waveforms recorded from the three SPE shots and precisely determined their yields. These high-frequency seismograms exhibit significant lateral path effects in spectrogram analysis and 3D numerical computations, but the source equalization technique is independent of any variation as long as their instrument characteristics are well preserved. We are currently estimating the uncertainty in the derived source parameters assuming the yields of the SPE shots as unknown. We also collected regional waveforms from 95 NTS explosions at regional stations ALQ, ANMO, CMB, COR, JAS LON, PAS, PFO and RSSD. We are

  14. TURBO EQUALIZATION WITH JOINTLY GAUSSIAN EQUALIZER

    Institute of Scientific and Technical Information of China (English)

    Jiang Sen; Sun Hong; Li Ping

    2005-01-01

    A Jointly Gaussian (JG) equalizer is derived for turbo equalization based on an augmented real matrix representation of channel model and a Gaussian approximation of the received symbol sequence. Using matrix inversion lemma and Cholesky decomposition, a lowcomplexity implementation of JG equalizer is also presented. The simulation results and complexity comparison confirm that turbo equalization with JG equalizer has a better performance and a lower complexity than the existing turbo equalization with linear minimum mean squared error equalizer.

  15. Biogenic methane potential of marine sediments. Application of chemical thermodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Arning, E.T.; Schulz, H.M. [Helmholtz Centre Potsdam GFZ, Potsdam (Germany); Berk, W. van [Technical Univ. of Clausthal (Germany). Dept. of Hydrogeology

    2013-08-01

    Accumulations of biogenic methane-dominated gas are widespread and occur in a variety of depositional settings and rock types. However, the potential of biogenic methane remains underexplored. This is mainly due to the fact that quantitative assessments applying numerical modeling techniques for exploration purposes are generally lacking to date. Biogenic methane formation starts in relatively shallow marine sediments below the sulfate reduction zone. When sulfate is exhausted, methanogenesis via the CO{sub 2} reduction pathway is often the dominant biogenic methane formation process in marine sediments (Claypool and Kaplan, 1974). The process can be simplified by the reaction: 2CH{sub 2}O + Ca{sup 2+} + H{sub 2}O {yields} CH{sub 4} + CaCO{sub 3} + 2H{sup +}. The products of early diagenetic reactions initiate coupled equilibrium reactions that induce a new state of chemical equilibrium among minerals, pore water and gas. The driving force of the complex biogeochemical reactions in sedimentary environments during early diagenesis is the irreversible redox-conversion of organic matter. Early diagenetic formation of biogenic methane shortly after deposition ('early diagenesis') was retraced using PHREEQC computer code that is applied to calculate homogenous and heterogeneous mass-action equations in combination with one-dimensional diffusion driven transport (Parkhurst and Appelo, 1999). Our modeling approach incorporates interdependent diagenetic reactions evolving into a diffusive multi-component and multiphase system by means of thermodynamic equilibrium calculations of species distribution (Arning et al., 2011, 2012, 2013). Reaction kinetics of organic carbon conversion is integrated into the set of equilibrium reactions by defining type and amount of converted organic matter in a certain time step. It is the aim (1) to calculate quantitatively thermodynamic equilibrium conditions (composition of pore water, mineral phase and gas phase assemblage) in

  16. Black Hole Phase Transitions and the Chemical Potential

    CERN Document Server

    Maity, Reevu; Sarkar, Tapobrata

    2015-01-01

    In the context of extended phase space thermodynamics and the AdS-CFT correspondence, we consider the chemical potential ($\\mu$) dual to the number of colours ($N$) of the boundary gauge theory, in the grand canonical ensemble. By appropriately defining $\\mu$ via densities of thermodynamic quantities, we show that it changes sign precisely at the Hawking-Page transition for AdS-Schwarzschild and RN-AdS black holes in five dimensions, signalling the onset of quantum effects at the transition point. Such behaviour is absent for non-rotating black holes in four dimensions. For Kerr-AdS black holes in four and five dimensions, our analysis points to the fact that $\\mu$ can change sign in the stable black hole region, i.e above the Hawking-Page transition temperature, for a range of angular frequencies. We also analyse AdS black holes in five dimensional Gauss-Bonnet gravity, and find similar features for $\\mu$ as in the Kerr-AdS case.

  17. Determination of the chemical potential using energy-biased sampling

    CERN Document Server

    Delgado-Buscalioni, R; Coveney, P V

    2005-01-01

    An energy-biased method to evaluate ensemble averages requiring test-particle insertion is presented. The method is based on biasing the sampling within the subdomains of the test-particle configurational space with energies smaller than a given value freely assigned. These energy-wells are located via unbiased random insertion over the whole configurational space and are sampled using the so called Hit&Run algorithm, which uniformly samples compact regions of any shape immersed in a space of arbitrary dimensions. Because the bias is defined in terms of the energy landscape it can be exactly corrected to obtain the unbiased distribution. The test-particle energy distribution is then combined with the Bennett relation for the evaluation of the chemical potential. We apply this protocol to a system with relatively small probability of low-energy test-particle insertion, liquid argon at high density and low temperature, and show that the energy-biased Bennett method is around five times more efficient than t...

  18. Molecular Spectrum Capture by Tuning the Chemical Potential of Graphene

    Science.gov (United States)

    Cheng, Yue; Yang, Jingjing; Lu, Qiannan; Tang, Hao; Huang, Ming

    2016-01-01

    Due to its adjustable electronic properties and effective excitation of surface plasmons in the infrared and terahertz frequency range, research on graphene has attracted a great deal of attention. Here, we demonstrate that plasmon modes in graphene-coated dielectric nanowire (GNW) waveguides can be excited by a monolayer graphene ribbon. What is more the transverse resonant frequency spectrum of the GNW can be flexibly tuned by adjusting the chemical potential of graphene, and amplitude of the resonance peak varies linearly with the imaginary part of the analyte permittivity. As a consequence, the GNW works as a probe for capturing the molecular spectrum. Broadband sensing of toluene, ethanol and sulfurous anhydride thin layers is demonstrated by calculating the changes in spectral intensity of the propagating mode and the results show that the intensity spectra correspond exactly to the infrared spectra of these molecules. This may open an effective avenue to design sensors for detecting nanometric-size molecules in the terahertz and infrared regimes. PMID:27240372

  19. Molecular Spectrum Capture by Tuning the Chemical Potential of Graphene

    Directory of Open Access Journals (Sweden)

    Yue Cheng

    2016-05-01

    Full Text Available Due to its adjustable electronic properties and effective excitation of surface plasmons in the infrared and terahertz frequency range, research on graphene has attracted a great deal of attention. Here, we demonstrate that plasmon modes in graphene-coated dielectric nanowire (GNW waveguides can be excited by a monolayer graphene ribbon. What is more the transverse resonant frequency spectrum of the GNW can be flexibly tuned by adjusting the chemical potential of graphene, and amplitude of the resonance peak varies linearly with the imaginary part of the analyte permittivity. As a consequence, the GNW works as a probe for capturing the molecular spectrum. Broadband sensing of toluene, ethanol and sulfurous anhydride thin layers is demonstrated by calculating the changes in spectral intensity of the propagating mode and the results show that the intensity spectra correspond exactly to the infrared spectra of these molecules. This may open an effective avenue to design sensors for detecting nanometric-size molecules in the terahertz and infrared regimes.

  20. Cavitation in a quark gluon plasma with finite chemical potential and several transport coefficients

    CERN Document Server

    Sanches, S M; Navarra, F S; Marrochio, H

    2015-01-01

    We study the effects of a finite chemical potential on the occurrence of cavitation in a quark gluon plasma (QGP). We solve the evolution equations of second order viscous relativistic hydrodynamics using three different equations of state. The first one was derived in lattice QCD and represents QGP at zero chemical potential. It was previously used in the study of cavitation. The second equation of state also comes from lattice QCD and is a recent parametrization of the QGP at finite chemical potential. The third one is similar to the MIT equation of state with chemical potential and includes nonperturbative effects through the gluon condensates. We conclude that at finite chemical potential cavitation in the QGP occurs earlier than at zero chemical potential. We also consider transport coefficients from a holographic model of a non-conformal QGP at zero chemical potential. In this case cavitation does not occur.

  1. Chemical potentials in three-dimensional higher spin anti-de Sitter gravity

    OpenAIRE

    Henneaux, Marc(Université Libre de Bruxelles, ULB-Campus Plaine CP231, 1050, Brussels, Belgium); Pérez, Alfredo; Tempo, David; Troncoso, Ricardo(Centro de Estudios Científicos (CECs), Av. Arturo Prat 514, Valdivia, Chile)

    2013-01-01

    We indicate how to introduce chemical potentials for higher spin charges in higher spin anti-de Sitter gravity in a manner that manifestly preserves the original asymptotic W-symmetry. This is done by switching on a non-vanishing component of the connection along the temporal (thermal) circles. We first recall the procedure in the pure gravity case (no higher spin) where the only "chemical potentials" are the temperature and the chemical potential associated with the angular momentum. We then...

  2. Evaluation of the Component Chemical Potentials in Analytical Models for Ordered Alloy Phases

    Directory of Open Access Journals (Sweden)

    W. A. Oates

    2011-01-01

    Full Text Available The component chemical potentials in models of solution phases with a fixed number of sites can be evaluated easily when the Helmholtz energy is known as an analytical function of composition. In the case of ordered phases, however, the situation is less straightforward, because the Helmholtz energy is a functional involving internal order parameters. Because of this, the chemical potentials are usually obtained numerically from the calculated integral Helmholtz energy. In this paper, we show how the component chemical potentials can be obtained analytically in ordered phases via the use of virtual cluster chemical potentials. Some examples are given which illustrate the simplicity of the method.

  3. Two-Color QCD with Non-zero Chiral Chemical Potential

    CERN Document Server

    Braguta, V V; Ilgenfritz, E -M; Kotov, A Yu; Molochkov, A V; Muller-Preussker, M; Petersson, B

    2015-01-01

    The phase diagram of two-color QCD with non-zero chiral chemical potential is studied by means of lattice simulation. We focus on the influence of a chiral chemical potential on the confinement/deconfinement phase transition and the breaking/restoration of chiral symmetry. The simulation is carried out with dynamical staggered fermions without rooting. The dependences of the Polyakov loop, the chiral condensate and the corresponding susceptibilities on the chiral chemical potential and the temperature are presented. The critical temperature is observed to increase with increasing chiral chemical potential.

  4. Two-color QCD with non-zero chiral chemical potential

    Science.gov (United States)

    Braguta, V. V.; Goy, V. A.; Ilgenfritz, E. M.; Kotov, A. Yu.; Molochkov, A. V.; Müller-Preussker, M.; Petersson, B.

    2015-06-01

    The phase diagram of two-color QCD with non-zero chiral chemical potential is studied by means of lattice simulation. We focus on the influence of a chiral chemical potential on the confinement/deconfinement phase transition and the breaking/restoration of chiral symmetry. The simulation is carried out with dynamical staggered fermions without rooting. The dependences of the Polyakov loop, the chiral condensate and the corresponding susceptibilities on the chiral chemical potential and the temperature are presented. The critical temperature is observed to increase with increasing chiral chemical potential.

  5. Equal-area polygons used in design and installation of a well network for long-term monitoring of agricultural chemicals in the High Plains Aquifer, Colorado

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data are in support of report DS 456 (Arnold and others, 2009). 30 equal-area polygons generated using techniques described in Scott (1990). Polygons include...

  6. Low Energy Effective Theory of QCD at High Isospin Chemical Potential

    CERN Document Server

    Cohen, Thomas D

    2015-01-01

    The goal of this paper is to arrive at a low energy effective theory of QCD with two massless flavors of quarks at very high isospin density and zero baryon density. In a seminal paper by Son and Stephanov in the year 2001, it was conjectured that the low energy dynamics of QCD with two light flavors at asymptotically high isospin density was described by that of a pure Yang-Mills effective Lagrangian. Since the existence of a first order deconfinement phase transition with increasing temperature is a feature of every pure SU(N) Yang-Mills theory with N greater than or equal to 3, the regime considered in this paper is also expected to exhibit a first order deconfinement phase transition with increasing temperature. However, the low energy constants(LEC) of this pure Yang-Mills theory have not been calculated till date. We calculate the LEC s for this effective theory which in turn enables us to calculate the critical temperature of the deconfinement transition as a function of the isospin chemical potential ...

  7. Survey of knowledge of hazards of chemicals potentially associated with the advanced isotope separation processes

    International Nuclear Information System (INIS)

    Hazards of chemical potentially associated with the advanced isotope separation processes are estimated based on open literature references. The tentative quantity of each chemical associated with the processes and the toxicity of the chemical are used to estimate this hazard. The chemicals thus estimated to be the most potentially hazardous to health are fluorine, nitric acid, uranium metal, uranium hexafluoride, and uranium dust. The estimated next most hazardous chemicals are bromine, hydrobromic acid, hydrochloric acid, and hydrofluoric acid. For each of these chemicals and for a number of other process-associated chemicals the following information is presented: (1) any applicable standards, recommended standards and their basis; (2) a brief discussion to toxic effects including short exposure tolerance, atmospheric concentration immediately hazardous to life, evaluation of exposures, recommended control procedures, chemical properties, and a list of any toxicology reviews; and (3) recommendations for future research

  8. Bandwidth Study on Energy Use and Potential Energy Saving Opportunities in U.S. Chemical Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Sabine Brueske, Caroline Kramer, Aaron Fisher

    2015-06-01

    Energy bandwidth studies of U.S. manufacturing sectors can serve as foundational references in framing the range (or bandwidth) of potential energy savings opportunities. This bandwidth study examines energy consumption and potential energy savings opportunities in U.S. chemical manufacturing. The study relies on multiple sources to estimate the energy used in the production of 74 individual chemicals, representing 57% of sector-wide energy consumption. Energy savings opportunities for individual chemicals and for 15 subsectors of chemicals manufacturing are based on technologies currently in use or under development; these potential savings are then extrapolated to estimate sector-wide energy savings opportunity.

  9. Potential Impacts of Spilled Hydraulic Fracturing Fluid Chemicals on Water Resources: Types, volumes, and physical-chemical properties of chemicals

    Science.gov (United States)

    Hydraulic fracturing (HF) fluid chemicals spilled on-site may impact drinking water resources. While chemicals generally make up <2% of the total injected fluid composition by mass, spills may have undiluted concentrations. HF fluids typically consist of a mixture of base flui...

  10. Chemical Potential Dependence of the Dressed-Quark Propagator from an Effective Quark-Quark Interaction

    Institute of Scientific and Technical Information of China (English)

    ZONG Hong-Shi; PING Jia-Lun; SUN Wei-Min; CHANG Chao-Hsi; WANG Fan

    2002-01-01

    We exhibit a method for obtaining the low chemical potential dependence of the dressed quark propagatorfrom an effective quark-quark interaction model. Within this approach we explore the chemical potential dependenceof the dressed-quark propagator, which provides a means of determining the behavior of the chiral and deconfinementorder parameters. A comparison with the results of previous researches is given.

  11. Amazonian Buriti oil: chemical characterization and antioxidant potential

    OpenAIRE

    Speranza, P.; de Oliveira Falcão, A.; Alves Macedo, J.; da Silva, L. H.M.; da C. Rodrigues, A. M.; Alves Macedo, G.

    2016-01-01

    Buriti oil is an example of an Amazonian palm oil of economic importance. The local population uses this oil for the prevention and treatment of different diseases; however, there are few studies in the literature that evaluate its properties. In this study, detailed chemical and antioxidant properties of Buriti oil were determined. The predominant fatty acid was oleic acid (65.6%) and the main triacylglycerol classes were tri-unsaturated (50.0%) and di-unsaturated-mono-saturated (39.3%) tria...

  12. Chemical diversity and antiviral potential in the pantropical Diospyros genus.

    Science.gov (United States)

    Peyrat, Laure-Anne; Eparvier, Véronique; Eydoux, Cécilia; Guillemot, Jean-Claude; Stien, Didier; Litaudon, Marc

    2016-07-01

    A screening using a dengue replicon virus-cell-based assay was performed on 3563 ethyl acetate (EtOAc) extracts from different parts of 1500 plants. The screening led to the selection of species from the genus Diospyros (Ebenaceae), among which 25 species distributed in tropical areas showed significant inhibitory activity on dengue virus replication. A metabolic analysis was conducted from the UPLC-HRMS profiles of 33 biologically active and inactive plant extracts, and their metabolic proximity is presented in the form of a dendrogram. The results of the study showed that chemical similarity is not related to plant species or organ. Overall, metabolomic profiling allowed us to define large groups of extracts, comprising both active and inactive ones. Closely related profiles from active extracts might indicate that the common major components of these extracts were responsible for the antiviral activity, while the comparison of chemically similar active and inactive extracts, will permit to find compounds of interest. Eventually, the phytochemical investigation of Diospyros glans bark EtOAc extract afforded usnic acid and 7 known ursane- and lupane-type triterpenoids, among which 5 were found significantly active against dengue virus replication. The inhibitory potency of these compounds was also evaluated on a DENV-NS5 RNA-dependant RNA polymerase assay. PMID:27126897

  13. Capacitive technology for energy extraction from chemical potential differences

    NARCIS (Netherlands)

    Bastos Sales, B.

    2013-01-01

    This thesis introduces the principle of Capacitive energy extraction based on Donnan Potential (CDP) to exploit salinity gradients. It also shows the fundamental characterization and improvements of CDP. An alternative application of this technology aimed at thermal gradients was tested.  

  14. Chemical analysis and potential health risks of hookah charcoal.

    Science.gov (United States)

    Elsayed, Yehya; Dalibalta, Sarah; Abu-Farha, Nedal

    2016-11-01

    Hookah (waterpipe) smoking is a very common practice that has spread globally. There is growing evidence on the hazardous consequences of smoking hookah, with studies indicating that its harmful effects are comparable to cigarette smoking if not worse. Charcoal is commonly used as a heating source for hookah smoke. Although charcoal briquettes are thought to be one of the major contributors to toxicity, their composition and impact on the smoke generated remains largely unidentified. This study aims to analyze the elemental composition of five different raw synthetic and natural charcoals by using Carbon-Hydrogen-Nitrogen (CHN) analysis, inductively coupled plasma (ICP), and scanning electron microscopy coupled with energy dispersive X-Ray spectrometry (SEM-EDS). Elemental analysis showed that the raw charcoals contain heavy metals such as zinc, iron, cadmium, vanadium, aluminum, lead, chromium, manganese and cobalt at concentrations similar, if not higher than, cigarettes. In addition, thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) was used to analyze the chemical composition of the smoke produced from burning the charcoal samples. The smoke emitted from charcoal was found to be the source of numerous compounds which could be hazardous to health. A total of seven carcinogens, 39 central nervous system depressants and 31 respiratory irritants were identified. PMID:27343945

  15. Evaluation of the teratogenic potential of chemicals in the rat.

    Science.gov (United States)

    Fritz, H; Giese, K

    1990-01-01

    On the basis of the results of a variety of teratogenicity studies in Sprague-Dawley-derived albino rats, carried out over several years in our laboratory, an appraisal of the principal experimental procedures is set forth. Various categories of chemicals were used for the evaluation of dosage-related teratogenic potency. Salicylate, prednisolone, cyclophosphamide, 5-hydroxytryptamine (serotonin), glycinonitrile, and dimethylformamide have proven to be teratogenic under certain of the experimental conditions used. Particular differences in the embryotropic effects of acetylsalicylic acid were caused by qualitative and quantitative changes of the vehicle. Fetal morphological abnormalities, classified either as 'malformations' or as 'anomalies', may occur independently of overt maternal toxicity and/or embryotoxicity. Further, they may be closely correlated with general inhibitory effects on growth. Drugs may affect developing tissues and organs selectively due to their pharmacological activity and/or specific organ toxicity. The limitation of maternal treatment to a very short period of gestation may disclose a specific susceptibility of developmental stages of the embryo or fetus. Finally, the importance of data collected from a historical control population to the interpretation of teratogenicity data is emphasised.

  16. Signatures for Wigner crystal formation in the chemical potential of a two-dimensional electron system.

    Science.gov (United States)

    Zhang, Ding; Huang, Xuting; Dietsche, Werner; von Klitzing, Klaus; Smet, Jurgen H

    2014-08-15

    We investigate the evolution of the chemical potential of a two-dimensional electron system (2DES) as a function of density at a fixed magnetic field. By using a bilayer system, changes in the chemical potential of one 2DES are determined from the density variation induced in the second, nearby 2DES. At high magnetic fields around a filling factor of ν=1 or ν=2, the chemical potential jump associated with the condensation in a quantum Hall state exhibits two anomalies symmetrically located around these integer filling factors. They are attributed to the formation of a 2D Wigner crystal of quasiparticles. PMID:25170727

  17. Fungal phytotoxins with potential herbicidal activity: chemical and biological characterization.

    Science.gov (United States)

    Cimmino, Alessio; Masi, Marco; Evidente, Marco; Superchi, Stefano; Evidente, Antonio

    2015-12-19

    Covering: 2007 to 2015 Fungal phytotoxins are secondary metabolites playing an important role in the induction of disease symptoms interfering with host plant physiological processes. Although fungal pathogens represent a heavy constraint for agrarian production and for forest and environmental heritage, they can also represent an ecofriendly alternative to manage weeds. Indeed, the phytotoxins produced by weed pathogenic fungi are an efficient tool to design natural, safe bioherbicides. Their use could avoid that of synthetic pesticides causing resistance in the host plants and the long term impact of residues in agricultural products with a risk to human and animal health. The isolation and structural and biological characterization of phytotoxins produced by pathogenic fungi for weeds, including parasitic plants, are described. Structure activity relationships and mode of action studies for some phytotoxins are also reported to elucidate the herbicide potential of these promising fungal metabolites. PMID:26443032

  18. Chemical composition and methane potential of commercial food wastes.

    Science.gov (United States)

    Lopez, Victoria M; De la Cruz, Florentino B; Barlaz, Morton A

    2016-10-01

    There is increasing interest in anaerobic digestion in the U.S. However, there is little information on the characterization of commercial food waste sources as well as the effect of waste particle size on methane yield. The objective of this research was to characterize four commercial food waste sources: (1) university dining hall waste, (2) waste resulting from prepared foods and leftover produce at a grocery store, (3) food waste from a hotel and convention center, and (4) food preparation waste from a restaurant. Each sample was tested in triplicate 8L batch anaerobic digesters after shredding and after shredding plus grinding. Average methane yields for the university dining, grocery store, hotel, and restaurant wastes were 363, 427, 492, and 403mL/dry g, respectively. Starch exhibited the most complete consumption and particle size did not significantly affect methane yields for any of the tested substrates. Lipids represented 59-70% of the methane potential of the fresh substrates.

  19. [Recent development in animal testing to predict the skin and respiratory sensitizing potential of chemicals].

    Science.gov (United States)

    Aoyama, Kohji

    2010-01-01

    The identification of chemicals with skin and/or respiratory sensitizing potential is important for the prevention of allergic diseases in both living and work environments. Although a number of animal models for respiratory allergic diseases have been reported, none of these models meets the goals of broad assessments of chemical sensitizing potential. We are attempting to develop a test for predicting the respiratory sensitization of chemicals. In the evaluation of skin sensitization of chemicals, the mostly used predictive tests are the guinea pig maximization test, Buehler test, and mouse local lymph node assay (LLNA). However, only LLNA has been validated formally and independently. Recent studies have revealed that EC3 estimated by LLNA correlates well with human skin sensitizing potency and the threshold for the induction of skin sensitization in the human repeat patch test. Thus, LLNA can predict the potency of skin sensitizing potential of a chemical and its risk in humans. PMID:20134104

  20. Chemical composition and methane potential of commercial food wastes.

    Science.gov (United States)

    Lopez, Victoria M; De la Cruz, Florentino B; Barlaz, Morton A

    2016-10-01

    There is increasing interest in anaerobic digestion in the U.S. However, there is little information on the characterization of commercial food waste sources as well as the effect of waste particle size on methane yield. The objective of this research was to characterize four commercial food waste sources: (1) university dining hall waste, (2) waste resulting from prepared foods and leftover produce at a grocery store, (3) food waste from a hotel and convention center, and (4) food preparation waste from a restaurant. Each sample was tested in triplicate 8L batch anaerobic digesters after shredding and after shredding plus grinding. Average methane yields for the university dining, grocery store, hotel, and restaurant wastes were 363, 427, 492, and 403mL/dry g, respectively. Starch exhibited the most complete consumption and particle size did not significantly affect methane yields for any of the tested substrates. Lipids represented 59-70% of the methane potential of the fresh substrates. PMID:27506286

  1. Amazonian Buriti oil: chemical characterization and antioxidant potential

    Directory of Open Access Journals (Sweden)

    Speranza, P.

    2016-06-01

    Full Text Available Buriti oil is an example of an Amazonian palm oil of economic importance. The local population uses this oil for the prevention and treatment of different diseases; however, there are few studies in the literature that evaluate its properties. In this study, detailed chemical and antioxidant properties of Buriti oil were determined. The predominant fatty acid was oleic acid (65.6% and the main triacylglycerol classes were tri-unsaturated (50.0% and di-unsaturated-mono-saturated (39.3% triacylglycerols. The positional distribution of the classes of fatty acids on the triacylglycerol backbone indicated a saturated and unsaturated fatty acid relationship similar in the three-triacylglycerol positions. All tocopherol isomers were present, with a total content of 2364.1 mg·kg−1. α-tocopherol constitutes 48% of the total tocopherol content, followed by γ- tocopherol (45%. Total phenolic (107.0 mg gallic acid equivalent·g−1 oil and β-carotene (781.6 mg·kg−1 were particularly high in this oil. The highest antioxidant activity against the free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH was obtained at an oil concentration of 50 mg·mL−1 (73.15%. The antioxidant activity evaluated by the Oxygen Radical Absorbance Capacity (ORAC was 95.3 μmol Trolox equivalent·g−1 oil. These results serve to present Buriti oil as an Amazonian resource for cosmetic, food and pharmaceuticals purposes.El aceite de Buriti es un ejemplo de aceite de palma amazónica de gran importancia económica. La población local utiliza este aceite para la prevención y el tratamiento de diferentes enfermedades; sin embargo, hay pocos estudios científicos que evalúen sus propiedades. En este estudio, se determinaron las propiedades antioxidantes del aceite de Buriti. El ácido graso predominante fue el oleico (65,6 % y las principales clases de triglicéridos fueron tri-insaturadas (50,0 % y Di-insaturados-mono-saturada (39,3 %. La distribución posicional de las

  2. Renormalization of the chemical potential due to multiphonon effects at the surface of metals

    Institute of Scientific and Technical Information of China (English)

    Ma Lei; Kang Guang-Zhen; Li Jun

    2012-01-01

    We study the relation between renormalization of the chemical potential due to multiphonon effects at the surface of Be(0001) and doping by solving the strong-coupling self-consistent equations of a two-dimensional (2D) electronphonon interaction system. We present the quasiparticle dispersions and inverse lifetimes of a 2D electron system interacting with Einstein phonons under the different dopings (corresponding to chemical potentials).We find that the effect of electron-phonon interaction on electron structure is strongest at the half filling,but it has no effect on the chemical potential.However,the chemical potential shows distinct renormalization effects away from half filling due to the electron-phonon interaction.

  3. Drag force of Anisotropic plasma at finite U(1) chemical potential

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Long; Ge, Xian-Hui [Shanghai University, Department of Physics, Shanghai (China); Wu, Shang-Yu [National Chiao Tung University, Department of Electrophysics, Yau Shing Tung Center, Hsinchu (China); National Center for Theoretical Science, Hsinchu (China)

    2016-05-15

    We perform the calculation of the drag force acting on a massive quark moving through an anisotropic N = 4 SU(N) Super Yang-Mills plasma in the presence of a U(1) chemical potential. We present the numerical results for any value of the anisotropy and arbitrary direction of the quark velocity with respect to the direction of the anisotropy. We find the effect of the chemical potential or charge density will enhance the drag force for our charged solution. (orig.)

  4. Self-consistent Study on Color Transport in the Quark Gluon Plasma at Finite Chemical Potential

    CERN Document Server

    Defu, H; Jiarong, L; Defu, Hou; Ochs, Stefan; Jiarong, Li

    1996-01-01

    We calculate the relaxation time self-consistently to study the damping of collective color modes and the color conductivity in a QGP by deriving self-consistent equations for the damping rates of gluons and quarks to leading order QCD by TFD including a chemical potential for quarks. We show that the damping rates are not sensitive to the chemical potential whereas color conductivity is enhanced considerably.

  5. The potential role of life cycle assessment in regulation of chemicals in the European Union

    DEFF Research Database (Denmark)

    Christensen, Frans Møller; Olsen, Stig Irving

    2004-01-01

    Scope and Background. This paper presents the preliminary results from an ongoing feasibility study, investigating potential application of elements from the life cycle assessment (LCA) framework in European chemicals' policy. Many policy areas affect manufacturing, marketing and use of chemicals......- orientated risk assessment approaches. However, the increasing need for regulatory priority setting and comparative/ cumulative assessments might in the future convey LCIA principles into the regulatory framework. The same underlying databases on inherent properties of chemicals are already applied in both...... incorporation of core findings in future chemical regulation and related policy areas....

  6. Effect of chemical potential on the computer simulation of hydrogen storage in single walled carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    ZHENG Hong; WANG Shaoqing; CHENG Huiming

    2004-01-01

    Grand canonical Monte Carlo molecular simulations were carried out for hydrogen adsorption in single-walled carbon nanotubes. It was found that variations in chemical potential may result in a great change in the hydrogen storage capacity of single-walled carbon nanotubes. Hydrogen adsorption isotherms of single-walled carbon nanotubes at 298.15 K were calculated using a modified chemical potential, and the result obtained is closer to the experimental results. By comparing the experimental and simulation results, it is proposed that chemical adsorption may exist for hydrogen adsorption in single-walled carbon nanotubes.

  7. Potential of best practice technology to improve energy efficiency in the global chemical and petrochemical sector

    NARCIS (Netherlands)

    Saygin, D.; Patel, M.K.; Worrell, E.; Tam, C.; Gielen, D.J.

    2011-01-01

    The chemical and petrochemical sector is by far the largest industrial energy user, accounting for 30% of the industry's total final energy use. However, due to its complexity its energy efficiency potential is not well understood. This article analyses the energy efficiency potential on a country l

  8. On the Equality Assumption of Latent and Sensible Heat Energy Transfer Coefficients of the Bowen Ratio Theory for Evapotranspiration Estimations: Another Look at the Potential Causes of Inequalities

    Directory of Open Access Journals (Sweden)

    Suat Irmak

    2014-08-01

    Full Text Available Evapotranspiration (ET and sensible heat (H flux play a critical role in climate change; micrometeorology; atmospheric investigations; and related studies. They are two of the driving variables in climate impact(s and hydrologic balance dynamics. Therefore, their accurate estimate is important for more robust modeling of the aforementioned relationships. The Bowen ratio energy balance method of estimating ET and H diffusions depends on the assumption that the diffusivities of latent heat (KV and sensible heat (KH are always equal. This assumption is re-visited and analyzed for a subsurface drip-irrigated field in south central Nebraska. The inequality dynamics for subsurface drip-irrigated conditions have not been studied. Potential causes that lead KV to differ from KH and a rectification procedure for the errors introduced by the inequalities were investigated. Actual ET; H; and other surface energy flux parameters using an eddy covariance system and a Bowen Ratio Energy Balance System (located side by side on an hourly basis were measured continuously for two consecutive years for a non-stressed and subsurface drip-irrigated maize canopy. Most of the differences between KV and KH appeared towards the higher values of KV and KH. Although it was observed that KV was predominantly higher than KH; there were considerable data points showing the opposite. In general; daily KV ranges from about 0.1 m2∙s−1 to 1.6 m2∙s−1; and KH ranges from about 0.05 m2∙s−1 to 1.1 m2∙s−1. The higher values for KV and KH appear around March and April; and around September and October. The lower values appear around mid to late December and around late June to early July. Hourly estimates of KV range between approximately 0 m2∙s−1 to 1.8 m2∙s−1 and that of KH ranges approximately between 0 m2∙s−1 to 1.7 m2∙s−1. The inequalities between KV and KH varied diurnally as well as seasonally. The inequalities were greater during the non

  9. Three-loop HTLpt thermodynamics at finite temperature and isospin chemical potential

    CERN Document Server

    Andersen, Jens O; Mustafa, Munshi G; Strickland, Michael

    2015-01-01

    In a previous paper (JHEP {\\bf 05} (2014) 27), we calculated the three-loop thermodynamic potential of QCD at finite temperature $T$ and quark chemical potentials $\\mu_q$ using the hard-thermal-loop perturbation theory (HTLpt) reorganization of finite temperature and density QCD. The result allows us to study the thermodynamics of QCD at finite temperature and isospin chemical potential $\\mu_I$. We calculate the pressure, energy density, and entropy density, the trace anomaly, and the speed of sound at zero and nonzero $\\mu_I$. The second, fourth, and sixth-order isospin susceptibilities are calculated at zero $\\mu_I$. Our results can be directly compared to lattice QCD without Taylor expansions around $\\mu_q=0$ since QCD has no sign problem at finite isospin chemical potential.

  10. Education, equality and difference

    Directory of Open Access Journals (Sweden)

    Penny Enslin

    1994-03-01

    Full Text Available Does the pursuit of equality in post-apartheid education require the removal of difference? This article examines the concepts of difference and equality by exploring two contemporary texts in political philosophy. It is argued that the pursuit of equality can and should, under certain circumstances, accommodate difference in the form of decentralisation and private schools.

  11. Thermodynamics of large N gauge theories with chemical potentials in a 1/ D expansion

    Science.gov (United States)

    Morita, Takeshi

    2010-08-01

    In order to understand thermodynamical properties of N D-branes with chemical potentials associated with R-symmetry charges, we study a one dimensional large N gauge theory (bosonic BFSS type model) as a first step. This model is obtained through a dimensional reduction of a 1 + D dimensional SU( N) Yang-Mills theory and we use a 1 /D expansion to investigate the phase structure. We find three phases in the μ - T plane. We also show that all the adjoint scalars condense at large D and obtain a mass dynamically. This dynamical mass protects our model from the usual perturbative instability of massless scalars in a non-zero chemical potential. We find that the system is at least meta-stable for arbitrary large values of the chemical potentials in D → ∞ limit. We also explore the existence of similar condensation in higher dimensional gauge theories in a high temperature limit. In 2 and 3 dimensions, the condensation always happens as in one dimensional case. On the other hand, if the dimension is higher than 4, there is a critical chemical potential and the condensation happens only if the chemical potentials are below it.

  12. Evaluation of the potential of benchmarking to facilitate the measurement of chemical persistence in lakes.

    Science.gov (United States)

    Zou, Hongyan; MacLeod, Matthew; McLachlan, Michael S

    2014-01-01

    The persistence of chemicals in the environment is rarely measured in the field due to a paucity of suitable methods. Here we explore the potential of chemical benchmarking to facilitate the measurement of persistence in lake systems using a multimedia chemical fate model. The model results show that persistence in a lake can be assessed by quantifying the ratio of test chemical and benchmark chemical at as few as two locations: the point of emission and the outlet of the lake. Appropriate selection of benchmark chemicals also allows pseudo-first-order rate constants for physical removal processes such as volatilization and sediment burial to be quantified. We use the model to explore how the maximum persistence that can be measured in a particular lake depends on the partitioning properties of the test chemical of interest and the characteristics of the lake. Our model experiments demonstrate that combining benchmarking techniques with good experimental design and sensitive environmental analytical chemistry may open new opportunities for quantifying chemical persistence, particularly for relatively slowly degradable chemicals for which current methods do not perform well.

  13. Equal opportunities in diversity

    CERN Multimedia

    Laëtitia Pedroso

    2010-01-01

    Promoting equal opportunities at CERN and advising the Director-General on all related matters is the task of the Equal Opportunities Officer, Doris Chromek-Burckhart, and Tim Smith, chair of the Equal Opportunities Advisory Panel. Changes are being introduced: in future, the focus of their work will be broadened to cover all aspects of diversity promotion.   The term "equal opportunities" has always been broader in scope than the equal treatment of men and women but this is what it has traditionally been confined to in practice. "We wanted to change how people see our mission", explains Doris Chromek-Burckhart. The word "diversity" has much wider connotations than "equal opportunities" and makes it clearer that we are also dealing with differences in nationality, religion, age, culture and physical ability”. Getting away from the old clichés is vital to ensuring equal treatment for everyone. The diversit...

  14. Decision trees for evaluating skin and respiratory sensitizing potential of chemicals in accordance with European regulations.

    Science.gov (United States)

    Selgrade, Maryjane K; Sullivan, Katherine S; Boyles, Rebecca R; Dederick, Elizabeth; Serex, Tessa L; Loveless, Scott E

    2012-08-01

    Guidance for determining the sensitizing potential of chemicals is available in EC Regulation No. 1272/2008 Classification, Labeling, and Packaging of Substances; REACH guidance from the European Chemicals Agency; and the United Nations Globally Harmonized System (GHS). We created decision trees for evaluating potential skin and respiratory sensitizers. Our approach (1) brings all the regulatory information into one brief document, providing a step-by-step method to evaluate evidence that individual chemicals or mixtures have sensitizing potential; (2) provides an efficient, uniform approach that promotes consistency when evaluations are done by different reviewers; (3) provides a standard way to convey the rationale and information used to classify chemicals. We applied this approach to more than 50 chemicals distributed among 11 evaluators with varying expertise. Evaluators found the decision trees easy to use and recipients (product stewards) of the analyses found that the resulting documentation was consistent across users and met their regulatory needs. Our approach allows for transparency, process management (e.g., documentation, change management, version control), as well as consistency in chemical hazard assessment for REACH, EC Regulation No. 1272/2008 Classification, Labeling, and Packaging of Substances and the GHS. PMID:22584521

  15. Chemical composition and in vitro antioxidative potential of essential oil isolated from Curcuma longa L. leaves

    Institute of Scientific and Technical Information of China (English)

    R. Priya; A. Prathapan; K.G Raghu; A. Nirmala Menon

    2012-01-01

    Objective: To determine the chemical composition and antioxidant potential of essential oil isolated from the leaves of Curcuma longa (turmeric). Methods: Chemical composition of the oil was analyzed using GC-MS. Antiperoxidative potential was evaluated using linoliec acid emulsion system. Free radical scavenging activity was evaluated using stable DPPH and ABTS free radicals. Results: GC-MS analyses showed that major compound present in the turmeric leaf oil is b-sesquiphellandrene (22.8%) followed by terpinolene (9.5%). Essential oil also exhibited reductive potential and antioxidant potential in linoleic acid emulsion system along with DPPH and ABTS free radical scavenging potential. Conclusions: The overall result suggests that turmeric leaf oil is capable of retarding oxidation reaction and free radical mediated damage and can be developed as a potent natural antioxidant.

  16. Magnon spin transport driven by the magnon chemical potential in a magnetic insulator

    Science.gov (United States)

    Cornelissen, L. J.; Peters, K. J. H.; Bauer, G. E. W.; Duine, R. A.; van Wees, B. J.

    2016-07-01

    We develop a linear-response transport theory of diffusive spin and heat transport by magnons in magnetic insulators with metallic contacts. The magnons are described by a position-dependent temperature and chemical potential that are governed by diffusion equations with characteristic relaxation lengths. Proceeding from a linearized Boltzmann equation, we derive expressions for length scales and transport coefficients. For yttrium iron garnet (YIG) at room temperature we find that long-range transport is dominated by the magnon chemical potential. We compare the model's results with recent experiments on YIG with Pt contacts [L. J. Cornelissen et al., Nat. Phys. 11, 1022 (2015), 10.1038/nphys3465] and extract a magnon spin conductivity of σm=5 ×105 S/m. Our results for the spin Seebeck coefficient in YIG agree with published experiments. We conclude that the magnon chemical potential is an essential ingredient for energy and spin transport in magnetic insulators.

  17. On Extraction of Chemical Potentials of Quarks from Particle Transverse Momentum Spectra in High Energy Collisions

    Directory of Open Access Journals (Sweden)

    Hong Zhao

    2015-01-01

    Full Text Available We present two methods to extract the chemical potentials of quarks in high energy collisions. The first method is based on the ratios of negatively/positively charged particles, and the temperatures extracted from the transverse momentum spectra of related hadrons are needed. The second method is based on the chemical potentials of some particles, and we also need the transverse momentum spectra of related hadrons. To extract the quark chemical potentials, we would like to propose experimental collaborations to measure simultaneously not only the transverse momentum spectra of p-, p, K-, K+, π-, and π+, but also those of D-, D+, B-, and B+ (even those of Δ++, Δ-, and Ω- in high energy nuclear collisions.

  18. On Extraction of Chemical Potentials of Quarks from Particle Transverse Momentum Spectra in High Energy Collisions

    CERN Document Server

    Zhao, Hong

    2015-01-01

    We present two methods to extract the chemical potentials of quarks in high energy collisions. The first method is based on the ratios of negatively/positively charged particles, and the temperatures extracted from the transverse momentum spectra of related hadrons are needed. The second method is based on the chemical potentials of some particles, and we also need the transverse momentum spectra of related hadrons. To extract the quark chemical potentials, we would like to propose experimental collaborations to measure simultaneously not only the transverse momentum spectra of anti-p, p, K^-, K^+, pion^-, and pion^+, but also those of D^-, D^+, B^-, and B^+ (even those of Delta^++, Delta^-, and Omega^-) in high energy nuclear collisions

  19. Chiral condensate at nonzero chemical potential in the microscopic limit of QCD

    International Nuclear Information System (INIS)

    The chiral condensate in QCD at zero temperature does not depend on the quark chemical potential (up to one-third the nucleon mass), whereas the spectral density of the Dirac operator shows a strong dependence on the chemical potential. The cancellations which make this possible also occur on the microscopic scale, where they can be investigated by means of a random matrix model. We show that they can be understood in terms of orthogonality properties of orthogonal polynomials. In the strong non-Hermiticity limit they are related to integrability properties of the spectral density. As a by-product we find exact analytical expressions for the partially quenched chiral condensate in the microscopic domain at nonzero chemical potential.

  20. Lattice QCD with chemical potential: Evading the fermion-sign problem

    Indian Academy of Sciences (India)

    Sourendu Gupta

    2004-12-01

    Since the turn of the millennium there has been tremendous progress in understanding QCD at finite chemical potential, . Apart from qualitative results obtained using models, and exact results at very large obtained in weak coupling theory, there has been tremendous progress in getting exact and quantitative results from lattice simulations. I summarize the status of lattice QCD at finite chemical potential – locating the critical end-point in the QCD phase diagram, predicting event-to-event fluctuation rates of conserved quantities, and finding the rate of strangeness production.

  1. Negative-energy spinors and the Fock space of lattice fermions at finite chemical potential

    CERN Document Server

    Mendel, E

    1994-01-01

    Abstract: Recently it was suggested that the problem of species doubling with Kogut-Susskind lattice fermions entails, at finite chemical potential, a confusion of particles with antiparticles. What happens instead is that the familiar correspondence of positive-energy spinors to particles, and of negative-energy spinors to antiparticles, ceases to hold for the Kogut-Susskind time derivative. To show this we highlight the role of the spinorial ``energy'' in the Osterwalder-Schrader reconstruction of the Fock space of non-interacting lattice fermions at zero temperature and nonzero chemical potential. We consider Kogut-Susskind fermions and, for comparison, fermions with an asymmetric one-step time derivative.

  2. The $\\mathbb{C}$P(2) Model at Non-Zero Chemical Potential

    CERN Document Server

    Evans, Wynne; Wiese, Uwe-Jens

    2016-01-01

    Recently the simulation of quantum field theories using man-made physical systems has become realistic. In this publication we present numerical results which support the use of quantum simulation experiments to study quantum field theories at non-zero chemical potential. We have numerically simulated the (1+1)-d $\\mathbb{C}$P(2) model, which shares several interesting features with QCD, namely asymptotic freedom, a dynamically generated mass gap and topological sectors, via dimensional reduction of a (2+1)-d microscopic theory of SU(3) quantum spins. Numerical results for the particle number density as a function of chemical potential are presented.

  3. Quark-Number Susceptibility at Finite Chemical Potential and Zero Temperature

    Institute of Scientific and Technical Information of China (English)

    HE Deng-Ke; JIANG Yu; FENG Hong-Tao; SUN Wei-Min; ZONG Hong-Shi

    2008-01-01

    We give a direct method for calculating the quark-number susceptibility at finite chemical potential and zero temperature.In this approach the quark-number susceptibility is totally determined by G[μ](p)(the dressed quark propagator at finite chemical potential μ).By applying the general result in our previous study[Phys.Rev.C 71(2005)015205,034901,73 (2006) 016004] G[μ](p)is calculated from the model quark propagator proposed by Pagels and Stokar[Phys.Rev.D 20(1979)2947].The full analytic expression of the quark-number susceptibility at finite μ and zero T is obtained.

  4. Shot noise in superconducting wires with a periodic modulation of the chemical potential

    Science.gov (United States)

    Chen, Qiao; Zhao, Hong-Kang; Xu, H. Q.

    2015-04-01

    We investigate the shot noise in superconducting wires under the periodic modulation of the chemical potential. The nonequilibrium Green's function technique is employed, and the formula for current and shot noise is obtained. The coupling between the Majorana bound states at ends of wire can be tuned by the periodic modulation of chemical potential. It is related with the strength A and the phase δ intimately. The current, shot noise and the corresponding Fano factor display oscillation behavior as the strength A increases. In addition, the coupling between Majorana bound states can be suppressed by strong coupling between leads and superconducting wire.

  5. Hot QCD equation of state and quark-gluon plasma-- finite quark chemical potential

    CERN Document Server

    Chandra, Vinod

    2008-01-01

    We explore the relevance of a hot QCD equation of state of $O[g^6\\ln(1/g)]$, which has been obtained\\cite{avrn} for non-vanishing quark-chemical potentials to heavy ion collisions. Employing a method proposed in a recent paper \\cite{chandra1}, we use the EOS to determine a host of thermodynamic quantities, the energy density, specific heat, entropy dnesity, and the temperature dependence of screening lengths, with the behaviour of QGP at RHIC and LHC in mind. We also investigate the sensitivity of these observables to the quark chemical potential.

  6. Nucleation rate of the quark-gluon plasma droplet at finite quark chemical potential

    Indian Academy of Sciences (India)

    D S Gosain; S Somorendro Singh; Agam K Jha

    2012-05-01

    The nucleation rate of quark-gluon plasma (QGP) droplet is computed at finite quark chemical potential. In the course of computing the nucleation rate, the finite size effects of the QGP droplet are taken into account. We consider the phenomenological flow parameter of quarks and gluons, which is dependent on quark chemical potential and we calculate the nucleation rate of the QGP droplet with this parameter. While calculating the nucleation rate, we find that for low values of quark phenomenological parameter $ q$, nucleation rate is negligible and when increases, nucleation rate increases significantly.

  7. A lattice theory for low energy fermions at finite chemical potential

    CERN Document Server

    Chen, J W; Chen, Jiunn-Wei; Kaplan, David B.

    2003-01-01

    We construct a lattice theory describing a system of interacting nonrelativistic spin s=1/2 fermions at finite chemical potential, which does not suffer from a sign problem. The theory is applicable whenever the interparticle separation is large compared to the range of the two-body potential. The theory could have applications to realistic atomic Bose-Einstein condensates and dilute neutron gases.

  8. Chemicals from Biomass: A Market Assessment of Bioproducts with Near-Term Potential

    Energy Technology Data Exchange (ETDEWEB)

    Biddy, Mary J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Scarlata, Christopher [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kinchin, Christopher [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-03-23

    Production of chemicals from biomass offers a promising opportunity to reduce U.S. dependence on imported oil, as well as to improve the overall economics and sustainability of an integrated biorefinery. Given the increasing momentum toward the deployment and scale-up of bioproducts, this report strives to: (1) summarize near-term potential opportunities for growth in biomass-derived products; (2) identify the production leaders who are actively scaling up these chemical production routes; (3) review the consumers and market champions who are supporting these efforts; (4) understand the key drivers and challenges to move biomass-derived chemicals to market; and (5) evaluate the impact that scale-up of chemical strategies will have on accelerating the production of biofuels.

  9. Optimal performance of a generalized irreversible four-reservoir isothermal chemical potential transformer

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A new cyclic model of a four-reservoir isothermal chemical potential transformer with irreversible mass transfer, mass leakage and internal dissipation is put forward in this paper. The optimal relation be-tween the coefficient of performance (COP) and the rate of energy pumping of the generalized irre-versible four-reservoir isothermal chemical potential transformer has been derived by using finite-time thermodynamics or thermodynamic optimization. The maximum COP and the corresponding rate of energy pumping, as well as the maximum rate of energy pumping and the corresponding COP, have been obtained. Moreover, the influences of the irreversibility on the optimal performance of the iso-thermal chemical potential transformer have been revealed. It was found that the mass leakage affects the optimal performance both qualitatively and quantitatively, while the internal dissipation affects the optimal performance quantitatively. The results obtained herein can provide some new theoretical guidelines for the optimal design and development of a class of isothermal chemical potential trans-formers, such as mass exchangers, electrochemical, photochemical and solid state devices, fuel pumps, etc.

  10. Optimal performance of a generalized irreversible four-reservoir isothermal chemical potential transformer

    Institute of Scientific and Technical Information of China (English)

    XIA Dan; CHEN LinGen; SUN FengRui

    2008-01-01

    A new cyclic model of a four-reservoir isothermal chemical potential transformer with irreversible mass transfer, mass leakage and internal dissipation is put forward in this paper. The optimal relation between the coefficient of performance (COP) and the rate of energy pumping of the generalized irreversible four-reservoir isothermal chemical potential transformer has been derived by using finite-time thermodynamics or thermodynamic optimization. The maximum COP and the corresponding rate of energy pumping, as well as the maximum rate of energy pumping and the corresponding COP, have been obtained. Moreover, the influences of the irreversibility on the optimal performance of the isothermal chemical potential transformer have been revealed. It was found that the mass leakage affects the optimal performance both qualitatively and quantitatively, while the internal dissipation affects the optimal performance quantitatively. The results obtained herein can provide some new theoretical guidelines for the optimal design and development of a class of isothermal chemical potential transformers, such as mass exchangers, electrochemical, photochemical and solid state devices, fuel pumps, etc.

  11. Electrical chemical potential and the π- - π+ asymmetry in heavy ion collisions

    International Nuclear Information System (INIS)

    We calculate an electrical chemical potential, μe, for hadronic matter produced in relativistic collisions of nuclei with (extremely) large atomic numbers. We find μe -/π+>1) and a difference between positive and negative pion spectra at low transverse momenta. (author). 10 refs., 6 tab

  12. Cosmology with dark energy decaying through its chemical-potential contribution

    CERN Document Server

    Besprosvany, J

    2008-01-01

    The consideration of dark energy's quanta, required also by thermodynamics, introduces its chemical potential into the cosmological equations. Isolating its main contribution, we obtain solutions with dark energy decaying to matter or radiation. When dominant, their energy densities tend asymptotically to a constant ratio, explaining today's dark energy-dark matter coincidence, and in agreement with supernova redshift data.

  13. Chemical Potential Dependence of the Dressed—Quark Propagator from an Effective Quark—Quark Interaction

    Institute of Scientific and Technical Information of China (English)

    ZONGHong-Shi; PINGJia-Lun; 等

    2002-01-01

    We exhibit a method for obtaining the low chemical potential dependence of the dressed quark propagator from the dressed-quark propagator,which provides a means of determining the behavior of the chiral and deconfinement order parameters.A comparison with the results of previous researches is given.

  14. Iso-chemical potential trajectories in the P-T plane for He II

    Science.gov (United States)

    Maytal, B.; Nissen, J. A.; Van Sciver, S. W.

    1990-01-01

    Trajectories of constant chemical potential in the P-T plane serve as an integral formulation of London's equation. The trajectories are useful for analysis and synthesis of fountain effect pump performance. A family of trajectories is generated from available numerical codes.

  15. Influence of Finite Chemical Potential on Critical Boson Mass in QED3

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yun-Qiang; LI Zhen; FENG Hong-Tao

    2007-01-01

    Using the coupled Dyson-Schwinger equation for the fermion propagator at finite chemical potential μ,we investigate the fermion chiral condensate when the gauge boson mass is nonzero in QED3. We show that the chiral symmetry restores when the boson mass is large enough, and the critical boson mass depends little on μ.

