A staggered-grid convolutional differentiator for elastic wave modelling
Sun, Weijia; Zhou, Binzhong; Fu, Li-Yun
2015-11-01
The computation of derivatives in governing partial differential equations is one of the most investigated subjects in the numerical simulation of physical wave propagation. An analytical staggered-grid convolutional differentiator (CD) for first-order velocity-stress elastic wave equations is derived in this paper by inverse Fourier transformation of the band-limited spectrum of a first derivative operator. A taper window function is used to truncate the infinite staggered-grid CD stencil. The truncated CD operator is almost as accurate as the analytical solution, and as efficient as the finite-difference (FD) method. The selection of window functions will influence the accuracy of the CD operator in wave simulation. We search for the optimal Gaussian windows for different order CDs by minimizing the spectral error of the derivative and comparing the windows with the normal Hanning window function for tapering the CD operators. It is found that the optimal Gaussian window appears to be similar to the Hanning window function for tapering the same CD operator. We investigate the accuracy of the windowed CD operator and the staggered-grid FD method with different orders. Compared to the conventional staggered-grid FD method, a short staggered-grid CD operator achieves an accuracy equivalent to that of a long FD operator, with lower computational costs. For example, an 8th order staggered-grid CD operator can achieve the same accuracy of a 16th order staggered-grid FD algorithm but with half of the computational resources and time required. Numerical examples from a homogeneous model and a crustal waveguide model are used to illustrate the superiority of the CD operators over the conventional staggered-grid FD operators for the simulation of wave propagations.
Gerya, T.; Duretz, T.; May, D. A.
2012-04-01
We present new 2D adaptive mesh refinement (AMR) algorithm based on stress-conservative finite-differences formulated for non-uniform rectangular staggered grid. The refinement approach is based on a repetitive cell splitting organized via a quad-tree construction (every parent cell is split into 4 daughter cells of equal size). Irrespective of the level of resolution every cell has 5 staggered nodes (2 horizontal velocities, 2 vertical velocities and 1 pressure) for which respective governing equations, boundary conditions and interpolation equations are formulated. The connectivity of the grid is achieved via cross-indexing of grid cells and basic nodal points located in their corners: four corner nodes are indexed for every cell and up to 4 surrounding cells are indexed for every node. The accuracy of the approach depends critically on the formulation of the stencil used at the "hanging" velocity nodes located at the boundaries between different levels of resolution. Most accurate results are obtained for the scheme based on the volume flux balance across the resolution boundary combined with stress-based interpolation of velocity orthogonal to the boundary. We tested this new approach with a number of 2D variable viscosity analytical solutions. Our tests demonstrate that the adaptive staggered grid formulation has convergence properties similar to those obtained in case of a standard, non-adaptive staggered grid formulation. This convergence is also achieved when resolution boundary crosses sharp viscosity contrast interfaces. The convergence rates measured are found to be insensitive to scenarios when the transition in grid resolution crosses sharp viscosity contrast interfaces. We compared various grid refinement strategies based on distribution of different field variables such as viscosity, density and velocity. According to these tests the refinement allows for significant (0.5-1 order of magnitude) increase in the computational accuracy at the same
Kou, Jisheng
2017-06-09
In this paper, a new three-field weak formulation for Stokes problems is developed, and from this, a dual-mixed finite element method is proposed on a rectangular mesh. In the proposed mixed methods, the components of stress tensor are approximated by piecewise constant functions or Q1 functions, while the velocity and pressure are discretized by the lowest-order Raviart-Thomas element and the piecewise constant functions, respectively. Using quadrature rules, we demonstrate that this scheme can be reduced into a finite volume method on staggered grid, which is extensively used in computational fluid mechanics and engineering.
Calculation of cell face velocity of non-staggered grid system
Li, Wang; Yu, Bo; Wang, Xinran; Sun, Shuyu
2012-01-01
In this paper, the cell face velocities in the discretization of the continuity equation, the momentum equation, and the scalar equation of a non-staggered grid system are calculated and discussed. Both the momentum interpolation and the linear
Energy Technology Data Exchange (ETDEWEB)
Pechstein, Astrid, E-mail: astrid.pechstein@jku.at [Johannes Kepler University Linz, Institute of Technical Mechanics (Austria); Gerstmayr, Johannes, E-mail: johannes.gerstmayr@accm.co.at [Austrian Center of Competence in Mechatronics (Austria)
2013-10-15
In the scope of this paper, a finite-element formulation for an axially moving beam is presented. The beam element is based on the absolute nodal coordinate formulation, where position and slope vectors are used as degrees of freedom instead of rotational parameters. The equations of motion for an axially moving beam are derived from generalized Lagrange equations in a Lagrange-Eulerian sense. This procedure yields equations which can be implemented as a straightforward augmentation to the standard equations of motion for a Bernoulli-Euler beam. Moreover, a contact model for frictional contact between an axially moving strip and rotating rolls is presented. To show the efficiency of the method, simulations of a belt drive are presented.
Carpenter, Mark H.; Parsani, Matteo; Fisher, Travis C.; Nielsen, Eric J.
2015-01-01
Staggered grid, entropy stable discontinuous spectral collocation operators of any order are developed for Burgers' and the compressible Navier-Stokes equations on unstructured hexahedral elements. This generalization of previous entropy stable spectral collocation work [1, 2], extends the applicable set of points from tensor product, Legendre-Gauss-Lobatto (LGL) to a combination of tensor product Legendre-Gauss (LG) and LGL points. The new semi-discrete operators discretely conserve mass, momentum, energy and satisfy a mathematical entropy inequality for both Burgers' and the compressible Navier-Stokes equations in three spatial dimensions. They are valid for smooth as well as discontinuous flows. The staggered LG and conventional LGL point formulations are compared on several challenging test problems. The staggered LG operators are significantly more accurate, although more costly to implement. The LG and LGL operators exhibit similar robustness, as is demonstrated using test problems known to be problematic for operators that lack a nonlinearly stability proof for the compressible Navier-Stokes equations (e.g., discontinuous Galerkin, spectral difference, or flux reconstruction operators).
Energy stable and high-order-accurate finite difference methods on staggered grids
O'Reilly, Ossian; Lundquist, Tomas; Dunham, Eric M.; Nordström, Jan
2017-10-01
For wave propagation over distances of many wavelengths, high-order finite difference methods on staggered grids are widely used due to their excellent dispersion properties. However, the enforcement of boundary conditions in a stable manner and treatment of interface problems with discontinuous coefficients usually pose many challenges. In this work, we construct a provably stable and high-order-accurate finite difference method on staggered grids that can be applied to a broad class of boundary and interface problems. The staggered grid difference operators are in summation-by-parts form and when combined with a weak enforcement of the boundary conditions, lead to an energy stable method on multiblock grids. The general applicability of the method is demonstrated by simulating an explosive acoustic source, generating waves reflecting against a free surface and material discontinuity.
Modeling seismic wave propagation using staggered-grid mimetic finite differences
Directory of Open Access Journals (Sweden)
Freysimar Solano-Feo
2017-04-01
Full Text Available Mimetic finite difference (MFD approximations of continuous gradient and divergence operators satisfy a discrete version of the Gauss-Divergence theorem on staggered grids. On the mimetic approximation of this integral conservation principle, an unique boundary flux operator is introduced that also intervenes on the discretization of a given boundary value problem (BVP. In this work, we present a second-order MFD scheme for seismic wave propagation on staggered grids that discretized free surface and absorbing boundary conditions (ABC with same accuracy order. This scheme is time explicit after coupling a central three-level finite difference (FD stencil for numerical integration. Here, we briefly discuss the convergence properties of this scheme and show its higher accuracy on a challenging test when compared to a traditional FD method. Preliminary applications to 2-D seismic scenarios are also presented and show the potential of the mimetic finite difference method.
Zou, Peng; Cheng, Jiubing
2017-01-01
-difference method, we propose a modified pseudo-spectral method for wave propagation in arbitrary anisotropic media. Compared with an existing remedy of staggered-grid pseudo-spectral method based on stiffness matrix decomposition and a possible alternative using
A fast Poisson solver for unsteady incompressible Navier-Stokes equations on the half-staggered grid
Golub, G. H.; Huang, L. C.; Simon, H.; Tang, W. -P.
1995-01-01
In this paper, a fast Poisson solver for unsteady, incompressible Navier-Stokes equations with finite difference methods on the non-uniform, half-staggered grid is presented. To achieve this, new algorithms for diagonalizing a semi-definite pair are developed. Our fast solver can also be extended to the three dimensional case. The motivation and related issues in using this second kind of staggered grid are also discussed. Numerical testing has indicated the effectiveness of this algorithm.
Zou, Peng
2017-05-10
Staggering grid is a very effective way to reduce the Nyquist errors and to suppress the non-causal ringing artefacts in the pseudo-spectral solution of first-order elastic wave equations. However, the straightforward use of a staggered-grid pseudo-spectral method is problematic for simulating wave propagation when the anisotropy level is greater than orthorhombic or when the anisotropic symmetries are not aligned with the computational grids. Inspired by the idea of rotated staggered-grid finite-difference method, we propose a modified pseudo-spectral method for wave propagation in arbitrary anisotropic media. Compared with an existing remedy of staggered-grid pseudo-spectral method based on stiffness matrix decomposition and a possible alternative using the Lebedev grids, the rotated staggered-grid-based pseudo-spectral method possesses the best balance between the mitigation of artefacts and efficiency. A 2D example on a transversely isotropic model with tilted symmetry axis verifies its effectiveness to suppress the ringing artefacts. Two 3D examples of increasing anisotropy levels demonstrate that the rotated staggered-grid-based pseudo-spectral method can successfully simulate complex wavefields in such anisotropic formations.
Calculation of cell face velocity of non-staggered grid system
Li, Wang
2012-07-28
In this paper, the cell face velocities in the discretization of the continuity equation, the momentum equation, and the scalar equation of a non-staggered grid system are calculated and discussed. Both the momentum interpolation and the linear interpolation are adopted to evaluate the coefficients in the discretized momentum and scalar equations. Their performances are compared. When the linear interpolation is used to calculate the coefficients, the mass residual term in the coefficients must be dropped to maintain the accuracy and convergence rate of the solution. © Shanghai University and Springer-Verlag Berlin Heidelberg 2012.
Parsani, Matteo
2016-10-04
Staggered grid, entropy stable discontinuous spectral collocation operators of any order are developed for the compressible Euler and Navier--Stokes equations on unstructured hexahedral elements. This generalization of previous entropy stable spectral collocation work [M. H. Carpenter, T. C. Fisher, E. J. Nielsen, and S. H. Frankel, SIAM J. Sci. Comput., 36 (2014), pp. B835--B867, M. Parsani, M. H. Carpenter, and E. J. Nielsen, J. Comput. Phys., 292 (2015), pp. 88--113], extends the applicable set of points from tensor product, Legendre--Gauss--Lobatto (LGL), to a combination of tensor product Legendre--Gauss (LG) and LGL points. The new semidiscrete operators discretely conserve mass, momentum, energy, and satisfy a mathematical entropy inequality for the compressible Navier--Stokes equations in three spatial dimensions. They are valid for smooth as well as discontinuous flows. The staggered LG and conventional LGL point formulations are compared on several challenging test problems. The staggered LG operators are significantly more accurate, although more costly from a theoretical point of view. The LG and LGL operators exhibit similar robustness, as is demonstrated using test problems known to be problematic for operators that lack a nonlinear stability proof for the compressible Navier--Stokes equations (e.g., discontinuous Galerkin, spectral difference, or flux reconstruction operators).
Chen, Huangxin
2017-09-01
In this paper we consider the energy stability estimates for some fully discrete schemes which both consider time and spatial discretizations for the incompressible Navier–Stokes equations. We focus on three kinds of fully discrete schemes, i.e., the linear implicit scheme for time discretization with the finite difference method (FDM) on staggered grids for spatial discretization, pressure-correction schemes for time discretization with the FDM on staggered grids for the solutions of the decoupled velocity and pressure equations, and pressure-stabilization schemes for time discretization with the FDM on staggered grids for the solutions of the decoupled velocity and pressure equations. The energy stability estimates are obtained for the above each fully discrete scheme. The upwind scheme is used in the discretization of the convection term which plays an important role in the design of unconditionally stable discrete schemes. Numerical results are given to verify the theoretical analysis.
Projection of the rotation form Navier-Stokes equation onto the half-staggered grid
Energy Technology Data Exchange (ETDEWEB)
Cho, Ji Ryong [Inje University, Kimhae (Korea, Republic of)
2016-07-15
A projection method for computing incompressible fluid flow is proposed. For the method, the rotation form Navier-Stokes equation (NSE), for which the velocity and the total pressure are employed, is discretized on the half-staggered, finite difference spatial grid. The total pressure couples the static pressure gradient and the convection of momentum in the continuous NSE while the half-staggered grid provides weak pressure-velocity coupling in discrete space. These two features interact synergistically for the discretized NSE to produce smooth pressure fields without additional numerical artifacts such as the momentum interpolation. The method preserves the kinetic energy at the inviscid limit condition. Numerical solutions of the decaying Taylor vortex, the inviscid Taylor vortex, the sudden expansion channel and the square-prism wake are presented.
Energy Technology Data Exchange (ETDEWEB)
Aldridge, David Franklin; Collier, Sandra L. (U.S. Army Research Laboratory); Marlin, David H. (U.S. Army Research Laboratory); Ostashev, Vladimir E. (NOAA/Environmental Technology Laboratory); Symons, Neill Phillip; Wilson, D. Keith (U.S. Army Cold Regions Research Engineering Lab.)
2005-05-01
This document is intended to serve as a users guide for the time-domain atmospheric acoustic propagation suite (TDAAPS) program developed as part of the Department of Defense High-Performance Modernization Office (HPCMP) Common High-Performance Computing Scalable Software Initiative (CHSSI). TDAAPS performs staggered-grid finite-difference modeling of the acoustic velocity-pressure system with the incorporation of spatially inhomogeneous winds. Wherever practical the control structure of the codes are written in C++ using an object oriented design. Sections of code where a large number of calculations are required are written in C or F77 in order to enable better compiler optimization of these sections. The TDAAPS program conforms to a UNIX style calling interface. Most of the actions of the codes are controlled by adding flags to the invoking command line. This document presents a large number of examples and provides new users with the necessary background to perform acoustic modeling with TDAAPS.
DEFF Research Database (Denmark)
Thorborg, Jesper
, however, is constituted by the implementation of the $J_2$ flow theory in the control volume method. To apply the control volume formulation on the process of hardening concrete viscoelastic stress-strain models has been examined in terms of various rheological models. The generalized 3D models are based...... on two different suggestions in the literature, that is compressible or incompressible behaviour of the viscos response in the dashpot element. Numerical implementation of the models has shown very good agreement with corresponding analytical solutions. The viscoelastic solid mechanical model is used...
The Stagger-grid: A grid of 3D stellar atmosphere models. I. Methods and general properties
Magic, Z.; Collet, R.; Asplund, M.; Trampedach, R.; Hayek, W.; Chiavassa, A.; Stein, R. F.; Nordlund, Å.
2013-09-01
Aims: We present the Stagger-grid, a comprehensive grid of time-dependent, three-dimensional (3D), hydrodynamic model atmospheres for late-type stars with realistic treatment of radiative transfer, covering a wide range in stellar parameters. This grid of 3D models is intended for various applications besides studies of stellar convection and atmospheres per se, including stellar parameter determination, stellar spectroscopy and abundance analysis, asteroseismology, calibration of stellar evolution models, interferometry, and extrasolar planet search. In this introductory paper, we describe the methods we applied for the computation of the grid and discuss the general properties of the 3D models as well as of their temporal and spatial averages (here denoted ⟨3D⟩ models). Methods: All our models were generated with the Stagger-code, using realistic input physics for the equation of state (EOS) and for continuous and line opacities. Our ~ 220 grid models range in effective temperature, Teff, from 4000 to 7000 K in steps of 500 K, in surface gravity, log g, from 1.5 to 5.0 in steps of 0.5 dex, and metallicity, [Fe/H], from - 4.0 to + 0.5 in steps of 0.5 and 1.0 dex. Results: We find a tight scaling relation between the vertical velocity and the surface entropy jump, which itself correlates with the constant entropy value of the adiabatic convection zone. The range in intensity contrast is enhanced at lower metallicity. The granule size correlates closely with the pressure scale height sampled at the depth of maximum velocity. We compare the ⟨3D⟩ models with currently widely applied one-dimensional (1D) atmosphere models, as well as with theoretical 1D hydrostatic models generated with the same EOS and opacity tables as the 3D models, in order to isolate the effects of using self-consistent and hydrodynamic modeling of convection, rather than the classical mixing length theory approach. For the first time, we are able to quantify systematically over a broad
Lagrange multipliers and gravitational theory
International Nuclear Information System (INIS)
Elston, F.D.
1977-01-01
The Lagrange multiplier variational method is extended to nonlinear Lagrangians in a Riemann space, where it is shown explicitly for the quadratic Lagrangians that, as expected, this approach is equivalent to the Hilbert variational method. It is not, in general, equivalent to the Palatini variational method. The nonvanishing Lagrange multipliers for the quadratic Lagrangians are explicitly obtained in covariant form. A similiar analysis is then carried out in a Riemann--Cartan torsional metric space for the specific Lagrangians g/sup 1/2/R tilde and g/sup 1/2/R/sub uv/tilde R/sup uv/tilde. The possible relevance of the R/sub uv/R/sup u anti v/ invariant to an action-principle formulation of the Rainich--Misner--Wheeler (RMW) already-unified theory is also discussed. It is then pointed out how a different use of the Lagrange multiplier technique in the language of the 3 + 1 canonical formalism developed by Arnowitt, Deser, and Misner (ADM) permits the recasting of the equations of motion for quadratic and general higher-order invariants into the ADM canonical formalism. In general, without this Lagrange multiplier approach, the higher-order ADM problem could not be solved. This is done explicitly for the simplest quadratic Langrangian g/sup 1/2/R 2 as an example
Noncommutative Lagrange Mechanics
Directory of Open Access Journals (Sweden)
Denis Kochan
2008-02-01
Full Text Available It is proposed how to impose a general type of ''noncommutativity'' within classical mechanics from first principles. Formulation is performed in completely alternative way, i.e. without any resort to fuzzy and/or star product philosophy, which are extensively applied within noncommutative quantum theories. Newton-Lagrange noncommutative equations of motion are formulated and their properties are analyzed from the pure geometrical point of view. It is argued that the dynamical quintessence of the system consists in its kinetic energy (Riemannian metric specifying Riemann-Levi-Civita connection and thus the inertia geodesics of the free motion. Throughout the paper, ''noncommutativity'' is considered as an internal geometric structure of the configuration space, which can not be ''observed'' per se. Manifestation of the noncommutative phenomena is mediated by the interaction of the system with noncommutative background under the consideration. The simplest model of the interaction (minimal coupling is proposed and it is shown that guiding affine connection is modified by the quadratic analog of the Lorentz electromagnetic force (contortion term.
Lagrange and Classical Mechanics
Indian Academy of Sciences (India)
over the 17th century by Galileo followed by Newton - the principle of inertia, the ... The importance of Lagrange's method can be appreciated in the following manner. Suppose one starts ... Indian Institute of Science, Bangalore 560 012, India.
Extension Of Lagrange Interpolation
Directory of Open Access Journals (Sweden)
Mousa Makey Krady
2015-01-01
Full Text Available Abstract In this paper is to present generalization of Lagrange interpolation polynomials in higher dimensions by using Gramers formula .The aim of this paper is to construct a polynomials in space with error tends to zero.
Kou, Jisheng; Sun, Shuyu
2017-01-01
In this paper, a new three-field weak formulation for Stokes problems is developed, and from this, a dual-mixed finite element method is proposed on a rectangular mesh. In the proposed mixed methods, the components of stress tensor are approximated
Energy Technology Data Exchange (ETDEWEB)
Zou, Ling; Zhao, Haihua; Zhang, Hongbin
2016-04-01
The phase appearance/disappearance issue presents serious numerical challenges in two-phase flow simulations. Many existing reactor safety analysis codes use different kinds of treatments for the phase appearance/disappearance problem. However, to our best knowledge, there are no fully satisfactory solutions. Additionally, the majority of the existing reactor system analysis codes were developed using low-order numerical schemes in both space and time. In many situations, it is desirable to use high-resolution spatial discretization and fully implicit time integration schemes to reduce numerical errors. In this work, we adapted a high-resolution spatial discretization scheme on staggered grid mesh and fully implicit time integration methods (such as BDF1 and BDF2) to solve the two-phase flow problems. The discretized nonlinear system was solved by the Jacobian-free Newton Krylov (JFNK) method, which does not require the derivation and implementation of analytical Jacobian matrix. These methods were tested with a few two-phase flow problems with phase appearance/disappearance phenomena considered, such as a linear advection problem, an oscillating manometer problem, and a sedimentation problem. The JFNK method demonstrated extremely robust and stable behaviors in solving the two-phase flow problems with phase appearance/disappearance. No special treatments such as water level tracking or void fraction limiting were used. High-resolution spatial discretization and second- order fully implicit method also demonstrated their capabilities in significantly reducing numerical errors.
Yang, Lei; Yan, Hongyong; Liu, Hong
2017-03-01
Implicit staggered-grid finite-difference (ISFD) scheme is competitive for its great accuracy and stability, whereas its coefficients are conventionally determined by the Taylor-series expansion (TE) method, leading to a loss in numerical precision. In this paper, we modify the TE method using the minimax approximation (MA), and propose a new optimal ISFD scheme based on the modified TE (MTE) with MA method. The new ISFD scheme takes the advantage of the TE method that guarantees great accuracy at small wavenumbers, and keeps the property of the MA method that keeps the numerical errors within a limited bound at the same time. Thus, it leads to great accuracy for numerical solution of the wave equations. We derive the optimal ISFD coefficients by applying the new method to the construction of the objective function, and using a Remez algorithm to minimize its maximum. Numerical analysis is made in comparison with the conventional TE-based ISFD scheme, indicating that the MTE-based ISFD scheme with appropriate parameters can widen the wavenumber range with high accuracy, and achieve greater precision than the conventional ISFD scheme. The numerical modeling results also demonstrate that the MTE-based ISFD scheme performs well in elastic wave simulation, and is more efficient than the conventional ISFD scheme for elastic modeling.
DEFF Research Database (Denmark)
Collet, Remo; Magic, Zazralt; Asplund, Martin
2011-01-01
In this contribution, we present the STAGGERGRID, a collaborative project for the construction of a comprehensive grid of time-dependent, three-dimensional (3-D), hydrodynamic model atmospheres of solar- and late-type stars with different effective temperatures, surface gravities, and chemical...
Chiavassa, A.; Casagrande, L.; Collet, R.; Magic, Z.; Bigot, L.; Thévenin, F.; Asplund, M.
2018-03-01
Context. The surface structures and dynamics of cool stars are characterised by the presence of convective motions and turbulent flows which shape the emergent spectrum. Aims: We used realistic three-dimensional (3D) radiative hydrodynamical simulations from the STAGGER-grid to calculate synthetic spectra with the radiative transfer code OPTIM3D for stars with different stellar parameters to predict photometric colours and convective velocity shifts. Methods: We calculated spectra from 1000 to 200 000 Å with a constant resolving power of λ/Δλ = 20 000 and from 8470 and 8710 Å (Gaia Radial Velocity Spectrometer - RVS - spectral range) with a constant resolving power of λ/Δλ = 300 000. Results: We used synthetic spectra to compute theoretical colours in the Johnson-Cousins UBV (RI)C, SDSS, 2MASS, Gaia, SkyMapper, Strömgren systems, and HST-WFC3. Our synthetic magnitudes are compared with those obtained using 1D hydrostatic models. We showed that 1D versus 3D differences are limited to a small percent except for the narrow filters that span the optical and UV region of the spectrum. In addition, we derived the effect of the convective velocity fields on selected Fe I lines. We found the overall convective shift for 3D simulations with respect to the reference 1D hydrostatic models, revealing line shifts of between -0.235 and +0.361 km s-1. We showed a net correlation of the convective shifts with the effective temperature: lower effective temperatures denote redshifts and higher effective temperatures denote blueshifts. We conclude that the extraction of accurate radial velocities from RVS spectra need an appropriate wavelength correction from convection shifts. Conclusions: The use of realistic 3D hydrodynamical stellar atmosphere simulations has a small but significant impact on the predicted photometry compared with classical 1D hydrostatic models for late-type stars. We make all the spectra publicly available for the community through the POLLUX database
A range of formulations to couple mass and momentum equations
International Nuclear Information System (INIS)
Darbandi, M.; Schneider, G.E.
2002-01-01
Since the innovation of control-volume-based methods, the issue of pressure-velocity decoupling has prompted the researcher to develop and employ staggered grid arrangement. The difficulties and disadvantages of staggered-grid-based schemes have encouraged the workers to investigate more in alternative scheme, i.e., the collocated-grid-based scheme. The primitive idea in collocated scheme is to couple the mass and momentum equations with the help of two types of velocity definitions instead of two types of grid arrangements. Following the work of preceding workers, we introduce a general strategy which enables the workers to develop a wide range of velocity definitions which can be properly used in collocated formulations. The developed formulations are then tested in a domain with source and sink. The results of the extended formulations are eventually discussed. (author)
-Dimensional Fractional Lagrange's Inversion Theorem
Directory of Open Access Journals (Sweden)
F. A. Abd El-Salam
2013-01-01
Full Text Available Using Riemann-Liouville fractional differential operator, a fractional extension of the Lagrange inversion theorem and related formulas are developed. The required basic definitions, lemmas, and theorems in the fractional calculus are presented. A fractional form of Lagrange's expansion for one implicitly defined independent variable is obtained. Then, a fractional version of Lagrange's expansion in more than one unknown function is generalized. For extending the treatment in higher dimensions, some relevant vectors and tensors definitions and notations are presented. A fractional Taylor expansion of a function of -dimensional polyadics is derived. A fractional -dimensional Lagrange inversion theorem is proved.
Calculation of reactivity without Lagrange interpolation
International Nuclear Information System (INIS)
Suescun D, D.; Figueroa J, J. H.; Rodriguez R, K. C.; Villada P, J. P.
2015-09-01
A new method to solve numerically the inverse equation of punctual kinetics without using Lagrange interpolating polynomial is formulated; this method uses a polynomial approximation with N points based on a process of recurrence for simulating different forms of nuclear power. The results show a reliable accuracy. Furthermore, the method proposed here is suitable for real-time measurements of reactivity, with step sizes of calculations greater that Δt = 0.3 s; due to its precision can be used to implement a digital meter of reactivity in real time. (Author)
Fluid-structure coupling in Lagrange-Lagrange and Euler-Lagrange descriptions
International Nuclear Information System (INIS)
Jones, A.V.
1981-01-01
Fluid-structure interaction problems are very common in the reactor safety field, examples being containment loading in LMFBR systems and the downcomer problem in LWRs. This article reviews the principal finite difference methodes employed for their solution. After a survey of the chief representations of the equations of motion of the fluid and structure and of their coupling, the Lagrange-Lagrange and Euler-Lagrange representations are examined in detail. The practical necessity of treating the structure in Lagrangian coordinates and the respective merits of the Lagrangian and Eulerian representations for the fluid are explained, both for coupling between continua and for coupling between a fluid and a thin shell. Detailed analyses of the stability and numerical dissipation of the Lagrange-Lagrange and Euler-Lagrange coupling techniques in a very simple one-dimensional problem are provided to supply indicators as to stability and dissipation in more complex multidimensional situations and to bring out the theoretical complexity of seemingly simple coupling algorithms. The article then presents some practical examples of coupled problems in which calculations can be compared with experiment, and concludes with a section on future trends in the field of fluid-structure coupling
Joseph Louis Lagrange (1736 - 1813)
Indian Academy of Sciences (India)
to diverse areas of mathematics, is best remembered for his work on number theory, ... father was in the service of the King of Sardinia, the family was not wealthy, as the ... of Prussia arranged for Lagrange to be offered a position in 1765 there. ... taught courses on elementary mathematics for training school teachers.
Institute of Scientific and Technical Information of China (English)
李俊峰; 倪明玖
2011-01-01
在低磁场雷诺数条件下,基于电势泊松方程,发展了交错网格下可以精确计算电流和洛伦兹力(电磁力)的相容守恒格式.采用压力为变量的原始变量法求解不可压缩Navier-Stokes方程,所计算的电流满足电荷守恒定律,所计算的电磁力满足动量守恒定律.对金属流体在Hartmann数50～5000范围内验证了格式的精确性.交错网格下相容守恒格式的发展为后续MHD稳定性分析、湍流的大涡模拟及直接数值模拟提供很好的选择.%A consistent and conservative scheme has been extended and developed on a staggered grid system for liquid metal MHD flow at a low magnetic Reynolds number by solving electrical potential Poisson equation based on the Ohm's law and the charge conservation law. The consistent scheme is used to ensure the calculated current density conserves the charge, and the divergence formula of the Lorentz force is used to ensure the momentum conservation. Simulation of liquid metal flows in a three-dimensional straight channel is conducted and compared with the analytical solutions from Shercliff's and Hunt's. The numerical results are in good agreement with analytical solutions for the Hartmann numbers from 50 to 5000. A fully conservative scheme on a staggered grid, which can conserve mass, momentum and kinetic energy and charge, is then developed with the central-symmetrical scheme for the convective term and the pressure term and with the consistent and conservative scheme for the calculation of the current density and the Lorentz force. A fully conservative scheme can be a good tool for numerical analysis of MHD flow instability, large eddy simulation (LES) and direct-numerical simulation (DNS) of MHD turbulence.
Energy Technology Data Exchange (ETDEWEB)
Suescun D, D.; Figueroa J, J. H. [Pontificia Universidad Javeriana Cali, Departamento de Ciencias Naturales y Matematicas, Calle 18 No. 118-250, Cali, Valle del Cauca (Colombia); Rodriguez R, K. C.; Villada P, J. P., E-mail: dsuescun@javerianacali.edu.co [Universidad del Valle, Departamento de Fisica, Calle 13 No. 100-00, Cali, Valle del Cauca (Colombia)
2015-09-15
A new method to solve numerically the inverse equation of punctual kinetics without using Lagrange interpolating polynomial is formulated; this method uses a polynomial approximation with N points based on a process of recurrence for simulating different forms of nuclear power. The results show a reliable accuracy. Furthermore, the method proposed here is suitable for real-time measurements of reactivity, with step sizes of calculations greater that Δt = 0.3 s; due to its precision can be used to implement a digital meter of reactivity in real time. (Author)
Canonical form of Euler-Lagrange equations and gauge symmetries
Energy Technology Data Exchange (ETDEWEB)
Geyer, B [Naturwissenschaftlich-Theoretisches Zentrum und Institut fuer Theoretische Physik, Universitaet Leipzig, Leipzig (Germany); Gitman, D M [Institute of Physics, University of Sao Paulo, Sao Paulo (Brazil); Tyutin, I V [Lebedev Physics Institute, Moscow (Russian Federation)
2003-06-13
The structure of the Euler-Lagrange equations for a general Lagrangian theory (e.g. singular, with higher derivatives) is studied. For these equations we present a reduction procedure to the so-called canonical form. In the canonical form the equations are solved with respect to highest-order derivatives of nongauge coordinates, whereas gauge coordinates and their derivatives enter the right-hand sides of the equations as arbitrary functions of time. The reduction procedure reveals constraints in the Lagrangian formulation of singular systems and, in that respect, is similar to the Dirac procedure in the Hamiltonian formulation. Moreover, the reduction procedure allows one to reveal the gauge identities between the Euler-Lagrange equations. Thus, a constructive way of finding all the gauge generators within the Lagrangian formulation is presented. At the same time, it is proved that for local theories all the gauge generators are local in time operators.
Integrals of Lagrange functions and sum rules
Energy Technology Data Exchange (ETDEWEB)
Baye, Daniel, E-mail: dbaye@ulb.ac.be [Physique Quantique, CP 165/82, Universite Libre de Bruxelles, B 1050 Bruxelles (Belgium); Physique Nucleaire Theorique et Physique Mathematique, CP 229, Universite Libre de Bruxelles, B 1050 Bruxelles (Belgium)
2011-09-30
Exact values are derived for some matrix elements of Lagrange functions, i.e. orthonormal cardinal functions, constructed from orthogonal polynomials. They are obtained with exact Gauss quadratures supplemented by corrections. In the particular case of Lagrange-Laguerre and shifted Lagrange-Jacobi functions, sum rules provide exact values for matrix elements of 1/x and 1/x{sup 2} as well as for the kinetic energy. From these expressions, new sum rules involving Laguerre and shifted Jacobi zeros and weights are derived. (paper)
Schwartz distributions in the Lagrange variational problem
International Nuclear Information System (INIS)
Anton, H.; Bahar, L.Y.
1978-01-01
Schwartz distributions are used to eliminate the necessity of imposing a priori conditions on the class of admissible functions in the Lagrange fixed end-point variational problem. This makes it possible to defer the imposition of conditions on the extremals until such conditions become apparent from physical considerations
Taylor-Lagrange regularization scheme and light-front dynamics
International Nuclear Information System (INIS)
Grange, P.; Mathiot, J.-F.; Mutet, B.; Werner, E.
2010-01-01
The recently proposed renormalization scheme based on the definition of field operators as operator valued distributions acting on specific test functions is shown to be very convenient in explicit calculations of physical observables within the framework of light-front dynamics. We first recall the main properties of this procedure based on identities relating the test functions to their Taylor remainder of any order expressed in terms of Lagrange's formulae, hence the name given to this scheme. We thus show how it naturally applies to the calculation of state vectors of physical systems in the covariant formulation of light-front dynamics. As an example, we consider the case of the Yukawa model in the simple two-body Fock state truncation.
On fictitious domain formulations for Maxwell's equations
DEFF Research Database (Denmark)
Dahmen, W.; Jensen, Torben Klint; Urban, K.
2003-01-01
We consider fictitious domain-Lagrange multiplier formulations for variational problems in the space H(curl: Omega) derived from Maxwell's equations. Boundary conditions and the divergence constraint are imposed weakly by using Lagrange multipliers. Both the time dependent and time harmonic formu...
Characterization of initiation and detonation by Lagrange gage techniques. Final report
International Nuclear Information System (INIS)
Cowperthwaite, M.
1983-08-01
The work on reactive flow Lagrange analysis (RFLA) was concerned with Lagrange particle velocity histories that exhibit double maxima similar to those recorded in RX26 and PBX9404. Conditions for particle velocity histories to exhibit extrema were formulated in terms of envelopes formed by Lagrange pressure histories. Lagrange analysis of the flow produced by the expansion of a detonation wave at a free surface was proposed to extend the determination of the release adiabat of detonation products from the Chapman-Jouguet (CJ) state to zero pressure. Solutions were constructed for steady-state nonideal detonation waves propagating in polytropic explosive with two reacting components. Overdriven detonation was treated both as a reactive discontinuity and as a Zeldovich-von Neumann-Doering (ZND) wave. The Rankine-Hugoniot (RH) jump conditions were used to calculate the first and second derivatives on the detonation velocity versus particle velocity Hugoniot at the CJ point. Methods of differential geometry were used to determine the conditions that allow the flow equations and RH boundary conditions to admit similarity solutions for overdriven detonation waves
Variational problems with fractional derivatives: Euler-Lagrange equations
International Nuclear Information System (INIS)
Atanackovic, T M; Konjik, S; Pilipovic, S
2008-01-01
We generalize the fractional variational problem by allowing the possibility that the lower bound in the fractional derivative does not coincide with the lower bound of the integral that is minimized. Also, for the standard case when these two bounds coincide, we derive a new form of Euler-Lagrange equations. We use approximations for fractional derivatives in the Lagrangian and obtain the Euler-Lagrange equations which approximate the initial Euler-Lagrange equations in a weak sense
Energy Technology Data Exchange (ETDEWEB)
Griess, F.
1958-03-14
Hamiltonian formalism - Canonical transformations - Invariants of Liouville, Helmholtz-Lagrange, Busch, Stoermer and Lagrange - Synchrotron's Hamiltonian - Betatron oscillation damping. (author) [French] Formalisme Hamiltonien. Transformations canoniques. Invariants de Liouville, Helmholtz-Lagrange, Busch, Stoermer et Lagrange, Hamiltonien pour le synchrotron, Amortissement des oscillations betatrons (auteur)
Teleparallel Lagrange geometry and a unified field theory
Energy Technology Data Exchange (ETDEWEB)
Wanas, M I [Department of Astronomy, Faculty of Science, Cairo University, CTP of the British University in Egypt (BUE) (Egypt); Youssef, Nabil L; Sid-Ahmed, A M, E-mail: wanas@frcu.eun.eg, E-mail: nyoussef@frcu.eun.e, E-mail: nlyoussef2003@yahoo.f, E-mail: amrs@mailer.eun.e, E-mail: amrsidahmed@gmail.co [Department of Mathematics, Faculty of Science, Cairo University (Egypt)
2010-02-21
In this paper, we construct a field theory unifying gravity and electromagnetism in the context of extended absolute parallelism (EAP) geometry. This geometry combines, within its structure, the geometric richness of the tangent bundle and the mathematical simplicity of absolute parallelism (AP) geometry. The constructed field theory is a generalization of the generalized field theory (GFT) formulated by Mikhail and Wanas. The theory obtained is purely geometric. The horizontal (resp. vertical) field equations are derived by applying the Euler-Lagrange equations to an appropriate horizontal (resp. vertical) scalar Lagrangian. The symmetric part of the resulting horizontal (resp. vertical) field equations gives rise to a generalized form of Einstein's field equations in which the horizontal (resp. vertical) energy-momentum tensor is purely geometric. The skew-symmetric part of the resulting horizontal (resp. vertical) field equations gives rise to a generalized form of Maxwell equations in which the electromagnetic field is purely geometric. Some interesting special cases, which reveal the role of the nonlinear connection in the obtained field equations, are examined. Finally, the condition under which our constructed field equations reduce to the GFT is explicitly established.
Reminder of Lagrange-Hamilton formalism and of the corpuscular optics invariants
International Nuclear Information System (INIS)
Griess, F.
1958-01-01
Hamiltonian formalism - Canonical transformations - Invariants of Liouville, Helmholtz-Lagrange, Busch, Stoermer and Lagrange - Synchrotron's Hamiltonian - Betatron oscillation damping. (author) [fr
CDCC calculations with the Lagrange-mesh technique
International Nuclear Information System (INIS)
Druet, T.; Baye, D.; Descouvemont, P.; Sparenberg, J.-M.
2010-01-01
We apply the Lagrange-mesh technique to the Continuum Discretized Coupled Channel (CDCC) theory. The CDCC equations are solved with the R-matrix method, using Lagrange functions as variational basis. The choice of Lagrange functions is shown to be efficient and accurate for elastic scattering as well as for breakup reactions. We describe the general formalism for two-body projectiles, and apply it to the d+ 58 Ni collision at E d =80 MeV. Various numerical and physical aspects are discussed. Benchmark calculations on elastic scattering and breakup are presented.
Laser Gravitational-wave Antenna in Geodetic Orbit: LAGRANGE and LAGRANGE 2020
International Nuclear Information System (INIS)
Buchman, S.; Balakrishnan, K.; Byer, R.L.; Cutler, G.D.; Debra, D.B.; Hultgren, E.; Lantz, B.; Lipa, J.A.; Saraf, S.; Zoellner, A.; Conklin, J.W.; Aguero, V.; Williams, S.D.; Alfauwaz, A.; Aljadaan, A.; Almajed, M.; Altwaijry, H.; Al Saud, T.; Bower, K.; Costello, B.; Hooper, K.; Klavins, A.; Palmer, A.; Plante, B.; Schaechter, D.; Shu, K.L.; Smith, E.; Tenerelli, D.; Vanbezooijen, R.; Vasudevan, G.; Faied, D.M.; Foster, C.; Genova, A.L.; Sanchez, H.S.; Worden, S.P.; Hanson, J.
2014-01-01
We describe a Laser Gravitational-wave Antenna in Geodic Orbit design called LAGRANGE that maintains all important LISA science at about half the cost of the original LISA mission and with reduced technical risk. It consists of 3 drag-free spacecraft (SC) in a geocentric formation. Fixed antennas allow continuous contact with the Earth, solving the problem of communications bandwidth and latency. A 70 mm diameter sphere with a 35 mm gap to its enclosure serves as the single inertial reference per SC, operating in 'true' drag-free mode (no test mass forcing). Other advantages are: a single caging design based on the DISCOS 1972 drag-free mission, an all optical read-out with pm fine and nm coarse sensors, and the extreme technology heritage from the Honeywell gyroscopes, and the DISCOS and Gravity Probe B drag-free sensors. An interferometric Measurement System, designed with reflective optics and a highly stabilized frequency standard, performs the ranging between test masses and requires a single optical bench with one laser per SC. Two 20 cm diameter telescope per SC, each with infield pointing, incorporate novel technology developed for advanced optical systems by Lockheed Martin, who also designed the SC based on a multi-flight proven bus structure. Additional technological advancements include include updated propulsion technology, improved thermal control, and a UV-LED charge management system. LAGRANGE subsystems are designed to be scalable and modular, making them interchangeable with those of LISA or other gravitational science missions. We plan to space qualify critical technologies on small and nano satellite flights, with the first launch (UV-LED Sat) in 2013. We further propose a relaxed performance version of LAGRANGE to be flown before 2020 at one quarter the cost of LISA. The requirements on the drag-free sensors and interferometers are relaxed by factors of 10-100 while the core science, super massive black hole (MBH) mergers, is maintained
Lagrange formalism for a system of several fluids interacting electromagnetically
International Nuclear Information System (INIS)
Vuillemin, M.
1964-01-01
After giving the Lagrange expression for a conducting fluid in an external electromagnetic field, the author shows that a Lagrange expression exists for describing the evolution of a system of interacting fluids obtained by adding the Lagrange expression of each fluid.to that of the electromagnetic field. By variation are obtained the fluid movement equation coupled to the Maxwell equations. It is shown that the study of small movements around a stationary state can be deduced from the Lagrange equation expanded to the second power order of the perturbation. It is then possible to deduce the normal mode equations and the study the stability by examining the modes which are marginally stable. (author) [fr
kantorovich-euler lagrange-galerkin's method for bending analysis
African Journals Online (AJOL)
user
OF CIVIL ENGINEERING, ENUGU STATE UNIVERSITY OF SCIENCE & TECHNOLOGY, ... In this work, the Kantorovich method is applied to solve the bending problem of thin ... Lagrange differential equation is determined for this functional.
Lagrange polynomial interpolation method applied in the calculation of the J({xi},{beta}) function
Energy Technology Data Exchange (ETDEWEB)
Fraga, Vinicius Munhoz; Palma, Daniel Artur Pinheiro [Centro Federal de Educacao Tecnologica de Quimica de Nilopolis, RJ (Brazil)]. E-mails: munhoz.vf@gmail.com; dpalma@cefeteq.br; Martinez, Aquilino Senra [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE) (COPPE). Programa de Engenharia Nuclear]. E-mail: aquilino@lmp.ufrj.br
2008-07-01
The explicit dependence of the Doppler broadening function creates difficulties in the obtaining an analytical expression for J function . The objective of this paper is to present a method for the quick and accurate calculation of J function based on the recent advances in the calculation of the Doppler broadening function and on a systematic analysis of its integrand. The methodology proposed, of a semi-analytical nature, uses the Lagrange polynomial interpolation method and the Frobenius formulation in the calculation of Doppler broadening function . The results have proven satisfactory from the standpoint of accuracy and processing time. (author)
Lagrange polynomial interpolation method applied in the calculation of the J(ξ,β) function
International Nuclear Information System (INIS)
Fraga, Vinicius Munhoz; Palma, Daniel Artur Pinheiro; Martinez, Aquilino Senra
2008-01-01
The explicit dependence of the Doppler broadening function creates difficulties in the obtaining an analytical expression for J function . The objective of this paper is to present a method for the quick and accurate calculation of J function based on the recent advances in the calculation of the Doppler broadening function and on a systematic analysis of its integrand. The methodology proposed, of a semi-analytical nature, uses the Lagrange polynomial interpolation method and the Frobenius formulation in the calculation of Doppler broadening function . The results have proven satisfactory from the standpoint of accuracy and processing time. (author)
Extension of meshless Galerkin/Petrov-Galerkin approach without using Lagrange multipliers
International Nuclear Information System (INIS)
Kamitani, Atsushi; Takayama, Teruou; Itoh, Taku; Nakamura, Hiroaki
2011-01-01
By directly discretizing the weak form used in the finite element method, meshless methods have been derived. Neither the Lagrange multiplier method nor the penalty method is employed in the derivation of the methods. The resulting methods are divided into two groups, depending on whether the discretization is based on the Galerkin or the Petrov-Galerkin approach. Each group is further subdivided into two groups, according to the method for imposing the essential boundary condition. Hence, four types of the meshless methods have been formulated. The accuracy of these methods is illustrated for two-dimensional Poisson problems. (author)
Lowrank seismic-wave extrapolation on a staggered grid
Fang, Gang; Fomel, Sergey; Du, Qizhen; Hu, Jingwei
2014-01-01
© 2014 Society of Exploration Geophysicists. We evaluated a new spectral method and a new finite-difference (FD) method for seismic-wave extrapolation in time. Using staggered temporal and spatial grids, we derived a wave-extrapolation operator using a lowrank decomposition for a first-order system of wave equations and designed the corresponding FD scheme. The proposed methods extend previously proposed lowrank and lowrank FD wave extrapolation methods from the cases of constant density to those of variable density. Dispersion analysis demonstrated that the proposed methods have high accuracy for a wide wavenumber range and significantly reduce the numerical dispersion. The method of manufactured solutions coupled with mesh refinement was used to verify each method and to compare numerical errors. Tests on 2D synthetic examples demonstrated that the proposed method is highly accurate and stable. The proposed methods can be used for seismic modeling or reverse-time migration.
Lowrank seismic-wave extrapolation on a staggered grid
Fang, Gang
2014-05-01
© 2014 Society of Exploration Geophysicists. We evaluated a new spectral method and a new finite-difference (FD) method for seismic-wave extrapolation in time. Using staggered temporal and spatial grids, we derived a wave-extrapolation operator using a lowrank decomposition for a first-order system of wave equations and designed the corresponding FD scheme. The proposed methods extend previously proposed lowrank and lowrank FD wave extrapolation methods from the cases of constant density to those of variable density. Dispersion analysis demonstrated that the proposed methods have high accuracy for a wide wavenumber range and significantly reduce the numerical dispersion. The method of manufactured solutions coupled with mesh refinement was used to verify each method and to compare numerical errors. Tests on 2D synthetic examples demonstrated that the proposed method is highly accurate and stable. The proposed methods can be used for seismic modeling or reverse-time migration.
Directory of Open Access Journals (Sweden)
Ying Chen
2018-03-01
Full Text Available Rate-distortion optimization (RDO plays an essential role in substantially enhancing the coding efficiency. Currently, rate-distortion optimized mode decision is widely used in scalable video coding (SVC. Among all the possible coding modes, it aims to select the one which has the best trade-off between bitrate and compression distortion. Specifically, this tradeoff is tuned through the choice of the Lagrange multiplier. Despite the prevalence of conventional method for Lagrange multiplier selection in hybrid video coding, the underlying formulation is not applicable to 3-D wavelet-based SVC where the explicit values of the quantization step are not available, with on consideration of the content features of input signal. In this paper, an efficient content adaptive Lagrange multiplier selection algorithm is proposed in the context of RDO for 3-D wavelet-based SVC targeting quality scalability. Our contributions are two-fold. First, we introduce a novel weighting method, which takes account of the mutual information, gradient per pixel, and texture homogeneity to measure the temporal subband characteristics after applying the motion-compensated temporal filtering (MCTF technique. Second, based on the proposed subband weighting factor model, we derive the optimal Lagrange multiplier. Experimental results demonstrate that the proposed algorithm enables more satisfactory video quality with negligible additional computational complexity.
Dark energy from modified gravity with Lagrange multipliers
International Nuclear Information System (INIS)
Capozziello, Salvatore; Matsumoto, Jiro; Nojiri, Shin'ichi; Odintsov, Sergei D.
2010-01-01
We study scalar-tensor theory, k-essence and modified gravity with Lagrange multiplier constraint which role is to reduce the number of degrees of freedom. Dark Energy cosmology of different types (ΛCDM, unified inflation with DE, smooth non-phantom/phantom transition epoch) is reconstructed in such models. It is demonstrated that presence of Lagrange multiplier simplifies the reconstruction scenario. It is shown that mathematical equivalence between scalar theory and F(R) gravity is broken due to presence of constraint. The cosmological evolution is defined by the second F 2 (R) function dictated by the constraint. The convenient F(R) gravity sector is relevant for local tests. This opens the possibility to make originally non-realistic theory to be viable by adding the corresponding constraint. A general discussion on the role of Lagrange multipliers to make higher-derivative gravity canonical is developed.
Invariant Lagrangians, mechanical connections and the Lagrange-Poincare equations
International Nuclear Information System (INIS)
Mestdag, T; Crampin, M
2008-01-01
We deal with Lagrangian systems that are invariant under the action of a symmetry group. The mechanical connection is a principal connection that is associated with Lagrangians which have a kinetic energy function that is defined by a Riemannian metric. In this paper, we extend this notion to arbitrary Lagrangians. We then derive the reduced Lagrange-Poincare equations in a new fashion and we show how solutions of the Euler-Lagrange equations can be reconstructed with the help of the mechanical connection. Illustrative examples confirm the theory
Directory of Open Access Journals (Sweden)
De Vuyst Florian
2016-11-01
Full Text Available In a recent paper [Poncet R., Peybernes M., Gasc T., De Vuyst F. (2016 Performance modeling of a compressible hydrodynamics solver on multicore CPUs, in “Parallel Computing: on the road to Exascale”], we have achieved the performance analysis of staggered Lagrange-remap schemes, a class of solvers widely used for hydrodynamics applications. This paper is devoted to the rethinking and redesign of the Lagrange-remap process for achieving better performance using today’s computing architectures. As an unintended outcome, the analysis has lead us to the discovery of a new family of solvers – the so-called Lagrange-flux schemes – that appear to be promising for the CFD community.
Generalized force in classical field theory. [Euler-Lagrange equations
Energy Technology Data Exchange (ETDEWEB)
Krause, J [Universidad Central de Venezuela, Caracas
1976-02-01
The source strengths of the Euler-Lagrange equations, for a system of interacting fields, are heuristically interpreted as generalized forces. The canonical form of the energy-momentum tensor thus consistently appears, without recourse to space-time symmetry arguments. A concept of 'conservative' generalized force in classical field theory is also briefly discussed.
Real-time dispersion calculation using the Lagrange model LASAT
International Nuclear Information System (INIS)
Janicke, L.
1987-01-01
The LASAT (Lagrange Simulation of Aerosol Transport) dispersion model demonstrates pollutant transport in the atmosphere by simulating the paths of representative random samples of pollutant particles on the computer as natural as possible. The author demonstrates the generated particle paths and refers to literature for details of the model algorithm. (DG) [de
Sufficient conditions for Lagrange, Mayer, and Bolza optimization problems
Directory of Open Access Journals (Sweden)
Boltyanski V.
2001-01-01
Full Text Available The Maximum Principle [2,13] is a well known necessary condition for optimality. This condition, generally, is not sufficient. In [3], the author proved that if there exists regular synthesis of trajectories, the Maximum Principle also is a sufficient condition for time-optimality. In this article, we generalize this result for Lagrange, Mayer, and Bolza optimization problems.
Conservative numerical schemes for Euler-Lagrange equations
Energy Technology Data Exchange (ETDEWEB)
Vazquez, L. [Universidad Complutense, Madrid (Spain). Dept. de Matematica Aplicada; Jimenez, S. [Universidad Alfonso X El Sabio, Madrid (Spain). Dept. de Matematica Aplicada
1999-05-01
As a preliminary step to study magnetic field lines, the authors seek numerical schemes that reproduce at discrete level the significant feature of the continuous model, based on an underling Lagrangian structure. The resulting scheme give discrete counterparts of the variation law for the energy as well of as the Euler-Lagrange equations and their symmetries.
Mechanics, analysis and geometry 200 years after Lagrange
1991-01-01
Providing a logically balanced and authoritative account of the different branches and problems of mathematical physics that Lagrange studied and developed, this volume presents up-to-date developments in differential goemetry, dynamical systems, the calculus of variations, and celestial and analytical mechanics.
Smooth bifurcation for variational inequalities based on Lagrange multipliers
Czech Academy of Sciences Publication Activity Database
Eisner, Jan; Kučera, Milan; Recke, L.
2006-01-01
Roč. 19, č. 9 (2006), s. 981-1000 ISSN 0893-4983 R&D Projects: GA AV ČR(CZ) IAA100190506 Institutional research plan: CEZ:AV0Z10190503 Keywords : abstract variational inequality * bifurcation * Lagrange multipliers Subject RIV: BA - General Mathematics
Detection of differential item functioning using Lagrange multiplier tests
Glas, Cornelis A.W.
1998-01-01
Abstract: In the present paper it is shown that differential item functioning can be evaluated using the Lagrange multiplier test or Rao’s efficient score test. The test is presented in the framework of a number of IRT models such as the Rasch model, the OPLM, the 2-parameter logistic model, the
Detection of differential item functioning using Lagrange multiplier tests
Glas, Cornelis A.W.
1996-01-01
In this paper it is shown that differential item functioning can be evaluated using the Lagrange multiplier test or C. R. Rao's efficient score test. The test is presented in the framework of a number of item response theory (IRT) models such as the Rasch model, the one-parameter logistic model, the
Lagrange-multiplier tests for weak exogeneity: a synthesis.
