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Sample records for optimized effective potential

  1. A parametrized optimized effective potential for atoms

    Energy Technology Data Exchange (ETDEWEB)

    Sarsa, A; Galvez, F J; BuendIa, E [Departamento de FIsica Moderna, Facultad de Ciencias, Universidad de Granada, E-18071 Granada (Spain)

    2003-11-28

    The optimized effective potential equations for atoms have been solved by parametrizing the potential. The expansion is tailored to match the known asymptotic behaviour of the effective potential at both short and long distances. Both single configuration and multi-configuration trial wavefunctions are implemented. Applications to several atomic systems are presented, improving on previous works. The results obtained here are very close to those calculated in either the Hartree-Fock (HF) or the multi-configurational HF framework.

  2. First-principle optimal local pseudopotentials construction via optimized effective potential method

    Science.gov (United States)

    Mi, Wenhui; Zhang, Shoutao; Wang, Yanchao; Ma, Yanming; Miao, Maosheng

    2016-04-01

    The local pseudopotential (LPP) is an important component of orbital-free density functional theory, a promising large-scale simulation method that can maintain information on a material's electron state. The LPP is usually extracted from solid-state density functional theory calculations, thereby it is difficult to assess its transferability to cases involving very different chemical environments. Here, we reveal a fundamental relation between the first-principles norm-conserving pseudopotential (NCPP) and the LPP. On the basis of this relationship, we demonstrate that the LPP can be constructed optimally from the NCPP for a large number of elements using the optimized effective potential method. Specially, our method provides a unified scheme for constructing and assessing the LPP within the framework of first-principles pseudopotentials. Our practice reveals that the existence of a valid LPP with high transferability may strongly depend on the element.

  3. The role of orbital products in the optimized effective potential method

    NARCIS (Netherlands)

    Kollmar, Christian; Filatov, Michael

    2008-01-01

    The orbital products of occupied and virtual orbitals are employed as an expansion basis for the charge density generating the local potential in the optimized effective potential method thus avoiding the use of auxiliary basis sets. The high computational cost arising from the quadratic increase of

  4. Alternative derivation of an exchange-only density-functional optimized effective potential

    Science.gov (United States)

    Joubert, D. P.

    2007-10-01

    An alternative derivation of the exchange-only density-functional optimized effective potential equation is given. It is shown that the localized Hartree-Fock common energy denominator Green’s function approximation (LHF-CEDA) for the density-functional exchange potential proposed independently by Della Sala and Görling [J. Chem. Phys. 115, 5718 (2001)] and Gritsenko and Baerends [Phys. Rev. A 64, 42506 (2001)] can be derived as an approximation to the OEP exchange potential in a similar way that the KLI approximation [Phys. Rev. A 45, 5453 (1992)] was derived. An exact expression for the correction term to the LHF-CEDA approximation can thus be found. The correction term can be expressed in terms of the first-order perturbation-theory many-electron wave function shift when the Kohn-Sham Hamiltonian is subjected to a perturbation equal to the difference between the density-functional exchange potential and the Hartree-Fock nonlocal potential, expressed in terms of the Kohn-Sham orbitals. An explicit calculation shows that the density weighted mean of the correction term is zero, confirming that the LHF-CEDA approximation can be interpreted as a mean-field approximation. The corrected LHF-CEDA equation and the optimized effective potential equation are shown to be identical, with information distributed differently between terms in the equations. For a finite system the correction term falls off at least as fast as 1/r4 for large r .

  5. The Effects of Creatine Supplementation on Explosive Performance and Optimal Individual Postactivation Potentiation Time

    Directory of Open Access Journals (Sweden)

    Chia-Chi Wang

    2016-03-01

    Full Text Available Creatine plays an important role in muscle energy metabolism. Postactivation potentiation (PAP is a phenomenon that can acutely increase muscle power, but it is an individualized process that is influenced by muscle fatigue. This study examined the effects of creatine supplementation on explosive performance and the optimal individual PAP time during a set of complex training bouts. Thirty explosive athletes performed tests of back squat for one repetition maximum (1RM strength and complex training bouts for determining the individual optimal timing of PAP, height and peak power of a counter movement jump before and after the supplementation. Subjects were assigned to a creatine or placebo group and then consumed 20 g of creatine or carboxymethyl cellulose per day for six days. After the supplementation, the 1RM strength in the creatine group significantly increased (p < 0.05. The optimal individual PAP time in the creatine group was also significant earlier than the pre-supplementation and post-supplementation of the placebo group (p < 0.05. There was no significant difference in jump performance between the groups. This study demonstrates that creatine supplementation improves maximal muscle strength and the optimal individual PAP time of complex training but has no effect on explosive performance.

  6. Precise response functions in all-electron methods: Application to the optimized-effective-potential approach

    Science.gov (United States)

    Betzinger, Markus; Friedrich, Christoph; Görling, Andreas; Blügel, Stefan

    2012-06-01

    The optimized-effective-potential method is a special technique to construct local Kohn-Sham potentials from general orbital-dependent energy functionals. In a recent publication [M. Betzinger, C. Friedrich, S. Blügel, A. Görling, Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.83.045105 83, 045105 (2011)] we showed that uneconomically large basis sets were required to obtain a smooth local potential without spurious oscillations within the full-potential linearized augmented-plane-wave method. This could be attributed to the slow convergence behavior of the density response function. In this paper, we derive an incomplete-basis-set correction for the response, which consists of two terms: (1) a correction that is formally similar to the Pulay correction in atomic-force calculations and (2) a numerically more important basis response term originating from the potential dependence of the basis functions. The basis response term is constructed from the solutions of radial Sternheimer equations in the muffin-tin spheres. With these corrections the local potential converges at much smaller basis sets, at much fewer states, and its construction becomes numerically very stable. We analyze the improvements for rock-salt ScN and report results for BN, AlN, and GaN, as well as the perovskites CaTiO3, SrTiO3, and BaTiO3. The incomplete-basis-set correction can be applied to other electronic-structure methods with potential-dependent basis sets and opens the perspective to investigate a broad spectrum of problems in theoretical solid-state physics that involve response functions.

  7. Reply to ``Comment on `Nonanalyticity of the optimized effective potential with finite basis sets' ''

    Science.gov (United States)

    Gidopoulos, Nikitas I.; Lathiotakis, Nektarios N.

    2013-10-01

    The Comment by Friedrich does not dispute the central result of our paper [Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.85.052508 85, 052508 (2012)] that nonanalytic behavior is present in long-established mathematical pathologies arising in the solution of finite basis optimized effective potential (OEP) equations. In the Comment, the terms “balancing of basis sets” and “basis-set convergence” imply a particular order towards the limit of a large orbital basis sets where the large-orbital-base limit is always taken first, before the large-auxiliary-base limit, until overall convergence is achieved, at a high computational cost. The authors claim that, on physical grounds, this order of limits is not only sufficient, but also necessary in order to avoid the mathematical pathologies. In response to the Comment, we remark that it is already written in our paper that the nonanalyticity trivially disappears with large orbital basis sets. We point out that the authors of the Comment give an incorrect proof of this statement. We also show that the order of limits towards convergence of the potential is immaterial. A recent paper by the authors of the Comment proposes a partial correction for the incomplete orbital basis error in the full-potential linearized augmented-plane-wave method. Similar to the correction developed in our paper, this correction also benefits from an effectively complete orbital basis, even though only a finite orbital basis is employed in the calculation. This shows that it is unnecessary to take, in practice, the limit of an infinite orbital basis in order to avoid mathematical pathologies in the OEP. Our paper is a significant contribution in that direction with general applicability to any choice of basis sets. Finally, contrary to an allusion in the abstract and assertions in the main text of the Comment that unphysical oscillations of the OEP are supposedly attributed to the common energy denominator approximation, in fact, such

  8. Exchange-only optimized-effective-potential calculations using Slater-type basis functions : Atoms and diatomic molecules

    NARCIS (Netherlands)

    Fernandez, J. J.; Alvarellos, J. E.; Garcia-Gonzalez, P.; Filatov, M.

    2012-01-01

    The exchange-only optimized-effective-potential method is implemented with the use of Slater-type basis functions, seeking an alternative to the standard methods of solution with some computational advantages. This procedure has been tested in a small group of closed-shell atoms and diatomic molecul

  9. Self-consistent double-hybrid density-functional theory using the optimized-effective-potential method

    CERN Document Server

    Smiga, Szymon; Mussard, Bastien; Buksztel, Adam; Grabowski, Ireneusz; Luppi, Eleonora; Toulouse, Julien

    2016-01-01

    We introduce an orbital-optimized double-hybrid (DH) scheme using the optimized-effective-potential (OEP) method. The orbitals are optimized using a local potential corresponding to the complete exchange-correlation energy expression including the second-order M{{\\o}}ller-Plesset (MP2) correlation contribution. We have implemented a one-parameter version of this OEP-based self-consistent DH scheme using the BLYP density-functional approximation and compared it to the corresponding non-self-consistent DH scheme for calculations on a few closed-shell atoms and molecules. While the OEP-based self-consistency does not provide any improvement for the calculations of ground-state total energies and ionization potentials, it does improve the accuracy of electron affinities and restores the meaning of the LUMO orbital energy as being connected to a neutral excitation energy. Moreover, the OEP-based self-consistent DH scheme provides reasonably accurate exchange-correlation potentials and correlated densities.

  10. Hierarchy of model Kohn–Sham potentials for orbital-dependent functionals: A practical alternative to the optimized effective potential method

    Energy Technology Data Exchange (ETDEWEB)

    Kohut, Sviataslau V.; Staroverov, Viktor N., E-mail: vstarove@uwo.ca [Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7 (Canada); Ryabinkin, Ilya G. [Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4 (Canada)

    2014-05-14

    We describe a method for constructing a hierarchy of model potentials approximating the functional derivative of a given orbital-dependent exchange-correlation functional with respect to electron density. Each model is derived by assuming a particular relationship between the self-consistent solutions of Kohn–Sham (KS) and generalized Kohn–Sham (GKS) equations for the same functional. In the KS scheme, the functional is differentiated with respect to density, in the GKS scheme—with respect to orbitals. The lowest-level approximation is the orbital-averaged effective potential (OAEP) built with the GKS orbitals. The second-level approximation, termed the orbital-consistent effective potential (OCEP), is based on the assumption that the KS and GKS orbitals are the same. It has the form of the OAEP plus a correction term. The highest-level approximation is the density-consistent effective potential (DCEP), derived under the assumption that the KS and GKS electron densities are equal. The analytic expression for a DCEP is the OCEP formula augmented with kinetic-energy-density-dependent terms. In the case of exact-exchange functional, the OAEP is the Slater potential, the OCEP is roughly equivalent to the localized Hartree–Fock approximation and related models, and the DCEP is practically indistinguishable from the true optimized effective potential for exact exchange. All three levels of the proposed hierarchy require solutions of the GKS equations as input and have the same affordable computational cost.

  11. Time-Local Equation for the Exact Optimized Effective Potential in Time-Dependent Density Functional Theory

    Science.gov (United States)

    Liao, Sheng-Lun; Ho, Tak-San; Rabitz, Herschel; Chu, Shih-I.

    2017-06-01

    A long-standing challenge in the time-dependent density functional theory is to efficiently solve the exact time-dependent optimized effective potential (TDOEP) integral equation derived from orbital-dependent functionals, especially for the study of nonadiabatic dynamics in time-dependent external fields. In this Letter, we formulate a completely equivalent time-local TDOEP equation that admits a unique real-time solution in terms of time-dependent Kohn-Sham and effective memory orbitals. The time-local formulation is numerically implemented, with the incorporation of exponential memory loss to address the unaccounted for correlation component in the exact-exchange-only functional, to enable the study of the many-electron dynamics of a one-dimensional hydrogen chain. It is shown that the long time behavior of the electric dipole converges correctly and the zero-force theorem is fulfilled in the current implementation.

  12. Orbital-dependent second-order scaled-opposite-spin correlation functionals in the optimized effective potential method

    Science.gov (United States)

    Grabowski, Ireneusz; Fabiano, Eduardo; Teale, Andrew M.; Śmiga, Szymon; Buksztel, Adam; Della Sala, Fabio

    2014-07-01

    The performance of correlated optimized effective potential (OEP) functionals based on the spin-resolved second-order correlation energy is analysed. The relative importance of singly- and doubly- excited contributions as well as the effect of scaling the same- and opposite- spin components is investigated in detail comparing OEP results with Kohn-Sham (KS) quantities determined via an inversion procedure using accurate ab initio electronic densities. Special attention is dedicated in particular to the recently proposed scaled-opposite-spin OEP functional [I. Grabowski, E. Fabiano, and F. Della Sala, Phys. Rev. B 87, 075103 (2013)] which is the most advantageous from a computational point of view. We find that for high accuracy, a careful, system dependent, selection of the scaling coefficient is required. We analyse several size-extensive approaches for this selection. Finally, we find that a composite approach, named OEP2-SOSh, based on a post-SCF rescaling of the correlation energy can yield high accuracy for many properties, being comparable with the most accurate OEP procedures previously reported in the literature but at substantially reduced computational effort.

  13. Orbital-dependent second-order scaled-opposite-spin correlation functionals in the optimized effective potential method

    Energy Technology Data Exchange (ETDEWEB)

    Grabowski, Ireneusz, E-mail: ig@fizyka.umk.pl; Śmiga, Szymon; Buksztel, Adam [Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun (Poland); Fabiano, Eduardo [National Nanotechnology Laboratory, Istituto Nanoscienze–CNR, Via per Arnesano, I-73100 Lecce (Italy); Teale, Andrew M. [School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom); Centre for Theoretical and Computational Chemistry, Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, N-0315 Oslo (Norway); Sala, Fabio Della [National Nanotechnology Laboratory, Istituto Nanoscienze–CNR, Via per Arnesano, I-73100 Lecce (Italy); Center for Biomolecular Nanotechnologies @UNILE, Istituto Italiano di Tecnologia (IIT), Via Barsanti, 73010 Arnesano (LE) (Italy)

    2014-07-14

    The performance of correlated optimized effective potential (OEP) functionals based on the spin-resolved second-order correlation energy is analysed. The relative importance of singly- and doubly- excited contributions as well as the effect of scaling the same- and opposite- spin components is investigated in detail comparing OEP results with Kohn–Sham (KS) quantities determined via an inversion procedure using accurate ab initio electronic densities. Special attention is dedicated in particular to the recently proposed scaled-opposite–spin OEP functional [I. Grabowski, E. Fabiano, and F. Della Sala, Phys. Rev. B 87, 075103 (2013)] which is the most advantageous from a computational point of view. We find that for high accuracy, a careful, system dependent, selection of the scaling coefficient is required. We analyse several size-extensive approaches for this selection. Finally, we find that a composite approach, named OEP2-SOSh, based on a post-SCF rescaling of the correlation energy can yield high accuracy for many properties, being comparable with the most accurate OEP procedures previously reported in the literature but at substantially reduced computational effort.

  14. Effect of host immunity on metastatic potential in renal cell carcinoma: the assessment of optimal in vivo models to study metastatic behavior of renal cancer cells.

    Science.gov (United States)

    Kobayashi, Minoru; Morita, Tatsuo; Chun, Nicole A L; Matsui, Aya; Takahashi, Masafumi; Murakami, Takashi

    2012-04-01

    There has been little information about metastatic behavior of renal cell carcinoma (RCC) cells because human cancers metastasize only rarely in immunodeficient mice. Moreover, it is difficult to know the effect of host immunity on RCC metastasis due to lack of such RCC cells as transplantable in not only xenograft models but also counterparts with intact immunity. Therefore, we scrutinized in vivo metastasis of RCC cells to seek for the optimal preclinical model to study metastatic behavior. The luciferase-expressing three representative human RCC cell lines (Caki-1, A498, and 786-O) and rat ACI-RCC cell which were established in our laboratory were transplanted into nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice or immunocompetent ACI rats by intracardiac injection as well as orthotopic inoculation. Metastasis was monitored using a bioluminescent imaging technique. Metastasis was rare in the three human RCC cells even when they were directly disseminated into systemic circulation under the condition least susceptible to host immune attack in NOD/SCID mice. In contrast, ACI-RCC cells spontaneously metastasized to pulmonary tissue from orthotopic tumor sites and systemically spread via intracardiac route. Metastases were more extensive when the cells were inoculated into an immunodeficient host, implying suppressive effect of host immunity on colonization of RCC cells. These results suggest that the representative human RCC cells are not adequate resource to study metastasis but that the luciferase-labeled ACI-RCC cell characterized by its luminescent stability, enhanced tumorigenicity, and widespread metastatic potential provides a useful in vivo model for preclinical assessment of cancer progression and potential therapies against RCC.

  15. The Hubble effective potential

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, T.M.; Miao, S.P.; Prokopec, T. [Institute for Theoretical Physics and Spinoza Institute, Utrecht University, Leuvenlaan 4, Postbus 80.195, 3508 TD Utrecht (Netherlands); Woodard, R.P., E-mail: T.M.Janssen@uu.nl, E-mail: S.Miao@uu.nl, E-mail: T.Prokopec@uu.nl, E-mail: woodard@phys.ufl.edu [Department of Physics, University of Florida, Gainesville, FL 32611 (United States)

    2009-05-15

    We generalize the effective potential to scalar field configurations which are proportional to the Hubble parameter of a homogeneous and isotropic background geometry. This may be useful in situations for which curvature effects are significant. We evaluate the one loop contribution to the Hubble Effective Potential for a massless scalar with arbitrary conformal and quartic couplings, on a background for which the deceleration parameter is constant. Among other things, we find that inflationary particle production leads to symmetry restoration at late times.

  16. Design and development of a new micro-beam treatment planning system: effectiveness of algorithms of optimization and dose calculations and potential of micro-beam treatment.

    Science.gov (United States)

    Tachibana, Hidenobu; Kojima, Hiroyuki; Yusa, Noritaka; Miyajima, Satoshi; Tsuda, Akihisa; Yamashita, Takashi

    2012-07-01

    A new treatment planning system (TPS) was designed and developed for a new treatment system, which consisted of a micro-beam-enabled linac with robotics and a real-time tracking system. We also evaluated the effectiveness of the implemented algorithms of optimization and dose calculations in the TPS for the new treatment system. In the TPS, the optimization procedure consisted of the pseudo Beam's-Eye-View method for finding the optimized beam directions and the steepest-descent method for determination of beam intensities. We used the superposition-/convolution-based (SC-based) algorithm and Monte Carlo-based (MC-based) algorithm to calculate dose distributions using CT image data sets. In the SC-based algorithm, dose density scaling was applied for the calculation of inhomogeneous corrections. The MC-based algorithm was implemented with Geant4 toolkit and a phase-based approach using a network-parallel computing. From the evaluation of the TPS, the system can optimize the direction and intensity of individual beams. The accuracy of the dose calculated by the SC-based algorithm was less than 1% on average with the calculation time of 15 s for one beam. However, the MC-based algorithm needed 72 min for one beam using the phase-based approach, even though the MC-based algorithm with the parallel computing could decrease multiple beam calculations and had 18.4 times faster calculation speed using the parallel computing. The SC-based algorithm could be practically acceptable for the dose calculation in terms of the accuracy and computation time. Additionally, we have found a dosimetric advantage of proton Bragg peak-like dose distribution in micro-beam treatment.

  17. Optimal Set Anode Potentials Vary in Bioelectrochemical Systems

    KAUST Repository

    Wagner, Rachel C.

    2010-08-15

    In bioelectrochemical systems (BESs), the anode potential can be set to a fixed voltage using a potentiostat, but there is no accepted method for defining an optimal potential. Microbes can theoretically gain more energy by reducing a terminal electron acceptor with a more positive potential, for example oxygen compared to nitrate. Therefore, more positive anode potentials should allow microbes to gain more energy per electron transferred than a lower potential, but this can only occur if the microbe has metabolic pathways capable of capturing the available energy. Our review of the literature shows that there is a general trend of improved performance using more positive potentials, but there are several notable cases where biofilm growth and current generation improved or only occurred at more negative potentials. This suggests that even with diverse microbial communities, it is primarily the potential of the terminal respiratory proteins used by certain exoelectrogenic bacteria, and to a lesser extent the anode potential, that determines the optimal growth conditions in the reactor. Our analysis suggests that additional bioelectrochemical investigations of both pure and mixed cultures, over a wide range of potentials, are needed to better understand how to set and evaluate optimal anode potentials for improving BES performance. © 2010 American Chemical Society.

  18. Optimal schooling formations using a potential flow model

    Science.gov (United States)

    Tchieu, Andrew; Gazzola, Mattia; de Brauer, Alexia; Koumoutsakos, Petros

    2012-11-01

    A self-propelled, two-dimensional, potential flow model for agent-based swimmers is used to examine how fluid coupling affects schooling formation. The potential flow model accounts for fluid-mediated interactions between swimmers. The model is extended to include individual agent actions by means of modifying the circulation of each swimmer. A reinforcement algorithm is applied to allow the swimmers to learn how to school in specified lattice formations. Lastly, schooling lattice configurations are optimized by combining reinforcement learning and evolutionary optimization to minimize total control effort and energy expenditure.

  19. Reaction Path Optimization with Holonomic Constraints and Kinetic Energy Potentials.

    Science.gov (United States)

    Brokaw, Jason B; Haas, Kevin R; Chu, Jhih-Wei

    2009-08-11

    Two methods are developed to enhance the stability, efficiency, and robustness of reaction path optimization using a chain of replicas. First, distances between replicas are kept equal during path optimization via holonomic constraints. Finding a reaction path is, thus, transformed into a constrained optimization problem. This approach avoids force projections for finding minimum energy paths (MEPs), and fast-converging schemes such as quasi-Newton methods can be readily applied. Second, we define a new objective function - the total Hamiltonian - for reaction path optimization, by combining the kinetic energy potential of each replica with its potential energy function. Minimizing the total Hamiltonian of a chain determines a minimum Hamiltonian path (MHP). If the distances between replicas are kept equal and a consistent force constant is used, then the kinetic energy potentials of all replicas have the same value. The MHP in this case is the most probable isokinetic path. Our results indicate that low-temperature kinetic energy potentials (optimization and can significantly reduce the required steps of minimization by 2-3 times without causing noticeable differences between a MHP and MEP. These methods are applied to three test cases, the C7eq-to-Cax isomerization of an alanine dipeptide, the (4)C1-to-(1)C4 transition of an α-d-glucopyranose, and the helix-to-sheet transition of a GNNQQNY heptapeptide. By applying the methods developed in this work, convergence of reaction path optimization can be achieved for these complex transitions, involving full atomic details and a large number of replicas (>100). For the case of helix-to-sheet transition, we identify pathways whose energy barriers are consistent with experimental measurements. Further, we develop a method based on the work energy theorem to quantify the accuracy of reaction paths and to determine whether the atoms used to define a path are enough to provide quantitative estimation of energy barriers.

  20. Stabilized Quasi-Newton Optimization of Noisy Potential Energy Surfaces

    CERN Document Server

    Schaefer, Bastian; Roy, Shantanu; Goedecker, Stefan

    2014-01-01

    Optimizations of atomic positions belong to the most commonly performed tasks in electronic structure calculations. Many simulations like global minimum searches or characterizations of chemical reactions require performing hundreds or thousands of minimizations or saddle computations. To automatize these tasks, optimization algorithms must not only be efficient, but also very reliable. Unfortunately computational noise in forces and energies is inherent to electronic structure codes. This computational noise poses a sever problem to the stability of efficient optimization methods like the limited-memory Broyden-Fletcher-Goldfarb-Shanno algorithm. We here present a technique that allows obtaining significant curvature information of noisy potential energy surfaces. We use this technique to construct both, a stabilized quasi-Newton minimization method and a stabilized quasi-Newton saddle finding approach. We demonstrate with the help of benchmarks that both the minimizer and the saddle finding approach are sup...

  1. Effective potential for relativistic scattering

    CERN Document Server

    Elbistan, Mahmut; Balog, Janos

    2016-01-01

    We consider quantum inverse scattering with singular potentials and calculate the Sine-Gordon model effective potential in the laboratory and centre-of-mass frames. The effective potentials are frame dependent but closely resemble the zero-momentum potential of the equivalent Ruijsenaars-Schneider model.

  2. Enterprise marketing potential modeling taking into account optimizing and dynamic essence of the potential

    Directory of Open Access Journals (Sweden)

    Potrashkova Lyudmyla Vladimirovna

    2014-12-01

    Full Text Available The aim of the article. The aim of the research is to develop models system concerning b2b-enterprise marketing potential result-based estimation, which will consider enterprise potential optimizing essence, its hierarchic structure (i.e. strategic, tactic and operative potential levels and marketing resources dynamics. The results of the analysis. The simulation and optimization models system of the b2b-enterprise marketing potential estimation is suggested. The suggested models system is based on the following theoretical grounds: 1 enterprise marketing potential is interpreted as enterprise ability to satisfy consumers’ needs and to get maximum economic benefits from it; 2 the result-based estimation of the enterprise marketing potential is set of the best results (profit from sales, which sales and marketing enterprise subsystem may achieve in the prognosticative period in the view of environmental conditions variants. The suggested system unites models to estimate three managerial levels of the marketing potential (operative, tactic and strategic, which are different from each other by: the set of the given managerial decisions; the set of the changeable managerial decisions; descriptions of the environment parameters; specification of the resources featured describing. Model of each marketing potential level has the following constituents: - objective function, which is the sum of profit from production realization during the whole prognosticative period; - model of the constrained optimization, oriented to define maximum possible profit value from production realization in each elementary period with given marketing resources features values, environmental parameters and marketing complex parameters; - model of the enterprise marketing resources dynamics. Developed models system belongs to the simulation class, because search of the optimal decisions there is conducted with method concerning controllable parameters alternative variants

  3. Optimized Benzalkonium Chloride Gel: A Potential Vaginal Microbicides

    Institute of Scientific and Technical Information of China (English)

    Xun-cheng DING; Wei-hua LI; Jie-fei LI; Qiang-yi WANG

    2007-01-01

    Objective To develop an optimized BZK gel with good pharmaceutical effect and less toxicity to vaginal mucosa.Methods Four methods as below were used to research the spermicidal activity of BZK gel: 1)in vitro spermicidal test; 2) in vivo spermicidal test in rabbits; 3) anti-fertility test in rabbits; 4)contraceptive test in rabbits. Mucosal irritation test was used in rats to evaluate the safety of optimized BZK gel. Microbiological assessments were used to research anti-STI pathogens (including treponema pallidum, neisseria gonorrhoeae, trichomona vaginalis, candida albicans,ureaplama urealyticum, herpes simplex virus type-2, chlamydiae trachomatis) effect of optimized BZK gel.Results In vitro spermicidal test, EC50 of BZK gel was 0.029 mg/ml, a little higher than that of N-9 (0.019 mg/ml). The MIC of BZK gel was 0.25 mg/ml, similar to that of N-9 (0.20 mg/ml).The vaginal mucosal irritation test in rats showed that 0.429% BZK gel showed only minimal vaginal irritation, and did not damage the vaginal epithelium or cause local inflammation in rats. Microbiological assessments showed that optimized BZK gel could inhibit or inactivate common STI pathogens even after 3-fold or 5-fold dilution.Conclusion Optimized BZK gel was an effective microbicides.

  4. Estimating individual optimal sleep duration and potential sleep debt

    OpenAIRE

    Shingo Kitamura; Yasuko Katayose; Kyoko Nakazaki; Yuki Motomura; Kentaro Oba; Ruri Katsunuma; Yuri Terasawa; Minori Enomoto; Yoshiya Moriguchi; Akiko Hida; Kazuo Mishima

    2016-01-01

    In this study, we hypothesized that dynamics of sleep time obtained over consecutive days of extended sleep in a laboratory reflect an individual’s optimal sleep duration (OSD) and that the difference between OSD and habitual sleep duration (HSD) at home represents potential sleep debt (PSD). We found that OSD varies among individuals and PSD showed stronger correlation with subjective/objective sleepiness than actual sleep time, interacting with individual’s vulnerability of sleep loss. Furt...

  5. Performance evaluation for intelligent optimization algorithms in self-potential data inversion

    Institute of Scientific and Technical Information of China (English)

    崔益安; 朱肖雄; 陈志学; 刘嘉文; 柳建新

    2016-01-01

    The self-potential method is widely used in environmental and engineering geophysics. Four intelligent optimization algorithms are adopted to design the inversion to interpret self-potential data more accurately and efficiently: simulated annealing, genetic, particle swarm optimization, and ant colony optimization. Using both noise-free and noise-added synthetic data, it is demonstrated that all four intelligent algorithms can perform self-potential data inversion effectively. During the numerical experiments, the model distribution in search space, the relative errors of model parameters, and the elapsed time are recorded to evaluate the performance of the inversion. The results indicate that all the intelligent algorithms have good precision and tolerance to noise. Particle swarm optimization has the fastest convergence during iteration because of its good balanced searching capability between global and local minimisation.

  6. Optimizing Interacting Potentials to Form Targeted Materials Structures

    Energy Technology Data Exchange (ETDEWEB)

    Torquato, Salvatore [Princeton Univ., NJ (United States)

    2015-09-28

    Conventional applications of the principles of statistical mechanics (the "forward" problems), start with particle interaction potentials, and proceed to deduce local structure and macroscopic properties. Other applications (that may be classified as "inverse" problems), begin with targeted configurational information, such as low-order correlation functions that characterize local particle order, and attempt to back out full-system configurations and/or interaction potentials. To supplement these successful experimental and numerical "forward" approaches, we have focused on inverse approaches that make use of analytical and computational tools to optimize interactions for targeted self-assembly of nanosystems. The most original aspect of our work is its inherently inverse approach: instead of predicting structures that result from given interaction potentials among particles, we determine the optimal potential that most robustly stabilizes a given target structure subject to certain constraints. Our inverse approach could revolutionize the manner in which materials are designed and fabricated. There are a number of very tangible properties (e.g. zero thermal expansion behavior), elastic constants, optical properties for photonic applications, and transport properties.

  7. Charge optimized many-body potential for aluminum

    Science.gov (United States)

    Choudhary, Kamal; Liang, Tao; Chernatynskiy, Aleksandr; Lu, Zizhe; Goyal, Anuj; Phillpot, Simon R.; Sinnott, Susan B.

    2015-01-01

    An interatomic potential for Al is developed within the third generation of the charge optimized many-body (COMB3) formalism. The database used for the parameterization of the potential consists of experimental data and the results of first-principles and quantum chemical calculations. The potential exhibits reasonable agreement with cohesive energy, lattice parameters, elastic constants, bulk and shear modulus, surface energies, stacking fault energies, point defect formation energies, and the phase order of metallic Al from experiments and density functional theory. In addition, the predicted phonon dispersion is in good agreement with the experimental data and first-principles calculations. Importantly for the prediction of the mechanical behavior, the unstable stacking fault energetics along the direction on the (1 1 1) plane are similar to those obtained from first-principles calculations. The polycrsytal when strained shows responses that are physical and the overall behavior is consistent with experimental observations.

  8. Conversion potential energy and its application to thermodynamic optimization

    Institute of Scientific and Technical Information of China (English)

    WU Jing; GUO ZengYuan

    2012-01-01

    In general,heat transfers can be classified into two categories according to the purposes of object heating or cooling and the heat to work conversion.Recently,a new physical quantity,entransy (or potential energy),was proposed to describe the ability of heat transfer with the former purpose.This paper addresses the concept of potential energy in terms of the heat transfer processes for the latter purpose,named the conversion potential energy.The physical meaning of this newly introduced concept is the potential energy for the heat to work conversion stored in the equivalent mass of heat (thermomass) derived on the basis of the Einstein's special theory of relativity.The dissipation of conversion potential energy occurs during the real irreversible heat to work conversion processes as a measure of the conversion irreversibility.Finally,a heat to work conversion problem of a heat exchanger group is provided to show that the minimum conversion potential energy dissipation rate can be used as an optimization criterion for the heat transfer performance with the purpose of the heat to work conversion.

  9. Continuous Control Artificial Potential Function Methods and Optimal Control

    Science.gov (United States)

    2014-03-27

    Method, namely r̈VDSVAPF = −K̇SKR∇φ−KSK̇R∇φ−KSKRH(φ)ṙ −KD (KSKR∇φ+ ṙ) . The above dynamics are very nonlinear due to the trigonometric functions (inside...constraints (on KS and θ) and the deletion of trigonometric functions . The suspected reasons for the larger computa- tional expense are twofold. First, this...Continuous Control Artificial Potential Function Methods and Optimal Control THESIS R. Andrew Fields, Civ, USAF AFIT-ENY-14-M-20 DEPARTMENT OF THE

  10. Automated parameterization of intermolecular pair potentials using global optimization techniques

    Science.gov (United States)

    Krämer, Andreas; Hülsmann, Marco; Köddermann, Thorsten; Reith, Dirk

    2014-12-01

    In this work, different global optimization techniques are assessed for the automated development of molecular force fields, as used in molecular dynamics and Monte Carlo simulations. The quest of finding suitable force field parameters is treated as a mathematical minimization problem. Intricate problem characteristics such as extremely costly and even abortive simulations, noisy simulation results, and especially multiple local minima naturally lead to the use of sophisticated global optimization algorithms. Five diverse algorithms (pure random search, recursive random search, CMA-ES, differential evolution, and taboo search) are compared to our own tailor-made solution named CoSMoS. CoSMoS is an automated workflow. It models the parameters' influence on the simulation observables to detect a globally optimal set of parameters. It is shown how and why this approach is superior to other algorithms. Applied to suitable test functions and simulations for phosgene, CoSMoS effectively reduces the number of required simulations and real time for the optimization task.

  11. Charge optimized many body (COMB) potentials for Pt and Au

    Science.gov (United States)

    Antony, A. C.; Akhade, S. A.; Lu, Z.; Liang, T.; Janik, M. J.; Phillpot, S. R.; Sinnott, S. B.

    2017-06-01

    Interatomic potentials for Pt and Au are developed within the third generation charge optimized many-body (COMB3) formalism. The potentials are capable of reproducing phase order, lattice constants, and elastic constants of Pt and Au systems as experimentally measured or calculated by density functional theory. We also fit defect formation energies, surface energies and stacking fault energies for Pt and Au metals. The resulting potentials are used to map a 2D contour of the gamma surface and simulate the tensile test of 16-grain polycrystalline Pt and Au structures at 300 K. The stress-strain behaviour is investigated and the primary slip systems {1 1 1} are identified. In addition, we perform high temperature (1800 K for Au and 2300 K for Pt) molecular dynamics simulations of 30 nm Pt and Au truncated octahedron nanoparticles and examine morphological changes of each particle. We further calculate the activation energy barrier for surface diffusion during simulations of several nanoseconds and report energies of 0.62+/- 0.16 eV for Pt and 1.44+/- 0.06 eV for Au. This initial parameterization and application of the Pt and Au potentials demonstrates a starting point for the extension of these potentials to multicomponent systems within the COMB3 framework.

  12. Optimizing the tube potential for lumbar spine radiography with a flat-panel digital detector.

    Science.gov (United States)

    Geijer, H; Norrman, E; Persliden, J

    2009-01-01

    The purpose of this study was to find the optimal settings for lumbar spine radiography with a flat-panel detector. A CDRAD contrast-detail phantom was imaged at various tube potentials, system speeds and filtration settings. Factorial experiments yielded a range of optimized exposure settings, which were submitted to visual grading analysis with images of an Alderson phantom. The first optimized settings involved a system speed increase from 400 to 800. For anteroposterior projection, the optimal tube potential was reduced from the default of 77 kV to 60 kV to give the best image quality without increasing the effective dose, or to 66 kV to give the lowest dose without reducing image quality. For lateral projection, the tube potential was similarly reduced from the default of 90 kV to 70 kV or 77 kV. Visual grading analysis confirmed the results, with significantly better image quality when optimizing for image quality. The study thus shows that the tube potential can be reduced as long as the system speed is increased simultaneously. This leads to a lower effective dose and/or increased image quality depending on the settings chosen. The factorial experiments provided a powerful way to evaluate several parameters concomitantly.

  13. Numerical Simulation of Groundwater Flow, Resource Optimization, and Potential Effects of Prolonged Drought for the Citizen Potawatomi Nation Tribal Jurisdictional Area, Central Oklahoma

    Science.gov (United States)

    Ryter, Derek W.; Kunkel, Christopher D.; Peterson, Steven M.; Traylor, Jonathan P.

    2015-08-13

    A hydrogeological study including two numerical groundwater-flow models was completed for the Citizen Potawatomi Nation Tribal Jurisdictional Area of central Oklahoma. One numerical groundwater-flow model, the Citizen Potawatomi Nation model, encompassed the jurisdictional area and was based on the results of a regional-scale hydrogeological study and numerical groundwater flow model of the Central Oklahoma aquifer, which had a geographic extent that included the Citizen Potawatomi Nation Tribal Jurisdictional Area. The Citizen Potawatomi Nation numerical groundwater-flow model included alluvial aquifers not in the original model and improved calibration using automated parameter-estimation techniques. The Citizen Potawatomi Nation numerical groundwater-flow model was used to analyze the groundwater-flow system and the effects of drought on the volume of groundwater in storage and streamflow in the North Canadian River. A more detailed, local-scale inset model was constructed from the Citizen Potawatomi Nation model to estimate available groundwater resources for two Citizen Potawatomi Nation economic development zones near the North Canadian River, the geothermal supply area and the Iron Horse Industrial Park.

  14. Estimating individual optimal sleep duration and potential sleep debt.

    Science.gov (United States)

    Kitamura, Shingo; Katayose, Yasuko; Nakazaki, Kyoko; Motomura, Yuki; Oba, Kentaro; Katsunuma, Ruri; Terasawa, Yuri; Enomoto, Minori; Moriguchi, Yoshiya; Hida, Akiko; Mishima, Kazuo

    2016-10-24

    In this study, we hypothesized that dynamics of sleep time obtained over consecutive days of extended sleep in a laboratory reflect an individual's optimal sleep duration (OSD) and that the difference between OSD and habitual sleep duration (HSD) at home represents potential sleep debt (PSD). We found that OSD varies among individuals and PSD showed stronger correlation with subjective/objective sleepiness than actual sleep time, interacting with individual's vulnerability of sleep loss. Furthermore, only 1 h of PSD takes four days to recover to their optimal level. Recovery from PSD was also associated with the improvement in glycometabolism, thyrotropic activity and hypothalamic-pituitary-adrenocortical axis. Additionally, the increase (rebound) in total sleep time from HSD at the first extended sleep would be a simple indicator of PSD. These findings confirmed self-evaluating the degree of sleep debt at home as a useful clinical marker. To establish appropriate sleep habits, it is necessary to evaluate OSD, vulnerability to sleep loss, and sleep homeostasis characteristics on an individual basis.

  15. Mapping optimal areas of ecosystem services potential in Vilnius (Lithuania)

    Science.gov (United States)

    Pereira, Paulo; Depellegrin, Daniel; Misiune, Ieva; Cerda, Artemi

    2016-04-01

    Maps are fundamental to understand the spatial pattern of natural and human impacts on the landscape (Brevik et al., 2016; Lavado Contador et al., 2009; Pereira et al., 2010a,b). Urban areas are subjected to an intense human pressure (Beniston et al., 2015), contributing to the degradation of the ecosystems, reducing their capacity to provide services in quality and quantity (Requier-Desjardins et al., 2011; Zhang et al., 2011). Environments that can provide a high number and quality of ecosystem services (ES) must be identified and managed correctly, since are spaces that can mitigate the impacts of human settlements and improve their quality. thus is of major importance have identify the areas that can provide better ES (Deppelegrin and Pereira, 2015). The aim of this work is to identify areas with high ES potential in Vilnius city. Here, we identified a total of 4 different land uses, agricultural areas (32.48%), water bodies (1.46%), forest and semi-natural (31.91%) areas and artificial surfaces (34.16%). CORINE land cover 2006 was used as base information to classify ES potential. The assessment of each land cover potential was carried out using expert assessment. Each land use type was ranked from 0 (no potential) to 5 (High potential). In this work the sum of total regulating, providing and cultural ES were assessed. The areas with optimal ES were the ones with the sum of all ranks equal or higher than the 3rd Quartil of each distribution. After identifying these areas, data was mapped using ArcGIS software. The results showed that on average Vilnius city has a higher potential for regulating services (20.35±15.92), followed by cultural (14.43±8.81) and providing (14.26±8.87). There was a significant correlation among the different type of services. Regulating vs cultural (0.92, p<0.001), regulating vs providing (0.72, p<0.001) and providing vs cultural (0.65, p<0.001). The results of Morans I autocorrelation index showed that regulating (Z-score: 10

  16. Potential neuroprotective effects of cinnamon

    Directory of Open Access Journals (Sweden)

    Rebecca Crews Stavinoha

    2015-07-01

    Full Text Available Summary. The pathogenesis of neurodegenerative diseases involves complex interactions between multiple mechanisms, including but not limited to oxidative stress, inflammation, and proteotoxicity, which have yet to be ameliorated by pharmaceutical drugs with single targets. Natural products have been recognized for their health promoting effects for thousands of years. Plants produce a vast collection of secondary products, such as alkaloids, phenolic compounds, and terpenes that have shown health benefits in a variety of conditions including cancer, cardiovascular disease, and neurodegenerative diseases. In the search for more effective and safe treatment options for neurodegenerative diseases, several dietary sources of phytochemicals have been investigated. Historical usage in traditional medicine, along with modern research has identified several key products with potential benefits in neurodegenerative diseases. Among the dietary sources, cinnamon shows particular merit as a therapeutic potential for neurodegenerative diseases. Accumulating evidence suggesting neuroprotective effects via modulation of various risk factors relevant to neurodegeneration has been reviewed here. Industrial relevance. Cinnamon has been cherished for its health-promoting effects for thousands of years. Today, while modern medicine provides critical pharmaceutical agents that have assisted in ameliorating many diseases and extended the average lifespan significantly in the past century, these agents are associated with many side effects and expenses. As such, the search for efficient therapies with limited side effects is a significant target of research. Cinnamon, as a rich source of phytochemicals and long history in traditional medicine, has been a popular spice in recent decades for investigations elucidating its health-promoting effects. This review evaluates the therapeutic potential of cinnamon in ameliorating the risk factors responsible for the development

  17. Optimization potential of a standard tractor in road transportation

    Directory of Open Access Journals (Sweden)

    Michael Mederle

    2015-10-01

    Full Text Available In numerous farms road transportation is of high importance in the task range of a standard tractor. During the harvest of grain or biomass as well as during the application of organic substrates a certain number of tractors exclusively runs on the road. The present study shows under practical conditions opportunities to optimize standard tractors for road transportation with acceptable effort to increase machine utilization and process efficiency at the same time. By realizing certain optimizing measures fuel consumption can be reduced by 11.4 % on average. Increasing the maximum speed from 50 to 60 km/h results in time savings of 8.5 % on average, causing a 5.5 % higher fuel consumption on average. The benefits of the examined optimization measures always have to be judged farm- and situation specifically.

  18. Potential and challenges in home care service process optimization : a route optimization approach

    OpenAIRE

    Nakari, Pentti J. E.

    2016-01-01

    Aging of the population is an increasing problem in many countries, including Finland, and it poses a challenge to public services such as home care. Vehicle routing optimization (VRP) type optimization solutions are one possible way to decrease the time required for planning home visits and driving to customer addresses, as well as decreasing transportation costs. Although VRP optimization is widely and succesfully applied to commercial and industrial logistics, the home care ...

  19. The optimality of potential rescaling approaches in land data assimilation

    Science.gov (United States)

    It is well-known that systematic differences exist between modeled and observed realizations of hydrological variables like soil moisture. Prior to data assimilation, these differences must be removed in order to obtain an optimal analysis. A number of rescaling approaches have been proposed for rem...

  20. Two Effective Heuristics for Beam Angle Optimization in Radiation Therapy

    CERN Document Server

    Yarmand, Hamed

    2013-01-01

    In radiation therapy, mathematical methods have been used for optimizing treatment planning for delivery of sufficient dose to the cancerous cells while keeping the dose to critical surrounding structures minimal. This optimization problem can be modeled using mixed integer programming (MIP) whose solution gives the optimal beam orientation as well as optimal beam intensity. The challenge, however, is the computation time for this large scale MIP. We propose and investigate two novel heuristic approaches to reduce the computation time considerably while attaining high-quality solutions. We introduce a family of heuristic cuts based on the concept of 'adjacent beams' and a beam elimination scheme based on the contribution of each beam to deliver the dose to the tumor in the ideal plan in which all potential beams can be used simultaneously. We show the effectiveness of these heuristics for intensity modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT) on a clinical liver case.

  1. The effective crystal field potential

    CERN Document Server

    Mulak, J

    2000-01-01

    As it results from the very nature of things, the spherical symmetry of the surrounding of a site in a crystal lattice or an atom in a molecule can never occur. Therefore, the eigenfunctions and eigenvalues of any bound ion or atom have to differ from those of spherically symmetric respective free ions. In this way, the most simplified concept of the crystal field effect or ligand field effect in the case of individual molecules can be introduced. The conventional notion of the crystal field potential is narrowed to its non-spherical part only through ignoring the dominating spherical part which produces only a uniform energy shift of gravity centres of the free ion terms. It is well understood that the non-spherical part of the effective potential "seen" by open-shell electrons localized on a metal ion plays an essential role in most observed properties. Light adsorption, electron paramagnetic resonance, inelastic neutron scattering and basic characteristics derived from magnetic and thermal measurements, ar...

  2. Potential Energy Savings in Refrigeration Systems Using Optimal Setpoints

    DEFF Research Database (Denmark)

    Larsen, Lars Finn Slot; Thybo, Claus

    2004-01-01

    Energy efficiency of refrigeration systems has gradually been improved with help of control schemes utilizing the more flexible components. This paper proposes an approach in line with this trend, where a suboptimal condenser pressure is found in order to minimize the energy consumption. The obje......Energy efficiency of refrigeration systems has gradually been improved with help of control schemes utilizing the more flexible components. This paper proposes an approach in line with this trend, where a suboptimal condenser pressure is found in order to minimize the energy consumption....... The objective is to give an idea of how this optimization scheme works as well as to show what amount of energy it is possible to save. A steady state model of a simple refrigeration system will be used as a basis for the optimization....

  3. Status of effective potential calculations

    CERN Document Server

    Quiros, M.

    1995-01-01

    We review various effective potential methods which have been useful to compute the Higgs mass spectrum and couplings of the minimal supersymmetric standard model. We compare results where all-loop next-to-leading-log corrections are resummed by the renormalization group, with those where just the leading-log corrections are kept. Pole masses are obtained from running masses by addition of convenient self-energy diagrams. Approximate analytical expressions are worked out, providing an excellent approximation to the numerical results which include all next-to-leading-log terms. An appropriate treatment of squark decoupling allows to consider large values of the stop and/or sbottom mixing parameters and thus fix a reliable upper bound on the mass of the lightest CP-even Higgs boson mass.

  4. Ising Processing Units: Potential and Challenges for Discrete Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Coffrin, Carleton James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nagarajan, Harsha [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bent, Russell Whitford [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-07-05

    The recent emergence of novel computational devices, such as adiabatic quantum computers, CMOS annealers, and optical parametric oscillators, presents new opportunities for hybrid-optimization algorithms that leverage these kinds of specialized hardware. In this work, we propose the idea of an Ising processing unit as a computational abstraction for these emerging tools. Challenges involved in using and bench- marking these devices are presented, and open-source software tools are proposed to address some of these challenges. The proposed benchmarking tools and methodology are demonstrated by conducting a baseline study of established solution methods to a D-Wave 2X adiabatic quantum computer, one example of a commercially available Ising processing unit.

  5. Effects of optimism on creativity under approach and avoidance motivation

    Directory of Open Access Journals (Sweden)

    Tamar eIcekson

    2014-02-01

    Full Text Available Focusing on avoiding failure or negative outcomes (avoidance motivation can undermine creativity, due to cognitive (e.g., threat appraisals, affective (e.g., anxiety, and volitional processes (e.g., low intrinsic motivation. This can be problematic for people who are avoidance motivated by nature and in situations in which threats or potential losses are salient. Here, we review the relation between avoidance motivation and creativity, and the processes underlying this relation. We highlight the role of optimism as a potential remedy for the creativity undermining effects of avoidance motivation, due to its impact on the underlying processes. Optimism, expecting to succeed in achieving success or avoiding failure, may reduce negative effects of avoidance motivation, as it eases threat appraisals, anxiety, and disengagement - barriers playing a key role in undermining creativity. People experience these barriers more under avoidance than under approach motivation, and beneficial effects of optimism should therefore be more pronounced under avoidance than approach motivation. Moreover, due to their eagerness, approach motivated people may even be more prone to unrealistic over-optimism and its negative consequences.

  6. Effects of optimism on creativity under approach and avoidance motivation.

    Science.gov (United States)

    Icekson, Tamar; Roskes, Marieke; Moran, Simone

    2014-01-01

    Focusing on avoiding failure or negative outcomes (avoidance motivation) can undermine creativity, due to cognitive (e.g., threat appraisals), affective (e.g., anxiety), and volitional processes (e.g., low intrinsic motivation). This can be problematic for people who are avoidance motivated by nature and in situations in which threats or potential losses are salient. Here, we review the relation between avoidance motivation and creativity, and the processes underlying this relation. We highlight the role of optimism as a potential remedy for the creativity undermining effects of avoidance motivation, due to its impact on the underlying processes. Optimism, expecting to succeed in achieving success or avoiding failure, may reduce negative effects of avoidance motivation, as it eases threat appraisals, anxiety, and disengagement-barriers playing a key role in undermining creativity. People experience these barriers more under avoidance than under approach motivation, and beneficial effects of optimism should therefore be more pronounced under avoidance than approach motivation. Moreover, due to their eagerness, approach motivated people may even be more prone to unrealistic over-optimism and its negative consequences.

  7. Optimizing rice yields while minimizing yield-scaled global warming potential.

    Science.gov (United States)

    Pittelkow, Cameron M; Adviento-Borbe, Maria A; van Kessel, Chris; Hill, James E; Linquist, Bruce A

    2014-05-01

    To meet growing global food demand with limited land and reduced environmental impact, agricultural greenhouse gas (GHG) emissions are increasingly evaluated with respect to crop productivity, i.e., on a yield-scaled as opposed to area basis. Here, we compiled available field data on CH4 and N2 O emissions from rice production systems to test the hypothesis that in response to fertilizer nitrogen (N) addition, yield-scaled global warming potential (GWP) will be minimized at N rates that maximize yields. Within each study, yield N surplus was calculated to estimate deficit or excess N application rates with respect to the optimal N rate (defined as the N rate at which maximum yield was achieved). Relationships between yield N surplus and GHG emissions were assessed using linear and nonlinear mixed-effects models. Results indicate that yields increased in response to increasing N surplus when moving from deficit to optimal N rates. At N rates contributing to a yield N surplus, N2 O and yield-scaled N2 O emissions increased exponentially. In contrast, CH4 emissions were not impacted by N inputs. Accordingly, yield-scaled CH4 emissions decreased with N addition. Overall, yield-scaled GWP was minimized at optimal N rates, decreasing by 21% compared to treatments without N addition. These results are unique compared to aerobic cropping systems in which N2 O emissions are the primary contributor to GWP, meaning yield-scaled GWP may not necessarily decrease for aerobic crops when yields are optimized by N fertilizer addition. Balancing gains in agricultural productivity with climate change concerns, this work supports the concept that high rice yields can be achieved with minimal yield-scaled GWP through optimal N application rates. Moreover, additional improvements in N use efficiency may further reduce yield-scaled GWP, thereby strengthening the economic and environmental sustainability of rice systems.

  8. Optimizing analog-to-digital converters for sampling extracellular potentials.

    Science.gov (United States)

    Artan, N Sertac; Xu, Xiaoxiang; Shi, Wei; Chao, H Jonathan

    2012-01-01

    In neural implants, an analog-to-digital converter (ADC) provides the delicate interface between the analog signals generated by neurological processes and the digital signal processor that is tasked to interpret these signals for instance for epileptic seizure detection or limb control. In this paper, we propose a low-power ADC architecture for neural implants that process extracellular potentials. The proposed architecture uses the spike detector that is readily available on most of these implants in a closed-loop with an ADC. The spike detector determines whether the current input signal is part of a spike or it is part of noise to adaptively determine the instantaneous sampling rate of the ADC. The proposed architecture can reduce the power consumption of a traditional ADC by 62% when sampling extracellular potentials without any significant impact on spike detection accuracy.

  9. Optimal electric potential profile in a collisional magnetized thruster

    Science.gov (United States)

    Fruchtman, Amnon; Makrinich, Gennady

    2016-10-01

    A major figure of merit in propulsion in general and in electric propulsion in particular is the thrust per unit of deposited power, the ratio of thrust over power. We have recently demonstrated experimentally and theoretically that for a fixed deposited power in the ions, the momentum delivered by the electric force is larger if the accelerated ions collide with neutrals during the acceleration. As expected, the higher thrust for given power is achieved for a collisional plasma at the expense of a lower thrust per unit mass flow rate. Operation in the collisional regime can be advantageous for certain space missions. We analyze a Hall thruster configuration in which the flow is only weakly ionized but there are frequent ion-neutral collisions. With a variational method we seek an electric potential profile that maximizes thrust over power. We then examine what radial magnetic field profile should determine such a potential profile. Supported by the Israel Science Foundation Grant 765/11.

  10. Molecular Breeding to Create Optimized Crops: From Genetic Manipulation to Potential Applications in Plant Factories.

    Science.gov (United States)

    Hiwasa-Tanase, Kyoko; Ezura, Hiroshi

    2016-01-01

    Crop cultivation in controlled environment plant factories offers great potential to stabilize the yield and quality of agricultural products. However, many crops are currently unsuited to these environments, particularly closed cultivation systems, due to space limitations, low light intensity, high implementation costs, and high energy requirements. A major barrier to closed system cultivation is the high running cost, which necessitates the use of high-margin crops for economic viability. High-value crops include those with enhanced nutritional value or containing additional functional components for pharmaceutical production or with the aim of providing health benefits. In addition, it is important to develop cultivars equipped with growth parameters that are suitable for closed cultivation. Small plant size is of particular importance due to the limited cultivation space. Other advantageous traits are short production cycle, the ability to grow under low light, and high nutriculture availability. Cost-effectiveness is improved from the use of cultivars that are specifically optimized for closed system cultivation. This review describes the features of closed cultivation systems and the potential application of molecular breeding to create crops that are optimized for cost-effectiveness and productivity in closed cultivation systems.

  11. Molecular breeding to create optimized crops: from genetic manipulation to potential applications in plant factories

    Directory of Open Access Journals (Sweden)

    Kyoko eHiwasa-Tanase

    2016-04-01

    Full Text Available Crop cultivation in controlled environment plant factories offers great potential to stabilize the yield and quality of agricultural products. However, many crops are currently unsuited to these environments, particularly closed cultivation systems, due to space limitations, low light intensity, high implementation costs, and high energy requirements. A major barrier to closed system cultivation is the high running cost, which necessitates the use of high-margin crops for economic viability. High-value crops include those with enhanced nutritional value or containing additional functional components for pharmaceutical production or with the aim of providing health benefits. In addition, it is important to develop cultivars equipped with growth parameters that are suitable for closed cultivation. Small plant size is of particular importance due to the limited cultivation space. Other advantageous traits are short production cycle, the ability to grow under low light, and high nutriculture availability. Cost-effectiveness is improved from the use of cultivars that are specifically optimized for closed system cultivation. This review describes the features of closed cultivation systems and the potential application of molecular breeding to create crops that are optimized for cost-effectiveness and productivity in closed cultivation systems.

  12. Towards an optimal paradigm for simultaneously recording cortical and brainstem auditory evoked potentials.

    Science.gov (United States)

    Bidelman, Gavin M

    2015-02-15

    Simultaneous recording of brainstem and cortical event-related brain potentials (ERPs) may offer a valuable tool for understanding the early neural transcription of behaviorally relevant sounds and the hierarchy of signal processing operating at multiple levels of the auditory system. To date, dual recordings have been challenged by technological and physiological limitations including different optimal parameters necessary to elicit each class of ERP (e.g., differential adaptation/habitation effects and number of trials to obtain adequate response signal-to-noise ratio). We investigated a new stimulus paradigm for concurrent recording of the auditory brainstem frequency-following response (FFR) and cortical ERPs. The paradigm is "optimal" in that it uses a clustered stimulus presentation and variable interstimulus interval (ISI) to (i) achieve the most ideal acquisition parameters for eliciting subcortical and cortical responses, (ii) obtain an adequate number of trials to detect each class of response, and (iii) minimize neural adaptation/habituation effects. Comparison between clustered and traditional (fixed, slow ISI) stimulus paradigms revealed minimal change in amplitude or latencies of either the brainstem FFR or cortical ERP. The clustered paradigm offered over a 3× increase in recording efficiency compared to conventional (fixed ISI presentation) and thus, a more rapid protocol for obtaining dual brainstem-cortical recordings in individual listeners. We infer that faster recording of subcortical and cortical potentials might allow more complete and sensitive testing of neurophysiological function and aid in the differential assessment of auditory function. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Potential use of nutritional factors to optimize performance under stress

    Science.gov (United States)

    Munro, H. N.

    1977-01-01

    A study of the effects of amino acids on hypothalamo-pituitary capacity to secrete ACTH, and the response of the adrenal gland in terms of corticosterone level in the plasma was discussed in the first part of this report. Second, the report includes a study of the response of protein metabolism in various levels of corticosterone elevation in the plasma. This second part is regarded as having considerable significance for space travel, since this data indicate a threshold level of plasma corticosteroids above which there is increased catabolism of muscle protein.

  14. UAV path planning using artificial potential field method updated by optimal control theory

    Science.gov (United States)

    Chen, Yong-bo; Luo, Guan-chen; Mei, Yue-song; Yu, Jian-qiao; Su, Xiao-long

    2016-04-01

    The unmanned aerial vehicle (UAV) path planning problem is an important assignment in the UAV mission planning. Based on the artificial potential field (APF) UAV path planning method, it is reconstructed into the constrained optimisation problem by introducing an additional control force. The constrained optimisation problem is translated into the unconstrained optimisation problem with the help of slack variables in this paper. The functional optimisation method is applied to reform this problem into an optimal control problem. The whole transformation process is deduced in detail, based on a discrete UAV dynamic model. Then, the path planning problem is solved with the help of the optimal control method. The path following process based on the six degrees of freedom simulation model of the quadrotor helicopters is introduced to verify the practicability of this method. Finally, the simulation results show that the improved method is more effective in planning path. In the planning space, the length of the calculated path is shorter and smoother than that using traditional APF method. In addition, the improved method can solve the dead point problem effectively.

  15. Potential energy savings using dynamically optimizing control in refrigeration systems under daily variations in ambient temperature

    DEFF Research Database (Denmark)

    Larsen, Lars Finn Sloth; Thybo, Claus; Wisniewski, Rafal;

    2007-01-01

    The objective of this study is to investigate the energy saving potential for refrigeration systems by refrigeration more at the colder night time than at the warmer day time. The potential is evaluated using an optimal control policy and illustrated on a simulation example. The results show that...

  16. Rosemary Aromatization of Extra Virgin Olive Oil and Process Optimization Including Antioxidant Potential and Yield

    Directory of Open Access Journals (Sweden)

    Erkan Karacabey

    2016-08-01

    Full Text Available Aromatization of olive oil especially by spices and herbs has been widely used technique throughout the ages in Mediterranean diets. The present study was focused on aromatization of olive oil by rosemary (Rosmarinus officinalis L.. Aromatization process was optimized by response surface methodology as a function of malaxation’s conditions (temperature and time. According to authors’ best knowledge it was first time for examination of oil yield performance with antioxidant potential and pigments under effect of aromatization parameters. For all oil samples, values of the free acidity, peroxide, K232 and K270 as quality parameters fell within the ranges established for the highest quality category “extra virgin oil”. Oil yield (mL oil/kg olive paste changed from 158 to 208 with respect to design parameters. Total phenolic content and free radical scavenging activity as antioxidant potential of olive oil samples were varied in the range of 182.44 – 348.65 mg gallic acid equivalent/kg oil and 28.91 – 88.75 % inhibition of 2,2-Diphenyl-1-picrylhydrazyl-(DPPH•, respectively. Total contents of carotenoid, chlorophyll and pheophytin a as pigments in oil samples were found to be in between 0.09 – 0.48 mg carotenoid/kg oil, 0.11 – 0.96 mg chlorophyll/kg oil, 0.15 – 4.44 mg pheo α/kg oil, respectively. The proposed models for yield, pigments and antioxidant potential responses were found to be good enough for successful prediction of experimental results. Total phenolics, carotenoids and free radical scavenging activity of aromatized olive oil and oil yield were maximized to gather and optimal conditions were determined as 25°C, 84 min, and 2 % (Rosemary/olive paste; w/w.

  17. 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.

  18. 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.

  19. An optimized interatomic potential for Cu–Ni alloys with the embedded-atom method

    OpenAIRE

    Onat, Berk; Durukanoğlu Feyiz, Sondan; Durukanoglu Feyiz, Sondan

    2013-01-01

    We have developed a semi-empirical and many-body type model potential using a modified charge density profile for Cu–Ni alloys based on the embedded-atom method (EAM) formalism with an improved optimization technique. The potential is determined by fitting to experimental and first-principles data for Cu, Ni and Cu–Ni binary compounds, such as lattice constants, cohesive energies, bulk modulus, elastic constants, diatomic bond lengths and bond energies. The generated potentials were tested by...

  20. Evaluating potential benefits of burning lower quality fuel oils using the oil burn optimization model

    Energy Technology Data Exchange (ETDEWEB)

    Babilonia, P.

    1995-09-01

    As a result of a 1987 New York State Public Service Commission Audit of Niagara Mohawk`s Fuel Supply operations, Niagara Mohawk (NMPC) became interested in analyzing the plant performance impacts of burning fuels of differing qualities at its various generating stations. Black & Veatch (B&V) had previously developed a computer model for EPRI that analyzed coal quality impacts (i.e., Coal Quality Impact Model). As a result of B&V`s work, NMPC contracted with B&V to first develop custom-designed software for its coal stations (Coal Burn Optimization Model (CBOM)). Subsequently, B&V was retained to develop a similar designed software for its oil stations, Oswego and Albany Steam Stations. The Oil Burn Optimization Model (OBOM) was, therefore, developed. OBOM was designed to be used to evaluate residual fuel oil supply options by predicting their fuel-related plant operating and maintenance costs. Fuel oil-related costs can also be compared to natural gas-related costs. Costs are estimated by predicting performance of various plant equipment. Predictions focus on combustion calculations, material flows, auxiliary power, boiler efficiency, precipitator and fan performance, fuel pumping and preheating requirements, and corrosion considerations. Total costs at the busbar attributed to fuel are calculated from these predictions. OBOM is a PC-based system operating under MS-DOS. The model produces hard copy results for quick comparison of fuels and their potential effects on plant operating and maintenance costs.

  1. Enhanced engraftment, proliferation, and therapeutic potential in heart using optimized human iPSC-derived cardiomyocytes

    Science.gov (United States)

    Funakoshi, Shunsuke; Miki, Kenji; Takaki, Tadashi; Okubo, Chikako; Hatani, Takeshi; Chonabayashi, Kazuhisa; Nishikawa, Misato; Takei, Ikue; Oishi, Akiko; Narita, Megumi; Hoshijima, Masahiko; Kimura, Takeshi; Yamanaka, Shinya; Yoshida, Yoshinori

    2016-01-01

    Human pluripotent stem cell-derived cardiomyocytes (CMs) are a promising tool for cardiac cell therapy. Although transplantation of induced pluripotent stem cell (iPSC)-derived CMs have been reported in several animal models, the treatment effect was limited, probably due to poor optimization of the injected cells. To optimize graft cells for cardiac reconstruction, we compared the engraftment efficiency of intramyocardially-injected undifferentiated-iPSCs, day4 mesodermal cells, and day8, day20, and day30 purified iPSC-CMs after initial differentiation by tracing the engraftment ratio (ER) using in vivo bioluminescence imaging. This analysis revealed the ER of day20 CMs was significantly higher compared to other cells. Transplantation of day20 CMs into the infarcted hearts of immunodeficient mice showed good engraftment, and echocardiography showed significant functional improvement by cell therapy. Moreover, the imaging signal and ratio of Ki67-positive CMs at 3 months post injection indicated engrafted CMs proliferated in the host heart. Although this graft growth reached a plateau at 3 months, histological analysis confirmed progressive maturation from 3 to 6 months. These results suggested that day20 CMs had very high engraftment, proliferation, and therapeutic potential in host mouse hearts. They also demonstrate this model can be used to track the fate of transplanted cells over a long time. PMID:26743035

  2. Potential Ergogenic Effects of Saffron.

    Science.gov (United States)

    Meamarbashi, Abbas; Rajabi, Ali

    2016-01-01

    Crocus sativus, commonly known as saffron, is a rich source of carotenoids with many health benefits. The muscular strength, pulmonary function, and reaction time are vital to the athlete's performance, and this study aimed to investigate an ergogenic effect of saffron. Twenty-eight nonactive and healthy male university students were randomly assigned into the saffron (n = 14) and control (n = 15) groups. The experimental group received dried saffron stigma (300 mg/day for 10 days) and the control group received a placebo. After one session, familiarization with the tests, anthropometric parameters, visual and audio reaction times, and the maximum isometric and isotonic forces on a leg press machine were measured accordingly, 1 day before and after the supplementation period. This study shows that 10 days of supplementation with saffron significantly increased (10.1%) the isometric force (p saffron (increase in the forces) may contribute to increase in the muscle mitochondrial biogenesis and positive effect on the motor cortex, both of which may explain faster audio and visual reaction times. Saffron supplementation was also possibly responsible for improvement of muscle blood perfusion and facilitation in the oxygen transport.

  3. Least dissipation principle of heat transport potential capacity and its application in heat conduction optimization

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In the viewpoint of heat transfer, heat transport potential capacity and its dissipation are defined based on the essence of heat transport phenomenon. Respectively, their physical meanings are the overall heat transfer capabilityand the dissipation rate of the heat transfer capacity. Then the least dissipation principle of heat transport potential capacity is presented to enhance the heat conduction efficiency in the heat conduction optimization. The principle is,for a conduction process with the constant integral of the thermal conductivityover the region, the optimal distribution of thermal conductivity, which corresponds to the highest heat conduction efficiency, is characterized by the least dissipation of heat transport potential capacity. Finally the principle is applied to some cases in heat conduction optimization.