  16. Steady-state properties of a finite system driven by a chemical-potential gradient

    DEFF Research Database (Denmark)

    Andersen, Jørgen Vitting; Mouritsen, Ole G.

    1990-01-01

    A two-dimensional lattice-gas model with repulsive interactions periodically infinite in one dimension and finite in the other is driven into a mass-transporting steady state by asymmetric chemical potentials applied at the open edges. By computer-simulation techniques the steady-state current...

  17. Deconfinement transitions of large N QCD with chemical potential at weak and strong coupling

    NARCIS (Netherlands)

    Hollowood, Timothy J.; Myers, Joyce C.

    2012-01-01

    We calculate the deconfinement line of transitions for large N-c QCD at finite temperature and chemical potential in two different regimes: weak coupling in the continuum, and, strong coupling on the lattice, working in the limit where N-f is of order N-c. In the first regime we extend previous weak

  18. The statistical shift of the chemical potential causing anomalous conductivity in hydrogenated microcrystalline silicon

    NARCIS (Netherlands)

    Lof, R.W.; Schropp, R.E.I.

    2010-01-01

    The behavior of the electrical conductivity in hydrogenated microcrystalline silicon (μ c-Si:H) that is frequently observed is explained by considering the statistical shift in the chemical potential as a function of the crystalline fraction (Xc), the dangling bond density (N db), and the doping den

  19. Equal Opportunities Questionnaire

    CERN Multimedia

    2007-01-01

    The initiative to promote Equal Opportunities at CERN started in 1993. The first Equal Opportunities Officer was appointed in 1996 followed by the creation of the Equal Opportunities Advisory Panel in 1998. Initially the concern was mainly the fair treatment of women in the work-place. Today the emphasis has evolved to ensuring that diversity is used to increase creativity and productivity in the work-place. In order to ensure that all aspects of Equal Opportunities and Diversity are covered, CERN’s Equal Opportunities team has prepared a survey to obtain your input. Your answers are confidential and will only be used for generating statistics. The questionnaire is on-line and can be accessed via: https://espace.cern.ch/EOQ. We hope that you will take a few minutes of your time to give your input and would be grateful if you could reply before 15/10/07. For further information about Equal Opportunities at CERN see: http://cern.ch/equal-opportunities The Equal Opportuni...

  20. Equality, Innovation and Diversity.

    Science.gov (United States)

    Smith, Janet

    1999-01-01

    Offers some ideas concerning promotion of gender equality and diversity within European Union-funded programs and activities. Reviews efforts since the 1970s to foster equal access in European schools and universities, examines some principles of innovation and entrepreneurship, and considers stages in diversity policy development. (DB)

  1. Equality and Economy

    Science.gov (United States)

    Brink, Chris

    2012-01-01

    The two big events in higher education during 2010 were the implementation of the Equality Act, and the introduction of a new dispensation on fees and funding. The former is intended to promote equality, the latter is premised on the need for economy. In this article, the author focuses on the effect of the latter on the former. He considers this…

  2. Searching for Equality.

    Science.gov (United States)

    Giese, James; Miller, Barbara

    1987-01-01

    Offers an activity designed to illustrate the historical context of current legal questions relating to equal rights. The activity shows how the definition of equality has been expanded as a result of the continuous hard work of individuals and civil rights groups. (JDH)

  3. Chemical diversity of microbial volatiles and their potential for plant growth and productivity

    Directory of Open Access Journals (Sweden)

    CHIDANANDA NAGAMANGALA KANCHISWAMY

    2015-03-01

    Full Text Available Microbial volatile organic compounds (MVOCs are produced by a wide array of microorganisms ranging from bacteria to fungi. A growing body of evidence indicates that MVOCs are ecofriendly and can be exploited as a cost-effective sustainable strategy for use in agricultural practice as agents that enhance plant growth, productivity and disease resistance. As naturally occurring chemicals, MVOCs have potential as possible alternatives to harmful pesticides, fungicides and bactericides as well as genetic modification. Recent studies performed under open field conditions demonstrate that efficiently adopting MVOCs may contribute to sustainable crop protection and production. We review here the chemical diversity of MVOCs and their potential physiological effects on crops and analyze potential and actual limitations for MVOC use as a sustainable strategy for improving productivity and reducing pesticide use.

  4. Equal Opportunities Questionnaire

    CERN Multimedia

    2007-01-01

    The initiative to promote Equal Opportunities at CERN started in 1993. The first Equal Opportunities Officer was appointed in 1996, which was followed by the creation of the Equal Opportunities Advisory Panel in 1998. Initially the concern was mainly the fair treatment of women in the work-place. Today the emphasis has evolved to ensuring that diversity is used to increase creativity and productivity in the work-place. In order to ensure that all aspects of Equal Opportunities and Diversity are covered, CERN’s Equal Opportunities team has prepared a survey to obtain your input. Your answers are confidential and will only be used for generating statistics. The questionnaire is on-line and can be accessed via: https://espace.cern.ch/EOQ. We hope that you will take a few minutes of your time to give your input and would be grateful if you could reply before 15/10/07. For further information about Equal Opportunities at CERN see: http://cern.ch/equal-opportunities The Equa...

  5. Compression by Noise Equalization

    OpenAIRE

    Jähne, Bernd

    2013-01-01

    For any relation of the noise variance with the gray value, a nonlinear transform h(g) can be applied so that the variance of the transformed signal h is constant. The number of bits required to represent the noise-equalized signal is in good approximation equal to the maximum signal/noise ratio (SNRmax). Thus the noise-equalized signal of any imaging sensor with a full-well capacity of less than 2^16 can be represented by only 8 bit or less with only a slight increase in the overall noise le...

  6. Chemical potential and solid-solid equilibrium of near-spherical Lennard-Jones dumbbell crystal

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sangwon; Kim, Minkyu; Chang, Jaeeon [University of Seoul, Seoul (Korea, Republic of)

    2016-03-15

    We studied the orientational order-disorder transition of crystals made up of near-spherical Lennard-Jones dumbbells, of which reduced bond lengths are 0.225, 0.250 and 0.275. Various techniques of Monte Carlo (MC) simulations are used to calculate the chemical potentials of ordered and disordered crystals, and thereby to predict order disorder phase transition. First, we performed NPT MC simulations to determine crystal structure, equilibrium positions and orientations of the molecules. We then calculated the free energies of the crystals using the expanded ensemble MC simulations combined with the Einstein-molecule method and the thermodynamic integration method. The solid-solid phase equilibrium is determined from the free energy profiles of the individual phases by equating the chemical potential. The predictions of phase transition obtained from the conventional NPT MC simulation and the free energy simulation were in excellent agreement with each other, which confirms the validity of the present method of calculating the chemical potential of crystal. In addition, the Gibbs-Duhem integration was performed to obtain a complete coexistence curve between the two crystal phases. Orientational probability distributions of molecular axes were analyzed to find the characteristic behavior of rotational motion of molecule in the crystal. At sufficiently low temperature, flipping rotation of molecule in the ordered crystal is suppressed. In contrast, the flipping rotation occurs at higher temperature close to the transition while orientationally ordered structure is still maintained. In the free energy calculation, such a unique rotational behavior requires to use a suitable form of external rotational potential with proper symmetry number. The present study demonstrates how one can judiciously choose a correct simulation scheme for the calculation of chemical potentials of molecular crystals.

  7. Chemical Composition of Ethanolic Extracts of Some Wild Mushrooms from Tanzania and Their Medicinal Potentials.

    Science.gov (United States)

    Chelela, Baraka Luca; Chacha, Musa; Matemu, Athanasia

    2016-01-01

    The ethanolic extracts of 5 edible and inedible wild mushrooms collected from the Southern Highlands of Tanzania were characterized by gas chromatography-mass spectrometry. A total of 75 chemical compounds were obtained, mainly fatty acids, carotenoids, alkaloids, phenols, terpernes, steroids, pyranoside, saccharides, and amino acids. Chemical compounds were identified from the ethanolic extract of Russula cellulata, R. kivuensis, Lactarius densifolius, L. gymnocarpoides, and Lactarius sp. In addition, mass spectra of 4 major groups of compounds were also determined. This study confirms the presence of some important bioactive compounds, such as essential fatty acids (oleic and linoleic), amino acids, and carotenoids. The reported chemical profiles give an insight into the use of wild mushrooms as a potential source of bioactive compounds for nutraceuticals and pharmaceuticals. PMID:27649607

  8. Chemical Compounds Toxic to Invertebrates Isolated from Marine Cyanobacteria of Potential Relevance to the Agricultural Industry

    KAUST Repository

    Essack, Magbubah

    2014-10-29

    In spite of advances in invertebrate pest management, the agricultural industry is suffering from impeded pest control exacerbated by global climate changes that have altered rain patterns to favour opportunistic breeding. Thus, novel naturally derived chemical compounds toxic to both terrestrial and aquatic invertebrates are of interest, as potential pesticides. In this regard, marine cyanobacterium-derived metabolites that are toxic to both terrestrial and aquatic invertebrates continue to be a promising, but neglected, source of potential pesticides. A PubMed query combined with hand-curation of the information from retrieved articles allowed for the identification of 36 cyanobacteria-derived chemical compounds experimentally confirmed as being toxic to invertebrates. These compounds are discussed in this review.

  9. Chemical Compounds Toxic to Invertebrates Isolated from Marine Cyanobacteria of Potential Relevance to the Agricultural Industry

    Directory of Open Access Journals (Sweden)

    Magbubah Essack

    2014-10-01

    Full Text Available In spite of advances in invertebrate pest management, the agricultural industry is suffering from impeded pest control exacerbated by global climate changes that have altered rain patterns to favour opportunistic breeding. Thus, novel naturally derived chemical compounds toxic to both terrestrial and aquatic invertebrates are of interest, as potential pesticides. In this regard, marine cyanobacterium-derived metabolites that are toxic to both terrestrial and aquatic invertebrates continue to be a promising, but neglected, source of potential pesticides. A PubMed query combined with hand-curation of the information from retrieved articles allowed for the identification of 36 cyanobacteria-derived chemical compounds experimentally confirmed as being toxic to invertebrates. These compounds are discussed in this review.

  10. Chiral random matrix model at finite chemical potential: Characteristic determinant and edge universality

    Science.gov (United States)

    Liu, Yizhuang; Nowak, Maciej A.; Zahed, Ismail

    2016-08-01

    We derive an exact formula for the stochastic evolution of the characteristic determinant of a class of deformed Wishart matrices following from a chiral random matrix model of QCD at finite chemical potential. In the WKB approximation, the characteristic determinant describes a sharp droplet of eigenvalues that deforms and expands at large stochastic times. Beyond the WKB limit, the edges of the droplet are fuzzy and described by universal edge functions. At the chiral point, the characteristic determinant in the microscopic limit is universal. Remarkably, the physical chiral condensate at finite chemical potential may be extracted from current and quenched lattice Dirac spectra using the universal edge scaling laws, without having to solve the QCD sign problem.

  11. The $N_f= 2$ chiral phase transition from imaginary chemical potential with Wilson Fermions

    CERN Document Server

    Philipsen, Owe

    2015-01-01

    The order of the thermal transition in the chiral limit of QCD with two dynamical flavours of quarks is a long-standing issue. Still, it is not definitely known whether the transition is of first or second order in the continuum limit. Which of the two scenarios is realized has important implications for the QCD phase diagram and the existence of a critical endpoint at finite densities. Settling this issue by simulating at successively decreased pion mass was not conclusive yet. Recently, an alternative approach was proposed, extrapolating the first order phase transition found at imaginary chemical potential to zero chemical potential with known exponents, which are induced by the Roberge-Weiss symmetry. For staggered fermions on $N_t=4$ lattices, this results in a first order transition in the chiral limit. Here we report of $N_t=4$ simulations with Wilson fermions, where the first order region is found to be large.

  12. Use of genotoxicity tests in a TIE to identify chemicals potentially affecting human health

    International Nuclear Information System (INIS)

    Imperial Oil operates a sour gas processing plant in southern Alberta that has, for the past several years, been the focus of considerable public and regulatory concern over perceived contamination of soils and groundwater on a nearby ranch. Elevated concentrations of DOC (∼140 mg/L) have been received in groundwater underlying the plant site. Two process-related chemicals, sulfolane and diisopropanolamine (DIPA), had been previously identified as the primary components of the DOC plume, although the chemicals associated with 30% of the DOC could not be identified. A risk assessment was initiated in 1994 to determine whether off-site migration of sulfolane and DIPA or of other unidentified contaminants poses a risks to human health and/or ecological receptors. One component of the risk assessment included conducting a TIE to help identify the chemical(s) in contaminated groundwater underlying the gas plant that might adversely affect human health. Three endpoints were utilized in the TIE: MicroTox, SOS-Chromotest and the Ames test. MicroTox was used since it exhibited a response to whole groundwater from the site, while the genotoxicity tests were used because DIPA reportedly causes a response in the Ames test and because of the concern over potential human health affects arising from other unidentified contaminants. Results of the TIE indicated that the chemicals causing the toxicity in the groundwater sample were water soluble compounds, with similar characteristics to the process chemicals used at the gas plant and detected at high concentrations in groundwater from the plant site. These results provided additional evidence to help focus the risk assessment on the chemicals sulfolane and diisopropanolamine

  13. Phase Diagram of Wilson and Twisted Mass Fermions at finite isospin chemical potential

    CERN Document Server

    Kieburg, M; Verbaarschot, J J M; Zafeiropoulos, S

    2014-01-01

    Wilson Fermions with untwisted and twisted mass are widely used in lattice simulations. Therefore one important question is whether the twist angle and the lattice spacing affect the phase diagram. We briefly report on the study of the phase diagram of QCD in the parameter space of the degenerate quark masses, isospin chemical potential, lattice spacing, and twist angle by employing chiral perturbation theory. Moreover we calculate the pion masses and their dependence on these four parameters.

  14. Quantum origins of the Iczkowski-Margrave model of chemical potential

    Energy Technology Data Exchange (ETDEWEB)

    Valone, Steven M [Los Alamos National Laboratory

    2010-01-01

    Charge flow in materials is controlled at the atomistic level through some model of the chemical potential, such as the Iczkowski-Margrave (IM) model. This model is built largely on heuristic arguments. Here a model Hamiltonian is constructed at the atomistic level commensurate with the IM model. Essential properties of the model Hamiltonian are presented, including a possible revision of the charge dependence in the IM model. Transitional properties of the model are shown to be central to regulating charge flow.

  15. S-parameter at Non-Zero Temperature and Chemical Potential

    DEFF Research Database (Denmark)

    Søndergaard, Ulrik Ishøj; Sannino, Francesco; Pica, Claudio

    2011-01-01

    a reduction of the S-parameter in the physically relevant region of small external momenta for any non-zero chemical potential and T. In particular, the S-parameter vanishes at small m/T, where m is the mass of the fermions, due to the finite extent of the temporal direction. Our results are directly...... applicable to the determination of the S-parameter via first principle lattice simulations performed with anti-periodic boundary conditions in the temporal direction....

  16. Use of terrestrial field studies in the derivation of bioaccumulation potential of chemicals

    Science.gov (United States)

    van den Brink, Nico W.; Arblaster, Jennifer A.; Bowman, Sarah R.; Conder, Jason M.; Elliott, John E.; Johnson, Mark S.; Muir, Derek C.G.; Natal-da-Luz, Tiago; Rattner, Barnett A.; Sample, Bradley E.; Shore, Richard F.

    2016-01-01

    Field-based studies are an essential component of research addressing the behavior of organic chemicals, and a unique line of evidence that can be used to assess bioaccumulation potential in chemical registration programs and aid in development of associated laboratory and modeling efforts. To aid scientific and regulatory discourse on the application of terrestrial field data in this manner, this article provides practical recommendations regarding the generation and interpretation of terrestrial field data. Currently, biota-to-soil-accumulation factors (BSAFs), biomagnification factors (BMFs), and bioaccumulation factors (BAFs) are the most suitable bioaccumulation metrics that are applicable to bioaccumulation assessment evaluations and able to be generated from terrestrial field studies with relatively low uncertainty. Biomagnification factors calculated from field-collected samples of terrestrial carnivores and their prey appear to be particularly robust indicators of bioaccumulation potential. The use of stable isotope ratios for quantification of trophic relationships in terrestrial ecosystems needs to be further developed to resolve uncertainties associated with the calculation of terrestrial trophic magnification factors (TMFs). Sampling efforts for terrestrial field studies should strive for efficiency, and advice on optimization of study sample sizes, practical considerations for obtaining samples, selection of tissues for analysis, and data interpretation is provided. Although there is still much to be learned regarding terrestrial bioaccumulation, these recommendations provide some initial guidance to the present application of terrestrial field data as a line of evidence in the assessment of chemical bioaccumulation potential and a resource to inform laboratory and modeling efforts.

  17. Evaluation of bacterial aerotaxis for its potential use in detecting the toxicity of chemicals to microorganisms.

    Science.gov (United States)

    Shitashiro, Maiko; Kato, Junichi; Fukumura, Tsuyoshi; Kuroda, Akio; Ikeda, Tsukasa; Takiguchi, Noboru; Ohtake, Hisao

    2003-02-27

    Bacterial aerotaxis (the movement of a cell toward oxygen) was evaluated for its potential use in detecting the toxicity of chemicals to microorganisms. The level of toxicity was determined by the concentration of test chemicals resulting in a 50% inhibition of aerotaxis of Pseudomonas aeruginosa PAO1 after 40 min of exposure. The aerotactic responses of P. aeruginosa were measured by using chemotaxis well chambers. Each clear acrylic chamber had a lower and upper well separated by a polycarbonate filter with a uniform pore size of 8.0 microm. To automatically detect bacterial cells that crossed the filter in response to a gradient of oxygen, P. aeruginosa PAO1 was marked with green fluorescent protein (GFP), and the GFP fluorescence intensity in the upper well was continuously monitored by using a fluorescence spectrometer. By using this technique, volatile chlorinated aliphatic compounds, including trichloroethylene (TCE), trichloroethane, and tetrachloroethylene, were found to be inhibitory to bacterial aerotaxis, suggesting their possible toxicity to microorganisms. We also examined more than 20 potential toxicants for their ability to inhibit the aerotaxis of P. aeruginosa. Based on these experimental results, we concluded that bacterial aerotaxis has potential for use as a fast and reliable indicator in assessing the toxicity of chemicals to microorganisms.

  18. Thermodynamics of Large N Gauge Theories with Chemical Potentials in a 1/D Expansion

    CERN Document Server

    Morita, Takeshi

    2010-01-01

    In order to understand thermodynamical properties of N D-branes with chemical potentials associated with R-symmetry charges, we study a one dimensional large N gauge theory (bosonic BFSS type model) as a first step. This model is obtained through a dimensional reduction of a 1+D dimensional SU(N) Yang-Mills theory and we use a 1/D expansion to investigate the phase structure. We find three phases in the \\mu-T plane. We also show that all the adjoint scalars condense at large D and obtain a mass dynamically. This dynamical mass protects our model from the usual perturbative instability of massless scalars in a non-zero chemical potential. We find that the system is at least meta-stable for arbitrary large values of the chemical potentials in D \\to \\infty limit. We also explore the existence of similar condensation in higher dimensional gauge theories in a high temperature limit. In 2 and 3 dimensions, the condensation always happens as in one dimensional case. On the other hand, if the dimension is higher than...

  19. Chemical Potential Tuning and Enhancement of Thermoelectric Properties in Indium Selenides

    Directory of Open Access Journals (Sweden)

    Jong-Soo Rhyee

    2015-03-01

    Full Text Available Researchers have long been searching for the materials to enhance thermoelectric performance in terms of nano scale approach in order to realize phonon-glass-electron-crystal and quantum confinement effects. Peierls distortion can be a pathway to enhance thermoelectric figure-of-merit ZT by employing natural nano-wire-like electronic and thermal transport. The phonon-softening known as Kohn anomaly, and Peierls lattice distortion decrease phonon energy and increase phonon scattering, respectively, and, as a result, they lower thermal conductivity. The quasi-one-dimensional electrical transport from anisotropic band structure ensures high Seebeck coefficient in Indium Selenide. The routes for high ZT materials development of In4Se3−δ are discussed from quasi-one-dimensional property and electronic band structure calculation to materials synthesis, crystal growth, and their thermoelectric properties investigations. The thermoelectric properties of In4Se3−δ can be enhanced by electron doping, as suggested from the Boltzmann transport calculation. Regarding the enhancement of chemical potential, the chlorine doped In4Se3−δCl0.03 compound exhibits high ZT over a wide temperature range and shows state-of-the-art thermoelectric performance of ZT = 1.53 at 450 °C as an n-type material. It was proven that multiple elements doping can enhance chemical potential further. Here, we discuss the recent progress on the enhancement of thermoelectric properties in Indium Selenides by increasing chemical potential.

  20. Evaluating fiscal equalization in Indonesia

    OpenAIRE

    Hofman, Bert; Kadjatmiko; Kaiser, Kai; Suharnoko Sjahrir, Bambang

    2006-01-01

    This paper presents a methodology to evaluate fiscal decentralization focusing on the potential mis-targeting of intergovernmental fiscal equalization transfers. The approach builds on an explicit comparison and the summary measurement of different (horizontal) allocation distributions across states or localities. Whereas formula-based fiscal transfers have the merit of being transparent and promoting revenue predictability in fiscal decentralization, in practice, two challenges emerge: (1) W...

  1. 等电位间隔电位滴定法测定葡萄酒中游离二氧化硫%Determination of free sulfur dioxide in wine by the equal potential interval potentiometric titration

    Institute of Scientific and Technical Information of China (English)

    冯俊贤; 李家栋; 孙晓丽; 苏洪茹; 刘元昀

    2013-01-01

    目的:建立等电位间隔电位滴定法测定葡萄酒中游离SO2的方法.方法:采用间接碘量滴定,以等电位间隔法识别滴定终点.结果:方法RSD≤0.5%,游离二氧化硫回收率在94.50% ~ 103.7%,与自动电位滴定法比较,相对误差小于1.0%.结论:间接碘量法无需碘标准溶液,等电位间隔电位滴定法识别滴定终点准确可靠,重现性好,适合葡萄酒中游离二氧化硫含量的测定.%Objective:To establish a method for determination of free sulfur dioxide in wine by the equal potential interval potentiometric titration. Methods: According to indirect iodimetry, the end - point of titration could be judged with the equal potential interval potentiometric titration. Results: The RSD was 0.3% ~0.5% , the recovery rate for free sulfur dioxide was 94. 50% ~ 103. 7%. Compared with automatic potentiometric titration, the relative deviation for free sulfur dioxide was less than 1.0%. Conclusion: The indirect iodimetry is simple, accurate without iodine standard solution. The equal potential interval potentiometric titration is accurate, reliable with good repeatability. It is suitable for determination of free sulfur dioxid in wine.

  2. Equalization equations in reactant resolution

    Indian Academy of Sciences (India)

    Jacek Korchowiec

    2005-09-01

    The chemical system can be analyzed in different resolutions. The assumed resolution imposes a given partitioning of the system in physical or functional space. The most frequently explored are global, reactant, atoms-in-molecule, orbital, and local resolutions. In this paper we have considered reactant resolution, i.e., the mutually polarized reactants before the charge-transfer among them. We have demonstrated that a certain type of generalized sensitivity, the system responses to the population variables, is equalized throughout the space up to the infinite order in the perturbation expansion.

  3. Properties of baryonic, electric and strangeness chemical potentials and some of their consequences in relativistic heavy ion collisions

    CERN Document Server

    Mekjian, Aram Z

    2007-01-01

    Analytic expressions are given for the baryonic, electric and strangeness chemical potentials which explicitly show the importance of various terms. Simple scaling relations connecting these chemical potentials are found. Applications to particle ratios and to fluctuations and related thermal properties such as the isothermal compressibility kappaT are illustrated. A possible divergence of kappaT is discussed.

  4. Development and validation of animal-free test methods to predict the skin sensitizing potential of chemicals

    OpenAIRE

    Bauch, Caroline D.

    2013-01-01

    Skin sensitization is the development of the allergic contact dermatitis caused by chemicals. Regulatory accepted methods to assess skin sensitizing potential of chemicals are animal based tests, but increasing interest in animal welfare presses the development of animal-free methods. The aim of this work was the development, establishment and validation of several alternative methods to animal testing to predict the skin sensitizing potential of chemicals. Therefore several methods reflectin...

  5. Transhumanism and moral equality.

    Science.gov (United States)

    Wilson, James

    2007-10-01

    Conservative thinkers such as Francis Fukuyama have produced a battery of objections to the transhumanist project of fundamentally enhancing human capacities. This article examines one of these objections, namely that by allowing some to greatly extend their capacities, we will undermine the fundamental moral equality of human beings. I argue that this objection is groundless: once we understand the basis for human equality, it is clear that anyone who now has sufficient capacities to count as a person from the moral point of view will continue to count as one even if others are fundamentally enhanced; and it is mistaken to think that a creature which had even far greater capacities than an unenhanced human being should count as more than an equal from the moral point of view.

  6. Potential Challenges Faced by the U.S. Chemicals Industry under a Carbon Policy

    Directory of Open Access Journals (Sweden)

    Andrea Bassi

    2009-09-01

    Full Text Available Chemicals have become the backbone of manufacturing within industrialized economies. Being energy-intensive materials to produce, this sector is threatened by policies aimed at combating and adapting to climate change. This study examines the worst-case scenario for the U.S. chemicals industry when a medium CO2 price policy is employed. After examining possible industry responses, the study goes on to identify and provide a preliminary evaluation of potential opportunities to mitigate these impacts. If climate regulations are applied only in the United States, and no action is taken to invest in advanced low- and no-carbon technologies to mitigate the impacts of rising energy costs, the examination shows that climate policies that put a price on carbon could have substantial impacts on the competiveness of the U.S. chemicals industry over the next two decades. In the long run, there exist technologies that are available to enable the chemicals sector to achieve sufficient efficiency gains to offset and manage the additional energy costs arising from a climate policy.

  7. Chemical production from waste carbon monoxide: its potential for energy conservation

    Energy Technology Data Exchange (ETDEWEB)

    Rohrmann, C.A.; Schiefelbein, G.F.; Molton, P.M.; Li, C.T.; Elliott, D.C.; Baker, E.G.

    1977-11-01

    Results of a study of the potential for energy conservation by producing chemicals from by-product or waste carbon monoxide (CO) from industrial sources are summarized. Extensive compilations of both industrial sources and uses for carbon monoxide were developed and included. Reviews of carbon monoxide purification and concentration technology and preliminary economic evaluations of carbon monoxide concentration, pipeline transportation and utilization of CO in the synthesis of ammonia and methanol are included. Preliminary technical and economic feasibility studies were made of producing ammonia and methanol from the by-product CO produced by a typical elemental phosphorus plant. Methanol synthesis appears to be more attractive than ammonia synthesis when using CO feedstock because of reduced water gas shift and carbon dioxide removal requirements. The economic studies indicate that methanol synthesis from CO appears to be competitive with conventional technology when the price of natural gas exceeds $0.82/million Btu, while ammonia synthesis from CO is probably not competitive until the price of natural gas exceeds $1.90/million Btu. It is concluded that there appears to be considerable potential for energy conservation in the chemical industry, by collecting CO rather than flaring it, and using it to make major chemicals such as ammonia and methanol.

  8. CO{sub 2} emissions and reduction potential in China's chemical industry

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Bing [Department of Chemical Engineering, Tsinghua University, Beijing 100084 (China); International Institute for Applied Systems Analysis, Schlossplatz 1, A-2361 Laxenburg (Austria); Zhou, Wenji; Hu, Shanying; Li, Qiang; Jin, Yong [Department of Chemical Engineering, Tsinghua University, Beijing 100084 (China); Griffy-Brown, Charla [Graziadio School of Business, Pepperdine University, Los Angeles, CA 90045 (United States)

    2010-12-15

    GHG (Increasing greenhouse gas) emissions in China imposes enormous pressure on China's government and society. The increasing GHG trend is primarily driven by the fast expansion of high energy-intensive sectors including the chemical industry. This study investigates energy consumption and CO{sub 2} emissions in the processes of chemical production in China through calculating the amounts of CO{sub 2} emissions and estimating the reduction potential in the near future. The research is based on a two-level perspective which treats the entire industry as Level one and six key sub-sectors as Level two, including coal-based ammonia, calcium carbide, caustic soda, coal-based methanol, sodium carbonate, and yellow phosphorus. These two levels are used in order to address the complexity caused by the fact that there are more than 40 thousand chemical products in this industry and the performance levels of the technologies employed are extremely uneven. Three scenarios with different technological improvements are defined to estimate the emissions of the six sub-sectors and analyze the implied reduction potential in the near future. The results highlight the pivotal role that regulation and policy administration could play in controlling the CO{sub 2} emissions by promoting average technology performances in this industry. (author)

  9. Potential role of redox cycling as a mechanism for chemical teratogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Juchau, M.R.; Fantel, A.G.; Harris, C.; Beyer, B.K.

    1986-12-01

    A survey of the literature indicates that several chemicals whose reduced metabolites are capable of undergoing redox cycling in biological systems also possess significant teratogenic properties when tested in vivo. The authors have initiated investigations to determine whether the embryotoxic effects of such chemicals could result from their redox cycling properties and whether redox cycling could be an important mechanism in chemical teratogenesis. In order to obviate the potentially confounding influences of maternal factors, the initial studies have been performed with a whole embryo culture system with redox cycling agents added directly to the culture medium. Several representative redox cycling agents including doxorubicin, paraquat, a series of nitroheterocycles, nitrosofluorene, and diethylstilbestrol (converted metabolically to redox cycling quinone/semiquinone radicals) have been investigated thus far. The nitroheterocycles which bear nitro groups with comparatively high redox potentials produced a striking, asymmetric defect involving primarily the right half of the prosencephalic and mesencephalic regions. The effect was exacerbated under conditions of low O/sub 2/ tension. Accumulated data to date strongly suggest that reduction of the nitro group is an essential feature in the embryotoxic mechanism. Quinones (doxorubicin, paraquat) and compounds metabolically converted to quinones (diethylstilbestrol) appeared to produce embryotoxic effects via mechanisms not associated with redox cycling. Nitrosofluorene embryotoxicity was markedly exacerbated by changes in both intra- and extracellular glutathione levels, but definitive dependence on a radical-mediated effect or redox cycling was not demonstrated.

  10. Energy prices, equalization and federalism

    International Nuclear Information System (INIS)

    A rise in oil prices over the last 30 years has shaped the debate on the equalization formula as well as the nature of fiscal federalism. The oil shocks of 1973 and 1979 contributed to the creation of the National Energy Program (NEP) in 1980 and the Energy Pricing and Taxation Agreement (EPTA) between Ottawa and Alberta in 1981. The current surge in oil prices, to recent highs of $70 a barrel has resulted in a new debate on energy pricing, equalization and fiscal frameworks. This article presented a review of the history of oil and federalism, and proposed a remedy to the horizontal fiscal imbalance by allocating the fixed equalization pool in accordance with fiscal capacity disparities relating to non-resource revenues. An interprovincial revenue-sharing pool was suggested for resource revenues, agreed to and operated by the provinces. It was suggested that after the price spike in 1973 in which the price of oil tripled, a key part of the rationale for imposing export taxes on oil equal to the difference between domestic and world prices was that the federal government could subsidize oil imports into eastern Canada and maintain a uniform domestic price across the country. By continuing to subsidize imports and maintaining a domestic price below the world price, the government has been diverting potential energy revenues from energy-rich provinces and transferring them directly to Canadians in terms of subsidized energy prices. It was noted that energy price surges cannot send equalization payments soaring as they did before because of the 2004 Framework Agreement, in which the overall equalization will be increased to $10.9 billion. A 2-tier approach to equalization was presented, in which it was suggested that the $10.9 billion pool should be allocated with fiscal capacity disparities relating to non-resource revenues. The creation of a revenue sharing pool for resource revenues was recommended. It was suggested that the 2 approaches will result in a strategic

  11. Structure and stability of pyrophyllite edge surfaces: Effect of temperature and water chemical potential

    Science.gov (United States)

    Kwon, Kideok D.; Newton, Aric G.

    2016-10-01

    The surfaces of clay minerals, which are abundant in atmospheric mineral dust, serve as an important medium to catalyze ice nucleation. The lateral edge surface of 2:1 clay minerals is postulated to be a potential site for ice nucleation. However, experimental investigations of the edge surface structure itself have been limited compared to the basal planes of clay minerals. Density functional theory (DFT) computational studies have provided insights into the pyrophyllite edge surface. Pyrophyllite is an ideal surrogate mineral for the edge surfaces of 2:1 clay minerals as it possesses no or little structural charge. Of the two most-common hydrated edge surfaces, the AC edge, (1 1 0) surface in the monoclinic polytype notation, is predicted to be more stable than the B edge, (0 1 0) surface. These stabilities, however, were determined based on the total energies calculated at 0 K and did not consider environmental effects such as temperature and humidity. In this study, atomistic thermodynamics based on periodic DFT electronic calculations was applied to examine the effects of environmental variables on the structure and thermodynamic stability of the common edge surfaces in equilibrium with bulk pyrophyllite and water vapor. We demonstrate that the temperature-dependent vibrational energy of sorbed water molecules at the edge surface is a significant component of the surface free energy and cannot be neglected when determining the surface stability of pyrophyllite. The surface free energies were calculated as a function of temperature from 240 to 600 K and water chemical potential corresponding to conditions from ultrahigh vacuum to the saturation vapor pressure of water. We show that at lower water chemical potentials (dry conditions), the AC and B edge surfaces possessed similar stabilities; at higher chemical potentials (humid conditions) the AC edge surface was more stable than the B edge surface. At high temperatures, both surfaces showed similar stabilities

  12. Heat and Moisture Transport in Unsaturated Porous Media -- A Coupled Model in Terms of Chemical Potential

    CERN Document Server

    Sullivan, Eric

    2013-01-01

    Transport phenomena in porous media are commonplace in our daily lives. Examples and applications include heat and moisture transport in soils, baking and drying of food stuffs, curing of cement, and evaporation of fuels in wild fires. Of particular interest to this study are heat and moisture transport in unsaturated soils. Historically, mathematical models for these processes are derived by coupling classical Darcy's, Fourier's, and Fick's laws with volume averaged conservation of mass and energy and empirically based source and sink terms. Recent experimental and mathematical research has proposed modifications and suggested limitations in these classical equations. The primary goal of this thesis is to derive a thermodynamically consistent system of equations for heat and moisture transport in terms of the chemical potential that addresses some of these limitations. The physical processes of interest are primarily diffusive in nature and, for that reason, we focus on using the macroscale chemical potentia...

  13. Financing for Gender Equality

    OpenAIRE

    Kim, Jim Yong

    2015-01-01

    Remarks delivered by Jim Yong Kim, President of the World Bank Group. The Third International Conference on Financing for Development represents an important milestone in efforts to achieve universal and sustainable development as we move beyond 2015 and introduce a new set of Sustainable Development Goals. This event aims to mobilize high-level political support for financing gender equality and women’s...

  14. Measuring the Chemical Potential of the Martian Regolith to Generate and Sustain Life

    Science.gov (United States)

    Kounaves, S. P.; Buehler, M. G.; Kuhlman, K. R.

    1999-01-01

    A critical component for identifying chemical biosignatures is the ability to assess in-situ the potential of an aqueous geochemical environment to generate and sustain life. On Mars or other solar bodies, in-situ chemical characterization could provide evidence as to whether the chemical composition of the regolith or evaporites in suspected ancient water bodies have been biologically influenced or possess the chemical parameters within which life may have existed, or may still exist. A variety of analytical techniques have been proposed for use in detecting and identify signatures of past or present life. These techniques fall into two groups; visual observation with instruments such as cameras or optical/atomic-force microscopes; or elemental chemical analysis with such instruments as X-ray fluorescence (XRF) and diffraction (XRD), a-proton backscatter (APX), y-ray, Mossbauer, Raman, IR, UV/VIS spectroscopies, gas chromatography (GC), or mass spectrometry (MS). Direct observation of an identifiable lifeform by the first set of instruments in a single sample is highly unlikely, especially for extinct organisms or on the surface. The later instruments can provide vital data as to the elemental mineralogy and geological history of the planet, but are highly inadequate for understanding the chemistry of the planet in terms of indigenous life or interactions with human explorers. Techniques such as XRD, XRF, and APX, provide elemental composition at high limits of detection. Some of this data can be extrapolated or interpolated to provide chemical parameters such as oxidation state or composition. Gas chromatography (GC) without standards and non-specific detectors, has little chance of identifying a mixture of unknown components. Combined with GC or by itself, mass spectrometry (MS) can provide identification of compounds, but in both cases the sample must be appropriately prepared for accurate and reliable analysis. Life as we know it, and probably identify it as

  15. Chemical analyses of wasp-associated streptomyces bacteria reveal a prolific potential for natural products discovery.

    Directory of Open Access Journals (Sweden)

    Michael Poulsen

    Full Text Available Identifying new sources for small molecule discovery is necessary to help mitigate the continuous emergence of antibiotic-resistance in pathogenic microbes. Recent studies indicate that one potentially rich source of novel natural products is Actinobacterial symbionts associated with social and solitary Hymenoptera. Here we test this possibility by examining two species of solitary mud dauber wasps, Sceliphron caementarium and Chalybion californicum. We performed enrichment isolations from 33 wasps and obtained more than 200 isolates of Streptomyces Actinobacteria. Chemical analyses of 15 of these isolates identified 11 distinct and structurally diverse secondary metabolites, including a novel polyunsaturated and polyoxygenated macrocyclic lactam, which we name sceliphrolactam. By pairing the 15 Streptomyces strains against a collection of fungi and bacteria, we document their antifungal and antibacterial activity. The prevalence and anti-microbial properties of Actinobacteria associated with these two solitary wasp species suggest the potential role of these Streptomyces as antibiotic-producing symbionts, potentially helping defend their wasp hosts from pathogenic microbes. Finding phylogenetically diverse and chemically prolific Actinobacteria from solitary wasps suggests that insect-associated Actinobacteria can provide a valuable source of novel natural products of pharmaceutical interest.

  16. Local chemical potentials and pressures in heterogeneous systems: Adsorptive, absorptive, interfaces

    Science.gov (United States)

    Tovbin, Yu. K.

    2016-07-01

    Equations self-consistently describing chemical and mechanical equilibria in heterogeneous systems are derived. The equations are based on the lattice gas model using discrete distributions of molecules in space (on a scale comparable to molecular size) and continuum distributions of molecules (at short distances inside the cells) during their translational and vibrational motions. It is shown that the theory provides a unified description of the equilibrium distributions of molecules in three aggregate states and at their interfaces. Potential functions of intermolecular interactions (such as Mie pair potentials) in several coordination spheres that determine the compressibility of the lattice structure are considered. For simplicity, it is assumed that differences between the sizes of mixture components are small. Expressions for the local components of the pressure tensor inside multicomponent solid phases and heterogeneous systems (adsorptive, absorptive, and interfaces) are obtained. It is established that they can be used to calculate the lattice parameters of deforming phases and the thermodynamic characteristics of interfaces, including surface tension. The tensor nature of the chemical potential in heterogeneous systems is discussed.

  17. A local chemical potential approach within the variable charge method formalism

    Science.gov (United States)

    Elsener, A.; Politano, O.; Derlet, P. M.; Van Swygenhoven, H.

    2008-03-01

    A new and computationally efficient implementation of the variable charge method of Streitz and Mintmire (1994 Phys. Rev. B 50 11996) is presented. In particular a local chemical potential approach that optimizes the charge on only those atoms expected to be ionic is developed. By doing so, the charge fluctuation problem experienced in regions far from any oxygen is solved, leading to a linear minimization problem of the electrostatic energy. In the dilute oxygen limit, such an approach can lead to at least an order of magnitude saving in computation.

  18. Computed Potential Energy Surfaces and Minimum Energy Pathway for Chemical Reactions

    Science.gov (United States)

    Walch, Stephen P.; Langhoff, S. R. (Technical Monitor)

    1994-01-01

    Computed potential energy surfaces are often required for computation of such observables as rate constants as a function of temperature, product branching ratios, and other detailed properties. We have found that computation of the stationary points/reaction pathways using CASSCF/derivative methods, followed by use of the internally contracted CI method with the Dunning correlation consistent basis sets to obtain accurate energetics, gives useful results for a number of chemically important systems. Applications to complex reactions leading to NO and soot formation in hydrocarbon combustion are discussed.

  19. Chemical Potential and the Nature of the Dark Energy: The case of phantom

    CERN Document Server

    Lima, J A S

    2008-01-01

    The influence of a possible non zero chemical potential $\\mu$ on the nature of dark energy is investigated by assuming that the dark energy is a relativistic perfect simple fluid obeying the equation of state (EoS), $p=\\omega \\rho$ ($\\omega 0$, the $\\omega$-parameter must be greater than -1 (vacuum is forbidden) while for $\\mu 0$ are permmited only if $-1 < \\omega < -1/2$. The thermodynamics and statistical arguments constrain the EoS parameter to be $\\omega < -1/2$, a result surprisingly close to the maximal value required to accelerate a FRW type universe dominated by matter and dark energy ($\\omega \\lesssim -10/21$).

  20. Phase structure of two-flavor QCD at finite chemical potential.

    Science.gov (United States)

    Braun, Jens; Haas, Lisa M; Marhauser, Florian; Pawlowski, Jan M

    2011-01-14

    We study the phase diagram of two-flavor QCD at imaginary chemical potentials in the chiral limit. To this end we compute order parameters for chiral symmetry breaking and quark confinement. The interrelation of quark confinement and chiral symmetry breaking is analyzed with a new order parameter for the confinement phase transition. We show that it is directly related to both the quark density as well as the Polyakov loop expectation value. Our analytical and numerical results suggest a close relation between the chiral and the confinement phase transition. PMID:21405221

  1. A density functional theory-based chemical potential equalisation approach to molecular polarizability

    Indian Academy of Sciences (India)

    Amita Wadehra; Swapan K Ghosh

    2005-09-01

    The electron density changes in molecular systems in the presence of external electric fields are modeled for simplicity in terms of the induced charges and dipole moments at the individual atomic sites. A chemical potential equalisation scheme is proposed for the calculation of these quantities and hence the dipole polarizability within the framework of density functional theory based linear response theory. The resulting polarizability is expressed in terms of the contributions from individual atoms in the molecule. A few illustrative numerical calculations are shown to predict the molecular polarizabilities in good agreement with available results. The usefulness of the approach to the calculation of intermolecular interaction needed for computer simulation is highlighted.

  2. Probing the nature of phases across the phase transition at finite isospin chemical potential

    CERN Document Server

    Bali, Gunnar S; Gavai, Rajiv V; Mathur, N

    2016-01-01

    We compare the low eigenvalue spectra of the Overlap Dirac operator on two sets of configurations at $\\mu_I/\\mu_I^c$ = 0.5 and 1.5 generated with dynamical staggered fermions at these isospin chemical potential on $24^3 \\times 6$ lattices. We find very small changes in the number of zero modes and low lying modes which is in stark contrast with those across the corresponding finite temperature phases where one sees a drop across the phase transition. Possible consequences are discussed.

  3. Spatial Distribution of Oxygen Chemical Potential under Potential Gradients and Theoretical Maximum Power Density with 8YSZ Electrolyte

    Science.gov (United States)

    Lim, Dae-Kwang; Im, Ha-Ni; Song, Sun-Ju

    2016-01-01

    The maximum power density of SOFC with 8YSZ electrolyte as the function of thickness was calculated by integrating partial conductivities of charge carriers under various DC bias conditions at a fixed oxygen chemical potential gradient at both sides of the electrolyte. The partial conductivities were successfully taken using the Hebb-Wagner polarization method as a function of temperature and oxygen partial pressure, and the spatial distribution of oxygen partial pressure across the electrolyte was calculated based on Choudhury and Patterson’s model by considering zero electrode polarization. At positive voltage conditions corresponding to SOFC and SOEC, the high conductivity region was expanded, but at negative cell voltage condition, the low conductivity region near n-type to p-type transition was expanded. In addition, the maximum power density calculated from the current-voltage characteristic showed approximately 5.76 W/cm2 at 700 oC with 10 μm thick-8YSZ, while the oxygen partial pressure of the cathode and anode sides maintained ≈0.21 and 10-22 atm.

  4. Kaempferitrin from Uncaria guianensis (Rubiaceae) and its potential as a chemical marker for the species

    Energy Technology Data Exchange (ETDEWEB)

    Valente, Ligia M.M.; Liechocki, Sally; Barboza, Rodolfo S.; Paixao, Djavan da [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica], e-mail: valente@iq.ufrj.br; Bizarri, Carlos H.B.; Almeida, M. Beatriz S.; Benevides, Paulo J.C.; Siani, Antonio C. [Fundacao Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). Inst. de Tecnologia em Farmacos; Magalhaes, Alvicler [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Quimica

    2009-07-01

    Uncaria tomentosa (Willd.) DC. and U. guianensis (Aubl.) Gmel., known as cat's claw, are large woody vines native to the Amazonian and Central American rain forests. The species contain, in different proportions, indole and oxindole alkaloids, triterpenoid glycosides, sterols and proanthocyanidins. U. tomentosa can be chemically identified by its oxindole alkaloid profile and content, whereas U. guianensis has no satisfactorily established chemical markers. This work describes, for the first time, the isolation of kaempferol-3,7-O-(a)-dirhamnoside (kaempferitrin) in Uncaria species. Screening for this compound in leaves, stems or bark of both species through TLC and HPLC-DAD-MS showed the presence of kaempferitrin only in the leaves and stems of U. guianensis, at a ratio almost thirty six times greater in the leaves than in the stems. These results reveal the selectivity of U. guianensis to produce this bioactive flavonoid glycoside, and suggest this compound as a potential chemical marker for the species.(author)

  5. Assessing the Equalization Potential of Education.

    Science.gov (United States)

    Levin, Henry M.

    The human capital concept of neoclassical economics holds that increased education will lead to increased productivity and to higher wages. Job queue and labor market segmentation theories argue that improved education merely drives up employment criteria and that the socioeconomic background of the employee is a more significant indicator of…

  6. The limits of local correlation theory: electronic delocalization and chemically smooth potential energy surfaces.

    Science.gov (United States)

    Subotnik, Joseph E; Sodt, Alex; Head-Gordon, Martin

    2008-01-21

    Local coupled-cluster theory provides an algorithm for measuring electronic correlation quickly, using only the spatial locality of localized electronic orbitals. Previously, we showed [J. Subotnik et al., J. Chem. Phys. 125, 074116 (2006)] that one may construct a local coupled-cluster singles-doubles theory which (i) yields smooth potential energy surfaces and (ii) achieves near linear scaling. That theory selected which orbitals to correlate based only on the distances between the centers of different, localized orbitals, and the approximate potential energy surfaces were characterized as smooth using only visual identification. This paper now extends our previous algorithm in three important ways. First, locality is now based on both the distances between the centers of orbitals as well as the spatial extent of the orbitals. We find that, by accounting for the spatial extent of a delocalized orbital, one can account for electronic correlation in systems with some electronic delocalization using fast correlation methods designed around orbital locality. Second, we now enforce locality on not just the amplitudes (which measure the exact electron-electron correlation), but also on the two-electron integrals themselves (which measure the bare electron-electron interaction). Our conclusion is that we can bump integrals as well as amplitudes, thereby gaining a tremendous increase in speed and paradoxically increasing the accuracy of our LCCSD approach. Third and finally, we now make a rigorous definition of chemical smoothness as requiring that potential energy surfaces not support artificial maxima, minima, or inflection points. By looking at first and second derivatives from finite difference techniques, we demonstrate complete chemical smoothness of our potential energy surfaces (bumping both amplitudes and integrals). These results are significant both from a theoretical and from a computationally practical point of view. PMID:18205484

  7. Dissociative electron transfer in polychlorinated aromatics. Reduction potentials from convolution analysis and quantum chemical calculations.

    Science.gov (United States)

    Romańczyk, Piotr P; Rotko, Grzegorz; Kurek, Stefan S

    2016-08-10

    Formal potentials of the first reduction leading to dechlorination in dimethylformamide were obtained from convolution analysis of voltammetric data and confirmed by quantum chemical calculations for a series of polychlorinated benzenes: hexachlorobenzene (-2.02 V vs. Fc(+)/Fc), pentachloroanisole (-2.14 V), and 2,4-dichlorophenoxy- and 2,4,5-trichlorophenoxyacetic acids (-2.35 V and -2.34 V, respectively). The key parameters required to calculate the reduction potential, electron affinity and/or C-Cl bond dissociation energy, were computed at both DFT-D and CCSD(T)-F12 levels. Comparison of the obtained gas-phase energies and redox potentials with experiment enabled us to verify the relative energetics and the performance of various implicit solvent models. Good agreement with the experiment was achieved for redox potentials computed at the DFT-D level, but only for the stepwise mechanism owing to the error compensation. For the concerted electron transfer/C-Cl bond cleavage process, the application of a high level coupled cluster method is required. Quantum chemical calculations have also demonstrated the significant role of the π*ring and σ*C-Cl orbital mixing. It brings about the stabilisation of the non-planar, C2v-symmetric C6Cl6˙(-) radical anion, explains the experimentally observed low energy barrier and the transfer coefficient close to 0.5 for C6Cl5OCH3 in an electron transfer process followed by immediate C-Cl bond cleavage in solution, and an increase in the probability of dechlorination of di- and trichlorophenoxyacetic acids due to substantial population of the vibrational excited states corresponding to the out-of-plane C-Cl bending at ambient temperatures. PMID:27477334

  8. Dissociative electron transfer in polychlorinated aromatics. Reduction potentials from convolution analysis and quantum chemical calculations.

    Science.gov (United States)

    Romańczyk, Piotr P; Rotko, Grzegorz; Kurek, Stefan S

    2016-08-10

    Formal potentials of the first reduction leading to dechlorination in dimethylformamide were obtained from convolution analysis of voltammetric data and confirmed by quantum chemical calculations for a series of polychlorinated benzenes: hexachlorobenzene (-2.02 V vs. Fc(+)/Fc), pentachloroanisole (-2.14 V), and 2,4-dichlorophenoxy- and 2,4,5-trichlorophenoxyacetic acids (-2.35 V and -2.34 V, respectively). The key parameters required to calculate the reduction potential, electron affinity and/or C-Cl bond dissociation energy, were computed at both DFT-D and CCSD(T)-F12 levels. Comparison of the obtained gas-phase energies and redox potentials with experiment enabled us to verify the relative energetics and the performance of various implicit solvent models. Good agreement with the experiment was achieved for redox potentials computed at the DFT-D level, but only for the stepwise mechanism owing to the error compensation. For the concerted electron transfer/C-Cl bond cleavage process, the application of a high level coupled cluster method is required. Quantum chemical calculations have also demonstrated the significant role of the π*ring and σ*C-Cl orbital mixing. It brings about the stabilisation of the non-planar, C2v-symmetric C6Cl6˙(-) radical anion, explains the experimentally observed low energy barrier and the transfer coefficient close to 0.5 for C6Cl5OCH3 in an electron transfer process followed by immediate C-Cl bond cleavage in solution, and an increase in the probability of dechlorination of di- and trichlorophenoxyacetic acids due to substantial population of the vibrational excited states corresponding to the out-of-plane C-Cl bending at ambient temperatures.

  9. Equal Love Rights

    Institute of Scientific and Technical Information of China (English)

    Zhou; Mingyang

    2015-01-01

    Recently,the LGBT community(including Lesbians,Gays,Bisexuals,Transgenders)has won big.In terms of their marriage rights,on July 2015,the Supreme Court of the United States has passed judegment to recognize same-sex marriage and grant most of their rights,which means one’s marriage with same sex is not only legal from then on,but also equal to that of opposite sex.