Boswijk, H.P.; Urbain, J.P.
1997-01-01
This paper unifies two seemingly separate approaches to test weak exogeneity in dynamic regression models with Lagrange-multiplier statistics. The first class of tests focuses on the orthogonality between innovations and conditioning variables, and thus is related to the Durbin-Wu-Hausman
The Work of Lagrange in Number Theory and Algebra
Indian Academy of Sciences (India)
GENERAL I ARTICLE. The Work of Lagrange in Number Theory and Algebra. D P Patil, C R Pranesachar and Renuka RafJindran. (left) D P Patil got his Ph.D from the School of Math- ematics, TIFR and joined. IISc in 1992. His interests are commutative algebra, algebraic geometry and algebraic number theory. (right) C R ...
Generalized variational formulations for extended exponentially fractional integral
Directory of Open Access Journals (Sweden)
Zuo-Jun Wang
2016-01-01
Full Text Available Recently, the fractional variational principles as well as their applications yield a special attention. For a fractional variational problem based on different types of fractional integral and derivatives operators, corresponding fractional Lagrangian and Hamiltonian formulation and relevant Euler–Lagrange type equations are already presented by scholars. The formulations of fractional variational principles still can be developed more. We make an attempt to generalize the formulations for fractional variational principles. As a result we obtain generalized and complementary fractional variational formulations for extended exponentially fractional integral for example and corresponding Euler–Lagrange equations. Two illustrative examples are presented. It is observed that the formulations are in exact agreement with the Euler–Lagrange equations.
Weyl-Euler-Lagrange Equations of Motion on Flat Manifold
Directory of Open Access Journals (Sweden)
Zeki Kasap
2015-01-01
Full Text Available This paper deals with Weyl-Euler-Lagrange equations of motion on flat manifold. It is well known that a Riemannian manifold is said to be flat if its curvature is everywhere zero. Furthermore, a flat manifold is one Euclidean space in terms of distances. Weyl introduced a metric with a conformal transformation for unified theory in 1918. Classical mechanics is one of the major subfields of mechanics. Also, one way of solving problems in classical mechanics occurs with the help of the Euler-Lagrange equations. In this study, partial differential equations have been obtained for movement of objects in space and solutions of these equations have been generated by using the symbolic Algebra software. Additionally, the improvements, obtained in this study, will be presented.
Thierry Lagrange: A transparent, service-oriented approach to finance
2009-01-01
The motto for the new Finance and Purchasing Department Head, Thierry Lagrange, is "strengthening services for users". With a head-count of around sixty, the Finance and Purchasing Department is small compared to the large technical departments. But its work is crucial and supports all the Laboratory’s activities. The FP Department manages the Organization’s financial resources and commitments, checking that resources match expenses, that sufficient cash is available, that contracts are concluded on the best possible terms - in short, that monies are available and properly managed. In these lean times, this delicate balancing act requires the skills of an insider, someone who knows the Organization like the back of his hand. Thierry Lagrange, recently appointed Head of Finance and Purchasing, has spent most of his career at CERN, and the past five years as Deputy Head of the Finance Department. Nobody knows the subtleties and p...
Inverse mass matrix via the method of localized lagrange multipliers
Czech Academy of Sciences Publication Activity Database
González, José A.; Kolman, Radek; Cho, S.S.; Felippa, C.A.; Park, K.C.
2018-01-01
Roč. 113, č. 2 (2018), s. 277-295 ISSN 0029-5981 R&D Projects: GA MŠk(CZ) EF15_003/0000493; GA ČR GA17-22615S Institutional support: RVO:61388998 Keywords : explicit time integration * inverse mass matrix * localized Lagrange multipliers * partitioned analysis Subject RIV: BI - Acoustics OBOR OECD: Applied mechanics Impact factor: 2.162, year: 2016 https://onlinelibrary.wiley.com/doi/10.1002/nme.5613
On Lagrange Multipliers in Work with Quality and Reliability Assurance
DEFF Research Database (Denmark)
Vidal, Rene Victor Valqui; Becker, P.
1986-01-01
In optimizing some property of a system, reliability say, a designer usually has to accept certain constraints regarding cost, completion time, volume, weight, etc. The solution of optimization problems with boundary constraints can be helped substantially by the use of Lagrange multipliers...... in the areas of sales promotion and teaching. These maps illuminate the logic structure of solution sequences. One such map is shown, illustrating the application of LMT in one of the examples....
Analytical stiffness matrices with Green-Lagrange strain measure
DEFF Research Database (Denmark)
Pedersen, Pauli
2005-01-01
Separating the dependence on material and stress/strain state from the dependence on initial geometry, we obtain analytical secant and tangent stiffness matrices. For the case of a linear displacement triangle with uniform thickness and uniform constitutive behaviour closed-form results are listed...... a solution based on Green-Lagrange strain measure. The approach is especially useful in design optimization, because analytical sensitivity analysis then can be performed. The case of a three node triangular ring element for axisymmetric analysis involves small modifications and extension to four node...
LA INTERPOLACIÓN DE LAGRANGE EN EL ESPACIO m
Directory of Open Access Journals (Sweden)
Gabriel Poveda Ramos
Full Text Available En este artículo se deduce de manera original una fórmula de interpolación en el espacio real de m dimensiones (m, inspirada en la conocida fórmula de Lagrange para funciones reales (F(x de una variable, es decir en la recta real . Los resultados que aquí se obtienen no parecen ser muy conocidos, al menos, en los medios universitarios de Colombia. El autor los ha buscado durante mucho tiempo, sin hallarlos. Finalmente tuvo que deducirlos por sí solo.
Lagrange-Noether method for solving second-order differential equations
Institute of Scientific and Technical Information of China (English)
Wu Hui-Bin; Wu Run-Heng
2009-01-01
The purpose of this paper is to provide a new method called the Lagrange-Noether method for solving second-order differential equations. The method is,firstly,to write the second-order differential equations completely or partially in the form of Lagrange equations,and secondly,to obtain the integrals of the equations by using the Noether theory of the Lagrange system. An example is given to illustrate the application of the result.
Three-body continuum states on a Lagrange mesh
International Nuclear Information System (INIS)
Descouvemont, P.; Tursunov, E.; Baye, D.
2006-01-01
Three-body continuum states are investigated with the hyperspherical method on a Lagrange mesh. The R-matrix theory is used to treat the asymptotic behaviour of scattering wave functions. The formalism is developed for neutral as well as for charged systems. We point out some specificities of continuum states in the hyperspherical method. The collision matrix can be determined with a good accuracy by using propagation techniques. The method is applied to the 6 He (=α+n+n) and 6 Be (=α+p+p) systems, as well as to 14 Be (=Be12+n+n). For 6 He, we essentially recover results of the literature. Application to 14 Be suggests the existence of an excited 2 + state below threshold. The calculated B(E2) value should make this state observable with Coulomb excitation experiments
Jacobi equations as Lagrange equations of the deformed Lagrangian
International Nuclear Information System (INIS)
Casciaro, B.
1995-03-01
We study higher-order variational derivatives of a generic Lagrangian L 0 = L 0 (t,q,q). We introduce two new Lagrangians, L 1 and L 2 , associated to the first and second-order deformations of the original Lagrangian L 0 . In terms of these Lagrangians, we are able to establish simple relations between the variational derivatives of different orders of a Lagrangian. As a consequence of these relations the Euler-Lagrange and the Jacobi equations are obtained from a single variational principle based on L 1 . We can furthermore introduce an associated Hamiltonian H 1 = H 1 (t,q,q radical,η,η radical) with η equivalent to δq. If L 0 is independent of time then H 1 is a conserved quantity. (author). 15 refs
LAGRANGE: LAser GRavitational-wave ANtenna in GEodetic Orbit
Buchman, S.; Conklin, J. W.; Balakrishnan, K.; Aguero, V.; Alfauwaz, A.; Aljadaan, A.; Almajed, M.; Altwaijry, H.; Saud, T. A.; Byer, R. L.; Bower, K.; Costello, B.; Cutler, G. D.; DeBra, D. B.; Faied, D. M.; Foster, C.; Genova, A. L.; Hanson, J.; Hooper, K.; Hultgren, E.; Klavins, A.; Lantz, B.; Lipa, J. A.; Palmer, A.; Plante, B.; Sanchez, H. S.; Saraf, S.; Schaechter, D.; Shu, K.; Smith, E.; Tenerelli, D.; Vanbezooijen, R.; Vasudevan, G.; Williams, S. D.; Worden, S. P.; Zhou, J.; Zoellner, A.
2013-01-01
We describe a new space gravitational wave observatory design called LAG-RANGE that maintains all important LISA science at about half the cost and with reduced technical risk. It consists of three drag-free spacecraft in a geocentric formation. Fixed antennas allow continuous contact with the Earth, solving the problem of communications bandwidth and latency. A 70 mm diameter sphere with a 35 mm gap to its enclosure serves as the single inertial reference per spacecraft, operating in “true” drag-free mode (no test mass forcing). Other advantages are: a simple caging design based on the DISCOS 1972 drag-free mission, an all optical read-out with pm fine and nm coarse sensors, and the extensive technology heritage from the Honeywell gyroscopes, and the DISCOS and Gravity Probe B drag-free sensors. An Interferometric Measurement System, designed with reflective optics and a highly stabilized frequency standard, performs the ranging between test masses and requires a single optical bench with one laser per spacecraft. Two 20 cm diameter telescopes per spacecraft, each with infield pointing, incorporate novel technology developed for advanced optical systems by Lockheed Martin, who also designed the spacecraft based on a multi-flight proven bus structure. Additional technological advancements include updated drag-free propulsion, thermal control, charge management systems, and materials. LAGRANGE subsystems are designed to be scalable and modular, making them interchangeable with those of LISA or other gravitational science missions. We plan to space qualify critical technologies on small and nano satellite flights, with the first launch (UV-LED Sat) in 2013.
Analytical Solution of Nonlinear Problems in Classical Dynamics by Means of Lagrange-Ham
DEFF Research Database (Denmark)
Kimiaeifar, Amin; Mahdavi, S. H; Rabbani, A.
2011-01-01
In this work, a powerful analytical method, called Homotopy Analysis Methods (HAM) is coupled with Lagrange method to obtain the exact solution for nonlinear problems in classic dynamics. In this work, the governing equations are obtained by using Lagrange method, and then the nonlinear governing...
Euler-Lagrange Equations of Networks with Higher-Order Elements
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Z. Biolek
2017-06-01
Full Text Available The paper suggests a generalization of the classic Euler-Lagrange equation for circuits compounded of arbitrary elements from Chua’s periodic table. Newly defined potential functions for general (α, β elements are used for the construction of generalized Lagrangians and generalized dissipative functions. Also procedures of drawing the Euler-Lagrange equations are demonstrated.
Directory of Open Access Journals (Sweden)
B. Kuldeep
2015-06-01
Full Text Available Fractional calculus has recently been identified as a very important mathematical tool in the field of signal processing. Digital filters designed by fractional derivatives give more accurate frequency response in the prescribed frequency region. Digital filters are most important part of multi-rate filter bank systems. In this paper, an improved method based on fractional derivative constraints is presented for the design of two-channel quadrature mirror filter (QMF bank. The design problem is formulated as minimization of L2 error of filter bank transfer function in passband, stopband interval and at quadrature frequency, and then Lagrange multiplier method with fractional derivative constraints is applied to solve it. The proposed method is then successfully applied for the design of two-channel QMF bank with higher order filter taps. Performance of the QMF bank design is then examined through study of various parameters such as passband error, stopband error, transition band error, peak reconstruction error (PRE, stopband attenuation (As. It is found that, the good design can be obtained with the change of number and value of fractional derivative constraint coefficients.
Hamiltonian formulation of theory with higher order derivatives
International Nuclear Information System (INIS)
Gitman, D.M.; Lyakhovich, S.L.; Tyutin, I.V.
1983-01-01
A method of ''hamiltonization'' of a special theory with higher order derivatives is described. In a nonspecial case the result coincides with the known Ostrogradsky formulation. It is shown that in the nonspecial theory the lagrange equations of motion are reduced to the normal form
The symplectic structure of Euler-Lagrange superequations and Batalin-Vilkoviski formalism
Monterde, J
2003-01-01
We study the graded Euler-Lagrange equations from the viewpoint of graded Poincare-Cartan forms. An application to a certain class of solutions of the Batalin-Vilkoviski master equation is also given.
Solution of second order linear fuzzy difference equation by Lagrange's multiplier method
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Sankar Prasad Mondal
2016-06-01
Full Text Available In this paper we execute the solution procedure for second order linear fuzzy difference equation by Lagrange's multiplier method. In crisp sense the difference equation are easy to solve, but when we take in fuzzy sense it forms a system of difference equation which is not so easy to solve. By the help of Lagrange's multiplier we can solved it easily. The results are illustrated by two different numerical examples and followed by two applications.
Integración automatizada de las ecuaciones de Lagrange en el movimiento orbital.
Abad, A.; San Juan, J. F.
The new techniques of algebraic manipulation, especially the Poisson Series Processor, permit the analytical integration of the more and more complex problems of celestial mechanics. The authors are developing a new Poisson Series Processor, PSPC, and they use it to solve the Lagrange equation of the orbital motion. They integrate the Lagrange equation by using the stroboscopic method, and apply it to the main problem of the artificial satellite theory.
A DIDACTIC SURVEY OVER MAIN CHARACTERISTICS OF LAGRANGE'S THEOREM IN MATHEMATICS AND IN ECONOMICS
Xhonneux, Sebastian; Henry, Valérie
2011-01-01
Because of its many uses, the constrained optimization problem is presented in most calculus courses for mathematicians but also for economists. Looking at Lagrange's Theorem we are interested in studying the teaching of this theorem in both branches of study, mathematics and economics. This paper faces a twofold objective: first, we show the methodology of our research project concerning the didactic transposition of Lagrange's Theorem in university mathematics courses. Sec...
Lagrange constraint neural networks for massive pixel parallel image demixing
Szu, Harold H.; Hsu, Charles C.
2002-03-01
We have shown that the remote sensing optical imaging to achieve detailed sub-pixel decomposition is a unique application of blind source separation (BSS) that is truly linear of far away weak signal, instantaneous speed of light without delay, and along the line of sight without multiple paths. In early papers, we have presented a direct application of statistical mechanical de-mixing method called Lagrange Constraint Neural Network (LCNN). While the BSAO algorithm (using a posteriori MaxEnt ANN and neighborhood pixel average) is not acceptable for remote sensing, a mirror symmetric LCNN approach is all right assuming a priori MaxEnt for unknown sources to be averaged over the source statistics (not neighborhood pixel data) in a pixel-by-pixel independent fashion. LCNN reduces the computation complexity, save a great number of memory devices, and cut the cost of implementation. The Landsat system is designed to measure the radiation to deduce surface conditions and materials. For any given material, the amount of emitted and reflected radiation varies by the wavelength. In practice, a single pixel of a Landsat image has seven channels receiving 0.1 to 12 microns of radiation from the ground within a 20x20 meter footprint containing a variety of radiation materials. A-priori LCNN algorithm provides the spatial-temporal variation of mixture that is hardly de-mixable by other a-posteriori BSS or ICA methods. We have already compared the Landsat remote sensing using both methods in WCCI 2002 Hawaii. Unfortunately the absolute benchmark is not possible because of lacking of the ground truth. We will arbitrarily mix two incoherent sampled images as the ground truth. However, the constant total probability of co-located sources within the pixel footprint is necessary for the remote sensing constraint (since on a clear day the total reflecting energy is constant in neighborhood receiving pixel sensors), we have to normalized two image pixel-by-pixel as well. Then, the
Numerical simulation using vorticity-vector potential formulation
Tokunaga, Hiroshi
1993-01-01
An accurate and efficient computational method is needed for three-dimensional incompressible viscous flows in engineering applications. On solving the turbulent shear flows directly or using the subgrid scale model, it is indispensable to resolve the small scale fluid motions as well as the large scale motions. From this point of view, the pseudo-spectral method is used so far as the computational method. However, the finite difference or the finite element methods are widely applied for computing the flow with practical importance since these methods are easily applied to the flows with complex geometric configurations. However, there exist several problems in applying the finite difference method to direct and large eddy simulations. Accuracy is one of most important problems. This point was already addressed by the present author on the direct simulations on the instability of the plane Poiseuille flow and also on the transition to turbulence. In order to obtain high efficiency, the multi-grid Poisson solver is combined with the higher-order, accurate finite difference method. The formulation method is also one of the most important problems in applying the finite difference method to the incompressible turbulent flows. The three-dimensional Navier-Stokes equations have been solved so far in the primitive variables formulation. One of the major difficulties of this method is the rigorous satisfaction of the equation of continuity. In general, the staggered grid is used for the satisfaction of the solenoidal condition for the velocity field at the wall boundary. However, the velocity field satisfies the equation of continuity automatically in the vorticity-vector potential formulation. From this point of view, the vorticity-vector potential method was extended to the generalized coordinate system. In the present article, we adopt the vorticity-vector potential formulation, the generalized coordinate system, and the 4th-order accurate difference method as the
How to use the Sun-Earth Lagrange points for fundamental physics and navigation
Tartaglia, A.; Lorenzini, E. C.; Lucchesi, D.; Pucacco, G.; Ruggiero, M. L.; Valko, P.
2018-01-01
We illustrate the proposal, nicknamed LAGRANGE, to use spacecraft, located at the Sun-Earth Lagrange points, as a physical reference frame. Performing time of flight measurements of electromagnetic signals traveling on closed paths between the points, we show that it would be possible: (a) to refine gravitational time delay knowledge due both to the Sun and the Earth; (b) to detect the gravito-magnetic frame dragging of the Sun, so deducing information about the interior of the star; (c) to check the possible existence of a galactic gravitomagnetic field, which would imply a revision of the properties of a dark matter halo; (d) to set up a relativistic positioning and navigation system at the scale of the inner solar system. The paper presents estimated values for the relevant quantities and discusses the feasibility of the project analyzing the behavior of the space devices close to the Lagrange points.
Dakin, Gautier; Després, Bruno; Jaouen, Stéphane
2018-01-01
We propose a new high-order accurate numerical boundary treatment for solving hyperbolic systems of conservation laws and Euler equations using a Lagrange-remap approach on Cartesian grids in cases of physical boundaries not aligned with the mesh. The method is an adaptation of the Inverse Lax-Wendroff procedure [34-38] to the Lagrange-remap approach, which considerably alleviates the algebra. High-order accurate ghost values of conservative variables are imposed using Taylor expansions whose coefficients are found by inverting a (linear or non-linear) system which is well posed in all our examples. For 2D problems, a least-square procedure is added to prevent extrapolation instabilities. The Lagrange-remap formalism also provides a simpler fluid-structure coupling which is also described. Numerical examples are given for the linear case and Euler equations in 1D and 2D.
Directory of Open Access Journals (Sweden)
FEMY AYU ASTITI
2013-01-01
Full Text Available Optimization problems can be solved by various methods, such as Lagrange Method. This method can be used to find the solution. Using Lagrange method, the extreme value can be obtained, so that the optimal solution can be found. In this research, the maximum revenue of UD. Sari Madu is a limited by several constraints. After the objective function and constraint function being model, than maximum revenue is found. From first until fourth quarterly, the maximum revenue is found Rp. 9.701.333, Rp. 10.064.148, 9.793.272 and Rp. 9.397.730 respectively.
Dynamic Modeling and Simulation of Marine Satellite Tracking Antenna Using Lagrange Method
DEFF Research Database (Denmark)
Wang, Yunlong; Soltani, Mohsen; Hussain, Dil muhammed Akbar
2016-01-01
Marine Satellite Tracking Antenna (MSTA) is a necessary device in ships for receiving satellite signals when they are sailing on the sea. This paper presents a simple methodology to obtain the dynamic equations of MSTA through Lagrange method, which is fundamental in design of modelbased controll......Marine Satellite Tracking Antenna (MSTA) is a necessary device in ships for receiving satellite signals when they are sailing on the sea. This paper presents a simple methodology to obtain the dynamic equations of MSTA through Lagrange method, which is fundamental in design of modelbased...
Optimization of Wireless Optical Communication System Based on Augmented Lagrange Algorithm
International Nuclear Information System (INIS)
He Suxiang; Meng Hongchao; Wang Hui; Zhao Yanli
2011-01-01
The optimal model for wireless optical communication system with Gaussian pointing loss factor is studied, in which the value of bit error probability (BEP) is prespecified and the optimal system parameters is to be found. For the superiority of augmented Lagrange method, the model considered is solved by using a classical quadratic augmented Lagrange algorithm. The detailed numerical results are reported. Accordingly, the optimal system parameters such as transmitter power, transmitter wavelength, transmitter telescope gain and receiver telescope gain can be established, which provide a scheme for efficient operation of the wireless optical communication system.
New Lagrange Multipliers for the Blind Adaptive Deconvolution Problem Applicable for the Noisy Case
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Monika Pinchas
2016-02-01
Full Text Available Recently, a new blind adaptive deconvolution algorithm was proposed based on a new closed-form approximated expression for the conditional expectation (the expectation of the source input given the equalized or deconvolutional output where the output and input probability density function (pdf of the deconvolutional process were approximated with the maximum entropy density approximation technique. The Lagrange multipliers for the output pdf were set to those used for the input pdf. Although this new blind adaptive deconvolution method has been shown to have improved equalization performance compared to the maximum entropy blind adaptive deconvolution algorithm recently proposed by the same author, it is not applicable for the very noisy case. In this paper, we derive new Lagrange multipliers for the output and input pdfs, where the Lagrange multipliers related to the output pdf are a function of the channel noise power. Simulation results indicate that the newly obtained blind adaptive deconvolution algorithm using these new Lagrange multipliers is robust to signal-to-noise ratios (SNR, unlike the previously proposed method, and is applicable for the whole range of SNR down to 7 dB. In addition, we also obtain new closed-form approximated expressions for the conditional expectation and mean square error (MSE.
Euler-Lagrange modeling of the hydrodynamics of dense multiphase flows
Padding, J.T.; Deen, N.G.; Peters, E. A. J. F.; Kuipers, J. A. M.
2015-01-01
The large-scale hydrodynamic behavior of relatively dense dispersed multiphase flows, such as encountered in fluidized beds, bubbly flows, and liquid sprays, can be predicted efficiently by use of Euler-Lagrange models. In these models, grid-averaged equations for the continuous-phase flow field are
3D Staggered-Grid Finite-Difference Simulation of Acoustic Waves in Turbulent Moving Media
Symons, N. P.; Aldridge, D. F.; Marlin, D.; Wilson, D. K.; Sullivan, P.; Ostashev, V.
2003-12-01
Acoustic wave propagation in a three-dimensional heterogeneous moving atmosphere is accurately simulated with a numerical algorithm recently developed under the DOD Common High Performance Computing Software Support Initiative (CHSSI). Sound waves within such a dynamic environment are mathematically described by a set of four, coupled, first-order partial differential equations governing small-amplitude fluctuations in pressure and particle velocity. The system is rigorously derived from fundamental principles of continuum mechanics, ideal-fluid constitutive relations, and reasonable assumptions that the ambient atmospheric motion is adiabatic and divergence-free. An explicit, time-domain, finite-difference (FD) numerical scheme is used to solve the system for both pressure and particle velocity wavefields. The atmosphere is characterized by 3D gridded models of sound speed, mass density, and the three components of the wind velocity vector. Dependent variables are stored on staggered spatial and temporal grids, and centered FD operators possess 2nd-order and 4th-order space/time accuracy. Accurate sound wave simulation is achieved provided grid intervals are chosen appropriately. The gridding must be fine enough to reduce numerical dispersion artifacts to an acceptable level and maintain stability. The algorithm is designed to execute on parallel computational platforms by utilizing a spatial domain-decomposition strategy. Currently, the algorithm has been validated on four different computational platforms, and parallel scalability of approximately 85% has been demonstrated. Comparisons with analytic solutions for uniform and vertically stratified wind models indicate that the FD algorithm generates accurate results with either a vanishing pressure or vanishing vertical-particle velocity boundary condition. Simulations are performed using a kinematic turbulence wind profile developed with the quasi-wavelet method. In addition, preliminary results are presented using high-resolution 3D dynamic turbulent flowfields generated by a large-eddy simulation model of a stably stratified planetary boundary layer. Sandia National Laboratories is a operated by Sandia Corporation, a Lockheed Martin Company, for the USDOE under contract 94-AL85000.
Time dependent numerical simulations of a viscoelastic fluid on a staggered grid
Gerritsma, Marcus Iwan
1996-01-01
In dit proefschrift wordt naar een klasse van differentiaalmodellen gekeken. Speciale aandacht gaat daarbij uit naar een nieuw ingevoerde tijdsafgeleide: de geconvecteerde tijdsafgeleide. ... Zie: Samenvatting
Hybrid multicore/vectorisation technique applied to the elastic wave equation on a staggered grid
Titarenko, Sofya; Hildyard, Mark
2017-07-01
In modern physics it has become common to find the solution of a problem by solving numerically a set of PDEs. Whether solving them on a finite difference grid or by a finite element approach, the main calculations are often applied to a stencil structure. In the last decade it has become usual to work with so called big data problems where calculations are very heavy and accelerators and modern architectures are widely used. Although CPU and GPU clusters are often used to solve such problems, parallelisation of any calculation ideally starts from a single processor optimisation. Unfortunately, it is impossible to vectorise a stencil structured loop with high level instructions. In this paper we suggest a new approach to rearranging the data structure which makes it possible to apply high level vectorisation instructions to a stencil loop and which results in significant acceleration. The suggested method allows further acceleration if shared memory APIs are used. We show the effectiveness of the method by applying it to an elastic wave propagation problem on a finite difference grid. We have chosen Intel architecture for the test problem and OpenMP (Open Multi-Processing) since they are extensively used in many applications.
The Finite-Surface Method for incompressible flow: a step beyond staggered grid
Hokpunna, Arpiruk; Misaka, Takashi; Obayashi, Shigeru
2017-11-01
We present a newly developed higher-order finite surface method for the incompressible Navier-Stokes equations (NSE). This method defines the velocities as a surface-averaged value on the surfaces of the pressure cells. Consequently, the mass conservation on the pressure cells becomes an exact equation. The only things left to approximate is the momentum equation and the pressure at the new time step. At certain conditions, the exact mass conservation enables the explicit n-th order accurate NSE solver to be used with the pressure treatment that is two or four order less accurate without loosing the apparent convergence rate. This feature was not possible with finite volume of finite difference methods. We use Fourier analysis with a model spectrum to determine the condition and found that the range covers standard boundary layer flows. The formal convergence and the performance of the proposed scheme is compared with a sixth-order finite volume method. Finally, the accuracy and performance of the method is evaluated in turbulent channel flows. This work is partially funded by a research colloaboration from IFS, Tohoku university and ASEAN+3 funding scheme from CMUIC, Chiang Mai University.
Nili, Samaun; Park, Chanyoung; Haftka, Raphael T.; Kim, Nam H.; Balachandar, S.
2017-11-01
Point particle methods are extensively used in simulating Euler-Lagrange multiphase dispersed flow. When particles are much smaller than the Eulerian grid the point particle model is on firm theoretical ground. However, this standard approach of evaluating the gas-particle coupling at the particle center fails to converge as the Eulerian grid is reduced below particle size. We present an approach to model the interaction between particles and fluid for finite size particles that permits convergence. We use the generalized Faxen form to compute the force on a particle and compare the results against traditional point particle method. We apportion the different force components on the particle to fluid cells based on the fraction of particle volume or surface in the cell. The application is to a one-dimensional model of shock propagation through a particle-laden field at moderate volume fraction, where the convergence is achieved for a well-formulated force model and back coupling for finite size particles. Comparison with 3D direct fully resolved numerical simulations will be used to check if the approach also improves accuracy compared to the point particle model. Work supported by the U.S. Department of Energy, National Nuclear Security Administration, Advanced Simulation and Computing Program, as a Cooperative Agreement under the Predictive Science Academic Alliance Program, under Contract No. DE-NA0002378.
Directory of Open Access Journals (Sweden)
Héctor Torres-Silva
2008-11-01
Full Text Available This work deals with the problem of the construction of the Lagrange functional for an electromagnetic field. The generalised Maxwell equations for an electromagnetic field in free space are introduced. The main idea relies on the change of Lagrange function under the integral action. Usually, the Lagrange functional which describes the electromagnetic field is built with the quadrate of the electromagnetic field tensor . Such a quadrate term is the reason, from a mathematical point of view, for the linear form of the Maxwell equations in free space. The author does not make this assumption and nonlinear Maxwell equations are obtained. New material parameters of free space are established. The equations obtained are quite similar to the well-known Maxwell equations. The energy tensor of the electromagnetic field from a chiral approach to the Born Infeld Lagrangian is discussed in connection with the cosmological constant.Se aborda el problema de la construcción de la funcional de Lagrange de un campo electromagnético. Se introducen las ecuaciones generalizadas de Maxwell de un campo electromagnético en el espacio libre. La idea principal se basa en el cambio de función de Lagrange en virtud de la acción integral. Por lo general, la funcional de lagrange, que describe el campo electromagnético, se construye con el cuadrado del tensor de campo electromagnético. Ese término cuadrático es la razón, desde un punto de vista matemático, de la forma lineal de las ecuaciones de Maxwell en el espacio libre. Se obtienen las ecuaciones no lineales de Maxwell sin considerar esta suposición. Las ecuaciones de Maxwell obtenidas son bastante similares a las conocidas ecuaciones de Maxwell. Se analiza el tensor de energía del campo electromagnético en un enfoque quiral de la Lagrangiana de Born Infeld en relación con la constante cosmológica.
Lagrange and Noether analysis of polarization laws of conservation for electromagnetic field
International Nuclear Information System (INIS)
Krivskij, I.Yu.; Simulik, V.M.
1988-01-01
Both well-known Bessel-Hagen conservation laws and conservation laws of polarized character are derived for electromagnetic field in the Lagrange approach to electrodynamics in terms of intensities (without using the A μ potentials as variation variables). The laws mentioned are derived according to Noether theorem because symmetry to which such concervation laws correspond is lost during the transition from intensities to potentials. Based on Noether theorem (and its generalization for Naeik's symmetries) and Lagrange function scalar in relation to complete Poincare group in terms of intensity tensor, a convenient formula for calculating and values conserved for electromagnetic field is derived which sets up a physically adequate symmetry operator -conservation law correlation and thus links the presence of conservation laws of polarized character with symmetry properties of Maxwell equations. Adiabaticity of conservation laws of polarized character under the presence of interaction with currents and charges is indicated
Almost Kaehler Ricci Flows and Einstein and Lagrange-Finsler Structures on Lie Algebroids
Vacaru, Sergiu I
2015-01-01
In this work we investigate Ricci flows of almost Kaehler structures on Lie algebroids when the fundamental geometric objects are completely determined by (semi) Riemannian metrics, or effective) regular generating Lagrange/ Finsler, functions. There are constructed canonical almost symplectic connections for which the geometric flows can be represented as gradient ones and characterized by nonholonomic deformations of Grigory Perelman's functionals. The first goal of this paper is to define such thermodynamical type values and derive almost K\\"ahler - Ricci geometric evolution equations. The second goal is to study how fixed Lie algebroid, i.e. Ricci soliton, configurations can be constructed for Riemannian manifolds and/or (co) tangent bundles endowed with nonholonomic distributions modelling (generalized) Einstein or Finsler - Cartan spaces. Finally, there are provided some examples of generic off-diagonal solutions for Lie algebroid type Ricci solitons and (effective) Einstein and Lagrange-Finsler algebro...
Jet Riemann-Lagrange Geometry Applied to Evolution DEs Systems from Economy
Neagu, Mircea
2007-01-01
The aim of this paper is to construct a natural Riemann-Lagrange differential geometry on 1-jet spaces, in the sense of nonlinear connections, generalized Cartan connections, d-torsions, d-curvatures, jet electromagnetic fields and jet Yang-Mills energies, starting from some given non-linear evolution DEs systems modelling economic phenomena, like the Kaldor model of the bussines cycle or the Tobin-Benhabib-Miyao model regarding the role of money on economic growth.
Guo, H. Y.; Li, Y. Q.; Wu, K.; Wang, S. K.
2001-01-01
We study the difference discrete variational principle in the framework of multi-parameter differential approach by regarding the forward difference as an entire geometric object in view of noncomutative differential geometry. By virtue of this variational principle, we get the difference discrete Euler-Lagrange equations and canonical ones for the difference discrete versions of the classical mechanics and classical field theory. We also explore the difference discrete versions for the Euler...
The validity of PPP: evidence from Lagrange multiplier unit root tests for ASEAN countries
Alper ASLAN
2010-01-01
The univariate and panel Lagrange Multiplier (LM) unit root tests with one and two structural breaks proposed by Lee and Strazicich (2003, 2004) which are considerably more powerful than traditional tests are employed to investigate whether the purchasing power parity (PPP) theory holds true for ASEAN countries by using both black market and official exchange rates. We find strong evidence in favour of long-run PPP for six ASEAN countries namely, Indonesia, Malaysia, Myanmar, Philippines, Sin...
On generalizations of the series of Taylor, Lagrange, Laurent and Teixeira
Directory of Open Access Journals (Sweden)
L. M. B. C. Campos
1990-01-01
Full Text Available The classical theorems of Taylor, Lagrange, Laurent and Teixeira, are extended from the representation of a complex function F(z, to its derivative F(ν(z of complex order ν, understood as either a Liouville (1832 or a Rieman (1847 differintegration (Campos 1984, 1985; these results are distinct from, and alternative to, other extensions of Taylor's series using differintegrations (Osler 1972, Lavoie & Osler & Tremblay 1976. We consider a complex function F(z, which is analytic (has an isolated singularity at ζ, and expand its derivative of complex order F(ν(z, in an ascending (ascending-descending series of powers of an auxiliary function f(z, yielding the generalized Teixeira (Lagrange series, which includes, for f(z=z−ζ, the generalized Taylor (Laurent series. The generalized series involve non-integral powers and/or coefficients evaluated by fractional derivatives or integrals, except in the case ν=0, when the classical theorems of Taylor (1715, Lagrange (1770, Laurent (1843 and Teixeira (1900 are regained. As an application, these generalized series can be used to generate special functions with complex parameters (Campos 1986, e.g., the Hermite and Bessel types.
Investigating Trojan Asteroids at the L4/L5 Sun-Earth Lagrange Points
John, K. K.; Graham, L. D.; Abell, P. A.
2015-01-01
Investigations of Earth's Trojan asteroids will have benefits for science, exploration, and resource utilization. By sending a small spacecraft to the Sun-Earth L4 or L5 Lagrange points to investigate near-Earth objects, Earth's Trojan population can be better understood. This could lead to future missions for larger precursor spacecraft as well as human missions. The presence of objects in the Sun-Earth L4 and L5 Lagrange points has long been suspected, and in 2010 NASA's Wide-field Infrared Survey Explorer (WISE) detected a 300 m object. To investigate these Earth Trojan asteroid objects, it is both essential and feasible to send spacecraft to these regions. By exploring a wide field area, a small spacecraft equipped with an IR camera could hunt for Trojan asteroids and other Earth co-orbiting objects at the L4 or L5 Lagrange points in the near-term. By surveying the region, a zeroth-order approximation of the number of objects could be obtained with some rough constraints on their diameters, which may lead to the identification of potential candidates for further study. This would serve as a precursor for additional future robotic and human exploration targets. Depending on the inclination of these potential objects, they could be used as proving areas for future missions in the sense that the delta-V's to get to these targets are relatively low as compared to other rendezvous missions. They can serve as platforms for extended operations in deep space while interacting with a natural object in microgravity. Theoretically, such low inclination Earth Trojan asteroids exist. By sending a spacecraft to L4 or L5, these likely and potentially accessible targets could be identified.
The Lagrange Points in a Binary Black Hole System: Applications to Electromagnetic Signatures
Schnittman, Jeremy
2010-01-01
We study the stability and evolution of the Lagrange points L_4 and L-5 in a black hole (BH) binary system, including gravitational radiation. We find that gas and stars can be shepherded in with the BH system until the final moments before merger, providing the fuel for a bright electromagnetic counterpart to a gravitational wave signal. Other astrophysical signatures include the ejection of hyper-velocity stars, gravitational collapse of globular clusters, and the periodic shift of narrow emission lines in AGN.
Guermond, Jean-Luc; Nazarov, Murtazo; Popov, Bojan; Yang, Yong
2014-01-01
© 2014 Society for Industrial and Applied Mathematics. This paper proposes an explicit, (at least) second-order, maximum principle satisfying, Lagrange finite element method for solving nonlinear scalar conservation equations. The technique is based on a new viscous bilinear form introduced in Guermond and Nazarov [Comput. Methods Appl. Mech. Engrg., 272 (2014), pp. 198-213], a high-order entropy viscosity method, and the Boris-Book-Zalesak flux correction technique. The algorithm works for arbitrary meshes in any space dimension and for all Lipschitz fluxes. The formal second-order accuracy of the method and its convergence properties are tested on a series of linear and nonlinear benchmark problems.
Algebraic equations an introduction to the theories of Lagrange and Galois
Dehn, Edgar
2004-01-01
Meticulous and complete, this presentation of Galois' theory of algebraic equations is geared toward upper-level undergraduate and graduate students. The theories of both Lagrange and Galois are developed in logical rather than historical form. And they are given a more thorough exposition than is customary. For this reason, and also because the author concentrates on concrete applications of algebraic theory, Algebraic Equations is an excellent supplementary text, offering students a concrete introduction to the abstract principles of Galois theory. Of further value are the many numerical ex
International Nuclear Information System (INIS)
Choi, Sunghwan; Hong, Kwangwoo; Kim, Jaewook; Kim, Woo Youn
2015-01-01
We developed a self-consistent field program based on Kohn-Sham density functional theory using Lagrange-sinc functions as a basis set and examined its numerical accuracy for atoms and molecules through comparison with the results of Gaussian basis sets. The result of the Kohn-Sham inversion formula from the Lagrange-sinc basis set manifests that the pseudopotential method is essential for cost-effective calculations. The Lagrange-sinc basis set shows faster convergence of the kinetic and correlation energies of benzene as its size increases than the finite difference method does, though both share the same uniform grid. Using a scaling factor smaller than or equal to 0.226 bohr and pseudopotentials with nonlinear core correction, its accuracy for the atomization energies of the G2-1 set is comparable to all-electron complete basis set limits (mean absolute deviation ≤1 kcal/mol). The same basis set also shows small mean absolute deviations in the ionization energies, electron affinities, and static polarizabilities of atoms in the G2-1 set. In particular, the Lagrange-sinc basis set shows high accuracy with rapid convergence in describing density or orbital changes by an external electric field. Moreover, the Lagrange-sinc basis set can readily improve its accuracy toward a complete basis set limit by simply decreasing the scaling factor regardless of systems
On a Desert Island with Unit Sticks, Continued Fractions and Lagrange
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Victor J. Ricchezza
2016-07-01
Full Text Available GLY 4866, Computational Geology, provides an opportunity, welcomed by our faculty, to teach quantitative literacy to geology majors at USF. The course continues to evolve although the second author has been teaching it for some 20 years. This paper describes our experiences with a new lab activity that we are developing on the core issue of measurement and units. The activity is inspired by a passage in the 2008 publication of lectures that Joseph Louis Lagrange delivered at the Ecole Normale in 1795. The activity envisions that young scientists are faced with the need to determine the dimensions of a rectangle with no measuring device other than an unruled stick of unknown length – to hundredths of a stick length. Following Lagrange, the students use the stick to measure the lengths with continued fractions, and then they reduce the continued fractions and convert them to decimal form. In the process, these student veterans of calculus instruction learn that as a group they are not very good at the arithmetic of fractions, which they thought they learned in the fifth grade. The group score on a continued fraction item improved from 44% on the pre-course test to 84% on the post-course test in the first semester in which the new lab was included (Fall 2015.
De la representación de sistemas Euler - Lagrange a la Hamiltoniana generalizada
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L. H. Rodríguez - Alfaro
2015-01-01
Full Text Available La representación Hamiltoniana generalizada de sistemas brinda una estructura que puede ser utilizada con ventaja en muchas áreas, entre las cuales se puede mencionar el diseño de observadores y el diagnóstico de fallas basado en modelos. Muchos de los trabajos en estos te mas tienen como punto de partida al sistema en forma Hamiltoniana generalizada y, en general, se omite la explicación de cómo llegar a esta representación, por ejemplo, a partir de un modelo no lineal basado en las ecuaciones de Euler - Lagrange. En este tra bajo se presenta un análisis detallado de cómo es que se obtiene la representación Hamiltoniana generalizada de un sistema a partir de las n ecuaciones diferenciales de segundo orden obtenidas con el formalismo Euler - Lagrange. Con la finalidad de mostrar e n lo particular, después del caso general, cómo se obtiene la representación Hamiltoniana generalizada, se presentan algunos casos de estudio.
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Maheswari Subramanian
2018-01-01
Full Text Available Information hiding techniques have a significant role in recent application areas. Steganography is the embedding of information within an innocent cover work in a way which cannot be detected by any person without accessing the steganographic key. The proposed work uses a steganographic scheme for useful information with the help of human skin tone regions as cover image. The proposed algorithm has undergone Lagrange interpolation encryption for enhancement of the security of the hidden information. First, the skin tone regions are identified by using YCbCr color space which can be used as a cover image. Image pixels which belong to the skin regions are used to carry more secret bits, and the secret information is hidden in both horizontal and vertical sequences of the skin areas of the cover image. The secret information will hide behind the human skin regions rather than other objects in the same image because the skin pixels have high intensity value. The performance of embedding is done and is quite invisible by the vector discrete wavelet transformation (VDWT technique. A new Lagrange interpolation-based encryption method is introduced to achieve high security of the hidden information with higher payload and better visual quality.
Chen, Gang; Song, Yongduan; Lewis, Frank L
2016-05-03
This paper investigates the distributed fault-tolerant control problem of networked Euler-Lagrange systems with actuator and communication link faults. An adaptive fault-tolerant cooperative control scheme is proposed to achieve the coordinated tracking control of networked uncertain Lagrange systems on a general directed communication topology, which contains a spanning tree with the root node being the active target system. The proposed algorithm is capable of compensating for the actuator bias fault, the partial loss of effectiveness actuation fault, the communication link fault, the model uncertainty, and the external disturbance simultaneously. The control scheme does not use any fault detection and isolation mechanism to detect, separate, and identify the actuator faults online, which largely reduces the online computation and expedites the responsiveness of the controller. To validate the effectiveness of the proposed method, a test-bed of multiple robot-arm cooperative control system is developed for real-time verification. Experiments on the networked robot-arms are conduced and the results confirm the benefits and the effectiveness of the proposed distributed fault-tolerant control algorithms.
Augmented lagrange hopfield network for economic dispatch with multiple fuel options
International Nuclear Information System (INIS)
Dieu, Vo Ngoc; Ongsakul, Weerakorn; Polprasert, Jirawadee
2011-01-01
This paper proposes an augmented Lagrange Hopfield network (ALHN) for solving economic dispatch (ED) problem with multiple fuel options. The proposed ALHN method is a continuous Hopfield neural network with its energy function based on augmented Lagrangian function. The advantages of ALHN over the conventional Hopfield neural network are easier use, more general applications, faster convergence, better optimal solution, and larger scale of problem implementation. The method solves the problem by directly searching the most suitable fuel among the available fuels of each unit and finding the optimal solution for the problem based on minimization of the energy function of the continuous Hopfield neural network. The proposed method is tested on systems up to 100 units and the obtained results are compared to those from other methods in the literature. The results have shown that the proposed method is efficient for solving the ED problem with multiple fuel options and favorable for implementation in large scale problems.
Android Used in The Learning Innovation Atwood Machines on Lagrange Mechanics Methods
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Shabrina Shabrina
2017-12-01
Full Text Available Android is one of the smartphone operating system platforms that is now widely developed in learning media. Android allows the learning process to be more flexible and not oriented to be teacher center, but it allows to be student center. The Atwood machines is an experimental tool that is often used to observe mechanical laws in constantly accelerated motion which can also be described by the Lagrange mechanics methods. As an innovative and alternative learning activity, Atwood Android-based learning apps are running for two experimental variations, which are variations in load in cart and load masses that are hung. The experiment of load-carrier mass variation found that the larger load mass in the cart, the smaller the acceleration experienced by the system. Meanwhile, the experiment on the variation of the loaded mass found that the larger the loaded mass, the greater the acceleration experienced by the system.
The Application of Euler-Lagrange Method of Optimization for Electromechanical Motion Control
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Cristian VASILACHE
2000-12-01
Full Text Available Industrial and non-industrial processes such as production plans, robots, pumps, compressors, home applications, transportation of people and goods etc., require some kinds of motion control. The main functions of electromechanical drives are to adjust these processes by controlling the torque, speed or position. The objective of this paper is to perform the control of motion while minimizing power losses, that is ∫Ri2dt, in process conversion of electrical energy to mechanical energy. The optimal control laws for our problem is find using the Euler - Lagrange principle. We consider three types of controlled drives: torque, speed and position. Each of them has different control laws. By implementation of these controls with Borland C++ and Matlab environment, substantial energy savings are obtained.
Error estimates of Lagrange interpolation and orthonormal expansions for Freud weights
Kwon, K. H.; Lee, D. W.
2001-08-01
Let Sn[f] be the nth partial sum of the orthonormal polynomials expansion with respect to a Freud weight. Then we obtain sufficient conditions for the boundedness of Sn[f] and discuss the speed of the convergence of Sn[f] in weighted Lp space. We also find sufficient conditions for the boundedness of the Lagrange interpolation polynomial Ln[f], whose nodal points are the zeros of orthonormal polynomials with respect to a Freud weight. In particular, if W(x)=e-(1/2)x2 is the Hermite weight function, then we obtain sufficient conditions for the inequalities to hold:andwhere and k=0,1,2...,r.
The geometry of higher-order Lagrange spaces applications to mechanics and physics
Miron, Radu
1997-01-01
This monograph is devoted to the problem of the geometrizing of Lagrangians which depend on higher-order accelerations It presents a construction of the geometry of the total space of the bundle of the accelerations of order k>=1 A geometrical study of the notion of the higher-order Lagrange space is conducted, and the old problem of prolongation of Riemannian spaces to k-osculator manifolds is solved Also, the geometrical ground for variational calculus on the integral of actions involving higher-order Lagrangians is dealt with Applications to higher-order analytical mechanics and theoretical physics are included as well Audience This volume will be of interest to scientists whose work involves differential geometry, mechanics of particles and systems, calculus of variation and optimal control, optimization, optics, electromagnetic theory, and biology
Han, Zifa; Leung, Chi Sing; So, Hing Cheung; Constantinides, Anthony George
2017-08-15
A commonly used measurement model for locating a mobile source is time-difference-of-arrival (TDOA). As each TDOA measurement defines a hyperbola, it is not straightforward to compute the mobile source position due to the nonlinear relationship in the measurements. This brief exploits the Lagrange programming neural network (LPNN), which provides a general framework to solve nonlinear constrained optimization problems, for the TDOA-based localization. The local stability of the proposed LPNN solution is also analyzed. Simulation results are included to evaluate the localization accuracy of the LPNN scheme by comparing with the state-of-the-art methods and the optimality benchmark of Cramér-Rao lower bound.
LAGRANGE SOLUTIONS TO THE DISCRETE-TIME GENERAL THREE-BODY PROBLEM
International Nuclear Information System (INIS)
Minesaki, Yukitaka
2013-01-01
There is no known integrator that yields exact orbits for the general three-body problem (G3BP). It is difficult to verify whether a numerical procedure yields the correct solutions to the G3BP because doing so requires knowledge of all 11 conserved quantities, whereas only six are known. Without tracking all of the conserved quantities, it is possible to show that the discrete general three-body problem (d-G3BP) yields the correct orbits corresponding to Lagrange solutions of the G3BP. We show that the d-G3BP yields the correct solutions to the G3BP for two special cases: the equilateral triangle and collinear configurations. For the triangular solution, we use the fact that the solution to the three-body case is a superposition of the solutions to the three two-body cases, and we show that the three bodies maintain the same relative distances at all times. To obtain the collinear solution, we assume a specific permutation of the three bodies arranged along a straight rotating line, and we show that the d-G3BP maintains the same distance ratio between two bodies as in the G3BP. Proving that the d-G3BP solutions for these cases are equivalent to those of the G3BP makes it likely that the d-G3BP and G3BP solutions are equivalent in other cases. To our knowledge, this is the first work that proves the equivalence of the discrete solutions and the Lagrange orbits.
Abbiati, Giuseppe; La Salandra, Vincenzo; Bursi, Oreste S.; Caracoglia, Luca
2018-02-01
Successful online hybrid (numerical/physical) dynamic substructuring simulations have shown their potential in enabling realistic dynamic analysis of almost any type of non-linear structural system (e.g., an as-built/isolated viaduct, a petrochemical piping system subjected to non-stationary seismic loading, etc.). Moreover, owing to faster and more accurate testing equipment, a number of different offline experimental substructuring methods, operating both in time (e.g. the impulse-based substructuring) and frequency domains (i.e. the Lagrange multiplier frequency-based substructuring), have been employed in mechanical engineering to examine dynamic substructure coupling. Numerous studies have dealt with the above-mentioned methods and with consequent uncertainty propagation issues, either associated with experimental errors or modelling assumptions. Nonetheless, a limited number of publications have systematically cross-examined the performance of the various Experimental Dynamic Substructuring (EDS) methods and the possibility of their exploitation in a complementary way to expedite a hybrid experiment/numerical simulation. From this perspective, this paper performs a comparative uncertainty propagation analysis of three EDS algorithms for coupling physical and numerical subdomains with a dual assembly approach based on localized Lagrange multipliers. The main results and comparisons are based on a series of Monte Carlo simulations carried out on a five-DoF linear/non-linear chain-like systems that include typical aleatoric uncertainties emerging from measurement errors and excitation loads. In addition, we propose a new Composite-EDS (C-EDS) method to fuse both online and offline algorithms into a unique simulator. Capitalizing from the results of a more complex case study composed of a coupled isolated tank-piping system, we provide a feasible way to employ the C-EDS method when nonlinearities and multi-point constraints are present in the emulated system.
A second order anti-diffusive Lagrange-remap scheme for two-component flows
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Lagoutière Frédéric
2011-11-01
Full Text Available We build a non-dissipative second order algorithm for the approximate resolution of the one-dimensional Euler system of compressible gas dynamics with two components. The considered model was proposed in [1]. The algorithm is based on [8] which deals with a non-dissipative first order resolution in Lagrange-remap formalism. In the present paper we describe, in the same framework, an algorithm that is second order accurate in time and space, and that preserves sharp interfaces. Numerical results reported at the end of the paper are very encouraging, showing the interest of the second order accuracy for genuinely non-linear waves. Nous construisons un algorithme d’ordre deux et non dissipatif pour la résolution approchée des équations d’Euler de la dynamique des gaz compressibles à deux constituants en dimension un. Le modèle que nous considérons est celui à cinq équations proposé et analysé dans [1]. L’algorithme est basé sur [8] qui proposait une résolution approchée à l’ordre un et non dissipative au moyen d’un splitting de type Lagrange-projection. Dans le présent article, nous décrivons, dans le même formalisme, un algorithme d’ordre deux en temps et en espace, qui préserve des interfaces « parfaites » entre les constituants. Les résultats numériques rapportés à la fin de l’article sont très encourageants ; ils montrent clairement les avantages d’un schéma d’ordre deux pour les ondes vraiment non linéaires.
Zhou, X.; Solberger, M.
2013-01-01
We consider an exact factor model and derive a Lagrange multiplier-type test for unit roots in the idiosyncratic components. The asymptotic distribution of the statistic is derived under the misspecification that the differenced factors are white noise. We prove that the asymptotic distribution is
International Nuclear Information System (INIS)
Vladimir V Chudanov; Alexei A Leonov
2005-01-01
Full text of publication follows: One of the mathematical models (hyperbolic type) for describing evolution of compressible two-phase mixtures was offered in [1] to deal with the following applications: interfaces between compressible materials; shock waves in multiphase mixtures; evolution of homogeneous two-phase flows; cavitation in liquids. The basic difficulties of this model was connected to discretization of the non-conservative equation terms. As result, the class of problems concerned with passage of shock waves through fields with a discontinuing profile of a volume fraction was not described by means of this model. A class of schemes that are able to converge to the correct solution of such problems was received in [2] due to a deeper analysis of two-phase model. The technique offered in [2] was implemented on a Eulerian grid via the Godunov scheme. In present paper the additional analysis of two-phase model in view of microstructure of an mixture topology is carried out in Lagrange mass coordinates. As result, the equations averaged over the set of all possible realizations for two-phase mixture are received. The numerical solution is carried out with use of PPM method [3] in two steps: at first - the equations averaged over mass variable are solved; on the second - the solution, found on the previous step, is re-mapped to a fixed Eulerian grid. Such approach allows to expand the proposed technique on two-dimensional (three-dimensional) case, as in the Lagrange variables the Euler equations system is split on two (three) identical subsystems, each of which describes evolution of considered medium in the given direction. The accuracy and robustness of the described procedure are demonstrated on a sequence of the numerical problems. References: (1). R. Saurel, R. Abgrall, A multiphase Godunov method for compressible multi-fluid and multiphase flows, J. Comput. Phys. 150 (1999) 425-467; (2). R. Saurel, R. Abgrall, Discrete equations for physical and
Optimal control of two coupled spinning particles in the Euler–Lagrange picture
International Nuclear Information System (INIS)
Delgado-Téllez, M; Ibort, A; Peña, T Rodríguez de la; Salmoni, R
2016-01-01
A family of optimal control problems for a single and two coupled spinning particles in the Euler–Lagrange formalism is discussed. A characteristic of such problems is that the equations controlling the system are implicit and a reduction procedure to deal with them must be carried out. The reduction of the implicit control equations arising in these problems will be discussed in the slightly more general setting of implicit equations defined by invariant one-forms on Lie groups. As an example the first order differential equations describing the extremal solutions of an optimal control problem for a single spinning particle, obtained by using Pontryagin’s Maximum Principle (PMP), will be found and shown to be completely integrable. Then, again using PMP, solutions for the problem of two coupled spinning particles will be characterized as solutions of a system of coupled non-linear matrix differential equations. The reduction of the implicit system will show that the reduced space for them is the product of the space of states for the independent systems, implying the absence of ‘entanglement’ in this instance. Finally, it will be shown that, in the case of identical systems, the degree three matrix polynomial differential equations determined by the optimal feedback law, constitute a completely integrable Hamiltonian system and some of its solutions are described explicitly. (paper)
Hyperspherical Harmonics Expansion on Lagrange Meshes for Bosonic Systems in One Dimension
International Nuclear Information System (INIS)
Timofeyuk, N. K.; Baye, D.