  4. Potential Therapeutic Effects of Psilocybin.

    Science.gov (United States)

    Johnson, Matthew W; Griffiths, Roland R

    2017-07-01

    Psilocybin and other 5-hydroxytryptamine2A agonist classic psychedelics have been used for centuries as sacraments within indigenous cultures. In the mid-twentieth century they were a focus within psychiatry as both probes of brain function and experimental therapeutics. By the late 1960s and early 1970s these scientific inquires fell out of favor because classic psychedelics were being used outside of medical research and in association with the emerging counter culture. However, in the twenty-first century, scientific interest in classic psychedelics has returned and grown as a result of several promising studies, validating earlier research. Here, we review therapeutic research on psilocybin, the classic psychedelic that has been the focus of most recent research. For mood and anxiety disorders, three controlled trials have suggested that psilocybin may decrease symptoms of depression and anxiety in the context of cancer-related psychiatric distress for at least 6 months following a single acute administration. A small, open-label study in patients with treatment-resistant depression showed reductions in depression and anxiety symptoms 3 months after two acute doses. For addiction, small, open-label pilot studies have shown promising success rates for both tobacco and alcohol addiction. Safety data from these various trials, which involve careful screening, preparation, monitoring, and follow-up, indicate the absence of severe drug-related adverse reactions. Modest drug-related adverse effects at the time of medication administration are readily managed. US federal funding has yet to support therapeutic psilocybin research, although such support will be important to thoroughly investigate efficacy, safety, and therapeutic mechanisms.

  5. Electric potential invariants and ions-in-molecules effective potentials for molecular Rydberg states

    Science.gov (United States)

    Coy, Stephen L.; Grimes, David D.; Zhou, Yan; Field, Robert W.; Wong, Bryan M.

    2016-12-01

    The dependence of multipole moments and polarizabilities on external fields appears in many applications including biomolecular molecular mechanics, optical non-linearity, nanomaterial calculations, and the perturbation of spectroscopic signatures in atomic clocks. Over a wide range of distances, distributed multipole and polarizability potentials can be applied to obtain the variation of atom-centered atoms-in-molecules electric properties like bonding-quenched polarizability. For cylindrically symmetric charge distributions, we examine single-center and atom-centered effective polarization potentials in a non-relativistic approximation for Rydberg states. For ions, the multipole expansion is strongly origin-dependent, but we note that origin-independent invariants can be defined. The several families of invariants correspond to optimized representations differing by origin and number of terms. Among them, a representation at the center of dipole polarizability optimizes the accuracy of the potential with terms through 1/r4. We formulate the single-center expansion in terms of polarization-modified effective multipole moments, defining a form related to the source-multipole expansion of Brink and Satchler. Atom-centered potentials are an origin independent alternative but are limited both by the properties allowed at each center and by the neglected effects like bond polarizability and charge flow. To enable comparisons between single-center effective potentials in Cartesian or spherical form and two-center effective potentials with differing levels of mutual induction between atomic centers, we give analytical expressions for the bond-length and origin-dependence of multipole and polarizability terms projected in the multipole and polarizability expansion of Buckingham. The atom-centered potentials can then be used with experimental data and ab initio calculations to estimate atoms-in-molecules properties. Some results are given for BaF+ and HF showing the

  6. A two-stage method to determine optimal product sampling considering dynamic potential market.

    Science.gov (United States)

    Hu, Zhineng; Lu, Wei; Han, Bing

    2015-01-01

    This paper develops an optimization model for the diffusion effects of free samples under dynamic changes in potential market based on the characteristics of independent product and presents a two-stage method to figure out the sampling level. The impact analysis of the key factors on the sampling level shows that the increase of the external coefficient or internal coefficient has a negative influence on the sampling level. And the changing rate of the potential market has no significant influence on the sampling level whereas the repeat purchase has a positive one. Using logistic analysis and regression analysis, the global sensitivity analysis gives a whole analysis of the interaction of all parameters, which provides a two-stage method to estimate the impact of the relevant parameters in the case of inaccuracy of the parameters and to be able to construct a 95% confidence interval for the predicted sampling level. Finally, the paper provides the operational steps to improve the accuracy of the parameter estimation and an innovational way to estimate the sampling level.

  7. The coalbed methane production potential method for optimization of wells location selection

    Institute of Scientific and Technical Information of China (English)

    Feng-Ke DOU; Yong-Shang KANG; Shao-Feng QIN; De-Lei MAO; Jun HAN

    2013-01-01

    A gas production potential method for optimization of gas wellsite locations selection is proposed in terms of the coalbed gas resources volume and the recoverability.The method uses the actual data about reservoirs in a coalbed gas field in central China to optimize wellsite locations in the studied area in combination with the dynamic data about actual production in the coalbed gas field,selects a favorable subarea for gas wells deployment.The method is established based on the basic properties of coal reservoirs,in combination with the coalbed thickness and the gas content to make an analysis of the gas storage potential of a coal reservoir,as well as resources volume and the permeability of a coal reservoir.This method can be popularized for optimization of wellsite locations in other methane gas development areas or blocks.

  8. Effective potential in the BET formalism

    CERN Document Server

    Bessa, A; Fraga, E S; Gelis, F

    2011-01-01

    We calculate the one-loop effective potential at finite temperature for a system of massless scalar fields with quartic interaction $\\lambda\\phi^4$ in the framework of the boundary effective theory (BET) formalism. The calculation relies on the solution of the classical equation of motion for the field, and Gaussian fluctuations around it. Our result is non-perturbative and differs from the standard one-loop effective potential for field values larger than $T/\\sqrt{\\lambda}$.

  9. Silver ion impregnated composite biomaterial optimally prepared using zeta potential measurements.

    Science.gov (United States)

    Sakthivel, N; Socrates, R; Shanthini, G M; Rajaram, A; Kalkura, S Narayana

    2015-02-01

    Biodegradable, antimicrobial composite of various silver ion concentrations was synthesized using zeta potential and isoelectric point measurements, for a controlled release of silver ions, and in addition to assess the effect of protein adsorption with the increase of the silver ion concentration. The interaction between hydroxyapatite (HAp) and silver incorporated hydroxyapatite (AgHAp) with gelatin was increased by optimally adjusting the zeta potential and isoelectric point of the ceramic (HAp and AgHAp), and bio-polymer individually. The electrostatic interactions between the ceramic and biopolymer were confirmed, through shifts in N-H stretching, decrease in the swelling ratio, and increase in the degradation temperature observed by the derivative thermo-gravimetric analysis (DTG). These results substantiate that, the zeta potential is a novel tool to increase the ceramic-biopolymer interaction. Increasing electrostatic interaction between the biopolymer and ceramic, decreases the release of silver ions in the simulated body fluid, due to the controlled degradation of the biopolymer. The isoelectric point decreases with the increase of the silver ion concentration, which evidenced the change in the net surface charge. With the increase of the silver ion concentration, the protein adsorption decreases due to an increase in hydrophilic character of the composite. This study examines the minimum concentration of silver ion essential for maximum protein adsorption, antimicrobial and hemocompatibility. This study provides a novel route to control the release of silver ions by enhancing the ceramic-polymer interaction and estimate the silver ion concentration suitable for protein adsorption. The prepared composite is nontoxic, degradable, and antimicrobial, with the controlled release of silver ions in the simulated body fluid.

  10. A charge optimized many-body potential for titanium nitride (TiN).

    Science.gov (United States)

    Cheng, Y-T; Liang, T; Martinez, J A; Phillpot, S R; Sinnott, S B

    2014-07-01

    This work presents a new empirical, variable charge potential for TiN systems in the charge-optimized many-body potential framework. The potential parameters were determined by fitting them to experimental data for the enthalpy of formation, lattice parameters, and elastic constants of rocksalt structured TiN. The potential does a good job of describing the fundamental physical properties (defect formation and surface energies) of TiN relative to the predictions of first-principles calculations. This potential is used in classical molecular dynamics simulations to examine the interface of fcc-Ti(0 0 1)/TiN(0 0 1) and to characterize the adsorption of oxygen atoms and molecules on the TiN(0 0 1) surface. The results indicate that the potential is well suited to model TiN thin films and to explore the chemistry associated with their oxidation.

  11. Optimization of Weighting Factors for Multiple Window Spectrogram of Event-Related Potentials

    Directory of Open Access Journals (Sweden)

    Maria Hansson-Sandsten

    2010-01-01

    Full Text Available This paper concerns the mean square error optimal weighting factors for multiple window spectrogram of different stationary and nonstationary processes. It is well known that the choice of multiple windows is important, but here we show that the weighting of the different multiple window spectrograms in the final average is as important to consider and that the equally averaged spectrogram is not mean square error optimal for non-stationary processes. The cost function for optimization is the normalized mean square error where the normalization factor is the multiple window spectrogram. This means that the unknown weighting factors will be present in the numerator as well as in the denominator. A quasi-Newton algorithm is used for the optimization. The optimization is compared for a number of well-known sets of multiple windows and common weighting factors and the results show that the number and the shape of the windows are important for a small mean square error. Multiple window spectrograms using these optimal weighting factors, from ElectroEncephaloGram data including steady-state visual evoked potentials, are shown as examples.

  12. A methodology for the assessment of potential demand and optimal supply of entrepreneurial microcredit

    Directory of Open Access Journals (Sweden)

    Ayi Gavriel Ayayi

    2012-04-01

    Full Text Available We propose a methodology for the assessment of potential demand and optimal supply for microcredit. We show that the total demand is a combination of the demand that stems from the active poor plus the demand generated by a motivator agent among the entrepreneurial non-motivated poor. We use French data to provide an illustration of the assessment of potential demand for microcredit. We also show that the proportion of the potential demand satisfied by a microfinance institution depends on its objective i.e. either it is socially oriented or a profit maximizer.

  13. A single particle effective potential for interacting positron and positronium

    CERN Document Server

    Zubiaga, A; Puska, M

    2013-01-01

    We have studied small systems composed by an atom and a positron or a positronium atom. We have used many-body quantum mechanical calculations to describe the correlation effects of light particles. Explicitly correlated gaussian for the basis functions and a stochastical variational optimization method has allowed to obtain accurate wavefunctions and energies. We have discussed the chemistry of positrons in those systems by means of analyzing the densities of the light particles (electrons and positrons). During the discussion, we propose an effective potential that describes the properties of the positron in those systems, valid also when it forms a Ps cluster. The effective potential is a mean field description of the interaction of the positron that can be used to calculate the distribution of the positron and its interaction energy. This potential can be a step forward for an accurate single particle description of the positron in cases when it forms positronium, specially molecular soft matter.

  14. Two Loop Effective Kähler Potential

    CERN Document Server

    Nyawelo, T S; Nyawelo, Tino S.; Nibbelink, Stefan Groot

    2007-01-01

    In this talk we study the renormalization of the effective Kaehler potential at one and two loops for general four dimensional (non--renormalizable) N=1 supersymmetric theories described by arbitrary Kaehler potential, superpotential and gauge kinetic function. We consider the Wess-Zumino model as an example.

  15. Potential Health Effects from Groundwater Pollution.

    Science.gov (United States)

    Goyer, Robert A.

    1985-01-01

    Discusses the growing awareness of potential toxicological effects of synthetic organic chemicals contaminating groundwater. Problems concerning pesticides, chlorination, epidemiologic studies, cancer, nephrotoxicity, and considerations of risk are addressed. Additional research in this area is advocated. (DH)

  16. Potential environmental effects of controlled thermonuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Young, J.R.; Gore, B.F.

    1976-01-01

    The following topics are discussed: (1) the fusion reaction, (2) approach to the environmental analysis, (3) the reference CTR, (4) CTR environmental effects, (5) CTR accident potential, and (6) the advanced CTR. (MOW)

  17. Potential Odor Intensity Grid Based UAV Path Planning Algorithm with Particle Swarm Optimization Approach

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2016-01-01

    Full Text Available This paper proposes a potential odor intensity grid based optimization approach for unmanned aerial vehicle (UAV path planning with particle swarm optimization (PSO technique. Odor intensity is created to color the area in the searching space with highest probability where candidate particles may locate. A potential grid construction operator is designed for standard PSO based on different levels of odor intensity. The potential grid construction operator generates two potential location grids with highest odor intensity. Then the middle point will be seen as the final position in current particle dimension. The global optimum solution will be solved as the average. In addition, solution boundaries of searching space in each particle dimension are restricted based on properties of threats in the flying field to avoid prematurity. Objective function is redesigned by taking minimum direction angle to destination into account and a sampling method is introduced. A paired samples t-test is made and an index called straight line rate (SLR is used to evaluate the length of planned path. Experiments are made with other three heuristic evolutionary algorithms. The results demonstrate that the proposed method is capable of generating higher quality paths efficiently for UAV than any other tested optimization techniques.

  18. Optimizing bulk milk dioxin monitoring based on costs and effectiveness.

    Science.gov (United States)

    Lascano-Alcoser, V H; Velthuis, A G J; van der Fels-Klerx, H J; Hoogenboom, L A P; Oude Lansink, A G J M

    2013-07-01

    Dioxins are environmental pollutants, potentially present in milk products, which have negative consequences for human health and for the firms and farms involved in the dairy chain. Dioxin monitoring in feed and food has been implemented to detect their presence and estimate their levels in food chains. However, the costs and effectiveness of such programs have not been evaluated. In this study, the costs and effectiveness of bulk milk dioxin monitoring in milk trucks were estimated to optimize the sampling and pooling monitoring strategies aimed at detecting at least 1 contaminated dairy farm out of 20,000 at a target dioxin concentration level. Incidents of different proportions, in terms of the number of contaminated farms, and concentrations were simulated. A combined testing strategy, consisting of screening and confirmatory methods, was assumed as well as testing of pooled samples. Two optimization models were built using linear programming. The first model aimed to minimize monitoring costs subject to a minimum required effectiveness of finding an incident, whereas the second model aimed to maximize the effectiveness for a given monitoring budget. Our results show that a high level of effectiveness is possible, but at high costs. Given specific assumptions, monitoring with 95% effectiveness to detect an incident of 1 contaminated farm at a dioxin concentration of 2 pg of toxic equivalents/g of fat [European Commission's (EC) action level] costs €2.6 million per month. At the same level of effectiveness, a 73% cost reduction is possible when aiming to detect an incident where 2 farms are contaminated at a dioxin concentration of 3 pg of toxic equivalents/g of fat (EC maximum level). With a fixed budget of €40,000 per month, the probability of detecting an incident with a single contaminated farm at a dioxin concentration equal to the EC action level is 4.4%. This probability almost doubled (8.0%) when aiming to detect the same incident but with a dioxin

  19. Optimal Product Variety, Scale Effects and Growth

    NARCIS (Netherlands)

    de Groot, H.L.F.; Nahuis, R.

    1997-01-01

    We analyze the social optimality of growth and product variety in a model of endogenous growth. The model contains two sectors, one assembly sector producing a homogenous consumption good, and one intermediate goods sector producing a differentiated input used in the assembly sector. Growth results

  20. Effective Potential in Noncommutative BTZ Black Hole

    Science.gov (United States)

    Sadeghi, Jafar; Shajiee, Vahid Reza

    2016-02-01

    In this paper, we investigated the noncommutative rotating BTZ black hole and showed that such a space-time is not maximally symmetric. We calculated effective potential for the massive and the massless test particle by geodesic equations, also we showed effect of non-commutativity on the minimum mass of BTZ black hole.

  1. Optimized distance-dependent atom-pair-based potential DOOP for protein structure prediction.

    Science.gov (United States)

    Chae, Myong-Ho; Krull, Florian; Knapp, Ernst-Walter

    2015-05-01

    The DOcking decoy-based Optimized Potential (DOOP) energy function for protein structure prediction is based on empirical distance-dependent atom-pair interactions. To optimize the atom-pair interactions, native protein structures are decomposed into polypeptide chain segments that correspond to structural motives involving complete secondary structure elements. They constitute near native ligand-receptor systems (or just pairs). Thus, a total of 8609 ligand-receptor systems were prepared from 954 selected proteins. For each of these hypothetical ligand-receptor systems, 1000 evenly sampled docking decoys with 0-10 Å interface root-mean-square-deviation (iRMSD) were generated with a method used before for protein-protein docking. A neural network-based optimization method was applied to derive the optimized energy parameters using these decoys so that the energy function mimics the funnel-like energy landscape for the interaction between these hypothetical ligand-receptor systems. Thus, our method hierarchically models the overall funnel-like energy landscape of native protein structures. The resulting energy function was tested on several commonly used decoy sets for native protein structure recognition and compared with other statistical potentials. In combination with a torsion potential term which describes the local conformational preference, the atom-pair-based potential outperforms other reported statistical energy functions in correct ranking of native protein structures for a variety of decoy sets. This is especially the case for the most challenging ROSETTA decoy set, although it does not take into account side chain orientation-dependence explicitly. The DOOP energy function for protein structure prediction, the underlying database of protein structures with hypothetical ligand-receptor systems and their decoys are freely available at http://agknapp.chemie.fu-berlin.de/doop/.

  2. DESTINATION MARKETING STRATEGY IN BALI THROUGH OPTIMIZING THE POTENTIAL OF LOCAL PRODUCTS

    OpenAIRE

    I Gusti Ayu Oka Suryawardani; Agung Suryawan Wiranatha; Petr, Christine

    2014-01-01

    This study was designed to study destination marketing strategy in Bali through optimizing the potential of local products. Seventy nine of hotel managers were interviewed based on cluster sampling method to gain their point of view. The results show that destination must build their images around unique attributes that provide them sustainable competitive advantage including its attraction which should be designed to meet the needs of the target market and should be served by local produc...

  3. Optimizing transformations of structural balance in signed networks with potential relationships

    Science.gov (United States)

    Du, Haifeng; He, Xiaochen; Wang, Shanfeng; Gong, Maoguo; Feldman, Marcus W.

    2017-01-01

    A signed network includes positive edges, negative edges and "0" edges, the last of which denote potential relationships. However, "0" edges are commonly ignored in transformations of unbalanced networks. In this paper, we take "0" edges into account and solve the optimization problem in a more comprehensive way. We transform the unbalanced network by not only changing signs of edges but also changing edges into potential. The experimental results show that our method can solve this problem efficiently, and that our solutions are cost-saving.

  4. Optimal Dose of Vitamin D3 400 I.U. for Average Adults has A Significant Anti-Cancer Effect, While Widely Used 2000 I.U. or Higher Promotes Cancer: Marked Reduction of Taurine & 1α, 25(OH)2D3 Was Found In Various Cancer Tissues and Oral Intake of Optimal Dose of Taurine 175mg for Average Adults, Rather Than 500mg, Was Found to Be A New Potentially Safe and More Effective Method of Cancer Treatment.

    Science.gov (United States)

    Omura, Yoshiaki; Lu, Dominic; Jones, Marilyn K; Nihrane, Abdallah; Duvvi, Harsha; Yapor, Dario; Shimotsuura, Yasuhiro; Ohki, Motomu

    2016-01-01

    During the past 10 years, the author had found that the optimal dose of Vitamin D3 400 I.U. has safe & effective anticancer effects, while commonly used 2000-5000 I.U. of Vit. D3 often creates a 2-3 time increase in cancer markers. We examined the concentration of Taurine in normal internal organs and in cancer using Bi-Digital O-Ring Test. We found that Taurine levels in normal tissue are 4-6ng. But, the amount of Taurine of average normal value of 5.0-5.25ng was strikingly reduced to 0.0025-0.0028ng in this study of several examples in adenocarcinomas of the esophagus, stomach, pancreas, colon, prostate, and lung, as well as breast cancer. The lowest Taurine levels of 0.0002-0.0005ng were found in so called Zika virus infected babies from Brazil with microcephaly. While Vitamin D3 receptor stimulant 1α, 25 (OH)2D3 in normal tissues was 0.45-0.53ng, they were reduced to 0.025-0.006ng in cancers (1/100th-1/200th of normal value), particularly in various adenocarcinomas. All of these adenocarcinomas had about 1500ng HPV-16 viral infection. In 500 breast cancers, about 97% had HPV-16. The optimal dose of Taurine for average adult has been found to be about 175mg, rather than the widely used 500mg. In addition, since Taurine is markedly reduced to close to 1/1000th-1/2000th of its normal value in these cancer tissues, we examined the effect of the optimal dose of Taurine on cancer patients. Optimal dose of Taurine produced a very significant decrease in cancer-associated parameters, such as Oncogene C-fosAb2 & Integrin α5β1 being reduced to less than 1/1,000th, and 8-OH-dG (which increases in the presence of DNA mutation) reduced to less than 1/10th. The optimal dose of Taurine 175mg for average adult various cancer patient 3 times a day alone provide beneficial effects with very significant anti-cancer effects with strikingly increased urinary excretion of bacteria, viruses, & funguses, asbestos, toxic metals & other toxic substances. However, optimal doses of

  5. Hierarchical particle swarm optimizer for minimizing the non-convex potential energy of molecular structure.

    Science.gov (United States)

    Cheung, Ngaam J; Shen, Hong-Bin

    2014-11-01

    The stable conformation of a molecule is greatly important to uncover the secret of its properties and functions. Generally, the conformation of a molecule will be the most stable when it is of the minimum potential energy. Accordingly, the determination of the conformation can be solved in the optimization framework. It is, however, not an easy task to achieve the only conformation with the lowest energy among all the potential ones because of the high complexity of the energy landscape and the exponential computation increasing with molecular size. In this paper, we develop a hierarchical and heterogeneous particle swarm optimizer (HHPSO) to deal with the problem in the minimization of the potential energy. The proposed method is evaluated over a scalable simplified molecular potential energy function with up to 200 degrees of freedom and a realistic energy function of pseudo-ethane molecule. The experimental results are compared with other six PSO variants and four genetic algorithms. The results show HHPSO is significantly better than the compared PSOs with p-value less than 0.01277 over molecular potential energy function.

  6. Raising yield potential of wheat. III. Optimizing partitioning to grain while maintaining lodging resistance.

    Science.gov (United States)

    Foulkes, M John; Slafer, Gustavo A; Davies, William J; Berry, Pete M; Sylvester-Bradley, Roger; Martre, Pierre; Calderini, Daniel F; Griffiths, Simon; Reynolds, Matthew P

    2011-01-01

    A substantial increase in grain yield potential is required, along with better use of water and fertilizer, to ensure food security and environmental protection in future decades. For improvements in photosynthetic capacity to result in additional wheat yield, extra assimilates must be partitioned to developing spikes and grains and/or potential grain weight increased to accommodate the extra assimilates. At the same time, improvement in dry matter partitioning to spikes should ensure that it does not increase stem or root lodging. It is therefore crucial that improvements in structural and reproductive aspects of growth accompany increases in photosynthesis to enhance the net agronomic benefits of genetic modifications. In this article, six complementary approaches are proposed, namely: (i) optimizing developmental pattern to maximize spike fertility and grain number, (ii) optimizing spike growth to maximize grain number and dry matter harvest index, (iii) improving spike fertility through desensitizing floret abortion to environmental cues, (iv) improving potential grain size and grain filling, and (v) improving lodging resistance. Since many of the traits tackled in these approaches interact strongly, an integrative modelling approach is also proposed, to (vi) identify any trade-offs between key traits, hence to define target ideotypes in quantitative terms. The potential for genetic dissection of key traits via quantitative trait loci analysis is discussed for the efficient deployment of existing variation in breeding programmes. These proposals should maximize returns in food production from investments in increased crop biomass by increasing spike fertility, grain number per unit area and harvest index whilst optimizing the trade-offs with potential grain weight and lodging resistance.

  7. Promotion Potentiality and Optimal Strategies Analysis of Provincial Energy Efficiency in China

    Directory of Open Access Journals (Sweden)

    Jinpeng Liu

    2016-08-01

    should be integrated afresh to promote the energy efficiency level. Some optimal strategies on energy efficiency promotion are discussed, finally, aiming to provide effective references for the Chinese government to make relative policies. The study proposes a new perspective for provincial energy efficiency research which can also provide a reference for other countries.

  8. An Effective Hybrid Optimization Algorithm for Capacitated Vehicle Routing Problem

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Capacitated vehicle routing problem (CVRP) is an important combinatorial optimization problem. However, it is quite difficult to achieve an optimal solution with the traditional optimization methods owing to the high computational complexity. A hybrid algorithm was developed to solve the problem, in which an artificial immune clonal algorithm (AICA) makes use of the global search ability to search the optimal results and simulated annealing (SA) algorithm employs certain probability to avoid becoming trapped in a local optimum. The results obtained from the computational study show that the proposed algorithm is a feasible and effective method for capacitated vehicle routing problem.

  9. A Stochastic Inversion Method for Potential Field Data: Ant Colony Optimization

    Science.gov (United States)

    Liu, Shuang; Hu, Xiangyun; Liu, Tianyou

    2014-07-01

    Simulating natural ants' foraging behavior, the ant colony optimization (ACO) algorithm performs excellently in combinational optimization problems, for example the traveling salesman problem and the quadratic assignment problem. However, the ACO is seldom used to inverted for gravitational and magnetic data. On the basis of the continuous and multi-dimensional objective function for potential field data optimization inversion, we present the node partition strategy ACO (NP-ACO) algorithm for inversion of model variables of fixed shape and recovery of physical property distributions of complicated shape models. We divide the continuous variables into discrete nodes and ants directionally tour the nodes by use of transition probabilities. We update the pheromone trails by use of Gaussian mapping between the objective function value and the quantity of pheromone. It can analyze the search results in real time and promote the rate of convergence and precision of inversion. Traditional mapping, including the ant-cycle system, weaken the differences between ant individuals and lead to premature convergence. We tested our method by use of synthetic data and real data from scenarios involving gravity and magnetic anomalies. The inverted model variables and recovered physical property distributions were in good agreement with the true values. The ACO algorithm for binary representation imaging and full imaging can recover sharper physical property distributions than traditional linear inversion methods. The ACO has good optimization capability and some excellent characteristics, for example robustness, parallel implementation, and portability, compared with other stochastic metaheuristics.

  10. Effects of optimism on motivation in rats.

    Science.gov (United States)

    Rygula, Rafal; Golebiowska, Joanna; Kregiel, Jakub; Kubik, Jakub; Popik, Piotr

    2015-01-01

    In humans, optimism is a cognitive construct related to motivation; optimists exert effort, whereas pessimists disengage from effort. In this study, using a recently developed ambiguous-cue interpretation (ACI) paradigm we took the unique opportunity to investigate whether "optimism" as a trait is correlated with motivation in rodents. In a series of ACI tests (cognitive bias screening, CBS), we identified rats displaying "pessimistic" and "optimistic" traits. Subsequently, we investigated the trait differences in the motivation of these rats to gain reward and to avoid punishment using a progressive ratio (PR) schedule of reinforcement paradigm. Although "optimistic" and "pessimistic" animals did not differ in their motivation to avoid punishment, the "optimistic" rats were significantly more motivated to gain reward than their "pessimistic" conspecifics. For the first time, we showed an association between cognitive judgment bias and motivation in an animal model. Because both investigated processes are closely related to mental health and wellbeing, our results may be valuable for preclinical modeling of many psychiatric disorders.

  11. Effective potential in density matrix functional theory.

    Science.gov (United States)

    Nagy, A; Amovilli, C

    2004-10-01

    In the previous paper it was shown that in the ground state the diagonal of the spin independent second-order density matrix n can be determined by solving a single auxiliary equation of a two-particle problem. Thus the problem of an arbitrary system with even electrons can be reduced to a two-particle problem. The effective potential of the two-particle equation contains a term v(p) of completely kinetic origin. Virial theorem and hierarchy of equations are derived for v(p) and simple approximations are proposed. A relationship between the effective potential u(p) of the shape function equation and the potential v(p) is established.

  12. An optimized interatomic potential for Cu-Ni alloys with the embedded-atom method.

    Science.gov (United States)

    Onat, Berk; Durukanoğlu, Sondan

    2014-01-22

    We have developed a semi-empirical and many-body type model potential using a modified charge density profile for Cu-Ni alloys based on the embedded-atom method (EAM) formalism with an improved optimization technique. The potential is determined by fitting to experimental and first-principles data for Cu, Ni and Cu-Ni binary compounds, such as lattice constants, cohesive energies, bulk modulus, elastic constants, diatomic bond lengths and bond energies. The generated potentials were tested by computing a variety of properties of pure elements and the alloy of Cu, Ni: the melting points, alloy mixing enthalpy, lattice specific heat, equilibrium lattice structures, vacancy formation and interstitial formation energies, and various diffusion barriers on the (100) and (111) surfaces of Cu and Ni.

  13. Detection Of Ventricular Late Potentials Using Wavelet Transform And ANT Colony Optimization

    Science.gov (United States)

    Subramanian, A. Sankara; Gurusamy, G.; Selvakumar, G.

    2010-10-01

    Ventricular late Potentials (VLPs) are low-level high frequency signals that are usually found with in the terminal part of the QRS complex from patients after Myocardial Infraction. Patients with VLPs are at risk of developing Ventricular Tachycardia, which is the major cause of death if patients suffering from heart disease. In this paper the Discrete Wavelet Transform was used to detect VLPs and then ANT colony optimization (ACO) was applied to classify subjects with and without VLPs. A set of Discrete Wavelet Transform (DWT) coefficients is selected from the wavelet decomposition. Three standard parameters of VLPs such as QRST, D40 and V40 are also established. After that a novel clustering algorithm based on Ant Colony Optimization is developed for classifying arrhythmia types. The wavelet decomposition enabled us to perform the task efficiently and produced reliable results.

  14. Charge optimized many-body (COMB) potential for dynamical simulation of Ni-Al phases

    Science.gov (United States)

    Kumar, Aakash; Chernatynskiy, Aleksandr; Liang, Tao; Choudhary, Kamal; Noordhoek, Mark J.; Cheng, Yu-Ting; Phillpot, Simon R.; Sinnott, Susan B.

    2015-08-01

    An interatomic potential for the Ni-Al system is presented within the third-generation charge optimized many-body (COMB3) formalism. The potential has been optimized for Ni3Al, or the γ‧ phase in Ni-based superalloys. The formation energies predicted for other Ni-Al phases are in reasonable agreement with first-principles results. The potential further predicts good mechanical properties for Ni3Al, which includes the values of the complex stacking fault (CSF) and the anti-phase boundary (APB) energies for the (1 1 1) and (1 0 0) planes. It is also used to investigate dislocation propagation across the Ni3Al (1 1 0)-Ni (1 1 0) interface, and the results are consistent with simulation results reported in the literature. The potential is further used in combination with a recent COMB3 potential for Al2O3 to investigate the Ni3Al (1 1 1)-Al2O3 (0 0 01) interface, which has not been modeled previously at the classical atomistic level due to the lack of a reactive potential to describe both Ni3Al and Al2O3 as well as interactions between them. The calculated work of adhesion for this interface is predicted to be 1.85 J m-2, which is in agreement with available experimental data. The predicted interlayer distance is further consistent with the available first-principles results for Ni (1 1 1)-Al2O3 (0 0 0 1).

  15. Distributed and boundary optimal control of the Allen-Cahn equation with regular potential and dynamic boundary conditions

    Science.gov (United States)

    Benincasa, T.; Donado Escobar, L. D.; Moroşanu, C.

    2016-08-01

    This paper is concerned with an optimal control problem (P) (both distributed control as well as boundary control) for the nonlinear phase-field (Allen-Cahn) equation, involving a regular potential and dynamic boundary condition. A family of approximate optimal control problems (Pɛ) is introduced and results for the existence of an optimal control for problems (P) and (Pɛ) are proven. Furthermore, the convergence result of the optimal solution of problem (Pɛ) to the optimal solution of problem (P) is proved. Besides the existence of an optimal control in problem (Pɛ), necessary optimality conditions (Pontryagin's principle) as well as a conceptual gradient-type algorithm to approximate the optimal control, were established in the end.

  16. Optimal escape from potential wells-patterns of regular and chaotic bifurcation

    Science.gov (United States)

    Stewart, H. B.; Thompson, J. M. T.; Ueda, Y.; Lansbury, A. N.

    The patterns of bifurcation governing the escape of periodically forced oscillations from a potential well over a smooth potential barrier are studied by numerical simulation. Both the generic asymmetric single-well cubic potential and the symmetric twin-well potential Duffing oscillator are surveyed by varying three parameters: forcing frequency, forcing amplitude, and damping coefficient. The close relationship between optimal escape and nonlinear resonance within the well is confirmed over a wide range of damping. Subtle but significant differences are observed at higher damping ratios. The possibility of indeterminate outcomes of jumps to and from resonance near optimal escape is cmppletely suppressed above a critical level of the damping ratio (about 0.12 for the asymmetric single-well oscillator). Coincidentally, at almost the same level of damping, the optimal escape condition becomes distinct from the apex in the (ω, F) plane of the bistable regime; this corresponds to the appearance of chaotic attractors which subsume both resonant and non-resonant motions within one well. At higher damping levels, further changes occur involving conversions from chaotic-saddle to regular-saddle bifurcations. These changes in optimal escape phenomena correspond to codimension three bifurcations at exceptional points in the space of three parameters. These bifurcations are described in terms of homoclinic and heteroclinic structures of invariant manifolds, and changes in accessible boundary orbits. The same sequence of codimension three bifurcations is observed in both the twin-well Duffing oscillator and the asymmetric single-well escape equation. Within the codimension three bifurcation patterns governing escape, one particular codimension two global bifurcation involves a chaotic attractor explosion, or interior crisis, compounded with a blue sky catastrophe or boundary crisis of the exploded attractor. This codimension two bifurcation has structure containing a form of

  17. Effective Length Design of Humanoid Robot Fingers Using Biomimetic Optimization

    Directory of Open Access Journals (Sweden)

    Byoung-Ho Kim

    2015-10-01

    Full Text Available In this study, we propose an effective design method for the phalangeal parameters and the total size of humanoid robot fingers based on a biomimetic optimization. For the optimization, an interphalangeal joint coordination parameter and the length constraints inherent in human fingers are considered from a biomimetic perspective. A reasonable grasp formulation is also taken into account from the viewpoint of power grasping, where the grasp space of a humanoid robot finger is importantly considered to determine the phalangeal length parameters. The usefulness of the devised biomimetic optimization method is shown through the design examples of various humanoid robot fingers. In fact, the optimization-based finger design method enables us to determine effectively the proper phalangeal size of humanoid robot fingers for human-like object handling tasks. In addition, we discuss its contribution to the structural configuration and coordinated motion of a humanoid robot finger, and address its practical availability in terms of effective finger design.

  18. Effects of optimism on motivation in rats

    Directory of Open Access Journals (Sweden)

    Rafal eRygula

    2015-02-01

    Full Text Available In humans, optimism is a cognitive construct related to motivation; optimists exert effort, whereas pessimists disengage from effort. In this study, using a recently developed ambiguous-cue interpretation (ACI paradigm we took the unique opportunity to investigate whether ‘optimism’ as a trait is correlated with motivation in rodents. In a series of ACI tests (cognitive bias screening, CBS, we identified rats displaying ‘pessimistic’ and ‘optimistic’ traits. Subsequently, we investigated the trait differences in the motivation of these rats to gain reward and to avoid punishment using a progressive ratio schedule of reinforcement paradigm. Although ‘optimistic’ and ‘pessimistic’ animals did not differ in their motivation to avoid punishment, the ‘optimistic’ rats were significantly more motivated to gain reward than their ‘pessimistic’ conspecifics. For the first time, we showed an association between cognitive judgment bias and motivation in an animal model. Because both investigated processes are closely related to mental health and wellbeing, our results may be valuable for preclinical modeling of many psychiatric disorders.

  19. The effect of prediction error correlation on optimal sensor placement in structural dynamics

    Science.gov (United States)

    Papadimitriou, Costas; Lombaert, Geert

    2012-04-01

    The problem of estimating the optimal sensor locations for parameter estimation in structural dynamics is re-visited. The effect of spatially correlated prediction errors on the optimal sensor placement is investigated. The information entropy is used as a performance measure of the sensor configuration. The optimal sensor location is formulated as an optimization problem involving discrete-valued variables, which is solved using computationally efficient sequential sensor placement algorithms. Asymptotic estimates for the information entropy are used to develop useful properties that provide insight into the dependence of the information entropy on the number and location of sensors. A theoretical analysis shows that the spatial correlation length of the prediction errors controls the minimum distance between the sensors and should be taken into account when designing optimal sensor locations with potential sensor distances up to the order of the characteristic length of the dynamic problem considered. Implementation issues for modal identification and structural-related model parameter estimation are addressed. Theoretical and computational developments are illustrated by designing the optimal sensor configurations for a continuous beam model, a discrete chain-like stiffness-mass model and a finite element model of a footbridge in Wetteren (Belgium). Results point out the crucial effect the spatial correlation of the prediction errors have on the design of optimal sensor locations for structural dynamics applications, revealing simultaneously potential inadequacies of spatially uncorrelated prediction errors models.

  20. De novo design of potential RecA inhibitors using multi objective optimization.

    Science.gov (United States)

    Sengupta, Soumi; Bandyopadhyay, Sanghamitra

    2012-01-01

    De novo ligand design involves optimization of several ligand properties such as binding affinity, ligand volume, drug likeness, etc. Therefore, optimization of these properties independently and simultaneously seems appropriate. In this paper, the ligand design problem is modeled in a multiobjective using Archived MultiObjective Simulated Annealing (AMOSA) as the underlying search algorithm. The multiple objectives considered are the energy components similarity to a known inhibitor and a novel drug likeliness measure based on Lipinski's rule of five. RecA protein of Mycobacterium tuberculosis, causative agent of tuberculosis, is taken as the target for the drug design. To gauge the goodness of the results, they are compared to the outputs of LigBuilder, NEWLEAD, and Variable genetic algorithm (VGA). The same problem has also been modeled using a well-established genetic algorithm-based multiobjective optimization technique, Nondominated Sorting Genetic Algorithm-II (NSGA-II), to find the efficacy of AMOSA through comparative analysis. Results demonstrate that while some small molecules designed by the proposed approach are remarkably similar to the known inhibitors of RecA, some new ones are discovered that may be potential candidates for novel lead molecules against tuberculosis.

  1. Optimizing production of asperolide A, a potential anti-tumor tetranorditerpenoid originally produced by the algal-derived endophytic fungus Aspergillus wentii EN-48

    Science.gov (United States)

    Xu, Rui; Li, Xiaoming; Xu, Gangming; Wang, Bingui

    2016-07-01

    The marine algal-derived endophytic fungus Aspergillus wentii EN-48 produces the potential anti-tumor agent asperolide A, a tetranorlabdane diterpenoid active against lung cancer. However, the fermentation yield of asperolide A was very low and only produced in static cultures. Static fermentation conditions of A. wentii EN-48 were optimized employing response surface methodology to enhance the production of asperolide A. The optimized conditions resulted in a 13.9-fold yield enhancement, which matched the predicted value, and the optimized conditions were successfully used in scale-up fermentation for the production of asperolide A. Exogenous addition of plant hormones (especially 10 μmol/L methyl jasmonate) stimulated asperolide A production. To our knowledge, this is first optimized production of an asperolide by a marine-derived fungus. The optimization is Effective and valuable to supply material for further anti-tumor mechanism studies and preclinical evaluation of asperolide A and other norditerpenoids.

  2. The Stark effect in linear potentials

    Energy Technology Data Exchange (ETDEWEB)

    Robinett, R W [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States)], E-mail: rick@phys.psu.edu

    2010-01-15

    We examine the Stark effect (the second-order shifts in the energy spectrum due to an external constant force) for two one-dimensional model quantum mechanical systems described by linear potentials, the so-called quantum bouncer (defined by V(z) = Fz for z > 0 and V(z) = {infinity} for z < 0) and the symmetric linear potential (given by V(z) = F|z|). We show how straightforward use of the most obvious properties of the Airy function solutions and simple Taylor expansions gives closed form results for the Stark shifts in both systems. These exact results are then compared to other approximation techniques, such as perturbation theory and WKB methods. These expressions add to the small number of closed-form descriptions available for the Stark effect in model quantum mechanical systems.

  3. The Stark effect in linear potentials

    CERN Document Server

    Robinett, R W

    2009-01-01

    We examine the Stark effect (the second-order shift in the energy spectrum due to an external constant force) for two 1-dimensional model quantum mechanical systems described by linear potentials, the so-called quantum bouncer (defined by V(z) = Fz for z>0 and V(z) infinite for z<0) and the symmetric linear potential (given by V(z) = F|z|). We show how straightforward use of the most obvious properties of the Airy function solutions and simple Taylor expansions give closed form results for the Stark shifts in both systems. These exact results are then compared to other approximation techniques, such as perturbation theory and WKB methods. These expressions add to the small number of closed-form descriptions available for the Stark effect in model quantum mechanical systems.

  4. Optimally doped hybridization gap semiconductor FeGa3 as potential thermoelectric alloy*

    Science.gov (United States)

    Ponnambalam, Vijayabarathi; Morelli, Donald T.

    2014-03-01

    FeGa3, a hybridization gap semiconductor with a band gap of ~ 0.5 eV can be a potential thermoelectric material if optimally doped. Due to the involvement of d-band in the transport, high Seebeck coefficient is a possibility. To achieve the optimum doping level, Mn, Co and Zn containing FeGa3 alloys are being prepared either via the flux or solid state reaction method. Phase characterization will be carried out. Electrical and transport properties including resistivity, Seebeck and Hall coefficients and thermal conductivity will be measured over a wide temperature range of 80- 1000 K. These results will be presented and the potential of these compositions as thermoelectrics will be discussed.

  5. The Stark Effect in Linear Potentials

    Science.gov (United States)

    Robinett, R. W.

    2010-01-01

    We examine the Stark effect (the second-order shifts in the energy spectrum due to an external constant force) for two one-dimensional model quantum mechanical systems described by linear potentials, the so-called quantum bouncer (defined by V(z) = Fz for z greater than 0 and V(z) = [infinity] for z less than 0) and the symmetric linear potential…

  6. Effective Depletion Potential of Colloidal Spheres

    Institute of Scientific and Technical Information of China (English)

    LI Wei-Hua; MA Hong-Ru

    2004-01-01

    @@ A new semianalytical method, which is a combination of the density functional theory with Rosenfeld density functional and the Ornstein-Zernike equation, is proposed for the calculation of the effective depletion potentials between a pair of big spheres immersed in a small hard sphere fluid. The calculated results are almost identical to the integral equation method with the Percus-Yevick approximation, and are also in agreement well with the Monte Carlo simulation results.

  7. Taming Infrared Divergences in the Effective Potential

    CERN Document Server

    Elias-Miro, J; Konstandin, T

    2014-01-01

    The Higgs effective potential in the Standard Model (SM), calculated perturbatively, generically suffers from infrared (IR) divergences when the (field-dependent) tree-level mass of the Goldstone bosons goes to zero. Such divergences can affect both the potential and its first derivative and become worse with increasing loop order. In this paper we show that these IR divergences are spurious, we perform a simple resummation of all IR-problematic terms known (up to three loops) and explain how to extend the resummation to cure all such divergences to any order. The method is of general applicability and would work in scenarios other than the SM. Our discussion has some bearing on a scenario recently proposed as a mechanism for gauge mediation of scale breaking in the ultraviolet, in which it is claimed that the low-energy Higgs potential is non-standard. We argue that all non-decoupling effects from the heavy sector can be absorbed in the renormalization of low-energy parameters leading to a SM-like effective ...

  8. Effective Basemetal Hedging: The Optimal Hedge Ratio and Hedging Horizon

    Directory of Open Access Journals (Sweden)

    Michaël Dewally

    2008-12-01

    Full Text Available This study investigates optimal hedge ratios in all base metal markets. Using recent hedging computation techniques, we find that 1 the short-run optimal hedging ratio is increasing in hedging horizon, 2 that the long-term horizon limit to the optimal hedging ratio is not converging to one but is slightly higher for most of these markets, and 3 that hedging effectiveness is also increasing in hedging horizon. When hedging with futures in these markets, one should hedge long-term at about 6 to 8 weeks with a slightly greater than one hedge ratio. These results are of interest to many purchasing departments and other commodity hedgers.

  9. Aging and the Optimal Viewing Position Effect in Chinese

    Directory of Open Access Journals (Sweden)

    Pingping eLiu

    2015-10-01

    Full Text Available Substantial evidence indicates that where readers fixate within a word affects the efficiency with which that word is recognized. Indeed, words in alphabetic languages (e.g., English, French are recognized most efficiently when fixated at their optimal viewing position (OVP, which is near the word center. However, little is known about the effects of fixation location on word recognition in non-alphabetic languages, such as Chinese. Moreover, studies to date have not investigated if effects of fixation location vary across adult age-groups, although it is well-established that older readers experience greater difficulty recognizing words due to visual and cognitive declines. Accordingly, the present research examined OVP effects by young and older adult readers when recognizing Chinese words presented in isolation. Most words in Chinese are formed from two or more logograms called characters and so the present experiment investigated the influence of fixation location on the recognition of 2-, 3-, and 4-character words (and nonwords. The older adults experienced generally greater word recognition difficulty. But whereas the young adults recognized words most efficiently when initially fixating the first character of 2-character words and second character of 3- and 4-character words, the older adults recognized words most efficiently when initially fixating the first character for words of each length. The findings therefore reveal subtle but potentially important adult age differences in the effects of fixation location on Chinese word recognition. Moreover, the similarity in effects for words and nonwords implies a more general age-related change in oculomotor strategy when processing Chinese character-strings.

  10. Aging and the optimal viewing position effect in Chinese.

    Science.gov (United States)

    Liu, Pingping; Liu, Danlu; Han, Buxin; Paterson, Kevin B

    2015-01-01

    Substantial evidence indicates that where readers fixate within a word affects the efficiency with which that word is recognized. Indeed, words in alphabetic languages (e.g., English, French) are recognized most efficiently when fixated at their optimal viewing position (OVP), which is near the word center. However, little is known about the effects of fixation location on word recognition in non-alphabetic languages, such as Chinese. Moreover, studies to date have not investigated if effects of fixation location vary across adult age-groups, although it is well-established that older readers experience greater difficulty recognizing words due to visual and cognitive declines. Accordingly, the present research examined OVP effects by young and older adult readers when recognizing Chinese words presented in isolation. Most words in Chinese are formed from two or more logograms called characters and so the present experiment investigated the influence of fixation location on the recognition of 2-, 3-, and 4-character words (and nonwords). The older adults experienced generally greater word recognition difficulty. But whereas the young adults recognized words most efficiently when initially fixating the first character of 2-character words and second character of 3- and 4-character words, the older adults recognized words most efficiently when initially fixating the first character for words of each length. The findings therefore reveal subtle but potentially important adult age differences in the effects of fixation location on Chinese word recognition. Moreover, the similarity in effects for words and nonwords implies a more general age-related change in oculomotor strategy when processing Chinese character-strings.

  11. Aging and the optimal viewing position effect in Chinese

    Science.gov (United States)

    Liu, Pingping; Liu, Danlu; Han, Buxin; Paterson, Kevin B.

    2015-01-01

    Substantial evidence indicates that where readers fixate within a word affects the efficiency with which that word is recognized. Indeed, words in alphabetic languages (e.g., English, French) are recognized most efficiently when fixated at their optimal viewing position (OVP), which is near the word center. However, little is known about the effects of fixation location on word recognition in non-alphabetic languages, such as Chinese. Moreover, studies to date have not investigated if effects of fixation location vary across adult age-groups, although it is well-established that older readers experience greater difficulty recognizing words due to visual and cognitive declines. Accordingly, the present research examined OVP effects by young and older adult readers when recognizing Chinese words presented in isolation. Most words in Chinese are formed from two or more logograms called characters and so the present experiment investigated the influence of fixation location on the recognition of 2-, 3-, and 4-character words (and nonwords). The older adults experienced generally greater word recognition difficulty. But whereas the young adults recognized words most efficiently when initially fixating the first character of 2-character words and second character of 3- and 4-character words, the older adults recognized words most efficiently when initially fixating the first character for words of each length. The findings therefore reveal subtle but potentially important adult age differences in the effects of fixation location on Chinese word recognition. Moreover, the similarity in effects for words and nonwords implies a more general age-related change in oculomotor strategy when processing Chinese character-strings. PMID:26579039

  12. Dopamine D(3) receptor antagonists: The quest for a potentially selective PET ligand. Part two: Lead optimization.

    Science.gov (United States)

    Micheli, Fabrizio; Holmes, Ian; Arista, Luca; Bonanomi, Giorgio; Braggio, Simone; Cardullo, Francesca; Di Fabio, Romano; Donati, Daniele; Gentile, Gabriella; Hamprecht, Dieter; Terreni, Silvia; Heidbreder, Christian; Savoia, Chiara; Griffante, Cristiana; Worby, Angela

    2009-08-01

    The lead optimization process to identify new selective dopamine D(3) receptor antagonists is reported. DMPK parameters and binding data suggest that selective D(3) receptor antagonists as potential PET ligands might have been identified.

  13. Application of the Optimized Effective Potential Method to Quantum Chemistry

    Science.gov (United States)

    2007-11-02

    Y. Li, R.O. Esquivel and M.J. Stott, Bulletin of the American Physical Society 40, 142(1995). 5) Capacitive Nature of Atomic Sized Structures, G.J...Polarized Atomic Systems, Jiqiang Chen, J.B. Krieger, R.O. Esquivel , M.J. Stott and G.J. Iafrate, Physical Review A54, 1910 (1996). Enclosura 2

  14. Could piracetam potentiate behavioural effects of psychostimulants?

    Science.gov (United States)

    Slais, Karel; Machalova, Alena; Landa, Leos; Vrskova, Dagmar; Sulcova, Alexandra

    2012-08-01

    Press and internet reports mention abuse of nootropic drug piracetam (PIR) in combination with psychostimulants methamphetamine (MET) or 4-methylenedioxymethamphetamine (MDMA). These combinations are believed to produce more profound desirable effects, while decreasing hangover. However, there is a lack of valid experimental studies on such drug-drug interactions in the scientific literature available. Our hypothesis proposes that a functional interaction exists between PIR and amphetamine psychostimulants (MET and MDMA) which can potentiate psychostimulant behavioural effects. Our hypothesis is supported by the results of our pilot experiment testing acute effects of drugs given to mice intraperitoneally (Vehicle, n=12; MET 2.5mg/kg, n=10; MDMA 2.5mg/kg, n=11; PIR 300 mg/kg, n=12; PIR+MET, n=12; PIR+MDMA, n=11) in the Open Field Test (Actitrack, Panlab, Spain). PIR given alone caused no significant changes in mouse locomotor/exploratory behaviour, whereas the same dose combined with either MET or MDMA significantly enhanced their stimulatory effects. Different possible neurobiological mechanism underlying drug-drug interaction of PIR with MET or MDMA are discussed, as modulation of dopaminergic, glutamatergic or cholinergic brain systems. However, the interaction with membrane phospholipids seems as the most plausible mechanism explaining PIR action on activities of neurotransmitter systems. Despite that our behavioural experiment cannot serve for explanation of the pharmacological mechanisms of these functional interactions, it shows that PIR effects can increase behavioural stimulation of amphetamine drugs. Thus, the reported combining of PIR with MET or MDMA by human abusers is not perhaps a coincidental phenomenon and may be based on existing PIR potential to intensify acute psychostimulant effects of these drugs of abuse. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Optimism

    Science.gov (United States)

    Carver, Charles S.; Scheier, Michael F.; Segerstrom, Suzanne C.

    2010-01-01

    Optimism is an individual difference variable that reflects the extent to which people hold generalized favorable expectancies for their future. Higher levels of optimism have been related prospectively to better subjective well-being in times of adversity or difficulty (i.e., controlling for previous well-being). Consistent with such findings, optimism has been linked to higher levels of engagement coping and lower levels of avoidance, or disengagement, coping. There is evidence that optimism is associated with taking proactive steps to protect one's health, whereas pessimism is associated with health-damaging behaviors. Consistent with such findings, optimism is also related to indicators of better physical health. The energetic, task-focused approach that optimists take to goals also relates to benefits in the socioeconomic world. Some evidence suggests that optimism relates to more persistence in educational efforts and to higher later income. Optimists also appear to fare better than pessimists in relationships. Although there are instances in which optimism fails to convey an advantage, and instances in which it may convey a disadvantage, those instances are relatively rare. In sum, the behavioral patterns of optimists appear to provide models of living for others to learn from. PMID:20170998

  16. Effective potential evaluations in a modified PQCD

    Energy Technology Data Exchange (ETDEWEB)

    Cabo Montes de Oca, A.; Martinez-Pedrera, D. [International Center for Theoretical Physics, Trieste (Italy); Instituto de Cibernetica, Matematica y Fisica, Group of Theoretical Physics, La Habana (Cuba)

    2006-08-15

    A procedure discussed in a previous work for properly defining the Feynman diagrams at any number of loops in a modified version of PQCD, is employed here to evaluate some zero- and one-loop corrections to the effective potential, as functions of the gluon and quark condensate parameters. The calculated terms indicate an instability of massless QCD under the development of quark condensates even in the absence of the gluon one. Therefore, a mechanism is suggested for the dynamical generation of quark masses and condensates. The absence of indications coming from lattice calculations to this possibility could be determined by the current limitations in treating fermion determinants. (orig.)

  17. Optimization

    CERN Document Server

    Pearce, Charles

    2009-01-01

    Focuses on mathematical structure, and on real-world applications. This book includes developments in several optimization-related topics such as decision theory, linear programming, turnpike theory, duality theory, convex analysis, and queuing theory.

  18. Performance Optimization of Alternative Lower Global Warming Potential Refrigerants in Mini-Split Room Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [ORNL; Abdelaziz, Omar [ORNL; Shrestha, Som S [ORNL

    2017-01-01

    Oak Ridge National laboratory (ORNL) recently conducted extensive laboratory, drop-in investigations for lower Global Warming Potential (GWP) refrigerants to replace R-22 and R-410A. ORNL studied propane, DR-3, ARM-20B, N-20B and R-444B as lower GWP refrigerant replacement for R-22 in a mini-split room air conditioner (RAC) originally designed for R-22; and, R-32, DR-55, ARM-71A, and L41-2, in a mini-split RAC designed for R-410A. We obtained laboratory testing results with very good energy balance and nominal measurement uncertainty. Drop-in studies are not enough to judge the overall performance of the alternative refrigerants since their thermodynamic and transport properties might favor different heat exchanger configurations, e.g. cross-flow, counter flow, etc. This study compares optimized performances of individual refrigerants using a physics-based system model tools. The DOE/ORNL Heat Pump Design Model (HPDM) was used to model the mini-split RACs by inputting detailed heat exchangers geometries, compressor displacement and efficiencies as well as other relevant system components. The RAC models were calibrated against the lab data for each individual refrigerant. The calibrated models were then used to conduct a design optimization for the cooling performance by varying the compressor displacement to match the required capacity, and changing the number of circuits, refrigerant flow direction, tube diameters, air flow rates in the condenser and evaporator at 100% and 50% cooling capacities. This paper compares the optimized performance results for all alternative refrigerants and highlights best candidates for R-22 and R-410A replacement.

  19. Identifying Potential Areas for Siting Interim Nuclear Waste Facilities Using Map Algebra and Optimization Approaches

    Energy Technology Data Exchange (ETDEWEB)

    Omitaomu, Olufemi A [ORNL; Liu, Cheng [ORNL; Cetiner, Sacit M [ORNL; Belles, Randy [ORNL; Mays, Gary T [ORNL; Tuttle, Mark A [ORNL

    2013-01-01

    The renewed interest in siting new nuclear power plants in the United States has brought to the center stage, the need to site interim facilities for long-term management of spent nuclear fuel (SNF). In this paper, a two-stage approach for identifying potential areas for siting interim SNF facilities is presented. In the first stage, the land area is discretized into grids of uniform size (e.g., 100m x 100m grids). For the continental United States, this process resulted in a data matrix of about 700 million cells. Each cell of the matrix is then characterized as a binary decision variable to indicate whether an exclusion criterion is satisfied or not. A binary data matrix is created for each of the 25 siting criteria considered in this study. Using map algebra approach, cells that satisfy all criteria are clustered and regarded as potential siting areas. In the second stage, an optimization problem is formulated as a p-median problem on a rail network such that the sum of the shortest distance between nuclear power plants with SNF and the potential storage sites from the first stage is minimized. The implications of obtained results for energy policies are presented and discussed.

  20. Autonomous robot navigation based on the evolutionary multi-objective optimization of potential fields

    Science.gov (United States)

    Herrera Ortiz, Juan Arturo; Rodríguez-Vázquez, Katya; Padilla Castañeda, Miguel A.; Arámbula Cosío, Fernando

    2013-01-01

    This article presents the application of a new multi-objective evolutionary algorithm called RankMOEA to determine the optimal parameters of an artificial potential field for autonomous navigation of a mobile robot. Autonomous robot navigation is posed as a multi-objective optimization problem with three objectives: minimization of the distance to the goal, maximization of the distance between the robot and the nearest obstacle, and maximization of the distance travelled on each field configuration. Two decision makers were implemented using objective reduction and discrimination in performance trade-off. The performance of RankMOEA is compared with NSGA-II and SPEA2, including both decision makers. Simulation experiments using three different obstacle configurations and 10 different routes were performed using the proposed methodology. RankMOEA clearly outperformed NSGA-II and SPEA2. The robustness of this approach was evaluated with the simulation of different sensor masks and sensor noise. The scheme reported was also combined with the wavefront-propagation algorithm for global path planning.

  1. Analysis of Energy Saving Potential and Optimization of Thermally Broken Fiberglass Window Frames

    DEFF Research Database (Denmark)

    Zajas, Jan Jakub; Heiselberg, Per

    2011-01-01

    are considered, as a simple benchmark for various investigations. Further on, the complexity is gradually increased. Various means of diminishing the heat flow are evaluated. Results show that large improvement can be obtained, when cavities are subdivided by vertical walls or filled with insulation. U value......This paper elaborates on the energy saving potential and development process of fiberglass window frames, with intention for application in cold climates. A method is presented, where different means of improving thermal performance of a window frame are evaluated. Firstly, very simple geometries...... of a window frame can be significantly reduced by these means. Performance of an actual fiberglass frame optimized in this work is significantly improved, but still not competitive against state of the art frames. This indicates that more drastic improvements need to be done in order to achieve satisfying...

  2. The choice of directions for optimization of Ukrainian marine transport potential

    Directory of Open Access Journals (Sweden)

    Igor Kolegaev

    2013-06-01

    Full Text Available A proper marine transport development should provide independence of foreign trade and increase efficiency of national economy due to expansion of transport services export. However, to achieve these goals, optimization of investments and proper development and management of functional activity of fleet and ports are required. Normalized development and marine transport potential of a country, as shown by the experience of world’s leading maritime states, predetermine high functional efficiency of capital assets and freight independence of a country with respect to international division of labour. Thus development and production activity of fleet and ports influence a country’s investment complex activity as maritime transport is a large consumer of other branches resources.

  3. Exploiting the full potential of photometric quasar surveys: Optimal power spectra through blind mitigation of systematics

    CERN Document Server

    Leistedt, Boris

    2014-01-01

    We present optimal measurements of the angular power spectrum of the XDQSOz catalogue of photometric quasars from the Sloan Digital Sky Survey. These measurements rely on a quadratic maximum likelihood estimator that simultaneously measures the auto- and cross-power spectra of four redshift samples, and provides minimum-variance, unbiased estimates even at the largest angular scales. Since photometric quasars are known to be strongly affected by systematics such as spatially-varying depth and stellar contamination, we introduce a new framework of extended mode projection to robustly mitigate the impact of systematics on the power spectrum measurements. This technique involves constructing template maps of potential systematics, decorrelating them on the sky, and projecting out modes which are significantly correlated with the data. Our method is able to simultaneously process several thousands of nonlinearly-correlated systematics, and mode projection is performed in a blind fashion. Using our final power spe...

  4. Effects of optimism on recovery and mental health after a tornado outbreak.

    Science.gov (United States)

    Carbone, Eric G; Echols, Erin Thomas

    2017-05-01

    Dispositional optimism, a stable expectation that good things will happen, has been shown to improve health outcomes in a wide range of contexts, but very little research has explored the impact of optimism on post-disaster health and well-being. Data for this study come from the Centers for Disease Control and Prevention's Public health systems and mental health community recovery (PHSMHCR) Survey. Participants included 3216 individuals living in counties affected by the April 2011 tornado outbreak in Mississippi and Alabama. This study assesses the effect of dispositional optimism on post-disaster recovery and mental health. Dispositional optimism was found to have a positive effect on personal recovery and mental health after the disaster. Furthermore, it moderated the relationship between level of home damage and personal recovery as well as the relationship between home damage and post-traumatic stress disorder (PTSD), with stronger effects for those with increased levels of home damage. The utility of screening for optimism is discussed, along with the potential for interventions to increase optimism as a means of mitigating adverse mental health effects and improving the recovery of individuals affected by disasters and other traumatic events.

  5. Optimizing insulin pump therapy: the potential advantages of using a structured diabetes management program.

    Science.gov (United States)

    Lange, Karin; Ziegler, Ralph; Neu, Andreas; Reinehr, Thomas; Daab, Iris; Walz, Marion; Maraun, Michael; Schnell, Oliver; Kulzer, Bernhard; Reichel, Andreas; Heinemann, Lutz; Parkin, Christopher G; Haak, Thomas

    2015-03-01

    Use of continuous subcutaneous insulin infusion (CSII) therapy improves glycemic control, reduces hypoglycemia and increases treatment satisfaction in individuals with diabetes. As a number of patient- and clinician-related factors can hinder the effectiveness and optimal usage of CSII therapy, new approaches are needed to address these obstacles. Ceriello and colleagues recently proposed a model of care that incorporates the collaborative use of structured SMBG into a formal approach to personalized diabetes management within all diabetes populations. We adapted this model for use in CSII-treated patients in order to enable the implementation of a workflow structure that enhances patient-physician communication and supports patients' diabetes self-management skills. We recognize that time constraints and current reimbursement policies pose significant challenges to healthcare providers integrating the Personalised Diabetes Management (PDM) process into clinical practice. We believe, however, that the time invested in modifying practice workflow and learning to apply the various steps of the PDM process will be offset by improved workflow and more effective patient consultations. This article describes how to implement PDM into clinical practice as a systematic, standardized process that can optimize CSII therapy.

  6. Thermal grill conditioning: Effect on contact heat evoked potentials

    Science.gov (United States)

    Jutzeler, Catherine R.; Warner, Freda M.; Wanek, Johann; Curt, Armin; Kramer, John L. K.

    2017-01-01

    The ‘thermal grill illusion’ (TGI) is a unique cutaneous sensation of unpleasantness, induced through the application of interlacing warm and cool stimuli. While previous studies have investigated optimal parameters and subject characteristics to evoke the illusion, our aim was to examine the modulating effect as a conditioning stimulus. A total of 28 healthy control individuals underwent three testing sessions on separate days. Briefly, 15 contact heat stimuli were delivered to the right hand dorsum, while the left palmar side of the hand was being conditioned with either neutral (32 °C), cool (20 °C), warm (40 °C), or TGI (20/40 °C). Rating of perception (numeric rating scale: 0–10) and evoked potentials (i.e., N1 and N2P2 potentials) to noxious contact heat stimuli were assessed. While cool and warm conditioning decreased cortical responses to noxious heat, TGI conditioning increased evoked potential amplitude (N1 and N2P2). In line with other modalities of unpleasant conditioning (e.g., sound, visual, and olfactory stimulation), cortical and possibly sub-cortical modulation may underlie the facilitation of contact heat evoked potentials. PMID:28079118

  7. Finding quantum effects in strong classical potentials

    Science.gov (United States)

    Hegelich, B. Manuel; Labun, Lance; Labun, Ou Z.

    2017-06-01

    The long-standing challenge to describing charged particle dynamics in strong classical electromagnetic fields is how to incorporate classical radiation, classical radiation reaction and quantized photon emission into a consistent unified framework. The current, semiclassical methods to describe the dynamics of quantum particles in strong classical fields also provide the theoretical framework for fundamental questions in gravity and hadron-hadron collisions, including Hawking radiation, cosmological particle production and thermalization of particles created in heavy-ion collisions. However, as we show, these methods break down for highly relativistic particles propagating in strong fields. They must therefore be improved and adapted for the description of laser-plasma experiments that typically involve the acceleration of electrons. Theory developed from quantum electrodynamics, together with dedicated experimental efforts, offer the best controllable context to establish a robust, experimentally validated foundation for the fundamental theory of quantum effects in strong classical potentials.

  8. Pseudomonas Exotoxin A: optimized by evolution for effective killing

    Directory of Open Access Journals (Sweden)

    Marta eMichalska

    2015-09-01

    Full Text Available Pseudomonas Exotoxin A (PE is the most toxic virulence factor of the pathogenic bacterium Pseudomonas aeruginosa. This review describes current knowledge about the intoxication pathways of PE. Moreover, PE represents a remarkable example for pathoadaptive evolution, how bacterial molecules have been structurally and functionally optimized under evolutionary pressure to effectively impair and kill their host cells.

  9. Engineering patterns of supply chain optimization to manage oscillation effect

    Directory of Open Access Journals (Sweden)

    Thokozani Patmond Mbhele

    2017-06-01

    Full Text Available The cascading order variability from downstream trumping up the upstream site of the supply chain network indicates the deleterious effect to the performance of the fast moving consumer goods industry. The fundamental likelihood to optimization in this industry requires dexterous flows of quasi-real-time information, as well as reliable product availability. In this context, this study analyzes the challenges of bullwhip effect on the perspective of ingenious optimization strategies, and further contemplates to establish the engineering patterns of interrelationships on the magnitude of pooling the resources to advance supply chain capabilities. The suppression of bullwhip effect on underlying optimization strategies is sought to elevate accelerated responsiveness, improve network demand visibility and reduce volatility in frequencies to inventory replenishment. A rigorous and disciplined quantitative approach afforded the tentatively development of pattern of interrelated supply chain dimensions. The factor analysis method was used on 448 responses and insightful findings were produced from the compelling purposive sampling technique. The findings indicate that the magnitude of better ameliorating bullwhip effect, the value of competitive economic information and strength of selected optimization strategies depend on the model of unified engineering patterns. This paper provides insights to FMCG industry on using innovative strategies and modern technology to enhance supply chain visibility through integrated systems networks.