  10. Thoughts upon Equality

    Institute of Scientific and Technical Information of China (English)

    申辰瑜

    2015-01-01

    <正>Anyone who has some basic knowledge about The Declaration of Independence might not be unfamiliar with the following lines,"We hold these truths to be self-evident,that all men are created equal,that they are endowed by their Creator with certain unalienable rights,that they are among these are life,liberty and the pursuit of happiness."Those words were truly respectable and encouraging at that time as well as

  11. Equal Opportunities Advisory Panel

    CERN Multimedia

    HR Department

    2006-01-01

    At its meeting on 7 December 2006, the Standing Concertation Committee took note of the appointment of four new members of the Panel: Wisla Carena, Pierre Charrue, Sue Foffano and Markus Nordberg. The present composition of the Panel (appointed ad personam) is as follows: Tiziano Camporesi (Chairperson), Wisla Carena, Pierre Charrue, Sue Foffano, Josi Schinzel (Equal Opportunities Officer), Markus Nordberg, Christine Petit-Jean-Genaz et Elena Wildner. Human Resources Department Tel. 74480

  12. Democracy, Redistribution, and Equality

    Directory of Open Access Journals (Sweden)

    Adam Przeworski

    2012-06-01

    Full Text Available The article argues that economic inequality inevitably generates politicalinequality, which in turn reproduces economic inequality. Basic concepts areintroduced first along with strong caveats concerning the quality of the crossnationaldata on income distributions; historical patterns of income inequalityare summarized next, and with these preliminaries, a distinction is made betweenredistribution of consumption at a particular time and equalization of incomeearning capacities over time. Following this economic considerations, the articlediscussion moves to political factors that may block redistributions.

  13. Screening of heavy quark free energies at finite temperature and non-zero baryon chemical potential

    CERN Document Server

    Döring, M; Kaczmarek, O; Karsch, Frithjof; Laermann, E

    2006-01-01

    We analyze the dependence of heavy quark free energies on the baryon chemical potential (mu_b) in 2-flavour QCD using improved (p4) staggered fermions with a bare quark mass of m/T = 0.4. By performing a 6th order Taylor expansion in the chemical potential which circumvents the sign problem. The Taylor expansion coefficients of colour singlet and colour averaged free energies are calculated and from this the expansion coefficients for the corresponding screening masses are determined. We find that for small mu_b the free energies of a static quark anti-quark pair decrease in a medium with a net excess of quarks and that screening is well described by a screening mass which increases with increasing mu_b. The mu_b-dependent corrections to the screening masses are well described by perturbation theory for T > 2 T_c. In particular, we find for all temperatures above T_c that the expansion coefficients for singlet and colour averaged screening masses differ by a factor 2.

  14. Two-photon absorption in gapped bilayer graphene with a tunable chemical potential.

    Science.gov (United States)

    Brinkley, M K; Abergel, D S L; Clader, B D

    2016-09-14

    Despite the now vast body of two-dimensional materials under study, bilayer graphene remains unique in two ways: it hosts a simultaneously tunable band gap and electron density; and stems from simple fabrication methods. These two advantages underscore why bilayer graphene is critical as a material for optoelectronic applications. In the work that follows, we calculate the one- and two-photon absorption coefficients for degenerate interband absorption in a graphene bilayer hosting an asymmetry gap and adjustable chemical potential-all at finite temperature. Our analysis is comprehensive, characterizing one- and two-photon absorptive behavior over wide ranges of photon energy, gap, chemical potential, and thermal broadening. The two-photon absorption coefficient for bilayer graphene displays a rich structure as a function of photon energy and band gap due to the existence of multiple absorption pathways and the nontrivial dispersion of the low energy bands. This systematic work will prove integral to the design of bilayer-graphene-based nonlinear optical devices. PMID:27392275

  15. Nf=2 QCD chiral phase transition with Wilson fermions at zero and imaginary chemical potential

    Science.gov (United States)

    Philipsen, Owe; Pinke, Christopher

    2016-06-01

    The order of the thermal phase transition in the chiral limit of quantum chromodynamics (QCD) with two dynamical flavors of quarks is a long-standing issue and still not known in the continuum limit. Whether the transition is first or second order has important implications for the QCD phase diagram and the existence of a critical end point at finite densities. We follow a recently proposed approach to explicitly determine the region of first order chiral transitions at imaginary chemical potential, where it is large enough to be simulated, and extrapolate it to zero chemical potential with known critical exponents. Using unimproved Wilson fermions on coarse Nt=4 lattices, the first order region turns out to be so large that no extrapolation is necessary. The critical pion mass mπc≈560 MeV is by nearly a factor 10 larger than the corresponding one using staggered fermions. Our results are in line with investigations of three-flavor QCD using improved Wilson fermions and indicate that the systematic error on the two-flavor chiral transition is still of order 100%.

  16. Baryon chemical potential and in-medium properties of BPS skyrmions

    CERN Document Server

    Adam, C; Naya, C; Sanchez-Guillen, J; Vazquez, R; Wereszczynski, A

    2015-01-01

    We continue the investigation of thermodynamical properties of the BPS Skyrme model. In particular, we analytically compute the baryon chemical potential both in the full field theory and in a mean-field approximation. In the full field theory case, we find that the baryon chemical potential is always exactly proportional to the baryon density, for arbitrary solutions. We further find that, in the mean-field approximation, the BPS Skyrme model approaches the Walecka model in the limit of high density - their thermodynamical functions as well as the equation of state agree in this limit. This fact allows to read off some properties of the $\\omega$-meson from the BPS Skyrme action, even though the latter model is entirely based on the (pionic) $SU(2)$ Skyrme field. On the other hand, at low densities, at the order of the usual nuclear matter density, the equations of state of the two models are no longer universal, such that a comparison depends on some model details. Still, also the BPS Skyrme model gives rise...

  17. Transient receptor potential channels encode volatile chemicals sensed by rat trigeminal ganglion neurons.

    Directory of Open Access Journals (Sweden)

    Matthias Lübbert

    Full Text Available Primary sensory afferents of the dorsal root and trigeminal ganglia constantly transmit sensory information depicting the individual's physical and chemical environment to higher brain regions. Beyond the typical trigeminal stimuli (e.g. irritants, environmental stimuli comprise a plethora of volatile chemicals with olfactory components (odorants. In spite of a complete loss of their sense of smell, anosmic patients may retain the ability to roughly discriminate between different volatile compounds. While the detailed mechanisms remain elusive, sensory structures belonging to the trigeminal system seem to be responsible for this phenomenon. In order to gain a better understanding of the mechanisms underlying the activation of the trigeminal system by volatile chemicals, we investigated odorant-induced membrane potential changes in cultured rat trigeminal neurons induced by the odorants vanillin, heliotropyl acetone, helional, and geraniol. We observed the dose-dependent depolarization of trigeminal neurons upon application of these substances occurring in a stimulus-specific manner and could show that distinct neuronal populations respond to different odorants. Using specific antagonists, we found evidence that TRPA1, TRPM8, and/or TRPV1 contribute to the activation. In order to further test this hypothesis, we used recombinantly expressed rat and human variants of these channels to investigate whether they are indeed activated by the odorants tested. We additionally found that the odorants dose-dependently inhibit two-pore potassium channels TASK1 and TASK3 heterologously expressed In Xenopus laevis oocytes. We suggest that the capability of various odorants to activate different TRP channels and to inhibit potassium channels causes neuronal depolarization and activation of distinct subpopulations of trigeminal sensory neurons, forming the basis for a specific representation of volatile chemicals in the trigeminal ganglia.

  18. Synthesis, physical and chemical properties, and potential applications of graphite fluoride fibers

    Science.gov (United States)

    Hung, Ching-Cheh; Long, Martin; Stahl, Mark

    1987-01-01

    Graphite fluoride fibers can be produced by fluorinating pristine or intercalated graphite fibers. The higher the degree of graphitization of the fibers, the higher the temperature needed to reach the same degree of fluorination. Pitched based fibers were fluorinated to flourine-to-carbon atom rations between 0 and 1. The graphite fluoride fibers with a fluorine-to-carbon atom ration near 1 have extensive visible structural damage. On the other hand, fluorination of fibers pretreated with bromine or fluorine and bromine result in fibers with a fluorine-to-carbon atom ratio nearly equal to 0.5 with no visible structural damage. The electrical resistivity of the fibers is dependent upon the fluorine to carbon atom ratio and ranged from .01 to 10 to the 11th ohm/cm. The thermal conductivity of these fibers ranged from 5 to 73 W/m-k, which is much larger than the thermal conductivity of glass, which is the regular filler in epoxy composites. If graphite fluoride fibers are used as a filler in epoxy or PTFE, the resulting composite may be a high thermal conductivity material with an electrical resistivity in either the insulator or semiconductor range. The electrically insulating product may provide heat transfer with lower temperature gradients than many current electrical insulators. Potential applications are presented.

  19. Physico-chemical characteristics and market potential of sawdust charcoal briquette

    Energy Technology Data Exchange (ETDEWEB)

    Akowuah, Joseph O.; Kemausuor, Francis [Kwame Nkrumah Univ. of Science and Technology, Kumasi (Ghana). Dept. of Agricultural Engineering; Mitchual, Stephen J. [Univ. of Education, Winneba, Kumasi (Ghana). Dept. of Design and Technology Education

    2012-11-01

    In the absence of the widespread distribution of modern cooking fuels in developing countries, efforts are being made to utilise biomass residues which abound in most of these countries. This is intended to replace portions of firewood and charcoal and thereby reduce the cutting down of forests for fuel purposes. Briquettes from agro-residues have therefore been promoted as a better replacement to firewood and charcoals for heating, cooking and other industrial applications in both urban and rural communities. This study sought to assess the physico-chemical properties of charcoal briquettes produced in Ghana and also establish demand for and willingness of potential users to substitute charcoal and firewood with a charcoal briquette. A laboratory experiment was conducted to determine the physicochemical characteristics of the briquettes. This was done prior to the distribution of the briquette to potential users to collaborate their views or otherwise on the handling and burning characteristics of the charcoal briquette. A survey was undertaken a week later using questionnaires to access the willingness of the potential users to use the briquettes. Sixty respondents were purposively selected from households and the hospitality industry for the survey. Results of the physico-chemical assessment of the briquettes were as follows: length (75 to 120 mm), moisture content (5.7% dry basis), density (1.1 g/cm{sup 3}), ash content (2.6%), fixed carbon (20.7%), volatile matter (71%) and calorific value (4,820 kcal/kg). Responses from the survey indicated that the briquette is easy to ignite, has a long burning time and has good heat output. Respondents also observed that the briquettes did not give off sparks and had less smoke and ash content as compared to the regular charcoal they often used. Finally, 93% of the respondents indicated their willingness to use the briquettes if the price was comparable to charcoal. (orig.)

  20. Electrochemical metal speciation analysis of chemically heterogeneous samples: the outstanding features of stripping chronopotentiometry at scanned deposition potential

    NARCIS (Netherlands)

    Leeuwen, van H.P.; Town, R.M.

    2003-01-01

    The application of depletive stripping chronopotentiometry at scanned deposition potential (SSCP) to metal ion speciation analysis of chemically heterogeneous complex systems is described. In this electroanalytical stripping technique, metal which is accumulated in the electrode during the depositio

  1. EQUAL OPPORTUNITIES IN ROMANIA

    OpenAIRE

    CECILIA IRINA RĂBONŢU; AMELIA GEORGIANA BONCEA; MARCEL ROMANESCU

    2008-01-01

    The European Union (EU) has every reason to be proud of its anti-discrimination legislation, one of the most extensive in the world. In 2000, the European Union adopted two very wide-ranging laws to prohibit discrimination based on racial or ethnic origin, religion or belief, disability, age or sexual orientation in the workplace and, as far as racial and ethnic origin is concerned, in other aspects of daily life. These texts build on the extensive provisions at EU level to promote equality b...

  2. Gender (sic) Equality (sic)

    OpenAIRE

    Martin Sewell

    2008-01-01

    This article is a response to both a Letter to the Editor by Dr Ambily Banerjee (Banerjee, 2007) and the recent UCL Gender Equality Event. Dr Banerjee claimed to be ‘astounded’ to find a ‘glass ceiling’ (sic) within her own discipline, Anatomy. She concludes her letter with, ‘I have never believed motherhood is a valid excuse for not realising one’s potential’. Both points are wrongheaded, and are the result of bogus feminist thinking. Firstly, men and women are different; and secondly, we ha...

  3. Chemical Composition of Artemisia annua L. Leaves and Antioxidant Potential of Extracts as a Function of Extraction Solvents

    OpenAIRE

    Iqbal, Shahid; Younas, Umer; Chan, Kim Wei; Zia-Ul-Haq, Muhammad; Ismail, Maznah

    2012-01-01

    This study was conducted to investigate the chemical and nutritional composition of Artemisia annua leaves in addition to determination of antioxidant potential of their extracts prepared in different solvents. Chemical composition was determined by quantifying fat, protein, carbohydrate, fiber, tocopherol, phytate, and tannin contents. Extraction of A. annua leaves, for antioxidant potential evaluation, was carried out using five solvents of different polarities, i.e., hexane, chloroform, et...

  4. Endocrine disrupting chemicals as potential risk factor for estrogen-dependent cancers.

    Science.gov (United States)

    Rutkowska, Aleksandra Z; Szybiak, Aleksandra; Serkies, Krystyna; Rachoń, Dominik

    2016-08-01

    Civilization, industrialization, and urbanization create an environment where humans are continuously exposed to endocrine disrupting chemicals (EDCs). Some of breast cancers and endometrial cancer, which are the most common female malignant neoplasms, are estrogen-dependent tumors. Prolonged exposure to estrogens or substances with estrogenic properties may be a risk factor for their development. This paper aimed to discuss the potential adverse effect of EDCs on human health, including the role of EDCs in hormone-dependent carcinogenesis. A review of literature regarding the sources of environmental exposure to EDCs and molecular mechanisms of their action was performed. We analyzed the possible mechanisms of how these substances alter the function of the endocrine system, resulting in adverse health effects. Hundreds of substances with endocrine disrupting potential have been identified in our environment. There is accumulating evidence linking exposure to EDCs with the development of mammary and endometrial cancer. By interacting with steroid receptors, EDCs can impact the cellular processes potentially leading to carcinogenesis. There are also data showing the effect of EDCs on immune dysfunction. During lifespan, people are usually exposed to a mixture of various EDCs, which complicates the assessment of individual substances or compounds implicated in cancer development. As the prevalence of hormone-dependent tumors among women continues to increase, their successful prevention is of human benefit. Institutions representing medicine, science, industry, and governments should develop joint strategies to decrease exposure to EDC, and thus to reduce the risk of hormonedependent tumors in women. PMID:27509913

  5. Computed Potential Energy Surfaces and Minimum Energy Pathways for Chemical Reactions

    Science.gov (United States)

    Walch, Stephen P.; Langhoff, S. R. (Technical Monitor)

    1994-01-01

    Computed potential energy surfaces are often required for computation of such parameters as rate constants as a function of temperature, product branching ratios, and other detailed properties. For some dynamics methods, global potential energy surfaces are required. In this case, it is necessary to obtain the energy at a complete sampling of all the possible arrangements of the nuclei, which are energetically accessible, and then a fitting function must be obtained to interpolate between the computed points. In other cases, characterization of the stationary points and the reaction pathway connecting them is sufficient. These properties may be readily obtained using analytical derivative methods. We have found that computation of the stationary points/reaction pathways using CASSCF/derivative methods, followed by use of the internally contracted CI method to obtain accurate energetics, gives usefull results for a number of chemically important systems. The talk will focus on a number of applications including global potential energy surfaces, H + O2, H + N2, O(3p) + H2, and reaction pathways for complex reactions, including reactions leading to NO and soot formation in hydrocarbon combustion.

  6. Genes and equality.

    Science.gov (United States)

    Farrelly, C

    2004-12-01

    The way people think about equality as a value will influence how they think genetic interventions should be regulated. In this paper the author uses the taxonomy of equality put forth by Derek Parfit and applies this to the issue of genetic interventions. It is argued that telic egalitarianism is untenable and that deontic egalitarianism collapses into prioritarianism. The priority view maintains that it is morally more important to benefit the people who are worse off. Once this precision has been given to the concerns egalitarians have, a number of diverse issues must be considered before determining what the just regulation of genetic interventions would be. Consideration must be given to the current situation of the least advantaged, the fiscal realities behind genetic interventions, the budget constraints on other social programmes egalitarians believe should receive scarce public funds, and the interconnected nature of genetic information. These considerations might lead egalitarians to abandon what they take to be the obvious policy recommendations for them to endorse regarding the regulation of gene therapies and enhancements. PMID:15574450

  7. Fiscal equalization under political pressures

    OpenAIRE

    Alejandro Esteller-Moré; Umberto Galmarini; Leonzio Rizzo

    2015-01-01

    We examine the design of fiscal equalization transfers aimed at inter-regional redistribution in a setting in which special interest groups distort the fiscal policies of local governments. Equity always calls for tax-base equalization while efficiency calls for tax-base equalization of fiscal capacities backed by strong lobby groups and for tax-revenue equalization of those backed by weak lobby groups. Hence, it is optimal to rely only on tax-base equalization if the special interest groups ...

  8. Selection of potential cold water marine species for testing of oil dispersants, and chemically dispersed oil

    Energy Technology Data Exchange (ETDEWEB)

    Perkins, R.A. [Alaska Univ., Fairbanks, AK (United States). Dept. of Civil and Environmental Engineering

    2000-07-01

    A study regarding marine species for toxicity testing for Alaska conditions was presented and the potential adverse impacts of a large marine oil spill in cold water were discussed with the objective to determine if the spill should be treated by the use of oil dispersants. Without dispersion, the oil can pollute marine epifauna and can deposit on beaches. The decision to apply dispersants to a marine oil spill requires knowledge of the toxicity of the undispersed oil to pelagic marine life occurring via natural dispersion as opposed to the toxicity of the oil-dispersant mixture. Most standard toxicity tests apply to warm water species. This paper discussed the need to have a standard test species relevant to Alaska waters for toxicity testing. In this study, toxicity testing was done according to the methods of the Chemical Response to Oil Spills : Ecological Effects Research Forum (CROSERF). The testing included capturing adult species in the winter and holding them until larval hatching. Toxicity testing was completed in a narrow time frame before hatching ceased. Many chemical samples were tested. Topsmelt, urchins, shellfish, mysids, copepods, pink salmon fry, and tidepool sculpin were considered by the author to be the most useful for certain types of toxicity testing. 29 refs.

  9. Two-photon absorption in gapped bilayer graphene with a tunable chemical potential

    Science.gov (United States)

    Brinkley, M. K.; Abergel, D. S. L.; Clader, B. D.

    2016-09-01

    Despite the now vast body of two-dimensional materials under study, bilayer graphene remains unique in two ways: it hosts a simultaneously tunable band gap and electron density; and stems from simple fabrication methods. These two advantages underscore why bilayer graphene is critical as a material for optoelectronic applications. In the work that follows, we calculate the one- and two-photon absorption coefficients for degenerate interband absorption in a graphene bilayer hosting an asymmetry gap and adjustable chemical potential—all at finite temperature. Our analysis is comprehensive, characterizing one- and two-photon absorptive behavior over wide ranges of photon energy, gap, chemical potential, and thermal broadening. The two-photon absorption coefficient for bilayer graphene displays a rich structure as a function of photon energy and band gap due to the existence of multiple absorption pathways and the nontrivial dispersion of the low energy bands. This systematic work will prove integral to the design of bilayer-graphene-based nonlinear optical devices.

  10. Use of biosensors to screen urine samples for potentially toxic chemicals.

    Science.gov (United States)

    Horswell, Jacqui; Dickson, Stuart

    2003-09-01

    Forensic toxicology laboratories are often required to implicate or exclude poisoning as a factor in a death or unexplained illness. An analytical tool which enables toxicologists to screen a wide variety of common poisons would be extremely useful. In this paper, we describe the use of a bacterial biosensor for detecting the presence of commonly encountered potentially toxic chemicals in urine. The biosensor responds to any chemical that causes metabolic stress to the bacterial cell and the response is in direct proportion to the concentration of the stressor. This allows a measure of the concentration of a toxicant in urine, without knowing exactly what the toxic compound(s) may be. This affords a distinct advantage over conventional analytical techniques, which require an extensive screening program before it is even known that a toxic compound is present. This preliminary investigation has shown that this biosensor can indicate the presence, in urine, of herbicides such as glyphosate, 2,4-dichlorophenoxyacetic acid, and 2,4,5-trichlorophenoxyacetic acid; the biocide pentachlorophenol; or inorganic poisons such as arsenic, mercury, and cyanide. The biosensor was also shown to be sensitive to a concentration range of these toxicants likely to be found in samples submitted for toxicological analysis.

  11. Holographic dual of a boost-invariant plasma with chemical potential

    International Nuclear Information System (INIS)

    We construct a gravity dual of a boost-invariant flow of an N=4 SU(N) supersymmetric Yang-Mills gauge theory plasma with chemical potential. We present both a first-order corrected late-time solution in Eddington-Finkelstein coordinates and a zeroth-order solution in parametric form in Fefferman-Graham coordinates. The resulting background takes the form of a time-dependent AdS Reissner-Nordstroem-type black hole whose horizons move into the bulk of the AdS space. The solution correctly reproduces the energy and charge density as well as the viscosity of the plasma previously computed in the literature. (orig.)

  12. Holographic dual of a boost-invariant plasma with chemical potential

    Energy Technology Data Exchange (ETDEWEB)

    Kalaydzhyan, Tigran; Kirsch, Ingo

    2010-12-15

    We construct a gravity dual of a boost-invariant flow of an N=4 SU(N) supersymmetric Yang-Mills gauge theory plasma with chemical potential. We present both a first-order corrected late-time solution in Eddington-Finkelstein coordinates and a zeroth-order solution in parametric form in Fefferman-Graham coordinates. The resulting background takes the form of a time-dependent AdS Reissner-Nordstroem-type black hole whose horizons move into the bulk of the AdS space. The solution correctly reproduces the energy and charge density as well as the viscosity of the plasma previously computed in the literature. (orig.)

  13. Solving the sign problem of two flavor scalar electrodynamics at finite chemical potential

    CERN Document Server

    Mercado, Ydalia Delgado; Schmidt, Alexander

    2013-01-01

    We explore two flavor scalar electrodynamics on the lattice, which has a complex phase problem at finite chemical potential. By rewriting the action in terms of dual variables this complex phase problem can be solved exactly. The dual variables are link- and plaquette occupation numbers, subject to local constraints that have to be respected by the Monte Carlo algorithm. For the simulation we use a local update as well as the newly developed "surface worm algorithm", which is a generalization of the Prokof'ev Svistunov worm algorithm concept for simulating the dual representation of abelian Gauge-Higgs models on a lattice. We assess the performance of the two algorithms, present results for the phase diagram and discuss condensation phenomena.

  14. Phase of the Fermion Determinant for QCD at Finite Chemical Potential

    CERN Document Server

    Splittorff, K

    2008-01-01

    In this lecture we discuss various properties of the phase factor of the fermion determinant for QCD at nonzero chemical potential. Its effect on physical observables is elucidated by comparing the phase diagram of QCD and phase quenched QCD and by illustrating the failure of the Banks-Casher formula with the example of one-dimensional QCD. The average phase factor and the distribution of the phase are calculated to one-loop order in chiral perturbation theory. In quantitative agreement with lattice QCD results, we find that the distribution is Gaussian with a width $\\sim \\mu T \\sqrt V$ (for $m_\\pi \\ll T \\ll \\Lambda_{\\rm QCD}$). Finally, we introduce, so-called teflon plated observables which can be calculated accurately by Monte Carlo even though the sign problem is severe.

  15. Relativistic second-order dissipative fluid dynamics at finite chemical potential

    Science.gov (United States)

    Jaiswal, Amaresh; Friman, Bengt; Redlich, Krzysztof

    2016-07-01

    We employ a Chapman-Enskog like expansion for the distribution function close to equilibrium to solve the Boltzmann equation in the relaxation time approximation and subsequently derive second-order evolution equations for dissipative charge currentand shear stress tensor for a system of massless quarks and gluons. We use quantum statistics for the phase space distribution functions to calculate the transport coefficients. We show that, the second-order evolution equations for the dissipative charge current and the shear stress tensor can be decoupled. We find that, for large chemical potential, the charge conductivity is small compared to the shear viscosity. Moreover, we demonstrate that the limiting behaviour of the ratio of heat conductivity to shear viscosity is identicalto that obtained for a strongly coupled conformal plasma.

  16. Hydrodynamics of a quark droplet II: Implications of a non-zero baryon chemical potential

    Energy Technology Data Exchange (ETDEWEB)

    Bjerrum-Bohr, Johan J. [Frankfurt Institute for Advanced Studies (FIAS), Goethe-University, Ruth-Moufang Str. 1, 60438 Frankfurt am Main (Germany); Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 København Ø (Denmark); Mishustin, Igor N. [Frankfurt Institute for Advanced Studies (FIAS), Goethe-University, Ruth-Moufang Str. 1, 60438 Frankfurt am Main (Germany); Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 København Ø (Denmark); Kurchatov Institute, Russian Research Center, Akademika Kurchatova Sqr., Moscow 123182 (Russian Federation); Døssing, Thomas [Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 København Ø (Denmark)

    2014-03-01

    We present an extended version of the dynamical model for a multi-quark droplet evolution described in our proceeding paper. The model includes collective expansion of the droplet, effects of the vacuum pressure and surface tension, and now a non-zero baryon number. The hadron emission from the droplet is described following Weisskopf's statistical model. We consider evolutions of droplets with different initial temperatures and net baryon number. It is found that the introduction of a non-zero net baryon number does not change the lifetime of the droplets significantly. Only when we consider an initially very baryon-rich, low-temperature droplets is the lifetime is decreased significantly. We have, furthermore, found a convergence of both baryon chemical potential and temperature toward the values μ{sub B}≈450 MeV and T≈150 MeV. This convergence is linked to the competing emission of baryons versus mesons.

  17. Hydrodynamics of a quark droplet II: Implications of a non-zero baryon chemical potential

    CERN Document Server

    Bjerrum-Bohr, Johan J; Døssing, Thomas

    2013-01-01

    We present an extended version of the dynamical model for a multi-quark droplet evolution described in our proceeding paper. The model includes collective expansion of the droplet, effects of the vacuum pressure and surface tension, and now a non-zero baryon number. The hadron emission from the droplet is described following Weisskopf's statistical model. We consider evolutions of droplets with different initial temperatures and net baryon number. It is found that the introduction of a non-zero net baryon number does not change the lifetime of the droplets significantly. Only when we consider an initially very baryon-rich, low-temperature droplets is the lifetime is decreased significantly. We have, furthermore, found a convergence of both baryon chemical potential and temperature toward the values $T \\approx 150$ MeV and $\\mu_{\\rm B} \\approx$ 450 MeV. This convergence seems to be linked to the competing emission of baryons versus mesons.

  18. Effective Polyakov loop models for QCD-like theories at finite chemical potential

    CERN Document Server

    Scior, Philipp

    2016-01-01

    We study genuine finite density effects in QCD-like theories with three-dimensional Polyakov-loop effective theories for heavy quarks. These are derived from the full QCD-like theories by combined strong-coupling and hopping expansions. In particular, we investigate the cold and dense regimes of phase diagrams where we expect to find Bose-Einstein-condensation of diquark baryons or a fermionic first-order liquid-gas transition, depending on the gauge group of the theory. In two-color QCD, for example, we observe evidence of a continuous zero-temperature transition to finite diquark density when the quark chemical potential $\\mu$ reaches half the diquark mass, i.e. without binding energy. In G$_2$-QCD we observe, in addition to this "Silver Blaze" onset of diquark density, a second transition in the density towards an exponential increase by roughly $3\\mu/T$ corresponding to a finite density of G$_2$-nucleons.

  19. Top Value Added Chemicals from Biomass - Volume I, Results of Screening for Potential Candidates from Sugars and Synthesis Gas

    Energy Technology Data Exchange (ETDEWEB)

    None

    2004-08-01

    This report identifies twelve building block chemicals that can be produced from sugars via biological or chemical conversions. The twelve building blocks can be subsequently converted to a number of high-value bio-based chemicals or materials. Building block chemicals, as considered for this analysis, are molecules with multiple functional groups that possess the potential to be transformed into new families of useful molecules. The twelve sugar-based building blocks are 1,4-diacids (succinic, fumaric and malic), 2,5-furan dicarboxylic acid, 3-hydroxy propionic acid, aspartic acid, glucaric acid, glutamic acid, itaconic acid, levulinic acid, 3-hydroxybutyrolactone, glycerol, sorbitol, and xylitol/arabinitol.

  20. Variations in amounts and potential sources of volatile organic chemicals in new cars.

    Science.gov (United States)

    Chien, Yeh-Chung

    2007-09-01

    This study examines inter-brand, intra-brand and intra-model variations in volatile organic chemical (VOC) levels inside new cars. The effect of temperature on interior VOC levels was examined using model automobiles with and without the air-conditioning running. Potential sources of VOC were assessed by comparing VOC levels with two interior trims (leather and fabric) and by analyzing VOC emissions from various interior components. Five brands of new car, both domestic and imported, were tested. Twelve targeted VOCs were collected on solid sorbents and analyzed using thermal desorption and GC/FID. VOCs from interior parts and adhesives were identified using solid phase micro-extraction (SPME) coupled with GC/MS. The VOC concentrations varied markedly among brands and within models, and individual VOC levels ranged from below the detection limit (a few mug per cubic meter) to thousands of mug per cubic meter. The intra-model variability (mean, 47%) in the VOC levels was approximately 50% that within each brand (mean, 95%). Although interior trim levels affected VOC levels, the effects differed among brands. Reduction of the cabin temperature reduced most VOC levels, but the impact was not statistically significant. Screening tests for VOCs from interior parts revealed that butylated hydroxytoluene (BHT), a common anti-oxidant, was the most common chemical. Long-chain aliphatic hydrocarbons, particularly C14-C17, were identified in most grease (lubricant) samples, and toluene and xylenes were ubiquitously present in adhesive samples. Process-related compounds, such as plasticizer, were also identified in interior parts. In-cabin VOC levels varied significantly among makes/models and interior trims. Concerned consumers should purchase older new cars from manufacturers since VOC levels inside car cabins normally declines over time. Improved processes or materials with lower VOC emission potential should be used to minimize in-cabin VOC sources for new cars.

  1. Variations in amounts and potential sources of volatile organic chemicals in new cars

    Energy Technology Data Exchange (ETDEWEB)

    Chien, Y.-C. [Department Industrial Safety and Health, Hungkuang University, 34 Chung-chie Road, Shalu 433, Taiwan (China)]. E-mail: yc@sunrise.hk.edu.tw

    2007-09-01

    This study examines inter-brand, intra-brand and intra-model variations in volatile organic chemical (VOC) levels inside new cars. The effect of temperature on interior VOC levels was examined using model automobiles with and without the air-conditioning running. Potential sources of VOC were assessed by comparing VOC levels with two interior trims (leather and fabric) and by analyzing VOC emissions from various interior components. Five brands of new car, both domestic and imported, were tested. Twelve targeted VOCs were collected on solid sorbents and analyzed using thermal desorption and GC/FID. VOCs from interior parts and adhesives were identified using solid phase micro-extraction (SPME) coupled with GC/MS. The VOC concentrations varied markedly among brands and within models, and individual VOC levels ranged from below the detection limit (a few {mu}g per cubic meter) to thousands of {mu}g per cubic meter. The intra-model variability (mean, 47%) in the VOC levels was approximately 50% that within each brand (mean, 95%). Although interior trim levels affected VOC levels, the effects differed among brands. Reduction of the cabin temperature reduced most VOC levels, but the impact was not statistically significant. Screening tests for VOCs from interior parts revealed that butylated hydroxytoluene (BHT), a common anti-oxidant, was the most common chemical. Long-chain aliphatic hydrocarbons, particularly C14-C17, were identified in most grease (lubricant) samples, and toluene and xylenes were ubiquitously present in adhesive samples. Process-related compounds, such as plasticizer, were also identified in interior parts. In-cabin VOC levels varied significantly among makes/models and interior trims. Concerned consumers should purchase older new cars from manufacturers since VOC levels inside car cabins normally declines over time. Improved processes or materials with lower VOC emission potential should be used to minimize in-cabin VOC sources for new cars.

  2. Contributorships Are Not 'Weighable' to be Equal.

    Science.gov (United States)

    Moustafa, Khaled

    2016-05-01

    A new trend to assign some authors as 'first co-authors' is noticeable in scientific publications as a statement highlighting that two or more authors 'contributed equally' to a reported work. However, the requirements of scientific rigor, honesty, and accuracy in academic standards make such statements invalid and, thus, should be avoided. A potential solution is to specify the role of each co-author, from study conception to communication of results, and let readers judge the importance of each contribution by themselves. Alternatively, authors should demonstrate how they contributed 'equally' when they are defined as 'equal contributors'. PMID:27025412

  3. Effects of chemical carcinogens of hemopoiesis, immunopoiesis and viral oncogenesis. Technical progress report, December 1, 1977--September 30, 1978. [Mechanisms of potentiation of viral leukemogenesis by MMS, benzopyrene, and DMBA

    Energy Technology Data Exchange (ETDEWEB)

    OKunewick, J.P.; Raikow, R.B.; Meredith, R.F.

    1978-10-01

    During the past year we have concentrated on defining the circumstances under which methyl methanesulfonate (MMS), benzo(a) pyrene (BP), and 7,12-dimethylbenz(a)anthracene (DMBA) interact with Friend virus (FLV) to produce leukemia. The optimum scheduling for each and also the effective dose levels of the chemicals have been partially determined. There are at least three critical factors which govern whether or not a leukemogenic interaction can be shown between the chemical agents and the virus. These are chemical dose, virus dose, and their relative time of administration. The most critical of these is virus dose. The optimum virus dose is that which results in between 25 and 40% incidence of leukemia within 40 days after virus infection when virus is given alone. The chemical carcinogens have a lower dose threshold, below which no significant potentiating effect can be observed. The only upper limit would appear to be acute drug toxicity. The third element, timing, is equally critical and varies according to the chemical. This variation may reflect different mechanisms of action by the chemical agents and/or different pharmacology. Data on the effects of MMS, BP, and DMBA on the immune system have indicated that the viral enhancement is probably not dependent on this function. Further enhancement of the potentiation of viral leukemogenesis was observed using benzo(a)pyrene and caffeine, indicating that the inhibition by caffeine of DNA repair may be an important factor in virus potentiation. (ERB)

  4. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

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

  5. Early evaluation of potential environmental impacts of carbon nanotube synthesis by chemical vapor deposition.

    Science.gov (United States)

    Plata, Desirée L; Hart, A John; Reddy, Christopher M; Gschwend, Philip M

    2009-11-01

    The carbon nanotube (CNT) industry is expanding rapidly, yet little is known about the potential environmental impacts of CNT manufacture. Here, we evaluate the effluent composition of a representative multiwalled CNT synthesis by catalytic chemical vapor deposition (CVD) in order to provide data needed to design strategies for mitigating any unacceptable emissions. During thermal pretreatment of the reactant gases (ethene and H(2)), we found over 45 side-products were formed, including methane, volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). This finding suggests several environmental concerns with the existing process, including potential discharges of the potent greenhouse gas, methane (up to 1.7%), and toxic compounds such as benzene and 1,3-butadiene (up to 36000 ppmv). Extrapolating these laboratory-scale data to future industrial CNT production, we estimate that (1) contributions of atmospheric methane will be negligible compared to other existing sources and (2) VOC and PAH emissions may become important on local scales but will be small when compared to national industrial sources. As a first step toward reducing such unwanted emissions, we used continuous in situ measures of CNT length during growth and sought to identify which thermally generated compounds correlated with CNT growth rate. The results suggested that, in future CNT production approaches, key reaction intermediates could be delivered to the catalyst without thermal treatment. This would eliminate the most energetically expensive component of CVD synthesis (heating reactant gases), while reducing the formation of unintended byproducts. PMID:19924971

  6. Permethrin is a potential thyroid-disrupting chemical: In vivo and in silico envidence.

    Science.gov (United States)

    Tu, Wenqing; Xu, Chao; Jin, Yuanxiang; Lu, Bin; Lin, Chunmian; Wu, Yongming; Liu, Weiping

    2016-06-01

    Permethrin (PM), one of the most heavily used synthetic pyrethroids, has the potential to interfere with thyroid hormones in mammals, however, the effect is poorly recognized in aquatic organisms. Herein, embryonic zebrafish were exposed to PM (0, 1, 3 and 10μg/L) until 72h post-fertilization. We demonstrated that PM readily accumulated in larvae with a preference for cis-PM, inhibited development and increased thyroxine and 3,5,3'-triiodothyronine levels accompanying increase in the transcription of most target genes, i.e., thyroid-stimulating hormone β, deiodinases, thyroid receptors, involved in the hypothalamic-pituitary-thyroid axis. Further Western blot analysis indicated that transthyretin (TTR) protein was significantly increased. Molecular docking analysis and molecular dynamics simulations revealed that PM fits into three hydrophobic binding pocket of TTR, one of the molecular targets of thyroid hormone disrupting chemicals (THDCs), and forms strong van der Waals interactions with six resides of TTR, including Leu8, Leu 101, Leu125, Thr214, Leu218 and Val229, thus altering TTR activity. Both in vivo and in silico studies clearly disclosed that PM potentially disrupts the thyroid endocrine system in fish. This study provides a rapid and cost-effective approach for identifying THDCs and the underlying mechanisms. PMID:26994367

  7. Chemical characteristics and methane potentials of source-separated and pre-treated organic municipal solid waste

    DEFF Research Database (Denmark)

    Hansen, Trine Lund; Svärd, Å; Angelidaki, Irini;

    2003-01-01

    A research project has investigated the biogas potential of pre-screened source-separated organic waste. Wastes from five Danish cities have been pre-treated by three methods: screw press; disc screen; and shredder and magnet. This paper outlines the sampling procedure used, the chemical...... composition of the wastes and the estimated methane potentials....

  8. 77 FR 41406 - Evaluation of In Vitro Tests for Identifying Eye Injury Hazard Potential of Chemicals and...

    Science.gov (United States)

    2012-07-13

    ... HUMAN SERVICES Evaluation of In Vitro Tests for Identifying Eye Injury Hazard Potential of Chemicals and... assess the validation status of in vitro tests and integrated non-animal testing strategies proposed for... tested in in vitro tests for identifying eye injury hazard potential. Of particular interest are...

  9. Ab Initio Thermodynamic Modeling of Electrified Metal–Oxide Interfaces: Consistent Treatment of Electronic and Ionic Chemical Potentials

    DEFF Research Database (Denmark)

    Zeng, Zhenhua; Hansen, Martin Hangaard; Greeley, Jeffrey Philip;

    2014-01-01

    Solid oxide fuel cells are attractive devices in a sustainable energy context because of their fuel flexibility and potentially highly efficient conversion of chemical to electrical energy. The performance of the device is to a large extent determined by the atomic structure of the electrode......–electrolyte interface. Lack of atomic-level information about the interface has limited the fundamental understanding, which further limits the opportunity for optimization. The atomic structure of the interface is affected by electrode potential, chemical potential of oxygen ions, temperature, and gas pressures....... In this paper we present a scheme to determine the metal–oxide interface structure at a given set of these environmental parameters based on quantum chemical calculations. As an illustration we determine the structure of a Ni-YSZ anode as a function of electrode potential at 0 and 1000 K. We further describe...

  10. TAXATION. FAIRNESS. EQUALITY

    Directory of Open Access Journals (Sweden)

    Morar Ioan Dan

    2014-12-01

    of the tax burden between them, depending on how the tax base, depending on the type of taxpayer and according to other criteria. Another coordinated taxation is part of contemporary consumerist polticilor new tax, taxing certain income, especially income individuals is marked by the overall objective of capitalist society, that consumption growth. Fiscal policies are policies the new contemporary consumerism. And this phenomenon influences the distribution of the tax burden among taxpayers, more or less fair. What is tax fairness and how we can quantify? Here's a question that I try to raspunt from equality before the law tax payers. Equality before the tax law is not a primary goal of modern tax policy, it losing ground to tax efficiency goals and its economic and social components. On the other hand though fiscal phenomenon can help to ensure social peace through taxation to keep Sean absolute size of the tax burden and the fact that all are equal before the law, tax law and within given social policies in broadly, social security or insurance in respect restrains can be promoted by themselves and less by fiscal policy.

  11. Chemical variability of zeolites at a potential nuclear waste repository, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    The compositions of clinoptilolites and their host tuffs have been examined by electron microprobe and x-ray fluorescence, respectively, to determine their variability at a potential nuclear waste repository, Yucca Mountain, Nevada. Because of their sorptive properties, these zeolites could provide important geologic barriers to radionuclide migration. Variations in clinoptilolite composition can strongly affect the mineral's thermal and ion-exchange properties, thus influencing its behavior in the repository environment. Clinoptilolites and heulandites closest to the proposed repository have calcium-rich compositions (60 to 90 mol. % Ca) and silica-to-aluminum ratios that concentrate between 4.0 and 4.6. In contrast, clinoptilolites and their host tuffs deeper in the volcanic sequence have highly variable compositions that vary vertically and laterally. Deeper-occurring clinoptilolites in the eastern part of Yucca Mountain are characterized by calcic-potassic compositions and tend to become more calcium-rich with depth. Clinoptilolites at equivalent stratigraphic levels on the western side of Yucca Mountain have sodic-potassic compositions and tend to become more sodium-rich with depth. Despite their differences in exchangeable cation compositions these two deeper-occurring compositional suites have similar silica-to-aluminum ratios, concentrating between 4.4 and 5.0. The chemical variability of clinoptilolites and their host tuffs at Yucca Mountain suggest that their physical and chemical properties will also vary. Compositionally-dependent clinoptilolite properties important for repository performance assessment include expansion/contraction behavior, hydration/dehydration behavior, and ion-exchange properties

  12. Anaerobic sediment potential acidification and metal release risk assessment by chemical characterization and batch resuspension experiments

    Energy Technology Data Exchange (ETDEWEB)

    Nanno, M.P. di [Univ. de San Martin, Buenos Aires (Argentina). Escuela de Ciencia y Technologia; Curutchet, G. [Univ. de San Martin, Buenos Aires (Argentina). Escuela de Ciencia y Technologia; CONICET, Buenos Aires (Argentina); Ratto, S. [Univ. de Buenos Aires (Argentina). Catedra de Edafologia

    2007-06-15

    Background, Aim and Scope: Sediments act as a sink for toxic substances (heavy metals, organic pollutants) and, consequently, dredged materials often contain pollutants which are above safe limits. In polluted anaerobic sediments, the presence of sulphides and redox potential changes creates a favorable condition for sulphide oxidation to sulphate, resulting in potential toxic metal release. The oxidation reaction is catalyzed by several microorganisms. Some clean up measures, such as dredging, can initiate the process. The aim of the present work is to assess the acidification and metal release risk in the event of sediment dredging and also to compare two different acid base account techniques with the resuspension results. The oxidation mechanism by means of inoculation with an Acidithiobacillus ferrooxidans strain was also evaluated. Materials and Methods: The sediments were chemically characterized (pH; organic oxidizable carbon; acid volatile sulphides; total sulphur; moisture; Cr, Cu and Zn aqua regia contents). A metal sequential extraction procedure (Community Bureau of Reference, BCR technique) was applied to calculate the Acid Producing Potential (APP) and Acid Consuming Capacity (ACC) of the sediment samples through Fe, Ca{sup 2+} and SO{sub 4}{sup 2-} measurements. The acid base account was also performed by the Sobek methodology (Acid producing potential - AP - calculated with total sulphur and neutralization potential - NP - by titration of the remaining acid after a reaction period with the sample). Fresh sediments were placed in agitated shake flasks and samples were taken at different times to evaluate pH, SO{sub 4}{sup 2-} and Cr, Cu, Zn and Fe{sup 2+} concentration. Some of the systems were inoculated with an Acidithiobacillus ferrooxidans strain to assess the biological catalysis on sulphide oxidation. Results: Sediment chemical characterization showed high organic matter content (5.4-10.6%), total sulphur (0.36-0.86%) and equivalent CaCO{sub 3

  13. Top Value Added Chemicals From Biomass: I. Results of Screening for Potential Candidates from Sugars and Synthesis Gas

    Energy Technology Data Exchange (ETDEWEB)

    Werpy, Todd A.; Holladay, John E.; White, James F.

    2004-11-01

    This report identifies twelve building block chemicals that can be produced from sugars via biological or chemical conversions. The twelve building blocks can be subsequently converted to a number of high-value bio-based chemicals or materials. Building block chemicals, as considered for this analysis, are molecules with multiple functional groups that possess the potential to be transformed into new families of useful molecules. The twelve sugar-based building blocks are 1,4-diacids (succinic, fumaric and malic), 2,5-furan dicarboxylic acid, 3-hydroxy propionic acid, aspartic acid, glucaric acid, glutamic acid, itaconic acid, levulinic acid, 3-hydroxybutyrolactone, glycerol, sorbitol, and xylitol/arabinitol. In addition to building blocks, the report outlines the central technical barriers that are preventing the widespread use of biomass for products and chemicals.

  14. Transport coefficients of heavy quarks around $T_c$ at finite quark chemical potential

    CERN Document Server

    Berrehrah, H; Aichelin, J; Cassing, W; Torres-Rincon, J M; Bratkovskaya, E

    2014-01-01

    The interactions of heavy quarks with the partonic environment at finite temperature $T$ and finite quark chemical potential $\\mu_q$ are investigated in terms of transport coefficients within the Dynamical Quasi-Particle model (DQPM) designed to reproduce the lattice-QCD results (including the partonic equation of state) in thermodynamic equilibrium. These results are confronted with those of nuclear many-body calculations close to the critical temperature $T_c$. The hadronic and partonic spatial diffusion coefficients join smoothly and show a pronounced minimum around $T_c$, at $\\mu_q=0$ as well as at finite $\\mu_q$. Close and above $T_c$ its absolute value matches the lQCD calculations for $\\mu_q=0$. The smooth transition of the heavy quark transport coefficients from the hadronic to the partonic medium corresponds to a cross over in line with lattice calculations, and differs substantially from perturbative QCD (pQCD) calculations which show a large discontinuity at $T_c$. This indicates that in the vicini...

  15. Mapping the chemical potential dependence of current-induced spin polarization in a topological insulator

    Science.gov (United States)

    Lee, Joon Sue; Richardella, Anthony; Hickey, Danielle Reifsnyder; Mkhoyan, K. Andre; Samarth, Nitin

    2015-10-01

    We report electrical measurements of the current-induced spin polarization of the surface current in topological insulator devices where contributions from bulk and surface conduction can be disentangled by electrical gating. The devices use a ferromagnetic tunnel junction (permalloy/Al 2O3 ) as a spin detector on a back-gated (Bi,Sb ) 2Te3 channel. We observe hysteretic voltage signals as the magnetization of the detector ferromagnet is switched parallel or antiparallel to the spin polarization of the surface current. The amplitude of the detected voltage change is linearly proportional to the applied dc bias current in the (Bi,Sb ) 2Te3 channel. As the chemical potential is tuned from the bulk bands into the surface state band, we observe an enhancement of the spin-dependent voltages up to 300% within the range of the electrostatic gating. Using a simple model, we extract the spin polarization near charge neutrality (i.e., the Dirac point).

  16. Subcellular distribution and chemical forms of cadmium in Impatiens walleriana in relation to its phytoextraction potential.

    Science.gov (United States)

    Lai, Hung-Yu

    2015-11-01

    Impatiens (Impatiens walleriana) has been shown to be a potential cadmium (Cd) hyperaccumulator, but its mechanisms in accumulation and detoxification have not been reported. Rooted cuttings of Impatiens were planted in artificially Cd-contaminated soils for 50 days with total target concentrations of 0, 10, 20, 40, 80, and 120 mg/kg. The subcellular distribution and chemical forms of Cd in the different organs were analyzed after the pot experiment. Compared with the control group, various Cd treatments affected the growth exhibitions of Impatiens, but most of them were not statistically significant. The Cd accumulation of different organs increased with an increase in the soil Cd concentrations for most of the treatments, and it was in the decreasing order of root>stem>leaf. In the roots of Impatiens, Cd was mainly compartmentalized in the soluble fraction (Fs), which has a high migration capacity and will further translocate to the shoot. The Cd was mainly compartmentalized in the cell wall fraction (Fcw) in the shoots as a mechanism of tolerance. Most of the Cd in the various organs of Impatiens was mainly in the forms of pectate and protein-integrated (FNaCl), whereas a minor portion was a water soluble fraction (FW). The experimental results show that the Cd in the Fs, FW, and FNaCl in the roots of Impatiens had a high mobility and will further translocate to the shoot. They could be used to estimate the Cd accumulated in the shoots of Impatiens.

  17. EFFECTS OF RADIO FREQUENCY / MICROWAVE ON THE CHEMICAL COMPOSITION AND ANTIOXIDANT POTENTIAL OF LYCOPERSICON ESCULENTUM L.

    Directory of Open Access Journals (Sweden)

    Rammal Marwa

    2013-09-01

    Full Text Available In our work, the effects of radio frequency / microwave on the morphology, chemical composition and the antioxidant power of the plant Lycopersicon esculentum Mill. grown in our laboratory have been accomplished. The obtained results showed that after 10 days of exposure of this plant to electromagnetic fields with high frequency (1250 MHz the stems were long with less leaves than the non exposed plant. However, after 20 days of exposure to this same frequency the stems were long and contain more leaves than the non exposed plant. These leaves were larger and thicker in comparison with those of the non exposed plant. On the other side, the phytochemical screening of the ethanolic extract revealed the presence of flavonoids in the exposed and non exposed plant. Alkaloids, phenols and saponins were only present in non exposed plant. The tannins were absent in the exposed and non exposed plant. Therefore, resins were highly expressed in the exposed plant. On the other side, the x-ray fluorescence indicated the presence of various trace elements more particularly niobium and molybdenum. After exposure, the amount of these elements varies. On the other hand, the DPPH and H2O2 tests showed an important decrease in the antioxidant potential after exposure to studied frequency. This decrease was from 42 % to 18 % at the concentration 0.5 mg/ml. All of these results show that the high frequency emitted by the electromagnetic fields exert a strong effect on the plant and by consequence on human health.

  18. Chemical Speciation and Potential Mobility of Heavy Metals in the Soil of Former Tin Mining Catchment

    Directory of Open Access Journals (Sweden)

    M. A. Ashraf

    2012-01-01

    Full Text Available This study describes the chemical speciation of Pb, Zn, Cu, Cr, As, and Sn in soil of former tin mining catchment. Total five sites were selected for sampling and subsequent subsamples were collected from each site in order to create a composite sample for analysis. Samples were analysed by the sequential extraction procedure using optical emission spectrometry (ICP OES. Small amounts of Cu, Cr, and As retrieved from the exchangeable phase, the ready available for biogeochemical cycles in the ecosystem. Low quantities of Cu and As could be taken up by plants in these kind of acidic soils. Zn not detected in the bioavailable forms while Pb is only present in negligible amounts in very few samples. The absence of mobile forms of Pb eliminates the toxic risk both in the trophic chain and its migration downwards the soil profile. The results also indicate that most of the metals have high abundance in residual fraction indicating lithogenic origin and low bioavailability of the metals in the studied soil. The average potential mobility for the metals giving the following order: Sn > Cu > Zn > Pb > Cr > As.

  19. Chromophore-immobilized luminescent metal-organic frameworks as potential lighting phosphors and chemical sensors.

    Science.gov (United States)

    Wang, Fangming; Liu, Wei; Teat, Simon J; Xu, Feng; Wang, Hao; Wang, Xinlong; An, Litao; Li, Jing

    2016-08-11

    An organic chromophore H4tcbpe-F was synthesized and immobilized into metal-organic frameworks along with two bipyridine derivatives as co-ligands to generate two strongly luminescent materials [Zn2(tcbpe-F)(4,4'-bpy)·xDMA] (1) and [Zn2(tcbpe-F)(bpee)·xDMA] (2) [4,4'-bpy = 4,4'-bipyridine, bpee = 4,4'-bipyridyl-ethylene, tcbpe-F = 4',4''',4''''',4'''''''-(ethene-1,1,2,2-tetrayl)tetrakis(3-fluoro-[1,1'-biphenyl]-4-carboxylic acid), DMA = N,N-dimethylacetamide]. Compounds 1 and 2 are isoreticular and feature a 2-fold interpenetrated three-dimensional porous structure. Both compounds give green-yellow emission under blue light excitation. Compound 1 has a high internal quantum yield of ∼51% when excited at 455 nm and shows selective luminescence signal change (e.g. emission energy and/or intensity) towards different solvents, including both aromatic and nonaromatic volatile organic species. These properties make it potentially useful as a lighting phosphor and a chemical sensor. PMID:27465685

  20. Chemical reactivity trends of ergotamine and butenolide from electrostatic potentials and charge sensitivities

    Energy Technology Data Exchange (ETDEWEB)

    Mrozek, J.; Michalak, A. [Jagiellonian Univ., Cracow (Poland)

    1995-12-05

    A set of reactivity indices, including maps of the electrostatic potential and local and condensed Fukui function (FF) indices in the atomic resolution, are reported for two vasoconstricting mycotoxins: butenolide and ergotamine; both the finite difference approach of Parr and Yan as well as charge sensitivity analysis, determining the charge responses via the inversion of the hardness tensor, have been used to generate the FF data. These two routes of arriving at the atomic FF indices provide an opportunity to evaluate the available parametrizations of the semiempirical NDDO-type of methods which have been used to determine the input charge distribution; namely, the best parametrization should generate consistent FF predictions resulting from both approaches. For butenolide, the MNDO parametrization was found to fulfill this consistency requirement. The chemical reactivity information has been used to trace possible similarities in reactivity trends of the butenolide molecule and the related fragment of ergotamine, toward hypothetical nucleophilic, electrophilic, and radical attacks. These predictions have been compared to experimental data available for other unsaturated lactones. 13 refs., 18 figs., 1 tab.

