Proposal of a critical test of the Navier-Stokes-Fourier paradigm for compressible fluid continua.

Science.gov (United States)

Brenner, Howard

2013-01-01

A critical, albeit simple experimental and/or molecular-dynamic (MD) simulation test is proposed whose outcome would, in principle, establish the viability of the Navier-Stokes-Fourier (NSF) equations for compressible fluid continua. The latter equation set, despite its longevity as constituting the fundamental paradigm of continuum fluid mechanics, has recently been criticized on the basis of its failure to properly incorporate volume transport phenomena-as embodied in the proposed bivelocity paradigm [H. Brenner, Int. J. Eng. Sci. 54, 67 (2012)]-into its formulation. Were the experimental or simulation results found to accord, even only qualitatively, with bivelocity predictions, the temperature distribution in a gas-filled, thermodynamically and mechanically isolated circular cylinder undergoing steady rigid-body rotation in an inertial reference frame would not be uniform; rather, the temperature would be higher at the cylinder wall than along the axis of rotation. This radial temperature nonuniformity contrasts with the uniformity of the temperature predicted by the NSF paradigm for these same circumstances. Easily attainable rates of rotation in centrifuges and readily available tools for measuring the expected temperature differences render experimental execution of the proposed scheme straightforward in principle. As such, measurement-via experiment or MD simulation-of, say, the temperature difference ΔT between the gas at the wall and along the axis of rotation would provide quantitative tests of both the NSF and bivelocity hydrodynamic models, whose respective solutions for the stated set of circumstances are derived in this paper. Independently of the correctness of the bivelocity model, any temperature difference observed during the proposed experiment or simulation, irrespective of magnitude, would preclude the possibility of the NSF paradigm being correct for fluid continua, except for incompressible flows.

Finite elements of nonlinear continua

CERN Document Server

Oden, John Tinsley

1972-01-01

Geared toward undergraduate and graduate students, this text extends applications of the finite element method from linear problems in elastic structures to a broad class of practical, nonlinear problems in continuum mechanics. It treats both theory and applications from a general and unifying point of view.The text reviews the thermomechanical principles of continuous media and the properties of the finite element method, and then brings them together to produce discrete physical models of nonlinear continua. The mathematical properties of these models are analyzed, along with the numerical s

MODELO ESTRATÉGICO DE MEJORA CONTINUA PARA LA PEQUEÑA Y MEDIANA EMPRESA MEXICANA

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Aleida González González

2007-12-01

Full Text Available

 Las organizaciones en la búsqueda de la competitividad global tienen la necesidad de lograr productos y servicios al menor costo, con el mejor nivel de calidad y con la capacidad de responder a la demanda tanto en tiempo como en cantidad. El presente artículo, señala el diseño de un modelo estratégico de mejora continua, destinado a la pequeña y mediana organización con tendencia a la mejora continua. El modelo propone el diseño a través del proceso estratégico de mejora continua, basado en las normas ISO- 9000-2000. Está respaldado en los cinco procesos centrales: Organización, proceso estratégico, formación de personal, gestión de competencias laborales y servicio al cliente. Desde este punto de vista, el presente modelo facilita la mejora continua promoviendo el cambio cultural en las organizaciones y mejorar la eficiencia y eficacia.

ANTHROPOMETRIC PREDICTIVE EQUATIONS FOR ...

African Journals Online (AJOL)

Keywords: Anthropometry, Predictive Equations, Percentage Body Fat, Nigerian Women, Bioelectric Impedance ... such as Asians and Indians (Pranav et al., 2009), ... size (n) of at least 3o is adjudged as sufficient for the ..... of people, gender and age (Vogel eta/., 1984). .... Fish Sold at Ile-Ife Main Market, South West Nigeria.

Electrostatics of proteins in dielectric solvent continua. I. An accurate and efficient reaction field description.

Science.gov (United States)

Bauer, Sebastian; Mathias, Gerald; Tavan, Paul

2014-03-14

We present a reaction field (RF) method which accurately solves the Poisson equation for proteins embedded in dielectric solvent continua at a computational effort comparable to that of an electrostatics calculation with polarizable molecular mechanics (MM) force fields. The method combines an approach originally suggested by Egwolf and Tavan [J. Chem. Phys. 118, 2039 (2003)] with concepts generalizing the Born solution [Z. Phys. 1, 45 (1920)] for a solvated ion. First, we derive an exact representation according to which the sources of the RF potential and energy are inducible atomic anti-polarization densities and atomic shielding charge distributions. Modeling these atomic densities by Gaussians leads to an approximate representation. Here, the strengths of the Gaussian shielding charge distributions are directly given in terms of the static partial charges as defined, e.g., by standard MM force fields for the various atom types, whereas the strengths of the Gaussian anti-polarization densities are calculated by a self-consistency iteration. The atomic volumes are also described by Gaussians. To account for covalently overlapping atoms, their effective volumes are calculated by another self-consistency procedure, which guarantees that the dielectric function ε(r) is close to one everywhere inside the protein. The Gaussian widths σ(i) of the atoms i are parameters of the RF approximation. The remarkable accuracy of the method is demonstrated by comparison with Kirkwood's analytical solution for a spherical protein [J. Chem. Phys. 2, 351 (1934)] and with computationally expensive grid-based numerical solutions for simple model systems in dielectric continua including a di-peptide (Ac-Ala-NHMe) as modeled by a standard MM force field. The latter example shows how weakly the RF conformational free energy landscape depends on the parameters σ(i). A summarizing discussion highlights the achievements of the new theory and of its approximate solution particularly by

Electrostatics of proteins in dielectric solvent continua. I. An accurate and efficient reaction field description

Energy Technology Data Exchange (ETDEWEB)

Bauer, Sebastian; Mathias, Gerald; Tavan, Paul, E-mail: paul.tavan@physik.uni-muenchen.de [Lehrstuhl für BioMolekulare Optik, Ludwig–Maximilians Universität München, Oettingenstr. 67, 80538 München (Germany)

2014-03-14

We present a reaction field (RF) method which accurately solves the Poisson equation for proteins embedded in dielectric solvent continua at a computational effort comparable to that of an electrostatics calculation with polarizable molecular mechanics (MM) force fields. The method combines an approach originally suggested by Egwolf and Tavan [J. Chem. Phys. 118, 2039 (2003)] with concepts generalizing the Born solution [Z. Phys. 1, 45 (1920)] for a solvated ion. First, we derive an exact representation according to which the sources of the RF potential and energy are inducible atomic anti-polarization densities and atomic shielding charge distributions. Modeling these atomic densities by Gaussians leads to an approximate representation. Here, the strengths of the Gaussian shielding charge distributions are directly given in terms of the static partial charges as defined, e.g., by standard MM force fields for the various atom types, whereas the strengths of the Gaussian anti-polarization densities are calculated by a self-consistency iteration. The atomic volumes are also described by Gaussians. To account for covalently overlapping atoms, their effective volumes are calculated by another self-consistency procedure, which guarantees that the dielectric function ε(r) is close to one everywhere inside the protein. The Gaussian widths σ{sub i} of the atoms i are parameters of the RF approximation. The remarkable accuracy of the method is demonstrated by comparison with Kirkwood's analytical solution for a spherical protein [J. Chem. Phys. 2, 351 (1934)] and with computationally expensive grid-based numerical solutions for simple model systems in dielectric continua including a di-peptide (Ac-Ala-NHMe) as modeled by a standard MM force field. The latter example shows how weakly the RF conformational free energy landscape depends on the parameters σ{sub i}. A summarizing discussion highlights the achievements of the new theory and of its approximate solution

Desarrollo de simuladores para procesos industriales. Parte I. (Colada continua

Directory of Open Access Journals (Sweden)

Ramírez, A.

2006-06-01

Full Text Available This work was written for illustrating the development of computer simulators for production process. As an example a simulator for continuous casting process was made, this is the most popular method to produce some steel products like billets and slabs. The simulator (SSCC was programmed by the present authors in C++; but mathematical procedures, algorithms and flow charts shown here can be used as a base in any other programming language. This is the first part of the work; it is focused to the development of some computational tools to describe the real continuous casting process

Este trabajo se realiza con el objeto de ilustrar el desarrollo de simuladores para procesos industriales; como ejemplo se realizó un sistema de simulación para representar el proceso de colada continua que es el proceso más común para la producción de perfiles de acero. El sistema de simulación para colada continua (SSCC fue programado por los presentes autores en lenguaje C++; sin embargo, los procedimientos matemáticos, algoritmos y diagramas de flujo ilustrados en este trabajo pueden ser programados en cualquier lenguaje de programación. Esta primera parte del trabajo se enfoca a desarrollar herramientas de cálculo para representar lo que sucede físicamente durante el proceso de colada continua.

Generally covariant Hamilton-Jacobi equation and rotated liquid sphere metrics

International Nuclear Information System (INIS)

Abdil'din, M.M.; Abdulgafarov, M.K.; Abishev, M.E.

2005-01-01

In the work Lense-Thirring problem on corrected Fock's first approximation metrics by Hamilton-Jacobi method considered. Generally covariant Hamilton-Jacobi equation had been sold by separation of variable method. Path equation of probe particle motion in rotated liquid sphere field is obtained. (author)

Probabilistic finite elements for transient analysis in nonlinear continua

Science.gov (United States)

Liu, W. K.; Belytschko, T.; Mani, A.

1985-01-01

The probabilistic finite element method (PFEM), which is a combination of finite element methods and second-moment analysis, is formulated for linear and nonlinear continua with inhomogeneous random fields. Analogous to the discretization of the displacement field in finite element methods, the random field is also discretized. The formulation is simplified by transforming the correlated variables to a set of uncorrelated variables through an eigenvalue orthogonalization. Furthermore, it is shown that a reduced set of the uncorrelated variables is sufficient for the second-moment analysis. Based on the linear formulation of the PFEM, the method is then extended to transient analysis in nonlinear continua. The accuracy and efficiency of the method is demonstrated by application to a one-dimensional, elastic/plastic wave propagation problem. The moments calculated compare favorably with those obtained by Monte Carlo simulation. Also, the procedure is amenable to implementation in deterministic FEM based computer programs.

Continua with microstructure

CERN Document Server

Capriz, Gianfranco

1989-01-01

This book proposes a new general setting for theories of bodies with microstructure when they are described within the scheme of the con­ tinuum: besides the usual fields of classical thermomechanics (dis­ placement, stress, temperature, etc.) some new fields enter the picture (order parameters, microstress, etc.). The book can be used in a semester course for students who have already followed lectures on the classical theory of continua and is intended as an introduction to special topics: materials with voids, liquid crystals, meromorphic con­ tinua. In fact, the content is essentially that of a series of lectures given in 1986 at the Scuola Estiva di Fisica Matematica in Ravello (Italy). I would like to thank the Scientific Committee of the Gruppo di Fisica Matematica of the Italian National Council of Research (CNR) for the invitation to teach in the School. I also thank the Committee for Mathematics of CNR and the National Science Foundation: they have supported my research over many years and given ...

EL PROFESORADO COMO AGENTE DE CAMBIO EN ESPACIOS DE FORMACIÓN CONTINUA

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Patricia Raquimán Ortega

2008-01-01

Full Text Available Esta propuesta2 pretende ser una aproximación y reflexión hacia el concepto de formación continua como un proceso de cambio profesional, en el contexto del aprendizaje de adultos, específicamente profesores en ejercicio. Investigaciones y literatura sobre el cambio en educación y la formación en adultos, han servido de base para el diálogo que este texto ha querido desarrollar, como un espacio para la reflexión y la apertura a nuevas interrogantes en el contexto de la formación continua profesional en educación.

Interaction between resonances through autoionization continua near the 4s-threshold in KrII

International Nuclear Information System (INIS)

Demekhin, Ph V; Petrov, I D; Lagutin, B M; Sukhorukov, V L; Vollweiler, F; Klumpp, S; Ehresmann, A; Schartner, K-H; Schmoranzer, H

2005-01-01

The interaction between resonances through autoionization continua and the interaction between autoionization continua were investigated theoretically and experimentally for the photoionization process of the 4p- and 4s-shells and for the population of 4p 4 ( 3 P)5s 4 P J , 4p 4 ( 3 P)5s 2 P J and 4p 4 ( 3 P)4d 4 D J satellites of KrII. Cross sections for the satellite production and the angular distribution parameter of the fluorescence radiation were measured by photon-induced fluorescence spectroscopy after excitationx with linearly polarized monochromatized synchrotron radiation at exciting-photon energies between 28.45 eV and 29.95 eV with an exciting-photon energy resolution of 10 meV (FWHM). Measured cross sections are in good agreement with the computed ones. A refined assignment of resonances in the proximity of the 4s 1 4p 6 5p resonance was performed. It was concluded that there is a strong influence of the core rearrangement, of the interaction between resonances through the autoionization continua and of the interaction between autoionization continua, on the investigated processes on the basis of the observed good overall agreement between the computed and measured quantities

Internal and External Factors Affecting The Size of Paddy Field Sold

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Endang Rostiana

2016-12-01

Full Text Available This study attempted  to identify internal condition of the farmers who sold their paddy field and analyze the effects of age, education level, number of family members, field productivity, location, and production cost to the total area of paddy field sold. This study used quantitative descriptive method. This research found that age, education level, number of family members, and location of the land had positive relation to the total area of paddy field sold. On the other hand, production cost and field productivity had negative relation to the total area of paddy field sold. Partially, field production and number of family members had no significant effect to the total area of paddy field sold.

The chainable continua are the spaces approximated by finite COTS

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Judy A. Kennedy

2001-10-01

Full Text Available We show that the chainable continua (also called snake-like or arc-likecontinua, are precisely the Hausdorff reflections of inverse limits of sequences of finite COTS under maps which are continuous and are separating.

Análisis de programas de mejora continua. Un estudio longitudinal en una empresa industrial Estudo longitudinal dos resultados da melhora continua em uma empresa industrial

Directory of Open Access Journals (Sweden)

Juan A. Marin-Garcia

2008-12-01

Full Text Available Las empresas han utilizado diversas herramientas que permiten que los operarios contribuyan al proceso de mejora continua. Entre las herramientas más usadas podemos destacar los sistemas de sugerencias tanto individuales como en grupo. En esta comunicación haremos un repaso de las principales características de ambos sistemas y los modos habituales de implantación. Nuestra ponencia pretende intentar responder a estas preguntas de investigación. ¿Qué resultados se derivan de la implantación de sistemas de sugerencias individuales o en grupo? ¿Cuál de los dos sistemas es más beneficioso para la empresa? ¿Qué problemas surgen durante el funcionamiento de estos programas? Para ello, analizaremos los datos de un caso de empresa industrial donde hemos recogido los datos históricos de 5 años de aplicación de un programa de mejora continua. Ambos programas han demostrado ser provechosos para la empresa, aunque las posibilidades de los sistemas de grupo parecen ser significativamente mayores.As empresas tem utilizado diversas ferramentas que permitem que os operarios comtribuam ao processo de melhora continua. Entre as ferramentas mas usadas podemos destacar os sistemas de sugestoes tanto individual como em grupo. Nesta comunicação faremos um repaso das principais caracteristicas de ambos sistemas e os modos habituais de implantação. Nossa comunicação pretende responder a estas perguntas de pesquisa. Que resultados derivam da implantaçao de sistemas de sugestoes individuais ou em grupo? Qual dos dois sistemas beneficia mais a empresa? Que problemas surgem durante o funcionamento destes programas? Para isso analisaremos os dados de um caso de empresa industrial, onde tiramos os dados historicos de 5 anos de aplicação de um programa melhora continua. Ambos programas demonstraram ser aproveitados para a empresa, ainda que as possibilidades dos sistemas de grupo se mostram significativamente maiores.

Quasi-stationary mechanics of elastic continua with bending stiffness wrapping on a pulley system

Science.gov (United States)

Kaczmarczyk, S.; Mirhadizadeh, S.

2016-05-01

In many engineering applications elastic continua such as ropes and belts often are subject to bending when they pass over pulleys / sheaves. In this paper the quasi-stationary mechanics of a cable-pulley system is studied. The cable is modelled as a moving Euler- Bernoulli beam. The distribution of tension is non-uniform along its span and due to the bending stiffness the contact points at the pulley-beam boundaries are not unknown. The system is described by a set of nonlinear ordinary differential equations with undetermined boundary conditions. The resulting nonlinear Boundary Value Problem (BVP) with unknown boundaries is solved by converting the problem into the ‘standard’ form defined over a fixed interval. Numerical results obtained for a range of typical configurations with relevant boundary conditions applied demonstrate that due to the effects of bending stiffness the angels of wrap are reduced and the span tensions are increased.

Modulación Vectorial de Inversores Multinivel con Diodos de Enclavamiento con Balance del Bus de Continua

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Santiago A. Verne

2009-04-01

Full Text Available Resumen: En este trabajo se presenta un algoritmo de modulación para convertidores multinivel de enclavamiento por diodos que optimiza el balance del bus de continua. Se describe el mecanismo de modulación vectorial para convertidores multinivel y se desarrolla un método que permite mantener equilibradas las tensiones del bus de continua utilizando la redundancia del convertidor. El presente algoritmo puede aplicarse a convertidores con un número arbitrario de niveles. Se consideran en el desarrollo dos situaciones prácticas: presencia o ausencia de una fuente de tensión continua sobre el bus. El desempeño del modulador es estudiado mediante simulaciones digitales. Palabras clave: convertidores multinivel, modulación, vector espacial

Medicinal plants sold at traditional markets in southern Ecuador.