2017-01-01
A one-dimensional system of bosons interacting with contact and single-Gaussian forces is studied with an expansion in hyperspherical harmonics. The hyper radial potentials are calculated using the link between the hyperspherical harmonics and the single-particle harmonic-oscillator basis while the coupled hyper radial equations are solved with the Lagrange-mesh method. Extensions of this method are proposed to achieve good convergence with small numbers of mesh points for any truncation of hyper momentum. The convergence with hyper momentum strongly depends on the range of the two-body forces: it is very good for large ranges but deteriorates as the range decreases, being the worst for the contact interaction. In all cases, the lowest-order energy is within 4.5% of the exact solution and shows the correct cubic asymptotic behaviour at large boson numbers. Details of the convergence studies are presented for 3, 5, 20 and 100 bosons. A special treatment for three bosons was found to be necessary. For single-Gaussian interactions, the convergence rate improves with increasing boson number, similar to what happens in the case of three-dimensional systems of bosons. (author)
Uncertainties of Predictions from Parton Distribution Functions 1, the Lagrange Multiplier Method
Stump, D R; Brock, R; Casey, D; Huston, J; Kalk, J; Lai, H L; Tung, W K
2002-01-01
We apply the Lagrange Multiplier method to study the uncertainties of physical predictions due to the uncertainties of parton distribution functions (PDFs), using the cross section for W production at a hadron collider as an archetypal example. An effective chi-squared function based on the CTEQ global QCD analysis is used to generate a series of PDFs, each of which represents the best fit to the global data for some specified value of the cross section. By analyzing the likelihood of these "alterative hypotheses", using available information on errors from the individual experiments, we estimate that the fractional uncertainty of the cross section due to current experimental input to the PDF analysis is approximately 4% at the Tevatron, and 10% at the LHC. We give sets of PDFs corresponding to these up and down variations of the cross section. We also present similar results on Z production at the colliders. Our method can be applied to any combination of physical variables in precision QCD phenomenology, an...
Sensing Aerosol Height in the O2 A and B Bands from Lagrange-1 Point
Xu, X.; Wang, J.; Wang, Y.; Zeng, J.; Torres, O.; Yang, Y.; Marshak, A.; Reid, J. S.; Miller, S. D.
2017-12-01
Aerosol vertical distribution is an important but poorly constrained variable that determines the impacts of aerosols on earth's climate and environment. Detailed aerosol profile can be probed by space-borne Lidar such as the CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization), but its spatial coverage is limited as a "curtain" captured along the Lidar's sub-orbital track. Passive techniques, though of less accuracy, can add an important augmentation due to the better spatial coverage. In this study, we present an algorithm for sensing aerosol height and optical depth using radiance measured in the oxygen A and B bands by the Earth Polychromatic Imaging Camera (EPIC), an instrument aboard the Deep Space Climate Observatory (DSCOVR) residing at Lagrange-1 point. The algorithm was applied to EPIC imagery of dust plumes over the North Atlantic Ocean. Retrieved aerosol heights and optical depths were evaluated against counterparts observed by CALIOP, Moderate Resolution Imaging Spectroradiometer (MODIS), and Aerosol Robotic Network (AERONET). The accuracies in EIPC retrieved aerosol heights and optical depths are found better than ±0.5 km and ±(0.1+10%), respectively. This study demonstrates the potential of EPIC measurements for retrieving global aerosol height multiple times daily, which are essential for evaluating aerosol profile simulated in climate models and for better estimating aerosol radiative effects.
Wang, Wei; Wen, Changyun; Huang, Jiangshuai; Fan, Huijin
2017-11-01
In this paper, a backstepping based distributed adaptive control scheme is proposed for multiple uncertain Euler-Lagrange systems under directed graph condition. The common desired trajectory is allowed totally unknown by part of the subsystems and the linearly parameterized trajectory model assumed in currently available results is no longer needed. To compensate the effects due to unknown trajectory information, a smooth function of consensus errors and certain positive integrable functions are introduced in designing virtual control inputs. Besides, to overcome the difficulty of completely counteracting the coupling terms of distributed consensus errors and parameter estimation errors in the presence of asymmetric Laplacian matrix, extra information transmission of local parameter estimates are introduced among linked subsystem and adaptive gain technique is adopted to generate distributed torque inputs. It is shown that with the proposed distributed adaptive control scheme, global uniform boundedness of all the closed-loop signals and asymptotically output consensus tracking can be achieved. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.
Uncertainties of predictions from parton distribution functions. I. The Lagrange multiplier method
International Nuclear Information System (INIS)
Stump, D.; Pumplin, J.; Brock, R.; Casey, D.; Huston, J.; Kalk, J.; Lai, H. L.; Tung, W. K.
2002-01-01
We apply the Lagrange multiplier method to study the uncertainties of physical predictions due to the uncertainties of parton distribution functions (PDF's), using the cross section σ W for W production at a hadron collider as an archetypal example. An effective χ 2 function based on the CTEQ global QCD analysis is used to generate a series of PDF's, each of which represents the best fit to the global data for some specified value of σ W . By analyzing the likelihood of these 'alterative hypotheses', using available information on errors from the individual experiments, we estimate that the fractional uncertainty of σ W due to current experimental input to the PDF analysis is approximately ±4% at the Fermilab Tevatron, and ±8-10% at the CERN Large Hadron Collider. We give sets of PDF's corresponding to these up and down variations of σ W . We also present similar results on Z production at the colliders. Our method can be applied to any combination of physical variables in precision QCD phenomenology, and it can be used to generate benchmarks for testing the accuracy of approximate methods based on the error matrix
Distributed-Lagrange-Multiplier-based computational method for particulate flow with collisions
Ardekani, Arezoo; Rangel, Roger
2006-11-01
A Distributed-Lagrange-Multiplier-based computational method is developed for colliding particles in a solid-fluid system. A numerical simulation is conducted in two dimensions using the finite volume method. The entire domain is treated as a fluid but the fluid in the particle domains satisfies a rigidity constraint. We present an efficient method for predicting the collision between particles. In earlier methods, a repulsive force was applied to the particles when their distance was less than a critical value. In this method, an impulsive force is computed. During the frictionless collision process between two particles, linear momentum is conserved while the tangential forces are zero. Thus, instead of satisfying a condition of rigid body motion for each particle separately, as done when particles are not in contact, both particles are rigidified together along their line of centers. Particles separate from each other when the impulsive force is less than zero and after this time, a rigidity constraint is satisfied for each particle separately. Grid independency is implemented to ensure the accuracy of the numerical simulation. A comparison between this method and previous collision strategies is presented and discussed.
PID position regulation in one-degree-of-freedom Euler-Lagrange systems actuated by a PMSM
Verastegui-Galván, J.; Hernández-Guzmán, V. M.; Orrante-Sakanassi, J.
2018-02-01
This paper is concerned with position regulation in one-degree-of-freedom Euler-Lagrange Systems. We consider that the mechanical subsystem is actuated by a permanent magnet synchronous motor (PMSM). Our proposal consists of a Proportional-Integral-Derivative (PID) controller for the mechanical subsystem and a slight variation of field oriented control for the PMSM. We take into account the motor electric dynamics during the stability analysis. We present, for the first time, a global asymptotic stability proof for such a control scheme without requiring the mechanical subsystem to naturally possess viscous friction. Finally, as a corollary of our main result we prove global asymptotic stability for output feedback PID regulation of one-degree-of-freedom Euler-Lagrange systems when generated torque is considered as the system input, i.e. when the electric dynamics of PMSM's is not taken into account.
Li, Mingming; Li, Lin; Li, Qiang; Zou, Zongshu
2018-05-01
A filter-based Euler-Lagrange multiphase flow model is used to study the mixing behavior in a combined blowing steelmaking converter. The Euler-based volume of fluid approach is employed to simulate the top blowing, while the Lagrange-based discrete phase model that embeds the local volume change of rising bubbles for the bottom blowing. A filter-based turbulence method based on the local meshing resolution is proposed aiming to improve the modeling of turbulent eddy viscosities. The model validity is verified through comparison with physical experiments in terms of mixing curves and mixing times. The effects of the bottom gas flow rate on bath flow and mixing behavior are investigated and the inherent reasons for the mixing result are clarified in terms of the characteristics of bottom-blowing plumes, the interaction between plumes and top-blowing jets, and the change of bath flow structure.
Directory of Open Access Journals (Sweden)
Jianke Zhang
2018-01-01
Full Text Available We study in this paper the Atangana-Baleanu fractional derivative of fuzzy functions based on the generalized Hukuhara difference. Under the condition of gH-Atangana-Baleanu fractional differentiability, we prove the generalized necessary and sufficient optimality conditions for problems of the fuzzy fractional calculus of variations with a Lagrange function. The new kernel of gH-Atangana-Baleanu fractional derivative has no singularity and no locality, which was not precisely illustrated in the previous definitions.
Störmer problem restricted to a spherical surface and the Euler and Lagrange tops
International Nuclear Information System (INIS)
Piña, Eduardo; Cortés, Emilio
2016-01-01
In a recent work, Cortés and Poza (2015 Eur. J. Phys. 36 055009) analysed, in full, the dynamics of a charged particle in the field of a magnetic dipole restricted to a spherical surface with the dipole at its centre. This model can be considered as the classical non-relativistic Störmer problem on a sphere. Here, we started from a Lagrangian approach: we derived the Hamilton equations of motion and observed that in this restricted case the equations can be reduced to quadratures, and they were integrated numerically. From the Hamiltonian function we found, for the polar angle, an equivalent one-dimensional system of a particle in the presence of an effective potential. In the present work we start from a change of variable to the cosine of the polar angle. In terms of this variable we obtain an equation that turns out to be the same as the one of a particle in a quartic potential. Then, we can actually solve the equations of motion for the polar angle using Jacobi elliptic functions, and for the azimuthal angle we use the same integrals which were expressed by Jacobi in terms of theta functions, both in the Euler and Lagrange tops. In this restricted Störmer problem, the student at undergraduate or graduate level will have a good example of an integrable nonlinear physical system in which, after analysis of its complex dynamics, one can obtain an analytical solution by means of some special functions of mathematical physics. Additionally, one discovers that the equations of motion of this restricted case of a charge in a magnetic dipole field have the same mathematical structure as the corresponding equations of other well known integrable classical dynamical systems. (paper)
On the Nature of the Microwave Background at the Lagrange 2 Point. Part II
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Borissova L.
2007-10-01
Full Text Available In this work the mathematical methods of General Relativity are used to answer the following questions: if a microwave background originates from the Earth, what would be its density and associated dipole measured at the altitude of a U2 aeroplane (25 km, the COBE satellite (900 km, and the 2nd Lagrange point (1.5 million km, the position of the WMAP and PLANCK satellites? The first problem is solved via Einstein’s equations for the electromagnetic field of the Earth. The second problem is solved using the geodesic equations for light-like particles (photons which are mediators for electromagnetic radiation. We have determined that a microwave background that originates at the Earth (the Earth microwave background decreases with altitude so that the density of the energy of such a background at the altitude of the COBE orbit (900 km is 0.68 times less than that at the altitude of a U2 aeroplane. The density of the energy of the background at the L2 point is only ~1E-7 of the value detected by a U2 aeroplane or at the COBE orbit. The dipole anisotropy of the Earth microwave background, due to the rapid motion of the Earth relative to the source of another field which isn’t connected to the Earth but is located in depths of the cosmos, doesn’t depend on altitute from the surface of the Earth. Such a dipole will be the same irrespective of the position at which measurements are taken.
Chen, Huangxin; Sun, Shuyu; Zhang, Tao
2017-01-01
In this paper we consider the energy stability estimates for some fully discrete schemes which both consider time and spatial discretizations for the incompressible Navier–Stokes equations. We focus on three kinds of fully discrete schemes, i
Parsani, Matteo; Carpenter, Mark H.; Fisher, Travis C.; Nielsen, Eric J.
2016-01-01
set of points from tensor product, Legendre--Gauss--Lobatto (LGL), to a combination of tensor product Legendre--Gauss (LG) and LGL points. The new semidiscrete operators discretely conserve mass, momentum, energy, and satisfy a mathematical entropy
VizieR Online Data Catalog: STAGGER-grid of 3D stellar models. V. (Chiavassa+, 2018)
Chiavassa, A.; Casagrande, L.; Collet, R.; Magic, Z.; Bigot, L.; Thevenin, F.; Asplund, M.
2018-01-01
Table B0: RHD simulations' stellar parameters, bolometric magnitude, and bolometric correction for Johnson-Cousins, 2MASS, SDSS (columns 13 to 17), and Gaia systems Table 4: RHD simulations' stellar parameters, bolometric magnitude, and bolometric correction for SkyMapper photometric system, and Stroemgren index b-y, m1=(v-b)-(b-y), and c1=(u-v)-(v-b) Table 5: RHD simulations' stellar parameters, bolometric magnitude, and bolometric correction for the HST-WFC3 in VEGA system Table 6: RHD simulations' stellar parameters, bolometric magnitude, and bolometric correction for the HST-WFC3 in ST system Table 7: RHD simulations' stellar parameters, bolometric magnitude, and bolometric correction for the HST-WFC3 in AB system (5 data files).
Crystallization Formulation Lab
Federal Laboratory Consortium — The Crystallization Formulation Lab fills a critical need in the process development and optimization of current and new explosives and energetic formulations. The...
Andrews, A. E.
2016-12-01
CarbonTracker-Lagrange (CT-L) is a flexible modeling framework developed to take advantage of newly available atmospheric data for CO2 and other long-lived gases such as CH4 and N2O. The North American atmospheric CO2 measurement network has grown from three sites in 2004 to >100 sites in 2015. The US network includes tall tower, mountaintop, surface, and aircraft sites in the NOAA Global Greenhouse Gas Reference Network along with sites maintained by university, government and private sector researchers. The Canadian network is operated by Environment and Climate Change Canada. This unprecedented dataset can provide spatially and temporally resolved CO2 emissions and uptake flux estimates and quantitative information about drivers of variability, such as drought and temperature. CT-L is a platform for systematic comparison of data assimilation techniques and evaluation of assumed prior, model and observation errors. A novel feature of CT-L is the optimization of boundary values along with surface fluxes, leveraging vertically resolved data available from NOAA's aircraft sampling program. CT-L uses observation footprints (influence functions) from the Weather Research and Forecasting/Stochastic Time-Inverted Lagrangian Transport (WRF-STILT) modeling system to relate atmospheric measurements to upwind fluxes and boundary values. Footprints are pre-computed and the optimization algorithms are efficient, so many variants of the calculation can be performed. Fluxes are adjusted using Bayesian or Geostatistical methods to provide optimal agreement with observations. Satellite measurements of CO2 and CH4 from GOSAT are available starting in July 2009 and from OCO-2 since September 2014. With support from the NASA Carbon Monitoring System, we are developing flux estimation strategies that use remote sensing and in situ data together, including geostatistical inversions using satellite retrievals of solar-induced chlorophyll fluorescence. CT-L enables quantitative
Directory of Open Access Journals (Sweden)
John Michael Rassias
2017-07-01
Full Text Available The aim of this paper is to investigate generalized Ulam-Hyers stabilities of the following Euler-Lagrange-Jensen-$(a,b$-sextic functional equation $$ f(ax+by+f(bx+ay+(a-b^6\\left[f\\left(\\frac{ax-by}{a-b}\\right+f\\left(\\frac{bx-ay}{b-a}\\right\\right]\\\\ = 64(ab^2\\left(a^2+b^2\\right\\left[f\\left(\\frac{x+y}{2}\\right+f\\left(\\frac{x-y}{2}\\right\\right]\\\\ +2\\left(a^2-b^2\\right\\left(a^4-b^4\\right[f(x+f(y] $$ where $a\
Institute of Scientific and Technical Information of China (English)
GUO Han-Ying,; LI Yu-Qi; WU Ke1; WANG Shi-Kun
2002-01-01
In this first paper of a series, we study the difference discrete variational principle in the framework of multi-parameter differential approach by regarding the forward difference as an entire geometric object in view of noncommutative differential geometry. Regarding the difference as an entire geometric object, the difference discrete version of Legendre transformation can be introduced. By virtue of this variational principle, we can discretely deal with the variation problems in both the Lagrangian and Hamiltonian formalisms to get difference discrete Euler-Lagrange equations and canonical ones for the difference discrete versions of the classical mechanics and classical field theory.
Dias, Clenilda F; Carvalho-Santos, Vagson L
2012-01-01
The Euler-Lagrange equations (EL) are very important in the theoretical description of several physical systems. In this work we have used a simplified form of EL to study one-dimensional motions under the action of a constant force. From using the definition of partial derivative, we have proposed two operators, here called \\textit{mean delta operators}, which may be used to solve the EL in a simplest way. We have applied this simplification to solve three simple mechanical problems under th...
On the Fermat-Lagrange principle for mixed smooth convex extremal problems
International Nuclear Information System (INIS)
Brinkhuis, Ya
2001-01-01
A simple geometric condition that can be attached to an extremal problem of a fairly general form included in a family of problems is indicated. This is used to demonstrate that the task of formulating a uniform condition for smooth convex problems can be satisfactorily accomplished. On the other hand, the necessity of this new condition of optimality is proved under certain technical assumptions
Jian, Jigui; Wan, Peng
2017-07-01
This paper deals with the problem on Lagrange α-exponential stability and α-exponential convergence for a class of fractional-order complex-valued neural networks. To this end, some new fractional-order differential inequalities are established, which improve and generalize previously known criteria. By using the new inequalities and coupling with the Lyapunov method, some effective criteria are derived to guarantee Lagrange α-exponential stability and α-exponential convergence of the addressed network. Moreover, the framework of the α-exponential convergence ball is also given, where the convergence rate is related to the parameters and the order of differential of the system. These results here, which the existence and uniqueness of the equilibrium points need not to be considered, generalize and improve the earlier publications and can be applied to monostable and multistable fractional-order complex-valued neural networks. Finally, one example with numerical simulations is given to show the effectiveness of the obtained results. Copyright © 2017 Elsevier Ltd. All rights reserved.
Prediction of a Densely Loaded Particle-Laden Jet using a Euler-Lagrange Dense Spray Model
Pakseresht, Pedram; Apte, Sourabh V.
2017-11-01
Modeling of a dense spray regime using an Euler-Lagrange discrete-element approach is challenging because of local high volume loading. A subgrid cluster of droplets can lead to locally high void fractions for the disperse phase. Under these conditions, spatio-temporal changes in the carrier phase volume fractions, which are commonly neglected in spray simulations in an Euler-Lagrange two-way coupling model, could become important. Accounting for the carrier phase volume fraction variations, leads to zero-Mach number, variable density governing equations. Using pressure-based solvers, this gives rise to a source term in the pressure Poisson equation and a non-divergence free velocity field. To test the validity and predictive capability of such an approach, a round jet laden with solid particles is investigated using Direct Numerical Simulation and compared with available experimental data for different loadings. Various volume fractions spanning from dilute to dense regimes are investigated with and without taking into account the volume displacement effects. The predictions of the two approaches are compared and analyzed to investigate the effectiveness of the dense spray model. Financial support was provided by National Aeronautics and Space Administration (NASA).
The shallow water equations on the sphere and their Lagrange- Galerkin-solution
Heinze, T
2002-01-01
The shallow water equations are formulated on the sphere in a three- dimensional coordinate system with the aid of tangential velocity components and differential operators. We introduce a modified semi- Lagrangian scheme for the discretization in time. The discretization in space is solved by linear finite elements. The grids we use are regular refinements of a macro triangulation which itself is derived from a highly symmetric polyeder also known as a bucky or soccer ball. The good numerical results show that this combination is a promising approach. The numerical algorithm is stable and its strength is the conservation of mass and energy. (16 refs).
Kamensky, David; Evans, John A; Hsu, Ming-Chen; Bazilevs, Yuri
2017-11-01
This paper discusses a method of stabilizing Lagrange multiplier fields used to couple thin immersed shell structures and surrounding fluids. The method retains essential conservation properties by stabilizing only the portion of the constraint orthogonal to a coarse multiplier space. This stabilization can easily be applied within iterative methods or semi-implicit time integrators that avoid directly solving a saddle point problem for the Lagrange multiplier field. Heart valve simulations demonstrate applicability of the proposed method to 3D unsteady simulations. An appendix sketches the relation between the proposed method and a high-order-accurate approach for simpler model problems.
Charles, Alexandre; Ballard, Patrick
2016-08-01
The dynamics of mechanical systems with a finite number of degrees of freedom (discrete mechanical systems) is governed by the Lagrange equation which is a second-order differential equation on a Riemannian manifold (the configuration manifold). The handling of perfect (frictionless) unilateral constraints in this framework (that of Lagrange's analytical dynamics) was undertaken by Schatzman and Moreau at the beginning of the 1980s. A mathematically sound and consistent evolution problem was obtained, paving the road for many subsequent theoretical investigations. In this general evolution problem, the only reaction force which is involved is a generalized reaction force, consistently with the virtual power philosophy of Lagrange. Surprisingly, such a general formulation was never derived in the case of frictional unilateral multibody dynamics. Instead, the paradigm of the Coulomb law applying to reaction forces in the real world is generally invoked. So far, this paradigm has only enabled to obtain a consistent evolution problem in only some very few specific examples and to suggest numerical algorithms to produce computational examples (numerical modeling). In particular, it is not clear what is the evolution problem underlying the computational examples. Moreover, some of the few specific cases in which this paradigm enables to write down a precise evolution problem are known to show paradoxes: the Painlevé paradox (indeterminacy) and the Kane paradox (increase in kinetic energy due to friction). In this paper, we follow Lagrange's philosophy and formulate the frictional unilateral multibody dynamics in terms of the generalized reaction force and not in terms of the real-world reaction force. A general evolution problem that governs the dynamics is obtained for the first time. We prove that all the solutions are dissipative; that is, this new formulation is free of Kane paradox. We also prove that some indeterminacy of the Painlevé paradox is fixed in this
Dias, Clenilda F.; Araújo, Maria A. S.; Carvalho-Santos, Vagson L.
2018-01-01
The Euler-Lagrange equations (ELE) are very important in the theoretical description of several physical systems. In this work we have used a simplified form of ELE to study one-dimensional motions under the action of a constant force. From the use of the definition of partial derivative, we have proposed two operators, here called mean delta operators, which may be used to solve the ELE in a simplest way. We have applied this simplification to solve three simple mechanical problems in which the particle is under the action of the gravitational field: a free fall body, the Atwood’s machine and the inclined plan. The proposed simplification can be used to introduce the lagrangian formalism in teaching classical mechanics in introductory physics courses.
Hopkins, Randall C.; Stahl, H. Philip
2007-01-01
The payload mass and volume capabilities of the planned Ares V launch vehicle provide the science community with unprecedented opportunities to place large science payloads into low earth orbit and beyond. One example, the outcome of a recent study conducted at the NASA Marshall Space Flight Center, is a large, monolithic telescope with a primary mirror diameter of 6.2 meters placed into a halo orbit about the second Sun-Earth Lagrange point, or L2, approximately 1.5 million kin beyond Earth's orbit. Operating in the visible and ultraviolet regions of the electromagnetic spectrum, such a large telescope would allow astronomers to detect bio-signatures and characterize the atmospheres of transiting exoplanets, provide high resolution imaging three or more times better than the Hubble Space Telescope and the James Webb Space Telescope, and observe the ultraviolet light from warm baryonic matter.
Directory of Open Access Journals (Sweden)
Kokh Samuel
2012-04-01
Full Text Available We propose a method dedicated to the simulation of interface flows involving an arbitrary number m of compressible components. Our task is two-fold: we first introduce a m-component flow model that generalizes the two-material five-equation model of [2,3]. Then, we present a discretization strategy by means of a Lagrange-Remap [8,10] approach following the lines of [5,7,12]. The projection step involves an anti-dissipative mechanism derived from [11,12]. This feature allows to prevent the numerical diffusion of the material interfaces. We present two-dimensional simulation results of three-material flow. Nous proposons une méthode de simulation pour des écoulements comportant un nombre arbitraire m de composants compressibles séparés par des interfaces. Nous procdons en deux tapes : tout d’abord nous introduisons un modèle d’écoulementm composants qui généralise le modèle à cinq équations de [2,3]. Ensuite nous présentons une stratégie de discrétisation de type Lagrange-Projection [8,10] inspirée de [5,7,12]. La phase de projection met en œuvre une technique de transport anti-diffusive [11,12] qui permet de limiter la diffusion numérique des interfaces matérielles. Nous présentons des résultats de calcul bidimensionnel d’écoulement à trois composants.
Energy Technology Data Exchange (ETDEWEB)
Vuillemin, M [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires
1964-07-01
After giving the Lagrange expression for a conducting fluid in an external electromagnetic field, the author shows that a Lagrange expression exists for describing the evolution of a system of interacting fluids obtained by adding the Lagrange expression of each fluid.to that of the electromagnetic field. By variation are obtained the fluid movement equation coupled to the Maxwell equations. It is shown that the study of small movements around a stationary state can be deduced from the Lagrange equation expanded to the second power order of the perturbation. It is then possible to deduce the normal mode equations and the study the stability by examining the modes which are marginally stable. (author) [French] Apres avoir rappele l'expression, du Lagrangien pour un fluide conducteur dans un champ electromagnetique exterieur, on montre qu'il existe un Lagrangien pour decrire l'evolution d'un systeme de fluides en.interaction que l'on obtient par la superposition du Lagrangien de chaque fluide et du Lagrangien du champ electromagnetique. On obtient par variation, les equations du mouvement des fluides, couplees aux equations de Maxwell. On montre que l'etude des petits mouvements autour d'un etat stationnaire se deduit du Lagrangien developpe au second1 ordre en puissance de la perturbation. On peut alors retrouver les equations des modes normaux et etudier la stabilite en recherchant les modes marginalement stables. (auteur)
Audits of radiopharmaceutical formulations
International Nuclear Information System (INIS)
Castronovo, F.P. Jr.
1992-01-01
A procedure for auditing radiopharmaceutical formulations is described. To meet FDA guidelines regarding the quality of radiopharmaceuticals, institutional radioactive drug research committees perform audits when such drugs are formulated away from an institutional pharmacy. All principal investigators who formulate drugs outside institutional pharmacies must pass these audits before they can obtain a radiopharmaceutical investigation permit. The audit team meets with the individual who performs the formulation at the site of drug preparation to verify that drug formulations meet identity, strength, quality, and purity standards; are uniform and reproducible; and are sterile and pyrogen free. This team must contain an expert knowledgeable in the preparation of radioactive drugs; a radiopharmacist is the most qualified person for this role. Problems that have been identified by audits include lack of sterility and apyrogenicity testing, formulations that are open to the laboratory environment, failure to use pharmaceutical-grade chemicals, inadequate quality control methods or records, inadequate training of the person preparing the drug, and improper unit dose preparation. Investigational radiopharmaceutical formulations, including nonradiolabeled drugs, must be audited before they are administered to humans. A properly trained pharmacist should be a member of the audit team
Reactive decontamination formulation
Giletto, Anthony [College Station, TX; White, William [College Station, TX; Cisar, Alan J [Cypress, TX; Hitchens, G Duncan [Bryan, TX; Fyffe, James [Bryan, TX
2003-05-27
The present invention provides a universal decontamination formulation and method for detoxifying chemical warfare agents (CWA's) and biological warfare agents (BWA's) without producing any toxic by-products, as well as, decontaminating surfaces that have come into contact with these agents. The formulation includes a sorbent material or gel, a peroxide source, a peroxide activator, and a compound containing a mixture of KHSO.sub.5, KHSO.sub.4 and K.sub.2 SO.sub.4. The formulation is self-decontaminating and once dried can easily be wiped from the surface being decontaminated. A method for decontaminating a surface exposed to chemical or biological agents is also disclosed.
Nguyen, Louis H.; Ramakrishnan, Jayant; Granda, Jose J.
2006-01-01
The assembly and operation of the International Space Station (ISS) require extensive testing and engineering analysis to verify that the Space Station system of systems would work together without any adverse interactions. Since the dynamic behavior of an entire Space Station cannot be tested on earth, math models of the Space Station structures and mechanical systems have to be built and integrated in computer simulations and analysis tools to analyze and predict what will happen in space. The ISS Centrifuge Rotor (CR) is one of many mechanical systems that need to be modeled and analyzed to verify the ISS integrated system performance on-orbit. This study investigates using Bond Graph modeling techniques as quick and simplified ways to generate models of the ISS Centrifuge Rotor. This paper outlines the steps used to generate simple and more complex models of the CR using Bond Graph Computer Aided Modeling Program with Graphical Input (CAMP-G). Comparisons of the Bond Graph CR models with those derived from Euler-Lagrange equations in MATLAB and those developed using multibody dynamic simulation at the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) are presented to demonstrate the usefulness of the Bond Graph modeling approach for aeronautics and space applications.
Directory of Open Access Journals (Sweden)
Mahdi M. M. El-Arini
2013-01-01
Full Text Available In recent years, the solar energy has become one of the most important alternative sources of electric energy, so it is important to operate photovoltaic (PV panel at the optimal point to obtain the possible maximum efficiency. This paper presents a new optimization approach to maximize the electrical power of a PV panel. The technique which is based on objective function represents the output power of the PV panel and constraints, equality and inequality. First the dummy variables that have effect on the output power are classified into two categories: dependent and independent. The proposed approach is a multistage one as the genetic algorithm, GA, is used to obtain the best initial population at optimal solution and this initial population is fed to Lagrange multiplier algorithm (LM, then a comparison between the two algorithms, GA and LM, is performed. The proposed technique is applied to solar radiation measured at Helwan city at latitude 29.87°, Egypt. The results showed that the proposed technique is applicable.
Directory of Open Access Journals (Sweden)
Anatolij K. Prykarpatski
2017-12-01
Full Text Available The classical Lagrange-d’Alembert principle had a decisive influence on formation of modern analytical mechanics which culminated in modern Hamilton and Poisson mechanics. Being mainly interested in the geometric interpretation of this principle, we devoted our review to its deep relationships to modern Lie-algebraic aspects of the integrability theory of nonlinear heavenly type dynamical systems and its so called Lax-Sato counterpart. We have also analyzed old and recent investigations of the classical M. A. Buhl problem of describing compatible linear vector field equations, its general M.G. Pfeiffer and modern Lax-Sato type special solutions. Especially we analyzed the related Lie-algebraic structures and integrability properties of a very interesting class of nonlinear dynamical systems called the dispersionless heavenly type equations, which were initiated by Plebański and later analyzed in a series of articles. As effective tools the AKS-algebraic and related R -structure schemes are used to study the orbits of the corresponding co-adjoint actions, which are intimately related to the classical Lie-Poisson structures on them. It is demonstrated that their compatibility condition coincides with the corresponding heavenly type equations under consideration. It is also shown that all these equations originate in this way and can be represented as a Lax-Sato compatibility condition for specially constructed loop vector fields on the torus. Typical examples of such heavenly type equations, demonstrating in detail their integrability via the scheme devised herein, are presented.
Constraint propagation of C2-adjusted formulation: Another recipe for robust ADM evolution system
International Nuclear Information System (INIS)
Tsuchiya, Takuya; Yoneda, Gen; Shinkai, Hisa-aki
2011-01-01
With a purpose of constructing a robust evolution system against numerical instability for integrating the Einstein equations, we propose a new formulation by adjusting the ADM evolution equations with constraints. We apply an adjusting method proposed by Fiske (2004) which uses the norm of the constraints, C 2 . One of the advantages of this method is that the effective signature of adjusted terms (Lagrange multipliers) for constraint-damping evolution is predetermined. We demonstrate this fact by showing the eigenvalues of constraint propagation equations. We also perform numerical tests of this adjusted evolution system using polarized Gowdy-wave propagation, which show robust evolutions against the violation of the constraints than that of the standard ADM formulation.
Preparation of radiopharmaceutical formulations
International Nuclear Information System (INIS)
Simon, J.; Garlich, J.R.; Frank, R.K.; McMillan, K.
1998-01-01
Radiopharmaceutical formulations for complexes comprising at least one radionuclide complexed with a ligand, or its physiologically-acceptable salts thereof, especially 153 samarium-ethylenediaminetetramethylenephosphonic acid, which optionally contains a divalent metal ion, e.g. calcium, and is frozen, thawed, and then administered by injection. Alternatively, the radiopharmaceutical formulations must contain the divalent metal and are frozen only if the time before administration is sufficiently long to cause concern for radiolysis of the ligand. 2 figs., 9 tabs
Tariff formulation and equalization
International Nuclear Information System (INIS)
Svartsund, Trond
2003-01-01
The primary goal of the transmission tariff is to provide for socioeconomic use of the transmission grid. The present tariff structure is basically right. The responsibility for the formulation of the tariff resides with the local grid owner. This must take place in agreement with the current regulations which are passed by the authorities. The formulation must be adaptable to the local requirements. EBL (Norwegian Electricity Industry Association) is content with the current regulations
Daniele, C. J.; Lorenzo, C. F.
1979-01-01
Lumped volume dynamic equations are derived using an energy-state formulation. This technique requires that kinetic and potential energy state functions be written for the physical system being investigated. To account for losses in the system, a Rayleigh dissipation function is also formed. Using these functions, a Lagrangian is formed and using Lagrange's equation, the equations of motion for the system are derived. The results of the application of this technique to a lumped volume are used to derive a model for the free-piston Stirling engine. The model was simplified and programmed on an analog computer. Results are given comparing the model response with experimental data.
Directory of Open Access Journals (Sweden)
Hakan Kum
2012-01-01
Full Text Available This study examines the validity of the purchasing power parity (PPP in Turkey for annual data from 1953 to 2009. While results from both the ADF unit root and the DF-GLS unit root test indicate mixed results, PPP holds for Turkey with the presence of structural breaks which are obtained by Zivot and Andrews and Lagrange Multiplier unit root tests.
Modelado, SimulaciÃ³n y Control de SatÃ©lites en los Puntos de Lagrange del Sistema Tierra - Luna
Directory of Open Access Journals (Sweden)
F. Alonso Zotes
2011-07-01
Full Text Available Resumen: El objetivo de este artÃculo es modelar, analizar y controlar una constelaciÃ³n de cinco satÃ©lites, situados en los puntos de Lagrange del sistema Tierra â Luna. El modelo se ha desarrollado incluyendo efectos complejos no considerados habitualmente, como el viento solar, la no esfericidad de los planetas y la deriva de la Ã³rbita lunar, para hacerlo mÃ¡s realista. Sobre los satÃ©lites se ejerce una propulsiÃ³n continua, calculada por medio de controladores tipo PD, tanto convencionales como borrosos, y cuya finalidad es situar y mantener a cada satÃ©lite en su punto de Lagrange frente a las inestabilidades y derivas inherentes al sistema. El sistema completo se ha implementado en el lenguaje de modelado Modelica, para el que se han creado una serie de elementos aeroespaciales, y las simulaciones se han desarrollado con el software Dymola. Tanto con los controladores clÃ¡sicos como con los borrosos se han obtenido muy buenos resultados. Palabras clave: modelado, simulaciÃ³n, control borroso, satÃ©lites, puntos de Lagrange, sistema Tierra-Luna
Granulated decontamination formulations
Tucker, Mark D.
2007-10-02
A decontamination formulation and method of making that neutralizes the adverse health effects of both chemical and biological compounds, especially chemical warfare (CW) and biological warfare (BW) agents, and toxic industrial chemicals. The formulation provides solubilizing compounds that serve to effectively render the chemical and biological compounds, particularly CW and BW compounds, susceptible to attack, and at least one reactive compound that serves to attack (and detoxify or kill) the compound. The formulation includes at least one solubilizing agent, a reactive compound, a sorbent additive, and water. A highly adsorbent sorbent additive (e.g., amorphous silica, sorbitol, mannitol, etc.) is used to "dry out" one or more liquid ingredients into a dry, free-flowing powder that has an extended shelf life, and is more convenient to handle and mix in the field.
Directory of Open Access Journals (Sweden)
Fan Meng
Full Text Available This paper studies the problem of the restoration of images corrupted by mixed Gaussian-impulse noise. In recent years, low-rank matrix reconstruction has become a research hotspot in many scientific and engineering domains such as machine learning, image processing, computer vision and bioinformatics, which mainly involves the problem of matrix completion and robust principal component analysis, namely recovering a low-rank matrix from an incomplete but accurate sampling subset of its entries and from an observed data matrix with an unknown fraction of its entries being arbitrarily corrupted, respectively. Inspired by these ideas, we consider the problem of recovering a low-rank matrix from an incomplete sampling subset of its entries with an unknown fraction of the samplings contaminated by arbitrary errors, which is defined as the problem of matrix completion from corrupted samplings and modeled as a convex optimization problem that minimizes a combination of the nuclear norm and the l(1-norm in this paper. Meanwhile, we put forward a novel and effective algorithm called augmented Lagrange multipliers to exactly solve the problem. For mixed Gaussian-impulse noise removal, we regard it as the problem of matrix completion from corrupted samplings, and restore the noisy image following an impulse-detecting procedure. Compared with some existing methods for mixed noise removal, the recovery quality performance of our method is dominant if images possess low-rank features such as geometrically regular textures and similar structured contents; especially when the density of impulse noise is relatively high and the variance of Gaussian noise is small, our method can outperform the traditional methods significantly not only in the simultaneous removal of Gaussian noise and impulse noise, and the restoration ability for a low-rank image matrix, but also in the preservation of textures and details in the image.
How (not) to use the Palatini formulation of scalar-tensor gravity
International Nuclear Information System (INIS)
Iglesias, Alberto; Kaloper, Nemanja; Park, Minjoon; Padilla, Antonio
2007-01-01
We revisit the problem of defining nonminimal gravity in the first order formalism. Specializing to scalar-tensor theories, which may be disguised as ''higher-derivative'' models with the gravitational Lagrangians that depend only on the Ricci scalar, we show how to recast these theories as Palatini-like gravities. The correct formulation utilizes the Lagrange multiplier method, which preserves the canonical structure of the theory, and yields the conventional metric scalar-tensor gravity. We explain the discrepancies between the naieve Palatini and the Lagrange multiplier approach, showing that the naieve Palatini approach really swaps the theory for another. The differences disappear only in the limit of ordinary general relativity, where an accidental redundancy ensures that the naieve Palatini approach works there. We outline the correct decoupling limits and the strong coupling regimes. As a corollary we find that the so-called ''modified source gravity'' models suffer from strong coupling problems at very low scales, and hence cannot be a realistic approximation of our universe. We also comment on a method to decouple the extra scalar using the chameleon mechanism
The Hamiltonian formulation of regular rth-order Lagrangian field theories
International Nuclear Information System (INIS)
Shadwick, W.F.
1982-01-01
A Hamiltonian formulation of regular rth-order Lagrangian field theories over an m-dimensional manifold is presented in terms of the Hamilton-Cartan formalism. It is demonstrated that a uniquely determined Cartan m-form may be associated to an rth-order Lagrangian by imposing conditions of congruence modulo a suitably defined system of contact m-forms. A geometric regularity condition is given and it is shown that, for a regular Lagrangian, the momenta defined by the Hamilton-Cartan formalism, together with the coordinates on the (r-1)st-order jet bundle, are a minimal set of local coordinates needed to express the Euler-Lagrange equations. When r is greater than one, the number of variables required is strictly less than the dimension of the (2r-1)st order jet bundle. It is shown that, in these coordinates, the Euler-Lagrange equations take the first-order Hamiltonian form given by de Donder. It is also shown that the geometrically natural generalization of the Hamilton-Jacobi procedure for finding extremals is equivalent to de Donder's Hamilton-Jacobi equation. (orig.)
Antunes, J; Debut, V
2017-02-01
Most musical instruments consist of dynamical subsystems connected at a number of constraining points through which energy flows. For physical sound synthesis, one important difficulty deals with enforcing these coupling constraints. While standard techniques include the use of Lagrange multipliers or penalty methods, in this paper, a different approach is explored, the Udwadia-Kalaba (U-K) formulation, which is rooted on analytical dynamics but avoids the use of Lagrange multipliers. This general and elegant formulation has been nearly exclusively used for conceptual systems of discrete masses or articulated rigid bodies, namely, in robotics. However its natural extension to deal with continuous flexible systems is surprisingly absent from the literature. Here, such a modeling strategy is developed and the potential of combining the U-K equation for constrained systems with the modal description is shown, in particular, to simulate musical instruments. Objectives are twofold: (1) Develop the U-K equation for constrained flexible systems with subsystems modelled through unconstrained modes; and (2) apply this framework to compute string/body coupled dynamics. This example complements previous work [Debut, Antunes, Marques, and Carvalho, Appl. Acoust. 108, 3-18 (2016)] on guitar modeling using penalty methods. Simulations show that the proposed technique provides similar results with a significant improvement in computational efficiency.
Bravo M., D. A.; Rengifo R., C. F.
2014-01-01
En este trabajo se propone una herramienta para la enseñanza de la mecánica clásica, modelando sistemas dinámicos con las ecuaciones de Lagrange, a partir de la simulación en Matlab ©. Este enfoque permite a los estudiantes de ingeniería y ciencias básicas, desarrollar competencias en programación, análisis numérico, con el uso de la física como herramienta fundamental para modelar y simular sistemas dinámicos complejos, como por ejemplo: robots industriales, robots bípedos y cualquier sistem...
Systematic Equation Formulation
DEFF Research Database (Denmark)
Lindberg, Erik
2007-01-01
A tutorial giving a very simple introduction to the set-up of the equations used as a model for an electrical/electronic circuit. The aim is to find a method which is as simple and general as possible with respect to implementation in a computer program. The “Modified Nodal Approach”, MNA, and th......, and the “Controlled Source Approach”, CSA, for systematic equation formulation are investigated. It is suggested that the kernel of the P Spice program based on MNA is reprogrammed....
International Nuclear Information System (INIS)
Tan, Sirui; Huang, Lianjie
2014-01-01
For modeling scalar-wave propagation in geophysical problems using finite-difference schemes, optimizing the coefficients of the finite-difference operators can reduce numerical dispersion. Most optimized finite-difference schemes for modeling seismic-wave propagation suppress only spatial but not temporal dispersion errors. We develop a novel optimized finite-difference scheme for numerical scalar-wave modeling to control dispersion errors not only in space but also in time. Our optimized scheme is based on a new stencil that contains a few more grid points than the standard stencil. We design an objective function for minimizing relative errors of phase velocities of waves propagating in all directions within a given range of wavenumbers. Dispersion analysis and numerical examples demonstrate that our optimized finite-difference scheme is computationally up to 2.5 times faster than the optimized schemes using the standard stencil to achieve the similar modeling accuracy for a given 2D or 3D problem. Compared with the high-order finite-difference scheme using the same new stencil, our optimized scheme reduces 50 percent of the computational cost to achieve the similar modeling accuracy. This new optimized finite-difference scheme is particularly useful for large-scale 3D scalar-wave modeling and inversion
Drug delivery and formulations.
Breitkreutz, Jörg; Boos, Joachim
2011-01-01
Paediatric drug delivery is a major challenge in drug development. Because of the heterogeneous nature of the patient group, ranging from newborns to adolescents, there is a need to use appropriate excipients, drug dosage forms and delivery devices for different age groups. So far, there is a lack of suitable and safe drug formulations for children, especially for the very young and seriously ill patients. The new EU legislation will enforce paediatric clinical trials and drug development. Current advances in paediatric drug delivery include interesting new concepts such as fast-dissolving drug formulations, including orodispersible tablets and oral thin strips (buccal wafers), and multiparticulate dosage forms based on mini-tabletting or pelletization technologies. Parenteral administration is likely to remain the first choice for children in the neonatal period and for emergency cases. Alternative routes of administration include transdermal, pulmonary and nasal drug delivery systems. A few products are already available on the market, but others still need further investigations and clinical proof of concept.
Ether formulations of relativity
International Nuclear Information System (INIS)
Duffy, M.C.
1980-01-01
Contemporary ether theories are surveyed and criticised, especially those formally identical to orthodox Relativity. The historical development of Relativity, Special and General, in terms of an ether, is briefly indicated. Classical interpretations of Generalized Relativity using ether are compared to Euclidean formulations using a background space. The history of a sub-group of theories, formulating a 'new' Relativity involving modified transforms, is outlined. According to the theory with which they agree, recent supposed detections of drift are classified and criticised. Cosmological evidence suggesting an ether is mentioned. Only ether theories formally identical to Relativity have been published in depth. They stand criticised as being contrary to the positivist spirit. The history of mechanical analogues is traced, from Hartley's representing gravitating matter as spherical standing waves, to recent suggestions that vortex-sponge might model electromagnetic, quantum, uncertainty and faster-than-light phenomena. Contemporary theories are particular physical theories, themselves 'second interpretations' of a primary mathematical model. Mechanical analogues are auxiliary, not necessary, to other theory, disclosing relationships between classical and non-classical descriptions of assemblies charging state. The ether-relativity polemic, part of a broader dispute about relativity, is founded on mistaken conceptions of the roles of mathematical and physical models, mechanical analogues; and a distored view of history, which indicates that ether theories have become relativistic. (author)
Energy Technology Data Exchange (ETDEWEB)
Olivares Pilón, Horacio, E-mail: holivare@ulb.ac.be [Physique Quantique, CP 165/82, Université Libre de Bruxelles, B 1050 Brussels (Belgium)
2012-04-09
Accurate calculations for the ground state of the molecular ions He{sup 3+}{sub 2} and HeH{sup 2+} placed in a strong magnetic field B≳10{sup 2} a.u. (≈2.35×10{sup 11} G) using the Lagrange-mesh method are presented. The Born–Oppenheimer approximation of zero order (infinitely massive centers) and the parallel configuration (molecular axis parallel to the magnetic field) are considered. Total energies are found with 9–10 s.d. The obtained results show that the molecular ions He{sup 3+}{sub 2} and HeH{sup 2+} exist at B>100 a.u. and B>1000 a.u., respectively, as predicted in Turbiner and López Vieyra (2007) while a saddle point in the potential curve appears for the first time at B∼80 a.u. and B∼740 a.u., respectively. -- Highlights: ► Application of the Lagrange-mesh method to two exotic molecular systems. ► He{sup 3+}{sub 2} and HeH{sup 2+} exist at B>100 a.u. and B>1000 a.u., respectively. ► Accurate results for the total energy. ► A saddle point in the potential appears at B∼80 a.u. and B∼740 a.u., respectively.
Zbožínek, Adam
2009-01-01
Tato práce uvádí základní pravidla a předpoklady pro konstrukci a použití vozů formule 1. Hlavní zaměření je na aerodynamiku, která je nejdůležitější disciplínou v tomto motoristickém sportu, dále je tato práce zaměřena na základní faktory týkající se motoru vozu, kol, nové technologie KERS a provedení volantu. This work shows basic rules and conditions for construction and use of cars formula 1. The main part of this work focus on the aerodynamics which is the most important discipline of...
Assessment of strategy formulation
DEFF Research Database (Denmark)
Acur, Nuran; Englyst, Linda
2006-01-01
of the success criteria through face-to-face interviews with 46 managers, workshops involving 40 managers, and two in-depth case studies. The success criteria have been slightly modified due to the empirical results, to yield the assessment tool. Findings – The resulting assessment tool integrates three generic...... approaches to strategy assessment, namely the goal-centred, comparative and improvement approaches, as found in the literature. Furthermore, it encompasses three phases of strategy formulation processes: strategic thinking, strategic planning and embedding of strategy. The tool reflects that the different......, but cases and managerial perceptions indicate that the need for accurate and detailed plans might be overrated in the literature, as implementation relies heavily on continuous improvement and empowerment. Concerning embedding, key aspects relate both to the goal-centred and improvement approaches, while...
Baseline LAW Glass Formulation Testing
International Nuclear Information System (INIS)
Kruger, Albert A.; Mooers, Cavin; Bazemore, Gina; Pegg, Ian L.; Hight, Kenneth; Lai, Shan Tao; Buechele, Andrew; Rielley, Elizabeth; Gan, Hao; Muller, Isabelle S.; Cecil, Richard
2013-01-01
The major objective of the baseline glass formulation work was to develop and select glass formulations that are compliant with contractual and processing requirements for each of the LAW waste streams. Other objectives of the work included preparation and characterization of glasses with respect to the properties of interest, optimization of sulfate loading in the glasses, evaluation of ability to achieve waste loading limits, testing to demonstrate compatibility of glass melts with melter materials of construction, development of glass formulations to support ILAW qualification activities, and identification of glass formulation issues with respect to contract specifications and processing requirements
Tóth, Balázs
2018-03-01
Some new dual and mixed variational formulations based on a priori nonsymmetric stresses will be developed for linearly coupled irreversible thermoelastodynamic problems associated with second sound effect according to the Lord-Shulman theory. Having introduced the entropy flux vector instead of the entropy field and defining the dissipation and the relaxation potential as the function of the entropy flux, a seven-field dual and mixed variational formulation will be derived from the complementary Biot-Hamilton-type variational principle, using the Lagrange multiplier method. The momentum-, the displacement- and the infinitesimal rotation vector, and the a priori nonsymmetric stress tensor, the temperature change, the entropy field and its flux vector are considered as the independent field variables of this formulation. In order to handle appropriately the six different groups of temporal prescriptions in the relaxed- and/or the strong form, two variational integrals will be incorporated into the seven-field functional. Then, eliminating the entropy from this formulation through the strong fulfillment of the constitutive relation for the temperature change with the use of the Legendre transformation between the enthalpy and Gibbs potential, a six-field dual and mixed action functional is obtained. As a further development, the elimination of the momentum- and the velocity vector from the six-field principle through the a priori satisfaction of the kinematic equation and the constitutive relation for the momentum vector leads to a five-field variational formulation. These principles are suitable for the transient analyses of the structures exposed to a thermal shock of short temporal domain or a large heat flux.
Novel Formulations for Antimicrobial Peptides
Directory of Open Access Journals (Sweden)
Ana Maria Carmona-Ribeiro
2014-10-01
Full Text Available Peptides in general hold much promise as a major ingredient in novel supramolecular assemblies. They may become essential in vaccine design, antimicrobial chemotherapy, cancer immunotherapy, food preservation, organs transplants, design of novel materials for dentistry, formulations against diabetes and other important strategical applications. This review discusses how novel formulations may improve the therapeutic index of antimicrobial peptides by protecting their activity and improving their bioavailability. The diversity of novel formulations using lipids, liposomes, nanoparticles, polymers, micelles, etc., within the limits of nanotechnology may also provide novel applications going beyond antimicrobial chemotherapy.
Novel Formulations for Antimicrobial Peptides
Carmona-Ribeiro, Ana Maria; Carrasco, Letícia Dias de Melo
2014-01-01
Peptides in general hold much promise as a major ingredient in novel supramolecular assemblies. They may become essential in vaccine design, antimicrobial chemotherapy, cancer immunotherapy, food preservation, organs transplants, design of novel materials for dentistry, formulations against diabetes and other important strategical applications. This review discusses how novel formulations may improve the therapeutic index of antimicrobial peptides by protecting their activity and improving their bioavailability. The diversity of novel formulations using lipids, liposomes, nanoparticles, polymers, micelles, etc., within the limits of nanotechnology may also provide novel applications going beyond antimicrobial chemotherapy. PMID:25302615
Directory of Open Access Journals (Sweden)
Musilová Jana
2016-12-01
Full Text Available As widely accepted, justified by the historical developments of physics, the background for standard formulation of postulates of physical theories leading to equations of motion, or even the form of equations of motion themselves, come from empirical experience. Equations of motion are then a starting point for obtaining specific conservation laws, as, for example, the well-known conservation laws of momenta and mechanical energy in mechanics. On the other hand, there are numerous examples of physical laws or equations of motion which can be obtained from a certain variational principle as Euler-Lagrange equations and their solutions, meaning that the \\true trajectories" of the physical systems represent stationary points of the corresponding functionals.
Neonates need tailored drug formulations.
Allegaert, Karel
2013-02-08
Drugs are very strong tools used to improve outcome in neonates. Despite this fact and in contrast to tailored perfusion equipment, incubators or ventilators for neonates, we still commonly use drug formulations initially developed for adults. We would like to make the point that drug formulations given to neonates need to be tailored for this age group. Besides the obvious need to search for active compounds that take the pathophysiology of the newborn into account, this includes the dosage and formulation. The dosage or concentration should facilitate the administration of low amounts and be flexible since clearance is lower in neonates with additional extensive between-individual variability. Formulations need to be tailored for dosage variability in the low ranges and also to the clinical characteristics of neonates. A specific focus of interest during neonatal drug development therefore is a need to quantify and limit excipient exposure based on the available knowledge of their safety or toxicity. Until such tailored vials and formulations become available, compounding practices for drug formulations in neonates should be evaluated to guarantee the correct dosing, product stability and safety.