  1. The effect of finite temperature and chemical potential on nucleon properties in the logarithmic quark sigma model

    Science.gov (United States)

    Abu-Shady, M.; Abu-Nab, A.

    2015-12-01

    The logarithmic quark sigma model is applied to study the nucleon properties at finite temperature and chemical potential. The field equations have been solved numerically in the mean-field approximation by using the extended iteration method at finite temperature and baryon chemical potential. Baryon properties are investigated, such as the hedgehog mass, the magnetic moments of the proton and neutron, and the pion-nucleon coupling constant. We find that the hedgehog mass and the magnetic moments of the proton and neutron increase with increasing temperature and chemical potential, while the pion-nucleon coupling constant decreases. A comparison with the original sigma model and QCD sum rules is presented. We conclude that the logarithmic quark sigma model successfully describes baryon properties of a hot and dense medium.

  2. Shear Viscosity to Non-Equilibrium Entropy Density Ratio of Hot Quark-Gluon Plasma at Finite Chemical Potential

    Institute of Scientific and Technical Information of China (English)

    LIU Hui; HOU De-Fu; LI Jia-Rong

    2007-01-01

    In the framework of irreversible thermodynamics, we study the transport properties of hot quark-gluon plasmas. The viscous entropy production at finite chemical potential as well as the shear viscosity to non-equilibrium entropy density ratio is investigated in weakly coupled limit by using kinetic theory. The results show that the chemical potential contributes positively to their ratio compared to the pure temperature case. The ratio exhibits two boundaries in the coupling strength in which a minimum value of 0.42 is found at αs = 0.6.

  3. The influence of chiral chemical potential, parallel electric and magnetic fields on the critical temperature of QCD

    CERN Document Server

    Ruggieri, M; Peng, G X

    2016-01-01

    We study the influence of external electric, $E$, and magnetic, $B$, fields parallel to each other, and of a chiral chemical potential, $\\mu_5$, on the chiral phase transition of Quantum Chromodynamics. Our theoretical framework is a Nambu-Jona-Lasinio model with a contact interaction. Within this model we compute the critical temperature of chiral symmetry restoration, $T_c$, as a function of the chiral chemical potential and field strengths. We find that the fields inhibit and $\\mu_5$ enhances chiral symmetry breaking, in agreement with previous studies.

  4. A Rat α-Fetoprotein Binding Activity Prediction Model to Facilitate Assessment of the Endocrine Disruption Potential of Environmental Chemicals

    Science.gov (United States)

    Hong, Huixiao; Shen, Jie; Ng, Hui Wen; Sakkiah, Sugunadevi; Ye, Hao; Ge, Weigong; Gong, Ping; Xiao, Wenming; Tong, Weida

    2016-01-01

    Endocrine disruptors such as polychlorinated biphenyls (PCBs), diethylstilbestrol (DES) and dichlorodiphenyltrichloroethane (DDT) are agents that interfere with the endocrine system and cause adverse health effects. Huge public health concern about endocrine disruptors has arisen. One of the mechanisms of endocrine disruption is through binding of endocrine disruptors with the hormone receptors in the target cells. Entrance of endocrine disruptors into target cells is the precondition of endocrine disruption. The binding capability of a chemical with proteins in the blood affects its entrance into the target cells and, thus, is very informative for the assessment of potential endocrine disruption of chemicals. α-fetoprotein is one of the major serum proteins that binds to a variety of chemicals such as estrogens. To better facilitate assessment of endocrine disruption of environmental chemicals, we developed a model for α-fetoprotein binding activity prediction using the novel pattern recognition method (Decision Forest) and the molecular descriptors calculated from two-dimensional structures by Mold2 software. The predictive capability of the model has been evaluated through internal validation using 125 training chemicals (average balanced accuracy of 69%) and external validations using 22 chemicals (balanced accuracy of 71%). Prediction confidence analysis revealed the model performed much better at high prediction confidence. Our results indicate that the model is useful (when predictions are in high confidence) in endocrine disruption risk assessment of environmental chemicals though improvement by increasing number of training chemicals is needed. PMID:27023588

  5. A Rat α-Fetoprotein Binding Activity Prediction Model to Facilitate Assessment of the Endocrine Disruption Potential of Environmental Chemicals

    Directory of Open Access Journals (Sweden)

    Huixiao Hong

    2016-03-01

    Full Text Available Endocrine disruptors such as polychlorinated biphenyls (PCBs, diethylstilbestrol (DES and dichlorodiphenyltrichloroethane (DDT are agents that interfere with the endocrine system and cause adverse health effects. Huge public health concern about endocrine disruptors has arisen. One of the mechanisms of endocrine disruption is through binding of endocrine disruptors with the hormone receptors in the target cells. Entrance of endocrine disruptors into target cells is the precondition of endocrine disruption. The binding capability of a chemical with proteins in the blood affects its entrance into the target cells and, thus, is very informative for the assessment of potential endocrine disruption of chemicals. α-fetoprotein is one of the major serum proteins that binds to a variety of chemicals such as estrogens. To better facilitate assessment of endocrine disruption of environmental chemicals, we developed a model for α-fetoprotein binding activity prediction using the novel pattern recognition method (Decision Forest and the molecular descriptors calculated from two-dimensional structures by Mold2 software. The predictive capability of the model has been evaluated through internal validation using 125 training chemicals (average balanced accuracy of 69% and external validations using 22 chemicals (balanced accuracy of 71%. Prediction confidence analysis revealed the model performed much better at high prediction confidence. Our results indicate that the model is useful (when predictions are in high confidence in endocrine disruption risk assessment of environmental chemicals though improvement by increasing number of training chemicals is needed.

  6. A Rat α-Fetoprotein Binding Activity Prediction Model to Facilitate Assessment of the Endocrine Disruption Potential of Environmental Chemicals.

    Science.gov (United States)

    Hong, Huixiao; Shen, Jie; Ng, Hui Wen; Sakkiah, Sugunadevi; Ye, Hao; Ge, Weigong; Gong, Ping; Xiao, Wenming; Tong, Weida

    2016-04-01

    Endocrine disruptors such as polychlorinated biphenyls (PCBs), diethylstilbestrol (DES) and dichlorodiphenyltrichloroethane (DDT) are agents that interfere with the endocrine system and cause adverse health effects. Huge public health concern about endocrine disruptors has arisen. One of the mechanisms of endocrine disruption is through binding of endocrine disruptors with the hormone receptors in the target cells. Entrance of endocrine disruptors into target cells is the precondition of endocrine disruption. The binding capability of a chemical with proteins in the blood affects its entrance into the target cells and, thus, is very informative for the assessment of potential endocrine disruption of chemicals. α-fetoprotein is one of the major serum proteins that binds to a variety of chemicals such as estrogens. To better facilitate assessment of endocrine disruption of environmental chemicals, we developed a model for α-fetoprotein binding activity prediction using the novel pattern recognition method (Decision Forest) and the molecular descriptors calculated from two-dimensional structures by Mold² software. The predictive capability of the model has been evaluated through internal validation using 125 training chemicals (average balanced accuracy of 69%) and external validations using 22 chemicals (balanced accuracy of 71%). Prediction confidence analysis revealed the model performed much better at high prediction confidence. Our results indicate that the model is useful (when predictions are in high confidence) in endocrine disruption risk assessment of environmental chemicals though improvement by increasing number of training chemicals is needed. PMID:27023588

  7. Local autonomy and interregional equality : fiscal equalization with balanced budgets

    OpenAIRE

    Cappelen, Alexander W; Tungodden, Bertil

    2003-01-01

    This paper contributes to the literature on fiscal equalization in three ways. First, it shows how two important types of transfer schemes, the foundation grant and the power equalization grant, can be seen as two different interpretations of equal opportunity ethics. Second, it characterizes versions of these transfers schemes that ensure a balanced budget for the central government. Third, it clarifies the nature of various fiscal spillover effects within the framework of ...

  8. Potential of plant growth promoting rhizobacteria and chemical fertilizers on soil enzymes and plant growth

    International Nuclear Information System (INIS)

    The present investigation deals with the role of Plant Growth Promoting Rhizobacteria and chemical fertilizers alone or in combination on urease, invertase and phosphatase activities of rhizospheric soil and also on general impact on growth of safflower cvv. Thori and Saif-32. The PGPR (Azospirillum brasilense and Azotobacter vinelandii) were applied at 10/sup 6/ cells/mL as seed inoculation prior to sowing. Chemical fertilizers were applied at full (Urea 60 Kg ha/sup -1/ and Diammonium phosphate (DAP) 30 Kg ha/sup -1/), half (Urea 30 Kg ha/sup -1/ and DAP 15 Kg ha/sup -1/) and quarter doses (Urea 15 Kg ha-1 and DAP 7.5 Kg ha/sup -1/) during sowing. The chemical fertilizers and PGPR enhanced urease and invertase activities of soil. Presence of PGPR in combination with quarter and half doses of chemical fertilizers further augmented their effect on soil enzymes activities. The soil phosphatase activity was greater in Azospirillum and Azotobacter in combination with half dose of chemical fertilizers. Maximum increase in leaf melondialdehyde content was recorded in full dose of chemical fertilizers whereas coinoculation treatment exhibited significant reduction in cv. Thori. Half and quarter dose of chemical fertilizers increased the shoot length of safflower whereas maximum increase in leaf protein was recorded in Azotobacter in combination with full dose of chemical fertilizers. Root length was improved by Azospirillum and Azotobacter in combination with quarter dose of chemical fertilizers. Leaf area and chlorophyll contents were significantly improved by Azotobacter in combination with half dose of chemical fertilizers. It is inferred that PGPR can supplement 50 % chemical fertilizers for better plant growth and soil health. (author)

  9. Calculation of Equation of State of QCD at Finite Chemical Potential and Temperature

    Institute of Scientific and Technical Information of China (English)

    QIAO Qing-Peng; ZONG Hong-Shi; TANG Jian; HOU Feng-Yao; LI Xue-Qian; SUN Wei-Min; L(U) Xiao-Fu

    2008-01-01

    In this paper, using path integral techniques we derive a model-independent formula for the pressure density (μ, T) (or equivalently the partition function) of Quantum Chromodynamics (QCD), which gives the equation of state (EOS) of QCD at finite chemical potential and temperature. In this formula the pressure density (μ, T) consists of two terms: the first term (μ,T) T=0) is a #-independent (but T-dependent) constant; the second term is totally determined by G[μ, T] (p ωn) (the dressed quark propagator at finite μ and finite T), which contains all the nontrivial μ-dependence. Then, in the framework of the rainbow-ladder approximation of the Dyson-Schwinger (DS) approach and under the approximation of neglecting the μ-dependence of the dressed gluon propagator, we show that G[μ, T] (p, ωn) can be obtained from G[T] (p, ωn) (the dressed quark propagator at μ = 0) by the substitution ωn →ωn + iμ. This result facilitates numerical calculations considerably. By this result, once G[T](p, ωn) is known, one can determine the EOS of QCD under the above approximations (up to the additive term (μ, T)[T=0). Finally, a comparison of the present EOS of QCD and the EOS obtained in the previous literatures in the framework of the rainbow-ladder approximation of the DS approach is given. It is found that the EOS given in the previous literatures does not satisfy the thermodynamic relation p(μ, T) = T.

  10. Pyrolysis of oil at high temperatures: Gas potentials, chemical and carbon isotopic signatures

    Institute of Scientific and Technical Information of China (English)

    TIAN Hui; XIAO XianMing; YANG LiGuo; XIAO ZhongYao; GUO LiGuo; SHEN JiaGui; LU YuHong

    2009-01-01

    Although the gas cracked from oil has been believed to be one of the important sources in highly ma-tured marine basins, there are still some debates on its resource potentials and chemical and isotopic compositions. In this study a Cambrian-sourced marine oil sample from the Silurian reservoir of well TZ62 in the central Tarim basin was pyrolyzed using sealed gold tubes with two different pyrolysis schemes: continuous pyrolysis in a closed system and stepwise semi-open pyrolysis. The results show that the maximum weight yield of C1-5 gases occurs at EasyRo=2.3% and the residual gas poten-tial after this maturity is only 43.4 mL/g, about 12% of the yield of 361 mL/g at EasyRo=2.3%. Combined with the results of kinetic modeling, the main stage of gas generation from oil cracking is believed within the EasyRo=1.6%-2.3%. The increase in the volume yield of C1-5 gases at EasyRo2.3% in a closed system is mainly related to the re-cracking of previously formed C2-5 wet gases, not the direct cracking of oil. The stepwise pyrolysis experiments show that the gas from the cracking of residual oil at EasyRo2.3% is characterized by very high dryness index (higher than 92%) and heavy methane carbon isotopes ranging from -28.7‰ to -26.7‰, which is quite different from the gases from the con-tinuous pyrolysis in a closed system. The kinetic modeling of methane carbon isotope fractionation shows that the carbon isotopes of methane within the main stage of gas generation (EasyRo<2.3%) are far lighter than the carbon isotopes of the precursor oils under a geological heating rate of 2℃/Ma. The above observations and results provide some new clues to the accurate recognition and objective re-source evaluation of oil cracking gas in highly mature marine basins.

  11. Redox Disrupting Potential of ToxCast™Chemicals Ranked by Activity in Mouse Embryonic Stem Cells

    Science.gov (United States)

    Little is known regarding the adverse outcome pathways responsible for developmental toxicity following exposure to chemicals. An evaluation of Toxoast™ Phase I chemicals in an adherent mouse embryonic stem cell (mESC) assay revealed a redox sensitive pathway that correlated with...

  12. REDOX DISRUPTING POTENTIAL OF TOXCAST CHEMICALS RANKED BY ACTIVITY IN MOUSE EMBRYONIC STEM CELLS

    Science.gov (United States)

    To gain insight regarding the adverse outcome pathways leading to developmental toxicity following exposure to chemicals, we evaluated ToxCast™ Phase I chemicals in an adherent mouse embryonic stem cell (mESC) assay and identified a redox sensitive pathway that correlated with al...

  13. Chemically aged and mixed aerosols over the Central Atlantic Ocean - Potential impacts

    NARCIS (Netherlands)

    Astitha, M.; Kallos, G.; Spyrou, C.; O'Hirok, W.; Lelieveld, J.; Denier Gon, H.A.C. van der

    2010-01-01

    Detailed information on the chemical and physical properties of aerosols is important for assessing their role in air quality and climate. This work explores the origin and fate of continental aerosols transported over the Central Atlantic Ocean, in terms of chemical composition, number and size dis

  14. Modelling the chemically aged and mixed aerosols over the eastern central Atlantic Ocean-potential impacts

    NARCIS (Netherlands)

    Astitha, M.; Kallos, G.; Spyrou, C.; O'Hirok, W.; Lelieveld, J.; Denier Gon, H.A.C. van der

    2010-01-01

    Detailed information on the chemical and physical properties of aerosols is important for assessing their role in air quality and climate. This work explores the origin and fate of continental aerosols transported over the Central Atlantic Ocean, in terms of chemical composition, number and size dis

  15. Non-Chemical Distant Cellular Interactions as a potential confounder of Cell Biology Experiments

    Directory of Open Access Journals (Sweden)

    Ashkan eFarhadi

    2014-10-01

    Full Text Available Distant cells can communicate with each other through a variety of methods. Two such methods involve electrical and/or chemical mechanisms. Non-chemical, distant cellular interactions may be another method of communication that cells can use to modify the behavior of other cells that are mechanically separated. Moreover, non-chemical, distant cellular interactions may explain some cases of confounding effects in Cell Biology experiments. In this article, we review non-chemical, distant cellular interactions studies to try to shed light on the mechanisms in this highly unconventional field of cell biology. Despite the existence of several theories that try to explain the mechanism of non-chemical, distant cellular interactions, this phenomenon is still speculative. Among candidate mechanisms, electromagnetic waves appear to have the most experimental support. In this brief article, we try to answer a few key questions that may further clarify this mechanism.

  16. Genetic and Chemical Profiling of Gymnema sylvestre Accessions from Central India: Its Implication for Quality Control and Therapeutic Potential of Plant

    Science.gov (United States)

    Verma, Ashutosh Kumar; Dhawan, Sunita Singh; Singh, Seema; Bharati, Kumar Avinash; Jyotsana

    2016-01-01

    Background: Gymnema sylvestre, a vulnerable plant species, is mentioned in Indian Pharmacopeia as an antidiabetic drug Objective: Study of genetic and chemical diversity and its implications in accessions of G. sylvestre Materials and Methods: Fourteen accessions of G. sylvestre collected from Central India and assessment of their genetic and chemical diversity were carried out using ISSR (inter simple sequence repeat) and HPLC (high performance liquid chromatography) fingerprinting methods Results: Among the screened 40 ISSR primers, 15 were found polymorphic and collectively produced nine unique accession-specific bands. The maximum and minimum numbers of amplicones were noted for ISSR-15 and ISSR-11, respectively. The ISSR -11 and ISSR-13 revealed 100% polymorphism. HPLC chromatograms showed that accessions possess the secondary metabolites of mid-polarity with considerable variability. Unknown peaks with retention time 2.63, 3.41, 23.83, 24.50, and 44.67 were found universal type. Comparative hierarchical clustering analysis based on foresaid fingerprints indicates that both techniques have equal potential to discriminate accessions according to percentage gymnemic acid in their leaf tissue. Second approach was noted more efficiently for separation of accessions according to their agro-climatic/collection site Conclusion: Highly polymorphic ISSRs could be utilized as molecular probes for further selection of high gymnemic acid yielding accessions. Observed accession specific bands may be used as a descriptor for plant accessions protection and converted into sequence tagged sites markers. Identified five universal type peaks could be helpful in identification of G. sylvestre-based various herbal preparations. SUMMARY Nine accession specific unique bandsFive marker peaks for G. sylvestre.Suitability of genetic and chemical fingerprinting Abbreviations used: HPLC: High Performance Liquid Chromatography, ISSR: Inter Simple Sequence Repeats, CTAB: Cetyl

  17. Chemical potential shift in organic field-effect transistors identified by soft X-ray operando nano-spectroscopy

    Science.gov (United States)

    Nagamura, Naoka; Kitada, Yuta; Tsurumi, Junto; Matsui, Hiroyuki; Horiba, Koji; Honma, Itaru; Takeya, Jun; Oshima, Masaharu

    2015-06-01

    A chemical potential shift in an organic field effect transistor (OFET) during operation has been revealed by soft X-ray operando nano-spectroscopy analysis performed using a three-dimensional nanoscale electron-spectroscopy chemical analysis system. OFETs were fabricated using ultrathin (3 ML or 12 nm) single-crystalline C10-DNBDT-NW films on SiO2 (200 nm)/Si substrates with a backgate electrode and top source/drain Au electrodes, and C 1s line profiles under biasing at the backgate and drain electrodes were measured. When applying -30 V to the backgate, there is C 1s core level shift of 0.1 eV; this shift can be attributed to a chemical potential shift corresponding to band bending by the field effect, resulting in p-type doping.

  18. Chemical potential shift in organic field-effect transistors identified by soft X-ray operando nano-spectroscopy

    International Nuclear Information System (INIS)

    A chemical potential shift in an organic field effect transistor (OFET) during operation has been revealed by soft X-ray operando nano-spectroscopy analysis performed using a three-dimensional nanoscale electron-spectroscopy chemical analysis system. OFETs were fabricated using ultrathin (3 ML or 12 nm) single-crystalline C10-DNBDT-NW films on SiO2 (200 nm)/Si substrates with a backgate electrode and top source/drain Au electrodes, and C 1s line profiles under biasing at the backgate and drain electrodes were measured. When applying −30 V to the backgate, there is C 1s core level shift of 0.1 eV; this shift can be attributed to a chemical potential shift corresponding to band bending by the field effect, resulting in p-type doping

  19. Chemical potential shift in organic field-effect transistors identified by soft X-ray operando nano-spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nagamura, Naoka, E-mail: NAGAMURA.Naoka@nims.go.jp; Kitada, Yuta; Honma, Itaru [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Tsurumi, Junto; Matsui, Hiroyuki; Takeya, Jun [Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan); Horiba, Koji [Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Oshima, Masaharu [Synchrotron Radiation Research Organization, The University of Tokyo, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan)

    2015-06-22

    A chemical potential shift in an organic field effect transistor (OFET) during operation has been revealed by soft X-ray operando nano-spectroscopy analysis performed using a three-dimensional nanoscale electron-spectroscopy chemical analysis system. OFETs were fabricated using ultrathin (3 ML or 12 nm) single-crystalline C10-DNBDT-NW films on SiO{sub 2} (200 nm)/Si substrates with a backgate electrode and top source/drain Au electrodes, and C 1s line profiles under biasing at the backgate and drain electrodes were measured. When applying −30 V to the backgate, there is C 1s core level shift of 0.1 eV; this shift can be attributed to a chemical potential shift corresponding to band bending by the field effect, resulting in p-type doping.

  20. Sol-gels with fiber-optic chemical sensor potential: Effects of preparation, aging, and long-term storage

    Science.gov (United States)

    Badini, G. E.; Grattan, K. T. V.; Tseung, A. C. C.

    1995-08-01

    The features of sol-gels, incorporating pH-sensitive dyes, designed as potential substrates for fiber-optic chemical sensors, have been investigated in terms of a variety of characteristics resulting from the preparation methods used and following the storage of samples for a period of several years. These materials, organically doped sol-gels, have been used as the heart of a number of prototype chemical sensing instruments, and a key issue in their effective use in instrumentation is their long-term durability and stability. In this work, it has been shown that such aged gel substrates can withstand immersion in water, drying, and reimmersion without fragmenting. Such impregnated gels were shown to still exhibit strong fluorescence, although some changes to the gel structure, determined from microhardness measurements, were observed and reported, reflecting their potential for use in chemically sensitive fiber optic-based instruments.

  1. Metastability of the Two-Dimensional Blume-Capel Model with Zero Chemical Potential and Small Magnetic Field

    Science.gov (United States)

    Landim, C.; Lemire, P.

    2016-07-01

    We consider the two-dimensional Blume-Capel model with zero chemical potential and small magnetic field evolving on a large but finite torus. We obtain sharp estimates for the transition time, we characterize the set of critical configurations, and we prove the metastable behavior of the dynamics as the temperature vanishes.

  2. Properties of lightest mesons at finite temperature and quark/baryon chemical potential in instanton model of QCD vacuum

    International Nuclear Information System (INIS)

    The paper is focussed on calculating the finite temperature and quark/baryon chemical potential dependence of quark condensate π- and σ-meson masses together with quark mass in precritical region in the instanton model of QCD vacuum. The impact of phonon-like excitations of instanton liquid on the characteristics of σ meson in such an environment is also examined

  3. Assessment of the technical and economic potentials of biomass use for the production of steam, chemicals and polymers

    NARCIS (Netherlands)

    Saygin, D.; Gielen, D. J.; Draeck, M.; Worrell, E.; Patel, M. K.

    2014-01-01

    Fossil fuel substitution with biomass is one of the measures to reduce carbon dioxide (CO2) emissions. This paper estimates the cost-effectiveness of raising industrial steam and producing materials (i.e. chemicals, polymers) from biomass. We quantify their long-term global potentials in terms of en

  4. An in vitro screening method to evaluate chemicals as potential chemotherapeutants to control Aeromonas hydrophila infection in channel catfish

    Science.gov (United States)

    Using catfish gill cells G1B and four chemicals (hydrogen peroxide, sodium chloride, potassium permanganate, and D-mannose), the feasibility of using an in vitro screening method to identify potential effective chemotherapeutants was evaluated in this study. In vitro screening results revealed that,...

  5. Chemical Potential for the Interacting Classical Gas and the Ideal Quantum Gas Obeying a Generalized Exclusion Principle

    Science.gov (United States)

    Sevilla, F. J.; Olivares-Quiroz, L.

    2012-01-01

    In this work, we address the concept of the chemical potential [mu] in classical and quantum gases towards the calculation of the equation of state [mu] = [mu](n, T) where n is the particle density and "T" the absolute temperature using the methods of equilibrium statistical mechanics. Two cases seldom discussed in elementary textbooks are…

  6. Open Innovation Drug Discovery (OIDD): a potential path to novel therapeutic chemical space.

    Science.gov (United States)

    Alvim-Gaston, Maria; Grese, Timothy; Mahoui, Abdelaziz; Palkowitz, Alan D; Pineiro-Nunez, Marta; Watson, Ian

    2014-01-01

    The continued development of computational and synthetic methods has enabled the enumeration or preparation of a nearly endless universe of chemical structures. Nevertheless, the ability of this chemical universe to deliver small molecules that can both modulate biological targets and have drug-like physicochemical properties continues to be a topic of interest to the pharmaceutical industry and academic researchers alike. The chemical space described by public, commercial, in-house and virtual compound collections has been interrogated by multiple approaches including biochemical, cellular and virtual screening, diversity analysis, and in-silico profiling. However, current drugs and known chemical probes derived from these efforts are contained within a remarkably small volume of the predicted chemical space. Access to more diverse classes of chemical scaffolds that maintain the properties relevant for drug discovery is certainly needed to meet the increasing demands for pharmaceutical innovation. The Lilly Open Innovation Drug Discovery platform (OIDD) was designed to tackle barriers to innovation through the identification of novel molecules active in relevant disease biology models. In this article we will discuss several computational approaches towards describing novel, biologically active, drug-like chemical space and illustrate how the OIDD program may facilitate access to previously untapped molecules that may aid in the search for innovative pharmaceuticals.

  7. Open Innovation Drug Discovery (OIDD): a potential path to novel therapeutic chemical space.

    Science.gov (United States)

    Alvim-Gaston, Maria; Grese, Timothy; Mahoui, Abdelaziz; Palkowitz, Alan D; Pineiro-Nunez, Marta; Watson, Ian

    2014-01-01

    The continued development of computational and synthetic methods has enabled the enumeration or preparation of a nearly endless universe of chemical structures. Nevertheless, the ability of this chemical universe to deliver small molecules that can both modulate biological targets and have drug-like physicochemical properties continues to be a topic of interest to the pharmaceutical industry and academic researchers alike. The chemical space described by public, commercial, in-house and virtual compound collections has been interrogated by multiple approaches including biochemical, cellular and virtual screening, diversity analysis, and in-silico profiling. However, current drugs and known chemical probes derived from these efforts are contained within a remarkably small volume of the predicted chemical space. Access to more diverse classes of chemical scaffolds that maintain the properties relevant for drug discovery is certainly needed to meet the increasing demands for pharmaceutical innovation. The Lilly Open Innovation Drug Discovery platform (OIDD) was designed to tackle barriers to innovation through the identification of novel molecules active in relevant disease biology models. In this article we will discuss several computational approaches towards describing novel, biologically active, drug-like chemical space and illustrate how the OIDD program may facilitate access to previously untapped molecules that may aid in the search for innovative pharmaceuticals. PMID:24283973

  8. Gender equality and equal opportunity mechanisms in Italy

    Directory of Open Access Journals (Sweden)

    Mršević Zorica

    2007-01-01

    Full Text Available As a country of Southern European mentality Italy may be taken as the nearest-to-the-Balkans model of the gender equality mechanisms and necessity of their existence. Italy also might be taken as a model of domain and methods of functioning of the gender equality mechanisms as well as their connections with the EU development funds. Besides the Italian Ministry for Rights and Equal opportunities and the National Committee, the attention was paid to the whole range of local mechanisms and legal regulations dealing with advancement of women’s employment and counteracting discrimination on the labor market. In the text are analyzed through the five chapters the Italian mechanisms/institutions for gender equality as located within the European institutional environment but also within the context of Italian recent history of struggle against gender based discrimination. It was stressed that the essence of the accumulated European institutional wisdom is in diversity of the gender equality bodies rather then in their uniformity. Although the Italian mechanisms for gender equality are part of the European institutional environment their aim is to meet the internal needs for advancement of gender equality. Besides, the mechanisms also meet the demands of the international standards comprised in the documents issued by the UN and the EU. In European countries these mechanisms are frequently established and function in the domains of the labor and employment regulations, but also are located within the human rights portfolios while somewhere are connected with the minority rights and equal opportunity implementation.

  9. Reframing Inclusive Education: Educational Equality as Capability Equality

    Science.gov (United States)

    Terzi, Lorella

    2014-01-01

    In this paper, I argue that rethinking questions of inclusive education in the light of the value of educational equality--specifically conceived as capability equality, or genuine opportunities to achieve educational functionings--adds some important insights to the current debate on inclusive education. First, it provides a cohesive value…

  10. The potential role of Life Cycle Assessment in regulation of chemicals in the European Union

    DEFF Research Database (Denmark)

    Christensen, Frans Møller; Olsen, Stig Irving

    2003-01-01

    consequence, the European Chemicals Bureau (ECB) has enrolled in the OMNIITOX project with the clear aim of investigating possible applications of LCA in future EU regulation of chemicals. Implementation of REACH will expand and change the activities and services currently delivered by ECB as the focal point......The regulation of chemicals in EU is undergoing substantial changes these years with implementation of the “REACH” system. Simultaneously, the concepts of LCA and Integrated Product Policy (IPP) are becoming increasingly integrated in European standardisation and regulatory activities. As a logical...

  11. Process chemicals in the oil and gas industry: potential occupational hazards.

    Science.gov (United States)

    Cottle, M K; Guidotti, T L

    1990-01-01

    Numerous chemicals are used in various processes of the oil and gas industry: drilling, cementing, completion, stimulation, and production. The number and the complexity of composition of process chemicals has increased greatly over the last three decades. The occupational hazards of exposure to these agents has received little attention. We reviewed the various processes in the industry, the type of chemicals used in each process, and some of their characteristics. We placed emphasis on those for which significant toxicity has been established or is suspected, and those for which there is incomplete information on their chemistry and health hazards. This report is intended to form a basis for a more complete survey of the process chemicals, and to draw attention to the possibilities for toxic exposure resulting from use of these agents in the oil and gas industry. The ultimate objective is to promote the safe use of these agents in the industry. PMID:2190356

  12. Quantum chemical study of the isomerization of 24-methylenecycloartanol, a potential marker of olive oil refining

    NARCIS (Netherlands)

    Wedler, H.B.; Pemberton, R.P.; Lounnas, V.; Vriend, G.; Tantillo, D.J.; Wang, S.C.

    2015-01-01

    Quantum chemical calculations on the isomerization of 24-methylenecycloartanol are described. An energetically viable mechanism, with a rate-determining protonation step, is proposed. This rearrangement may find applicability in tests for determining if an olive oil has been refined.

  13. Can phylogeny predict chemical diversity and potential medicinal activity of plants? A case study of Amaryllidaceae

    DEFF Research Database (Denmark)

    Rønsted, Nina; Symonds, Matthew RE; Birkholm, Trine;

    2012-01-01

    Background: During evolution, plants and other organisms have developed a diversity of chemical defences, leading to the evolution of various groups of specialized metabolites selected for their endogenous biological function. A correlation between phylogeny and biosynthetic pathways could offer ...

  14. Quantum chemical study of the isomerization of 24-methylenecycloartanol, a potential marker of olive oil refining.

    Science.gov (United States)

    Wedler, Henry B; Pemberton, Ryan P; Lounnas, Valère; Vriend, Gert; Tantillo, Dean J; Wang, Selina C

    2015-05-01

    Quantum chemical calculations on the isomerization of 24-methylenecycloartanol are described. An energetically viable mechanism, with a rate-determining protonation step, is proposed. This rearrangement may find applicability in tests for determining if an olive oil has been refined.

  15. Data Quality Objectives Workbook for Assessing Chemical Vulnerability Potential in REDOX and U Plants

    International Nuclear Information System (INIS)

    The purpose of this data quality objective workbook is to present the rationale for selecting the sampling and characterization strategy that supports the assessment of the chemical vulnerabilities of the five tanks. Since characterization of the tanks' contents is likely to be expensive, a secondary goal was established to characterize the tank contents for proper waste designation and disposal at the same time the tanks are characterized for chemical vulnerability

  16. Embedded Fragments from U.S. Military Personnel—Chemical Analysis and Potential Health Implications

    OpenAIRE

    Centeno, José A.; Duane A. Rogers; Gijsbert B. van der Voet; Elisa Fornero; Lingsu Zhang; Mullick, Florabel G.; Chapman, Gail D.; Olabisi, Ayodele O.; Wagner, Dean J.; Alexander Stojadinovic; Potter, Benjamin K.

    2014-01-01

    Background: The majority of modern war wounds are characterized by high-energy blast injuries containing a wide range of retained foreign materials of a metallic or composite nature. Health effects of retained fragments range from local or systemic toxicities to foreign body reactions or malignancies, and dependent on the chemical composition and corrosiveness of the fragments in vivo. Information obtained by chemical analysis of excised fragments can be used to guide clinical decisions rega...

  17. Most Plastic Products Release Estrogenic Chemicals: A Potential Health Problem That Can Be Solved

    OpenAIRE

    Yang, Chun Z.; Yaniger, Stuart I.; Jordan, V. Craig; Klein, Daniel J.; Bittner, George D

    2011-01-01

    Background: Chemicals having estrogenic activity (EA) reportedly cause many adverse health effects, especially at low (picomolar to nanomolar) doses in fetal and juvenile mammals. Objectives: We sought to determine whether commercially available plastic resins and products, including baby bottles and other products advertised as bisphenol A (BPA) free, release chemicals having EA. Methods: We used a roboticized MCF-7 cell proliferation assay, which is very sensitive, accurate, and repeatable,...

  18. Chemical Ecology of the Colorado Potato Beetle, Leptinotarsa decemlineata (Say (Coleoptera: Chrysomelidae, and Potential for Alternative Control Methods

    Directory of Open Access Journals (Sweden)

    François J. Verheggen

    2012-12-01

    Full Text Available The Colorado potato beetle (CPB has been a major insect pest to potato farming for over 150 years and various control methods have been established to reduce its impact on potato fields. Crop rotation and pesticide use are currently the most widely used approaches, although alternative methods are being developed. Here we review the role of various volatile and nonvolatile chemicals involved in behavior changes of CPB that may have potential for their control. First, we describe all volatile and nonvolatile chemicals involved in host plant localization and acceptance by CPB beetles, including glycoalcaloids and host plant volatiles used as kairomones. In the second section, we present the chemical signals used by CPB in intraspecific communication, including sex and aggregation pheromones. Some of these chemicals are used by natural enemies of CPBs to locate their prey and are presented in the third section. The last section of this review is devoted a discussion of the potential of some natural chemicals in biological control of CPB and to approaches that already reached efficient field applications.

  19. Equality and Education -- Part 1

    Science.gov (United States)

    Porter, John

    1975-01-01

    Discusses equality in education within the framework of the ideas of John Rawls, asserting that even though in the real world it is not easy to implement his version of equality and justice without endangering his prior principle of liberty, he provides a philosophical foundation for the reconsideration of the meritocratic principle. (Author/JM)

  20. Quantum chemical approach for condensed-phase thermochemistry (III): Accurate evaluation of proton hydration energy and standard hydrogen electrode potential

    Science.gov (United States)

    Ishikawa, Atsushi; Nakai, Hiromi

    2016-04-01

    Gibbs free energy of hydration of a proton and standard hydrogen electrode potential were evaluated using high-level quantum chemical calculations. The solvent effect was included using the cluster-continuum model, which treated short-range effects by quantum chemical calculations of proton-water complexes, and the long-range effects by a conductor-like polarizable continuum model. The harmonic solvation model (HSM) was employed to estimate enthalpy and entropy contributions due to nuclear motions of the clusters by including the cavity-cluster interactions. Compared to the commonly used ideal gas model, HSM treatment significantly improved the contribution of entropy, showing a systematic convergence toward the experimental data.

  1. Potential of Palm Olein as Green Lubricant Source: Lubrication Analysis and Chemical Characterisation

    International Nuclear Information System (INIS)

    Palm olein (POo) is widely used as edible oil in tropical countries. The lubrication properties and chemical compositions of POo being considered to be used as renewable raw material for bio lubricant synthesis. POo is suitable to be used directly as bio lubricant for medium temperature industrial applications. Palm olein has good viscosity index, oxidative stability, flash and fire point as a lubricant source. POo contains unsaturated triacylglycerols (TAG): Palmitin-Olein-Olein, POO (33.3 %), Palmitin-Olein-Palmitin, POP (29.6 %), which are very important to produce good lubricant properties. This unsaturated bond is preferable in chemical modification to produce bio lubricant. The chemical compositions of POo were tested by using high performance liquid chromatography (HPLC) and gas chromatography (GC) techniques. (author)

  2. Toxicity tests with crustaceans for detecting sublethal effects of potential endocrine disrupting chemicals

    DEFF Research Database (Denmark)

    Wollenberger, Leah

    of effective concentrations (ECx). After having demonstrated that larval development of A. tonsa was a very sensitive endpoint for evaluating effects of chemicals that might interfere with the endocrine system of crustaceans, the larval development test has been applied to two groups of emerging environmental...... of in vitro assays and (sub)chronic copepod tests, as applied in this study, is a valuable tool when screening chemicals suspected to be specifically toxic, in particular, to interfere with the endocrine system. The results of the experimental work as well as the literature survey demonstrated clearly......New and updated test methods to detect and characterise endocrine disrupting chemicals are urgently needed for the purpose of environmental risk assessment. Although endocrine disruption in invertebrates has not been studied as extensive as in vertebrates, in particular in fish, numerous reports...

  3. The past, present and potential for microfluidic reactor technology in chemical synthesis.

    Science.gov (United States)

    Elvira, Katherine S; Casadevall i Solvas, Xavier; Wootton, Robert C R; deMello, Andrew J

    2013-11-01

    The past two decades have seen far-reaching progress in the development of microfluidic systems for use in the chemical and biological sciences. Here we assess the utility of microfluidic reactor technology as a tool in chemical synthesis in both academic research and industrial applications. We highlight the successes and failures of past research in the field and provide a catalogue of chemistries performed in a microfluidic reactor. We then assess the current roadblocks hindering the widespread use of microfluidic reactors from the perspectives of both synthetic chemistry and industrial application. Finally, we set out seven challenges that we hope will inspire future research in this field.

  4. Chemical Reaction CO+OH(•) → CO2+H(•) Autocatalyzed by Carbon Dioxide: Quantum Chemical Study of the Potential Energy Surfaces.

    Science.gov (United States)

    Masunov, Artëm E; Wait, Elizabeth; Vasu, Subith S

    2016-08-01

    The supercritical carbon dioxide medium, used to increase efficiency in oxy combustion fossil energy technology, may drastically alter both rates and mechanisms of chemical reactions. Here we investigate potential energy surface of the second most important combustion reaction with quantum chemistry methods. Two types of effects are reported: formation of the covalent intermediates and formation of van der Waals complexes by spectator CO2 molecule. While spectator molecule alter the activation barrier only slightly, the covalent bonding opens a new reaction pathway. The mechanism includes sequential covalent binding of CO2 to OH radical and CO molecule, hydrogen transfer from oxygen to carbon atoms, and CH bond dissociation. This reduces the activation barrier by 11 kcal/mol at the rate-determining step and is expected to accelerate the reaction rate. The finding of predicted catalytic effect is expected to play an important role not only in combustion but also in a broad array of chemical processes taking place in supercritical CO2 medium. It may open a new venue for controlling reaction rates for chemical manufacturing. PMID:27351778

  5. Ecological Recovery Potential of Freshwater Organisms: Consequences for Environmental Risk Assessment of Chemicals.

    Science.gov (United States)

    Gergs, Andre; Classen, Silke; Strauss, Tido; Ottermanns, Richard; Brock, Theo C M; Ratte, Hans Toni; Hommen, Udo; Preuss, Thomas G

    2016-01-01

    Chemical contaminants released into the in the environment may have adverse effects on (non-target) species, populations and communities. The return of a stressed system to its pre-disturbance or other reference state, i.e. the ecological recovery, may depend on various factors related to the affected taxon, the ecosystem of concern and the type of stressor with consequences for the assessment and management of risks associated with chemical contaminants. Whereas the effects caused by short-term exposure might be acceptable to some extent, the conditions under which ecological recovery can serve as a decision criterion in the environmental risk assessment of chemical stressors remains to be evaluated. For a generic consideration of recovery in the risk assessment of chemicals, we reviewed case studies of natural and artificial aquatic systems and evaluate five aspects that might cause variability in population recovery time: (1) taxonomic differences and life-history variability, (2) factors related to ecosystem type and community processes, (3) type of disturbance, (4) comparison of field and semi-field studies, and (5) effect magnitude, i.e., the decline in population size following disturbance. We discuss our findings with regard to both retrospective assessments and prospective risk assessment.

  6. Machine learning predictions of molecular properties: Accurate many-body potentials and nonlocality in chemical space

    International Nuclear Information System (INIS)

    Simultaneously accurate and efficient prediction of molecular properties throughout chemical compound space is a critical ingredient toward rational compound design in chemical and pharmaceutical industries. Aiming toward this goal, we develop and apply a systematic hierarchy of efficient empirical methods to estimate atomization and total energies of molecules. These methods range from a simple sum over atoms, to addition of bond energies, to pairwise interatomic force fields, reaching to the more sophisticated machine learning approaches that are capable of describing collective interactions between many atoms or bonds. In the case of equilibrium molecular geometries, even simple pairwise force fields demonstrate prediction accuracy comparable to benchmark energies calculated using density functional theory with hybrid exchange-correlation functionals; however, accounting for the collective many-body interactions proves to be essential for approaching the 'holy grail' of chemical accuracy of 1 kcal/mol for both equilibrium and out-of-equilibrium geometries. This remarkable accuracy is achieved by a vectorized representation of molecules (so-called Bag of Bonds model) that exhibits strong nonlocality in chemical space. The same representation allows us to predict accurate electronic properties of molecules, such as their polarizability and molecular frontier orbital energies

  7. Assessment of the atmospheric hazards and risks of new chemicals: procedures to estimate "hazard potentials"

    NARCIS (Netherlands)

    de Leeuw FAAM

    1993-01-01

    In this report a procedure for the assessment of atmospheric hazards and risks of newly introduced chemicals is discussed. However, an assessment of direct effects caused by exposure to expected ambient concentrations or by deposition is not discussed ; here emphasis is on the role which new subst

  8. Equalization of data transmission cable

    Science.gov (United States)

    Zobrist, G. W.

    1975-01-01

    The paper describes an equalization approach utilizing a simple RLC network which can obtain a maximum slope of -12dB/octave for reshaping the frequency characteristics of a data transmission cable, so that data may be generated and detected at the receiver. An experimental procedure for determining equalizer design specifications using distortion analysis is presented. It was found that for lengths of 16 PEV-L cable of up to 5 miles and data transmission rates of up to 1 Mbs, the equalization scheme proposed here is sufficient for generation of the data with acceptable error rates.

  9. The multi-flavor Schwinger model with chemical potential - Overcoming the sign problem with Matrix Product States

    CERN Document Server

    Bañuls, Mari Carmen; Cirac, J Ignacio; Jansen, Karl; Kühn, Stefan; Saito, Hana

    2016-01-01

    During recent years there has been an increasing interest in the application of matrix product states, and more generally tensor networks, to lattice gauge theories. This non-perturbative method is sign problem free and has already been successfully used to compute mass spectra, thermal states and phase diagrams, as well as real-time dynamics for Abelian and non-Abelian gauge models. In previous work we showed the suitability of the method to explore the zero-temperature phase structure of the multi-flavor Schwinger model at non-zero chemical potential, a regime where the conventional Monte Carlo approach suffers from the sign problem. Here we extend our numerical study by looking at the spatially resolved chiral condensate in the massless case. We recover spatial oscillations, similar to the theoretical predictions for the single-flavor case, with a chemical potential dependent frequency and an amplitude approximately given by the homogeneous zero density condensate value.

  10. Extracting chemical potentials of quarks from ratios of negatively/positively charged particles in high-energy collisions

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Fu-Hu; Tian, Tian; Zhao, Hong; Li, Bao-Chun [Shanxi University, Institute of Theoretical Physics, Taiyuan (China)

    2014-03-15

    The transverse momentum spectrums of π{sup -}, π{sup +}, K{sup -}, K{sup +}, anti p, and p produced in p-Pb collisions at √(s{sub NN}) = 5.02 TeV measured by the CMS Collaboration and in Pb-Pb collisions at √(s{sub NN}) = 2.76 TeV measured by the ALICE Collaboration are described by the Tsallis distribution. Then, the ratios of negatively/positively charged particles are obtained. The chemical potentials of u-quark, d-quark, s-quark, baryon number, isospin, and strangeness are obtained by using different configurations of the ratios. Comparing with the masses of final-state particles, all the six types of chemical potentials are small. (orig.)

  11. Understanding chemical-potential-related transient pore-pressure response to improve real-time borehole (in)stability predictions

    Energy Technology Data Exchange (ETDEWEB)

    Tare, U. A.; Mody, F. K.; Mese, A. I. [Haliburton Energy Services, TX (United States)

    2002-07-01

    In order to develop a real-time wellbore (in)stability modelling capability, experimental work was carried out to investigate the role of the chemical potential of drilling fluids on transient pore pressure and time-dependent rock property alterations of shale formations. Time-dependent alterations in the pore pressure, acoustic and rock properties of formations subjected to compressive tri-axial test were recorded during the experiments involving the Pore Pressure Transmission (PPT) test. Based on the transient pore pressure of shale exposed to the test fluid presented here, the 20 per cent calcium chloride showed a very low membrane efficiency of 4.45 per cent. The need for a thorough understanding of the drilling fluid/shale interaction prior to applying any chemical potential wellbore (in)stability model to real-time drilling operations was emphasized. 9 refs., 5 figs.

  12. The effect of the chiral chemical potential on the chiral phase transition in the NJL model with different regularization schemes

    CERN Document Server

    Yu, Lang; Huang, Mei

    2015-01-01

    We study the chiral phase transition in the presence of the chiral chemical potential $\\mu_5$ using the two-flavor Nambu--Jona-Lasinio model. In particular, we analyze the reason why one can obtain two opposite behaviors of the chiral critical temperature as a function of $\\mu_5$ in the framework of different regularization schemes. We compare the modifications of the chiral condensate and the critical temperature due to $\\mu_5$ in different regularization schemes, analytically and numerically. Finally, we find that, for the conventional hard-cutoff regularization scheme, the increasing dependence of the critical temperature on the chiral chemical potential is an artifact, which is caused by the fact that it does not include complete contribution from the thermal fluctuations. When the thermal contribution is fully taken into account, the chiral critical temperature should decrease with $\\mu_5$.

  13. Chemical Potentials of Quarks Extracted from Particle Transverse Momentum Distributions in Heavy Ion Collisions at RHIC Energies

    Directory of Open Access Journals (Sweden)

    Hong Zhao

    2014-01-01

    Full Text Available In the framework of a multisource thermal model, the transverse momentum distributions of charged particles produced in nucleus-nucleus (A-A and deuteron-nucleus (d-A collisions at relativistic heavy ion collider (RHIC energies are investigated by a two-component revised Boltzmann distribution. The calculated results are in agreement with the PHENIX experimental data. It is found that the source temperature increases obviously with increase of the particle mass and incident energy, but it does not show an obvious change with the collision centrality. Then, the values of chemical potentials for up, down, and strange quarks can be obtained from the antiparticle to particle yield ratios in a wide transverse momentum range. The relationship between the chemical potentials of quarks and the transverse momentum with different centralities is investigated, too.

  14. On the velocity and chemical-potential dependence of the heavy-quark interaction in N=4 SYM plasmas

    CERN Document Server

    Avramis, S D; Zoakos, D; Avramis, Spyros D.; Sfetsos, Konstadinos; Zoakos, Dimitrios

    2006-01-01

    We consider the interaction of a heavy quark-antiquark pair moving in N=4 SYM plasma in the presence of non-vanishing chemical potentials. Of particular importance is the maximal length beyond which the interaction is practically turned off. We propose a simple phenomenological law that takes into account the velocity dependence of this screening length beyond the leading order and in addition its dependence on the R-charge. Our proposal is based on studies using rotating D3-branes.

  15. Big Data in Chemical Toxicity Research: The Use of High-Throughput Screening Assays To Identify Potential Toxicants

    OpenAIRE

    Zhu, Hao; Zhang, Jun; Kim, Marlene T.; Boison, Abena; Sedykh, Alexander; Moran, Kimberlee

    2014-01-01

    High-throughput screening (HTS) assays that measure the in vitro toxicity of environmental compounds have been widely applied as an alternative to in vivo animal tests of chemical toxicity. Current HTS studies provide the community with rich toxicology information that has the potential to be integrated into toxicity research. The available in vitro toxicity data is updated daily in structured formats (e.g., deposited into PubChem and other data-sharing web portals) or in an unstructured way ...

  16. Explanation of a strange bulk-edge equality

    Directory of Open Access Journals (Sweden)

    Vishwanath Ashvin

    2012-03-01

    Full Text Available In the infrared limit the N-particle ground-state wavefunctions of the bulk happen to be exactly equal to the N-point space-time correlation functions for certain topological superconductors. We explain this [1], beginning with the p+ip state in D=2+1. We write Z(J, the generating function for wavefunctions, as a path Euclidean integral. Varying the chemical potential as a function of Euclidean time between weak and strong pairing states is shown to extract the wavefunction. Upon a Euclidean rotation that exchanges time and space, approximate Lorentz invariance converts the system to one with a spatial edge and Z(J to the generator of spacetime correlation functions for the edge fields. We also provide a D=3+1 example, superfluid 3He- B, and a pwave superfluid in D=1+1. Our method works only when particle number is not conserved, as in superconductors.

  17. NUMERICAL ALGORITHMS AT NON-ZERO CHEMICAL POTENTIAL. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, VOLUME 19

    Energy Technology Data Exchange (ETDEWEB)

    BLUM,T.

    1999-09-14

    The RIKEN BNL Research Center hosted its 19th workshop April 27th through May 1, 1999. The topic was Numerical Algorithms at Non-Zero Chemical Potential. QCD at a non-zero chemical potential (non-zero density) poses a long-standing unsolved challenge for lattice gauge theory. Indeed, it is the primary unresolved issue in the fundamental formulation of lattice gauge theory. The chemical potential renders conventional lattice actions complex, practically excluding the usual Monte Carlo techniques which rely on a positive definite measure for the partition function. This ''sign'' problem appears in a wide range of physical systems, ranging from strongly coupled electronic systems to QCD. The lack of a viable numerical technique at non-zero density is particularly acute since new exotic ''color superconducting'' phases of quark matter have recently been predicted in model calculations. A first principles confirmation of the phase diagram is desirable since experimental verification is not expected soon. At the workshop several proposals for new algorithms were made: cluster algorithms, direct simulation of Grassman variables, and a bosonization of the fermion determinant. All generated considerable discussion and seem worthy of continued investigation. Several interesting results using conventional algorithms were also presented: condensates in four fermion models, SU(2) gauge theory in fundamental and adjoint representations, and lessons learned from strong; coupling, non-zero temperature and heavy quarks applied to non-zero density simulations.

  18. Consensus on the solubility of NaCl in water from computer simulations using the chemical potential route

    Science.gov (United States)

    Benavides, A. L.; Aragones, J. L.; Vega, C.