  10. Optimal counterterrorism and the recruitment effect of large terrorist attacks

    DEFF Research Database (Denmark)

    Jensen, Thomas

    2011-01-01

    We analyze a simple dynamic model of the interaction between terrorists and authorities. Our primary aim is to study optimal counterterrorism and its consequences when large terrorist attacks lead to a temporary increase in terrorist recruitment. First, we show that an increase in counterterrorism...... makes it more likely that terrorist cells plan small rather than large attacks and therefore may increase the probability of a successful attack. Analyzing optimal counterterrorism we see that the recruitment effect makes authorities increase the level of counterterrorism after large attacks. Therefore...

  11. Dispositional and Explanatory Style Optimism as Potential Moderators of the Relationship between Hopelessness and Suicidal Ideation

    Science.gov (United States)

    Hirsch, Jameson K.; Conner, Kenneth R.

    2006-01-01

    To test the hypothesis that higher levels of optimism reduce the association between hopelessness and suicidal ideation, 284 college students completed self-report measures of optimism and Beck scales for hopelessness, suicidal ideation, and depression. A statistically significant interaction between hopelessness and one measure of optimism was…

  12. Constructs of highly effective heat transport paths by bionic optimization

    Institute of Scientific and Technical Information of China (English)

    CHENG; Xinguang; (程新广); LI; Zhixin; (李志信); GUO; Zengyuan; (过增元)

    2003-01-01

    The optimization approach based on the biological evolution principle is used to construct the heat transport paths for volume-to-point problem. The transport paths are constructed by inserting high conductivity materials in the heat conduction domain where uniform or nonuniform heat sources exist. In the bionic optimization process, the optimal constructs of the high conductivity material are obtained by numerically simulating the evolution and degeneration process according to the uniformity principle of the temperature gradient. Finally, preserving the features of the optimal constructs, the constructs are regularized for the convenience of engineering manufacture. The results show that the construct obtained by bionic optimization is approximate to that obtained by the tree-network constructal theory when the heat conduction is enhanced for the domain with a uniform heat source and high conductivity ratio of the inserting material to the substrate, the high conductivity materials are mainly concentrated on the heat outlet for the case with a uniform heat source and low thermal conductivity ratio, and for the case with nonuniform heat sources, the high conductivity material is concentrated in the heat source regions and construacts several highly effective heat transport paths to connect the regions to the outlet.

  13. Effective field theory approaches for tensor potentials

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, Maximilian

    2016-11-14

    Effective field theories are a widely used tool to study physical systems at low energies. We apply them to systematically analyze two and three particles interacting via tensor potentials. Two examples are addressed: pion interactions for anti D{sup 0}D{sup *0} scattering to dynamically generate the X(3872) and dipole interactions for two and three bosons at low energies. For the former, the one-pion exchange and for the latter, the long-range dipole force induce a tensor-like structure of the potential. We apply perturbative as well as non-perturbative methods to determine low-energy observables. The X(3872) is of major interest in modern high-energy physics. Its exotic characteristics require approaches outside the range of the quark model for baryons and mesons. Effective field theories represent such methods and provide access to its peculiar nature. We interpret the X(3872) as a hadronic molecule consisting of neutral D and D{sup *} mesons. It is possible to apply an effective field theory with perturbative pions. Within this framework, we address chiral as well as finite volume extrapolations for low-energy observables, such as the binding energy and the scattering length. We show that the two-point correlation function for the D{sup *0} meson has to be resummed to cure infrared divergences. Moreover, next-to-leading order coupling constants, which were introduced by power counting arguments, appear to be essential to renormalize the scattering amplitude. The binding energy as well as the scattering length display a moderate dependence on the light quark masses. The X(3872) is most likely deeper bound for large light quark masses. In a finite volume on the other hand, the binding energy significantly increases. The dependence on the light quark masses and the volume size can be simultaneously obtained. For bosonic dipoles we apply a non-perturbative, numerical approach. We solve the Lippmann-Schwinger equation for the two-dipole system and the Faddeev

  14. Effects of metformin on weight loss: potential mechanisms.

    Science.gov (United States)

    Malin, Steven K; Kashyap, Sangeeta R

    2014-10-01

    Despite the known glucose-lowering effects of metformin, more recent clinical interest lies in its potential as a weight loss drug. Herein, we discuss the potential mechanisms by which metformin decreases appetite and opposes unfavorable fat storage in peripheral tissues. Many individuals struggle to maintain clinically relevant weight loss from lifestyle and bariatric surgery interventions. Long-term follow-up from the Diabetes Prevention Program demonstrates that metformin produces durable weight loss, and decreased food intake by metformin is the primary weight loss mechanism. Although the effect of metformin on appetite is likely to be multifactorial, changes in hypothalamic physiology, including leptin and insulin sensitivity, have been documented. In addition, novel work in obesity highlights the gastrointestinal physiology and circadian rhythm changes by metformin as not only affecting food intake, but also the regulation of fat oxidation and storage in liver, skeletal muscle, and adipose tissue. Metformin induces modest weight loss in overweight and obese individuals at risk for diabetes. A more detailed understanding of how metformin induces weight loss will likely lead to optimal co-prescription of lifestyle modification with pharmacology for the treatment of obesity independent of diabetes.

  15. Potential of global cropland phytolith carbon sink from optimization of cropping system and fertilization.

    Science.gov (United States)

    Song, Zhaoliang; Parr, Jeffrey F; Guo, Fengshan

    2013-01-01

    The occlusion of carbon (C) by phytoliths, the recalcitrant silicified structures deposited within plant tissues, is an important persistent C sink mechanism for croplands and other grass-dominated ecosystems. By constructing a silica content-phytolith content transfer function and calculating the magnitude of phytolith C sink in global croplands with relevant crop production data, this study investigated the present and potential of phytolith C sinks in global croplands and its contribution to the cropland C balance to understand the cropland C cycle and enhance long-term C sequestration in croplands. Our results indicate that the phytolith sink annually sequesters 26.35 ± 10.22 Tg of carbon dioxide (CO2) and may contribute 40 ± 18% of the global net cropland soil C sink for 1961-2100. Rice (25%), wheat (19%) and maize (23%) are the dominant contributing crop species to this phytolith C sink. Continentally, the main contributors are Asia (49%), North America (17%) and Europe (16%). The sink has tripled since 1961, mainly due to fertilizer application and irrigation. Cropland phytolith C sinks may be further enhanced by adopting cropland management practices such as optimization of cropping system and fertilization.

  16. Potential of global cropland phytolith carbon sink from optimization of cropping system and fertilization.

    Directory of Open Access Journals (Sweden)

    Zhaoliang Song

    Full Text Available The occlusion of carbon (C by phytoliths, the recalcitrant silicified structures deposited within plant tissues, is an important persistent C sink mechanism for croplands and other grass-dominated ecosystems. By constructing a silica content-phytolith content transfer function and calculating the magnitude of phytolith C sink in global croplands with relevant crop production data, this study investigated the present and potential of phytolith C sinks in global croplands and its contribution to the cropland C balance to understand the cropland C cycle and enhance long-term C sequestration in croplands. Our results indicate that the phytolith sink annually sequesters 26.35 ± 10.22 Tg of carbon dioxide (CO2 and may contribute 40 ± 18% of the global net cropland soil C sink for 1961-2100. Rice (25%, wheat (19% and maize (23% are the dominant contributing crop species to this phytolith C sink. Continentally, the main contributors are Asia (49%, North America (17% and Europe (16%. The sink has tripled since 1961, mainly due to fertilizer application and irrigation. Cropland phytolith C sinks may be further enhanced by adopting cropland management practices such as optimization of cropping system and fertilization.

  17. Design and optimization of aspartate N-acetyltransferase inhibitors for the potential treatment of Canavan disease.

    Science.gov (United States)

    Thangavelu, Bharani; Mutthamsetty, Vinay; Wang, Qinzhe; Viola, Ronald E

    2017-02-01

    Canavan disease is a fatal neurological disorder caused by defects in the metabolism of N-acetyl-l-aspartate (NAA). Recent work has shown that the devastating symptoms of this disorder are correlated with the elevated levels of NAA observed in these patients, caused as a consequence of the inability of mutated forms of aspartoacylase to adequately catalyze its breakdown. The membrane-associated enzyme responsible for the synthesis of NAA, aspartate N-acetyltransferase (ANAT), has recently been purified and examined (Wang et al., Prot Expr Purif. 2016;119:11). With the availability, for the first time, of a stable and soluble form of ANAT we can now report the identification of initial inhibitors against this biosynthetic enzyme, obtained from the screening of several focused compound libraries. Two core structures of these moderate binding compounds have subsequently been optimized, with the most potent inhibitors in these series possessing sub-micromolar inhibition constants (Ki values) against ANAT. Slowing the production of NAA via the inhibition of ANAT will lower the elevated levels of this metabolite and can potentially serve as a treatment option to moderate the symptoms of Canavan disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. The Potential for Zinc Stable Isotope Techniques and Modelling to Determine Optimal Zinc Supplementation

    Directory of Open Access Journals (Sweden)

    Cuong D. Tran

    2015-05-01

    Full Text Available It is well recognised that zinc deficiency is a major global public health issue, particularly in young children in low-income countries with diarrhoea and environmental enteropathy. Zinc supplementation is regarded as a powerful tool to correct zinc deficiency as well as to treat a variety of physiologic and pathologic conditions. However, the dose and frequency of its use as well as the choice of zinc salt are not clearly defined regardless of whether it is used to treat a disease or correct a nutritional deficiency. We discuss the application of zinc stable isotope tracer techniques to assess zinc physiology, metabolism and homeostasis and how these can address knowledge gaps in zinc supplementation pharmacokinetics. This may help to resolve optimal dose, frequency, length of administration, timing of delivery to food intake and choice of zinc compound. It appears that long-term preventive supplementation can be administered much less frequently than daily but more research needs to be undertaken to better understand how best to intervene with zinc in children at risk of zinc deficiency. Stable isotope techniques, linked with saturation response and compartmental modelling, also have the potential to assist in the continued search for simple markers of zinc status in health, malnutrition and disease.

  19. Multifactorial Experimental Design to Optimize the Anti-Inflammatory and Proangiogenic Potential of Mesenchymal Stem Cell Spheroids.

    Science.gov (United States)

    Murphy, Kaitlin C; Whitehead, Jacklyn; Falahee, Patrick C; Zhou, Dejie; Simon, Scott I; Leach, J Kent

    2017-06-01

    Mesenchymal stem cell therapies promote wound healing by manipulating the local environment to enhance the function of host cells. Aggregation of mesenchymal stem cells (MSCs) into three-dimensional spheroids increases cell survival and augments their anti-inflammatory and proangiogenic potential, yet there is no consensus on the preferred conditions for maximizing spheroid function in this application. The objective of this study was to optimize conditions for forming MSC spheroids that simultaneously enhance their anti-inflammatory and proangiogenic nature. We applied a design of experiments (DOE) approach to determine the interaction between three input variables (number of cells per spheroid, oxygen tension, and inflammatory stimulus) on MSC spheroids by quantifying secretion of prostaglandin E2 (PGE2 ) and vascular endothelial growth factor (VEGF), two potent molecules in the MSC secretome. DOE results revealed that MSC spheroids formed with 40,000 cells per spheroid in 1% oxygen with an inflammatory stimulus (Spheroid 1) would exhibit enhanced PGE2 and VEGF production versus those formed with 10,000 cells per spheroid in 21% oxygen with no inflammatory stimulus (Spheroid 2). Compared to Spheroid 2, Spheroid 1 produced fivefold more PGE2 and fourfold more VEGF, providing the opportunity to simultaneously upregulate the secretion of these factors from the same spheroid. The spheroids induced macrophage polarization, sprout formation with endothelial cells, and keratinocyte migration in a human skin equivalent model-demonstrating efficacy on three key cell types that are dysfunctional in chronic non-healing wounds. We conclude that DOE-based analysis effectively identifies optimal culture conditions to enhance the anti-inflammatory and proangiogenic potential of MSC spheroids. Stem Cells 2017;35:1493-1504. © 2017 AlphaMed Press.

  20. Circular neighbor-balanced designs universally optimal for total effects

    Institute of Scientific and Technical Information of China (English)

    Ming-yao AI; Gen-nian GE; Ling-yau CHAN

    2007-01-01

    In many experiments, the performance of a subject may be affected by some previous treatments applied to it apart from the current treatment. This motivates the studies of the residual effects of the treatments in a block design. This paper shows that a circular block design neighborbalanced at distances up to γ≤ k- 1, where k is the block size, is universally optimal for total effects under the linear models containing the neighbor effects at distances up to γ among the class of all circular binary block designs. Some combinatorial approaches to constructing these circular block designs neighbor-balanced at distances up to k - 1 are provided.

  1. Circular neighbor-balanced designs universally optimal for total effects

    Institute of Scientific and Technical Information of China (English)

    Ling-yau; CHAN

    2007-01-01

    In many experiments, the performance of a subject may be affected by some previous treatments applied to it apart from the current treatment. This motivates the studies of the residual effects of the treatments in a block design. This paper shows that a circular block design neighbor-balanced at distances up toγ≤k - 1, where k is the block size, is universally optimal for total effects under the linear models containing the neighbor effects at distances up toγamong the class of all circular binary block designs. Some combinatorial approaches to constructing these circular block designs neighbor-balanced at distances up to k - 1 are provided.

  2. Gas Turbine Heavy Hybrid Powertrain Variants. Opportunities and Potential for Systems Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Smith, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Chambon, Paul H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-07-01

    Widespread use of alternative hybrid powertrains is currently inevitable, and many opportunities for substantial progress remain. Hybrid electric vehicles (HEVs) have attracted considerable attention due to their potential to reduce petroleum consumption and greenhouse gas emissions in the transportation sector. This capability is mainly attributed to (a) the potential for downsizing the engine, (b) the potential for recovering energy during braking and thus recharging the energy storage unit, and (c) the ability to minimize the operation of the engine outside of its most efficient brake specific fuel consumption (BSFC) regime. Hybridization of the Class 8, heavy-duty (HD) powertrain is inherently challenging due to the expected long-haul driving requirements and limited opportunities for regenerative braking. The objective of this project is to develop control strategies aiming at optimizing the operation of a Class 8 HEV that features a micro-turbine as the heat engine. The micro-turbine application shows promise in fuel efficiency, even when compared to current diesel engines, and can meet regulated exhaust emissions levels with no exhaust after-treatment system. Both parallel and series HEV variants will be examined to understand the merits of each approach of the micro-turbine to MD advanced powertrain applications. These powertrain configurations enable new paradigms in operational efficiency, particularly in the Class 8 truck fleet. The successful development of these HEV variants will require a thorough technical understanding of the complex interactions between various energy sources and energy consumption components, for various operating modes. PACCAR will be integrating the first generation of their series HEV powertrain with a Brayton Energy micro-turbine into a Class 8 HD truck tractor that has both regional haul and local pick-up and delivery (P&D) components to its drive cycle. The vehicle will be deployed into fleet operation for a demonstration

  3. Optimal counterterrorism and the recruitment effect of large terrorist attacks

    DEFF Research Database (Denmark)

    Jensen, Thomas

    2011-01-01

    We analyze a simple dynamic model of the interaction between terrorists and authorities. Our primary aim is to study optimal counterterrorism and its consequences when large terrorist attacks lead to a temporary increase in terrorist recruitment. First, we show that an increase in counterterrorism...... makes it more likely that terrorist cells plan small rather than large attacks and therefore may increase the probability of a successful attack. Analyzing optimal counterterrorism we see that the recruitment effect makes authorities increase the level of counterterrorism after large attacks. Therefore......, in periods following large attacks a new attack is more likely to be small compared to other periods. Finally, we analyze the long-run consequences of the recruitment effect. We show that it leads to more counterterrorism, more small attacks, and a higher sum of terrorism damage and counterterrorism costs...

  4. EFFECT OF OPTIMISM ON LIFE SATISFACTION AND ACADEMIC ACHIEVEMENT

    Directory of Open Access Journals (Sweden)

    BURCU KÜMBÜL GÜLER

    2013-06-01

    Full Text Available The present study, in the field of psychology’s current trend positive psychology, explores the effect of optimism in university students on their life satisfaction and academic achievement. To a sample of 443 Turkish university students, a questionnaire was delivered including the scales of optimism, life satisfaction, academic achievement, monthly household income, montly personal expenditure level, satisfaction with the department, unemployment concern, career expectation for the future, place of living, religious belief and some other demographical information. As a result, optimism and life satisfaction were found to be significantly positively correlated, however there was no correlation between optimism and academic achievement. According to OLS Regression analysis; females, those who are more satisfied with their lives, who have not girl/boy friend, whose parents live together, whose religious belief is higher, whose departments are higher in the preference rank and whose monthly expenditure level is lower have higher GPAs than their counterparts. In the other OLS regression analysis where the dependent variable is life satisfactio; females, optimists, whose religious belief is higher, who have lived mostly in urban, who have not unemployment concern, who have good career expectations and whose monthly expenditure is higher are more satisfied with their lives than their counterparts.

  5. Towards an optimization of stimulus parameters for brain-computer interfaces based on steady state visual evoked potentials.

    Directory of Open Access Journals (Sweden)

    Anna Duszyk

    Full Text Available Efforts to construct an effective brain-computer interface (BCI system based on Steady State Visual Evoked Potentials (SSVEP commonly focus on sophisticated mathematical methods for data analysis. The role of different stimulus features in evoking strong SSVEP is less often considered and the knowledge on the optimal stimulus properties is still fragmentary. The goal of this study was to provide insight into the influence of stimulus characteristics on the magnitude of SSVEP response. Five stimuli parameters were tested: size, distance, colour, shape, and presence of a fixation point in the middle of each flickering field. The stimuli were presented on four squares on LCD screen, with each square highlighted by LEDs flickering with different frequencies. Brighter colours and larger dimensions of flickering fields resulted in a significantly stronger SSVEP response. The distance between stimulation fields and the presence or absence of the fixation point had no significant effect on the response. Contrary to a popular belief, these results suggest that absence of the fixation point does not reduce the magnitude of SSVEP response. However, some parameters of the stimuli such as colour and the size of the flickering field play an important role in evoking SSVEP response, which indicates that stimuli rendering is an important factor in building effective SSVEP based BCI systems.

  6. Optimizing event-related potential based brain-computer interfaces: a systematic evaluation of dynamic stopping methods

    Science.gov (United States)

    Schreuder, Martijn; Höhne, Johannes; Blankertz, Benjamin; Haufe, Stefan; Dickhaus, Thorsten; Tangermann, Michael

    2013-06-01

    Objective. In brain-computer interface (BCI) research, systems based on event-related potentials (ERP) are considered particularly successful and robust. This stems in part from the repeated stimulation which counteracts the low signal-to-noise ratio in electroencephalograms. Repeated stimulation leads to an optimization problem, as more repetitions also cost more time. The optimal number of repetitions thus represents a data-dependent trade-off between the stimulation time and the obtained accuracy. Several methods for dealing with this have been proposed as ‘early stopping’, ‘dynamic stopping’ or ‘adaptive stimulation’. Despite their high potential for BCI systems at the patient's bedside, those methods are typically ignored in current BCI literature. The goal of the current study is to assess the benefit of these methods. Approach. This study assesses for the first time the existing methods on a common benchmark of both artificially generated data and real BCI data of 83 BCI sessions, allowing for a direct comparison between these methods in the context of text entry. Main results. The results clearly show the beneficial effect on the online performance of a BCI system, if the trade-off between the number of stimulus repetitions and accuracy is optimized. All assessed methods work very well for data of good subjects, and worse for data of low-performing subjects. Most methods, however, are robust in the sense that they do not reduce the performance below the baseline of a simple no stopping strategy. Significance. Since all methods can be realized as a module between the BCI and an application, minimal changes are needed to include these methods into existing BCI software architectures. Furthermore, the hyperparameters of most methods depend to a large extend on only a single variable—the discriminability of the training data. For the convenience of BCI practitioners, the present study proposes linear regression coefficients for directly estimating

  7. CNT welding through Ar bombardment using AIREBO potential and optimization of an extensionded AIREO potential for F atom to simulate hydrofluorocarbons

    Science.gov (United States)

    Kucukkal, Mustafa Umut

    Molecular Dynamics (MD) is an effective method to study diverse systems to gain atomistic level details from the trajectories of particles in the system. MD require a potential which describes the interaction of the particles within the system, which is then used to solve Newton's equation of motion to obtain the trajectories of the particles. For an accurate simulation of a system, an appropriate potential should be used for the MD simulations. The Adaptive Interactive Reactive Empirical Bond Order (AIREBO) potential is a promising potential for MD simulations of systems involving bond breakage or formation [1, 2]. The AIREBO potential is a Tersoff-style bond order potential which adds LJ and torsional interactions to REBO potential developed by Brenner et al [3, 4]. Currently, the AIREBO potential is well parameterized to study carbonaceous and hydrocarbon systems. In the first part of this study, the AIREBO potential is used in MD simulations to study the welding of single wall carbon nanotubes (SWCNTs) through Ar bombardment. SWCNTs have unique electronic properties which make them an appropriate candidate to use in nanoscale transistor and nanocomputer studies. An optimum conductivity through SWCNTs is required for these applications in electronic devices and it is achieved by the bonding arrangements of the carbon atoms in the junction area. This spatial bonding between SWCNTs can be obtained by various experimental methods such as electron beam radiation, fast atom bombardment and chemical vapor deposition. This study focuses on simulating Ar bombardment over cross junction of two SWCNTs placed on an imaginary Lennard-Jones surface perpendicular to each other. The cross junction area of SWCNTs was bombarded with Ar atoms of various kinetic energies in microcanical ensemble which is followed by annealing at various temperatures. The main goal of this study is to find optimum conditions to obtain the highest number of connections between the SWCNTs and the

  8. CODON OPTIMIZATION OF THE POTENTIAL ANTIGENS ENCODING GENES FROM MYCOBACTERIUM TUBERCULOSIS

    Directory of Open Access Journals (Sweden)

    Indra Mani

    2010-10-01

    Full Text Available Current approach for controlling of tuberculosis is going on by recommended doses of vaccines. Codon optimization and simulation techniques are used to improve the protein expression in living organism by increasing their translational efficiency of gene of interest. We have designed; optimized the codon and simulated in nineteen indigenous genes of Mycobacterium tuberculosis H37Rv in the Escherichia coli. We minimized the G+C content in optimized genes from 64.75% to 59.67% of the studied genes as the richness of G+C content is reflected in a strong bias. CAI and AT of optimized DNA were enhanced by 1.9 (47.8% and 1.1 (12.5% fold more with respect to its native type. Our finding indicates the optimized genes can be useful for over expression in host and the study provides a new insight for the emerging research in synthetic biology.

  9. Analyzing the impact of shading on photovoltaic arrays to optimize system effectiveness

    Energy Technology Data Exchange (ETDEWEB)

    Ho Jo, Jin; Kennell, Dave; Richey, Steve [Illinois State University (United States)], e-mail: jjo@ilstu.edu, email: drkennell@ilstu.edu, email: spriche@ilstu.edu

    2011-07-01

    The empirical and simulation modeling analyses of the impact of partial shading on a photovoltaic array by rooftop objects, e.g. HVAC equipment, is reported in this paper to determine optimized system capacity, configuration and orientation. In this study, a design approach that can be applied to determine both the appropriate area for photovoltaic system installation and the system capacity that optimizes the overall performance of the photovoltaic system is proposed. On-site data collection from the installed photovoltaic system was compared with a renewable energy computer simulation, the System Advisor Model, developed by the National Renewable Energy Laboratory, which has been used to examine the potential effects of different application options and suggest optimized array designs to maximize energy production and boost return-on-investment throughout the year. It was found that partial shading may not have a significant impact on the annual electrical output and can be tolerable within a certain range.

  10. Combinatorial optimization of La, Ce-co-doped pyrosilicate phosphors as potential scintillator materials.

    Science.gov (United States)

    Wei, Qinhua; Wan, Jieqiong; Liu, Guanghui; Zhou, Zhenzhen; Yang, Hua; Wang, Jiacheng; Liu, Qian

    2015-04-13

    A combinatorial method was employed to rapidly screen the effects of La, Ce-co-doping on the luminescent properties of Gd2Si2O7 pyrosilicate using an 8 × 8 library. The candidate formulations (Gd1-x-yLax)2Si2O7:Ce2y were evaluated by luminescence pictures under ultraviolet excitation. The optimal composition was found to be (Gd0.89La0.1)2Si2O7:Ce0.02 after scaled-up preparation and detailed characterization of powder samples, which shows an excellent light output under both ultraviolet and X-ray excitation (about 5.43 times of commercial YAG:Ce powders). The XRD results indicate that the phase structure sequence is tetragonal-orthorhombic-triclinic for different calcination temperatures and doping ions. The (Gd0.89La0.1)2Si2O7:Ce0.02 powder sample also demonstrated excellent temperature stability of luminescence up to 200 °C and a short decay time of several tens of nanoseconds, suggesting that this may represent a new kind of scintillation material, such as single crystals, ceramics, glass, or phosphors.

  11. Topology optimization of embedded piezoelectric actuators considering control spillover effects

    Science.gov (United States)

    Gonçalves, Juliano F.; De Leon, Daniel M.; Perondi, Eduardo A.

    2017-02-01

    This article addresses the problem of active structural vibration control by means of embedded piezoelectric actuators. The topology optimization method using the solid isotropic material with penalization (SIMP) approach is employed in this work to find the optimum design of actuators taken into account the control spillover effects. A coupled finite element model of the structure is derived assuming a two-phase material and this structural model is written into the state-space representation. The proposed optimization formulation aims to determine the distribution of piezoelectric material which maximizes the controllability for a given vibration mode. The undesirable effects of the feedback control on the residual modes are limited by including a spillover constraint term containing the residual controllability Gramian eigenvalues. The optimization of the shape and placement of the conventionally embedded piezoelectric actuators are performed using a Sequential Linear Programming (SLP) algorithm. Numerical examples are presented considering the control of the bending vibration modes for a cantilever and a fixed beam. A Linear-Quadratic Regulator (LQR) is synthesized for each case of controlled structure in order to compare the influence of the additional constraint.

  12. Effects of electron emission on sheath potential

    Science.gov (United States)

    Dow, Ansel; Khrabrov, Alexander; Kaganovich, Igor; Schamis, Hanna

    2015-11-01

    We investigate the potential profile of a sheath under the influence of surface electron emission. The plasma and sheath profiles are simulated using the Large Scale Plasma (LSP) particle-in-cell code. Using one dimensional models we corroborate the analytical relationship between sheath potential and plasma electron and emitted electron temperatures derived earlier. This work was made possible by funding from the Department of Energy for the Summer Undergraduate Laboratory Internship (SULI) program. This work is supported by the US DOE Contract No. DE-AC02-09CH11466.

  13. Optimizing Production of Two Potential Probiotic Lactobacilli Strains Isolated from Piglet Feces as Feed Additives for Weaned Piglets

    Directory of Open Access Journals (Sweden)

    Ming-Lun Chiang

    2015-08-01

    Full Text Available Two probiotic strains, Lactobacillus johnsonii x-1d-2 and Lactobacillus mucosae x-4w-1, originally isolated from piglet feces, have been demonstrated to possess antimicrobial activities, antibiotic resistances and interleukin-6 induction ability in RAW 267.4 macrophages in our previous study. These characteristics make L. johnsonii x-1d-2 and L. mucosae x-4w-1 good candidates for application in feed probiotics. In this study, soybeal meal, molasses and sodium acetate were selected to optimize the growth medium for cultivation of L. johnsonii x-1d-2 and L. mucosae x-4w-1. These two strains were then freeze-dried and mixed into the basal diet to feed the weaned piglets. The effects of L. johnsonii x-1d-2 and L. mucosae x-4w-1 on the growth performance and fecal microflora of weaned piglets were investigated. The results showed that the bacterial numbers of L. johnsonii x-1d-2 and L. mucosae x-4w-1 reached a maximum of 8.90 and 9.30 log CFU/mL, respectively, when growing in optimal medium consisting of 5.5% (wt/vol soybean meal, 1.0% (wt/vol molasses and 1.0% (wt/vol sodium acetate. The medium cost was 96% lower than the commercial de Man, Rogosa and Sharpe medium. In a further feeding study, the weaned piglets fed basal diet supplemented with freeze-dried probiotic cultures exhibited higher (p<0.05 body weight gain, feed intake, and gain/feed ratio than weaned piglets fed basal diet. Probiotic feeding also increased the numbers of lactobacilli and decreased the numbers of E. coli in the feces of weaned piglets. This study demonstrates that L. johnsonii x-1d-2 and L. mucosae x-4w-1 have high potential to be used as feed additives in the pig industry.

  14. Optimizing Production of Two Potential Probiotic Lactobacilli Strains Isolated from Piglet Feces as Feed Additives for Weaned Piglets.

    Science.gov (United States)

    Chiang, Ming-Lun; Chen, Hsi-Chia; Chen, Kun-Nan; Lin, Yu-Chun; Lin, Ya-Ting; Chen, Ming-Ju

    2015-08-01

    Two probiotic strains, Lactobacillus johnsonii x-1d-2 and Lactobacillus mucosae x-4w-1, originally isolated from piglet feces, have been demonstrated to possess antimicrobial activities, antibiotic resistances and interleukin-6 induction ability in RAW 267.4 macrophages in our previous study. These characteristics make L. johnsonii x-1d-2 and L. mucosae x-4w-1 good candidates for application in feed probiotics. In this study, soybeal meal, molasses and sodium acetate were selected to optimize the growth medium for cultivation of L. johnsonii x-1d-2 and L. mucosae x-4w-1. These two strains were then freeze-dried and mixed into the basal diet to feed the weaned piglets. The effects of L. johnsonii x-1d-2 and L. mucosae x-4w-1 on the growth performance and fecal microflora of weaned piglets were investigated. The results showed that the bacterial numbers of L. johnsonii x-1d-2 and L. mucosae x-4w-1 reached a maximum of 8.90 and 9.30 log CFU/mL, respectively, when growing in optimal medium consisting of 5.5% (wt/vol) soybean meal, 1.0% (wt/vol) molasses and 1.0% (wt/vol) sodium acetate. The medium cost was 96% lower than the commercial de Man, Rogosa and Sharpe medium. In a further feeding study, the weaned piglets fed basal diet supplemented with freeze-dried probiotic cultures exhibited higher (ppiglets fed basal diet. Probiotic feeding also increased the numbers of lactobacilli and decreased the numbers of E. coli in the feces of weaned piglets. This study demonstrates that L. johnsonii x-1d-2 and L. mucosae x-4w-1 have high potential to be used as feed additives in the pig industry.

  15. Effects of La3+ on H+ Transmembrane Gradient and Membrane Potential in Rice Seedling Roots

    Institute of Scientific and Technical Information of China (English)

    郑海雷; 张春光; 赵中秋; 马建华; 李利

    2002-01-01

    The effects of LaCl3 on membrane potential and transmembrane proton gradient for rice (Oryza sativa) seedling roots were studied. Highly purified plasma membrane was isolated by aqueous two-phase partitioning method. Both the gradient of transmembrane proton and membrane potential were stimulated by certain low concentration of LaCl3 and depressed by high concentration of LaCl3. The optimal concentration of La3+ is around 40~60 μmolL-1 for transmembrane proton gradient and membrane potential. It shows that La3+ can influence the generations and maintenances of membrane potential and transmembrane proton gradient in rice seedling roots.

  16. Synthesis and optimization of chitosan nanoparticles: Potential applications in nanomedicine and biomedical engineering

    OpenAIRE

    Ghadi, Arezou; Mahjoub, Soleiman; Tabandeh, Fatemeh; Talebnia, Farid

    2014-01-01

    Background: Chitosan nanoparticles have become of great interest for nanomedicine, biomedical engineering and development of new therapeutic drug release systems with improved bioavailability, increased specificity and sensitivity, and reduced pharmacological toxicity. The aim of the present study was to synthesis and optimize of the chitosan nanoparticles for industrial and biomedical applications. Methods: Fe3O4 was synthesized and optimized as magnetic core nanoparticles and then chitosan ...

  17. Post-Gaussian Effective Potential of Double sine-Gordon Field

    Institute of Scientific and Technical Information of China (English)

    CAI Wei-Ran; LOU Sen-Yue

    2005-01-01

    In the framework of the functional integral formalism, we calculate the effective potential of the double sine-Gordon (DsG) model up to the second order with an optimized expansion and the Coleman's normal-ordering prescription. Within the range of convergence, we make a comparison among the classicaland the effective potential of the first and second order. The numerical analysis shows that the DsG post-Gaussian EP possesses some fine global properties and makes a substantial and a concordant quantum correction to the features of the classical potential.

  18. DESTINATION MARKETING STRATEGY IN BALI THROUGH OPTIMIZING THE POTENTIAL OF LOCAL PRODUCTS

    Directory of Open Access Journals (Sweden)

    I Gusti Ayu Oka Suryawardani

    2014-03-01

    Full Text Available This study was designed to study destination marketing strategy in Bali through optimizing the potential of local products. Seventy nine of hotel managers were interviewed based on cluster sampling method to gain their point of view. The results show that destination must build their images around unique attributes that provide them sustainable competitive advantage including its attraction which should be designed to meet the needs of the target market and should be served by local products. The results also show that hotel managers thought that foreign tourists always preferred imported products, meanwhile previous statistical results indicate that foreign tourists significantly look for local products. There is a need to encourage hotel managers to change their perception and attitude about local and imported products. In fact, hoteliers expressed willingness to use local products as long as these meet the quality standard. As tourism involves four types of activities, namely something to see, something to do, something to buy, something to learn, destination product development could be focused in the above activities through offering foreign tourist, such as to stay in hotels, homestays or villas owned by Balinese; to eat in restaurants owned by Balinese by choosing the authentic local foods that are using local meat, seafood and vegetables, exotic local fruits and beverages; and to buy products that are produced by the Balinese. By promoting vacation on the real Balinese atmosphere such as stay in accommodations owned by the Balinese supported by the authenticity of local Balinese foods, fruits and beverages, these will strengthen the local economy, so the benefit of tourism development can be more beneficial to the local Balinese. The results suggests that destination management related to improvement of service and hospitality are really important through improvement of human resource by giving training to their employees, educate

  19. Ascent trajectory optimization for stratospheric airship with thermal effects

    Science.gov (United States)

    Guo, Xiao; Zhu, Ming

    2013-09-01

    Ascent trajectory optimization with thermal effects is addressed for a stratospheric airship. Basic thermal characteristics of the stratospheric airship are introduced. Besides, the airship’s equations of motion are constructed by including the factors about aerodynamic force, added mass and wind profiles which are developed based on horizontal-wind model. For both minimum-time and minimum-energy flights during ascent, the trajectory optimization problem is described with the path and terminal constraints in different scenarios and then, is converted into a parameter optimization problem by a direct collocation method. Sparse Nonlinear OPTimizer(SNOPT) is employed as a nonlinear programming solver and two scenarios are adopted. The solutions obtained illustrate that the trajectories are greatly affected by the thermal behaviors which prolong the daytime minimum-time flights of about 20.8% compared with that of nighttime in scenario 1 and of about 10.5% in scenario 2. And there is the same trend for minimum-energy flights. For the energy consumption of minimum-time flights, 6% decrease is abstained in scenario 1 and 5% decrease in scenario 2. However, a few energy consumption reduction is achieved for minimum-energy flights. Solar radiation is the principal component and the natural wind also affects the thermal behaviors of stratospheric airship during ascent. The relationship between take-off time and performance of airship during ascent is discussed. it is found that the take-off time at dusk is best choice for stratospheric airship. And in addition, for saving energy, airship prefers to fly downwind.

  20. Effect of Parabolic Potential on Bipolaron

    Institute of Scientific and Technical Information of China (English)

    RUANYong-Hong; CHENQing-Hu; JIAOZheng-Kuan

    2004-01-01

    We apply a Feynman path-integral variational approach combining with the average for the relative motion to study the stability of bipolaron in a quantum dot. The binding energy is calculated in different parameters. We find that an optimum quantum potential favors the formation of bipolaron. Compared with other methods in literature, the present approach is better than Laudau Pekar one in all coupling regime and full path-integral one in the strong coupling regime.

  1. Effect of Parabolic Potential on Bipolaron

    Institute of Scientific and Technical Information of China (English)

    RUAN Yong-Hong; CHEN Qing-Hu; JIAO Zheng-Kuan

    2004-01-01

    We apply a Feynman path-integral variational approach combining with the average for the relative motion to study the stability of bipolaron in a quantum dot. The binding energy is calculated in different parameters. We find that an optimum quantum potential favors the formation of bipolaron. Compared with other methods in literature, the present pproach is better than Laudau-Pekar one in all coupling regime and full path-integral one in the strong coupling regime.

  2. Graphene base heterojunction transistor: An explorative study on device potential, optimization, and base parasitics

    Science.gov (United States)

    Di Lecce, Valerio; Grassi, Roberto; Gnudi, Antonio; Gnani, Elena; Reggiani, Susanna; Baccarani, Giorgio

    2015-12-01

    The Graphene-Base Heterojunction Transistor (GBHT) is a novel device concept with a high potential for analog high-frequency RF operation, in which the current is due to both thermionic emission and tunneling. In this paper we study through numerical simulations the influence of previously uninvestigated aspects of Si- and Ge-based GBHTs-namely, crystallographic orientation and doping density values-on the device performance; a comparison with an aggressively scaled HBT structure is then reported. The simulations are carried out with an in-house developed code based on a 1-D quantum transport model within the effective mass approximation and the assumptions of ballistic transport with non-parabolic corrections and ideal semiconductor-graphene interface. We show that crystallographic orientation has a negligible effect on the GBHT performance. The doping density values in the GBHT emitter and collector regions can be tailored to maximize the device performance: the Si device shows better overall performance than the Ge one, yielding a peak cut-off frequency fT higher than 4 THz together with an intrinsic voltage gain above 10, or even higher fT at the cost of a lower gain. The Si-based GBHT can potentially outperform the SiGe HBT by a 2.8 higher fT . For a Si-based GBHT with a circular active region of diameter 50-100 nm, a theoretical balanced value for fT and fmax above 2 THz can be achieved, provided the base parasitics are carefully minimized.

  3. Potential negative ecological effects of corridors.

    Science.gov (United States)

    Haddad, Nick M; Brudvig, Lars A; Damschen, Ellen I; Evans, Daniel M; Johnson, Brenda L; Levey, Douglas J; Orrock, John L; Resasco, Julian; Sullivan, Lauren L; Tewksbury, Josh J; Wagner, Stephanie A; Weldon, Aimee J

    2014-10-01

    Despite many studies showing that landscape corridors increase dispersal and species richness for disparate taxa, concerns persist that corridors can have unintended negative effects. In particular, some of the same mechanisms that underlie positive effects of corridors on species of conservation interest may also increase the spread and impact of antagonistic species (e.g., predators and pathogens), foster negative effects of edges, increase invasion by exotic species, increase the spread of unwanted disturbances such as fire, or increase population synchrony and thus reduce persistence. We conducted a literature review and meta-analysis to evaluate the prevalence of each of these negative effects. We found no evidence that corridors increase unwanted disturbance or non-native species invasion; however, these have not been well-studied concerns (1 and 6 studies, respectively). Other effects of corridors were more often studied and yielded inconsistent results; mean effect sizes were indistinguishable from zero. The effect of edges on abundances of target species was as likely to be positive as negative. Corridors were as likely to have no effect on antagonists or population synchrony as they were to increase those negative effects. We found 3 deficiencies in the literature. First, despite studies on how corridors affect predators, there are few studies of related consequences for prey population size and persistence. Second, properly designed studies of negative corridor effects are needed in natural corridors at scales larger than those achievable in experimental systems. Third, studies are needed to test more targeted hypotheses about when corridor-mediated effects on invasive species or disturbance may be negative for species of management concern. Overall, we found no overarching support for concerns that construction and maintenance of habitat corridors may result in unintended negative consequences. Negative edge effects may be mitigated by widening

  4. Optimal measurement strategies for effective suppression of drift errors

    Energy Technology Data Exchange (ETDEWEB)

    Yashchuk, Valeriy V.

    2009-04-16

    Drifting of experimental set-ups with change of temperature or other environmental conditions is the limiting factor of many, if not all, precision measurements. The measurement error due to a drift is, in some sense, in-between random noise and systematic error. In the general case, the error contribution of a drift cannot be averaged out using a number of measurements identically carried out over a reasonable time. In contrast to systematic errors, drifts are usually not stable enough for a precise calibration. Here a rather general method for effective suppression of the spurious effects caused by slow drifts in a large variety of instruments and experimental set-ups is described. An analytical derivation of an identity, describing the optimal measurement strategies suitable for suppressing the contribution of a slow drift described with a certain order polynomial function, is presented. A recursion rule as well as a general mathematical proof of the identity is given. The effectiveness of the discussed method is illustrated with an application of the derived optimal scanning strategies to precise surface slope measurements with a surface profiler.

  5. The potential of papain and alcalase enzymes and process optimizations to reduce allergenic gliadins in wheat flour.

    Science.gov (United States)

    Li, Ying; Yu, Jianmei; Goktepe, Ipek; Ahmedna, Mohamed

    2016-04-01

    The objectives of this study were to select effective enzymes that catalyze the hydrolysis of allergenic proteins, gliadins, in wheat flour and to optimize the enzymatic treatment conditions. Six proteases were tested. Hydrolyzed samples were tested for residual gliadin concentrations and in vitro allergenicity. The hydrolysis conditions of wheat protein by the effective enzymes were optimized by central composite design. Results showed that alcalase from Bacillus licheniformis, and papain from latex of papaya fruit had greater ability to reduce gliadin content of wheat flour than flavourzyme, pepsin, trypsin or α-chymotrypsin. The sequential-treatment of wheat flour by alcalase-papain was more effective in reducing gliadin content than single enzyme treatment. Under the optimal conditions of sequential enzymatic treatment, gliadin was almost completely removed, resulting in the flour extract showing lowest IgE-binding. Therefore, this could be a promising biotechnology for preparing low allergenic wheat products.

  6. Engineering of Sub-Nanometer SiOx Thickness in Si Photocathodes for Optimized Open Circuit Potential.

    Science.gov (United States)

    Das, Chittaranjan; Kot, Malgorzata; Henkel, Karsten; Schmeisser, Dieter

    2016-09-01

    Silicon is one of the most promising materials to be used for tandem-cell water-splitting devices. However, the electrochemical instability of bare Si makes it difficult to be used for stable devices. Besides that, the photovoltage loss in Si, caused by several factors (e.g., metal oxide protection layer and/or SiO2 /Si or catalyst/Si interface), limits its use in these devices. In this work, we present that an optimized open circuit potential (OCP) of Si can be obtained by controlling the SiOx thickness in sub-nanometer range. It can be done by means of a simple and cost-effective way using the combination of a wet chemical etching and the low temperature atomic layer deposition (ALD) of TiO2 . We have found that a certain thickness of the native SiOx is necessary to prevent further oxidation of the Si photocathode during the ALD growth of TiO2 . Moreover, covering the Si photocathode with an ALD TiO2 layer enhances its stability.

  7. Dimension reduction: additional benefit of an optimal filter for independent component analysis to extract event-related potentials.

    Science.gov (United States)

    Cong, Fengyu; Leppänen, Paavo H T; Astikainen, Piia; Hämäläinen, Jarmo; Hietanen, Jari K; Ristaniemi, Tapani

    2011-09-30

    The present study addresses benefits of a linear optimal filter (OF) for independent component analysis (ICA) in extracting brain event-related potentials (ERPs). A filter such as the digital filter is usually considered as a denoising tool. Actually, in filtering ERP recordings by an OF, the ERP' topography should not be changed by the filter, and the output should also be able to be modeled by the linear transformation. Moreover, an OF designed for a specific ERP source or component may remove noise, as well as reduce the overlap of sources and even reject some non-targeted sources in the ERP recordings. The OF can thus accomplish both the denoising and dimension reduction (reducing the number of sources) simultaneously. We demonstrated these effects using two datasets, one containing visual and the other auditory ERPs. The results showed that the method including OF and ICA extracted much more reliable components than the sole ICA without OF did, and that OF removed some non-targeted sources and made the underdetermined model of EEG recordings approach to the determined one. Thus, we suggest designing an OF based on the properties of an ERP to filter recordings before using ICA decomposition to extract the targeted ERP component. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Cropping system effects on wind erosion potential

    Science.gov (United States)

    Wind erosion of soil is a destructive process impacting crop productivity and human health and safety. The mechanics of wind erosion and soil properties that influence erosion are well understood. Less well-studied are the effects that cropping intensity has upon those soil properties. We collected ...

  9. The potential health effects of dietary phytoestrogens

    NARCIS (Netherlands)

    Rietjens, Ivonne M.C.M.; Louisse, Jochem; Beekmann, Karsten

    2017-01-01

    Phytoestrogens are plant-derived dietary compounds with structural similarity to 17-β-oestradiol (E2), the primary female sex hormone. This structural similarity to E2 enables phytoestrogens to cause (anti)oestrogenic effects by binding to the oestrogen receptors. The aim of the present review is to

  10. The potential health effects of dietary phytoestrogens

    NARCIS (Netherlands)

    Rietjens, Ivonne M.C.M.; Louisse, Jochem; Beekmann, Karsten

    2016-01-01

    Phytoestrogens are plant-derived dietary compounds with structural similarity to 17-β-oestradiol (E2), the primary female sex hormone. This structural similarity to E2 enables phytoestrogens to cause (anti)oestrogenic effects by binding to the oestrogen receptors. The aim of the present review is

  11. Optimization of liquid culture conditions of Philippine wild edible mushrooms as potential source of bioactive lipids

    Science.gov (United States)

    With remarkable bioactivities and delightful taste, mushrooms have been a commercial nutraceutical around the world. Mushrooms are cultivated on solid materials. Here we report the successful cultivation of four Philippine edible mushrooms in liquid medium. This work highlights the optimal liquid cu...

  12. Cost Effectiveness Analysis of Optimal Malaria Control Strategies in Kenya

    Directory of Open Access Journals (Sweden)

    Gabriel Otieno

    2016-03-01

    Full Text Available Malaria remains a leading cause of mortality and morbidity among the children under five and pregnant women in sub-Saharan Africa, but it is preventable and controllable provided current recommended interventions are properly implemented. Better utilization of malaria intervention strategies will ensure the gain for the value for money and producing health improvements in the most cost effective way. The purpose of the value for money drive is to develop a better understanding (and better articulation of costs and results so that more informed, evidence-based choices could be made. Cost effectiveness analysis is carried out to inform decision makers on how to determine where to allocate resources for malaria interventions. This study carries out cost effective analysis of one or all possible combinations of the optimal malaria control strategies (Insecticide Treated Bednets—ITNs, Treatment, Indoor Residual Spray—IRS and Intermittent Preventive Treatment for Pregnant Women—IPTp for the four different transmission settings in order to assess the extent to which the intervention strategies are beneficial and cost effective. For the four different transmission settings in Kenya the optimal solution for the 15 strategies and their associated effectiveness are computed. Cost-effective analysis using Incremental Cost Effectiveness Ratio (ICER was done after ranking the strategies in order of the increasing effectiveness (total infections averted. The findings shows that for the endemic regions the combination of ITNs, IRS, and IPTp was the most cost-effective of all the combined strategies developed in this study for malaria disease control and prevention; for the epidemic prone areas is the combination of the treatment and IRS; for seasonal areas is the use of ITNs plus treatment; and for the low risk areas is the use of treatment only. Malaria transmission in Kenya can be minimized through tailor-made intervention strategies for malaria control

  13. Genetic effects and potential parents in cowpea

    Directory of Open Access Journals (Sweden)

    Francisco Tiago Cunha Dias

    2016-11-01

    Full Text Available Six cowpea genotypes and their F2 hybrid combinations were evaluated for general and specific combining ability. The Griffing’s diallel cross design, Method 2, and mixed model B were used. The genotypes and hybrids differed statistically (p <0.01 for the 10 studied traits. With regard to the general and specific combining ability, there were statistical differences at 1% probability for all traits. The presence of additive and non-additive gene effects paves the way for breeding new hybrid cultivars. However, additive gene effects were predominant in the trait expression. Genotypes CE-542, CE-954 and CE-796 were identified as the most promising of the test group for inclusion in cowpea breeding programs.

  14. Anger and health in dementia caregivers: exploring the mediation effect of optimism.

    Science.gov (United States)

    López, J; Romero-Moreno, R; Márquez-González, M; Losada, A

    2015-04-01

    Although previous studies indicate a negative association between caregivers' anger and health, the potential mechanisms linking this relationship are not yet fully understood. The aim of this study was to explore the potential mediating role of optimism in the relationship between anger and caregivers' physical health. Dementia caregivers (n = 108) were interviewed and filled out instruments assessing their anger (reaction), optimism and health (vitality). A mediational model was tested to determine whether optimism partially mediated the relationship between anger and vitality. Angry reaction was negatively associated with optimism and vitality; optimism was positively associated with vitality. Finally, the relationship between angry reaction and vitality decreased when optimism was entered simultaneously. A non-parametric bootstrap approach confirmed that optimism significantly mediated some of the relationship between angry reaction and vitality. These findings suggest that low optimism may help explain the association between caregivers' anger and reduced sense of vitality. The results provide a specific target for intervention with caregivers.

  15. Potential beneficial effects of garlic in oncohematology.

    Science.gov (United States)

    Miroddi, M; Calapai, F; Calapai, G

    2011-06-01

    The use of non-conventional medicines, especially herbal medicine, is common in patients with cancers including haematologic malignancies. Diet components may also modify the risk of cancer through the influence on multiple processes, including DNA repair, cell proliferation and apoptosis. Garlic (Allium sativum), considered either food or herbal medicine, possesses antimutagenic and antiproliferative properties that can be used in anticancer interventions. We analyzed literature data on effects of garlic and garlic compounds which can serve as basic information to design clinical approach in oncohematology. Garlic contains water soluble and oil-soluble sulfur compounds. The latter are responsible for anticancer effects exerted through multiple mechanisms such as: inhibition of metabolic carcinogenic activation, arrest of cell cycle, antioxidant and pro-apoptotic action. Evidence about the effects of main sulfur compounds diallyl sulfide (DAS), diallyl disulfide (DADS), diallyl trisulfide (DATS), ajoene and S-allylmercaptocysteine (SAMC) in oncohematology was described. Our research highlights that data on garlic in oncohematology are essentially represented by pre-clinical studies. Although these studies must be considered as preliminary, they provided insight into biological activities of garlic compounds and support a rationale for the use of substances such as DAS, DADS, DATS and ajoene as promising anticancer agents in oncohematology.

  16. Potential effect of ultrasound on carbohydrates.

    Science.gov (United States)

    Bera, Smritilekha; Mondal, Dhananjoy; Martin, Jacob T; Singh, Man

    2015-06-17

    The use of ultrasound has emerged as one of the most useful alternative energy sources for the synthesis of carbohydrate-derived biologically and pharmaceutically potential compounds. Spectacular advances have been made in the field of sonication-assisted organic reactions, which are known for producing superior yields, enhanced reactivity of the reactant, improved stereoselectivity, and shortened reaction times. Orthogonal protection-deprotection reactions and/or modification and manipulation of functional groups in carbohydrates are common synthetic steps in carbohydrate chemistry. These reaction steps can be driven by the ultrasonic energy generated by acoustic cavitation via the formation and subsequent collapse of ultrasound-induced bubbles. The ultrasound-assisted synthesis of differently functionalised monosaccharides is useful in a wide variety of applications of carbohydrate chemistry such as the glycosylation of oligosaccharides, one pot domino reactions, thioglycoside syntheses, azidoglycoside syntheses, 1,3-dipolar cycloaddition reactions, and syntheses of natural products. This review article covers ultrasound-mediated reactions on carbohydrates that have been described in the literature since 2000.

  17. Effective Kratzer and Coulomb potentials as limit cases of a multiparameter exponential-type potential

    Energy Technology Data Exchange (ETDEWEB)

    García-Ravelo, J., E-mail: g.ravelo@hotmail.com [Departamento de Física, Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Edificio 9, Unidad Profesional Adolfo López Mateos, México D.F., 07738 (Mexico); Menéndez, A.; García-Martínez, J. [Departamento de Física, Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Edificio 9, Unidad Profesional Adolfo López Mateos, México D.F., 07738 (Mexico); Schulze-Halberg, A. [Department of Mathematics and Actuarial Science and Department of Physics, Indiana University Northwest, 3400 Broadway, Gary, IN 46408 (United States)

    2014-06-13

    We show that the effective Kratzer and Coulomb potentials can be obtained by taking particular limits of a multiparameter exponential potential that was studied recently. Moreover, we demonstrate that the bound state solutions of the exponential potential reduce correctly to their well-known counterparts associated with the Kratzer and Coulomb potentials. As a byproduct, we obtain a new limit relation for the hypergeometric function. - Highlights: • Kratzer and Coulomb potentials are limit cases of an exponential-type potential. • From exact s-waves, approximate solutions for l-waves are obtained. • l-waves of the potential tend to the solutions of the Kratzer and Coulomb potentials. • A non-evident identity between hypergeometric functions is demonstrated.

  18. E-Finance, Entry Deterrence, and Optimal Loan Rate of a Potential Entrant: An Option-Based Valuation

    OpenAIRE

    Chuen-Ping Chang

    2010-01-01

    This paper examines the relationships among electronic finance (e-finance), entry deterrence, and the potential entrant's optimal loan interest rate in a two-stage model where the sunk costs are the entry barriers. The two key findings are: (i) in the loan rate determination stage, the potential entrant's loan rate is negatively related to its involvement level in e-finance with its own strategic substitutes, to the incumbent's involvement level in e-finance in realization of a more risky sta...

  19. Radiobiological effect based treatment plan optimization with the linear quadratic model

    Energy Technology Data Exchange (ETDEWEB)

    Schell, Stefan; Wilkens, Jan J.; Oelfke, Uwe [German Cancer Research Center, Heidelberg (Germany). Dept. of Medical Physics in Radiation Oncology

    2010-07-01

    As an approach towards more biology-oriented treatment planning for external beam radiation therapy, we present the incorporation of local radiation damage models into three dimensional treatment planning. This allows effect based instead of dose based plan optimization which could potentially better match the biologically relevant tradeoff between target and normal tissues. In particular, our approach facilitates an effective comparison of different fractionation schemes. It is based on the linear quadratic model to describe the biological radiation effect. Effect based optimization was integrated into our inverse treatment planning software KonRad, and we demonstrate the resulting differences between conventional and biological treatment planning. Radiation damage can be analyzed both qualitatively and quantitatively in dependence of the fractionation scheme and tissue specific parameters in a three dimensional voxel based system. As an example the potential advantages as well as the associated risks of hypofractionation for prostate cancer are analyzed and visualized with the help of effective dose volume histograms. Our results suggest a very conservative view regarding alternative fractionation schemes since uncertainties in biological parameters are still too big to make reliable clinical predictions. (orig.)

  20. Reducing multisensor monthly mean aerosol optical depth uncertainty: 2. Optimal locations for potential ground observation deployments

    Science.gov (United States)

    Li, Jing; Li, Xichen; Carlson, Barbara E.; Kahn, Ralph A.; Lacis, Andrew A.; Dubovik, Oleg; Nakajima, Teruyuki

    2017-04-01

    Surface remote sensing of aerosol properties provides "ground truth" for satellite and model validation and is an important component of aerosol observation system. Due to the different characteristics of background aerosol variability, information obtained at different locations usually has different spatial representativeness, implying that the location should be carefully chosen so that its measurement could be extended to a greater area. In this study, we present an objective observation array design technique that automatically determines the optimal locations with the highest spatial representativeness based on the Ensemble Kalman Filter (EnKF) theory. The ensemble is constructed using aerosol optical depth (AOD) products from five satellite sensors. The optimal locations are solved sequentially by minimizing the total analysis error variance, which means that observations at these locations will reduce the background error variance to the largest extent. The location determined by the algorithm is further verified to have larger spatial representativeness than some other arbitrary location. In addition to the existing active Aerosol Robotic Network (AERONET) sites, the 40 selected optimal locations are mostly concentrated on regions with both high AOD inhomogeneity and its spatial representativeness, namely, the Sahel, South Africa, East Asia, and North Pacific Islands. These places should be the focuses of establishing future AERONET sites in order to further reduce the uncertainty in the monthly mean AOD. Observations at these locations contribute to approximately 50% of the total background uncertainty reduction.

  1. Beyond the Coleman–Weinberg Effective Potential

    CERN Document Server

    CERN. Geneva

    2015-01-01

    The Two-Particle-Irreducible (2PI) formalism as introduced by Cornwall, Jackiw and Tomboulis provides a systematic analytic approach to consistently describing non-perturbative phenomena in Quantum Field Theory. In spite of its great success, one major problem of the 2PI approach is that its loopwise expansion gives rise to residual violations of symmetries and hence to massive Goldstone bosons in the spontaneously broken phase of the theory. In my talk I will present a novel symmetry-improved 2PI formalism which consistently encodes global symmetries in a loopwise expansion. Unlike other methods, I will illustrate how the symmetry-improved 2PI effective action satisfies a number of important field-theoretic properties, such as the masslessness of the Goldstone boson and the fact that the phase transition is of second order in O(N) theories, already in the Hartree-Fock approximation. After taking the sunset diagrams into account, I show how the symmetry-improved 2PI approach properly describe...

  2. Joint optimization toward effective and efficient image search.

    Science.gov (United States)

    Wei, Shikui; Xu, Dong; Li, Xuelong; Zhao, Yao

    2013-12-01

    The bag-of-words (BoW) model has been known as an effective method for large-scale image search and indexing. Recent work shows that the performance of the model can be further improved by using the embedding method. While different variants of the BoW model and embedding method have been developed, less effort has been made to discover their underlying working mechanism. In this paper, we systematically investigate the image search performance variation with respect to a few factors of the BoW model, and study how to employ the embedding method to further improve the image search performance. Subsequently, we summarize several observations based on the experiments on descriptor matching. To validate these observations in a real image search, we propose an effective and efficient image search scheme, in which the BoW model and embedding method are jointly optimized in terms of effectiveness and efficiency by following these observations. Our comprehensive experiments demonstrate that it is beneficial to employ these observations to develop an image search algorithm, and the proposed image search scheme outperforms state-of-the art methods in both effectiveness and efficiency.

  3. Topological Effects and Performance Optimization in Transportation Continuous Network Design

    Directory of Open Access Journals (Sweden)

    Jianjun Wu

    2014-01-01

    Full Text Available Because of the limitation of budget, in the planning of road works, increased efforts should be made on links that are more critical to the whole traffic system. Therefore, it would be helpful to model and evaluate the vulnerability and reliability of the transportation network when the network design is processing. This paper proposes a bilevel transportation network design model, in which the upper level is to minimize the performance of the network under the given budgets, while the lower level is a typical user equilibrium assignment problem. A new solution approach based on particle swarm optimization (PSO method is presented. The topological effects on the performance of transportation networks are studied with the consideration of three typical networks, regular lattice, random graph, and small-world network. Numerical examples and simulations are presented to demonstrate the proposed model.

  4. Optimal Portfolios in Wishart Models and Effects of Discrete Rebalancing on Portfolio Distribution and Strategy Selection

    OpenAIRE

    Li, Zejing

    2012-01-01

    This dissertation is mainly devoted to the research of two problems - the continuous-time portfolio optimization in different Wishart models and the effects of discrete rebalancing on portfolio wealth distribution and optimal portfolio strategy.

  5. An effective docking strategy for virtual screening based on multi-objective optimization algorithm

    Directory of Open Access Journals (Sweden)

    Kang Ling

    2009-02-01

    Full Text Available Abstract Background Development of a fast and accurate scoring function in virtual screening remains a hot issue in current computer-aided drug research. Different scoring functions focus on diverse aspects of ligand binding, and no single scoring can satisfy the peculiarities of each target system. Therefore, the idea of a consensus score strategy was put forward. Integrating several scoring functions, consensus score re-assesses the docked conformations using a primary scoring function. However, it is not really robust and efficient from the perspective of optimization. Furthermore, to date, the majority of available methods are still based on single objective optimization design. Results In this paper, two multi-objective optimization methods, called MOSFOM, were developed for virtual screening, which simultaneously consider both the energy score and the contact score. Results suggest that MOSFOM can effectively enhance enrichment and performance compared with a single score. For three different kinds of binding sites, MOSFOM displays an excellent ability to differentiate active compounds through energy and shape complementarity. EFMOGA performed particularly well in the top 2% of database for all three cases, whereas MOEA_Nrg and MOEA_Cnt performed better than the corresponding individual scoring functions if the appropriate type of binding site was selected. Conclusion The multi-objective optimization method was successfully applied in virtual screening with two different scoring functions that can yield reasonable binding poses and can furthermore, be ranked with the potentially compromised conformations of each compound, abandoning those conformations that can not satisfy overall objective functions.

  6. Effective hybrid evolutionary computational algorithms for global optimization and applied to construct prion AGAAAAGA fibril models

    CERN Document Server

    Zhang, Jiapu

    2010-01-01

    Evolutionary algorithms are parallel computing algorithms and simulated annealing algorithm is a sequential computing algorithm. This paper inserts simulated annealing into evolutionary computations and successful developed a hybrid Self-Adaptive Evolutionary Strategy $\\mu+\\lambda$ method and a hybrid Self-Adaptive Classical Evolutionary Programming method. Numerical results on more than 40 benchmark test problems of global optimization show that the hybrid methods presented in this paper are very effective. Lennard-Jones potential energy minimization is another benchmark for testing new global optimization algorithms. It is studied through the amyloid fibril constructions by this paper. To date, there is little molecular structural data available on the AGAAAAGA palindrome in the hydrophobic region (113-120) of prion proteins.This region belongs to the N-terminal unstructured region (1-123) of prion proteins, the structure of which has proved hard to determine using NMR spectroscopy or X-ray crystallography ...

  7. Matter-wave bright solitons in effective bichromatic lattice potentials

    Indian Academy of Sciences (India)

    Golam Ali Sekh

    2013-08-01

    Matter-wave bright solitons in bichromatic lattice potentials are considered and their dynamics for different lattice environments are studied. Bichromatic potentials are created from superpositions of (i) two linear optical lattices and (ii) a linear and a nonlinear optical lattice. Effective potentials are found for the solitons in both bichromatic lattices and a comparative study is done on the dynamics of solitons with respect to the effective potentials. The effects of dispersion on solitons in bichromatic lattices are studied and it is found that the dispersive spreading can be minimized by appropriate combinations of lattice and interaction parameters. Stability of nondispersive matter-wave solitons is checked from phase portrait analysis.

  8. Potential Projective Material on the Rorschach: Comparing Comprehensive System Protocols to Their Modeled R-Optimized Administration Counterparts.

    Science.gov (United States)

    Pianowski, Giselle; Meyer, Gregory J; Villemor-Amaral, Anna Elisa de

    2016-01-01

    Exner ( 1989 ) and Weiner ( 2003 ) identified 3 types of Rorschach codes that are most likely to contain personally relevant projective material: Distortions, Movement, and Embellishments. We examine how often these types of codes occur in normative data and whether their frequency changes for the 1st, 2nd, 3rd, 4th, or last response to a card. We also examine the impact on these variables of the Rorschach Performance Assessment System's (R-PAS) statistical modeling procedures that convert the distribution of responses (R) from Comprehensive System (CS) administered protocols to match the distribution of R found in protocols obtained using R-optimized administration guidelines. In 2 normative reference databases, the results indicated that about 40% of responses (M = 39.25) have 1 type of code, 15% have 2 types, and 1.5% have all 3 types, with frequencies not changing by response number. In addition, there were no mean differences in the original CS and R-optimized modeled records (M Cohen's d = -0.04 in both databases). When considered alongside findings showing minimal differences between the protocols of people randomly assigned to CS or R-optimized administration, the data suggest R-optimized administration should not alter the extent to which potential projective material is present in a Rorschach protocol.

  9. Does Operation Scheduling Make a Difference: Tapping the Potential of Optimized Design for Skipping-Stop Strategy in Reducing Bus Emissions

    Directory of Open Access Journals (Sweden)

    Xumei Chen

    2017-09-01

    Full Text Available The idea of corporate social responsibility has promoted bus operation agencies to rethink how to provide not only efficient but also environmentally friendly services for residents. A study on the potential of using an optimized design of skip-stop services, one of the essential operational strategies in practice, to reduce emissions is conducted in this paper. The underlying scheduling problem is formulated as a nonlinear programming problem with the primary objective of optimizing the total costs for both passengers and operating agencies, as well as with the secondary objective of minimizing bus emissions. A solution method is developed to solve the problem. A real-world case of Route 16 in Beijing is studied, in which the optimal scheduling strategy that maximizes the cost savings and environmental benefits is determined. The costs and emissions of the proposed scheduling strategy are compared with the optimal scheduling with skip-stop services without considering bus emissions. The results show that the proposed scheduling strategy outperforms the other operating strategy with respect to operational costs and bus emissions. A sensitivity study is then conducted to investigate the impact of the fleet size in operations and passenger demand on the effectiveness of the proposed stop-skipping strategy considering bus emissions.

  10. Optimization of co-digestion of various industrial sludges for biogas production and sludge treatment: methane production potential experiments and modeling.

    Science.gov (United States)

    Mahanty, Biswanath; Zafar, Mohd; Han, Man Jae; Park, Hung-Suck

    2014-06-01

    Optimal biogas production and sludge treatment were studied by co-digestion experiments and modeling using five different wastewater sludges generated from paper, chemical, petrochemical, automobile, and food processing industries situated in Ulsan Industrial Complex, Ulsan, South Korea. The biomethane production potential test was conducted in simplex-centroid mixture design, fitted to regression equation, and some optimal co-digestion scenarios were given by combined desirability function based multi-objective optimization technique for both methane yield and the quantity of sludge digested. The co-digestion model incorporating main and interaction effects among sludges were utilized to predict the maximum possible methane yield. The optimization routine for methane production with different industrial sludges in batches were repeated with the left-over sludge of earlier cycle, till all sludges have been completely treated. Among the possible scenarios, a maximum methane yield of 1161.53 m(3) is anticipated in three batches followed by 1130.33 m(3) and 1045.65 m(3) in five and two batches, respectively. This study shows a scientific approach to find a practical solution to utilize diverse industrial sludges in both treatment and biogas production perspectives.