Microcanonical formulation of quantum field theories
International Nuclear Information System (INIS)
Iwazaki, A.
1984-03-01
A microcanonical formulation of Euclidean quantum field theories is presented. In the formulation, correlation functions are given by a microcanonical ensemble average of fields. Furthermore, the perturbative equivalence of the formulation and the standard functional formulation is proved and the equipartition low is derived in our formulation. (author)
Tactile friction of topical formulations.
Skedung, L; Buraczewska-Norin, I; Dawood, N; Rutland, M W; Ringstad, L
2016-02-01
The tactile perception is essential for all types of topical formulations (cosmetic, pharmaceutical, medical device) and the possibility to predict the sensorial response by using instrumental methods instead of sensory testing would save time and cost at an early stage product development. Here, we report on an instrumental evaluation method using tactile friction measurements to estimate perceptual attributes of topical formulations. Friction was measured between an index finger and an artificial skin substrate after application of formulations using a force sensor. Both model formulations of liquid crystalline phase structures with significantly different tactile properties, as well as commercial pharmaceutical moisturizing creams being more tactile-similar, were investigated. Friction coefficients were calculated as the ratio of the friction force to the applied load. The structures of the model formulations and phase transitions as a result of water evaporation were identified using optical microscopy. The friction device could distinguish friction coefficients between the phase structures, as well as the commercial creams after spreading and absorption into the substrate. In addition, phase transitions resulting in alterations in the feel of the formulations could be detected. A correlation was established between skin hydration and friction coefficient, where hydrated skin gave rise to higher friction. Also a link between skin smoothening and finger friction was established for the commercial moisturizing creams, although further investigations are needed to analyse this and correlations with other sensorial attributes in more detail. The present investigation shows that tactile friction measurements have potential as an alternative or complement in the evaluation of perception of topical formulations. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Directory of Open Access Journals (Sweden)
Aksjonov Andrei
2015-12-01
Full Text Available The mathematical model of the three-dimensional crane using the Euler-Lagrange approach is derived. A state-space representation of the derived model is proposed and explored in the Simulink® environment and on the laboratory stand. The obtained control design was simulated, analyzed and compared with existing encoder-based system provided by the three-dimensional (3D Crane manufacturer Inteco®. As well, an anti-swing fuzzy logic control has been developed, simulated, and analyzed. Obtained control algorithm is compared with the existing anti-swing proportional-integral controller designed by the 3D crane manufacturer Inteco®. 5-degree of freedom (5DOF control schemes are designed, examined and compared with the various load masses. The topicality of the problem is due to the wide usage of gantry cranes in industry. The solution is proposed for the future research in sensorless and intelligent control of complex motor driven application.
Petrie, Gordon; Pevtsov, Alexei; Schwarz, Andrew; DeRosa, Marc
2018-06-01
The solar photospheric magnetic flux distribution is key to structuring the global solar corona and heliosphere. Regular full-disk photospheric magnetogram data are therefore essential to our ability to model and forecast heliospheric phenomena such as space weather. However, our spatio-temporal coverage of the photospheric field is currently limited by our single vantage point at/near Earth. In particular, the polar fields play a leading role in structuring the large-scale corona and heliosphere, but each pole is unobservable for {>} 6 months per year. Here we model the possible effect of full-disk magnetogram data from the Lagrange points L4 and L5, each extending longitude coverage by 60°. Adding data also from the more distant point L3 extends the longitudinal coverage much further. The additional vantage points also improve the visibility of the globally influential polar fields. Using a flux-transport model for the solar photospheric field, we model full-disk observations from Earth/L1, L3, L4, and L5 over a solar cycle, construct synoptic maps using a novel weighting scheme adapted for merging magnetogram data from multiple viewpoints, and compute potential-field models for the global coronal field. Each additional viewpoint brings the maps and models into closer agreement with the reference field from the flux-transport simulation, with particular improvement at polar latitudes, the main source of the fast solar wind.
Formulations of classical and quantum dynamical theory
Rosen, Gerald
1969-01-01
In this book, we study theoretical and practical aspects of computing methods for mathematical modelling of nonlinear systems. A number of computing techniques are considered, such as methods of operator approximation with any given accuracy; operator interpolation techniques including a non-Lagrange interpolation; methods of system representation subject to constraints associated with concepts of causality, memory and stationarity; methods of system representation with an accuracy that is the best within a given class of models; methods of covariance matrix estimation;methods for low-rank
Decontamination formulation with sorbent additive
Tucker; Mark D. , Comstock; Robert H.
2007-10-16
A decontamination formulation and method of making that neutralizes the adverse health effects of both chemical and biological compounds, especially chemical warfare (CW) and biological warfare (BW) agents, and toxic industrial chemicals. The formulation provides solubilizing compounds that serve to effectively render the chemical and biological compounds, particularly CW and BW compounds, susceptible to attack, and at least one reactive compound that serves to attack (and detoxify or kill) the compound. The formulation includes at least one solubilizing agent, a reactive compound, a bleaching activator, a sorbent additive, and water. The highly adsorbent, water-soluble sorbent additive (e.g., sorbitol or mannitol) is used to "dry out" one or more liquid ingredients, such as the liquid bleaching activator (e.g., propylene glycol diacetate or glycerol diacetate) and convert the activator into a dry, free-flowing powder that has an extended shelf life, and is more convenient to handle and mix in the field.
Curcumin nanodisks: formulation and characterization
Ghosh, Mistuni; Singh, Amareshwar T. K.; Xu, Wenwei; Sulchek, Todd; Gordon, Leo I.; Ryan, Robert O.
2010-01-01
Nanodisks (ND) are nanoscale, disk-shaped phospholipid bilayers whose edge is stabilized by apolipoproteins. In the present study, ND were formulated with the bioactive polyphenol, curcumin, at a 6:1 phospholipid:curcumin molar ratio. Atomic force microscopy revealed that curcumin-ND are particles with diameters
Covariant Formulation of Hooke's Law.
Gron, O.
1981-01-01
Introducing a four-vector strain and a four-force stress, Hooke's law is written as a four-vector equation. This formulation is shown to clarify seemingly paradoxical results in connection with uniformly accelerated motion, and rotational motion with angular acceleration. (Author/JN)
Hamiltonian formulation of the supermembrane
International Nuclear Information System (INIS)
Bergshoeff, E.; Sezgin, E.; Tanii, Y.
1987-06-01
The Hamiltonian formulation of the supermembrane theory in eleven dimensions is given. The covariant split of the first and second class constraints is exhibited, and their Dirac brackets are computed. Gauge conditions are imposed in such a way that the reparametrizations of the membrane with divergence free 2-vectors are unfixed. (author). 10 refs
Thermomechanical constraints and constitutive formulations in thermoelasticity
Directory of Open Access Journals (Sweden)
Baek S.
2003-01-01
Full Text Available We investigate three classes of constraints in a thermoelastic body: (i a deformation-temperature constraint, (ii a deformation-entropy constraint, and (iii a deformation-energy constraint. These constraints are obtained as limits of unconstrained thermoelastic materials and we show that constraints (ii and (iii are equivalent. By using a limiting procedure, we show that for the constraint (i, the entropy plays the role of a Lagrange multiplier while for (ii and (iii, the absolute temperature plays the role of Lagrange multiplier. We further demonstrate that the governing equations for materials subject to constraint (i are identical to those of an unconstrained material whose internal energy is an affine function of the entropy, while those for materials subject to constraints (ii and (iii are identical to those of an unstrained material whose Helmholtz potential is affine in the absolute temperature. Finally, we model the thermoelastic response of a peroxide-cured vulcanizate of natural rubber and show that imposing the constraint in which the volume change depends only on the internal energy leads to very good predictions (compared to experimental results of the stress and temperature response under isothermal and isentropic conditions.
Andrews, A. E.; Trudeau, M.; Hu, L.; Thoning, K. W.; Shiga, Y. P.; Michalak, A. M.; Benmergui, J. S.; Mountain, M. E.; Nehrkorn, T.; O'Dell, C.; Jacobson, A. R.; Miller, J.; Sweeney, C.; Chen, H.; Ploeger, F.; Tans, P. P.
2017-12-01
CarbonTracker-Lagrange (CT-L) is a regional inverse modeling system for estimating CO2 fluxes with rigorous uncertainty quantification. CT-L uses footprints from the Stochastic Time-Inverted Lagrangian Transport (STILT) model driven by high-resolution (10 to 30 km) meteorological fields from the Weather Research and Forecasting (WRF) model. We have computed a library of footprints corresponding to in situ and remote sensing measurements of CO2 over North America for 2007-2015. GOSAT and OCO-2 XCO2 retrievals are simulated using a suite of CT-L terrestrial ecosystem flux estimates that have been optimized with respect to in situ atmospheric CO2 measurements along with fossil fuel fluxes from emissions inventories. A vertical profile of STILT-WRF footprints was constructed corresponding to each simulated satellite retrieval, and CO2 profiles are generated by convolving the footprints with fluxes and attaching initial values advected from the domain boundaries. The stratospheric contribution to XCO2 has been estimated using 4-dimensional CO2 fields from the NOAA CarbonTracker model (version CT2016) and from the Chemical Lagrangian Model of the Stratosphere (CLaMS), after scaling the model fields to match data from the NOAA AirCore surface-to-stratosphere air sampling system. Tropospheric lateral boundary conditions are from CT2016 and from an empirical boundary value product derived from aircraft and marine boundary layer data. The averaging kernel and a priori CO2 profile are taken into account for direct comparisons with retrievals. We have focused on North America due to the relatively dense in situ measurements available with the aim of developing strategies for combined assimilation of in situ and remote sensing data. We will consider the extent to which interannual variability in terrestrial fluxes is manifest in the real and simulated satellite retrievals, and we will investigate possible systematic biases in the satellite retrievals and in the model.
Langevin formulation of quantum dynamics
International Nuclear Information System (INIS)
Roncadelli, M.
1989-03-01
We first show that nonrelativistic quantum mechanics formulated at imaginary-(h/2 π) can formally be viewed as the Fokker-Planck description of a frictionless brownian motion, which occurs (in general) in an absorbing medium. We next offer a new formulation of quantum mechanics, which is basically the Langevin treatment of this brownian motion. Explicitly, we derive a noise-average representation for the transition probability W(X'',t''|X',t'), in terms of the solutions to a Langevin equation with a Gaussian white-noise. Upon analytic continuation back to real-(h/2 π),W(X'',t''|X',t') becomes the propagator of the original Schroedinger equation. Our approach allows for a straightforward application to quantum dynamical problems of the mathematical techniques of classical stochastic processes. Moreover, computer simulations of quantum mechanical systems can be carried out by using numerical programs based on the Langevin dynamics. (author). 19 refs, 1 tab
Optimization of chlorphenesin emulgel formulation
Mohamed, Magdy I.
2004-01-01
This study was conducted to develop an emulgel formulation of chlorphenesin (CHL) using 2 types of gelling agents: hydroxypropylmethyl cellulose (HPMC) and Carbopol 934. The influence of the type of the gelling agent and the concentration of both the oil phase and emulsifying agent on the drug release from the prepared emulgels was investigated using a 23 factorial design. The prepared emulgels were evaluated for their physical appearance, rheological behavior, drug release, antifungal activi...
Variational formulation for dissipative continua and an incremental J-integral
Rahaman, Md. Masiur; Dhas, Bensingh; Roy, D.; Reddy, J. N.
2018-01-01
Our aim is to rationally formulate a proper variational principle for dissipative (viscoplastic) solids in the presence of inertia forces. As a first step, a consistent linearization of the governing nonlinear partial differential equations (PDEs) is carried out. An additional set of complementary (adjoint) equations is then formed to recover an underlying variational structure for the augmented system of linearized balance laws. This makes it possible to introduce an incremental Lagrangian such that the linearized PDEs, including the complementary equations, become the Euler-Lagrange equations. Continuous groups of symmetries of the linearized PDEs are computed and an analysis is undertaken to identify the variational groups of symmetries of the linearized dissipative system. Application of Noether's theorem leads to the conservation laws (conserved currents) of motion corresponding to the variational symmetries. As a specific outcome, we exploit translational symmetries of the functional in the material space and recover, via Noether's theorem, an incremental J-integral for viscoplastic solids in the presence of inertia forces. Numerical demonstrations are provided through a two-dimensional plane strain numerical simulation of a compact tension specimen of annealed mild steel under dynamic loading.
Parks, Helen Frances
This dissertation presents two projects related to the structured integration of large-scale mechanical systems. Structured integration uses the considerable differential geometric structure inherent in mechanical motion to inform the design of numerical integration schemes. This process improves the qualitative properties of simulations and becomes especially valuable as a measure of accuracy over long time simulations in which traditional Gronwall accuracy estimates lose their meaning. Often, structured integration schemes replicate continuous symmetries and their associated conservation laws at the discrete level. Such is the case for variational integrators, which discretely replicate the process of deriving equations of motion from variational principles. This results in the conservation of momenta associated to symmetries in the discrete system and conservation of a symplectic form when applicable. In the case of Lagrange-Dirac systems, variational integrators preserve a discrete analogue of the Dirac structure preserved in the continuous flow. In the first project of this thesis, we extend Dirac variational integrators to accommodate interconnected systems. We hope this work will find use in the fields of control, where a controlled system can be thought of as a "plant" system joined to its controller, and in the approach of very large systems, where modular modeling may prove easier than monolithically modeling the entire system. The second project of the thesis considers a different approach to large systems. Given a detailed model of the full system, can we reduce it to a more computationally efficient model without losing essential geometric structures in the system? Asked without the reference to structure, this is the essential question of the field of model reduction. The answer there has been a resounding yes, with Principal Orthogonal Decomposition (POD) with snapshots rising as one of the most successful methods. Our project builds on previous work
Nevison, C. D.; Andrews, A. E.; Thoning, K. W.; Dlugokencky, E. J.; Sweeney, C.; Saikawa, E.; Miller, S. M.; Benmergui, J. S.; Fischer, M. L.
2017-12-01
North American nitrous oxide (N2O) emissions of 1.5 ± 0.2 Tg N/yr over 2008-2013 are estimated using the Carbon Tracker-Lagrange (CT-L) regional inversion framework. The estimated N2O emissions are largely consistent with the EDGAR global inventory and with the results of global atmospheric inversions, but offer more spatial and temporal detail and improved uncertainty quantification over North America. Emissions are strongest from the Midwestern corn/soybean belt, which accounts for about one fourth of the total North American N2O source. The emissions are maximum in spring/early summer, consistent with a nitrogen fertilizer-driven source, but also show a late winter spike suggestive of freeze-thaw effects. Interannual variability in emissions across the primary months of fertilizer application is positively correlated to mean soil moisture and precipitation. The inversion results, in combination with gridded N fertilizer datasets, are used to estimate the fraction of synthetic N fertilizer that is released as N2O. The estimated N2O flux from the Midwestern corn/soybean belt and the more northerly U.S./Canadian wheat belt corresponds to 3.6-4.5% and 1.4-3.5%, respectively, of total synthetic + organic N fertilizer applied to those regions. Consideration of additional N inputs from soybean N2 fixation reduces the N2O yield from the Midwestern corn/soybean belt to 2-2.6% of total N inputs. Figure 1. Posterior N2O flux integrated over the central Midwestern Corn/Soybean belt (38° to 43°N, 102° to 80°W, in grids where 5% or more of land area was planted in corn and/or soybean). Cases 1 (red) and 2 (blue) are defined based on different covariance matrix parameters, representing alternative scenarios of tighter prior/looser model-data mismatch and looser prior/tighter model-data mismatch. Both cases use a standard prior derived from a coarser resolution global inversion. Triangles show the approximate day when soil temperature climbs above 0°C and drops below 10
Perfume formulation: words and chats.
Ellena, Céline
2008-06-01
What does it mean to create fragrances with materials from chemistry and/or from nature? How are they used to display their characteristic differences, their own personality? Is it easier to create with synthetic raw materials or with essential oils? This review explains why a perfume formulation corresponds in fact to a conversation, an interplay between synthetic and natural perfumery materials. A synthetic raw material carries a single information, and usually is very linear. Its smell is uniform, clear, and faithful. Natural raw materials, on the contrary, provide a strong, complex and generous image. While a synthetic material can be seen as a single word, a natural one such as rose oil could be compared to chatting: cold, warm, sticky, heavy, transparent, pepper, green, metallic, smooth, watery, fruity... full of information. Yet, if a very small amount of the natural material is used, nothing happens, the fragrance will not change. However, if a large amount is used, the rose oil will swallow up everything else. The fragrance will smell of nothing else except rose! To formulate a perfume is not to create a culinary recipe, with only dosing the ingredients in well-balanced amounts. To formulate rather means to flexibly knit materials together with a lively stitch, meeting or repelling each other, building a pleasant form, which is neither fixed, nor solid, nor rigid. A fragrance has an overall structure, which ranges from a clear sound, made up of stable, unique, and linear items, to a background chat, comfortable and reassuring. But that does, of course, not mean that there is only one way of creating a fragrance!
Formulation of soy oil products
Directory of Open Access Journals (Sweden)
Woerfel, John B.
1995-12-01
Full Text Available The paper comments different formulations of soy oil products such as salad and cooking oils, margarine, shortenings, commercial shortenings, frying shortenings, and fluid shortenings. Hydrogenation and its influence on final products is also included.
El trabajo presenta diferentes formulaciones a base de aceite de soja tales como aceites para ensalada y cocinado, margarina, grasas sólidas (shortenings, grasas sólidas comerciales, grasas sólidas para frituras y grasas fluidas. Hace también referencia al proceso de hidrogenación y a sus efectos en los productos finales.
Formulation and Characterization of Sustained Release Floating ...
African Journals Online (AJOL)
Purpose: To formulate sustained release gastroretentive microballoons of metformin hydrochloride with the objective of improving its bioavailability. Methods: Microballoons of metformin hydrochloride were formulated by solvent evaporation and diffusion method using varying mixtures of hydroxypropyl methylcellulose ...
Bioequivalence assessment of two formulations of ibuprofen
Al-Talla, Zeyad; Akrawi, Sabah H; Tolley, Luke T; Sioud, Salim H; Zaater, Mohammed F; Emwas, Abdul-Hamid M
2011-01-01
Background: This study assessed the relative bioavailability of two formulations of ibuprofen. The first formulation was Doloraz , produced by Al-Razi Pharmaceutical Company, Amman, Jordan. The second forumulation was Brufen , manufactured by Boots
Modern approach to relativity theory (radar formulation)
International Nuclear Information System (INIS)
Strel'tsov, V.N.
1991-01-01
The main peculiarities of the radar formulation of the relativity theory are presented. This formulation operates with the retarded (light) distances and relativistic or radar length introduced on their basis. 21 refs.; 1 tab
Formulation, Preparation, and Characterization of Polyurethane Foams
Pinto, Moises L.
2010-01-01
Preparation of laboratory-scale polyurethane foams is described with formulations that are easy to implement in experiments for undergraduate students. Particular attention is given to formulation aspects that are based on the main chemical reactions occurring in polyurethane production. This allows students to develop alternative formulations to…
Performance Evaluation of Abrasive Grinding Wheel Formulated ...
African Journals Online (AJOL)
This paper presents a study on the formulation and manufacture of abrasive grinding wheel using locally formulated silicon carbide abrasive grains. Six local raw material substitutes were identified through pilot study and with the initial mix of the identified materials, a systematic search for an optimal formulation of silicon ...
Optimization of chlorphenesin emulgel formulation.
Mohamed, Magdy I
2004-10-11
This study was conducted to develop an emulgel formulation of chlorphenesin (CHL) using 2 types of gelling agents: hydroxypropylmethyl cellulose (HPMC) and Carbopol 934. The influence of the type of the gelling agent and the concentration of both the oil phase and emulsifying agent on the drug release from the prepared emulgels was investigated using a 2(3) factorial design. The prepared emulgels were evaluated for their physical appearance, rheological behavior, drug release, antifungal activity, and stability. Commercially available CHL topical powder was used for comparison. All the prepared emulgels showed acceptable physical properties concerning color, homogeneity, consistency, spreadability, and pH value. They also exhibited higher drug release and antifungal activity than the CHL powder. It was found that the emulsifying agent concentration had the most pronounced effect on the drug release from the emulgels followed by the oil phase concentration and finally the type of the gelling agent. The drug release from all the emulgels was found to follow diffusion-controlled mechanism. Rheological studies revealed that the CHL emulgels exhibited a shear-thinning behavior with thixotropy. Stability studies showed that the physical appearance, rheological properties, drug release, and antifungal activity in all the prepared emulgels remained unchanged upon storage for 3 months. As a general conclusion, it was suggested that the CHL emulgel formulation prepared with HPMC with the oil phase concentration in its low level and emulsifying agent concentration in its high level was the formula of choice since it showed the highest drug release and antifungal activity.
Formulation development for PREPP concreted waste forms
International Nuclear Information System (INIS)
Neilson, R.M. Jr.; Welch, J.M.
1984-05-01
Analysis of variance and logistic regression techniques have been used to develop models describing the effects of formulation variables and their interactions on compressive strength, solidification, free-standing water, and workability of hydraulic cement grouts incorporating simulated Process Experimental Pilot Plant (PREPP) wastes. These models provide the basis for specifications of grout formulations to solidify these wastes. The experimental test matrix, formulation preparation, and test methods employed are described. The development of analytical models for formulation behavior and the conclusions drawn regarding appropriate formulation variable ranges are discussed. 13 references, 9 figures, 15 tables
Energy policy formulation for Pakistan
International Nuclear Information System (INIS)
Riaz, T.
1981-01-01
Pakistan is a low income, low energy consumption country. In view of the close interdependence between economic growth and energy consumption, she will need increasing energy supplies in order to maintain her economic growth. This paper develops an energy sector optimization model for the Pakistan economy, which consists of production models for five energy industries, ie oil, gas, coal, electricity (including electricity generated in nuclear power plants) and non-commercial fuels. The model is first used to forecast energy balances for the period 1975 - 2006. The model is then employed to formulate a long-term comprehensive energy policy for Pakistan. Finally the suggested policy is compared with the current official energy programme. (author)
On Scalar Energy: Mathematical Formulation
International Nuclear Information System (INIS)
Hathout, A.M.
2011-01-01
A new kind of electromagnetic waves (EMW), which exists only in vacuum of the empty space, will be discussed and mathematically formulated in this paper. The mathematical existence of this energy was first proposed in a series of groundbreaking equations by Scottish Mathematician, James Clerk Maxwell, in the mid of 1800 and 39;s. This energy is called scalar energy. It is characterized by both particle and wave like. The waves of this energy are called longitudinal EMW to distinguish them from transverse EM, the kind we are familiar with in our daily life. Teslas name of this energy is scalar energy or zero point energy. It is aimed at this paper to explain more details and to verify the scalar EM concept in vacuum.
Slag-based saltstone formulations
International Nuclear Information System (INIS)
Langton, C.A.
1987-01-01
Approximately 400 x 10 6 liters of low-level alkaline salt solution will be treated at the Savannah River Plant (SRP) Defense Waste Processing Facility (DWPF) prior to disposal in concrete vaults at SRP. Treatment involves removal of CS + and Sr +2 followed by solidification and stabilization of potential contaminants in saltstone, a hydrated ceramic waste form. Chromium, technetium, and nitrate releases from saltstone can be significantly reduced by substituting hydraulic blast furnace slag for portland cement in the formulation designs. Slag-based mixes are also compatible with Class F fly ash used in saltstone as a functional extender to control heat of hydration and reduce permeability. A monolithic waste form is produced by the hydration of the slag and fly ash. Soluble ion release (NO 3 - ) is controlled by the saltstone microstructure. Chromium and technetium are less leachable from slag mixes compared to cement-based waste forms because these species are chemically reduced to a lower valence state by ferrous iron in the slag and precipitated as relatively insoluble phases, such as CR(OH) 3 and TcO 2 . 5 refs., 4 figs., 4 tabs
Slag-based saltstone formulations
International Nuclear Information System (INIS)
Langton, C.A.
1987-08-01
Approximately 400 x 10 6 L of low-level alkaline salt solution will be treated at the Savannah River Plant (SRP) Defense Waste Processing Facility (DWPF) prior to disposal in concrete vaults at SRP. Treatment involves removal of Cs + and Sr +2 , followed by solidification and stabilization of potential contaminants in saltstone, a hydrated ceramic wasteform. Chromium, technetium, and nitrate releases from saltstone can be significantly reduced by substituting hydraulic blast furnace slag for portland cement in the formulation designs. Slag-based mixes are also compatible with the Class F flyash used in saltstone as a functional extender to control heat of hydration and reduce permeability. (Class F flyash is also locally available at SRP.) A monolithic wasteform is produced by the hydration of the slag and flyash. Soluble ion release (NO 3- ) is controlled by the saltstone microstructure. Chromium and technetium are less leachable from slag mixes because these species are chemically reduced to a lower valence state by ferrous iron in the slag and are precipitated as relatively insoluble phases, such as Cr(OH) 3 and TcO 2 . 3 refs., 3 figs., 2 tabs
Policy formulation of public acceptance
International Nuclear Information System (INIS)
Kasai, Akihiro
1978-01-01
Since 1970, the new policy formulation for public acceptance of the new consideration on the location of electric power generation has been set and applied. The planning and the enforcement being conducted by local public organizations for the local economic build-up with plant location and also the adjustement of the requirements for fishery are two main specific characters in this new policy. The background of this new public acceptance policy, the history and the actual problems about the compensation for the location of power generation plants are reviewed. One new proposal, being recommended by the Policy and Science Laboratory to MITI in 1977 is explained. This is based on the method of promoting the location of power generation plants by public participation placing the redevelopment of regional societies as its basis. The problems concerning the industrial structures in farm villages, fishing villages and the areas of commerce and industry should be systematized, and explained from the viewpoint of outside impact, the characteristics of local areas and the location problems in this new proposal. Finally, the location process and its effectiveness should be put in order. (Nakai, Y.)
Hamiltonian formulation of reduced magnetohydrodynamics
International Nuclear Information System (INIS)
Morrison, P.J.; Hazeltine, R.D.
1983-07-01
Reduced magnetohydrodynamics (RMHD) has become a principal tool for understanding nonlinear processes, including disruptions, in tokamak plasmas. Although analytical studies of RMHD turbulence have been useful, the model's impressive ability to simulate tokamak fluid behavior has been revealed primarily by numerical solution. The present work describes a new analytical approach, not restricted to turbulent regimes, based on Hamiltonian field theory. It is shown that the nonlinear (ideal) RMHD system, in both its high-beta and low-beta versions, can be expressed in Hanmiltonian form. Thus a Poisson bracket, [ , ], is constructed such that each RMHD field quantitity, xi/sub i/, evolves according to xi/sub i/ = [xi/sub i/,H], where H is the total field energy. The new formulation makes RMHD accessible to the methodology of Hamiltonian mechanics; it has lead, in particular, to the recognition of new RMHD invariants and even exact, nonlinear RMHD solutions. A canonical version of the Poisson bracket, which requires the introduction of additional fields, leads to a nonlinear variational principle for time-dependent RMHD
Formulation of disperse systems science and technology
Tadros, Tharwat F
2014-01-01
This book presents comprehensively the science and technology behind the formulation of disperse systems like emulsions, suspensions, foams and others. Starting with a general introduction, the book covers a broad range of topics like the role of different classes of surfactants, stability of disperse systems, formulation of different dispersions, evaluation of formulations and many more. Many examples are included, too. Written by the experienced author and editor Tharwart Tadros, this book is indispensable for every scientist working in the field.
Formulated arthropod cadavers for pest suppression
2001-01-01
Pesticidal and/or antimicrobial biological agent-infected arthropod cadavers are formulated by applying a coating agent once on the surface of the cadaver which either (a) prevents the cadavers from sticking together and/or rupturing or (b) acts as an adhesive for a powder or granule applied to the cadaver to prevent sticking and rupturing. The formulated cadavers maintain or improve infectivity, reproducibility, and survivability. The formulated cadavers can be partially desiccated to improv...
Multiple excitation of supports - Part 1. Formulation
International Nuclear Information System (INIS)
Galeao, A.C.N.R.; Barbosa, H.J.C.
1980-12-01
The formulation and the solution of a simple specific problem of support movement are presented. The formulation is extended to the general case of infinitesimal elasticity where the approximated solutions are obtained by the variational formulation with spatial discretization by Finite Element Method. Finally, the present usual numerical techniques for the treatment of the resulting ordinary differential equations system are discused: Direct integration, Modal overlap, Spectral response. (E.G.) [pt
Superspace formulation of new nonlinear sigma models
International Nuclear Information System (INIS)
Gates, S.J. Jr.
1983-07-01
The superspace formulation of two classes of supersymmetric nonlinear σ-models are presented. Two alternative N=1 superspace formulations are given for the d=2 supersymmetric nonlinear σ-models with Killing vector potentials: (a) formulation uses an active central charge and, (b) formulation uses a spurion superfield without inducing a classical breakdown of supersymmetry. The N=2 vector multiplet is used to construct a new class of d=4 nonlinear σ-models which when reduced to d=2 possess N=4 supersymmetry. Implications of these two classes of nonlinear σ-models for N>=4 superfield supergravity are discussed. (author)
Directory of Open Access Journals (Sweden)
Pål Johan From
2012-04-01
Full Text Available This paper presents the explicit dynamic equations of a mechanical system. The equations are presented so that they can easily be implemented in a simulation software or controller environment and are also well suited for system and controller analysis. The dynamics of a general mechanical system consisting of one or more rigid bodies can be derived from the Lagrangian. We can then use several well known properties of Lie groups to guarantee that these equations are well defined. This will, however, often lead to rather abstract formulation of the dynamic equations that cannot be implemented in a simulation software directly. In this paper we close this gap and show what the explicit dynamic equations look like. These equations can then be implemented directly in a simulation software and no background knowledge on Lie theory and differential geometry on the practitioner's side is required. This is the first of two papers on this topic. In this paper we derive the dynamics for single rigid bodies, while in the second part we study multibody systems. In addition to making the equations more accessible to practitioners, a motivation behind the papers is to correct a few errors commonly found in literature. For the first time, we show the detailed derivations and how to arrive at the correct set of equations. We also show through some simple examples that these correspond with the classical formulations found from Lagrange's equations. The dynamics is derived from the Boltzmann--Hamel equations of motion in terms of local position and velocity variables and the mapping to the corresponding quasi-velocities. Finally we present a new theorem which states that the Boltzmann--Hamel formulation of the dynamics is valid for all transformations with a Lie group topology. This has previously only been indicated through examples, but here we also present the formal proof. The main motivation of these papers is to allow practitioners not familiar with
Glass Ceramic Formulation Data Package
International Nuclear Information System (INIS)
Crum, Jarrod V.; Rodriguez, Carmen P.; McCloy, John S.; Vienna, John D.; Chung, Chul-Woo
2012-01-01
A glass ceramic waste form is being developed for treatment of secondary waste streams generated by aqueous reprocessing of commercial used nuclear fuel (Crum et al. 2012b). The waste stream contains a mixture of transition metals, alkali, alkaline earths, and lanthanides, several of which exceed the solubility limits of a single phase borosilicate glass (Crum et al. 2009; Caurant et al. 2007). A multi-phase glass ceramic waste form allows incorporation of insoluble components of the waste by designed crystallization into durable heat tolerant phases. The glass ceramic formulation and processing targets the formation of the following three stable crystalline phases: (1) powellite (XMoO4) where X can be (Ca, Sr, Ba, and/or Ln), (2) oxyapatite Yx,Z(10-x)Si6O26 where Y is alkaline earth, Z is Ln, and (3) lanthanide borosilicate (Ln5BSi2O13). These three phases incorporate the waste components that are above the solubility limit of a single-phase borosilicate glass. The glass ceramic is designed to be a single phase melt, just like a borosilicate glass, and then crystallize upon slow cooling to form the targeted phases. The slow cooling schedule is based on the centerline cooling profile of a 2 foot diameter canister such as the Hanford High-Level Waste canister. Up to this point, crucible testing has been used for glass ceramic development, with cold crucible induction melter (CCIM) targeted as the ultimate processing technology for the waste form. Idaho National Laboratory (INL) will conduct a scaled CCIM test in FY2012 with a glass ceramic to demonstrate the processing behavior. This Data Package documents the laboratory studies of the glass ceramic composition to support the CCIM test. Pacific Northwest National Laboratory (PNNL) measured melt viscosity, electrical conductivity, and crystallization behavior upon cooling to identify a processing window (temperature range) for melter operation and cooling profiles necessary to crystallize the targeted phases in the
A New Resistance Formulation for Carbon Nanotubes
Directory of Open Access Journals (Sweden)
Ji-Huan He
2008-01-01
Full Text Available A new resistance formulation for carbon nanotubes is suggested using fractal approach. The new formulation is also valid for other nonmetal conductors including nerve fibers, conductive polymers, and molecular wires. Our theoretical prediction agrees well with experimental observation.
Advanced Query Formulation in Deductive Databases.
Niemi, Timo; Jarvelin, Kalervo
1992-01-01
Discusses deductive databases and database management systems (DBMS) and introduces a framework for advanced query formulation for end users. Recursive processing is described, a sample extensional database is presented, query types are explained, and criteria for advanced query formulation from the end user's viewpoint are examined. (31…
Aerosol formulation and clinical efficacy of bronchodilators
Zanen, Pieter
1998-01-01
This thesis subject is the improvement of the formulation of inhaled aerosols. It is well known that the formulation of inhaled drugs is not optimal: the major part of the mass delivered does not reach the lower airways. This phenomenon is due to the particle size of the inhaled particles, which
Hamiltonian formulation of anomaly free chiral bosons
International Nuclear Information System (INIS)
Abdalla, E.; Abdalla, M.C.B.; Devecchi, F.P.; Zadra, A.
1988-01-01
Starting out of an anomaly free Lagrangian formulation for chiral scalars, which a Wess-Zumino Term (to cancel the anomaly), we formulate the corresponding hamiltonian problem. Ther we use the (quantum) Siegel invariance to choose a particular, which turns out coincide with the obtained by Floreanini and Jackiw. (author) [pt
Undefined cellulase formulations hinder scientific reproducibility.
Himmel, Michael E; Abbas, Charles A; Baker, John O; Bayer, Edward A; Bomble, Yannick J; Brunecky, Roman; Chen, Xiaowen; Felby, Claus; Jeoh, Tina; Kumar, Rajeev; McCleary, Barry V; Pletschke, Brett I; Tucker, Melvin P; Wyman, Charles E; Decker, Stephen R
2017-01-01
In the shadow of a burgeoning biomass-to-fuels industry, biological conversion of lignocellulose to fermentable sugars in a cost-effective manner is key to the success of second-generation and advanced biofuel production. For the effective comparison of one cellulase preparation to another, cellulase assays are typically carried out with one or more engineered cellulase formulations or natural exoproteomes of known performance serving as positive controls. When these formulations have unknown composition, as is the case with several widely used commercial products, it becomes impossible to compare or reproduce work done today to work done in the future, where, for example, such preparations may not be available. Therefore, being a critical tenet of science publishing, experimental reproducibility is endangered by the continued use of these undisclosed products. We propose the introduction of standard procedures and materials to produce specific and reproducible cellulase formulations. These formulations are to serve as yardsticks to measure improvements and performance of new cellulase formulations.
Formulation of heat absorbing glasses
Directory of Open Access Journals (Sweden)
Álvarez-Casariego, Pedro
1996-06-01
Full Text Available In the thermal exchanges between buildings and environment, glazing is an element of major importance, for it largely influences the so-called Solar Heat Gain and Thermal Losses. These parameters can be modified by applying different type of coatings onto glass surface or by adding colorant compounds during glass melting.
The latter is a cheaper way to control the Solar Heat Gain. The knowledge of the laws governing the interaction between colorant compounds and solar radiation, allows us to define glass formulations achieving specific aesthetic requirements and solar energy absorption.
In this paper two examples of application of the modelling of glass colorants spectral absorptance are presented. First is addressed to obtaining a glass with high luminous transmittance and low solar energy transmittance, and the other one to obtaining a glass with neutral colour appearance and minimized solar energy transmittance. Calculation formulas are defined together with photometric properties so-obtained. These type of glasses are particularly suitable to be used as building and automotive glazing, for they retain the mechanical characteristics and possibilities of transformation of standard glass.
En los intercambios de energía entre un edificio y el medio exterior, el vidrio es el elemento de mayor importancia, por su influencia en la Ganancia de Calor Solar y en las Pérdidas Térmicas. Estos parámetros pueden ser modificados mediante el depósito de capas sobre el vidrio o mediante la adición de compuestos absorbentes de la radiación solar.
Esta última vía es la más económica para controlar la Ganancia de Calor Solar. El conocimiento de las leyes que gobiernan la interacción de los diversos colorantes con la radiación solar, permite definir formulaciones de vidrios con características especificas de tipo estético y de absorción energética.
En este trabajo se presentan dos ejemplos de aplicación de esta modelización de las
Canonical operator formulation of nonequilibrium thermodynamics
International Nuclear Information System (INIS)
Mehrafarin, M.
1992-09-01
A novel formulation of nonequilibrium thermodynamics is proposed which emphasises the fundamental role played by the Boltzmann constant k in fluctuations. The equivalence of this and the stochastic formulation is demonstrated. The k → 0 limit of this theory yields the classical deterministic description of nonequilibrium thermodynamics. The new formulation possesses unique features which bear two important results namely the thermodynamic uncertainty principle and the quantisation of entropy production rate. Such a theory becomes indispensable whenever fluctuations play a significant role. (author). 7 refs
Application of UV Imaging in Formulation Development
DEFF Research Database (Denmark)
Sun, Yu; Østergaard, Jesper
2017-01-01
defining formulation behavior after exposure to the aqueous environments and pharmaceutical performance is critical in pharmaceutical development, manufacturing and quality control of drugs. UV imaging has been explored as a tool for qualitative and quantitative characterization of drug dissolution...... related to the structural properties of the drug substance or formulation can be monitored. UV imaging is a non-intrusive and simple-to-operate analytical technique which holds potential for providing a mechanistic foundation for formulation development. This review aims to cover applications of UV...
Formulation of 11-dimensional supergravity in superspace
International Nuclear Information System (INIS)
Cremmer, E.; Ferrara, S.
1980-01-01
We formulate on-shell 11-dimensional supergravity in superspace and express its equations of motion in terms of purely geometrical quantities. All torsion and curvature components are solved in terms of a single superfield Wsub(rstu), totally antisymmetric in its (flat vector) indices. The dimensional reduction of this formulation is expected to be related to the superspace formulation of N = 8 extended supergravity and might explain the origin of the hidden (local) SU(8) and (global) E 7 symmetries present in this theory. (orig.)
An exact approach for aggregated formulations
DEFF Research Database (Denmark)
Gamst, Mette; Spoorendonk, Simon; Røpke, Stefan
Aggregating formulations is a powerful approach for problems to take on tractable forms. Aggregation may lead to loss of information, i.e. the aggregated formulation may be an approximation of the original problem. In branch-and-bound context, aggregation can also complicate branching, e.g. when...... optimality cannot be guaranteed by branching on aggregated variables. We present a generic exact solution method to remedy the drawbacks of aggregation. It combines the original and aggregated formulations and applies Benders' decomposition. We apply the method to the Split Delivery Vehicle Routing Problem....
Chemical-Based Formulation Design: Virtual Experimentation
DEFF Research Database (Denmark)
Conte, Elisa; Gani, Rafiqul
This paper presents a software, the virtual Product-Process Design laboratory (virtual PPD-lab) and the virtual experimental scenarios for design/verification of consumer oriented liquid formulated products where the software can be used. For example, the software can be employed for the design......, the additives and/or their mixtures (formulations). Therefore, the experimental resources can focus on a few candidate product formulations to find the best product. The virtual PPD-lab allows various options for experimentations related to design and/or verification of the product. For example, the selection...... design, model adaptation). All of the above helps to perform virtual experiments by blending chemicals together and observing their predicted behaviour. The paper will highlight the application of the virtual PPD-lab in the design and/or verification of different consumer products (paint formulation...
Understanding Pesticide Risks: Toxicity and Formulation
Muntz, Helen; Miller, Rhonda; Alston, Diane
2016-01-01
This fact sheet provides information about pesticide risks to human health, primary means of pesticide exposure, standardized measures of pesticide toxicity, pesticide signal words and type of pesticide formulations.
Emulsifying Formulation of Rosuvastatin Calcium for Improved ...
African Journals Online (AJOL)
solubility study, liquid formulations were prepared using LAS/Capryol 90: Maisine 35-1 as oil phase and. Tween 20 with ... evaluated for globule size, zeta potential, and emulsion properties. ..... surfactants which decreases the electrostatic.
Drug Nanoparticle Formulation Using Ascorbic Acid Derivatives
Directory of Open Access Journals (Sweden)
Kunikazu Moribe
2011-01-01
Full Text Available Drug nanoparticle formulation using ascorbic acid derivatives and its therapeutic uses have recently been introduced. Hydrophilic ascorbic acid derivatives such as ascorbyl glycoside have been used not only as antioxidants but also as food and pharmaceutical excipients. In addition to drug solubilization, drug nanoparticle formation was observed using ascorbyl glycoside. Hydrophobic ascorbic acid derivatives such as ascorbyl mono- and di-n-alkyl fatty acid derivatives are used either as drugs or carrier components. Ascorbyl n-alkyl fatty acid derivatives have been formulated as antioxidants or anticancer drugs for nanoparticle formulations such as micelles, microemulsions, and liposomes. ASC-P vesicles called aspasomes are submicron-sized particles that can encapsulate hydrophilic drugs. Several transdermal and injectable formulations of ascorbyl n-alkyl fatty acid derivatives were used, including ascorbyl palmitate.
Dynamic psychiatry and the psychodynamic formulation
African Journals Online (AJOL)
processes and psychiatric disorders are biological, the range ... The formulation furthermore helps with the initial orientation towards the patient: it anticipates and predicts how the patient ..... contributed to problems with his sexual identity.
Formulation of Thermosensitive Hydrogel Containing Cyclodextrin ...
African Journals Online (AJOL)
Materials. Chitosan (deacetylation degree, DDA = 80 %) was obtained from HiMedia Laboratories Pvt. ... Sterile formulations were ... Chilled β-GP aqueous solution (sterilized through ..... generally decreasing away from the center of the tumor.
Current advances on polynomial resultant formulations
Sulaiman, Surajo; Aris, Nor'aini; Ahmad, Shamsatun Nahar
2017-08-01
Availability of computer algebra systems (CAS) lead to the resurrection of the resultant method for eliminating one or more variables from the polynomials system. The resultant matrix method has advantages over the Groebner basis and Ritt-Wu method due to their high complexity and storage requirement. This paper focuses on the current resultant matrix formulations and investigates their ability or otherwise towards producing optimal resultant matrices. A determinantal formula that gives exact resultant or a formulation that can minimize the presence of extraneous factors in the resultant formulation is often sought for when certain conditions that it exists can be determined. We present some applications of elimination theory via resultant formulations and examples are given to explain each of the presented settings.
Formulation and Characterization of Biodegradable Medicated ...
African Journals Online (AJOL)
PEG)-600, tributyl citrate, PEG-200, PEG-300, PEG-400, PEG-4000, triethyl citrate and castor oil. The gum formulations were characterized for the following parameters: texture profile analysis (TPA), biodegradation, in vitro drug release using a ...
A simplectic formulation of relativistic particle dynamics
International Nuclear Information System (INIS)
Tulczyjew, W.M.
1976-12-01
Particle mechanics is formulated in terms of symplectic relations and infinitesimal symplectic relations. Generating functions of symplectic relations are shown to be classical counterparts of Green's functions of wave mechanics. (orig.) [de
A sympletic formulation of relativistic particle dynamics
International Nuclear Information System (INIS)
Tulczyjew, W.M.
1977-01-01
Particle mechanics is formulated in terms of sympletic relations and infinitesimal symplectic relations. Generating functions of symplectic relations are shown to be classical counterparts of Green's functions of wave mechanics. (author)
Paclitaxel Albumin-stabilized Nanoparticle Formulation
This page contains brief information about paclitaxel albumin-stabilized nanoparticle formulation and a collection of links to more information about the use of this drug, research results, and ongoing clinical trials.
The Boltzmann equation in the difference formulation
Energy Technology Data Exchange (ETDEWEB)
Szoke, Abraham [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brooks III, Eugene D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2015-05-06
First we recall the assumptions that are needed for the validity of the Boltzmann equation and for the validity of the compressible Euler equations. We then present the difference formulation of these equations and make a connection with the time-honored Chapman - Enskog expansion. We discuss the hydrodynamic limit and calculate the thermal conductivity of a monatomic gas, using a simplified approximation for the collision term. Our formulation is more consistent and simpler than the traditional derivation.
Limitations of high dose carrier based formulations.
Yeung, Stewart; Traini, Daniela; Tweedie, Alan; Lewis, David; Church, Tanya; Young, Paul M
2018-06-10
This study was performed to investigate how increasing the active pharmaceutical ingredient (API) content within a formulation affects the dispersion of particles and the aerosol performance efficiency of a carrier based dry powder inhalable (DPI) formulation, using a custom dry powder inhaler (DPI) development rig. Five formulations with varying concentrations of API beclomethasone dipropionate (BDP) between 1% and 30% (w/w) were formulated as a multi-component carrier system containing coarse lactose and fine lactose with magnesium stearate. The morphology of the formulation and each component were investigated using scanning electron micrographs while the particle size was measured by laser diffraction. The aerosol performance, in terms of aerodynamic diameter, was assessed using the British pharmacopeia Apparatus E cascade impactor (Next generation impactor). Chemical analysis of the API was observed by high performance liquid chromatography (HPLC). Increasing the concentration of BDP in the blend resulted in increasing numbers and size of individual agglomerates and densely packed BDP multi-layers on the surface of the lactose carrier. BDP present within the multi-layer did not disperse as individual primary particles but as dense agglomerates, which led to a decrease in aerosol performance and increased percentage of BDP deposition within the Apparatus E induction port and pre-separator. As the BDP concentration in the blends increases, aerosol performance of the formulation decreases, in an inversely proportional manner. Concurrently, the percentage of API deposition in the induction port and pre-separator could also be linked to the amount of micronized particles (BDP and Micronized composite carrier) present in the formulation. The effect of such dose increase on the behaviour of aerosol dispersion was investigated to gain greater insight in the development and optimisation of higher dosed carrier-based formulations. Copyright © 2018 Elsevier B.V. All
Chemicals-Based Formulation Design: Virtual Experimentations
DEFF Research Database (Denmark)
Conte, Elisa; Gani, Rafiqul
2011-01-01
This paper presents a systematic procedure for virtual experimentations related to the design of liquid formulated products. All the experiments that need to be performed when designing a liquid formulated product (lotion), such as ingredients selection and testing, solubility tests, property mea...... on the design of an insect repellent lotion will show that the software is an essential instrument in decision making, and that it reduces time and resources since experimental efforts can be focused on one or few product alternatives....
Comments on alternate formulations for preequilibrium decay
International Nuclear Information System (INIS)
Blann, M.
1978-01-01
The physical and mathematical differences of several formulations for preequilibrium decay are discussed. Mathematical models and examples are presented or referred to in order to illustrate what the author believes to be errors in the exciton formulation as being due to improper inclusion of spectator effects. An earlier work of Gadioli et al. is reinterpreted, and quotations therein to work of the present author are corrected
The coevent formulation of quantum theory
International Nuclear Information System (INIS)
Wallden, Petros
2013-01-01
Understanding quantum theory has been a subject of debate from its birth. Many different formulations and interpretations have been proposed. Here we examine a recent novel formulation, namely the coevents formulation. It is a histories formulation and has as starting point the Feynman path integral and the decoherence functional. The new ontology turns out to be that of a coarse-grained history. We start with a quantum measure defined on the space of histories, and the existence of zero covers rules out single-history as potential reality (the Kochen Specker theorem casted in histories form is a special case of a zero cover). We see that allowing coarse-grained histories as potential realities avoids the previous paradoxes, maintains deductive non-contextual logic (alas non-Boolean) and gives rise to a unique classical domain. Moreover, we can recover the probabilistic predictions of quantum theory with the use of the Cournot's principle. This formulation, being both a realist formulation and based on histories, is well suited conceptually for the purposes of quantum gravity and cosmology.
An herbal formulation for hemorrhoids treatment
Directory of Open Access Journals (Sweden)
S. Dehdari
2017-11-01
Full Text Available Background and objectives: Hemorrhoids is the most painful rectal disease. Straining and pregnancy seem playing chief roles in the development of hemorrhoids. Symptoms of hemorrhoids may include bleeding, inflammation and pain. Despite current medical efforts, many discomforts of hemorrhoids have not been handled. The aim of the present study was to formulate and evaluate Itrifal-e muqil (IM tablet to achieve desired pharmaceutical properties. Method: Quality control tests of Allium ampeloperasum L, Commiphora mukul (Hook. ex Stocks Engl., Phyllanthus emblica L., Terminalia chebula Retz. and Terminalia bellerica Retz. were performed. Afterwards, different formulations were prepared and their physical properties were evaluated. Subsequently, the formulation was coated and its physicochemical characteristics were assessed. Result: All of the herbs demonstrated good results in quality control tests according to United State Pharmacopeia (USP. Formulation-1 that was completely prepared based on explained manufacturing process of IM in traditional medicine manuscripts did not show suitable pharmaceutical properties. Among different formulations, Formulation-3 that consisted of A. ampeloperasum, C. mukul, P. emblica, T. chebula and T. bellerica, displayed best outcomes through different tests. Conclusion: Modern pharmaceutical approaches can excellently be adapted for IM preparations.
Directory of Open Access Journals (Sweden)
Pål Johan From
2012-04-01
Full Text Available This paper presents the explicit dynamic equations of multibody mechanical systems. This is the second paper on this topic. In the first paper the dynamics of a single rigid body from the Boltzmann--Hamel equations were derived. In this paper these results are extended to also include multibody systems. We show that when quasi-velocities are used, the part of the dynamic equations that appear from the partial derivatives of the system kinematics are identical to the single rigid body case, but in addition we get terms that come from the partial derivatives of the inertia matrix, which are not present in the single rigid body case. We present for the first time the complete and correct derivation of multibody systems based on the Boltzmann--Hamel formulation of the dynamics in Lagrangian form where local position and velocity variables are used in the derivation to obtain the singularity-free dynamic equations. The final equations are written in global variables for both position and velocity. The main motivation of these papers is to allow practitioners not familiar with differential geometry to implement the dynamic equations of rigid bodies without the presence of singularities. Presenting the explicit dynamic equations also allows for more insight into the dynamic structure of the system. Another motivation is to correct some errors commonly found in the literature. Unfortunately, the formulation of the Boltzmann-Hamel equations used here are presented incorrectly. This has been corrected by the authors, but we present here, for the first time, the detailed mathematical details on how to arrive at the correct equations. We also show through examples that using the equations presented here, the dynamics of a single rigid body is reduced to the standard equations on a Lagrangian form, for example Euler's equations for rotational motion and Euler--Lagrange equations for free motion.
Formulation studies for mirtazapine orally disintegrating tablets.
Yıldız, Simay; Aytekin, Eren; Yavuz, Burçin; Bozdağ Pehlivan, Sibel; Ünlü, Nurşen
2016-01-01
Orally disintegrating tablets (ODTs) recently have gained much attention to fulfill the needs for pediatric, geriatric, and psychiatric patients with dysphagia. Aim of this study was to develop new ODT formulations containing mirtazapine, an antidepressant drug molecule having bitter taste, by using simple and inexpensive preparation methods such as coacervation, direct compression and to compare their characteristics with those of reference product (Remereon SolTab). Coacervation method was chosen for taste masking of mirtazapine. In vitro characterization studies such as diameter and thickness, weight variation, tablet hardness, tablet friability and disintegration time were performed on tablet formulations. Wetting time and in vitro dissolution tests of developed ODTs also studied using 900 mL 0.1 N HCl medium, 900 mL pH 6.8 phosphate buffer or 900 mL pH 4.5 acetate buffer at 37 ± 0.2 °C as dissolution medium. Ratio of Eudragit® E-100 was chosen as 6% (w/w) since the dissolution profile of A1 (6% Eudragit® E-100) was found closer to the reference product than A2 (4% Eudragit® E-100) and A3 (8% Eudragit® E-100). Group D, E and F formulations were presented better results in terms of disintegration time. Dissolution results indicated that Group E and F formulations showed optimum properties in all three dissolution media. Formulations D1, D4, D5, E3, E4, F1 and F5 found suitable as ODT formulations due to their favorable disintegration times and dissolution profiles. Developed mirtazapine ODTs were found promising in terms of showing the similar characteristics to the original formulation.