Science.gov (United States)

Tinitana, Fani; Rios, Montserrat; Romero-Benavides, Juan Carlos; de la Cruz Rot, Marcelino; Pardo-de-Santayana, Manuel

2016-07-05

The traditional markets in southern Ecuador and within the Andean region are especially important for plant resource trading among local people, even since before Spanish colonization; therefore, ethnobotanical studies are currently necessary and important. These strategic spaces persist for the traditional medicine cultural value reflected in the higher consumption of medicinal plants, which span all socioeconomic levels of rural and urban people. The purpose of this study includes the following: 1) to create a novel list of medicinal plants sold at 33 traditional markets; 2) to establish medicinal plant use agreement amongst vendors with the Factor of Informant Consensus (FIC); and 3) to determine the most sold medicinal plant species using the Fidelity Level (FL). This study focus on traditional markets ethnobotany utilizes the largest sample of medicinal plants market vendors up to date in Ecuador, interviewing them at 33 traditional markets, located within the Loja province. In order to determine the most sold medicinal plants and their ethnobotanical information, structured questionnaires and personal conversations were conducted with 196 medicinal plant vendors, and voucher specimens were created. Agreement among vendors about the therapeutic use of medicinal plants was measured using the FIC, and the most sold medicinal plant species were assessed with the FL. This research registered 160 medicinal plant species, grouped in 126 genera and 57 families that were sold in 33 traditional markets. The uses of medicinal plants in southern Ecuador are related to a long history of traditional medicine health practices that has persisted until today as well as high plant diversity. The 53 therapeutic uses recorded were grouped into 12 medical categories that were adapted from the World Health Organization. Three medical categories shared the highest value for FIC = 0.92, which showed a high level of agreement of market vendors for 57 medicinal plant species sold

Approximate scattering wave functions for few-particle continua

International Nuclear Information System (INIS)

Briggs, J.S.

1990-01-01

An operator identity which allows the wave operator for N particles interacting pairwise to be expanded as products of operators in which fewer than N particles interact is given. This identity is used to derive appproximate scattering wave functions for N-particle continua that avoid certain difficulties associated with Faddeev-type expansions. For example, a derivation is given of a scattering wave function used successfully recently to describe the three-particle continuum occurring in the electron impact ionization of the hydrogen atom

Arquitectura de Auditoría continua para el Control Fiscal Colombiano. Una versión preliminar

OpenAIRE

Valencia Duque, Francisco Javier

2013-01-01

La auditoría continua es una modalidad de auditoría, y como tal, contempla las diferentes fases del ciclo general de auditoría, teniendo en cuenta que los resultados de un proceso de auditoría continua "se integran al proceso de auditoría en todos sus aspectos, desde el desarrollo y mantenimiento del plan de auditoría empresarial, hasta la realización y el seguimiento de auditorías específicas" (Coderre, 2005,1)

29 CFR 779.333 - Goods sold for use as raw materials in other products.

Science.gov (United States)

2010-07-01

... are not considered sold for resale if sold for general industrial or commercial uses, such as coal for... stores or meat markets in cooling and preserving groceries and meat to be sold. Similarly, ice used for...

Foundations of the non-linear mechanics of continua

CERN Document Server

Sedov, L I

1966-01-01

International Series of Monographs on Interdisciplinary and Advanced Topics in Science and Engineering, Volume 1: Foundations of the Non-Linear Mechanics of Continua deals with the theoretical apparatus, principal concepts, and principles used in the construction of models of material bodies that fill space continuously. This book consists of three chapters. Chapters 1 and 2 are devoted to the theory of tensors and kinematic applications, focusing on the little-known theory of non-linear tensor functions. The laws of dynamics and thermodynamics are covered in Chapter 3.This volume is suitable

Educación Continua para Trabajadores de la Salud

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Ricardo Galán Morera

1986-08-01

Full Text Available

Introducción

En los países del tercer mundo la educación continua surge como una alternativa para la formación de adultos y es utilizada en programas de desarrollo implementados por el Estado.

El SENA la ha definido como “el proceso de formación profesional integral que apunta a generar en el hombre las herramientas prácticas y conceptuales, necesarias para inscribirse críticamente en la realidad y transformarla en beneficio propio, de su familia y su comunidad y no solamente como capacitación para el trabajo. (1

En el sector salud la educación continua se entiende “como una forma de educación para graduados o trabajadores en servicio, de cualquier nivel (profesional, técnico, auxiliar que busca perfeccionar su labor y al mismo tiempo solucionar problemas concretos de salud, mediante procesos educativos que cubren a todos los implicados, con técnicas que en lo posible, evitan el abandono o interrupción de su trabajo. Se ubica en el campo de la capacitación independientemente de la ubicación o categoría académica de sus ejecutores”.
(2.

Si consideramos la educación continua como una estrategia de capacitación, ésta, al igual que todo proceso de capacitación debe:

1. Contribuir a solucionar problemas concretos de salud.
2. Proporcionar conocimientos y destrezas diferenciales a los usuarios del programa, según su nivel educativo y laboral, con el propósito de que enfrenten el problema de salud desde diferentes ángulos.
3. Permitir ubicar, personal y socialmente al capacitado.
4. Proveer los medios y el apoyo necesario para que el capacitado pueda poner en práctica la información recibida en la capacitación.
5. Proveer la información y la asesoría necesaria, hasta que las acciones de capacitación y el producto de éstas se consolide...

Status and methodology of publicly available national HIV care continua and 90-90-90 targets: A systematic review.

Directory of Open Access Journals (Sweden)

Reuben Granich

2017-04-01

Full Text Available In 2014, the Joint United Nations Program on HIV/AIDS (UNAIDS issued treatment goals for human immunodeficiency virus (HIV. The 90-90-90 target specifies that by 2020, 90% of individuals living with HIV will know their HIV status, 90% of people with diagnosed HIV infection will receive antiretroviral treatment (ART, and 90% of those taking ART will be virally suppressed. Consistent methods and routine reporting in the public domain will be necessary for tracking progress towards the 90-90-90 target.For the period 2010-2016, we searched PubMed, UNAIDS country progress reports, World Health Organization (WHO, UNAIDS reports, national surveillance and program reports, United States President's Emergency Plan for AIDS Relief (PEPFAR Country Operational Plans, and conference presentations and/or abstracts for the latest available national HIV care continuum in the public domain. Continua of care included the number and proportion of people living with HIV (PLHIV who are diagnosed, on ART, and virally suppressed out of the estimated number of PLHIV. We ranked the described methods for indicators to derive high-, medium-, and low-quality continuum. For 2010-2016, we identified 53 national care continua with viral suppression estimates representing 19.7 million (54% of the 2015 global estimate of PLHIV. Of the 53, 6 (with 2% of global burden were high quality, using standard surveillance methods to derive an overall denominator and program data from national cohorts for estimating steps in the continuum. Only nine countries in sub-Saharan Africa had care continua with viral suppression estimates. Of the 53 countries, the average proportion of the aggregate of PLHIV from all countries on ART was 48%, and the proportion of PLHIV who were virally suppressed was 40%. Seven countries (Sweden, Cambodia, United Kingdom, Switzerland, Denmark, Rwanda, and Namibia were within 12% and 10% of achieving the 90-90-90 target for "on ART" and for "viral suppression

5 CFR 6701.103 - Prohibited purchases of property sold by GSA.

Science.gov (United States)

2010-01-01

... paragraph (a) of this section does not apply to the purchase of foreign gifts deposited with the agency... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Prohibited purchases of property sold by... purchases of property sold by GSA. (a) General prohibition. Except as provided in paragraphs (b) and (c) of...

Persistencia de Preconcepciones sobre los Circuitos Eléctricos de Corriente Continua

OpenAIRE

Solano,F.; Gil,J.; Pérez,A.L.; Suero,M.I.

2002-01-01

En este trabajo pretendemos comprobar que las preconcepciones que los alumnos poseen sobre los circuitos eléctricos de corriente continua son comunes a alumnos de diferentes edades y están tan fuertemente arraigadas que ni la instrucción durante muchos años permite modificarlas.

7 CFR 170.3 - What products may be sold at the USDA Farmers Market?

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false What products may be sold at the USDA Farmers Market...) MISCELLANEOUS MARKETING PRACTICES UNDER THE AGRICULTURAL MARKETING ACT OF 1946 USDA FARMERS MARKET § 170.3 What products may be sold at the USDA Farmers Market? Products that may be sold at the market include, but are...

FORMACIÓN CONTINUA: ¿HACIA DÓNDE VAMOS?

OpenAIRE

Macazana Fernandez, Dante Manuel

2014-01-01

En nuestros contextos, la formación continua de los docentes es prioritaria para responder a las necesidades de mejora de la calidad de la educación. En esta perspectiva; a pesar de los condicionamientos de carácter socioeconómico que ha creado la aplicación del neoliberalismo en nuestro país; se plantea como prioridad buscar con una nueva visión el desarrollo social, cultural y económico, a partir de las reflexiones, consensos y redefiniciones de la profesión docente y su función social, y e...

Deforestation of Peano continua and minimal deformation retracts☆

Science.gov (United States)

Conner, G.; Meilstrup, M.

2012-01-01

Every Peano continuum has a strong deformation retract to a deforested continuum, that is, one with no strongly contractible subsets attached at a single point. In a deforested continuum, each point with a one-dimensional neighborhood is either fixed by every self-homotopy of the space, or has a neighborhood which is a locally finite graph. A minimal deformation retract of a continuum (if it exists) is called its core. Every one-dimensional Peano continuum has a unique core, which can be obtained by deforestation. We give examples of planar Peano continua that contain no core but are deforested. PMID:23471120

Clinical course and variability of non-Rasmussen, nonstroke motor and sensory epilepsia partialis continua: a European survey and analysis of 65 cases

DEFF Research Database (Denmark)

Mameniskiene, Ruta; Bast, Thomas; Bentes, Carla

2011-01-01

To gain new insights into the clinical presentation, causes, treatment and prognosis of epilepsia partialis continua (EPC), and to develop hypotheses to be tested in a prospective investigation.......To gain new insights into the clinical presentation, causes, treatment and prognosis of epilepsia partialis continua (EPC), and to develop hypotheses to be tested in a prospective investigation....

An investigation of the quality of meat sold in Lesotho

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T.M. Seeiso

2009-05-01

Full Text Available Since the closure of the Lesotho abattoir in 2003, only imported meat can be legally sold. However, it was estimated in 2007 that 80 % of the meat sold at butcheries comes from informal slaughter. The aim of this study was to investigate the situation. The number and location of informal butcheries in Lesotho (n = 143 were recorded and mapped using Geographical Information Systems. Observations (photographs of informal slaughter indicated a lack of hygiene, unskilled slaughtermen and illegal disposal of offal with possible environmental pollution. In addition, a cross-sectional study was undertaken to determine the microbiological quality of meat from randomly selected carcasses (n = 237 of cattle, sheep and pigs from a sample of 44 butcheries, 4 of which were associated with registered supermarkets. As a control, samples for microbiological assay were taken from imported meat originating from carcasses (n = 20 slaughtered at a registered abattoir in South Africa. Of the 44 butcheries investigated only the 4 commercial butcheries associated with supermarkets sold imported meat only; 3 butcheries sold meat inspected at government slaughter slabs (n = 3, while the rest (n = 37 sold both imported and informally slaughtered meat. In terms of Lesotho legislation, informally slaughtered meat is only for home consumption. The bacteriological counts from all samples showed a total bacterial plate count exceeding 30 organisms per mℓ in contrast with the controls which all showed a count less than 5 colonies per mℓ. This was found for both imported and informally slaughtered meat sold in Lesotho. In addition, meat samples from butcheries showed the presence of the potential pathogens Salmonella (n = 2, Staphylococcus aureus (n = 12 and Escherichia coli (n=15. During the study, anthrax was confirmed in 9 human patients, 5 of whom died, after consumption of informally slaughtered livestock. Although no cases of animal abuse were detected, it was

Infusión de antibióticos continua versus intermitente para el tratamiento de las infecciones agudas graves

Directory of Open Access Journals (Sweden)

2014-05-01

Conclusiones de los autores: No hubo diferencias de la mortalidad, la recurrencia de la infección, la curación clínica, la sobreinfección posterior al tratamiento ni en los resultados de seguridad al comparar las infusiones de antibióticos intravenosos continuas con las infusiones tradicionales de antibióticos intermitentes. Sin embargo, los intervalos de confianza amplios indican que no es posible descartar los efectos beneficiosos o perjudiciales de todos los resultados. Por lo tanto, las pruebas actuales no son suficientes para recomendar la adopción generalizada de la infusión de antibióticos continua en lugar de las infusiones de antibióticos intermitentes. Se necesitan ensayos aleatorios prospectivos grandes adicionales, con un informe consistente y completo de medidas de resultado clínicas, realizados con estudios simultáneos farmacocinéticos y farmacodinámicos en poblaciones especiales para determinar si la adopción de las infusiones de antibióticos continuas se justifica en circunstancias específicas.

Electrostatics of proteins in dielectric solvent continua. II. Hamiltonian reaction field dynamics

Energy Technology Data Exchange (ETDEWEB)

Bauer, Sebastian; Tavan, Paul; Mathias, Gerald, E-mail: gerald.mathias@physik.uni-muenchen.de [Lehrstuhl für BioMolekulare Optik, Ludig-Maximilians Universität München, Oettingenstr. 67, 80538 München (Germany)

2014-03-14

In Paper I of this work [S. Bauer, G. Mathias, and P. Tavan, J. Chem. Phys. 140, 104102 (2014)] we have presented a reaction field (RF) method, which accurately solves the Poisson equation for proteins embedded in dielectric solvent continua at a computational effort comparable to that of polarizable molecular mechanics (MM) force fields. Building upon these results, here we suggest a method for linearly scaling Hamiltonian RF/MM molecular dynamics (MD) simulations, which we call “Hamiltonian dielectric solvent” (HADES). First, we derive analytical expressions for the RF forces acting on the solute atoms. These forces properly account for all those conditions, which have to be self-consistently fulfilled by RF quantities introduced in Paper I. Next we provide details on the implementation, i.e., we show how our RF approach is combined with a fast multipole method and how the self-consistency iterations are accelerated by the use of the so-called direct inversion in the iterative subspace. Finally we demonstrate that the method and its implementation enable Hamiltonian, i.e., energy and momentum conserving HADES-MD, and compare in a sample application on Ac-Ala-NHMe the HADES-MD free energy landscape at 300 K with that obtained in Paper I by scanning of configurations and with one obtained from an explicit solvent simulation.

Wild and native plants and mushrooms sold in the open-air markets of south-eastern Poland.

Science.gov (United States)

Kasper-Pakosz, Renata; Pietras, Marcin; Łuczaj, Łukasz

2016-10-07

The study of plants and fungi sold in open-air markets is an important part of ethnobotanical enquiry. Only few such studies were carried out in Europe. Four of the largest open-air markets of south-eastern Poland were visited regularly, and the plants sold in them were recorded between 2013 and 2015. The aim of the study was to record native and/or wild species sold in the markets. All the plants sold in the markets were photographed regularly. In each market, 25 sellers were interviewed. Voucher specimens were collected and fungi were identified using DNA barcoding. Altogether, 468 species of plants were recorded, 117 of them native to south-eastern Poland - 19 only collected from the wild and 11 both wild and cultivated. Seventeen of the species are under legal protection. Most protected plants were sold from cultivation, although proper authorization procedures had not been performed. Thirty-two species of fungi were sold (including two cultivated species), all of them for culinary purposes. Two species (Lactarius quieticolor, Leccinum schistophilum) are new to the mycobiota of Poland. Ornamental plants constituted a large section of the market, and they dominated the group of native species. Food plants dominated among wild-collected plants and were sold mainly as fruits for jams, juices and alcoholic drinks, or as culinary herbs. Very few medicinal or green vegetable plants were sold. An interesting feature of the markets was the sale of Ledum palustre as an insect repellent. Finding two species of fungi which are new to Poland highlights the importance of DNA barcoding in ethnomycological studies. Most items in the markets are ornamental plants, or edible fruits and mushrooms. Very few medicinal plants and green vegetables are sold, which differentiates the markets from southern European ones. Such a pattern is probably the model for most central European markets.

Foods Sold in School Vending Machines are Associated with Overall Student Dietary Intake

Science.gov (United States)

Rovner, Alisha J.; Nansel, Tonja R.; Wang, Jing; Iannotti, Ronald J.