  11. Sugammadex to reverse neuromuscular blockade and provide optimal conditions for motor-evoked potential monitoring

    Directory of Open Access Journals (Sweden)

    Mehdi Trifa

    2017-01-01

    Full Text Available Sugammadex is a novel pharmacologic agent, which reverses neuromuscular blockade (NMB via a mechanism that differs completely from acetylcholinesterase inhibitors. By encapsulating rocuronium, sugammadex can provide recovery of neuromuscular function even when there is a profound degree of NMB. We report anecdotal experience with the use of sugammadex to reverse NMB to facilitate intraoperative neurophysiological monitoring (motor evoked potentials in an adolescent with scoliosis during posterior spinal fusion. Its potential application in this unique clinical scenario is discussed, and potential dosing schemes are reviewed.

  12. Designing a potential game via pricing for optimal resource management in non-cooperative Cognitive Radio networks

    Directory of Open Access Journals (Sweden)

    M.F. Sabahi

    2013-12-01

    Full Text Available In this paper, based on the game theory, an optimized resource management algorithm for cognitive radio networks has been presented. Considering the personal interests, each user selects its own desired utility function and competes for channel and power selection. This non-cooperative approach is controlled through an appropriate pricing method. We have shown that if the profit function in a cooperative potential game is used as the pricing function in a non-cooperative network, the game governing the non-cooperative network will also become potential and will thus converge to Nash equilibrium. If the network is designed based on the cooperation of the users, the existence of selfish users among them will make the network be unstable. Besides, it decreases resource utilization gain. Using the recommended pricing has been shown to equilibrate the network. In simulations, by studying parameters like sum-rate of network and its total interference, it is shown that the resource utilization will be improved. Simulation results show that the equilibrium points also enjoy some optimality criteria such as Pareto optimality.

  13. Evaluation and Optimization of Paper-Based SERS Substrate for Potential Label-Free Raman Analysis of Seminal Plasma

    Directory of Open Access Journals (Sweden)

    Zufang Huang

    2017-01-01

    Full Text Available Characterization and optimization of paper SERS substrate were performed in detail, in which morphologies and distribution of silver nanoparticles (AgNPs on the paper substrate pretreated with different concentrations of NaCl and the subsequent soaking with colloidal AgNPs for different period of time were evaluated. Our results show that both NaCl concentration and soaking time with AgNPs have a significant influence on SERS enhancement, showing that an optimal EF of 2.27 × 107 was achieved when the paper substrate was treated with 20 mM NaCl and one-hour soak with AgNPs. Moreover, seminal plasma (SP was specifically selected to evaluate the performance of paper-based SERS substrate for potential clinical detection and diagnosis. The optimization of the paper SERS substrate demonstrates potential applications in reliable on-site detection of SP and clinical diagnosis of fertility-related diseases as well.

  14. Taming the Goldstone contributions to the effective potential

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Stephen P. [Fermilab

    2014-07-28

    The standard perturbative effective potential suffers from two related problems of principle involving the field-dependent Goldstone boson squared mass, G. First, in general G can be negative, and it actually is negative in the Standard Model; this leads to imaginary contributions to the effective potential that are not associated with a physical instability, and therefore spurious. Second, in the limit that G approaches zero, the effective potential minimization condition is logarithmically divergent already at two-loop order, and has increasingly severe power-law singularities at higher loop orders. I resolve both issues by resumming the Goldstone boson contributions to the effective potential. For the resulting resummed effective potential, the minimum value and the minimization condition that gives the vacuum expectation value are obtained in forms that do not involve G at all.

  15. Real parameter optimization by an effective differential evolution algorithm

    Directory of Open Access Journals (Sweden)

    Ali Wagdy Mohamed

    2013-03-01

    Full Text Available This paper introduces an Effective Differential Evolution (EDE algorithm for solving real parameter optimization problems over continuous domain. The proposed algorithm proposes a new mutation rule based on the best and the worst individuals among the entire population of a particular generation. The mutation rule is combined with the basic mutation strategy through a linear decreasing probability rule. The proposed mutation rule is shown to promote local search capability of the basic DE and to make it faster. Furthermore, a random mutation scheme and a modified Breeder Genetic Algorithm (BGA mutation scheme are merged to avoid stagnation and/or premature convergence. Additionally, the scaling factor and crossover of DE are introduced as uniform random numbers to enrich the search behavior and to enhance the diversity of the population. The effectiveness and benefits of the proposed modifications used in EDE has been experimentally investigated. Numerical experiments on a set of bound-constrained problems have shown that the new approach is efficient, effective and robust. The comparison results between the EDE and several classical differential evolution methods and state-of-the-art parameter adaptive differential evolution variants indicate that the proposed EDE algorithm is competitive with , and in some cases superior to, other algorithms in terms of final solution quality, efficiency, convergence rate, and robustness.

  16. Kv3 potassium conductance is necessary and kinetically optimized for high-frequency action potential generation in hippocampal interneurons.

    Science.gov (United States)

    Lien, Cheng-Chang; Jonas, Peter

    2003-03-15

    Kv3 channels are thought to be essential for the fast-spiking (FS) phenotype in GABAergic interneurons, but how these channels confer the ability to generate action potentials (APs) at high frequency is unknown. To address this question, we developed a fast dynamic-clamp system (approximately 50 kHz) that allowed us to add a Kv3 model conductance to CA1 oriens alveus (OA) interneurons in hippocampal slices. Selective pharmacological block of Kv3 channels by 0.3 mm 4-aminopyridine or 1 mm tetraethylammonium ions led to a marked broadening of APs during trains of short stimuli and a reduction in AP frequency during 1 sec stimuli. The addition of artificial Kv3 conductance restored the original AP pattern. Subtraction of Kv3 conductance by dynamic clamp mimicked the effects of the blockers. Application of artificial Kv3 conductance also led to FS in OA interneurons after complete K+ channel block and even induced FS in hippocampal pyramidal neurons in the absence of blockers. Adding artificial Kv3 conductance with altered deactivation kinetics revealed a nonmonotonic relationship between mean AP frequency and deactivation rate, with a maximum slightly above the original value. Insertion of artificial Kv3 conductance with either lowered activation threshold or inactivation also led to a reduction in the mean AP frequency. However, the mechanisms were distinct. Shifting the activation threshold induced adaptation, whereas adding inactivation caused frequency-dependent AP broadening. In conclusion, Kv3 channels are necessary for the FS phenotype of OA interneurons, and several of their gating properties appear to be optimized for high-frequency repetitive activity.

  17. Potential of a Pharmacogenetic-Guided Algorithm to Predict Optimal Warfarin Dosing in a High-Risk Hispanic Patient

    Directory of Open Access Journals (Sweden)

    Dagmar F. Hernandez-Suarez MD

    2016-12-01

    Full Text Available Deep abdominal vein thrombosis is extremely rare among thrombotic events secondary to the use of contraceptives. A case to illustrate the clinical utility of ethno-specific pharmacogenetic testing in warfarin management of a Hispanic patient is reported. A 37-year-old Hispanic Puerto Rican, non-gravid female with past medical history of abnormal uterine bleeding on hormonal contraceptive therapy was evaluated for abdominal pain. Physical exam was remarkable for unspecific diffuse abdominal tenderness, and general initial laboratory results—including coagulation parameters—were unremarkable. A contrast-enhanced computed tomography showed a massive thrombosis of the main portal, splenic, and superior mesenteric veins. On admission the patient was started on oral anticoagulation therapy with warfarin at 5 mg/day and low-molecular-weight heparin. The prediction of an effective warfarin dose of 7.5 mg/day, estimated by using a recently developed pharmacogenetic-guided algorithm for Caribbean Hispanics, coincided with the actual patient’s warfarin dose to reach the international normalized ratio target. We speculate that the slow rise in patient’s international normalized ratio observed on the initiation of warfarin therapy, the resulting high risk for thromboembolic events, and the required warfarin dose of 7.5 mg/day are attributable in some part to the presence of the NQO1*2 (g.559C>T, p.P187S polymorphism, which seems to be significantly associated with resistance to warfarin in Hispanics. By adding genotyping results of this novel variant, the predictive model can inform clinicians better about the optimal warfarin dose in Caribbean Hispanics. The results highlight the potential for pharmacogenetic testing of warfarin to improve patient care.

  18. Recreation Embedded State Tuning for Optimal Readiness and Effectiveness (RESTORE)

    Science.gov (United States)

    Pope, Alan T.; Prinzel, Lawrence J., III

    2005-01-01

    Physiological self-regulation training is a behavioral medicine intervention that has demonstrated capability to improve psychophysiological coping responses to stressful experiences and to foster optimal behavioral and cognitive performance. Once developed, these psychophysiological skills require regular practice for maintenance. A concomitant benefit of these physiologically monitored practice sessions is the opportunity to track crew psychophysiological responses to the challenges of the practice task in order to detect shifts in adaptability that may foretell performance degradation. Long-duration missions will include crew recreation periods that will afford physiological self-regulation training opportunities. However, to promote adherence to the regimen, the practice experience that occupies their recreation time must be perceived by the crew as engaging and entertaining throughout repeated reinforcement sessions on long-duration missions. NASA biocybernetic technologies and publications have developed a closed-loop concept that involves adjusting or modulating (cybernetic, for governing) a person's task environment based upon a comparison of that person's physiological responses (bio-) with a training or performance criterion. This approach affords the opportunity to deliver physiological self-regulation training in an entertaining and motivating fashion and can also be employed to create a conditioned association between effective performance state and task execution behaviors, while enabling tracking of individuals psychophysiological status over time in the context of an interactive task challenge. This paper describes the aerospace spin-off technologies in this training application area as well as the current spin-back application of the technologies to long-duration missions - the Recreation Embedded State Tuning for Optimal Readiness and Effectiveness (RESTORE) concept. The RESTORE technology is designed to provide a physiological self

  19. Glycosylation of therapeutic proteins: an effective strategy to optimize efficacy.

    Science.gov (United States)

    Solá, Ricardo J; Griebenow, Kai

    2010-02-01

    During their development and administration, protein-based drugs routinely display suboptimal therapeutic efficacies due to their poor physicochemical and pharmacological properties. These innate liabilities have driven the development of molecular strategies to improve the therapeutic behavior of protein drugs. Among the currently developed approaches, glycoengineering is one of the most promising, because it has been shown to simultaneously afford improvements in most of the parameters necessary for optimization of in vivo efficacy while allowing for targeting to the desired site of action. These include increased in vitro and in vivo molecular stability (due to reduced oxidation, cross-linking, pH-, chemical-, heating-, and freezing-induced unfolding/denaturation, precipitation, kinetic inactivation, and aggregation), as well as modulated pharmacodynamic responses (due to altered potencies from diminished in vitro enzymatic activities and altered receptor binding affinities) and improved pharmacokinetic profiles (due to altered absorption and distribution behaviors, longer circulation lifetimes, and decreased clearance rates). This article provides an account of the effects that glycosylation has on the therapeutic efficacy of protein drugs and describes the current understanding of the mechanisms by which glycosylation leads to such effects.

  20. Optimal composite scores for longitudinal clinical trials under the linear mixed effects model.

    Science.gov (United States)

    Ard, M Colin; Raghavan, Nandini; Edland, Steven D

    2015-01-01

    Clinical trials of chronic, progressive conditions use rate of change on continuous measures as the primary outcome measure, with slowing of progression on the measure as evidence of clinical efficacy. For clinical trials with a single prespecified primary endpoint, it is important to choose an endpoint with the best signal-to-noise properties to optimize statistical power to detect a treatment effect. Composite endpoints composed of a linear weighted average of candidate outcome measures have also been proposed. Composites constructed as simple sums or averages of component tests, as well as composites constructed using weights derived from more sophisticated approaches, can be suboptimal, in some cases performing worse than individual outcome measures. We extend recent research on the construction of efficient linearly weighted composites by establishing the often overlooked connection between trial design and composite performance under linear mixed effects model assumptions and derive a formula for calculating composites that are optimal for longitudinal clinical trials of known, arbitrary design. Using data from a completed trial, we provide example calculations showing that the optimally weighted linear combination of scales can improve the efficiency of trials by almost 20% compared with the most efficient of the individual component scales. Additional simulations and analytical results demonstrate the potential losses in efficiency that can result from alternative published approaches to composite construction and explore the impact of weight estimation on composite performance.

  1. The effect of cost distributions on evolutionary optimization algorithms

    NARCIS (Netherlands)

    Waas, F.; Galindo-Legaria, C.A.

    2000-01-01

    According to the No-Free-Lunch theorems of Wolpert and Macready, we cannot expect one generic optimization technique to outperform others on average. For every optimization technique there exist ``easy'' and ``hard'' problems. However, only little is known as to what criteria determine the particula

  2. Decomposition Techniques and Effective Algorithms in Reliability-Based Optimization

    DEFF Research Database (Denmark)

    Enevoldsen, I.; Sørensen, John Dalsgaard

    1995-01-01

    The common problem of an extensive number of limit state function calculations in the various formulations and applications of reliability-based optimization is treated. It is suggested to use a formulation based on decomposition techniques so the nested two-level optimization problem can be solved...

  3. Novel potential for optimization of antitubercular therapy: Pulmonary delivery of rifampicin lipospheres

    Directory of Open Access Journals (Sweden)

    Charan Singh

    2015-12-01

    Full Text Available The aim of the present work is to develop rifampicin loaded phospholipid lipospheres containing sulfphobutyl ether β-cyclodextrin and Vitamin C for inhalation to test their potential for deep lung delivery. The findings of the solid state characterization revealed the amorphous nature of the lipospheres. These exhibited a better flowability, an aerodynamic diameter in the range of 1.76 to 3.99 µm. Moreover, the fine particle fraction and emitted dose was found in the range of 68.84–83.73% and 80–93%, respectively. Moreover, lipospheres exhibited enhanced/equivalent efficacy in vitro in H37Rv strain. Hence, the results show the potential of lipospheres for pulmonary delivery of rifampicin.

  4. Optimal sampling efficiency in Monte Carlo simulation with an approximate potential.

    Science.gov (United States)

    Coe, Joshua D; Sewell, Thomas D; Shaw, M Sam

    2009-04-28

    Building on the work of Iftimie et al. [J. Chem. Phys. 113, 4852 (2000)] and Gelb [J. Chem. Phys. 118, 7747 (2003)], Boltzmann sampling of an approximate potential (the "reference" system) is used to build a Markov chain in the isothermal-isobaric ensemble. At the end points of the chain, the energy is evaluated at a more accurate level (the "full" system) and a composite move encompassing all of the intervening steps is accepted on the basis of a modified Metropolis criterion. For reference system chains of sufficient length, consecutive full energies are statistically decorrelated and thus far fewer are required to build ensemble averages with a given variance. Without modifying the original algorithm, however, the maximum reference chain length is too short to decorrelate full configurations without dramatically lowering the acceptance probability of the composite move. This difficulty stems from the fact that the reference and full potentials sample different statistical distributions. By manipulating the thermodynamic variables characterizing the reference system (pressure and temperature, in this case), we maximize the average acceptance probability of composite moves, lengthening significantly the random walk between consecutive full energy evaluations. In this manner, the number of full energy evaluations needed to precisely characterize equilibrium properties is dramatically reduced. The method is applied to a model fluid, but implications for sampling high-dimensional systems with ab initio or density functional theory potentials are discussed.

  5. Gibbs ensemble Monte Carlo simulation using an optimized potential model: pure acetic acid and a mixture of it with ethylene.

    Science.gov (United States)

    Zhang, Minhua; Chen, Lihang; Yang, Huaming; Sha, Xijiang; Ma, Jing

    2016-07-01

    Gibbs ensemble Monte Carlo simulation with configurational bias was employed to study the vapor-liquid equilibrium (VLE) for pure acetic acid and for a mixture of acetic acid and ethylene. An improved united-atom force field for acetic acid based on a Lennard-Jones functional form was proposed. The Lennard-Jones well depth and size parameters for the carboxyl oxygen and hydroxyl oxygen were determined by fitting the interaction energies of acetic acid dimers to the Lennard-Jones potential function. Four different acetic acid dimers and the proportions of them were considered when the force field was optimized. It was found that the new optimized force field provides a reasonable description of the vapor-liquid phase equilibrium for pure acetic acid and for the mixture of acetic acid and ethylene. Accurate values were obtained for the saturated liquid density of the pure compound (average deviation: 0.84 %) and for the critical points. The new optimized force field demonstrated greater accuracy and reliability in calculations of the solubility of the mixture of acetic acid and ethylene as compared with the results obtained with the original TraPPE-UA force field.

  6. Exploring the high lipid production potential of a thermotolerant microalga using statistical optimization and semi-continuous cultivation.

    Science.gov (United States)

    Ho, Shih-Hsin; Chen, Ching-Nen Nathan; Lai, Yen-Ying; Lu, Wei-Bin; Chang, Jo-Shu

    2014-07-01

    A recently isolated thermotolerant microalga Desmodesmus sp. F2 has the traits of becoming potential biodiesel feedstock, such as high growth rate, high lipid content, and quick precipitation. Its overall lipid productivity was 113 mg/L/d when grown under non-optimal conditions using batch cultivation. A two-step response surface methodology was adopted to optimize its cultivation conditions. The overall lipid productivity was increased to 263 mg/L/d when the cells were grown under the optimized conditions of 6.6mM initial nitrogen level and 6 days nitrogen depletion treatment in 700 μmol/m(2)/s light intensity at 35°C using batch cultivation. Fed-batch and semi-continuous cultivations were employed to further increase its lipid productivity to 213 and 302 mg/L/d, respectively. The 302 mg/L/d is the highest overall lipid productivity of microalgae ever reported in the literature. This study provides the information required for the design and operation of photobioreactors for large scale outdoor cultivation of this species.

  7. THE POTENTIAL OF INFORMATION AND COMMUNICATIONS TECHNOLOGICAL IN THE OPTIMIZATION OF LOCAL GOVERNMENT FUNCTIONING IN RUSSIA

    Directory of Open Access Journals (Sweden)

    Виктор Павлович Ляхов

    2014-05-01

    Full Text Available The shift to a new type of relations in the system of “community-state” with regard to informational and network nature of modern society seemed to be the most important strategic course in the realization of modernization project in Russia. On this ground the article deals with the opportunities of local government system optimization through the active implementation of informational and communication technologies into state authorities and local government activity.The purpose of e-municipality is the reduction of informational inequality level, the transparency and increase of local authorities controllability by society, engaging general community in governing process.It is necessary to cope with the problem of creating and realizing the strategy of the shift from the closed style of performance to the open one by the active development of informational and communication technologies and their implementation into the performance of local government.As a required and compulsory mechanism we suggest monitoring municipal management efficiency as well as legal determining and differentiating of functions, powers and liabilities of local authorities’ structures.The informational component of modernization process in Russia will enable to attain a new level of communicative management activity of local authorities as well as the monitoring of its results.DOI: http://dx.doi.org/10.12731/2218-7405-2013-10-41

  8. Topology optimized microbioreactors

    DEFF Research Database (Denmark)

    Schäpper, Daniel; Lencastre Fernandes, Rita; Eliasson Lantz, Anna

    2011-01-01

    . Topology optimization is then used to change the spatial distribution of cells in the reactor in order to optimize for maximal product flow out of the reactor. This distribution accounts for potentially negative effects of, for example, by-product inhibition. We show that the theoretical improvement...... in productivity is at least fivefold compared with the homogeneous reactor. The improvements obtained by applying topology optimization are largest where either nutrition is scarce or inhibition effects are pronounced....

  9. Interpolation of multi-sheeted multi-dimensional potential-energy surfaces via a linear optimization procedure.

    Science.gov (United States)

    Opalka, Daniel; Domcke, Wolfgang

    2013-06-14

    Significant progress has been achieved in recent years with the development of high-dimensional permutationally invariant analytic Born-Oppenheimer potential-energy surfaces, making use of polynomial invariant theory. In this work, we have developed a generalization of this approach which is suitable for the construction of multi-sheeted multi-dimensional potential-energy surfaces exhibiting seams of conical intersections. The method avoids the nonlinear optimization problem which is encountered in the construction of multi-sheeted diabatic potential-energy surfaces from ab initio electronic-structure data. The key of the method is the expansion of the coefficients of the characteristic polynomial in polynomials which are invariant with respect to the point group of the molecule or the permutation group of like atoms. The multi-sheeted adiabatic potential-energy surface is obtained from the Frobenius companion matrix which contains the fitted coefficients. A three-sheeted nine-dimensional adiabatic potential-energy surface of the (2)T2 electronic ground state of the methane cation has been constructed as an example of the application of this method.

  10. Integrated and Consistent Active Control Formulation and Piezotransducer Position Optimization of Plate Structures considering Spillover Effects

    Directory of Open Access Journals (Sweden)

    Mojtaba Biglar

    2014-01-01

    Full Text Available This study addresses new formulation for active vibration control of plates by optimal locations of attached piezotransducers. Free vibrations are solved by Rayleigh-Ritz and transient by assumed modes methods. Optimal orientations of patches are determined by spatial controllability/observability, as well as residual modes to reduce spillover. These criteria are used to achieve optimal fitness function defined for genetic algorithm to find optimal locations. To control vibrations, negative velocity feedback control is designed. Results indicate that, by locating piezopatches at optimal positions, depreciation rate increases and amplitudes of vibrations reduce effectively. The effect of number of piezodevices is analyzed.

  11. Effect of the earth's ellipticity on the lunar tidal potential

    Science.gov (United States)

    Dahlen, F. A.

    1993-01-01

    The earth's orbital acceleration about the moon is influenced by its ellipticity. In this paper it shown that the ellipticity affects tidal gravity by contributing directly to the lunar tide-generating potential (in addition to effecting the elastic-gravitational response of the solid earth and oceans to this potential).

  12. Effective potentials for atom-atom interaction at low temperatures

    OpenAIRE

    Gao, Bo

    2002-01-01

    We discuss the concept and design of effective atom-atom potentials that accurately describe any physical processes involving only states around the threshold. The existence of such potentials gives hope to a quantitative, and systematic, understanding of quantum few-atom and quantum many-atom systems at relatively low temperatures.

  13. An automatic and effective parameter optimization method for model tuning

    Directory of Open Access Journals (Sweden)

    T. Zhang

    2015-05-01

    Full Text Available Physical parameterizations in General Circulation Models (GCMs, having various uncertain parameters, greatly impact model performance and model climate sensitivity. Traditional manual and empirical tuning of these parameters is time consuming and ineffective. In this study, a "three-step" methodology is proposed to automatically and effectively obtain the optimum combination of some key parameters in cloud and convective parameterizations according to a comprehensive objective evaluation metrics. Different from the traditional optimization methods, two extra steps, one determines parameter sensitivity and the other chooses the optimum initial value of sensitive parameters, are introduced before the downhill simplex method to reduce the computational cost and improve the tuning performance. Atmospheric GCM simulation results show that the optimum combination of these parameters determined using this method is able to improve the model's overall performance by 9%. The proposed methodology and software framework can be easily applied to other GCMs to speed up the model development process, especially regarding unavoidable comprehensive parameters tuning during the model development stage.

  14. Trial Study of Vibration-Induced Effects on Spontaneous Potential

    Institute of Scientific and Technical Information of China (English)

    SunWeibin; QiuWeiting; HeZhanxiang

    2003-01-01

    Vibratory excitation generates not only reflections and refractions of wave fields on the subsurface interfaces but also electromagnetic waves with different frequencies. In this paper we address the vibration-induced effects on the spontaneous potential field. The effects of controllable vibration on the spontaneous potential field were studied under real field geologic conditions. Experimental data confirmed that the vibration-induced effects on the spontaneous potential field do exist under field conditions. Monitoring records over a long time interval showed that there existed three information zones in the vibration-induced effects on spontaneous potential field:These are the signal-variant zone, the extreme-stable zone and the relaxation-recovery zone. Combined with different well-site data, it was concluded that the time-variant features of the anomalies in the information zones was closely related to the properties of the subsurface liquid (oil and water).

  15. Emerging evidence of ozone metabolic effects and potential mechanisms

    Science.gov (United States)

    SOT 2014 Abstract: Invitational Emerging evidence of ozone metabolic effects and potential mechanisms U.P. Kodavanti NHEERL, USEPA, Research Triangle Park, NC Recent evidence suggests that air pollutants are linked to metabolic syndrome and impact several key metabolic proce...

  16. Effective multi-objective optimization with the coral reefs optimization algorithm

    Science.gov (United States)

    Salcedo-Sanz, S.; Pastor-Sánchez, A.; Portilla-Figueras, J. A.; Prieto, L.

    2016-06-01

    In this article a new algorithm for multi-objective optimization is presented, the Multi-Objective Coral Reefs Optimization (MO-CRO) algorithm. The algorithm is based on the simulation of processes in coral reefs, such as corals' reproduction and fight for space in the reef. The adaptation to multi-objective problems is a process based on domination or non-domination during the process of fight for space in the reef. The final MO-CRO is an easily-implemented and fast algorithm, simple and robust, since it is able to keep diversity in the population of corals (solutions) in a natural way. The experimental evaluation of this new approach for multi-objective optimization problems is carried out on different multi-objective benchmark problems, where the MO-CRO has shown excellent performance in cases with limited computational resources, and in a real-world problem of wind speed prediction, where the MO-CRO algorithm is used to find the best set of features to predict the wind speed, taking into account two objective functions related to the performance of the prediction and the computation time of the regressor.

  17. The effects of redundant control inputs in optimal control

    Institute of Scientific and Technical Information of China (English)

    DUAN ZhiSheng; HUANG Lin; YANG Ying

    2009-01-01

    For a stabillzable system,the extension of the control inputs has no use for stabllizability,but it is important for optimal control.In this paper,a necessary and sufficient condition is presented to strictly decrease the quadratic optimal performance index after control input extensions.A similar result is also provided for H_2 optimal control problem.These results show an essential difference between single-input and multi-input control systems.Several examples are taken to illustrate related problems.

  18. Effect of Ionic Diffusion on Extracellular Potentials in Neural Tissue.

    Directory of Open Access Journals (Sweden)

    Geir Halnes

    2016-11-01

    Full Text Available Recorded potentials in the extracellular space (ECS of the brain is a standard measure of population activity in neural tissue. Computational models that simulate the relationship between the ECS potential and its underlying neurophysiological processes are commonly used in the interpretation of such measurements. Standard methods, such as volume-conductor theory and current-source density theory, assume that diffusion has a negligible effect on the ECS potential, at least in the range of frequencies picked up by most recording systems. This assumption remains to be verified. We here present a hybrid simulation framework that accounts for diffusive effects on the ECS potential. The framework uses (1 the NEURON simulator to compute the activity and ionic output currents from multicompartmental neuron models, and (2 the electrodiffusive Kirchhoff-Nernst-Planck framework to simulate the resulting dynamics of the potential and ion concentrations in the ECS, accounting for the effect of electrical migration as well as diffusion. Using this framework, we explore the effect that ECS diffusion has on the electrical potential surrounding a small population of 10 pyramidal neurons. The neural model was tuned so that simulations over ∼100 seconds of biological time led to shifts in ECS concentrations by a few millimolars, similar to what has been seen in experiments. By comparing simulations where ECS diffusion was absent with simulations where ECS diffusion was included, we made the following key findings: (i ECS diffusion shifted the local potential by up to ∼0.2 mV. (ii The power spectral density (PSD of the diffusion-evoked potential shifts followed a 1/f2 power law. (iii Diffusion effects dominated the PSD of the ECS potential for frequencies up to several hertz. In scenarios with large, but physiologically realistic ECS concentration gradients, diffusion was thus found to affect the ECS potential well within the frequency range picked up in

  19. Optimization of retroviral gene transfer protocol to maintain the lymphoid potential of progenitor cells.

    Science.gov (United States)

    Hacein-Bey, S; Gross, F; Nusbaum, P; Hue, C; Hamel, Y; Fischer, A; Cavazzana-Calvo, M

    2001-02-10

    We have attempted to improve retrovirus-mediated gene transfer efficacy into hematopoietic progenitor cells (HPCs) without causing them to lose their lymphoid potential. Highly purified CD34(+) cells on CH-296 fibronectin fragments have been transduced with three different cytokine combinations. Murine CD2 was used as a marker gene. Transgene expression was assayed by FACS analysis shortly after transduction of CD34(+) cells and after long-term culture (LTC) extended by differentiation of various lymphoid lineages: NK cells, B cells, and dendritic cells. Compared with the historical cytokine mix, i.e., SCF (stem cell factor) + IL-3 (interleukin 3) + IL-6, the combination SCF + FL (Flt-3 ligand) + M-GDF (megakaryocyte growth and differentiation factor) + IL-3 significantly improved the total number of viable cells and CD34(+) cells after transduction and the long term-cultured progenitors after 6 weeks. In addition, the combination of SCF + FL + M-GDF + IL-3 maintained more efficiently the lymphoid potential of the progeny of transduced long term-cultured CD34(+) cells, as attested by the significantly higher number of CD56(+), CD19(+), and CD1a(+) cells recovered when FL and M-GDF were added to SCF + IL-3. Thus, even though additional improvements may still be needed in transduction of HPCs, these conditions were adopted for a clinical trial of gene therapy for X-linked severe combined immunodeficiency.

  20. The effect of jogging on P300 event related potentials.

    Science.gov (United States)

    Nakamura, Y; Nishimoto, K; Akamatu, M; Takahashi, M; Maruyama, A

    1999-03-01

    Physical exercise has beneficial effects not only on cardiovascular system and fat metabolism, may also directly effect the cognitive process. We studied the effect of physical exercise on cognitive processes by measuring the P300 event related-potential (ERP) after jogging. Seven well-trained joggers were enrolled in this study and the P300 potentials using auditory oddball paradigm. ERPs were measured before and after 30 minutes of jogging. The amplitude of the P300 significantly increased after jogging compared to values recorded before jogging. These findings suggest that jogging has the effect of facilitating cognitive processes involved in generation of the P300.

  1. Effects of tax depreciation on optimal firm investments

    NARCIS (Netherlands)

    Wielhouwer, J.L.; Kort, P.M.; De Waegenaere, A.M.B.

    1999-01-01

    This paper studies how the difference between technical depreciation and tax depreciation affects the firm's optimal investment strategy. The objective is maximization of shareholder value. When tax depreciation differs from technical depreciation, an additional investment not only generates value d

  2. Effects of tax depreciation on optimal firm investments

    NARCIS (Netherlands)

    Wielhouwer, J.L.; Kort, P.M.; De Waegenaere, A.M.B.

    1999-01-01

    This paper studies how the difference between technical depreciation and tax depreciation affects the firm's optimal investment strategy. The objective is maximization of shareholder value. When tax depreciation differs from technical depreciation, an additional investment not only generates value d

  3. Instanton effects on the heavy-quark static potential

    Science.gov (United States)

    Yakhshiev, U. T.; Kim, Hyun-Chul; Turimov, B.; Musakhanov, M. M.; Hiyama, Emiko

    2017-08-01

    We investigate instanton effects on the heavy-quark potential, including its spin-dependent part, based on the instanton liquid model. Starting with the central potential derived from the instanton vacuum, we obtain the spin-dependent part of the heavy-quark potential. We discuss the results of the heavy-quark potential from the instanton vacuum. Finally, we solve the nonrelativistic two-body problem, associated with the heavy-quark potential from the instanton vacuum. The instanton effects on the quarkonia spectra are marginal but are required for quantitative description of the spectra. Supported by Basic Science Research Program through the National Research Foundation (NRF) of Korea funded by the Korean government (Ministry of Education, Science and Technology, MEST), Grant Numbers 2016R1D1A1B03935053 (UY) and 2015R1D1A1A01060707 (HChK) and The work was also partly Supported by RIKEN iTHES Project

  4. Toward optimizing the use of deferasirox: potential benefits of combined use with deferoxamine.

    Science.gov (United States)

    Grady, Robert W; Galanello, Renzo; Randolph, Rachel E; Kleinert, Dorothy A; Dessi, Carlo; Giardina, Patricia J

    2013-01-01

    Patients with β-thalassemia require iron chelation therapy to protect against progressive iron overload and non-transferrin-bound iron. Some patients fail to respond adequately to deferoxamine and deferasirox monotherapy while others have side effects which limit their use of these drugs. Since combining deferiprone and deferoxamine has an additive effect, placing all patients into net negative iron balance, we investigated the possibility that combining deferasirox and deferoxamine would lead to similar results. We conducted 34-day metabolic iron balance studies in six patients in whom the relative effectiveness of deferasirox (30 mg/kg/day) and deferoxamine (40 mg/kg/day) was compared, alone and in combination. Patients consumed fixed low-iron diets; daily urinary and stool iron excretion were determined by atomic absorption. Red blood cell transfusions were given prior to each drug treatment to minimize the effects of ineffective erythropoiesis. Serial safety measures, hematologic parameters, serum chemistries, ferritin levels and urinalyses were determined. All patients were in negative iron balance when treated with deferoxamine alone while four of six patients remained in positive balance when deferasirox monotherapy was evaluated. Daily use of both drugs had a synergistic effect in two patients and an additive effect in three others. Five of six patients would be in negative iron balance if they used the combination of drugs just 3 days a week. No significant or drug-related changes were observed in the blood work-ups or urinalyses performed. We conclude that supplementing the daily use of deferasirox with 2 - 3 days of deferoxamine therapy would place all patients into net negative iron balance thereby providing a convenient way to tailor chelation therapy to the individual needs of each patient.

  5. Toward optimizing the use of deferasirox: potential benefits of combined use with deferoxamine

    Science.gov (United States)

    Grady, Robert W.; Galanello, Renzo; Randolph, Rachel E.; Kleinert, Dorothy A.; Dessi, Carlo; Giardina, Patricia J.

    2013-01-01

    Patients with β-thalassemia require iron chelation therapy to protect against progressive iron overload and non-transferrin-bound iron. Some patients fail to respond adequately to deferoxamine and deferasirox monotherapy while others have side effects which limit their use of these drugs. Since combining deferiprone and deferoxamine has an additive effect, placing all patients into net negative iron balance, we investigated the possibility that combining deferasirox and deferoxamine would lead to similar results. We conducted 34-day metabolic iron balance studies in six patients in whom the relative effectiveness of deferasirox (30 mg/kg/day) and deferoxamine (40 mg/kg/day) was compared, alone and in combination. Patients consumed fixed low-iron diets; daily urinary and stool iron excretion were determined by atomic absorption. Red blood cell transfusions were given prior to each drug treatment to minimize the effects of ineffective erythropoiesis. Serial safety measures, hematologic parameters, serum chemistries, ferritin levels and urinalyses were determined. All patients were in negative iron balance when treated with deferoxamine alone while four of six patients remained in positive balance when deferasirox monotherapy was evaluated. Daily use of both drugs had a synergistic effect in two patients and an additive effect in three others. Five of six patients would be in negative iron balance if they used the combination of drugs just 3 days a week. No significant or drug-related changes were observed in the blood work-ups or urinalyses performed. We conclude that supplementing the daily use of deferasirox with 2 – 3 days of deferoxamine therapy would place all patients into net negative iron balance thereby providing a convenient way to tailor chelation therapy to the individual needs of each patient. PMID:22875626

  6. Optimizing the culture environment and embryo manipulation to help maintain embryo developmental potential.

    Science.gov (United States)

    Swain, Jason E; Carrell, Doug; Cobo, Ana; Meseguer, Marcos; Rubio, Carmen; Smith, Gary D

    2016-03-01

    With increased use of comprehensive chromosome screening (CCS), the question remains as to why some practices do not experience the same high levels of clinical success after implementation of the approach. Indeed, the debate surrounding the efficacy and usefulness of blastocyst biopsy and CCS continues. Importantly, several variables impact the success of an assisted reproductive technology cycle. Transfer of a euploid embryo is but one factor in an intricate system that requires numerous steps to occur successfully. Certainly, the culture environment and the manipulations of the embryo during its time in the laboratory can impact its reproductive potential. Environmental stressors ranging from culture media to culture conditions and even culture platform can impact biochemical, metabolic, and epigenetic patterns that can affect the developing cell independent of chromosome number. Furthermore, accompanying procedures, such as biopsy and vitrification, are complex and, when performed improperly, can negatively impact embryo quality. These are areas that likely still carry room for improvement within the IVF laboratory.

  7. Effective polarization interaction potentials of the partially ionized dense plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ramazanov, T S [IETP, Al Farabi Kazakh National University, Tole Bi 96a, 050012 Almaty (Kazakhstan); Dzhumagulova, K N [IETP, Al Farabi Kazakh National University, Tole Bi 96a, 050012 Almaty (Kazakhstan); Omarbakiyeva, Yu A [IETP, Al Farabi Kazakh National University, Tole Bi 96a, 050012 Almaty (Kazakhstan); Roepke, G [Institute of Physics, University of Rostock, D-18051 Rostock (Germany)

    2006-04-28

    The effective polarization interaction potential between charged and neutral particles is considered for a partially ionized plasma. This pseudopotential is deduced taking into account quantum-mechanical effects at short distances as well as screening effects at large distances. Furthermore, a cutoff radius is obtained using a modified effective-range theory. Explicit results for parameters describing the interaction of the atom with charged particles are given.

  8. Effective Form of Reproducing the Total Financial Potential of Ukraine

    Directory of Open Access Journals (Sweden)

    Portna Oksana V.

    2015-03-01

    Full Text Available Development of scientific principles of reproducing the total financial potential of the country and its effective form is an urgent problem both in theoretical and practical aspects of the study, the solution of which is intended to ensure the active mobilization and effective use of the total financial potential of Ukraine, and as a result — its expanded reproduction as well, which would contribute to realization of the internal capacities for stabilization of the national economy. The purpose of the article is disclosing the essence of the effective form of reproducing the total financial potential of the country, analyzing the results of reproducing the total financial potential of Ukraine. It has been proved that the basis for the effective form of reproducing the total financial potential of the country is the volume and flow of resources, which are associated with the «real» economy, affect the dynamics of GDP and define it, i.e. resource and process forms of reproducing the total financial potential of Ukraine (which precede the effective one. The analysis of reproducing the total financial potential of Ukraine has shown that in the analyzed period there was an increase in the financial possibilities of the country, but steady dynamics of reduction of the total financial potential was observed. If we consider the amount of resources involved in production, creating a net value added and GDP, it occurs on a restricted basis. Growth of the total financial potential of Ukraine is connected only with extensive quantitative factors rather than intensive qualitative changes.

  9. Process Parameters Optimization of Potential SO42-/ZnO Acid Catalyst for Heterogeneous Transesterification of Vegetable Oil to Biodiesel

    Directory of Open Access Journals (Sweden)

    Istadi Istadi

    2012-12-01

    Full Text Available Among the possible renewable energy resources, diesel fuels derived from triglycerides of vegetable oils and animal fats have shown potential as substitutes for petroleum-based diesel fuels. The biodiesel could be produced from vegetable oils over homogeneous catalyst, heterogeneous catalyst, or enzymatic catalyst. In this study, the synthesized SO42-/ZnO catalyst was explored to be used in the heterogeneous biodiesel production by using the vegetable oils and methanol. The study began with the preparation of SO42-/ZnO catalyst followed by the transesterification reaction between vegetable oil with methanol. The independent variables (reaction time and the weight ratio of catalyst/oil were optimized to obtain the optimum biodiesel (fatty acid methyl ester yield. The results of this study showed that the acid catalyst SO42-/ZnO was potential to be used as catalyst for biodiesel production through heterogeneous transesterification of vegetable oils. Optimum operating condition for this catalytic reaction was the weight ratio of catalyst/oil of 8:1 and reaction time of 2.6 h with respect to 75.5% yield of methyl ester products. The biodiesel product was also characterized to identify the respected fatty acid methyl ester components. Copyright © 2012 by BCREC UNDIP. All rights reserved. (Selected Paper from International Conference on Chemical and Material Engineering (ICCME 2012Received: 23rd October 2012, Revised: 25th November 2012, Accepted: 25th November 2012[How to Cite: I. Istadi, Didi D. Anggoro, Luqman Buchori, Inshani Utami, Roikhatus Solikhah, (2012. Process Parameters Optimization of Potential SO42-/ZnO Acid Catalyst for Heterogeneous Transesterification of Vegetable Oil to Biodiesel. Bulletin of Chemical Reaction Engineering & Catalysis, 7(2: 150-157. (doi:10.9767/bcrec.7.2.4064.150-157][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.2.4064.150-157 ] | View in 

  10. Optimal behavior by rats in a choice task is associated to a persistent conditioned inhibition effect.

    Science.gov (United States)

    Trujano, R Emmanuel; López, Paulina; Rojas-Leguizamón, Maryed; Orduña, Vladimir

    2016-09-01

    When given a choice between an alternative with a low probability of reinforcement and discriminative stimuli, and another with a higher probability of reinforcement and non-discriminative stimuli, pigeons show a clear preference for the former but rats clearly prefer the later. It has been reported that pigeon's suboptimal choice is associated to a diminishing effect of the stimulus correlated with non-reinforcement. In the present paper, we explored the possibility that rats' optimal choice is more strongly influenced than pigeons' by the stimulus associated to non-reinforcement and that the effects of it do not dissipate during training. We trained rats to choose between an alternative with 0.50 probability of reinforcement and discriminative stimuli, and an alternative with 0.75 probability of reinforcement and non-discriminative stimuli. We replicated the strong preference for the optimal alternative. Then, after several sessions of training, we presented summation trials in which both the stimulus associated to reinforcement and the stimulus associated to non-reinforcement were simultaneously presented. The results showed that the stimulus associated to non-reinforcement exerted a strong effect on choice, and, more importantly, that it did not seem to dissipate across training. These results suggest that the strong difference found between pigeons and rats in the suboptimal choice procedure is potentially related to differences in the impact of conditioned inhibitors.

  11. Potential of the pseudo-inverse method as a constrained static optimization for musculo-tendon forces prediction.

    Science.gov (United States)

    Moissenet, Florent; Chèze, Laurence; Dumas, Raphaël

    2012-06-01

    Inverse dynamics combined with a constrained static optimization analysis has often been proposed to solve the muscular redundancy problem. Typically, the optimization problem consists in a cost function to be minimized and some equality and inequality constraints to be fulfilled. Penalty-based and Lagrange multipliers methods are common optimization methods for the equality constraints management. More recently, the pseudo-inverse method has been introduced in the field of biomechanics. The purpose of this paper is to evaluate the ability and the efficiency of this new method to solve the muscular redundancy problem, by comparing respectively the musculo-tendon forces prediction and its cost-effectiveness against common optimization methods. Since algorithm efficiency and equality constraints fulfillment highly belong to the optimization method, a two-phase procedure is proposed in order to identify and compare the complexity of the cost function, the number of iterations needed to find a solution and the computational time of the penalty-based method, the Lagrange multipliers method and pseudo-inverse method. Using a 2D knee musculo-skeletal model in an isometric context, the study of the cost functions isovalue curves shows that the solution space is 2D with the penalty-based method, 3D with the Lagrange multipliers method and 1D with the pseudo-inverse method. The minimal cost function area (defined as the area corresponding to 5% over the minimal cost) obtained for the pseudo-inverse method is very limited and along the solution space line, whereas the minimal cost function area obtained for other methods are larger or more complex. Moreover, when using a 3D lower limb musculo-skeletal model during a gait cycle simulation, the pseudo-inverse method provides the lowest number of iterations while Lagrange multipliers and pseudo-inverse method have almost the same computational time. The pseudo-inverse method, by providing a better suited cost function and an

  12. Study on the Effect of the Separating Unit Optimization on the Economy of Stable Isotope Separation

    Directory of Open Access Journals (Sweden)

    YANG Kun

    2015-01-01

    Full Text Available An economic criterion called as yearly net profit of single separating unit (YNPSSU was presented to evaluate the influence of structure optimization on the economy. Using YNPSSU as a criterion, economic analysis was carried out for the structure optimization of separating unit in the case of separating SiF4 to obtain the 28Si and 29Si isotope. YNPSSU was calculated and compared with that before optimization. The results showed that YNPSSU was increased by 12.3% by the structure optimization. Therefore, the structure optimization could increase the economy of the stable isotope separation effectively.

  13. Higgs effective potential in a perturbed Robertson-Walker background

    CERN Document Server

    Maroto, Antonio L

    2014-01-01

    We calculate the one-loop effective potential of a scalar field in a Robertson-Walker background with scalar metric perturbations. A complete set of orthonormal solutions of the perturbed equations is obtained by using the adiabatic approximation for comoving observers. After analyzing the problem of renormalization in inhomogeneous backgrounds, we get the explicit contribution of metric perturbations to the effective potential. We apply these results to the Standard Model Higgs effective potential and evaluate the effects of metric perturbations on the Higgs vacuum expectation value. Space-time variations are found, which are proportional to the gravitational slip parameter, with a typical amplitude of the order of $\\Delta\\phi/\\phi\\simeq 10^{-11}$ on cosmological scales. We also discuss possible astrophysical signatures in the Solar System and in the Milky Way that could open new possibilities to explore the symmetry breaking sector of the electroweak interactions.

  14. Experimental design for the optimization and robustness testing of a liquid chromatography tandem mass spectrometry method for the trace analysis of the potentially genotoxic 1,3-diisopropylurea.

    Science.gov (United States)

    Székely, György; Henriques, Bruno; Gil, Marco; Alvarez, Carlos

    2014-09-01

    This paper discusses a design of experiments (DoE) assisted optimization and robustness testing of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method development for the trace analysis of the potentially genotoxic 1,3-diisopropylurea (IPU) impurity in mometasone furoate glucocorticosteroid. Compared to the conventional trial-and-error method development, DoE is a cost-effective and systematic approach to system optimization by which the effects of multiple parameters and parameter interactions on a given response are considered. The LC and MS factors were studied simultaneously: flow (F), gradient (G), injection volume (Vinj), cone voltage (E(con)), and collision energy (E(col)). The optimization was carried out with respect to four responses: separation of peaks (Sep), peak area (A(p)), length of the analysis (T), and the signal-to-noise ratio (S/N). An optimization central composite face (CCF) DoE was conducted leading to the early discovery of carry-over effect which was further investigated in order to establish the maximum injectable sample load. A second DoE was conducted in order to obtain the optimal LC-MS/MS method. As part of the validation of the obtained method, its robustness was determined by conducting a fractional factorial of resolution III DoE, wherein column temperature and quadrupole resolution were considered as additional factors. The method utilizes a common Phenomenex Gemini NX C-18 HPLC analytical column with electrospray ionization and a triple quadrupole mass detector in multiple reaction monitoring (MRM) mode, resulting in short analyses with a 10-min runtime. The high sensitivity and low limit of quantification (LOQ) was achieved by (1) MRM mode (instead of single ion monitoring) and (2) avoiding the drawbacks of derivatization (incomplete reaction and time-consuming sample preparation). Quantitatively, the DoE method development strategy resulted in the robust trace analysis of IPU at 1.25 ng/mL absolute concentration

  15. Power Optimization on a Network: The effects of randomness

    CERN Document Server

    Moustakas, Aris L

    2012-01-01

    Consider a wireless network of transmitter-receiver pairs. The transmitters adjust their powers to maintain a particular SINR target in the presence of interference from neighboring transmitters. In this paper we analyze the optimal power vector that may achieve this target in the presence of randomness in the network. Specifically, we start from a regular grid of transmitter-receiver pairs and randomly turn-off a finite fraction of them. We apply concepts from random matrix theory to evaluate the asymptotic mean optimal power per link, as well as its variance. Our analytical results show remarkable agreement with numerically generated networks, not only in one-dimensional network arrays but also in two dimensional network geometries. Remarkably, we observe that the optimal power in random networks does not go to infinity in a continuous fashion as in regular grids. Rather, beyond a certain point, no finite power solution exists.

  16. Effective attractive potential between identical dielectric molecules via Lifshitz theory

    Institute of Scientific and Technical Information of China (English)

    陈来文; 李椿萱

    2001-01-01

    A general theory of Van der Waals forces developed by Lifshitz based on quantum electrodynamics theory is applied in the range Rλ0 (where the Casimir effects may be neglected) to construct Van der Waals attractive potential between identical dielectric molecules in rarefied media in order that the effective attractive potential between the like-molecules (including the repeat units) is offered. A closed form solution for the integral formulation of the attractive potential between like-particles is first obtained based on certain assumptions made in this work. On the basis of the theory of electric polarization, the derived expression in terms of bulk properties is then compared with the well-known London formula, the former differs from the latter only by the factor (4)/(π)or (4)/(π)(ε∞+2)/(3)2. The validity of the effective potential can be verified by testing cases composed of several types of dielectric materials. The computed results are presented in this paper, and comparisons with the results computed by London dispersion formula, as well as the recommended values in virtue of the experimental and theoretical techniques, are also presented. The effective potential of polyethylene is also computed to demonstrate the effectiveness of the developed model, and it is found that the computed well depth fall within a reasonable range of accuracy.

  17. An algorithm to locate optimal bond breaking points on a potential energy surface for applications in mechanochemistry and catalysis

    Science.gov (United States)

    Bofill, Josep Maria; Ribas-Ariño, Jordi; García, Sergio Pablo; Quapp, Wolfgang

    2017-10-01

    The reaction path of a mechanically induced chemical transformation changes under stress. It is well established that the force-induced structural changes of minima and saddle points, i.e., the movement of the stationary points on the original or stress-free potential energy surface, can be described by a Newton Trajectory (NT). Given a reactive molecular system, a well-fitted pulling direction, and a sufficiently large value of the force, the minimum configuration of the reactant and the saddle point configuration of a transition state collapse at a point on the corresponding NT trajectory. This point is called barrier breakdown point or bond breaking point (BBP). The Hessian matrix at the BBP has a zero eigenvector which coincides with the gradient. It indicates which force (both in magnitude and direction) should be applied to the system to induce the reaction in a barrierless process. Within the manifold of BBPs, there exist optimal BBPs which indicate what is the optimal pulling direction and what is the minimal magnitude of the force to be applied for a given mechanochemical transformation. Since these special points are very important in the context of mechanochemistry and catalysis, it is crucial to develop efficient algorithms for their location. Here, we propose a Gauss-Newton algorithm that is based on the minimization of a positively defined function (the so-called σ -function). The behavior and efficiency of the new algorithm are shown for 2D test functions and for a real chemical example.

  18. Optimization of absorption bands of dye-sensitized and perovskite tandem solar cells based on loss-in-potential values.

    Science.gov (United States)

    Sobuś, Jan; Ziółek, Marcin

    2014-07-21

    A numerical study of optimal bandgaps of light absorbers in tandem solar cell configurations is presented with the main focus on dye-sensitized solar cells (DSSCs) and perovskite solar cells (PSCs). The limits in efficiency and the expected improvements of tandem structures are investigated as a function of total loss-in-potential (V(L)), incident photon to current efficiency (IPCE) and fill factor (FF) of individual components. It is shown that the optimal absorption onsets are significantly smaller than those derived for multi-junction devices. For example, for double-cell devices the onsets are at around 660 nm and 930 nm for DSSCs with iodide based electrolytes and at around 720 nm and 1100 nm for both DSSCs with cobalt based electrolytes and PSCs. Such configurations can increase the total sunlight conversion efficiency by about 35% in comparison to single-cell devices of the same VL, IPCE and FF. The relevance of such studies for tandem n-p DSSCs and for a proposed new configuration for PSCs is discussed. In particular, it is shown that maximum total losses of 1.7 V for DSSCs and 1.4 V for tandem PSCs are necessary to give any efficiency improvement with respect to the single bandgap device. This means, for example, a tandem n-p DSSC with TiO2 and NiO porous electrodes will hardly work better than the champion single DSSC. A source code of the program used for calculations is also provided.

  19. Density functional theory based generalized effective fragment potential method

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Kiet A., E-mail: kiet.nguyen@wpafb.af.mil, E-mail: ruth.pachter@wpafb.af.mil [Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States); UES, Inc., Dayton, Ohio 45432 (United States); Pachter, Ruth, E-mail: kiet.nguyen@wpafb.af.mil, E-mail: ruth.pachter@wpafb.af.mil [Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States); Day, Paul N. [Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States); General Dynamics Information Technology, Inc., Dayton, Ohio 45431 (United States)

    2014-06-28

    We present a generalized Kohn-Sham (KS) density functional theory (DFT) based effective fragment potential (EFP2-DFT) method for the treatment of solvent effects. Similar to the original Hartree-Fock (HF) based potential with fitted parameters for water (EFP1) and the generalized HF based potential (EFP2-HF), EFP2-DFT includes electrostatic, exchange-repulsion, polarization, and dispersion potentials, which are generated for a chosen DFT functional for a given isolated molecule. The method does not have fitted parameters, except for implicit parameters within a chosen functional and the dispersion correction to the potential. The electrostatic potential is modeled with a multipolar expansion at each atomic center and bond midpoint using Stone's distributed multipolar analysis. The exchange-repulsion potential between two fragments is composed of the overlap and kinetic energy integrals and the nondiagonal KS matrices in the localized molecular orbital basis. The polarization potential is derived from the static molecular polarizability. The dispersion potential includes the intermolecular D3 dispersion correction of Grimme et al. [J. Chem. Phys. 132, 154104 (2010)]. The potential generated from the CAMB3LYP functional has mean unsigned errors (MUEs) with respect to results from coupled cluster singles, doubles, and perturbative triples with a complete basis set limit (CCSD(T)/CBS) extrapolation, of 1.7, 2.2, 2.0, and 0.5 kcal/mol, for the S22, water-benzene clusters, water clusters, and n-alkane dimers benchmark sets, respectively. The corresponding EFP2-HF errors for the respective benchmarks are 2.41, 3.1, 1.8, and 2.5 kcal/mol. Thus, the new EFP2-DFT-D3 method with the CAMB3LYP functional provides comparable or improved results at lower computational cost and, therefore, extends the range of applicability of EFP2 to larger system sizes.

  20. Optimized Mie potentials for phase equilibria: Application to noble gases and their mixtures with n-alkanes.

    Science.gov (United States)

    Mick, Jason R; Soroush Barhaghi, Mohammad; Jackman, Brock; Rushaidat, Kamel; Schwiebert, Loren; Potoff, Jeffrey J

    2015-09-21

    Transferrable force fields, based on n-6 Mie potentials, are presented for noble gases. By tuning the repulsive exponent, ni, it is possible to simultaneously reproduce experimental saturated liquid densities and vapor pressures with high accuracy, from the normal boiling point to the critical point. Vapor-liquid coexistence curves for pure fluids are calculated using histogram reweighting Monte Carlo simulations in the grand canonical ensemble. For all noble gases, saturated liquid densities and vapor pressures are reproduced to within 1% and 4% of experiment, respectively. Radial distribution functions, extracted from NVT and NPT Monte Carlo simulations, are in similarly excellent agreement with experimental data. The transferability of the optimized force fields is assessed through calculations of binary mixture vapor-liquid equilibria. These mixtures include argon + krypton, krypton + xenon, methane + krypton, methane + xenon, krypton + ethane, and xenon + ethane. For all mixtures, excellent agreement with experiment is achieved without the introduction of any binary interaction parameters or multi-body interactions.

  1. Strict convexity and C 1, α regularity of potential functions in optimal transportation under condition A3w

    Science.gov (United States)

    Chen, Shibing; Wang, Xu-Jia

    2016-01-01

    In this paper we prove the strict c-convexity and the C 1, α regularity for potential functions in optimal transportation under condition (A3w). These results were obtained by Caffarelli [1,3,4] for the cost c (x, y) =| x - y | 2, by Liu [11], Loeper [15], Trudinger and Wang [20] for costs satisfying the condition (A3). For costs satisfying the condition (A3w), the results have also been proved by Figalli, Kim, and McCann [6], assuming that the initial and target domains are uniformly c-convex, see also [21]; and by Guillen and Kitagawa [8], assuming the cost function satisfies A3w in larger domains. In this paper we prove the strict c-convexity and the C 1, α regularity assuming either the support of source density is compactly contained in a larger domain where the cost function satisfies A3w, or the dimension 2 ≤ n ≤ 4.

  2. Atomic bound state and scattering properties of effective momentum-dependent potentials

    Science.gov (United States)

    Dharuman, Gautham; Verboncoeur, John; Christlieb, Andrew; Murillo, Michael S.

    2016-10-01

    Effective classical dynamics provide a potentially powerful avenue for modeling large-scale dynamical quantum systems. We have examined the accuracy of a Hamiltonian-based approach that employs effective momentum-dependent potentials (MDPs) within a molecular-dynamics framework through studies of atomic ground states, excited states, ionization energies, and scattering properties of continuum states. Working exclusively with the Kirschbaum-Wilets (KW) formulation with empirical MDPs [C. L. Kirschbaum and L. Wilets, Phys. Rev. A 21, 834 (1980), 10.1103/PhysRevA.21.834], optimization leads to very accurate ground-state energies for several elements (e.g., N, F, Ne, Al, S, Ar, and Ca) relative to Hartree-Fock values. The KW MDP parameters obtained are found to be correlated, thereby revealing some degree of transferability in the empirically determined parameters. We have studied excited-state orbits of electron-ion pair to analyze the consequences of the MDP on the classical Coulomb catastrophe. From the optimized ground-state energies, we find that the experimental first- and second-ionization energies are fairly well predicted. Finally, electron-ion scattering was examined by comparing the predicted momentum transfer cross section to a semiclassical phase-shift calculation; optimizing the MDP parameters for the scattering process yielded rather poor results, suggesting a limitation of the use of the KW MDPs for plasmas.

  3. Effect of functionalization on drug delivery potential of carbon nanotubes.

    Science.gov (United States)

    Sharma, Sonam; Mehra, Neelesh Kumar; Jain, Keerti; Jain, Narendra Kumar

    2016-12-01

    The main aim of the present investigation was to explore the effect of functionalization on drug delivery potential of carbon nanotubes (CNTs) and to compare the in vitro and in vivo cancer targeting potential of doxorubicin HCL (DOX)-loaded ox-/multi-walled CNTs (MWCNTs), DOX-loaded PEG-MWCNTs and DOX-loaded FA-PEG-MWCNTs. The DOX/PEG-FA-MWCNTs showed enhanced cytotoxicity and were most preferentially taken up by the cancerous cells. The obtained results also support the extended resistance time and sustained release profile of drug-loaded surface-engineered MWCNTs. Overall, we concluded that the developed MWCNTs nanoformulations have higher cancer targeting potential.

  4. Effective constraint potential in lattice Weinberg - Salam model

    CERN Document Server

    Polikarpov, M I

    2011-01-01

    We investigate lattice Weinberg - Salam model without fermions for the value of the Weinberg angle $\\theta_W \\sim 30^o$, and bare fine structure constant around $\\alpha \\sim 1/150$. We consider the value of the scalar self coupling corresponding to bare Higgs mass around 150 GeV. The effective constraint potential for the zero momentum scalar field is used in order to investigate phenomena existing in the vicinity of the phase transition between the physical Higgs phase and the unphysical symmetric phase of the lattice model. This is the region of the phase diagram, where the continuum physics is to be approached. We compare the above mentioned effective potential (calculated in selected gauges) with the effective potential for the value of the scalar field at a fixed space - time point. We also calculate the renormalized fine structure constant using the correlator of Polyakov lines and compare it with the one - loop perturbative estimate.

  5. Space Nutrition: Effects on Bone and Potential Nutrition Countermeasures

    Science.gov (United States)

    Smith, Scott M.

    2008-01-01

    Optimal nutrition will be critical for crew members who embark on space exploration missions. Nutritional assessment provides an opportunity to ensure that crewmembers begin their missions in optimal nutritional status, to document changes during a mission and , if necessary, to provide intervention to maintain that status throughout the mission, and to assesses changes after landing in order to facilitate the return to their normal status as soon as possible after landing. We report here the findings from our nutritional assessment of the US astronauts who participated in the first eight International Space Station (ISS) missions. Bone loss during space flight remains one of the most critical challenges to astronaut health on space exploration missions. An increase in bone resorption of ISS crew members after flight was indicated by several markers. Vitamin D status also remains a challenge for long-duration space travelers, who lack ultraviolet light exposure in the shielded craft. Many nutrients affect bone, including calcium, protein, fatty acids, sodium, and others. Data supporting their potential as countermeasures for space flight, as published in many papers, will be reviewed in this presentation. Defining nutrient requirements, and being able to provide and maintain those nutrients on exploration missions, will be critical for maintaining crew member health. Please note, this abstract is not required for the meeting. A presentation on the topics described above will be given. This abstract is for travel documentation only.

  6. Context effects in the measurement of optimism in probability judgment

    NARCIS (Netherlands)

    Otten, W.; van der Pligt, J.

    1996-01-01

    Examined the role of contextual information such as comparison standard on self-other probability judgments regarding the occurrence of negative life events, which tend to be characterized by optimism. In Study 1, 80 undergraduates (mean age 19.5 yrs) completed a questionnaire on preventive

  7. Family Functioning and Maladaptive Schemas: The Moderating Effects of Optimism

    Science.gov (United States)

    Buri, John R.; Gunty, Amy L.

    2008-01-01

    Authoritarian parenting is often shown to be associated with negative outcomes for children, including the development of maladaptive schemas. However, this is not the case for all children who experience Authoritarian parenting. Optimism is examined as a moderator in the relationship between Authoritarian parenting and maladaptive schemas that…

  8. Potentials for food waste minimization and effects on potential biogas production through anaerobic digestion.

    Science.gov (United States)

    Schott, Anna Bernstad Saraiva; Vukicevic, Sanita; Bohn, Irene; Andersson, Tova

    2013-08-01

    Several treatment alternatives for food waste can result in both energy and nutrient recovery, and thereby potential environmental benefits. However, according to the European Union waste management hierarchy, waste prevention should be the prioritized strategy to decrease the environmental burdens from all solid waste management. The aim of the present study was therefore to investigate the potential for food waste minimization among Swedish households through an investigation of the amount of avoidable food waste currently disposed of. A further aim was to investigate the effect on the national biogas production potential through anaerobic digestion of food waste, considering minimization potentials. A method for waste composition analyses of household food waste, where a differentiation between avoidable and unavoidable food waste is made, was used in a total of 24 waste composition analyses of household waste from Swedish residential areas. The total household food waste generation reached 3.4 kg (household and week)(-1), on average, of which 34% is avoidable. The theoretical methane (CH4) potential in unavoidable food waste reached 442 Ndm(3) (kg VS)(-1) or 128 Nm(3) tonne(-1) wet waste, while the measured (mesophilic CH4 batch tests) CH4 production reached 399 Ndm(3) (kg VS)(-1), which is lower than several previous assessments of CH4 production from household food waste. According to this study the combination of a decrease in food waste generation-in case of successful minimization-and decreased CH4 production from unavoidable food waste will thus result in lower total potential energy recovery from household food waste through anaerobic digestion CH4 potential than previously stated.

  9. Exact RG invariance and symmetry improved 2PI effective potential

    Directory of Open Access Journals (Sweden)

    Apostolos Pilaftsis

    2017-07-01

    Full Text Available The Symmetry Improved Two-Particle-Irreducible (SI2PI formalism is a powerful tool to calculate the effective potential beyond perturbation theory, whereby infinite sets of selective loop-graph topologies can be resummed in a systematic and consistent manner. In this paper we study the Renormalization-Group (RG properties of this formalism, by proving for the first time a number of new field-theoretic results. First, the RG runnings of all proper 2PI couplings are found to be UV finite, in the Hartree–Fock and sunset approximations of the 2PI effective action. Second, the SI2PI effective potential is exactly RG invariant, in contrast to what happens in the ordinary One-Particle-Irreducible (1PI perturbation theory, where the effective potential is RG invariant only up to higher orders. Finally, we show how the effective potential of an O(2 theory evaluated in the SI2PI framework, appropriately RG improved, can reach a higher level of accuracy, even up to one order of magnitude, with respect to the corresponding one obtained in the 1PI formalism.

  10. Exact RG invariance and symmetry improved 2PI effective potential

    Science.gov (United States)

    Pilaftsis, Apostolos; Teresi, Daniele

    2017-07-01

    The Symmetry Improved Two-Particle-Irreducible (SI2PI) formalism is a powerful tool to calculate the effective potential beyond perturbation theory, whereby infinite sets of selective loop-graph topologies can be resummed in a systematic and consistent manner. In this paper we study the Renormalization-Group (RG) properties of this formalism, by proving for the first time a number of new field-theoretic results. First, the RG runnings of all proper 2PI couplings are found to be UV finite, in the Hartree-Fock and sunset approximations of the 2PI effective action. Second, the SI2PI effective potential is exactly RG invariant, in contrast to what happens in the ordinary One-Particle-Irreducible (1PI) perturbation theory, where the effective potential is RG invariant only up to higher orders. Finally, we show how the effective potential of an O (2) theory evaluated in the SI2PI framework, appropriately RG improved, can reach a higher level of accuracy, even up to one order of magnitude, with respect to the corresponding one obtained in the 1PI formalism.

  11. Effective potentials in a bidimensional vibrated granular gas

    Science.gov (United States)

    Velázquez-Pérez, Stephanie; Pérez-Ángel, Gabriel; Nahmad-Molinari, Yuri

    2016-09-01

    We present a numerical study of the spatial correlations of a quasi-two-dimensional granular fluid kept in a nonstatic steady state via vertical shaking. The simulations explore a wide range of vertical accelerations, restitution coefficients, and packing fractions, always staying below the crystallization limit. From the simulations we obtain the relevant pair distribution functions (PDFs), and effective potentials for the interparticle interaction are extracted from these PDFs via the Ornstein-Zernike equation with the Percus-Yevick closure. The correlations in the granular structures originating from these effective potentials are checked against the originating PDF using standard Monte Carlo simulations, and we find in general an excellent agreement. The resulting effective potentials show an increase of the spatial correlation at contact with the decreasing values of the restitution coefficient, and a tendency of the potentials to display deeper wells for more dissipative dynamics. A general exception to this trend appears for a range of values of the forcing, which depends on the restitution coefficient, but not on the density, where resonant bouncing increases correlations, resulting in deeper potential wells. The nature of these resonances is explored and shown to be the result of synchronization in the parabolic flights of the particles.

  12. An effective hybrid cuckoo search and genetic algorithm for constrained engineering design optimization

    Science.gov (United States)

    Kanagaraj, G.; Ponnambalam, S. G.; Jawahar, N.; Mukund Nilakantan, J.