TURVA-2012: Formulation of radionuclide release scenarios
International Nuclear Information System (INIS)
Marcos, Nuria; Hjerpe, Thomas; Snellman, Margit; Ikonen, Ari; Smith, Paul
2014-01-01
TURVA-2012 is Posiva's safety case in support of the Preliminary Safety Analysis Report (PSAR) and application for a construction licence for a repository for disposal of spent nuclear fuel at the Olkiluoto site in south-western Finland. This paper gives a summary of the scenarios and the methodology followed in formulating them as described in TURVA-2012: Formulation of Radionuclide Release Scenarios (Posiva, 2013). The scenarios are further analysed in TURVA-2012: Assessment of Radionuclide Release Scenarios for the Repository System and TURVA-2012: Biosphere Assessment (Posiva, 2012a, 2012b). The formulation of scenarios takes into account the safety functions of the main barriers of the repository system and the uncertainties in the features, events, and processes (FEP) that may affect the entire disposal system (i.e. repository system plus the surface environment) from the emplacement of the first canister until the far future. In the report TURVA-2012: Performance Assessment (2012d), the performance of the engineered and natural barriers has been assessed against the loads expected during the evolution of the repository system and the site. Uncertainties have been identified and these are taken into account in the formulation of radionuclide release scenarios. The uncertainties in the FEP and evolution of the surface environment are taken into account in formulating the surface environment scenarios used ultimately in estimating radiation exposure. Formulating radionuclide release scenarios for the repository system links the reports Performance Assessment and Assessment of Radionuclide Release Scenarios for the Repository System. The formulation of radionuclide release scenarios for the surface environment brings together biosphere description and the surface environment FEP and is the link to the assessment of the surface environment scenarios summarised in TURVA-2012: Biosphere Assessment. (authors)
Directory of Open Access Journals (Sweden)
Šoltýsová I.
2016-12-01
Full Text Available Active ingredients in pharmaceuticals differ by their physico-chemical properties and their bioavailability therefore varies. The most frequently used and most convenient way of administration of medicines is oral, however many drugs are little soluble in water. Thus they are not sufficiently effective and suitable for such administration. For this reason a system of lipid based formulations (LBF was developed. Series of formulations were prepared and tested in water and biorelevant media. On the basis of selection criteria, there were selected formulations with the best emulsification potential, good dispersion in the environment and physical stability. Samples of structurally different drugs included in the Class II of the Biopharmaceutics classification system (BCS were obtained, namely Griseofulvin, Glibenclamide, Carbamazepine, Haloperidol, Itraconazol, Triclosan, Praziquantel and Rifaximin, for testing of maximal saturation in formulations prepared from commercially available excipients. Methods were developed for preparation of formulations, observation of emulsification and its description, determination of maximum solubility of drug samples in the respective formulation and subsequent analysis. Saturation of formulations with drugs showed that formulations 80 % XA and 20 % Xh, 35 % XF and 65 % Xh were best able to dissolve the drugs which supports the hypothesis that it is desirable to identify limited series of formulations which could be generally applied for this purpose.
International Nuclear Information System (INIS)
Belsher, J.D.; Meinert, F.L.
2009-01-01
This document presents the differences between two HLW glass formulation models (GFM): The 1996 GFM and 2009 GFM. A glass formulation model is a collection of glass property correlations and associated limits, as well as model validity and solubility constraints; it uses the pretreated HLW feed composition to predict the amount and composition of glass forming additives necessary to produce acceptable HLW glass. The 2009 GFM presented in this report was constructed as a nonlinear optimization calculation based on updated glass property data and solubility limits described in PNNL-18501 (2009). Key mission drivers such as the total mass of HLW glass and waste oxide loading are compared between the two glass formulation models. In addition, a sensitivity study was performed within the 2009 GFM to determine the effect of relaxing various constraints on the predicted mass of the HLW glass.
Formulation of Sustained-Release Diltiazem Matrix Tablets Using ...
African Journals Online (AJOL)
Erah
surface, their drug release behavior appears simple, but ... matrix material for the formulation of ..... formulation F5 (,) and reference formulations. ( , □). 0. 50. 100. 150. 200. 250. 300. 0. 3. 6 .... Coviello T, Matricardi P, Marianecci C, Alhaique F.
Formulation of lubricating grease using Beeswax thickener
Suhaila, N.; Japar, A.; Aizudin, M.; Aziz, A.; Najib Razali, Mohd
2018-04-01
The issues on environmental pollution has brought the industries to seek the alternative green solutions for lubricating grease formulation. The significant challenges in producing modified grease are in which considering the chosen thickener as one of the environmental friendly material. The main purposes of the current research were to formulate lubricant grease using different types of base oils and to study the effect of thickener on the formulated lubricant grease. Used oil and motor oil were used as the base oils for the grease preparation. Beeswax and Damar were used as thickener and additive. The grease is tested based on its consistency, stability and oil bleeding. The prepared greases achieved grease consistency of grade 2 and 3 except for grease with unfiltered used oil. Grease formulated with used oil and synthetic oil tend to harden and loss its lubricating ability under high temperature compared to motor oil’ grease. Grease modification using environmental friendly thickener were successfully formulated but it is considered as a low temperature grease as the beeswax have low melting point of 62°C-65°C.
Bioequivalence assessment of two formulations of ibuprofen
Al-Talla, Zeyad
2011-10-19
Background: This study assessed the relative bioavailability of two formulations of ibuprofen. The first formulation was Doloraz , produced by Al-Razi Pharmaceutical Company, Amman, Jordan. The second forumulation was Brufen , manufactured by Boots Company, Nottingham, UK. Methods and results: A prestudy validation of ibuprofen demonstrated long-term stability, freeze-thaw stability, precision, and accuracy. Twenty-four healthy volunteers were enrolled in this study. After overnight fasting, the two formulations (test and reference) of ibuprofen (100 mg ibuprofen/5 mL suspension) were administered as a single dose on two treatment days separated by a one-week washout period. After dosing, serial blood samples were drawn for a period of 14 hours. Serum harvested from the blood samples was analyzed for the presence of ibuprofen by high-pressure liquid chromatography with ultraviolet detection. Pharmacokinetic parameters were determined from serum concentrations for both formulations. The 90% confidence intervals of the ln-transformed test/reference treatment ratios for peak plasma concentration and area under the concentration-time curve (AUC) parameters were found to be within the predetermined acceptable interval of 80%-125% set by the US Food and Drug Administration. Conclusion: Analysis of variance for peak plasma concentrations and AUC parameters showed no significant difference between the two formulations and, therefore, Doloraz was considered bioequivalent to Brufen. 2011 Al-Talla et al, publisher and licensee Dove Medical Press Ltd.
Cyclodextrins as excipients in tablet formulations.
Conceição, Jaime; Adeoye, Oluwatomide; Cabral-Marques, Helena Maria; Lobo, José Manuel Sousa
2018-04-22
This paper aims to provide a critical review of cyclodextrins as excipients in tablet formulations, highlighting: (i) the principal pharmaceutical applications of cyclodextrins; (ii) the most relevant technological aspects in pharmaceutical formulation development; and (iii) the actual regulatory status of cyclodextrins. Moreover, several illustrative examples are presented. Cyclodextrins can be used as complexing excipients in tablet formulations for low-dose drugs. By contrast, for medium-dose drugs and/or when the complexation efficiency is low, the methods to enhance the complexation efficiency play a key part in reducing the cyclodextrin quantity. In addition, these compounds are used as fillers, disintegrants, binders and multifunctional direct compression excipients of the tablets. Copyright © 2018 Elsevier Ltd. All rights reserved.
STRATEGY FORMULATION PROCESS AND INNOVATION PERFORMANCE NEXUS
Directory of Open Access Journals (Sweden)
Chijioke Nwachukwu
2018-03-01
Full Text Available The purpose of this study is to examine the link between strategy formulation process and innovation performance indicators in microfinance banks in Nigeria (MFBs. 100 employees of leading microfinance banks were randomly selected for this study. 80 questionnaires were returned but only 76 were found usable for the analysis. Regression analysis technique was used in examining the nature of the relationships of the variables and for hypotheses testing. The authors used exploratory factor analysis and Cronbach's alpha to test for the validity and reliability of the questionnaires. The results show that strategy formulation process has a positive effect on process innovation performance, product innovation performance and marketing innovation performance. Thus, all the three hypotheses tested were supported. The authors, therefore, concludes that a systematic strategy formulation process is necessary for firms to achieve and sustain process innovation performance, product innovation performance and marketing innovation performance. This study proposed suggestion for further studies.
Formulating viscous hydrodynamics for large velocity gradients
International Nuclear Information System (INIS)
Pratt, Scott
2008-01-01
Viscous corrections to relativistic hydrodynamics, which are usually formulated for small velocity gradients, have recently been extended from Navier-Stokes formulations to a class of treatments based on Israel-Stewart equations. Israel-Stewart treatments, which treat the spatial components of the stress-energy tensor τ ij as dynamical objects, introduce new parameters, such as the relaxation times describing nonequilibrium behavior of the elements τ ij . By considering linear response theory and entropy constraints, we show how the additional parameters are related to fluctuations of τ ij . Furthermore, the Israel-Stewart parameters are analyzed for their ability to provide stable and physical solutions for sound waves. Finally, it is shown how these parameters, which are naturally described by correlation functions in real time, might be constrained by lattice calculations, which are based on path-integral formulations in imaginary time
RAACFDb: Rheumatoid arthritis ayurvedic classical formulations database.
Mohamed Thoufic Ali, A M; Agrawal, Aakash; Sajitha Lulu, S; Mohana Priya, A; Vino, S
2017-02-02
In the past years, the treatment of rheumatoid arthritis (RA) has undergone remarkable changes in all therapeutic modes. The present newfangled care in clinical research is to determine and to pick a new track for better treatment options for RA. Recent ethnopharmacological investigations revealed that traditional herbal remedies are the most preferred modality of complementary and alternative medicine (CAM). However, several ayurvedic modes of treatments and formulations for RA are not much studied and documented from Indian traditional system of medicine. Therefore, this directed us to develop an integrated database, RAACFDb (acronym: Rheumatoid Arthritis Ayurvedic Classical Formulations Database) by consolidating data from the repository of Vedic Samhita - The Ayurveda to retrieve the available formulations information easily. Literature data was gathered using several search engines and from ayurvedic practitioners for loading information in the database. In order to represent the collected information about classical ayurvedic formulations, an integrated database is constructed and implemented on a MySQL and PHP back-end. The database is supported by describing all the ayurvedic classical formulations for the treatment rheumatoid arthritis. It includes composition, usage, plant parts used, active ingredients present in the composition and their structures. The prime objective is to locate ayurvedic formulations proven to be quite successful and highly effective among the patients with reduced side effects. The database (freely available at www.beta.vit.ac.in/raacfdb/index.html) hopefully enables easy access for clinical researchers and students to discover novel leads with reduced side effects. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Formulation and stability testing of photolabile drugs.
Tønnesen, H H
2001-08-28
Exposure of a drug to irradiation can influence the stability of the formulation, leading to changes in the physicochemical properties of the product. The influence of excipients of frequently used stabilizers is often difficult to predict and, therefore, stability testing of the final preparation is important. The selection of a protective packaging must be based on knowledge about the wavelength causing the instability. Details on drug photoreactivity will also be helpful in order to minimize side-effects and/or optimize drug targeting by developing photoresponsive drug delivery systems. This review focuses on practical problems related to formulation and stability testing of photolabile drugs.
Controlled-release tablet formulation of isoniazid.
Jain, N K; Kulkarni, K; Talwar, N
1992-04-01
Guar (GG) and Karaya gums (KG) alone and in combination with hydroxy-propylmethylcellulose (HPMC) were evaluated as release retarding materials to formulate a controlled-release tablet dosage form of isoniazid (1). In vitro release of 1 from tablets followed non-Fickian release profile with rapid initial release. Urinary excretion studies in normal subjects showed steady-state levels of 1 for 13 h. In vitro and in vivo data correlated (r = 0.9794). The studies suggested the potentiality of GG and KG as release retarding materials in formulating controlled-release tablet dosage forms of 1.
An exact approach for aggregated formulations
DEFF Research Database (Denmark)
Gamst, Mette; Spoorendonk, Simon
Aggregating formulations is a powerful approach for transforming problems into taking more tractable forms. Aggregated formulations can, though, have drawbacks: some information may get lost in the aggregation and { put in a branch-and-bound context { branching may become very di_cult and even....... The paper includes general considerations on types of problems for which the method is of particular interest. Furthermore, we prove the correctness of the procedure and consider how to include extensions such as cutting planes and advanced branching strategies....
Quaternionic formulation of the exact parity model
Energy Technology Data Exchange (ETDEWEB)
Brumby, S.P.; Foot, R.; Volkas, R.R.
1996-02-28
The exact parity model (EPM) is a simple extension of the standard model which reinstates parity invariance as an unbroken symmetry of nature. The mirror matter sector of the model can interact with ordinary matter through gauge boson mixing, Higgs boson mixing and, if neutrinos are massive, through neutrino mixing. The last effect has experimental support through the observed solar and atmospheric neutrino anomalies. In the paper it is shown that the exact parity model can be formulated in a quaternionic framework. This suggests that the idea of mirror matter and exact parity may have profound implications for the mathematical formulation of quantum theory. 13 refs.
Quaternionic formulation of the exact parity model
International Nuclear Information System (INIS)
Brumby, S.P.; Foot, R.; Volkas, R.R.
1996-01-01
The exact parity model (EPM) is a simple extension of the standard model which reinstates parity invariance as an unbroken symmetry of nature. The mirror matter sector of the model can interact with ordinary matter through gauge boson mixing, Higgs boson mixing and, if neutrinos are massive, through neutrino mixing. The last effect has experimental support through the observed solar and atmospheric neutrino anomalies. In the paper it is shown that the exact parity model can be formulated in a quaternionic framework. This suggests that the idea of mirror matter and exact parity may have profound implications for the mathematical formulation of quantum theory. 13 refs
Directory of Open Access Journals (Sweden)
J. Herman
2018-01-01
Full Text Available EPIC (Earth Polychromatic Imaging Camera on board the DSCOVR (Deep Space Climate Observatory spacecraft is the first earth science instrument located near the earth–sun gravitational plus centrifugal force balance point, Lagrange 1. EPIC measures earth-reflected radiances in 10 wavelength channels ranging from 317.5 to 779.5 nm. Of these channels, four are in the UV range 317.5, 325, 340, and 388 nm, which are used to retrieve O3, 388 nm scene reflectivity (LER: Lambert equivalent reflectivity, SO2, and aerosol properties. These new synoptic quantities are retrieved for the entire sunlit globe from sunrise to sunset multiple times per day as the earth rotates in EPIC's field of view. Retrieved ozone amounts agree with ground-based measurements and satellite data to within 3 %. The ozone amounts and LER are combined to derive the erythemal irradiance for the earth's entire sunlit surface at a nadir resolution of 18 × 18 km2 using a computationally efficient approximation to a radiative transfer calculation of irradiance. The results show very high summertime values of the UV index (UVI in the Andes and Himalayas (greater than 18, and high values of UVI near the Equator at equinox.
Screening of mucoadhesive vaginal gel formulations
Directory of Open Access Journals (Sweden)
Ana Ochoa Andrade
2014-12-01
Full Text Available Rational design of vaginal drug delivery formulations requires special attention to vehicle properties that optimize vaginal coating and retention. The aim of the present work was to perform a screening of mucoadhesive vaginal gels formulated with carbomer or carrageenan in binary combination with a second polymer (carbomer, guar or xanthan gum. The gels were characterised using in vitroadhesion, spreadability and leakage potential studies, as well as rheological measurements (stress and frequency sweep tests and the effect of dilution with simulated vaginal fluid (SVF on spreadability. Results were analysed using analysis of variance and multiple factor analysis. The combination of polymers enhanced adhesion of both primary gelling agents, carbomer and carrageenan. From the rheological point of view all formulations presented a similar behaviour, prevalently elastic and characterised by loss tangent values well below 1. No correlation between rheological and adhesion behaviour was found. Carbomer and carrageenan gels containing the highest percentage of xanthan gum displayed good in vitro mucoadhesion and spreadability, minimal leakage potential and high resistance to dilution. The positive results obtained with carrageenan-xanthan gum-based gels can encourage the use of natural biocompatible adjuvants in the composition of vaginal products, a formulation field that is currently under the synthetic domain.
Formulation of Sodium Alginate Nanospheres Containing ...
African Journals Online (AJOL)
Purpose: The aim of this work was to formulate sodium alginate nanospheres of amphotericin B by controlled gellification method and to evaluate the role of the nanospheres as a “passive carrier” in targeted antifungal therapy. Methods: Sodium alginate nanospheres of amphotericin B were prepared by controlled ...
[Optimization of formulations for dietetic pastry products].
Villarroel, M; Uquiche, E; Brito, G; Cancino, M
2000-03-01
Optimized formulations of dietetic pastry products such as cake and sponge cake premixes were formulated using the surface response methodology. % Emulsifier agent and baking time were the selected independent variables for cake, as well as % emulsifier agent % chlorinated flour the variables selected for sponge cake. Three different level of each variable summing up thirteen experimental formulae of each product were assessed to optimize the variables that could have some influence in the sensory characteristics of these dietetic products. The total sensory quality was determined for both dietetic products using the composite scoring test and a panel of 18 trained judges. Looking at the contour graphic and considering economic aspects the best combination of variables for cake formulation was 2% emulsifier agent and 48 minutes for baking time, With respect to sponge cake, the best combination was 6% emulsifier agent and 48% chlorinated flour. Shelf life studies showed that both dietetic formulations remained stable during storage conditions of 75 days at 30 degrees C. During this period, significant differences in sensory characteristics were not found (p pastry products had good acceptability, and open up marketing opportunities for new products with potential health benefits to consumers.
Facile Colorimetric Determination of Duloxetine in Formulations ...
African Journals Online (AJOL)
... the determination of duloxetine hydrochloride (DX). Methods: Ion-pair spectrophotometric method was employed for the determination of duloxetine hydrochloride (DX) in bulk and pharmaceutical formulations using acidic dye methyl orange (MO) as ion-pairing agent at pH 4 (phthalate buffer). The yellow ion-pair complex ...
Engaged Problem Formulation in IS Research
DEFF Research Database (Denmark)
Nielsen, Peter Axel; Persson, John Stouby
2016-01-01
problems requires a more substantial engagement with the different stakeholders, especially when their problems are ill structured and situated in complex organizational settings. On this basis, we present an engaged approach to formulating IS problems with, not for, IS practitioners. We have come...
Effects of Methionine Containing Paracetamol Formulation on ...
African Journals Online (AJOL)
Effects of Methionine Containing Paracetamol Formulation on Serum Vitamins and Trace Elements in Male Rats. AA Iyanda, JI Anetor, DP Oparinde, FAA Adeniyi. Abstract. Methionine is an effective antidote in the treatment of paracetamol-induced toxicity but at large doses it has been reported to induce or aggravate a ...
State-Space Formulation for Circuit Analysis
Martinez-Marin, T.
2010-01-01
This paper presents a new state-space approach for temporal analysis of electrical circuits. The method systematically obtains the state-space formulation of nondegenerate linear networks without using concepts of topology. It employs nodal/mesh systematic analysis to reduce the number of undesired variables. This approach helps students to…
Yang-Mills formulation of interacting strings
International Nuclear Information System (INIS)
Chan Hongmo; Tsou Sheungtsun
1988-06-01
A suggestion that the theory of interacting open bosonic string be reformulated as a generalised Yang-Mills theory is further elucidated. Moreover, a serious reservation regarding the ordering of operators in the earlier 'proof' of equivalence between the new and standard formulations is now removed. (author)
Initial value formulation of higher derivative gravity
International Nuclear Information System (INIS)
Noakes, D.R.
1983-01-01
The initial value problem is considered for the conformally coupled scalar field and higher derivative gravity, by expressing the equations of each theory in harmonic coordinates. For each theory it is shown that the (vacuum) equations can take the form of a diagonal hyperbolic system with constraints on the initial data. Consequently these theories possess well-posed initial value formulations
Release Properties of Paracetamol Granulationa Formulated with ...
African Journals Online (AJOL)
Theobroma cacao gum, TCG was derived as a dry powder from fresh fruits of Theobroma cacao. Various granulations of paracetamol were prepared with TCG at the concentrations of 0.5 – 4% w/w. Similar formulations were prepared using sodium carboxymethyl cellulose, SCMC and acacia gums as standards. In each ...
Probabilites in the general boundary formulation
Energy Technology Data Exchange (ETDEWEB)
Oeckl, Robert [Instituto de Matematicas, UNAM, Campus Morelia, C.P. 58190, Morelia, Michoacan (Mexico)
2007-05-15
We give an introductory account of the general boundary formulation of quantum theory. We refine its probability interpretation and emphasize a conceptual and historical perspective. We give motivations from quantum gravity and illustrate them with a scenario for describing gravitons in quantum gravity.
Necessity of rethinking oral pediatric formulations
DEFF Research Database (Denmark)
Bar-Shalom, Daniel
2014-01-01
by all patient groups, is needed, and an automated compounding concept is proposed. The finishing of the formulation is done at the dispensing pharmacy using an automated process. The individual components (pudding-like carrier, microencapsulated drug, and the dispensing robot and its software...
Lagrangian formulation of classical BMT-theory
International Nuclear Information System (INIS)
Pupasov-Maksimov, Andrey; Deriglazov, Alexei; Guzman, Walberto
2013-01-01
Full text: The most popular classical theory of electron has been formulated by Bargmann, Michel and Telegdi (BMT) in 1959. The BMT equations give classical relativistic description of a charged particle with spin and anomalous magnetic momentum moving in homogeneous electro-magnetic field. This allows to study spin dynamics of polarized beams in uniform fields. In particular, first experimental measurements of muon anomalous magnetic momentum were done using changing of helicity predicted by BMT equations. Surprisingly enough, a systematic formulation and the analysis of the BMT theory are absent in literature. In the present work we particularly fill this gap by deducing Lagrangian formulation (variational problem) for BMT equations. Various equivalent forms of Lagrangian will be discussed in details. An advantage of the obtained classical model is that the Lagrangian action describes a relativistic spinning particle without Grassmann variables, for both free and interacting cases. This implies also the possibility of canonical quantization. In the interacting case, an arbitrary electromagnetic background may be considered, which generalizes the BMT theory formulated to the case of homogeneous fields. The classical model has two local symmetries, which gives an interesting example of constrained classical dynamics. It is surprising, that the case of vanishing anomalous part of the magnetic momentum is naturally highlighted in our construction. (author)
A parcel formulation for Hamiltonian layer models
Bokhove, Onno; Oliver, M.
Starting from the three-dimensional hydrostatic primitive equations, we derive Hamiltonian N-layer models with isentropic tropospheric and isentropic or isothermal stratospheric layers. Our construction employs a new parcel Hamiltonian formulation which describes the fluid as a continuum of
Clinical pharmacology of novel anticancer drug formulations
Stuurman, F.E.
2013-01-01
Studies outlined in this thesis describe the impact of drug formulations on pharmacology of anticancer drugs. It consists of four parts and starts with a review describing the mechanisms of low oral bioavailability of anti-cancer drugs and strategies for improvement of the bioavailability. The
Comparative evaluation of organic formulations of Pseudomonas ...
African Journals Online (AJOL)
An experiment was conducted in the laboratory and farm of the Department of Biotechnology, Gauhati University, to explore the potentiality of various organic formulations of Pseudomonas fluorescens (Pf) and to manage bacterial wilt disease of brinjal (Solanum melongena L.) under local conditions. Different organic ...
Formulation and evaluation and terbutaline sulphate and ...
African Journals Online (AJOL)
We report the use of low rugosity lactose, product of controlled crystallization of this carrier, in the formulation of terbutaline sulphate and beclomethasone dipropionate dry powder inhalers. The deposition patterns obtained with inhalation mixtures consisting of the modified lactose and each of the micronised drugs ...
Development and Evaluation of Topical Gabapentin Formulations
Directory of Open Access Journals (Sweden)
Christopher J. Martin
2017-08-01
Full Text Available Topical delivery of gabapentin is desirable to treat peripheral neuropathic pain conditions whilst avoiding systemic side effects. To date, reports of topical gabapentin delivery in vitro have been variable and dependent on the skin model employed, primarily involving rodent and porcine models. In this study a variety of topical gabapentin formulations were investigated, including Carbopol® hydrogels containing various permeation enhancers, and a range of proprietary bases including a compounded Lipoderm® formulation; furthermore microneedle facilitated delivery was used as a positive control. Critically, permeation of gabapentin across a human epidermal membrane in vitro was assessed using Franz-type diffusion cells. Subsequently this data was contextualised within the wider scope of the literature. Although reports of topical gabapentin delivery have been shown to vary, largely dependent upon the skin model used, this study demonstrated that 6% (w/w gabapentin 0.75% (w/w Carbopol® hydrogels containing 5% (w/w DMSO or 70% (w/w ethanol and a compounded 10% (w/w gabapentin Lipoderm® formulation were able to facilitate permeation of the molecule across human skin. Further pre-clinical and clinical studies are required to investigate the topical delivery performance and pharmacodynamic actions of prospective formulations.
Development and Evaluation of Topical Gabapentin Formulations
Alcock, Natalie; Hiom, Sarah; Birchall, James C.
2017-01-01
Topical delivery of gabapentin is desirable to treat peripheral neuropathic pain conditions whilst avoiding systemic side effects. To date, reports of topical gabapentin delivery in vitro have been variable and dependent on the skin model employed, primarily involving rodent and porcine models. In this study a variety of topical gabapentin formulations were investigated, including Carbopol® hydrogels containing various permeation enhancers, and a range of proprietary bases including a compounded Lipoderm® formulation; furthermore microneedle facilitated delivery was used as a positive control. Critically, permeation of gabapentin across a human epidermal membrane in vitro was assessed using Franz-type diffusion cells. Subsequently this data was contextualised within the wider scope of the literature. Although reports of topical gabapentin delivery have been shown to vary, largely dependent upon the skin model used, this study demonstrated that 6% (w/w) gabapentin 0.75% (w/w) Carbopol® hydrogels containing 5% (w/w) DMSO or 70% (w/w) ethanol and a compounded 10% (w/w) gabapentin Lipoderm® formulation were able to facilitate permeation of the molecule across human skin. Further pre-clinical and clinical studies are required to investigate the topical delivery performance and pharmacodynamic actions of prospective formulations. PMID:28867811
Engaged Problem Formulation in IS Research
DEFF Research Database (Denmark)
Nielsen, Peter Axel; Persson, John Stouby
2016-01-01
“Is this the problem?”: the question that haunts many information systems (IS) researchers when they pursue work relevant to both practice and research. Nevertheless, a deliberate answer to this question requires more than simply asking the involved IS practitioners. Deliberately formulating...
Kit systems for granulated decontamination formulations
Tucker, Mark D.
2010-07-06
A decontamination formulation and method of making that neutralizes the adverse health effects of both chemical and biological compounds, especially chemical warfare (CW) and biological warfare (BW) agents, and toxic industrial chemicals. The formulation provides solubilizing compounds that serve to effectively render the chemical and biological compounds, particularly CW and BW compounds, susceptible to attack, and at least one reactive compound that serves to attack (and detoxify or kill) the compound. The formulation includes at least one solubilizing agent, a reactive compound, a sorbent additive, and water. A highly adsorbent sorbent additive (e.g., amorphous silica, sorbitol, mannitol, etc.) is used to "dry out" one or more liquid ingredients into a dry, free-flowing powder that has an extended shelf life, and is more convenient to handle and mix in the field. The formulation can be pre-mixed and pre-packaged as a multi-part kit system, where one or more of the parts are packaged in a powdered, granulated form for ease of handling and mixing in the field.
Application of UV Imaging in Formulation Development.
Sun, Yu; Østergaard, Jesper
2017-05-01
Efficient drug delivery is dependent on the drug substance dissolving in the body fluids, being released from dosage forms and transported to the site of action. A fundamental understanding of the interplay between the physicochemical properties of the active compound and pharmaceutical excipients defining formulation behavior after exposure to the aqueous environments and pharmaceutical performance is critical in pharmaceutical development, manufacturing and quality control of drugs. UV imaging has been explored as a tool for qualitative and quantitative characterization of drug dissolution and release with the characteristic feature of providing real-time visualization of the solution phase drug transport in the vicinity of the formulation. Events occurring during drug dissolution and release, such as polymer swelling, drug precipitation/recrystallization, or solvent-mediated phase transitions related to the structural properties of the drug substance or formulation can be monitored. UV imaging is a non-intrusive and simple-to-operate analytical technique which holds potential for providing a mechanistic foundation for formulation development. This review aims to cover applications of UV imaging in the early and late phase pharmaceutical development with a special focus on the relation between structural properties and performance. Potential areas of future advancement and application are also discussed.
Bioequivalence assessment of two formulations of ibuprofen
Directory of Open Access Journals (Sweden)
Al-Talla ZA
2011-10-01
Full Text Available Zeyad A Al-Talla1, Sabah H Akrawi2, Luke T Tolley3, Salim H Sioud1, Mohammed F Zaater4, Abdul-Hamid M Emwas1 1Analytical and NMR Core Laboratories, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudia Arabia; 2College of Pharmacy, Al-Ain University, Al-Ain, United Arab Emirates; 3Department of Chemistry and Biochemistry, Southern Illinois University Carbondale, Carbondale, IL, USA; 4Department of Chemistry, Jordan University of Science and Technology, Jordan University of Science and Technology, Irbid, Jordan Background: This study assessed the relative bioavailability of two formulations of ibuprofen. The first formulation was Doloraz®, produced by Al-Razi Pharmaceutical Company, Amman, Jordan. The second forumulation was Brufen®, manufactured by Boots Company, Nottingham, UK. Methods and results: A prestudy validation of ibuprofen demonstrated long-term stability, freeze-thaw stability, precision, and accuracy. Twenty-four healthy volunteers were enrolled in this study. After overnight fasting, the two formulations (test and reference of ibuprofen (100 mg ibuprofen/5 mL suspension were administered as a single dose on two treatment days separated by a one-week washout period. After dosing, serial blood samples were drawn for a period of 14 hours. Serum harvested from the blood samples was analyzed for the presence of ibuprofen by high-pressure liquid chromatography with ultraviolet detection. Pharmacokinetic parameters were determined from serum concentrations for both formulations. The 90% confidence intervals of the ln-transformed test/reference treatment ratios for peak plasma concentration and area under the concentration-time curve (AUC parameters were found to be within the predetermined acceptable interval of 80%–125% set by the US Food and Drug Administration. Conclusion: Analysis of variance for peak plasma concentrations and AUC parameters showed no significant difference between the two formulations and
Di Mambro, Valéria M; Borin, Maria F; Fonseca, Maria J V
2003-04-24
Three different topical formulations were supplemented with superoxide dismutase (SOD) and evaluated concerning physical and chemical stabilities in order to determine the most stable formulation that would maintain SOD activity. Physical stability was evaluated by storing the formulation at room temperature, and at 37 and 45 degrees C for 28 days. Samples were collected at 7-day intervals for assessment of rheological behavior. Chemical stability was evaluated by the measurement of enzymatic activity in formulations stored at room temperature and at 45 degrees C for 75 days. The formulations showed a pseudoplastic behavior, with a flow index of less than 1. There was no significant difference in the initial values of flow index, hysteresis loop or minimum apparent viscosity. The simple emulsion and the one stabilized with hydroxyethylcellulose showed decreased viscosity by the 21st day and with higher temperature, but no significant changes concerning the presence of SOD. Although there were no significant changes concerning storage time or temperature, the formulation stabilized with hydroxyethylcellulose showed a marked loss of SOD activity. The addition of SOD to the formulations studied did not affect their physical stability. Simple emulsions or emulsions stabilized with carboxypolymethylene seem to be better bases for enzyme addition than emulsion stabilized with hydroxyethylcellulose.
van Beurden, M.C.; Setija, Irwan
2017-01-01
We present two adapted formulations, one tailored to isotropic media and one for general anisotropic media, of the normal vector field framework previously introduced to improve convergence near arbitrarily shaped material interfaces in spectral simulation methods for periodic scattering geometries.
Directory of Open Access Journals (Sweden)
M. Gharavi
1990-07-01
Full Text Available In this study a pine tar shampoo as a new antidandruff formulation is presented. Assessment of antidandruff preparations has been hampered by the lack of standardized schedules, and reliable methods of evaluation.Some antidandruff agents such as : Zinc pyri-thione pine tar, selenium sulphide and (sulfure were used in shampoos. Samples were coded as numbers 1,2 formulated by us and 3,4 formulated commercially. The grading scheme based on 10 point scale, and corneocyte count was carried out on 50 selected volunte¬ers. Corneocyte count and fungal study proved that pine tor shampoo is effective against pityrosporum ovale. Draize lest was used for determination of the irritancy potential of the samples. Results showed that samples numbered 1,2 were relatively innocous in comparison with the others. I urthermore,s kin sensitination test on rabbit also confirmed the results obtained by Draize test. Consumer judgments proved that all formulations were acceptable.
CSIR Research Space (South Africa)
Katata, L
2012-10-01
Full Text Available statistical design with an L8 orthogonal array, was implemented to optimise the formulation parameters of PCL-EFV nanoparticles. The types of sugar (lactose or trehalose), surfactant concentration and solvent (dichloromethane and ethyl acetate) were chosen...
Consistency of canonical formulation of Horava gravity
International Nuclear Information System (INIS)
Soo, Chopin
2011-01-01
Both the non-projectable and projectable version of Horava gravity face serious challenges. In the non-projectable version, the constraint algebra is seemingly inconsistent. The projectable version lacks a local Hamiltonian constraint, thus allowing for an extra graviton mode which can be problematic. A new formulation (based on arXiv:1007.1563) of Horava gravity which is naturally realized as a representation of the master constraint algebra (instead of the Dirac algebra) studied by loop quantum gravity researchers is presented. This formulation yields a consistent canonical theory with first class constraints; and captures the essence of Horava gravity in retaining only spatial diffeomorphisms as the physically relevant non-trivial gauge symmetry. At the same time the local Hamiltonian constraint is equivalently enforced by the master constraint.
Formulation of diclofenac for dermal delivery.
Goh, Choon Fu; Lane, Majella E
2014-10-01
Diclofenac (DF) was first synthesized in the 1960's and is currently available as ophthalmic, oral, parenteral, rectal and skin preparations. This review focuses on the administration of DF to the skin. As a member of the non-steroidal anti-inflammatory (NSAID) group of drugs the primary indications of DF are for the management of inflammation and pain but it is also used to treat actinic keratosis. The specific aims of this paper are to: (i) provide an overview of the pharmacokinetics and metabolism of DF following oral and topical administration; (ii) examine critically the various formulation approaches which have been investigated to enhance dermal delivery of DF; and (iii) identify new formulation strategies for enhanced DF skin penetration. Copyright © 2014 Elsevier B.V. All rights reserved.
Consistency of canonical formulation of Horava gravity
Energy Technology Data Exchange (ETDEWEB)
Soo, Chopin, E-mail: cpsoo@mail.ncku.edu.tw [Department of Physics, National Cheng Kung University, Tainan, Taiwan (China)
2011-09-22
Both the non-projectable and projectable version of Horava gravity face serious challenges. In the non-projectable version, the constraint algebra is seemingly inconsistent. The projectable version lacks a local Hamiltonian constraint, thus allowing for an extra graviton mode which can be problematic. A new formulation (based on arXiv:1007.1563) of Horava gravity which is naturally realized as a representation of the master constraint algebra (instead of the Dirac algebra) studied by loop quantum gravity researchers is presented. This formulation yields a consistent canonical theory with first class constraints; and captures the essence of Horava gravity in retaining only spatial diffeomorphisms as the physically relevant non-trivial gauge symmetry. At the same time the local Hamiltonian constraint is equivalently enforced by the master constraint.
Principles of ration formulation for ruminants
International Nuclear Information System (INIS)
Jayasuriya, M.C.N.
2002-01-01
Feeding standards as practiced in developed countries could be misleading when non-conventional feed resources are used in formulating rations for ruminant livestock in developing countries. They tend to reject the poor quality feeds that are available in vast quantities. The non-availability of good quality forage throughout the year and the need to optimise the efficiency of utilisation of locally available feed resources have lead to the application of basic nutritional principles when considering ration formulation. The alternative approach to the use of feeding standards would be to ensure that the production system matches the available resources. The development of feed supplementation strategies based on locally available feed resources require the understanding of the relative roles and nutrient needs of the two-compartment system represented by the micro-organisms in the rumen and the host animal. (author)
Spray drying formulation of amorphous solid dispersions.
Singh, Abhishek; Van den Mooter, Guy
2016-05-01
Spray drying is a well-established manufacturing technique which can be used to formulate amorphous solid dispersions (ASDs) which is an effective strategy to deliver poorly water soluble drugs (PWSDs). However, the inherently complex nature of the spray drying process coupled with specific characteristics of ASDs makes it an interesting area to explore. Numerous diverse factors interact in an inter-dependent manner to determine the final product properties. This review discusses the basic background of ASDs, various formulation and process variables influencing the critical quality attributes (CQAs) of the ASDs and aspects of downstream processing. Also various aspects of spray drying such as instrumentation, thermodynamics, drying kinetics, particle formation process and scale-up challenges are included. Recent advances in the spray-based drying techniques are mentioned along with some future avenues where major research thrust is needed. Copyright © 2015 Elsevier B.V. All rights reserved.
Canonical formulation of general-relativistic theories
International Nuclear Information System (INIS)
Bergmann, P.G.
1987-01-01
With the birth of quantum field theory in the late twenties physicists decided that nature could not be half classical and half quantum, and that the gravitational field ought to be quanticized, just as the electromagnetic field had been. One could accept the group of differomorphisms as a fundamental characteristic of general relativity (and indeed of all general-relativistic theories), and proceed to construct a quantum field-theory that was adapted to that group. Quantization would be attempted by way of a Hamiltonian formulation of the (classical) theory, and quantum commutation relations be patterned after the Poisson brackets arising in that formulation. This program is usually called the canonical quantization program, whereas the weak-field approach is known as covariant quantization. The first steps, conceived entirely within the framework of the classical theory, turned out to be beset with technical and conceptual difficulties, which today are essentially resolved. In this paper the author traces out these initial steps
Planar multibody dynamics formulation, programming and applications
Nikravesh, Parviz E
2007-01-01
Introduction Multibody Mechanical Systems Types of Analyses Methods of Formulation Computer Programming Application Examples Unit System Remarks Preliminaries Reference Axes Scalars and Vectors Matrices Vector, Array, and Matrix Differentiation Equations and Expressions Remarks Problems Fundamentals of Kinematics A Particle Kinematics of a Rigid Body Definitions Remarks Problems Fundamentals of Dynamics Newton's Laws of Motion Dynamics of a Body Force Elements Applied Forces Reaction Force Remarks Problems Point-Coordinates: Kinematics Multipoint
Alternative formulations of the electricity tax
International Nuclear Information System (INIS)
2003-01-01
According to EFTA's surveillance authority ESA, the current form of the electricity tax may have a competition distorting effect since only the industry and a few other sectors are exempt from it. This document discusses four alternative formulations of the electricity tax: same tax for all business sectors and households, defining a maximum payment for each firm, introduce a tax on power transmission, or have taxation only on power used for heating.
Formulation and Evaluation of Bioadhesive Cyproheptadine Tablets ...
African Journals Online (AJOL)
Results: The shear stress of 3 % solution of HPMC was greater than that of an equivalent concentration of Carbopol 934P. The values of K, n, R2 and detachment force for the optimized formulation (F0) were 0.269, 0.696, 0.964 and 0.066 Newton (N), respectively, and showed good correlation with the predicted values, thus ...
Ising formulations of many NP problems
Lucas, Andrew
2013-01-01
We provide Ising formulations for many NP-complete and NP-hard problems, including all of Karp's 21 NP-complete problems. This collects and extends mappings to the Ising model from partitioning, covering and satisfiability. In each case, the required number of spins is at most cubic in the size of the problem. This work may be useful in designing adiabatic quantum optimization algorithms.
Ising formulations of many NP problems
Directory of Open Access Journals (Sweden)
Andrew eLucas
2014-02-01
Full Text Available We provide Ising formulations for many NP-complete and NP-hard problems, including all of Karp's 21 NP-complete problems. This collects and extends mappings to the Ising model from partitioning, covering and satisfiability. In each case, the required number of spins is at most cubic in the size of the problem. This work may be useful in designing adiabatic quantum optimization algorithms.
Microcanonical ensemble formulation of lattice gauge theory
International Nuclear Information System (INIS)
Callaway, D.J.E.; Rahman, A.
1982-01-01
A new formulation of lattice gauge theory without explicit path integrals or sums is obtained by using the microcanonical ensemble of statistical mechanics. Expectation values in the new formalism are calculated by solving a large set of coupled, nonlinear, ordinary differential equations. The average plaquette for compact electrodynamics calculated in this fashion agrees with standard Monte Carlo results. Possible advantages of the microcanonical method in applications to fermionic systems are discussed
Path Integral Formulation of Anomalous Diffusion Processes
Friedrich, Rudolf; Eule, Stephan
2011-01-01
We present the path integral formulation of a broad class of generalized diffusion processes. Employing the path integral we derive exact expressions for the path probability densities and joint probability distributions for the class of processes under consideration. We show that Continuous Time Random Walks (CTRWs) are included in our framework. A closed expression for the path probability distribution of CTRWs is found in terms of their waiting time distribution as the solution of a Dyson ...
FORMULATION AND EVALUATION OF A HERBAL SHAMPOO
Gouri Kumar Dash* and Noor Husna Nazirah Binti A. Razak
2017-01-01
The study was aimed at formulating and evaluating a complete herbal shampoo containing only traditionally used plant materials. The shampoo contained extracts of Hibiscus rosa-sinensis, Azadirachta indica, Trigonella foenumgraecum, Phyllanthus emblica, Sapindus mukorossi, Acacia concinna and fresh juice of Aloe vera. The physicochemical parameters such as colour, clarity, pH, skin irritation, percentage of solid contents, dirt dispersion, foaming ability and foam stability, wetting time and c...
Prednisone raw material characterization and formulation development
Leonardo Henrique Toehwé; Livia Deris Prado; Helvécio Vinícius Antunes Rocha
2018-01-01
ABSTRACT Solid dosage forms for oral use, particularly tablets, are the most highly used dosage forms in therapy because they are easily administered, have high productivity and relatively low cost and provide a more stable drug to form a semi-solid net. Numerous parameters influence the quality of the final dosage form. In this study, the dissolution profile of 20-mg prednisone tablets bioequivalent to the reference product and three test formulations were evaluated using stability testing. ...
A meshless scheme for incompressible fluid flow using a velocity-pressure correction method
Bourantas, Georgios
2013-12-01
A meshless point collocation method is proposed for the numerical solution of the steady state, incompressible Navier-Stokes (NS) equations in their primitive u-v-p formulation. The flow equations are solved in their strong form using either a collocated or a semi-staggered "grid" configuration. The developed numerical scheme approximates the unknown field functions using the Moving Least Squares approximation. A velocity, along with a pressure correction scheme is applied in the context of the meshless point collocation method. The proposed meshless point collocation (MPC) scheme has the following characteristics: (i) it is a truly meshless method, (ii) there is no need for pressure boundary conditions since no pressure constitutive equation is solved, (iii) it incorporates simplicity and accuracy, (iv) results can be obtained using collocated or semi-staggered "grids", (v) there is no need for the usage of a curvilinear system of coordinates and (vi) it can solve steady and unsteady flows. The lid-driven cavity flow problem, for Reynolds numbers up to 5000, has been considered, by using both staggered and collocated grid configurations. Following, the Backward-Facing Step (BFS) flow problem was considered for Reynolds numbers up to 800 using a staggered grid. As a final example, the case of a laminar flow in a two-dimensional tube with an obstacle was examined. © 2013 Elsevier Ltd.
Trigger chemistries for better industrial formulations.
Wang, Hsuan-Chin; Zhang, Yanfeng; Possanza, Catherine M; Zimmerman, Steven C; Cheng, Jianjun; Moore, Jeffrey S; Harris, Keith; Katz, Joshua S
2015-04-01
In recent years, innovations and consumer demands have led to increasingly complex liquid formulations. These growing complexities have provided industrial players and their customers access to new markets through product differentiation, improved performance, and compatibility/stability with other products. One strategy for enabling more complex formulations is the use of active encapsulation. When encapsulation is employed, strategies are required to effect the release of the active at the desired location and time of action. One particular route that has received significant academic research effort is the employment of triggers to induce active release upon a specific stimulus, though little has translated for industrial use to date. To address emerging industrial formulation needs, in this review, we discuss areas of trigger release chemistries and their applications specifically as relevant to industrial use. We focus the discussion on the use of heat, light, shear, and pH triggers as applied in several model polymeric systems for inducing active release. The goal is that through this review trends will emerge for how technologies can be better developed to maximize their value through industrial adaptation.
What is Quantum Mechanics? A Minimal Formulation
Friedberg, R.; Hohenberg, P. C.
2018-03-01
This paper presents a minimal formulation of nonrelativistic quantum mechanics, by which is meant a formulation which describes the theory in a succinct, self-contained, clear, unambiguous and of course correct manner. The bulk of the presentation is the so-called "microscopic theory", applicable to any closed system S of arbitrary size N, using concepts referring to S alone, without resort to external apparatus or external agents. An example of a similar minimal microscopic theory is the standard formulation of classical mechanics, which serves as the template for a minimal quantum theory. The only substantive assumption required is the replacement of the classical Euclidean phase space by Hilbert space in the quantum case, with the attendant all-important phenomenon of quantum incompatibility. Two fundamental theorems of Hilbert space, the Kochen-Specker-Bell theorem and Gleason's theorem, then lead inevitably to the well-known Born probability rule. For both classical and quantum mechanics, questions of physical implementation and experimental verification of the predictions of the theories are the domain of the macroscopic theory, which is argued to be a special case or application of the more general microscopic theory.
Development of formulation device for periodontal disease.
Sato, Yasuhiko; Oba, Takuma; Watanabe, Norio; Danjo, Kazumi
2012-01-01
In addition to providing standard surgical treatment that removes the plaque and infected tissues, medications that can regenerate periodontal tissue are also required in the treatment of periodontal disease. As a form of regenerative medication, various growth factors are expected to be used while treating periodontal disease. A protein-like growth factor is often developed as a lyophilized product with dissolution liquid, considering its instability in the solution state. We have clarified that the formulation for periodontal disease needs to be viscous. When the lyophilized product was dissolved using a sticky solution, various problems were encountered, difficulty in dissolving and air bubbles, for example, and some efforts were needed to prepare the formulation. In this research, to identify the problem of preparing a viscous formulation, a lyophilized product (placebo) and sticky liquid were prepared by using vial and ampoule as the conventional containers. Based on these problems, a prototype administration device was developed, and its functionality was confirmed. As a result, it was suggested that the device with a useful mixing system that could shorten the preparation time was developed.
Alibolandi, Mona; Abnous, Khalil; Mohammadi, Marzieh; Hadizadeh, Farzin; Sadeghi, Fatemeh; Taghavi, Sahar; Jaafari, Mahmoud Reza; Ramezani, Mohammad
2017-10-28
Due to the severe cardiotoxicity of doxorubicin, its usage is limited. This shortcoming could be overcome by modifying pharmacokinetics of the drugs via preparation of various nanoplatforms. Doxil, a well-known FDA-approved nanoplatform of doxorubicin as antineoplastic agent, is frequently used in clinics in order to reduce cardiotoxicity of doxorubicin. Since Doxil shows some shortcomings in clinics including hand and food syndrome and very slow release pattern thus, there is a demand for the development and preparation of new doxorubicin nanoformulation with fewer side effects. The new formulation of the doxorubicin, synthesized previously by our group was extensively examined in the current study. This new formulation is doxorubicin encapsulated in PEG-PLGA polymersomes (PolyDOX). The main aim of the study was to compare the distribution and treatment efficacy of a new doxorubicin-polymersomal formulation (PolyDOX) with regular liposomal formulation (Doxil-mimic) in murine colon adenocarcinoma model. Additionally, the pathological, hematological changes, pharmacodynamics, biodistribution, tolerated dose and survival rate in vivo were evaluated and compared. Murine colon cancer model was induced by subcutaneous inoculation of BALB/c mice with C26 cells. Afterwards, either Doxil-mimic or PolyDOX was administered intravenously. The obtained results from biodistribution study showed a remarkable difference in the distribution of drugs in murine organs. In this regard, Doxil-mimic exhibited prolonged (48h) presence within liver tissues while PolyDOX preferentially accumulate in tumor and the presence in liver 48h post-treatment was significantly lower than that of Doxil-mimic. Obtained results demonstrated comparable final length of life for mice receiving either Doxil-mimic or PolyDOX formulations whereas tolerated dose of mice receiving Doxil-mimic was remarkably higher than those receiving PolyDOX. Therapeutic efficacy of formulation in term of tumor growth rate
Mackenzie, S G; Leinonen, I; Ferguson, N; Kyriazakis, I
2016-05-28
The objective of this study was to develop a novel methodology that enables pig diets to be formulated explicitly for environmental impact objectives using a Life Cycle Assessment (LCA) approach. To achieve this, the following methodological issues had to be addressed: (1) account for environmental impacts caused by both ingredient choice and nutrient excretion, (2) formulate diets for multiple environmental impact objectives and (3) allow flexibility to identify the optimal nutritional composition for each environmental impact objective. An LCA model based on Canadian pig farms was integrated into a diet formulation tool to compare the use of different ingredients in Eastern and Western Canada. By allowing the feed energy content to vary, it was possible to identify the optimum energy density for different environmental impact objectives, while accounting for the expected effect of energy density on feed intake. A least-cost diet was compared with diets formulated to minimise the following objectives: non-renewable resource use, acidification potential, eutrophication potential, global warming potential and a combined environmental impact score (using these four categories). The resulting environmental impacts were compared using parallel Monte Carlo simulations to account for shared uncertainty. When optimising diets to minimise a single environmental impact category, reductions in the said category were observed in all cases. However, this was at the expense of increasing the impact in other categories and higher dietary costs. The methodology can identify nutritional strategies to minimise environmental impacts, such as increasing the nutritional density of the diets, compared with the least-cost formulation.
Instability of the cored barotropic disc: the linear eigenvalue formulation
Polyachenko, E. V.
2018-05-01
Gaseous rotating razor-thin discs are a testing ground for theories of spiral structure that try to explain appearance and diversity of disc galaxy patterns. These patterns are believed to arise spontaneously under the action of gravitational instability, but calculations of its characteristics in the gas are mostly obscured. The paper suggests a new method for finding the spiral patterns based on an expansion of small amplitude perturbations over Lagrange polynomials in small radial elements. The final matrix equation is extracted from the original hydrodynamical equations without the use of an approximate theory and has a form of the linear algebraic eigenvalue problem. The method is applied to a galactic model with the cored exponential density profile.
Role reductants in dilute chemical decontamination formulations
Energy Technology Data Exchange (ETDEWEB)
Ranganathan, S. [Univ. of New Brunswick (Canada). Dept. of Chemical Engineering; Srinivasan, M.P.; Narasimhan, S.V. [Bhabha Atomic Research Centre (BARC), Trombay, Mumbai (India). Water and Steam Chemistry Lab.; Raghavan, P.S. [Madras Christian Coll., Chennai (India); Gopalan, R. [Madras Christian Coll., Chennai (India). Dept. of Chemistry
2004-10-01
Iron(III) oxides are the major corrosion products formed in boiling water reactors. The iron(III) oxides are of two types, namely hematite ({alpha}-Fe{sub 2}O{sub 3}) and maghemite ({gamma}-Fe{sub 2}O{sub 3}). The dissolution of these oxides is in no way simple because of the labile nature of the Fe(III)-O bond towards the chelants. The leaching of metal ions is partially controlled by reductive dissolution. In order to understand the role of the reductant, it is essential to study the dissolution behaviour of a system like Fe{sub 2}O{sub 3}, which does not contain any Fe{sup 2+} in the crystal lattice. The present study was carried out with {gamma}-Fe{sub 2}O{sub 3} and dilute chemical decontamination (DCD) formulations containing ascorbic acid and citric acid with the addition of Fe(II)-L as a reductant. The chelants used for the dissolution process were nitrilotriacetic acid, 2,6-pyridinedicorboxylic acid and ethylenediaminetetraacetic acid. The {gamma}-Fe{sub 2}O{sub 3} was chosen since the earlier studies revealed that the dissolution kinetics of {alpha}-Fe{sub 2}O{sub 3} is slow and it is difficult to dissolve even by strong complexing agents, whereas {gamma}-Fe{sub 2}O{sub 3} dissolution is comparatively easier. This is due to the structural difference between these two oxides. The studies also revealed that the dissolution was partly influenced by the nature of the chelating agents but mainly controlled by the power of the reductants used in the formulation. The dissolution behaviour of {gamma}-Fe{sub 2}O{sub 3} under various experimental conditions is discussed and compared with that of magnetite in order to arrive at a suitable mechanism for the dissolution of iron oxides and emphasize the role of reductants in DCD formulations. (orig.)
Random path formulation of nonrelativistic quantum mechanics
International Nuclear Information System (INIS)
Roncadelli, M.