2010-01-01

Purpose To examine the association between foods sold in school vending machines and students’ dietary behaviors. Methods The 2005-2006 US Health Behavior in School Aged Children (HBSC) survey was administered to 6th to 10th graders and school administrators. Students’ dietary intake was estimated with a brief food frequency measure. Administrators completed questions about foods sold in vending machines. For each food intake behavior, a multilevel regression analysis modeled students (level 1) nested within schools (level 2), with the corresponding food sold in vending machines as the main predictor. Control variables included gender, grade, family affluence and school poverty. Analyses were conducted separately for 6th to 8th and 9th to 10th grades. Results Eighty-three percent of schools (152 schools, 5,930 students) had vending machines which primarily sold foods of minimal nutritional values (soft drinks, chips and sweets). In younger grades, availability of fruits/vegetables and chocolate/sweets was positively related to the corresponding food intake, with vending machine content and school poverty explaining 70.6% of between-school variation in fruit/vegetable consumption, and 71.7% in sweets consumption. In older grades, there was no significant effect of foods available in vending machines on reported consumption of those foods. Conclusions Vending machines are widely available in US public schools. In younger grades, school vending machines were related to students’ diets positively or negatively, depending on what was sold in them. Schools are in a powerful position to influence children’s diets; therefore attention to foods sold in them is necessary in order to try to improve children’s diets. PMID:21185519

Análisis de la producción científica hispana en mejora continua: 1990-2011

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Sánchez, Lidia

2016-03-01

Full Text Available The aim of this paper is to present the results of a review of Hispanic literature about continuous improvement. A rigorous review of papers included in the Dialnet data base was conducted, combining both qualitative and quantitative methods. The main results show that continuous improvement is an important field in Hispanic output although certain topics should be delved into more deeply. General knowledge journals aimed at practitioners are those that tend to publish papers related to continuous improvement, thus highlighting the relevance of the topic for practitioners. The paper offers two main contributions. First, it is novel research not been previously done in the Hispanic context. Secondly, it clarifies and complements the conclusions drawn by international reviews according to which continuous improvement seemed to be scarcely addressed in Hispanic output.El objetivo de este trabajo es realizar una revisión del campo de la Mejora Continua en la literatura. Para ello se realiza una revisión rigurosa tanto con métodos cualitativos como cuantitativos a partir de los trabajos recogidos en la base de datos Dialnet. Los principales resultados muestran que la mejora continua es un campo importante en la literatura hispana, aunque debe potenciarse en ciertas temáticas. También se detectó una clara orientación divulgativa del tema resaltando así la importancia de la mejora continua para los profesionales del sector. El trabajo tiene dos aportaciones principales. En primer lugar, es un estudio novedoso que no se había realizado previamente en la literatura hispana. Y, en segundo lugar, matiza y complementa las conclusiones obtenidas por revisiones internacionales según las cuales la mejora continua parecía no estar desarrollada en la literatura hispana.

Educación permanente y continua en una perspectiva de integridad del ser

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Izabel Cristina Feijó de Andrade

2014-12-01

Full Text Available Este artículo buscó discutir las articulaciones y distinciones entre los conceptos de educación permanente y educación continua de modo que favorezca la perspectiva de integridad del ser, vínculo que requiere saberes hasta entonces poco privilegiados en las Universidades y que demandan el rescate de dimensiones basadas en la experiencia, la didáctica y la existencia del educador, tanto individual, comportamental, cultural, social y espiritual. Consideramos que las nociones de educación permanente y educación continua poseen elementos entrelazables que nos permiten desarrollar la capacidad de reaccionar críticamente por medio de una relación autoformativa. Las revisiones teóricas implementadas permitieron algunas consideraciones sobre los procesos formativos actuales y las prácticas de profesores rumbo a una Educación para la Integridad. Concluimos provisoriamente que las aproximaciones y distinciones entre EP y EC pueden proporcionar a los profesores la toma de conciencia de su vinculación todo/parte y del sentido de la vida.

Design of a Real-Time and Continua-Based Framework for Care Guideline Recommendations

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Yu-Feng Lin

2014-04-01

Full Text Available Telehealth is an important issue in the medical and healthcare domains. Although a number of systems have been developed to meet the demands of emerging telehealth services, the following problems still remain to be addressed: (1 most systems do not monitor/predict the vital signs states so that they are able to send alarms to caregivers in real-time; (2 most systems do not focus on reducing the amount of work that caregivers need to do, and provide patients with remote care; and (3 most systems do not recommend guidelines for caregivers. This study thus proposes a framework for a real-time and Continua-based Care Guideline Recommendation System (Cagurs which utilizes mobile device platforms to provide caregivers of chronic patients with real-time care guideline recommendations, and that enables vital signs data to be transmitted between different devices automatically, using the Continua standard. Moreover, the proposed system adopts the episode mining approach to monitor/predict anomalous conditions of patients, and then offers related recommended care guidelines to caregivers so that they can offer preventive care in a timely manner.

General relativistic continuum mechanics and the post-Newtonian equations of motion

International Nuclear Information System (INIS)

Morrill, T.H.

1991-01-01

Aspects are examined of general relativistic continuum mechanics. Perfectly elastic materials are dealt with but not exclusively. The derivation of their equations of motion is emphasized, in the post-Newtonian approximation. A reformulation is presented based on the tetrad formalism, of Carter and Quintana's theory of general relativistic elastic continua. A field Lagrangian is derived describing perfect material media; show that the usual covariant conservations law for perfectly elastic media is fully equivalent to the Euler-Lagrange equations describing these same media; and further show that the equations of motion for such materials follow directly from Einstein's field equations. In addition, a version of this principle shows that the local mass density in curved space-time partially depends on the amount and distribution of mass energy in the entire universe and is related to the mass density that would occur if space-time were flat. The total Lagrangian was also expanded in an EIH (Einstein, Infeld, Hoffmann) series to obtain a total post-Newtonian Lagrangian. The results agree with those found by solving Einstein's equations for the metric coefficients and by deriving the post-Newtonian equations of motion from the covariant conservation law

Epilepsia partialis continua Kozevnikov. Correlation of cranial computertomography and EEG-findings

Energy Technology Data Exchange (ETDEWEB)

Lipinski, C.G.

1982-10-01

Two children with onset of epilepsia partialis continua (Epc) in the age of 8 years are described. EEG-findings and cranial computertomography are compared. Were as the CAT is demonstrating the underlaying morphological lesion of Epc, the EEG is showing the epileptic phenomena. Both, anatomic lesion and electronencephalographic focus can show quite different localisations. Despite this findings, to establish the diagnosis Epc, in our cases the computertomographic proof of a cortical and subcortical lesion seems to be important.

Cloning and expression of SOLD1 in ovine and caprine placenta, and their expected roles during the development of placentomes

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Kizaki Keiichiro

2010-01-01

Full Text Available Abstract Background The Ly-6 (Ly-6/uPAR superfamily members share the Ly-6 domain defined by distinct disulfide bonding patterns between 8 or 10 cysteine residues. They comprise membrane- and secretory-type proteins. We recently reported the gene and protein characterization of the bovine secreted protein of Ly-6 domain 1 (SOLD1. Bovine SOLD1 is expressed in trophoblast mononucleate cells (TMCs and is localized in the cotyledonary mesenchyme. Here, we compared the expression and functionality of SOLD1 among the ruminants. We examined mRNA expression by chorionic fibroblasts as a measure of one of the SOLD1 functions. Results Ovine and caprine SOLD1 mRNAs have 303 bp open reading frames and encode for deduced SOLD1 proteins with 100 amino acids, including a 22-aa-long signal peptide at the N-terminal. Both of the SOLD1 amino acid sequences have high similarities with the bovine sequence. Both SOLD1 mRNAs were also expressed in TMCs of cotyledons and intercotyledonary membranes. The mature SOLD1 proteins were localized in the mesenchymal villi of cotyledons after secretion. Bovine, ovine and caprine SOLD1 affected gene expression in mesenchymal fibroblasts in vitro; nucleoredoxin expression was upregulated and BCL2-like 13 was downregulated. Thus, we suggest that SOLD1 acts as a modulator of cell proliferation and apoptosis. Conclusion Expressing cells and protein localization of SOLD1 coincided among the three ruminants. SOLD1 participated in regulating nucleoredoxin and BCL2-like 13 expression in chorionic fibroblasts. SOLD1 is produced specifically in the cotyledons and intercotyledonary membranes in ruminants and appears to be involved in the construction of the ruminant placenta.

Aportaciones al estudio de la respuesta con la temperatura de las HFETs en continua

OpenAIRE

González Pérez, Benito

2011-01-01

Programa de doctorado: Ingeniería Electrónica. Premio Extraordinario, Área de Tecnológicas En esta memoria se presentan los resultados de las investigaciones realizadas sobre la influencia de la temperatura en el funcionamiento de los HFETs, cuando operan en régimen de continua.

Food sold in school vending machines is associated with overall student dietary intake.

Science.gov (United States)

Rovner, Alisha J; Nansel, Tonja R; Wang, Jing; Iannotti, Ronald J

2011-01-01

To examine the association between food sold in school vending machines and the dietary behaviors of students. The 2005-2006 U.S. Health Behavior in School-aged Children survey was administered to 6th to 10th graders and school administrators. Dietary intake in students was estimated with a brief food frequency measure. School administrators completed questions regarding food sold in vending machines. For each food intake behavior, a multilevel regression analysis modeled students (level 1) nested within schools (level 2), with the corresponding food sold in vending machines as the main predictor. Control variables included gender, grade, family affluence, and school poverty index. Analyses were conducted separately for 6th to 8th and 9th-10th grades. In all, 83% of the schools (152 schools; 5,930 students) had vending machines that primarily sold food of minimal nutritional values (soft drinks, chips, and sweets). In younger grades, availability of fruit and/or vegetables and chocolate and/or sweets was positively related to the corresponding food intake, with vending machine content and school poverty index providing an explanation for 70.6% of between-school variation in fruit and/or vegetable consumption and 71.7% in sweets consumption. Among the older grades, there was no significant effect of food available in vending machines on reported consumption of those food. Vending machines are widely available in public schools in the United States. In younger grades, school vending machines were either positively or negatively related to the diets of the students, depending on what was sold in them. Schools are in a powerful position to influence the diets of children; therefore, attention to the food sold at school is necessary to try to improve their diets. Copyright © 2011 Society for Adolescent Health and Medicine. All rights reserved.

Epilepsia partialis continua Kozevnikov. Correlation of cranial computertomography and EEG-findings

International Nuclear Information System (INIS)

Lipinski, C.G.

1982-01-01

Two children with onset of epilepsia partialis continua (Epc) in the age of 8 years are described. EEG-findings and cranial computertomography are compared. Were as the CAT is demonstrating the underlaying morphological lesion of Epc, the EEG is showing the epileptic phenomena. Both, anatomic lesion and electronencephalographic focus can show quite different localisations. Despite this findings, to establish the diagnosis Epc, in our cases the computertomographic proof of a cortical and subcortical lesion seems to be important. (orig.) [de

Symmetry aspects of multipole moments in electromagnetism and mechanics of continua

International Nuclear Information System (INIS)

Baleanu, D.; Dubovik, V.M.; Misiku, S.

1998-01-01

We investigate the form of some multipole tensors, which arise in the expansion of a system of charges and currents, in terms of second-order Killing-Yano tensors in the phase space of classical mechanics. We related some of these tensors to the generators of dynamical symmetries like the angular momentum, the mass-inertia tensor, the conformal operator and the momentum conjugate Runge-Lenz vector. In this way we associate a geometrical meaning to such physical observables of the continua

Nuevo método de sutura subcutánea percutánea continua New method of continuous percutaneous subcutaneous suture

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Germán Brito Sosa

2012-06-01

Full Text Available Objetivos: realizar un método de sutura continua, en las personas operadas en el Hospital "Julio Trigo López", que disminuya los granulomas a nivel de la herida quirúrgica, y compararlas con el método tradicional. Métodos: se realizó un estudio experimental sobre la aplicación de un método de sutura subcutánea percutánea continua, en un grupo de pacientes operados de diversas enfermedades, ya sea de urgencia, electivo o ambulatorio, en el Hospital "Julio Trigo López", en los años 2008 y 2009. Resultados: con el método de sutura subcutánea percutánea continua con nylon no se forman granulomas, mientras que con el método tradicional, sí ocurre en un porcentaje no despreciable. Las ventajas del método de sutura subcutánea percutánea continua con nylon son: en el plano celular subcutáneo de la pared abdominal no queda sutura, no se producen granulomas y es más económica. Conclusiones: la sutura de nylon es menos rechazada que la del cromado, ya que no se producen granulomas. El método de sutura subcutánea percutánea continua es una sutura más hemostática que el método tradicional, ya que el por ciento de hematomas es menor. El gasto económico es menor con el método de sutura subcutánea percutánea continua. Con el método de sutura subcutánea percutánea continua la sutura es extraída al 10mo. día de haberla aplicado.Objectives: to apply a continuous suture method to reduce granulomas in surgical wounds in patients operated on at "Julio Trigo Lopez" hospital, and to compare the results with those of the traditional method. Methods: an experimental study was conducted on the application of a continuous percutaneous subcutaneous suture in a group of patients operated on from several diseases, either under emergency, elective or outpatient conditions at "Julio Trigo Lopez" hospital during 2008 and 2009. Results: the continuous percutaneous subcutaneous suture method with nylon prevents formation of granulomas, whereas

Nonlinear mechanics a supplement to theoretical mechanics of particles and continua

CERN Document Server

Fetter, Alexander L

2006-01-01

In their prior Dover book, Theoretical Mechanics of Particles and Continua, Alexander L. Fetter and John Dirk Walecka provided a lucid and self-contained account of classical mechanics, together with appropriate mathematical methods. This supplement-an update of that volume-offers a bridge to contemporary mechanics.The original book's focus on continuum mechanics-with chapters on sound waves in fluids, surface waves on fluids, heat conduction, and viscous fluids-forms the basis for this supplement's discussion of nonlinear continuous systems. Topics include linearized stability analysis; a det

Metodología para seleccionar oportunidades de mejora continua en promociones de viviendas

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Del Solar, P.

2015-06-01

Full Text Available Continuous improvement should always be present in business, have they or not management systems on hand according to the UNE EN ISO 9001:2008 Standard. However, its application in the construction sector is especially hard due to the particular characteristics of this business (1. This paper focuses on how to apply four of the seven basic statistical continuous improvement tools (Data collection sheet, Stratification, Histogram and Pareto Diagram in order to select improvement opportunities within the planification phase of a continuous improvement project whose aims is the reduction of the construction failures in housing blocks which would be detected during the pre-delivery phase. The conclusion is that the three works in which it would be convenient to act in order to reduce significantly the construction failures during the pre-delivery phase are: Wood Carpentry, Ceramic Tile and Electricity.La mejora continua debería estar presente siempre en las empresas, dispongan o no de sistemas de gestión conforme a la Norma UNE EN ISO 9001:2008. Sin embargo, su aplicación en el sector de la construcción es especialmente difícil debido a las características particulares del mismo (1. Este articulo describe cómo aplicar cuatro de las siete herramientas estadísticas básicas de la mejora continua (Hoja de recogida de datos, Estratificación, Histograma y Diagrama de Pareto para seleccionar oportunidades de mejora, dentro de la fase de planificación de un proyecto de mejora continua que tenga como objetivo reducir los defectos de construcción en edificios de viviendas detectados en la fase de pre-entrega. Concluyendo que los tres oficios en los que convendría actuar para reducir de manera significativa los fallos de construcción en la fase de pre-entrega son: Carpintería de Madera, Revestimientos Cerámicos e Instalación de Electricidad.

Microbiological quality of commercially available poultry feeds sold ...

African Journals Online (AJOL)

Food poisoning and infection by bacterial and fungal genera pose obvious health threat to both animals and humans. Pfizer, Guinea, Extra, Top, NOM and Master brands of feed sold in Owerri Metropolis were analysed for their bacterial and fungal quality. The genera of bacteria and fungi isolated and their percentage ...

Foods and Beverages Sold Outside the School Meals Program

Science.gov (United States)

Foods and Beverages Sold Outside of the School Meals Programs About SHPPS: SHPPS is a national survey periodically conducted ... canteen, or snack bar where students could purchase foods or beverages. • 4.0% of states and 6.6% of ...

Finite-life fatigue constraints in 2D topology optimization of continua

DEFF Research Database (Denmark)

Oest, Jacob; Lund, Erik

2017-01-01

of fatigue damage are estimated using the stress-based Sines fatigue criterion and S − N curves, while the accumulated damage is estimated using Palmgren-Miner’s rule. The method is a natural extension of classical density-based topology optimization with static stress constraints, and thus utilizes many......Topology optimization of 2D continua with the objective of minimizing the mass while considering finite-life fatigue constraint is considered. The structure is subjected to proportional variable-amplitude loading. The topology optimization problem is solved using the density approach. The fractions...

On the Partial Analytical Solution of the Kirchhoff Equation

KAUST Repository

Michels, Dominik L.

2015-09-01

We derive a combined analytical and numerical scheme to solve the (1+1)-dimensional differential Kirchhoff system. Here the object is to obtain an accurate as well as an efficient solution process. Purely numerical algorithms typically have the disadvantage that the quality of solutions decreases enormously with increasing temporal step sizes, which results from the numerical stiffness of the underlying partial differential equations. To prevent that, we apply a differential Thomas decomposition and a Lie symmetry analysis to derive explicit analytical solutions to specific parts of the Kirchhoff system. These solutions are general and depend on arbitrary functions, which we set up according to the numerical solution of the remaining parts. In contrast to a purely numerical handling, this reduces the numerical solution space and prevents the system from becoming unstable. The differential Kirchhoff equation describes the dynamic equilibrium of one-dimensional continua, i.e. slender structures like fibers. We evaluate the advantage of our method by simulating a cilia carpet.

On the Partial Analytical Solution of the Kirchhoff Equation

KAUST Repository

Michels, Dominik L.; Lyakhov, Dmitry; Gerdt, Vladimir P.; Sobottka, Gerrit A.; Weber, Andreas G.