    2014-10-01

    This article presents an effective hybrid cuckoo search and genetic algorithm (HCSGA) for solving engineering design optimization problems involving problem-specific constraints and mixed variables such as integer, discrete and continuous variables. The proposed algorithm, HCSGA, is first applied to 13 standard benchmark constrained optimization functions and subsequently used to solve three well-known design problems reported in the literature. The numerical results obtained by HCSGA show competitive performance with respect to recent algorithms for constrained design optimization problems.

  13. Potential beneficial effects of butyrate in intestinal and extraintestinal diseases

    Institute of Scientific and Technical Information of China (English)

    Roberto Berni Canani; Margherita Di Costanzo; Ludovica Leone; Monica Pedata; Rosaria Meli; Antonio Calignano

    2011-01-01

    The multiple beneficial effects on human health of the short-chain fatty acid butyrate, synthesized from nonabsorbed carbohydrate by colonic microbiota, are well documented. At the intestinal level, butyrate plays a regulatory role on the transepithelial fluid transport,ameliorates mucosal inflammation and oxidative status,reinforces the epithelial defense barrier, and modulates visceral sensitivity and intestinal motility. In addition,a growing number of studies have stressed the role of butyrate in the prevention and inhibition of colorectal cancer. At the extraintestinal level, butyrate exerts potentially useful effects on many conditions, including hemoglobinopathies, genetic metabolic diseases,hypercholesterolemia, insulin resistance, and ischemic stroke. The mechanisms of action of butyrate are different;many of these are related to its potent regulatory effects on gene expression. These data suggest a wide spectrum of positive effects exerted by butyrate, with a high potential for a therapeutic use in human medicine.

  14. Optimizing decentralized renewable energy production by combining potentials and integrated environmental impact analysis. A case study in the Hannover region

    Energy Technology Data Exchange (ETDEWEB)

    Palmas, Claudia; Siewert, Almut [Leibniz Univ. of Hannover (Germany). Dept. of Environmental Planning

    2013-07-01

    In Europe, the integration of decentralized renewable energy production in regional planning processes plays a crucial role. In particular, regions face a major challenge in order to set up renewable decentralized energy systems and incorporate them into the electricity grid. This paper presents a methodological concept and preliminary tests of applications in order to create an optimization model for an improved renewable energy development and planning practice: firstly, the energy potentials of micro renewable resources are estimated, and secondly the outcomes are combined with an estimation of resulting environmental impacts. Including these data into the spatial analysis, different scenarios can be developed in order to support decision making in landscape planning on the basis of environmental and landscape criteria as well as energy issues, including technical aspects and costs. The case study area is the Hannover region. First results show good energy potentials, which will be in a next step evaluated and combined with environmental impacts in order to improve energy efficiency by integrated renewable, decentralized power plants and energy mix. (orig.)

  15. Conditioning of sewage sludge with electrolysis: effectiveness and optimizing study to improve dewaterability.

    Science.gov (United States)

    Yuan, Haiping; Zhu, Nanwen; Song, Lijie

    2010-06-01

    The potential benefits of electrolysis-conditioned sludge dewatering treatment were investigated in this paper. Focuses were placed on effectiveness and factors affecting such novel application of electrolysis process. Experiments have demonstrated that a significant improvement of sludge dewaterability evaluated by capillary suction time (CST) could be obtained at a relative low value of electrolysis voltage. A Box-Behnken experimental design based on the response surface methodology (RSM) was applied to evaluate the optimum of the influencing variables. The optimal values for electrolysis voltage, electrode distance and electrolysis time are 21 V, 5 cm and 12 min, respectively, at which the CST reduction efficiency of 18.8+/-3.1% could be achieved, this agreed with that predicted by an established polynomial model in this study.

  16. Ant groups optimally amplify the effect of transiently informed individuals

    Science.gov (United States)

    Gelblum, Aviram; Pinkoviezky, Itai; Fonio, Ehud; Ghosh, Abhijit; Gov, Nir; Feinerman, Ofer

    2015-01-01

    To cooperatively transport a large load, it is important that carriers conform in their efforts and align their forces. A downside of behavioural conformism is that it may decrease the group's responsiveness to external information. Combining experiment and theory, we show how ants optimize collective transport. On the single-ant scale, optimization stems from decision rules that balance individuality and compliance. Macroscopically, these rules poise the system at the transition between random walk and ballistic motion where the collective response to the steering of a single informed ant is maximized. We relate this peak in response to the divergence of susceptibility at a phase transition. Our theoretical models predict that the ant-load system can be transitioned through the critical point of this mesoscopic system by varying its size; we present experiments supporting these predictions. Our findings show that efficient group-level processes can arise from transient amplification of individual-based knowledge. PMID:26218613

  17. Ant groups optimally amplify the effect of transiently informed individuals

    Science.gov (United States)

    Gelblum, Aviram; Pinkoviezky, Itai; Fonio, Ehud; Ghosh, Abhijit; Gov, Nir; Feinerman, Ofer

    2015-07-01

    To cooperatively transport a large load, it is important that carriers conform in their efforts and align their forces. A downside of behavioural conformism is that it may decrease the group's responsiveness to external information. Combining experiment and theory, we show how ants optimize collective transport. On the single-ant scale, optimization stems from decision rules that balance individuality and compliance. Macroscopically, these rules poise the system at the transition between random walk and ballistic motion where the collective response to the steering of a single informed ant is maximized. We relate this peak in response to the divergence of susceptibility at a phase transition. Our theoretical models predict that the ant-load system can be transitioned through the critical point of this mesoscopic system by varying its size; we present experiments supporting these predictions. Our findings show that efficient group-level processes can arise from transient amplification of individual-based knowledge.

  18. Efficient and effective compound management to support lead optimization.

    Science.gov (United States)

    Johnson, Chad W; Chatterjee, Moneesh; Kubala, Steve; Helm, David; Houston, John; Banks, Martyn

    2009-06-01

    The introduction of lean thinking and Six Sigma methodologies into the drug discovery process has become an important approach for ensuring efficient workflows while containing costs. For the compound management department at Bristol-Myers Squibb, this has resulted in a partnership with the research community to evaluate and streamline processes to enable cost-disciplined science. The authors describe the results of Lean Six Sigma approaches in the automation and informatics environment that have been optimized to support parallel processing of compounds. This new platform facilitates the rapid and simultaneous data generation from structure activity and structure liability assays. As a result of these compound management improvements, reduction of timelines and quicker decision making has been achieved in the lead optimization process.

  19. Ant groups optimally amplify the effect of transiently informed individuals.

    Science.gov (United States)

    Gelblum, Aviram; Pinkoviezky, Itai; Fonio, Ehud; Ghosh, Abhijit; Gov, Nir; Feinerman, Ofer

    2015-07-28

    To cooperatively transport a large load, it is important that carriers conform in their efforts and align their forces. A downside of behavioural conformism is that it may decrease the group's responsiveness to external information. Combining experiment and theory, we show how ants optimize collective transport. On the single-ant scale, optimization stems from decision rules that balance individuality and compliance. Macroscopically, these rules poise the system at the transition between random walk and ballistic motion where the collective response to the steering of a single informed ant is maximized. We relate this peak in response to the divergence of susceptibility at a phase transition. Our theoretical models predict that the ant-load system can be transitioned through the critical point of this mesoscopic system by varying its size; we present experiments supporting these predictions. Our findings show that efficient group-level processes can arise from transient amplification of individual-based knowledge.

  20. QCD Effective action at high temperature and small chemical potential

    CERN Document Server

    Villavicencio, C

    2007-01-01

    We present a construction of an effective Yang-Mills action for QCD, from the expansion of the fermionic determinant in terms of powers of the chemical potential at high temperature, for the case of massless quarks. We analyze this expansion in the perturbative region and find that it gives extra spurious information. We propose for the non-perturbative sector a simplified effective action which, in principle, contains only the relevant information.

  1. [Classic psychedelic drugs and their potential therapeutic effect].

    Science.gov (United States)

    Bayat, Michael

    2017-09-11

    Over the past decade we have witnessed a renewed scientific interest in the classic hallucinogens (psychedelic drugs). These are substances which exert their effects by an agonist action on the 5-HT2A receptors. The purpose of this paper is to provide a short review and discussion of the psychedelic drugs, their safety profile and their potential antidepressive, anxiolytic and antiaddictive effects. The article primarily focusses on the most recent clinical trials.

  2. Screening and damping effects on the thermodynamic potential in QGP

    Institute of Scientific and Technical Information of China (English)

    王欣; 李家荣

    2003-01-01

    By using the spectral functions of gluons, which contain Debye screening and soft damping effects,the effective two-loop thermodynamic potential in quark-gluon plasma was evaluated via real-time temperatureQCD. The result that depends on screening and damping of gluons as physical parameters is obtained. It canbe seen that our analytical result and the recent lattice results are in agreement for T〉~2Tc.

  3. Potential effects of environmental regulatory procedures on geothermal development

    Energy Technology Data Exchange (ETDEWEB)

    Beeland, G.V.; Boies, D.B.

    1981-01-01

    The potential effects of several types of applicable environmental regulatory procedures on geothermal development were assessed, and particular problem areas were identified. The possible impact of procedures adopted pursuant to the following Federal statutes were analyzed: Clean Air Act; Clean Water Act; Safe Drinking Water Act; and Resource Conservation and Recovery Act. State regulations applicable, or potentially applicable, to geothermal facilities were also reviewed to determine: permit information requirements; pre-permit air or water quality monitoring requirements; effect of mandated time frames for permit approval; and potential for exemption of small facilities. The regulations of the following states were covered in the review: Alaska; Arizona; California; Colorado; Hawaii; Idaho; Montana; Nevada; New Mexico; Oregon; Utah; Washington; and Wyoming. (MHR)

  4. Potentiators exert distinct effects on human, murine, and Xenopus CFTR.

    Science.gov (United States)

    Cui, Guiying; Khazanov, Netaly; Stauffer, Brandon B; Infield, Daniel T; Imhoff, Barry R; Senderowitz, Hanoch; McCarty, Nael A

    2016-08-01

    VX-770 (Ivacaftor) has been approved for clinical usage in cystic fibrosis patients with several CFTR mutations. Yet the binding site(s) on CFTR for this compound and other small molecule potentiators are unknown. We hypothesize that insight into this question could be gained by comparing the effect of potentiators on CFTR channels from different origins, e.g., human, mouse, and Xenopus (frog). In the present study, we combined this comparative molecular pharmacology approach with that of computer-aided drug discovery to identify and characterize new potentiators of CFTR and to explore possible mechanism of action. Our results demonstrate that 1) VX-770, NPPB, GlyH-101, P1, P2, and P3 all exhibited ortholog-specific behavior in that they potentiated hCFTR, mCFTR, and xCFTR with different efficacies; 2) P1, P2, and P3 potentiated hCFTR in excised macropatches in a manner dependent on the degree of PKA-mediated stimulation; 3) P1 and P2 did not have additive effects, suggesting that these compounds might share binding sites. Also 4) using a pharmacophore modeling approach, we identified three new potentiators (IOWH-032, OSSK-2, and OSSK-3) that have structures similar to GlyH-101 and that also exhibit ortholog-specific potentiation of CFTR. These could potentially serve as lead compounds for development of new drugs for the treatment of cystic fibrosis. The ortholog-specific behavior of these compounds suggest that a comparative pharmacology approach, using cross-ortholog chimeras, may be useful for identification of binding sites on human CFTR.

  5. On the effect of phenotypic dimensionality on adaptation and optimality.

    Science.gov (United States)

    Brun-Usan, M; Marin-Riera, M; Salazar-Ciudad, I

    2014-12-01

    What proportion of the traits of individuals has been optimally shaped by natural selection and what has not? Here, we estimate the maximal number of those traits using a mathematical model for natural selection in multitrait organisms. The model represents the most ideal conditions for natural selection: a simple genotype-phenotype map and independent variation between traits. The model is also used to disentangle the influence of fitness functions and the number of traits, n, per se on the efficiency of natural selection. We also allow n to evolve. Our simulations show that, for all fitness functions and even in the best conditions optimal phenotypes are rarely encountered, only for n = 1, and that a large proportion of traits are always far from their optimum, specially for large n. This happens to different degrees depending on the fitness functions (additive linear, additive nonlinear, Gaussian and multiplicative). The traits that arise earlier in evolution account for a larger proportion of the absolute fitness of individuals. Thus, complex phenotypes have, in proportion, more traits that are far from optimal and the closeness to the optimum correlates with the age of the trait. Based on estimated population sizes, mutation rates and selection coefficients, we provide an upper estimation of the number of traits that can become and remain adapted by direct natural selection.

  6. Examining triclosan-induced potentiation of the estrogen uterotrophic effect

    Science.gov (United States)

    Triclosan (TCS), a widely used antibacterial, has been shown to be an endocrine disruptor. We reported previously that TCS potentiated the estrogenic effect of ethinyl estradiol (EE) on uterine growth in rats orally administered 3 μg/kg EE and TCS (2 to 18 mg/kg) in the utero...

  7. Potential effects of chlorogenic acids on platelet activiation

    Science.gov (United States)

    Coffee (Coffea sp) is a most consumed beverage world-wide. Chlorogenic acids (CHAs) are naturally occurring phenolic acid esters abundantly found in coffee. They are reported to have potential health effects on several chronic diseases such as obesity, diabetes and cardiovascular diseases (CVD). At...

  8. Why are effective potentials 'soft'?

    Energy Technology Data Exchange (ETDEWEB)

    Klapp, Sabine H L; Diestler, Dennis J; Schoen, Martin [Stranski-Laboratorium fuer Physikalische und Theoretische Chemie, Sekretariat TC7, Technische Universitaet Berlin, Strasse des 17 Juni 124, D-10623 Berlin (Germany)

    2004-10-20

    This paper is concerned with effective potentials W{sub 1}(R) between interacting supramolecular particles separated by a distance R. We focus on the question of why these potentials are typically 'soft', i.e., remain finite for R {yields} 0 and vary more weakly with R than the underlying interatomic interaction potentials. On the basis of a general expression linking W{sub 1}(R) to the free energy F of the supramolecular system we investigate the origin of the apparent 'softness' of W{sub 1}(R) by considering a number of special model systems, starting with an atom and a diatomic molecule. This simple model already yields a W{sub 1}(R) that is finite at R = 0, but W{sub 1}(R) does not exhibit the slowly varying character typical of effective potentials for realistic systems. We then show that the larger length scale is recovered when one introduces both many-body interactions and thermal fluctuations within the framework of a 'toy model', that is disc-shaped supramolecular units composed of thermalized configurations of Lennard-Jones atoms. In this case, W{sub 1}(R) varies so slowly that it can be parametrized by estimating the free energy change associated with the overlap of the discs. The resulting overlap approximation to W{sub 1}(R) behaves qualitatively like ad hoc effective potentials used in mesoscale simulations, such as dissipative particle dynamics. Indeed, on the basis of Monte Carlo simulations and a solution of hypernetted chain integral equations, we find that fluids interacting via DPD and overlap potentials have very similar structural and thermophysical properties. Moreover, the 'overlap' fluid (like other 'effective' fluids) turns out to be so 'soft' that its properties, particularly at high densities, can be very well estimated by a mean-field treatment.

  9. Molecular identification of potential denitrifying bacteria and use of D-optimal mixture experimental design for the optimization of denitrification process.

    Science.gov (United States)

    Ben Taheur, Fadia; Fdhila, Kais; Elabed, Hamouda; Bouguerra, Amel; Kouidhi, Bochra; Bakhrouf, Amina; Chaieb, Kamel

    2016-04-01

    Three bacterial strains (TE1, TD3 and FB2) were isolated from date palm (degla), pistachio and barley. The presence of nitrate reductase (narG) and nitrite reductase (nirS and nirK) genes in the selected strains was detected by PCR technique. Molecular identification based on 16S rDNA sequencing method was applied to identify positive strains. In addition, the D-optimal mixture experimental design was used to optimize the optimal formulation of probiotic bacteria for denitrification process. Strains harboring denitrification genes were identified as: TE1, Agrococcus sp LN828197; TD3, Cronobacter sakazakii LN828198 and FB2, Pedicoccus pentosaceus LN828199. PCR results revealed that all strains carried the nirS gene. However only C. sakazakii LN828198 and Agrococcus sp LN828197 harbored the nirK and the narG genes respectively. Moreover, the studied bacteria were able to form biofilm on abiotic surfaces with different degree. Process optimization showed that the most significant reduction of nitrate was 100% with 14.98% of COD consumption and 5.57 mg/l nitrite accumulation. Meanwhile, the response values were optimized and showed that the most optimal combination was 78.79% of C. sakazakii LN828198 (curve value), 21.21% of P. pentosaceus LN828199 (curve value) and absence (0%) of Agrococcus sp LN828197 (curve value).

  10. Coarse-grained models using local-density potentials optimized with the relative entropy: Application to implicit solvation

    Science.gov (United States)

    Sanyal, Tanmoy; Shell, M. Scott

    2016-07-01

    Bottom-up multiscale techniques are frequently used to develop coarse-grained (CG) models for simulations at extended length and time scales but are often limited by a compromise between computational efficiency and accuracy. The conventional approach to CG nonbonded interactions uses pair potentials which, while computationally efficient, can neglect the inherently multibody contributions of the local environment of a site to its energy, due to degrees of freedom that were coarse-grained out. This effect often causes the CG potential to depend strongly on the overall system density, composition, or other properties, which limits its transferability to states other than the one at which it was parameterized. Here, we propose to incorporate multibody effects into CG potentials through additional nonbonded terms, beyond pair interactions, that depend in a mean-field manner on local densities of different atomic species. This approach is analogous to embedded atom and bond-order models that seek to capture multibody electronic effects in metallic systems. We show that the relative entropy coarse-graining framework offers a systematic route to parameterizing such local density potentials. We then characterize this approach in the development of implicit solvation strategies for interactions between model hydrophobes in an aqueous environment.

  11. Asymptotic Near Nucleus Structure of the Electron-Interaction Potential in Local Effective Potential Theories

    Science.gov (United States)

    Sahni, Viraht; Qian, Zhixin

    2007-03-01

    In previous work, it has been shown that for spherically symmetric or sphericalized systems, the asymptotic near nucleus structure of the electron-interaction potential is vee(r) = vee(0) + βr + γr^2. In this paper we prove via time-independent Quantal Density Functional Theory[1](Q-DFT): (i) correlations due to the Pauli exclusion principle and Coulomb repulsion do not contribute to the linear structure;(ii) these Pauli and Coulomb correlations contribute quadratically; (iii) the linear structure is solely due to Correlation-Kinetic effects, the coefficient β being determined analytically. By application of adiabatic coupling constant perturbation theory via QDFT we further prove: (iv) the Kohn-Sham (KS-DFT) `exchange' potential vx(r) approaches the nucleus linearly, this structure being due solely to lowest- order Correlation-Kinetic effects: (v) the KS-DFT `correlation' potential vc(r) also approaches the nucleus linearly, being solely due to higher-order Correlation-Kinetic contributions. The above conclusions are equally valid for system of arbitrary symmetry, provided spherical averages of the properties are employed. 1 Quantal Density Functional Theory, V. Sahni (Springer-Verlag 2004)

  12. Quantum mechanics of effective potential at a metal surface

    Science.gov (United States)

    Solomatin, Alexander

    In this thesis we study the nonuniform electron density system at a metal-vacuum interface via the corresponding local effective potential confining the electrons, the metal being represented by the jellium and structureless pseudopotential models. The study is performed within conventional Kohn-Sham (KS) density-functional theory and its recently derived quantum-mechanical interpretation. In the latter, properties are determined in terms of the separate electron correlations due to the Pauli exclusion principle, Coulomb repulsion and the correlation contribution to the kinetc energy. We have derived the exact analytical structure, valid for self-consistent orbitals, of the KS theory exchange potential in the classically forbidden region. This structure is image-potential-like of the form -alphasb{KS,x}(beta)chi where the parameter betasp2 is the ratio of the surface barrier height to the metal Fermi energy. For a Wigner-Seitz radius of rsb{s} = 4.1, which is approximately that for which jellium metal is stable, the decay coefficient is precisely 1/4. Over the metallic range of densities rsb{s} = 2-6, the coefficient ranges from 0.195 to 0.274. Thus, if the asymptotic structure of the KS exchange-correlation potential is the image potential, then this structure is due principally to KS exchange effects, the KS correlation contribution being an order of magnitude smaller. These results, then lead to the concept of an 'image' charge localized to the surface region for asymptotic positions of the electron. We have further derived the exact analytical structure in the vacuum of the Slater exchange potential, and of the Pauli-correlation and correlation-kinetic components of the KS exchange potential. These structures are all image-potential-like, decaying respectively as -alphasb{S}(beta)chi,\\ -alphasb{W}(beta)chi and alphasbsp{tsb{c}}{(1)}(beta)/chi. The Pauli-correlation component constitutes the major fraction of the KS exchange potential asymptotically, but there

  13. Academic Optimism and Organizational Climate: An Elementary School Effectiveness Test of Two Measures

    Science.gov (United States)

    Reeves, Jonathan Bart

    2010-01-01

    This study examined the relationship of two climate constructs in academic optimism and organizational climate as each relates to school effectiveness. Academic optimism is an academic environment comprised of three dimensions: academic emphasis, collective efficacy, and faculty trust (Hoy, Tarter, & Hoy, 2006). The Organizational Climate…

  14. Academic Optimism and Organizational Climate: An Elementary School Effectiveness Test of Two Measures

    Science.gov (United States)

    Reeves, Jonathan Bart

    2010-01-01

    This study examined the relationship of two climate constructs in academic optimism and organizational climate as each relates to school effectiveness. Academic optimism is an academic environment comprised of three dimensions: academic emphasis, collective efficacy, and faculty trust (Hoy, Tarter, & Hoy, 2006). The Organizational Climate Index…

  15. Optimized vehicle scheduling and filling model based on effective space and integrated solving algorithm

    Institute of Scientific and Technical Information of China (English)

    ZHAO Peng; MU Xin; YAO Jin-hua; WANG Yong; YANG Xiu-tai

    2007-01-01

    We established an integrated and optimized model of vehicle scheduling problem and vehicle filling problem for solving an extremely complex delivery mode-multi-type vehicles, non-full loads, pickup and delivery in logistics and delivery system. The integrated and optimized model is based on our previous research result-effective space method. An integrated algorithm suitable for the integrated and optimized model was proposed and corresponding computer programs were designed to solve practical problems. The results indicates the programs can work out optimized delivery routes and concrete loading projects. The model and algorithm have many virtues and are valuable in practice.

  16. Effect of calibration data length on performance and optimal parameters of hydrological model

    Directory of Open Access Journals (Sweden)

    Chuan-Zhe LI

    2010-12-01

    Full Text Available In order to assess the effects of calibration data length on the performance and optimal parameter values of hydrological model in ungauged or data limited catchments (actually, data are non-continuous and fragmental in some catchments, we choose to use non-continuous calibration periods to have more independent streamflow data for SIMHYD model calibration. Nash-Sutcliffe efficiency (NSE and percentage water balance error (WBE are used as performance measures. The Particle Swarm Optimization (PSO method is used to calibrate the rainfall-runoff models. Different length of data range from 1 year to 10 years randomly sampled used for study on impact of calibration data length. 55 relatively unimpaired catchments all over Australia with daily precipitation, potential evapotranspiration (PET, and streamflow data are tested to obtain more general conclusions. The results show that, longer calibration data does not necessarily result in better model performance. In general, 8 years data are sufficient to obtain steady estimates of model performance and parameters for SIMHYD model. It is also show that most humid catchments require fewer calibration data to get good performance and stable parameter values. The model performs better in humid and semi-humid catchments than arid catchments. Our results may have useful and interesting implications in the efficiency of limited observation data used for hydrological model calibration in different climatic catchments.

  17. DAF optimization using Taguchi methods and the effect of thermal cycling parameters on DNA amplification.

    Science.gov (United States)

    Caetano-Anollés, G

    1998-09-01

    Taguchi methods, which are widely applied in industrial process design, were used to optimize DNA amplification finger-printing (DAF). Quadratic loss functions that penalize deviations from prediction values and L9 (3(4)) and L18 (3(8)) orthogonal arrays revealed effects and interactions of amplification reaction components and thermal cycling parameters. Analysis of variance (ANOVA) decomposed the contribution of individual factors to the experimental response (amplification yield and product number), while verification experiments established that optimum conditions were predictable, verifiable and reproducible. While several amplification components (primer, magnesium and enzyme) conditioned the amplification reaction, annealing temperature and time were the only important thermal cycling contributing factors. The Taguchi strategy defined a robust and transportable amplification protocol based on high annealing temperatures (typically 48 degrees C) and primer concentrations (typically 8 microM), which can be applied to the fingerprinting of a wide range of DNA templates of plant and fungal origin. The general strategy of robust experimental design holds potential as an optimization tool for other methods in molecular biology.

  18. Effects of auroral potential drops on plasma sheet dynamics

    Science.gov (United States)

    Xi, Sheng; Lotko, William; Zhang, Binzheng; Wiltberger, Michael; Lyon, John

    2016-11-01

    The reaction of the magnetosphere-ionosphere system to dynamic auroral potential drops is investigated using the Lyon-Fedder-Mobarry global model including, for the first time in a global simulation, the dissipative load of field-aligned potential drops in the low-altitude boundary condition. This extra load reduces the field-aligned current (j||) supplied by nightside reconnection dynamos. The system adapts by forcing the nightside X line closer to Earth, with a corresponding reduction in current lensing (j||/B = constant) at the ionosphere and additional contraction of the plasma sheet during substorm recovery and steady magnetospheric convection. For steady and moderate solar wind driving and with constant ionospheric conductance, the cross polar cap potential and hemispheric field-aligned current are lower by approximately the ratio of the peak field-aligned potential drop to the cross polar cap potential (10-15%) when potential drops are included. Hemispheric ionospheric Joule dissipation is less by 8%, while the area-integrated, average work done on the fluid by the reconnecting magnetotail field increases by 50% within |y| < 8 RE. Effects on the nightside plasma sheet include (1) an average X line 4 RE closer to Earth; (2) a 12% higher mean reconnection rate; and (3) dawn-dusk asymmetry in reconnection with a 17% higher rate in the premidnight sector.

  19. "Governance and Effectiveness of Japanese Aid: Towards Optimality"

    OpenAIRE

    Khan, Haider

    2005-01-01

    In this paper I have tried to pursue two related objectives. First, I have tried to gauge the impact of Japanese aid on South and Southeast Asia. My second objective in this paper is to offer an approach to relate governance and aid-effectveness that could be applied to the aid and macroeconomic time-series data from the region. Using a bounded rationality format presented in a model that allows to progress towards optimality over time invites thinking along the lines of inductive learning to...

  20. Reduction of exposure to acrylamide: achievements, potential of optimization, and problems encountered from the perspectives of a Swiss enforcement laboratory.

    Science.gov (United States)

    Grob, Koni

    2005-01-01

    The most important initiatives taken in Switzerland to reduce exposure of consumers to acrylamide are the separate sale of potatoes low in reducing sugars for roasting and frying, the optimization of the raw material and preparation of french fries, and campaigns to implement suitable preparation methods in the gastronomy and homes. Industry works on improving a range of other products. Although these measures can reduce high exposures by some 80%, they have little effect on the background exposure resulting from coffee, bread, and numerous other products for which no substantial improvement is in sight. At this stage, improvements should be achieved by supporting voluntary activity rather than legal limits. Committed and consistent risk communication is key, and the support of improvements presupposes innovative approaches.

  1. Evaluation Of Potential Cytotoxic Effects Of Herbal Extracts

    Directory of Open Access Journals (Sweden)

    Radovanovic Ana

    2015-12-01

    Full Text Available Herbal medicines have played an important role in treating different diseases since ancient times. Bioactive components of medicinal plants are a good starting point for discovering new drugs such as chemotherapeutics. Currently, there are four classes of plant-derived chemotherapeutic drugs used in clinical practice. However, to discover new potential cytotoxic molecules, the research effort on herbal extracts has not diminished. The aim of this review was to evaluate the chemical constituents of plants that possess cytotoxicity, the signalling pathways responsible for this effect, and the influence of solvent polarity on potential cytotoxic effect and to present the cytotoxic activity of selected herbal extracts. The polyphenolic, anthraquinon, diterpneoid, triterpenoid, flavonoid, betulinic acid and berberine content contributes to cytotoxicity of herbal extracts. The inhibitory effect on cancer cells viability could be a consequence of the non-apoptotic processes, such as cell cycle arrestment, and the apoptotic process in tumour cells through different signalling pathways. The influence of solvent polarity on potential cytotoxic effect of herbal extracts should not be ignored. In general, the best cytotoxic activity was found in nonpolar and moderately polar herbal extracts. The herbal extract with IC50 below 30 μg/ml could be considered a very strong cytotoxic agent. Considering that many antitumor drugs have been discovered from natural products, further research on plants and plant-derived chemicals may result in the discovery of potent anticancer agents.

  2. Music listening after stroke: beneficial effects and potential neural mechanisms.

    Science.gov (United States)

    Särkämö, Teppo; Soto, David

    2012-04-01

    Music is an enjoyable leisure activity that also engages many emotional, cognitive, and motor processes in the brain. Here, we will first review previous literature on the emotional and cognitive effects of music listening in healthy persons and various clinical groups. Then we will present findings about the short- and long-term effects of music listening on the recovery of cognitive function in stroke patients and the underlying neural mechanisms of these music effects. First, our results indicate that listening to pleasant music can have a short-term facilitating effect on visual awareness in patients with visual neglect, which is associated with functional coupling between emotional and attentional brain regions. Second, daily music listening can improve auditory and verbal memory, focused attention, and mood as well as induce structural gray matter changes in the early poststroke stage. The psychological and neural mechanisms potentially underlying the rehabilitating effect of music after stroke are discussed. © 2012 New York Academy of Sciences.

  3. Effect of synergism in the mechanics of multilayer designs. 2. synthesis of optimal acoustic systems

    Science.gov (United States)

    Urzhumtsev, Yu. S.; Babe, G. D.; Gusev, E. L.

    1985-07-01

    Use of the synergism effect in the mechanics of inhomogeneous systems, and algorithms constructed on the basis of the theory of optimal control makes it possible to synthesize multilayer designs that are optimum in terms of weight capacity, thermal stability, sound conduction, and sound insulation. The proposed approach to solution of the problem of the optimal design of multilayer acoustic systems makes it possible firstly to develop a rather effective method on the basis of this approach; this method reduces to a solution that is optimal in terms of the physical parameters of the layer materials, the layer thicknesses, and the number of layers; and, secondly, to establish a number of qualitative attributes of the parameters of optimal multilayer structures. This approach is also promising for the development of methods for the optimization of multilayer foundations and systems that dampen vibrational loadings, earthquake-resistant designs, and armor protection.

  4. Negative electron affinities from DFT: influence of asymptotic exchange-correlation potential and effective homogeneity under density scaling.

    Science.gov (United States)

    Borgoo, Alex; Tozer, David J

    2012-06-07

    The influence of the asymptotic exchange-correlation potential and density-scaling homogeneity on negative electron affinities determined using the approach of Tozer and De Proft [J. Phys. Chem. A2005, 109, 8923] is investigated. Application of an asymptotic correction to the potential improves the accuracy for several of the systems with the most negative affinities, reflecting their diffuse lowest unoccupied orbitals. For systems with modest affinities, it reduces the accuracy marginally. Enforcing a near-exact effective homogeneity through a simple shift in the potential leads to improved correlation with experimental values but significantly overestimated affinities. Optimal effective homogeneities are therefore determined, and a simple scheme is proposed for enforcing an average optimal value. Application of the scheme to a series of organic molecules maintains the excellent correlation with the experimental values while significantly reducing the absolute errors.

  5. Electron interactions in graphene through an effective Coulomb potential

    Science.gov (United States)

    Rodrigues, Joao N. B.; Adam, Shaffique

    A recent numerical work [H.-K. Tang et al, PRL 115, 186602 (2015)] considering graphene's π-electrons interacting through an effective Coulomb potential that is finite at short-distances, stressed the importance of the sp2 -electrons in determining the semimetal to Mott insulator phase transition in graphene. Some years ago, I. F. Herbut [PRL 97, 146401 (2006)] studied such a transition by mapping graphene's π-electrons into a Gross-Neveu model. From a different perspective, D. T. Son [PRB 75, 235423 (2007)] put the emphasis on the long-range interactions by modelling graphene as Dirac fermions interacting through a bare Coulomb potential. Here we build on these works and explore the phase diagram of Dirac fermions interacting through an effective Coulomb-like potential screened at short-distances. The interaction potential used allows for analytic results that controllably switch between the two perspectives above. This work was supported by the Singapore National Research Foundation (NRF-NRFF2012-01 and CA2DM medium-sized centre program) and by the Singapore Ministry of Education and Yale-NUS College (R-607-265-01312).

  6. Effective balance equations for elastic composites subject to inhomogeneous potentials

    Science.gov (United States)

    Penta, Raimondo; Ramírez-Torres, Ariel; Merodio, José; Rodríguez-Ramos, Reinaldo

    2017-08-01

    We derive the new effective governing equations for linear elastic composites subject to a body force that admits a Helmholtz decomposition into inhomogeneous scalar and vector potentials. We assume that the microscale, representing the distance between the inclusions (or fibers) in the composite, and its size (the macroscale) are well separated. We decouple spatial variations and assume microscale periodicity of every field. Microscale variations of the potentials induce a locally unbounded body force. The problem is homogenizable, as the results, obtained via the asymptotic homogenization technique, read as a well-defined linear elastic model for composites subject to a regular effective body force. The latter comprises both macroscale variations of the potentials, and nonstandard contributions which are to be computed solving a well-posed elastic cell problem which is solely driven by microscale variations of the potentials. We compare our approach with an existing model for locally unbounded forces and provide a simplified formulation of the model which serves as a starting point for its numerical implementation. Our formulation is relevant to the study of active composites, such as electrosensitive and magnetosensitive elastomers.

  7. Angle-resolved effective potentials for disk-shaped molecules

    Energy Technology Data Exchange (ETDEWEB)

    Heinemann, Thomas, E-mail: thomas.heinemann@tu-berlin.de; Klapp, Sabine H. L., E-mail: klapp@physik.tu-berlin.de [Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin (Germany); Palczynski, Karol, E-mail: karol.palczynski@helmholtz-berlin.de; Dzubiella, Joachim, E-mail: joachim.dzubiella@helmholtz-berlin.de [Institut für Physik, Humboldt Universität zu Berlin, Newtonstraße 15, 12489 Berlin (Germany); Helmholtz Zentrum Berlin (HZB), Institute of Soft Matter and Functional Materials, Hahn-Meitner Platz 1, 14109 Berlin (Germany)

    2014-12-07

    We present an approach for calculating coarse-grained angle-resolved effective pair potentials for uniaxial molecules. For integrating out the intramolecular degrees of freedom we apply umbrella sampling and steered dynamics techniques in atomistically-resolved molecular dynamics (MD) computer simulations. Throughout this study we focus on disk-like molecules such as coronene. To develop the methods we focus on integrating out the van der Waals and intramolecular interactions, while electrostatic charge contributions are neglected. The resulting coarse-grained pair potential reveals a strong temperature and angle dependence. In the next step we fit the numerical data with various Gay-Berne-like potentials to be used in more efficient simulations on larger scales. The quality of the resulting coarse-grained results is evaluated by comparing their pair and many-body structure as well as some thermodynamic quantities self-consistently to the outcome of atomistic MD simulations of many-particle systems. We find that angle-resolved potentials are essential not only to accurately describe crystal structures but also for fluid systems where simple isotropic potentials start to fail already for low to moderate packing fractions. Further, in describing these states it is crucial to take into account the pronounced temperature dependence arising in selected pair configurations due to bending fluctuations.

  8. Angle-resolved effective potentials for disk-shaped molecules.

    Science.gov (United States)

    Heinemann, Thomas; Palczynski, Karol; Dzubiella, Joachim; Klapp, Sabine H L

    2014-12-07

    We present an approach for calculating coarse-grained angle-resolved effective pair potentials for uniaxial molecules. For integrating out the intramolecular degrees of freedom we apply umbrella sampling and steered dynamics techniques in atomistically-resolved molecular dynamics (MD) computer simulations. Throughout this study we focus on disk-like molecules such as coronene. To develop the methods we focus on integrating out the van der Waals and intramolecular interactions, while electrostatic charge contributions are neglected. The resulting coarse-grained pair potential reveals a strong temperature and angle dependence. In the next step we fit the numerical data with various Gay-Berne-like potentials to be used in more efficient simulations on larger scales. The quality of the resulting coarse-grained results is evaluated by comparing their pair and many-body structure as well as some thermodynamic quantities self-consistently to the outcome of atomistic MD simulations of many-particle systems. We find that angle-resolved potentials are essential not only to accurately describe crystal structures but also for fluid systems where simple isotropic potentials start to fail already for low to moderate packing fractions. Further, in describing these states it is crucial to take into account the pronounced temperature dependence arising in selected pair configurations due to bending fluctuations.

  9. The effects of optimism, religion, and hope on mood and anxiety disorders in women with the FMR1 premutation.

    Science.gov (United States)

    Lowell, E P; Tonnsen, B L; Bailey, D B; Roberts, J E

    2017-10-01

    The FMR1 premutation, caused by a CGG trinucleotide repeat expansion on the FMR1 gene, has been identified as a genetic risk factor for mood and anxiety disorders. Building on recent studies identifying increased risk for mood and affective disorders in this population, we examined effects of potential protective factors (optimism, religion, hope) on depression and anxiety diagnoses in a prospective, longitudinal cohort. Eighty-three women with the FMR1 premutation participated in the Structured Clinical Interview for DSM-IV-TR Disorders at two-time points, 3 years apart. Participants also completed measures of optimism, religion, personal faith, hope, and child and family characteristics. We used logistic regression to examine correlates of major depressive disorder (MDD) and anxiety disorders at the initial assessment, as well as predictors of the diagnostic course over time. Lower optimism and higher religious participation relevant to fragile X syndrome at the initial assessment were associated with a lifetime history of MDD. Lower optimism also predicted the occurrence and reoccurrence of an anxiety disorder 3 years later. In women with the FMR1 premutation, elevated optimism may reduce the occurrence or severity of MDD and anxiety disorders. These findings underscore the importance of supporting mental health across the FMR1 spectrum of involvement. © 2017 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.

  10. Potential neoplastic effects of parathion-methyl on rat liver

    Institute of Scientific and Technical Information of China (English)

    M. Nisa UNALDI CORAL; Sonay UCMAN; Hasan YILDIZ; Haydar OZTAS; Semih DALKILIC

    2009-01-01

    The mutagenic and carcinogenic effects of parathion-methyl were examined by bacterial reverse assay and a long term experiment with Wistar rats. The potential mutagenic effect of parathion-methyl in Salmonella typhimurium TA100 bacterial cells was observed without rat liver S9 metabolic activation. Parathion-methyl was further investigated for pathological changes in rat pancreas and liver. The long-term rat experiments showed that parathion-methyl exposure for 3 months can cause pathological changes in rat pancreases acinar cells and pancreatic hepatocytes. Atypical acinar cell focuses (AACF) were determined in the liver and pancreas of the rats. The results from short-term Ames test and long-term rat experiments suggest that parathion-methyl would be potential carcinogenic.

  11. Quantum effective potential, electron transport and conformons in biopolymers

    Energy Technology Data Exchange (ETDEWEB)

    Dandoloff, Rossen [Laboratoire de Physique Theorique et Modelisation, Universite de Cergy-Pontoise, F-95302 Cergy-Pontoise (France); Balakrishnan, Radha [The Institute of Mathematical Sciences, Chennai 600113 (India)

    2005-07-08

    In the Kirchhoff model of a biopolymer, conformation dynamics can be described in terms of solitary waves, for certain special cross-section asymmetries. Applying this to the problem of electron transport, we show that the quantum effective potential arising due to the bends and twists of the polymer enables us to formalize and quantify the concept of a conformon that has been hypothesized in biology. Its connection to the soliton solution of the cubic nonlinear Schroedinger equation emerges in a natural fashion.

  12. Opinion on potential health effects of exposure to electromagnetic fields.

    Science.gov (United States)

    2015-09-01

    In January 2015, the Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) published its final opinion on "Potential health effects of exposure to electromagnetic fields." The purpose of this document was to update previous SCENIHR opinions in the light of recently available information since then, and to give special consideration to areas that had not been dealt with in the previous opinions or in which important knowledge gaps had been identified.

  13. EFFECTS OF MANGANESE ON THYROID HORMONE HOMEOSTASIS: POTENTIAL LINKS

    OpenAIRE

    Soldin, OP; Aschner, M.

    2007-01-01

    Manganese (Mn) is an essential trace nutrient that is potentially toxic at high levels of exposure. As a constituent of numerous enzymes and a cofactor, manganese plays an important role in a number of physiologic processes in mammals. The manganese-containing enzyme, manganese superoxide dismutase (Mn-SOD), is the principal antioxidant enzyme which neutralizes the toxic effects of reactive oxygen species. Other manganese-containing enzymes include oxidoreductases, transferases, hydrolases, l...

  14. Effects of finite element formulation on optimal plate and shell structural topologies

    CSIR Research Space (South Africa)

    Long, CS

    2009-09-01

    Full Text Available The effects of selected membrane, plate and flat shell finite element formulations on optimal topologies are numerically investigated. Two different membrane components are considered. The first is a standard 4-node bilinear quadrilateral...

  15. Optimal Coordinated Control of Power Extraction in LES of a Wind Farm with Entrance Effects

    Directory of Open Access Journals (Sweden)

    Jay P. Goit

    2016-01-01

    Full Text Available We investigate the use of optimal coordinated control techniques in large eddy simulations of wind farm boundary layer interaction with the aim of increasing the total energy extraction in wind farms. The individual wind turbines are considered as flow actuators, and their energy extraction is dynamically regulated in time, so as to optimally influence the flow field. We extend earlier work on wind farm optimal control in the fully-developed regime (Goit and Meyers 2015, J. Fluid Mech. 768, 5–50 to a ‘finite’ wind farm case, in which entrance effects play an important role. For the optimal control, a receding horizon framework is employed in which turbine thrust coefficients are optimized in time and per turbine. Optimization is performed with a conjugate gradient method, where gradients of the cost functional are obtained using adjoint large eddy simulations. Overall, the energy extraction is increased 7% by the optimal control. This increase in energy extraction is related to faster wake recovery throughout the farm. For the first row of turbines, the optimal control increases turbulence levels and Reynolds stresses in the wake, leading to better wake mixing and an inflow velocity for the second row that is significantly higher than in the uncontrolled case. For downstream rows, the optimal control mainly enhances the sideways mean transport of momentum. This is different from earlier observations by Goit and Meyers (2015 in the fully-developed regime, where mainly vertical transport was enhanced.

  16. Optimal Control of Renewable Resources Based on the Effective Utilization Rate

    Directory of Open Access Journals (Sweden)

    Rui Wu

    2015-01-01

    Full Text Available The effective utilization rate of exploited renewable resources affects the final total revenue and the further exploitation of renewable resources. Considering the effective utilization rate, we propose an optimal control model for the exploitation of the renewable resources in this study. Firstly, we can prove that the novel model is nonsingular compared with the singular basic model. Secondly, we solve the novel model and obtain the optimal solution by Bang-Bang theory. Furthermore, we can determine the optimal total resources and the maximal total revenue. Finally, a numerical example is provided to verify the obtained theoretical results.

  17. Optimal dynamic pricing for deteriorating items with reference-price effects

    Science.gov (United States)

    Xue, Musen; Tang, Wansheng; Zhang, Jianxiong

    2016-07-01

    In this paper, a dynamic pricing problem for deteriorating items with the consumers' reference-price effect is studied. An optimal control model is established to maximise the total profit, where the demand not only depends on the current price, but also is sensitive to the historical price. The continuous-time dynamic optimal pricing strategy with reference-price effect is obtained through solving the optimal control model on the basis of Pontryagin's maximum principle. In addition, numerical simulations and sensitivity analysis are carried out. Finally, some managerial suggestions that firm may adopt to formulate its pricing policy are proposed.

  18. Optimal distribution of wind farm turbines using PSO considering the wake effect

    Directory of Open Access Journals (Sweden)

    Juan David Ramírez Ramírez

    2016-02-01

    Full Text Available This paper proposes a novel algorithm for optimal location of the turbines of a wind farm, considering the wake effect and any provision of winds, using the metaheuristic technique for particle swarm optimization (PSO. Likewise, the provision that generates more energy for a proposed case is shown, taking into account the constraints of distances between the turbines, the wind farm area and the wake effect. The energy optimization generated by the park is realized for a compass rose over a period of time.

  19. Effective potential and Goldstone bosons in de Sitter space

    CERN Document Server

    Arai, Takashi

    2013-01-01

    We investigate nonperturbative infrared effects for the O(N) linear sigma model in de Sitter space using the two-particle irreducible effective action at the Hartree truncation level. This approximation resums the infinite series of so-called superdaisy diagrams. For the proper treatment of ultraviolet divergences, we first study the renormalization of this approximation on a general curved background. Then, we calculate radiatively corrected masses and the effective potential. As a result, spontaneous symmetry breaking is possible, on the other hand, the Goldstone modes acquire a positive definite mass term due to the screening effects of interaction. Possible infrared divergence is self-regulated by the mass term. Furthermore, there is a symmetry restoring phase transition as a function of the Hubble parameter. In our approximation, the phase transition is of first order.

  20. Optimizing bulk milk dioxin monitoring based on costs and effectiveness

    NARCIS (Netherlands)

    Lascano Alcoser, V.; Velthuis, A.G.J.; Fels-Klerx, van der H.J.; Hoogenboom, L.A.P.; Oude Lansink, A.G.J.M.

    2013-01-01

    Dioxins are environmental pollutants, potentially present in milk products, which have negative consequences for human health and for the firms and farms involved in the dairy chain. Dioxin monitoring in feed and food has been implemented to detect their presence and estimate their levels in food

  1. Optimizing bulk milk dioxin monitoring based on costs and effectiveness

    NARCIS (Netherlands)

    Lascano Alcoser, V.; Velthuis, A.G.J.; Fels-Klerx, van der H.J.; Hoogenboom, L.A.P.; Oude Lansink, A.G.J.M.

    2013-01-01

    Dioxins are environmental pollutants, potentially present in milk products, which have negative consequences for human health and for the firms and farms involved in the dairy chain. Dioxin monitoring in feed and food has been implemented to detect their presence and estimate their levels in food ch

  2. Optimizing bulk milk dioxin monitoring based on costs and effectiveness

    NARCIS (Netherlands)

    Lascano Alcoser, V.; Velthuis, A.G.J.; Fels-Klerx, van der H.J.; Hoogenboom, L.A.P.; Oude Lansink, A.G.J.M.

    2013-01-01

    Dioxins are environmental pollutants, potentially present in milk products, which have negative consequences for human health and for the firms and farms involved in the dairy chain. Dioxin monitoring in feed and food has been implemented to detect their presence and estimate their levels in food ch

  3. Hofmeister effects: interplay of hydration, nonelectrostatic potentials, and ion size.

    Science.gov (United States)

    Parsons, Drew F; Boström, Mathias; Lo Nostro, Pierandrea; Ninham, Barry W

    2011-07-21

    The classical Derjaguin-Landau-Verwey-Overbeek (DLVO) theory of colloids, and corresponding theories of electrolytes, are unable to explain ion specific forces between colloidal particles quantitatively. The same is true generally, for surfactant aggregates, lipids, proteins, for zeta and membrane potentials and in adsorption phenomena. Even with fitting parameters the theory is not predictive. The classical theories of interactions begin with continuum solvent electrostatic (double layer) forces. Extensions to include surface hydration are taken care of with concepts like inner and outer Helmholtz planes, and "dressed" ion sizes. The opposing quantum mechanical attractive forces (variously termed van der Waals, Hamaker, Lifshitz, dispersion, nonelectrostatic forces) are treated separately from electrostatic forces. The ansatz that separates electrostatic and quantum forces can be shown to be thermodynamically inconsistent. Hofmeister or specific ion effects usually show up above ≈10(-2) molar salt. Parameters to accommodate these in terms of hydration and ion size had to be invoked, specific to each case. Ionic dispersion forces, between ions and solvent, for ion-ion and ion-surface interactions are not explicit in classical theories that use "effective" potentials. It can be shown that the missing ionic quantum fluctuation forces have a large role to play in specific ion effects, and in hydration. In a consistent predictive theory they have to be included at the same level as the nonlinear electrostatic forces that form the skeletal framework of standard theory. This poses a challenge. The challenges go further than academic theory and have implications for the interpretation and meaning of concepts like pH, buffers and membrane potentials, and for their experimental interpretation. In this article we overview recent quantitative developments in our evolving understanding of the theoretical origins of specific ion, or Hofmeister effects. These are demonstrated

  4. Effects of disintegration-promoting agent, lubricants and moisture treatment on optimized fast disintegrating tablets.

    Science.gov (United States)

    Late, Sameer G; Yu, Yi-Ying; Banga, Ajay K

    2009-01-05

    Effects of calcium silicate (disintegration-promoting agent) and various lubricants on an optimized beta-cyclodextrin-based fast-disintegrating tablet formulation were investigated. Effects of moisture treatment were also evaluated at 75, 85 and 95% relative humidities. A two factor, three levels (3(2)) full factorial design was used to optimize concentrations of calcium silicate and lubricant. Magnesium stearate, being commonly used lubricant, was used to optimize lubricant concentration in optimization study. Other lubricants were evaluated at an obtained optimum concentration. Desiccator with saturated salt solutions was used to analyze effects of moisture treatments. Results of multiple linear regression analysis revealed that concentration of calcium silicate had no effect; however concentration of lubricant was found to be important for tablet disintegration and hardness. An optimized value of 1.5% of magnesium stearate gave disintegration time of 23.4 s and hardness of 1.42 kg. At an optimized concentration, glycerol dibehenate and L-leucine significantly affected disintegration time, while talc and stearic acid had no significant effect. Tablet hardness was significantly affected with L-leucine, while other lubricants had no significant effect. Hardness was not affected at 75% moisture treatment. Moisture treatment at 85 and 95% increased hardness of the tablets; however at the same time it negatively affected the disintegration time.

  5. A simple method to measure effective catalase activities: optimization, validation, and application in green coffee.

    Science.gov (United States)

    Montavon, Philippe; Kukic, Koraljka Rade; Bortlik, Karlheinz

    2007-01-15

    Oxidative metabolism in coffee cherries during maturation appears to be regulated by the timely expression of redox enzymes such as catalase (CAT), peroxidase (POD), and polyphenoloxidase (PPO). Among these enzymes, CAT is suspected to contribute significantly in setting the redox status of the healthy cherry and the processed bean. The initial redox status of the green bean might further control the nature and dynamics of reactions induced by roasting and eventually quality aspects of the end product. In this respect, Arabica (Coffea arabica) and Robusta (Coffea canephora) typically differ by their cup coffee flavor profiles. We developed an assay that allowed us to screen numerous green coffee samples for effective CAT activities. The proposed assay, which monitors CAT activities by online oxygen sensing in green coffee crude suspensions incubated with H2O2, seeks to integrate potential effects of endogenous inhibitors and activators. After optimization and validation of the assay, 23 Arabicas, 23 Robustas, and 8 Arabustas were analyzed. Nearly all Arabicas (22 of 23) harbored high CAT activity levels, whereas all Robustas harbored low ones. Arabustas performed like Arabicas of the lower CAT activity range. The traditional spectrophotometric assay did not reveal these specificities. Because of its simplicity, our assay might be valuable for assessing effective CAT activities in various plant tissues.

  6. Structural properties of effective potential model by liquid state theories

    Institute of Scientific and Technical Information of China (English)

    Xiang Yuan-Tao; Andrej Jamnik; Yang Kai-Wei

    2010-01-01

    This paper investigates the structural properties of a model fluid dictated by an effective inter-particle oscillatory potential by grand canonical ensemble Monte Carlo (GCEMC) simulation and classical liquid state theories. The chosen oscillatory potential incorporates basic interaction terms used in modeling of various complex fluids which is composed of mesoscopic particles dispersed in a solvent bath, the studied structural properties include radial distribution function in bulk and inhomogeneous density distribution profile due to influence of several external fields. The GCEMC results are employed to test the validity of two recently proposed theoretical approaches in the field of atomic fluids. One is an Ornstein-Zernike integral equation theory approach; the other is a third order + second order perturbation density functional theory. Satisfactory agreement between the GCEMC simulation and the pure theories fully indicates the ready adaptability of the atomic fluid theories to effective model potentials in complex fluids, and classifies the proposed theoretical approaches as convenient tools for the investigation of complex fluids under the single component macro-fluid approximation.

  7. Combining Slater-type orbitals and effective core potentials

    Science.gov (United States)

    Lesiuk, Michał; Tucholska, Aleksandra M.; Moszynski, Robert

    2017-05-01

    We present a general methodology to evaluate matrix elements of the effective core potentials (ECPs) within a one-electron basis set of Slater-type orbitals (STOs). The scheme is based on translation of individual STO distributions in the framework of the Barnett-Coulson method. We discuss different types of integrals which naturally appear and reduce them to a few basic quantities which can be calculated recursively or purely numerically. Additionally, we consider evaluation of the STOs matrix elements involving the core polarization potentials and effective spin-orbit potentials. Construction of the STOs basis sets designed specifically for use with ECPs is discussed and differences in comparison with all-electron basis sets are briefly summarized. We verify the validity of the present approach by calculating excitation energies, static dipole polarizabilities, and valence orbital energies for the alkaline-earth metals (Ca, Sr, and Ba). Finally, we evaluate interaction energies, permanent dipole moments, and ionization energies for barium and strontium hydrides, and compare them with the best available experimental and theoretical data.

  8. The Effects of Calorie Restriction in Depression and Potential Mechanisms

    Science.gov (United States)

    Zhang, Yifan; Liu, Changhong; Zhao, Yinghao; Zhang, Xingyi; Li, Bingjin; Cui, Ranji

    2015-01-01

    Depression, also called major depressive disorder, is a neuropsychiatric disorder jeopardizing an increasing number of the population worldwide. To date, a large number of studies have devoted great attention to this problematic condition and raised several hypotheses of depression. Based on these theories, many antidepressant drugs were developed for the treatment of depression. Yet, the depressed patients are often refractory to the antidepressant therapies. Recently, increasing experimental evidences demonstrated the effects of calorie restriction in neuroendocrine system and in depression. Both basic and clinical investigations indicated that short-term calorie restriction might induce an antidepressant efficacy in depression, providing a novel avenue for treatment. Molecular basis underlying the antidepressant actions of calorie restriction might involve multiple physiological processes, primarily including orexin signaling activation, increased CREB phosphorylation and neurotrophic effects, release of endorphin and ketone production. However, the effects of chronic calorie restriction were quite controversial, in the cases that it often resulted in the long-term detrimental effects via inhibiting the function of 5-HT system and decreasing leptin levels. Here we review such dual effects of calorie restriction in depression and potential molecular basis behind these effects, especially focusing on antidepressant effects. PMID:26412073

  9. Total synthesis of discodermolide: optimization of the effective synthetic route.

    Science.gov (United States)

    de Lemos, Elsa; Porée, François-Hugues; Bourin, Arnaud; Barbion, Julien; Agouridas, Evangelos; Lannou, Marie-Isabelle; Commerçon, Alain; Betzer, Jean-François; Pancrazi, Ange; Ardisson, Janick

    2008-01-01

    An efficient and modulable total synthesis of discodermolide (DDM), a unique marine anticancer polyketide is described including related alternative synthetic approaches. Particularly notable is the repeated application of a crotyltitanation reaction to yield homoallylic (Z)-O-ene-carbamate alcohols with excellent selectivity. Advantage was taken of this reaction not only for the stereocontrolled building of the syn-anti methyl-hydroxy-methyl triads of DDM, but also for the direct construction of the terminal (Z)-diene. Of particular interest is also the installation of the C13=C14 (Z)-double bond through a highly selective dyotropic rearrangement. The preparation of the middle C8-C14 fragment in two sequential stages and its coupling to the C1-C7 moiety was a real challenge and required careful optimization. Several synthetic routes were explored to allow high and reliable yields. Due to the flexibility and robust character of this approach, it might enable a systematic structural variation of DDM and, therefore, the elaboration and exploration of novel discodermolide structural analogues.

  10. A semiempirical study of the optimized ground and excited state potential energy surfaces of retinal and its protonated Schiff base

    Science.gov (United States)

    Parusel, A. B.; Pohorille, A.

    2001-01-01

    The electronic ground and first excited states of retinal and its Schiff base are optimized for the first time using the semiempirical AM1 Hamiltonian. The barrier for rotation about the C(11)-C(12) double bond is characterized by variation of both the twist angle delta(C(10)-C(11)-C(12)-C(13)) and the bond length d(C(11)-C(12)). The potential energy surface is obtained by varying these two parameters. The calculated ground state rotational barrier is equal to 15.6 kcal/mol for retinal and 20.5 kcal/mol for its Schiff base. The all-trans conformation is more stable by 3.7 kcal/mol than the 11-cis geometry. For the first excited state, S(1,) the 90 degrees twisted geometry represents a saddle point for retinal with the rotational barrier of 14.6 kcal/mol. In contrast, this conformation is an energy minimum for the Schiff base. It can be easily reached at room temperature from the planar minima since it is separated from them by a barrier of only 0.6 kcal/mol. The 90 degrees minimum conformation is more stable than the all-trans by 8.6 kcal/mol. We are thus able to present a reaction path on the S(1) surface of the retinal Schiff base with an almost barrier-less geometrical relaxation into a twisted minimum geometry, as observed experimentally. The character of the ground and first excited singlet states underscores the need for the inclusion of double excitations in the calculations.

  11. Optimal use of biofuels to reduce the contribution to the greenhouse effect; Optimal anvaendning av biobraensle foer minskning av vaexthuseffekten

    Energy Technology Data Exchange (ETDEWEB)

    Aasblad, A.; Franck, P.Aa.; Berntsson, T. [Chalmers Industriteknik, Goeteborg (Sweden). CIT Energiteknisk Analys

    1995-12-31

    This report analyses whether the use of biofuels in district heating systems is a cost effective measure to decrease the emissions of greenhouse gases in Sweden or not. We have taken the year 2005 as an average for the next 15 to 20 years and used prognosis from NUTEK to estimate the national electricity production system together with fuel and electricity prices. Three sizes of district heating systems have been considered with annual heat loads of 2, 60 and 300 GWh. We have identified the optimal mix of production techniques that produces heat to the lowest total cost for a given allowed level of greenhouse gas emissions. Conclusions about the individual technologies can be drawn by studying the change in the cost optimal production mix when the allowed level of emission changes. To get substantially lower carbon dioxide emissions, CHP-plants based on biofuels must be introduced. In Sweden, however, the carbon dioxide emissions associated with electricity production are low (even in the year 2005) and the prognosis for the electricity price does not make it profitable to introduce CHP-plants on economical grounds. This means that the cost for decreasing emission substantially below 50 kg/MWh with CHP-plants normally is expensive since the decrease in emissions is low and the increase in cost is high. 17 refs, 34 figs, 21 tabs

  12. TOPOLOGY OPTIMIZATION OF OPTICAL BAND GAP EFFECTS IN SLAB STRUCTURES MODULATED BY PERIODIC RAYLEIGHWAVES

    DEFF Research Database (Denmark)

    This paper is concerned with topology optimization of a coupled optical and mechanical wave propagation problem in photonic crystals. It is motivated by the potential gain in functionality of optical devices where mechanical Rayleigh waves (travelling in the surface of the material) play a leadin...

  13. Brain potentials associated with the outcome processing in framing effects.

    Science.gov (United States)

    Ma, Qingguo; Feng, Yandong; Xu, Qing; Bian, Jun; Tang, Huixian

    2012-10-24

    Framing effect is a cognitive bias referring to the phenomenon that people respond differently to different but objectively equivalent descriptions of the same problem. By measuring event-related potentials, the present study aimed to investigate the neural mechanisms underlying the framing effect, especially how the negative and positive frames influence the outcome processing in our brain. Participants were presented directly with outcomes framed either positively in terms of lives saved or negatively in terms of lives lost in large and small group conditions, and were asked to rate the favorableness of each of them. The behavioral results showed that the framing effect occurred in both group size conditions, with more favorable evaluations associated with positive framing. Compared with outcomes in positive framing condition, a significant feedback-related negativity (FRN) effect was elicited by outcomes in negative framing condition, even though the outcomes in different conditions were objectively equivalent. The results are explained in terms of the associative model of attribute framing effect which states that attribute framing effect occurs as a result of a valence-based associative processing.

  14. The RG-improved Twin Higgs effective potential at NNLL

    Science.gov (United States)

    Greco, Davide; Mimouni, Kin

    2016-11-01

    We present the Renormalization Group improvement of the Twin Higgs effective potential at cubic order in logarithmic accuracy. We first introduce a model-independent low-energy effective Lagrangian that captures both the pseudo-Nambu-Goldstone boson nature of the Higgs field and the twin light degrees of freedom charged under a copy of the Standard Model. We then apply the background field method to systematically re-sum all the one loop diagrams contributing to the potential. We show how this technique can be efficient to implicitly renormalize the higher-dimensional operators in the twin sector without classifying all of them. A prediction for the Higgs mass in the Twin Higgs model is derived and found to be of the order of M H ˜ 120 GeV with an ultraviolet cut-off m * ˜ 10-20 TeV. Irrespective of any possible ultraviolet completion of the low-energy Lagrangian, the infrared degrees of freedom alone are therefore enough to account for the observed value of the Higgs mass through running effects.

  15. Syringin may exert sleep-potentiating effects through the NOS/NO pathway.

    Science.gov (United States)

    Cui, Yue; Zhang, Ying; Liu, Gang

    2015-04-01

    Sleep is essential for basic survival as well as for optimal physical and cognitive performance in both human beings and animals. To investigate the effect of syringin on sleep of anesthetized mice and the potential mechanisms, 35 male Kunming mice were randomly divided into six experimental groups (n = 5) and one control group (n = 5). Sleep latency and sleep duration, as well as nitric oxide (NO) content and nitric oxide synthase (NOS) activity, were determined after syringin administration. The NO precursor l-Arginine (l-Arg) or NOS inhibitor NG-Nitro-l-arginine methyl ester (l-NAME) was administered alone or in combination with syringin, and time for sleep latency and duration was recorded. After intragastric administration of syringin, sleep latency decreased in a dose- and time-dependent manner, concomitant with increased sleep duration. The optimal sleep performance was obtained when syringin was given at a dose of 80 mg/kg for eight consecutive days. Syringin significantly reduced NO concentration and NOS activity. Administration of l-Arg prolonged sleep latency and shortened sleep duration, and the effects were fully reversed by syringin coadministration. Administration of L-NAME induced a significant reduction in sleep latency and a corresponding increase in sleep duration, and coadministration of syringin further enhanced the effects. The finding of our study demonstrated that syringin could exert sleep-potentiating effects on anesthetized mice in a time- and dose-dependent manner, and these effects may be intimately correlated with the NO/NOS pathway. © 2014 Société Française de Pharmacologie et de Thérapeutique.

  16. Sample size calculation in cost-effectiveness cluster randomized trials: optimal and maximin approaches.

    Science.gov (United States)

    Manju, Md Abu; Candel, Math J J M; Berger, Martijn P F

    2014-07-10

    In this paper, the optimal sample sizes at the cluster and person levels for each of two treatment arms are obtained for cluster randomized trials where the cost-effectiveness of treatments on a continuous scale is studied. The optimal sample sizes maximize the efficiency or power for a given budget or minimize the budget for a given efficiency or power. Optimal sample sizes require information on the intra-cluster correlations (ICCs) for effects and costs, the correlations between costs and effects at individual and cluster levels, the ratio of the variance of effects translated into costs to the variance of the costs (the variance ratio), sampling and measuring costs, and the budget. When planning, a study information on the model parameters usually is not available. To overcome this local optimality problem, the current paper also presents maximin sample sizes. The maximin sample sizes turn out to be rather robust against misspecifying the correlation between costs and effects at the cluster and individual levels but may lose much efficiency when misspecifying the variance ratio. The robustness of the maximin sample sizes against misspecifying the ICCs depends on the variance ratio. The maximin sample sizes are robust under misspecification of the ICC for costs for realistic values of the variance ratio greater than one but not robust under misspecification of the ICC for effects. Finally, we show how to calculate optimal or maximin sample sizes that yield sufficient power for a test on the cost-effectiveness of an intervention.

  17. Occurrence and Potential Biological Effects of Amphetamine on Stream Communities.

    Science.gov (United States)

    Lee, Sylvia S; Paspalof, Alexis M; Snow, Daniel D; Richmond, Erinn K; Rosi-Marshall, Emma J; Kelly, John J

    2016-09-06

    The presence of pharmaceuticals, including illicit drugs in aquatic systems, is a topic of environmental significance because of their global occurrence and potential effects on aquatic ecosystems and human health, but few studies have examined the ecological effects of illicit drugs. We conducted a survey of several drug residues, including the potentially illicit drug amphetamine, at 6 stream sites along an urban to rural gradient in Baltimore, Maryland, U.S.A. We detected numerous drugs, including amphetamine (3 to 630 ng L(-1)), in all stream sites. We examined the fate and ecological effects of amphetamine on biofilm, seston, and aquatic insect communities in artificial streams exposed to an environmentally relevant concentration (1 μg L(-1)) of amphetamine. The amphetamine parent compound decreased in the artificial streams from less than 1 μg L(-1) on day 1 to 0.11 μg L(-1) on day 22. In artificial streams treated with amphetamine, there was up to 45% lower biofilm chlorophyll a per ash-free dry mass, 85% lower biofilm gross primary production, 24% greater seston ash-free dry mass, and 30% lower seston community respiration compared to control streams. Exposing streams to amphetamine also changed the composition of bacterial and diatom communities in biofilms at day 21 and increased cumulative dipteran emergence by 65% and 89% during the first and third weeks of the experiment, respectively. This study demonstrates that amphetamine and other biologically active drugs are present in urban streams and have the potential to affect both structure and function of stream communities.