1993-01-01
Quantum amplitudes satisfy (almost) the same calculus that probabilities obey in the theory of classical stochastic diffusion processes. As a consequence of this structural analogy, a new formulation of (nonrelativistic) quantum mechanics naturally arises as the quantum counterpart of the Langevin description of (classical) stochastic diffusion processes. Quantum fluctuations are simulated here by a Fresnel white noise (FWN), which is a (real) white noise with imaginary diffusion constant, whose functional (pseudo) measure yields the amplitude distribution for its configurations. Central to this approach is the idea that classical dynamical trajectories in configuration space are perturbed by the FWN. Hence, a single (arbitrary) classical dynamical path gets replaced by a family of quantum random paths (QRPs) - one for each FWN sample - all originating from the same space-time point (x', t'). The QRPs are the basic objects of the present formulation and are given by a Langevin equation with the FWN, whose drift is controlled by a (arbitrary) solution to the classical Hamilton-Jacobi equation. So, our approach is manifestly based on classical dynamics. Now, a transition amplitude is associated with each QRP: it gives the amplitude that a particle starting from (x', t') will reach (x'', t'') by travelling just along the considered QRP. The quantum mechanical propagator (x'', t'' modul x', t') then emerges as the FWN average of the transition amplitude along a QRP. Thus, quantum mechanics looks like classical mechanics as perturbed by the FWN. The general structure of this formulation is discussed in detail, along with some practical and conceptual implications. (author). 14 refs
Formulation of optimal international freight transport objective
Directory of Open Access Journals (Sweden)
A. Jarašūnienė
2002-10-01
Full Text Available To increase the attraction of Lithuania as a transit country striving to promote carriers' border crossing activities and facilitate customs clearance procedures as well as freight delivery to clients it is necessary to identify the main obstacles, to analyse them and to select adequate measures and means for their elimination. Therefore, on the basis of the formulation of transport freight management objective, as well as basing on the assessment of indeterminacy of external impacts, it would be possible to deduce the main causes of idle time of transport means in customs, to estimate the dependence of service time in proportion to transport flow.
Variational formulation of the Gardner's restacking algorithm
International Nuclear Information System (INIS)
Dodin, I.Y.; Fisch, N.J.
2004-01-01
The incompressibility of the phase flow of Hamiltonian wave-plasma interactions restrains the class of realizable wave-driven transformations of the particle distribution. After the interaction, the distribution remains composed of the original phase-space elements, or local densities, which are only rearranged (''restacked'') by the wave. A variational formalism is developed to study the corresponding limitations on the energy and momentum transfer. A case of particular interest is a toroidal plasma immersed in a dc magnetic field. The restacking algorithm by Gardner [Phys. Fluids 6, 839 (1963)] is formulated precisely. The minimum energy state for a plasma with a given current is determined
Canonical formulation of IIB D-branes
International Nuclear Information System (INIS)
Kamimura, K.
1998-01-01
We find Wess-Zumino actions for kappa invariant type IIB D-branes in explicit forms. A simple and compact expression is obtained by the use of spinor variables which are defined as power series of differential forms. Using the Wess-Zumino actions we develop the canonical formulation and find the complete set of the constraint equations for generic type IIB Dp-branes. The conserved global supersymmetry charges are determined and the algebra containing the central charges can be obtained explicitly. (orig.)
A geometric formulation of exceptional field theory
Energy Technology Data Exchange (ETDEWEB)
Bosque, Pascal du [Arnold Sommerfeld Center for Theoretical Physics,Department für Physik, Ludwig-Maximilians-Universität München,Theresienstraße 37, 80333 München (Germany); Max-Planck-Institut für Physik, Werner-Heisenberg-Institut, Föhringer Ring 6, 80805 München (Germany); Hassler, Falk [Department of Physics and Astronomy, University of North Carolina, Phillips Hall, CB #3255, 120 E. Cameron Ave., Chapel Hill, NC 27599-3255 (United States); City University of New York, The Graduate Center, 365 Fifth Avenue, New York, NY 10016 (United States); Department of Physics, Columbia University, Pupin Hall, 550 West 120th St., New York, NY 10027 (United States); Lüst, Dieter [Arnold Sommerfeld Center for Theoretical Physics,Department für Physik, Ludwig-Maximilians-Universität München,Theresienstraße 37, 80333 München (Germany); Max-Planck-Institut für Physik, Werner-Heisenberg-Institut, Föhringer Ring 6, 80805 München (Germany); Malek, Emanuel [Arnold Sommerfeld Center for Theoretical Physics,Department für Physik, Ludwig-Maximilians-Universität München,Theresienstraße 37, 80333 München (Germany)
2017-03-01
We formulate the full bosonic SL(5) exceptional field theory in a coordinate-invariant manner. Thereby we interpret the 10-dimensional extended space as a manifold with SL(5)×ℝ{sup +}-structure. We show that the algebra of generalised diffeomorphisms closes subject to a set of closure constraints which are reminiscent of the quadratic and linear constraints of maximal seven-dimensional gauged supergravities, as well as the section condition. We construct an action for the full bosonic SL(5) exceptional field theory, even when the SL(5)×ℝ{sup +}-structure is not locally flat.
Preparation and characterization of Slow Release Formulations of ...
African Journals Online (AJOL)
alginate beads and characterize the resulting slow release formulations (SRFs) using scanning electron microscopy (SEM), and Fourier Transform infrared spectroscopy (FTIR). Two sets of formulations were made by extrusion into 0.25 M calcium ...
Walsh, Jennifer; Mills, Simon
2013-01-01
The fourth annual European Paediatric Formulation Initiative (EuPFI) conference on Formulating Better Medicines for Children was held on 19-20 September 2012 at the Institute of Molecular Genetics Congress Centre, Prague, Czech Republic. The 2-day conference concentrated on the latest advances, challenges and opportunities for developing medicinal products and administration devices for pediatric use, both from European and US perspectives. It was aimed specifically at providing exposure to emerging practical applications, and for illustrating remedies utilized by pediatric drug-development teams to overcome hurdles faced in developing medicines for pediatric patients. The conference format included plenary talks, focus sessions on each of the EuPFI work streams (extemporaneous preparations, excipients, pediatric administration devices, taste masking and taste assessment, age-appropriate formulations), case studies, soapbox sessions and a parallel poster display. This conference report summarizes the keynote lectures and also gives a flavor of other presentations and posters from the conference.
DCS Terrain Submission for Lagrange County, IN
Federal Emergency Management Agency, Department of Homeland Security — Terrain data, as defined in FEMA Guidelines and Specifications, Appendix N: Data Capture Standards, describes the digital topographic data that was used to create...
Formulation and Pharmacokinetic Evaluation of Controlled-Release ...
African Journals Online (AJOL)
A coating layer was then applied with a mixture of HPMC, ethylcellulose, shellac, and HPMC phthalate. The effect of several formulation variables on in vitro drug release was studied; furthermore, the drug release kinetics of the optimized formulation was evaluated. The in vivo pharmacokinetics of the optimized formulation ...
Super-Group Field Cosmology in Batalin-Vilkovisky Formulation
Upadhyay, Sudhaker
2016-09-01
In this paper we study the third quantized super-group field cosmology, a model in multiverse scenario, in Batalin-Vilkovisky (BV) formulation. Further, we propose the superfield/super-antifield dependent BRST symmetry transformations. Within this formulation we establish connection between the two different solutions of the quantum master equation within the BV formulation.
Standardization Of A Siddha Formulation Amukkara Curanam By ...
African Journals Online (AJOL)
Amukkara curanam, a Siddha formulation, currently used in all types of gastric disorders, rheumatic pain, insomnia and sexual insufficiency, was investigated for the estimation of the marker compounds, withaferine A and piperine contents in a prepared standard formulation and a commercial formulation by using HPTLC ...
Studies on the antimicrobial properties of formulated creams and ...
African Journals Online (AJOL)
Their performances were compared with those of standard antiseptic creams and ointments. The results of agar diffusion studies on cream and ointment formulations revealed that the topical bases used to disperse the medicaments could significantly affect the antimicrobial effectiveness of the formulation. Formulations ...
Formulation and method for preparing gels comprising hydrous aluminum oxide
Collins, Jack L.
2014-06-17
Formulations useful for preparing hydrous aluminum oxide gels contain a metal salt including aluminum, an organic base, and a complexing agent. Methods for preparing gels containing hydrous aluminum oxide include heating a formulation to a temperature sufficient to induce gel formation, where the formulation contains a metal salt including aluminum, an organic base, and a complexing agent.
Herbal antihyperlipidemic formulation of cocoa tea: Preparation and ...
African Journals Online (AJOL)
Purpose: To prepare and characterize a formulation containing an ethanol extract of Camellia ptilophylla leaves (cocoa tea), with a focus on antihyperlipidemic and anti-obesity activities. Methods: An aloe vera–based formulation of an ethanol extract of cocoa tea (C. ptilophylla) was prepared. The formulation was given ...
A displacement based FE formulation for steady state problems
Yu, Y.
2005-01-01
In this thesis a new displacement based formulation is developed for elasto-plastic deformations in steady state problems. In this formulation the displacements are the primary variables, which is in contrast to the more common formulations in terms of the velocities as the primary variables. In a
Animal Diet Formulation with Floating Price
Directory of Open Access Journals (Sweden)
S.H Nasseri
2016-12-01
Full Text Available In the process of milk production, the highest cost relates to animal feed. Based on reports provided by the experts, around seventy percent of dairy livestock costs included feed costs. In order to minimize the total price of livestock feed, according to the limits of feed sources in each region or season, and also the transportation and maintenance costs and ultimately milk price reduction, optimization of the livestock nutrition program is an essential issue. Because of the uncertainty and lack of precision in the optimal food ration done with existing methods based on linear programming, there is a need to use appropriate methods to meet this purpose. Therefore, in this study formulation of completely mixed nutrient diets of dairy cows is done by using a fuzzy linear programming in early lactation. Application of fuzzy optimization method and floating price make it possible to formulate and change the completely mixed diets with adequate safety margins. Therefore, applications of fuzzy methods in feed rations of dairy cattle are recommended to optimize the diets. Obviously, it would be useful to design suitable software, which provides the possibility of using floating prices to set feed rations by the use of fuzzy optimization method.
The covariant formulation of f ( T ) gravity
International Nuclear Information System (INIS)
Krššák, Martin; Saridakis, Emmanuel N
2016-01-01
We show that the well-known problem of frame dependence and violation of local Lorentz invariance in the usual formulation of f ( T ) gravity is a consequence of neglecting the role of spin connection. We re-formulate f ( T ) gravity starting from, instead of the ‘pure tetrad’ teleparallel gravity, the covariant teleparallel gravity, using both the tetrad and the spin connection as dynamical variables, resulting in a fully covariant, consistent, and frame-independent version of f ( T ) gravity, which does not suffer from the notorious problems of the usual, pure tetrad, f ( T ) theory. We present the method to extract solutions for the most physically important cases, such as the Minkowski, the Friedmann–Robertson–Walker (FRW) and the spherically symmetric ones. We show that in covariant f ( T ) gravity we are allowed to use an arbitrary tetrad in an arbitrary coordinate system along with the corresponding spin connection, resulting always in the same physically relevant field equations. (paper)
Comparison of different formulations of vitamin D
International Nuclear Information System (INIS)
Rashid, H.M.F.; Khalil, K.
2017-01-01
Vitamin D Deficiency (VDD) is responsible for a wide spectrum of clinical diseases and vitamin D deficiency prevalence is frightening in most parts of the world including Pakistan. Therefore, supplementations of vitamin D are used in the population at high risk for the prevention and the treatment of vitamin D deficiency. Vitamin D supplementation comes in various formulations both oral and intramuscular. Cholecalciferol is the most commonly used preparation which is given through these routes of administration. There is need to study the fact that how much vitamin D levels are raised after administration of these different formulations as this can be a pivotal factor in determining dosage and route of vitamin D3. Methods: This cross-sectional study conducted on 320 cases and compared the efficacy of various Vitamin D3 preparations in raising Vitamin D levels conducted in Department of Endocrinology and Metabolism, Services Hospital, Lahore from February to July, 2016. Blood serum was drawn for vitamin D level in the cases at the time of presentation and after treatment. Results: Three hundred and twenty patients were enrolled in study and divided into four groups (A, B, C, D). There was no significant difference between groups (A, B, C, D) in change in vitamin d levels after 3 months of treatment (p-Value 0.446). Conclusion: Different preparations of vitamin D are equally effective in raising vitamin D levels at 12 weeks. However, there is a need to conduct large scale studies to further validate these results. (author)
Statistical formulation of gravitational radiation reaction
International Nuclear Information System (INIS)
Schutz, B.F.
1980-01-01
A new formulation of the radiation-reaction problem is proposed, which is simpler than alternatives which have been used before. The new approach is based on the initial-value problem, uses approximations which need be uniformly valid only in compact regions of space-time, and makes no time-asymmetric assumptions (no a priori introduction of retarded potentials or outgoing-wave asymptotic conditions). It defines radiation reaction to be the expected evolution of a source obtained by averaging over a statistical ensemble of initial conditions. The ensemble is chosen to reflect one's complete lack of information (in real systems) about the initial data for the radiation field. The approach is applied to the simple case of a weak-field, slow-motion source in general relativity, where it yields the usual expressions for radiation reaction when the gauge is chosen properly. There is a discussion of gauge freedom, and another of the necessity of taking into account reaction corrections to the particle-conservation equation. The analogy with the second law of thermodynamics is very close, and suggests that the electromagnetic and thermodynamic arrows of time are the same. Because the formulation is based on the usual initial-value problem, it has no spurious ''runaway'' solutions
Terbinafine: novel formulations that potentiate antifungal activities.
Ma, Y; Chen, X; Guan, S
2015-03-01
Terbinafine, an orally and topically active antifungal agent, has been available for the treatment of dermatophytic infections and onychomycosis for more than a decade. In addition, oral administration has been shown to be associated with drug-drug interactions, hepatotoxicity, low concentration at the infected sites, gastrointestinal and systemic side effects and other adverse effects. Since topical drug delivery can provide higher patient compliance, allow immediate access to the infected site and reduce unwanted systemic drug exposure, an improved topical drug delivery approach with high permeability, sustained release and prolonged retainment could overcome the limitations and side effects caused by oral administration. Conventional topical formulations cannot keep the drug in the targeted sites for a long duration of time and hence a novel drug delivery that can avoid the side effects while still providing sustained efficacy in treatment should be developed. This brief review of novel formulations based on polymers and nanostructure carriers provides insight into the efficacy and topical delivery of terbinafine. Copyright 2015 Prous Science, S.A.U. or its licensors. All rights reserved.
Stabilisation de la formule des traces tordue
Moeglin, Colette
2016-01-01
Ce travail en deux volumes donne la preuve de la stabilisation de la formule des trace tordue. Stabiliser la formule des traces tordue est la méthode la plus puissante connue actuellement pour comprendre l'action naturelle du groupe des points adéliques d'un groupe réductif, tordue par un automorphisme, sur les formes automorphes de carré intégrable de ce groupe. Cette compréhension se fait en réduisant le problème, suivant les idées de Langlands, à des groupes plus petits munis d'un certain nombre de données auxiliaires; c'est ce que l'on appelle les données endoscopiques. L'analogue non tordu a été résolu par J. Arthur et dans ce livre on suit la stratégie de celui-ci. Publier ce travail sous forme de livre permet de le rendre le plus complet possible. Les auteurs ont repris la théorie de l'endoscopie tordue développée par R. Kottwitz et D. Shelstad et par J.-P. Labesse. Ils donnent tous les arguments des démonstrations même si nombre d'entre eux se trouvent déjà dans les travaux d'Ar...
Cumulative irritation potential of topical retinoid formulations.
Leyden, James J; Grossman, Rachel; Nighland, Marge
2008-08-01
Localized irritation can limit treatment success with topical retinoids such as tretinoin and adapalene. The factors that influence irritant reactions have been shown to include individual skin sensitivity, the particular retinoid and concentration used, and the vehicle formulation. To compare the cutaneous tolerability of tretinoin 0.04% microsphere gel (TMG) with that of adapalene 0.3% gel and a standard tretinoin 0.025% cream. The results of 2 randomized, investigator-blinded studies of 2 to 3 weeks' duration, which utilized a split-face method to compare cumulative irritation scores induced by topical retinoids in subjects with healthy skin, were combined. Study 1 compared TMG 0.04% with adapalene 0.3% gel over 2 weeks, while study 2 compared TMG 0.04% with tretinoin 0.025% cream over 3 weeks. In study 1, TMG 0.04% was associated with significantly lower cumulative scores for erythema, dryness, and burning/stinging than adapalene 0.3% gel. However, in study 2, there were no significant differences in cumulative irritation scores between TMG 0.04% and tretinoin 0.025% cream. Measurements of erythema by a chromameter showed no significant differences between the test formulations in either study. Cutaneous tolerance of TMG 0.04% on the face was superior to that of adapalene 0.3% gel and similar to that of a standard tretinoin cream containing a lower concentration of the drug (0.025%).
Projecting India's energy requirements for policy formulation
International Nuclear Information System (INIS)
Parikh, Kirit S.; Karandikar, Vivek; Rana, Ashish; Dani, Prasanna
2009-01-01
Energy policy has to have a long-term perspective. To formulate it one needs to know the contours of energy requirements and options. Different approaches have been followed in literature, each with their own problems. A top down econometric approach provides little guidance on policies, while a bottom up approval requires too much knowledge and too many assumptions. Using top-down econometric approach for aggregate overall benchmarking and a detailed activity analysis model, Integrated Energy System Model, for a few large sectors, provides a unique combination for easing the difficulties of policy formulation. The model is described in this paper. Eleven alternate scenarios are built, designed to map out extreme points of feasible options. Results show that even after employing all domestic energy resource to their full potential, there will be a continued rise of fossil fuel use, continued importance of coal, and continued rise of import dependence. Energy efficiency emerges as a major option with a potential to reduce energy requirement by as much as 17%. Scenario results point towards pushing for development of alternative sources. (author)
Factors for formulating strategies for environmental restoration
International Nuclear Information System (INIS)
1998-07-01
This publication focusses on factors which are important for formulating a strategy for environmental restoration. In parallel to this effort, the IAEA has conducted activities in related areas which have been reported in companion reports dealing with (1) the characterization of radioactively contaminated sites for remediation purposes and (2) available technology for cleanup and remediation of radioactively contaminated sites. Additionally, follow-up activities will focus on two other areas, viz. planning and management options for cleanup of contaminated groundwater, and post-restoration monitoring of decommissioned sites. In a separate initiative the IAEA has developed preliminary guidance on radiological criteria for determining when cleanup action is needed and for deciding on when areas have been cleaned up to a sufficient extent. It is also concerned with radioactive contamination of soils, groundwaters, structures and biota which may have the potential for harm to people. It is intended that it will serve as an important source of information and data on the key factors to be considered in the formulation of an environmental restoration strategy
Perturbation theory and importance functions in integral transport formulations
International Nuclear Information System (INIS)
Greenspan, E.
1976-01-01
Perturbation theory expressions for the static reactivity derived from the flux, collision density, birth-rate density, and fission-neutron density formulations of integral transport theory, and from the integro-differential formulation, are intercompared. The physical meaning and relation of the adjoint functions corresponding to each of the five formulations are established. It is found that the first-order approximation of the perturbation expressions depends on the transport theory formulation and on the adjoint function used. The approximations of the integro-differential formulation corresponding to different first-order approximations of the integral transport theory formulations are identified. It is found that the accuracy of all first-order approximations of the integral transport formulations examined is superior to the accuracy of first-order integro-differential perturbation theory
Flow Formulations for Curriculum-based Course Timetabling
DEFF Research Database (Denmark)
Bagger, Niels-Christian Fink; Kristiansen, Simon; Sørensen, Matias
2017-01-01
lower bound on one data instance in the benchmark data set from the second international timetabling competition. Regarding upper bounds, the formulation based on the minimum cost flow problem performs better on average than other mixed integer programming approaches for the CTT.......In this paper we present two mixed-integer programming formulations for the Curriculum based Course Timetabling Problem (CTT). We show that the formulations contain underlying network structures by dividing the CTT into two separate models and then connect the two models using flow formulation...... techniques. The first mixed-integer programming formulation is based on an underlying minimum cost flow problem, which decreases the number of integer variables significantly and improves the performance compared to an intuitive mixed-integer programming formulation. The second formulation is based...
Determination of Fluoride in Different Toothpaste Formulations
International Nuclear Information System (INIS)
Kamau, N.G.; Njoroge, M.; Njau, M.
1998-01-01
Fluoride ion selective electrode was used to determine fluoride ion concentrations in seven brands of toothpaste. These were the only available formulations found in Kenya. The brands were classified into three groups-fluoridated, non fluoridated or not indicated. However, there was no independent indication of their quantitative composition. The analysed brands had fluoride content between 0.0033% and 0.096%. These values compared favourably with those obtained elsewhere. The calculated lowest limit of detection (LLD) was 0.01 ppmF- . The mean calibration curve gave a slope of of -50.0mV. which was not significantly different from the theoretical value of 5.88mV at 23 degrees celsius at 95% confidence level
Real symplectic formulation of local special geometry
Ferrara, Sergio; Ferrara, Sergio; Macia, Oscar
2006-01-01
We consider a formulation of local special geometry in terms of Darboux special coordinates $P^I=(p^i,q_i)$, $I=1,...,2n$. A general formula for the metric is obtained which is manifestly $\\mathbf{Sp}(2n,\\mathbb{R})$ covariant. Unlike the rigid case the metric is not given by the Hessian of the real function $S(P)$ which is the Legendre transform of the imaginary part of the holomorphic prepotential. Rather it is given by an expression that contains $S$, its Hessian and the conjugate momenta $S_I=\\frac{\\partial S}{\\partial P^I}$. Only in the one-dimensional case ($n=1$) is the real (two-dimensional) metric proportional to the Hessian with an appropriate conformal factor.
Grout formulations for nuclear-waste isolation
International Nuclear Information System (INIS)
Buck, A.D.; Mather, K.
1982-06-01
It is imperative that control parameters for a grout mixture such as flow time, setting time, compressive strength, permeability, or combinations of these or of other properties be specified before a grout mixture is formulated and used. Once such parameters have been specified, it is possible to proportion a hydraulic cement-based grout mixture to meet the applicable requirements. This may be from experience or by trial mixtures or by both. While longevity of cemetitious mixtures in nonaggressive environments is known from history, satisfactory data involving specific mixtures in selected environments are still needed. Such testing is underway. While compatibility, especially long-term compatibility, of cemetitious mixtures with various rock types is also known, it is necessary to have such evidence for specific mixtures in contact with specific rocks in a selected environment or environments. Satisfactory grout mixtures may be proportioned using the standard practice set forth in Appendix A
Single-particle Schroedinger fluid. I. Formulation
International Nuclear Information System (INIS)
Kan, K.K.; Griffin, J.J.
1976-01-01
The problem of a single quantal particle moving in a time-dependent external potential well is formulated specifically to emphasize and develop the fluid dynamical aspects of the matter flow. This idealized problem, the single-particle Schroedinger fluid, is shown to exhibit already a remarkably rich variety of fluid dynamical features, including compressible flow and line vortices. It provides also a sufficient framework to encompass simultaneously various simplified fluidic models for nuclei which have earlier been postulated on an ad hoc basis, and to illuminate their underlying restrictions. Explicit solutions of the single-particle Schroedinger fluid problem are studied in the adiabatic limit for their mathematical and physical implications (especially regarding the collective kinetic energy). The basic generalizations for extension of the treatment to the many-body Schroedinger fluid are set forth
Formulating transgenerational technology critique as conflictual collaboration
DEFF Research Database (Denmark)
Chimirri, Niklas Alexander
2015-01-01
In the fields of technology design studies and human-computer interaction (HCI), participatory technology design involving children has been on the rise. Particularly studies applying and developing the cooperative inquiry methodology or inspired by it are of growing interest to media technology...... designers. While the underlying impetus of actively involving the intended users in the design process and thereby taking the children as seriously as adult users is laudable, the overarching framing and directionality of the technology design process is rendered unquestionable for the children....... The presentation illustrates that the pristine intention of engaging in intergenerational technology design is potentially helpful for collectively formulating a productive and sustainable technology critique. On the downside the applied methodologies lack viable concepts for meaningfully analyzing its...
Peridynamic Formulation for Coupled Thermoelectric Phenomena
Directory of Open Access Journals (Sweden)
Migbar Assefa
2017-01-01
Full Text Available Modeling of heat and electrical current flow simultaneously in thermoelectric convertor using classical theories do not consider the influence of defects in the material. This is because traditional methods are developed based on partial differential equations (PDEs and lead to infinite fluxes at the discontinuities. The usual way of solving such PDEs is by using numerical technique, like Finite Element Method (FEM. Although FEM is robust and versatile, it is not suitable to model evolving discontinuities. To avoid such shortcomings, we propose the concept of peridynamic theory to derive the balance of energy and charge equations in the coupled thermoelectric phenomena. Therefore, this paper presents the transport of heat and charge in thermoelectric material in the framework of peridynamic (PD theory. To illustrate the reliability of the PD formulation, numerical examples are presented and results are compared with those from literature, analytical solutions, or finite element solutions.
Spontaneously broken extended supersymmetry: Full superfield formulation
International Nuclear Information System (INIS)
Kandelakis, E.S.
1984-01-01
The superfield description, given by Samuel and Wess, of the non-linear Akulov-Volkov realization of (broken) supersymmetry, is generalized for the interesting cases of N=2 and 4 extended supersymmetry. The generalization, in terms of the full-superfield formulation, is straightforward. For the proof we first define the corresponding THETA-algebras; we then present explicitly many of the calculations. The schematic explanation makes the generalization manifest. We perform, for N=2, the coupling of the A-V field to standard-matter, in the way introduced by S-W, and schematically we make manifest the generalization for every N. The importance of our results consists in a complete, calculable description of the A-V fields (goldstinos) and of their interactions, easily applied to the tasks of today's phenomenology. (orig.) [de
Problem formulation as a discursive design activity
DEFF Research Database (Denmark)
Hansen, Claus Thorp; Dorst, Kees; Andreasen, Mogens Myrup
2009-01-01
In the design methodology literature, design is often described as a rational problem solving process. This approach has been very successful; it has lead to the creation of design process models, tools, methods and techniques. Design methods teaching along these lines has become an indispensable...... part of any engineering design education. Yet the assumptions behind the rational problem solving approach to design do not sit well with some of the experiences we have in design teaching and design practice. Problem formulation is one such area where we might have to look for a different way...... to describe what is happening in design, beyond the problem solving approach. In this paper an extensive educational case study will be used to see whether a framework for describing design as a discursive activity (based on the notions of ‘discourse’ and ‘paradox’) could be more appropriate to describe...
FORMATE-BASED FLUIDS: FORMULATION AND APPLICATION
Directory of Open Access Journals (Sweden)
Nediljka Gaurina-Međimurec
2008-12-01
Full Text Available Formate-based fluids has been successfully used in over hunders HPHT well operations since they introduced in field practice. They have many advantages when compared with conventional HPHT drilling and completion fluids such as: minimal formation damage, maintenance of additve properties at high temperatures, reduced hydraulic flow resistance, low potential for differential sticking, naturally lubricating, very low corrosion rates, biodegradable and pose little risk to the environment etc. Formate-based fluids can be applied during deep slim hole drilling, shale drilling, reservoir drilling, salt and gas hydrate formations drilling. The laboratory research was carried out to evaluate the rheological behavior of formate-based fluids as a function of temperature. Formate-based fluids were formulated using potassium formate brine, xanthan polymer, PAC, starch and calcium carbonate. Experimental results show that potassium formate improves the thermal stability of polymers.
Towards strategy formulation in a complex environment
Directory of Open Access Journals (Sweden)
René Pellissier
2014-01-01
Full Text Available The management sciences offer mainly linear solutions to an environment that is becoming increasingly complex. This is aggravated by the need for innovation outcomes. Formulating and implementing strategy is therefore far more complicated. Since developing economies face far less stable environments, businesses operating in these domains are more accustomed (even adept to deal with complexity. This article compares the deployment of complexity in strategy to achieve innovation in either a developing or a developed economy setting. From interviews conducted with selected CEOs from both economies, it was found that the businesses in the developing economies include complexity factors in their strategies whereas those in developed economies focus on operational excellence and not on complexity. Therefore, at this point, businesses in developed economies may want to explore the strategies adopted by those in developing economies to accommodate diversity and the dynamic environment that require innovations.
A lattice formulation of chiral gauge theories
International Nuclear Information System (INIS)
Bodwin, G.T.
1995-12-01
The authors present a method for formulating gauge theories of chiral fermions in lattice field theory. The method makes use of a Wilson mass to remove doublers. Gauge invariance is then restored by modifying the theory in two ways: the magnitude of the fermion determinant is replaced with the square root of the determinant for a fermion with vector-like couplings to the gauge field; a double limit is taken in which the lattice spacing associated with the fermion field is taken to zero before the lattice spacing associated with the gauge field. The method applies only to theories whose fermions are in an anomaly-free representation of the gauge group. They also present a related technique for computing matrix elements of operators involving fermion fields. Although the analyses of these methods are couched in weak-coupling perturbation theory, it is argued that computational prescriptions are gauge invariant in the presence of a nonperturbative gauge-field configuration
Covariant formulation of scalar-torsion gravity
Hohmann, Manuel; Järv, Laur; Ualikhanova, Ulbossyn
2018-05-01
We consider a generalized teleparallel theory of gravitation, where the action contains an arbitrary function of the torsion scalar and a scalar field, f (T ,ϕ ) , thus encompassing the cases of f (T ) gravity and a nonminimally coupled scalar field as subclasses. The action is manifestly Lorentz invariant when besides the tetrad one allows for a flat but nontrivial spin connection. We derive the field equations and demonstrate how the antisymmetric part of the tetrad equations is automatically satisfied when the spin connection equation holds. The spin connection equation is a vital part of the covariant formulation, since it determines the spin connection associated with a given tetrad. We discuss how the spin connection equation can be solved in general and provide the cosmological and spherically symmetric examples. Finally, we generalize the theory to an arbitrary number of scalar fields.
Prednisone raw material characterization and formulation development
Directory of Open Access Journals (Sweden)
Leonardo Henrique Toehwé
2018-01-01
Full Text Available ABSTRACT Solid dosage forms for oral use, particularly tablets, are the most highly used dosage forms in therapy because they are easily administered, have high productivity and relatively low cost and provide a more stable drug to form a semi-solid net. Numerous parameters influence the quality of the final dosage form. In this study, the dissolution profile of 20-mg prednisone tablets bioequivalent to the reference product and three test formulations were evaluated using stability testing. During the study, prednisone tablets and the active pharmaceutical ingredient (API prednisone from two different manufacturers were characterized with respect to their physical and physicochemical properties. The results showed that the dissolution profiles of the test batches and the reference product did not retain pharmaceutical equivalence throughout all the stability study. Notably, both samples of API prednisone were of the same crystal form, and any phase transition that occurred during the study could not be attributed to dissolution variation during stability.
Formulation of similarity porous media systems
International Nuclear Information System (INIS)
Anderson, R.M.; Ford, W.T.; Ruttan, A.; Strauss, M.J.
1982-01-01
The mathematical formulation of the Porous Media System (PMS) describing two-phase, immiscible, compressible fluid flow in linear, homogeneous porous media is reviewed and expanded. It is shown that families of common vertex, coaxial parabolas and families of parallel lines are the only families of curves on which solutions of the PMS may be constant. A coordinate transformation is used to change the partial differential equations of the PMS to a system of ordinary differential equations, referred to as a similarity Porous Media System (SPMS), in which the independent variable denotes movement from curve to curve in a selected family of curves. Properties of solutions of the first boundary value problem are developed for the SPMS
Comparative bioavailability of two formulations of sibutramine.
Franco Spínola, A C; Almeida, S; Filipe, A; Neves, R; Abolfathi, Z; Yritia, M; Anctil, D
2009-10-01
This study was conducted in order to compare the bioavailability of two capsule formulations containing 15 mg of sibutramine, N-{1-[1-(4-chlorophenyl)cyclobutyl]-3-methylbutyl}-N,N-dimethylamine hydrochloride monohydrate, 84485-00-7 CAS registry number. 62 healthy subjects were enrolled in a single-center, randomized, single-dose, open-label, 2-way crossover study, with a minimum washout period of 14 days. Plasma samples were collected up to 72.0 hours post-dosing. R-sibutramine, S-sibutramine, N-mono-desmethyl-sibutramine (M1) and N-di-desmethyl-sibutramine (M2) levels were determined by reverse liquid chromatography and detected by tandem mass spectrometry detection, LC/MS/MS method. Pharmacokinetic parameters used for bioequivalence assessment were the area under the concentration-time curve from time zero to time of last non-zero concentration (AUC0-t) and the maximum observed concentration (Cmax). These parameters were determined from sibutramine enantiomers as well from M1 and M2 concentration data using non-compartmental analysis. The 90% confidence intervals obtained by analysis of variance were 89.25 - 122.88% for Cmax, 90.37 - 123.18% for AUC0-t and 91.20 - 122.38% for AUCinf for R-sibutramine and 88.27 - 124.08% for Cmax, 86.15 - 121.78% for AUC0-t and 88.02 - 120.96% for AUCinf for S-sibutramine. These results were all within the range of 80.00 - 125.00% established by regulatory requirements. Bioequivalence between formulations was concluded both in terms of rate and extent of absorption.
Formulation and Characterization of Benzoyl Peroxide Gellified Emulsions
Thakur, Naresh Kumar; Bharti, Pratibha; Mahant, Sheefali; Rao, Rekha
2012-01-01
The present investigation was carried out with the objective of formulating a gellified emulsion of benzoyl peroxide, an anti-acne agent. The formulations were prepared using four different vegetable oils, viz. almond oil, jojoba oil, sesame oil, and wheat germ oil, owing to their emollient properties. The idea was to overcome the skin irritation and dryness caused by benzoyl peroxide, making the formulation more tolerable. The gellified emulsions were characterized for their homogeneity, rheology, spreadability, drug content, and stability. In vitro permeation studies were performed to check the drug permeation through rat skin. The formulations were evaluated for their antimicrobial activity, as well as their acute skin irritation potential. The results were compared with those obtained for the marketed formulation. Later, the histopathological examination of the skin treated with various formulations was carried out. Formulation F3 was found to have caused a very mild dysplastic change to the epidermis. On the other hand, the marketed formulation led to the greatest dysplastic change. Hence, it was concluded that formulation F3, containing sesame oil (6%w/w), was the optimized formulation. It exhibited the maximum drug release and anti-microbial activity, in addition to the least skin irritation potential. PMID:23264949
Etodolac Containing Topical Niosomal Gel: Formulation Development and Evaluation
Directory of Open Access Journals (Sweden)
Gyati Shilakari Asthana
2016-01-01
Full Text Available The present study aimed to investigate the delivery potential of Etodolac (ETD containing topical niosomal gel. Niosomal formulations were prepared by thin film hydration method at various ratios of cholesterol and Span 60 and were evaluated with respect to particle size, shape, entrapment efficiency, and in vitro characteristics. Dicetyl phosphate (DCP was also added in the niosomal formulation. Mean particle size of niosomal formulation was found to be in the range of 2 μm to 4 μm. Niosomal formulation N2 (1 : 1 ratio of cholesterol and surfactant displayed good entrapment efficiency (96.72%. TEM analyses showed that niosomal formulation was spherical in shape. Niosomal formulation (N2 displayed high percentage of drug release after 24 h (94.91 at (1 : 1 ratio of cholesterol : surfactant. Further selected niosomal formulation was used to formulate topical gel and was characterized with respect to its various parameters such as pH, viscosity, spreadability, ex vivo study, and in vivo potential permeation. Ex vivo study showed that niosomal gel possessed better skin permeation study than the plain topical gel. Further in vivo study revealed good inhibition of inflammation in case of topical niosomal gel than plain gel and niosomal formulation. The present study suggested that topical niosomal gel formulations provide sustained and prolonged delivery of drug.
Nonequilibrium formulation of abelian gauge theories
Energy Technology Data Exchange (ETDEWEB)
Zoeller, Thorsten
2013-09-01
This work is about a formulation of abelian gauge theories out-of-equilibrium. In contrast to thermal equilibrium, systems out-of-equilibrium are not constant in time, and the interesting questions in such systems refer to time evolution problems. After a short introduction to quantum electrodynamics (QED), the two-particle irreducible (2PI) effective action is introduced as an essential technique for the study of quantum field theories out-of-equilibrium. The equations of motion (EOMs) for the propagators of the theory are then derived from it. It follows a discussion of the physical degrees of freedom (DOFs) of the theory, in particular with respect to the photons, since in covariant formulations of gauge theories unphysical DOFs are necessarily contained. After that the EOMs for the photon propagator are examined more closely. It turns out that they are structurally complicated, and a reformulation of the equations is presented which for the untruncated theory leads to an essential structural simplification of the EOMs. After providing the initial conditions which are necessary in order to solve the EOMs, the free photon EOMs are solved with the help of the reformulated equations. It turns out that the solutions diverge in time, i.e. they are secular. This is a manifestation of the fact that gauge theories contain unphysical DOFs. It is reasoned that these secularities exist only in the free case and are therefore ''artificial''. It is however emphasized that they may not be a problem in principle, but certainly are in practice, in particular for the numerical solution of the EOMs. Further, the origin of the secularities, for which there exists an illustrative explanation, is discussed in more detail. Another characteristic feature of 2PI formulations of gauge theories is the fact that quantities calculated from approximations of the 2PI effective action, which are gauge invariant in the exact theory as well as in an approximated theory at
States in the Hilbert space formulation and in the phase space formulation of quantum mechanics
International Nuclear Information System (INIS)
Tosiek, J.; Brzykcy, P.
2013-01-01
We consider the problem of testing whether a given matrix in the Hilbert space formulation of quantum mechanics or a function considered in the phase space formulation of quantum theory represents a quantum state. We propose several practical criteria for recognising states in these two versions of quantum physics. After minor modifications, they can be applied to check positivity of any operators acting in a Hilbert space or positivity of any functions from an algebra with a ∗-product of Weyl type. -- Highlights: ► Methods of testing whether a given matrix represents a quantum state. ► The Stratonovich–Weyl correspondence on an arbitrary symplectic manifold. ► Criteria for checking whether a function on a symplectic space is a Wigner function
Neural networks to formulate special fats
Directory of Open Access Journals (Sweden)
Garcia, R. K.
2012-09-01
Full Text Available Neural networks are a branch of artificial intelligence based on the structure and development of biological systems, having as its main characteristic the ability to learn and generalize knowledge. They are used for solving complex problems for which traditional computing systems have a low efficiency. To date, applications have been proposed for different sectors and activities. In the area of fats and oils, the use of neural networks has focused mainly on two issues: the detection of adulteration and the development of fatty products. The formulation of fats for specific uses is the classic case of a complex problem where an expert or group of experts defines the proportions of each base, which, when mixed, provide the specifications for the desired product. Some conventional computer systems are currently available to assist the experts; however, these systems have some shortcomings. This article describes in detail a system for formulating fatty products, shortenings or special fats, from three or more components by using neural networks (MIX. All stages of development, including design, construction, training, evaluation, and operation of the network will be outlined.
Las redes neuronales son una rama de la inteligencia artificial basadas en la estructura y funcionamiento de sistemas biológicos, teniendo como principal característica la capacidad de aprender y generalizar conocimiento. Estas son utilizadas en la resolución de problemas complejos, en los cuales los sistemas computacionales tradicionales presentan una eficiencia baja. Hasta la fecha, han sido propuestas aplicaciones para los más diversos sectores y actividades. En el área de grasas y aceites, la utilización de redes neuronales se ha concentrado principalmente en dos asuntos: la detección de adulteraciones y la formulación de productos grasos. La formulación de grasas para uso específico es el caso clásico de problema complejo donde un experto o grupo de
Element free Galerkin formulation of composite beam with longitudinal slip
Energy Technology Data Exchange (ETDEWEB)
Ahmad, Dzulkarnain; Mokhtaram, Mokhtazul Haizad [Department of Civil Engineering, Universiti Selangor, Bestari Jaya, Selangor (Malaysia); Badli, Mohd Iqbal; Yassin, Airil Y. Mohd [Faculty of Civil Engineering, Universiti Teknologi Malaysia, Skudai, Johor (Malaysia)
2015-05-15
Behaviour between two materials in composite beam is assumed partially interact when longitudinal slip at its interfacial surfaces is considered. Commonly analysed by the mesh-based formulation, this study used meshless formulation known as Element Free Galerkin (EFG) method in the beam partial interaction analysis, numerically. As meshless formulation implies that the problem domain is discretised only by nodes, the EFG method is based on Moving Least Square (MLS) approach for shape functions formulation with its weak form is developed using variational method. The essential boundary conditions are enforced by Langrange multipliers. The proposed EFG formulation gives comparable results, after been verified by analytical solution, thus signify its application in partial interaction problems. Based on numerical test results, the Cubic Spline and Quartic Spline weight functions yield better accuracy for the EFG formulation, compares to other proposed weight functions.
Formulating accident occurrence as a survival process.
Chang, H L; Jovanis, P P
1990-10-01
A conceptual framework for accident occurrence is developed based on the principle of the driver as an information processor. The framework underlies the development of a modeling approach that is consistent with the definition of exposure to risk as a repeated trial. Survival theory is proposed as a statistical technique that is consistent with the conceptual structure and allows the exploration of a wide range of factors that contribute to highway operating risk. This survival model of accident occurrence is developed at a disaggregate level, allowing safety researchers to broaden the scope of studies which may be limited by the use of traditional aggregate approaches. An application of the approach to motor carrier safety is discussed as are potential applications to a variety of transportation industries. Lastly, a typology of highway safety research methodologies is developed to compare the properties of four safety methodologies: laboratory experiments, on-the-road studies, multidisciplinary accident investigations, and correlational studies. The survival theory formulation has a mathematical structure that is compatible with each safety methodology, so it may facilitate the integration of findings across methodologies.
New formulations for tsunami runup estimation
Kanoglu, U.; Aydin, B.; Ceylan, N.
2017-12-01
We evaluate shoreline motion and maximum runup in two folds: One, we use linear shallow water-wave equations over a sloping beach and solve as initial-boundary value problem similar to the nonlinear solution of Aydın and Kanoglu (2017, Pure Appl. Geophys., https://doi.org/10.1007/s00024-017-1508-z). Methodology we present here is simple; it involves eigenfunction expansion and, hence, avoids integral transform techniques. We then use several different types of initial wave profiles with and without initial velocity, estimate shoreline properties and confirm classical runup invariance between linear and nonlinear theories. Two, we use the nonlinear shallow water-wave solution of Kanoglu (2004, J. Fluid Mech. 513, 363-372) to estimate maximum runup. Kanoglu (2004) presented a simple integral solution for the nonlinear shallow water-wave equations using the classical Carrier and Greenspan transformation, and further extended shoreline position and velocity to a simpler integral formulation. In addition, Tinti and Tonini (2005, J. Fluid Mech. 535, 33-64) defined initial condition in a very convenient form for near-shore events. We use Tinti and Tonini (2005) type initial condition in Kanoglu's (2004) shoreline integral solution, which leads further simplified estimates for shoreline position and velocity, i.e. algebraic relation. We then use this algebraic runup estimate to investigate effect of earthquake source parameters on maximum runup and present results similar to Sepulveda and Liu (2016, Coast. Eng. 112, 57-68).
New formulation of the discrete element method
Rojek, Jerzy; Zubelewicz, Aleksander; Madan, Nikhil; Nosewicz, Szymon
2018-01-01
A new original formulation of the discrete element method based on the soft contact approach is presented in this work. The standard DEM has heen enhanced by the introduction of the additional (global) deformation mode caused by the stresses in the particles induced by the contact forces. Uniform stresses and strains are assumed for each particle. The stresses are calculated from the contact forces. The strains are obtained using an inverse constitutive relationship. The strains allow us to obtain deformed particle shapes. The deformed shapes (ellipses) are taken into account in contact detection and evaluation of the contact forces. A simple example of a uniaxial compression of a rectangular specimen, discreti.zed with equal sized particles is simulated to verify the DDEM algorithm. The numerical example shows that a particle deformation changes the particle interaction and the distribution of forces in the discrete element assembly. A quantitative study of micro-macro elastic properties proves the enhanced capabilities of the DDEM as compared to standard DEM.
A quasilinear formulation of turbulence driven current
Energy Technology Data Exchange (ETDEWEB)
McDevitt, C. J.; Tang, Xian-Zhu; Guo, Zehua [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2014-02-15
Non-inductive current drive mechanisms, such as the familiar neoclassical bootstrap current correspond to an essential component to the realization of steady state tokamak operation. In this work, we discuss a novel collisionless mechanism through which a mean plasma current may be driven in the presence of microturbulence. In analogy with the traditional neoclassical bootstrap current drive mechanism, in which the collisional equilibrium established between trapped and passing electrons results in the formation of a steady state plasma current, here we show that resonant scattering of electrons by drift wave microturbulence provides an additional means of determining the equilibrium between trapped and passing electrons. The resulting collisionless equilibrium is shown to result in the formation of an equilibrium current whose magnitude is a function of the thermodynamic forces. A mean field formulation is utilized to incorporate the above components into a unified framework through which both collisional as well as collisionless current drive mechanisms may be self-consistently treated. Utilizing a linearized Fokker-Planck collision operator, the plasma current in the presence of both collisions as well as turbulent stresses is computed, allowing for the relative strength of these two mechanisms to be quantified as a function of collisionality and fluctuation amplitude.
Considering the cultural context in psychopathology formulations
Directory of Open Access Journals (Sweden)
Junaid Hassim
2013-03-01
Full Text Available Background. Mental health research appears to be continually transforming. Recent literature reflects a greater appreciation for the ways in which pathoplastic features of culture modulate emotional regulation. This article introduces those aspects of the literature which explore the (reconsideration of culture as a dynamic and essential construct in the clinical formulation of psychopathology. Objectives. The study aims to review literature that focuses on the dynamic influence of culture in psychopathology. Furthermore, the researchers aim to present a view on the ways in which culture appeared to shape the topography of psychopathology nosology. Method. A literature review of 31 sources. Results. The review indicated that 29 literature sources were conceptual in design, suggesting a great need for more empirical research. This section also explored themes identified during the literature review. The literature was tabulated according to features and emerging themes. Three major themes were identified and included: the cultural context; the evolving definitions of culture; and culture and psychopathology. Conclusion/discussion. An analysis of the themes was offered. The authors concluded by highlighting the significance of the literature at present. Areas of particular interest suggested that health and behaviour are dependent, at least in part, on culture; psychopathology may also be appreciated as a social construct; culture influences psychopathology regardless of the aetiology; diagnostic classes do not adequately consider operational definitions; and a greater focus on hermeneutic perceptivity in appreciating cultural dynamics in psychopathology will benefit clinical assessment.
A quasilinear formulation of turbulence driven current
International Nuclear Information System (INIS)
McDevitt, C. J.; Tang, Xian-Zhu; Guo, Zehua
2014-01-01
Non-inductive current drive mechanisms, such as the familiar neoclassical bootstrap current correspond to an essential component to the realization of steady state tokamak operation. In this work, we discuss a novel collisionless mechanism through which a mean plasma current may be driven in the presence of microturbulence. In analogy with the traditional neoclassical bootstrap current drive mechanism, in which the collisional equilibrium established between trapped and passing electrons results in the formation of a steady state plasma current, here we show that resonant scattering of electrons by drift wave microturbulence provides an additional means of determining the equilibrium between trapped and passing electrons. The resulting collisionless equilibrium is shown to result in the formation of an equilibrium current whose magnitude is a function of the thermodynamic forces. A mean field formulation is utilized to incorporate the above components into a unified framework through which both collisional as well as collisionless current drive mechanisms may be self-consistently treated. Utilizing a linearized Fokker-Planck collision operator, the plasma current in the presence of both collisions as well as turbulent stresses is computed, allowing for the relative strength of these two mechanisms to be quantified as a function of collisionality and fluctuation amplitude
Controlled Release Formulations of Auxinic Herbicides
Kowalski, Witold J.; Siłowiecki, Andrzej.; Romanowska, Iwona; Glazek, Mariola; Bajor, Justyna; Cieciwa, Katarzyna; Rychter, Piotr
2013-04-01
Controlled release formulations are applied extensively for the release of active ingredients such as plant protection agents and fertilizers in response to growing concern for ecological problems associated with increased use of plant protection chemicals required for intensive agricultural practices [1]. We synthesized oligomeric mixtures of (R,S)-3-hydroxy butyric acid chemically bonded with 2,4-D, Dicamba and MCPA herbicides (HBA) respectively, and determined their molecular structure and molecular weight dispersion by the size exclusion chromatography, proton magnetic resonance spectrometry and electro-spray ionization mass spectrometry. Further we carried out bioassays of herbicidal effectiveness of the HBA herbicides vs. series of dicotyledonous weeds and crop injury tests [2, 3, 4]. Field bioassays were accomplished according to the EPPO standards [5]. Groups of representative weeds (the development stages in the BCCH scale: 10 - 30) were selected as targets. Statistical variabilities were assessed by the Fisher LSD test for plants treated with the studied herbicides in form of HBA oligomers, the reference herbicides in form of dimethyl ammonium salts (DMA), and untreated plants. No statistically significant differences in the crop injuries caused by the HBA vs. the DMA reference formulation were observed. The effectiveness of the HBA herbicides was lower through the initial period (ca. 2 weeks) relative to the DMA salts, but a significant increase in the effectiveness of the HBA systems followed during the remaining fraction of each assay. After 6 weeks all observed efficiencies approached 100%. The death of weeds treated with the HBA herbicides was delayed when compared with the DMA reference herbicides. The delayed uptake observed for the HBA oligomers relative to the DMA salts was due to controlled release phenomena. In case of the DMA salts the total amount of active ingredients was available at the target site. By contrast, the amount of an active
Effect of formulation compositions on niosomal preparations.
Chaw, Cheng Shu; Kim, Kwong Yioung Ah
2013-01-01
This study was aimed to investigate the effects of molar ratio of cholesterol to Span 60 and stabilizers (Solutol HS 15 or dicetyl phosphate (DCP)) on the entrapment of methylene blue, a model hydrophilic drug. The niosomes were prepared by the film hydration method and characterized for drug entrapment efficiency (EE), vesicle size, zeta potential and thermal properties of niosomal membrane. It was found that niosomal vesicles possessed median diameter ranging from 0.35 to 1.85 μm. The niosomes that were formulated with lower molar ratios of cholesterol to Span 60 of 0.33 and 0.50 produced significantly higher EE with both stabilizers when compared to cholesterol to Span 60 molar ratios of 1.0 and above (p Solutol HS 15 except at a molar ratio of cholesterol to Span 60 of 0.33. In conclusion, with low molar ratios of cholesterol to Span 60, more drugs could be entrapped within the niosomes regardless of the type of stabilizers. Furthermore, EE and median diameter of niosomes containing DCP were higher than those stabilized with Solutol HS 15.
Biosurfactants in cosmetic formulations: trends and challenges.
Vecino, X; Cruz, J M; Moldes, A B; Rodrigues, L R
2017-11-01
Cosmetic products play an essential role in everyone's life. People everyday use a large variety of cosmetic products such as soap, shampoo, toothpaste, deodorant, skin care, perfume, make-up, among others. The cosmetic industry encompasses several environmental, social and economic impacts that are being addressed through the search for more efficient manufacturing techniques, the reduction of waste and emissions and the promotion of personal hygiene, contributing to an improvement of public health and at the same time providing employment opportunities. The current trend among consumers is the pursuit for natural ingredients in cosmetic products, as many of these products exhibit equal, better or additional benefits in comparison with the chemical-based products. In this sense, biosurfactants are natural compounds with great potential in the formulation of cosmetic products given by their biodegradability and impact in health. Indeed, many of these biosurfactants could exhibit a "prebiotic" character. This review covers the current state-of-the-art of biosurfactant research for cosmetic purposes and further discusses the future challenges for cosmetic applications.
Extended release formulations for local anaesthetic agents.
Weiniger, C F; Golovanevski, L; Domb, A J; Ickowicz, D
2012-08-01
Systemic toxicity through overdose of local anaesthetic agents is a real concern. By encapsulating local anaesthetics in biodegradable carriers to produce a system for prolonged release, their duration of action can be extended. This encapsulation should also improve the safety profile of the local anaesthetic as it is released at a slower rate. Work with naturally occurring local anaestheticss has also shown promise in the area of reducing systemic and neurotoxicity. Extended duration local anaesthetic formulations in current development or clinical use include liposomes, hydrophobic based polymer particles such as Poly(lactic-co-glycolic acid) microspheres, pasty injectable and solid polymers like Poly(sebacic-co-ricinoleic acid) P(SA:RA) and their combination with synthetic and natural local anaesthetic. Their duration of action, rationale and limitations are reviewed. Direct comparison of the different agents is limited by their chemical properties, the drug doses encapsulated and the details of in vivo models described. Anaesthesia © 2012 The Association of Anaesthetists of Great Britain and Ireland.
Botulinum neurotoxin formulations: overcoming the confusion
Directory of Open Access Journals (Sweden)
Samizadeh S
2018-05-01
Full Text Available Souphiyeh Samizadeh,1 Koenraad De Boulle2 1Great British Academy of Aesthetic Medicine, London, UK; 2Aalst Dermatology Clinic, Aalst, Belgium Abstract: Botulinum toxin A is produced by anaerobic spore-forming bacteria and is used for various therapeutic and cosmetic purposes. Botulinum toxin A injections are the most popular nonsurgical procedure worldwide. Despite an increased demand for botulinum toxin A injections, the clinical pharmacology and differences in formulation of commonly available products are poorly understood. The various products available in the market are unique and vary in terms of units, chemical properties, biological activities, and weight, and are therefore not interchangeable. For safe clinical practice and to achieve optimal results, the practitioners need to understand the clinical issues of potency, conversion ratio, and safety issues (toxin spread and immunogenicity. In this paper, the basic clinical pharmacology of botulinum toxin A and differences between onabotulinum toxin A, abobotulinum toxin A, and incobotulinum toxin A are discussed. Keywords: botulinum toxin, botulinum neurotoxin, moiety, protein complexes
Artificial intelligence in pharmaceutical product formulation: neural computing
Svetlana Ibrić; Jelena Petrović; Jelena Parojčić; Zorica Djurić
2009-01-01
The properties of a formulation are determined not only by the ratios in which the ingredients are combined but also by the processing conditions. Although the relationships between the ingredient levels, processing conditions, and product performance may be known anecdotally, they can rarely be quantified. In the past, formulators tended to use statistical techniques to model their formulations, relying on response surfaces to provide a mechanism for optimazation. However, the optimization b...