2015-01-01

We derive a combined analytical and numerical scheme to solve the (1+1)-dimensional differential Kirchhoff system. Here the object is to obtain an accurate as well as an efficient solution process. Purely numerical algorithms typically have the disadvantage that the quality of solutions decreases enormously with increasing temporal step sizes, which results from the numerical stiffness of the underlying partial differential equations. To prevent that, we apply a differential Thomas decomposition and a Lie symmetry analysis to derive explicit analytical solutions to specific parts of the Kirchhoff system. These solutions are general and depend on arbitrary functions, which we set up according to the numerical solution of the remaining parts. In contrast to a purely numerical handling, this reduces the numerical solution space and prevents the system from becoming unstable. The differential Kirchhoff equation describes the dynamic equilibrium of one-dimensional continua, i.e. slender structures like fibers. We evaluate the advantage of our method by simulating a cilia carpet.

APLICACIÓN DEL PROCESO DE INTEGRACIÓN CONTINUA EN EL CENTRO DE TELEMÁTICA DE LA UNIVERSIDAD DE LAS CIENCIAS INFORMÁTICAS

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Hernández A

2014-06-01

Full Text Available La Integración Continua es una práctica de software expuesta por Martin Fowler, que permite entre otras bondades la reducción de riesgos y la realización de tareas repetitivas, automatizando al máximo los procesos involucrados en el desarrollo de software y permitiendo la generación de software listo para desplegar e incremento de su calidad. Cuando se cumplen los principios que rigen la Integración Continua se obtiene una herramienta eficaz y útil que ayuda a la sinergia del desarrollo de los proyectos de software. En este trabajo se pretenden mostrar las experiencias en la utilización del proceso de Integración Continua en el centro de Telemática de la Universidad de las Ciencias Informáticas. Se presentan las etapas, herramientas utilizadas y resultados obtenidos con la aplicación de esta técnica, resaltando las ventajas que se obtienen para todas las personas involucradas, principalmente los desarrolladores, los cuales son los mayores implicados en este proceso. Se utilizan los lenguajes de programación PHP y Python por ser éstos los utilizados en el centro y como servidor de Integración Continua Jenkins, uno de los más populares, robusto y fácil de usar. Las etapas y herramientas que fueron establecidas son libres de ser modificadas de acuerdo a las necesidades que se requieran.

Bacteriological quality of bottled water sold on the Ghanaian market ...

African Journals Online (AJOL)

Bacteriological quality of bottled water sold on the Ghanaian market. ... Consumption of bottled water is increasing rapidly in developing countries especially among ... limits set by WHO guidelines and therefore safe for human consumption.

Evaluation of the adequacy of the consume-by date of rice balls sold at convenience stores.

Science.gov (United States)

Sato, Jun; Yokokawa, Kana

2014-01-01

The adequacy of the consume-by date was validated for rice balls sold at convenience stores (CVSs),taking into account the process of distribution. The results indicated that the increase in the viable cell counts differed significantly depending on the type of rice balls and the storage temperature. At 19 h after delivery, Staphylococcus spp. were detected in 4 samples (26.7%) of the Tunamayo samples of Company A and in the majority of the Plum samples of Company B. Results showed there was a strong correlation between the elapsed time after delivery and the viable cell counts for all samples except for the Plum samples of Company B. The regression equations varied for the different types of rice balls and the different storage temperatures. Using the obtained regression equations and assuming a safety factor of 0.7, the appropriate consume-by date was determined to be 11 h for the Tunamayo and 38 h for the Plum of Company A, and 21 h for the Tunamayo of Company B. Among 14 strains of isolated Gram-negative bacteria, 11 strains (78.6%) belonged to the genus Serratia.

Evaluation of the pharmaceutical quality of some quinine preparations sold in Nigeria.

Science.gov (United States)

Nnamdi, Jolly A; Arhewoh, Ikhuoria M; Okhamafe, Augustine O; Enato, Ehijie F O

2009-01-01

The purpose of this study was to determine the pharmaceutical quality of quinine preparations sold in Nigerian markets. The organoleptic and physicochemical properties of quinine tablets, as well as oral liquids and parenteral quinine preparations, were assessed according to British Pharmacopoeia (BP) and unofficial standards as recommended by the manufacturers. Of the 6 brands of tablets assessed, 4 passed the uniformity of content test and 5 the disintegration test, but only 2 the dissolution test. The pH of 2 of the 6 brands of oral liquid preparations met BP standards, while only 1 oral liquid met the BP standard for percentage content. The assay further demonstrated that 4 brands of the parenteral preparations met BP standards for quinine content. All the parenteral preparations were found to be sterile. Quinine preparations sold in Nigeria varied considerably in their pharmaceutical quality. A strict check of the quality of brands of quinine by regulatory agencies and distributors before they are sold to the public is therefore recommended. Copyright 2009 S. Karger AG, Basel.

More Than a Feeling? An Empirical Analysis of the Dual-Continua Model on a National Sample of Lesbian, Gay, and Bisexual Identified Canadians.

Science.gov (United States)

Peter, Tracey

2017-08-11

The goal of the study is to investigate whether positive mental health complements mental illness within a theoretically informed (the dual-continua model) and psychometrically tested (the Mental Health Continuum-Short Form) framework. National-level, population-based data from the 2012 Canadian Community Health Survey on Mental Health (CCHS-MH) was used, with comparisons between sexual minority and heterosexual adults. Results show that gay, lesbian, and bisexual Canadians have substantially lower rates of positive mental health and are more likely to have been diagnosed with a mental illness, with the disparities between health and illness being the most pronounced among lesbians and bisexual females. Results show considerable support for the dual-continua model, which posits that the absence of health does not automatically translate into the presence of illness, and vice versa. Suggestions are made for practitioners and researchers toward the use of the dual-continua model as a surveillance tool, especially among sexual minority individuals.

PREFACE: The 7th International Seminar on Geometry, Continua and Microstructures

Science.gov (United States)

Burton, David A.

2007-04-01

It gives me great pleasure to present the proceedings of the 7th International Seminar on Geometry, Continua and Microstructures (GCM 7). The conference took place on 25-27 September 2006 at Lancaster University and the local organisers were Robin Tucker, Tim Walton, myself and Jonathan Gratus of the Lancaster University Mathematical Physics Group. Modern field theories of mechanically and electrically responsive continua have a wealth of interesting applications in physics. Such theories provide effective macroscopic models of complex systems, such as living tissue and material with dynamical defects, that capture macroscopic consequences of microscopic phenomena. GCM is an interdisciplinary conference series, initiated by the Eringen medallist Gérard A Maugin, that brings together physicists and applied mathematicians who have interests in continuum mechanics and differential geometry and who aim to develop new and powerful methods for analysing the behaviour of complex mechanical systems. The earlier conferences in the series were held in Paris, Madrid, Mannheim, Turin, Sinaia and Belgrade. This volume addresses a variety of topics including the physics of saturated porous media, the relationship between growth in living tissue and molecular transport, the mechanics of polymer bonds, the macroscopic properties of damaged elastomers, the mechanics of carbon nanotubes, the geometry of balance systems in Continuum Thermodynamics and wave propagation in the material manifold. I would like to warmly thank the rest of the organising committee and the conference participants for making GCM 7 an enjoyable and rewarding occasion. Photographs may be found at http://www.lancs.ac.uk/depts/spc/conf/gcm7/wss/index.htm David A Burton Editor

Wild vegetable mixes sold in the markets of Dalmatia (southern Croatia).

Science.gov (United States)

Łuczaj, Łukasz; Zovkokončić, Marijana; Miličević, Tihomir; Dolina, Katija; Pandža, Marija

2013-01-03

Dalmatia is an interesting place to study the use of wild greens as it lies at the intersection of influence of Slavs, who do not usually use many species of wild greens, and Mediterranean culinary culture, where the use of multiple wild greens is common. The aim of the study was to document the mixtures of wild green vegetables which are sold in all the vegetable markets of Dalmatia. All vendors (68) in all 11 major markets of the Dalmatian coast were interviewed. The piles of wild vegetables they sold were searched and herbarium specimens taken from them. The mean number of species in the mix was 5.7. The most commonly sold wild plants are: Sonchus oleraceus L., Allium ampeloprasum L., Foeniculum vulgare Mill., Urospermum picroides F.W.Schmidt, Papaver rhoeas L., Daucus carota L., Taraxacum sp., Picris echioides L., Silene latifolia Poir. and Crepis spp. Also the cultivated beet (Beta vulgaris L.) and a few cultivated Brassicaceae varieties are frequent components. Wild vegetables from the mix are usually boiled for 20-30 minutes and dressed with olive oil and salt. Altogether at least 37 wild taxa and 13 cultivated taxa were recorded.Apart from the mixes, Asparagus acutifolius L. and Tamus communis L. shoots are sold in separate bunches (they are usually eaten with eggs), as well as some Asteraceae species, the latter are eaten raw or briefly boiled. The rich tradition of eating many wild greens may result both from strong Venetian and Greek influences and the necessity of using all food resources available in the barren, infertile land in the past. Although the number of wild-collected green vegetables is impressive we hypothesize that it may have decreased over the years, and that further in-depth local ethnobotanical studies are needed in Dalmatia to record the disappearing knowledge of edible plants.

Prevalence of intestinal parasites in vegetables sold in major ...

African Journals Online (AJOL)

Studies were carried out in Ibadan City, South-West Nigeria between March and June 2011, to determine the prevalence of intestinal parasites in vegetables sold in various markets within the city. Fifty samples each of 5 different vegetable types, Cabbage (Brassica deracea), Lettuce (Lactus sativa), Carrot (Daucus carota), ...

The effects of acute administration of Chinese aphrodisiacs sold in ...

African Journals Online (AJOL)

The effects of acute administration of Chinese aphrodisiacs sold in Blantyre City on sperm characteristics and fertility profile in guinea pigs. ... However, selling of these drugs seems not to be well regulated. Probably the aphrodisiacs that are ...

Occurrence of Clostridium perfringens in sausages sold in Meknes ...

African Journals Online (AJOL)

In Morocco, the consumption of meat products has experienced a sharp increase in recent years despite the presence of pathogenic bacteria due to hygiene failure. The present study was designed to determine the prevalence of Clostridium perfringens in sausages sold in Meknes city (Morocco) and to study the different ...

Quality characteristics of commercial bottled water sold in Owerri ...

African Journals Online (AJOL)

The quality characteristics of commercial bottled water sold in Owerri, Imo State, Nigeria were investigated to determine their physical, chemical and bacteriological content. The four brands of bottled water investigated were Mevok ®, Ozonized April ®, Lacrystal ® and Eva ®. The mean turbidity value of all the samples were ...

Evaluación continua y autoevaluación como herramientas de aprendizaje

OpenAIRE

Zubcoff Vallejo, José Jacobo

2014-01-01

En el contexto actual, en los planes de estudio de los grados se incluye la evaluación continua como parte fundamental de la evaluación. En este trabajo se resumen las principales conclusiones y aspectos destacados del debate de los trabajos presentados en la mesa 12 de comunicaciones orales de las Jornadas de Redes de Investigación en Docencia Universitaria desarrollada en la Universidad de Alicante durante los días 3 y 4 de Julio de 2014. Entre las herramientas que han mostrado resultados p...

Parasitic Contamination of Fruits and Vegetables Sold at Kaduna ...

African Journals Online (AJOL)

The safety of fruits and vegetables sold in Kaduna metropolis, Nigeria for consumption was assessed with respect to their contamination by Ova and Cysts of parasites. Out of 320 samples of seven (7) varieties of vegetables and fruits examined from three different markets in Kaduna metropolis, 45 (14.00%) were positive ...

Cuadro de Mando ODUNPLUS y su mejora continua

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Rafael H Soler-González

2016-01-01

Full Text Available Debido al desarrollo de nuevos mod elos de gestión, que han aumentado el número de objetivos e indicadores en pos del control y de una efectiva toma de decisiones, los cuadros de mando se han convertido en herramientas necesarias para el desarrollo exitoso de la gestión empresarial en los ú ltimos años. En medio del Proyecto Prometeo y la implementación del Balanced Scorecard en la Escuela Superior Politécnica de Chimborazo (ESPOCH, se ha creado una nueva herramienta informática denominada ODUN que tiene mejoras continuas y la hacen un produ cto a seguir. ODUNPLUS es una nueva versión de este cuadro de mando que está programado con herramientas y librerías libres de tecnología web y bajo Licencia Pública General de GNU (GPL que permite su libre distribución y uso. Este artículo expone las nu evas bondades del de Mando ODUNPLUS.

Microbial quality of chevon and mutton sold in Tamale Metropolis of ...

African Journals Online (AJOL)

Michael Horsfall

All rights reserved. J. Appl. Sci. ... Universiti Sains Malaysia, School of Industry Technology, 11800 Pulau Pinang, Malaysia. ABSTRACT: ... sold in the open market to consumers. Although ... microbiologically safe is increasing tremendously in.

Wild vegetable mixes sold in the markets of Dalmatia (southern Croatia

Directory of Open Access Journals (Sweden)

Łuczaj Łukasz

2013-01-01

Full Text Available Abstract Background Dalmatia is an interesting place to study the use of wild greens as it lies at the intersection of influence of Slavs, who do not usually use many species of wild greens, and Mediterranean culinary culture, where the use of multiple wild greens is common. The aim of the study was to document the mixtures of wild green vegetables which are sold in all the vegetable markets of Dalmatia. Methods All vendors (68 in all 11 major markets of the Dalmatian coast were interviewed. The piles of wild vegetables they sold were searched and herbarium specimens taken from them. Results The mean number of species in the mix was 5.7. The most commonly sold wild plants are: Sonchus oleraceus L., Allium ampeloprasum L., Foeniculum vulgare Mill., Urospermum picroides F.W.Schmidt, Papaver rhoeas L., Daucus carota L., Taraxacum sp., Picris echioides L., Silene latifolia Poir. and Crepis spp. Also the cultivated beet (Beta vulgaris L. and a few cultivated Brassicaceae varieties are frequent components. Wild vegetables from the mix are usually boiled for 20–30 minutes and dressed with olive oil and salt. Altogether at least 37 wild taxa and 13 cultivated taxa were recorded. Apart from the mixes, Asparagus acutifolius L. and Tamus communis L. shoots are sold in separate bunches (they are usually eaten with eggs, as well as some Asteraceae species, the latter are eaten raw or briefly boiled. Conclusions The rich tradition of eating many wild greens may result both from strong Venetian and Greek influences and the necessity of using all food resources available in the barren, infertile land in the past. Although the number of wild-collected green vegetables is impressive we hypothesize that it may have decreased over the years, and that further in-depth local ethnobotanical studies are needed in Dalmatia to record the disappearing knowledge of edible plants.

Parasites and Morphometric Indices of Frozen Fish Sold in Nsukka ...

African Journals Online (AJOL)

The parasites and morphometric indices of frozen fish sold in Nsukka Urban Market in Nsukka Local Government Area of Enugu State, Nigeria were investigated between June and December 2008 to determine the parasite prevalence, mean intensity and abundance and some morphometric indices associated with ...

Evolución de la participación del personal en la mejora continua en España.

OpenAIRE

García Lorenzo, Anotnio; Prado Prado, José Carlos

2001-01-01

La mejora continua constituye una vía fundamental para mantener e incrementar la competitividad de las compañías. Debido a que se sustenta en la contribución de todos los miembros de una organización, es necesario habilitar mecanismo

Medicinal plants sold at the El Rio Market, Camaguey, Cuba

NARCIS (Netherlands)

Godinez-Caraballo, D.; Volpato, G.

2008-01-01

Information regarding medicinal plants sold in the El Rio Market, Camaguey, Cuba, revealed 184 species belonging to 69 vascular plant families. The most important family was Fabaceae s.l. with 13 species, followed by Lamiaceae with 12, and Asteraceae with 8. More than 90 general medicinal

Quality assessment of sachet and bottled water sold in Gboko ...

African Journals Online (AJOL)

The quality of selected sachet and bottled water produced and sold within Gboko town, Benue State was investigated to determine their Shelf life. Eight brands of sachet water and four brands of bottled water samples were collected from different manufacturers within 24 hours and stored at ambient temperature.

quality and safety characteristics of cassava crisps sold in urban

African Journals Online (AJOL)

ACSS

QUALITY AND SAFETY CHARACTERISTICS OF CASSAVA CRISPS SOLD IN. URBAN KENYA. G.O. ABONG', S.I. SHIBAIRO, ... This study sought to characterise the quality and safety in terms of cyanide levels of cassava crisps ... Crantz) to food security and incomes for rural communities in sub-Saharan Africa, cannot be.

Microbial Load of Some Medicinal Plants Sold in Some Local ...

African Journals Online (AJOL)

Microbial Load of Some Medicinal Plants Sold in Some Local Markets in Abeokuta, Nigeria. I MacDonald, S Omonigho, J Erhabor, H Efijuemue. Abstract. Purpose: To evaluate the microbial load on 17 randomly selected plant samples from 60 ethnobotanically collected medicinal plants from five local markets in Abeokuta, ...

Microbiological Quality Assessment of Ready-To-Eat Kilishi Sold in ...

African Journals Online (AJOL)

Microbiological Quality Assessment of Ready-To-Eat Kilishi Sold in Abuja, Nigeria. ... Animal Production Research Advances ... A total of twelve samples of ready-to-eat dried meat product, kilishi, were purchased from different sale-points in Abuja, Nigeria and a study conducted on them to assess their microbiological ...

Quality of Artesunate Tablets Sold in Pharmacies in Kumasi, Ghana ...