    2016-03-01

    The solubility of NaCl in water is evaluated by using three force field models: Joung-Cheatham for NaCl dissolved in two different water models (SPC/E and TIP4P/2005) and Smith Dang NaCl model in SPC/E water. The methodology based on free-energy calculations [E. Sanz and C. Vega, J. Chem. Phys. 126, 014507 (2007)] and [J. L. Aragones et al., J. Chem. Phys. 136, 244508 (2012)] has been used, except, that all calculations for the NaCl in solution were obtained by using molecular dynamics simulations with the GROMACS package instead of homemade MC programs. We have explored new lower molalities and made longer runs to improve the accuracy of the calculations. Exploring the low molality region allowed us to obtain an analytical expression for the chemical potential of the ions in solution as a function of molality valid for a wider range of molalities, including the infinite dilute case. These new results are in better agreement with recent estimations of the solubility obtained with other methodologies. Besides, two empirical simple rules have been obtained to have a rough estimate of the solubility of a certain model, by analyzing the ionic pairs formation as a function of molality and/or by calculating the difference between the NaCl solid chemical potential and the standard chemical potential of the salt in solution.

  19. Big data in chemical toxicity research: the use of high-throughput screening assays to identify potential toxicants.

    Science.gov (United States)

    Zhu, Hao; Zhang, Jun; Kim, Marlene T; Boison, Abena; Sedykh, Alexander; Moran, Kimberlee

    2014-10-20

    High-throughput screening (HTS) assays that measure the in vitro toxicity of environmental compounds have been widely applied as an alternative to in vivo animal tests of chemical toxicity. Current HTS studies provide the community with rich toxicology information that has the potential to be integrated into toxicity research. The available in vitro toxicity data is updated daily in structured formats (e.g., deposited into PubChem and other data-sharing web portals) or in an unstructured way (papers, laboratory reports, toxicity Web site updates, etc.). The information derived from the current toxicity data is so large and complex that it becomes difficult to process using available database management tools or traditional data processing applications. For this reason, it is necessary to develop a big data approach when conducting modern chemical toxicity research. In vitro data for a compound, obtained from meaningful bioassays, can be viewed as a response profile that gives detailed information about the compound's ability to affect relevant biological proteins/receptors. This information is critical for the evaluation of complex bioactivities (e.g., animal toxicities) and grows rapidly as big data in toxicology communities. This review focuses mainly on the existing structured in vitro data (e.g., PubChem data sets) as response profiles for compounds of environmental interest (e.g., potential human/animal toxicants). Potential modeling and mining tools to use the current big data pool in chemical toxicity research are also described. PMID:25195622

  20. Shear viscosity, bulk viscosity, and relaxation times of causal dissipative relativistic fluid-dynamics at finite temperature and chemical potential

    Science.gov (United States)

    Huang, Xu-Guang; Koide, Tomoi

    2012-09-01

    The microscopic formulas for the shear viscosity η, the bulk viscosity ζ, and the corresponding relaxation times τπ and τΠ of causal dissipative relativistic fluid-dynamics are obtained at finite temperature and chemical potential by using the projection operator method. The non-triviality of the finite chemical potential calculation is attributed to the arbitrariness of the operator definition for the bulk viscous pressure. We show that, when the operator definition for the bulk viscous pressure Π is appropriately chosen, the leading-order result of the ratio, ζ over τΠ, coincides with the same ratio obtained at vanishing chemical potential. We further discuss the physical meaning of the time-convolutionless (TCL) approximation to the memory function, which is adopted to derive the main formulas. We show that the TCL approximation violates the time reversal symmetry appropriately and leads results consistent with the quantum master equation obtained by van Hove. Furthermore, this approximation can reproduce an exact relation for transport coefficients obtained by using the f-sum rule derived by Kadanoff and Martin. Our approach can reproduce also the result in Baier et al. (2008) [8] by taking into account the next-order correction to the TCL approximation, although this correction causes several problems.

  1. Chemical composition and bioethanol potential of different plant species found in pacific northwest conservation buffers

    Science.gov (United States)

    Increase in energy demand has led towards considering lignocellulosic feedstocks as potential for ethanol production. Aim of this study was to estimate the potential of grass straws from conservation reserve program (CRP) lands as feedstocks for ethanol production. The CRP was initiated to ensure re...

  2. Non-equal-time Poisson brackets

    OpenAIRE

    Nikolic, H.

    1998-01-01

    The standard definition of the Poisson brackets is generalized to the non-equal-time Poisson brackets. Their relationship to the equal-time Poisson brackets, as well as to the equal- and non-equal-time commutators, is discussed.

  3. All Men are Created Equal

    Institute of Scientific and Technical Information of China (English)

    黄婉欣

    2015-01-01

    <正>I have a dream that one day this nation will rise up and live out the true meaning of its creed:"We hold these truths to be self-evident,that all men are created equal."This is an abstract from Martin Luther King’s famous speech I Have a Dream,which we all learnt in middle school."All men are created equal",he said,and he devoted his

  4. Strategies and chemical design approaches to reduce the potential for formation of reactive metabolic species.

    Science.gov (United States)

    Argikar, Upendra A; Mangold, James B; Harriman, Shawn P

    2011-01-01

    Metabolic activation of new chemical entities to reactive intermediates is routinely monitored in drug discovery and development. Reactive intermediates may bind to cellular macromolecules such as proteins, DNA and may eventually lead to cell death via necrosis, apoptosis or oxidative stress. The evidence that the ultimate outcome of metabolic activation is an adverse drug reaction manifested as in vivo toxicity, is at best circumstantial. However, understanding the process of bioactivation of structural alerts by trapping the reactive intermediates is critical to guide medicinal chemistry efforts in quest for safer and potent molecules. This commentary provides a brief introduction to adverse drug reactions and mechanisms of reactive intermediate formation for various functional groups, followed by a review of chemical design approaches, examples of such strategies, possible isosteric replacements for structural alerts and rationalization of laboratory approaches to determine reactive intermediates, as a guide to today's medicinal chemist. PMID:21320068

  5. Embedded Fragments from U.S. Military Personnel—Chemical Analysis and Potential Health Implications

    Directory of Open Access Journals (Sweden)

    José A. Centeno

    2014-01-01

    Full Text Available Background: The majority of modern war wounds are characterized by high-energy blast injuries containing a wide range of retained foreign materials of a metallic or composite nature. Health effects of retained fragments range from local or systemic toxicities to foreign body reactions or malignancies, and dependent on the chemical composition and corrosiveness of the fragments in vivo. Information obtained by chemical analysis of excised fragments can be used to guide clinical decisions regarding the need for fragment removal, to develop therapeutic interventions, and to better anticipate future medical problems from retained fragment related injuries. In response to this need, a new U.S Department of Defense (DoD directive has been issued requiring characterization of all removed fragments to provide a database of fragment types occurring in combat injuries. Objectives: The objective of this study is to determine the chemical composition of retained embedded fragments removed from injured military personnel, and to relate results to histological findings in tissue adjacent to fragment material. Methods: We describe an approach for the chemical analysis and characterization of retained fragments and adjacent tissues, and include case examples describing fragments containing depleted uranium (DU, tungsten (W, lead (Pb, and non-metal foreign bodies composed of natural and composite materials. Fragments obtained from four patients with penetrating blast wounds to the limbs were studied employing a wide range of chemical and microscopy techniques. Available adjacent tissues from three of the cases were histologically, microscopically, and chemically examined. The physical and compositional properties of the removed foreign material surfaces were examined with energy dispersive x-ray fluorescence spectrometry (EDXRF, scanning electron microscopy (SEM, laser ablation inductively-coupled plasma mass-spectrometry (LA-ICP-MS, and confocal laser Raman

  6. Embedded Fragments from U.S. Military Personnel—Chemical Analysis and Potential Health Implications

    Science.gov (United States)

    Centeno, José A.; Rogers, Duane A.; van der Voet, Gijsbert B.; Fornero, Elisa; Zhang, Lingsu; Mullick, Florabel G.; Chapman, Gail D.; Olabisi, Ayodele O.; Wagner, Dean J.; Stojadinovic, Alexander; Potter, Benjamin K.

    2014-01-01

    Background: The majority of modern war wounds are characterized by high-energy blast injuries containing a wide range of retained foreign materials of a metallic or composite nature. Health effects of retained fragments range from local or systemic toxicities to foreign body reactions or malignancies, and dependent on the chemical composition and corrosiveness of the fragments in vivo. Information obtained by chemical analysis of excised fragments can be used to guide clinical decisions regarding the need for fragment removal, to develop therapeutic interventions, and to better anticipate future medical problems from retained fragment related injuries. In response to this need, a new U.S Department of Defense (DoD) directive has been issued requiring characterization of all removed fragments to provide a database of fragment types occurring in combat injuries. Objectives: The objective of this study is to determine the chemical composition of retained embedded fragments removed from injured military personnel, and to relate results to histological findings in tissue adjacent to fragment material. Methods: We describe an approach for the chemical analysis and characterization of retained fragments and adjacent tissues, and include case examples describing fragments containing depleted uranium (DU), tungsten (W), lead (Pb), and non-metal foreign bodies composed of natural and composite materials. Fragments obtained from four patients with penetrating blast wounds to the limbs were studied employing a wide range of chemical and microscopy techniques. Available adjacent tissues from three of the cases were histologically, microscopically, and chemically examined. The physical and compositional properties of the removed foreign material surfaces were examined with energy dispersive x-ray fluorescence spectrometry (EDXRF), scanning electron microscopy (SEM), laser ablation inductively-coupled plasma mass-spectrometry (LA-ICP-MS), and confocal laser Raman

  7. Morphological and physico-chemical properties of British aquatic habitats potentially exposed to pesticides.

    OpenAIRE

    Brown, Colin D.; Turner, Nigel; Hollis, John; Bellamy, Patricia H.; Biggs, Jeremy; Williams, Penny; Arnold, Dave; Pepper, Tim; Maund, Steve

    2006-01-01

    Approaches to describe the exposure of non-target aquatic organisms to agricultural pesticides can be limited by insufficient knowledge of the environmental conditions where the compounds are used. This study analysed information from national and regional datasets gathered in the UK describing the morphological and physico-chemical properties of rivers, streams, ponds and ditches. An aggregation approach was adopted, whereby the landscape was divided into 12 hydrogeological classes for agric...

  8. Modelling the chemically aged and mixed aerosols over the eastern central Atlantic Ocean – potential impacts

    Directory of Open Access Journals (Sweden)

    M. Astitha

    2010-07-01

    Full Text Available Detailed information on the chemical and physical properties of aerosols is important for assessing their role in air quality and climate. This work explores the origin and fate of continental aerosols transported over the Central Atlantic Ocean, in terms of chemical composition, number and size distribution, using chemistry-transport models, satellite data and in situ measurements. We focus on August 2005, a period with intense hurricane and tropical storm activity over the Atlantic Ocean. A mixture of anthropogenic (sulphates, nitrates, natural (desert dust, sea salt and chemically aged (sulphate and nitrate on dust aerosols is found entering the hurricane genesis region, most likely interacting with clouds in the area. Results from our modelling study suggest rather small amounts of accumulation mode desert dust, sea salt and chemically aged dust aerosols in this Atlantic Ocean region. Aerosols of smaller size (Aitken mode are more abundant in the area and in some occasions sulphates of anthropogenic origin and desert dust are of the same magnitude in terms of number concentrations. Typical aerosol number concentrations are derived for the vertical layers near shallow cloud formation regimes, indicating that the aerosol number concentration can reach several thousand particles per cubic centimetre. The vertical distribution of the aerosols shows that the desert dust particles are often transported near the top of the marine cloud layer as they enter into the region where deep convection is initiated. The anthropogenic sulphate aerosol can be transported within a thick layer and enter the cloud deck through multiple ways (from the top, the base of the cloud, and by entrainment. The sodium (sea salt related aerosol is mostly found below the cloud base. The results of this work may provide insights relevant for studies that consider aerosol influences on cloud processes and storm development in the Central Atlantic region.

  9. Chemically aged and mixed aerosols over the Central Atlantic Ocean – potential impacts

    Directory of Open Access Journals (Sweden)

    H. A. C. Denier van der Gon

    2010-02-01

    Full Text Available Detailed information on the chemical and physical properties of aerosols is important for assessing their role in air quality and climate. This work explores the origin and fate of continental aerosols transported over the Central Atlantic Ocean, in terms of chemical composition, number and size distribution, using chemistry-transport models, satellite data and in situ measurements. We focus on August 2005, a period with intense hurricane and tropical storm activity over the Atlantic Ocean. A mixture of anthropogenic (sulphates, nitrates, natural (desert dust, sea salt and chemically aged (sulphate and nitrate on dust aerosols is found entering the hurricane genesis region, most likely interacting with clouds in the area. Results from our modelling study suggest rather small amounts of accumulation mode desert dust, sea salt and chemically aged dust aerosols in this Atlantic Ocean region. Aerosols of smaller size (Aitken mode are more abundant in the area and in some occasions sulphates of anthropogenic origin and desert dust are of the same magnitude in terms of number concentrations. Typical aerosol number concentrations are derived for the vertical layers near shallow cloud formation regimes, designating that the aerosol number concentration can reach several thousand particles per cubic centimetre. The vertical distribution of the aerosols indicates that the desert dust particles are often transported near the top of the marine cloud layer as they enter into the region where deep convection is initiated. The anthropogenic sulphate aerosol can be transported within a thick layer and enter the cloud deck through multiple ways (from the top, the base of the cloud and entrainment. The sodium (sea salt related aerosol is mostly found below the cloud base. The results of this work may provide insights relevant for studies that consider aerosol influences on cloud processes and storm development in the Central Atlantic region.

  10. CHEMICAL MODIFICATION AND CHARACTERIZATION OF PECTIN AS A POTENTIAL DRUG RELEASE RETARDANT

    Directory of Open Access Journals (Sweden)

    Harika Puppala Satya Krishna

    2011-02-01

    Full Text Available The present study deals with the chemical modification of pectin by acetylation of their free hydroxyl groups to yield high ester pectin and to evaluate its solubility and swelling behaviour along with the effect on the release pattern of the drug. Modified pectins were prepared by acetylation process using various strengths of 20%, 40% and 60% v/v acetyl chloride in ethanol. The prepared modified pectins were subjected to various physico-chemical characteristics like solubility, gelling studies, acid value, saponification value and ester value. FTIR studies were carried out to confirm the chemical modification of pectin. Matrix tablets of tramadol were formulated using various strengths of modified pectins in different concentrations and its impact on drug release was studied. All the formulated batches were subjected to weight variation, hardness, friability, drug content and the values obtained were within the acceptable range. The in-vitro drug release characteristics from the formulated tablets were compared with commercial sustained release tablet of tramadol. The optimized tablet formulation F4 sustained the drug release over a period of 8hours as comparable to the marketed product. Thus the synthesized modified pectin proved to be an ideal drug release retarding polymer.

  11. Kalman Filtering in the Presence of State Space Equality Constraints

    OpenAIRE

    Gupta, Nachi

    2007-01-01

    We discuss two separate techniques for Kalman Filtering in the presence of state space equality constraints. We then prove that despite the lack of similarity in their formulations, under certain conditions, the two methods result in mathematically equivalent constrained estimate structures. We conclude that the potential benefits of using equality constraints in Kalman Filtering often outweigh the computational costs, and as such, equality constraints, when present, should be enforced by way...

  12. Application of Fast and Robust Equalization in Communication Technology

    Institute of Scientific and Technical Information of China (English)

    Ye Hua(叶桦); Zhou Wanlei; Ye Lin; Lanham Elicia; Raitman Ruth

    2003-01-01

    In this paper, the authors explore the potential of several popular equalization techniques while overcoming their disadvantages. First, extensive literature survey on equalization is conducted. The focus is on popular linear equalization algorithms such as the conventional least-mean-square (LMS ) algorithm, the recursive least-squares ( RLS ) algorithm, the filtered-X LMS algorithm and their development. To overcome the slow convergence problem while keeping the simplicity of the LMS based algorithms, an H2 optimal initialization is proposed.

  13. Equal Representation : New Perspectives in Democratic Theory

    OpenAIRE

    2016-01-01

    Representation is not only a buzz–word in contemporary political theory butalso a conceptual platform from which questions about the performance of old forms of democracy and the potential of new varieties are launched. This volume is primarily concerned with equality as a basic component of the democraticcharacter of representation. In other words, of the many types of equalitythat have attracted the attention of theorists since democracy’s beginnings –political, socio-economic, anthropologi...

  14. Asymmetric catalysis in Brazil: development and potential for advancement of Brazilian chemical industry

    International Nuclear Information System (INIS)

    The preparation of enantiomerically pure or enriched substances is of fundamental importance to pharmaceutical, food, agrochemical, and cosmetics industries and involves a growing market of hundreds of billions of dollars. However, most chemical processes used for their production are not environmentally friendly because in most cases, stoichiometric amounts of chiral inductors are used and substantial waste is produced. In this context, asymmetric catalysis has emerged as an efficient tool for the synthesis of enantiomerically enriched compounds using chiral catalysts. More specifically, considering the current scenario in the Brazilian chemical industry, especially that of pharmaceuticals, the immediate prospect for the use of synthetic routes developed in Brazil in an enantioselective fashion or even the discovery of new drugs is practically null. Currently, the industrial production of drugs in Brazil is primarily focused on the production of generic drugs and is basically supported by imports of intermediates from China and India. In order to change this panorama and move forward toward the gradual incorporation of genuinely Brazilian synthetic routes, strong incentive policies, especially those related to continuous funding, will be needed. These incentives could be a breakthrough once we establish several research groups working in the area of organic synthesis and on the development and application of chiral organocatalysts and ligands in asymmetric catalysis, thus contributing to boost the development of the Brazilian chemical industry. Considering these circumstances, Brazil can benefit from this opportunity because we have a wide biodiversity and a large pool of natural resources that can be used as starting materials for the production of new chiral catalysts and are creating competence in asymmetric catalysis and related areas. This may decisively contribute to the growth of chemistry in our country. (author)

  15. Predicting physico-chemical properties of polychlorinated diphenyl ethers (PCDEs):potential persistent organic pollutants (POPs)

    Institute of Scientific and Technical Information of China (English)

    HUANG Jun; YU Gang; YANG Xi; ZHANG Zu-lin

    2004-01-01

    Polychlorinated diphenyl ethers(PCDEs) have received more and more concerns as a category of potentialpersistent organic pollutants( POPs). Modeling its environmental fate and exposure assessment require a number offundamental physico-chemical properties. However, the experimental data are currently limited due to the difficulty inanalysis caused by the complexity of PCDE congeners. As an alternative, the quantitative structure propertyrelationship(QSPR) approach could be used. In this paper, twelve kinds of molecular connectivity indices(MCIs) ofall 209 possible molecular structure patterns of PCDEs were calculated. Based on 106 PCDEs with three observedphysico-chemical properties-vapour pressure(PoL), aqueous solubility(Sw) and n-octanol/water(Kow) and theirMCIs data, a series of QSPR equations were established using multiple linear regression(MLR) method. As aresult, three equations with best performance were selected mainly from the view of high regression coefficient(R)and low standard error( SE). All of them showed significant relationship and high accuracy. With these equationsthe properties of other 103 patterns of PCDEs without the reported observed values were predicted. Furthermore,three partition properties for PCDE congeners-Henry' s Law constants(H), partition coefficients between gas/water(Kgw) and gas/n-octanol ( Kgo ) were calculated according to the internal relationship among these six properties.These observed and predicted values, in contrast with the criteria listed in the Stockholm treaty about POPs whichhas been signed by more than ninety countries in May 2001, illustrated that most of PCDEs congeners are potentialpersistent organic pollutants. As all descriptors/predictors are derived just from the molecular structure itself andwithout the import of any empirical parameters, this method is impersonal and promising for the estimation ofphysico-chemical properties of PCDEs.

  16. Mineralogical, chemical and physical study of potential buffer and backfill materials from ABM. Test Package 1

    Energy Technology Data Exchange (ETDEWEB)

    Kumpulainen, S.; Kiviranta, L. (B and Tech Oy, Helsinki (Finland))

    2011-07-15

    In the ABM experiment, three test packages with centre steel heaters surrounded by stacks of compacted bentonite rings of various clay materials were placed in boreholes in Aespoe tunnel. The first parcel was saturated with Aespoe groundwater and the heater was turned on simultaneously with the start of saturation. This parcel was excavated 30 months after its installation. Chemical, mineralogical and physical properties of the MX-80, Dep-CaN, Asha and Friedland clay samples from the ABM parcel 1 were analysed and compared to reference samples. Chemical analyses (ICP-AES, C, CO{sub 3}, S, water soluble SO{sub 4}, Fe2+/Fe3+), exchangeable cation analyses, mineralogical analyses (XRD, FTIR) and selective extractions were used to determine changes in the chemistry and mineralogy of ABM materials. Swelling pressure and hydraulic conductivity measurements were performed both for extracted samples and for ground and recompacted samples. Major changes in exchangeable cation composition were observed in all samples originating from equilibration with Aespoe groundwater and interactions with equilibrated waters from neighbouring block materials. Some minor changes in chemical composition were observed as well. Increases in soluble sulphate content in the vicinity of the heater were thought to result from precipitation of sulphate salts. Decreases in sodium content and increases in calcium content were ascribed to changes in exchangeable cations. Interaction with iron was observed to occur only in the close vicinity (first few mm) of the heater. No significantly measureable change in mineralogical composition was seen in any of the studied materials. Extracted Dep-CaN samples showed a slight decrease in swelling pressure. However, when the material was ground, compacted and measured again the swelling pressure was fully recovered. No related change in hydraulic conductivities was observed. (orig.)

  17. Chemical synthesis of a dual branched malto-decaose: A potential substrate for alpha-amylases

    DEFF Research Database (Denmark)

    Damager, Iben; Jensen, Morten; Olsen, Carl Erik;

    2005-01-01

    . Using this chemically defined branched oligosaccharide as a substrate, the cleavage pattern of seven different alpha-amylases were investigated. alpha-Amylases from human saliva, porcine pancreas, barley alpha-amylose 2 and recombinant barley alpha-amylase 1 all hydrolysed the decasaccharide selectively....... This resulted in a branched hexasaccharide and a branched tetrasoccharide. alpha-Amylases from Asperagillus oryzae, Bacillus licheniformis and Bacillus sp. cleaved the decasoccharide at two distinct sites, either producing two branched pentasoccharides, or a branched hexasoccharide and a branched...

  18. Prediction of rodent carcinogenic potential of naturally occurring chemicals in the human diet using high-throughput QSAR predictive modeling

    International Nuclear Information System (INIS)

    Consistent with the U.S. Food and Drug Administration (FDA) Critical Path Initiative, predictive toxicology software programs employing quantitative structure-activity relationship (QSAR) models are currently under evaluation for regulatory risk assessment and scientific decision support for highly sensitive endpoints such as carcinogenicity, mutagenicity and reproductive toxicity. At the FDA's Center for Food Safety and Applied Nutrition's Office of Food Additive Safety and the Center for Drug Evaluation and Research's Informatics and Computational Safety Analysis Staff (ICSAS), the use of computational SAR tools for both qualitative and quantitative risk assessment applications are being developed and evaluated. One tool of current interest is MDL-QSAR predictive discriminant analysis modeling of rodent carcinogenicity, which has been previously evaluated for pharmaceutical applications by the FDA ICSAS. The study described in this paper aims to evaluate the utility of this software to estimate the carcinogenic potential of small, organic, naturally occurring chemicals found in the human diet. In addition, a group of 19 known synthetic dietary constituents that were positive in rodent carcinogenicity studies served as a control group. In the test group of naturally occurring chemicals, 101 were found to be suitable for predictive modeling using this software's discriminant analysis modeling approach. Predictions performed on these compounds were compared to published experimental evidence of each compound's carcinogenic potential. Experimental evidence included relevant toxicological studies such as rodent cancer bioassays, rodent anti-carcinogenicity studies, genotoxic studies, and the presence of chemical structural alerts. Statistical indices of predictive performance were calculated to assess the utility of the predictive modeling method. Results revealed good predictive performance using this software's rodent carcinogenicity module of over 1200 chemicals

  19. Evaluation of a high-throughput peptide reactivity format assay for assessment of the skin sensitization potential of chemicals

    Directory of Open Access Journals (Sweden)

    Chin Lin eWong

    2016-03-01

    Full Text Available The direct peptide reactivity assay (DPRA is a validated method for in vitro assessment of the skin sensitization potential of chemicals. In the present work, we describe a peptide reactivity assay using 96-well plate format and systematically identified the optimal assay conditions for accurate and reproducible classification of chemicals with known sensitizing capacity. The aim of the research is to ensure that the analytical component of the peptide reactivity assay is robust, accurate and reproducible in accordance with criteria that are used for the validation of bioanalytical methods. Analytical performance was evaluated using quality control samples (QCs; heptapeptides at low, medium and high concentrations and incubation of control chemicals (chemicals with known sensitization capacity, weak, moderate, strong, extreme and non-sensitizers with each of three synthetic heptapeptides, viz Cor1-C420 (Ac-NKKCDLF, cysteine- (Ac-RFAACAA and lysine- (Ac-RFAAKAA containing heptapeptides. The optimal incubation temperature for all three heptapeptides was 25°C. Apparent heptapeptide depletion was affected by vial material composition. Incubation of test chemicals with Cor1-C420, showed that peptide depletion was unchanged in polypropylene vials over 3-days storage in an autosampler but this was not the case for borosilicate glass vials. For cysteine-containing heptapeptide, the concentration was not stable by day 3 post-incubation in borosilicate glass vials. Although the lysine-containing heptapeptide concentration was unchanged in both polypropylene and borosilicate glass vials, the apparent extent of lysine-containing heptapeptide depletion by ethyl acrylate, differed between polypropylene (24.7% and glass (47.3% vials. Additionally, the peptide-chemical complexes for Cor1-C420-cinnamaldehyde and cysteine-containing heptapeptide-2,4-dinitrochlorobenzene were partially reversible during 3-days of autosampler storage. These observations further

  20. Potential for MERLIN-Expo, an advanced tool for higher tier exposure assessment, within the EU chemical legislative frameworks.

    Science.gov (United States)

    Suciu, Nicoleta; Tediosi, Alice; Ciffroy, Philippe; Altenpohl, Annette; Brochot, Céline; Verdonck, Frederik; Ferrari, Federico; Giubilato, Elisa; Capri, Ettore; Fait, Gabriella

    2016-08-15

    MERLIN-Expo merges and integrates advanced exposure assessment methodologies, allowing the building of complex scenarios involving several pollution sources and targets. The assessment of exposure and risks to human health from chemicals is of major concern for policy and ultimately benefits all citizens. The development and operational fusion of the advanced exposure assessment methodologies envisaged in the MERLIN-Expo tool will have a significant impact in the long term on several policies dealing with chemical safety management. There are more than 30 agencies in Europe related to exposure and risk evaluation of chemicals, which have an important role in implementing EU policies, having especially tasks of technical, scientific, operational and/or regulatory nature. The main purpose of the present paper is to introduce MERLIN-Expo and to highlight its potential for being effectively integrated within the group of tools available to assess the risk and exposure of chemicals for EU policy. The main results show that the tool is highly suitable for use in site-specific or local impact assessment, with minor modifications it can also be used for Plant Protection Products (PPPs), biocides and REACH, while major additions would be required for a comprehensive application in the field of consumer and worker exposure assessment. PMID:27107646

  1. Chemical composition and potential health risks of raw Arabian incense (Bakhour

    Directory of Open Access Journals (Sweden)

    Yehya Elsayed

    2016-07-01

    Full Text Available Burning Arabian incense (Bakhour is a common indoor practice in the Middle East and the Arabian Gulf region. However, the chemical composition of this substance has never been studied. Three different Bakhour brands were selected for this study. A complete chemical profile for the raw samples was determined using carbon, hydrogen, and nitrogen elemental analysis, inductively coupled plasma optical emission spectroscopy, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy and gas chromatography mass spectrometry techniques. A wide range of elements and compounds were identified, many of which are hazardous to health. Nitrogen was found in all samples which should raise concerns due to the known health implications of amines, nitrogen oxides and nitrites. In addition toxic metals such as cobalt, copper, iron, nickel, lead, and zinc were also determined in all samples. The amounts of these metals are equivalent to those in raw tobacco, where they are known to pose health risks. Three types of solvents (acetone, dichloromethane and toluene were used for the extraction of organic compounds. Carcinogens, toxins and irritants were found along others of different health implications. Isolation of these compounds provides preliminary evidence on the harmful consequences of being exposed to Bakhour.

  2. hERGAPDbase: a database documenting hERG channel inhibitory potentials and APD-prolongation activities of chemical compounds.

    Science.gov (United States)

    Hishigaki, Haretsugu; Kuhara, Satoru

    2011-01-01

    Drug-induced QT interval prolongation is one of the most common reasons for the withdrawal of drugs from the market. In the past decade, at least nine drugs, i.e. terfenadine, astemizole, grepafloxacin, terodiline, droperidol, lidoflazine, sertindole, levomethadyl and cisapride, have been removed from the market or their use has been severely restricted because of drug-induced QT interval prolongation. Therefore, this irregularity is a major safety concern in the case of drugs submitted for regulatory approval. The most common mechanism of drug-induced QT interval prolongation may be drug-related inhibition of the human ether-á-go-go-related gene (hERG) channel, which subsequently results in prolongation of the cardiac action potential duration (APD). hERGAPDbase is a database of electrophysiological experimental data documenting potential hERG channel inhibitory actions and the APD-prolongation activities of chemical compounds. All data entries are manually collected from scientific papers and curated by a person. With hERGAPDbase, we aim to provide useful information for chemical and pharmacological scientists and enable easy access to electrophysiological experimental data on chemical compounds. Database URL: http://www.grt.kyushu-u.ac.jp/hergapdbase/. PMID:21586548

  3. Tuning Chemical Potential Difference across Alternately Doped Graphene p-n Junctions for High-Efficiency Photodetection.

    Science.gov (United States)

    Lin, Li; Xu, Xiang; Yin, Jianbo; Sun, Jingyu; Tan, Zhenjun; Koh, Ai Leen; Wang, Huan; Peng, Hailin; Chen, Yulin; Liu, Zhongfan

    2016-07-13

    Being atomically thin, graphene-based p-n junctions hold great promise for applications in ultrasmall high-efficiency photodetectors. It is well-known that the efficiency of such photodetectors can be improved by optimizing the chemical potential difference of the graphene p-n junction. However, to date, such tuning has been limited to a few hundred millielectronvolts. To improve this critical parameter, here we report that using a temperature-controlled chemical vapor deposition process, we successfully achieved modulation-doped growth of an alternately nitrogen- and boron-doped graphene p-n junction with a tunable chemical potential difference up to 1 eV. Furthermore, such p-n junction structure can be prepared on a large scale with stable, uniform, and substitutional doping and exhibits a single-crystalline nature. This work provides a feasible method for synthesizing low-cost, large-scale, high efficiency graphene p-n junctions, thus facilitating their applications in optoelectronic and energy conversion devices. PMID:27351273

  4. Biochemical methane potential, biodegradability, alkali treatment and influence of chemical composition on methane yield of yard wastes.

    Science.gov (United States)

    Gunaseelan, Victor Nallathambi

    2016-03-01

    In this study, the biochemical CH4 potential, rate, biodegradability, NaOH treatment and the influence of chemical composition on CH4 yield of yard wastes generated from seven trees were examined. All the plant parts were sampled for their chemical composition and subjected to the biochemical CH4 potential assay. The component parts exhibited significant variation in biochemical CH4 potential, which was reflected in their ultimate CH4 yields that ranged from 109 to 382 ml g(-1) volatile solids added and their rate constants that ranged from 0.042 to 0.173 d(-1). The biodegradability of the yard wastes ranged from 0.26 to 0.86. Variation in the biochemical CH4 potential of the yard wastes could be attributed to variation in the chemical composition of the different fractions. In the Thespesia yellow withered leaf, Tamarindus fruit pericarp and Albizia pod husk, NaOH treatment enhanced the ultimate CH4 yields by 17%, 77% and 63%, respectively, and biodegradability by 15%, 77% and 61%, respectively, compared with the untreated samples. The effectiveness of NaOH treatment varied for different yard wastes, depending on the amounts of acid detergent fibre content. Gliricidia petals, Prosopis leaf, inflorescence and immature pod, Tamarindus seeds, Albizia seeds, Cassia seeds and Delonix seeds exhibited CH4 yields higher than 300 ml g(-1) volatile solids added. Multiple linear regression models for predicting the ultimate CH4 yield and biodegradability of yard wastes were designed from the results of this work.

  5. Chemical Reactivity Dynamics and Quantum Chaos in Highly Excited Hydrogen Atoms in an External Field: A Quantum Potential Approach

    Directory of Open Access Journals (Sweden)

    B. Maiti

    2002-04-01

    Full Text Available Abstract: Dynamical behavior of chemical reactivity indices like electronegativity, hardness, polarizability, electrophilicity and nucleophilicity indices is studied within a quantum fluid density functional framework for the interactions of a hydrogen atom in its ground electronic state (n = 1 and an excited electronic state (n = 20 with monochromatic and bichromatic laser pulses. Time dependent analogues of various electronic structure principles like the principles of electronegativity equalization, maximum hardness, minimum polarizability and maximum entropy have been found to be operative. Insights into the variation of intensities of the generated higher order harmonics on the color of the external laser field are obtained. The quantum signature of chaos in hydrogen atom has been studied using a quantum theory of motion and quantum fluid dynamics. A hydrogen atom in the electronic ground state (n = 1 and in an excited electronic state ( n = 20 behaves differently when placed in external oscillating monochromatic and bichromatic electric fields. Temporal evolutions of Shannon entropy, quantum Lyapunov exponent and Kolmogorov – Sinai entropy defined in terms of the distance between two initially close Bohmian trajectories for these two cases show marked differences. It appears that a larger uncertainty product and a smaller hardness value signal a chaotic behavior.

  6. PUBLIC EQUALITY, DEMOCRACY AND JUSTICE

    Directory of Open Access Journals (Sweden)

    Ivan Mladenović

    2016-07-01

    Full Text Available This paper examines the principle of public equality which, according to the view Thomas Christiano defends in his book The Constitution of Equality: Democratic Authority and Its Limits, is of central importance for social justice and democracy. Christiano also holds that the authority of democracy, and its limits, are grounded in this principle. Christiano’s democratic theory can be, broadly speaking, divided in two parts. The first part deals with the derivation and justification of the principle of public equality. The second part argues why and how the authority of democracy, and its limits, are based on this principle. This article will deal only with the first part of Christiano’s theory. While I believe that the second part is crucially important for Christiano’s democratic theory, I think that before examining the role of the principle of public equality, it is necessary to examine its nature. For that reason, this paper deals primarily with the nature of the principle of public equality as the requirement of social justice and the basis for the justification of democracy.

  7. Chemical analyses of wasp-associated streptomyces bacteria reveal a prolific potential for natural products discovery

    DEFF Research Database (Denmark)

    Poulsen, Michael; Oh, Dong-Chan; Clardy, Jon;

    2011-01-01

    Identifying new sources for small molecule discovery is necessary to help mitigate the continuous emergence of antibiotic-resistance in pathogenic microbes. Recent studies indicate that one potentially rich source of novel natural products is Actinobacterial symbionts associated with social...... of these isolates identified 11 distinct and structurally diverse secondary metabolites, including a novel polyunsaturated and polyoxygenated macrocyclic lactam, which we name sceliphrolactam. By pairing the 15 Streptomyces strains against a collection of fungi and bacteria, we document their antifungal...... and antibacterial activity. The prevalence and anti-microbial properties of Actinobacteria associated with these two solitary wasp species suggest the potential role of these Streptomyces as antibiotic-producing symbionts, potentially helping defend their wasp hosts from pathogenic microbes. Finding...

  8. Machine learning scheme for fast extraction of chemically interpretable interatomic potentials

    Science.gov (United States)

    Dolgirev, Pavel E.; Kruglov, Ivan A.; Oganov, Artem R.

    2016-08-01

    We present a new method for a fast, unbiased and accurate representation of interatomic interactions. It is a combination of an artificial neural network and our new approach for pair potential reconstruction. The potential reconstruction method is simple and computationally cheap and gives rich information about interactions in crystals. This method can be combined with structure prediction and molecular dynamics simulations, providing accuracy similar to ab initio methods, but at a small fraction of the cost. We present applications to real systems and discuss the insight provided by our method.

  9. Thermo-chemical and biological conversion potential of various biomass feedstocks to ethanol

    Science.gov (United States)

    The goal of this study is to evaluate the potential and the economy of producing ethanol from gasification-fermentation of various biomass feedstocks. The biomass feedstocks include winter cover crops (wheat, rye, clover, hairy betch), summer cover crop (sunhemp), chicken litter, and woody biomass. ...

  10. Chemical Composition, Antioxidant Potential, and Antibacterial Activity of Essential Oil Cones of Tunisian Cupressus sempervirens

    Directory of Open Access Journals (Sweden)

    Aicha Ben Nouri

    2015-01-01

    Full Text Available The extraction yield of the essential oil (EO extracted by hydrodistillation from the cones of Tunisian Cupressus sempervirens L. was of 0.518%. The chemical composition was analyzed by GC-MS. Results showed that this essential oil was mainly composed of monoterpene hydrocarbons (65% with α-pinene as the major constituent (47.51%. Its antioxidant activity was ascertained by evaluating the total antioxidant capacity and also by evaluating its inhibitory effect against DPPH and ABTS radicals. In addition, it showed a strong antioxidant power against the DPPH (IC50 = 151 µg/mL and ABTS (IC50 = 176.454 µg/mL radicals scavenging. Moreover, its antibacterial activity was tested against different species of pathogenic bacteria (three Gram-positive and eight Gram-negative bacteria. The bacterial strains susceptible to the evaluated oil were Bacillus subtilis, Escherichia coli, Klebsiella oxytoca, Morganella morganii, Shigella, and Vibrio cholerae.

  11. Prebiotic coordination chemistry: The potential role of transition-metal complexes in the chemical evolution

    Science.gov (United States)

    Beck, M.

    1979-01-01

    In approaching the extremely involved and complex problem of the origin of life, consideration of the coordination chemistry appeared not only as a possibility but as a necessity. The first model experiments appear to be promising because of prebiotic-type synthesis by means of transition-metal complexes. It is especially significant that in some instances various types of vitally important substances (nucleic bases, amino acids) are formed simultaneously. There is ground to hope that systematic studies in this field will clarify the role of transition-metal complexes in the organizatorial phase of chemical evolution. It is obvious that researchers working in the fields of the chemistry of cyano and carbonyl complexes, and of the catalytic effect of transition-metal complexes are best suited to study these aspects of the attractive and interesting problem of the origin of life.

  12. Gender equality as a politics of declaration

    DEFF Research Database (Denmark)

    Andreassen, Rikke

    2016-01-01

    This article draws on the research results for Denmark’s participation in the WIME project and has two aims: firstly, it throws light on the specific Danish research results, including the results from the TV monitoring phase, and discusses these results in their Danish context; second, it reflec....... Using this concept, this article critically discussed diversity policies and gender equality policies as they apply to media institutions....... on the kinds of gendered understanding that underline research surveys like the WIME project and discusses the potential limitations of this approach to gender analysis. Furthermore, it discusses the benefits and potential problems of applying gender inclusive policies to media institutions by drawing upon...

  13. Magnesium carbide synthesis from methane and magnesium oxide - a potential methodology for natural gas conversion to premium fuels and chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, A.F.; Modestino, A.J.; Howard, J.B. [Massachusetts Institute of Technology, Cambridge, MA (United States)] [and others

    1995-12-31

    Diversification of the raw materials base for manufacturing premium fuels and chemicals offers U.S. and international consumers economic and strategic benefits. Extensive reserves of natural gas in the world provide a valuable source of clean gaseous fuel and chemical feedstock. Assuming the availability of suitable conversion processes, natural gas offers the prospect of improving flexibility in liquid fuels and chemicals manufacture, and thus, the opportunity to complement, supplement, or displace petroleum-based production as economic and strategic considerations require. The composition of natural gas varies from reservoir to reservoir but the principal hydrocarbon constituent is always methane (CH{sub 4}). With its high hydrogen-to-carbon ratio, methane has the potential to produce hydrogen or hydrogen-rich products. However, methane is a very chemically stable molecule and, thus, is not readily transformed to other molecules or easily reformed to its elements (H{sub 2} and carbon). In many cases, further research is needed to augment selectivity to desired product(s), increase single-pass conversions, or improve economics (e.g. there have been estimates of $50/bbl or more for liquid products) before the full potential of these methodologies can be realized on a commercial scale. With the trade-off between gas conversion and product selectivity, a major challenge common to many of these technologies is to simultaneously achieve high methane single-pass conversions and high selectivity to desired products. Based on the results of the scoping runs, there appears to be strong indications that a breakthrough has finally been achieved in that synthesis of magnesium carbides from MgO and methane in the arc discharge reactor has been demonstrated.

  14. The Europeanisation of gender equality

    DEFF Research Database (Denmark)

    Martinsen, Dorte Sindbjerg

    2007-01-01

    The paper examines the extent to which member states control the impact of European Union (EU) policies. It does so through an historical study of what is considered to be the ‘least likely case’ – the Europeanization of Danish gender equality. The analytical findings identify various and diverse...... effects of European integration over time on national policy, politics and law. Historically, the EU has had a major role in furthering and putting into effect equality rights – even in the ‘least likely’ case of Denmark. From a theoretical perspective, the paper argues that the study of Europeanization...

  15. Landfill mining: Resource potential of Austrian landfills--Evaluation and quality assessment of recovered municipal solid waste by chemical analyses.

    Science.gov (United States)

    Wolfsberger, Tanja; Aldrian, Alexia; Sarc, Renato; Hermann, Robert; Höllen, Daniel; Budischowsky, Andreas; Zöscher, Andreas; Ragoßnig, Arne; Pomberger, Roland

    2015-11-01

    Since the need for raw materials in countries undergoing industrialisation (like China) is rising, the availability of metal and fossil fuel energy resources (like ores or coal) has changed in recent years. Landfill sites can contain considerable amounts of recyclables and energy-recoverable materials, therefore, landfill mining is an option for exploiting dumped secondary raw materials, saving primary sources. For the purposes of this article, two sanitary landfill sites have been chosen for obtaining actual data to determine the resource potential of Austrian landfills. To evaluate how pretreating waste before disposal affects the resource potential of landfills, the first landfill site has been selected because it has received untreated waste, whereas mechanically-biologically treated waste was dumped in the second. The scope of this investigation comprised: (1) waste characterisation by sorting analyses of recovered waste; and (2) chemical analyses of specific waste fractions for quality assessment regarding potential energy recovery by using it as solid recovered fuels. The content of eight heavy metals and the net calorific values were determined for the chemical characterisation tests. PMID:26347181

  16. NMR analysis of male fathead minnow urinary metabolites: A potential approach for studying impacts of chemical exposures

    Energy Technology Data Exchange (ETDEWEB)

    Ekman, D.R. [Ecosystems Research Division, U.S. EPA, 960 College Station Road, Athens, GA 30605 (United States)], E-mail: ekman.drew@epa.gov; Teng, Q. [Ecosystems Research Division, U.S. EPA, 960 College Station Road, Athens, GA 30605 (United States); Jensen, K.M.; Martinovic, D.; Villeneuve, D.L.; Ankley, G.T. [Mid-Continent Ecology Division, U.S. EPA, 6201 Congdon Boulevard, Duluth, MN 55804 (United States); Collette, T.W. [Ecosystems Research Division, U.S. EPA, 960 College Station Road, Athens, GA 30605 (United States)

    2007-11-30

    The potential for profiling metabolites in urine from male fathead minnows (Pimephales promelas) to assess chemical exposures was explored using nuclear magnetic resonance (NMR) spectroscopy. Both one-dimensional (1D) and two-dimensional (2D) NMR spectroscopy was used for the assignment of metabolites in urine from unexposed fish. Because fathead minnow urine is dilute, we lyophilized these samples prior to analysis. Furthermore, 1D {sup 1}H NMR spectra of unlyophilized urine from unexposed male fathead minnow and Sprague-Dawley rat were acquired to qualitatively compare rat and fish metabolite profiles and to provide an estimate of the total urinary metabolite pool concentration difference. As a small proof-of-concept study, lyophilized urine samples from male fathead minnows exposed to three different concentrations of the antiandrogen vinclozolin were analyzed by 1D {sup 1}H NMR to assess exposure-induced changes. Through a combination of principal components analysis (PCA) and measurements of {sup 1}H NMR peak intensities, several metabolites were identified as changing with statistical significance in response to exposure. Among those changes occurring in response to exposure to the highest concentration (450 {mu}g/L) of vinclozolin were large increases in taurine, lactate, acetate, and formate. These increases coincided with a marked decrease in hippurate, a combination potentially indicative of hepatotoxicity. The results of these investigations clearly demonstrate the potential utility of an NMR-based approach for assessing chemical exposures in male fathead minnow, using urine collected from individual fish.

  17. ToxAlerts: a Web server of structural alerts for toxic chemicals and compounds with potential adverse reactions.

    Science.gov (United States)

    Sushko, Iurii; Salmina, Elena; Potemkin, Vladimir A; Poda, Gennadiy; Tetko, Igor V

    2012-08-27

    The article presents a Web-based platform for collecting and storing toxicological structural alerts from literature and for virtual screening of chemical libraries to flag potentially toxic chemicals and compounds that can cause adverse side effects. An alert is uniquely identified by a SMARTS template, a toxicological endpoint, and a publication where the alert was described. Additionally, the system allows storing complementary information such as name, comments, and mechanism of action, as well as other data. Most importantly, the platform can be easily used for fast virtual screening of large chemical datasets, focused libraries, or newly designed compounds against the toxicological alerts, providing a detailed profile of the chemicals grouped by structural alerts and endpoints. Such a facility can be used for decision making regarding whether a compound should be tested experimentally, validated with available QSAR models, or eliminated from consideration altogether. The alert-based screening can also be helpful for an easier interpretation of more complex QSAR models. The system is publicly accessible and tightly integrated with the Online Chemical Modeling Environment (OCHEM, http://ochem.eu). The system is open and expandable: any registered OCHEM user can introduce new alerts, browse, edit alerts introduced by other users, and virtually screen his/her data sets against all or selected alerts. The user sets being passed through the structural alerts can be used at OCHEM for other typical tasks: exporting in a wide variety of formats, development of QSAR models, additional filtering by other criteria, etc. The database already contains almost 600 structural alerts for such endpoints as mutagenicity, carcinogenicity, skin sensitization, compounds that undergo metabolic activation, and compounds that form reactive metabolites and, thus, can cause adverse reactions. The ToxAlerts platform is accessible on the Web at http://ochem.eu/alerts, and it is constantly

  18. Energy surface, chemical potentials, Kohn-Sham energies in spin-polarized density functional theory

    CERN Document Server

    Gal, T

    2009-01-01

    On the basis of the zero-temperature grand canonical ensemble generalization of the energy E[N,Ns,v,B] for fractional particle N and spin Ns numbers, the energy surface over the (N,Ns) plane is displayed and analyzed in the case of homogeneous external magnetic fields B(r). The (negative of the) left/right-side derivatives of the energy with respect to N, N_up, and N_down give the fixed-Ns, spin-up, and spin-down ionization potentials/electron affinities, respectively, while the derivative of E[N,Ns,v,B] with respect to Ns gives (signed) half excitation energies to states with Ns greater by 2. The highest occupied and lowest unoccupied Kohn-Sham spin-orbital energies are identified as the corresponding spin-up and spin-down ionization potentials and electron affinities.

  19. Exploring potential energy surfaces for chemical reactions: an overview of some practical methods.

    Science.gov (United States)

    Schlegel, H Bernhard

    2003-09-01

    Potential energy surfaces form a central concept in the application of electronic structure methods to the study of molecular structures, properties, and reactivities. Recent advances in tools for exploring potential energy surfaces are surveyed. Methods for geometry optimization of equilibrium structures, searching for transition states, following reaction paths and ab initio molecular dynamics are discussed. For geometry optimization, topics include methods for large molecules, QM/MM calculations, and simultaneous optimization of the wave function and the geometry. Path optimization methods and dynamics based techniques for transition state searching and reaction path following are outlined. Developments in the calculation of ab initio classical trajectories in the Born-Oppenheimer and Car-Parrinello approaches are described. PMID:12868114

  20. Chemical Composition and Food Potential of Pachymerus nucleorum Larvae Parasitizing Acrocomia aculeata Kernels

    OpenAIRE

    Ariana Vieira Alves; Eliana Janet Sanjinez Argandoña; Adelita Maria Linzmeier; Claudia Andrea Lima Cardoso; Maria Lígia Rodrigues Macedo

    2016-01-01

    Insect consumption as food is culturally practiced in various regions of the world. In Brazil, there are more than 130 species of edible insects registered, from nine orders, among which stands out the Coleoptera. The larva of the beetle Pachymerus nucleorum Fabricius, 1792, grows into the bocaiuva fruit (Acrocomia aculeata (Jacq.) Lodd. Ex Mart., 1845), which has proven nutritional quality. The aim of this work was to evaluate the nutritional potential of P. nucleorum larvae compared to boca...

  1. Evaluating the chemical compatibility of potential substrate materials for Bi-Sr-Ca-Cu-O films

    International Nuclear Information System (INIS)

    Potential substrate and buffer layer materials for Bi2Sr2CaCu2Ox (BSCCO) were surveyed using bulk ceramic processing techniques. Of the materials tested, only Ag was inert with respect to BSCCO. MgO slightly degrades the superconducting onset temperature and volume fraction. LaGaO3 may be a feasible ceramic substrate for BSCCO, although some reaction appears to occur

  2. Temperature-driven and chemical-potential-driven adiabatic pumping in coherent electron transport

    OpenAIRE

    Hasegawa, M.(Graduate School of Science, Kobe University, Kobe, Japan); Kato, T

    2016-01-01

    In this study, we investigate adiabatic pumping induced by the modulation of thermodynamic variables of reservoirs, i.e., temperatures and electrochemical potentials in coherent mesoscopic devices. A simple setup that adopts an impurity Anderson model was used to examine charge pumping under the periodic modulation of the thermodynamic parameters of reservoirs. Consequently, the possibility of charge pumping in the presence of Coulomb interaction is confirmed. Finally, a formula describing ch...

  3. Physical and chemical characterization of the pulp of different varieties of avocado targeting oil extraction potential

    OpenAIRE

    Edinéia Dotti Mooz; Natália Moreno Gaiano; Marilis Yoshie Hayashi Shimano; Rodrigo Dantas Amancio; Marta Helena Fillet Spoto

    2012-01-01

    The aim of this study was to evaluate the physicochemical properties of avocado pulp of four different varieties (Avocado, Guatemala, Dickinson, and Butter pear) and to identify which has the greatest potential for oil extraction. Fresh avocado pulp was characterized by moisture, protein, fat, ash, carbohydrates and energy contents were determined. The carotenoids and chlorophyll contents were determined by the organic solvent extraction method. The results showed significant differences in t...