Formulation and evaluation of antipsoriatic gel using natural excipients
Raghupatruni Jhansi Laxmi; R. Karthikeyan; P. Srinivasa Babu; R.V.V. Narendra Babu
2013-01-01
Objective: To develop topical gel formulations of Psoralen using natural excipients to minimize the side effects of synthetic drugs. Methods: The Psoralen gel formulations were prepared using different natural gums and polymers. The physicochemical compatibility between Psoralen and other excipients was confirmed by using Fourier transform infrared spectroscopy. All prepared gel formulations were evaluated for drug content uniformity, viscosity, pH, and stability. The release of psoralen f...
Formulating Fermat's principle for light traveling in negative refraction materials
International Nuclear Information System (INIS)
Veselago, Viktor G
2002-01-01
The formulation of Fermat's principle for electromagnetic waves traveling in materials with a negative refractive index is refined. It is shown that a formulation in terms of the minimum (or extremum) of wave travel time between two points is not correct in general. The correct formulation involves the extremum of the total optical length, with the optical length for the wave propagation through left-handed materials taken to be negative. (methodological notes)
Diffeomorphism invariance in the Hamiltonian formulation of General Relativity
International Nuclear Information System (INIS)
Kiriushcheva, N.; Kuzmin, S.V.; Racknor, C.; Valluri, S.R.
2008-01-01
It is shown that when the Einstein-Hilbert Lagrangian is considered without any non-covariant modifications or change of variables, its Hamiltonian formulation leads to results consistent with principles of General Relativity. The first-class constraints of such a Hamiltonian formulation, with the metric tensor taken as a canonical variable, allow one to derive the generator of gauge transformations, which directly leads to diffeomorphism invariance. The given Hamiltonian formulation preserves general covariance of the transformations derivable from it. This characteristic should be used as the crucial consistency requirement that must be met by any Hamiltonian formulation of General Relativity
High-Order Entropy Stable Formulations for Computational Fluid Dynamics
Carpenter, Mark H.; Fisher, Travis C.
2013-01-01
A systematic approach is presented for developing entropy stable (SS) formulations of any order for the Navier-Stokes equations. These SS formulations discretely conserve mass, momentum, energy and satisfy a mathematical entropy inequality. They are valid for smooth as well as discontinuous flows provided sufficient dissipation is added at shocks and discontinuities. Entropy stable formulations exist for all diagonal norm, summation-by-parts (SBP) operators, including all centered finite-difference operators, Legendre collocation finite-element operators, and certain finite-volume operators. Examples are presented using various entropy stable formulations that demonstrate the current state-of-the-art of these schemes.
Physical and chemical stability of different formulations with superoxide dismutase.
Di Mambro, V M; Campos, P M B G Maia; Fonseca, M J V
2004-10-01
Topical formulations with superoxide dismutase (SOD), a scavenger of superoxide radicals, have proved to be effective against some skin diseases. Nevertheless, formulations with proteins are susceptible to both chemical and physical instability. Three different formulations (anionic and non-ionic gel and emulsion) were developed and supplemented with SOD in order to determine the most stable formulation that would maintain SOD activity. Physical stability was evaluated by assessing the rheological behavior of the formulations stored at room temperature, 37 and 45 degrees C. Chemical stability was evaluated by the measurement of enzymatic activity in the formulations stored at room temperature and at 45 degrees C. Formulations showed a flow index less than one, characterizing pseudoplastic behavior. There was no significant difference in initial values of flow index, tixotropy or minimum apparent viscosity. Neither gel showed significant changes in minimum apparent viscosity concerning storage time or temperature, as well, SOD presence and its activity. The emulsion showed decreased viscosity by the 28th day, but no significant changes concerning storage temperature or SOD presence, although it showed a decreased activity. The addition of SOD to the formulations studied did not affect their physical stability but gel formulations seem to be better bases for enzyme addition.
Summary of Remediated Nitrate Salt Surrogate Formulation and Testing
Energy Technology Data Exchange (ETDEWEB)
Brown, Geoffrey Wayne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Leonard, Philip [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hartline, Ernest Leon [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tian, Hongzhao [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2016-05-05
High Explosives Science and Technology (M-7) completed all required formulation and testing of Remediated Nitrate Salt (RNS) surrogates on April 27, 2016 as specified in PLAN-TA9-2443 Rev B, "Remediated Nitrate Salt (RNS) Surrogate Formulation and Testing Standard Procedure", released February 16, 2016. This report summarizes the results of the work and also includes additional documentation required in that test plan. All formulation and testing was carried out according to PLAN-TA9-2443 Rev B. The work was carried out in three rounds, with the full matrix of samples formulated and tested in each round. Results from the first round of formulation and testing were documented in memorandum M7-J6-6042, " Results from First Round of Remediated Nitrate Salt Surrogate Formulation and Testing." Results from the second round of formulation and testing were documented in M7-16-6053 , "Results from the Second Round of Remediated Nitrate Salt Surrogate Formulation and Testing." Initial results from the third round were documented in M7-16-6057, "Initial Results from the Third Round of Remediated Nitrate Salt Formulation and Testing."
Developing a new formulation of sodium phenylbutyrate.
Guffon, Nathalie; Kibleur, Yves; Copalu, William; Tissen, C; Breitkreutz, Joerg
2012-12-01
Sodium phenylbutyrate (NaPB) is used as a treatment for urea cycle disorders (UCD). However, the available, licensed granule form has an extremely bad taste, which can compromise compliance and metabolic control. A new, taste-masked, coated-granule formulation (Luc 01) under development was characterised for its in vitro taste characteristics, dissolution profiles and bioequivalence compared with the commercial product. Taste, safety and tolerability were also compared in healthy adult volunteers. The in vitro taste profile of NaPB indicated a highly salty and bitter tasting molecule, but Luc 01 released NaPB only after a lag time of ∼10 s followed by a slow release over a few minutes. In contrast, the licensed granules released NaPB immediately. The pharmacokinetic study demonstrated the bioequivalence of a single 5 g dose of the two products in 13 healthy adult volunteers. No statistical difference was seen either for maximal plasma concentration (C(max)) or for area under the plasma concentration-time curve (AUC). CI for C(max) and AUC(0-inf) of NaPB were included in the bioequivalence range of 0.80-1.25. One withdrawal for vomiting and five reports of loss of taste perception (ageusia) were related to the licensed product. Acceptability, bitterness and saltiness assessed immediately after administration indicated a significant preference for Luc 01 (p<0.01), confirming the results of the taste prediction derived from in vitro measurements. In vitro dissolution, in vitro and in vivo taste profiles support the view that the newly developed granules can be swallowed before release of the bitter active substance, thus avoiding stimulation of taste receptors. Moreover, Luc 01 was shown to be bioequivalent to the licensed product. The availability of a taste-masked form should improve compliance which is critical to the efficacy of NaPB treatment in patients with UCD.
Operator formulation of the droplet model
International Nuclear Information System (INIS)
Lee, B.W.
1987-01-01
We study in detail the implications of the operator formulation of the droplet model. The picture of high-energy scattering that emerges from this model attributed the interaction between two colliding particles at high energies to an instantaneous, multiple exchange between two extended charge distributions. Thus the study of charge correlation functions becomes the most important problem in the droplet model. We find that in order for the elastic cross section to have a finite limit at infinite energy, the charge must be a conserved one. In quantum electrodynamics the charge in question is the electric charge. In hadronic physics, we conjecture, it is the baryonic charge. Various arguments for and implications of this hypothesis are presented. We study formal properties of the charge correlation functions that follow from microcausality, T, C, P invariances, and charge conservation. Perturbation expansion of the correlation functions is studied, and their cluster properties are deduced. A cluster expansion of the high-energy T matrix is developed, and the exponentiation of the interaction potential in this scheme is noted. The operator droplet model is put to the test of reproducing the high-energy limit of elastic scattering quantum electrodynamics found by Cheng and Wu in perturbation theory. We find that the droplet model reproduces exactly the results of Cheng and Wu as to the impact factor. In fact, the ''impact picture'' of Cheng and Wu is completely equivalent to the droplet model in the operator version. An appraisal is made of the possible limitation of the model. (author). 13 refs
Concise CIO based precession-nutation formulations
Capitaine, N.; Wallace, P. T.
2008-01-01
Context: The IAU 2000/2006 precession-nutation models have precision goals measured in microarcseconds. To reach this level of performance has required series containing terms at over 1300 frequencies and involving several thousand amplitude coefficients. There are many astronomical applications for which such precision is not required and the associated heavy computations are wasteful. This justifies developing smaller models that achieve adequate precision with greatly reduced computing costs. Aims: We discuss strategies for developing simplified IAU 2000/2006 precession-nutation procedures that offer a range of compromises between accuracy and computing costs. Methods: The chain of transformations linking celestial and terrestrial coordinates comprises frame bias, precession-nutation, Earth rotation and polar motion. We address the bias and precession-nutation (NPB) portion of the chain, linking the Geocentric Celestial Reference System (GCRS) with the Celestial Intermediate Reference System (CIRS), the latter based on the Celestial Intermediate Pole (CIP) and Celestial Intermediate Origin (CIO). Starting from direct series that deliver the CIP coordinates X,Y and (via the quantity s + XY/2) the CIO locator s, we look at the opportunities for simplification. Results: The biggest reductions come from truncating the series, but some additional gains can be made in the areas of the matrix formulation, the expressions for the nutation arguments and by subsuming long period effects into the bias quantities. Three example models are demonstrated that approximate the IAU 2000/2006 CIP to accuracies of 1 mas, 16 mas and 0.4 arcsec throughout 1995-2050 but with computation costs reduced by 1, 2 and 3 orders of magnitude compared with the full model. Appendices A to G are only available in electronic form at http://www.aanda.org
FORMULATION OF INDONESIAN PUBLIC HEALTH DEVELOPMENT INDEX
Directory of Open Access Journals (Sweden)
Puti Sari Hidayangsih
2012-11-01
Full Text Available The objective of formulation the Indonesian Public Health Development Index (IPHDI was to describe the successful development of public health based on composite several community-based health indicators. Cross sectional study design.The data analyzed was a combination of a nationwide survey covering Baseline Health Research (Riskesdas 2007, National Social Economic Survey (Susenas 2007 and the Village Potential (Podes in 2008. Selection of appropriate indicators included in IPHDI associated with LE at birth, selected on the basis of consensus expert team. When the indicator has the RSE (relative standard error value of less than 30% and the value was held for more than 75% of districts. then the indicator is a candidate in the calculation IPHDI. The team doing the analysis on 22 models of the combination of indicators. The number of indicators chat involved between 18 to 24. These models have been made and tested for correlation weighting of life expectancy each district. Results of correlation ranged from 0.314 to 0.512 and all models have a significance value p< 0.001. The model was chosen considering the variables that are considered priorities and values of correlation. IPHDI Highest value is 0.708959 (Magelang City, Central Java and the lowest is 0.247059 (Pegunungan Bintang district, Papua. Conclusion. IPHDI utilization is to know district who has severe health problems, resulting in enhancement programs that have intervened, resulting in focusing the target location, and became one of the parameters for the calculation of aid allocations fairly from center to the region. Key words: health indicators, Indonesian public health development index, life expectancy
Cast Stone Formulation At Higher Sodium Concentrations
International Nuclear Information System (INIS)
Fox, K. M.; Edwards, T. A.; Roberts, K. B.
2013-01-01
A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium
Cast Stone Formulation At Higher Sodium Concentrations
International Nuclear Information System (INIS)
Fox, K. M.; Roberts, K. A.; Edwards, T. B.
2014-01-01
A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium
Cast Stone Formulation At Higher Sodium Concentrations
Energy Technology Data Exchange (ETDEWEB)
Fox, K. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Roberts, K. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2014-02-28
A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium
Cast Stone Formulation At Higher Sodium Concentrations
Energy Technology Data Exchange (ETDEWEB)
Fox, K. M.; Edwards, T. A.; Roberts, K. B.
2013-10-02
A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium
Cast Stone Formulation At Higher Sodium Concentrations
Energy Technology Data Exchange (ETDEWEB)
Fox, K. M.; Roberts, K. A.; Edwards, T. B.
2013-09-17
A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium
Formulation variables affecting deposition with the Kchaler device, a ...
African Journals Online (AJOL)
As a result of current focus on tightening regulatory requirements, it is imperative that reproducibility of the metered dose of drugs be ensured during the formulation, packaging and use. We developed a dry powder inhalation package in our laboratories consisting of formulation mixes, design and a device, KCHALER, ...
Validation of flexible multibody dynamics beam formulations using benchmark problems
Bauchau, O.A.; Wu, Genyong; Betsch, P.; Cardona, A.; Gerstmayr, J.; Jonker, Jan B.; Masarati, P.; Sonneville, V.
2016-01-01
As the need to model flexibility arose in multibody dynamics, the floating frame of reference formulation was developed, but this approach can yield inaccurate results when elastic displacements becomes large. While the use of three-dimensional finite element formulations overcomes this problem, the
Dermal pharmacokinetics of microemulsion formulations determined by in vivo microdialysis
DEFF Research Database (Denmark)
Kreilgaard, Mads
2001-01-01
To investigate the potential of improving dermal drug delivery of hydrophilic and lipophilic substances by formulation in microemulsion vehicles and to establish a reliable pharmacokinetic model to analyze cutaneous microdialysis data.......To investigate the potential of improving dermal drug delivery of hydrophilic and lipophilic substances by formulation in microemulsion vehicles and to establish a reliable pharmacokinetic model to analyze cutaneous microdialysis data....
Nutritional and sensory evaluation of food formulations from malted ...
African Journals Online (AJOL)
Malting and fermentation were investigated as simple technologies for improving the nutritional and organoleptic properties of maize/sesame food formulations. Various maize flour samples were blended with defatted sesame flour, by material balancing, to give four food formulations consisting of unmalted maize + defatted ...
Effect of Nutrient Formulations on Permeation of Proteins and Lipids ...
African Journals Online (AJOL)
Purpose: To investigate the effect of nutrient formulations on the permeation of proteins and lipids through porcine intestine in vitro. Method: In vitro permeation studies of proteins and lipids of two peptide-based formulations, composed of various compounds and sources of hydrolyzed protein was carried out, and compared ...
Investigation of the effects of certain formulation factors on release ...
African Journals Online (AJOL)
Objective: To study the effects of three formulation variables (PVP, stearic acid and Avicel PH101) on disintegration time and release properties of paracetamol tablets using a 23 factorial experimental design. Methodology: Three formulation variables; Polyvinyl pyrrolidone (factor A), Stearic acid (factor B) and Avicel PH 101 ...
Formulation of gastro-retentive floating tables of Diltiazem ...
African Journals Online (AJOL)
Sodium bicarbonate (30%) was incorporated as gas generating agent. Formulations were either prepared alone with the individual polymer or admixed with carnauba wax. Formulations containing carnauba wax were prepared by melt granulation technique. Tablets were evaluated for tensile strength, in vitro buoyancy and ...
Formulation and Evaluation of Tramadol HCl Matrix Tablets Using ...
African Journals Online (AJOL)
Formulation and Evaluation of Tramadol HCl Matrix Tablets Using Carbopol ... to 83 % compared with the release rate of 99 % for the formulation with D:P ratio of 10:3. Kinetic analysis indicates that drug release mechanism was anomalous ...
Formulation and Pharmacokinetic Evaluation of Controlled-Release ...
African Journals Online (AJOL)
The effect of several formulation variables on in ... The in vivo pharmacokinetics of the optimized formulation was compared ... Results: The core tablets exhibited extended release consisting of drug release from the embedded ... important factor in medical treatment with respect ... The solvents for high-performance liquid.
A quantum formulation of the Feynman-Kac formula
International Nuclear Information System (INIS)
Accardi, L.
1981-01-01
The author discusses a formulation, in the general setting of W*- (or C*)-algebras, of the classical Feynman-Kac formula. The equivalence, in the commutative case, of the present formulation and the usual one is based on the identification between stochastic processes and local algebras. (Auth.)
Formulation of Fast-Dissolving Tablets of Promethazine Theoclate ...
African Journals Online (AJOL)
Purpose: To optimize and formulate promethazine theoclate fast-dissolving tablets that offer a suitable approach to the treatment of nausea and vomiting. Method: The solubility of promethazine theoclate was increased by formulating it as a fast-dissolving tablet containing β-cyclodextrin, crospovidone, and camphor, using ...
Formulation of Higher Education Institutional Strategy Using Operational Research Approaches
Labib, Ashraf; Read, Martin; Gladstone-Millar, Charlotte; Tonge, Richard; Smith, David
2014-01-01
In this paper a framework is proposed for the formulation of a higher education institutional (HEI) strategy. This work provides a practical example, through a case study, to demonstrate how the proposed framework can be applied to the issue of formulation of HEI strategy. The proposed hybrid model is based on two operational research…
Formulation and Evaluation of Ascorbic acid Tablets by Direct ...
African Journals Online (AJOL)
Formulation and Evaluation of Ascorbic acid Tablets by Direct Compression using Microcrystalline Starch as a Direct Compression Excipient. ... Abstract. PURPOSE: To evaluate the tableting properties of microcrystalline starch (MCS) used as a direct ... RESULTS: Mechanical properties of tablets formulated with MCS were
Nano-formulations of drugs: Recent developments, impact and challenges.
Jeevanandam, Jaison; Chan, Yen San; Danquah, Michael K
2016-01-01
Nano-formulations of medicinal drugs have attracted the interest of many researchers for drug delivery applications. These nano-formulations enhance the properties of conventional drugs and are specific to the targeted delivery site. Dendrimers, polymeric nanoparticles, liposomes, nano-emulsions and micelles are some of the nano-formulations that are gaining prominence in pharmaceutical industry for enhanced drug formulation. Wide varieties of synthesis methods are available for the preparation of nano-formulations to deliver drugs in biological system. The choice of synthesis methods depend on the size and shape of particulate formulation, biochemical properties of drug, and the targeted site. This article discusses recent developments in nano-formulation and the progressive impact on pharmaceutical research and industries. Additionally, process challenges relating to consistent generation of nano-formulations for drug delivery are discussed. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.
Enabling Strategy Formulation by ICT: A Viable Systems Approach
Vriens, D.J.; Achterbergh, J.M.I.M.; Vriens, D.J.
2003-01-01
In this chapter the role of ICT for competitive intelligence is approached from the perspective of strategy formulation. The authors hold the view that competitive intelligence can be seen as knowledge necessary for the process of strategy formulation. To determine the role of ICT, it is proposed to
Evaluation and Selection of Gel Base for the Formulation of ...
African Journals Online (AJOL)
Purpose: To formulate dexpanthenol gels with enhanced in vivo absorption properties via skin. Methods: Carboxyvinyl derivatives (Carbopol 980 and Ultrez 10) and poloxamer (Lutrol F 127) were used as the hydrogel base in the formulations. Changes in rheological properties (apparent viscosity and penetration values) ...
STRATEGY FORMULATION FOR DEVELOPING BATIK TULIS
Directory of Open Access Journals (Sweden)
Indah Eko Suryani
2015-01-01
Full Text Available The objective of this study was to formulate a development strategy in order to maintain the existence of Batik Tulis Rolla Junior. The study used a case study approach with Rumah Batik Tulis Rolla Junior as the research object. The data were analyzed by a value chain approach to determine the internal and external conditions influencing the existence of the Batik Tulis Rolla Junior. Furthermore, this study also used the analysis of Internal Factor Evaluation (IFE, External Factor Evaluation (EFE, Internal-External (IE Matrix, SWOT, dan Quantitative Strategic Planning Matrix (QSPM to create the development strategy. The results show that the strategies that can be recommended to Rolla Junior include 1 increasing the capital by Kredit Usaha Rakyat (KUR program, 2 conductiong expansions to other regencies, 3 creating a website/blog to promote and perform business transactions, 4 increasing the frequency in joining exhibitions or EXPO both in regional and national levels, 5 conducting researches to solve the problem of coloring which requires sun rays, 6 conducting cooperations with raw material suppliers (backward integration, and 7 finding alternative suppliers of raw materials especially from the areas closer to Jember district.Keywords: development strategy, batik tulis Rolla Junior, SWOT, QSPMABSTRAKPenelitian ini bertujuan merumuskan strategi pengembangan sehingga dapat menjaga eksistensi Batik Tulis Rolla Junior. Penelitian menggunakan pendekatan studi kasus dengan Rolla Junior sebagai objek penelitiannya. Data dianalisis dengan pendekatan rantai nilai untuk mengetahui kondisi internal dan eksternal yang berpengaruh terhadap Batik Tulis kemudian menggunakan analisis Internal Factor Evaluation (IFE, External Factor Evaluation (EFE, Internal-External (IE Matrix, SWOT, dan Quantitative Strategic Planning Matrix (QSPM untuk menyusun strategi pengembangan Batik Tulis Rolla Junior. Hasil penelitian menunjukkan bahwa strategi-straegi prioritas
CRYSTALLINE CERAMIC WASTE FORMS: REFERENCE FORMULATION REPORT
Energy Technology Data Exchange (ETDEWEB)
Brinkman, K.; Fox, K.; Marra, J.
2012-05-15
The research conducted in this work package is aimed at taking advantage of the long term thermodynamic stability of crystalline ceramics to create more durable waste forms (as compared to high level waste glass) in order to reduce the reliance on engineered and natural barrier systems. Durable ceramic waste forms that incorporate a wide range of radionuclides have the potential to broaden the available disposal options and to lower the storage and disposal costs associated with advanced fuel cycles. Assemblages of several titanate phases have been successfully demonstrated to incorporate radioactive waste elements, and the multiphase nature of these materials allows them to accommodate variation in the waste composition. Recent work has shown that they can be successfully produced from a melting and crystallization process. The objective of this report is to explain the design of ceramic host systems culminating in a reference ceramic formulation for use in subsequent studies on process optimization and melt property data assessment in support of FY13 melter demonstration testing. The waste stream used as the basis for the development and testing is a combination of the projected Cs/Sr separated stream, the Trivalent Actinide - Lanthanide Separation by Phosphorous reagent Extraction from Aqueous Komplexes (TALSPEAK) waste stream consisting of lanthanide fission products, the transition metal fission product waste stream resulting from the transuranic extraction (TRUEX) process, and a high molybdenum concentration with relatively low noble metal concentrations. In addition to the combined CS/LN/TM High Mo waste stream, variants without Mo and without Mo and Zr were also evaluated. Based on the results of fabricating and characterizing several simulated ceramic waste forms, two reference ceramic waste form compositions are recommended in this report. The first composition targets the CS/LN/TM combined waste stream with and without Mo. The second composition targets
On the Correct Formulation of the First Law of Thermodynamics
Kalanov, Temur Z.
2006-04-01
The critical analysis of the generally accepted formulation of the first law of thermodynamics is proposed. The purpose of the analysis is to prove that the standard formulation contains a mathematical error and to offer the correct formulation. The correct formulation is based on the concepts of function and differential of function. Really, if internal energy Uof a system is a function of two independent variables Q=Q(t) (describing of the thermal form of energy) and R=R(t) (describing non-thermal form of energy), then the correct formulation of the first law of thermodynamics is: dU(Q,R)dt=( UQ )RdQdt+( UR )QdRdt, where t and -( UR )Q / ( UR )Q ( UQ ) . - ( UQ )R are time and measure of mutual transformation of forms of energy, correspondingly. General conclusion: standard thermodynamics is incorrect.
Pai, Amy Barton
2017-11-01
Intravenous iron formulations are a class of complex drugs that are commonly used to treat a wide variety of disease states associated with iron deficiency and anemia. Venofer® (iron-sucrose) is one of the most frequently used formulations, with more than 90% of dialysis patients in the United States receiving this formulation. Emerging data from global markets outside the United States, where many iron-sucrose similars or copies are available, have shown that these formulations may have safety and efficacy profiles that differ from the reference listed drug. This may be attributable to uncharacterized differences in physicochemical characteristics and/or differences in labile iron release. As bioequivalence evaluation guidance evolves, clinicians should be educated on these potential clinical issues before a switch to the generic formulation is made in the clinical setting. © 2017 New York Academy of Sciences.
Evaluation method for the drying performance of enzyme containing formulations
DEFF Research Database (Denmark)
Sloth, Jakob; Bach, P.; Jensen, Anker Degn
2008-01-01
A method is presented for fast and cheap evaluation of the performance of enzyme containing formulations in terms of preserving the highest enzyme activity during spray drying. The method is based on modeling the kinetics of the thermal inactivation reaction which occurs during the drying process....... Relevant kinetic parameters are determined from differential scanning calorimeter (DSC) experiments and the model is used to simulate the severity of the inactivation reaction for temperatures and moisture levels relevant for spray drying. After conducting experiments and subsequent simulations...... for a number of different formulations it may be deduced which formulation performs best. This is illustrated by a formulation design study where 4 different enzyme containing formulations are evaluated. The method is validated by comparison to pilot scale spray dryer experiments....
Engaged Problem Formulation of IT Management in Danish Municipalities
DEFF Research Database (Denmark)
Nielsen, Peter Axel; Persson, John Stouby
2012-01-01
Municipalities’ effectiveness in managing information technology (IT) is increasingly important in adhering to their responsibilities for providing services to citizens. While the municipalities’ difficulty in managing IT has been well documented, it is more elusive what specific problems are most...... relevant in contemporary municipal IT management practice. On this basis, we present an engaged scholarship approach to formulate IT management problems together with municipalities - not for municipalities. We have come to understand such engaged problem formulation as joint researching and defining...... of a contemporary and complex problem by researchers and those who experience and know the problem. We present the formulated IT management problems and discuss the engaged problem formulation process in relation to engaged scholarship. Furthermore, we discuss how engaged problem formulation may contribute...
How reliable are case formulations? A systematic literature review.
Flinn, Lucinda; Braham, Louise; das Nair, Roshan
2015-09-01
This systematic literature review investigated the inter-rater and test-retest reliability of case formulations. We considered the reliability of case formulations across a range of theoretical modalities and the general quality of the primary research studies. A systematic search of five electronic databases was conducted in addition to reference list trawling to find studies that assessed the reliability of case formulation. This yielded 18 studies for review. A methodological quality assessment tool was developed to assess the quality of studies, which informed interpretation of the findings. Results indicated inter-rater reliability mainly ranging from slight (.1-.4) to substantial (.81-1.0). Some studies highlighted that training and increased experience led to higher levels of agreement. In general, psychodynamic formulations appeared to generate somewhat increased levels of reliability than cognitive or behavioural formulations; however, these studies also included methods that may have served to inflate reliability, for example, pooling the scores of judges. Only one study investigated the test-retest reliability of case formulations yielding support for the stability of formulations over a 3-month period. Reliability of case formulations is varied across a range of theoretical modalities, but can be improved; however, further research is required to strengthen our conclusions. Clinical implications: The findings from the review evidence some support for case formulation being congruent with the scientist-practitioner approach. The reliability of case formulation is likely to be improved through training and clinical experience. Limitations: The broad inclusion criteria may have introduced heterogeneity into the sample, which may have affected the results. Studies reviewed were limited to peer-reviewed journal articles written in the English language, which may represent a source of publication and selection bias. © 2014 The British Psychological Society.
A formulation to encapsulate nootkatone for tick control.
Behle, Robert W; Flor-Weiler, Lina B; Bharadwaj, Anuja; Stafford, Kirby C
2011-11-01
Nootkatone is a component of grapefruit oil that is toxic to the disease-vectoring tick, Ixodes scapularis Say, but unfortunately causes phytotoxicity to treated plants and has a short residual activity due to volatility. We prepared a lignin-encapsulated nootkatone formulation to compare with a previously used emulsifiable formulation for volatility, plant phytotoxicity, and toxicity to unfed nymphs of I. scapularis. Volatility of nootkatone was measured directly by trapping nootkatone vapor in a closed system and indirectly by measuring nootkatone residue on treated filter paper after exposure to simulated sunlight (Xenon). After 24 h in the closed system, traps collected only 15% of the nootkatone applied as the encapsulated formulation compared with 40% applied as the emulsifiable formulation. After a 1-h light exposure, the encapsulated formulation retained 92% of the nootkatone concentration compared with only 26% retained by the emulsifiable formulation. For plant phytotoxicity, cabbage, Brassica oleracea L., leaves treated with the encapsulated formulation expressed less necrosis, retaining greater leaf weight compared with leaves treated with the emusifiable formulation. The nootkatone in the emulsifiable formulation was absorbed by cabbage and oat, Avena sativa L., plants (41 and 60% recovered 2 h after application, respectively), as opposed to 100% recovery from the plants treated with encapsulated nootkatone. Using a treated vial technique, encapsulated nootkatone was significantly more toxic to I. scapularis nymphs (LC50 = 20 ng/cm2) compared with toxicity of the emulsifiable formulation (LC50 = 35 ng/cm2). Thus, the encapsulation of nootkatone improved toxicity for tick control, reduced nootkatone volatility, and reduced plant phytotoxicity.
Michel, M. C.; Korstanje, C.; Klauwinkel, W.; Shear, M.; Davies, J.; Quartel, A.
2005-01-01
Objective: The potential to interfere with efferent adrenergic drive in the cardiovascular system was tested in elderly healthy subjects for the new oral controlled absorption system (OCAS) 0.4 mg tablet formulation of tamsulosin compared to the modified release (MR) 0.4 mg capsule formulation of
Chandrasekaran, Prabagaran; Kandasamy, Ruckmani
2017-08-01
Development of palatable formulations for pediatric and geriatric patients involves various challenges. However, an innovative development with beneficial characteristics of marketed formulations in a single formulation platform was attempted. The goal of this research was to develop solid oral flexible tablets (OFTs) as a platform for pediatrics and geriatrics as oral delivery is the most convenient and widely used mode of drug administration. For this purpose, a flexible tablet formulation using cetirizine hydrochloride as model stability labile class 1 and 3 drug as per the Biopharmaceutical Classification System was developed. Betadex, Eudragit E100, and polacrilex resin were evaluated as taste masking agents. Development work focused on excipient selection, formulation processing, characterization methods, stability, and palatability testing. Formulation with a cetirizine-to-polacrilex ratio of 1:2 to 1:3 showed robust physical strength with friability of 0.1% (w/w), rapid in vitro dispersion within 30 s in 2-6 ml of water, and 0.2% of total organic and elemental impurities. Polacrilex resin formulation shows immediate drug release within 30 min in gastric media, better taste masking, and acceptable stability. Hence, it is concluded that ion exchange resins can be appropriately used to develop taste-masked, rapidly dispersible, and stable tablet formulations with tailored drug release suitable for pediatrics and geriatrics. Flexible formulations can be consumed as swallowable, orally disintegrating, chewable, and as dispersible tablets. Flexibility in dose administration would improve compliance in pediatrics and geriatrics. This drug development approach using ion exchange resins can be a platform for formulating solid oral flexible drug products with low to medium doses.
Evaluating Suspension Formulations of Theophylline Cocrystals With Artificial Sweeteners.
Aitipamula, Srinivasulu; Wong, Annie B H; Kanaujia, Parijat
2018-02-01
Pharmaceutical cocrystals have garnered significant interest as potential solids to address issues associated with formulation development of drug substances. However, studies concerning the understanding of formulation behavior of cocrystals are still at the nascent stage. We present results of our attempts to evaluate suspension formulations of cocrystals of an antiasthmatic drug, theophylline, with 2 artificial sweeteners. Stability, solubility, drug release, and taste of the suspension formulations were evaluated. Suspension that contained cocrystal with acesulfame showed higher drug release rate, while a cocrystal with saccharin showed a significant reduction in drug release rate. The cocrystal with saccharin was found stable in suspension for over 9 weeks at accelerated test condition; in contrast, the cocrystal with acesulfame was found unstable. Taste analysis using an electronic taste-sensing system revealed improved sweetness of the suspension formulations with cocrystals. Theophylline has a narrow therapeutic index with a short half-life which necessitates frequent dosing. This adversely impacts patient compliance and enhances risk of gastrointestinal and cardiovascular adverse effects. The greater thermodynamic stability, sweetness, and sustained drug release of the suspension formulation of theophylline-saccharin could offer an alternative solution to the short half-life of theophylline and make it a promising formulation for treating asthmatic pediatric and geriatric patients. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.
Significance of Strain in Formulation in Theory of Solid Mechanics
Patnaik, Surya N.; Coroneos, Rula M.; Hopkins, Dale A.
2003-01-01
The basic theory of solid mechanics was deemed complete circa 1860 when St. Venant provided the strain formulation or the field compatibility condition. The strain formulation was incomplete. The missing portion has been formulated and identified as the boundary compatibility condition (BCC). The BCC, derived through a variational formulation, has been verified through integral theorem and solution of problems. The BCC, unlike the field counterpart, do not trivialize when expressed in displacements. Navier s method and the stiffness formulation have to account for the extra conditions especially at the inter-element boundaries in a finite element model. Completion of the strain formulation has led to the revival of the direct force calculation methods: the Integrated Force Method (IFM) and its dual (IFMD) for finite element analysis, and the completed Beltrami-Michell formulation (CBMF) in elasticity. The benefits from the new methods in elasticity, in finite element analysis, and in design optimization are discussed. Existing solutions and computer codes may have to be adjusted for the compliance of the new conditions. Complacency because the discipline is over a century old and computer codes have been developed for half a century can lead to stagnation of the discipline.
Formulation and Characterization of Waste Glasses with Varying Processing Temperature
Energy Technology Data Exchange (ETDEWEB)
Kim, Dong-Sang; Schweiger, M. J.; Rodriguez, Carmen P.; Lepry, William C.; Lang, Jesse B.; Crum, Jarrod V.; Vienna, John D.; Johnson, Fabienne; Marra, James C.; Peeler, David K.
2011-10-17
This report documents the preliminary results of glass formulation and characterization accomplished within the finished scope of the EM-31 technology development tasks for WP-4 and WP-5, including WP-4.1.2: Glass Formulation for Next Generation Melter, WP-5.1.2.3: Systematic Glass Studies, and WP-5.1.2.4: Glass Formulation for Specific Wastes. This report also presents the suggested studies for eventual restart of these tasks. The initial glass formulation efforts for the cold crucible induction melter (CCIM), operating at {approx}1200 C, with selected HLW (AZ-101) and LAW (AN-105) successfully developed glasses with significant increase of waste loading compared to that is likely to be achieved based on expected reference WTP formulations. Three glasses formulated for AZ-101HLW and one glass for AN-105 LAW were selected for the initial CCIM demonstration melter tests. Melter tests were not performed within the finished scope of the WP-4.1.2 task. Glass formulations for CCIM were expanded to cover additional HLWs that have high potential to successfully demonstrate the unique advantages of the CCIM technologies based on projected composition of Hanford wastes. However, only the preliminary scoping tests were completed with selected wastes within the finished scope. Advanced glass formulations for the reference WTP melter, operating at {approx}1200 C, were initiated with selected specific wastes to determine the estimated maximum waste loading. The incomplete results from these initial formulation efforts are summarized. For systematic glass studies, a test matrix of 32 high-aluminum glasses was completed based on a new method developed in this study.
Formulation and Characterization of Waste Glasses with Varying Processing Temperature
International Nuclear Information System (INIS)
Kim, Dong-Sang; Schweiger, M.J.; Rodriguez, Carmen P.; Lepry, William C.; Lang, Jesse B.; Crum, Jarrod V.; Vienna, John D.; Johnson, Fabienne; Marra, James C.; Peeler, David K.
2011-01-01
This report documents the preliminary results of glass formulation and characterization accomplished within the finished scope of the EM-31 technology development tasks for WP-4 and WP-5, including WP-4.1.2: Glass Formulation for Next Generation Melter, WP-5.1.2.3: Systematic Glass Studies, and WP-5.1.2.4: Glass Formulation for Specific Wastes. This report also presents the suggested studies for eventual restart of these tasks. The initial glass formulation efforts for the cold crucible induction melter (CCIM), operating at ∼1200 C, with selected HLW (AZ-101) and LAW (AN-105) successfully developed glasses with significant increase of waste loading compared to that is likely to be achieved based on expected reference WTP formulations. Three glasses formulated for AZ-101HLW and one glass for AN-105 LAW were selected for the initial CCIM demonstration melter tests. Melter tests were not performed within the finished scope of the WP-4.1.2 task. Glass formulations for CCIM were expanded to cover additional HLWs that have high potential to successfully demonstrate the unique advantages of the CCIM technologies based on projected composition of Hanford wastes. However, only the preliminary scoping tests were completed with selected wastes within the finished scope. Advanced glass formulations for the reference WTP melter, operating at ∼1200 C, were initiated with selected specific wastes to determine the estimated maximum waste loading. The incomplete results from these initial formulation efforts are summarized. For systematic glass studies, a test matrix of 32 high-aluminum glasses was completed based on a new method developed in this study.
Beverages formulated with whey protein and added lutein
Directory of Open Access Journals (Sweden)
Juliana de Cássia Gomes Rocha
Full Text Available ABSTRACT: This study aimed to develop and characterize beverages formulated with whey protein and added lutein. Beverages formulated with 0.5 (F1, 2.0 (F2, 4.0 (F3 and 6.0% w/v (F4 whey protein were physicochemically and microbiologically characterized, and sensory evaluated. The physicochemical analyses indicated that the protein content significantly changed (P0.05 with increased protein content. The F2 formulation showed the highest sensory acceptance. Beverages offer a promising alternative to whey use and enhance the value of the product by the addition of lutein.
[Formulation optimization of panax notoginsenoside orally fast disintegration tablets].
Wang, Zhi; Wei, Li; Chen, Ting
2008-07-01
To optimize the formulation of panax notoginsenoside orally fast disintegrating tablets. Mannitol, microcrystalline cellulose (PH 102) and lactose 80 were used as diluent. A polynomial regression algorithm was used to evaluate the relationship between the controlling factor, compacting pressure and diluent ratio, and disintegration time, tensile strength of tablets. Optimum formulation and process parameters could be determined by contrast the contour plot of tensile strength to that of disintegration time. The disintegration time and tensile strength of panax notoginsenoside oral disintegrating tablets were good, and the taste was satisfactory. Panax notoginsenoside oral disintegrating tablets achieve the goal of design and this method can be fairly used in formulation screening.
Sood, Jatin; Sapra, Bharti; Tiwary, Ashok K
2017-08-01
The objective of the study was to optimize the proportion of different components for formulating oil in water microemulsion formulation meant for simultaneous transdermal delivery of two poorly soluble antihypertensive drugs. Surface response methodology of Box-Behnken design was utilized to evaluate the effect of two oils (Captex 500 - x1 and Capmul MCM - x2) and surfactant (Acrysol EL135 - x3) on response y1 (particle size), y2 (solubility of valsartan), and y3 (solubility of nifedipine). The important factors which significantly affected the responses were identified and validated using ANOVA. The model was diagnosed using normal plot of residuals and Box-Cox plot. The design revealed an inverse correlation between particle size and concentration of Capmul MCM and Acrysol EL 135. However, an increase in concentration of Captex 500 led to an increase in particle size of microemulsion. Solubility of valsartan decreased while that of nifedipine increased with increase in concentration of Captex 500. Capmul MCM played a significant role in increasing the solubility of valsartan. The effect of Acrysol EL 135 on solubility of both drugs, although significant, was only marginal as compared to that of Captex 500 and Capmul MCM. The optimized microemulsion was able to provide an enhancement ratio of 27.21 and 63.57-fold for valsartan and nifedipine, respectively, with respect to drug dispersion in aqueous surfactant system when evaluated for permeation studies. The current studies candidly suggest the scope of microemulsion systems for solubilizing as well as promoting the transport of both drugs across rat skin at an enhanced permeation rate.
Viscous-inviscid interaction using the parabolized Navier-Stokes equations
DEFF Research Database (Denmark)
Filippone, Antonino; Sørensen, Jens Nørkær
1997-01-01
adaptive grid is used.The interaction is achieved by iterative updatingof the boundary conditions, through the wall transpiration concept. The Navier-Stokes equationsare discretized on a semi-staggered grid.Space-marching integration is performed starting from the stagnation streamline ontwo independent......A numerical model for the calculation of incompressible viscous flows past airfoils andwings has been developed. The approach is based on a strong viscous-inviscid coupling of aboundary element method with the Navier-Stokesequations in vorticity-streamfunction formulation.A semi-adaptive or fully...
E3D, 3-D Elastic Seismic Wave Propagation Code
International Nuclear Information System (INIS)
Larsen, S.; Harris, D.; Schultz, C.; Maddix, D.; Bakowsky, T.; Bent, L.
2004-01-01
1 - Description of program or function: E3D is capable of simulating seismic wave propagation in a 3D heterogeneous earth. Seismic waves are initiated by earthquake, explosive, and/or other sources. These waves propagate through a 3D geologic model, and are simulated as synthetic seismograms or other graphical output. 2 - Methods: The software simulates wave propagation by solving the elasto-dynamic formulation of the full wave equation on a staggered grid. The solution scheme is 4-order accurate in space, 2-order accurate in time
Formulation of humic-based soil conditioners
Amanova, M. A.; Mamytova, G. A.; Mamytova, B. A.; Kydralieva, K. A.; Jorobekova, Sh. J.
2009-04-01
The goal of the study is to prepare soil conditioners (SC) able to carry out the following functions: (i) the chemical conditioning of soil mainly comprising the adjustment of pH, (ii) the balancing of inorganic nutrients, (iii) the physical conditioning of soil mainly comprising the improvement of water permeability, air permeability and water retention properties, and (iv) improvement of the ecological system concerning of useful microorganisms activity in the soil. The SC was made of a mixture of inorganic ingredients, a chemical composition and physical and chemical properties of which promoted improvement of physical characteristic of soil and enrichment by its mineral nutritious elements. In addition to aforesaid ingredients, this soil conditioner contains agronomical-valued groups of microorganisms having the function promoting the growth of the crop. As organic component of SC humic acids (HA) was used. HA serve many major functions that result in better soil and plant health. In soil, HA can increase microbial and mycorrhizal activity while enhancing nutrient uptake by plant roots. HA work as a catalyst by stimulating root and plant growth, it may enhance enzymatic activity that in turn accelerates cell division which can lead to increased yields. HA can help to increase crop yields, seed germination, and much more. In short, humic acids helps keep healthy plants health. The first stage goal was to evaluate mineral and organic ingredients for formulation of SC. Soil conditioners assessed included ash and slag. The use of slags has been largelly used in agriculture as a source of lime and phosphoric acid. The silicic acid of slags reduces Al-acitivity thus, promoting a better assimilation of P-fertilizer by plants. Additionally, silicic acid is also known to improve soil moisture capacity, thus enhancing soil water availability to plants. Physico-chemical characteristics of ash and slag were determined, as a total - about 20 samples. Results include
Magnetic Resonance Imaging to Visualize Disintegration of Oral Formulations.
Curley, Louise; Hinton, Jordan; Marjoribanks, Cameron; Mirjalili, Ali; Kennedy, Julia; Svirskis, Darren
2017-03-01
This article demonstrates that magnetic resonance imaging can visualize the disintegration of a variety of paracetamol containing oral formulations in an in vitro setting and in vivo in the human stomach. The different formulations had unique disintegration profiles which could be imaged both in vitro and in vivo. No special formulation approaches or other contrast agents were required. These data demonstrate the potential for further use of magnetic resonance imaging to investigate and understand the disintegration behavior of different formulation types in vivo, and could potentially be used as a teaching tool in pharmaceutical and medical curricula. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.
Enhanced formulations for neutralization of chemical, biological and industrial toxants
Tucker, Mark D [Albuqueque, NM
2008-06-24
An enhanced formulation and method of making that neutralizes the adverse health effects of both chemical and biological compounds, especially chemical warfare (CW) and biological warfare (BW) agents, and toxic industrial chemicals. The enhanced formulation according to the present invention is non-toxic and non-corrosive and can be delivered by a variety of means and in different phases. The formulation provides solubilizing compounds that serve to effectively render the chemical and biological compounds, particularly CW and BW compounds, susceptible to attack, and at least one reactive compound that serves to attack (and detoxify or kill) the compound. The formulation includes at least one solubilizing agent, a reactive compound, a bleaching activator and water.
Preclinical efficacy and safety of herbal formulation for management ...
African Journals Online (AJOL)
Preclinical efficacy and safety of herbal formulation for management of wounds. ... The effects of the treatments on rate of wound closure, epithelialisation time ... inflammation and better tissue remodeling for rats treated with herbal product.
Design, formulation and evaluation of nicotine chewing gum
Directory of Open Access Journals (Sweden)
Abolfazl Aslani
2012-01-01
Conclusion: Taste enhancement of nicotine gums was achieved where formulations comprised aspartame as the sweetener and cherry and eucalyptus as the flavoring agents. Nicotine gums of pleasant taste may, therefore, be used as NRT to assist smokers quit smoking.
Continuous-release formulation for environmental doses to moving receptors
International Nuclear Information System (INIS)
Piepho, M.G.
1981-01-01
Atmospheric dispersion models frequently assume a puff release or several puff releases, each of which are described separately. A dispersion model should better describe a continuous release as more puffs are assumed, but the computational cost and bookkeeping difficulty increases with additional puffs. A new formulism is derived in this work which replaces the puff approximation. With the new continuous release formulation, radioactive dose calculations to moving receptors are more accurately calculated without any great additional computation. There are several advantages of a continuous release formulation. With this formulation, a dose rate to a moving receptor is calculated as a function of time. The dose-rate will increase (decrease) as the bulk of the release gets closer (farther) to (from) the receptor which is at position x(t), y(t). The receptor may follow any x, y trajectory as a function of time, and the dose rate will be calculated along the path
LP formulation of asymmetric zero-sum stochastic games
Li, Lichun
2014-12-15
This paper provides an efficient linear programming (LP) formulation of asymmetric two player zero-sum stochastic games with finite horizon. In these stochastic games, only one player is informed of the state at each stage, and the transition law is only controlled by the informed player. Compared with the LP formulation of extensive stochastic games whose size grows polynomially with respect to the size of the state and the size of the uninformed player\\'s actions, our proposed LP formulation has its size to be linear with respect to the size of the state and the size of the uninformed player, and hence greatly reduces the computational complexity. A travelling inspector problem is used to demonstrate the efficiency of the proposed LP formulation.
Formulation Optimization and In-vitro Evaluation of Oral Floating ...
African Journals Online (AJOL)
matrix tablets and to systematically optimize its drug release using varying levels of xanthan gum and hydroxypropyl ... stomach and improve oral bioavailability of drugs that have ... which can affect its sustained release formulation. [19].
Hypersensitivity Reactions from Excipients in Systemic Glucocorticoid Formulations
DEFF Research Database (Denmark)
Calogiuri, Gianfranco; Garvey, Lene H; Romita, Paolo
2016-01-01
Glucocorticoids are the most widely used drugs for the treatment of hypersensitivity, however these drugs themselves and the excipients contained in commercial corticosteroid formulations are able to induce severe immediate-type hypersensitivity reactions. Reactions involving excipients have been...
Comparative study of performance of shoe polishes formulated from ...
African Journals Online (AJOL)
GARZALI
1Department of Pure and Industrial Chemistry, Bayero University, Kano. 2College of Science ... carbon black pigment. Polyethylene polish like the one formulated using carbon black pigment was ... into fine black powder. Purification of Wax.
Finite element formulation for a digital image correlation method
International Nuclear Information System (INIS)
Sun Yaofeng; Pang, John H. L.; Wong, Chee Khuen; Su Fei
2005-01-01
A finite element formulation for a digital image correlation method is presented that will determine directly the complete, two-dimensional displacement field during the image correlation process on digital images. The entire interested image area is discretized into finite elements that are involved in the common image correlation process by use of our algorithms. This image correlation method with finite element formulation has an advantage over subset-based image correlation methods because it satisfies the requirements of displacement continuity and derivative continuity among elements on images. Numerical studies and a real experiment are used to verify the proposed formulation. Results have shown that the image correlation with the finite element formulation is computationally efficient, accurate, and robust
A Nanodroplet Processor for Advanced Microencapsulated Drug Formulations, Phase II
National Aeronautics and Space Administration — During this Phase II program we propose to build on the key aspects of the nanodroplet encapsulation technology to demonstrate optimized formulation and...
Formulated linear programming problems from game theory and its ...
African Journals Online (AJOL)
Formulated linear programming problems from game theory and its computer implementation using Tora package. ... Game theory, a branch of operations research examines the various concepts of decision ... AJOL African Journals Online.
IRIS Assessment Plan for Uranium (Scoping and Problem Formulation Materials)
In January 2018, EPA released the IRIS Assessment Plan for Uranium (Oral Reference Dose) (Scoping and Problem Formulation Materials). An IRIS Assessment Plan (IAP) communicates to the public the plan for assessing each individual chemical and includes summary informatio...
Formulation and evaluation of antipsoriatic gel using natural excipients
Directory of Open Access Journals (Sweden)
Raghupatruni Jhansi Laxmi
2013-01-01
Conclusions: In vitro anti-psoriatic activity of F3 showed the significant orthokeratosis in the mouse tail test when compared to control thus indicating that the formulation is effective in treating psoriasis.
Controlled Release Formulation of Indomethacin Prepared With Bee ...
African Journals Online (AJOL)
Erah
2010-12-27
Dec 27, 2010 ... Results: The results show that, although the release rate of formulations F1 - F7 did not show any ... Keywords: Propolis (bee glue), Indomethacin, Controlled release, Zero order kinetics, Waxy materials ... focus of interest.
Improvability of assembly systems I: Problem formulation and performance evaluation
Directory of Open Access Journals (Sweden)
S.-Y. Chiang
2000-01-01
Full Text Available This work develops improvability theory for assembly systems. It consists of two parts. Part I includes the problem formulation and the analysis technique. Part II presents the so-called improvability indicators and a case study.
LP formulation of asymmetric zero-sum stochastic games
Li, Lichun; Shamma, Jeff S.
2014-01-01
This paper provides an efficient linear programming (LP) formulation of asymmetric two player zero-sum stochastic games with finite horizon. In these stochastic games, only one player is informed of the state at each stage, and the transition law is only controlled by the informed player. Compared with the LP formulation of extensive stochastic games whose size grows polynomially with respect to the size of the state and the size of the uninformed player's actions, our proposed LP formulation has its size to be linear with respect to the size of the state and the size of the uninformed player, and hence greatly reduces the computational complexity. A travelling inspector problem is used to demonstrate the efficiency of the proposed LP formulation.
Characterization of 99m Tc-Macroaggregates formulation
International Nuclear Information System (INIS)
Rivero Santamaria, Alejandro; Alfonso Marin, Yumisley; Zayas Crespo, Francisco; Mesa Duennas, Niurka; Rodriguez Fernandez, Rolando
2009-01-01
The aim of this paper was to study the formation and radiolabelling of 99m Tcalbumin macroaggregates. Comparatives studies of three formulations to establish the role of denaturalization and Sn 2+ in the formulation of 99m TcSnMAA were carried out. A qualitative structural analysis of human serum albumin was performed in order to give a description of the studied system using a graph model. The results showed important differences in the radiochemical behavior of the three formulations. 99m TcSnMAA (A) formulation had the best behavior, with radiochemical purity close to 95% and dissociation below 20% after 24 h of being radiolabeled. The graph model explained with simple representations the process involved in the studied system; thus allowing a better knowledge of it. (author)
Reactive formulations for a neutralization of toxic industrial chemicals
Tucker, Mark D [Albuqueruqe, NM; Betty, Rita G [Rio Rancho, NM
2006-10-24
Decontamination formulations for neutralization of toxic industrial chemicals, and methods of making and using same. The formulations are effective for neutralizing malathion, hydrogen cyanide, sodium cyanide, butyl isocyanate, carbon disulfide, phosgene gas, capsaicin in commercial pepper spray, chlorine gas, anhydrous ammonia gas; and may be effective at neutralizing hydrogen sulfide, sulfur dioxide, formaldehyde, ethylene oxide, methyl bromide, boron trichloride, fluorine, tetraethyl pyrophosphate, phosphorous trichloride, arsine, and tungsten hexafluoride.
Process Formulations And Curing Conditions That Affect Saltstone Properties
Energy Technology Data Exchange (ETDEWEB)
Reigel, M. M.; Pickenheim, B. R.; Daniel, W. E.
2012-09-28
The first objective of this study was to analyze saltstone fresh properties to determine the feasibility of reducing the formulation water to premix (w/p) ratio while varying the amount of extra water and admixtures used during processing at the Saltstone Production Facility (SPF). The second part of this study was to provide information for understanding the impact of curing conditions (cure temperature, relative humidity (RH)) and processing formulation on the performance properties of cured saltstone.
A new formulation of non-relativistic diffeomorphism invariance
Energy Technology Data Exchange (ETDEWEB)
Banerjee, Rabin, E-mail: rabin@bose.res.in [S.N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake City, Kolkata-700 098 (India); Mitra, Arpita, E-mail: arpita12t@bose.res.in [S.N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake City, Kolkata-700 098 (India); Mukherjee, Pradip, E-mail: mukhpradip@gmail.com [Department of Physics, Barasat Government College, Barasat, West Bengal (India)
2014-10-07
We provide a new formulation of non-relativistic diffeomorphism invariance. It is generated by localising the usual global Galilean symmetry. The correspondence with the type of diffeomorphism invariant models currently in vogue in the theory of fractional quantum Hall effect has been discussed. Our construction is shown to open up a general approach of model building in theoretical condensed matter physics. Also, this formulation has the capacity of obtaining Newton–Cartan geometry from the gauge procedure.
Two field formulation of closed string field theory
International Nuclear Information System (INIS)
Bogojevic, A.R.