African Journals Online (AJOL)

Purpose: The study was carried out to evaluate the quality of artesunate tablets sold in retail and wholesale pharmacies in Kumasi, Ghana. In particular, the study sought to ascertain the presence or otherwise of counterfeit artesunate tablets in Kumasi. Method: Artesunate tablets were purchased from pharmacies in Kumasi ...

Uso de ecuaciones estructurales en áreas de manufactura y mejora continua. El caso de plantas de manufactura

Directory of Open Access Journals (Sweden)

Carlos Monge

2016-03-01

Full Text Available El uso de la modelación mediante ecuaciones estructurales ha sido empleado de manera amplia en las áreas de las ciencias del comportamiento, mercadotecnia, preferencias del consumidor y servicio al cliente. Sin embargo, existe poca bibliografía que muestre su uso en áreas de manufactura, calidad o mejora continua. El presente artículo presenta la aplicación exitosa, estadísticamente significativa y relevante de ecuaciones estructurales en una investigación realizada en plantas de manufactura de Apodaca, México. En ese estudio se analizan aspectos de manufactura y mejora continua y su impacto en la eficiencia operacional de las plantas, y se presentan los resultados de la aplicación en las áreas mencionadas, sugiriendo que las ecuaciones estructurales pueden ser utilizadas  en distintas áreas con la misma eficacia y confiabilidad que otras técnicas estadísticas de análisis multivariado.

Microbial safety of raw mixed-vegetable salad sold as an ...

African Journals Online (AJOL)

A survey of 90 randomly selected subjects indicated raw mixed-vegetable salad as a popular accompaniment to cooked rice sold by street-food vendors in the Kokomlemle municipality of Accra, Ghana, but the salad was generally considered unwholesome and a potential cause of diarrhoea. A survey of 15 vendors of ...

The mineral composition of five insects as sold for human ...

African Journals Online (AJOL)

Edible insects have been proposed as an alternative protein source that is economically and environmentally preferable to livestock, and certain species may be high in nutrients that benefit human health. We present data describing the mineral content of five edible insects as sold in South Africa and Zimbabwe. We report ...

Microbiological Safety of Ready-to-eat Foods Sold in Primary ...

African Journals Online (AJOL)

A study was conducted to assess the microbial safety of ready-to-eat (RTE) foods sold in private and public primary schools in Abeokuta, South-western Nigeria. One hundred and sixty RTE food samples were collected from forty food vendors in thirty primary schools and analysed microbiologically. Socio-economic status ...

17 CFR 210.12-12A - Investments-securities sold short.

Science.gov (United States)

2010-04-01

... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Investments-securities sold... EXCHANGE ACT OF 1934, PUBLIC UTILITY HOLDING COMPANY ACT OF 1935, INVESTMENT COMPANY ACT OF 1940, INVESTMENT ADVISERS ACT OF 1940, AND ENERGY POLICY AND CONSERVATION ACT OF 1975 Form and Content of Schedules...

Ethics and quality assessment of cowpea grains sold in southern ...

African Journals Online (AJOL)

The study examined the supply side of cowpea markets in two states of Nigeria. Specifically, quality status; grades of cowpea grains sold and effect of ethics on sales, quality and price were determined. A multi-stage sampling technique was used to select four hundred cowpea grain sellers in the study areas. Questionnaire ...

Potassium bromate content of some baked breads sold in Kano ...

African Journals Online (AJOL)

Background: Potassium bromate is an additive used by some bakers to make the bread rise rapidly, create a good texture in the finished product and to give bulkiness to the dough. Objective: The main objective of this work was to assess the potassium bromate residues of some baked breads sold in some selected local ...

Microbial assessment of un-bottled synthetic juices sold in Peshawar

International Nuclear Information System (INIS)

Abid, H.; Ali, J.; Hussain, A.

2010-01-01

Un-bottled synthetic juices are sold by street vendors and hawkers raising the concern about their safety. To examine the quality of un-bottled synthetic beverages from different locations of Peshawar city using Standard techniques. A total of 56 samples of un-bottled synthetic juices were collected from 8 different locations of Peshawar City and analyzed for Total Plate Count, Total Coliform Bacteria, Total Fecal Coliform bacteria E. coli, Yeast and Mould. In all localities, the street vended un-bottled synthetic juices were found hygienically of poor quality as all had high total plate count which ranged from 2 x 102 to 5 x 107 and total coliform bacteria ranged from 110 MPN/ml. Total Fecal Coliform ranged from < 0.3 to 110M PN/ml. The presence of E coli, contamination was found in (25) 44 % Samples, while all the analyzed samples were contaminated with yeasts and moulds. All un-bottled synthetic juices sold on roadside were highly contaminated with disease causing microorganisms. Policy message: Periodic monitoring of street beverage should be carried out to make them safe for consumption. (author)

Eficacia y seguridad de la terbinafina oral en pauta intermitente o pulsátil versus pauta continua para el tratamiento de la onicomicosis en mayores de 18 años

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Ernesto Andrade Cerquera

2016-01-01

Conclusiones. La terbinafina intermitente tiene menor éxito de cura clínica y micológica que la continua; su RR corregido demuestra que la pauta intermitente es 13% menos eficiente que la continua. Clínicamente los hallazgos son significativos pero estadísticamente falta poder en los estudios y un mayor tamaño de muestra agrupado para mejorar la evidencia.

Jornada escolar partida y continua. ¿Existen evidencias que motiven el cambio en la gestión del tiempo escolar en España?

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Francisco José Morales Yago

2017-07-01

Full Text Available El efecto del tipo de jornada escolar (partida frente a continua sobre los resultados de los estudiantes ha sido un tema poco estudiado, aunque conflictivo en el ámbito nacional por sus implicaciones sociales y laborales. Los objetivos generales del trabajo son dos: primero constatar si existe asociación entre resultados académicos y tipo de jornada escolar y, segundo, analizar las preferencias del profesorado por un tipo u otro de jornada y las razones que las motivan. Trascurridas tres décadas desde que comenzó a implantarse la jornada continua en algunas comunidades autónomas, se puede concluir que los progresos académicos esperados han sido reducidos y equiparables a los experimentados por comunidades que han permanecido en jornada escolar partida. Para realizar un estudio de la cuestión desde la percepción del profesorado, se ha utilizado metodología de encuesta (N=400, combinada con entrevistas semiestructuradas (N=30. Los resultados evidencian que los profesores prefieren la jornada escolar continua, aduciendo motivos como la posibilidad de incrementar su formación o menos desplazamientos al centro.

Microbial safety of raw mixed-vegetable salad sold as an ...

African Journals Online (AJOL)

Alex

2012-06-21

Jun 21, 2012 ... A recent popular street vended food is fried rice, which is a good imitation of that sold in Chinese restaurants, especially in the cities. Semi boiled rice is fried in oil with chopped vegetables, soy sauce and egg, and served with tomato ketchup and fried chicken. Kose is fried fritters of dehulled cowpea paste ...

Mycological Assessment of Suya Sold in Some Parts of Minna, Niger ...

African Journals Online (AJOL)

Mycological assessments of Suya sold in some part of Minna were conducted. A total of 20 samples were collected from 10 randomly selected suya spots from ten (10) locations in Minna namely- Tunga, Ungwan Daji , Dutsen Kuran Hausa, Chanchaga, Bosso, Maikunkele, Maitumbi, Kwangila, Barikin Sale and Sayeko.

Schaum's outline of theory and problems of differential equations

CERN Document Server

Bronson, Richard

1994-01-01

If you want top grades and thorough understanding of differential equations, this powerful study tool is the best tutor you can have! It takes you step-by-step through the subject and gives you 563 accompanying problems with fully worked solutions. You also get plenty of practice problems to do on your own, working at your own speed. (Answers at the back show you how you're doing.) Famous for their clarity, wealth of illustrations and examples, and lack of dreary minutiae, Schaum’s Outlines have sold more than 30 million copies worldwide—and this guide will show you why!

Una alternativa de autogestión de los centros de educación continua

OpenAIRE

José Luís Flores Galavíz; J. Jesús Ceja Pizano; Israel Patiño Galván

2013-01-01

La educación continua y a distancia es un mecanismo “ad-hoc” que impulsa a los particulares y a las universidades aún públicas a hacerse de recursos extraordinarios y a auto gestionar su función en el sistema educativo mundial, bajo programas respaldados sobre todo por los Organismos Multinacionales sociales y financieros como a la UNESCO y el Banco Mundial respectivamente, que promueven en la actualidad su adopción en todo el mundo y para el caso de México, esta forma de impartir actualizaci...

Microbiological and physicochemical characterization of shea butter sold on Benin markets

NARCIS (Netherlands)

Honfo, G.F.; Hell, K.; Akissoe, N.H.; Linnemann, A.R.; Coulibaly, O.

2012-01-01

Shea butter, a fat from the nuts of shea tree, is of great nutritional and commercial value for local communities of Africa. The sanitary and physicochemical qualities of shea butter sold in Benin markets are unknown. This study assesses the quality characteristics of 54 samples of shea butter

Antibiotic resistance profile of bacterial isolates from food sold on a ...

African Journals Online (AJOL)

The antibiotic resistance profile of bacterial isolates from cooked food samples sold in different eateries on the campus of the University of Ado-Ekiti was investigated. A total of seventy-eight bacterial isolates belonging to six genera were encountered in the following proportion: Escherichia coli (29.5%), Klebsiella spp.

Marketing and utilization survey of some forest plant tubers sold in ...

African Journals Online (AJOL)

A marketing and utilization survey of some forest plants tubers sold in Abeokuta markets was conducted. Four markets were chosen namely, Itoku, Kuto, Adatan and Iberekodo with ,35, 25, 20, and 20 herb sellers respectively. Hundred percent enumerations of questionnaire were administered in the Markets. The number of ...

Applicability of IHE/Continua components for PHR systems: learning from experiences.

Science.gov (United States)

Urbauer, Philipp; Sauermann, Stefan; Frohner, Matthias; Forjan, Mathias; Pohn, Birgit; Mense, Alexander

2015-04-01

Capturing personal health data using smartphones, PCs or other devices, and the reuse of the data in personal health records (PHR) is becoming more and more attractive for modern health-conscious populations. This paper analyses interoperability specifications targeting standards-based communication of computer systems and personal health devices (e.g. blood pressure monitor) in healthcare from initiatives like Integrating the Healthcare Enterprise (IHE) and Continua Health Alliance driven by industry and healthcare professionals. Furthermore it identifies certain contradictions and gaps in the specifications and suggests possible solutions. Despite these shortcomings, the specifications allow fully functional implementations of PHR systems. Henceforth, both big business and small and medium-sized enterprises (SMEs) can actively contribute to the widespread use of large-scale interoperable PHR systems. Copyright © 2013 Elsevier Ltd. All rights reserved.

Characteristics of illegal and legal cigarette packs sold in Guatemala.

Science.gov (United States)

Arevalo, Rodrigo; Corral, Juan E; Monzon, Diego; Yoon, Mira; Barnoya, Joaquin

2016-11-25

Guatemala, as a party to the Framework Convention on Tobacco Control (FCTC), is required to regulate cigarette packaging and labeling and eliminate illicit tobacco trade. Current packaging and labeling characteristics (of legal and illegal cigarettes) and their compliance with the FCTC is unknown. We sought to analyze package and label characteristics of illegal and legal cigarettes sold in Guatemala. We visited the 22 largest traditional markets in the country to purchase illegal cigarettes. All brands registered on tobacco industry websites were purchased as legal cigarettes. Analysis compared labeling characteristics of illegal and legal packs. Most (95%) markets and street vendors sold illegal cigarettes; 104 packs were purchased (79 illegal and 25 legal). Ten percent of illegal and none of the legal packs had misleading terms. Half of the illegal packs had a warning label covering 26 to 50% of the pack surface. All legal packs had a label covering 25% of the surface. Illegal packs were more likely to have information on constituents and emissions (85% vs. 45%, p Guatemala, neither illegal nor legal cigarette packs comply with FCTC labeling mandates. Urgent implementation and enforcement of the FCTC is necessary to halt the tobacco epidemic.

Microbial analysis of meat and meat products sold in fast food ...

African Journals Online (AJOL)

The present study was carried out to investigate the rate of microbial contamination of ready-to-eat meat and meat products sold in different fast food restaurants in Aba. This study was carried out between June and August, 2015. Samples were collected aseptically from five fast food restaurants using sterile polythene bags.

Acute Porphyria Presenting as Epilepsia Partialis Continua

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Thi Phuoc Yen Tran

2013-06-01

Full Text Available Purpose: The porphyrias are a defect in the biosynthesis of heme which can be associated with different neurological symptoms during acute attacks such as peripheral neuropathy, mental disturbance and seizures. So far, there have only been a few case reports of status epilepticus, none of which were of epilepsia partialis continua (EPC. We present here two cases of hereditary coproporphyria (HCP manifesting EPC as part of the clinical presentation. Method: The patients' medical charts, EEG and imaging studies were carefully reviewed. Results: Case 1 is a 49-year-old male who first presented a tonic-clonic seizure. Case 2 is a 30-year-old male who came to the emergency room for a convulsive status epilepticus. Both evolved to EPC over the next days. EPC persisted despite several antiepileptic drug trials. Diagnosis of HCP was confirmed by a high level of urine, fecal and serum porphyrins in both cases and by genetic testing in one. Over the last 3 years, the first patient has continued to present non-disabling EPC and has had four tonic-clonic seizures associated with alcohol consumption. The second patient died from brain edema one month and half after admission. Conclusion: Acute porphyrias should be included in the differential diagnosis of new onset status epilepticus, including EPC. Their recognition is important as it modifies significantly patient management, since many anticonvulsants are porphyrogenic.

Radioactivity in bottled waters sold in Mexico

International Nuclear Information System (INIS)

Davila Rangel, J.I.; Lopez del Rio, H.; Mireles Garcia, F.; Quirino Torres, L.L.; Villalba, M.L.; Colmenero Sujo, L.; Montero Cabrera, M.E.

2002-01-01

Measurements of gross alpha and beta activities were made on 21 domestic and international brands of bottled (purified and mineral) water sold in the Mexican market to assess its radiological quality. Alpha and beta activities were determined using a liquid-scintillation detector with pulse-shape analysis feature. All the purified water had values of beta activity lower than the limit for potable drinking water (1.0 Bq/l), while three brands surpassed the limit of alpha activity (0.1 Bq/l). The limit for alpha radioactivity content was exceed by three mineral waters; the results show a correlation between radioactivity content and mineral salts, which are related with the origin and treatment of the waters

7 CFR 205.309 - Agricultural products in other than packaged form at the point of retail sale that are sold...

Science.gov (United States)

2010-01-01

... the point of retail sale that are sold, labeled, or represented as âmade with organic (specified..., Labeling, and Market Information § 205.309 Agricultural products in other than packaged form at the point of retail sale that are sold, labeled, or represented as “made with organic (specified ingredients or...

The importance of Thermo-Hydro-Mechanical couplings and microstructure to strain localization in 3D continua with application to seismic faults. Part I: Theory and linear stability analysis

Science.gov (United States)

Rattez, Hadrien; Stefanou, Ioannis; Sulem, Jean

2018-06-01

A Thermo-Hydro-Mechanical (THM) model for Cosserat continua is developed to explore the influence of frictional heating and thermal pore fluid pressurization on the strain localization phenomenon. A general framework is presented to conduct a bifurcation analysis for elasto-plastic Cosserat continua with THM couplings and predict the onset of instability. The presence of internal lengths in Cosserat continua enables to estimate the thickness of the localization zone. This is done by performing a linear stability analysis of the system and looking for the selected wavelength corresponding to the instability mode with fastest finite growth coefficient. These concepts are applied to the study of fault zones under fast shearing. For doing so, we consider a model of a sheared saturated infinite granular layer. The influence of THM couplings on the bifurcation state and the shear band width is investigated. Taking representative parameters for a centroidal fault gouge, the evolution of the thickness of the localized zone under continuous shear is studied. Furthermore, the effect of grain crushing inside the shear band is explored by varying the internal length of the constitutive law.

MOST SOLD CATEGORIES FOOD SUPPLEMENTS IN BULGARIAN PHARMACIES - RESEARCH

OpenAIRE

Elina Petkova1, Kalin Ivanov2, Stanislava Ivanova2*, Stanislav Gueorguiev3, Radiana Staynova3

2017-01-01

The aim of this study is to investigate which are the most sold categories food supplements in Bulgarian pharmacies. The survey covers 820 pharmacies across the country. We have found that the leading category of food supplements is “Immune and digestive health” (41.5%). The second place is for the “Bone and joint health” (12.9%). The “Urology” category (consisted mainly by plant extracts) is about 7.9%. Food supplements in the “Urology” category are not only recommended by pharmacists but of...

Sub-50-as isolated extreme ultraviolet continua generated by 1.6-cycle near-infrared pulse combined with double optical gating scheme

Science.gov (United States)

Oguri, Katsuya; Mashiko, Hiroki; Ogawa, Tatsuya; Hanada, Yasutaka; Nakano, Hidetoshi; Gotoh, Hideki

2018-04-01

We demonstrate the generation of ultrabroad bandwidth attosecond continua extending to sub-50-as duration in the extreme ultraviolet (EUV) region based on a 1.6-cycle Ti:sapphire laser pulse. The combination of the amplitude gating scheme with a sub-two-cycle driver pulse and the double optical gating scheme achieves the continuum generation with a bandwidth of 70 eV at the full width at half maximum near the peak photon energy of 140 eV, which supports a Fourier-transform-limited pulse duration as short as 32 as. The carrier-envelope-phase (CEP) dependence of the attosecond continua shows a single-peak structure originating from the half-cycle cut-off at appropriate CEP values, which strongly indicates the generation of a single burst of an isolated attosecond pulse. Our approach suggests a possibility for isolated sub-50-as pulse generation in the EUV region by compensating for the intrinsic attosecond chirp with a Zr filter.