  18. Effective Potential Theory for Diffusion in Binary Ionic Mixtures

    CERN Document Server

    Shaffer, Nathaniel R; Daligault, Jérôme

    2016-01-01

    Self-diffusion and interdiffusion coefficients of binary ionic mixtures are evaluated using the Effective Potential Theory (EPT), and the predictions are compared with the results of molecular dynamics simulations. We find that EPT agrees with molecular dynamics from weak coupling well into the strong coupling regime, which is a similar range of coupling strengths as previously observed in comparisons with the one-component plasma. Within this range, typical relative errors of approximately 20% and worst-case relative errors of approximately 40% are observed. We also examine the Darken model, which approximates the interdiffusion coefficients based on the self-diffusion coefficients.

  19. Virgin coconut oil and its potential cardioprotective effects.

    Science.gov (United States)

    Babu, Abraham Samuel; Veluswamy, Sundar Kumar; Arena, Ross; Guazzi, Marco; Lavie, Carl J

    2014-11-01

    Emphasis on diet to improve the cardiovascular (CV) risk profile has been the focus of many studies. Recently, virgin coconut oil (VCO) has been growing in popularity due to its potential CV benefits. The chemical properties and the manufacturing process of VCO make this oil healthier than its copra-derived counterpart. This review highlights the mechanism through which saturated fatty acids contribute to CV disease (CVD), how oils and fats contribute to the risk of CVD, and the existing views on VCO and how its cardioprotective effects may make this a possible dietary intervention in isolation or in combination with exercise to help reduce the burden of CVDs.

  20. Resummation of Goldstone boson contributions to the MSSM effective potential

    CERN Document Server

    Kumar, Nilanjana

    2016-01-01

    We discuss the resummation of the Goldstone boson contributions to the effective potential of the Minimal Supersymmetric Standard Model (MSSM). This eliminates the formal problems of spurious imaginary parts and logarithmic singularities in the minimization conditions when the tree-level Goldstone boson squared masses are negative or approach zero. The numerical impact of the resummation is shown to be almost always very small. We also show how to write the two-loop minimization conditions so that Goldstone boson squared masses do not appear at all, and so that they can be solved without iteration.

  1. Resummation of Goldstone boson contributions to the MSSM effective potential

    Science.gov (United States)

    Kumar, Nilanjana; Martin, Stephen P.

    2016-07-01

    We discuss the resummation of the Goldstone boson contributions to the effective potential of the minimal supersymmetric Standard Model. This eliminates the formal problems of spurious imaginary parts and logarithmic singularities in the minimization conditions when the tree-level Goldstone boson squared masses are negative or approach zero. The numerical impact of the resummation is shown to be almost always very small. We also show how to write the two-loop minimization conditions so that Goldstone boson squared masses do not appear at all, and so that they can be solved without iteration.

  2. Potential role of optimal velocity as a qualitative factor of physical functional performance in women aged 72 to 96 years.

    Science.gov (United States)

    Clémençon, Michel; Hautier, Christophe A; Rahmani, Abdel; Cornu, Catherine; Bonnefoy, Marc

    2008-08-01

    To assess the relationship of maximal leg power and its corresponding determinants (eg, optimal velocity and optimal torque) measured during maximal voluntary knee extension to physical functional performance of older women. Descriptive. Community retirement homes. Women (N=39) aged 72 to 96 years. Not applicable. Volunteers performed in sitting position maximal knee extensions on an Ergopower dynamometer to calculate maximal leg power, optimal velocity, and optimal torque. Three standardized tests were also performed to evaluate physical performance: walking speed over 6m, time taken to rise 5 times from a chair, and time to climb 6 stairs. On multiple regression analysis, leg power (mean, 1.37+/-0.80 W/kg) significantly correlated with physical performance as measured by 6-m walking speed (mean, .85+/-.40 m/s), chair-stand time (mean, 16.3+/-7.7s), and stair-climb time (mean, 7+/-4s), describing 16% to 33% of the variance. Optimal velocity (mean, 1.79+/-1.20 rad/s) also significantly correlated with 6-m walking speed, chair-stand time, and stair-climb time, describing 46% to 89% of the variance. Optimal torque (50.8+/-16.9 Nm) did not correlate with physical performance. Maximal power and moreover optimal velocity were thus found to be determinants of physical performance, both appearing as significant mobility factors in older adults. This may provide more focus on velocity-oriented training as a means of improving functional status.

  3. Optimal multiple testing under a Gaussian prior on the effect sizes.

    Science.gov (United States)

    Dobriban, Edgar; Fortney, Kristen; Kim, Stuart K; Owen, Art B

    2015-12-01

    We develop a new method for large-scale frequentist multiple testing with Bayesian prior information. We find optimal [Formula: see text]-value weights that maximize the average power of the weighted Bonferroni method. Due to the nonconvexity of the optimization problem, previous methods that account for uncertain prior information are suitable for only a small number of tests. For a Gaussian prior on the effect sizes, we give an efficient algorithm that is guaranteed to find the optimal weights nearly exactly. Our method can discover new loci in genome-wide association studies and compares favourably to competitors. An open-source implementation is available.

  4. Semantic parafoveal-on-foveal effects and preview benefits in reading: Evidence from Fixation Related Potentials.

    Science.gov (United States)

    López-Peréz, P J; Dampuré, J; Hernández-Cabrera, J A; Barber, H A

    2016-11-01

    During reading parafoveal information can affect the processing of the word currently fixated (parafovea-on-fovea effect) and words perceived parafoveally can facilitate their subsequent processing when they are fixated on (preview effect). We investigated parafoveal processing by simultaneously recording eye movements and EEG measures. Participants read word pairs that could be semantically associated or not. Additionally, the boundary paradigm allowed us to carry out the same manipulation on parafoveal previews that were displayed until reader's gaze moved to the target words. Event Related Potentials time-locked to the prime-preview presentation showed a parafoveal-on-foveal N400 effect. Fixation Related Potentials time locked to the saccade offset showed an N400 effect related to the prime-target relationship. Furthermore, this later effect interacted with the semantic manipulation of the previews, supporting a semantic preview benefit. These results demonstrate that at least under optimal conditions foveal and parafoveal information can be simultaneously processed and integrated. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Potential environmental effects of energy conservation measures in northwest industries

    Energy Technology Data Exchange (ETDEWEB)

    Baechler, M C; Gygi, K F; Hendrickson, P L

    1992-01-01

    The Bonneville Power Administration (Bonneville) has identified 101 plants in the Pacific Northwest that account for 80% of the region's industrial electricity consumption. These plants offer a precise target for a conservation program. PNL determined that most of these 101 plants were represented by 11 major industries. We then reviewed 36 major conservation technologies used in these 11 industrial settings to determine their potential environmental impacts. Energy efficiency technologies designed for industrial use may result in direct or indirect environmental impacts. Effects may result from the production of the conservation measure technology, changes in the working environment due to different energy and material requirements, or changes to waste streams. Industry type, work-place conditions, worker training, and environmental conditions inside and outside the plant are all key variables that may affect environmental outcomes. To address these issues this report has three objectives: Describe potential conservation measures that Bonneville may employ in industrial programs and discuss potential primary impacts. Characterize industrial systems and processes where the measure may be employed and describe general environmental issues associated with each industry type. Review environmental permitting, licensing, and other regulatory actions required for industries and summarize the type of information available from these sources for further analysis.

  6. Potentiating Effects of Lactuca sativa on Pentobarbital-Induced Sleep.

    Science.gov (United States)

    Ghorbani, Ahmad; Rakhshandeh, Hassan; Sadeghnia, Hamid Reza

    2013-01-01

    Traditionally, Lactuca sativa (lettuce) has been recommended for its hypnotic property. The present study was planned to investigate sleep-prolonging effect of this plant. The hydro-alcoholic extract (HAE) of lettuce and its water fraction (WF), ethyl acetate fraction (EAF), and n-butanol fraction (NBF) were administrated (IP) to mice 30 min before the pentobarbital injection. Moreover, both in-vivo and in-vitro toxicity of the extracts were determined. The quality of HAE and NBF was also evaluated using HPLC fingerprint. The HAE prolonged the pentobarbital-induced sleep duration at dose of 400 mg/Kg. The NBF was the only fraction which could increase the sleep duration and decrease sleep latency. The effects of NBF were comparable to those of induced by diazepam. The LD50-value for HAE was found to be 4.8 g/Kg. No neurotoxic effect was observed either by HAE or by its fractions in cultured PC12 neuron-like cells. The results suggest that lettuce potentiates pentobarbital hypnosis without major toxic effect. The main component(s) responsible for this effect is most likely to be non-polar agent(s) which found in NBF of this plant.

  7. The Potential Effect of Puerarin in Preventing Atherosclerosis

    Institute of Scientific and Technical Information of China (English)

    朱庆磊; 何爱霞; 韩慧蓉; 吕欣然; 王士雯

    2002-01-01

    Objective:To study the activity of Puerarin (Pue) in scavenging oxygen free radical(OFR) and its inhibitory effect on the oxidative modification of low density lipoprotein (LDL). Methods:Riboflavin-light system was used to generate superoxide anion, and Fenton reaction to generate hydroxylfree radical to study the activity of Pue in scavenging OFR. Hydrogen peroxide-induced hemolysis wasused to study the effect of Pue on erythrocyte hemolysis and malondialdehyde (MDA) production. And ul-traviolet ray and cupric sulfate were used to cause the oxidative modification of LDL for studying the inhib-itory effect of Pue on LDL oxidative modification. Results: (1) Pue could, at concentration of 0.01-1.0mmol/L, scavenge superoxide anion radical and at concentration of 7.5-75μmol/L scavenge hydroxyl rad-ical in a concentration dependent manner. (2) Pue could, at concentration of 0.1-10 mmol/L, inhibit sig-nificantly oxidative hemolysis and MDA production of erythrocyte induced by hydrogen peroxide. (3) Pueof 0.01-1.0 mmol/L could inhibit the oxidative modification of LDL in a concentration dependent man-ner. Conclusion: Pue has an anti-peroxidation effect and shows a potential effect in preventing atherosclero-sis.

  8. Baroreceptor activation attenuates attentional effects on pain-evoked potentials.

    Science.gov (United States)

    Gray, Marcus A; Minati, Ludovico; Paoletti, Giulia; Critchley, Hugo D

    2010-12-01

    Focused attention typically enhances neural nociceptive responses, reflected electroencephalographically as increased amplitude of pain-evoked event-related potentials (ERPs). Additionally, pain-evoked ERPs are attenuated by hypertension and baroreceptor activity, through as yet unclear mechanisms. There is indirect evidence that these two effects may interact, suggesting that baroreceptor-related modulation of nociception is more than a low-level gating phenomenon. To address this hypothesis, we explored in a group of healthy participants the combined effects of cue-induced expectancy and baroreceptor activity on the amplitude of pain-evoked ERPs. Brief nociceptive skin stimuli were delivered during a simple visual task; half were preceded by a visual forewarning cue, and half were unpredictable. Nociceptive stimuli were timed to coincide either with systole (maximum activation of cardiac baroreceptors) or with diastole (minimum baroreceptor activation). We observed a strong interaction between expectancy and cardiac timing for the amplitude of the P2 ERP component; no effects were observed for the N2 component. Cued stimuli were associated with larger P2 amplitude, but this effect was abolished for stimuli presented during baroreceptor activation. No cardiac timing effect was observed for un-cued stimuli. Taken together, these findings suggest a close integration of cognitive-affective aspects of expectancy and baroreceptor influences on pain, and as such may cast further light on mechanisms underlying mental and physiological contributions to clinical pain.

  9. Dysfunctional immunometabolic effects of vitamin D deficiency, increased cardiometabolic risk. Potential epidemiological alert in America?

    Science.gov (United States)

    Rosas-Peralta, Martin; Holick, Michael F; Borrayo-Sánchez, Gabriela; Madrid-Miller, Alejandra; Ramírez-Árias, Erick; Arizmendi-Uribe, Efrain

    2017-03-01

    Vitamin D deficiency is a serious public health problem worldwide that affects not only skeletal health, but also a wide range of acute and chronic diseases. However, there is still skepticism because of the lack of randomized, controlled trials to support association studies on the benefits of vitamin D for non-skeletal health. This review was based on articles published during the 1980-2015 obtained from the Cochrane Central Register of controlled trials, MEDLINE and PubMed, and focuses on recent challenges with regard to the definition of vitamin D deficiency and how to achieve optimal serum 25-hydroxyvitamin D levels from dietary sources, supplements, and sun exposure. The effect of vitamin D on epigenetic fetal programming and regulation of genes that may potentially explain why vitamin D could have such lifelong comprehensive health benefits is reviewed. Optimization of vitamin D levels in children and adults around the world has potential benefits to improve skeletal health and to reduce the risk of chronic diseases, including some types of cancer, autoimmune diseases, infectious diseases, type 2 diabetes mellitus, and severe cardiovascular disorders such as atherothrombosis, neurocognitive disorders, and mortality. Copyright © 2017 SEEN. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. Efficacy of very fast simulated annealing global optimization method for interpretation of self-potential anomaly by different forward formulation over 2D inclined sheet type structure

    Science.gov (United States)

    Biswas, A.; Sharma, S. P.

    2012-12-01

    Self-Potential anomaly is an important geophysical technique that measures the electrical potential due natural source of current in the Earth's subsurface. An inclined sheet type model is a very familiar structure associated with mineralization, fault plane, groundwater flow and many other geological features which exhibits self potential anomaly. A number of linearized and global inversion approaches have been developed for the interpretation of SP anomaly over different structures for various purposes. Mathematical expression to compute the forward response over a two-dimensional dipping sheet type structures can be described in three different ways using five variables in each case. Complexities in the inversion using three different forward approaches are different. Interpretation of self-potential anomaly using very fast simulated annealing global optimization has been developed in the present study which yielded a new insight about the uncertainty and equivalence in model parameters. Interpretation of the measured data yields the location of the causative body, depth to the top, extension, dip and quality of the causative body. In the present study, a comparative performance of three different forward approaches in the interpretation of self-potential anomaly is performed to assess the efficacy of the each approach in resolving the possible ambiguity. Even though each forward formulation yields the same forward response but optimization of different sets of variable using different forward problems poses different kinds of ambiguity in the interpretation. Performance of the three approaches in optimization has been compared and it is observed that out of three methods, one approach is best and suitable for this kind of study. Our VFSA approach has been tested on synthetic, noisy and field data for three different methods to show the efficacy and suitability of the best method. It is important to use the forward problem in the optimization that yields the

  11. Lithium effects: protection against nitrogen narcosis, potentiation of HPNS.

    Science.gov (United States)

    Bennett, P B; Leventhal, B L; Coggin, R; Roby, J; Racanska, L

    1980-03-01

    The effect of either 10, 8, or 6 meq/kg of intraperitoneal lithium chloride or sodium chloride on the loss of righting response (RR50) produced by 18.2 ATA N2-ATA O2 was examined in rats. Results were compared to the effects of 10, 8, 6, or 4 meq/kg of intraperitoneal lithium chloride given 24 h before determination of the convulsion pressure (PC) in 40 rats compressed with He-O2 at 160 atm/h at 37 +/- 0.5 degrees C. Lithium (10 meq/kg) prevented the nitrogen-narcosis-induced loss of righting response but significantly potentiated the pressure (depth) at which convulsions and tremors occurred.

  12. Long-term Advertising Effects and Optimal Budgeting

    DEFF Research Database (Denmark)

    Hansen, Flemming; Bech Christensen, Lars

    2004-01-01

    Using pure single-source data, this paper provides evidence for theexistence and magnitude of long-term advertising effects across FMCG productcategories. Furthermore, we focus on the difficulties that arise for wellestablishedbrands when new products are introduced into the market andproduct...

  13. Balancing Online Teaching Activities: Strategies for Optimizing Efficiency and Effectiveness

    Science.gov (United States)

    Raffo, Deana M.; Brinthaupt, Thomas M.; Gardner, Justin G.; Fisher, Lawanna S.

    2015-01-01

    Increased demands in professional expectations have required online faculty to learn how to balance multiple roles in an open-ended, changing, and relatively unstructured job. In this paper, we argue that being strategic about one's balance of the various facets of online teaching will improve one's teaching efficiency and effectiveness. We…

  14. Approaches to diagnosis social and economic potential of regions as the basis for effective management strategies

    Directory of Open Access Journals (Sweden)

    N.V. Kuzminchuk

    2016-12-01

    Full Text Available The aim of article. The aim of article is development and justification of the directions of an effective strategy of regional development based on quantitative evaluation and analysis of the socio-economic potential of the region. The results of the analysis. In the article the methods of quantitative evaluation and analysis of the socio-economic potential of the region (in terms of regional resources, resulting in a set that is still no unified system of regional development and general methods of combining these indicators into one integrated quantitative index. All this creates problems when assessing and managing the development of the region. Based on the concept of socio-economic potential of the region, proposed the evaluation of regional resources to carry out the following blocks: human resources, property potential social potential. Summarizing the analysis of views of scientists on the possible assessment of the level of socio-economic potential of the region, we note that despite the constant improvement of definitions and study the factors that influence its components (human resources, property potential social potential scorecard is imperfect and methodical approach to determine the integral index of socio-economic potential – incomplete or representative. The value of the proposed approach is the ability to explore and comprehensively assess the current level of social and economic potential of the region at any given time. The proposed system of indicators to assess regional resources will solve the problem of lack of unity in the evaluation of selected indicators and provide an opportunity to determine the main direction of improvement of regional development based on the results. The main directions of effective strategy of regional development based on the results of quantitative assessment and analysis of the socio-economic potential of the region should increase national wealth by optimizing the use of resources in the

  15. The RG-improved Twin Higgs effective potential at NNLL

    CERN Document Server

    Greco, Davide

    2016-01-01

    We present the Renormalization Group improvement of the Twin Higgs effective potential at cubic order in logarithmic accuracy. We first introduce a model-independent low-energy effective Lagrangian that captures both the pseudo-Nambu-Goldstone boson nature of the Higgs field and the twin light degrees of freedom charged under a copy of the Standard Model. We then apply the background field method to systematically re-sum all the one loop diagrams contributing to the potential. We show how this technique can be efficient to implicitly renormalize the higher-dimensional operators in the twin sector without classifying all of them. A prediction for the Higgs mass in the Twin Higgs model is derived and found to be of the order of $M_H \\sim 120 ~\\text{GeV}$ with an ultraviolet cut-off $m_*\\sim 10-20 ~\\text{TeV}$. Irrespective of any possible ultraviolet completion of the low-energy Lagrangian, the infrared degrees of freedom alone are therefore enough to account for the observed value of the Higgs mass through run...

  16. A statistical approach for optimizing parameters for electrodeposition of indium (III) sulfide (In2S3) films, potential low-hazard buffer layers for photovoltaic applications

    Science.gov (United States)

    Mughal, Maqsood Ali

    Clean and environmentally friendly technologies are centralizing industry focus towards obtaining long term solutions to many large-scale problems such as energy demand, pollution, and environmental safety. Thin film solar cell (TFSC) technology has emerged as an impressive photovoltaic (PV) technology to create clean energy from fast production lines with capabilities to reduce material usage and energy required to manufacture large area panels, hence, lowering the costs. Today, cost ($/kWh) and toxicity are the primary challenges for all PV technologies. In that respect, electrodeposited indium sulfide (In2S3) films are proposed as an alternate to hazardous cadmium sulfide (CdS) films, commonly used as buffer layers in solar cells. This dissertation focuses upon the optimization of electrodeposition parameters to synthesize In2S3 films of PV quality. The work describe herein has the potential to reduce the hazardous impact of cadmium (Cd) upon the environment, while reducing the manufacturing cost of TFSCs through efficient utilization of materials. Optimization was performed through use of a statistical approach to study the effect of varying electrodeposition parameters upon the properties of the films. A robust design method referred-to as the "Taguchi Method" helped in engineering the properties of the films, and improved the PV characteristics including optical bandgap, absorption coefficient, stoichiometry, morphology, crystalline structure, thickness, etc. Current density (also a function of deposition voltage) had the most significant impact upon the stoichiometry and morphology of In2S3 films, whereas, deposition temperature and composition of the solution had the least significant impact. The dissertation discusses the film growth mechanism and provides understanding of the regions of low quality (for example, cracks) in films. In2S3 films were systematically and quantitatively investigated by varying electrodeposition parameters including bath

  17. Long-term Advertising Effects and Optimal Budgeting

    OpenAIRE

    Hansen, Flemming; Bech Christensen, Lars

    2004-01-01

    Using pure single-source data, this paper provides evidence for the existence and magnitude of long-term advertising effects across FMCG product categories. Furthermore, we focus on the difficulties that arise for wellestablished brands when new products are introduced into the market and product innovations take place. Our research shows that such occurrences drastically alter the relationship between share of voice and share of market in any given FMCG market, hence making...

  18. An Effective Vacuum Assisted Extraction Method for the Optimization of Labdane Diterpenoids from Andrographis paniculata by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Ya-Qi Wang

    2014-12-01

    Full Text Available An effective vacuum assisted extraction (VAE technique was proposed for the first time and applied to extract bioactive components from Andrographis paniculata. The process was carefully optimized by response surface methodology (RSM. Under the optimized experimental conditions, the best results were obtained using a boiling temperature of 65 °C, 50% ethanol concentration, 16 min of extraction time, one extraction cycles and a 12:1 liquid-solid ratio. Compared with conventional ultrasonic assisted extraction and heat reflux extraction, the VAE technique gave shorter extraction times and remarkable higher extraction efficiency, which indicated that a certain degree of vacuum gave the solvent a better penetration of the solvent into the pores and between the matrix particles, and enhanced the process of mass transfer. The present results demonstrated that VAE is an efficient, simple and fast method for extracting bioactive components from A. paniculata, which shows great potential for becoming an alternative technique for industrial scale-up applications.

  19. Abuse potential and adverse cognitive effects of mitragynine (kratom).

    Science.gov (United States)

    Yusoff, Nurul H M; Suhaimi, Farah W; Vadivelu, Raja K; Hassan, Zurina; Rümler, Anne; Rotter, Andrea; Amato, Davide; Dringenberg, Hans C; Mansor, Sharif M; Navaratnam, Visweswaran; Müller, Christian P

    2016-01-01

    Mitragynine is the major psychoactive alkaloid of the plant kratom/ketum. Kratom is widely used in Southeast Asia as a recreational drug, and increasingly appears as a pure compound or a component of 'herbal high' preparations in the Western world. While mitragynine/kratom may have analgesic, muscle relaxant and anti-inflammatory effects, its addictive properties and effects on cognitive performance are unknown. We isolated mitragynine from the plant and performed a thorough investigation of its behavioural effects in rats and mice. Here we describe an addictive profile and cognitive impairments of acute and chronic mitragynine administration, which closely resembles that of morphine. Acute mitragynine has complex effects on locomotor activity. Repeated administration induces locomotor sensitization, anxiolysis and conditioned place preference, enhances expression of dopamine transporter- and dopamine receptor-regulating factor mRNA in the mesencephalon. While there was no increase in spontaneous locomotor activity during withdrawal, animals showed hypersensitivity towards small challenging doses for up to 14 days. Severe somatic withdrawal signs developed after 12 hours, and increased level of anxiety became evident after 24 hours of withdrawal. Acute mitragynine independently impaired passive avoidance learning, memory consolidation and retrieval, possibly mediated by a disruption of cortical oscillatory activity, including the suppression of low-frequency rhythms (delta and theta) in the electrocorticogram. Chronic mitragynine administration led to impaired passive avoidance and object recognition learning. Altogether, these findings provide evidence for an addiction potential with cognitive impairments for mitragynine, which suggest its classification as a harmful drug.

  20. Autonomous Optimization of a Solidification Pattern and Its Effect on Porosity and Segregation in Steel Castings

    DEFF Research Database (Denmark)

    Kotas, Petr; Tutum, Cem Celal; Hattel, Jesper Henri

    2011-01-01

    distribution. This was accomplished by coupling a casting simulation software package with an optimization module. The casting process of the original casting design was simulated using a transient 3D thermal model incorporated in a commercial simulation software package to determine potential flaws......-objective optimization case with two conflicting objectives was considered in which minimization of the riser volume together with minimization of centerline porosity and elimination of macrosegregation issues were performed. Note: Copyrights belong to the AFS, therefore it is not allowed to be shared on the web....

  1. Potential component Allee effects and their impact on wetland management in the conservation of endangered anurans.

    Directory of Open Access Journals (Sweden)

    Michele A Gaston

    Full Text Available Effective management of wetland quantity and quality is crucial for effective conservation of declining amphibian populations. In particular, frogs and toads that employ aggregative breeding strategies may suffer negative population impacts in response to changes in availability of aquatic breeding habitat, including overabundance of suitable habitat, if density of conspecifics attending aggregations is positively correlated with reproductive success. Here we document such a positive relationship, potentially the first example of a component Allee effect in an anuran, in the critically endangered Houston toad (Bufo houstonensis. We assessed the relationship between mean yearly chorus size and reproductive success of males at the pond level using an information theoretic model selection approach and a two-sample t-test. The chosen model contained the single variable of mean yearly chorus size to predict probability of reproduction, as selected using the Akaike Information Criterion corrected for small sample size and Akaike weight. Mean chorus sizes were significantly higher among ponds exhibiting evidence of reproduction than in those that showed no evidence of reproduction. Our results suggest that chorusing alone is a poor proxy for inference of population stability and highlight a need for reassessment of widely-used amphibian monitoring protocols. Further, amphibian conservation efforts should account for potential Allee effects in order to optimize benefits and avoid underestimating critical population thresholds, particularly in species exhibiting rapid population declines.

  2. Optimization of total body irradiation: the match between (maximal) leukemic cell kill and (minimal) late effects

    NARCIS (Netherlands)

    Harteveld, M.L. van

    2007-01-01

    Optimization of total body irradiation: the match between (maximal) leukemic cell kill and (minimal) late effects: In this thesis, cataract formation and renal dysfunction as late effects of high-dose total body irradiation (TBI) as part of the conditioning before hematological stem cell transplanta

  3. CLIC 3TeV Beamsize Optimization with Radiation Effects

    CERN Document Server

    Blanco, OR; Tomas, R

    2013-01-01

    Oide effect and radiation in bending magnets are reviewed aiming to include this in the optical design process to minimize the beam size. The Oide double integral is expressed in simpler terms in order to speed up calculations. Part of the Oide function is used to evaluate how prone is a quadrupole magnet to contribute to the beam size increase, concluding in larger magnets with lower gradients. Radiation in bending magnets is reviewed for linear lattices, solving the case when the dispersion is different from zero and using the result to compare with theoretical results and a tracking code. An agreement between the theory, the implemented approximation included in MAPCLASS2 and the six-dimensional radiation in PLACET has been found.

  4. Fast engineering optimization: A novel highly effective control parameterization approach for industrial dynamic processes.

    Science.gov (United States)

    Liu, Ping; Li, Guodong; Liu, Xinggao

    2015-09-01

    Control vector parameterization (CVP) is an important approach of the engineering optimization for the industrial dynamic processes. However, its major defect, the low optimization efficiency caused by calculating the relevant differential equations in the generated nonlinear programming (NLP) problem repeatedly, limits its wide application in the engineering optimization for the industrial dynamic processes. A novel highly effective control parameterization approach, fast-CVP, is first proposed to improve the optimization efficiency for industrial dynamic processes, where the costate gradient formulae is employed and a fast approximate scheme is presented to solve the differential equations in dynamic process simulation. Three well-known engineering optimization benchmark problems of the industrial dynamic processes are demonstrated as illustration. The research results show that the proposed fast approach achieves a fine performance that at least 90% of the computation time can be saved in contrast to the traditional CVP method, which reveals the effectiveness of the proposed fast engineering optimization approach for the industrial dynamic processes. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  5. Potential effects of forest management on surface albedo

    Science.gov (United States)

    Otto, J.; Bréon, F.-M.; Schelhaas, M.-J.; Pinty, B.; Luyssaert, S.

    2012-04-01

    Currently 70% of the world's forests are managed and this figure is likely to rise due to population growth and increasing demand for wood based products. Forest management has been put forward by the Kyoto-Protocol as one of the key instruments in mitigating climate change. For temperate and boreal forests, the effects of forest management on the stand-level carbon balance are reasonably well understood, but the biophysical effects, for example through changes in the albedo, remain elusive. Following a modeling approach, we aim to quantify the variability in albedo that can be attributed to forest management through changes in canopy structure and density. The modelling approach chains three separate models: (1) a forest gap model to describe stand dynamics, (2) a Monte-Carlo model to estimate the probability density function of the optical path length of photons through the canopy and (3) a physically-based canopy transfer model to estimate the interaction between photons and leaves. The forest gap model provides, on a monthly time step the position, height, diameter, crown size and leaf area index of individual trees. The Monte-Carlo model computes from this the probability density function of the distance a photon travels through crown volumes to determine the direct light reaching the forest floor. This information is needed by the canopy transfer model to calculate the effective leaf area index - a quantity that allows it to correctly represent a 3D process with a 1D model. Outgoing radiation is calculated as the result of multiple processes involving the scattering due to the canopy layer and the forest floor. Finally, surface albedo is computed as the ratio between incident solar radiation and calculated outgoing radiation. The study used two time series representing thinning from below of a beech and a Scots pine forest. The results show a strong temporal evolution in albedo during stand establishment followed by a relatively stable albedo once the canopy

  6. An effective, robust and parallel implementation of an interior point algorithm for limit state optimization

    DEFF Research Database (Denmark)

    Dollerup, Niels; Jepsen, Michael S.; Frier, Christian;

    2014-01-01

    A robust and effective finite element based implementation of lower bound limit state analysis applying an interior point formulation is presented in this paper. The lower bound formulation results in a convex optimization problem consisting of a number of linear constraints from the equilibrium...... equations and a number of convex non-linear constraints from the yield criteria. The computational robustness has been improved by eliminating a large number of the equilibrium equations a priori leaving only the statical redundant variables as free optimization variables. The elimination of equilibrium...... equations is based on a optimized numbering of elements and stress variables based on the frontal method approach used in the standard finite element method. The optimized numbering secures sparsity in the formulation. The convex non-linear yield criteria are treated directly in the interior point...

  7. Maximum power, ecological function and efficiency of an irreversible Carnot cycle. A cost and effectiveness optimization

    CERN Document Server

    Aragon-Gonzalez, G; Leon-Galicia, A; Morales-Gomez, J R

    2007-01-01

    In this work we include, for the Carnot cycle, irreversibilities of linear finite rate of heat transferences between the heat engine and its reservoirs, heat leak between the reservoirs and internal dissipations of the working fluid. A first optimization of the power output, the efficiency and ecological function of an irreversible Carnot cycle, with respect to: internal temperature ratio, time ratio for the heat exchange and the allocation ratio of the heat exchangers; is performed. For the second and third optimizations, the optimum values for the time ratio and internal temperature ratio are substituted into the equation of power and, then, the optimizations with respect to the cost and effectiveness ratio of the heat exchangers are performed. Finally, a criterion of partial optimization for the class of irreversible Carnot engines is herein presented.

  8. Wind Turbine Power Curve Design for Optimal Power Generation in Wind Farms Considering Wake Effect

    DEFF Research Database (Denmark)

    Tian, Jie; Zhou, Dao; Su, Chi

    2017-01-01

    In modern wind farms, maximum power point tracking (MPPT) is widely implemented. Using the MPPT method, each individual wind turbine is controlled by its pitch angle and tip speed ratio to generate the maximum active power. In a wind farm, the upstream wind turbine may cause power loss to its...... downstream wind turbines due to the wake effect. According to the wake model, downstream power loss is also determined by the pitch angle and tip speed ratio of the upstream wind turbine. By optimizing the pitch angle and tip speed ratio of each wind turbine, the total active power of the wind farm can...... be increased. In this paper, the optimal pitch angle and tip speed ratio are selected for each wind turbine by the exhausted search. Considering the estimation error of the wake model, a solution to implement the optimized pitch angle and tip speed ratio is proposed, which is to generate the optimal control...

  9. Automatic analog IC sizing and optimization constrained with PVT corners and layout effects

    CERN Document Server

    Lourenço, Nuno; Horta, Nuno

    2017-01-01

    This book introduces readers to a variety of tools for automatic analog integrated circuit (IC) sizing and optimization. The authors provide a historical perspective on the early methods proposed to tackle automatic analog circuit sizing, with emphasis on the methodologies to size and optimize the circuit, and on the methodologies to estimate the circuit’s performance. The discussion also includes robust circuit design and optimization and the most recent advances in layout-aware analog sizing approaches. The authors describe a methodology for an automatic flow for analog IC design, including details of the inputs and interfaces, multi-objective optimization techniques, and the enhancements made in the base implementation by using machine leaning techniques. The Gradient model is discussed in detail, along with the methods to include layout effects in the circuit sizing. The concepts and algorithms of all the modules are thoroughly described, enabling readers to reproduce the methodologies, improve the qual...

  10. Potential Climate Effects of Dust Aerosols' over West Africa

    Science.gov (United States)

    JI, Z.; Wang, G.; Pal, J. S.; Yu, M.

    2014-12-01

    Climate in West Africa is under the influence of the West African monsoon circulation and mineral dust emitted from the Sahara desert (which is the world's largest source of mineral dust emission). Dust aerosols alter the atmospheric radiative fluxes and act as cloud condensation nuclei in the process of emission, transportation and deposition. However, our understanding regarding how dust aerosols influence the present-day and future climate of West Africa is very limited. In this study, a regional climate model RegCM4.3.4-CLM4.5 is used to investigate the potential climatic effects of dust aerosols both in present (1981-2000) and future (2081-2100) periods over WA. First, the model performance and dust climatic effects are evaluated. The contribution of dust climatic effects under RCP8.5 scenario and their confounding effects with land use change are assessed. Our results indicate that the model can reproduce with reasonable accuracy the spatial and temporal distribution of climatology, aerosol optical depth and surface concentration over WA. The shortwave radiative forcing of dust is negative in the surface and positive in the atmosphere, with greater changes in JJA and MAM compared to those in SON and DJF. Over most of West Africa, cooling is the dominant effect on temperature. Their impact on precipitation features a dipole pattern, with decrease in the north and increase in the south of West Africa. Despite the dust-induced decrease of precipitation amount, dusts cause extreme precipitation to increase. To evaluate the uncertainties surrounding our modeling results, sensitivity experiments driven by ICBC from MIROC-ESM and CESM and their dynamic downscaling results are used for comparisons. Results from these sensitivity experiments indicate that the impact of dust aerosols on present and future climate is robust.

  11. Potential ergogenic effects of arginine and creatine supplementation.

    Science.gov (United States)

    Paddon-Jones, Douglas; Børsheim, Elisabet; Wolfe, Robert R

    2004-10-01

    The rationale for the use of nutritional supplements to enhance exercise capacity is based on the assumption that they will confer an ergogenic effect above and beyond that afforded by regular food ingestion alone. The proposed or advertised ergogenic effect of many supplements is based on a presumptive metabolic pathway and may not necessarily translate to quantifiable changes in a variable as broadly defined as exercise performance. L-arginine is a conditionally essential amino acid that has received considerable attention due to potential effects on growth hormone secretion and nitric oxide production. In some clinical circumstances (e.g., burn injury, sepsis) in which the demand for arginine cannot be fully met by de novo synthesis and normal dietary intake, exogenous arginine has been shown to facilitate the maintenance of lean body mass and functional capacity. However, the evidence that supplemental arginine may also confer an ergogenic effect in normal healthy individuals is less compelling. In contrast to arginine, numerous studies have reported that supplementation with the arginine metabolite creatine facilitates an increase in anaerobic work capacity and muscle mass when accompanied by resistance training programs in both normal and patient populations. Whereas improvement in the rate of phosphocreatine resynthesis is largely responsible for improvements in acute work capacity, the direct effect of creatine supplementation on skeletal muscle protein synthesis is less clear. The purpose of this review is to summarize the role of arginine and its metabolite creatine in the context of a nutrition supplement for use in conjunction with an exercise stimulus in both healthy and patient populations.

  12. Potential biological and ecological effects of flickering artificial light.

    Directory of Open Access Journals (Sweden)

    Richard Inger

    Full Text Available Organisms have evolved under stable natural lighting regimes, employing cues from these to govern key ecological processes. However, the extent and density of artificial lighting within the environment has increased recently, causing widespread alteration of these regimes. Indeed, night-time electric lighting is known significantly to disrupt phenology, behaviour, and reproductive success, and thence community composition and ecosystem functioning. Until now, most attention has focussed on effects of the occurrence, timing, and spectral composition of artificial lighting. Little considered is that many types of lamp do not produce a constant stream of light but a series of pulses. This flickering light has been shown to have detrimental effects in humans and other species. Whether a species is likely to be affected will largely be determined by its visual temporal resolution, measured as the critical fusion frequency. That is the frequency at which a series of light pulses are perceived as a constant stream. Here we use the largest collation to date of critical fusion frequencies, across a broad range of taxa, to demonstrate that a significant proportion of species can detect such flicker in widely used lamps. Flickering artificial light thus has marked potential to produce ecological effects that have not previously been considered.

  13. Burnout and work engagement of academics in higher education institutions: effects of dispositional optimism.

    Science.gov (United States)

    Barkhuizen, Nicolene; Rothmann, Sebastiaan; van de Vijver, Fons J R

    2014-10-01

    The aim of this study was to investigate the relationships among dispositional optimism, job demands and resources, burnout, work engagement, ill health and organizational commitment of South African academic staff in higher education institutions. A cross-sectional survey design was used, with stratified random samples (N = 595) taken of academics in South African higher education institutions. The results confirmed that job demands and a lack of job resources contributed to burnout, whereas job resources contributed to work engagement. Dispositional optimism had a strong direct effect on perceptions of job resources as well as strong indirect effects (via job resources) on burnout, work engagement, ill health and organizational commitment. The results of this study extend the dual-process model of burnout and engagement by demonstrating the strong effects of dispositional optimism on the constructs in the model.

  14. Clarifying Cutting and Sewing Processes with Due Windows Using an Effective Ant Colony Optimization

    Directory of Open Access Journals (Sweden)

    Rong-Hwa Huang

    2013-01-01

    Full Text Available The cutting and sewing process is a traditional flow shop scheduling problem in the real world. This two-stage flexible flow shop is often commonly associated with manufacturing in the fashion and textiles industry. Many investigations have demonstrated that the ant colony optimization (ACO algorithm is effective and efficient for solving scheduling problems. This work applies a novel effective ant colony optimization (EACO algorithm to solve two-stage flexible flow shop scheduling problems and thereby minimize earliness, tardiness, and makespan. Computational results reveal that for both small and large problems, EACO is more effective and robust than both the particle swarm optimization (PSO algorithm and the ACO algorithm. Importantly, this work demonstrates that EACO can solve complex scheduling problems in an acceptable period of time.

  15. One-loop potential with scale invariance and effective operators

    CERN Document Server

    Ghilencea, D M

    2016-01-01

    We study quantum corrections to the scalar potential in classically scale invariant theories, using a manifestly scale invariant regularization. To this purpose, the subtraction scale $\\mu$ of the dimensional regularization is generated after spontaneous scale symmetry breaking, from a subtraction function of the fields, $\\mu(\\phi,\\sigma)$. This function is then uniquely determined from general principles showing that it depends on the dilaton only, with $\\mu(\\sigma)\\sim \\sigma$. The result is a scale invariant one-loop potential $U$ for a higgs field $\\phi$ and dilaton $\\sigma$ that contains an additional {\\it finite} quantum correction $\\Delta U(\\phi,\\sigma)$, beyond the Coleman Weinberg term. $\\Delta U$ contains new, non-polynomial effective operators like $\\phi^6/\\sigma^2$ whose quantum origin is explained. A flat direction is maintained at the quantum level, the model has vanishing vacuum energy and the one-loop correction to the mass of $\\phi$ remains small without tuning (of its self-coupling, etc) bey...

  16. Effective potential for moment-method simulation of quantum devices

    Science.gov (United States)

    Kriman, A. M.; Zhou, J.-R.; Kluksdahl, N. C.; Choi, H. H.; Ferry, D. K.

    1989-12-01

    In the simulation of submicron devices, complete quantum descriptions can be extremely computationally intensive, and reduced descriptions are desirable. One such description utilizes a few low-order moments of the momentum distribution that are defined by the Wigner function. Two major difficulties occur in applying this moment method: (i) An independent calculation is required to find quantum mechanically accurate initial conditions. (ii) For a system in a mixed state, the hierarchy of time evolution equations for the moments does not close. We describe an approach to solve these problems. The initial distribution is determined in equilibrium by means of a new effective potential, chosen for its ability to treat the sharp potential features which occur in heterostructures. It accurately describes barrier penetration and repulsion, as well as quantum broadening of the momentum distribution. The moment equation hierarchy is closed at the level of the second-moment time evolution equation, using a closure that is exact for a shifted Fermi distribution. Band-bending is included by simultaneous self-consistent determination of all the moments.

  17. Estimation of Potential Population Level Effects of Contaminants on Wildlife

    Energy Technology Data Exchange (ETDEWEB)

    Loar, J.M.

    2001-06-11

    The objective of this project is to provide DOE with improved methods to assess risks from contaminants to wildlife populations. The current approach for wildlife risk assessment consists of comparison of contaminant exposure estimates for individual animals to literature-derived toxicity test endpoints. These test endpoints are assumed to estimate thresholds for population-level effects. Moreover, species sensitivities to contaminants is one of several criteria to be considered when selecting assessment endpoints (EPA 1997 and 1998), yet data on the sensitivities of many birds and mammals are lacking. The uncertainties associated with this approach are considerable. First, because toxicity data are not available for most potential wildlife endpoint species, extrapolation of toxicity data from test species to the species of interest is required. There is no consensus on the most appropriate extrapolation method. Second, toxicity data are represented as statistical measures (e.g., NOAEL s or LOAELs) that provide no information on the nature or magnitude of effects. The level of effect is an artifact of the replication and dosing regime employed, and does not indicate how effects might increase with increasing exposure. Consequently, slight exceedance of a LOAEL is not distinguished from greatly exceeding it. Third, the relationship of toxic effects on individuals to effects on populations is poorly estimated by existing methods. It is assumed that if the exposure of individuals exceeds levels associated with impaired reproduction, then population level effects are likely. Uncertainty associated with this assumption is large because depending on the reproductive strategy of a given species, comparable levels of reproductive impairment may result in dramatically different population-level responses. This project included several tasks to address these problems: (1) investigation of the validity of the current allometric scaling approach for interspecies extrapolation

  18. An effective quintessence field with a power-law potential

    CERN Document Server

    Khurshudyan, M; Myrzakulov, R; Chattopadhyay, S; Kahya, E O

    2014-01-01

    In this paper, we will consider an effective quintessence scalar field with a power-law potential interacting with a $P_{b}=\\xi q\\rho_{b}$ barotropic fluid as a first model, where $q$ is a deceleration parameter. For the second model we assume viscous polytropic gas interacting with the scalar field. We investigate problem numerically and analyze behavior of different cosmological parameter concerning to components and behavior of Universe. We also compare our results with observational data to fix parameters of the models. We find some instabilities in the first model which may disappear in the second model for the appropriate parameters. Therefore, we can propose interacting quintessence dark energy with viscous polytropic gas as a successful model to describe Universe.

  19. Effective potential kinetic theory for strongly coupled plasmas

    Science.gov (United States)

    Baalrud, Scott D.; Daligault, Jérôme

    2016-11-01

    The effective potential theory (EPT) is a recently proposed method for extending traditional plasma kinetic and transport theory into the strongly coupled regime. Validation from experiments and molecular dynamics simulations have shown it to be accurate up to the onset of liquid-like correlation parameters (corresponding to Γ ≃ 10-50 for the one-component plasma, depending on the process of interest). Here, this theory is briefly reviewed along with comparisons between the theory and molecular dynamics simulations for self-diffusivity and viscosity of the one-component plasma. A number of new results are also provided, including calculations of friction coefficients, energy exchange rates, stopping power, and mobility. The theory is also cast in the Landau and Fokker-Planck kinetic forms, which may prove useful for enabling efficient kinetic computations.

  20. Effective Potential and Interdiffusion in Binary Ionic Mixtures

    CERN Document Server

    Beznogov, M V

    2014-01-01

    We calculate interdiffusion coefficients in a two-component, weakly or strongly coupled ion plasma (gas or liquid, composed of two ion species immersed into a neutralizing electron background). We use an effective potential method proposed recently by Baalrud and Daligaut [PRL, 110, 235001, (2013)]. It allows us to extend the standard Chapman-Enskog procedure of calculating the interdiffusion coefficients to the case of strong Coulomb coupling. We compute binary diffusion coefficients for several ionic mixtures and fit them by convenient expressions in terms of the generalized Coulomb logarithm. These fits cover a wide range of plasma parameters spanning from weak to strong Coulomb couplings. They can be used to simulate diffusion of ions in ordinary stars as well as in white dwarfs and neutron stars.

  1. Autonomous Optimization of a Solidification Pattern and Its Effect on Porosity and Segregation in Steel Castings

    DEFF Research Database (Denmark)

    Kotas, Petr; Tutum, Cem Celal; Hattel, Jesper Henri

    2011-01-01

    The present paper considers optimization of a solidification pattern of a gravity sand-cast steel part. That is, the choice of proper riser and chill designs has been investigated using genetic algorithms while simultaneously considering their impact on centerline porosity and macrosegregation...... distribution. This was accomplished by coupling a casting simulation software package with an optimization module. The casting process of the original casting design was simulated using a transient 3D thermal model incorporated in a commercial simulation software package to determine potential flaws...... and inadequacies. After this initial assessment, a new geometrical model was suggested with the redesigned gating system and rearranged chills to obtain better filling and solidification patterns. Based on the improved model, relevant optimization targets and constraints were defined. One multi...

  2. The Application of Multiobjective Genetic Algorithm to the Parameter Optimization of Single-Well Potential Stochastic Resonance Algorithm Aimed at Simultaneous Determination of Multiple Weak Chromatographic Peaks

    Directory of Open Access Journals (Sweden)

    Haishan Deng

    2014-01-01

    Full Text Available Simultaneous determination of multiple weak chromatographic peaks via stochastic resonance algorithm attracts much attention in recent years. However, the optimization of the parameters is complicated and time consuming, although the single-well potential stochastic resonance algorithm (SSRA has already reduced the number of parameters to only one and simplified the process significantly. Even worse, it is often difficult to keep amplified peaks with beautiful peak shape. Therefore, multiobjective genetic algorithm was employed to optimize the parameter of SSRA for multiple optimization objectives (i.e., S/N and peak shape and multiple chromatographic peaks. The applicability of the proposed method was evaluated with an experimental data set of Sudan dyes, and the results showed an excellent quantitative relationship between different concentrations and responses.

  3. Optimal Sizing of wind power systems in three high wind potential zones in Kuwait for remote housing electrification

    OpenAIRE

    Hajiah, Ali; M. Sebzali

    2016-01-01

    This paper presents a technical study for wind power systems in three sites in Kuwait namely Al-Wafra, Um-Omara and Al-Taweel. Hourly wind speed data for three years are used in order to optimally sizing the wind power systems. Firstly, the Wiebull, function is used to model the wind speed data for each sites. After that a numerical method is used to optimize the energy sources in the power system (wind turbine and battery) using MATLAB. After that the MATLAB is used to analyze the performanc...

  4. Optimal hostage rescue problem where action can only be taken once : case where effect vanishes thereafter

    OpenAIRE

    Shi, Fengbo

    2001-01-01

    we propose the following model for optimal rescue problems concerning hostages. Suppose that a person is taken as a hostage and that a decision has to be made from among three alternatives: rescuing, no rescuing, or taking one action which will save the situation. It is assumed that the action can only be taken once and it will be effective only at that time, i.e., the effect vanishes thereafter. The objective here is to find the optimal decision rule so as to maximize the probability of the ...

  5. Optimal and maximin sample sizes for multicentre cost-effectiveness trials.

    Science.gov (United States)

    Manju, Md Abu; Candel, Math J J M; Berger, Martijn P F

    2015-10-01

    This paper deals with the optimal sample sizes for a multicentre trial in which the cost-effectiveness of two treatments in terms of net monetary benefit is studied. A bivariate random-effects model, with the treatment-by-centre interaction effect being random and the main effect of centres fixed or random, is assumed to describe both costs and effects. The optimal sample sizes concern the number of centres and the number of individuals per centre in each of the treatment conditions. These numbers maximize the efficiency or power for given research costs or minimize the research costs at a desired level of efficiency or power. Information on model parameters and sampling costs are required to calculate these optimal sample sizes. In case of limited information on relevant model parameters, sample size formulas are derived for so-called maximin sample sizes which guarantee a power level at the lowest study costs. Four different maximin sample sizes are derived based on the signs of the lower bounds of two model parameters, with one case being worst compared to others. We numerically evaluate the efficiency of the worst case instead of using others. Finally, an expression is derived for calculating optimal and maximin sample sizes that yield sufficient power to test the cost-effectiveness of two treatments. © The Author(s) 2015.

  6. Model optimization of cadmium and accumulation in switchgrass (Panicum virgatum L.): potential use for ecological phytoremediation in Cd-contaminated soils.

    Science.gov (United States)

    Wang, Quanzhen; Gu, Muyu; Ma, Xiaomin; Zhang, Hongjuan; Wang, Yafang; Cui, Jian; Gao, Wei; Gui, Jing

    2015-11-01

    Soil pollution with heavy metals is an increasingly serious threat to the environment, food security, and human health. Therefore, it is urgent to develop economic and highly efficient soil restoration technology for environmental improvement; phytoremediation is an option that is safe, has low cost, and is environmentally friendly. However, in selecting hyperaccumulators or tolerant plants, theories and operation technologies for optimal restoration should be satisfied. In this study, the switchgrass growth response and performance of phytoextraction under the coupling effect of Cd and pH were investigated by evaluating seed germination, seedling growth, and the Cd content in the plant to evaluate the potential use of switchgrass as a phytoremediation plant in cadmium contaminated soil. This study conducted three sets of independent experiments with five levels of Cd concentrations, including two orthogonal matrix designs of combining Cd with pH values. The results showed that switchgrass was germinated well under all treatments (Cd concentration of 0-500 μM), but the seedling growth was significantly affected by Cd and pH, as shown by multivariate regression analyses. Hormesis was found during the growth of switchgrass plants exposed to low Cd concentrations under hydroponic conditions, and switchgrass plants were capable of developing with a Cd concentration of 100-175 μM and pH of 4.1-5.9. Mild acidic conditions can enhance the ability of Cd to accumulate in switchgrass. Switchgrass was moderately tolerant to Cd and may be used as a phytoremediation plant for Cd-contaminated soils in the future. Our results also suggest that hormetic effects should be taken into consideration in the phytoremediation of Cd-contaminated soils. We discuss the physiological and biochemical mechanisms contributing to the effective application of the plant for the phytoremediation of Cd-contaminated soils.

  7. Power optimization and effective stiffness for a vibration energy harvester with displacement constraints

    Science.gov (United States)

    Truong, Binh Duc; Phu Le, Cuong; Halvorsen, Einar

    2016-12-01

    This paper presents experiments on how to approach the physical limits on power from vibration energy harvesting under displacement-constrained operation. A MEMS electrostatic vibration energy harvester with voltage-control of the system stiffness is used for this purpose. The power saturation problem, when the proof-mass displacement reaches a maximum amplitude for sufficient acceleration amplitude, is shifted to higher accelerations by use of load optimization. In addition, we demonstrate the effect of varying the electromechanical coupling k 2. Measurement results show that harvested power can also be made to follow the optimal power of the velocity-damped generator for a range of accelerations, which implies displacement constraints. Compared to the saturated power, the power increases 1.5 times with the optimal load for electromechanical coupling at k 2  =  8.7%. This is improved 2.3 times for a higher coupling of {{k}2}=17.9 % . The obtained system effectiveness exceeds 60%. This work shows a first demonstration of reaching optimal power in the intermediate acceleration-range between the two extremes of maximum efficiency and maximum power transfer. The experimental results follow the theoretical results for a device with both load and stiffness tuning surprisingly well, despite only optimizing the load here. We compared a linearized lumped-model of the device with the same augmented by end-stop nonlinearities. The comparison shows that an effective stiffness due to end-stop impacts in the latter model closely matches the optimal stiffness for the former model, and therefore can explain why the experimental output power is close to optimal despite the lack of deliberate stiffness tuning.

  8. Optimization of Cat’s Whiskers Tea (Orthosiphon stamineus Using Supercritical Carbon Dioxide and Selective Chemotherapeutic Potential against Prostate Cancer Cells

    Directory of Open Access Journals (Sweden)

    Fouad Saleih R. Al-Suede

    2014-01-01

    Full Text Available Cat’s whiskers (Orthosiphon stamineus leaves extracts were prepared using supercritical CO2 (SC-CO2 with full factorial design to determine the optimum extraction parameters. Nine extracts were obtained by varying pressure, temperature, and time. The extracts were analysed using FTIR, UV-Vis, and GC-MS. Cytotoxicity of the extracts was evaluated on human (colorectal, breast, and prostate cancer and normal fibroblast cells. Moderate pressure (31.1 MPa and temperature (60°C were recorded as optimum extraction conditions with high yield (1.74% of the extract (B2 at 60 min extraction time. The optimized extract (B2 displayed selective cytotoxicity against prostate cancer (PC3 cells (IC50 28 µg/mL and significant antioxidant activity (IC50 42.8 µg/mL. Elevated levels of caspases 3/7 and 9 in B2-treated PC3 cells suggest the induction of apoptosis through nuclear and mitochondrial pathways. Hoechst and rhodamine assays confirmed the nuclear condensation and disruption of mitochondrial membrane potential in the cells. B2 also demonstrated inhibitory effects on motility and colonies of PC3 cells at its subcytotoxic concentrations. It is noteworthy that B2 displayed negligible toxicity against the normal cells. Chemometric analysis revealed high content of essential oils, hydrocarbon, fatty acids, esters, and aromatic sesquiterpenes in B2. This study highlights the therapeutic potentials of SC-CO2 extract of cat’s whiskers in targeting prostate carcinoma.

  9. Polarization energy gradients in combined quantum mechanics, effective fragment potential, and polarizable continuum model calculations.

    Science.gov (United States)

    Li, Hui; Gordon, Mark S

    2007-03-28

    A method that combines quantum mechanics (QM), typically a solute, the effective fragment potential (EFP) discrete solvent model, and the polarizable continuum model is described. The EFP induced dipoles and polarizable continuum model (PCM) induced surface charges are determined in a self-consistent fashion. The gradients of these two energies with respect to molecular coordinate changes are derived and implemented. In general, the gradients can be formulated as simple electrostatic forces and torques among the QM nuclei, electrons, EFP static multipoles, induced dipoles, and PCM induced charges. Molecular geometry optimizations can be performed efficiently with these gradients. The formulas derived for EFPPCM can be generally applied to other combined molecular mechanics and continuum methods that employ induced dipoles and charges.

  10. Optimal yield-related attributes of irrigated rice for high yield potential based on path analysis and stability analysis

    Directory of Open Access Journals (Sweden)

    Ganghua Li

    2014-08-01

    Full Text Available Improvement of yield in rice (Oryza sativa L. is vital for ensuring food security in China. Both rice breeders and growers need an improved understanding of the relationship between yield and yield-related traits. New indica cultivars (53 in 2007 and 48 in 2008 were grown in Taoyuan, Yunnan province, to identify important components contributing to yield. Additionally, two standard indica rice cultivars with similar yield potentials, II You 107 (a large-panicle type and Xieyou 107 (a heavy-panicle type, were planted in Taoyuan, Yunnan province and Nanjing, Jiangsu province, from 2006 to 2008 to evaluate the stability of yield and yield-related attributes. Growth duration (GD, leaf area index (LAI, panicles per m2 (PN, and spikelets per m2 (SM were significantly and positively correlated with grain yield (GY over all years. Sequential path analysis identified PN and panicle weight (PW as important first-order traits that influenced grain yield. All direct effects were significant, as indicated by bootstrap analysis. Yield potential varied greatly across locations but not across years. Plant height (PH, days from heading to maturity (HM, and grain weight (GW were stable traits that showed little variation across sites or years, whereas GD (mainly the pre-heading period, PHP and PN varied significantly across locations. To achieve a yield of 15 t ha− 1, a cultivar should have a PH of 110–125 cm, a long GD with HM of approximately 40 days, a PN of 300–400 m− 2, and a GW of 29–31 mg.

  11. Optimal yield-related attributes of irrigated rice for high yield potential based on path analysis and stability analysis

    Institute of Scientific and Technical Information of China (English)

    Ganghua; Li; Jun; Zhang; Congdang; Yang; Yunpan; Song; Chengyan; Zheng; Shaohua; Wang; Zhenghui; Liu; Yanfeng; Ding

    2014-01-01

    Improvement of yield in rice(Oryza sativa L.) is vital for ensuring food security in China. Both rice breeders and growers need an improved understanding of the relationship between yield and yield-related traits. New indica cultivars(53 in 2007 and 48 in 2008) were grown in Taoyuan,Yunnan province, to identify important components contributing to yield. Additionally, two standard indica rice cultivars with similar yield potentials, II You 107(a large-panicle type) and Xieyou 107(a heavy-panicle type), were planted in Taoyuan, Yunnan province and Nanjing,Jiangsu province, from 2006 to 2008 to evaluate the stability of yield and yield-related attributes.Growth duration(GD), leaf area index(LAI), panicles per m2(PN), and spikelets per m2(SM) were significantly and positively correlated with grain yield(GY) over all years. Sequential path analysis identified PN and panicle weight(PW) as important first-order traits that influenced grain yield. All direct effects were significant, as indicated by bootstrap analysis. Yield potential varied greatly across locations but not across years. Plant height(PH), days from heading to maturity(HM), and grain weight(GW) were stable traits that showed little variation across sites or years, whereas GD(mainly the pre-heading period, PHP) and PN varied significantly across locations. To achieve a yield of 15 t ha-1, a cultivar should have a PH of 110–125 cm, a long GD with HM of approximately 40 days, a PN of 300–400 m-2, and a GW of 29–31 mg.

  12. Potential retention effect at fish farms boosts zooplankton abundance

    Science.gov (United States)

    Fernandez-Jover, D.; Toledo-Guedes, K.; Valero-Rodríguez, J. M.; Fernandez-Gonzalez, V.; Sanchez-Jerez, P.

    2016-11-01

    Coastal aquaculture activities influence wild macrofauna in natural environments due to the introduction of artificial structures, such as floating cages, that provide structural complexity in the pelagic system. This alters the abundance and distribution of the affected species and also their feeding behaviour and diet. Despite this, the effects of coastal aquaculture on zooplankton assemblages and the potential changes in their abundance and distribution remain largely unstudied. Traditional plankton sampling hauls between the farm mooring systems entail some practical difficulties. As an alternative, light traps were deployed at 2 farms in the SW Mediterranean during a whole warm season. Total zooplankton capture by traps at farms was higher than at control locations on every sampling night. It ranged from 3 to 10 times higher for the taxonomic groups: bivalvia, cladocera, cumacea, fish early-life-stages, gastropoda, polychaeta and tanaidacea; 10-20 times higher for amphipoda, chaetognatha, isopoda, mysidacea and ostracoda, and 22 times higher for copepoda and the crustacean juvenile stages zoea and megalopa. Permutational analysis showed significant differences for the most abundant zooplankton groups (copepoda, crustacean larvae, chaetognatha, cladocera, mysidacea and polychaeta). This marked incremental increase in zooplankton taxa at farms was consistent, irrespective of the changing environmental variables registered every night. Reasons for the greater abundance of zooplankton at farms are discussed, although results suggest a retention effect caused by cage structures rather than active attraction through physical or chemical cues.

  13. Effect of stimulus check size on multifocal visual evoked potentials.

    Science.gov (United States)

    Balachandran, Chandra; Klistorner, Alexander I; Graham, Stuart L

    2003-03-01

    In this study we examined the effects of varying stimulus check size on multifocal visual evoked potential (VEP). We also evaluated the currently used cortical scaling of stimulus segments. The ObjectiVision multifocal objective perimeter stimulates the eye with random check patterns at 56 cortically scaled segments within the visual field extending to a radius of 26 degrees. All cortically scaled segments have equal number of checks, which gradually increase in size from the center to the periphery, proportional to the size of the segment. Stimuli with 9, 16, 25, 36 and 49 checks/segment were tested on 10 eyes belonging to 10 normal subjects. The check size varied inversely with number of checks per segment. VEP was recorded using bipolar occipital cross electrodes (7 min/eye), the amplitude and latency of responses obtained were compared with the check size at different eccentricities. Our findings suggest that the existing setting with 16 checks/segment subtending 26' to 140' from center to periphery, is the most effective amongst all the check sizes. Decreasing the check size prolongs the latency in the central field only. Cortical scaling of segments generates responses of the same order of magnitude throughout the field, but could be improved slightly to enhance the signal from the outer two rings.

  14. Investigations on potential co-mutagenic effects of formaldehyde.

    Science.gov (United States)

    Speit, Günter; Linsenmeyer, Regina; Duong, Giang; Bausinger, Julia

    2014-02-01

    The genotoxicity and mutagenicity of formaldehyde (FA) has been well-characterized during the last years. Besides its known direct DNA-damaging and mutagenic activity in sufficiently exposed cells, FA at low concentrations might also enhance the mutagenic and carcinogenic effects of other environmental mutagens by interfering with the repair of DNA lesions induced by these mutagens. To further assess potential co-mutagenic effects of FA, we exposed A549 human lung cells to FA in combination with various mutagens and measured the induction and removal of DNA damage by the comet assay and the production of chromosomal mutations by the cytokinesis-block micronucleus assay (CBMN assay). The mutagens tested were ionizing radiation (IR), (±)-anti-B[a]P-7,8-dihydrodiol-9,10-epoxide (BPDE), N-nitroso-N-methylurea (methyl nitrosourea; MNU) and methyl methanesulfonate (MMS). FA (10-75μM) did not enhance the genotoxic and mutagenic activity of these mutagens under the test conditions applied. FA alone and in combination with MNU or MMS did not affect the expression (mRNA level) of the gene of the O(6)-methylguanine-DNA methyltransferase (MGMT) in A549 cells. The results of these experiments do not support the assumption that low FA concentrations might interfere with the repair of DNA damage induced by other mutagens.

  15. Potential of carbon nanotube field effect transistors for analogue circuits

    KAUST Repository

    Hayat, Khizar

    2013-05-11

    This Letter presents a detailed comparison of carbon nanotube field effect transistors (CNFETs) and metal oxide semiconductor field effect transistors (MOSFETs) with special focus on carbon nanotube FET\\'s potential for implementing analogue circuits in the mm-wave and sub-terahertz range. The latest CNFET lithographic dimensions place it at-par with complementary metal oxide semiconductor in terms of current handling capability, whereas the forecasted improvement in the lithography enables the CNFETs to handle more than twice the current of MOSFETs. The comparison of RF parameters shows superior performance of CNFETs with a g m , f T and f max of 2.7, 2.6 and 4.5 times higher, respectively. MOSFET- and CNFET-based inverter, three-stage ring oscillator and LC oscillator have been designed and compared as well. The CNFET-based inverters are found to be ten times faster, the ring oscillator demonstrates three times higher oscillation frequency and CNFET-based LC oscillator also shows improved performance than its MOSFET counterpart.

  16. Potential energetic effects of mountain climbers on foraging grizzly bears

    Science.gov (United States)

    White, D.; Kendall, K.C.; Picton, H.D.

    1999-01-01

    Most studies of the effects of human disturbance on grizzly bears (Ursus arctos horribilis) have not quantified the energetic effects of such interactions. In this study, we characterized activity budgets of adult grizzly bears as they foraged on aggregations of adult army cutworm moths (Euxoa auxiliaris) in the alpine of Glacier National Park, Montana, during 1992, 1994, and 1995. We compared the activity budgets of climber-disturbed bears to those of undisturbed bears to estimate the energetic impact of climber disturbance. When bears detected climbers, they subsequently spent 53% less time foraging on moths, 52% more time moving within the foraging area, and 23% more time behaving aggressively, compared to when they were not disturbed. We estimated that grizzly bears could consume approximately 40,000 moths/day or 1,700 moths/hour. At 0.44 kcal/moth, disruption of moth feeding cost bears approximately 12 kcal/minute in addition to the energy expended in evasive maneuvers and defensive behaviors. To reduce both climber interruption of bear foraging and the potential for aggressive bear-human encounters, we recommend routing climbers around moth sites used by bears or limiting access to these sites during bear-use periods.

  17. Wind Turbine Power Curve Design for Optimal Power Generation in Wind Farms Considering Wake Effect

    Directory of Open Access Journals (Sweden)

    Jie Tian

    2017-03-01

    Full Text Available In modern wind farms, maximum power point tracking (MPPT is widely implemented. Using the MPPT method, each individual wind turbine is controlled by its pitch angle and tip speed ratio to generate the maximum active power. In a wind farm, the upstream wind turbine may cause power loss to its downstream wind turbines due to the wake effect. According to the wake model, downstream power loss is also determined by the pitch angle and tip speed ratio of the upstream wind turbine. By optimizing the pitch angle and tip speed ratio of each wind turbine, the total active power of the wind farm can be increased. In this paper, the optimal pitch angle and tip speed ratio are selected for each wind turbine by the exhausted search. Considering the estimation error of the wake model, a solution to implement the optimized pitch angle and tip speed ratio is proposed, which is to generate the optimal control curves for each individual wind turbine off-line. In typical wind farms with regular layout, based on the detailed analysis of the influence of pitch angle and tip speed ratio on the total active power of the wind farm by the exhausted search, the optimization is simplified with the reduced computation complexity. By using the optimized control curves, the annual energy production (AEP is increased by 1.03% compared to using the MPPT method in a case-study of a typical eighty-turbine wind farm.

  18. Effect of mobile phase composition on the SMB processes efficiency. Stochastic optimization of isocratic and gradient operation.

    Science.gov (United States)

    Ziomek, G; Kaspereit, M; Jezowski, J; Seidel-Morgenstern, A; Antos, D

    2005-04-08

    The solvent composition was adjusted in a theoretical study in order to maximize the efficiency of a simulated moving bed (SMB) process. The isocratic realization of the process as well as the solvent gradient mode were considered. The solvent composition and the flow rates were used as decision variables in a random search optimization algorithm known to be a reliable tool for nonlinear programming problems. The results of the optimization indicate that the optimal composition of the mobile phase depends strongly on the feed concentration. The asymmetry of the internal concentration profiles, which has a negative effect on the separation efficiency, can be partly damped by an increase of the solvent strength. In the cases studied the optimal solvent strength determined for concentrated feed streams is higher than that for diluted ones. Moreover, the optimum is strongly influenced by the value of the selectivity factor and its dependency on the mobile phase composition. Different results were obtained for cases, in which the separation factor increases with increasing the modifier concentration, than for cases, in which the separation factor decreases with increasing the modifier concentration. A similar analysis was performed for a solvent gradient SMB process, in which different solvents are used at the two inlet ports: a weak solvent in the feed stream and a strong solvent in the desorbent stream. Again the optimal mobile phase composition was strongly affected by the type of the isotherms and their non-linearity. The potential of a gradient SMB process in terms of increasing the productivity and reducing the eluent consumption is exemplified.