  4. Physico-chemical analysis and antimicrobial potential of Apis dorsata, Apis mellifera and Ziziphus jujube honey samples from Pakistan

    Institute of Scientific and Technical Information of China (English)

    Hira Fahim; Javid Iqbal Dasti; Ihsan Ali; Safia Ahmed; Muhammad Nadeem

    2014-01-01

    Objective: To evaluate physico-chemical properties and antimicrobial potential of indigenous honey samples against different reference strains including Escherichia coli ATCC 8739, Enterobacter aerogenes ATCC 13048, Pseudomonas aeroginosa ATCC 9027, Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 25923, Salmonella typhi ATCC 14028, Klebsiella pneumonia ATCC 13883, Aspergillus niger ATCC 16404, Rhizopus oligosporus PCSIR1, Candida albicans ATCC 14053 and Candida utilis ATCC 9950. Methods: By using standard methods samples were evaluated for their antimicrobial properties including additive effect of starch and non-peroxidase activity, antioxidative properties (phenol contents, flavonoid contents, 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity). Prior to this evaluation, complete physico-chemical properties including pH, color, ash contents, protein contents, moisture contents, hydroxymethyl furfural contents, total sugar contents, reducing sugar and non-reducing sugar contents were analyzed. Results: Relatively higher ash contents were found in the Siddar honey i.e. (0.590 0±0.033 6)%and small honey showed relatively higher protein contents i.e. (777.598±9.880) mg/kg. The moisture contents of tested honey samples ranged between 13.8%-16.6%, total sugar contents from 61.672%-72.420%and non-reducing sugar contents from 1.95%-3.93%. Presences of phenolic contents indicate higher antioxidant potential of these honey samples. All bacteria showed clear inhibition zones in response to tested honey samples whereas fungi and yeast showed inhibition at higher concentrations of these honey samples. For Escherichia coli, Bacillus subtilis, Salmonella typhi, Pseudomonas aeroginosa and Aspergillus niger, overall the small honey showed the higher activity than other honey samples. Conclusion: Physico-chemical analysis of honey samples confirmed good quality of honey according to the standards set by European Union Commission and Codex Alimentarius Commission

  5. Chemical and Physical Approaches to Extend the Replicative and Differentiation Potential of Stem Cells.

    Science.gov (United States)

    Hwang, Eun Seong; Ok, Jeong Soo; Song, SeonBeom

    2016-06-01

    Cell therapies using mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs) are increasing in regenerative medicine, with applications to a growing number of aging-associated dysfunctions and degenerations. For successful therapies, a certain mass of cells is needed, requiring extensive ex vivo expansion of the cells. However, the proliferation of both MSCs and EPCs is limited as a result of telomere shortening-induced senescence. As cells approach senescence, their proliferation slows down and differentiation potential decreases. Therefore, ways to delay senescence and extend the replicative lifespan these cells are needed. Certain proteins and pathways play key roles in determining the replicative lifespan by regulating ROS generation, damage accumulation, or telomere shortening. And, their agonists and gene activators exert positive effects on lifespan. In many of the treatments, importantly, the lifespan is extended with the retention of differentiation potential. Furthermore, certain culture conditions, including the use of specific atmospheric conditions and culture substrates, exert positive effects on not only the proliferation rate, but also the extent of proliferation and differentiation potential as well as lineage determination. These strategies and known underlying mechanisms are introduced in this review, with an evaluation of their pros and cons in order to facilitate safe and effective MSC expansion ex vivo. PMID:27085715

  6. Potential role of p53 mutation in chemical hepatocarcinogenesis of rats

    Institute of Scientific and Technical Information of China (English)

    Wei-Guo Deng; Yan Fu; Yu-Lin Li; Toshihiro Sugiyama

    2004-01-01

    AIM: Inactivation of p53 gene is one of the most frequent genetic alterations in carcinogenesis. The mutation status of p53 gene was analyzed, in order to understand the effect of p53 mutation on chemical hepatocarcinogenesis of rats.METHODS: During hepatocarcinogenesis of rats induced by 3′-methyl-4- dimethylaminoazobenzene (3′-Me-DAB),prehepatocarcinoma and hepatocarcinoma foci were collected by laser capture microdissection (LCMl), and quantitatively analyzed for levels of p53 mRNA by LightCyclerTM real-time RT-PCR and for mutations in p53 gene exons 5-8 by direct sequencing.RESULTS: Samples consisting of 44 precancerous foci and 24 cancerous foci were collected by LCMl. A quantitative analysis of p53 mRNA showed that p53 mRNA peaked at an early stage (week 6) in the prehepatocarcinoma lesion, more than ten times that of adjacent normal tissue, and gradually decreased from week 6 to week 24. The expression of p53 mRNA in adjacent normal tissue was significantly lower than that in prehepatocarcinoma. Similar to prehepatocarcinoma,p53 mRNA in cancer was markedly higher than that in adjacent normal tissue at week 12, and was closer to normal at week 24. Direct p53 gene sequencing showed that 35.3% (24/68) (9 precancer, 15 cancer) LCM samples exhibited point mutations, 20.5% of prehepatocarcinoma LCM samples presented missense mutations at exon 6/7 or/and 8, and was markedly lower than 62.5% of hepatocarcinoma ones (P<0.01). Mlutation of p53 gene formed the mutant hot spots at 5 codons. Positive immunostaining for p53 protein could be seen in prehepatocarcinoma and hepatocarcinoma foci at 24 weeks.CONCLUSION: p53 gene mutation is present in initial chemical hepatocarcinogenesis, and the mutation of p53 gene induced by 3′-Me-DAB is an important factor of hepatocarcinogenesis.

  7. Chemical composition and antioxidant potential of Ruta montana L. essential oil from Algeria.

    Science.gov (United States)

    Kambouche, N; Merah, B; Bellahouel, S; Bouayed, J; Dicko, A; Derdour, A; Younos, C; Soulimani, R

    2008-09-01

    The essential oil of aerial parts of Ruta montana L. growing in the Oran region in the west of Algeria was obtained by hydrodistillation with a 1.63% yield on a dry weight basis. Gas chromatography (GC) and GC/mass spectrometry (MS) analyses were carried out to identify the chemical composition of R. montana essential oil. Moreover, spectrophotometric analyses were employed to highlight the scavenger capacity of this oil using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test. Twenty compounds were identified by GC and CG/MS analyses, and the bulk of the compounds of the oil were undecan-2-one (32.8%), nonan-2-one (29.5%), nonanol-2-acetate (18.2%), and psoralen (3.5%). The results obtained using the DPPH test show that R. montana essential oil possesses antiradical activity in a concentration-dependent manner. Thus, a linear correlation (correlation coefficient R(2) = 0.971, P < .001) was found between the reduction of DPPH stable free radical and the concentration of R. montana essential oil.

  8. Dimethylglycine and chemically related amines tested for mutagenicity under potential nitrosation conditions.

    Science.gov (United States)

    Hoorn, A J

    1989-04-01

    Dimethylglycine (DMG) and the chemically related amino acids glycine, sarcosine (monomethylglycine) and betaine (trimethylglycine) were tested in Salmonella typhimurium strain TA100 after treatment with sodium nitrite under acidic conditions using a modified Ames Salmonella/microsome assay as reported by Colman et al. (1980). The increase in the number of revertants observed both with and without metabolic activation was also induced in the control mixtures without adding the amines. From the subsequent testing of the individual components of the mixtures, we concluded that non-consumed nitrite was responsible for the mutagenic responses observed in the different reaction mixtures, and not the amines themselves. There were no consistent indications of mutagenic activity of the DMG test mixture as compared to the control mixture which exhibited both consistent mutagenic activity and a toxic effect which was not increased by the addition of DMG. In fact, DMG seemed to decrease the toxicity of the control reaction solution to the Salmonella which was clearly observed at the higher doses. DMG cannot be considered mutagenic under the test conditions employed. The same can be said of the other amino acids as well. PMID:2468082

  9. Promote Equality in the Classroom.

    Science.gov (United States)

    Brown, Sharon; And Others

    1996-01-01

    Presents suggestions to help physical educators treat all students equally and avoid unconsciously making inequitable gender-based statements and practicing other gender discrimination. Suggestions include encouraging girls to talk more, praising girls' performance and boys' appearance, using gender-neutral language, not stereotyping either sex,…

  10. Chemical characterization and hydrothermal pretreatment of Salicornia bigelovii straw for enhanced enzymatic hydrolysis and bioethanol potential

    DEFF Research Database (Denmark)

    Cybulska, Iwona; Chaturvedi, Tanmay; Brudecki, Grzegorz P.;

    2014-01-01

    Salicornia bigelovii straw was characterized and evaluated as a potential lignocellulosic bioethanol feedstock. S. bigelovii used in the study was grown in the United Arab Emirates using saltwater (40. ppt) for irrigation. Salt removal was performed prior to pretreatment to protect the processing...... equipment and avoid inhibition of enzymes and yeast. Composition of the washed biomass was comparable to traditional lignocellulosic biomasses with relatively high glucan and xylan content (26 and 22. g/100. gDM, respectively) but with lower lignin content (7. g/100. gDM). The washed feedstock was subjected...

  11. Physical and chemical characterization of the pulp of different varieties of avocado targeting oil extraction potential

    Directory of Open Access Journals (Sweden)

    Edinéia Dotti Mooz

    2012-06-01

    Full Text Available The aim of this study was to evaluate the physicochemical properties of avocado pulp of four different varieties (Avocado, Guatemala, Dickinson, and Butter pear and to identify which has the greatest potential for oil extraction. Fresh avocado pulp was characterized by moisture, protein, fat, ash, carbohydrates and energy contents were determined. The carotenoids and chlorophyll contents were determined by the organic solvent extraction method. The results showed significant differences in the composition of the fruit when varieties are compared. However, the striking feature in all varieties is high lipid content; Avocado and Dickinson are the most suitable varieties for oil extraction, taking into account moisture content and the levels of lipids in the pulp. Moreover, it could be said that the variety Dickinson is the most affected by the parameters evaluated in terms of overall quality. Chlorophyll and carotenoids, fat-soluble pigments, showed a negative correlation with respect to lipids since it could be related to its function in the fruit. The varieties Avocado and Dickinson are an alternative to oil extraction having great commercial potential to be exploited thus avoiding waste and increasing farmers’ income.

  12. Identifying potential endocrine disruptors among industrial chemicals and their metabolites--development and evaluation of in silico tools.

    Science.gov (United States)

    Rybacka, Aleksandra; Rudén, Christina; Tetko, Igor V; Andersson, Patrik L

    2015-11-01

    The aim of this study was to improve the identification of endocrine disrupting chemicals (EDCs) by developing and evaluating in silico tools that predict interactions at the estrogen (E) and androgen (A) receptors, and binding to transthyretin (T). In particular, the study focuses on evaluating the use of the EAT models in combination with a metabolism simulator to study the significance of bioactivation for endocrine disruption. Balanced accuracies of the EAT models ranged from 77-87%, 62-77%, and 65-89% for E-, A-, and T-binding respectively. The developed models were applied on a set of more than 6000 commonly used industrial chemicals of which 9% were predicted E- and/or A-binders and 1% were predicted T-binders. The numbers of E- and T-binders increased 2- and 3-fold, respectively, after metabolic transformation, while the number of A-binders marginally changed. In-depth validation confirmed that several of the predicted bioactivated E- or T-binders demonstrated in vivo estrogenic activity or influenced blood levels of thyroxine in vivo. The metabolite simulator was evaluated using in vivo data from the literature which showed a 50% accuracy for studied chemicals. The study stresses, in summary, the importance of including metabolic activation in prioritization activities of potentially emerging contaminants. PMID:26210185

  13. Immigrants in the Netherlands: equal access for equal needs?

    OpenAIRE

    Stronks, K.; Ravelli, ACJ; Reijneveld, SA

    2001-01-01

    OBJECTIVE—This paper examines whether equal utilisation of health care services for first generation immigrant groups has been achieved in the Netherlands.
DESIGN—Survey data were linked to an insurance register concerning people aged 16-64. Ethnic differences in the use of a broad range of health care services were examined in this group, with and without adjustment for health status and socioeconomic status, using logistic regression.
SETTING—Publicly insured population in Amsterdam, the Ne...

  14. Chemical Composition and Allelopathic Potential of Essential Oils from Tipuana tipu (Benth.) Kuntze Cultivated in Tunisia.

    Science.gov (United States)

    El Ayeb-Zakhama, Asma; Sakka-Rouis, Lamia; Bergaoui, Afifa; Flamini, Guido; Jannet, Hichem Ben; Harzallah-Skhiri, Fethia

    2016-03-01

    In Tunisia, Tipuana tipu (Benth.) Kuntze is an exotic tree, which was introduced many years ago and planted as ornamental street, garden, and park tree. The present work reported, for the first time, the chemical composition and evaluates the allelopathic effect of the hydrodistilled essential oils of the different parts of this tree, viz., roots, stems, leaves, flowers, and pods gathered in the area of Sousse, a coastal region, in the East of Tunisia. In total, 86 compounds representing 89.9 - 94.9% of the whole oil composition, were identified in these oils by GC-FID and GC/MS analyses. The root essential oil was clearly distinguished for its high content in sesquiterpene hydrocarbons (β-caryophyllene, 1 (44); 24.1% and germacrene D, 2 (53); 20.0%), while those obtained from pods, leaves, stems, and flowers were dominated by non-terpene hydrocarbons. The most important ones were n-tetradecane (41, 16.3%, pod oil), 1,7-dimethylnaphthalene (43, 15.6%, leaf oil), and n-octadecane (77, 13.1%, stem oil). The leaf oil was rich in the apocarotene (E)-β-ionone (4 (54); 33.8%), and the oil obtained from flowers was characterized by hexahydrofarnesylacetone (5 (81); 19.9%) and methyl hexadecanoate (83, 10.2%). Principal component and hierarchical cluster analyses separated the five essential oils into three groups and two subgroups, each characterized by the major oil constituents. Contact tests showed that the germination of lettuce seeds was totally inhibited by the root essential oil tested at 1 mg/ml. The inhibitory effect on the shoot and root elongation varied from -1.6% to -32.4%, and from -2.5% to -64.4%, respectively.

  15. Cloud Formation Potential of Biomass Burning Aerosol Surrogate-Particles Chemically Aged by OH

    Science.gov (United States)

    Slade, J. H.; Thalman, R. M.; Wang, J.; Li, Z. Q.; Knopf, D. A.

    2014-12-01

    Heterogeneous or multiphase reactions between trace gases such as OH and atmospheric aerosol can influence physicochemical properties of the particles including composition, morphology and lifetime. In this work, the cloud condensation nuclei (CCN) activity of laboratory-generated biomass burning aerosol (BBA) exposed to OH radicals is evaluated by determining the hygroscopicity parameter, κ, as a function of particle type and OH exposure ([OH]×time) using a CCN counter coupled to a custom-built aerosol flow reactor (AFR). The composition of particles collected by a micro-orifice uniform deposit impactor (MOUDI) first subjected to different OH exposures is analyzed by Raman and scanning transmission X-ray microscopy coupled with near edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS). Levoglucosan (LEV), 4-methyl-5-nitrocatechol (MNC), and potassium sulfate (KS) serve as representative compounds found in BBA that have different hygroscopicity, chemical functionalities, and reactivity with OH radicals. BBA surrogate-particles are generated following atomization of aqueous solutions with mass ratios LEV:MNC:KS of 1:0:0, 0:1:0, 0:0:1, 1:1:0, 0:1:1, 1:0:1, 1:1:1, and 1:0.03:0.3. OH radicals are generated in the AFR following photolysis of O3 in the presence of H2O using a variable intensity ultra-violet (UV) lamp, which allows equivalent atmospheric OH exposures from days to weeks. In addition, we investigate how κ changes i) in response to varying [O3] with and without OH, and ii) at a fixed OH exposure while varying RH. The impact of OH exposure on the CCN activity of BBA will be presented and its atmospheric implications will be discussed.

  16. VirtualToxLab — A platform for estimating the toxic potential of drugs, chemicals and natural products

    International Nuclear Information System (INIS)

    The VirtualToxLab is an in silico technology for estimating the toxic potential (endocrine and metabolic disruption, some aspects of carcinogenicity and cardiotoxicity) of drugs, chemicals and natural products. The technology is based on an automated protocol that simulates and quantifies the binding of small molecules towards a series of proteins, known or suspected to trigger adverse effects. The toxic potential, a non-linear function ranging from 0.0 (none) to 1.0 (extreme), is derived from the individual binding affinities of a compound towards currently 16 target proteins: 10 nuclear receptors (androgen, estrogen α, estrogen β, glucocorticoid, liver X, mineralocorticoid, peroxisome proliferator-activated receptor γ, progesterone, thyroid α, and thyroid β), four members of the cytochrome P450 enzyme family (1A2, 2C9, 2D6, and 3A4), a cytosolic transcription factor (aryl hydrocarbon receptor) and a potassium ion channel (hERG). The interface to the technology allows building and uploading molecular structures, viewing and downloading results and, most importantly, rationalizing any prediction at the atomic level by interactively analyzing the binding mode of a compound with its target protein(s) in real-time 3D. The VirtualToxLab has been used to predict the toxic potential for over 2500 compounds: the results are posted on (http://www.virtualtoxlab.org). The free platform — the OpenVirtualToxLab — is accessible (in client–server mode) over the Internet. It is free of charge for universities, governmental agencies, regulatory bodies and non-profit organizations. -- Highlights: ► In silico technology for estimating the toxic potential of drugs and chemicals. ► Simulation of binding towards 16 proteins suspected to trigger adverse effects. ► Mechanistic interpretation and real-time 3D visualization. ► Accessible over the Internet. ► Free of charge for universities, governmental agencies, regulatory bodies and NPOs.

  17. VirtualToxLab — A platform for estimating the toxic potential of drugs, chemicals and natural products

    Energy Technology Data Exchange (ETDEWEB)

    Vedani, Angelo, E-mail: angelo.vedani@unibas.ch [Biographics Laboratory 3R, Klingelbergstrasse 50, 4056 Basel (Switzerland); Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056 Basel (Switzerland); Dobler, Max [Biographics Laboratory 3R, Klingelbergstrasse 50, 4056 Basel (Switzerland); Smieško, Martin [Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056 Basel (Switzerland)

    2012-06-01

    The VirtualToxLab is an in silico technology for estimating the toxic potential (endocrine and metabolic disruption, some aspects of carcinogenicity and cardiotoxicity) of drugs, chemicals and natural products. The technology is based on an automated protocol that simulates and quantifies the binding of small molecules towards a series of proteins, known or suspected to trigger adverse effects. The toxic potential, a non-linear function ranging from 0.0 (none) to 1.0 (extreme), is derived from the individual binding affinities of a compound towards currently 16 target proteins: 10 nuclear receptors (androgen, estrogen α, estrogen β, glucocorticoid, liver X, mineralocorticoid, peroxisome proliferator-activated receptor γ, progesterone, thyroid α, and thyroid β), four members of the cytochrome P450 enzyme family (1A2, 2C9, 2D6, and 3A4), a cytosolic transcription factor (aryl hydrocarbon receptor) and a potassium ion channel (hERG). The interface to the technology allows building and uploading molecular structures, viewing and downloading results and, most importantly, rationalizing any prediction at the atomic level by interactively analyzing the binding mode of a compound with its target protein(s) in real-time 3D. The VirtualToxLab has been used to predict the toxic potential for over 2500 compounds: the results are posted on (http://www.virtualtoxlab.org). The free platform — the OpenVirtualToxLab — is accessible (in client–server mode) over the Internet. It is free of charge for universities, governmental agencies, regulatory bodies and non-profit organizations. -- Highlights: ► In silico technology for estimating the toxic potential of drugs and chemicals. ► Simulation of binding towards 16 proteins suspected to trigger adverse effects. ► Mechanistic interpretation and real-time 3D visualization. ► Accessible over the Internet. ► Free of charge for universities, governmental agencies, regulatory bodies and NPOs.

  18. Potential for in situ chemical oxidation of acid extractable organics in oil sands process affected groundwater.

    Science.gov (United States)

    Sohrabi, V; Ross, M S; Martin, J W; Barker, J F

    2013-11-01

    The process of bitumen extraction from oil sands in Alberta, Canada leads to an accumulation of toxic acid-extractable organics (AEOs) in oil sands process water (OSPW). Infiltration of OSPW from tailings ponds and from their retaining sand dykes and subsequent transport towards surface water has occurred. Given the apparent lack of significant natural attenuation of AEOs in groundwater, remediation may be required. This laboratory study evaluates the potential use of unactivated persulfate and permanganate as in situ oxidation agents for remediation of AEOs in groundwater. Naphthenic acids (NAs; CnH2n+zO2), which are a component of the acutely toxic AEOs, were degraded by both oxidants in OSPW samples. Permanganate oxidation yielded some residual dissolved organic carbon (DOC) whereas persulfate mineralized the AEO compounds with less residual DOC. Acid-extractable organics from oxidized OSPW had essentially no Microtox toxicity.

  19. Gene expression-based chemical genomics identifies potential therapeutic drugs in hepatocellular carcinoma.

    Directory of Open Access Journals (Sweden)

    Ming-Huang Chen

    Full Text Available Hepatocellular carcinoma (HCC is an aggressive tumor with a poor prognosis. Currently, only sorafenib is approved by the FDA for advanced HCC treatment; therefore, there is an urgent need to discover candidate therapeutic drugs for HCC. We hypothesized that if a drug signature could reverse, at least in part, the gene expression signature of HCC, it might have the potential to inhibit HCC-related pathways and thereby treat HCC. To test this hypothesis, we first built an integrative platform, the "Encyclopedia of Hepatocellular Carcinoma genes Online 2", dubbed EHCO2, to systematically collect, organize and compare the publicly available data from HCC studies. The resulting collection includes a total of 4,020 genes. To systematically query the Connectivity Map (CMap, which includes 6,100 drug-mediated expression profiles, we further designed various gene signature selection and enrichment methods, including a randomization technique, majority vote, and clique analysis. Subsequently, 28 out of 50 prioritized drugs, including tanespimycin, trichostatin A, thioguanosine, and several anti-psychotic drugs with anti-tumor activities, were validated via MTT cell viability assays and clonogenic assays in HCC cell lines. To accelerate their future clinical use, possibly through drug-repurposing, we selected two well-established drugs to test in mice, chlorpromazine and trifluoperazine. Both drugs inhibited orthotopic liver tumor growth. In conclusion, we successfully discovered and validated existing drugs for potential HCC therapeutic use with the pipeline of Connectivity Map analysis and lab verification, thereby suggesting the usefulness of this procedure to accelerate drug repurposing for HCC treatment.

  20. Potential hazards to embryo implantation: A human endometrial in vitro model to identify unwanted antigestagenic actions of chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, L.; Deppert, W.R. [Department of Obstetrics and Gynecology, University Hospital Freiburg (Germany); Pfeifer, D. [Department of Hematology and Oncology, University Hospital Freiburg (Germany); Stanzel, S.; Weimer, M. [Department of Biostatistics, German Cancer Research Center, Heidelberg (Germany); Hanjalic-Beck, A.; Stein, A.; Straßer, M.; Zahradnik, H.P. [Department of Obstetrics and Gynecology, University Hospital Freiburg (Germany); Schaefer, W.R., E-mail: wolfgang.schaefer@uniklinik-freiburg.de [Department of Obstetrics and Gynecology, University Hospital Freiburg (Germany)

    2012-05-01

    Embryo implantation is a crucial step in human reproduction and depends on the timely development of a receptive endometrium. The human endometrium is unique among adult tissues due to its dynamic alterations during each menstrual cycle. It hosts the implantation process which is governed by progesterone, whereas 17β-estradiol regulates the preceding proliferation of the endometrium. The receptors for both steroids are targets for drugs and endocrine disrupting chemicals. Chemicals with unwanted antigestagenic actions are potentially hazardous to embryo implantation since many pharmaceutical antiprogestins adversely affect endometrial receptivity. This risk can be addressed by human tissue-specific in vitro assays. As working basis we compiled data on chemicals interacting with the PR. In our experimental work, we developed a flexible in vitro model based on human endometrial Ishikawa cells. Effects of antiprogestin compounds on pre-selected target genes were characterized by sigmoidal concentration–response curves obtained by RT-qPCR. The estrogen sulfotransferase (SULT1E1) was identified as the most responsive target gene by microarray analysis. The agonistic effect of progesterone on SULT1E1 mRNA was concentration-dependently antagonized by RU486 (mifepristone) and ZK137316 and, with lower potency, by 4-nonylphenol, bisphenol A and apigenin. The negative control methyl acetoacetate showed no effect. The effects of progesterone and RU486 were confirmed on the protein level by Western blotting. We demonstrated proof of principle that our Ishikawa model is suitable to study quantitatively effects of antiprogestin-like chemicals on endometrial target genes in comparison to pharmaceutical reference compounds. This test is useful for hazard identification and may contribute to reduce animal studies. -- Highlights: ► We compare progesterone receptor-mediated endometrial effects of chemicals and drugs. ► 4-Nonylphenol, bisphenol A and apigenin exert weak

  1. Few-Layer Nanoplates of Bi 2 Se 3 and Bi 2 Te 3 with Highly Tunable Chemical Potential

    KAUST Repository

    Kong, Desheng

    2010-06-09

    A topological insulator (TI) represents an unconventional quantum phase of matter with insulating bulk band gap and metallic surface states. Recent theoretical calculations and photoemission spectroscopy measurements show that group V-VI materials Bi2Se3, Bi2Te3, and Sb2Te3 are TIs with a single Dirac cone on the surface. These materials have anisotropic, layered structures, in which five atomic layers are covalently bonded to form a quintuple layer, and quintuple layers interact weakly through van der Waals interaction to form the crystal. A few quintuple layers of these materials are predicted to exhibit interesting surface properties. Different from our previous nanoribbon study, here we report the synthesis and characterizations of ultrathin Bi2Te3 and Bi2Se3 nanoplates with thickness down to 3 nm (3 quintuple layers), via catalyst-free vapor-solid (VS) growth mechanism. Optical images reveal thickness-dependent color and contrast for nanoplates grown on oxidized silicon (300 nm SiO2/Si). As a new member of TI nanomaterials, ultrathin TI nanoplates have an extremely large surface-to-volume ratio and can be electrically gated more effectively than the bulk form, potentially enhancing surface state effects in transport measurements. Low-temperature transport measurements of a single nanoplate device, with a high-k dielectric top gate, show decrease in carrier concentration by several times and large tuning of chemical potential. © 2010 American Chemical Society.

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

    Science.gov (United States)

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

    2016-02-01

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

  3. Chemical composition and potential health effects of prunes: a functional food?

    Science.gov (United States)

    Stacewicz-Sapuntzakis, M; Bowen, P E; Hussain, E A; Damayanti-Wood, B I; Farnsworth, N R

    2001-05-01

    Prunes are dried plums, fruits of Prunus domestica L., cultivated and propagated since ancient times. Most dried prunes are produced from cultivar d'Agen, especially in California and France, where the cultivar originated. After harvest, prune-making plums are dehydrated in hot air at 85 to 90 degrees C for 18 h, then further processed into prune juice, puree, or other prune products. This extensive literature review summarizes the current knowledge of chemical composition of prunes and their biological effects on human health. Because of their sweet flavor and well-known mild laxative effect, prunes are considered to be an epitome of functional foods, but the understanding of their mode of action is still unclear. Dried prunes contain approximately 6.1 g of dietary fiber per 100 g, while prune juice is devoid of fiber due to filtration before bottling. The laxative action of both prune and prune juice could be explained by their high sorbitol content (14.7 and 6.1 g/100 g, respectively). Prunes are good source of energy in the form of simple sugars, but do not mediate a rapid rise in blood sugar concentration, possibly because of high fiber, fructose, and sorbitol content. Prunes contain large amounts of phenolic compounds (184 mg/100 g), mainly as neochlorogenic and chlorogenic acids, which may aid in the laxative action and delay glucose absorption. Phenolic compounds in prunes had been found to inhibit human LDL oxidation in vitro, and thus might serve as preventive agents against chronic diseases, such as heart disease and cancer. Additionally, high potassium content of prunes (745 mg/100 g) might be beneficial for cardiovascular health. Dried prunes are an important source of boron, which is postulated to play a role in prevention of osteoporosis. A serving of prunes (100 g) fulfills the daily requirement for boron (2 to 3 mg). More research is needed to assess the levels of carotenoids and other phytochemicals present in prunes to ensure correct labeling and

  4. NOx Direct Decomposition: Potentially Enhanced Thermodynamics and Kinetics on Chemically Modified Ferroelectric Surfaces

    Science.gov (United States)

    Kakekhani, Arvin; Ismail-Beigi, Sohrab

    2014-03-01

    NOx are regulated pollutants produced during automotive combustion. As part of an effort to design catalysts for NOx decomposition that operate in oxygen rich environment and permit greater fuel efficiency, we study chemistry of NOx on (001) ferroelectric surfaces. Changing the polarization at such surfaces modifies electronic properties and leads to switchable surface chemistry. Using first principles theory, our previous work has shown that addition of catalytic RuO2 monolayer on ferroelectric PbTiO3 surface makes direct decomposition of NO thermodynamically favorable for one polarization. Furthermore, the usual problem of blockage of catalytic sites by strong oxygen binding is overcome by flipping polarization that helps desorb the oxygen. We describe a thermodynamic cycle for direct NO decomposition followed by desorption of N2 and O2. We provide energy barriers and transition states for key steps of the cycle as well as describing their dependence on polarization direction. We end by pointing out how a switchable order parameter of substrate,in this case ferroelectric polarization, allows us to break away from some standard compromises for catalyst design(e.g. the Sabatier principle). This enlarges the set of potentially catalytic metals. Primary support from Toyota Motor Engineering and Manufacturing, North America, Inc.

  5. Chemical Composition and Nutraceutical Potential of Indian Borage (Plectranthus amboinicus Stem Extract

    Directory of Open Access Journals (Sweden)

    Praveena Bhatt

    2013-01-01

    Full Text Available The stem of Indian borage (Plectranthus amboinicus was found to be an antioxidant rich fraction as evaluated by in vitro models such as DPPH free radical scavenging, reducing power assay, superoxide anion radical scavenging, and total antioxidant capacity. The extract also exhibited antiplatelet aggregation ability, antibacterial activity, and antiproliferative effect against cancer cell lines: Caco-2, HCT-15, and MCF-7. Phytochemical evaluation of the extract revealed the occurrence of total phenolics (49.91 mg GAE/g extract, total flavonoids (26.6 mg RE/g extract, and condensed tannins (0.7 mg TAE/g extract. Among the major phenolics, rosmarinic acid (6.160 mg/g extract was predominant, followed by caffeic acid (0.770 mg/g extract, rutin (0.324 mg/g extract, gallic acid (0.260 mg/g extract, quercetin (0.15 mg/g extract, and p-coumaric acid (0.104 mg/g extract. The appreciable biological activity and presence of biomolecules in the methanolic extract of stem indicate its potential application as functional food ingredients and nutraceuticals.

  6. Chemical Composition and Food Potential of Pachymerus nucleorum Larvae Parasitizing Acrocomia aculeata Kernels.

    Science.gov (United States)

    Alves, Ariana Vieira; Sanjinez Argandoña, Eliana Janet; Linzmeier, Adelita Maria; Cardoso, Claudia Andrea Lima; Macedo, Maria Lígia Rodrigues

    2016-01-01

    Insect consumption as food is culturally practiced in various regions of the world. In Brazil, there are more than 130 species of edible insects registered, from nine orders, among which stands out the Coleoptera. The larva of the beetle Pachymerus nucleorum Fabricius, 1792, grows into the bocaiuva fruit (Acrocomia aculeata (Jacq.) Lodd. Ex Mart., 1845), which has proven nutritional quality. The aim of this work was to evaluate the nutritional potential of P. nucleorum larvae compared to bocaiuva kernels for human consumption. Proteins were the second largest portion of the larvae nutritional composition (33.13%), with percentage higher than the bocaiuva kernels (14.21%). The larval lipid content (37.87%) was also high, very close to the kernels (44.96%). The fraction corresponding to fatty acids in the oil extracted from the larvae was 40.17% for the saturated and 46.52% for the unsaturated. The antioxidant activity value was 24.3 uM trolox/g of oil extracted from larvae. The larvae tryptic activity was 0.032±0.006 nmol BAPNA/min. Both the larvae and the bocaiuva kernel presented absence of anti-nutritional factors. These results favor the use of P. nucleorum larvae as food, which are a great protein and lipid sources with considerable concentrations of unsaturated fatty acids compared to the bocaiuva kernel. PMID:27031500

  7. Centrifugal microfluidic platform for radiochemistry: potentialities for the chemical analysis of nuclear spent fuels.

    Science.gov (United States)

    Bruchet, Anthony; Taniga, Vélan; Descroix, Stéphanie; Malaquin, Laurent; Goutelard, Florence; Mariet, Clarisse

    2013-11-15

    The use of a centrifugal microfluidic platform is for the first time reported as an alternative to classical chromatographic procedures for radiochemistry. The original design of the microfluidic platform has been thought to fasten and simplify the prototyping process with the use of a circular platform integrating four rectangular microchips made of thermoplastic. The microchips, dedicated to anion-exchange chromatographic separations, integrate a localized monolithic stationary phase as well as injection and collection reservoirs. The results presented here were obtained with a simplified simulated nuclear spent fuel sample composed of non-radioactive isotopes of Europium and Uranium, in proportion usually found for uranium oxide nuclear spent fuel. While keeping the analytical results consistent with the conventional procedure (extraction yield for Europium of ≈97%), the use of the centrifugal microfluidic platform allowed to reduce the volume of liquid needed by a factor of ≈250. Thanks to their unique "easy-to-use" features, centrifugal microfluidic platforms are potential successful candidates for the downscaling of chromatographic separation of radioactive samples (automation, multiplexing, easy integration in glove-boxes environment and low cost of maintenance).

  8. Chemical Composition and Food Potential of Pachymerus nucleorum Larvae Parasitizing Acrocomia aculeata Kernels.

    Directory of Open Access Journals (Sweden)

    Ariana Vieira Alves

    Full Text Available Insect consumption as food is culturally practiced in various regions of the world. In Brazil, there are more than 130 species of edible insects registered, from nine orders, among which stands out the Coleoptera. The larva of the beetle Pachymerus nucleorum Fabricius, 1792, grows into the bocaiuva fruit (Acrocomia aculeata (Jacq. Lodd. Ex Mart., 1845, which has proven nutritional quality. The aim of this work was to evaluate the nutritional potential of P. nucleorum larvae compared to bocaiuva kernels for human consumption. Proteins were the second largest portion of the larvae nutritional composition (33.13%, with percentage higher than the bocaiuva kernels (14.21%. The larval lipid content (37.87% was also high, very close to the kernels (44.96%. The fraction corresponding to fatty acids in the oil extracted from the larvae was 40.17% for the saturated and 46.52% for the unsaturated. The antioxidant activity value was 24.3 uM trolox/g of oil extracted from larvae. The larvae tryptic activity was 0.032±0.006 nmol BAPNA/min. Both the larvae and the bocaiuva kernel presented absence of anti-nutritional factors. These results favor the use of P. nucleorum larvae as food, which are a great protein and lipid sources with considerable concentrations of unsaturated fatty acids compared to the bocaiuva kernel.

  9. Chitosan-lignosulfonates sono-chemically prepared nanoparticles: characterisation and potential applications.

    Science.gov (United States)

    Kim, Suyeon; Fernandes, Margarida M; Matamá, Teresa; Loureiro, Ana; Gomes, Andreia C; Cavaco-Paulo, Artur

    2013-03-01

    Due to their recognised properties of biocompatibility, biodegradability and sustainability, chitosan nanocarriers have been successfully used as new delivery systems. In this work, nanoparticles combining chitosan and lignosulfonates were developed for the first time for cosmetic and biomedical applications. The ability of lignosulfonates to act as a counter polyion for stabilisation of chitosan particles, generated using high intensity ultrasound, was investigated. Several conditions for particles preparation were tested and optimised and the resulting nanoparticles were comprehensively characterised by measuring particle size, zeta potential and polydispersity index. The pH of chitosan solution, sonication time and the presence of an adequate surfactant, poloxamer 407, were determinant factors on the development of smaller particles with low polydispersity index (an average particle size of 230 nm was obtained at pH 5 after 8 min of sonication). The beneficial effects of lignosulfonates complex on chitosan nanoparticles were further characterised. Greater stability to lysozyme degradation, biocompatibility with human cells and antimicrobial activity was found upon lignosulfonates incorporation into chitosan nanoparticles. Furthermore, these particles were able to incorporate a hydrophilic model protein - RNase A. A burst release was observed when nanoparticles were loaded with low amount of protein while with high protein content, a sustained release was found, suggesting that the protein cargo maybe loaded both at the surface as in the bulk of the particle, depending on the concentration of drug incorporated.

  10. Chemical characterisation of dredged sediments in relation to their potential use in civil engineering.

    Science.gov (United States)

    Zuliani, Tea; Mladenovič, Ana; Ščančar, Janez; Milačič, Radmila

    2016-04-01

    During capital and/or maintenance dredging operations, large amounts of material are produced. Instead of their discharge, dredged sediments may be a valuable natural resource if not contaminated. One of the possible areas of application is civil engineering. In the present work, the environmental status of seaport dredged sediment was evaluated in order to investigate its potential applicability as a secondary raw material. Sediments were analysed for element concentrations in digested samples, aqueous extracts and fractions from sequential extraction; for fluoride, chloride and sulphate concentrations in aqueous extracts; and for tributyltin (TBT). Granulometric and mineralogical compositions were also analysed. The elemental impact was evaluated by calculation of the enrichment factors. The total element concentrations determined showed moderate contamination of the dredged sediments as was confirmed also by their moderate enrichment factors, presumably as a result of industrial and port activities. Elemental concentrations in the aqueous extract were very low and therefore do not represent any hazard for the environment. The water-soluble element concentrations were under the threshold levels set by the EU Directive on the landfill of waste, on the basis of which the applicability of dredged sediments in civil engineering is evaluated, while the content of chloride and sulphate were above the threshold levels. It was found out that due to the large amounts of sediment available, civil engineering applications such as the construction of embankments and backfilling is the most beneficial recycling solution at present.

  11. The Equity-Equality Conflict

    DEFF Research Database (Denmark)

    Scheuer, Steen

    2013-01-01

    -for-performance systems) perceived as fair and when are they not? When can differences in contribution (equity) overrule the social norm of equality? Which contingent reward structure should be applied for teamwork members, if any? Which structure to motivate employees to a continuous search for smarter working...... procedures and solutions? These are central concerns of motivation theory, where rational choice decisions are counterbalanced by endowment effectsor other fairness concerns. Management is placed in a dilemma between what is, e.g., an economically rational structure of incentives, on the one hand, and what...... is considered as equitable by employees, on the other. Since equality in reward counts for more among employees, while equity in contribution counts more for employers, this is an inherent dilemma, constantly having to be negotiated and solved, but never reaching any ‘final solution’ in any company...

  12. Revising the Musical Equal Temperament

    CERN Document Server

    Hinrichsen, Haye

    2015-01-01

    Western music is predominantly based on the equal temperament with a constant semitone frequency ratio of $2^{1/12}$. Although this temperament has been in use since the 19th century and in spite of its high degree of symmetry, various musicians have repeatedly expressed their discomfort with the harmonicity of certain intervals. Recently it was suggested that this problem can be overcome by introducing a modified temperament with a constant but slightly increased frequency ratio. In this paper we confirm this conjecture quantitatively. Using entropy as a measure for harmonicity, we show numerically that the harmonic optimum is in fact obtained for frequency ratios larger than $2^{1/12}$. This suggests that the equal temperament should be replaced by a harmonized temperament as a new standard.

  13. Equal opportunity in the workplace.

    Science.gov (United States)

    Allen, A

    1992-04-01

    The Equal Employment Opportunity Commission (EEOC) was created by the Civil Rights Act of 1964. The commission encourages voluntary compliance with equal employment opportunity practices, and has authority to investigate complaints alleging discrimination in hiring, firing, wage rates, testing, training, apprenticeship, and other conditions of employment. In October 1991, during the Senate Judiciary Committee hearings, the confirmation of Judge Clarence Thomas for a seat on the United States Supreme Court was placed in jeopardy by a charge of sexual harassment while Thomas was head of the EEOC. This article focuses on aspects of sexual harassment in the workplace, the role of the EEOC, and offers some suggestions for keeping the work environment free of abusive behavior.

  14. Potential of Coproduction of Energy, Fuels and Chemicals from Biobased Renewable Resources. Transition Path 3. Co-production of Energy, Fuels and Chemicals

    International Nuclear Information System (INIS)

    This report shows how in 2030, biobased alternatives can potentially cover up to 30% of the Netherlands' domestic energy and chemicals demand, effectively reducing CO2 emissions. Maximizing the economical potential of biobased alternatives seems the most attractive strategy. The method to compare various routes has been highly simplified and the conclusions of this report are only valid within the limitations of the underlying assumptions. Nevertheless, the Working group WISE BIOMAS of the Platform Biobased Raw Materials feels that the conclusions are valuable for Dutch policy makers and others interested in the use of biobased raw materials. In 2030, biobased alternatives are expected to be sufficiently competitive to fossil-based alternatives, even without subsidies. They are expected to play a significant role in an energy mix comprised of other renewables as well as 'clean' fossil energy sources. Presently, however, the Netherlands needs to step up its stimulation of biobased applications, through substantial investments in R and D programmes, demonstration plants, as well as measures to stimulate implementation. The whole package of tax reductions, local government purchases, etc., as well as direct financial support should amount to approximately 500 million euros per year. The simplified study presented here provides input for more realistic macro-economic scenario analysis taking actual and updated cost-availability relations including second generation biofuels and biochemicals, land use, international trade, etc., into account. Initial discussions with for instance the Netherlands Bureau for Economic Policy Analysis (Centraal Plan Bureau or CPB) have taken place, but are not covered in this report. It is urgently suggested to update macro-economic scenarios for securing the best Netherlands' position among the accelerating global development towards biobased resources

  15. Office of Equal Opportunity Programs

    Science.gov (United States)

    Chin, Jennifer L.

    2004-01-01

    The NASA Glenn Office of Equal Opportunity Programs works to provide quality service for all programs and/or to assist the Center in becoming a model workplace. During the summer of 2004, I worked with Deborah Cotleur along with other staff members to create and modify customer satisfaction surveys. This office aims to assist in developing a model workplace by providing functions as a change agent to the center by serving as an advisor to management to ensure equity throughout the Center. In addition, the office serves as a mediator for the Center in addressing issues and concerns. Lastly, the office provides assistance to employees to enable attainment of personal and organizational goals. The Office of Equal Opportunities is a staff office which reports and provides advice to the Center Director and Executive Leadership, implements laws, regulations, and presidential executive orders, and provides center wide leadership and assistance to NASA GRC employees. Some of the major responsibilities of the office include working with the discrimination complaints program, special emphasis programs (advisory groups), management support, monitoring and evaluation, contract compliance, and community outreach. During my internship in this office, my main objective was to create four customer satisfaction surveys based on EO retreats, EO observances, EO advisory boards, and EO mediation/counseling. I created these surveys after conducting research on past events and surveys as well as similar survey research created and conducted by other NASA centers, program for EO Advisory group members, leadership training sessions for supervisors, preventing sexual harassment training sessions, and observance events. I also conducted research on the style and format from feedback surveys from the Marshall Equal Opportunity website, the Goddard website, and the main NASA website. Using the material from the Office of Equal Opportunity Programs at Glenn Research Center along with my

  16. Reminder - Equal Opportunities Advisory Panel

    CERN Multimedia

    HR Department

    2007-01-01

    At its meeting on 7 December 2006, the Standing Concertation Committee also took note of the nomination of a fourth new member of the Panel: Wisla Carena. The present composition of the Panel (appointed ad personam) is now as follows: Tiziano Camporesi (Chairperson), Wisla Carena, Pierre Charrue, Sue Foffano, Josi Schinzel (Equal Opportunities Officer), Markus Nordberg, Christine Petit-Jean-Genaz and Elena Wildner. Human Resources Department Tel. 74480

  17. Factor Price Equalization in Finland

    OpenAIRE

    Kerkelä, Leena; Kangasharju, Aki; Pekkala, Sari

    2003-01-01

    The Heckscher-Ohlin trade model leads to clear conclusions on the absolute and relative factor prices in a two-commodity specification of the model where both commodities are produced and factors can move freely within the economy. Even though the tests on factor price equalization fail in international comparisons, regional approach offers a prospective way of characterizing how factors of production, e.g. skilled and unskilled labor are utilized in optimally behaving markets and which poten...

  18. A new multimedia contaminant fate model for China:how important are environmental parameters in influencing chemical persistence and long-range transport potential?

    OpenAIRE

    Zhu, Ying; Price, Oliver R.; Tao, Shu; Jones, Kevin C.; Sweetman, Andrew

    2014-01-01

    We present a new multimedia chemical fate model (SESAMe) which was developed to assess chemical fate and behaviour across China. We apply the model to quantify the influence of environmental parameters on chemical overall persistence (POV) and long-range transport potential (LRTP) in China, which has extreme diversity in environmental conditions. Sobol sensitivity analysis was used to identify the relative importance of input parameters. Physicochemical properties were identified as more infl...

  19. Cellular uptake and cytotoxic potential of respirable bentonite particles with different quartz contents and chemical modifications in human lung fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Geh, Stefan; Rettenmeier, Albert W.; Dopp, Elke [University Hospital, Institute of Hygiene and Occupational Medicine, Essen (Germany); Yuecel, Raif [University Hospital, Institute of Cell Biology (Cancer Research), Essen (Germany); Duffin, Rodger [Institute of Environmental Health Research (IUF), Duesseldorf (Germany); University of Edinburgh, ELEGI COLT Lab, Scotland (United Kingdom); Albrecht, Catrin; Borm, Paul J.A. [Institute of Environmental Health Research (IUF), Duesseldorf (Germany); Armbruster, Lorenz [Verein fuer Technische Sicherheit und Umweltschutz e.V., Gotha (Germany); Raulf-Heimsoth, Monika; Bruening, Thomas [Research Institute for Occupational Medicine of the Institutions for Statutory Accident Insurance and Prevention (BGFA), Bochum (Germany); Hoffmann, Eik [University of Rostock, Institute of Biology, Department of Cell Biology and Biosystems Technology, Rostock (Germany)

    2006-02-01

    Considering the biological reactivity of pure quartz in lung cells, there is a strong interest to clarify the cellular effects of respirable siliceous dusts, like bentonites. In the present study, we investigated the cellular uptake and the cytotoxic potential of bentonite particles (Oe< 10 {mu}m) with an {alpha}-quartz content of up to 6% and different chemical modifications (activation: alkaline, acidic, organic) in human lung fibroblasts (IMR90). Additionally, the ability of the particles to induce apoptosis in IMR90-cells and the hemolytic activity was tested. All bentonite samples were tested for endotoxins with the in vitro-Pyrogen test and were found to be negative. Cellular uptake of particles by IMR90-cells was studied by transmission electron microscopy (TEM). Cytotoxicity was analyzed in IMR90-cells by determination of viable cells using flow cytometry and by measuring of the cell respiratory activity. Induced apoptotic cells were detected by AnnexinV/Propidiumiodide-staining and gel electrophoresis. Our results demonstrate that activated bentonite particles are better taken up by IMR90-cells than untreated (native) bentonite particles. Also, activated bentonite particles with a quartz content of 5-6% were more cytotoxic than untreated bentonites or bentonites with a quartz content lower than 4%. The bentonite samples induced necrotic as well as apoptotic cell death. In general, bentonites showed a high membrane-damaging potential shown as hemolytic activity in human erythrocytes. We conclude that cellular effects of bentonite particles in human lung cells are enhanced after chemical treatment of the particles. The cytotoxic potential of the different bentonites is primarily characterized by a strong lysis of the cell membrane. (orig.)

  20. Exploring the Reuse Potential of Chemical Sludge from Textile Wastewater Treatment Plants in India-A Hazardous Waste

    Directory of Open Access Journals (Sweden)

    Hema Patel

    2009-01-01

    Full Text Available Problem statement: This study was conducted to explore the reuse potential of the chemical sludge (considered as hazardous waste as per Indian Government Hazardous Waste Management Rules generated from combined effluent treatment in textile clusters. These textile clusters mainly cover the cotton dyeing and printing operations. Approach: Therefore, treatability studies of chemical sludge were conducted using solidification/stabilization treatment to examine the possibility of its reuse in construction materials. The sludge was characterised for its physico-chemical parameters and heavy metals. Standard blocks of dimensions 70.6×70.6×70.6 mm were prepared, in which chemical sludge was used as a partial replacement of cement by mixing 30-70 % of sludge in cement. After the experimental curing, the blocks were evaluated for physical engineering properties such as hardening time, block density, unconfined compressive strength. The chemical properties were determined in terms of concentrations of heavy metals in the TCLP leachate. Results: The hardening time ranged between 30-45 h. The compressive strength in the sludge cement blocks ranged from 2.63-22.54 N mm-2 after 14 days of water curing and 6.48-24.89 N mmm-2 after 28 days of water curing for 30, 40, 50, 60 and 70 % sludge replacement in cement. The block density varied between 1361. 3408-1813.8992 Kg m-3 after 14 days and 1386.3953-1842.3446 Kg m-3 after 28 days of water curing. The concentrations of heavy metals were negligible in the TCLP leachate and thus below USEPA regulatory limits. Conclusion/Recommendations: As far as structural applications is concerned, it is fulfilling the criteria of some of the classes (C to K as per the BIS standards of the bricks upto a strength of 25 N mm2. The use of sludge can definitely be explored for other structural and non-structural applications depending upon strength requirement. Other applications of textile sludge in the construction materials

  1. Potential Chemical Effects of Changes in the Source of Water Supply for the Albuquerque Bernalillo County Water Utility Authority

    Science.gov (United States)

    Bexfield, Laura M.; Anderholm, Scott K.

    2008-01-01

    Chemical modeling was used by the U.S. Geological Survey, in cooperation with the Albuquerque Bernalillo County Water Utility Authority (henceforth, Authority), to gain insight into the potential chemical effects that could occur in the Authority's water distribution system as a result of changing the source of water used for municipal and industrial supply from ground water to surface water, or to some mixture of the two sources. From historical data, representative samples of ground-water and surface-water chemistry were selected for modeling under a range of environmental conditions anticipated to be present in the distribution system. Mineral phases calculated to have the potential to precipitate from ground water were compared with the compositions of precipitate samples collected from the current water distribution system and with mineral phases calculated to have the potential to precipitate from surface water and ground-water/surface-water mixtures. Several minerals that were calculated to have the potential to precipitate from ground water in the current distribution system were identified in precipitate samples from pipes, reservoirs, and water heaters. These minerals were the calcium carbonates aragonite and calcite, and the iron oxides/hydroxides goethite, hematite, and lepidocrocite. Several other minerals that were indicated by modeling to have the potential to precipitate were not found in precipitate samples. For most of these minerals, either the kinetics of formation were known to be unfavorable under conditions present in the distribution system or the minerals typically are not formed through direct precipitation from aqueous solutions. The minerals with potential to precipitate as simulated for surface-water samples and ground-water/surface-water mixtures were quite similar to the minerals with potential to precipitate from ground-water samples. Based on the modeling results along with kinetic considerations, minerals that appear most likely to

  2. Computational Investigations of Potential Energy Function Development for Metal--Organic Framework Simulations, Metal Carbenes, and Chemical Warfare Agents

    Science.gov (United States)

    Cioce, Christian R.

    Metal-Organic Frameworks (MOFs) are three-dimensional porous nanomaterials with a variety of applications, including catalysis, gas storage and separation, and sustainable energy. Their potential as air filtration systems is of interest for designer carbon capture materials. The chemical constituents (i.e. organic ligands) can be functionalized to create rationally designed CO2 sequestration platforms, for example. Hardware and software alike at the bleeding edge of supercomputing are utilized for designing first principles-based molecular models for the simulation of gas sorption in these frameworks. The classical potentials developed herein are named PHAST --- Potentials with High Accuracy, Speed, and Transferability, and thus are designed via a "bottom-up" approach. Specifically, models for N2 and CH4 are constructed and presented. Extensive verification and validation leads to insights and range of applicability. Through this experience, the PHAST models are improved upon further to be more applicable in heterogeneous environments. Given this, the models are applied to reproducing high level ab initio energies for gas sorption trajectories of helium atoms in a variety of rare-gas clusters, the geometries of which being representative of sorption-like environments commonly encountered in a porous nanomaterial. This work seeks to push forward the state of classical and first principles materials modeling. Additionally, the characterization of a new type of tunable radical metal---carbene is presented. Here, a cobalt(II)---porphyrin complex, [Co(Por)], was investigated to understand its role as an effective catalyst in stereoselective cyclopropanation of a diazoacetate reagent. Density functional theory along with natural bond order analysis and charge decomposition analysis gave insight into the electronics of the catalytic intermediate. The bonding pattern unveiled a new class of radical metal---carbene complex, with a doublet cobalt into which a triplet carbene

  3. Physico-chemical analysis and antimicrobial potential of Apis dorsata,Apis mellifera and Ziziphus jujube honey samples from Pakistan

    Institute of Scientific and Technical Information of China (English)

    Hira; Fahim; Javid; Iqbal; Dasti; Ihsan; Ali; Safia; Ahmed; Muhammad; Nadeem

    2014-01-01

    Objective:To evaluale physico-chemical properties and antimicrobial potential of indigenous honey samples against different reference strains including Escherichia coli ATCC 8739.Enterobacter aerogenes ATCC 13048.Pseudomonas aeruginosa ATCC 9027.Bacillus subtilis ATCC6633.Staphylococcus aureus ATCC 25923.Salmonella typhi ATCC 14028,Klebsiella pneumonia ATCC 13883.Aspergillus niger ATCC 16404.Rhizopus oligasparus PCSIR1.Candida albicans ATCC14053 and Candida utilis ATCC 9950.Methods:By using standard methods samples were evaluated for their antimicrobial properties including additive effect of starch and non—peroxidase activity,antioxidative properties(phenol contents,flavonoid contents,1,1-diphenyl-2-pierylhydrazyl radical scavenging activity).Prior to this evaluation,complete physico-chemical properties including pH,color,ash contents,protein contents,moisture contents,hydroxymethyl furfural contents,total sugar contents,reducing sugar and non-reducing sugar contents were analyzed.Results:Relatively higher ash contents were found in the Siddar honey i.e.(0.5900±0.0336)%and small honey showed relatively higher protein contents i.e.(777.598±9.880) mg/kg.The moisture contents of tested honey samples ranged between 13.8%—16,6%,total sugar contents foam 61.672%-72.420%and non-reducing sugar contents from 1.95%—3.93%.Presences of phenolic contents indicate higher antioxidant potential of these honey samples.All bacteria showed clear inhibition zones in response to tested honey samples whereas fungi and yeast showed inhibition at higher concentrations of these honey samples.For Escherichia coli.Bacillus subtilis.Salmonella typhi.Pseudomonas aeruginosa and Aspergillus niger,overall the small honey showed the higher activity than other honey samples.Conclusion:Physico-chemical analysis of honey samples confirmed good quality of honey according to the standards set by European Union Commission and Codex Alimcntarius Commission.Evaluation of these honey samples

  4. Chemical Composition of Artemisia annua L. Leaves and Antioxidant Potential of Extracts as a Function of Extraction Solvents

    OpenAIRE

    Maznah Ismail; Shahid Iqbal; Umer Younas; Kim Wei Chan; Muhammad Zia-Ul-Haq

    2012-01-01

    This study was conducted to investigate the chemical and nutritional composition of Artemisia annua leaves in addition to determination of antioxidant potential of their extracts prepared in different solvents. Chemical composition was determined by quantifying fat, protein, carbohydrate, fiber, tocopherol, phytate, and tannin contents. Extraction of A. annua leaves, for antioxidant potential evaluation, was carried out using five solvents of differen...