Epilepsia partialis continua responsive to neocortical electrical stimulation.

Science.gov (United States)

Valentin, Antonio; Ughratdar, Ismail; Cheserem, Beverly; Morris, Robert; Selway, Richard; Alarcon, Gonzalo

2015-08-01

Epilepsia partialis continua (EPC), defined as a syndrome of continuous focal jerking, is a rare form of focal status epilepticus that usually affects a distal limb, and when prolonged, can produce long-lasting deficits in limb function. Substantial electrophysiologic evidence links the origin of EPC to the motor cortex; thus surgical resection carries the risk of significant handicap. We present two patients with focal, drug-resistant EPC, who were admitted for intracranial video-electroencephalography monitoring to elucidate the location of the epileptogenic focus and identification of eloquent motor cortex with functional mapping. In both cases, the focus resided at or near eloquent motor cortex and therefore precluded resective surgery. Chronic cortical stimulation delivered through subdural strips at the seizure focus (continuous stimulation at 60-130 Hz, 2-3 mA) resulted in >90% reduction in seizures and abolition of the EPC after a follow-up of 22 months in both patients. Following permanent implantation of cortical stimulators, no adverse effects were noted. EPC restarted when intensity was reduced or batteries depleted. Battery replacement restored previous improvement. This two-case report opens up avenues for the treatment of this debilitating condition. Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.

Leveraging corporate social responsibility to improve consumer safety of dietary supplements sold for weight loss and muscle building.

Science.gov (United States)

Kulkarni, Anvita; Huerto, Ryan; Roberto, Christina A; Austin, S Bryn

2017-03-01

The potential dangers associated with dietary supplements sold for weight loss and muscle building are well documented and increasingly garnering the attention of the media, public, and government leaders. Public health professionals have an opportunity to improve population health in the context of dietary supplement use by translating scientific evidence into action. In this commentary, we discuss the potential to motivate corporate social responsibility (CSR) among manufacturers and retailers of dietary supplements sold for weight loss and muscle building. We examine levers available to public health professionals for generating voluntary corporate self-regulation by reviewing examples from successful CSR initiatives in other domains of public health and offering recommendations highlighting effective advocacy strategies. We encourage public health professionals to use one or multiple advocacy strategies to improve consumer protections for dietary supplements sold for weight loss and muscle building.

Antioxidant potentials of local fruits and foreign wines sold in Ile-Ife ...

African Journals Online (AJOL)

Some locally consumed fruits, sugarcane and wines sold in Ile-Ife, Nigeria, were investigated for their phenol content and antioxidant potential of the methanolic extracts with a view of exploring the healthpromoting effect of the fruits and wines. The total phenolic content in each fruit and wines was determined ...

La formación continua en España: balance y retos de futuro. [Continous training in spain: situation and challenges

Directory of Open Access Journals (Sweden)

Pilar Pineda Herrero

2007-04-01

Full Text Available The article presents the results of a research on the situation of continuous training in Spain. The study focus on analysing the situation of this area of training, identifying the opinions of the agents involved, and see the challenges that training has to face in the near future. The method used are the interviews to key agents of continuous training. The results show that, although during the last decade training has improved notoriously –both from a quantity and from a quality point of view- there is still a lot to do, specially in the case of small companies and of workers with a low training level. El artículo presenta los resultados de un estudio que pretende analizar la formación continua en España. El estudio describe la situación en que se halla este subsistema de formación, analiza como lo valoran los agentes implicados y apunta los retos de futuro que debe afrontar para ser una estrategia efectiva en el mantenimiento del empleo y la mejora de su calidad. La metodología utilizada es eminentemente cualitativa, centrada en la realización de entrevistas a los agentes clave de la formación continua. Los resultados muestran que, a pesar de que en la última década la formación continua ha mejorado notablemente tanto a nivel de cantidad como de calidad, aun queda mucho camino por recorrer, sobre todo en el caso de las empresas pequeñas y de los colectivos laborales con menos formación.

Peritonitis fúngica en diálisis peritoneal continua ambulatoria: descripción de 10 casos

OpenAIRE

García Martos, P.; Gil de Sola, F.; Marín, P.; García-Agudo, L.; García-Agudo, R.; Tejuca, F.; Calle, L.

2009-01-01

Antecedentes: La peritonitis fúngica es una complicación infrecuente pero grave en pacientes en diálisis peritoneal continua ambulatoria (DPCA). Métodos: Durante un período de 10 años (1999-2008), de un total de 175 pacientes con insuficiencia renal crónica en tratamiento con DPCA, estudiamos retrospectivamente 10 casos de peritonitis fúngica, analizando los factores predisponentes, aspectos clínicos, agentes etiológicos y tratamiento. El diagnóstico se estableció por la presencia de efluente...

Euromech 579 Arpino 3-8 April 2017: Generalized and microstructured continua: new ideas in modeling and/or applications to structures with (nearly)inextensible fibers—a review of presentations and discussions

Science.gov (United States)

Laudato, Marco; Di Cosmo, Fabio

2018-04-01

In the present paper, a rational report on Euromech 579, Generalized and Microstructured Continua: New ideas in modeling and/or Applications to Structures with (nearly)inextensible fibers (Arpino 3-8 April 2017), is provided. The main aim of the colloquium was to provide a forum for experts in generalized and microstructured continua with inextensible fibers to exchange ideas and get informed about the latest research trends in the domain. The interested reader will find more details about the colloquium at the dedicated web page http://www.memocsevents.eu/euromech579.

Microbiological evaluation of drinking water sold by roadside vendors of Delhi, India

Science.gov (United States)

Chauhan, Abhishek; Goyal, Pankaj; Varma, Ajit; Jindal, Tanu

2017-07-01

Delhi has emerged as one of the greenest capital city of the world. Microbiological assessment of drinking water emphasizes estimation of the hygienic quality of the water sold with reference to community health significance. This study was conducted to evaluate the quality of drinking water sold by roadside vendors in east, west, north and south zones of capital of India. A total number of 36 samples (nine from each zone) were collected as per national guidelines and studied for microbiological assessment. All the drinking water samples were collected in gamma-sterilized bottles and were kept in an ice pack to prevent any significant change in the microbial flora of the samples during the transportation. The water samples were transported to the laboratory in vertical position maintaining the temperature 1-4 °C with ice pack enveloped conditions. Samples were analyzed for total MPN coliform per 100 ml and for the presence and absence of common human pathogenic bacteria such as Escherichia coli, Salmonella, Staphylococcus aureus and Pseudomonas aeruginosa. All the samples were found to be contaminated with coliform organisms in the range of 14 to >1600 per 100 ml of sample. Out of 36 water samples, the occurrence of E. coli was 61 %, Salmonella 25 % S. aureus 14 % and P. aeruginosa 53 % as 22, 9, 5 and 19 samples were found contaminated, respectively. The numbers of coliform bacteria and presence of some common pathogenic bacteria suggested that the quality of drinking water sold by roadside vendors is not within the Indian standard and WHO guidelines laid down for drinking water quality. Hence, there is a vital need to study the root cause in terms of hygiene, sanitation of vendors and source of contamination to prevent waterborne diseases.

Educación Médica Continua (EMC

Directory of Open Access Journals (Sweden)

Jorge Dagnino Sepúlveda

2007-08-01

Full Text Available La educación médica continua (EMC puede ser definida como todo medio o conjunto de ellos dirigidos a cambiar la conducta de un médico de manera de mejorar permanentemente los resultados de su actuar con los pacientes, individualmente, en una comunidad o en un sistema de salud. Los modelos prevalentes de EMC no aseguran estos resultados, por lo que es necesario un esfuerzo sostenido y sistemático de todas las partes involucradas: los individuos, las escuelas de Medicina y sociedades científicas, los entes acreditadores y certificadores y las instituciones de salud. La EMC debe ser autodirigida, basada en la responsabilidad individual, iniciarse con la determinación de necesidades de aprendizaje fundada en la práctica diaria, seguir con la identificación de soluciones para los problemas o brechas encontrados, con un aprendizaje experimental y el uso secuencial de diferentes metodologías que mejor aseguren el cambio conductual, el impacto real en el cuidado de los pacientes y su mantención en el tiempo. Para ello, debe iniciarse en el pregrado de la escuela de Medicina, perfeccionarse en el postítulo y seguir durante toda la vida activa del médico. Basar la educación y la práctica en la mejor evidencia disponible, en un enfoque sistémico y en el mejoramiento de la calidad es la mejor esperanza para generar estos resultados y prolongarlos en el tiempo.

Pricing and sales tax collection policies for e-cigarette starter kits and disposable products sold online.

Science.gov (United States)

Cuomo, Raphael E; Miner, Angela; Mackey, Tim K

2015-10-23

Previous studies have examined marketing characteristics of e-cigarettes sold online and others have examined e-cigarettes pricing in retail (non-Internet) settings. This study expands on these findings by examining pricing and marketing characteristics of interest among e-cigarette online vendors. Structured web searches were conducted from August-September 2014 to identify popular e-cigarette Internet vendors. We then collected pricing data (e-cigarette starter kits and disposables), sales tax collection policies and other vendor marketing characteristics. Average price for each product category was then compared with marketing characteristics using linear regression for continuous variables and independent t-tests for binary variables. Our searches yielded 44 e-cigarette Internet vendors of which 77% (n = 34) sold a total of 238 starter kit offerings (Mprice = $55.89). Half (n = 22) sold disposable types of e-cigarettes (Mprice = $7.17 p/e-cigarette) at a price lower than reported elsewhere in retail settings. Average disposable e-cigarette prices were also significantly higher for vendors displaying more health warning notices (P = 0.001). Only 46% disclosed sales tax collection policies and only 39% collected sales tax in their state of business. This study expands on current understanding of e-cigarette pricing and availability online and finds variation in e-cigarette pricing may be influenced by type of product, use of online health warnings and vendor sales tax collection policies. It also finds that e-cigarette online access and availability may be impacted by a combination of pricing and marketing strategies uniquely different from e-cigarette retail settings that requires further study and targeted policy-making. [Cuomo RE, Miner A, Mackey TK. Pricing and sales tax collection policies for e-cigarette starter kits and disposable products sold online. Drug Alcohol Rev 2015]. © 2015 Australasian Professional Society on Alcohol and

40 CFR 152.30 - Pesticides that may be transferred, sold, or distributed without registration.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Pesticides that may be transferred... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PESTICIDE REGISTRATION AND CLASSIFICATION PROCEDURES Exemptions § 152.30 Pesticides that may be transferred, sold, or distributed without registration...

Modeling reactive transport in deformable porous media using the theory of interacting continua.

Energy Technology Data Exchange (ETDEWEB)

Turner, Daniel Zack

2012-01-01

This report gives an overview of the work done as part of an Early Career LDRD aimed at modeling flow induced damage of materials involving chemical reactions, deformation of the porous matrix, and complex flow phenomena. The numerical formulation is motivated by a mixture theory or theory of interacting continua type approach to coupling the behavior of the fluid and the porous matrix. Results for the proposed method are presented for several engineering problems of interest including carbon dioxide sequestration, hydraulic fracturing, and energetic materials applications. This work is intended to create a general framework for flow induced damage that can be further developed in each of the particular areas addressed below. The results show both convincing proof of the methodologies potential and the need for further validation of the models developed.

Chemical Composition and Labeling of Substances Marketed as Selective Androgen Receptor Modulators and Sold via the Internet.

Science.gov (United States)

Van Wagoner, Ryan M; Eichner, Amy; Bhasin, Shalender; Deuster, Patricia A; Eichner, Daniel

2017-11-28

Recent reports have described the increasing use of nonsteroidal selective androgen receptor modulators, which have not been approved by the US Food and Drug Administration (FDA), to enhance appearance and performance. The composition and purity of such products is not known. To determine the chemical identity and the amounts of ingredients in dietary supplements and products marketed and sold through the internet as selective androgen receptor modulators and compare the analyzed contents with product labels. Web-based searches were performed from February 18, 2016, to March 25, 2016, using the Google search engine on the Chrome and Internet Explorer web browsers to identify suppliers selling selective androgen receptor modulators. The products were purchased and the identities of the compounds and their amounts were determined from April to August 2016 using chain-of-custody and World Anti-Doping Association-approved analytical procedures. Analytical findings were compared against the label information. Products marketed and sold as selective androgen receptor modulators. Chemical identities and the amount of ingredients in each product marketed and sold as selective androgen receptor modulators. Among 44 products marketed and sold as selective androgen receptor modulators, only 23 (52%) contained 1 or more selective androgen receptor modulators (Ostarine, LGD-4033, or Andarine). An additional 17 products (39%) contained another unapproved drug, including the growth hormone secretagogue ibutamoren, the peroxisome proliferator-activated receptor-δ agonist GW501516, and the Rev-ErbA agonist SR9009. Of the 44 tested products, no active compound was detected in 4 (9%) and substances not listed on the label were contained in 11 (25%). In only 18 of the 44 products (41%), the amount of active compound in the product matched that listed on the label. The amount of the compounds listed on the label differed substantially from that found by analysis in 26 of 44 products

Lead content of dried films of domestic paints currently sold in Nigeria

International Nuclear Information System (INIS)

Adebamowo, Eugenious O.; Scott Clark, C.; Roda, Sandy; Agbede, Oluwole A.; Sridhar, Mynepalli K.C.; Adebamowo, Clement A.

2007-01-01

Children are at higher risk from lead exposure because their developing neural system is susceptible to its neurotoxic effects. We studied lead levels of paints manufactured in Nigeria in 2006. Lead levels in 5 colors of paints, each from different manufacturers were measured using flame-atomic absorption spectroscopy. We found that 96% of the paints had higher than recommended levels of lead. The mean lead level of paints ranged from 84.8 to 50,000 ppm, with mean of 14,500 ppm and median of 15,800 ppm. The main determinant of lead levels was color of the paint. As lead levels in paint sold in the past years in Nigeria are likely to be at least as high as that currently sold, it is likely that many existing houses contain dangerously high levels of lead. Efforts need to be undertaken to assess the presence of high lead levels in existing housing and if detected, intervention programs for eliminating risk of exposure should be developed in addition to measures to increase awareness and enforce regulations leading to the elimination of lead based domestic paint

Optimal Overhaul-Replacement Policies for Repairable Machine Sold with Warranty

OpenAIRE

Soemadi, Kusmaningrum; Iskandar, Bermawi P; Taroepratjeka, Harsono

2014-01-01

This research deals with an overhaul-replacement policy for a repairable machine sold with Free Replacement Warranty (FRW). The machine will be used for a finite horizon, T (T <), and evaluated at a fixed interval, s (s< T). At each evaluation point, the buyer considers three alternative decisions i.e. Keep the machine, Overhaul it, or Replace it with a new identical one. An overhaul can reduce the machine age virtually, but not to a point that the machine is as good as new. If the mac...

Enablers and inhibitors for sustainability of continuous improvement: A study in the automotive industry suppliers in the Valencia Region Facilitadores y barreras para la sostenibilidad de la mejora continua: Un estudio en proveedores del automóvil de la Comunidad Valenciana

Directory of Open Access Journals (Sweden)

Juan A. Marin-Garcia

2009-04-01

Full Text Available In recent years it has been widely discussed the use of continuous improvement in all kind of business and particularly in companies belonging to the automotive industry. Many authors mention improvements, in key indicators of production through the use of continuous improvement tools. At the same time, different authors talk about how to sustain the continuous improvement over time, and try to identify inhibitors and enablers for the sustainability of continuous improvement. But despite this, one can still find first tier suppliers in the automotive industry which have not implemented systems of continuous improvement. This study aims to identify, classify, prioritize and discuss the different enablers and inhibitors which can be found in automotive suppliers companies. For that reason some interviews were conducted with first tier suppliers in the automotive industry that have succeeded or failed in implementing continuous improvement. We have tried to understand better the problems for the implementation and sustainability of continuous improvement.En los últimos años se ha descrito ampliamente el uso de la mejora continua en todo tipo de empresas y fundamentalmente, en las empresas pertenecientes al sector del automóvil. Muchos autores citan las mejoras de los principales indicadores productivos a través del uso de herramientas de mejora continua. Al mismo tiempo, diferentes autores hablan de cómo poder sostener dicha mejora continua a través del tiempo y tratan de identificar barreras y facilitadores para la sostenibilidad de la mejora continua. Pero, a pesar de ello, se pueden encontrar proveedores de primer nivel del sector del automóvil que no tienen implantados sistemas de mejora continua. El presente estudio tiene por objeto identificar clasificar y priorizar las diferentes barreras y facilitadores que se pueden encontrar en las empresas proveedoras de la industria del automóvil. Para ello se han realizado entrevistas con

Cálculo, mediante la aplicación del algoritmo de ajuste por mínimos cuadrados, de los componentes de velocidad para estaciones GNSS continuas

Directory of Open Access Journals (Sweden)

Jorge Moya Zamora

2014-07-01

Full Text Available El cálculo de la velocidad de una estación de observación continua GNSS representa un insumo fundamental en la geodesia moderna. El hecho de determinar la posición de las estaciones GNSS de forma diaria implica que se puedan establecer las series temporales de las estaciones, con base en las cuales se puede obtener información de la influencia de fenómenos que afecten el comportamiento de estas. En este artículo se plantea una descripción del algoritmo de ajuste por mínimos cuadrados adaptado y aplicado a la determinación de los componentes de velocidad de estaciones de observación continua. Además, se aplica este algoritmo para la calcular la velocidad de la estación ETCG, perteneciente al Sistema Geocéntrico para las Américas (SIRGAS.