1990-09-01
A formulation of closed string field theory is presented that is based on a two field action. It represents a generalization of Witten's Chern-Simons formulation of 3d gravity. The action contains only 3 string interactions and no string field truncations, unlike the previous non-polynomial action of Zwiebach. The two field action is found to follow from a purely cubic, background independent action similar to the one for open strings. (orig.)
Bioavailability of two oral formulations of triazolam using radioreceptor assay
Energy Technology Data Exchange (ETDEWEB)
Lapka, R; Cepelakova, H; Rejholec, V; Franc, Z
1986-04-01
The radioreceptor assay (RRA) was used to quantitate plasma triazolam concentration in eight female volunteers following single 0.5 mg doses of two tablet formulations in a cross-over study. Bioavailability in terms of area under the plasma concentration versus time curve, maximum plasma concentration, time to maximum, and mean residence time was not statistically significantly different from one formulation to the other.
Formulation matricielle des equations du mouvement d'un solide ...
African Journals Online (AJOL)
Plusieurs formulations des équations du mouvement d'un rigide ont été développées. Le bien connu d'entre elles est celle de Newton-Euler; elle est généralement appelée «équations d'Euler classiques". Cette formulation donne six équations scalaires pour un corps rigide. Dans cet article, nous avons décrit les équations ...
Energy Technology Data Exchange (ETDEWEB)
Simon, J.; Garlich, J.R.; Frank, R.K.; McMillan, K
1998-03-16
Radiopharmaceutical formulations for complexes comprising at least one radionuclide complexed with a ligand, or its physiologically-acceptable salts thereof, especially {sup 153}samarium-ethylenediaminetetramethylenephosphonic acid, which optionally contains a divalent metal ion, e.g. calcium, and is frozen, thawed, and then administered by injection. Alternatively, the radiopharmaceutical formulations must contain the divalent metal and are frozen only if the time before administration is sufficiently long to cause concern for radiolysis of the ligand. 2 figs., 9 tabs.
FORMULATION STRATEGY UNDER THE INFLUENCE OF POWER COMPETITION
Ljiljana Stošić Mihajlović
2014-01-01
In this work, the subject of the research is defined starting hypothesis that formulation in the form of answers to the question: What factors - competitive forces shape strategy? Strategy formulation essentially boils down to competition. Competitors are all - customers, suppliers, potential new entrants to the market and producers of substitutes - and depending on the industry, may be more or less important or active. The first primary determinant of a firm's prof...
The dual formulation of cosmic strings and vortices
Lee, Ki-Myeong
1993-01-01
We study four dimensional systems of global, axionic and local strings. By using the path integral formalism, we derive the dual formulation of these systems, where Goldstone bosons, axions and missive vector bosons are described by antisymmetric tensor fields, and strings appear as a source for these tensor fields. We show also how magnetic monopoles attached to local strings are described in the dual formulation. We conclude with some remarks.
Dissolution Model Development: Formulation Effects and Filter Complications
DEFF Research Database (Denmark)
Berthelsen, Ragna; Holm, Rene; Jacobsen, Jette
2016-01-01
This study describes various complications related to sample preparation (filtration) during development of a dissolution method intended to discriminate among different fenofibrate immediate-release formulations. Several dissolution apparatus and sample preparation techniques were tested. The fl....... With the tested drug–formulation combination, the best in vivo–in vitro correlation was found after filtration of the dissolution samples through 0.45-μm hydrophobic PTFE membrane filters....
Petrov-Galerkin mixed formulations for bidimensional elasticity
International Nuclear Information System (INIS)
Toledo, E.M.; Loula, A.F.D.; Guerreiro, J.N.C.
1989-10-01
A new formulation for two-dimensional elasticity in stress and displacements is presented. Consistently adding to the Galerkin classical formulation residuals forms of constitutive and equilibrium equations, the original saddle point is transformed into a minimization problem without any restrictions. We also propose a stress post processing technique using both equilibrium and constitutive equations. Numerical analysis error estimates and numerical results are presented confirming the predicted rates of convergence. (A.C.A.S.) [pt
Bioavailability of syrup and tablet formulations of cefetamet pivoxil.
Ducharme, M P; Edwards, D J; McNamara, P J; Stoeckel, K
1993-12-01
Two studies examining the bioavailability of cefetamet pivoxil in healthy male subjects were conducted. In the first, the bioavailabilities of the 250-mg (M250) and M500 tablet formulations of cefetamet pivoxil to be marketed were compared with that of a tablet used in clinical trials. All products were given with food at a dose of 500 mg. In the second study, the bioavailability of the syrup formulation was evaluated under both fasting and nonfasting conditions and compared with that of the M500 tablet formulation given with food. The absolute bioavailabilities of the M500 and M250 tablets (55.0% +/- 8.0% and 55.7% +/- 7.0%, respectively) were not significantly different from that of the clinical-trial formulation (49.8% +/- 8.5%). The newer tablet formulations exhibited faster absorption as evidenced by higher peak concentrations (3.8 [M500] and 3.9 [M250] mg/liter compared with 3.2 mg/liter for the clinical-trial formulation), a shorter time to peak concentration, and a shorter mean absorption time. The syrup formulation was found to have significantly lower absolute bioavailability (37.9% +/- 6.0%) compared with that of the M500 tablet (58.4% +/- 9.0%) when both were given with food. Food had no significant effect on the bioavailability of the syrup, which averaged 34.0% +/- 8.6% under fasting conditions, although absorption was delayed by food (mean absorption time increased from 2.2 to 3.9 h). This contrasts with the results of previous studies documenting significant increases in tablet bioavailability with food. Despite the lower bioavailability of the syrup, unbound-cefetamet concentrations are expected to remain above the MICs for 90% of the strains tested for susceptible organisms for approximately 10 h of the usual 12-h dosing interval with both syrup and tablet formulations of cefetamet pivoxil given with food.
"9th Annual Congress on Drug Formulation & Drug Design"
Monty Karl
2017-01-01
Conference Series has been instrumental in conducting international meetings for seven years, and very excited to expand Europe, America and Asia Pacific continents. Previous meetings were held in major cities like Belgium, Tokyo, Madrid, with success the meetings again scheduled in three continents. It’s time to announce 9th Annual Congress on Drug Formulation & Drug Design October 19-21, 2017 Seoul, South Korea . Drug Formulation 2017 is a 3-day event offering the Exhibition, at venue to sh...
Action principle for the generalized harmonic formulation of general relativity
International Nuclear Information System (INIS)
Brown, J. David
2011-01-01
An action principle for the generalized harmonic formulation of general relativity is presented. The action is a functional of the spacetime metric and the gauge source vector. An action principle for the Z4 formulation of general relativity has been proposed recently by Bona, Bona-Casas, and Palenzuela. The relationship between the generalized harmonic action and the Bona, Bona-Casas, and Palenzuela action is discussed in detail.
Topological Gravity on $(D,N)-$Shift Superspace Formulation
Lourenco, José A.; Neto, José A. Helayël; Spalenza, Wesley
2017-01-01
In this contribution, we re-assess the subject of topological gravity by following the Shift Supersymmetry formalism. The gauge-fixing of the theory goes under the Batallin-Vilkovisky (BV) prescription based on a diagram that contains both ghost and anti-ghost superfields, associated to the super-vielbein and the super-Lorentz connection. We extend the formulation of the topological gravity action to an arbitrary number of dimensions of the shift superspace by adopting a formulation based on ...
Noncanonical Hamiltonian density formulation of hydrodynamics and ideal MHD
International Nuclear Information System (INIS)
Morrison, P.J.; Greene, J.M.
1980-04-01
A new Hamiltonian density formulation of a perfect fluid with or without a magnetic field is presented. Contrary to previous work the dynamical variables are the physical variables, rho, v, B, and s, which form a noncanonical set. A Poisson bracket which satisfies the Jacobi identity is defined. This formulation is transformed to a Hamiltonian system where the dynamical variables are the spatial Fourier coefficients of the fluid variables
Design, formulation and evaluation of Aloe vera chewing gum
Aslani, Abolfazl; Ghannadi, Alireza; Raddanipour, Razieh
2015-01-01
Background: Aloe vera has antioxidant, antiinflammatory, healing, antiseptic, anticancer and antidiabetic effects. The aim of the present study was to design and evaluate the formulation of Aloe vera chewing gum with an appropriate taste and quality with the indications for healing oral wounds, such as lichen planus, mouth sores caused by cancer chemotherapy and mouth abscesses as well as reducing mouth dryness caused by chemotherapy. Materials and Methods: In Aloe vera powder, the carbohydrate content was determined according to mannose and phenolic compounds in terms of gallic acid. Aloe vera powder, sugar, liquid glucose, glycerin, sweeteners and different flavors were added to the soft gum bases. In Aloe vera chewing gum formulation, 10% of dried Aloe vera extract entered the gum base. Then the chewing gum was cut into pieces of suitable sizes. Weight uniformity, content uniformity, the organoleptic properties evaluation, releasing the active ingredient in the phosphate buffer (pH, 6.8) and taste evaluation were examined by Latin square method. Results: One gram of Aloe vera powder contained 5.16 ± 0.25 mg/g of phenolic compounds and 104.63 ± 4.72 mg/g of carbohydrates. After making 16 Aloe vera chewing gum formulations, the F16 formulation was selected as the best formulation according to its physicochemical and organoleptic properties. In fact F16 formulation has suitable hardness, lack of adhesion to the tooth and appropriate size and taste; and after 30 min, it released more than 90% of its drug content. Conclusion: After assessments made, the F16 formulation with maltitol, aspartame and sugar sweeteners was selected as the best formulation. Among various flavors used, peppermint flavor which had the most acceptance between consumers was selected. PMID:26605214
Simultaneously Exploiting Two Formulations: an Exact Benders Decomposition Approach
DEFF Research Database (Denmark)
Lusby, Richard Martin; Gamst, Mette; Spoorendonk, Simon
When modelling a given problem using linear programming techniques several possibilities often exist, and each results in a different mathematical formulation of the problem. Usually, advantages and disadvantages can be identified in any single formulation. In this paper we consider mixed integer...... to the standard branch-and-price approach from the literature, the method shows promising performance and appears to be an attractive alternative....
Static and kinematic formulation of planar reciprocal assemblies
DEFF Research Database (Denmark)
Parigi, Dario; Sassone, Mario; Kirkegaard, Poul Henning
2014-01-01
Planar reciprocal frames are two dimensional structures formed by elements joined together according to the principle of structural reciprocity. In this paper a rigorous formulation of the static and kinematic problem is proposed and developed extending the theory of pin-jointed assemblies....... This formulation is used to evaluate the static and kinematic determinacy of reciprocal assemblies from the properties of their equilibrium and kinematic matrices...
Empathy deficit in antisocial personality disorder: a psychodynamic formulation.
Malancharuvil, Joseph M
2012-09-01
Empathic difficulty is a highly consequential characteristic of antisocial personality structure. The origin, maintenance, and possible resolution of this profound deficit are not very clear. While reconstructing empathic ability is of primary importance in the treatment of antisocial personality, not many proven procedures are in evidence. In this article, the author offers a psychodynamic formulation of the origin, character, and maintenance of the empathic deficiency in antisocial personality. The author discusses some of the treatment implications from this dynamic formulation.
Allam, Ahmed N; Komeil, Ibrahim A; Abdallah, Ossama Y
2015-09-01
Curcumin, a naturally occurring lipophilic molecule can exert multiple and diverse bioactivities. However, its limited aqueous solubility and extensive presystemic metabolism restrict its bioavailability. Curcumin phytosomes were prepared by a simple solvent evaporation method where free flowing powder was obtained in addition to a newly developed semisolid formulation to increase curcumin content in softgels. Phytosomal powder was characterized in terms of drug content and zeta potential. Thirteen different softgel formulations were developed using oils such as Miglyol 812, castor oil and oleic acid, a hydrophilic vehicle such as PEG 400 and bioactive surfactants such as Cremophor EL and KLS P 124. Selected formulations were characterized in terms of curcumin in vitro dissolution. TEM analysis revealed good stability and a spherical, self-closed structure of curcumin phytosomes in complex formulations. Stability studies of chosen formulations prepared using the hydrophilic vehicle revealed a stable curcumin dissolution pattern. In contrast, a dramatic decrease in curcumin dissolution was observed in case of phytosomes formulated in oily vehicles.
Dissolution studies on Nickel ferrite in dilute chemical decontamination formulations
Energy Technology Data Exchange (ETDEWEB)
Ranganathan, S. [New Brunswick Univ., Fredericton, NB (Canada). Dept. of Chemical Engineering; Srinivasan, M.P. [Bhabha Atomic Research Centre (BARC) (India). Water and Steam Chemistry Laboratory; Raghavan, P.S. [Madras Christian College, Chennai (India); Narasimhan, S.V. [Bhabha Atomic Research Centre, Bombay (India); Gopalan, R. [Madras Christian College, Chennai (India). Department of Chemistry
2004-09-01
Nickel ferrite is one of the important corrosion products in the pipeline surfaces of water-cooled nuclear reactors. The dissolution of the nickel ferrite by chelating agents is very sensitive to the nature of the chelant, the nature of the reductant used in the formulation and the temperature at which the dissolution studies are performed. The dissolution is mainly controlled by the reductive dissolution of the ferrite particles, but complexing agents also play a significant role in the dissolution process. This study deals with the leaching of iron and nickel from nickel ferrite prepared by the solid-state method. The dissolution studies are performed in pyridine-2,6-dicarboxylic acid (PDCA), nitrilotriacetic acid (NTA), and ethylenediaminetetraacetic acid (EDTA) formulations containing organic reductants like ascorbic acid and low oxidation state transition metal ion reductants like Fe(II)-L (where L = PDCA, NTA, EDTA) at 85 C. The dissolution of nickel ferrite in PDCA, NTA and EDTA formulations is influenced by the presence of reductants in the formulations. The addition of Fe(II)-L in the formulation greatly enhances the dissolution of nickel ferrite. The preferential leaching of nickel over iron during the dissolution of nickel ferrite was observed in all the formulations. (orig.)
Dissolution studies on Nickel ferrite in dilute chemical decontamination formulations
International Nuclear Information System (INIS)
Ranganathan, S.; Narasimhan, S.V.; Gopalan, R.
2004-01-01
Nickel ferrite is one of the important corrosion products in the pipeline surfaces of water-cooled nuclear reactors. The dissolution of the nickel ferrite by chelating agents is very sensitive to the nature of the chelant, the nature of the reductant used in the formulation and the temperature at which the dissolution studies are performed. The dissolution is mainly controlled by the reductive dissolution of the ferrite particles, but complexing agents also play a significant role in the dissolution process. This study deals with the leaching of iron and nickel from nickel ferrite prepared by the solid-state method. The dissolution studies are performed in pyridine-2,6-dicarboxylic acid (PDCA), nitrilotriacetic acid (NTA), and ethylenediaminetetraacetic acid (EDTA) formulations containing organic reductants like ascorbic acid and low oxidation state transition metal ion reductants like Fe(II)-L (where L = PDCA, NTA, EDTA) at 85 C. The dissolution of nickel ferrite in PDCA, NTA and EDTA formulations is influenced by the presence of reductants in the formulations. The addition of Fe(II)-L in the formulation greatly enhances the dissolution of nickel ferrite. The preferential leaching of nickel over iron during the dissolution of nickel ferrite was observed in all the formulations. (orig.)
Validation of flexible multibody dynamics beam formulations using benchmark problems
Energy Technology Data Exchange (ETDEWEB)
Bauchau, Olivier A., E-mail: obauchau@umd.edu [University of Maryland (United States); Betsch, Peter [Karlsruhe Institute of Technology (Germany); Cardona, Alberto [CIMEC (UNL/Conicet) (Argentina); Gerstmayr, Johannes [Leopold-Franzens Universität Innsbruck (Austria); Jonker, Ben [University of Twente (Netherlands); Masarati, Pierangelo [Politecnico di Milano (Italy); Sonneville, Valentin [Université de Liège (Belgium)
2016-05-15
As the need to model flexibility arose in multibody dynamics, the floating frame of reference formulation was developed, but this approach can yield inaccurate results when elastic displacements becomes large. While the use of three-dimensional finite element formulations overcomes this problem, the associated computational cost is overwhelming. Consequently, beam models, which are one-dimensional approximations of three-dimensional elasticity, have become the workhorse of many flexible multibody dynamics codes. Numerous beam formulations have been proposed, such as the geometrically exact beam formulation or the absolute nodal coordinate formulation, to name just two. New solution strategies have been investigated as well, including the intrinsic beam formulation or the DAE approach. This paper provides a systematic comparison of these various approaches, which will be assessed by comparing their predictions for four benchmark problems. The first problem is the Princeton beam experiment, a study of the static large displacement and rotation behavior of a simple cantilevered beam under a gravity tip load. The second problem, the four-bar mechanism, focuses on a flexible mechanism involving beams and revolute joints. The third problem investigates the behavior of a beam bent in its plane of greatest flexural rigidity, resulting in lateral buckling when a critical value of the transverse load is reached. The last problem investigates the dynamic stability of a rotating shaft. The predictions of eight independent codes are compared for these four benchmark problems and are found to be in close agreement with each other and with experimental measurements, when available.
Intermediate release formulations of diclofenac potassium tablets for IVIVC.
Ali, Huma; Shoaib, Muhammad Harris; Zafar, Farya; Bushra, Rabia; Yasmin, Riffat; Siddiqui, Shehla; Alam, Zafar M
2016-07-01
In recent days response surface methodology (RSM) has widely been applied for development and optimization of cost effective formulations with required quality. Study comprised of three steps including micromeritic comparison of different powder blends of placebo and diclofenac potassium (DP), formulation designing with CCRD (Design Expert, version 7.0.0), and stability testing of selected formulations by using R Gui. Ten formulations (F11-F20) were developed using microcrystalline cellulose (Avicel PH-102) (X1) (13-72%), methocel K15M (X2) (6.59-23.4%) and magnesium stearate (X3) (1.32-4.68%), while responses were % friability and % drug release. Blending rate constant was determined at 3, 6, 9 and 12 minutes. The results of physicochemical parameters were found within acceptable limits. After in vitro testing at pH 1.2, pH 4.5 and pH 6.8, mechanism of drug release, kinetic analysis and statistical evaluation were carried out by model - independent, model-dependent and one-way ANOVA methods. Most formulations followed zero order kinetics at higher pH. Fickian release (0.326 ≤ n ≤0.449) was observed with β greater than 0.5 and less than 1. ANOVA indicated no significant variation within and between formulations as p-values were found to be > 0.05.
Microsphere based improved sunscreen formulation of ethylhexyl methoxycinnamate.
Gogna, Deepak; Jain, Sunil K; Yadav, Awesh K; Agrawal, G P
2007-04-01
Polymethylmethacrylate (PMMA) microspheres of ethylhexyl methoxycinnamate (EHM) were prepared by emulsion solvent evaporation method to improve its photostability and effectiveness as sunscreening agent. Process parameters like stirring speed and aqueous polyvinyl alcohol (PVA) concentration were analyzed in order to optimize the formulations. Shape and surface morphology of the microspheres were examined using scanning electron microscopy. Particle size of the microspheres was determined using laser diffraction particle size analyzer. The PMMA microspheres of EHM were incorporated in water-removable cream base. The in vitro drug release of EHM in pH 7.4 was performed using dialysis membrane. Thin layer chromatography was performed to determine photostability of EHM inside the microspheres. The formulations were evaluated for sun protection factor (SPF) and minimum erythema dose (MED) in albino rats. Cream base formulation containing microspheres prepared using EHM:PMMA in ratio of 1:3 (C(3)) showed slowest drug (EHM) release and those prepared with EHM: PMMA in ratio of 1:1 showed fastest release. The cream base formulations containing EHM loaded microspheres had shown better SPF (more than 16.0) as compared to formulation C(d) that contained 3% free EHM as sunscreen agent and showed SPF 4.66. These studies revealed that the incorporation of EHM loaded PMMA microspheres into cream base had greatly increased the efficacy of sunscreen formulation approximately four times. Further, photostability was also shown to be improved in PMMA microspheres.
Viability of lactobacillus acidophilus in various vaginal tablet formulations
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Fazeli M.R.
2006-07-01
Full Text Available The lactobacilli which are present in vaginal fluids play an important role in prevention of vaginosis and there are considerable interests in formulation of these friendly bacteria into suitable pharmaceutical dosage forms. Formulating these microorganisms for vaginal application is a critical issue as the products should retain viability of lactobacilli during formulation and also storage. The aim of this study was to examine the viability and release of Lactobacillus acidophilus from slow-release vaginal tablets prepared by using six different retarding polymers and from two effervescent tablets prepared by using citric or adipic acid. The Carbomer–based formulations showed high initial viablility compared to those based on HPMC-LV, HPMC-HV, Polycarbophil and SCMC polymers which showed one log decrease in viable cells. All retarding polymers in slow release formulations presented a strong bacterial release at about 2 h except Carbomer polymers which showed to be poor bacterial releasers. Although effervescent formulations produced a quick bacterial release in comparison with polymer based slow-release tablets, they were less stable in cold storage. Due to the strong chelating characteristic of citric acid, the viability was quickly lost for aqueous medium of citric acid in comparison with adipic acid based effervescent tablets.
DNA/RNA-based formulations for treatment of breast cancer.
Xie, Zhaolu; Zeng, Xianghui
2017-12-01
To develop a successful formulation for the gene therapy of breast cancer, an effective therapeutic nucleic acid and a proper delivery system are essential. Increased understanding of breast cancer, and developments in biotechnology, material science and nanotechnology have provided a major impetus in the development of effective formulations for the gene therapy of breast cancer. Areas covered: We discuss DNA/RNA-based formulations that can inhibit the growth of breast cancer cells and control the progress of breast cancer. Targets for the gene therapy of breast cancer, DNA/RNA-based therapeutics and delivery systems are summarized. And examples of successful DNA/RNA-based formulations for breast cancer gene therapy are reviewed. Expert opinion: Several challenges remain in developing effective DNA/RNA-based formulations for treatment of breast cancer. Firstly, most of the currently utilized targets are not effective enough as monotherapy for breast cancer. Secondly, the requirements for co-delivery system make the preparation of formulation more complicated. Thirdly, nanoparticles with the modification of tumor-targeting ligands could be more unstable in circulation and normal tissues. Lastly, immune responses against the viral vectors are unfavorable for the gene therapy of breast cancer because of the damage to the host and the impaired therapeutic ability.
Solid effervescent formulations as new approach for topical minoxidil delivery.
Pereira, Maíra N; Schulte, Heidi L; Duarte, Natane; Lima, Eliana M; Sá-Barreto, Livia L; Gratieri, Tais; Gelfuso, Guilherme M; Cunha-Filho, Marcilio S S
2017-01-01
Currently marketed minoxidil formulations present inconveniences that range from a grease hard aspect they leave on the hair to more serious adverse reactions as scalp dryness and irritation. In this paper we propose a novel approach for minoxidil sulphate (MXS) delivery based on a solid effervescent formulation. The aim was to investigate whether the particle mechanical movement triggered by effervescence would lead to higher follicle accumulation. Preformulation studies using thermal, spectroscopic and morphological analysis demonstrated the compatibility between effervescent salts and the drug. The effervescent formulation demonstrated a 2.7-fold increase on MXS accumulation into hair follicles casts compared to the MXS solution (22.0±9.7μg/cm 2 versus 8.3±4.0μg/cm 2 ) and a significant drug increase (around 4-fold) in remaining skin (97.1±29.2μg/cm 2 ) compared to the drug solution (23.5±6.1μg/cm 2 ). The effervescent formulations demonstrated a prominent increase of drug permeation highly dependent on the effervescent mixture concentration in the formulation, confirming the hypothesis of effervescent reaction favoring drug penetration. Clinically, therapy effectiveness could be improved, increasing the administration interval, hence, patient compliance. More studies to investigate the follicular targeting potential and safety of new formulations are needed. Copyright © 2016 Elsevier B.V. All rights reserved.
Wound Healing Activity of a New Formulation from Platelet Lysate
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Akram Jamshidzadeh
2016-03-01
Full Text Available Platelet-rich plasma (PRP is an attractive preparation in regenerative medicine due to its potential role in the healing process in different experimental models. This study was designed to investigate the wound healing activity of a new formulation of PRP. Different gel-based formulations of PRP were prepared. Open excision wounds were made on the back of male Sprague-Dawley rats, and PRP gel was administered topically once daily until the wounds healed completely (12 days. The results revealed that the tested PRP formulation significantly accelerated the wound healing process by increasing the wound contraction, tissue granulization, vascularization, and collagen regeneration. Interestingly, this study showed that there were no significant differences between the PRP and its gel-based formulation in all the above mentioned parameters. Although this investigation showed that PRP formulation had significant wound healing effects, the PRP gel-based formulation also had significant wound healing properties. This might indicate the wound healing properties of the PRP gel ingredients in the current investigation.
Formulation and Characterization of Aceclofenac -Aloe vera Transemulgel.
Raju, Y Prasanna; Haritha, K; Satyanarayana, Rao P; Vandana, K R; Bindu, D Thushara; Vinesha, V; Chowdary, V Harini
2015-01-01
The present research was aimed to formulate aceclofenac transemulgel using Aloe vera as gel base. The prepared formulations were subjected to physical characterization, in-vitro and in-vivo assessment. Aceclofenac, a hydrophobic potential non steroidal anti inflammatory drug, causes ulceration upon chronic oral administration, could be formulated into transemulgel to enhance therapeutic efficacy and to lower the unwanted side effects. The transemulgel was prepared from aqueous Aloe vera gel and aceclofenac emulsion. The prepared transemulgel was evaluated for its pH, viscosity, drug content, skin irritation, in-vitro diffusion and accelerated stability studies. The prepared aceclofenac-Aloe vera tranemulgel and commercial aceclofenac gel were subjected to pharmacodynamic studies in albino rats of Wistar strain employing carrageenan induced left hind paw edema method to assess the anti-inflammatory effect. The transemulgel showed a pH of 6.78 and viscosity of 18 cps. In-vitro diffusion data revealed better permeation characteristics. Topical application of formulation found no skin irritation. Stability study has proved the integrity of the formulation. The prepared aceclofenac Aloe vera transemulgel showed better in-vitro drug release when compared with the commercial aceclofenac gel formulation. Anti-inflammatory activity in treated rats showed the significant paw volume reduction at pAloe vera as gel base.
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Allam Ahmed N.
2015-09-01
Full Text Available Curcumin, a naturally occurring lipophilic molecule can exert multiple and diverse bioactivities. However, its limited aqueous solubility and extensive presystemic metabolism restrict its bioavailability. Curcumin phytosomes were prepared by a simple solvent evaporation method where free flowing powder was obtained in addition to a newly developed semisolid formulation to increase curcumin content in softgels. Phytosomal powder was characterized in terms of drug content and zeta potential. Thirteen different softgel formulations were developed using oils such as Miglyol 812, castor oil and oleic acid, a hydrophilic vehicle such as PEG 400 and bioactive surfactants such as Cremophor EL and KLS P 124. Selected formulations were characterized in terms of curcumin in vitro dissolution. TEM analysis revealed good stability and a spherical, self-closed structure of curcumin phytosomes in complex formulations. Stability studies of chosen formulations prepared using the hydrophilic vehicle revealed a stable curcumin dissolution pattern. In contrast, a dramatic decrease in curcumin dissolution was observed in case of phytosomes formulated in oily vehicles.
Optimized formulation of solid self-microemulsifying sirolimus delivery systems
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Cho W
2013-04-01
Full Text Available Wonkyung Cho,1,2 Min-Soo Kim,3 Jeong-Soo Kim,2 Junsung Park,1,2 Hee Jun Park,1,2 Kwang-Ho Cha,1,2 Jeong-Sook Park,2 Sung-Joo Hwang1,4 1Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Republic of Korea; 2College of Pharmacy, Chungnam National University, Daejeon, Republic of Korea; 3Department of Pharmaceutical Engineering, Inje University, Gimhae, Republic of Korea; 4College of Pharmacy, Yonsei University, Incheon, Republic of Korea Background: The aim of this study was to develop an optimized solid self-microemulsifying drug delivery system (SMEDDS formulation for sirolimus to enhance its solubility, stability, and bioavailability. Methods: Excipients used for enhancing the solubility and stability of sirolimus were screened. A phase-separation test, visual observation for emulsifying efficiency, and droplet size analysis were performed. Ternary phase diagrams were constructed to optimize the liquid SMEDDS formulation. The selected liquid SMEDDS formulations were prepared into solid form. The dissolution profiles and pharmacokinetic profiles in rats were analyzed. Results: In the results of the oil and cosolvent screening studies, Capryol™ Propylene glycol monocaprylate (PGMC and glycofurol exhibited the highest solubility of all oils and cosolvents, respectively. In the surfactant screening test, D-α-tocopheryl polyethylene glycol 1000 succinate (vitamin E TPGS was determined to be the most effective stabilizer of sirolimus in pH 1.2 simulated gastric fluids. The optimal formulation determined by the construction of ternary phase diagrams was the T32 (Capryol™ PGMC:glycofurol:vitamin E TPGS = 30:30:40 weight ratio formulation with a mean droplet size of 108.2 ± 11.4 nm. The solid SMEDDS formulations were prepared with Sucroester 15 and mannitol. The droplet size of the reconstituted solid SMEDDS showed no significant difference compared with the liquid SMEDDS. In the dissolution study, the release amounts of
Petereit, H U; Weisbrod, W
1999-01-01
General considerations concerning the stability of coated dosage forms are discussed, in order to avoid predictable interactions which may cause long-term stability problems. As polymers themselves maintain a high chemical stability and a low reactivity, instability phenomena mainly have to be explained by interactions of low molecular weight substances or physical changes. Possible interactions of functional groups can be predicted easily and insulating subcoates are proper countermeasures. Impurities, remaining in the polymeric material from the manufacturing process, may accelerate the hydrolysis of sensitive drugs. Instabilities of coated dosage forms are mainly based on physical interactions, caused by improper formulations of coating suspensions (i.e. plasticizers or pigments) or the film coating process. Residual moisture or solvents, probably enclosed in the core and migrating over time, may increase the permeability of coatings, due to plasticizing effects. The functionality of coatings from aqueous dispersions is linked to coalescence of latex particles. Thus any incomplete film formation, caused by too high or too low coating temperatures, may result in high permeable coatings. During storage, preferably under stress conditions this process will continue and thus change the release profile. Therefore bed temperatures of 10-20 degrees C above MFT must ensure the formation of homogeneous polymer layers during the coating process. Stability test procedures and packaging materials also need to be adapted to the physicochemical properties of the dosage form, in order to get meaningful results in stability tests.
Bioequivalence of a new cyclosporine a formulation to Neoral.
David-Neto, Elias; Kakehashi, Erica; Alves, Cristiane Feres; Pereira, Lilian M; de Castro, Maria Cristina R; de Mattos, Renata Maciel; Sumita, Nairo Massakazu; Romano, Paschoalina; Mendes, Maria Elizabete; Nahas, William Carlos; Ianhez, Luiz Estevam
2004-02-01
New cyclosporine A (CsA) formulations must prove their bioequivalence to Neoral, the reference CsA formulation, to allow free prescription for the patients. The aim of this study was to compare the pharmacokinetics (PK) of a new CsA formulation (Zinograf-ME), produced by Strides-Arcolab, to Neoral and to demonstrate their interchangeability in stable renal transplant recipients. Twelve-hour PK studies were obtained from 18 (13 M/5 F) adult patients (mean age 44.7 +/- 12 years). They received their renal allografts from 13 cadaver and 5 living donors. Before enrollment, all patients were receiving a third generic CsA for a mean of 48 months. Nine patients were also under azathioprine and 9 under mycophenolate mofetil; 17 received prednisone. A single oral dose of either Zinograf or Neoral was administered. The first PK study was performed with one formulation, and 1 week later, a second PK was done with the other formulation. During the washout period, patients continued taking the third CsA formulation. The drug substitution was done milligram-for-milligram. The CsA whole-blood level was measured by TDx immunoassay. Mean +/- SD of area under the curve (AUC), maximum concentration (C(max)), and concentration at the second hour (C2) of Zinograf were not statistically different from those with Neoral (4019 +/- 1466 vs 3971 +/- 1325 ng x h/mL, 998 +/- 376 vs 1021 +/- 356 ng/mL, and 707 +/- 254 vs 734 +/- 229 ng/mL, respectively). In the same way, the Zinograf 90% confidence interval for either C(max) (-123, +77 ng/mL) or AUC (-214, +311 ng.mL/h) were within the Neoral bioequivalence interval for the same parameters (+/-204 ng/mL and +/-794 ng x mL/h, respectively). These data demonstrate that the ZinografME CsA formulation is bioequivalent to Neoral.
Energy Technology Data Exchange (ETDEWEB)
Mancas, Stefan C. [Department of Mathematics, University of Central Florida, Orlando, FL 32816-1364 (United States)], E-mail: smancas@mail.ucf.edu; Roy Choudhury, S. [Department of Mathematics, University of Central Florida, Orlando, FL 32816-1364 (United States)], E-mail: choudhur@longwood.cs.ucf.edu
2009-04-15
Comprehensive numerical simulations (reviewed in Dissipative Solitons, Akhmediev and Ankiewicz (Eds.), Springer, Berlin, 2005) of pulse solutions of the cubic-quintic Ginzburg-Landau Equation (CGLE), a canonical equation governing the weakly nonlinear behavior of dissipative systems in a wide variety of disciplines, reveal various intriguing and entirely novel classes of solutions. In particular, there are five new classes of pulse or solitary waves solutions, viz. pulsating, creeping, snake, erupting, and chaotic solitons. In contrast to the regular solitary waves investigated in numerous integrable and non-integrable systems over the last three decades, these dissipative solitons are not stationary in time. Rather, they are spatially confined pulse-type structures whose envelopes exhibit complicated temporal dynamics. The numerical simulations also reveal very interesting bifurcations sequences of these pulses as the parameters of the CGLE are varied. In this paper, we address the issues of central interest in the area, i.e., the conditions for the occurrence of the five categories of dissipative solitons, as well the dependence of both their shape and their stability on the various parameters of the CGLE, viz. the nonlinearity, dispersion, linear and nonlinear gain, loss and spectral filtering parameters. Our predictions on the variation of the soliton amplitudes, widths and periods with the CGLE parameters agree with simulation results. First, we elucidate the Hopf bifurcation mechanism responsible for the various pulsating solitary waves, as well as its absence in Hamiltonian and integrable systems where such structures are absent. Next, we develop and discuss a variational formalism within which to explore the various classes of dissipative solitons. Given the complex dynamics of the various dissipative solutions, this formulation is, of necessity, significantly generalized over all earlier approaches in several crucial ways. Firstly, the starting formulation
FORMULATION AND STABILITY EVALUATION OF BAUHINIA VARIEGATA EXTRACT TOPICAL EMULSION.
Mohsin, Sabeeh; Akhtar, Naveed
2017-05-01
This study presents the results for the development of water in oil (W/O) emulsion containing 2 % Bauhinia variegata (BV) extract with good antioxidant potential for cosmetic application. Different ratios of surfactant, oil and water were investigated to optimize the ratio of ingredients. It was found that emulsifier and oil4ratio were important in improving the stability of emulsion. The formulation having 2.5% Abil EM90, 12% liquid paraffin, 83.5% distilled water and 2% BV extract was found to be most stable. Stability of the formulation was further evaluated by characterizing for organoleptic, sedimentation, microscopic and rheological properties at a range of storage conditions for a period of 12 weeks. Experimental findings showed stable formulation behavior with respect to color change, liquefaction and phase separation. Centrifugation test was carried out to predict the long term stability..The rheological parameters were evaluated from Power Law and the flow index value less than 1 suggested non-Newtonian behavior of the W/O emulsion. The mean droplet size of the internal phase of freshly prepared formulation was 4.06 ? 1.99 pm that did not change significantly (p > 0.05) during the storage. The newly developed formulation exhibited promising attributes over long term storage and open opportunities for the topical delivery of natural antioxidants for cosmetic and pharmaceutical objectives.
Formulating natural based cosmetic product - irradiated herbal lip balm
International Nuclear Information System (INIS)
Seri Chempaka Mohd Yusof; Ros Anita Ahmad Ramli; Foziah Ali; Zainab Harun
2007-01-01
Herbal lip balm was formulated in efforts to produce a safe product, attractive with multifunctional usage i.e. prevent chap lips, reduce mouth odour and benefits in improving the health quality. Problems faced in constructing formulations of herbal lip balm were focused to the extraction of anthocyanins, the stability of the pigments in the formulations and changes of colour during irradiation for the sterilization of herbal lip balm. Natural pigment, anthocyanin was used as a colorant agent in herbal lip balm, obtained from various herbs and vegetables i.e. Hibiscus sabdariffa L. (roselle), Brassica oleracea var. capitata f. rubra (red cabbage) and Daucus carota (carrot). Water based extraction method was used in extracting the anthocyanins. The incorporation of honey in the formulations improved the colour of the lip balm. The usage of plant based ingredient i.e. cocoa butter substituting the normal based ingredient i.e. petroleum jelly in lip balm also affecting the colour of herbal lip balm. Irradiation at 2.5, 5.0 and 10 kGy was carried out as preservation and reducing of microbial load of the herbal lip balm and changes in colour were observed in formulations irradiated at 10 kGy. (Author)
Influence of Differing Analgesic Formulations of Aspirin on Pharmacokinetic Parameters
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Kunal Kanani
2015-08-01
Full Text Available Aspirin has been used therapeutically for over 100 years. As the originator and an important marketer of aspirin-containing products, Bayer’s clinical trial database contains numerous reports of the pharmacokinetics of various aspirin formulations. These include evaluations of plain tablets, effervescent tablets, granules, chewable tablets, and fast-release tablets. This publication seeks to expand upon the available pharmacokinetic information concerning aspirin formulations. In the pre-systemic circulation, acetylsalicylic acid (ASA is rapidly converted into its main active metabolite, salicylic acid (SA. Therefore, both substances are measured in plasma and reported in the results. The 500 mg strength of each formulation was chosen for analysis as this is the most commonly used for analgesia. A total of 22 studies were included in the analysis. All formulations of 500 mg aspirin result in comparable plasma exposure to ASA and SA as evidenced by AUC. Tablets and dry granules provide a consistently lower Cmax compared to effervescent, granules in suspension and fast release tablets. Effervescent tablets, fast release tablets, and granules in suspension provide a consistently lower median Tmax compared to dry granules and tablets for both ASA and SA. This report reinforces the importance of formulation differences and their impact on pharmacokinetic parameters.
Characterization, sensorial evaluation and moisturizing efficacy of nanolipidgel formulations.
Estanqueiro, M; Conceição, J; Amaral, M H; Sousa Lobo, J M
2014-04-01
Nanostructured lipid carriers (NLC) have been widely studied for cosmetic and dermatological applications due to their favourable properties that include the formation of an occlusive film on the skin surface that reduces the transepidermal water loss (TEWL) and increase in water content in the skin which improves the appearance on healthy human skin and reduces symptoms of some skin disorders like eczema. The main objective of this study was the development of semisolid formulations based NLC with argan oil or jojoba oil as liquid lipids, by addition of Carbopol®934 or Carbopol®980 as gelling agents, followed by comparison between instrumental analysis and sensorial evaluation and in vivo efficacy evaluation. Nanostructured lipid carriers dispersions were produced by the ultrasound technique, and to obtain a semisolid formulation, gelling agents were dispersed in the aqueous dispersion. Particle size, polydispersity index and zeta potential were determined. Instrumental characterization was performed by rheological and textural analysis; the sensorial evaluation was also performed. Finally, skin hydration and TEWL were studied by capacitance and evaporimetry evaluation, respectively. Particles showed a nanometric size in all the analysed formulations. All the gels present pseudoplastic behaviour. There is a correspondence between the properties firmness and adhesiveness as determined by textural analysis and the sensory evaluation. The formulations that showed a greater increase in skin hydration also presented appropriate technological and sensorial attributes for skin application. Nanolipidgel formulations with the addition of humectants are promising systems for cosmetic application with good sensory and instrumental attributes and moisturizing efficacy.
Two different formulations of the heavy quark effective theory
International Nuclear Information System (INIS)
Balk, S.; Ilakovac, A.; Koerner, J.G.; Pirjol, D.
1994-01-01
We point out that there exist two different formulations of the Heavy Quark Effective Theory (HQET). The one formulation of HQET was mostly developed at Harvard and involves the use of the equation of motion to eliminate the small components of the heavy quark field. The second formulation, developed in Mainz, involves a series of Foldy-Wouthuysen-type field transformations which diagonalizes the heavy quark Lagrangian in terms of an effective quark and antiquark sector. Starting at O(1/m Q 2 ) the two formulations are different in that their effective Lagrangians, their effective currents, and their effective wave functions differ. However, when these three differences are properly taken into account, the two alternative formulations lead to identical transition or S-matrix elements. This is demonstrated in an explicit example at O(1/m Q 2 ). We point to an essential difficulty of the Harvard HQET in that the Harvard effective fields are not properly normalized starting at order O(1/m Q 2 ). We provide explicit higher order expressions for the effective fields and the Lagrangian in the Mainz approach, and write down an O(1/m Q 2 ) nonabelian version of the Pauli equation for the heavy quark effective field. (orig.)
Artificial intelligence in pharmaceutical product formulation: neural computing
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Svetlana Ibrić
2009-10-01
Full Text Available The properties of a formulation are determined not only by the ratios in which the ingredients are combined but also by the processing conditions. Although the relationships between the ingredient levels, processing conditions, and product performance may be known anecdotally, they can rarely be quantified. In the past, formulators tended to use statistical techniques to model their formulations, relying on response surfaces to provide a mechanism for optimazation. However, the optimization by such a method can be misleading, especially if the formulation is complex. More recently, advances in mathematics and computer science have led to the development of alternative modeling and data mining techniques which work with a wider range of data sources: neural networks (an attempt to mimic the processing of the human brain; genetic algorithms (an attempt to mimic the evolutionary process by which biological systems self-organize and adapt, and fuzzy logic (an attempt to mimic the ability of the human brain to draw conclusions and generate responses based on incomplete or imprecise information. In this review the current technology will be examined, as well as its application in pharmaceutical formulation and processing. The challenges, benefits and future possibilities of neural computing will be discussed.
Formulation and Evaluation of New Glimepiride Sublingual Tablets
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Wafa Al-Madhagi
2017-01-01
Full Text Available Oral mucosal delivery of drugs promotes rapid absorption and high bioavailability, with a subsequent immediate onset of pharmacological effect. However, many oral mucosal deliveries are compromised by the possibility of the patient swallowing the active substance before it has been released and absorbed locally into the systemic circulation. The aim of this research was to introduce a new glimepiride formula for sublingual administration and rapid drug absorption that can be used in an emergency. The new sublingual formulation was prepared after five trials to prepare the suitable formulation. Two accepted formulations of the new sublingual product were prepared, but one of them with disintegration time of 1.45 min and searching for preferred formulation, the binder, is changed with Flulac and starch slurry to prepare formula with disintegration time of 21 seconds that supports the aim of research to be used in an emergency. The five formulations were done, after adjusting to the binder as Flulac and aerosil with disintegration time of 21 seconds and accepted hardness as well as the weight variation. The assay of a new product (subglimepiride is 103% which is a promising result, confirming that the formula succeeded. The new product (subglimepiride is accepted in most quality control tests and it is ready for marketing.
Development and Evaluation of Herbal Formulations for Hair Growth
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Lipi Purwal
2008-01-01
Full Text Available Hair formulation of Emblica officinalis (Euphorbiaceae, Bacopa, monnieri (Scrophulariaceae, Trigonella foenumgraecum (Leguminosae, Murraya koenigii (Rutaceae in various concentrations in the form of herbal oil were studied for their hair growth activity. Each drug was tested for their hair growth activity in a concentration range for 1-10% separately. Based on these results mixture of crude drugs Murraya koeniigi, leaf (Rutaceae, Bacopa monnieri, leaf (Scrophulariaceae, Trigonella foenumgraecum (Leguminosae, Murraya koenigii (Rutaceae were prepared in varying concentration in the form of herbal hair oil by three different oils preparation techniques and were tested for hair growth activity. The result revealed that the hair growth activity of each drug was found proportional to the concentration range tested. Similarly higher concentrations of drug in the formulation were found to have higher hair growth activities. But looking towards the formulation viscosity the maximum concentration of combined drug was found to be 30% at their maximum level. The formulation containing 7.5% of each drug used for the study and showed excellent hair growth activity with standard (2% minoxidil ethanolic solution by an enlargement of follicular size and prolongation of the anagen phase. It holds the promise of potent herbal alternative for minoxidil. Excellent results of hair growth were seen in formulation prepared by cloth pouch decoction method of oils preparation technique.
Spasmolytic effect of traditional herbal formulation on guinea pig ileum
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Dushyant Kumar
2015-01-01
Full Text Available Background: The herbal formulation consisting of Andrographis paniculata Nees., Cassia fistula L., Foeniculum vulgare Mill. and Cuminum cyminum L. is widely used by the local traditional practitioners in rural Northern Karnataka for spasmodic abdominal pain. Objective: The present study was undertaken to evaluate safety and spasmolytic effect of poly-herbal formulation. Materials and Methods: Acute toxicity studies were carried out in Swiss mice, as per the Organization for Economic Co-operation and Development (OECD guidelines. The spasmolytic activity of the formulation was studied in isolated guinea pig ileum model using histamine and acetylcholine as agonists. The data were analyzed by one-way ANOVA, followed by Dunnetts post-hoc test and P ≤ 0.05 was considered as significant. Results: The formulation did not show any adverse toxic effects and found to be safe. It also showed significant (P < 0.05 relaxation in different agonist like histamine and acetylcholine-induced contractions in guinea pig ileum. Conclusions: Antispasmodic activity of the herbal formulation can be attributed to its atropine-like activity. The present findings, therefore, support its utility in spasmodic abdominal pain.
Design, formulation and evaluation of caffeine chewing gum.
Aslani, Abolfazl; Jalilian, Fatemeh
2013-01-01
Caffeine which exists in drinks such as coffee as well as in drug dosage forms in the global market is among the materials that increase alertness and decrease fatigue. Compared to other forms of caffeine, caffeine gum can create faster and more prominent effects. In this study, the main goal is to design a new formulation of caffeine gum with desirable taste and assess its physicochemical properties. Caffeine gum was prepared by softening of gum bases and then mixing with other formulation ingredients. To decrease the bitterness of caffeine, sugar, aspartame, liquid glucose, sorbitol, manitol, xylitol, and various flavors were used. Caffeine release from gum base was investigated by mechanical chewing set. Content uniformity test was also performed on the gums. The gums were evaluated in terms of organoleptic properties by the Latin-Square design at different stages. After making 22 formulations of caffeine gums, F11 from 20 mg caffeine gums and F22 from 50 mg caffeine gums were chosen as the best formulation in organoleptic properties. Both types of gum released about 90% of their own drug content after 30 min. Drug content of 20 and 50 mg caffeine gum was about 18.2-21.3 mg and 45.7-53.6 mg respectively. In this study, 20 and 50 mg caffeine gums with suitable and desirable properties (i.e., good taste and satisfactory release) were formulated. The best flavor for caffeine gum was cinnamon. Both kinds of 20 and 50 mg gums succeeded in content uniformity test.
Generalized metric formulation of double field theory on group manifolds
International Nuclear Information System (INIS)
Blumenhagen, Ralph; Bosque, Pascal du; Hassler, Falk; Lüst, Dieter
2015-01-01
We rewrite the recently derived cubic action of Double Field Theory on group manifolds http://dx.doi.org/10.1007/JHEP02(2015)001 in terms of a generalized metric and extrapolate it to all orders in the fields. For the resulting action, we derive the field equations and state them in terms of a generalized curvature scalar and a generalized Ricci tensor. Compared to the generalized metric formulation of DFT derived from tori, all these quantities receive additional contributions related to the non-trivial background. It is shown that the action is invariant under its generalized diffeomorphisms and 2D-diffeomorphisms. Imposing additional constraints relating the background and fluctuations around it, the precise relation between the proposed generalized metric formulation of DFT WZW and of original DFT from tori is clarified. Furthermore, we show how to relate DFT WZW of the WZW background with the flux formulation of original DFT.
Fish consumption and track to a fish feed formulation
Cai-Juan, Soong; Ramli, Razamin; Rahman, Rosshairy Abdul
2015-12-01
Strategically located in the equator, Malaysia is blessed with plenty of fish supply. The high demand in fish consumption has helped the development in the fishery industry and provided numerous jobs in the secondary sector, contributing significantly to the nation's income. A survey was conducted to understand the trend of current demands for fish for the purpose of designing a feed formulation, which is still limited in this area of study. Results showed that grouper fish in restaurants commanded a very high price compared to other species of fish. Tiger grouper gained the highest demand in most restaurants, while giant grouper had the highest price in restaurants. Due to the demand and challenges to culture this type of fish, a framework for fish feed formulation is proposed. The formulation framework when materialized could be an alternative to the use of trash fish as the feed for grouper.
Superactive cellulase formulation using cellobiohydrolase-1 from Penicillium funiculosum
Adney, William S.; Baker, John O.; Decker, Stephen R.; Chou, Yat-Chen; Himmel, Michael E.; Ding, Shi-You
2012-10-09
Purified cellobiohydrolase I (glycosyl hydrolase family 7 (Cel7A)) enzymes from Penicillium funiculosum demonstrate a high level of specific performance in comparison to other Cel7 family member enzymes when formulated with purified EIcd endoglucanase from A. cellulolyticus and tested on pretreated corn stover. This result is true of the purified native enzyme, as well as recombinantly expressed enzyme, for example, that enzyme expressed in a non-native Aspergillus host. In a specific example, the specific performance of the formulation using purified recombinant Cel7A from Penicillium funiculosum expressed in A. awamori is increased by more than 200% when compared to a formulation using purified Cel7A from Trichoderma reesei.
Fundamental theories of waves and particles formulated without classical mass
Fry, J. L.; Musielak, Z. E.
2010-12-01
Quantum and classical mechanics are two conceptually and mathematically different theories of physics, and yet they do use the same concept of classical mass that was originally introduced by Newton in his formulation of the laws of dynamics. In this paper, physical consequences of using the classical mass by both theories are explored, and a novel approach that allows formulating fundamental (Galilean invariant) theories of waves and particles without formally introducing the classical mass is presented. In this new formulation, the theories depend only on one common parameter called 'wave mass', which is deduced from experiments for selected elementary particles and for the classical mass of one kilogram. It is shown that quantum theory with the wave mass is independent of the Planck constant and that higher accuracy of performing calculations can be attained by such theory. Natural units in connection with the presented approach are also discussed and justification beyond dimensional analysis is given for the particular choice of such units.
Numerical performance of the parabolized ADM formulation of general relativity
International Nuclear Information System (INIS)
Paschalidis, Vasileios; Hansen, Jakob; Khokhlov, Alexei
2008-01-01
In a recent paper [Vasileios Paschalidis, Phys. Rev. D 78, 024002 (2008).], the first coauthor presented a new parabolic extension (PADM) of the standard 3+1 Arnowitt, Deser, Misner (ADM) formulation of the equations of general relativity. By parabolizing first-order ADM in a certain way, the PADM formulation turns it into a well-posed system which resembles the structure of mixed hyperbolic-second-order parabolic partial differential equations. The surface of constraints of PADM becomes a local attractor for all solutions and all possible well-posed gauge conditions. This paper describes a numerical implementation of PADM and studies its accuracy and stability in a series of standard numerical tests. Numerical properties of PADM are compared with those of standard ADM and its hyperbolic Kidder, Scheel, Teukolsky (KST) extension. The PADM scheme is numerically stable, convergent, and second-order accurate. The new formulation has better control of the constraint-violating modes than ADM and KST.
3N scattering in a three-dimensional operator formulation
International Nuclear Information System (INIS)
Gloeckle, W.; Fachruddin, I.; Elster, C.; Golak, J.; Skibinski, R.; Witala, H.
2010-01-01
A recently developed formulation for a direct treatment of the equations for two- and three-nucleon bound states as set of coupled equations of scalar functions depending only on vector momenta is extended to three-nucleon scattering. Starting from the spin-momentum dependence occurring as scalar products in two- and three-nucleon forces together with other scalar functions, we present the Faddeev multiple scattering series in which order by order the spin degrees can be treated analytically leading to 3D integrations over scalar functions depending on momentum vectors only. Such formulation is especially important in view of awaiting extension of 3N Faddeev calculations to projectile energies above the pion production threshold and applications of chiral perturbation theory 3N forces, which are to be most efficiently treated directly in such three-dimensional formulation without having to expand these forces into a partial-wave basis. (orig.)
A Generalized Formulation of Demand Response under Market Environments
Nguyen, Minh Y.; Nguyen, Duc M.
2015-06-01
This paper presents a generalized formulation of Demand Response (DR) under deregulated electricity markets. The problem is scheduling and controls the consumption of electrical loads according to the market price to minimize the energy cost over a day. Taking into account the modeling of customers' comfort (i.e., preference), the formulation can be applied to various types of loads including what was traditionally classified as critical loads (e.g., air conditioning, lights). The proposed DR scheme is based on Dynamic Programming (DP) framework and solved by DP backward algorithm in which the stochastic optimization is used to treat the uncertainty, if any occurred in the problem. The proposed formulation is examined with the DR problem of different loads, including Heat Ventilation and Air Conditioning (HVAC), Electric Vehicles (EVs) and a newly DR on the water supply systems of commercial buildings. The result of simulation shows significant saving can be achieved in comparison with their traditional (On/Off) scheme.