  5. Chemical Structure, Property and Potential Applications of Biosurfactants Produced by Bacillus subtilis in Petroleum Recovery and Spill Mitigation

    Directory of Open Access Journals (Sweden)

    Jin-Feng Liu

    2015-03-01

    Full Text Available Lipopeptides produced by microorganisms are one of the five major classes of biosurfactants known and they have received much attention from scientific and industrial communities due to their powerful interfacial and biological activities as well as environmentally friendly characteristics. Microbially produced lipopeptides are a series of chemical structural analogues of different families and, among them, 26 families covering about 90 lipopeptide compounds have been reported in the last two decades. This paper reviews the chemical structural characteristics and molecular behaviors of surfactin, one of the representative lipopeptides of the 26 families. In particular, two novel surfactin molecules isolated from cell-free cultures of Bacillus subtilis HSO121 are presented. Surfactins exhibit strong self-assembly ability to form sphere-like micelles and larger aggregates at very low concentrations. The amphipathic and surface properties of surfactins are related to the existence of the minor polar and major hydrophobic domains in the three 3-D conformations. In addition, the application potential of surfactin in bioremediation of oil spills and oil contaminants, and microbial enhanced oil recovery are discussed.

  6. Molecular Mechanism Underlying Pathogenesis of Lewisite-Induced Cutaneous Blistering and Inflammation: Chemical Chaperones as Potential Novel Antidotes.

    Science.gov (United States)

    Li, Changzhao; Srivastava, Ritesh K; Weng, Zhiping; Croutch, Claire R; Agarwal, Anupam; Elmets, Craig A; Afaq, Farrukh; Athar, Mohammad

    2016-10-01

    Lewisite is a potent arsenic-based chemical warfare agent known to induce painful cutaneous inflammation and blistering. Only a few modestly effective antidotes have so far been described in the literature. However, the discovery of effective antidotes for lewisite was hampered by the paucity of the exact molecular mechanism underlying its cutaneous pathogenesis. We investigated the molecular mechanism underlying lewisite-induced cutaneous blistering and inflammation and describe its novel antidotes. On the basis of our initial screening, we used a highly sensitive murine model that recapitulates the known human pathogenesis of arsenicals-induced cutaneous inflammation and blistering. Topically administered lewisite induced potent acute inflammation and microvesication in the skin of Ptch1(+/-)/SKH-1 mice. Even at a very low dose, lewisite up-regulates unfolded protein response signaling, inflammatory response, and apoptosis. These cutaneous lesions were associated with production of reactive oxygen species and extensive apoptosis of the epidermal keratinocytes. We confirmed that activation of reactive oxygen species-dependent unfolded protein response signaling is the underlying molecular mechanism of skin damage. Similar alterations were noticed in lewisite-treated cultured human skin keratinocytes. We discovered that chemical chaperone 4-phenyl butyric acid and antioxidant N-acetylcysteine, which significantly attenuate lewisite-mediated skin injury, can serve as potent antidotes. These data reveal a novel molecular mechanism underlying the cutaneous pathogenesis of lewisite-induced lesions. We also identified novel potential therapeutic targets for lewisite-mediated cutaneous injury. PMID:27528504

  7. Chemical structure, property and potential applications of biosurfactants produced by Bacillus subtilis in petroleum recovery and spill mitigation.

    Science.gov (United States)

    Liu, Jin-Feng; Mbadinga, Serge Maurice; Yang, Shi-Zhong; Gu, Ji-Dong; Mu, Bo-Zhong

    2015-01-01

    Lipopeptides produced by microorganisms are one of the five major classes of biosurfactants known and they have received much attention from scientific and industrial communities due to their powerful interfacial and biological activities as well as environmentally friendly characteristics. Microbially produced lipopeptides are a series of chemical structural analogues of different families and, among them, 26 families covering about 90 lipopeptide compounds have been reported in the last two decades. This paper reviews the chemical structural characteristics and molecular behaviors of surfactin, one of the representative lipopeptides of the 26 families. In particular, two novel surfactin molecules isolated from cell-free cultures of Bacillus subtilis HSO121 are presented. Surfactins exhibit strong self-assembly ability to form sphere-like micelles and larger aggregates at very low concentrations. The amphipathic and surface properties of surfactins are related to the existence of the minor polar and major hydrophobic domains in the three 3-D conformations. In addition, the application potential of surfactin in bioremediation of oil spills and oil contaminants, and microbial enhanced oil recovery are discussed. PMID:25741767

  8. Physical properties, chemical composition, and cloud forming potential of particulate emissions from a marine diesel engine at various load conditions.

    Science.gov (United States)

    Petzold, A; Weingartner, E; Hasselbach, J; Lauer, P; Kurok, C; Fleischer, F

    2010-05-15

    Particulate matter (PM) emissions from one serial 4-stroke medium-speed marine diesel engine were measured for load conditions from 10% to 110% in test rig studies using heavy fuel oil (HFO). Testing the engine across its entire load range permitted the scaling of exhaust PM properties with load. Emission factors for particle number, particle mass, and chemical compounds were determined. The potential of particles to form cloud droplets (cloud condensation nuclei, CCN) was calculated from chemical composition and particle size. Number emission factors are (3.43 +/- 1.26) x 10(16) (kg fuel)(-1) at 85-110% load and (1.06 +/- 0.10) x 10(16) (kg fuel)(-1) at 10% load. CCN emission factors of 1-6 x 10(14) (kg fuel)(-1) are at the lower bound of data reported in the literature. From combined thermal and optical methods, black carbon (BC) emission factors of 40-60 mg/(kg fuel) were determined for 85-100% load and 370 mg/(kg fuel) for 10% load. The engine load dependence of the conversion efficiency for fuel sulfur into sulfate of (1.08 +/- 0.15)% at engine idle to (3.85 +/- 0.41)% at cruise may serve as input to global emission calculations for various load conditions. PMID:20402501

  9. Higher spin extension of cosmological spacetimes in 3D: asymptotically flat behaviour with chemical potentials and thermodynamics

    CERN Document Server

    Matulich, Javier; Tempo, David; Troncoso, Ricardo

    2014-01-01

    A generalized set of asymptotic conditions for higher spin gravity without cosmological constant in three spacetime dimensions is constructed. They include the most general temporal components of the gauge fields that manifestly preserve the original asymptotic higher spin extension of the BMS$_{3}$ algebra, with the same central charge. By virtue of a suitable permissible gauge choice, it is shown that this set can be directly recovered as a limit of the boundary conditions that have been recently constructed in the case of negative cosmological constant, whose asymptotic symmetries are spanned by two copies of the centrally-extended W$_{3}$ algebra. Since the generalized asymptotic conditions allow to incorporate chemical potentials conjugated to the higher spin charges, a higher spin extension of locally flat cosmological spacetimes becomes naturally included within the set. It is shown that their thermodynamic properties can be successfully obtained exclusively in terms of gauge fields and the topology of...

  10. Physico-chemical properties of the potentially oxidative water and its capability of the instrumentation residual layer remotion

    Directory of Open Access Journals (Sweden)

    Daniel Silva-Herzog FLORES

    2006-11-01

    Full Text Available The purpose of the study was to elaborate the potentially oxidative water (POW and analyze some of the physico-chemical properties: pH density, superficial stress, contact angle, conductivity and REDOX potential; besides comparing its POW organic as well as non-organic matter removal capacity with hypochlorite sodium at 1% plus 17% EDTA. For the methodology the POW elaboration an electrolysis process was used and the physico-chemical properties were determined in 0, 1, 3, 5 and 7 days. For the removal capacity of teeth tartarevaluation, 30 extracted uniradicular premolars were used, divided in three groups:positive control (NaOCl at 1% + EDTA at 17%, negative control(distilled water and experimental (POW. Afterwards, the samples were observed under electronic microscopy with 2500x magnifying at the middle thirds and apical, analyzing them with the Rome scale (amount of open dental tubes. For the statistical analysis the Chi-square and the Fisher Exact Proofwas used. The results showed that the solution was constantly maintained at all times during the evaluation and there was found statistical difference between negative control and positive control and between negative control and the experimental group. With regards to the dental tartar removal it was found that there was no statistical difference between the control group and the experimental group (POW; reason why it is concluded that the POW has the capacity to remove dental tartar. Nevertheless, to be able to propose the use of the POW as an irrigator solution in Endodontics it is necessary to do further studies to evaluate its cytotoxicity and biocompability.

  11. Teachers’ challenges education for equality

    Directory of Open Access Journals (Sweden)

    Rocío Anguita Martínez

    2011-04-01

    Full Text Available Gender equality among women and men has been, and still is a key issue regarding the development of formal education systems. In some way, it can be seen as the cornerstone of equity. Although the most visible gender issues are drawing back in our country, others specially related to the hidden curriculum are still present. Teacher´s initial and lifelong training constitute the best tool to minimize the aforementioned hidden-curriculum-related gender inequalities. However, there is not much done with this regard in our current teacher´s formal training system.

  12. Midwives, gender equality and feminism.

    Science.gov (United States)

    Walsh, Denis

    2016-03-01

    Gender inequality and the harmful effects of patriarchy are sustaining the wide spread oppression of women across the world and this is also having an impact on maternity services with unacceptable rates of maternal mortality, the continued under investment in the midwifery profession and the limiting of women's place of birth options. However alongside these effects, the current zeitgeist is affirming an alignment of feminism and gender equality such that both have a high profile in public discourse. This presents a once in a generation opportunity for midwives to self-declare as feminists and commit to righting the wrongs of this most pernicious form of discrimination.

  13. Midwives, gender equality and feminism.

    Science.gov (United States)

    Walsh, Denis

    2016-03-01

    Gender inequality and the harmful effects of patriarchy are sustaining the wide spread oppression of women across the world and this is also having an impact on maternity services with unacceptable rates of maternal mortality, the continued under investment in the midwifery profession and the limiting of women's place of birth options. However alongside these effects, the current zeitgeist is affirming an alignment of feminism and gender equality such that both have a high profile in public discourse. This presents a once in a generation opportunity for midwives to self-declare as feminists and commit to righting the wrongs of this most pernicious form of discrimination. PMID:27044191

  14. Too many chemicals, too little time: Rapid in silico methods to characterize and predict ADME properties for chemical toxicity and exposure potential

    Science.gov (United States)

    Evaluating proposed alternative chemical structures to support the design of safer chemicals and products is an important component of EPA's Green Chemistry and Design for the Environment (DfE) Programs. As such, science-based alternatives assessment is essential to support EPA's...

  15. Linking hydrologic, physical and chemical habitat environments for the potential assessment of fish community rehabilitation in a developing city

    Science.gov (United States)

    Zhao, C. S.; Yang, S. T.; Liu, C. M.; Dou, T. W.; Yang, Z. L.; Yang, Z. Y.; Liu, X. L.; Xiang, H.; Nie, S. Y.; Zhang, J. L.; Mitrovic, S. M.; Yu, Q.; Lim, R. P.

    2015-04-01

    Aquatic ecological rehabilitation is increasingly attracting considerable public and research attention. An effective method that requires less data and expertise would help in the assessment of rehabilitation potential and in the monitoring of rehabilitation activities as complicated theories and excessive data requirements on assemblage information make many current assessment models expensive and limit their wide use. This paper presents an assessment model for restoration potential which successfully links hydrologic, physical and chemical habitat factors to fish assemblage attributes drawn from monitoring datasets on hydrology, water quality and fish assemblages at a total of 144 sites, where 5084 fish were sampled and tested. In this model three newly developed sub-models, integrated habitat index (IHSI), integrated ecological niche breadth (INB) and integrated ecological niche overlap (INO), are established to study spatial heterogeneity of the restoration potential of fish assemblages based on gradient methods of habitat suitability index and ecological niche models. To reduce uncertainties in the model, as many fish species as possible, including important native fish, were selected as dominant species with monitoring occurring over several seasons to comprehensively select key habitat factors. Furthermore, a detrended correspondence analysis (DCA) was employed prior to a canonical correspondence analysis (CCA) of the data to avoid the "arc effect" in the selection of key habitat factors. Application of the model to data collected at Jinan City, China proved effective reveals that three lower potential regions that should be targeted in future aquatic ecosystem rehabilitation programs. They were well validated by the distribution of two habitat parameters: river width and transparency. River width positively influenced and transparency negatively influenced fish assemblages. The model can be applied for monitoring the effects of fish assemblage restoration

  16. Stationary space-periodic structures with equal diffusion coefficients

    DEFF Research Database (Denmark)

    Andresen, Peter Ragnar; Bache, Morten; Mosekilde, Erik;

    1999-01-01

    The paper investigates a chemical reaction-diffusion model in an open flow system. It is shown that such a system may, with particular boundary conditions, exhibit stationary space-periodic structures even in the case of equal diffusion coefficients. This is confirmed through numerical simulations....

  17. The restructuring of the fiscal equalization system in Croatia

    Directory of Open Access Journals (Sweden)

    Marko Primorac

    2014-12-01

    Full Text Available The aim of this paper is to propose a model of fiscal equalization in Croatia. This paper tests the hypothesis of a lack of effectiveness of the existing fiscal equalization model compared to a model that would be based on alleviating the difference in the potential to collect revenue from the personal income tax and surtax. Fiscal inequalities of local government units are determined first under the current equalization system by calculating the Gini coefficients and graphically presented with Lorenz curves. Thereafter, a distribution of equalization grants is simulated based on the new (proposed model. The effectiveness of the proposed model in alleviating the fiscal inequalities is determined in relation to the effectiveness of the current equalization system. It was found that the model based on equalizing the difference in the capacity to collect revenue from the personal income tax and surtax alleviates inequalities in fiscal capacities of local government units much better than the existing system at the same cost. The main conclusion is that the fiscal equalization in Croatia should urgently be redesigned in order to improve efficiency and fairness, but also the transparency and credibility of the equalization system.

  18. Automated fit of high-dimensional potential energy surfaces using cluster analysis and interpolation over descriptors of chemical environment

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, René, E-mail: renef@yorku.ca; Orel, Slava [Department of Chemistry, York University, Toronto, Ontario M3J 1P3 (Canada)

    2013-12-21

    We present a method for fitting high-dimensional potential energy surfaces that is almost fully automated, can be applied to systems with various chemical compositions, and involves no particular choice of function form. We tested it on four systems: Ag{sub 20}, Sn{sub 6}Pb{sub 6}, Si{sub 10}, and Li{sub 8}. The cost for energy evaluation is smaller than the cost of a density functional theory (DFT) energy evaluation by a factor of 1500 for Li{sub 8}, and 60 000 for Ag{sub 20}. We achieved intermediate accuracy (errors of 0.4 to 0.8 eV on atomization energies, or, 1% to 3% on cohesive energies) with rather small datasets (between 240 and 1400 configurations). We demonstrate that this accuracy is sufficient to correctly screen the configurations with lowest DFT energy, making this function potentially very useful in a hybrid global optimization strategy. We show that, as expected, the accuracy of the function improves with an increase in the size of the fitting dataset.

  19. Assessment of potential biomarkers, metallothionein and vitellogenin mRNA expressions in various chemically exposed benthic Chironomus riparius larvae

    Science.gov (United States)

    Park, Kiyun; Kwak, Inn-Sil

    2012-12-01

    The objective of this study was conducted to identify the possibility of using Chironomus metallothionein (MT) and vitellogenin (VTG) as biomarkers of stress caused by endocrinedisrupting chemicals (EDCs), heavy metals, herbicides and veterinary antibiotics. We characterized the MT and VTG cDNA in Chironomus riparius and evaluated their mRNA expression profiles following exposure to different environmental pollutants. The gene expression analysis showed that the MT mRNA levels increased significantly after long-term exposure to cadmium (Cd), copper (Cu), Lead (Pb), di(2-ethylhexyl) phthalate (DEHP), and 2,4-dichlorophenoxyacetic acid (2,4-D). Moreover, the VTG mRNA expression increased significantly in C. riparius larvae exposed to BPA, NP, DEHP, Cd, 2,4-D and fenbendazole. Evaluation of the long-term effects of environmental pollutants revealed up regulation of Chironomus MT mRNA in response to DEHP exposure among EDCs, and the level of the VTG mRNA was increased significantly following treatment with Cd and herbicide 2,4-D at all concentrations in a dose-dependent manner. These results indicate that VTG could be used as a potential biomarker of herbicide and Cd as well as EDCs, while MT was a potential biomarker of heavy metals such as Cd, Cu, and Pb in aquatic environments.

  20. Aerobic biodegradation potential of endocrine disrupting chemicals in surface-water sediment at Rocky Mountains National Park, USA

    Science.gov (United States)

    Bradley, Paul M.; Battaglin, William A.; Iwanowicz, Luke; Clark, Jimmy M.; Journey, Celeste A.

    2016-01-01

    Endocrine disrupting chemicals (EDC) in surface water and bed sediment threaten the structure and function of aquatic ecosystems. In natural, remote, and protected surface-water environments where contaminant releases are sporadic, contaminant biodegradation is a fundamental driver of exposure concentration, timing, duration, and, thus, EDC ecological risk. Anthropogenic contaminants, including known and suspected EDC, were detected in surface water and sediment collected from 2 streams and 2 lakes in Rocky Mountains National Park (ROMO). The potential for aerobic EDC biodegradation was assessed in collected sediments using 6 14C-radiolabeled model compounds. Aerobic microbial mineralization of natural (estrone and 17β-estradiol) and synthetic (17α-ethinylestradiol) estrogen was significant at all sites. ROMO bed sediment microbial communities also effectively degraded the xenoestrogens, bisphenol-A and 4-nonylphenol. The same sediment samples exhibited little potential for aerobic biodegradation of triclocarban, however, illustrating the need to assess a wider range of contaminant compounds. The current results support recent concerns over the widespread environmental occurrence of carbanalide antibacterials, like triclocarban and triclosan, and suggest that backcountry use of products containing these compounds should be discouraged.

  1. Aerobic biodegradation potential of endocrine-disrupting chemicals in surface-water sediment at Rocky Mountain National Park, USA.

    Science.gov (United States)

    Bradley, Paul M; Battaglin, William A; Iwanowicz, Luke R; Clark, Jimmy M; Journey, Celeste A

    2016-05-01

    Endocrine-disrupting chemicals (EDCs) in surface water and bed sediment threaten the structure and function of aquatic ecosystems. In natural, remote, and protected surface-water environments where contaminant releases are sporadic, contaminant biodegradation is a fundamental driver of exposure concentration, timing, duration, and, thus, EDC ecological risk. Anthropogenic contaminants, including known and suspected EDCs, were detected in surface water and sediment collected from 2 streams and 2 lakes in Rocky Mountain National Park (Colorado, USA). The potential for aerobic EDC biodegradation was assessed in collected sediments using 6 (14) C-radiolabeled model compounds. Aerobic microbial mineralization of natural (estrone and 17β-estradiol) and synthetic (17α-ethinylestradiol) estrogen was significant at all sites. Bed sediment microbial communities in Rocky Mountain National Park also effectively degraded the xenoestrogens bisphenol-A and 4-nonylphenol. The same sediment samples exhibited little potential for aerobic biodegradation of triclocarban, however, illustrating the need to assess a wider range of contaminant compounds. The present study's results support recent concerns over the widespread environmental occurrence of carbanalide antibacterials, like triclocarban and triclosan, and suggest that backcountry use of products containing these compounds should be discouraged. Environ Toxicol Chem 2016;35:1087-1096. Published 2015 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America. PMID:26588039

  2. Free-energy calculations using classical molecular simulation: application to the determination of the melting point and chemical potential of a flexible RDX model.

    Science.gov (United States)

    Sellers, Michael S; Lísal, Martin; Brennan, John K

    2016-03-21

    We present an extension of various free-energy methodologies to determine the chemical potential of the solid and liquid phases of a fully-flexible molecule using classical simulation. The methods are applied to the Smith-Bharadwaj atomistic potential representation of cyclotrimethylene trinitramine (RDX), a well-studied energetic material, to accurately determine the solid and liquid phase Gibbs free energies, and the melting point (Tm). We outline an efficient technique to find the absolute chemical potential and melting point of a fully-flexible molecule using one set of simulations to compute the solid absolute chemical potential and one set of simulations to compute the solid-liquid free energy difference. With this combination, only a handful of simulations are needed, whereby the absolute quantities of the chemical potentials are obtained, for use in other property calculations, such as the characterization of crystal polymorphs or the determination of the entropy. Using the LAMMPS molecular simulator, the Frenkel and Ladd and pseudo-supercritical path techniques are adapted to generate 3rd order fits of the solid and liquid chemical potentials. Results yield the thermodynamic melting point Tm = 488.75 K at 1.0 atm. We also validate these calculations and compare this melting point to one obtained from a typical superheated simulation technique.

  3. VirtualToxLab - a platform for estimating the toxic potential of drugs, chemicals and natural products.

    Science.gov (United States)

    Vedani, Angelo; Dobler, Max; Smieško, Martin

    2012-06-01

    The VirtualToxLab is an in silico technology for estimating the toxic potential (endocrine and metabolic disruption, some aspects of carcinogenicity and cardiotoxicity) of drugs, chemicals and natural products. The technology is based on an automated protocol that simulates and quantifies the binding of small molecules towards a series of proteins, known or suspected to trigger adverse effects. The toxic potential, a non-linear function ranging from 0.0 (none) to 1.0 (extreme), is derived from the individual binding affinities of a compound towards currently 16 target proteins: 10 nuclear receptors (androgen, estrogen α, estrogen β, glucocorticoid, liver X, mineralocorticoid, peroxisome proliferator-activated receptor γ, progesterone, thyroid α, and thyroid β), four members of the cytochrome P450 enzyme family (1A2, 2C9, 2D6, and 3A4), a cytosolic transcription factor (aryl hydrocarbon receptor) and a potassium ion channel (hERG). The interface to the technology allows building and uploading molecular structures, viewing and downloading results and, most importantly, rationalizing any prediction at the atomic level by interactively analyzing the binding mode of a compound with its target protein(s) in real-time 3D. The VirtualToxLab has been used to predict the toxic potential for over 2500 compounds: the results are posted on http://www.virtualtoxlab.org. The free platform - the OpenVirtualToxLab - is accessible (in client-server mode) over the Internet. It is free of charge for universities, governmental agencies, regulatory bodies and non-profit organizations.

  4. Pythagorean triangles of equal areas

    Directory of Open Access Journals (Sweden)

    Malvina Baica

    1988-01-01

    Full Text Available The main intent in this paper is to find triples of Rational Pythagorean Triangles (abbr. RPT having equal areas. A new method of solving a2+ab+b2=c2 is to set a=y−1, b=y+1, y∈N−{0,1} and get Pell's equation c2−3y2=1. To solve a2−ab−b2=c2, we set a=12(y+1, b=y−1, y≥2, y∈N and get a corresponding Pell's equation. The infinite number of solutions in Pell's equation gives rise to an infinity of solutions to a2±ab+b2=c2. From this fact the following theorems are proved.

  5. Comparison of the mutagenic potential of 17 physical and chemical agents analyzed by the flow cytometry mutation assay

    Energy Technology Data Exchange (ETDEWEB)

    French, C. Tenley [Cytomation GTX Inc., Fort Collins, CO (United States); Ross, Carley D. [Cell and Molecular Biology Graduate Program, Colorado State University, Fort Collins, CO (United States); Keysar, Stephen B. [Cell and Molecular Biology Graduate Program, Colorado State University, Fort Collins, CO (United States); Joshi, Dhanashree D. [Cell and Molecular Biology Graduate Program, Colorado State University, Fort Collins, CO (United States); Lim, Chang-Uk [Cell and Molecular Biology Graduate Program, Colorado State University, Fort Collins, CO (United States); Fox, Michael H. [Cell and Molecular Biology Graduate Program, Colorado State University, Fort Collins, CO (United States) and Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523-1618 (United States)]. E-mail: mfox@colostate.edu

    2006-12-01

    Several methods to assess genotoxicity of physical and chemical agents have been developed, most of which depend on growing colonies in selective medium. We recently published a new method for detecting mutations in the CD59 gene in a Chinese hamster ovary cell line that contains a single copy of human chromosome 11 (CHO A{sub L}). The assay is based on detecting the surface expression of CD59 with monoclonal antibodies using flow cytometry. The capabilities of this flow cytometry mutation assay (FCMA) to detect mutations from a wide variety of genotoxic agents are described here. There was a 400-fold separation between CD59{sup -} and CD59{sup +} populations based on fluorescence intensity. Small numbers of negative cells mixed in with positive cells were detected in a highly linear fashion. Mutation dose response curves over a dose range yielding 80% to 20% survival are shown for ethyl methane sulfonate (EMS), mitomycin C (MMC) and lead acetate. EMS and lead acetate exhibited a threshold in response while MMC had a linear dose response over the full dose range. The mutant fraction was measured over time periods ranging up to 35 days following treatment. The mutant fraction peaked at different times ranging from 6 to 12 days after treatment. An additional 14 chemical and physical agents including point mutagens, heavy metals, ionizing and UV radiation, and DNA intercalators and cross linkers, were analyzed for mutagenic potential after doses giving 80% to 20% survival. The results presented here demonstrate the sensitivity and broad-ranging capability of the FCMA to detect mutations induced by a variety of genotoxic agents.

  6. Enhanced benzaldehyde tolerance in Zymomonas mobilis biofilms and the potential of biofilm applications in fine-chemical production.

    Science.gov (United States)

    Li, Xuan Zhong; Webb, Jeremy S; Kjelleberg, Staffan; Rosche, Bettina

    2006-02-01

    Biotransformation plays an increasingly important role in the industrial production of fine chemicals due to its high product specificity and low energy requirement. One challenge in biotransformation is the toxicity of substrates and/or products to biocatalytic microorganisms and enzymes. Biofilms are known for their enhanced tolerance of hostile environments compared to planktonic free-living cells. Zymomonas mobilis was used in this study as a model organism to examine the potential of surface-associated biofilms for biotransformation of chemicals into value-added products. Z. mobilis formed a biofilm with a complex three-dimensional architecture comprised of microcolonies with an average thickness of 20 microm, interspersed with water channels. Microscopic analysis and metabolic activity studies revealed that Z. mobilis biofilm cells were more tolerant to the toxic substrate benzaldehyde than planktonic cells were. When exposed to 50 mM benzaldehyde for 1 h, biofilm cells exhibited an average of 45% residual metabolic activity, while planktonic cells were completely inactivated. Three hours of exposure to 30 mM benzaldehyde resulted in sixfold-higher residual metabolic activity in biofilm cells than in planktonic cells. Cells inactivated by benzaldehyde were evenly distributed throughout the biofilm, indicating that the resistance mechanism was different from mass transfer limitation. We also found that enhanced tolerance to benzaldehyde was not due to the conversion of benzaldehyde into less toxic compounds. In the presence of glucose, Z. mobilis biofilms in continuous cultures transformed 10 mM benzaldehyde into benzyl alcohol at a steady rate of 8.11 g (g dry weight)(-1) day(-1) with a 90% molar yield over a 45-h production period.

  7. Potential energy profile, structural, vibrational and reactivity descriptors of trans-2-methoxycinnamic acid by FTIR, FT-Raman and quantum chemical studies

    Science.gov (United States)

    Arjunan, V.; Anitha, R.; Thenmozhi, S.; Marchewka, M. K.; Mohan, S.

    2016-06-01

    The stable conformers of trans-2-methoxycinnamic acid (trans-2MCA) are determined by potential energy profile analysis. The energies of the s-cis and s-trans conformers of trans-2MCA determined by B3LYP/cc-pVTZ method are -612.9788331 Hartrees and -612.9780953 Hartrees, respectively. The vibrational and electronic investigations of the stable s-cis and s-trans conformers of trans-2-methoxycinnamic acid have been carried out extensively with FTIR and FT-Raman spectral techniques. The s-cis conformer (I) with a (C16-C17-C18-O19) dihedral angle equal to 0° is found to be more favoured relative to the one s-trans (II) with (C16-C17-C18-O19) = 180°, possibly due to delocalization, hydrogen bonding and steric repulsion effects between the methoxy and acrylic acid groups. The DFT studies are performed with B3LYP method by utilizing 6-311++G** and cc-pVTZ basis sets to determine the structure, thermodynamic properties, vibrational characteristics and chemical shifts of the compound. The total dipole moments of the conformers determined by B3LYP/cc-pVTZ method are 3.35 D and 4.87 D for s-cis and s-trans, respectively. It reveals the higher polarity of s-trans conformer of trans-2MCA molecule. The electronic and steric influence of the methoxy group on the skeletal frequencies has been analysed. The energies of the frontier molecular orbitals and the LUMO-HOMO energy gap have been determined. The MEP of s-cis conformer lie in the range +1.374e × 10-2 to -1.374e × 10-2 while for s-trans it is +1.591e × 10-2 to -1.591e × 10-2. The total electron density of s-cis conformer lie in the range +5.273e × 10-2 to -5.273e × 10-2 while for s-trans it is +5.403e × 10-2 to -5.403e × 10-2. The MEP and total electron density shows that the s-cis conformer is less polar, less reactive and more stable than the s-trans conformer. All the reactivity descriptors of the molecule have been discussed. Intramolecular electronic interactions and their stabilisation energies have analysed

  8. Experimental terrestrial soil-core microcosm test protocol. A method for measuring the potential ecological effects, fate, and transport of chemicals in terrestrial ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Van Voris, P.; Tolle, D.A.; Arthur, M.F.

    1985-06-01

    In order to protect the environment properly and have a realistic appraisal of how a chemical will act in the environment, tests of ecological effects and chemical fate must be performed on complex assemblages of biotic and abiotic components (i.e., microcosms) as well as single species. This protocol is one which could be added to a series of tests recently developed as guidelines for Section 4 of the Toxic Substances Control Act (P.L. 94-469; U.S.C., Section 2601-2629). The terrestrial soil-core microcosm is designed to supply site-specific and possibly regional information on the probable chemical fate and ecological effects resulting from release of a chemical substance to a terrestrial ecosystem. The EPA will use the data resulting from this test system to compare the potential hazards of a chemical with others that have been previously evaluated.

  9. A Standardized Chemically Modified Curcuma longa Extract Modulates IRAK-MAPK Signaling in Inflammation and Potentiates Cytotoxicity.

    Science.gov (United States)

    Rana, Minakshi; Maurya, Preeti; Reddy, Sukka S; Singh, Vishal; Ahmad, Hafsa; Dwivedi, Anil K; Dikshit, Madhu; Barthwal, Manoj K

    2016-01-01

    The TLR/IL-1R pathway is a critical signaling module that is misregulated in pathologies like inflammation and cancer. Extracts from turmeric (Curcuma longa L.) enriched in curcumin and carbonyls like turmerones have been shown to exert potent anti-inflammatory effects. The present study evaluated the anti-inflammatory activity, cytotoxic effect and the underlying mechanism of a novel chemically modified, non-carbonyl compound enriched Curcuma longa L. (C. longa) extract (CMCE). CMCE (1 or 10 μg/mL; 14 h) significantly decreased LPS (50-100 ng/mL) induced TNF-α and IL-1β production in THP-1 cells, human, and mouse whole blood as measured by ELISA. LPS-induced IRAK1, MAPK activation, TLR4 expression, TLR4-MyD88 interaction, and IκBα degradation were significantly reduced in CMCE pre-treated THP-1 cells as assessed by Western blotting. CMCE (30, 100, and 300 mg/kg; 10 days p.o.) pre-treated and LPS (10 mg/kg) challenged Swiss mice exhibited attenuated plasma TNF-α, IL-1β, nitrite, aortic iNOS expression, and vascular dysfunction. In a PI permeability assay, cell lines derived from acute myeloid leukemia were most sensitive to the cytotoxic effects of CMCE. Analysis of Sub-G1 phase, Annexin V-PI positivity, loss of mitochondrial membrane potential, increased caspase-3, and PARP-1 activation confirmed CMCE induced apoptosis in HL-60 cells. IRAK inhibition also sensitized HL-60 cells to CMCE induced cytotoxicity. The present study defines the mechanism underlying the action of CMCE and suggests a therapeutic potential for its use in sepsis and leukemia.

  10. A Standardized Chemically Modified Curcuma longa Extract Modulates IRAK-MAPK Signaling in Inflammation and Potentiates Cytotoxicity

    Directory of Open Access Journals (Sweden)

    Minakshi Rana

    2016-07-01

    Full Text Available The TLR/IL-1R pathway is a critical signaling module that is misregulated in pathologies like inflammation and cancer. Extracts from turmeric (Curcuma longa L. enriched in curcumin and carbonyls like turmerones have been shown to exert potent anti-inflammatory effects. The present study evaluated the anti-inflammatory activity, cytotoxic effect and the underlying mechanism of a novel chemically modified, non-carbonyl compound enriched Curcuma longa L. (C. longa extract (CMCE. CMCE (1 or 10 µg/mL; 14 h significantly decreased LPS (50-100 ng/mL induced TNF-α and IL-1β production in THP-1 cells, human, and mouse whole blood as measured by ELISA. LPS-induced IRAK1, MAPK activation, TLR4 expression, TLR4-MyD88 interaction and IκBα degradation were significantly reduced in CMCE pre-treated THP-1 cells as assessed by Western blotting. CMCE (30, 100 and 300 mg/kg; 10 days p.o. pre-treated and LPS (10 mg/kg challenged Swiss mice exhibited attenuated plasma TNF-α, IL-1β, nitrite, aortic iNOS expression and vascular dysfunction. In a PI permeability assay, cell lines derived from acute myeloid leukemia were most sensitive to the cytotoxic effects of CMCE. Analysis of Sub-G1 phase, Annexin V-PI positivity, loss of mitochondrial membrane potential, increased caspase-3 and PARP-1 activation confirmed CMCE induced apoptosis in HL-60 cells. IRAK inhibition also sensitized HL-60 cells to CMCE induced cytotoxicity. The present study defines the mechanism underlying the action of CMCE and suggests a therapeutic potential for its use in sepsis and leukemia.

  11. A Standardized Chemically Modified Curcuma longa Extract Modulates IRAK-MAPK Signaling in Inflammation and Potentiates Cytotoxicity.

    Science.gov (United States)

    Rana, Minakshi; Maurya, Preeti; Reddy, Sukka S; Singh, Vishal; Ahmad, Hafsa; Dwivedi, Anil K; Dikshit, Madhu; Barthwal, Manoj K

    2016-01-01

    The TLR/IL-1R pathway is a critical signaling module that is misregulated in pathologies like inflammation and cancer. Extracts from turmeric (Curcuma longa L.) enriched in curcumin and carbonyls like turmerones have been shown to exert potent anti-inflammatory effects. The present study evaluated the anti-inflammatory activity, cytotoxic effect and the underlying mechanism of a novel chemically modified, non-carbonyl compound enriched Curcuma longa L. (C. longa) extract (CMCE). CMCE (1 or 10 μg/mL; 14 h) significantly decreased LPS (50-100 ng/mL) induced TNF-α and IL-1β production in THP-1 cells, human, and mouse whole blood as measured by ELISA. LPS-induced IRAK1, MAPK activation, TLR4 expression, TLR4-MyD88 interaction, and IκBα degradation were significantly reduced in CMCE pre-treated THP-1 cells as assessed by Western blotting. CMCE (30, 100, and 300 mg/kg; 10 days p.o.) pre-treated and LPS (10 mg/kg) challenged Swiss mice exhibited attenuated plasma TNF-α, IL-1β, nitrite, aortic iNOS expression, and vascular dysfunction. In a PI permeability assay, cell lines derived from acute myeloid leukemia were most sensitive to the cytotoxic effects of CMCE. Analysis of Sub-G1 phase, Annexin V-PI positivity, loss of mitochondrial membrane potential, increased caspase-3, and PARP-1 activation confirmed CMCE induced apoptosis in HL-60 cells. IRAK inhibition also sensitized HL-60 cells to CMCE induced cytotoxicity. The present study defines the mechanism underlying the action of CMCE and suggests a therapeutic potential for its use in sepsis and leukemia. PMID:27504095

  12. A Potential Magnetic Resonance Imaging Technique Based on Chemical Exchange Saturation Transfer for In Vivo γ-Aminobutyric Acid Imaging

    Science.gov (United States)

    Yan, Gen; Zhang, Tao; Dai, Zhuozhi; Yi, Meizhi; Jia, Yanlong; Nie, Tingting; Zhang, Handi; Xiao, Gang; Wu, Renhua

    2016-01-01

    Purpose We developed a novel magnetic resonance imaging (MRI) technique based on chemical exchange saturation transfer (CEST) for GABA imaging and investigated the concentration-dependent CEST effect ofGABA in a rat model of brain tumor with blood—brain barrier (BBB) disruption. Materials and Methods All MRI studies were performed using a 7.0-T Agilent MRI scanner. Z-spectra for GABA were acquired at 7.0 T, 37°C, and a pH of 7.0 using varying B1 amplitudes. CEST images of phantoms with different concentrations of GABA solutions (pH, 7.0) and other metabolites (glutamine, myoinositol, creatinine, and choline) were collected to investigate the concentration-dependent CEST effect of GABA and the potential contribution from other brain metabolites. CEST maps for GABA in rat brains with tumors were collected at baseline and 50 min, 1.5 h, and 2.0 h after the injection of GABA solution. Results The CEST effect of GABA was observed at approximately 2.75 parts per million(ppm) downfield from bulk water, and this effect increased with an increase in the B1 amplitude and remained steady after the B1 amplitude reached 6.0 μT (255 Hz). The CEST effect of GABA was proportional to the GABA concentration in vitro. CEST imaging of GABA in a rat brain with a tumor and compromised BBB showed a gradual increase in the CEST effect after GABA injection. Conclusion The findings of this study demonstrate the feasibility and potential of CEST MRI with the optimal B1 amplitude, which exhibits excellent spatial and temporal resolutions, to map changes in GABA. PMID:27711138

  13. Kirkwood-Buff Integrals for Aqueous Urea Solutions Based upon the Quantum Chemical Electrostatic Potential and Interaction Energies.

    Science.gov (United States)

    Chiba, Shuntaro; Furuta, Tadaomi; Shimizu, Seishi

    2016-08-11

    Cosolvents, such as urea, affect protein folding and binding, and the solubility of solutes. The modeling of cosolvents has been facilitated significantly by the rigorous Kirkwood-Buff (KB) theory of solutions, which can describe structural thermodynamics over the entire composition range of aqueous cosolvent mixtures based only on the solution density and the KB integrals (KBIs), i.e., the net excess radial distribution functions from the bulk. Using KBIs to describe solution thermodynamics has given rise to a clear guideline that an accurate prediction of KBIs is equivalent to accurate modeling of cosolvents. Taking urea as an example, here we demonstrate that an improvement in the prediction of KBIs comes from an improved reproduction of high-level quantum chemical (QC) electrostatic potential and molecular pairwise interaction energies. This rational approach to the improvement of the KBI prediction stems from a comparison of existing force fields, AMOEBA, and the generalized AMBER force field, as well as the further optimization of the former to enable better agreement with QC interaction energies. Such improvements would pave the way toward a rational and systematic determination of the transferable force field parameters for a number of important small molecule cosolvents. PMID:27434200

  14. Textural and chemical properties of swine-manure-derived biochar pertinent to its potential use as a soil amendment.

    Science.gov (United States)

    Tsai, Wen-Tien; Liu, Sii-Chew; Chen, Huei-Ru; Chang, Yuan-Ming; Tsai, Yi-Lin

    2012-09-01

    Biochars have received increasing attention in recent years because of their properties pertaining to soil fertility and contaminant immobilization as well as serving as carbon sinks. In this work, a series of biochars were produced from dried swine manure waste by slow pyrolysis at different temperatures (i.e., 673-1073 K). The characterization of the resulting biochars was examined for its relevance to its potential use as soil amendment. It was found that the pore properties, ash contents and pH values of all swine-manure-derived biochars basically increased as temperature increased, while the yield and nitrogen/oxygen contents decreased with increasing temperature as a result of pyrolytic volatilization during pyrolysis. From the organic and inorganic elements analyses, the manure-derived biochar was rich in soil nutrients such as N, P, Ca, Mg, and K. Furthermore, the pore, surface and chemical properties were also consistent with the observations of the SEM-EDS, XRD and FTIR. This result suggested that the mesoporous manure-derived biochar could be used as an excellent medium to soil environment. PMID:22743180

  15. Chiral Symmetry Restoration with a Chiral Chemical Potential: the Role of Momentum Dependent Quark Self-energy

    CERN Document Server

    Ruggieri, M

    2016-01-01

    In this article we study restoration of chiral symmetry at finite temperature for quark matter with a chiral chemical potential, $\\mu_5$, by means of a nonlocal Nambu-Jona-Lasinio model. This model allows to introduce in the simplest way possible a Euclidean momentum, $p_E$, dependent quark mass function which decays (neglecting logarithms) as $1/p_E^2$ for large $p_E$ in agreement with asymptotic behaviour expected in presence of a nonperturbative quark condensate. We show that the momentum dependence of the quark mass function, which has been neglected in all of the previous model studies, drastically affects the dependence of the critical temperature versus $\\mu_5$. We explain this in terms of a natural removal of ultraviolet modes at $T>0$ in the gap equation, as well as of the natural addition of these modes at $T=0$ which help to catalyze chiral symmetry breaking. As a result we find that within this model the critical temperature increases with $\\mu_5$.

  16. Black holes as gases of punctures with a chemical potential: Bose-Einstein condensation and logarithmic corrections to the entropy

    CERN Document Server

    Asin, Olivier; Geiller, Marc; Noui, Karim; Perez, Alejandro

    2014-01-01

    We study the thermodynamical properties of black holes when described as gases of indistinguishable punctures with a chemical potential. In this picture, which arises from loop quantum gravity, the black hole microstates are defined by finite families of half-integers spins coloring the punctures, and the near-horizon energy measured by quasi-local stationary observers defines the various thermodynamical ensembles. The punctures carry excitations of quantum geometry in the form of quanta of area, and the total horizon area $a_\\text{H}$ is given by the sum of these microscopic contributions. We assume here that the system satisfies the Bose-Einstein statistics, and that each microstate is degenerate with a holographic degeneracy given by $\\exp\\big(\\lambda a_\\text{H}/\\ell_\\text{Pl}^2\\big)$ and $\\lambda>0$. We analyze in detail the thermodynamical properties resulting from these inputs, and in particular compute the grand canonical entropy. We explain why the requirements that the temperature be fixed to the Unr...

  17. Physico-chemical Properties and Assessment of Edible Oil Potential of Peanuts Grown in Kurram Agency, Parachinar

    Directory of Open Access Journals (Sweden)

    Rahib Hussain

    2015-06-01

    Full Text Available This study was carried out to investigate the oil potential of peanuts for domestic and commercial uses. Peanut oil yield and the physico-chemical properties of extracted oil were investigated on different temperatures (50, 55, 60 and 65 °C and sun drying. Results showed maximum oil yield of 47.2 % at sun drying and lowest values of 37.0 % at 65 °C. Highest and lowest acid values are 25.52 and 5.89 mg/KOH/g at 60 °C and 50 °C respectively. The Free Fatty Acid (FFA content were obtained 12.76 and 2.94 mg/g at 60 °C and 50 °C, while saponification values were 61.71 and 32.25 mg/KOH/g at 60 °C and 50 °C respectively. The highest Peroxide value of 92 mg/KOH/g was recorded at 55 °C which dropped to 43.4 mg/KOH/g at 65 °C. Refractive index (RI and density were not changed significantly (p≤0.05 on all temperatures, while pH was somewhat higher on 50 °C. The moisture content was found lowest up to 3.0 % on 65 °C while highest was 5 % on 50 °C.

  18. Phase structure of two-color QCD at real and imaginary chemical potentials: Lattice simulations and model analyses

    Science.gov (United States)

    Makiyama, Takahiro; Sakai, Yuji; Saito, Takuya; Ishii, Masahiro; Takahashi, Junichi; Kashiwa, Kouji; Kouno, Hiroaki; Nakamura, Atsushi; Yahiro, Masanobu

    2016-01-01

    We investigate the phase structure of two-color QCD at both real and imaginary chemical potentials (μ ), performing lattice simulations and analyzing the data with the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model. Lattice QCD simulations are done on an 83×4 lattice with the clover-improved two-flavor Wilson fermion action and the renormalization-group-improved Iwasaki gauge action. We test the analytic continuation of physical quantities from imaginary μ to real μ by comparing lattice QCD results calculated at real μ with the results of an analytic function, the coefficients of which are determined from lattice QCD results at imaginary μ . We also test the validity of the PNJL model by comparing model results with lattice QCD ones. The PNJL model is good in the deconfinement region, but less accurate in the transition and confinement regions. This problem is cured by introducing the baryon degree of freedom to the model. It is also found that the vector-type four-quark interaction is necessary to explain lattice data on the quark number density.

  19. Phase structure of two-color QCD at real and imaginary chemical potentials; lattice simulations and model analyses

    CERN Document Server

    Makiyama, Takahiro; Saito, Takuya; Ishii, Masahiro; Takahashi, Junichi; Kashiwa, Kouji; Kouno, Hiroaki; Nakamura, Atsushi; Yahiro, Masanobu

    2015-01-01

    We investigate the phase structure of two-color QCD at both real and imaginary chemical potentials mu, performing lattice simulations and analyzing the data with the Polyakov-loop extended Nambu--Jona-Lasinio (PNJL) model. Lattice QCD simulations are done on an 8^3 times 4 lattice with the clover-improved two-flavor Wilson fermion action and the renormalization-group improved Iwasaki gauge action. We test the analytic continuation of physical quantities from imaginary mu to real mu by comparing lattice QCD results calculated at real mu with the result of analytic function the coefficients of which are determined from lattice QCD results at imaginary mu. We also test the validity of the PNJL model by comparing model results with lattice QCD ones. The PNJL model is good in the deconfinement region, but less accurate in the transition and confinement regions. This problem is improved by introducing the baryon degree of freedom to the model. It is also found that the vector-type four-quark interaction is necessar...

  20. Anti-biofilm potential of phenolic acids: the influence of environmental pH and intrinsic physico-chemical properties.

    Science.gov (United States)

    Silva, Sara; Costa, Eduardo M; Horta, Bruno; Calhau, Conceição; Morais, Rui M; Pintado, M Manuela

    2016-09-13

    Phenolic acids are a particular group of small phenolic compounds which have exhibited some anti-biofilm activity, although the link between their activity and their intrinsic pH is not clear. Therefore, the present work examined the anti-biofilm activity (inhibition of biomass and metabolic activity) of phenolic acids in relation to the environmental pH, as well as other physico-chemical properties. The results indicate that, while Escherichia coli was not inhibited by the phenolic acids, both methicillin resistant Staphylococcus aureus and methicillin resistant Staphylococcus epidermidis were susceptible to the action of all phenolic acids, with the pH playing a relevant role in the activity: a neutral pH favored MRSE inhibition, while acidic conditions favored MRSA inhibition. Some links between molecular polarity and size were associated only with their potential as metabolic inhibitors, with the overall interactions hinting at a membrane-based mechanism for MRSA and a cytoplasmic effect for MRSE. PMID:27434592

  1. Osteoconductive Potential of Barrier NanoSiO2 PLGA Membranes Functionalized by Plasma Enhanced Chemical Vapour Deposition

    Directory of Open Access Journals (Sweden)

    Antonia Terriza

    2014-01-01

    Full Text Available The possibility of tailoring membrane surfaces with osteoconductive potential, in particular in biodegradable devices, to create modified biomaterials that stimulate osteoblast response should make them more suitable for clinical use, hopefully enhancing bone regeneration. Bioactive inorganic materials, such as silica, have been suggested to improve the bioactivity of synthetic biopolymers. An in vitro study on HOB human osteoblasts was performed to assess biocompatibility and bioactivity of SiO2 functionalized poly(lactide-co-glycolide (PLGA membranes, prior to clinical use. A 15 nm SiO2 layer was deposited by plasma enhanced chemical vapour deposition (PECVD, onto a resorbable PLGA membrane. Samples were characterized by X-ray photoelectron spectroscopy, atomic force microscopy, scanning electron microscopy, and infrared spectroscopy (FT-IR. HOB cells were seeded on sterilized test surfaces where cell morphology, spreading, actin cytoskeletal organization, and focal adhesion expression were assessed. As proved by the FT-IR analysis of samples, the deposition by PECVD of the SiO2 onto the PLGA membrane did not alter the composition and other characteristics of the organic membrane. A temporal and spatial reorganization of cytoskeleton and focal adhesions and morphological changes in response to SiO2 nanolayer were identified in our model. The novedous SiO2 deposition method is compatible with the standard sterilization protocols and reveals as a valuable tool to increase bioactivity of resorbable PLGA membranes.

  2. Cadmium tolerance and accumulation of Althaea rosea Cav. and its potential as a hyperaccumulator under chemical enhancement.

    Science.gov (United States)

    Liu, Jia Nv; Zhou, Qi Xing; Wang, Song; Sun, Ting

    2009-02-01

    The role of ornamental plants has drawn much attention as the urban pollution levels exacerbate. Althaea rosea Cav. had showed its strong tolerance and accumulation ability of Cd in our previous work, thus, the effects of ethylenediamine triacetic acid (EDTA), ethylenegluatarotriacetic acid (EGTA) and sodium dodecyl sulfate (SDS) on its Cd phytoremediation capacity were further investigated in this work. It reconfirmed that the species had strong tolerance and accumulation ability of Cd. Particularly, the species can be regarded as a potential Cd-hyperaccumulator through applying chemical agents. However, different chelators and surfactants had great differences in affecting hyperaccumulating characteristics of the species. EGTA and SDS could not only increase the dry biomass of the plants, but also promote Cd accumulation in shoots and roots. On the contrary, EDTA was toxic to the species by restraining the growth of plants, although it could promote Cd accumulation in shoots and roots of the plants to a certain extent. Thus, EGTA and SDS were effective in enhancing phytoremediation with Althaea rosea Cav. for Cd contaminated soils, while EDTA is ineffective in this regard. PMID:18259884

  3. Physico-chemical properties and assessment of adible oil potential of peanuts grown in kurram agency, parachinar

    International Nuclear Information System (INIS)

    This study was carried out to investigate the oil potential of peanuts for domestic and commercial uses. Peanut oil yield and the physico-chemical properties of extracted oil were investigated on different temperatures (50, 55, 60 and 65 degree C) and sun drying. Results showed maximum oil yield of 47.2 % at sun drying and lowest values of 37.0 % at 65 degree C. Highest and lowest acid values are 25.52 and 5.89 mg/KOH/g at 60 degree C and 50 degree C respectively. The Free Fatty Acid (FFA) content were obtained 12.76 and 2.94 mg/g at 60 degree C and 50 degree C, while saponification values were 61.71 and 32.25 mg/KOH/g at 60 degree C and 50 degree C respectively. The highest Peroxide value of 92 mg/KOH/g was recorded at 55 degree C which dropped to 43.4 mg/KOH/g at 65 degree C. Refractive index (RI) and density were not changed significantly (p<=0.05) on all temperatures, while pH was somewhat higher on 50 degree C. The moisture content was found lowest up to 3.0 % on 65 degree C while highest was 5 % on 50 degree C. (author)

  4. Women Reaching Equality in Dubious Habit: Drinking

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_161640.html Women Reaching Equality in Dubious Habit: Drinking Females also ... 25, 2016 MONDAY, Oct. 24, 2016 (HealthDay News) -- Women have made major strides towards equality with men, ...