  19. Harmonic expansion of the effective potential in a functional renormalization group at finite chemical potential

    Science.gov (United States)

    Barnaföldi, G. G.; Jakovác, A.; Pósfay, P.

    2017-01-01

    In this paper we propose a method to study the functional renormalization group (FRG) at finite chemical potential. The method consists of mapping the FRG equations within the Fermi surface into a differential equation defined on a rectangle with zero boundary conditions. To solve this equation we use an expansion of the potential in a harmonic basis. With this method we determined the phase diagram of a simple Yukawa-type model; as expected, the bosonic fluctuations decrease the strength of the transition.

  20. Effect of experimental parameters on optimal reflection of light from opaque media

    CERN Document Server

    Anderson, Benjamin R; Eilers, Hergen

    2016-01-01

    Previously we considered the effect of experimental parameters on optimized transmission through opaque media using spatial light modulator (SLM)-based wavefront shaping. In this study we consider the opposite geometry, in which we optimize reflection from an opaque surface such that the backscattered light is focused onto a spot on an imaging detector. By systematically varying different experimental parameters (genetic algorithm iterations, bin size, SLM active area, target area, spot size, and sample angle with respect to the optical axis) and optimizing the reflected light we determine how each parameter affects the intensity enhancement. We find that the effects of the experimental parameters on the enhancement are similar to those measured for a transmissive geometry, but with the exact functional forms changed due to the different geometry and the use of a genetic algorithm instead of an iterative algorithm. Additionally, we find preliminary evidence of greater enhancements than predicted by random mat...

  1. Effect of land tenure and stakeholders attitudes on optimization of conservation practices in agricultural watersheds

    Science.gov (United States)

    Piemonti, A. D.; Babbar-Sebens, M.; Luzar, E. J.

    2012-12-01

    Modeled watershed management plans have become valuable tools for evaluating the effectiveness and impacts of conservation practices on hydrologic processes in watersheds. In multi-objective optimization approaches, several studies have focused on maximizing physical, ecological, or economic benefits of practices in a specific location, without considering the relationship between social systems and social attitudes on the overall optimality of the practice at that location. For example, objectives that have been commonly used in spatial optimization of practices are economic costs, sediment loads, nutrient loads and pesticide loads. Though the benefits derived from these objectives are generally oriented towards community preferences, they do not represent attitudes of landowners who might operate their land differently than their neighbors (e.g. farm their own land or rent the land to someone else) and might have different social/personal drivers that motivate them to adopt the practices. In addition, a distribution of such landowners could exist in the watershed, leading to spatially varying preferences to practices. In this study we evaluated the effect of three different land tenure types on the spatial-optimization of conservation practices. To perform the optimization, we used a uniform distribution of land tenure type and a spatially varying distribution of land tenure type. Our results show that for a typical Midwestern agricultural watershed, the most optimal solutions (i.e. highest benefits for minimum economic costs) found were for a uniform distribution of landowners who operate their own land. When a different land-tenure was used for the watershed, the optimized alternatives did not change significantly for nitrates reduction benefits and sediment reduction benefits, but were attained at economic costs much higher than the costs of the landowner who farms her/his own land. For example, landowners who rent to cash-renters would have to spend ~120

  2. ABOUT OPTIMIZING OF INVESTMENT VOLUMES TO IMPROVE THE BASIC INDICATORS OF THE ENTERPRISE EFFECTIVENESS

    Directory of Open Access Journals (Sweden)

    Z. M. Gasanov

    2014-12-01

    Full Text Available Purpose. Profit and profitability of any, including transport enterprises are the main economic indicators of the enterprise effectiveness. These indicators reflect the results and successful performance of the enterprise. On the other hand the enterprise effectiveness in the long term, assurance of rapid development and competitiveness is largely determined by the level of investment activity and the range of investment activity. The purpose of this study is the feasibility of the method to determine optimal investments volume for improving these or others (selectable by the management principal economic indicators of the enterprise effectiveness. Methodology. The basis of the proposed methodology for determining the optimal investments volume is the theory of optimal control, in particular, the procedure of dynamic programming since a managed development process of the enterprise is a multiple stage. This procedure, using a phased plan, allows not only simplifying the solution of optimization problems, but also solving those, which are impossible to apply the methods of mathematical analysis. Findings. The expediency of performing the calculations to determine the optimal investments volume to ensure high rates of enterprise development was proved, it is a key to the effectiveness of the enterprise in the long term and it improves its competitiveness. Originality. It is shown that using methods of the optimum control theory one can calculate the minimum volume of capital investments for the improvement of economic indicators, which determine the enterprise effectiveness. The proposed method of calculation does not depend on the specific content of economic indicators. The effectiveness of this calculation method is demonstrated on a model example. Practical value. The proposed method of calculating the minimum volume of capital investments to improve the economic effectiveness of enterprises is quite simple, but at the same time enables, on

  3. Absence of multiple local minima effects in intensity modulated optimization with dose-volume constraints

    Energy Technology Data Exchange (ETDEWEB)

    Llacer, Jorge [EC Engineering Consultants, LLC 130, Forest Hill Drive, Los Gatos, CA (United States); Deasy, Joseph O [Department of Radiation Oncology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO (United States); Bortfeld, Thomas R [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, 30 Fruit Street, Boston, MA (United States); Solberg, Timothy D [Department of Radiation Oncology, University of California, Los Angeles, CA (United States); Promberger, Claus [BrainLAB AG, Ammerthalstrasse 8, 85551 Heimstetten (Germany)

    2003-01-21

    This paper reports on the analysis of intensity modulated radiation treatment optimization problems in the presence of non-convex feasible parameter spaces caused by the specification of dose-volume constraints for the organs-at-risk (OARs). The main aim was to determine whether the presence of those non-convex spaces affects the optimization of clinical cases in any significant way. This was done in two phases: (1) Using a carefully designed two-dimensional mathematical phantom that exhibits two controllable minima and with randomly initialized beamlet weights, we developed a methodology for exploring the nature of the convergence characteristics of quadratic cost function optimizations (deterministic or stochastic). The methodology is based on observing the statistical behaviour of the residual cost at the end of optimizations in which the stopping criterion is progressively more demanding and carrying out those optimizations to very small error changes per iteration. (2) Seven clinical cases were then analysed with dose-volume constraints that are stronger than originally used in the clinic. The clinical cases are two prostate cases differently posed, a meningioma case, two head-and-neck cases, a spleen case and a spine case. Of the 14 different sets of optimizations (with and without the specification of maximum doses allowed for the OARs), 12 fail to show any effect due to the existence of non-convex feasible spaces. The remaining two sets of optimizations show evidence of multiple minima in the solutions, but those minima are very close to each other in cost and the resulting treatment plans are practically identical, as measured by the quality of the dose-volume histograms (DVHs). We discuss the differences between fluence maps resulting from those similar treatment plans. We provide a possible reason for the observed results and conclude that, although the study is necessarily limited, the annealing characteristics of a simulated annealing method may not be

  4. Absence of multiple local minima effects in intensity modulated optimization with dose-volume constraints

    Science.gov (United States)

    Llacer, Jorge; Deasy, Joseph O.; Bortfeld, Thomas R.; Solberg, Timothy D.; Promberger, Claus

    2003-01-01

    This paper reports on the analysis of intensity modulated radiation treatment optimization problems in the presence of non-convex feasible parameter spaces caused by the specification of dose-volume constraints for the organs-at-risk (OARs). The main aim was to determine whether the presence of those non-convex spaces affects the optimization of clinical cases in any significant way. This was done in two phases: (1) Using a carefully designed two-dimensional mathematical phantom that exhibits two controllable minima and with randomly initialized beamlet weights, we developed a methodology for exploring the nature of the convergence characteristics of quadratic cost function optimizations (deterministic or stochastic). The methodology is based on observing the statistical behaviour of the residual cost at the end of optimizations in which the stopping criterion is progressively more demanding and carrying out those optimizations to very small error changes per iteration. (2) Seven clinical cases were then analysed with dose-volume constraints that are stronger than originally used in the clinic. The clinical cases are two prostate cases differently posed, a meningioma case, two head-and-neck cases, a spleen case and a spine case. Of the 14 different sets of optimizations (with and without the specification of maximum doses allowed for the OARs), 12 fail to show any effect due to the existence of non-convex feasible spaces. The remaining two sets of optimizations show evidence of multiple minima in the solutions, but those minima are very close to each other in cost and the resulting treatment plans are practically identical, as measured by the quality of the dose-volume histograms (DVHs). We discuss the differences between fluence maps resulting from those similar treatment plans. We provide a possible reason for the observed results and conclude that, although the study is necessarily limited, the annealing characteristics of a simulated annealing method may not be

  5. Effects of AV-delay optimization on hemodynamic parameters in patients with VDD pacemakers.

    Science.gov (United States)

    Krychtiuk, Konstantin A; Nürnberg, Michael; Volker, Romana; Pachinger, Linda; Jarai, Rudolf; Freynhofer, Matthias K; Wojta, Johann; Huber, Kurt; Weiss, Thomas W

    2014-05-01

    Atrioventricular (AV) delay optimization improves hemodynamics and clinical parameters in patients treated with cardiac resynchronization therapy and dual-chamber-pacemakers (PM). However, data on optimizing AV delay in patients treated with VDD-PMs are scarce. We, therefore, investigated the acute and chronic effects of AV delay optimization on hemodynamics in patients treated with VDD-PMs due to AV-conduction disturbances. In this prospective, single-center interventional trial, we included 64 patients (38 men, 26 women, median age: 77 (70-82) years) with implanted VDD-PM. AV-delay optimization was performed using a formula based on the surface electrocardiogram (ECG). Hemodynamic parameters (stroke volume (SV), cardiac output (CO), heart rate (HR), and blood pressure (BP)) were measured at baseline and follow-up after 3 months using impedance cardiography. Using an ECG formula for AV-delay optimization, the AV interval was decreased from 180 (180-180) to 75 (75-100) ms. At baseline, AV-delay optimization led to a significant increase of both SV (71.3 ± 15.8 vs. 55.3 ± 12.7 ml, p AV delay vs. nominal AV interval, respectively) and CO (5.1 ± 1.4 vs. 3.9 ± 1.0 l/min, p AV-delay optimization in patients treated with VDD-PMs exhibits immediate beneficial effects on hemodynamic parameters that are sustained for 3 months.

  6. Effective flocculation of Chlorella vulgaris using chitosan with zeta potential measurement

    Science.gov (United States)

    Low, Y. J.; Lau, S. W.

    2017-06-01

    Microalgae are considered as one promising source of third-generation biofuels due to their fast growth rates, potentially higher yield rates and wide ranges of growth conditions. However, the extremely low biomass concentration in microalgae cultures presents a great challenge to the harvesting of microalgae because a large volume of water needs to be removed to obtain dry microalgal cells for the subsequent oil extraction process. In this study, the fresh water microalgae Chlorella vulgaris (C. vulgaris) was effectively harvested using both low molecular weight (MW) and high MW chitosan flocculants. The flocculation efficiency was evaluated by physical appearance, supernatant absorbance, zeta potential and solids content after centrifugal dewatering. High flocculation efficiency of 98.0-99.0% was achieved at the optimal dosage of 30-40 mg/g with formation of large microalgae flocs. This study suggests that the polymer bridging mechanism was governing the flocculation behaviour of C. vulgaris using high MW chitosan. Besides, charge patch neutralisation mechanism prevailed at low MW chitosan where lower dosage was sufficient to reach near-zero zeta potential compared with the high MW chitosan. The amount of chitosan polymer present in the culture may also affect the mechanism of flocculation.

  7. Solving Optimization Problems via Vortex Optimization Algorithm and Cognitive Development Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Ahmet Demir

    2017-01-01

    Full Text Available In the fields which require finding the most appropriate value, optimization became a vital approach to employ effective solutions. With the use of optimization techniques, many different fields in the modern life have found solutions to their real-world based problems. In this context, classical optimization techniques have had an important popularity. But after a while, more advanced optimization problems required the use of more effective techniques. At this point, Computer Science took an important role on providing software related techniques to improve the associated literature. Today, intelligent optimization techniques based on Artificial Intelligence are widely used for optimization problems. The objective of this paper is to provide a comparative study on the employment of classical optimization solutions and Artificial Intelligence solutions for enabling readers to have idea about the potential of intelligent optimization techniques. At this point, two recently developed intelligent optimization algorithms, Vortex Optimization Algorithm (VOA and Cognitive Development Optimization Algorithm (CoDOA, have been used to solve some multidisciplinary optimization problems provided in the source book Thomas' Calculus 11th Edition and the obtained results have compared with classical optimization solutions. 

  8. Exercise and oxidative stress: potential effects of antioxidant dietary strategies in sports.

    Science.gov (United States)

    Pingitore, Alessandro; Lima, Giuseppina Pace Pereira; Mastorci, Francesca; Quinones, Alfredo; Iervasi, Giorgio; Vassalle, Cristina

    2015-01-01

    Free radicals are produced during aerobic cellular metabolism and have key roles as regulatory mediators in signaling processes. Oxidative stress reflects an imbalance between production of reactive oxygen species and an adequate antioxidant defense. This adverse condition may lead to cellular and tissue damage of components, and is involved in different physiopathological states, including aging, exercise, inflammatory, cardiovascular and neurodegenerative diseases, and cancer. In particular, the relationship between exercise and oxidative stress is extremely complex, depending on the mode, intensity, and duration of exercise. Regular moderate training appears beneficial for oxidative stress and health. Conversely, acute exercise leads to increased oxidative stress, although this same stimulus is necessary to allow an up-regulation in endogenous antioxidant defenses (hormesis). Supporting endogenous defenses with additional oral antioxidant supplementation may represent a suitable noninvasive tool for preventing or reducing oxidative stress during training. However, excess of exogenous antioxidants may have detrimental effects on health and performance. Whole foods, rather than capsules, contain antioxidants in natural ratios and proportions, which may act in synergy to optimize the antioxidant effect. Thus, an adequate intake of vitamins and minerals through a varied and balanced diet remains the best approach to maintain an optimal antioxidant status. Antioxidant supplementation may be warranted in particular conditions, when athletes are exposed to high oxidative stress or fail to meet dietary antioxidant requirements. Aim of this review is to discuss the evidence on the relationship between exercise and oxidative stress, and the potential effects of dietary strategies in athletes. The differences between diet and exogenous supplementation as well as available tools to estimate effectiveness of antioxidant intake are also reported. Finally, we advocate the need

  9. Formulation development and systematic optimization of stabilized ziprasidone hydrochloride capsules devoid of any food effect.

    Science.gov (United States)

    Banerjee, Sabyasachi; Shankar, K Ravi; Prasad Y, Rajendra

    2016-11-01

    The objective of the study was to develop a stable capsule formulation of ziprasidone hydrochloride which can be administered without regards to food intake. The unstable anhydrous form of ziprasidone hydrochloride was stabilized employing hot-melt extrusion and further optimized by 3(2) central composite design. The formulation was optimized after establishing acceptable ranges for response variables like disintegration time, dissolution and impurity profile. A crossover fasted and fed in vivo study was conducted in human volunteers to assess the food-effect of optimized formulation vis-à-vis the marketed brand. The optimized formulation met in-house specifications for various response variables. Further, high values of correlation coefficient vouch the adequate selection of experimental design and its high prognostic ability. In our study, no significant difference was observed between the Cmax and AUC values after administration of the optimized formulation in fasted and fed states. On the contrary, there was a statistically significant increase in the Cmax and AUC values after oral administration of Zeldox in fed state in comparison to fasted state. The present study describes the successful development of a stable formulation of 20 mg of ziprasidone devoid of any food-effects.

  10. [Potentials for the combined therapy of urination disorders in men: the choice of optimal scheme of treatment].

    Science.gov (United States)

    Golubtsova, E N; Tomilov, A A; Veliev, E I

    2013-01-01

    Moderate to severe urination disorders occur in 13-29% of men, and their frequency increases progressively with age. The key for successful use of the capabilities of modern drug therapy is the understanding of the pathophysiological bases of urination disorders. Despite some successes of monotherapy with alpha-adrenoblockers and 5alpha-reductase inhibitors, combined use of drugs is appropriate, because the differences in mechanisms of action allows to simultaneously act on the smooth muscle tissue, causing its relax, and reduce the size of prostate by the induction of apoptosis, which ultimately allows to expect the maximum therapeutic effect. The goal of therapy in patients with BPH is not only a reduction in the severity of urination disorders, but the prevention of disease progression. Obviously, urination disorders in men are not always caused by an benign prostate hyperplasia. Hyperactive symptoms (primary and secondary, due to metabolic disorders in detrusor against the background of prolonged existence of bladder outlet obstruction) are revealed in significant proportion of men. In this cases, the use of M-anticholinergics is indicated. Administration of alpha-adrenoblockers and antimuscarinic drugs is one of potential variant of combined therapy. Thus, it is important to follow the principles of selectivity in patients with urination disorders. Modern pharmacotherapy has an arsenal of drugs, allowing to choose the drug therapy for patients with urination disorders depending on the prevalence of their types.

  11. Potential and optimization of two-phase anaerobic digestion of oil refinery waste activated sludge and microbial community study

    Science.gov (United States)

    Wang, Qinghong; Liang, Ying; Zhao, Peng; Li, Qing X.; Guo, Shaohui; Chen, Chunmao

    2016-12-01

    Oil refinery waste activated sludge produced from oil wastewater biological treatment is a major industrial sludge. Two-phase anaerobic digestion of oil refinery waste activated sludge was studied for the first time. Thermal pretreatment under 170 °C is effective on sludge solubilization. At the optimum hydrolytic-acidogenic condition which was pH of 6.5, temperature of 55 °C and HRT of 2 days, 2754 mg/L volatile fatty acids (VFAs) were produced and acetic acid and butyric acid were the key components. Comparative studies of single-phase and two-phase anaerobic digestion in terms of organic removal, biogas production and methane concentration were conducted. The cumulative methane production and soluble COD (SCOD) removal efficiency in the two-phase system were 228 mL/g COD added and 77.8%, respectively, which were 1.6 and 2.1 times higher than those in single-phase anaerobic digestion. Such improved performance is attributed to intensification of dominant microbial population in separated reactors. Caloramator, Ureibacillus, Dechloromonas, Petrobacter, and T78 played important roles in hydrolytic-acidification and oil-organics degradation. Syntrophic bacteria in the family Porphyromonadaceae and the genus Anaerobranca provide acetate for methanogen. The results demonstrated the potential and operating condition of two-phase anaerobic digestion in treatment of oil refinery waste activated sludge.

  12. Potential and optimization of two-phase anaerobic digestion of oil refinery waste activated sludge and microbial community study.

    Science.gov (United States)

    Wang, Qinghong; Liang, Ying; Zhao, Peng; Li, Qing X; Guo, Shaohui; Chen, Chunmao

    2016-12-01

    Oil refinery waste activated sludge produced from oil wastewater biological treatment is a major industrial sludge. Two-phase anaerobic digestion of oil refinery waste activated sludge was studied for the first time. Thermal pretreatment under 170 °C is effective on sludge solubilization. At the optimum hydrolytic-acidogenic condition which was pH of 6.5, temperature of 55 °C and HRT of 2 days, 2754 mg/L volatile fatty acids (VFAs) were produced and acetic acid and butyric acid were the key components. Comparative studies of single-phase and two-phase anaerobic digestion in terms of organic removal, biogas production and methane concentration were conducted. The cumulative methane production and soluble COD (SCOD) removal efficiency in the two-phase system were 228 mL/g COD added and 77.8%, respectively, which were 1.6 and 2.1 times higher than those in single-phase anaerobic digestion. Such improved performance is attributed to intensification of dominant microbial population in separated reactors. Caloramator, Ureibacillus, Dechloromonas, Petrobacter, and T78 played important roles in hydrolytic-acidification and oil-organics degradation. Syntrophic bacteria in the family Porphyromonadaceae and the genus Anaerobranca provide acetate for methanogen. The results demonstrated the potential and operating condition of two-phase anaerobic digestion in treatment of oil refinery waste activated sludge.

  13. Potential and optimization of two-phase anaerobic digestion of oil refinery waste activated sludge and microbial community study

    Science.gov (United States)

    Wang, Qinghong; Liang, Ying; Zhao, Peng; Li, Qing X.; Guo, Shaohui; Chen, Chunmao

    2016-01-01

    Oil refinery waste activated sludge produced from oil wastewater biological treatment is a major industrial sludge. Two-phase anaerobic digestion of oil refinery waste activated sludge was studied for the first time. Thermal pretreatment under 170 °C is effective on sludge solubilization. At the optimum hydrolytic-acidogenic condition which was pH of 6.5, temperature of 55 °C and HRT of 2 days, 2754 mg/L volatile fatty acids (VFAs) were produced and acetic acid and butyric acid were the key components. Comparative studies of single-phase and two-phase anaerobic digestion in terms of organic removal, biogas production and methane concentration were conducted. The cumulative methane production and soluble COD (SCOD) removal efficiency in the two-phase system were 228 mL/g COD added and 77.8%, respectively, which were 1.6 and 2.1 times higher than those in single-phase anaerobic digestion. Such improved performance is attributed to intensification of dominant microbial population in separated reactors. Caloramator, Ureibacillus, Dechloromonas, Petrobacter, and T78 played important roles in hydrolytic-acidification and oil-organics degradation. Syntrophic bacteria in the family Porphyromonadaceae and the genus Anaerobranca provide acetate for methanogen. The results demonstrated the potential and operating condition of two-phase anaerobic digestion in treatment of oil refinery waste activated sludge. PMID:27905538

  14. Interaction Between Shelf Layout and Marketing Effectiveness and Its Impact on Optimizing Shelf Arrangements

    NARCIS (Netherlands)

    van Nierop, Erjen; Fok, Dennis; Franses, Philip Hans

    2008-01-01

    In this paper, we propose and operationalize a new method for optimizing shelf arrangements. We show that there are important dependencies between the layout of the shelf and stock-keeping unit (SKU) sales and marketing effectiveness. The importance of these dependencies is further shown by the

  15. Optimizing the effectiveness of the ‘Read-Recite-Review’ study strategy in learning from text

    NARCIS (Netherlands)

    Reijners, Pauline; Kester, Liesbeth; Wetzels, Sandra; Kirschner, Paul A.

    2011-01-01

    Reijners, P. B. G., Kester, L., Wetzels, S. A. J., & Kirschner, P. A. (2011, 9 September). Optimizing the effectiveness of the ‘Read-Recite-Review’ study strategy in learning from text. Presentation given for visit of KU Leuven at CELSTEC, Heerlen, The Netherlands.

  16. Interaction Between Shelf Layout and Marketing Effectiveness and Its Impact on Optimizing Shelf Arrangements

    NARCIS (Netherlands)

    van Nierop, Erjen; Fok, Dennis; Franses, Philip Hans

    2008-01-01

    In this paper, we propose and operationalize a new method for optimizing shelf arrangements. We show that there are important dependencies between the layout of the shelf and stock-keeping unit (SKU) sales and marketing effectiveness. The importance of these dependencies is further shown by the subs

  17. Microbunching Instability Effect Studies and Laser Heater Optimization for the SPARX FEL Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Vaccarezza, C.; Chiadroni, E.; Ferrario, M.; Giannessi, L.; Quattromini, M.; Ronsivalle, C.; Venturini, C.; Migliorati, M.; Dattoli, G.

    2010-05-23

    The effects of microbunching instability for the SPARX accelerator have been analyzed by means of numerical simulations. The laser heater counteracting action has been addressed in order to optimize the parameters of the compression system, either hybrid RF plus magnetic chicane or only magnetic, and possibly enhance the FEL performance.

  18. Biodegradation of dye solution containing Malachite Green: optimization of effective parameters using Taguchi method.

    Science.gov (United States)

    Daneshvar, N; Khataee, A R; Rasoulifard, M H; Pourhassan, M

    2007-05-08

    In this paper, optimization of biological decolorization of synthetic dye solution containing Malachite Green was investigated. The effect of temperature, initial pH of the solution, type of algae, dye concentration and time of the reaction was studied and optimized using Taguchi method. Sixteen experiments were required to study the effect of parameters on biodegradation of the dye. Each of experiments was repeated three times to calculate signal/noise (S/N). Our results showed that initial pH of the solution was the most effective parameter in comparison with others and the basic pH was favorable. In this study, we also optimized the experimental parameters and chose the best condition by determination effective factors. Based on the S/N ratio, the optimized conditions for dye removal were temperature 25 degrees C, initial pH 10, dye concentration 5 ppm, algae type Chlorella and time 2.5h. The stability and efficiency of Chlorella sp. in long-term repetitive operations were also examined.

  19. The Effect of Slot-Code Optimization in Warehouse Order Picking

    Directory of Open Access Journals (Sweden)

    Andrea Fumi

    2013-07-01

    most appropriate material handling resource configuration. Building on previous work on the effect of slot-code optimization on travel times in single/dual command cycles, the authors broaden the scope to include the most general picking case, thus widening the range of applicability and realising former suggestions for future research.

  20. Effect of optimized antibiotic prophylaxis on the incidence of surgical site infection.

    NARCIS (Netherlands)

    Mannien, J.; Kasteren, M.E.E. van; Nagelkerke, N.J.; Gyssens, I.C.J.; Kullberg, B.J.; Wille, J.C.; Boer, A.S. de

    2006-01-01

    Objective. To compare the rate of surgical site infection (SSI) before and after an intervention period in which an optimized policy for antibiotic prophylaxis was implemented. To demonstrate that a more prudent, restrictive policy would not have a detrimental effect on patient outcomes.Design.

  1. Interaction Between Shelf Layout and Marketing Effectiveness and Its Impact on Optimizing Shelf Arrangements

    NARCIS (Netherlands)

    van Nierop, Erjen; Fok, Dennis; Franses, Philip Hans

    2008-01-01

    In this paper, we propose and operationalize a new method for optimizing shelf arrangements. We show that there are important dependencies between the layout of the shelf and stock-keeping unit (SKU) sales and marketing effectiveness. The importance of these dependencies is further shown by the subs

  2. Perceived Academic Control: Mediating the Effects of Optimism and Social Support on College Students' Psychological Health

    Science.gov (United States)

    Ruthig, Joelle C.; Haynes, Tara L.; Stupnisky, Robert H.; Perry, Raymond P.

    2009-01-01

    The first year of college presents numerous challenges experienced as overwhelming by some freshmen who may become overly stressed and depressed. This longitudinal study examined perceived academic control (PAC) as a mediator of optimism and social support's buffering effects on freshman students' psychological health. Multiple regressions…

  3. Potential Health Effects of Enzymatic Protein Hydrolysates from Chlorella vulgaris

    Directory of Open Access Journals (Sweden)

    Mahsa Sedighi

    2016-06-01

    Full Text Available Background and Objective: Chlorella vulgaris is a multi-cellular edible algal species with abundant proteins. Extraction of high value protein fractions for pharmaceutical and nutritional applications can significantly increase the commercial value of microalga biomasses. There is no known report on the anticancer peptides derived from the Chlorella vulgaris abundant protein.Materials and Methods: This study examined the antimicrobial and anticancer effects of peptides from a hydrolyzed Chlorella vulgaris protein with 62 kDa molecular weight. Protein hydrolysis was done by pepsin as a gastrointestinal protease, and was monitored through protein content measurement, sodium dodecyl sulfate polyacrylamide gel electrophoresis, and high performance liquidchromatography measurements. Inhibitory effect of the produced peptides on Escherichia coli cells and breast cancer cell lines was assayed.Results and Conclusion: Hydrolyzed peptides induced a decrease of about 34.1% in the growth of Escherichia coli, and the peptides of 3 to 5 kDa molecular weight had strong impact on the viability of breast cancer cells with IC50 value of 50 μg μl-1. The peptide fractions demonstrating antimicrobial and anti-cancer activities have the potential for use as functional food ingredients for health benefits. These results demonstrate that inexpensive algae proteinscould be a new alternative to produce anticancer peptides.Conflict of interest: The authors declare that there is no conflict of interest.

  4. Age and gender effects on submental motor-evoked potentials.

    Science.gov (United States)

    Sella, Oshrat; Jones, Richard D; Huckabee, Maggie-Lee

    2014-01-01

    It is not known whether there are age- and/or gender-related differences in magnitude of motor-evoked potentials (MEPs) of the submental muscles. Knowledge of this is important in investigations of neurophysiological aspects of swallowing. Forty healthy participants (20 males, 20 females; 20 young [21-35 years], 20 old [53-88 years]) were recruited. Surface electromyography (EMG) electrodes were placed at midline underlying the submental muscle group. Age- and gender-related differences were evaluated in two neurophysiologic measures of swallowing: MEPs stimulated by single-pulse transcranial magnetic stimulation (TMS) over the motor cortex and surface electromyography (sEMG) recorded from the same submental muscle group during non-stimulated swallows. The older participants had larger MEPs during saliva swallowing than the young participants (p = 0.04, d = 0.86). Conversely, the older participants had lower amplitude submental EMG activity during non-stimulated swallows (p = 0.045, d = 0.67). Gender had no significant effect on MEP magnitude and on submental activity during saliva swallowing. There were no effects of age or gender on MEP latencies. These findings suggest deterioration in muscle function with age in a sample of healthy adults presenting with functional swallowing. We speculate that muscular decline is partially ameliorated by increased cortical activity-i.e., increased submental MEPs-so as to preserve swallowing function in healthy older subjects. These findings emphasize the need for different reference points for evaluation of submental MEPs of different age groups.

  5. Investigations on potential co-mutagenic effects of formaldehyde

    Energy Technology Data Exchange (ETDEWEB)

    Speit, Günter, E-mail: guenter.speit@uni-ulm.de; Linsenmeyer, Regina; Duong, Giang; Bausinger, Julia

    2014-02-15

    Highlights: • A549 cells were exposed to formaldehyde in combination with various mutagens. • Formaldehyde did not affect the induction and removal of DNA damage (comet assay). • Formaldehyde did not affect the induction of micronuclei by the mutagens tested. • The expression of the O{sup 6}-methylguanine-DNA methyltransferase was not affected. - Abstract: The genotoxicity and mutagenicity of formaldehyde (FA) has been well-characterized during the last years. Besides its known direct DNA-damaging and mutagenic activity in sufficiently exposed cells, FA at low concentrations might also enhance the mutagenic and carcinogenic effects of other environmental mutagens by interfering with the repair of DNA lesions induced by these mutagens. To further assess potential co-mutagenic effects of FA, we exposed A549 human lung cells to FA in combination with various mutagens and measured the induction and removal of DNA damage by the comet assay and the production of chromosomal mutations by the cytokinesis-block micronucleus assay (CBMN assay). The mutagens tested were ionizing radiation (IR), (±)-anti-B[a]P-7,8-dihydrodiol-9,10-epoxide (BPDE), N-nitroso-N-methylurea (methyl nitrosourea; MNU) and methyl methanesulfonate (MMS). FA (10–75 μM) did not enhance the genotoxic and mutagenic activity of these mutagens under the test conditions applied. FA alone and in combination with MNU or MMS did not affect the expression (mRNA level) of the gene of the O{sup 6}-methylguanine-DNA methyltransferase (MGMT) in A549 cells. The results of these experiments do not support the assumption that low FA concentrations might interfere with the repair of DNA damage induced by other mutagens.

  6. Interactions among endophytic bacteria and fungi: effects and potentials

    Indian Academy of Sciences (India)

    W M M S Bandara; Gamini Seneviratne; S A Kulasooriya

    2006-12-01

    Plants benefit extensively by harbouring endophytic microbes. They promote plant growth and confer enhanced resistance to various pathogens. However, the way the interactions among endophytes influence the plant productivity has not been explained. Present study experimentally showed that endophytes isolated from rice (Oryza sativa) used as the test plant produced two types of interactions; biofilms (bacteria attached to mycelia) and mixed cultures with no such attachments. Acidity, as measured by pH in cultures with biofilms was higher than that of fungi alone, bacteria alone or the mixed cultures. Production of indoleacetic acid like substances (IAAS) of biofilms was higher than that of mixed cultures, fungi or bacteria. Bacteria and fungi produced higher quantities of IAAS than mixed cultures. In mixed cultures, the potential of IAAS production of resident microbes was reduced considerably. There was a negative relationship between IAAS and pH of the biofilms, indicating that IAAS was the main contributor to the acidity. However, such a relationship was not observed in mixed cultures. Microbial acid production is important for suppressing plant pathogens. Thus the biofilm formation in endophytic environment seems to be very important for healthy and improved plant growth. However, it is unlikely that an interaction among endophytes takes place naturally in the endophytic environment, due to physical barriers of plant tissues. Further, critical cell density dependant quorum sensing that leads to biofilm formation may not occur in the endophytic environment as there is a limited space. As such in vitro production and application of beneficial biofilmed inocula of endophytes are important for improved plant production in any agro-ecosystem. The conventional practice of plant inoculation with monocultures or mixed cultures of effective microbes may not give the highest microbial effect, which may only be achieved by biofilm formation.

  7. [Effect of sleep deprivation on visual evoked potentials and brain stem auditory evoked potentials in epileptics].

    Science.gov (United States)

    Urumova, L T; Kovalenko, G A; Tsunikov, A I; Sumskiĭ, L I

    1984-01-01

    The article reports on the first study of the evoked activity of the brain in epileptic patients (n = 20) following sleep deprivation. An analysis of the data obtained has revealed a tendency to the shortening of the peak latent intervals of visual evoked potentials in the range of 100-200 mu sec and the V component and the interpeak interval III-V of evoked auditory trunk potentials in patients with temporal epilepsy. The phenomenon may indicate the elimination of stabilizing control involving the specific conductive pathways and, possibly, an accelerated conduction of a specific sensor signal.

  8. Potential Effects of Pomegranate Polyphenols in Cancer Prevention and Therapy.

    Science.gov (United States)

    Turrini, Eleonora; Ferruzzi, Lorenzo; Fimognari, Carmela

    2015-01-01

    Cancer is the second leading cause of death and is becoming the leading one in old age. Vegetable and fruit consumption is inversely associated with cancer incidence and mortality. Currently, interest in a number of fruits high in polyphenols has been raised due to their reported chemopreventive and/or chemotherapeutic potential. Pomegranate has been shown to exert anticancer activity, which is generally attributed to its high content of polyphenols. This review provides a comprehensive analysis of known targets and mechanisms along with a critical evaluation of pomegranate polyphenols as future anticancer agents. Pomegranate evokes antiproliferative, anti-invasive, and antimetastatic effects, induces apoptosis through the modulation of Bcl-2 proteins, upregulates p21 and p27, and downregulates cyclin-cdk network. Furthermore, pomegranate blocks the activation of inflammatory pathways including, but not limited to, the NF-κB pathway. The strongest evidence for its anticancer activity comes from studies on prostate cancer. Accordingly, some exploratory clinical studies investigating pomegranate found a trend of efficacy in increasing prostate-specific antigen doubling time in patients with prostate cancer. However, the genotoxicity reported for pomegranate raised certain concerns over its safety and an accurate assessment of the risk/benefit should be performed before suggesting the use of pomegranate or its polyphenols for cancer-related therapeutic purposes.

  9. Effects of discontinuities of the derivatives of the inflaton potential

    Energy Technology Data Exchange (ETDEWEB)

    Gallego Cadavid, Alexander [Universidad de Antioquia, Instituto de Fisica, Medellin (Colombia); Kyoto University, Yukawa Institute for Theoretical Physics, Kyoto (Japan); Enea Romano, Antonio [Universidad de Antioquia, Instituto de Fisica, Medellin (Colombia); Kyoto University, Yukawa Institute for Theoretical Physics, Kyoto (Japan); University of Crete, Department of Physics, Heraklion (Greece)

    2015-12-15

    We study the effects of a class of features of the inflaton potential, corresponding to discontinuities in its derivatives. We perform fully numerical calculations and derive analytical approximations for the curvature perturbations spectrum and the bispectrum which are in good agreement with the numerical results. The spectrum of primordial perturbations has oscillations around the scale k{sub 0} which leaves the horizon at the time τ{sub 0} when the feature occurs, with the amplitude and phase of the oscillations determined by the size and the order of the discontinuity. The large scale bispectrum in the squeezed and equilateral limits have a very similar form and are linearly suppressed. Both in the squeezed and the equilateral small scale limit the bispectrum has an oscillatory behavior whose phase depends on the parameters determining the discontinuity, and whose amplitude is inversely proportional to the scale. Given the generality of this class of features they could be used to model or classify phenomenologically different types of non-Gaussian features encountered in observational data such as the cosmic microwave background radiation or large scale structure. (orig.)

  10. Potential estrogenic effects of phosphorus-containing flame retardants.

    Science.gov (United States)

    Zhang, Quan; Lu, Meiya; Dong, Xiaowu; Wang, Cui; Zhang, Chunlong; Liu, Weiping; Zhao, Meirong

    2014-06-17

    As the substitute of polybrominated diphenyl ethers (PBDEs), further assessments about the potential ecological safety and health risks of phosphorus-containing flame retardants (PFRs) are required because the worldwide demand for PFRs has been increasing every year. In this study, we examined the agonistic/antagonistic activity of a group of PFRs by three in vitro models (luciferase reporter gene assay, yeast two-hybrid assay, and E-screen assay). Molecule docking was used to further explain the interactions between ERα and PFRs. Data from luciferase reporter gene analysis showed three members of the nine tested PFRs significantly induced estrogenic effects, with the order of TPP > TCP > TDCPP, while TCEP and TEHP have remarkable antiestrogenic properties with calculated REC20 and RIC20 values of 10(-6) M or lower. Results from the luciferase reporter gene method are generally consistent with results obtained from the yeast two-hybrid assay and E-screen, except for the positive estrogenic activity of TBP in E-screen testing. Docking results showed that binding between ligands and ERα was stabilized by hydrophobic interactions. As a proposed alternative for brominated flame retardant, PFRs may have anti/estrogenic activity via ERα at the low dose typical of residue in environmental matrix or animals. PFRs with a short chain, halogen, and benzene ring in the substituent group tend to be estrogenic. Our research suggests that comprehensive evaluations, including health and ecological assessments, are required in determining whether PFRs are preferable as an emerging industrial substitute.

  11. Potential Therapeutic Effects of Meditation for Treating Affective Dysregulation

    Directory of Open Access Journals (Sweden)

    Natalie T. Y. Leung

    2014-01-01

    Full Text Available Affective dysregulation is at the root of many psychopathologies, including stress induced disorders, anxiety disorders, and depression. The root of these disorders appears to be an attenuated, top-down cognitive control from the prefrontal cortices over the maladaptive subcortical emotional processing. A form of mental training, long-term meditation practice can trigger meditation-specific neuroplastic changes in the brain regions underlying cognitive control and affective regulation, suggesting that meditation can act as a kind of mental exercise to foster affective regulation and possibly a cost-effective intervention in mood disorders. Increasing research has suggested that the cultivation of awareness and acceptance along with a nonjudgmental attitude via meditation promotes adaptive affective regulation. This review examined the concepts of affective regulation and meditation and discussed behavioral and neural evidence of the potential clinical application of meditation. Lately, there has been a growing trend toward incorporating the “mindfulness” component into existing psychotherapeutic treatment. Promising results have been observed thus far. Future studies may consider exploring the possibility of integrating the element of “compassion” into current psychotherapeutic approaches.

  12. Effects of discontinuities of the derivatives of the inflaton potential

    Energy Technology Data Exchange (ETDEWEB)

    Cadavid, Alexander Gallego [Instituto de Fisica, Universidad de Antioquia, A.A.1226, Medellin (Colombia); Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto (Japan); Romano, Antonio Enea, E-mail: aer@physics.uoc.gr [Instituto de Fisica, Universidad de Antioquia, A.A.1226, Medellin (Colombia); Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto (Japan); Department of Physics, University of Crete, 71003, Heraklion (Greece)

    2015-12-12

    We study the effects of a class of features of the inflaton potential, corresponding to discontinuities in its derivatives. We perform fully numerical calculations and derive analytical approximations for the curvature perturbations spectrum and the bispectrum which are in good agreement with the numerical results. The spectrum of primordial perturbations has oscillations around the scale k{sub 0} which leaves the horizon at the time τ{sub 0} when the feature occurs, with the amplitude and phase of the oscillations determined by the size and the order of the discontinuity. The large scale bispectrum in the squeezed and equilateral limits have a very similar form and are linearly suppressed. Both in the squeezed and the equilateral small scale limit the bispectrum has an oscillatory behavior whose phase depends on the parameters determining the discontinuity, and whose amplitude is inversely proportional to the scale. Given the generality of this class of features they could be used to model or classify phenomenologically different types of non-Gaussian features encountered in observational data such as the cosmic microwave background radiation or large scale structure.

  13. Optimal production lot sizing model in a supply chain with periodically fixed demand considering learning effect

    Institute of Scientific and Technical Information of China (English)

    熊中楷; SHEN; Tiesong

    2002-01-01

    This paper presents an optimal production model for manufacturer in a supply chain with a fixed demand at a fixed interval with respect to the learning effect on production capacity.An algorithm is employed to find theoptimal dela time for production and production time sequentially.It is found that the optimal delay time for production and the production time are not static,but dynamic and variant with time.It is important for a manufacturer to schedule the production so as to prevent facilities and workers from idling.

  14. Optimal Adaptive Droop Control for Effective Load Sharing in AC Microgrids

    DEFF Research Database (Denmark)

    Anvari-Moghaddam, Amjad; Shafiee, Qobad; Quintero, Juan Carlos Vasquez

    2016-01-01

    scheme. However, sharing powers among the sources based on the units’ rated capacities is not an optimal solution in terms of economy and efficiency. In this paper, a new adaptive droop-based control strategy is proposed for AC MGs to optimally share MG load between corresponding units. The mentioned......During the past few years, microgrids (MGs) have been becoming more attractive as effective means to integrate different distributed energy resources (DERs). To coordinate active and reactive power sharing among DERs, conventional droop control method is widely used as a decentralized control...

  15. Wake-Effect Minimising Optimal Control of Wind Farms, with Load Reduction

    DEFF Research Database (Denmark)

    Borchersen, Anders Bech; Larsen, Jesper Abildgaard; Sivabalan, Senthuran

    2014-01-01

    the wake effects in the farm, while maintaining optimal power output. A feature which enables the MPC to spare certain turbines, while maintaining the power output is also implemented. The MPC controller is able to minimize the wake effect in the wind farm, when the power demand is not using the full......A power generating wind turbine causes a speed reduction and an added turbulence to the wind. Wind turbines in wind farms are often caught in these wakes and are found to have a higher structural load than non affected wind turbines. This article investigates the possibility of designing a control...... strategy which optimizes the power production, while minimizing the effect of the wakes in the wind farm. A generic wind farm model which is able to calculate the wind turbines influence on each other is developed. Models for the reduction in wind speed as well as turbulence in the wake effects...

  16. Novel methods to optimize the effects of transcranial direct current stimulation: a systematic review of transcranial direct current stimulation patents.

    Science.gov (United States)

    Malavera, Alejandra; Vasquez, Alejandra; Fregni, Felipe

    2015-01-01

    Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that has been extensively studied. While there have been initial positive results in some clinical trials, there is still variability in tDCS results. The aim of this article is to review and discuss patents assessing novel methods to optimize the use of tDCS. A systematic review was performed using Google patents database with tDCS as the main technique, with patents filling date between 2010 and 2015. Twenty-two patents met our inclusion criteria. These patents attempt to address current tDCS limitations. Only a few of them have been investigated in clinical trials (i.e., high-definition tDCS), and indeed most of them have not been tested before in human trials. Further clinical testing is required to assess which patents are more likely to optimize the effects of tDCS. We discuss the potential optimization of tDCS based on these patents and the current experience with standard tDCS.

  17. Dynamic Optimization

    Science.gov (United States)

    Laird, Philip

    1992-01-01

    We distinguish static and dynamic optimization of programs: whereas static optimization modifies a program before runtime and is based only on its syntactical structure, dynamic optimization is based on the statistical properties of the input source and examples of program execution. Explanation-based generalization is a commonly used dynamic optimization method, but its effectiveness as a speedup-learning method is limited, in part because it fails to separate the learning process from the program transformation process. This paper describes a dynamic optimization technique called a learn-optimize cycle that first uses a learning element to uncover predictable patterns in the program execution and then uses an optimization algorithm to map these patterns into beneficial transformations. The technique has been used successfully for dynamic optimization of pure Prolog.

  18. Supersymmetry of Demkov-Ostrovsky effective potentials at zero energy

    CERN Document Server

    Rosu, H C; Wolf, K B; Obregón, O; Rosu, Haret C; Reyes, Marco A; Wolf, Kurt Bernardo; Obregon, Octavio

    1995-01-01

    We present a Natanzon-type supersymmetric analysis of the wave problem with Demkov-Ostrovsky (DO) spherically symmetric class of focusing potentials at zero energy. It is known that at zero binding energy there exists a degenerate ``bound" state for this class of potentials. Working at zero energy and in the so-called R_{0}=0 sector, we obtain the corresponding superpartner (fermionic) DO scattering potentials within the standard one-dimensional supersymmetric procedure.

  19. The Land-Potential Knowledge System (LandPKS): mobile apps and collaboration for optimizing climate change investments

    Science.gov (United States)

    Massive investments in climate change mitigation and adaptation are projected during coming decades. Many of these investments will seek to modify how land is managed. The return on both types of investments can be increased through an understanding of land potential: the potential of the land to s...

  20. Acid rock drainage passive remediation: Potential use of alkaline clay, optimal mixing ratio and long-term impacts.

    Science.gov (United States)

    Plaza, Fernando; Wen, Yipei; Perone, Hanna; Xu, Yi; Liang, Xu

    2017-01-15

    Acid rock drainage (ARD) is one of the most adverse environmental problems of the mining industry. Surface and ground water affected by this pollution are characterized by their acidity and the high content of sulfates and metals/metalloids. In this study, alkaline clay (AC), an industrial waste with a high alkalinity, which is utilized in the alumina refining process, was used as the remediation material to inhibit pyrite oxidation in waste coal piles. Through a series of laboratory experiments (static and kinetic), complemented with field measurements and geochemical modeling, three important issues associated with this passive and sustainable ARD remediation method were investigated: 1) the potential use of alkaline clay as an ARD remediation material, 2) the adequate alkaline clay/coal refuse mixing ratio (AC/CR) to ensure pH values close to neutral conditions, and, 3) the implications for long-term performance, in terms of the trends of the main parameters involved in this process such as pH, concentrations of sulfate, iron and other dissolved contaminants. Both field measurements and the samples used for the experiments came from a local waste coal site. Through the analysis of the field measurements and the outcome of the laboratory experiments, AC proved to be an effective remediation material for ARD. Compared to those found in mine tailings, the concentrations of contaminants such as iron, manganese or sulfate were significantly reduced with this remediation approach. Moreover, results suggest a reliable long-term stability of the remediation (i.e. neutral pH conditions are maintained), thus enhancing the generation of iron precipitates that could produce pyrite grain coating. These processes also made the amended layer less porous, thus increased water retention and hindered oxygen diffusion.

  1. The analysis of the effective lead-in helps optimize the English class

    Institute of Scientific and Technical Information of China (English)

    张蕾

    2014-01-01

    Lead-in, the first part of a class guides students to enter the teaching aspects of learning; it seems to be the simplest part which takes the least time during the whole class. But the effective lead-in helps optimize the English class. Lead-in of English class in junior high school teaching methods are various. This thesis lists several of effective and practical ways and some lead-in problems that need to be taken to avoid.

  2. Simultaneous optimal estimates of fixed effects and variance components in the mixed model

    Institute of Scientific and Technical Information of China (English)

    WU Mixia; WANG Songgui

    2004-01-01

    For a general linear mixed model with two variance components, a set of simple conditions is obtained, under which, (i) the least squares estimate of the fixed effects and the analysis of variance (ANOVA) estimates of variance components are proved to be uniformly minimum variance unbiased estimates simultaneously; (ii) the exact confidence intervals of the fixed effects and uniformly optimal unbiased tests on variance components are given; (iii) the exact probability expression of ANOVA estimates of variance components taking negative value is obtained.

  3. Effective mass density based topology optimization of locally resonant acoustic metamaterials for bandgap maximization

    Science.gov (United States)

    Yang, Xiong Wei; Lee, Joong Seok; Kim, Yoon Young

    2016-11-01

    Because effective material properties are essential concepts in the analyses of wave phenomena in metamaterials, they may also be utilized in the optimal design of metamaterials. In this work, we propose a topology optimization method directly using the Effective Mass Density (EMD) concept to maximize the first bandgaps of two-dimensional solid Locally Resonant Acoustic Metamaterials (LRAMs). When the first bandgap is characterized by the negative EMD, the bandgap maximization can be formulated efficiently as a topology optimization problem to broaden the frequency zone of the negative EMD values. In this work, EMD is calculated by considering the macroscopic isotropy of LRAMs in the long wavelength limit. To facilitate the analytical sensitivity analysis, we propose an elaborate calculation scheme of EMD. A sensitivity averaging technique is also suggested to guarantee the macroscopically isotropic behavior of the LRAMs. In the present study, the coating layer interfacing the core and the matrix of a ternary LRAM is chosen as the design region because it significantly influences the bandgap. By considering several numerical examples, the validity of this method is verified, and the effects of the mass constraint ratios on the optimized results are also investigated.

  4. Analysis of Variable Speed Optimization Operation Effect of Different-type Pumps in Jiangdu Pumping Station

    Science.gov (United States)

    Jinxian, Qiu; Jilin, Cheng; Jinyao, Luo; Rentian, Zhang; Lihua, Zhang; Yi, Gong

    2010-06-01

    The following paper puts forward 45 combination schemes of different-type pumps in different daily-average heads and operation loads in Jiangdu Pumping Station. Based on every scheme, the minimum electricity consumption cost selected as the objective function, this paper gives the results of variable speed optimal operations with dynamic planning methods in both considering time-sharing electricity prices and not, simultaneously, it gives the results of fixed speed conventional operation considering time-sharing electricity prices. Then according to the unit energy consumption cost, the paper gives comparison analysis of the effect of different-type pumps in variable speed optimization operation, the conclusions can offer decision-making bases for optimization research of pumping stations considering time-sharing electricity prices and tide levels of Yangtze River, and offer references for transformation and economical operation of large and medium-size pumping stations.

  5. Effect of wind turbine response time on optimal dynamic induction control of wind farms

    Science.gov (United States)

    Munters, Wim; Meyers, Johan

    2016-09-01

    In this work, we extend recent research efforts on induction-based optimal control in large-eddy simulations of wind farms in the turbulent atmospheric boundary layer. More precisely, we investigate the effect of wind turbine response time to requested power setpoints on achievable power gains. We do this by including a time-filtering of the thrust coefficient setpoints in the optimal control framework. We consider simulation cases restricted to underinduction compared to the Betz limit, as well as cases that also allow overinduction. Optimization results show that, except for the most restrictive underinductive slow-response case, all cases still yield increases in energy extraction in the order of 10% and more.

  6. The clinical potential of high energy, intensity and energy modulated electron beams optimized by simulated annealing for conformal radiation therapy

    Science.gov (United States)

    Salter, Bill Jean, Jr.

    Purpose. The advent of new, so called IVth Generation, external beam radiation therapy treatment machines (e.g. Scanditronix' MM50 Racetrack Microtron) has raised the question of how the capabilities of these new machines might be exploited to produce extremely conformal dose distributions. Such machines possess the ability to produce electron energies as high as 50 MeV and, due to their scanned beam delivery of electron treatments, to modulate intensity and even energy, within a broad field. Materials and methods. Two patients with 'challenging' tumor geometries were selected from the patient archives of the Cancer Therapy and Research Center (CTRC), in San Antonio Texas. The treatment scheme that was tested allowed for twelve, energy and intensity modulated beams, equi-spaced about the patient-only intensity was modulated for the photon treatment. The elementary beams, incident from any of the twelve allowed directions, were assumed parallel, and the elementary electron beams were modeled by elementary beam data. The optimal arrangement of elementary beam energies and/or intensities was optimized by Szu-Hartley Fast Simulated Annealing Optimization. Optimized treatment plans were determined for each patient using both the high energy, intensity and energy modulated electron (HIEME) modality, and the 6 MV photon modality. The 'quality' of rival plans were scored using three different, popular objective functions which included Root Mean Square (RMS), Maximize Dose Subject to Dose and Volume Limitations (MDVL - Morrill et. al.), and Probability of Uncomplicated Tumor Control (PUTC) methods. The scores of the two optimized treatments (i.e. HIEME and intensity modulated photons) were compared to the score of the conventional plan with which the patient was actually treated. Results. The first patient evaluated presented a deeply located target volume, partially surrounding the spinal cord. A healthy right kidney was immediately adjacent to the tumor volume, separated

  7. Differentiation of sensorimotor neuronal structures responsible for induction of motor evoked potentials, attenuation in detection of somatosensory stimuli, and induction of sensation of movement by mapping of optimal current directions.

    Science.gov (United States)

    Pascual-Leone, A; Cohen, L G; Brasil-Neto, J P; Valls-Solé, J; Hallett, M

    1994-06-01

    Transcranial magnetic stimulation (TMS) of the sensorimotor cortex can evoke motor evoked potentials (MEPs), attenuation in detection of somatosensory stimuli (ADSS), and sensation of movement (SOM) referred to the same body part. In this study we tried to differentiate the substrates responsible for these effects. In 6 normal volunteers, TMS was applied with a nearly monopolar Dantec stimulator and a butterfly coil. Optimal scalp location and current direction were determined for induction of MEPs in abductor pollicis brevis (APB), first dorsal interosseous (FDI), and adductor digiti minimi (ADM); SOM in digits 2 and 5 in an ischemically paralyzed hand; and ADSS applied to digits 2 and 5. All 3 muscles' MEPs and SOM and ADSS in both digits were optimally activated from a single scalp position. In all subjects, optimal current directions for MEPs pointed anteriorly; those for ADSS and SOM pointed posteriorly. Optimal current directions showed the same progression in all subjects for MEPs (ADM, FDI, and APB from antero-lateral to antero-medial), ADSS (digit 5 postero-medial, 2 postero-lateral), and SOM (digit 1 through 5 postero-lateral to postero-medial). We conclude that neuronal networks targeting corticospinal neurons responsible for MEPs are different from those leading to SOM and ADSS (which could not be differentiated).

  8. Effect of fixation tasks on multifocal visual evoked potentials.

    Science.gov (United States)

    Martins, Alessandra; Klistorner, Alexander; Graham, Stuart; Billson, Frank

    2005-10-01

    This study investigated the effects of cognitive influence on the multifocal visual evoked potential (mVEP) at different levels of eccentricity. Three different foveal fixation conditions were utilized involving varying levels of task complexity. A more complex visual fixation task has been known to suppress peripheral signals in subjective testing. Twenty normal subjects had monocular mVEPs recorded using the AccuMap objective perimeter. This allowed simultaneous stimulation of 58 segments of the visual field to an eccentricity of 24 degrees. The mVEP was recorded using three different fixation conditions in random order. During task 1 the subject passively viewed the central fixation area. For task 2 alternating numbers were displayed within the fixation area; the subject on viewing the number '3' in the central fixation area indicated recognition by pressing a button. Throughout task 3, numbers were displayed as in task 2. The subject had the cognitive task of summating all the numbers. Analysis revealed that the increased attention and concentration demanded by tasks 2 and 3 in comparison with task 1 resulted in significantly enhanced central amplitudes of 9.41% (Mann-Whitney P = 0.0002) and 13.45% (P = 0.0002), respectively. These amplitudes became reduced in the periphery and approached those of task 1, resulting in no significant difference between the three tasks. Latencies demonstrated no significant difference between each task nor at any eccentricity (P > 0.05). As the complexity of each task increased the amount of alpha rhythm was significantly reduced. Our findings indicate that task 1 required a minimal demand of cognition and was associated with the greatest amount of alpha rhythm. It was also the most difficult to perform because of loss of interest. The other two tasks required a greater demand of higher order cognitive skills resulting in significantly enhanced amplitudes centrally and the attenuation of alpha rhythm. Therefore, amplitudes are

  9. Estimating Potential Effects of Hypothetical Oil Spills on Polar Bears

    Science.gov (United States)

    Amstrup, Steven C.; Durner, G.M.; McDonald, T.L.; Johnson, W.R.

    2006-01-01

    Much is known about the transport and fate of oil spilled into the sea and its toxicity to exposed wildlife. Previously, however, there has been no way to quantify the probability that wildlife dispersed over the seascape would be exposed to spilled oil. Polar bears, the apical predator of the arctic, are widely dispersed near the continental shelves of the Arctic Ocean, an area also undergoing considerable hydrocarbon exploration and development. We used 15,308 satellite locations from 194 radiocollared polar bears to estimate the probability that polar bears could be exposed to hypothetical oil spills. We used a true 2 dimensional Gausian kernel density estimator, to estimate the number of bears likely to occur in each 1.00 km2 cell of a grid superimposed over near shore areas surrounding 2 oil production facilities: the existing Northstar oil production facility, and the proposed offshore site for the Liberty production facility. We estimated the standard errors of bear numbers per cell with bootstrapping. Simulated oil spill footprints for September and October, the times during which we hypothesized effects of an oil-spill would be worst, were estimated using real wind and current data collected between 1980 and 1996. We used ARC/Info software to calculate overlap (numbers of bears oiled) between simulated oil-spill footprints and polar bear grid-cell values. Numbers of bears potentially oiled by a hypothetical 5912 barrel spill (the largest spill thought probable from a pipeline breach) ranged from 0 to 27 polar bears for September open water conditions, and from 0 to 74 polar bears in October mixed ice conditions. Median numbers oiled by the 5912 barrel hypothetical spill from the Liberty simulation in September and October were 1 and 3 bears, equivalent values for the Northstar simulation were 3 and 11 bears. In October, 75% of trajectories from the 5912 barrel simulated spill at Liberty oiled 9 or fewer bears while 75% of the trajectories affected 20 or

  10. Spatial optimization of carbon-stocking projects across Africa integrating stocking potential with co-benefits and feasibility

    Science.gov (United States)

    Greve, Michelle; Reyers, Belinda; Mette Lykke, Anne; Svenning, Jens-Christian

    2013-12-01

    Carbon offset projects through forestation are employed within the emissions trading framework to store carbon. Yet, information about the potential of landscapes to stock carbon, essential to the design of offset projects, is often lacking. Here, based on data on vegetation carbon, climate and soil, we quantify the potential for carbon storage in woody vegetation across tropical Africa. The ability of offset projects to produce co-benefits for ecosystems and people is then quantified. When co-benefits such as biodiversity conservation are considered, the top-ranked sites are sometimes different to sites selected purely for their carbon-stocking potential, although they still possess up to 92% of the latter carbon-stocking potential. This work provides the first continental-scale assessment of which areas may provide the greatest direct and indirect benefits from carbon storage reforestation projects at the smallest costs and risks, providing crucial information for prioritization of investments in carbon storage projects.

  11. Optimal Control to Increase Energy Production of Wind Farm Considering Wake Effect and Lifetime Estimation

    DEFF Research Database (Denmark)

    Tian, Jie; Zhou, Dao; Su, Chi;

    2017-01-01

    In a wind farm, the upstream wind turbine may cause power loss to the downstream wind turbines due to the wake effect. Meanwhile, the energy production is determined by the power generation and the lifetime of the wind turbine. In this paper, an optimal active power control method is proposed...... to maximize the energy production of wind farms by considering the wake effect and the lifetime of wind turbine. It starts with the analysis of the pitch angle curve and active power curve seen from the Maximum Power Point Tracking (MPPT) of individual wind turbines. Taking the wake effect into account......, the pitch angle curve and active power curve are optimized with the aim of Maximum Power Generation (MPG) of the wind farm. Afterwards, considering the lifetime of wind turbines, a comparison is offered between the MPPT method and the MPG method for energy production using a simplified two-turbine wind farm...

  12. Chondrogenic potential and anti-senescence effect of hypoxia on canine adipose mesenchymal stem cells.

    Science.gov (United States)

    Lee, Jienny; Byeon, Jeong Su; Lee, Keum Sil; Gu, Na-Yeon; Lee, Gyeong Been; Kim, Hee-Ryang; Cho, In-Soo; Cha, Sang-Ho

    2016-03-01

    Mesenchymal stem cells (MSCs) have the ability to differentiate into multi-lineage cells, which confers great promise for use in regenerative medicine. In this study, canine adipose MSCs (cAD-MSCs) were isolated from canine adipose tissue. These cells clearly represented stemness (Oct4, Sox2, and Nanog) and differentiation potential into the mesoderm (adipocytes, chondrocytes, and osteoblasts) at early passages. The aim of this study was to evaluate the effects of hypoxia on the differentiation potential into mesoderm, and the expression of anti-apoptotic genes associated with cell survival for the optimal culturing of MSCs. We observed that the proliferation of the cAD-MSCs meaningfully increased when cultured under hypoxic condition than in normoxic condition, during 7 consecutive passages. Also, we found that hypoxia strongly expressed anti-senescence related genes such as HDAC1 (histone deacetylase 1), DNMT1 (DNA (cytosine-5)-methyltransferase 1), Bcl-2 (inhibitor of apoptosis), TERT (telomerase reverse transcriptase), LDHA (lactate dehydrogenase A), SLC2A1 (glucose transporter), and DKC1 (telomere holoenzyme complex) and differentiation potential of cAD-MSCs into chondrocytes, than seen under the normoxic culture conditions. We also examined the multipotency of hypoxic conditioned MSCs using quantitative real-time RT-PCR. We found that the expression levels of stemness genes such as Oct-4, Nanog, and Sox-2 were increased in hypoxic condition when compared to the normoxic condition. Collectively, these results suggest that hypoxic conditions have the ability to induce proliferation of MSCs and augment their chondrogenic potential. This study suggests that cell proliferation of cAD-MSC under hypoxia could be beneficial, when considering these cells for cell therapies of canine bone diseases.

  13. Topology optimized microbioreactors.

    Science.gov (United States)

    Schäpper, Daniel; Lencastre Fernandes, Rita; Lantz, Anna Eliasson; Okkels, Fridolin; Bruus, Henrik; Gernaey, Krist V

    2011-04-01

    This article presents the fusion of two hitherto unrelated fields--microbioreactors and topology optimization. The basis for this study is a rectangular microbioreactor with homogeneously distributed immobilized brewers yeast cells (Saccharomyces cerevisiae) that produce a recombinant protein. Topology optimization is then used to change the spatial distribution of cells in the reactor in order to optimize for maximal product flow out of the reactor. This distribution accounts for potentially negative effects of, for example, by-product inhibition. We show that the theoretical improvement in productivity is at least fivefold compared with the homogeneous reactor. The improvements obtained by applying topology optimization are largest where either nutrition is scarce or inhibition effects are pronounced.

  14. Identification of MCI using optimal sparse MAR modeled effective connectivity networks.

    Science.gov (United States)

    Wee, Chong-Yaw; Li, Yang; Jie, Biao; Peng, Zi-Wen; Shen, Dinggang

    2013-01-01

    Capability of detecting causal or effective connectivity from resting-state functional magnetic resonance imaging (R-fMRI) is highly desirable for better understanding the cooperative nature of the brain. Effective connectivity provides specific dynamic temporal information of R-fMRI time series and reflects the directional causal influence of one brain region over another. These causal influences among brain regions are normally extracted based on the concept of Granger causality. Conventionally, the effective connectivity is inferred using multivariate autoregressive (MAR) modeling with default model order q = 1, considering low frequency fluctuation of R-fMRI time series. This assumption, although reduces the modeling complexity, does not guarantee the best fitting of R-fMRI time series at different brain regions. Instead of using the default model order, we propose to estimate the optimal model order based upon MAR order distribution to better characterize these causal influences at each brain region. Due to sparse nature of brain connectivity networks, an orthogonal least square (OLS) regression algorithm is incorporated to MAR modeling to minimize spurious effective connectivity. Effective connectivity networks inferred using the proposed optimal sparse MAR modeling are applied to Mild Cognitive Impairment (MCI) identification and obtained promising results, demonstrating the importance of using optimal causal relationships between brain regions for neurodegeneration disorder identification.

  15. Optimization of 2-phenylcyclopropylmethylamines as selective serotonin 2C receptor agonists and their evaluation as potential antipsychotic agents.

    Science.gov (United States)

    Cheng, Jianjun; Giguère, Patrick M; Onajole, Oluseye K; Lv, Wei; Gaisin, Arsen; Gunosewoyo, Hendra; Schmerberg, Claire M; Pogorelov, Vladimir M; Rodriguiz, Ramona M; Vistoli, Giulio; Wetsel, William C; Roth, Bryan L; Kozikowski, Alan P

    2015-02-26

    The discovery of a new series of compounds that are potent, selective 5-HT2C receptor agonists is described herein as we continue our efforts to optimize the 2-phenylcyclopropylmethylamine scaffold. Modifications focused on the alkoxyl substituent present on the aromatic ring led to the identification of improved ligands with better potency at the 5-HT2C receptor and excellent selectivity against the 5-HT2A and 5-HT2B receptors. ADMET studies coupled with a behavioral test using the amphetamine-induced hyperactivity model identified four compounds possessing drug-like profiles and having antipsychotic properties. Compound (+)-16b, which displayed an EC50 of 4.2 nM at 5-HT2C, no activity at 5-HT2B, and an 89-fold selectivity against 5-HT2A, is one of the most potent and selective 5-HT2C agonists reported to date. The likely binding mode of this series of compounds to the 5-HT2C receptor was also investigated in a modeling study, using optimized models incorporating the structures of β2-adrenergic receptor and 5-HT2B receptor.