Nivel de desempeño en manufactura esbelta, manufactura sustentable y mejora continua

Directory of Open Access Journals (Sweden)

Carlos Monge

2016-02-01

Full Text Available 40 plantas de manufactura medianas (12 y grandes (28 de Apodaca, México, fueron encuestadas para investigar el nivel de implantación de la manufactura esbelta, la manufactura sustentable, la mejora continua y su impacto en la eficiencia operacional y responsabilidad ambiental en ellas. En las dos categorías de plantas se encontró que el desempeño es bajo. En ambos casos es preocupante que en el municipio altamente industrializado de Apodaca, México, no se estén adoptando de manera decisiva las filosofías mencionadas. Finalmente se muestran los resultados estadísticos obtenidos en las respuestas de los gerentes de planta a los ítems del cuestionario. Esta información puede ser útil a la administración de las plantas para identificar y definir acciones específicas de mejora.

Medicinal plants sold in the markets of Antananarivo, Madagascar.

Science.gov (United States)

Randriamiharisoa, Maria Nirina; Kuhlman, Alyse R; Jeannoda, Vololoniaina; Rabarison, Harison; Rakotoarivelo, Nivo; Randrianarivony, Tabita; Raktoarivony, Fortunat; Randrianasolo, Armand; Bussmann, Rainer W

2015-07-28

This study focuses on the large outdoor markets of the capital of Madagascar, Antananarivo. As the largest metropolitan area in Madagascar with a population of nearly two million, the region has great capacity for consumption of medicinal plant remedies despite numerous pharmacies. Medicinal plant use spans all socioeconomic levels, and the diverse metropolitan population allows us to study a wide variety of people who consume these plants for medical purposes. The purpose of this study is to identify and generate a list of medicinal plants sold in the traditional markets with a focus on those collected in the forests around Antananarivo, get an idea of the quantities of medicinal plants sold in the markets around Antananarivo, and assess the economy of the medicinal plant markets. In order to determine which medicinal plants are most consumed in Antananarivo, ethnobotanical enquiries were conducted in the five main markets of the capital city. Ethnobotanical surveys were conducted with medicinal plant traders, suppliers, harvesters and cultivators, with voucher specimens created from the plants discussed. Trade circuit information was established and the income generated by the trade of some of the species was assessed. The inventory of the Antananarivo markets resulted in a list of 89 commercialized plant species. Ten of the 89 were mentioned by 60-100 % of vendors. Profitability for vendors is high and competitive with other salaried positions within Antananarivo. Transportation costs are also high and therefore lower profitability for other members in the supply chain. The markets of Antananarivo have always played a vital cultural role in the lives of urban Malagasy, but our study shows they also play an economic role not only for urban residents but rural harvesters as well. Continued research and monitoring of the non-timber forest products trade in Antananarivo is needed to better understand the impact of trade on the wild plant populations.

Economic cost of electricity sold to new aluminium smelters

International Nuclear Information System (INIS)

Belanger, G.; Bernard, J.T.

2008-01-01

Low cost electricity was a key factor for establishing an aluminium industry in Quebec. Smelters in the province use 50 terawatt hours of electricity per year, which represents 25 per cent of the total consumed in Quebec. This article assessed the profitability of new industrial projects that require large quantities of electricity at a time when the cost of new power plants is increasing. However, electricity is being sold below cost and the difference is subsidized by the government. The investment is justified by the government because these new projects create high paying jobs. The authors presented cases of 2 new aluminium plants, and concluded that they represented a very high economic cost for the province. 1 tab

ANÁLISIS DE LOS ANGULOS LIMITES DE CONDUCCIÓN CONTINUA-DISCONTINUA EN EL REGULADOR CONMUTADO ELEVADOR COMO CFP

Directory of Open Access Journals (Sweden)

Hector S Trujillo Alvarado

2011-03-01

Full Text Available En este trabajo se analizan las formas de onda del regulador conmutado elevador como CFP trabajando parte deltiempo en operación continua y parte del tiempo en operación discontinua. Se evidencia el hecho de que los ánguloslímites de conducción no son simétricos respecto al máximo de la onda como sugieren trabajos publicados por otrosautores. La simulación con PSPICE confirma este hecho y a partir de los resultados de la simulación se calculanteóricamente las contribuciones a la corriente de directa en la carga que aportan las zonas discontinuas y la zonacontinua de forma aproximada. Se propone una vía para el cálculo analítico de la zona de operación continua.  The wave forms of a boost switching regulator working as a PFC part time in the continouos mode of operationand part time on the discontinouos mode are analysed. The fact that the limit conduction angles are not symmetricalwith respect to the maximum of the current (on the contrary of what stated in papers published by other authorsare evidenced. PSPICE simulations confirmed this assertion. From these results the contributions to the DC outputcurrent of the different operating zones are theoretically estimated. It is proposed a way to calculate analiticallythe contribution to the DC output current of the continuous zone.

Revision of the equation Calculated Cetane Index for the characteristics of diesel commercialized in the Parana-Brazil; Revisao da equacao de Calculo do Indice de Cetano para as caracteristicas do diesel comercializado no Parana

Energy Technology Data Exchange (ETDEWEB)

Souza, Tatiana Bittencourt de; Yamamoto, Carlos Itsuo; Cocco, Lilian Cristina [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Lab. de Analise de Combustiveis Automotivos (LACAUTets)

2008-07-01

This work presents the development of models for Calculated Cetane Index (CCI) determination with the purpose of tailor it to the diesel oil sold in Brazil, using optimization techniques. As the diesel is the main fuel on the Brazilian territory, their quality is of great importance. The CCI calculation is important to evaluate the diesel quality. The standard ASTM D 4737 does not take into account the presence of cetane booster additive and biodiesel, which creates the need to recast the equation of the CCI determination. About 300 representative samples were selected of diesel in Parana, during the 2006 to 2007 period, which had their physic-chemical properties determined using the methodology adopted by the ANP - the Brazilian petroleum, natural gas and biofuel agency. The Derived Cetane Number was obtained in the IQT apparatus and several models were proposed, all with better predictive capability than the equation of the standard ASTM D 4737. It is pointed out that biodiesel can act as cetane booster additive depending upon its origin, mostly in concentrations above 5%. The methodology can be expanded to generate a representative equation for the diesel sold in the whole Brazilian territory. (author)

Actividades de evaluación continua y valoración del estudiante: Estudio sobre su correlación

OpenAIRE

Pastor, Isidro M.; Trillo Alarcón, María Paz; Alonso, Diego A.; Albert-Soriano, María; Gómez-Martínez, Melania; Baeza, Alejandro; Ramón, Diego J.; Guillena, Gabriela; Chinchilla, Rafael; Gómez Lucas, Cecilia

2016-01-01

Nuestro grupo de investigación en docencia del Departamento de Química Orgánica viene desarrollando, en los últimos cursos, estudios sobre la influencia de la evaluación continua (EC) en la calificación final. En general, las calificaciones obtenidas durante el semestre en las diferentes acciones de la EC mejoran las notas finales de los estudiantes. De especial importancia son los créditos asociados a prácticas de laboratorio y la resolución de problemas. En el estudio se ha considerado la v...

Detection of genetically modified DNA in fresh and processed foods sold in Kuwait.

Science.gov (United States)

Al-Salameen, Fadila; Kumar, Vinod; Al-Aqeel, Hamed; Al-Hashash, Hanadi; Hejji, Ahmed Bin

2012-01-01

Developments in genetic engineering technology have led to an increase in number of food products that contain genetically engineered crops in the global market. However, due to lack of scientific studies, the presence of genetically modified organisms (GMOs) in the Kuwaiti food market is currently ambiguous. Foods both for human and animal consumption are being imported from countries that are known to produce GM food. Therefore, an attempt has been made to screen foods sold in the Kuwaiti market to detect GMOs in the food. For this purpose, samples collected from various markets in Kuwait have been screened by SYBR green-based real time polymerase chain reaction (RT-PCR) method. Further confirmation and GMO quantification was performed by TaqMan-based RT-PCR. Results indicated that a significant number of food commodities sold in Kuwait were tested positive for the presence of GMO. Interestingly, certain processed foods were tested positive for more than one transgenic events showing complex nature of GMOs in food samples. Results of this study clearly indicate the need for well-defined legislations and regulations on the marketing of approved GM food and its labeling to protect consumer's rights.

La formación continua en el sector financiero: implicaciones para las mujeres de más de 45 años

Directory of Open Access Journals (Sweden)

ESTHER FERNÁNDEZ MOSTAZA

2003-01-01

Full Text Available El objeto de estudio es la descripción de las actuaciones en formación continua que actualmente operan en el sector de la intermediación financiera, y más concretamente en el colectivo de mujeres de entre 45 y 55 años, empleadas en el sector bancario durante más de veinte años dentro de categorías poco cualificadas. Con la intención de poner de manifiesto que los determinantes de quién recibe formación en la empresa están muy relacionados con los costes y rendimiento de la inversión en capital humano, dos grandes cuestiones vertebran el núcleo fundamental del artículo: en primer lugar, ¿qué características definen y diferencian la generación de mujeres a la que nos referimos? Una vez trazadas las características, la cuestión es: ¿se benefician estas mujeres de los programas de formación continua de las empresas? Y si no es así, ¿por qué?

Quantitative spectroscopy of X-ray lines and continua in tokamaks

International Nuclear Information System (INIS)

Peacock, N.J.; Lawson, K.D.; Patel, A.; Barnsley, R.; Melnick, I.M.; O'Mullane, M.G.; Singleton, M.A.

1996-10-01

Crystal and synthetic multilayer diffractors, deployed either as flat Bragg reflectors, or curved, as in the Johann configuration, are used to study the spectrum of COMPASS-D and other tokamaks in the wavelength region 1-100 A. In this paper we concentrate on the measurement of absolute photon fluxes and the derivation of volume emissivities of the lines and continua in the X-ray region. The sensitivities of these instruments to absolute photon flux have been constructed ab initio from the individual component efficiencies, including published values of the diffractor reflectivities, which have been checked or supplemented by measurements using a double-axis goniometer or from line branching ratios. For these tokamak plasmas where the elemental abundances and effective ion charge are documented, the X-ray continuum intensity itself has been used as a calibration source to derive absolute instrument sensitivity, in reasonable agreement with the ab initio method. In the COMPASS-D tokamak, changes in the effective ion charge state, Z eff , have been derived for different operating conditions, from the absolute intensity of the continuum at ∼4 A. From the irradiances of the line emission, changes in the absolute level of impurities following ''boronisation'' of the vacuum vessel have also been documented. (UK)

Availability of Paracetamol Sold Over-the-Counter in Europe

DEFF Research Database (Denmark)

Morthorst, Britt Reuter; Erlangsen, Annette; Nordentoft, Merete

2018-01-01

Due to the risk of hepatotoxicity when excessive amounts of paracetamol are consumed, Poisons Information Centers (PICs) frequently receive paracetamol-related enquiries. This study examined how widely pack size restrictions of paracetamol sold over-the-counter have been implemented in Europe...... and also availability of paracetamol through non-pharmacy outlets and their possible associations with frequency of poisoning enquiries. A cross-sectional European multicentre questionnaire study was performed using a questionnaire to identify the extent and nature of paracetamol pack size restrictions......, non-pharmacy outlet sales and the frequency of paracetamol-related enquiries to PICs. In total, 21 European countries participated. All PICs provided telephone hotline services. In 14 (67%) countries, pack size restrictions had been implemented in pharmacies (range: 8-30 grams). No significant...

Evaluation of Parasitic Pollution in Fresh Unwashed Herbs Sold in Izeh City, Iran

Directory of Open Access Journals (Sweden)

Valipour Nouroozi

2015-11-01

Full Text Available Background Fresh herbs are a crucial part of a good diet. However, they can easily become contaminated with food-borne pathogens. Eating fresh unwashed or improperly washed herbs has a major role in transmission of some important parasitic diseases. Objectives This study was carried out to evaluate parasitic pollution in fresh unwashed herbs sold in Izeh city, Iran. Materials and Methods Four hundred samples of fresh unwashed herbs were purchased from a distributor in Izeh city during January 2014 to April 2015. Detergent solution was added to 240 g of each sample. The mixture was shaken and washed solution was filtered through 0.2 µm bottle-top filter. The filtrate was discarded and filter was placed in a 50 mL conical screw cap tube. Then, the detergent solution was added. Following vortex, filter was discarded. The sediment was examined by light microscope after centrifuge. Finally, data descriptive analyses were carried out. Results Parasitic pollution was detected in 3.5% of the examined samples, including Cryptosporidium spp. oocyst (1.5%, Giardia spp. cyst (1%, Blastocystis spp. cyst (0.5% and Taenia spp. egg (0.5%. Conclusions Parasitic contamination of fresh herbs sold in Izeh may pose a health risk to consumers if eaten as unwashed or improperly washed.

Nutrition Standards for Food Service Guidelines for Foods Served or Sold in Municipal Government Buildings or Worksites, United States, 2014.

Science.gov (United States)

Onufrak, Stephen J; Zaganjor, Hatidza; Moore, Latetia V; Carlson, Susan; Kimmons, Joel; Galuska, Deborah

2016-12-22

The Institute of Medicine and Centers for Disease Control and Prevention have recommended that government agencies use nutrition standards for foods and beverages sold and provided at their facilities. In this study, we examine written nutrition standards for foods sold or served in local government buildings or worksites among US municipalities. We used data from a 2014 national survey of 1,945 municipal governments serving populations of 1,000 or more to assess the presence of written nutrition standards, the food groups or nutrients addressed by standards, and the populations served by facilities where standards are applied. The prevalence of standards was estimated by municipality population size, rural-urban status, census region, poverty prevalence, education level, and racial/ethnic composition. Overall, 3.2% of US municipalities reported nutrition standards with greater prevalence observed among large municipalities (12.8% of municipalities with ≥50,000 people vs 2.2% of municipalities with <2,500 people, P < .001). Prevalence differed by region, and standards were most common in the West (6.6%) and least common in the Midwest (2.0%, P = .003).The most common nutrition topics addressed in standards were offering low-calorie beverages, fruits and vegetables, and free drinking water. Most standards applied to facilities serving government employees (67%) or the general public (66%), with fewer serving institutionalized populations (23%). Few municipal governments reported having written nutrition standards for foods and beverages sold in their facilities in 2014. Implementing nutrition standards for foods sold or served by local governments is a strategy for increasing access to healthier foods and beverages among municipal employees and local residents.

Sweet and salty. An assessment of the snacks and beverages sold in vending machines on US post-secondary institution campuses.

Science.gov (United States)

Byrd-Bredbenner, Carol; Johnson, Michelle; Quick, Virginia M; Walsh, Jennifer; Greene, Geoffrey W; Hoerr, Sharon; Colby, Sarah M; Kattelmann, Kendra K; Phillips, Beatrice W; Kidd, Tandalayo; Horacek, Tanya M

2012-06-01

This study assessed the nutritional quality of snacks and beverages sold in vending machines. The contents of snack and beverage vending machines in 78 buildings on 11 US post-secondary education campuses were surveyed. Of the 2607 snack machine slots surveyed, the most common snacks vended were salty snacks (e.g., chips, pretzels) and sweets (i.e., candy and candy bars). The 1650 beverage machine slots assessed contained twice as many sugar-sweetened beverages as non-calorie-containing beverages. Only two institutions sold both milk and 100% juice in vending machines. The portion of snacks and beverages sold averaged more than 200 cal. Neither snacks nor beverages were nutrient dense. The majority of snacks were low in fiber and high in calories and fat and almost half were high in sugar. Most beverages were high in calories and sugar. This study's findings suggest that vending machines provide limited healthful choices. Findings from benchmark assessments of components of the food environment, like the vending options reported here, can provide valuable input to campus administrators, health services, food service, and students who want to establish campus policies to promote healthful eating. Copyright © 2012 Elsevier Ltd. All rights reserved.

Inventarios probabilísticos con demanda independiente de revisión continua, modelos con nuevos pedidos

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Francy Ríos

2008-01-01

Full Text Available El propósito de este trabajo es explicar el sistema de inventario probabilístico con demanda independiente y revisión continua, con nuevos pedidos. Este análisis se realiza considerando la importancia que este tipo de modelos tiene para la adecuada toma de decisiones sobre la adquisición y manejo óptimo de recursos en las empresas. Estos modelos se caracterizan por poseer una demanda y/o tiempo de suministro variables en el tiempo y la necesidad o demanda del artículo es generada como consecuencia de las decisiones de muchos actores ajenos a la cadena logística (clientes o consumidores, por lo que la empresa no tiene control de la misma.