  5. The policy on gender equality in Denmark

    DEFF Research Database (Denmark)

    Agustin, Lise Rolandsen

    The briefing paper describes current Danish policies, practices and legislation within the area of gender equality. It addresses economic independence, reconciliation policies, participation in decision-making, gender-based violence and trafficking, gender stereotypes, and gender equality...

  6. Chemical contaminants in water and sediment near fish nesting sites in the Potomac River basin: determining potential exposures to smallmouth bass (Micropterus dolomieu)

    Science.gov (United States)

    Kolpin, Dana W.; Blazer, Vicki; Gray, James L.; Focazio, Michael J.; Young, John A.; Alvarez, David A.; Iwanowicz, Luke R.; Foreman, William T.; Furlong, Edward T.; Speiran, Gary K.; Zaugg, Steven D.; Hubbard, Laura E.; Meyer, Michael T.; Sandstrom, Mark W.; Barber, Larry B.

    2013-01-01

    The Potomac River basin is an area where a high prevalence of abnormalities such as testicular oocytes (TO), skin lesions, and mortality has been observed in smallmouth bass (SMB, Micropterus dolomieu). Previous research documented a variety of chemicals in regional streams, implicating chemical exposure as one plausible explanation for these biological effects. Six stream sites in the Potomac basin (and one out-of-basin reference site) were sampled to provide an assessment of chemicals in these streams. Potential early life-stage exposure to chemicals detected was assessed by collecting samples in and around SMB nesting areas. Target chemicals included those known to be associated with important agricultural and municipal wastewater sources in the Potomac basin. The prevalence and severity of TO in SMB were also measured to determine potential relations between chemistry and biological effects. A total of 39 chemicals were detected at least once in the discrete-water samples, with atrazine, caffeine, deethylatrazine, simazine, and iso-chlorotetracycline being most frequently detected. Of the most frequently detected chemicals, only caffeine was detected in water from the reference site. No biogenic hormones/sterols were detected in the discrete-water samples. In contrast, 100 chemicals (including six biogenic hormones/sterols) were found in a least one passive-water sample, with 25 being detected at all such samples. In addition, 46 chemicals (including seven biogenic hormones/sterols) were found in the bed-sediment samples, with caffeine, cholesterol, indole, para-cresol, and sitosterol detected in all such samples. The number of herbicides detected in discrete-water samples per site had a significant positive relation to TOrank (a nonparametric indicator of TO), with significant positive relations between TOrank and atrazine concentrations in discrete-water samples and to total hormone/sterol concentration in bed-sediment samples. Such significant correlations

  7. Vanishing linear term in chemical potential difference in volume term of work of critical nucleus formation for phase transition without volume change

    CERN Document Server

    Mori, Atsushi

    2013-01-01

    A question is given on the form n({\\mu}_{\\beta}-{\\mu}_{\\alpha}) for the volume term of work of formation of critical nucleus. Here, n is the number of molecule undergone the phase transition, {\\mu} denotes the chemical potential, {\\alpha} and {\\beta} represent the parent and nucleating phases, respectively. In this paper we concentrate phase transition without volume change. We have calculated the volume term in terms of the chemical potential difference {\\mu}_{re}-{\\mu}_{eq}$ for this case. Here, {\\mu}_{re} is the chemical potential of the reservoir and {\\mu}_{eq} that at the phase transition. We have W_{vol} = -[({\\kappa}_{\\beta}-{\\kappa}_{\\alpha})/(2v_{eq}^2)] ({\\mu}_{re}-{\\mu}_{eq})^2 V_{\\beta} with {\\kappa} denoting the isothermal compressibility, v_{eq} being the molecular volume at the phase transition, V_{\\beta} the volume of the nucleus.

  8. Chemical evaluation of citrus seeds, an agro-industrial waste, as a new potential source of vegetable oils

    Directory of Open Access Journals (Sweden)

    Matthaus, B.

    2012-09-01

    Full Text Available The seed oils from seven Turkish and ten Vietnamese varieties of Citrus fruits were examined for their fatty acid composition, tocopherols and sterol contents. The oil contents of the samples varied between 32.1 g/100 g and 58.8 g/100 g. The major fatty acid of the extracted seed oils was oleic (12.8-70.1%, followed by linoleic (19.5-58.8% and palmitic (5.1-28.3%. Stearic, vaccenic, linolenic and arachidic acids were found at low levels. The total content of vitamin E active compounds in the oils ranged between 0.8 and 21.0 mg/100 g. The predominant isomers were α- and γ-tocopherol, with approximate equal amounts between about 0.4 and 17.5 mg/100 g. The total sterol contents of the oils were found between 1310.54 and 3986.58 mg/kg, with β -sitosterol as the predominant sterol that accounted for more than 70% of the total amount of sterols. Other sterols, campesterol (8.03-15.26%, stigmasterol (2.55-7.69%, ∆5-avenasterol (1.80-5.67%, cholesterol (0.83-2.70% and chlerosterol (0.93-1.78% were detected in most of the oils. The results of the present study indicate that the seed oils of Citrus fruits are considered to be a potential oil source due to their fatty acid composition and important tocopherol and sterol, and might be used for edible applications as well as the production of potential value-added products.

    Aceites de semillas de siete y diez variedades de frutas cítricas turcas y de Vietnam respectivamente, fueron examinadas por su composición en ácidos grasos, tocoferoles y esteroles. El contenido de aceite de las muestras varió entre 32.1 g/100 g y 58.8 g/100 g. El principal ácido graso de los aceites extraídos de las semillas fue oleico (12.8 a 70.1%, seguido por linoleico (19.5-58.8% y palmítico (5.1 a 28.3%. Los ácidos esteárico, vacénico, linolénico y araquídico se encontraron en niveles bajos. El contenido total de compuestos de vitamina E activa en los aceites varió entre 0.8 y 21.0 mg/100 g. Los is

  9. Regulation vs. reality in Serbia: Gender equality, economy and state

    Directory of Open Access Journals (Sweden)

    Đurić-Kuzmanović Tatjana

    2010-01-01

    Full Text Available When the Law on Equality between Sexes (2009 and the National Strategy for Improving the Position of Women and Advancing Gender Equality (2009 were adopted, after a several years of obstruction of proceedings, in Serbia normative prerequisites for the implementation of the gender equality policy and for prevention and sanctioning of all kinds of gender based discrimination were created. In this paper, the author discusses the expected effect of the implementation of the Law on Equality between sexes. In addition, the key argument which restricts its implementation and potential positive effects is explained. The context of the dominate patriarchy and the prevailing human nondevelopment in Serbia does not stimulate neither women nor men, as development actors (manager, worker, trade union, state, to act in the direction to change gender regime and to take responsibility for development of the economy and society.

  10. 76 FR 31451 - Equal Credit Opportunity

    Science.gov (United States)

    2011-06-01

    ... / Wednesday, June 1, 2011 / Rules and Regulations#0;#0; ] FEDERAL RESERVE SYSTEM 12 CFR Part 202 Equal Credit.... SUMMARY: The Board is publishing amendments to Regulation B (Equal Credit Opportunity Act) to update the...) 263-4869. SUPPLEMENTARY INFORMATION: The Equal Credit Opportunity Act (ECOA), 15 U.S.C....

  11. Does 0.999... Really Equal 1?

    Science.gov (United States)

    Norton, Anderson; Baldwin, Michael

    2012-01-01

    This article confronts the issue of why secondary and post-secondary students resist accepting the equality of 0.999... and 1, even after they have seen and understood logical arguments for the equality. In some sense, we might say that the equality holds by definition of 0.999..., but this definition depends upon accepting properties of the real…

  12. Top Value-Added Chemicals from Biomass - Volume II—Results of Screening for Potential Candidates from Biorefinery Lignin

    Energy Technology Data Exchange (ETDEWEB)

    Holladay, John E.; White, James F.; Bozell, Joseph J.; Johnson, David

    2007-10-01

    This report evaluates lignin’s role as a renewable raw material resource. Opportunities that arise from utilizing lignin fit into one of three categories: 1)power, fuel and syngas (generally near-term opportunities) 2) macromolecules (generally medium-term opportunities) 3) aromatics and miscellaneous monomers (long-term opportunities). Biorefineries will receive and process massive amounts of lignin. For this reason, how lignin can be best used to support the economic health of the biorefinery must be defined. An approach that only considers process heat would be shortsighted. Higher value products present economic opportunities and the potential to significantly increase the amount of liquid transportation fuel available from biomass. In this analysis a list of potential uses of lignin was compiled and sorted into “product types” which are broad classifications (listed above as power—fuel—syngas; macromolecules; and aromatics). In the first “product type” (power—fuel—gasification) lignin is used purely as a carbon source and aggressive means are employed to break down its polymeric structure. In the second “product type” (macromolecules) the opposite extreme is considered and advantage of the macromolecular structure imparted by nature is retained in high-molecular weight applications. The third “product type” (aromatics) lies somewhere between the two extremes and employs technologies that would break up lignin’s macromolecular structure but maintain the aromatic nature of the building block molecules. The individual opportunities were evaluated based on their technical difficulty, market, market risk, building block utility, and whether a pure material or a mixture would be produced. Unlike the “Sugars Top 10” report it was difficult to identify the ten best opportunities, however, the potential opportunities fell nicely into near-, medium- and long-term opportunities. Furthermore, the near-, medium- and long-term opportunities

  13. Heat-flux control and solid-state cooling by regulating chemical potential of photons in near-field electromagnetic heat transfer

    Science.gov (United States)

    Chen, Kaifeng; Santhanam, Parthiban; Sandhu, Sunil; Zhu, Linxiao; Fan, Shanhui

    2015-04-01

    We consider near-field heat transfer with nonzero chemical potential for photons, as can occur between two semiconductor bodies, held at different temperatures with at least one of the bodies under external bias. We show that the dependence of radiative heat flux on chemical potential enables electronic control of both the direction and magnitude of near-field heat transfer between the two bodies. Moreover such a configuration can operate as a solid-state cooling device whose efficiency can approach the Carnot limit in the ideal case. Significant cooling can also be achieved in the presence of inherent nonidealities including Auger recombination and parasitic phonon-polariton heat transfer.

  14. Gandhigram: fostering equality through development.

    Science.gov (United States)

    Devi, R K

    1991-12-01

    A noticeable trend towards 1-child families reveals the success of Gandhigram, an integrated rural development program in Tamil Nadu, India. Founded in 1947 by T.S. Soundram, Gandhigram has adhered to Gandhian principles of truth, nonviolence, castlessness, and equality between the sexes. The program has combined health and family planning with social welfare, education, and economic development. From the outset, Gandhigram has sought community participation, including the involvement of women. Girls have been encouraged to attend school up to at least the 10th level, and employment opportunities for women have been increased. Women's increased economic independence and level of education have influenced their decision to delay marriage by about 2 1/2 years, to choose their own partners, and to decide on the number of children they want. And increasingly, women are opting to limit family size to 2 -- and sometimes 1 -- child. Women are choosing to undergo tubectomies at a younger age, partly because of the availability of recanalization surgery, which has allowed mothers who have lost a child to conceive again. Unlike typical government family planning programs, which usually provide only contraception to meet the objective of a small family norm, Gandhigram also offers infertility services. Not all of Gandhigram's efforts have resulted in success. For example, a plan to develop a health insurance program did not succeed. However, Gandhigram's 44 years of experience have revealed the necessary elements for success. These elements include community participation, the participation of women through educational and employment programs, and easy access to services. PMID:12317116

  15. E-quality and e-service equality

    OpenAIRE

    Shachaf, Pnina; Oltmann, Shannon M.

    2007-01-01

    Research is divided about the potential of e-service to bridge communication gaps, particularly to diverse user groups. According to the existing body of literature, e-service may increase or decrease the quality of service received. This study analyzes the level of service received by different genders and ethnic groups when public librarians answer online reference queries. Quality of e-service was evaluated along three dimensions: responsiveness, reliability, and courtesy. This study found...

  16. Trust, Welfare States and Income Equality

    DEFF Research Database (Denmark)

    Bergh, Andreas; Bjørnskov, Christian

    2014-01-01

    The cross-country correlation between social trust and income equality is well documented, but few studies examine the direction of causality. We show theoretically that by facilitating cooperation, trust may lead to more equal outcomes, while the feedback from inequality to trust is ambiguous....... Using a structural equation model estimated on a large country sample, we find that trust has a positive effect on both market and net income equality. Larger welfare states lead to higher net equality but neither net income equality nor welfare state size seems to have a causal effect on trust. We...

  17. Experimental and Quantum chemical studies on the inhibition potential of some Quinoxaline derivatives for mild steel in acid media

    Directory of Open Access Journals (Sweden)

    Saranya.J

    2014-12-01

    Full Text Available The inhibition potential of four Quinoxaline derivatives namely 1,4-dihydroquinoxaline-2,3-dione, (3E-3-hydrazinylidene-3,4-dihydroquinoxalin-2(1H-one, 1-[(2E-3-oxo-3,4-dihydroquinoxalin-2(1H-ylidene]urea and 1-[(2E-3-oxo-3,4-dihydroquinoxalin-2(1H-ylidene]thiourea have been investigated against mild steel in 1M H2SO4 solution using conventional weight loss, electrochemical impedance spectroscopy, potentiodynamic polarization and atomic absorption spectroscopy. The percentage inhibition efficiency was found to increase with increase in the inhibitor concentration due to the adsorption of the inhibitor molecules on the metal surface. In addition, it was established that the adsorption follows Langmuir adsorption isotherm. Moreover, some thermodynamic data were calculated and discussed. The density functional theory at the B3LYP/6-311G (d,p basis set level was performed for two inhibitors namely 1,4-dihydroquinoxaline-2,3-dione and (3E-3-hydrazinylidene-3,4-dihydroquinoxalin-2(1H-one. The quantum chemical parameters such as highest occupied molecular orbital energy (EHOMO, lowest unoccupied molecular orbital energy (ELUMO, energy gap (∆E, dipole moment (µ, softness (σ, hardness (η, electronegativity (χ, Mulliken atomic charges, the fraction of electrons transferred from the inhibitor to the metal surface (∆N and the total energy (TE have been calculated for these compounds. It was found that theoretical data support the experimental results.

  18. Evaluation of a chemical proxy for fire intensity: A potential tool for studying fire-climate feedbacks

    Science.gov (United States)

    Hockaday, W. C.; White, J. D.; Von Bargen, J.; Yao, J.

    2015-12-01

    The legacy of wildfire is recorded in the geologic record, due to the stability of charcoal. Well-preserved charcoal is abundant in paleo-soils and sediments, documenting paleo-fires affecting even the earliest land plants. The dominant role of fire in shaping the biosphere is evidenced by some 40% of the land surface which is occupied by fire-prone and fire-adapted biomes: boreal forest, savanna, grassland, and Mediterranean shrubland. While fire ecologists appreciate the role that fire played in the evolution of these ecosystems, and climate scientists appreciate the role of these biomes in the regulation of Earth's climate, our understanding of the system of fire-vegetation-climate feedbacks is poor. This knowledge gap exists because we lack tools for evaluating change in fire regimes of the past for which climate proxy records exist. Fire regime is a function of fire frequency and fire intensity. Although fire frequency estimates are available from laminated sediment and tree ring records, tools for estimating paleo-fire intensity are lacking. We have recently developed a chemical proxy for fire intensity that is based upon the molecular structure of charcoal, assessed using solid-state nuclear magnetic resonance (NMR) spectroscopy. The molecular dimensions of aromatic domains in charcoal increased linearly (R2 = 0.9) with the intensity (temperature x duration) of heating. Our initial field-based validation in prescribed fires shows a promising correlation (R2 = 0.7) between the proxy-based estimates and thermistor-based measurements of fire intensity. This presentation will discuss the competencies and potential limitations of this novel proxy.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-07-01

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

  20. Use of chemicals and biological products in Asian aquacultire and their potential environmental risks: a critical review

    NARCIS (Netherlands)

    Rico, A.; Satapornvanit, K.; Haque, M.M.; Min, J.; Nguyen, P.T.; Telfer, T.; Brink, van den P.J.

    2012-01-01

    Over the past few decades, Asian aquaculture production has intensified rapidly through the adoption of technological advances, and the use of a wide array of chemical and biological products to control sediment and water quality and to treat and prevent disease outbreaks. The use of chemicals in aq

  1. Enhancing the Benefit of the Chemical Mixture Methodology: A Report on Methodology Testing and Potential Approaches for Improving Performance

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Xiao-Ying; Yao, Juan; He, Hua; Glantz, Clifford S.; Booth, Alexander E.

    2012-01-01

    Extensive testing shows that the current version of the Chemical Mixture Methodology (CMM) is meeting its intended mission to provide conservative estimates of the health effects from exposure to airborne chemical mixtures. However, the current version of the CMM could benefit from several enhancements that are designed to improve its application of Health Code Numbers (HCNs) and employ weighting factors to reduce over conservatism.

  2. Use of the HepaRG Cell Line to Assess Potential Human Hepatotoxicity of ToxCast™ Chemicals

    Science.gov (United States)

    The HepaRG cell line is a promising model system for predicting human hepatotoxicity in part because of the greater capacity to metabolize chemicals than other cell models. We hypothesized that this cell line would be a relevant model for toxicity testing of industrial chemicals....

  3. A new multimedia contaminant fate model for China: how important are environmental parameters in influencing chemical persistence and long-range transport potential?

    Science.gov (United States)

    Zhu, Ying; Price, Oliver R; Tao, Shu; Jones, Kevin C; Sweetman, Andy J

    2014-08-01

    We present a new multimedia chemical fate model (SESAMe) which was developed to assess chemical fate and behaviour across China. We apply the model to quantify the influence of environmental parameters on chemical overall persistence (POV) and long-range transport potential (LRTP) in China, which has extreme diversity in environmental conditions. Sobol sensitivity analysis was used to identify the relative importance of input parameters. Physicochemical properties were identified as more influential than environmental parameters on model output. Interactive effects of environmental parameters on POV and LRTP occur mainly in combination with chemical properties. Hypothetical chemicals and emission data were used to model POV and LRTP for neutral and acidic chemicals with different KOW/DOW, vapour pressure and pKa under different precipitation, wind speed, temperature and soil organic carbon contents (fOC). Generally for POV, precipitation was more influential than the other environmental parameters, whilst temperature and wind speed did not contribute significantly to POV variation; for LRTP, wind speed was more influential than the other environmental parameters, whilst the effects of other environmental parameters relied on specific chemical properties. fOC had a slight effect on POV and LRTP, and higher fOC always increased POV and decreased LRTP. Example case studies were performed on real test chemicals using SESAMe to explore the spatial variability of model output and how environmental properties affect POV and LRTP. Dibenzofuran released to multiple media had higher POV in northwest of Xinjiang, part of Gansu, northeast of Inner Mongolia, Heilongjiang and Jilin. Benzo[a]pyrene released to the air had higher LRTP in south Xinjiang and west Inner Mongolia, whilst acenaphthene had higher LRTP in Tibet and west Inner Mongolia. TCS released into water had higher LRTP in Yellow River and Yangtze River catchments. The initial case studies demonstrated that SESAMe

  4. The generalized expression of chemical potential and its applications%化学势的普遍化表达式及其应用

    Institute of Scientific and Technical Information of China (English)

    王慧娟; 韩光泽

    2012-01-01

    化学势是判断热力学系统相平衡的依据,是物质相变、扩散和化学反应的推动力.以能量公理为基础,从热力学基本原理出发推广了化学势的定义,导出了外场作用下化学势的普遍化表达式.外场作用下的化学势不仅是温度、压强和组分摩尔分数的函数,还与外场的特征参数有关.利用该普遍化表达式导出了重力场、离心力场和电磁场作用下的化学势,尤其是电场作用下电介质的化学势.利用该化学势研究了电场作用下纯物质的气液相变过程,结果表明,电场作用可以使极性物质的蒸汽压略有上升,对非极性物质没有影响,该结论与实验相符.对外场强化萃取和蒸馏等传质过程提供了一种新的研究方法.%Chemical potential is not only the criterion to estimate chemical equilibrium but also the cause of diffusions, phase transitions and chemical reactions. In this paper, based on the energy postulate and thermodynamic principles, a generalized expression of chemical potential with the effect of external fields was derived , which shows that chemical potential not only depends on temperature, pressure and molar fraction of the components, but also is strongly affected by the characteristic parameters of the external fields. The gravitational, centrifugal, electric and magnetic chemical potentials were deduced from this generalized expression, especially the chemical potential of dielectric in electric field was also obtained. The vapor-liquid equilibrium of pure substance acted by electrostatic field was investigated with this new chemical potential. The results show that the electric field can slightly raise the saturated vapor pressure of polar substances, but no change of nonpolar substance, which coincide with the experimental results. This work provides a new method for the study of mass transfer, such as extraction and distillation, enhanced by external field.

  5. Present practice, on-going research and future potential for non-chemical pest management in fruit and berry production in Denmark

    OpenAIRE

    Sigsgaard, Lene

    2012-01-01

    Workshop prensentation - Present practice, ongoing research and future potential for non-chemical pest management in fruit and berry production in Denmark. Chinese-Danish networking on systemic approaches to pest management without pesticides. Hand-out (Flowerstrips and beneficials in orchards)

  6. Chemically modified ion-sensitive field-effect transistors: elimination of the liquid juction potential in a double sensor flow-injection analysis cell

    NARCIS (Netherlands)

    Cobben, Peter L.H.M.; Egberink, Richard J.M.; Bomer, J.G.; Schouwenaar, Robert; Brzozka, Zbigniew; Bergveld, Piet; Reinhoudt, David N.; Bos, Martinus

    1993-01-01

    A flow-through cell was designed that can be used for flow-injection analysis with two chemically modified ion-sensitive field-effect transistors (CHEMFETs) in close proximity. This offers the possibility of a differential measurement without influence of the liquid junction potential. The different

  7. Physico-chemical analysis and antimicrobial potential of A pis dorsata, A pis mellifera and Z iziphus jujube honey samples from Pakistan

    Directory of Open Access Journals (Sweden)

    Hira Fahim

    2014-08-01

    Conclusion: Physico-chemical analysis of honey samples confirmed good quality of honey according to the standards set by European Union Commission and Codex Alimentarius Commission. Evaluation of these honey samples confirms antimicrobial potential of particular types of honeys indigenous to Pakistan.

  8. Social Capital and the Equalizing Potential of the Internet

    NARCIS (Netherlands)

    H.D. Pruijt (Hans)

    2002-01-01

    textabstractSocial capital is predominantly seen as a public good. Internet communication tends to complement real-world interaction. Therefore, concerns that it might contribute to a decline of social capital seem unfounded. Internet communication can support and enhance communities that to some ex

  9. Comparative analysis of equalization methods for SC-FDMA

    DEFF Research Database (Denmark)

    Dogadaev, Anton Konstantinovich; Kozlov, Alexander; Ukhanova, Ann

    2010-01-01

    In this paper we introduce comparative analysis for different types of equalization schemes, based on the minimum mean square error (MMSE) optimization. The following types of equalizers were compared: linear equalization, decision feedback equalization (DFE) and turbo equalization. Performance and...

  10. The Uneasy Marriage between Law and Equality

    Directory of Open Access Journals (Sweden)

    Pauline C. Westerman

    2015-02-01

    Full Text Available There are two ways in which the social ideal of equality has found expression in the law: in the principle of equal treatment and in the principle of non-discrimination. In this article the meaning of these two legal principles is analysed, in order to answer the question to what extent they can be said to contribute to equality in the sense of an equal distribution of collective resources. It is argued that whereas the first just requires decision-making to be rule-based, the second principle demands that rules should be based on sound categorical distinctions. Neither of the two can, however, sensibly be linked to equality as equal distribution. The article concludes that the only way to establish such a link is by adding to the principle of non-discrimination “financial resources” as a suspect ground.

  11. Iterative Estimation in Turbo Equalization Process

    Directory of Open Access Journals (Sweden)

    MORGOS Lucian

    2014-05-01

    Full Text Available This paper presents the iterative estimation in turbo equalization process. Turbo equalization is the process of reception in which equalization and decoding are done together, not as separate processes. For the equalizer to work properly, it must receive before equalization accurate information about the value of the channel impulse response. This estimation of channel impulse response is done by transmission of a training sequence known at reception. Knowing both the transmitted and received sequence, it can be calculated estimated value of the estimated the channel impulse response using one of the well-known estimation algorithms. The estimated value can be also iterative recalculated based on the sequence data available at the output of the channel and estimated sequence data coming from turbo equalizer output, thereby refining the obtained results.

  12. Use of Fly Ash as a Potential Coagulant in the Physico-Chemical Treatment of Domestic Wastewater

    OpenAIRE

    SARI, Bülent; BAYAT, Belgin

    2002-01-01

    The effectiveness of fly ash as a coagulant for domestic wastewater treatment was investigated and compared with aluminium sulfate and ferric chloride. In these experiments, four fly ash samples with different chemical compositions obtained from different coal- fired power plants in Turkey were used. In all coagulation-flocculation experiments using fly ash, it was apparent that the predominant removal mechanism varied with the pH and the chemical components of the fly ash. According to our r...

  13. Chemical Species in the Vapor Phase of Hanford Double-Shell Tanks: Potential Impacts on Waste Tank Corrosion Processes

    Energy Technology Data Exchange (ETDEWEB)

    Felmy, Andrew R.; Qafoku, Odeta; Arey, Bruce W.; Boomer, Kayle D.

    2010-09-22

    The presence of corrosive and inhibiting chemicals on the tank walls in the vapor space, arising from the waste supernatant, dictate the type and degree of corrosion that occurs there. An understanding of how waste chemicals are transported to the walls and the affect on vapor species from changing supernatant chemistry (e.g., pH, etc.), are basic to the evaluation of risks and impacts of waste changes on vapor space corrosion (VSC). In order to address these issues the expert panel workshop on double-shell tank (DST) vapor space corrosion testing (RPP-RPT-31129) participants made several recommendations on the future data and modeling needs in the area of DST corrosion. In particular, the drying of vapor phase condensates or supernatants can form salt or other deposits at the carbon steel interface resulting in a chemical composition at the near surface substantially different from that observed directly in the condensates or the supernatants. As a result, over the past three years chemical modeling and experimental studies have been performed on DST supernatants and condensates to predict the changes in chemical composition that might occur as condensates or supernatants equilibrate with the vapor space species and dry at the carbon steel surface. The experimental studies included research on both the chemical changes that occurred as the supernatants dried as well as research on how these chemical changes impact the corrosion of tank steels. The chemical modeling and associated experimental studies were performed at the Pacific Northwest National Laboratory (PNNL) and the research on tank steel corrosion at the Savannah River National Laboratory (SRNL). This report presents a summary of the research conducted at PNNL with special emphasis on the most recent studies conducted in FY10. An overall summary of the project results as well as their broader implications for vapor space corrosion of the DST’s is given at the end of this report.

  14. Automated procedure to determine the thermodynamic stability of a material and the range of chemical potentials necessary for its formation relative to competing phases and compounds

    Science.gov (United States)

    Buckeridge, J.; Scanlon, D. O.; Walsh, A.; Catlow, C. R. A.

    2014-01-01

    We present a simple and fast algorithm to test the thermodynamic stability and determine the necessary chemical environment for the production of a multiternary material, relative to competing phases and compounds formed from the constituent elements. If the material is found to be stable, the region of stability, in terms of the constituent elemental chemical potentials, is determined from the intersection points of hypersurfaces in an (n-1)-dimensional chemical potential space, where n is the number of atomic species in the material. The input required is the free energy of formation of the material itself, and that of all competing phases. Output consists of the result of the test of stability, the intersection points in the chemical potential space and the competing phase to which they relate, and, for two- and three-dimensional spaces, a file which may be used for visualization of the stability region. We specify the use of the program by applying it both to a ternary system and to a quaternary system. The algorithm automates essential analysis of the thermodynamic stability of a material. This analysis consists of a process which is lengthy for ternary materials, and becomes much more complicated when studying materials of four or more constituent elements, which have become of increased interest in recent years for technological applications such as energy harvesting and optoelectronics. The algorithm will therefore be of great benefit to the theoretical and computational study of such materials.

  15. Chemical inhibition of autophagy: Examining its potential to increase the specific productivity of recombinant CHO cell lines.

    Science.gov (United States)

    Baek, Eric; Kim, Che Lin; Kim, Mi Gyeom; Lee, Jae Seong; Lee, Gyun Min

    2016-09-01

    Chinese hamster ovary (CHO) cells activate and undergo apoptosis and autophagy for various environmental stresses. Unlike apoptosis, studies on increasing the production of therapeutic proteins in CHO cells by targeting the autophagy pathway are limited. In order to identify the effects of chemical autophagy inhibitors on the specific productivity (qp ), nine chemical inhibitors that had been reported to target three different phases of autophagy (metformin, dorsomorphin, resveratrol, and SP600125 against initiation and nucleation; 3-MA, wortmannin, and LY294002 against elongation, and chloroquine and bafilomycin A1 against autophagosome fusion) were used to treat three recombinant CHO (rCHO) cell lines: the Fc-fusion protein-producing DG44 (DG44-Fc) and DUKX-B11 (DUKX-Fc) and antibody-producing DG44 (DG44-Ab) cell lines. Among the nine chemical inhibitors tested, 3-MA, dorsomorphin, and SP600125 significantly increased the qp of DG44-Fc and DUKX-Fc. In contrast, for DG44-Ab, only 3-MA significantly increased the qp . The autophagy-inhibiting activity of the nine chemical inhibitors on the rCHO cell lines was evaluated through Western blot analysis and flow cytometry. Unexpectedly, some chemical inhibitors did not exhibit any apparent inhibition activity on autophagy. The chemical inhibitors that enhanced the qp , 3-MA, dorsomorphin, and SP600125, exhibited instead an increased autophagic flux. Taken all together, the chemical inhibition of autophagy was not effective in increasing the qp in rCHO cell lines and the positive effect of 3-MA, dorsomorphin, and SP600125 on the qp was not due to the inhibition of autophagy. Biotechnol. Bioeng. 2016;113: 1953-1961. © 2016 Wiley Periodicals, Inc.

  16. Chemical inhibition of autophagy: Examining its potential to increase the specific productivity of recombinant CHO cell lines.

    Science.gov (United States)

    Baek, Eric; Kim, Che Lin; Kim, Mi Gyeom; Lee, Jae Seong; Lee, Gyun Min

    2016-09-01

    Chinese hamster ovary (CHO) cells activate and undergo apoptosis and autophagy for various environmental stresses. Unlike apoptosis, studies on increasing the production of therapeutic proteins in CHO cells by targeting the autophagy pathway are limited. In order to identify the effects of chemical autophagy inhibitors on the specific productivity (qp ), nine chemical inhibitors that had been reported to target three different phases of autophagy (metformin, dorsomorphin, resveratrol, and SP600125 against initiation and nucleation; 3-MA, wortmannin, and LY294002 against elongation, and chloroquine and bafilomycin A1 against autophagosome fusion) were used to treat three recombinant CHO (rCHO) cell lines: the Fc-fusion protein-producing DG44 (DG44-Fc) and DUKX-B11 (DUKX-Fc) and antibody-producing DG44 (DG44-Ab) cell lines. Among the nine chemical inhibitors tested, 3-MA, dorsomorphin, and SP600125 significantly increased the qp of DG44-Fc and DUKX-Fc. In contrast, for DG44-Ab, only 3-MA significantly increased the qp . The autophagy-inhibiting activity of the nine chemical inhibitors on the rCHO cell lines was evaluated through Western blot analysis and flow cytometry. Unexpectedly, some chemical inhibitors did not exhibit any apparent inhibition activity on autophagy. The chemical inhibitors that enhanced the qp , 3-MA, dorsomorphin, and SP600125, exhibited instead an increased autophagic flux. Taken all together, the chemical inhibition of autophagy was not effective in increasing the qp in rCHO cell lines and the positive effect of 3-MA, dorsomorphin, and SP600125 on the qp was not due to the inhibition of autophagy. Biotechnol. Bioeng. 2016;113: 1953-1961. © 2016 Wiley Periodicals, Inc. PMID:26914152

  17. Equality, consistency, and impartiality in tax legislation

    NARCIS (Netherlands)

    Gribnau, J.L.M.; Gribnau, J.L.M.

    2003-01-01

    The ideal of equality can be conceived in law in a formal as well as in a substantive way. Contrary to what some authors suppose, the principle of formal equality is not entirely meaningless. It generates standards for treatment, i.e., for legitimate discriminations in law. The principle is like a s

  18. Vocational Education and Equality of Opportunity.

    Science.gov (United States)

    Horowitz, Benjamin; Feinberg, Walter

    1990-01-01

    Examines the concepts of equality of opportunity and equality of educational opportunity and their relationship to vocational education. Traces the history of vocational education. Delineates the distinction between training and education as enumerated in Aristotelian philosophy. Discusses the role vocational education can play in the educative…

  19. Continuing Controversy in Equal Employment Law.

    Science.gov (United States)

    Vogt, Carl W.; Robles, Martin J.

    1980-01-01

    Some current controversies in the growing body of equal employment law are examined: wage comparability in the context of sex discrimination; procedural sections of the laws and related litigation; class actions by the Equal Employment Opportunities Commission; the scope of litigation; and the criteria for conferring standing on the plaintiff.…

  20. Does Russia need gender equality officers?

    OpenAIRE

    Krasilnikova, Oxana; Красильникова, Оксана

    2013-01-01

    The paper identifies the reasons for the lack of the gender equality officer in the Russian Federation against the background of the Nordic countries and Germany experience and conditions for the establishment of the gender equality in Europe. Using gender approach the political and cultural situation of the Russian society is analyzed and the ways to solve the problem are suggested.

  1. Equal Plate Charges on Series Capacitors?

    Science.gov (United States)

    Illman, B. L.; Carlson, G. T.

    1994-01-01

    Provides a line of reasoning in support of the contention that the equal charge proposition is at best an approximation. Shows how the assumption of equal plate charge on capacitors in series contradicts the conservative nature of the electric field. (ZWH)

  2. Blind Equalization Based on Evolution Strategies

    Institute of Scientific and Technical Information of China (English)

    SongYu; ZhangXianda; 等

    1997-01-01

    Conventional blind equalization algorithms suffer from ill convergence to local minima and slow convergence speed.This paper proposes a novel blind equalization algorithm.using random search methods-evolution strategies and existing cost functions,Simulation results verify the fast and global convergence of the proposed algorithm.

  3. 47 CFR 73.1941 - Equal opportunities.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Equal opportunities. 73.1941 Section 73.1941... Rules Applicable to All Broadcast Stations § 73.1941 Equal opportunities. (a) General requirements...-spot coverage of bona fide news events (including, but not limited to political conventions...

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

    Directory of Open Access Journals (Sweden)

    Alberto de J. Oliveros-Bastidas

    2013-01-01

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

  5. Potential for the integration of biological and chemical control of sheath blight disease caused by Rhizoctonia solani on rice.

    Science.gov (United States)

    Boukaew, Sawai; Klinmanee, Chanasirin; Prasertsan, Poonsuk

    2013-10-01

    Biological control using antagonistic microbes to minimize the use of chemical pesticides has recently become more prevalent. In an attempt to find an integrated control system for sheath blight, caused by Rhizoctonia solani in rice, Streptomyces philanthi RM-1-138, commercial formulations of Bacillus subtilis as Larminar® and B. subtilis strain NSRS 89-24+MK-007 as Biobest® and chemical fungicides including carbendazim®, validamycin®, propiconazole® and mancozeb® were applied alone and in combination with S. philanthi RM-1-138. In vitro experiments showed that all treatments tested did provide some control against mycelial growth and sclerotia production by R. solani PTRRS-9. In addition, the four chemical fungicides had no detrimental effects on S. philanthi RM-1-138 even at high concentrations (up to 100 μg/ml). The efficacy of S. philanthi RM-1-138, the commercial formulations of B. subtilis, chemical fungicides alone or in combination with S. philanthi RM-1-138 was also tested in a greenhouse experiment against sheath blight disease on rice plants. All treatments showed some protection of rice for sheath blight by 47-60 % when carbendazim® was applied alone and up to 74 % when combined with S. philanthi RM-1-138. PMID:23653261

  6. Using Alternative Approaches to Prioritize Testing for the Universe of Chemicals with Potential for Human Exposure (WC9)

    Science.gov (United States)

    One use of alternative methods is to target animal use at only those chemicals and tests that are absolutely necessary. We discuss prioritization of testing based on high-throughput screening assays (HTS), QSAR modeling, high-throughput toxicokinetics (HTTK), and exposure modelin...

  7. Slow-light enhanced absorption for bio-chemical sensing applications: potential of low-contrast lossy materials

    DEFF Research Database (Denmark)

    Pedersen, Jesper Goor; Xiao, Sanshui; Mortensen, Niels Asger

    2008-01-01

    Slow-light enhanced absorption in liquid-infiltrated photonic crystals has recently been proposed as a route to compensate for the reduced optical path in typical lab-on-a-chip systems for bio-chemical sensing applications. A simple perturbative expression has been applied to ideal structures...

  8. SLUG FLOW PROCESSING IN MICROREACTORS FOR BIO-BASED CHEMICAL MANUFACTURING: SYNTHESIS AND OXIDATION OF 5-HYDROXYMETHYLFURFURAL AS POTENTIAL APPLICATIONS

    NARCIS (Netherlands)

    Yue, Jun; Deuss, Peter; Zhang, Zheng; Hommes, Arne; Heeres, Hero

    2016-01-01

    The ever increasing global demand on fossil resources that are limited in reserves has directed numerous research efforts recently towards the development of more sustainable feedstocks as the source for the production of fuels, chemicals and (performance) materials. Conversion of biomass (particula

  9. Understanding the chemical properties of macerals and minerals in coal and its potential application for occupational lung disease prevention

    Energy Technology Data Exchange (ETDEWEB)

    Huang, X.; Finkelman, R.B. [NYU, New York, NY (United States). School of Medicine

    2008-07-01

    The objective of this review was to assess whether some chemical parameters in coal play a role in producing environmental health problems. Basic properties of coal - such as chemical forms of the organic materials, structure, compositions of minerals - vary from one coal mine region to another as well as from coals of different ranks. Most importantly, changes in chemical properties of coals due to exposure to air and humidity after mining - a dynamic process - significantly affect toxicity attributed to coal and environmental fate. Although coal is an extremely complex and heterogeneous material, the fundamental properties of coal responsible for environmental and adverse health problems are probably related to the same inducing components of coal. For instance, oxidation of pyrite (FeS{sub 2}) in the coal forms iron sulfate and sulfuric acid, which produces occupational lung diseases (e.g., pneumoconiosis) and other environmental problems (e.g., acid mine drainage and acid rain). Calcite (CaCO{sub 3}) contained in certain coals alters the end products of pyrite oxidation, which may make these coals less toxic to human inhalation and less hazardous to environmental pollution. Finally, knowledge gained on understanding of the chemical properties of coals is illustrated to apply for prediction of toxicity due to coal possibly before large-scale mining and prevention of occupational lung disease during mining.

  10. Programmable Thermal Dissociation of Reactive Gaseous Mercury, a Potential Approach to Chemical Speciation: Results from a Field Study§

    Directory of Open Access Journals (Sweden)

    Cheryl Tatum Ernest

    2014-08-01

    Full Text Available Programmable Thermal Dissociation (PTD has been used to investigate the chemical speciation of Reactive Gaseous Mercury (RGM, Hg2+. RGM was collected on denuders and analyzed using PTD. The technique was tested in a field campaign at a coal-fired power plant in Pensacola, Florida. Stack gas samples were collected from ducts located after the electrostatic precipitator and prior to entering the stack. An airship was used to sample from the stack plume, downwind of the stack exit. The PTD profiles from these samples were compared with PTD profiles of HgCl2. Comparison of stack and in-plume samples suggest that the chemical speciation are the same and that it is possible to track a specific chemical form of RGM from the stack and follow its evolution in the stack plume. Comparison of the measured plume RGM with the amount calculated from in-stack measurements and the measured plume dilution suggest that the stack and plume RGM concentrations are consistent with dilution. The PTD profiles of the stack and plume samples are consistent with HgCl2 being the chemical form of the sampled RGM. Comparison with literature PTD profiles of reference mercury compounds suggests no other likely candidates for the speciation of RGM.

  11. The critical review of methodologies and approaches to assess the inherent skin sensitization potential (skin allergies) of chemicals. Part II

    DEFF Research Database (Denmark)

    Thyssen, Jacob P; Giménez-Arnau, Elena; Lepoittevin, Jean-Pierre;

    2012-01-01

    To identify specific cases, classes or specific use situations of chemicals for which 'safety thresholds' or 'safety limits' were set (in regulations, standards, in scientific research/clinical work, etc.) and critically review the scientific and methodological parameters used to set those limits....

  12. Approximate Equalities on Rough Intuitionistic Fuzzy Sets and an Analysis of Approximate Equalities

    Directory of Open Access Journals (Sweden)

    B. K. Tripathy

    2012-03-01

    Full Text Available In order to involve user knowledge in determining equality of sets, which may not be equal in the mathematical sense, three types of approximate (rough equalities were introduced by Novotny and Pawlak ([8, 9, 10]. These notions were generalized by Tripathy, Mitra and Ojha ([13], who introduced the concepts of approximate (rough equivalences of sets. Rough equivalences capture equality of sets at a higher level than rough equalities. More properties of these concepts were established in [14]. Combining the conditions for the two types of approximate equalities, two more approximate equalities were introduced by Tripathy [12] and a comparative analysis of their relative efficiency was provided. In [15], the four types of approximate equalities were extended by considering rough fuzzy sets instead of only rough sets. In fact the concepts of leveled approximate equalities were introduced and properties were studied. In this paper we proceed further by introducing and studying the approximate equalities based on rough intuitionistic fuzzy sets instead of rough fuzzy sets. That is we introduce the concepts of approximate (rough equalities of intuitionistic fuzzy sets and study their properties. We provide some real life examples to show the applications of rough equalities of fuzzy sets and rough equalities of intuitionistic fuzzy sets.

  13. Use of short-term test systems for the prediction of the hazard represented by potential chemical carcinogens

    International Nuclear Information System (INIS)

    It has been hypothesized that results from short-term bioassays will ultimately provide information that will be useful for human health hazard assessment. Historically, the validity of the short-term tests has been assessed using the framework of the epidemiologic/medical screens. In this context, the results of the carcinogen (long-term) bioassay is generally used as the standard. However, this approach is widely recognized as being biased and, because it employs qualitative data, cannot be used to assist in isolating those compounds which may represent a more significant toxicologic hazard than others. In contrast, the goal of this research is to address the problem of evaluating the utility of the short-term tests for hazard assessment using an alternative method of investigation. Chemicals were selected mostly from the list of carcinogens published by the International Agency for Research on Carcinogens (IARC); a few other chemicals commonly recognized as hazardous were included. Tumorigenicity and mutagenicity data on 52 chemicals were obtained from the Registry of Toxic Effects of Chemical Substances (RTECS) and were analyzed using a relative potency approach. The data were evaluated in a format which allowed for a comparison of the ranking of the mutagenic relative potencies of the compounds (as estimated using short-term data) vs. the ranking of the tumorigenic relative potencies (as estimated from the chronic bioassays). Although this was a preliminary investigation, it offers evidence that the short-term tests systems may be of utility in ranking the hazards represented by chemicals which may contribute to increased carcinogenesis in humans as a result of occupational or environmental exposures. 177 refs., 8 tabs

  14. Use of short-term test systems for the prediction of the hazard represented by potential chemical carcinogens

    Energy Technology Data Exchange (ETDEWEB)

    Glass, L.R.; Jones, T.D.; Easterly, C.E.; Walsh, P.J.

    1990-10-01

    It has been hypothesized that results from short-term bioassays will ultimately provide information that will be useful for human health hazard assessment. Historically, the validity of the short-term tests has been assessed using the framework of the epidemiologic/medical screens. In this context, the results of the carcinogen (long-term) bioassay is generally used as the standard. However, this approach is widely recognized as being biased and, because it employs qualitative data, cannot be used to assist in isolating those compounds which may represent a more significant toxicologic hazard than others. In contrast, the goal of this research is to address the problem of evaluating the utility of the short-term tests for hazard assessment using an alternative method of investigation. Chemicals were selected mostly from the list of carcinogens published by the International Agency for Research on Carcinogens (IARC); a few other chemicals commonly recognized as hazardous were included. Tumorigenicity and mutagenicity data on 52 chemicals were obtained from the Registry of Toxic Effects of Chemical Substances (RTECS) and were analyzed using a relative potency approach. The data were evaluated in a format which allowed for a comparison of the ranking of the mutagenic relative potencies of the compounds (as estimated using short-term data) vs. the ranking of the tumorigenic relative potencies (as estimated from the chronic bioassays). Although this was a preliminary investigation, it offers evidence that the short-term tests systems may be of utility in ranking the hazards represented by chemicals which may contribute to increased carcinogenesis in humans as a result of occupational or environmental exposures. 177 refs., 8 tabs.

  15. Duality between chiral symmetry breaking and charged pion condensation at large $N_c$: Consideration of an NJL$_2$ model with baryon-, isospin- and chiral isospin chemical potentials

    CERN Document Server

    Ebert, D; Klimenko, K G

    2016-01-01

    In this paper we investigate the phase structure of a (1+1)-dimensional schematic quark model with four-quark interaction and in the presence of baryon ($\\mu_B$), isospin ($\\mu_I$) and chiral isospin ($\\mu_{I5}$) chemical potentials. It is established that in the large-$N_c$ limit ($N_c$ is the number of colored quarks) there exists a duality correspondence between the chiral symmetry breaking phase and the charged pion condensation (PC) one. The role and influence of this property on the phase structure of the model are studied. Moreover, it is shown that the chemical potential $\\mu_{I5}$ promotes the appearance of the charged PC phase with nonzero baryon density.

  16. Synergistic Potentiation of Cystic Fibrosis Transmembrane Conductance Regulator Gating by Two Chemically Distinct Potentiators, Ivacaftor (VX-770) and 5-Nitro-2-(3-Phenylpropylamino) Benzoate.

    Science.gov (United States)

    Lin, Wen-Ying; Sohma, Yoshiro; Hwang, Tzyh-Chang

    2016-09-01

    Cystic fibrosis (CF) is caused by loss-of-function mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene encoding a phosphorylation-activated but ATP-gated chloride channel. Previous studies suggested that VX-770 [ivacaftor, N-(2,4-di-tert-butyl-5-hydroxyphenyl)-4-oxo-1,4-dihydroquinoline-3-carboxamide], a CFTR potentiator now used in clinics, increases the open probability of CFTR by shifting the gating conformational changes to favor the open channel configuration. Recently the chloride channel blocker and CFTR potentiator 5-nitro-2-(3-phenylpropylamino) benzoate (NPPB) has been reported to enhance CFTR activity by a mechanism that exploits the ATP hydrolysis-driven, nonequilibrium gating mechanism unique to CFTR. Surprisingly however, NPPB increased the activity of nonhydrolytic G551D-CFTR, the third most common disease-associated mutation. Here, we further investigated the mechanism of NPPB's effects on CFTR gating by assessing its interaction with well-studied VX-770. Interestingly, once G551D-CFTR was maximally potentiated by VX-770, NPPB further increased its activity. However, quantitative analysis of this drug-drug interaction suggests that this pharmacologic synergism is not due to independent actions of NPPB and VX-770 on CFTR gating; instead, our data support a dependent mechanism involving two distinct binding sites. This latter idea is further supported by the observation that the locked-open time of a hydrolysis-deficient mutant K1250A was shortened by NPPB but prolonged by VX-770. In addition, the effectiveness of NPPB, but not of VX-770, was greatly diminished in a mutant whose second nucleotide-binding domain was completely removed. Interpreting these results under the framework of current understanding of CFTR gating not only reveals insights into the mechanism of action for different CFTR potentiators but also brings us one step forward to a more complete schematic for CFTR gating. PMID:27413118

  17. FINANCIAL EQUALIZATION TRANSFERS BETWEEN PUBLIC AUTHORITIES BUDGETS

    Directory of Open Access Journals (Sweden)

    Emilia Cornelia STOICA

    2015-07-01

    Full Text Available This paper presents financial balancing mechanisms that it is applied by the most of the states with competitive market economy, in order to ensure equity between local authorities, as well as the stability of the entire national tax and budgetary system. In this regard, it is described the concept of financial equalization and its structure according to two fundamental criteria: - equalization in accordance with the financial transfers orientation, distinguishing thus (1 horizontal equalization, which is carried out between local authorities and consists in assigning a part of the richest territorial collectivities resources to the disadvantaged ones; (2 vertical financial equalization, achieved through consolidated transfers the state / federal budget to the budgets by territorial administrative units, both for the operating budget section and for the development one; - financial equalization according to the regional or local disparities observed as a result of territorial-level analyzes: (1 financial equalization based on balancing public revenues of the administrative-territorial units, which tries to correct the differences between the financial resources of each local authority and (2 the financial balancing based on the costs, which aims to reduce differences between standard costs of public services per capita. Financial equalization mechanisms have as main objective the reduction as far as the total elimination of the regional or local disparities, which are also described in this article.

  18. Health and the elusive gender equality : Can the impact of gender equality on health be measured?

    OpenAIRE

    Sörlin, Ann

    2011-01-01

    Background: All over the world men and women show different health patterns, and therecan be many and various reasons for these differences. This thesis therefore evaluates theimpact of gender equality on health. To do this, we must be able to measure gender equality.In this thesis, we develop two new measurements of gender equality and evaluate the relationshipbetween gender equality and health. Methods: Two cross-sectional studies, one register-based and one survey study, are used tocompare...

  19. Visualizing the Positive-Negative Interface of Molecular Electrostatic Potentials as an Educational Tool for Assigning Chemical Polarity

    Science.gov (United States)

    Schonborn, Konrad; Host, Gunnar; Palmerius, Karljohan

    2010-01-01

    To help in interpreting the polarity of a molecule, charge separation can be visualized by mapping the electrostatic potential at the van der Waals surface using a color gradient or by indicating positive and negative regions of the electrostatic potential using different colored isosurfaces. Although these visualizations capture the molecular…

  20. On Striving to Simulate All Known Atmospheres Equally Well

    Science.gov (United States)

    Dowling, T. E.

    2004-05-01

    Creating a single general circulation model (GCM) that achieves both accuracy and impartiality for gas-giant and terrestrial atmospheres, and is implemented for all known atmospheres, is the primary development goal for the Explicit Planetary Isentropic-Coordinate (EPIC) atmospheric model. The idea is to make it easy to practice comparative planetology on the now more than one dozen atmospheres observed inside and outside the solar system, and---given that many parameterizations are needed to make GCMs work---to make it hard to fall into the trap of artificial tuning. Towards the goal of accuracy, we are using an isentropic vertical coordinate, which minimizes vertical truncation errors and increases the accuracy of long-range transport of chemical species and of moisture; interestingly, the latter yields better predictions than non-isentropic coordinate models even for non-isentropic storm activity, because the "fuel" is delivered more precisely. However, the isentropic-coordinate approach is not accurate at the bottom of either terrestrial or a gas-giant atmospheres, each for a different reason. For terrestrial atmospheres, isentropes tend to intersect topography at steep angles, causing technical headaches, and for gas giants, convection in their interiors renders entropy nearly constant and therefore not a viable coordinate. Enter the idea of a hybrid-isentropic vertical coordinate, which smoothly transitions into a pressure coordinate towards the bottom of the model. The hybrid idea provides both accuracy and impartiality because topography can be handled with a terrain-following pressure coordinate, traditionally called sigma, and a sigma coordinate works equally well for the deep atmospheres of gas giants, where the model's bottom layer may be chosen conveniently to be a constant-pressure surface. We describe the implementation of this idea in the EPIC model, including our definition of the hybrid coordinate, the calculation of the hybrid vertical velocity