  16. Effects of gas types and models on optimized gas fuelling station reservoir's pressure

    Directory of Open Access Journals (Sweden)

    M. Farzaneh-Gord

    2013-06-01

    Full Text Available There are similar algorithms and infrastructure for storing gas fuels at CNG (Compressed Natural Gas and CHG (Compressed Hydrogen Gas fuelling stations. In these stations, the fuels are usually stored in the cascade storage system to utilize the stations more efficiently. The cascade storage system generally divides into three reservoirs, commonly termed low, medium and high-pressure reservoirs. The pressures within these reservoirs have huge effects on performance of the stations. In the current study, based on the laws of thermodynamics, conservation of mass and real/ideal gas assumptions, a theoretical analysis has been constructed to study the effects of gas types and models on performance of the stations. It is intended to determine the optimized reservoir pressures for these stations. The results reveal that the optimized pressure differs between the gas types. For ideal and real gas models in both stations (CNG and CHG, the optimized non-dimensional low pressure-reservoir pressure is found to be 0.22. The optimized non-dimensional medium-pressure reservoir pressure is the same for the stations, and equal to 0.58.

  17. Effective factors on optimizing banks’ balance sheet using fuzzy analytical hierarchy process

    Directory of Open Access Journals (Sweden)

    Shoja Rezaei

    2013-11-01

    Full Text Available Every bank seeks methods to optimize its assets and liabilities, thus the main subject is managing assets-liabilities in the balance sheet and the main question is by which factor banks will be enabled to have an optimized combination of assets and liabilities in a common level of risk to get the most return. This case study is dedicated to Refah bank and is an applicable study. The data has collected from the headquarter by a questionnaire and finally effective factors weight on optimizing bank balance sheet determined by using Fuzzy analytical hierarchy process. Results showed that revenue has more effect on optimizing for %39.5 and also loan to deposit ratio for %.74, regarding revenue as a symbol of efficiency in banks, it seems to be the most important factor and goal in banking industry. Furthermore banks need to have some liquidity to respond customers demand to cover one of the most important risks of banking. This factor importance determined to be %18 in Refah Bank by using model and experts view.

  18. EFFECTIVE DIFFUSION AND EFFECTIVE DRAG COEFFICIENT OF A BROWNIAN PARTICLE IN A PERIODIC POTENTIAL

    Institute of Scientific and Technical Information of China (English)

    Hongyun Wang

    2011-01-01

    We study the stochastic motion of a Brownian particle driven by a constant force over a static periodic potential.We show that both the effective diffusion and the effective drag coefficient are mathematically well-defined and we derive analytic expressions for these two quantities.We then investigate the asymptotic behaviors of the effective diffusion and the effective drag coefficient,respectively,for small driving force and for large driving force.In the case of small driving force,the effective diffusion is reduced from its Brownian value by a factor that increases exponentially with the amplitude of the potential.The effective drag coefficient is increased by approximately the same factor.As a result,the Einstein relation between the diffusion coefficient and the drag coefficient is approximately valid when the driving force is small.For moderately large driving force,both the effective diffusion and the effective drag coefficient are increased from their Brownian values,and the Einstein relation breaks down. In the limit of very large driving force,both the effective diffusion and the effective drag coefficient converge to their Brownian values and the Einstein relation is once again valid.

  19. Effect of electric potential and heating on surface of KCI

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ The purpose of the work is research of morphology of structural changes of a surface { 100} crystals KCl under action of heating and electric field potential enclosed to one of fasets of a crystal.

  20. Effect of electric potential and heating on surface of KCI

    Institute of Scientific and Technical Information of China (English)

    Feodorov; Victor; A.; Sterelukhin; Andrey; A.; Karyev; Leonid; G.

    2005-01-01

    The purpose of the work is research of morphology of structural changes of a surface { 100} crystals KCl under action of heating and electric field potential enclosed to one of fasets of a crystal.……

  1. Compactification of gauge models and the effective potential

    Energy Technology Data Exchange (ETDEWEB)

    Shtykov, N.N. (Leningrad State University, Leningrad (SU))

    1989-07-01

    The one-loop potential for bosons and massive fermions in an Abelian model is obtained on the {ital M}{sup 2}{times}{ital S1}{times}{ital S1} manifold. Stability of the total potential against arbitrary homogeneous deformations of {ital S}{sup 1}{times}{ital S1} is studied. It is shown that attraction or repulsion depends on the relations connecting the radii of the spheres, the fermion masses, and the coupling constant.

  2. Proprioceptive event related potentials: gating and task effects

    DEFF Research Database (Denmark)

    Arnfred, Sidse M

    2005-01-01

    The integration of proprioception with vision, touch or audition is considered basic to the developmental formation of perceptions, conceptual objects and the creation of cognitive schemes. Thus, mapping of proprioceptive information processing is important in cognitive research. A stimulus...... of a brisk change of weight on a hand held load elicit a proprioceptive evoked potential (PEP). Here this is used to examine early and late information processing related to weight discrimination by event related potentials (ERP)....

  3. Effects of Asymmetry of Potential on Stochastic Stokes' Drift

    Institute of Scientific and Technical Information of China (English)

    LI Yu-Xiao; CAO Tian-Guang; WU Xi-Zhen; ZHUO Yi-Zhong

    2001-01-01

    The directed motion of Brownian particles is generated by a travelling asymmetric potential The asymptotic behaviour of the probability density of the particles at a long tie is a solitary wave. The Brownian particles can work against an external opposing force with high efficiency. The analytical expressions of the solitary wave and the efficiency of the Brownian particles are obtained. The average velocity and the efficiency of the particles depends strongly on the travelling speed and the asymmetry of the potential.

  4. Effects of Nonlocal One-Pion-Exchange Potential in Deuteron

    OpenAIRE

    Forest, J. L.

    1999-01-01

    The off-shell aspects of the one-pion-exchange potential (OPEP) are discussed. Relativistic Hamiltonians containing relativistic kinetic energy, relativistic OPEP with various off-shell behaviors and Argonne $v_{18}$ short-range parameterization are used to study the deuteron properties. The OPEP off-shell behaviors depend on whether a pseudovector or pseudoscalar pion-nucleon coupling is used and are characterized by a parameter $\\mu$. We study potentials having $\\mu$=-1, 0 and +1 and we fin...

  5. Computational modeling of protein mutant stability: analysis and optimization of statistical potentials and structural features reveal insights into prediction model development

    Directory of Open Access Journals (Sweden)

    Abhinandan Madenhalli

    2007-08-01

    Full Text Available Abstract Background Understanding and predicting protein stability upon point mutations has wide-spread importance in molecular biology. Several prediction models have been developed in the past with various algorithms. Statistical potentials are one of the widely used algorithms for the prediction of changes in stability upon point mutations. Although the methods provide flexibility and the capability to develop an accurate and reliable prediction model, it can be achieved only by the right selection of the structural factors and optimization of their parameters for the statistical potentials. In this work, we have selected five atom classification systems and compared their efficiency for the development of amino acid atom potentials. Additionally, torsion angle potentials have been optimized to include the orientation of amino acids in such a way that altered backbone conformation in different secondary structural regions can be included for the prediction model. This study also elaborates the importance of classifying the mutations according to their solvent accessibility and secondary structure specificity. The prediction efficiency has been calculated individually for the mutations in different secondary structural regions and compared. Results Results show that, in addition to using an advanced atom description, stepwise regression and selection of atoms are necessary to avoid the redundancy in atom distribution and improve the reliability of the prediction model validation. Comparing to other atom classification models, Melo-Feytmans model shows better prediction efficiency by giving a high correlation of 0.85 between experimental and theoretical ΔΔG with 84.06% of the mutations correctly predicted out of 1538 mutations. The theoretical ΔΔG values for the mutations in partially buried β-strands generated by the structural training dataset from PISCES gave a correlation of 0.84 without performing the Gaussian apodization of the

  6. Effect of number density on optimal design of gold nanoshells for plasmonic photothermal therapy.

    Science.gov (United States)

    Sikdar, Debabrata; Rukhlenko, Ivan D; Cheng, Wenlong; Premaratne, Malin

    2013-01-01

    Despite much research efforts being devoted to the design optimization of metallic nanoshells, no account is taken of the fact that the number of the nanoshells that can be delivered to a given cancerous site vary with their size. In this paper, we study the effect of the nanoshell number density on the absorption and scattering properties of a gold-nanoshell ensemble exposed to a broadband near-infrared radiation, and optimize the nanoshells' dimensions for efficient cancer treatment by analyzing a wide range of human tissues. We first consider the general situation in which the number of the delivered nanoshells decreases with their mean radius R as ∝ R(-β), and demonstrate that the optimal design of nanoshells required to treat cancer most efficiently depends critically on β. In the case of β = 2, the maximal energy absorbed (scattered) by the ensemble is achieved for the same dimensions that maximize the absorption (scattering) efficiency of a single nanoshell. We thoroughly study this special case by the example of gold nanoshells with silica core. To ensure that minimal thermal injury is caused to the healthy tissue surrounding a cancerous site, we estimate the optimal dimensions that minimize scattering by the nanoshells for a desired value of the absorption efficiency. The comparison of gold nanoshells with different cores shows that hollow nanoshells exhibiting relatively low absorption efficiency are less harmful to the healthy tissue and, hence, are preferred over the strongly absorbing nanoshells. For each of the cases analyzed, we provide approximate analytical expressions for the optimal nanoshell dimensions, which may be used as design guidelines by experimentalists, in order to optimize the synthesis of gold nanoshells for treating different types of human cancer at their various growth stages.

  7. A Parametric Optimization Approach to Mitigating the Urban Heat Island Effect: A Case Study in Ancona, Italy

    Directory of Open Access Journals (Sweden)

    Roberta Cocci Grifoni

    2016-09-01

    Full Text Available The aim of this paper is to identify a parameterization method that considers existing connections and relationships between traditional indicators of environmental sustainability as a step in combating climate change via urban strategies. A typical Mediterranean city (Ancona, Italy is investigated with a multi-objective optimization platform called modeFrontier, which uses Pareto optimality. This concept formalizes the trade-off between a given set of mutually contradicting objectives, such as high thermal comfort and low energy consumption, to identify a set of Pareto solutions. A solution is Pareto optimal when it is not possible to improve one objective without deteriorating at least one of the others. The optimization process employs given constraints (for example, meteorological scenarios with high temperature and low winds or morphological building parameters, custom procedural algorithms (recursive algorithms to generate the set of all non-dominated objective parameters, and genetic algorithms (inspired by the natural selection process to examine a wide urban space and identify interesting relationships among relevant variables for typical summer scenarios. Multi-objective optimizers involve many evaluations of two objectives (i.e., energy consumption and thermal comfort in this study while considering many analytical constraints. This approach entails a considerably more exhaustive search of environmental variables that can help the urban planning process to mitigate the urban heat island (UHI effect. Three quantitative metrics related to urban morphology and local climate conditions, as well as a thermal comfort indicator (the predicted mean vote, are defined and applied to Ancona to examine the potential for new sustainability in urban design. The results show that two parameters examined—compacity and a building-scale energy indicator—can offer insight when designing comfortable cities, while a citywide energy indicator shows

  8. Spatial optimization of carbon-stocking projects across Africa integrating stocking potential with co-benefits and feasibility

    DEFF Research Database (Denmark)

    Greve, Michelle; Reyers, Belinda; Lykke, Anne Mette

    2013-01-01

    Carbon (C) offset projects through forestation are employed within the emissions trading framework to store C. Yet, information about the potential of landscapes to stock C, essential to the design of offset projects, is often lacking. Based on data on vegetation C, climate and soil we quantified...... and risks, providing crucial information for prioritization of investments in C storage projects.......Carbon (C) offset projects through forestation are employed within the emissions trading framework to store C. Yet, information about the potential of landscapes to stock C, essential to the design of offset projects, is often lacking. Based on data on vegetation C, climate and soil we quantified...... the potential for C storage in woody vegetation across tropical Africa. The ability for offset projects to produce co-benefits for ecosystems and local communities was also investigated. When co-benefits such as biodiversity conservation were considered, the top-ranked sites were often different to sites...

  9. Theoretical and Methodological Aspects of Optimization of Relationship between Economic Potential and Sources for Public Needs Settlement

    Directory of Open Access Journals (Sweden)

    Stojanović Aleksandar

    2016-06-01

    Full Text Available The relative level of fiscal revenue in relation to the total aggregate domestic product or national income is a central indicator to be established in the national economy. This indicator is the “tax ratio”. The tendency of almost every economic and especially fiscal policy is that this indicator expresses the optimal ratio between the part of the domestic product or national income, which is intended to be used for the settlement of public needs and the general economic aggregate of the latter economic categories. Its special importance lies in the design concept of medium-term or long-term social and economic development. It is necessary to determine the framework of the global distribution of the domestic product or national income, which is acceptable, on the one hand, from the perspective of a balanced and stable economic growth, and on the other hand, from the standpoint of balancing interests of all social structures of modern mixed societies.

  10. Potential of Pervaporation and Vapor Separation with Water Selective Membranes for an Optimized Production of Biofuels—A Review

    Directory of Open Access Journals (Sweden)

    Catia Cannilla

    2017-06-01

    Full Text Available The development of processes based on the integration of new technologies is of growing interest to industrial catalysis. Recently, significant efforts have been focused on the design of catalytic membrane reactors to improve process performance. In particular, the use of membranes, that allow a selective permeation of water from the reaction mixture, positively affects the reaction evolution by improving conversion for all reactions thermodynamically or kinetically limited by the presence of water. In this paper, how pervaporation (PV and vapor permeation (VP technologies can improve the catalytic performance of reactions of industrial interest is considered. Specifically, technological approaches proposed in the literature are discussed with the aim of highlighting advantages and problems encountered in order to address research towards the optimization of membrane reactor configurations for liquid biofuel production in large scale.

  11. Optimal clinical trial design based on a dichotomous Markov-chain mixed-effect sleep model.

    Science.gov (United States)

    Steven Ernest, C; Nyberg, Joakim; Karlsson, Mats O; Hooker, Andrew C

    2014-12-01

    D-optimal designs for discrete-type responses have been derived using generalized linear mixed models, simulation based methods and analytical approximations for computing the fisher information matrix (FIM) of non-linear mixed effect models with homogeneous probabilities over time. In this work, D-optimal designs using an analytical approximation of the FIM for a dichotomous, non-homogeneous, Markov-chain phase advanced sleep non-linear mixed effect model was investigated. The non-linear mixed effect model consisted of transition probabilities of dichotomous sleep data estimated as logistic functions using piecewise linear functions. Theoretical linear and nonlinear dose effects were added to the transition probabilities to modify the probability of being in either sleep stage. D-optimal designs were computed by determining an analytical approximation the FIM for each Markov component (one where the previous state was awake and another where the previous state was asleep). Each Markov component FIM was weighted either equally or by the average probability of response being awake or asleep over the night and summed to derive the total FIM (FIM(total)). The reference designs were placebo, 0.1, 1-, 6-, 10- and 20-mg dosing for a 2- to 6-way crossover study in six dosing groups. Optimized design variables were dose and number of subjects in each dose group. The designs were validated using stochastic simulation/re-estimation (SSE). Contrary to expectations, the predicted parameter uncertainty obtained via FIM(total) was larger than the uncertainty in parameter estimates computed by SSE. Nevertheless, the D-optimal designs decreased the uncertainty of parameter estimates relative to the reference designs. Additionally, the improvement for the D-optimal designs were more pronounced using SSE than predicted via FIM(total). Through the use of an approximate analytic solution and weighting schemes, the FIM(total) for a non-homogeneous, dichotomous Markov-chain phase

  12. The effect of optimism on depression: the mediating and moderating role of insomnia.

    Science.gov (United States)

    Cheuk Yan Sing; Wong, Wing S

    2011-11-01

    This article aims to clarify if insomnia exerts a mediating or moderating effect on the optimism-depression association in Chinese college students. 529 Chinese college students completed the Beck Depression Inventory (BDI-II), the Pittsburgh Sleep Quality Index (PSQI), the Revised Life Orientation Test (LOT-R) and the Multidimensional Scale of Social Support (MSPSS). The results failed to show any moderating effect but after adjustment for age, gender and social support, a mediating effect was observed. In conclusion, insomnia qualifies as a mediator, suggesting considerable variance in depressive symptoms of college students could be due to change in their sleep status.

  13. Partially supervised P300 speller adaptation for eventual stimulus timing optimization: target confidence is superior to error-related potential score as an uncertain label

    Science.gov (United States)

    Zeyl, Timothy; Yin, Erwei; Keightley, Michelle; Chau, Tom

    2016-04-01

    Objective. Error-related potentials (ErrPs) have the potential to guide classifier adaptation in BCI spellers, for addressing non-stationary performance as well as for online optimization of system parameters, by providing imperfect or partial labels. However, the usefulness of ErrP-based labels for BCI adaptation has not been established in comparison to other partially supervised methods. Our objective is to make this comparison by retraining a two-step P300 speller on a subset of confident online trials using naïve labels taken from speller output, where confidence is determined either by (i) ErrP scores, (ii) posterior target scores derived from the P300 potential, or (iii) a hybrid of these scores. We further wish to evaluate the ability of partially supervised adaptation and retraining methods to adjust to a new stimulus-onset asynchrony (SOA), a necessary step towards online SOA optimization. Approach. Eleven consenting able-bodied adults attended three online spelling sessions on separate days with feedback in which SOAs were set at 160 ms (sessions 1 and 2) and 80 ms (session 3). A post hoc offline analysis and a simulated online analysis were performed on sessions two and three to compare multiple adaptation methods. Area under the curve (AUC) and symbols spelled per minute (SPM) were the primary outcome measures. Main results. Retraining using supervised labels confirmed improvements of 0.9 percentage points (session 2, p confidence measure resulted in the highest SPM of the partially supervised methods, indicating that ErrPs are not necessary to boost the performance of partially supervised adaptive classification. Partial supervision significantly improved SPM at a novel SOA, showing promise for eventual online SOA optimization.

  14. Design of an Os Complex-Modified Hydrogel with Optimized Redox Potential for Biosensors and Biofuel Cells.

    Science.gov (United States)

    Pinyou, Piyanut; Ruff, Adrian; Pöller, Sascha; Ma, Su; Ludwig, Roland; Schuhmann, Wolfgang

    2016-04-01

    Multistep synthesis and electrochemical characterization of an Os complex-modified redox hydrogel exhibiting a redox potential ≈+30 mV (vs. Ag/AgCl 3 M KCl) is demonstrated. The careful selection of bipyridine-based ligands bearing N,N-dimethylamino moieties and an amino-linker for the covalent attachment to the polymer backbone ensures the formation of a stable redox polymer with an envisaged redox potential close to 0 V. Most importantly, the formation of an octahedral N6-coordination sphere around the Os central atoms provides improved stability concomitantly with the low formal potential, a low reorganization energy during the Os(3+/2+) redox conversion and a negligible impact on oxygen reduction. By wiring a variety of enzymes such as pyrroloquinoline quinone (PQQ)-dependent glucose dehydrogenase, flavin adenine dinucleotide (FAD)-dependent glucose dehydrogenase and the FAD-dependent dehydrogenase domain of cellobiose dehydrogenase, low-potential glucose biosensors could be obtained with negligible co-oxidation of common interfering compounds such as uric acid or ascorbic acid. In combination with a bilirubin oxidase-based biocathode, enzymatic biofuel cells with open-circuit voltages of up to 0.54 V were obtained.

  15. Predictive simulations and optimization of nanowire field-effect PSA sensors including screening

    KAUST Repository

    Baumgartner, Stefan

    2013-05-03

    We apply our self-consistent PDE model for the electrical response of field-effect sensors to the 3D simulation of nanowire PSA (prostate-specific antigen) sensors. The charge concentration in the biofunctionalized boundary layer at the semiconductor-electrolyte interface is calculated using the propka algorithm, and the screening of the biomolecules by the free ions in the liquid is modeled by a sensitivity factor. This comprehensive approach yields excellent agreement with experimental current-voltage characteristics without any fitting parameters. Having verified the numerical model in this manner, we study the sensitivity of nanowire PSA sensors by changing device parameters, making it possible to optimize the devices and revealing the attributes of the optimal field-effect sensor. © 2013 IOP Publishing Ltd.

  16. Energy savings by optimization of drying processes through use of models and effective control; Energibesparelser ved optimering af toerreprocesser gennem anvendelse af modeller og effektiv regulering

    Energy Technology Data Exchange (ETDEWEB)

    Didriksen, H.; Sandvig Nielsen, J.; Weel Hansen, M.

    2001-06-01

    The aim of the project is to present a procedure to optimize existing drying processes. The optimization deals with energy consumption, capacity utilization and product quality. Other factors can also be included in the optimization, e.g. minimization of volume of discharged air. The optimization of existing drying processes will use calculation tool based on a mathematical simulation model for the process to calculate the most optimum operation situation on the basis of given conditions. In the project mathematical models have been developed precisely with this aim. The calculation tools have been developed with a user interface so that the tools can be used by technical staff in industrial companies and by consultants. The project also illustrates control of drying processes. Based on the developed models, the effect of using different types of control strategies by means of model simulations is illustrated. Three types of drying processes are treated: drum dryers, disc dryers and drying chambers. The work with the development of the simulation models has been very central in the project, as these have to be the basis for the optimization of the processes. The work is based on a large amount of information from academical literature and knowledge and experience about modelling thermal processes at dk-TEKNIK. The models constitute the core in the simulation programmes. The models describe the most important physical effects in connection with mass and energy transfer and transport under the drying for the three treated drying technologies. (EHS)

  17. Effects of Nonlocal One-Pion-Exchange Potential in Deuteron

    CERN Document Server

    Forest, J L

    2000-01-01

    The off-shell aspects of the one-pion-exchange potential (OPEP) are discussed. Relativistic Hamiltonians containing relativistic kinetic energy, relativistic OPEP with various off-shell behaviors and Argonne $v_{18}$ short-range parameterization are used to study the deuteron properties. The OPEP off-shell behaviors depend on whether a pseudovector or pseudoscalar pion-nucleon coupling is used and are characterized by a parameter $\\mu$. We study potentials having $\\mu$=-1, 0 and +1 and we find that they are nearly unitarily equivalent. We also find that a nonrelativistic Hamiltonian containing local potentials and nonrelativistic kinetic energy provides a good approximation to a Hamiltonian containing a relativistic OPEP based on pseudovector pion-nucleon coupling and relativistic kinetic energy.

  18. Long Range Potential Effects in Low Density Krypton Gas

    Energy Technology Data Exchange (ETDEWEB)

    Formisano, F.; Barocchi, F. [Dipartimento di Fisica, Universita degli Studi di Firenze, Largo E. Fermi 2, I-50125 Firenze (Italy); Formisano, F.; Barocchi, F.; Magli, R. [Istituto Nazionale di Fisica della Materia, Sezione di Firenze, Largo E. Fermi 2, I-50125 Firenze (Italy); Benmore, C.J.; Egelstaff, P.A. [Physics Department, University of Guelph, Ontario, N1G 2W1 (CANADA); Bafile, U. [Istituto di Elettronica Quantistica, Consiglio Nazionale delle Ricerche, Via Panciatichi 56/30, I-50127 Firenze (Italy); Magli, R. [Dipartimento di Energetica S. Stecco, Universita degli Studi di Firenze, Via di S. Marta 3, I-50139 Firenze (Italy); Verkerk, P. [Interfacultair Reactor Instituut, Technische Universiteit Delft, 2629 JB Delft (The Netherlands)

    1997-07-01

    Small angle neutron scattering (SANS) in low density {sup 86}Kr gas has been performed in order to measure the small-k behavior of the static structure factor S(k) . Three number densities between 1.52 and 2.42 nm{sup {minus}3} along the T=297 K isotherm have been studied. The small-k dependence of the Fourier transform c(k) of the direct correlation function c(r) has been derived. The experimental determination of the k{sup 3} term in the behavior of c(k) has led to a direct measurement of the London dispersion interaction in the pair potential of krypton. Also the contribution of the three-body potential in the asymptotic behavior of c(r) has been observed and related to the magnitude of the three-body interaction potential. {copyright} {ital 1997} {ital The American Physical Society}

  19. Optimization of dual effects of Mg-1Ca alloys on the behavior of chondrocytes and osteoblasts in vitro

    Institute of Scientific and Technical Information of China (English)

    Yana Dou; Ayeesha Mujeeb; Yufeng Zheng; Zigang Ge

    2014-01-01

    Mg ions can enhance the proliferation and redifferentiation of chondrocytes and the osteogenic differentiation of osteoblasts at specific concentrations, respectively. However, degradation of Mg alloys at varying degradation rates could lead to complex changes in the surrounding tissue environment, such as changes in the dynamic concentration of Mg ions and subsequent pH value. Considering the above mentioned factors, the comprehensive effects of Mg alloys on chondrocytes and osteoblasts behaviors have not yet been optimized. In this study, we evaluated the effects of Mg–1Ca microspheres on cell behavior with an aim to optimize conditions favorable for both cell types. Cells were cultured with Mg–1Ca microspheres prepared using the following concentrations:250μg/ml, 500μg/ml and 1000μg/ml. At specific time points, cytotoxicity, expression of specific genes and extracellular matrix deposition by cells (Alizarin Red Staining of osteoblasts and Alcian blue staining for chondrocytes) were evaluated. The experimental results revealed that Mg–1Ca microspheres prepared at a concentration of 250μg/ml were optimum for both cell types, where chondrocytes were found to be in hypertrophy state while osteoblasts in close proximity to the microspheres showed osteogenetic differentiation. Interestingly, a slight change in osteoblasts behavior was observed nearer to and at a relative distance away from Mg–1Ca microspheres, an important observation for administering the application of microspheres as potential scaffolds.

  20. Heavy quark potential from QCD-related effective coupling

    Science.gov (United States)

    Ayala, César; González, Pedro; Vento, Vicente

    2016-12-01

    We implement our past investigations of quark-antiquark interaction through a non-perturbative running coupling defined in terms of a gluon mass function, similar to that used in some Schwinger-Dyson approaches. This coupling leads to a quark-antiquark potential, which satisfies not only asymptotic freedom but also describes linear confinement correctly. From this potential, we calculate the bottomonium and charmonium spectra below the first open flavor meson-meson thresholds and show that for a small range of values of the free parameter determining the gluon mass function an excellent agreement with data is attained.

  1. Relativistic and quantum electrodynamics effects in the helium pair potential.

    Science.gov (United States)

    Przybytek, M; Cencek, W; Komasa, J; Łach, G; Jeziorski, B; Szalewicz, K

    2010-05-01

    The helium pair potential was computed including relativistic and quantum electrodynamics contributions as well as improved accuracy adiabatic ones. Accurate asymptotic expansions were used for large distances R. Error estimates show that the present potential is more accurate than any published to date. The computed dissociation energy and the average R for the (4)He(2) bound state are 1.62+/-0.03 mK and 47.1+/-0.5 A. These values can be compared with the measured ones: 1.1(-0.2)(+0.3) mK and 52+/-4 A [R. E. Grisenti, Phys. Rev. Lett. 85, 2284 (2000)].

  2. An Efficient Variable Screening Method for Effective Surrogate Models for Reliability-Based Design Optimization

    Science.gov (United States)

    2014-04-01

    reliability-based design optimization ( RBDO ) process, surrogate models are frequently used to reduce the number of simulations because analysis of a...the RBDO problem and thus mitigate the curse of dimensionality. Therefore, it is desirable to develop an efficient and effective variable...screening method for reduction of the dimension of the RBDO problem. In this paper, requirements of the variable screening method for deterministic design

  3. Optimized chord and twist angle distributions of wind turbine blade considering Reynolds number effects

    Energy Technology Data Exchange (ETDEWEB)

    Wang, L.; Tang, X. [Univ. of Central Lancashire. Engineering and Physical Sciences, Preston (United Kingdom); Liu, X. [Univ. of Cumbria. Sustainable Engineering, Workington (United Kingdom)

    2012-07-01

    The aerodynamic performance of a wind turbine depends very much on its blade geometric design, typically based on the blade element momentum (BEM) theory, which divides the blade into several blade elements. In current blade design practices based on Schmitz rotor design theory, the blade geometric parameters including chord and twist angle distributions are determined based on airfoil aerodynamic data at a specific Reynolds number. However, rotating wind turbine blade elements operate at different Reynolds numbers due to variable wind speed and different blade span locations. Therefore, the blade design through Schmitz rotor theory at a specific Reynolds number does not necessarily provide the best power performance under operational conditions. This paper aims to provide an optimal blade design strategy for horizontal-axis wind turbines operating at different Reynolds numbers. A fixed-pitch variable-speed (FPVS) wind turbine with S809 airfoil is chosen as a case study and a Matlab program which considers Reynolds number effects is developed to determine the optimized chord and twist angle distributions of the blade. The performance of the optimized blade is compared with that of the preliminary blade which is designed based on Schmitz rotor design theory at a specific Reynolds number. The results demonstrate that the proposed blade design optimization strategy can improve the power performance of the wind turbine. This approach can be further developed for any practice of horizontal axis wind turbine blade design. (Author)

  4. Music listening after stroke: beneficial effects and potential neural mechanisms

    National Research Council Canada - National Science Library

    Särkämö, Teppo; Soto, David

    2012-01-01

    .... Then we will present findings about the short‐ and long‐term effects of music listening on the recovery of cognitive function in stroke patients and the underlying neural mechanisms of these music effects...

  5. Effects of optimism, social support, fighting spirit, cancer worry and internal health locus of control on positive affect in cancer survivors: a path analysis.

    Science.gov (United States)

    Hodges, Kayleigh; Winstanley, Sue

    2012-12-01

    The psychological impact of a cancer diagnosis can extend through treatment, well into cancer survivorship and can be influenced by a range of psychosocial resources. At different stages in this trajectory, optimism is known to affect well-being directly. This study focusing upon the potential to flourish after cancer, investigates the relationship between optimism and positive affect during cancer survivorship together with four possible mediators: social support, fighting spirit, internal health locus of control and cancer worry, all of which have been shown to be important predictors of well-being in cancer patients. Participants (n = 102) from online cancer forums completed standardized questionnaires, and path analysis confirmed that optimism had a direct effect on positive affect in cancer survivors. Social support and fighting spirit were also shown to be significant mediators of this relationship, accounting collectively for 50% of the variance in positive affect. Whilst cancer worry and internal health locus of control could be predicted from levels of optimism, they did not mediate the optimism-positive affect relationship. Efforts to promote optimism and thus encourage fighting spirit at diagnosis through treatment may be worthwhile interventions, as would ensuring appropriate social support through the trajectory.

  6. Modeling the Effect of Temperature and Potential on the In Vitro Corrosion Performance of Biomedical Hydroxyapatite Coatings

    Science.gov (United States)

    Coşkun, M. İbrahim; Karahan, İsmail H.; Yücel, Yasin; Golden, Teresa D.

    2016-10-01

    CoCrMo biomedical alloys were coated with a hydroxyapatite layer to improve biocompatibility and in vitro corrosion performance. A fast electrodeposition process was completed in 5 minutes for the hydroxyapatite coating. Effect of the solution temperature and applied potential on the in vitro corrosion performance of the hydroxyapatite coatings was modeled by response surface methodology (RSM) coupled with central composite design (CCD). A 5-level-2-factor experimental plan designed by CCD was used; the experimental plan contained 13 coating experiments with a temperature range from 283 K to 347 K (10 °C to 74 °C) and potential range from -1.2 to -1.9 V. Corrosion potential ( E corr) of the coatings in a simulated body fluid solution was chosen as response for the model. Predicted and experimental values fitted well with an R 2 value of 0.9481. Response surface plots of the impedance and polarization resistance ( R P) were investigated. Optimized parameters for electrodeposition of hydroxyapatite were determined by RSM as solution temperature of 305.48 K (32.33 °C) and potential of -1.55 V. Hydroxyapatite coatings fabricated at optimized parameters showed excellent crystal formation and high in vitro corrosion resistance.

  7. Experimental study on the optimization of extraction process of garlic oil and its antibacterial effects.

    Science.gov (United States)

    Guo, Yajie

    2014-01-01

    Garlic oil which is the main active constituent of garlic has a wide range of pharmacological activities, and a broad antibacterial spectrum. It also has a strong anti-cancer activity, and can significantly inhibit a variety of tumors such as liver cancer, gastric cancer and colon cancer. The objective is to study the extraction process of garlic oil and its antibacterial effects. CO2 Supercritical extraction was used to investigate the optimal processing conditions for garlic oil extraction; filter paper test and suspension dilution test were applied to determine the bacteriostatic action of garlic oil. In the CO2 supercritical extraction experiment, factors influencing the yield of garlic oil were: extraction pressure > extraction temperature > extraction time in descending order. Range analysis showed that the optimal experimental conditions for CO2 supercritical extraction of garlic oil were extraction pressure of 15 Mpa, temperature of 40 °C, and duration of 1 h. Different concentrations of garlic oil could all inhibit the growth of Staphylococcus aureus, Escherichia coli and Bacillus subtilis, suggesting that garlic oil has an antibacterial effect. The optimal experimental conditions for CO2 supercritical extraction of garlic oil were: extraction pressure of 15 Mpa, temperature of 40 °C, and duration of 1 h; garlic oil has an antibacterial effect.

  8. Mind games : the effects of diazepam on Evoked Potentials

    NARCIS (Netherlands)

    Jongsma, Marie-Louise Albertien

    2000-01-01

    The electroencephalogram (EEG) represents the electrical activity of the brain. Evoked Potentials (EPs) are small voltage fluctuations in the EEG resulting from sensory, cognitive or motor evoked neural activity. Variations in the EP waveform may be caused by several factors. 1. By employing differe

  9. Tetrandrine potentiated hypnotic effect of pentobarbital through serotonergic system

    Institute of Scientific and Technical Information of China (English)

    XinZHAO; Yong-heZHAN; Xiang-yuCUI; Bao-qiongCHEN

    2004-01-01

    AIM: To investigate the hypnotic activity and mechanism of tetrandrine (TET, a major component of Stephania tetrandrae) in mice. METHODS: Each mouse was observed for the onset and duration of sleep, with the criterion for sleep being loss of righting reflex. RESULTS: TET potentiated pentobarbital (45 mg/kg, ip)-induced hypnosis significantly by reducing sleep latency and

  10. Effective momentum-dependent potentials for atomic bound states and scattering in strongly coupled plasmas

    Science.gov (United States)

    Christlieb, A.; Dharuman, G.; Verboncoeur, J.; Murillo, M. S.

    2016-10-01

    Modeling high energy-density experiments requires simulations spanning large length and time scales. These non-equilibrium experiments have time evolving ionization and partial degeneracy, obviating the direct use of the time-dependent Schrodinger equation. Therefore, efficient approximate methods are greatly needed. We have examined the accuracy of one such method based on an effective classical-dynamics approach employing effective momentum dependent potentials (MDPs) within a Hamiltonian framework that enables large-scale simulations. We have found that a commonly used formulation, based on Kirschbaum-Wilets MDPs leads to very accurate ground state energies and good first/second-ionization energies. The continuum scattering properties of free electrons were examined by comparing the momentum-transfer cross section (MTCS) predicted by KW MDP to a semi-classical phase-shift calculation. Optimizing the KW MDP parameters for the scattering process yielded poor MTCSs, suggesting a limitation of the use of KW MDP for plasmas. However, our new MDP yields MTCS values in much better agreement than KW MDP.

  11. Improvement Strategies, Cost Effective Production, and Potential Applications of Fungal Glucose Oxidase (GOD): Current Updates.

    Science.gov (United States)

    Dubey, Manish K; Zehra, Andleeb; Aamir, Mohd; Meena, Mukesh; Ahirwal, Laxmi; Singh, Siddhartha; Shukla, Shruti; Upadhyay, Ram S; Bueno-Mari, Ruben; Bajpai, Vivek K

    2017-01-01

    Fungal glucose oxidase (GOD) is widely employed in the different sectors of food industries for use in baking products, dry egg powder, beverages, and gluconic acid production. GOD also has several other novel applications in chemical, pharmaceutical, textile, and other biotechnological industries. The electrochemical suitability of GOD catalyzed reactions has enabled its successful use in bioelectronic devices, particularly biofuel cells, and biosensors. Other crucial aspects of GOD such as improved feeding efficiency in response to GOD supplemental diet, roles in antimicrobial activities, and enhancing pathogen defense response, thereby providing induced resistance in plants have also been reported. Moreover, the medical science, another emerging branch where GOD was recently reported to induce several apoptosis characteristics as well as cellular senescence by downregulating Klotho gene expression. These widespread applications of GOD have led to increased demand for more extensive research to improve its production, characterization, and enhanced stability to enable long term usages. Currently, GOD is mainly produced and purified from Aspergillus niger and Penicillium species, but the yield is relatively low and the purification process is troublesome. It is practical to build an excellent GOD-producing strain. Therefore, the present review describes innovative methods of enhancing fungal GOD production by using genetic and non-genetic approaches in-depth along with purification techniques. The review also highlights current research progress in the cost effective production of GOD, including key advances, potential applications and limitations. Therefore, there is an extensive need to commercialize these processes by developing and optimizing novel strategies for cost effective GOD production.

  12. Synergistic Effect of Compounds from a Chinese Herb: Compatibility and Dose Optimization of Compounds from N-Butanol Extract of Ipomoea stolonifera

    Science.gov (United States)

    Cai, Congyi; Chen, Yicun; Zhong, Shuping; Zhang, Yanmei; Jiang, Jiyang; Xu, Han; Shi, Ganggang

    2016-01-01

    The herbal medicine Ipomoea stolonifera (I. stolonifera) has previously been shown to have considerable anti-inflammatory potential in vivo and in vitro. To establish a method for exploring the synergistic effects of multiple compounds, we study the compatibility and dose optimization of compounds isolated from n-butanol extract of I. stolonifera (BE-IS). Raw264.7 cell was treated with lipopolysaccharide (LPS) in the presence of compounds from BE-IS, namely scopoletin, umbelliferone, esculetin, hesperetin and curcumin, using the orthogonal design, uniform design and median-effect method. To verify the best efficacy of principal constituents in vivo, the uniform design was used in the croton oil-induced mouse ear edema model. The results from LPS-induced the production of prostaglandin E2 (PGE2) show that, esculetin, curcumin and hesperetin were the principal constituents that had synergistic effects when used at the optimal ratio. Additionally, the principal constituents were found to work synergistically in the croton oil-induced mouse ear edema model at low doses. It turned out that the three experimental optimization and analysis methods (orthogonal design, uniform design and median-effect method) can be effectively used to solve both compatibility and dose optimization for combined use of multiple compounds. PMID:27255791

  13. Optimal discrimination and classification of neuronal action potential waveforms from multiunit, multichannel recordings using software-based linear filters.

    Science.gov (United States)

    Gozani, S N; Miller, J P

    1994-04-01

    We describe advanced protocols for the discrimination and classification of neuronal spike waveforms within multichannel electrophysiological recordings. The programs are capable of detecting and classifying the spikes from multiple, simultaneously active neurons, even in situations where there is a high degree of spike waveform superposition on the recording channels. The protocols are based on the derivation of an optimal linear filter for each individual neuron. Each filter is tuned to selectively respond to the spike waveform generated by the corresponding neuron, and to attenuate noise and the spike waveforms from all other neurons. The protocol is essentially an extension of earlier work [1], [13], [18]. However, the protocols extend the power and utility of the original implementations in two significant respects. First, a general single-pass automatic template estimation algorithm was derived and implemented. Second, the filters were implemented within a software environment providing a greatly enhanced functional organization and user interface. The utility of the analysis approach was demonstrated on samples of multiunit electrophysiological recordings from the cricket abdominal nerve cord.

  14. Optimized stimulus presentation patterns for an event-related potential EEG-based brain-computer interface.

    Science.gov (United States)

    Jin, Jing; Allison, Brendan Z; Sellers, Eric W; Brunner, Clemens; Horki, Petar; Wang, Xingyu; Neuper, Christa

    2011-02-01

    P300 brain-computer interface (BCI) systems typically use a row/column (RC) approach. This article presents a P300 BCI based on a 12 x 7 matrix and new paradigmatic approaches to flashing characters designed to decrease the number of flashes needed to identify a target character. Using an RC presentation, a 12 x 7 matrix requires 19 flashes to present all items twice (12 columns and seven rows) per trial. A 12 x 7 matrix contains 84 elements (characters). To identify a target character in 12 x 7 matrix using the RC pattern, 19 flashes (sub-trials) are necessary. In each flash, the selected characters (one column or one row in the RC pattern) are flashing. We present four new paradigms and compare the performance to the RC paradigm. These paradigms present quasi-random groups of characters using 9, 12, 14 and 16 flashes per trial to identify a target character. The 12-, 14- and 16-flash patterns were optimized so that the same character never flashed twice in succession. We assessed the practical bit rate and classification accuracy of the 9-, 12-, 14-, 16- and RC (19-flash) pattern conditions in an online experiment and with offline simulations. The results indicate that 16-flash pattern is better than other patterns and performance of an online P300 BCI can be significantly improved by selecting the best presentation paradigm for each subject.

  15. Optimal combinations of control strategies and cost-effective analysis for visceral leishmaniasis disease transmission

    Science.gov (United States)

    Biswas, Santanu; Subramanian, Abhishek; ELMojtaba, Ibrahim M.; Chattopadhyay, Joydev; Sarkar, Ram Rup

    2017-01-01

    Visceral leishmaniasis (VL) is a deadly neglected tropical disease that poses a serious problem in various countries all over the world. Implementation of various intervention strategies fail in controlling the spread of this disease due to issues of parasite drug resistance and resistance of sandfly vectors to insecticide sprays. Due to this, policy makers need to develop novel strategies or resort to a combination of multiple intervention strategies to control the spread of the disease. To address this issue, we propose an extensive SIR-type model for anthroponotic visceral leishmaniasis transmission with seasonal fluctuations modeled in the form of periodic sandfly biting rate. Fitting the model for real data reported in South Sudan, we estimate the model parameters and compare the model predictions with known VL cases. Using optimal control theory, we study the effects of popular control strategies namely, drug-based treatment of symptomatic and PKDL-infected individuals, insecticide treated bednets and spray of insecticides on the dynamics of infected human and vector populations. We propose that the strategies remain ineffective in curbing the disease individually, as opposed to the use of optimal combinations of the mentioned strategies. Testing the model for different optimal combinations while considering periodic seasonal fluctuations, we find that the optimal combination of treatment of individuals and insecticide sprays perform well in controlling the disease for the time period of intervention introduced. Performing a cost-effective analysis we identify that the same strategy also proves to be efficacious and cost-effective. Finally, we suggest that our model would be helpful for policy makers to predict the best intervention strategies for specific time periods and their appropriate implementation for elimination of visceral leishmaniasis. PMID:28222162

  16. Optimal cuts to extract the third-order piezoelectric constants and electrostictive constants of langasite single crystals through the electroelastic effect.

    Science.gov (United States)

    Zhang, Haifeng

    2013-07-01

    Optimal cuts to determine the third-order piezoelectric constants and electrostrictive constants of langasite single crystals by the resonator method are proposed. By selecting several langasite resonators with optimal cut angles and measuring their electroelastic effects, third-order piezoelectric constants and electrostrictive constants of langasite single crystals may be extracted. The numerical method to search these optimal cut angles is presented. The methodology has been validated by finite element analysis. This method will simplify traditional methods used to determine the third-order piezoelectric and electrostrictive constants for langasite single crystals and could potentially produce more accurate results. The method could also be used to determine the third-order piezoelectric and electrostrictive constants for other crystals with trigonal 32 symmetry.

  17. Analyzing the Quantum Zeno and anti-Zeno effects using optimal projective measurements.

    Science.gov (United States)

    Aftab, Muhammad Junaid; Chaudhry, Adam Zaman

    2017-09-18

    Measurements in quantum mechanics can not only effectively freeze the quantum system (the quantum Zeno effect) but also accelerate the time evolution of the system (the quantum anti-Zeno effect). In studies of these effects, a quantum state is prepared repeatedly by projecting the quantum state onto the initial state. In this paper, we repeatedly prepare the initial quantum state in a different manner. Instead of only performing projective measurements, we allow unitary operations to be performed, on a very short time-scale, after each measurement. We can then repeatedly prepare the initial state by performing some projective measurement and then, after each measurement, we perform a suitable unitary operation to end up with the same initial state as before. Our objective is to find the projective measurements that minimize the effective decay rate of the quantum state. We find such optimal measurements and the corresponding decay rates for a variety of system-environment models such as the pure dephasing model and the spin-boson model. We find that there can be considerable differences between this optimized effective decay rate and the usual decay rate obtained by repeatedly projecting onto the initial state. In particular, the Zeno and anti-Zeno regimes can be considerably modified.

  18. The effect of nonlinearity in relativistic nucleon–nucleon potential

    Indian Academy of Sciences (India)

    B B Sahu; S K Singh; M Bhuyan; S K Patra

    2014-04-01

    A simple form for nucleon–nucleon (NN) potential is introduced as an alternative to the popular M3Y form using the relativistic mean field theory (RMFT) with the non-linear terms in -meson for the first time. In contrast to theM3Y form, the new interaction becomes exactly zero at a finite distance and the expressions are analogous with the M3Y terms. Further, its applicability is examined by the study of proton and cluster radioactivity by folding it with the RMFT-densities of the cluster and daughter nuclei to obtain the optical potential in the region of proton-rich nuclides just above the double magic core 100Sn. The results obtained were found comparable with the widely used M3Y interactions.

  19. Reduction of Electronic Wavefunctions to Kohn-Sham Effective Potentials

    CERN Document Server

    Ryabinkin, Ilya G; Staroverov, Viktor N

    2015-01-01

    A method for calculating the Kohn--Sham exchange-correlation potential, $v_\\text{XC}(\\mathbf{r})$, from a given electronic wavefunction is devised and implemented. It requires on input one- and two-electron density matrices and involves construction of the generalized Fock matrix. The method is free from numerical limitations and basis-set artifacts of conventional schemes for constructing $v_\\text{XC}(\\mathbf{r})$ in which the potential is recovered from a given electron density, and is simpler than various many-body techniques. The chief significance of this development is that it allows one to directly probe the functional derivative of the true exchange-correlation energy functional and to rigorously test and improve various density-functional approximations.

  20. [Effects of nicotine on visually evoked EEG potentials].

    Science.gov (United States)

    Woodson, P P; Bättig, K; Rosecrans, J A

    1982-10-01

    The effects of nicotine were measured on the averaged visual evoked response (AVER) through the use of two types of experimental cigarettes which differed only in nicotine content (i.e., 0.14 vs. 1.34 mg/cig.). The results indicate that the restorative and/or enhancing effects of cigarette smoking on peak amplitudes are due predominantly to nicotine's psychopharmacologic effects, and support past research indicating that nicotine may enhance visual attentional processes in the quiescent smoker. This contrasts with other reports indicating nicotine to have a depressant effect on auditory processes.

  1. Analysis of some potential social effects of four coal technologies

    Energy Technology Data Exchange (ETDEWEB)

    Walker, C.A.; Gould, L.C.

    1980-09-01

    This is an analysis of the potential social impacts of four coal technologies: conventional combustion, fluidized-bed combustion, liquifaction, and gasification. Because of their flexibility, and the abundance and relatively low costs of coal, the potential benefits of these technologies would seem to outweigh their potential social costs, both in the intermediate and long term. Nevertheless, the social costs of a coal industry are far more obscure and hard to quantify than the benefits. In general, however, it maybe expected that those technologies that can be deployed most quickly, that provide fuels that can substitute most easily for oil and natural gas, that are the cheapest, and that are the most thermally efficient will minimize social costs most in the intermediate term, while technologies that can guide energy infrastructure changes to become the most compatable with the fuels that will be most easily derived from inexhaustible sources (electricity and hydrogen) will minimize social costs most in the long run. An industry structured to favor eastern over western coal and plant sites in moderate sized communities, which could easily adapt to inexhaustible energy technologies (nuclear or solar) in the future, would be favored in either time period.

  2. Newer Approaches to Identify Potential Untoward Effects in Functional Foods.

    Science.gov (United States)

    Marone, Palma Ann; Birkenbach, Victoria L; Hayes, A Wallace

    2016-01-01

    Globalization has greatly accelerated the numbers and variety of food and beverage products available worldwide. The exchange among greater numbers of countries, manufacturers, and products in the United States and worldwide has necessitated enhanced quality measures for nutritional products for larger populations increasingly reliant on functionality. These functional foods, those that provide benefit beyond basic nutrition, are increasingly being used for their potential to alleviate food insufficiency while enhancing quality and longevity of life. In the United States alone, a steady import increase of greater than 15% per year or 24 million shipments, over 70% products of which are food related, is regulated under the Food and Drug Administration (FDA). This unparalleled growth has resulted in the need for faster, cheaper, and better safety and efficacy screening methods in the form of harmonized guidelines and recommendations for product standardization. In an effort to meet this need, the in vitro toxicology testing market has similarly grown with an anticipatory 15% increase between 2010 and 2015 of US$1.3 to US$2.7 billion. Although traditionally occupying a small fraction of the market behind pharmaceuticals and cosmetic/household products, the scope of functional food testing, including additives/supplements, ingredients, residues, contact/processing, and contaminants, is potentially expansive. Similarly, as functional food testing has progressed, so has the need to identify potential adverse factors that threaten the safety and quality of these products.

  3. University students' psychopathology: correlates and the examiner's potential bias effect

    Directory of Open Access Journals (Sweden)

    Helena Espirito Santo

    2015-02-01

    Aims: the main objective was to verify if there is a difference on psychopathological symptoms between two groups questioned by two different examiners, controlling for the potential role of social desirability, and other potential covariates. Additionally, we want to assess the level of psychopathology and its socio-demographic correlates.Methods: 185 Coimbra's university students completed the Brief Symptom Inventory/BSI and the Marlowe-Crowne Social Desirability Scale. In one group the examiner was of the same age and academic status as the students, while in the other group the examiner was older and a teacher. We studied the psychopathological correlates with Pearson, point-biserial correlations, and qui-square analyses, and we controlled the potential role of covariates through Quade non-parametric ANCOVAs. Results: The level of distress was lower in comparison with other investigations. Women had higher level of distress and more symptoms of somatization, anxiety, phobic anxiety, obsessive-compulsion, and depression. The students that live a higher distance from home had more anxiety and obsessive-compulsive symptoms. The group assessed by the younger examiner scored higher in distress and in some BSI factors, and had lower levels on social desirability. Conclusions: Sex and distance from home seem important factors for university students' mental health. However, the examiner does have an influence in the evaluation, probably because of social desirability, suggesting that the examiner's characteristics should be given in investigations involving university students.

  4. Realization and optimization of bus bar current transducers based on Hall effect sensors

    Science.gov (United States)

    Blagojević, Marjan; Jovanović, Uglješa; Jovanović, Igor; Mančić, Dragan; Popović, Radivoje S.

    2016-06-01

    In this paper the realization and optimization of two coreless open-loop bus bar current transducers based on a Hall effect sensor are presented. Two types of bus bar are evaluated: flat rectangular and rectangular with a restrictive region in the middle. Both realized transducers are capable of measuring AC and DC currents up to 300 A and 10 kHz frequency with nonlinearity less than 0.3% in the entire range. Several methods for resolving issues with the skin effect and stray magnetic fields are presented along with the experimental test results. Some of the presented methods are novel and have never been evaluated.

  5. Effects of stimulus and recording parameters on the air conduction ocular vestibular evoked myogenic potential.

    Science.gov (United States)

    Murnane, Owen D; Akin, Faith W; Kelly, Kip J; Byrd, Stephanie

    2011-01-01

    Vestibular evoked myogenic potentials (VEMPs) have been recorded from the sternocleidomastoid muscle (cervical VEMP or cVEMP) and more recently from the eye muscles (ocular VEMP or oVEMP) in response to air conduction and bone conduction stimuli. Both cVEMPs and oVEMPs are mediated by the otoliths and thereby provide diagnostic information that is complementary to videonystagmography and rotational chair tests. In contrast to the air conduction cVEMP, which originates from the saccule/inferior vestibular nerve, recent evidence suggests the possibility that the air conduction oVEMP may be mediated by the utricle/superior vestibular nerve. The oVEMP, therefore, may provide complementary diagnostic information relative to the cVEMP. There are relatively few studies, however, that have quantified the effects of stimulus and recording parameters on the air conduction oVEMP, and there is a paucity of normative data. To evaluate the effects of several stimulus and recording parameters on the air conduction oVEMP and to establish normative data for clinical use. A prospective repeated measures design was utilized. Forty-seven young adults with no history of neurologic disease, hearing loss, middle ear pathology, open or closed head injury, cervical injury, or audiovestibular disorder participated in the study. The effects of stimulus frequency, stimulus level, gaze elevation, and recording electrode location on the amplitude and latency of the oVEMP for monaural air conduction stimuli were assessed using repeated measures analyses of variance in an initial group of 17 participants. The optimal stimulus and recording parameters obtained in the initial group were used subsequently to obtain oVEMPs from 30 additional participants. The effects of stimulus frequency, stimulus level, gaze elevation, and electrode location on the response prevalence, amplitude, and latency of the oVEMP for monaural air conduction stimuli were significant. The maximum N1-P1 amplitude and response

  6. Quantum vacuum effects from boundaries of designer potentials

    NARCIS (Netherlands)

    Konopka, T.J.

    2009-01-01

    Vacuum energy in quantum field theory, being the sum of zero-point energies of all field modes, is formally infinite but yet, after regularization or renormalization, can give rise to finite observable effects. One way of understanding how these effects arise is to compute the vacuum energy in an id

  7. Effect of experimental parameters on optimal reflection of light from opaque media

    Science.gov (United States)

    Anderson, Benjamin R.; Gunawidjaja, Ray; Eilers, Hergen

    2016-01-01

    Previously we considered the effect of experimental parameters on optimized transmission through opaque media using spatial light modulator (SLM)-based wavefront shaping. In this study we consider the opposite geometry, in which we optimize reflection from an opaque surface such that the backscattered light is focused onto a spot on an imaging detector. By systematically varying different experimental parameters (genetic algorithm iterations, bin size, SLM active area, target area, spot size, and sample angle with respect to the optical axis) and optimizing the reflected light we determine how each parameter affects the intensity enhancement. We find that the effects of the experimental parameters on the enhancement are similar to those measured for a transmissive geometry, but with the exact functional forms changed due to the different geometry and the use of a genetic algorithm instead of an iterative algorithm. Additionally, we find preliminary evidence of greater enhancements than predicted by random matrix theory, suggesting a possibly new physical mechanism to be investigated in future work.

  8. Slow high-frequency effects in mechanics: problems, solutions, potentials

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    Strong high-frequency excitation (HFE) may change the ‘slow’ (i.e. effective or average) properties of mechanical systems, e.g. their stiffness, natural frequencies, equilibriums, equilibrium stability, and bifurcation paths. This tutorial describes three general HFE effects: Stiffening – an appa......Strong high-frequency excitation (HFE) may change the ‘slow’ (i.e. effective or average) properties of mechanical systems, e.g. their stiffness, natural frequencies, equilibriums, equilibrium stability, and bifurcation paths. This tutorial describes three general HFE effects: Stiffening...... and compared: The Method of Direct Separation of Motions, the Method of Averaging, and the Method of Multiple Scales. The tutorial concludes by suggesting that more vibration experts, researchers and students should know about HFE effects, for the benefit not only of general vibration troubleshooting, but also...

  9. Estimating stellar effective temperatures and detected angular parameters using stochastic particle swarm optimization

    CERN Document Server

    Zhang, Chuan-Xin; Zhang, Hao-Wei; Shuai, Yong; Tan, He-Ping

    2016-01-01

    Considering features of stellar spectral radiation and survey explorers, we established a computational model for stellar effective temperatures, detected angular parameters, and gray rates. Using known stellar flux data in some band, we estimated stellar effective temperatures and detected angular parameters using stochastic particle swarm optimization (SPSO). We first verified the reliability of SPSO, and then determined reasonable parameters that produced highly accurate estimates under certain gray deviation levels. Finally, we calculated 177,860 stellar effective temperatures and detected angular parameters using the Midcourse Space Experiment (MSX) catalog data. These derived stellar effective temperatures were accurate when we compared them to known values from literatures. This research made full use of catalog data and presented an original technique for studying stellar characteristics. It proposed a novel method for calculating stellar effective temperatures and detected angular parameters, and pro...

  10. An Optimal Approach for Measuring the Integrated Sachs-Wolfe Effect

    CERN Document Server

    Dupe, F -X; Starck, J -L; Fadili, M J

    2010-01-01

    One of the main challenges of modern cosmology is to understand the primordial fluctuations of the early Universe and the nature of the mysterious dark energy which causes the cosmic acceleration. The Integrated Sachs-Wolfe (ISW) effect is sensitive to dark energy, and if reconstructed can be used to study primordial fluctuations in the CMB. The ISW effect occurs on large scales, where there are large amounts of missing data in the CMB and large scale structure maps. Moreover, existing methods in the literature often make strong assumptions about the statistics of the underlying fields or estimators. Together these effects can severely limit signal extraction. We define an optimal statistical method for detecting the ISW effect, which can handle large areas of missing data and minimise the number of underlying assumptions made about the data and estimators. We first review current detections (and non-detections) of the ISW effect, comparing the statistical subtleties of different methods found in the literatu...

  11. Estimating stellar effective temperatures and detected angular parameters using stochastic particle swarm optimization

    Science.gov (United States)

    Zhang, Chuan-Xin; Yuan, Yuan; Zhang, Hao-Wei; Shuai, Yong; Tan, He-Ping

    2016-09-01

    Considering features of stellar spectral radiation and sky surveys, we established a computational model for stellar effective temperatures, detected angular parameters and gray rates. Using known stellar flux data in some bands, we estimated stellar effective temperatures and detected angular parameters using stochastic particle swarm optimization (SPSO). We first verified the reliability of SPSO, and then determined reasonable parameters that produced highly accurate estimates under certain gray deviation levels. Finally, we calculated 177 860 stellar effective temperatures and detected angular parameters using data from the Midcourse Space Experiment (MSX) catalog. These derived stellar effective temperatures were accurate when we compared them to known values from literatures. This research makes full use of catalog data and presents an original technique for studying stellar characteristics. It proposes a novel method for calculating stellar effective temperatures and detecting angular parameters, and provides theoretical and practical data for finding information about radiation in any band.

  12. Probiotics in the Space Food System: Delivery, Microgravity Effects, and the Potential Benefit to Crew Health

    Science.gov (United States)

    Castro, S. L.; Ott, C. M.; Douglas, G. L.

    2014-01-01

    As mission distance and duration increase, the need grows for non-invasive disease prevention and immunomodulation, especially given the limited medical response capability expected for these missions and the immune dysregulation documented in crew. Additionally, changes in diet, lifestyle, antibiotic usage, and the environmental stresses during spaceflight may alter crewmembers' intestinal microbiome. The addition of probiotic bacteria to the space food system is expected to confer immunostimulatory benefits on crewmembers, with the potential to counteract the immune dysregulation that has been documented in spaceflight. Based on previous studies that demonstrated unique microbiological responses to the low shear environment of spaceflight, probiotic organisms hold the potential to induce enhanced beneficial responses through mechanisms, such as beneficial interactions with human immune cells and repression of colonization of pathogens on the mucosa. The work presented here will begin to address two research gaps related to providing probiotics in spaceflight: 1) delivery, and 2) the effect of the low shear microgravity environment on probiotic attributes. The probiotic Lactobacillus acidophilus was selected for investigation due to its wide commercial use and documented benefits that include inhibition of virulence related gene expression in pathogens and mucosal stimulation of immune cells. The delivery system for probiotics has not been determined for spaceflight, where the food system is shelf stable and the lack of refrigeration prevents the use of traditional dairy delivery methods. In order to demonstrate the potential of the space food system to deliver viable probiotic bacteria to crewmembers, the probiotic L. acidophilus was packaged in high barrier flight packaging in nonfat dry milk (NFDM) or retained in commercial capsule form. Viable cells were enumerated over 8 months of storage at 22, 4, and -80ºC. The survival of L. acidophilus rehydrated in NFDM

  13. Optimal cytoplasmatic density and flux balance model under macromolecular crowding effects.

    Science.gov (United States)

    Vazquez, Alexei

    2010-05-21

    Macromolecules occupy between 34% and 44% of the cell cytoplasm, about half the maximum packing density of spheres in three dimension. Yet, there is no clear understanding of what is special about this value. To address this fundamental question we investigate the effect of macromolecular crowding on cell metabolism. We develop a cell scale flux balance model capturing the main features of cell metabolism at different nutrient uptakes and macromolecular densities. Using this model we show there are two metabolic regimes at low and high nutrient uptakes. The latter regime is characterized by an optimal cytoplasmatic density where the increase of reaction rates by confinement and the decrease by diffusion slow-down balance. More important, the predicted optimal density is in the range of the experimentally determined density of Escherichia coli.

  14. Optimal geometry of nonlinear silicon slot waveguides accounting for the effect of waveguide losses.

    Science.gov (United States)

    Ong, Jun Rong; Chen, Valerian H

    2015-12-28

    The optimal geometry of silicon-organic hybrid slot waveguides is investigated in the context of the efficiency of four-wave mixing (FWM), a χ(3) nonlinear optical process. We study the effect of slot and waveguide widths, as well as waveguide asymmetry on the two-photon absorption (TPA) figure of merit and the roughness scattering loss. The optimal waveguide core width is shown to be 220nm (symmetric) with a slot width of 120nm, at a fixed waveguide height of 220nm. We also show that state-of-the-art slot waveguides can outperform rib waveguides, especially at high powers, due to the high TPA figure-of-merit.

  15. The Effects of Feature Optimization on High-Dimensional Essay Data

    Directory of Open Access Journals (Sweden)

    Bong-Jun Yi

    2015-01-01

    Full Text Available Current machine learning (ML based automated essay scoring (AES systems have employed various and vast numbers of features, which have been proven to be useful, in improving the performance of the AES. However, the high-dimensional feature space is not properly represented, due to the large volume of features extracted from the limited training data. As a result, this problem gives rise to poor performance and increased training time for the system. In this paper, we experiment and analyze the effects of feature optimization, including normalization, discretization, and feature selection techniques for different ML algorithms, while taking into consideration the size of the feature space and the performance of the AES. Accordingly, we show that the appropriate feature optimization techniques can reduce the dimensions of features, thus, contributing to the efficient training and performance improvement of AES.

  16. Optimal Control of Gene Regulatory Networks with Effectiveness of Multiple Drugs: A Boolean Network Approach

    Science.gov (United States)

    Kobayashi, Koichi; Hiraishi, Kunihiko

    2013-01-01

    Developing control theory of gene regulatory networks is one of the significant topics in the field of systems biology, and it is expected to apply the obtained results to gene therapy technologies in the future. In this paper, a control method using a Boolean network (BN) is studied. A BN is widely used as a model of gene regulatory networks, and gene expression is expressed by a binary value (0 or 1). In the control problem, we assume that the concentration level of a part of genes is arbitrarily determined as the control input. However, there are cases that no gene satisfying this assumption exists, and it is important to consider structural control via external stimuli. Furthermore, these controls are realized by multiple drugs, and it is also important to consider multiple effects such as duration of effect and side effects. In this paper, we propose a BN model with two types of the control inputs and an optimal control method with duration of drug effectiveness. First, a BN model and duration of drug effectiveness are discussed. Next, the optimal control problem is formulated and is reduced to an integer linear programming problem. Finally, numerical simulations are shown. PMID:24058904

  17. Effects of nutrient optimization on intra-annual wood formation in Norway spruce.

    Science.gov (United States)

    Kalliokoski, Tuomo; Mäkinen, Harri; Jyske, Tuula; Nöjd, Pekka; Linder, Sune

    2013-11-01

    In the Nordic countries, growth of Norway spruce (Picea abies (L.) Karst.) is generally limited by low availability of nutrients, especially nitrogen. Optimizing forest management requires better insight on how growth responds to the environmental conditions and their manipulation. The aim of this study was to analyse the effects of nutrient optimization on timing and the rate of tracheid formation of Norway spruce and to follow the differentiation of newly formed tracheids. The study was performed during two growing seasons in a long-term nutrient optimization experiment in northern Sweden, where all essential macro- and micronutrients were supplied in irrigation water every second day from mid-June to mid-August. The control plots were without additional nutrients and water. Tracheid formation in the stem was monitored throughout the growing season by weekly sampling of microcores at breast height. The onset of xylogenesis occurred in early June, but in early summer there were no significant between-treatment differences in the onset and relative rate of tracheid formation. In both treatments, the onset of secondary cell wall formation occurred in mid-June. The maximum rate of tracheid formation occurred close to the summer solstice and 50% of the tracheids had been accumulated in early July. Optimized nutrition resulted in the formation of ∼50% more tracheids and delayed the cessation of tracheid formation, which extended the tracheid formation period by 20-50%, compared with control trees. The increased growth was mainly an effect of enhanced tracheid formation rate during the mid- and later-part of the growing season. In the second year, the increased growth rate also resulted in 11% wider tracheids. We conclude that the onset and rate of tracheid formation and differentiation during summer is primarily controlled by photoperiod, temperature and availability of nutrients, rather than supply of carbohydrates.

  18. An effective theory for QCD with an axial chemical potential

    CERN Document Server

    Andrianov, Alexander A; Espriu, Domenec; Planells, Xumeu

    2013-01-01

    We consider the low energy realization of QCD in terms of meson fields when an axial chemical potential is present; a situation that may be relevant in heavy ion collisions. We shall demonstrate that the presence of an axial charge constitutes an explicit source of parity breaking. The eigenstates of strong interactions do not have a definite parity and interactions that would otherwise be forbidden compete with the familiar ones. In this work, we first focus on scalars and pseudoscalars that are described by a generalized linear sigma model; and next, we give some hints on how the Vector Meson Dominance model describes the vector sector.

  19. The potential protective effects of erythropoietin and estrogen on ...

    African Journals Online (AJOL)

    Noha I. Hussien

    2015-12-30

    Dec 30, 2015 ... Conclusion: It seems that EPO could protect the kidney against RIR, while this protective effect ... EPO is an essential growth factor of hemopoietic progeni- ...... Jerald Mahesh, Kuncha Madhusudana, Rachamalla Shyam Sun-.

  20. Effective potential for Polyakov loops in lattice QCD

    Science.gov (United States)

    Nemoto, Y.; RBC Collaboration

    2003-05-01

    Toward the derivation of an effective theory for Polyakov loops in lattice QCD, we examine Polyakov loop correlation functions using the multi-level algorithm which was recently developed by Luscher and Weisz.