Parasitic contamination of fresh vegetables sold at central markets in Khartoum state, Sudan

OpenAIRE

Mohamed, Mona Ali; Siddig, Emmanuel Edwar; Elaagip, Arwa Hassan; Edris, Ali Mahmoud Mohammed; Nasr, Awad Ahmed

2016-01-01

Background Fresh vegetables are considered as vital nutrients of a healthy diet as they supply the body with essential supplements. The consumption of raw vegetables is the main way for transmission of intestinal parasitic organisms. This study was aimed at detecting the parasitic contamination in fresh vegetables sold in two central open-aired markets in Khartoum state, Sudan. Methods In this prospective cross-sectional study, a total of 260 fresh vegetable samples and 50 water samples used ...

The Trading Balance Sheet Of Romania - Two Decades With An Annual Adverse Sold

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Simona Corina GUDEI

2011-03-01

Full Text Available The current communication, expressing the entirely special importance that must be granted to the fact that for two decades, year after year, the sold of the trading balance sheet of Romania was adverse. Moreover, it has increased greatly during the decade 2000-2009 towards the previous decade 1990-1999, respectively from 20 milliards dollars to 100 milliards of dollars, with especially serious consequences both on the external and on the internal economic balance.

Trace elements in rock phosphates and P containing mineral and organo-mineral fertilizers sold in Germany

Energy Technology Data Exchange (ETDEWEB)

Kratz, Sylvia, E-mail: sylvia.kratz@jki.bund.de; Schick, Judith; Schnug, Ewald

2016-01-15

68 rock phosphates and 162 P containing (organo-)mineral fertilizers sold in Germany were evaluated with regard to trace element contents. While Al, As, B, Be, Cd, Cr, Mo, Ni, Pb, Sb, Se, Tl, U, and Zn were higher in sedimentary than in igneous rock phosphates, the opposite was true for Co, Cu, Sn, Mn, Ti, Fe, and Sr. Comparing element concentrations to the currently valid legal limit values defined by the German Fertilizer Ordinance, it was found that some PK and many straight P fertilizers (superphosphate, triple superphosphate, partly acidulated rock phosphates) exceeded the limit of 50 mg Cd/kg P{sub 2}O{sub 5}. Mean values for As, Ni, Pb, and Tl remained below legal limits in almost all cases. While no legal limit has been defined for U in Germany yet, the limit of 50 mg U/kg P{sub 2}O{sub 5} for P containing fertilizers proposed by the German Commission for the Protection of Soils was clearly exceeded by mean values for all fertilizer types analyzed. A large share of the samples evaluated in this work contained essential trace elements at high concentrations, with many of them not being declared as such. Furthermore, trace elements supplied with these fertilizers at a fertilization rate leveling P uptake would exceed trace element uptake by crops. This may become most relevant for B and Fe, since many crops are sensitive to an oversupply of B, and Fe loads exceeding plant uptake may immobilize P supplies for the crops by forming Fe phosphate salts. The sample set included two products made from thermochemically treated sewage sludge ash. The products displayed very high concentrations of Fe and Mn and exceeded the legal limit for Ni, emphasizing the necessity to continue research on heavy metal removal from recycled raw materials and the development of environmentally friendly and agriculturally efficient fertilizer products. - Highlights: • Mineral fertilizers (MF) sold in Germany often exceed legal limits for Cd • MF sold in Germany contain high

Revisión de literatura sobre mejora continua en MIPYMEs iberoamericanas

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Carmen Patricia Jiménez Terrazas

2014-01-01

Full Text Available Este artículo presenta una revisión sistemática cualitativa de literatura de investigacio - nes aplicadas de mejora continua en MIPYMEs iberoamericanas y busca responder las siguientes preguntas: ¿cuáles son sus características (objetivos investigados, tipo y método de investigación y poblaciones donde se realizan? y ¿cuáles son los hallazgos encontrados? Los resultados analizan catorce investigaciones aplicadas cuyos objetivos de investigación se agrupan en tres temáticas principales: sostenibilidad, productividad e implementación. El 43% de las investigaciones son cualitativas y usan los métodos de caso de estudio y entrevistas, y un 43% son de enfoque cuantitativo y utilizan mé - todos de encuesta y cuestionario. La población más estudiada fueron las empresas, con 42.8%, y el país donde más se han realizado este tipo de investigaciones es España, con 35.7%. Los hallazgos incluyen identificación de barreras y facilitadores, niveles para su sostenibilidad, herramientas y técnicas con que se implementan, algunos relacionados con la productividad y con aspectos de abandono en su implementación.

Transferencia de calor en la colada continua de aceros. I parte. El molde

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Cicutti, C.

1997-10-01

Full Text Available The continuous casting mold plays the important role of receiving the liquid steel and allowing an uniform and defect free solidified skin to be developed. In this work, the different heat transfer mechanisms which are present from the liquid steel to the mold cooling water are reviewed. The effect of operating variables on heat extraction and the relationship between global and distributed heat flux are also analyzed.

El molde de colada continua cumple la importante función de recibir el acero líquido y permitir que se desarrolle una capa solidificada uniforme y libre de defectos. En este trabajo se revisan los distintos mecanismos implicados en el proceso de transferencia de calor, desde el acero líquido hasta el agua de refrigeración del molde. Se analiza también el efecto de las distintas variables de funcionamiento en la extracción calórica producida y la relación entre el flujo global de calor y su distribución a lo largo del molde.

Isolation of pathogenic Escherichia coli from buffalo meat sold in Parbhani city, Maharashtra, India

OpenAIRE

M. S. Vaidya; N. M. Markandeya; R. N. Waghamare; C. S. Shekh; V. V. Deshmukh

2013-01-01

Aim: Isolation, characterization, in-vitro pathogenicity and antibiogram study of E.coli from buffalo meat sold in Parbhani city. Materials and Methods: Meat samples were collected from buffalo immediately after slaughter. Isolation, identification and enumeration of E. coli were done by following standard methods and protocols. Hemolysin test and Congo red binding assay were used to study in-vitro pathogenicity of E. coli isolates. Disc diffusion method was used to study antibiogram of patho...

Palytoxin Found in Palythoa sp. Zoanthids (Anthozoa, Hexacorallia) Sold in the Home Aquarium Trade

OpenAIRE

Deeds, Jonathan R.; Handy, Sara M.; White, Kevin D.; Reimer, James D.

2011-01-01

Zoanthids (Anthozoa, Hexacorallia) are colonial anemones that contain one of the deadliest toxins ever discovered, palytoxin (LD(50) in mice 300 ng/kg), but it is generally believed that highly toxic species are not sold in the home aquarium trade. We previously showed that an unintentionally introduced zoanthid in a home aquarium contained high concentrations of palytoxin and was likely responsible for a severe respiratory reaction when an individual attempted to eliminate the contaminant co...

Hemicrania continua: Case series presenting in an orofacial pain clinic.

Science.gov (United States)

Hryvenko, Iryna; Cervantes-Chavarría, Andrés R; Law, Alan S; Nixdorf, Donald R

2018-01-01

Aim of investigation Hemicrania continua (HC) is an uncommon primary headache and little is known of the characteristics of such patients managed in an orofacial pain setting. This study provides clinical features of HC, its association with other disorders, and treatment outcomes of patients managed in the TMD and Orofacial Pain Clinic at the University of Minnesota. Methods A retrospective review of patient records was undertaken. Inclusion criteria were a diagnosis of HC and confirmation at follow-up. Results Six of the 1617 new patients seen between 2015 and 2017 met the selection criteria. Four patients presented with "facial pain", one with "toothache" and one with "jaw pain". All were female with mean age 55 ± 10.5 years (range = 41-69). Headache characteristics included unilateral (R:L = 1:1) pain of moderate intensity with severe exacerbations in the distribution of V 1 (1/6), V 1  + V 2 (3/6) and V 1  + V 2  + V 3 (2/6). Lacrimation and photophobia were the most common associated symptoms. Patient presentations were complicated by multiple medical and comorbid diagnoses. All were diagnosed with temporomandibular disorder (TMD). Indomethacin alone was sufficient for adequate headache control in 2/6 patients with several add-on medications providing sustained pain relief. Conclusions Comorbid pain conditions can be expected in patients with HC presenting to orofacial pain clinics. Symptom presentation varies, and multimodal treatment approach is necessary for success.

Nonhost resistance to rust pathogens - a continuation of continua.

Science.gov (United States)

Bettgenhaeuser, Jan; Gilbert, Brian; Ayliffe, Michael; Moscou, Matthew J

2014-01-01

The rust fungi (order: Pucciniales) are a group of widely distributed fungal plant pathogens, which can infect representatives of all vascular plant groups. Rust diseases significantly impact several crop species and considerable research focuses on understanding the basis of host specificity and nonhost resistance. Like many pathogens, rust fungi vary considerably in the number of hosts they can infect, such as wheat leaf rust (Puccinia triticina), which can only infect species in the genera Triticum and Aegilops, whereas Asian soybean rust (Phakopsora pachyrhizi) is known to infect over 95 species from over 42 genera. A greater understanding of the genetic basis determining host range has the potential to identify sources of durable resistance for agronomically important crops. Delimiting the boundary between host and nonhost has been complicated by the quantitative nature of phenotypes in the transition between these two states. Plant-pathogen interactions in this intermediate state are characterized either by (1) the majority of accessions of a species being resistant to the rust or (2) the rust only being able to partially complete key components of its life cycle. This leads to a continuum of disease phenotypes in the interaction with different plant species, observed as a range from compatibility (host) to complete immunity within a species (nonhost). In this review we will highlight how the quantitative nature of disease resistance in these intermediate interactions is caused by a continuum of defense barriers, which a pathogen needs to overcome for successfully establishing itself in the host. To illustrate continua as this underlying principle, we will discuss the advances that have been made in studying nonhost resistance towards rust pathogens, particularly cereal rust pathogens.

Hemicrania continua: clinical review, diagnosis and management

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Prakash S

2017-06-01

Full Text Available Sanjay Prakash,1 Payal Patel2 1Department of Neurology, Smt. B. K. Shah Medical Institute and Research Centre, Sumandeep Vidyapeeth University, Vadodara, Gujarat, India; 2Department of Neurology, Cleveland Clinic Foundation, Cleveland, OH, USA Abstract: Hemicrania continua (HC is an indomethacin-responsive primary headache disorder which is currently classified under the heading of trigeminal autonomic cephalalgias (TACs. It is a highly misdiagnosed and underreported primary headache. The pooled mean delay of diagnosis of HC is 8.0 ± 7.2 years. It is not rare. We noted more than 1000 cases in the literature. It represents 1.7% of total headache patients attending headache or neurology clinic. Just like other TACs, it is characterized by strictly unilateral pain in the trigeminal distribution, cranial autonomic features in the same area and agitation during exacerbations/attacks. It is different from other TACs in one aspect. While all other TACs are episodic, HC patients have continuous headaches with superimposed severe exacerbations. The central feature of HC is continuous background headache. However, the patients may be worried only for superimposed exacerbations. Focusing only on exacerbations and ignoring continuous background headache are the most important factors for the misdiagnosis of HC. A large number of patients may have migrainous features during exacerbation phase. Up to 70% patients may fulfill the diagnostic criteria for migraine during exacerbations. Besides migraine, its exacerbations can mimic a large number of other primary and secondary headaches. The other specific feature of HC is a remarkable response to indomethacin. However, a large number of patients develop side effects because of the long-term use of indomethacin. A few other medications may also be effective in a subset of patients with HC. Various surgical interventions have been suggested for patients who are intolerant to indomethacin. Several aspects of HC

Palytoxin found in Palythoa sp. zoanthids (Anthozoa, Hexacorallia sold in the home aquarium trade.

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Jonathan R Deeds

2011-04-01

Full Text Available Zoanthids (Anthozoa, Hexacorallia are colonial anemones that contain one of the deadliest toxins ever discovered, palytoxin (LD(50 in mice 300 ng/kg, but it is generally believed that highly toxic species are not sold in the home aquarium trade. We previously showed that an unintentionally introduced zoanthid in a home aquarium contained high concentrations of palytoxin and was likely responsible for a severe respiratory reaction when an individual attempted to eliminate the contaminant colonies using boiling water. To assess the availability and potential exposure of palytoxin to marine aquarium hobbyists, we analyzed zoanthid samples collected from local aquarium stores for palytoxin using liquid chromatography and high resolution mass spectrometry and attempted to identify the specimens through genetic analysis of 16S and cytochrome c oxidase 1 (COI markers. We found four specimens of the same apparent species of zoanthid, that we described previously to be responsible for a severe respiratory reaction in a home aquarium, to be available in three aquarium stores in the Washington D.C. area. We found all of these specimens (n = 4 to be highly toxic with palytoxin or palytoxin-like compounds (range 0.5-3.5 mg crude toxin/g zoanthid. One of the most potent non-protein compounds ever discovered is present in dangerous quantities in a select species of zoanthid commonly sold in the home aquarium trade.

Palytoxin found in Palythoa sp. zoanthids (Anthozoa, Hexacorallia) sold in the home aquarium trade.

Science.gov (United States)

Deeds, Jonathan R; Handy, Sara M; White, Kevin D; Reimer, James D

2011-04-04

Zoanthids (Anthozoa, Hexacorallia) are colonial anemones that contain one of the deadliest toxins ever discovered, palytoxin (LD(50) in mice 300 ng/kg), but it is generally believed that highly toxic species are not sold in the home aquarium trade. We previously showed that an unintentionally introduced zoanthid in a home aquarium contained high concentrations of palytoxin and was likely responsible for a severe respiratory reaction when an individual attempted to eliminate the contaminant colonies using boiling water. To assess the availability and potential exposure of palytoxin to marine aquarium hobbyists, we analyzed zoanthid samples collected from local aquarium stores for palytoxin using liquid chromatography and high resolution mass spectrometry and attempted to identify the specimens through genetic analysis of 16S and cytochrome c oxidase 1 (COI) markers. We found four specimens of the same apparent species of zoanthid, that we described previously to be responsible for a severe respiratory reaction in a home aquarium, to be available in three aquarium stores in the Washington D.C. area. We found all of these specimens (n = 4) to be highly toxic with palytoxin or palytoxin-like compounds (range 0.5-3.5 mg crude toxin/g zoanthid). One of the most potent non-protein compounds ever discovered is present in dangerous quantities in a select species of zoanthid commonly sold in the home aquarium trade.

SALMONELLA SPECIE AND TOTAL VIABLE BACTERIAL LOAD IN ROASTED CHICKENS SOLD IN JOS-NIGERIA

OpenAIRE

Carol Okoli; Okonji M.C; Ugoh S.C; Okolo S.N; Okoli A.C; Alu A.J

2007-01-01

The study was to investigate for the presence of Salmonella specie and total viable aerobic bacterial load in roasted chickens sold in Jos. The study was carried out on twenty five chicken samples. No salmonella specie was isolated from the samples. However, other bacterial organisms were isolates, viz: 9(36%) of the samples yielded E.coli; 5(20%) yielded Citobacter species; 3(12%) yielded Proteus species and 6(24%) yielded Klebsiella species while 2(8%) showed no growth. An average total via...

Integrating Positive and Clinical Psychology: Viewing Human Functioning as Continua from Positive to Negative Can Benefit Clinical Assessment, Interventions and Understandings of Resilience

OpenAIRE

Johnson, J; Wood, AM

2017-01-01

In this review we argue in favour of further integration between the disciplines of positive and clinical psychology. We argue that most of the constructs studied by both positive and clinical psychology exist on continua ranging from positive to negative (e.g., gratitude to ingratitude, anxiety to calmness) and so it is meaningless to speak of one or other field studying the “positive” or the “negative”. However, we highlight historical and cultural factors which have led positive and clinic...

Sodium, Sugar and Fat Content of Complimentary Infant and Toddler Foods Sold in the United States, 2015

Science.gov (United States)

In 2012, 72% of commercial toddler meals contained >210 mg/serving of sodium and >70% of infant and toddler snacks, desserts, and juice drinks contained one or more added sugars. The objective is to update the sodium, sugar and fat values of commercial infant and toddler foods sold in the U.S. in 20...

KAJIAN TERHADAP BEBERAPA METODE PENYUSUTAN DAN PENGARUHNYA TERHADAP PERHITUNGAN BEBAN POKOK PENJUALAN (COST OF GOOD SOLD

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Juniady Slamed Setiawan

2001-01-01

Full Text Available Every company must generate financial statement, that provide information about income, changes in financial position to whom that concerned. In preparing financial statement, each company has a power to choose the accounting methods and technics that recommended by Financial Accounting Standard. Accounting policies adopted by firm has a substanstial impact in financial statement.Therefore the company that has equal performance will report different result.This article try to present the impact of choosing depreciation method in calculating cost of goods sold. Abstract in Bahasa Indonesia : Setiap perusahaan wajib menerbitkan laporan keuangan, yang memberikan informasi mengenai hasil usaha, perubahan posisi keuangan kepada pihak yang memerlukan. Dalam menyusun laporan keuangan, perusahaan memiliki keleluasaan untuk memilih metode dan teknik sepanjang metode yang dipilih tersebut ada dalam SAK (Standar Akuntansi Keuangan. Pemilihan metode akuntansi memiliki dampak yang sangat besar terhadap laporan keuangan yang dihasilkan. Dengan demikian dimungkinkan perusahaan yang sebenarnya memiliki kinerja yang sama dapat melaporkan hasil yang berbeda. Tulisan ini mencoba untuk mengetengahkan dampak pemilihan metode penyusutan terhadap perhitungan beban pokok penjualan (cost of goods sold. Kata kunci: metode penyusutan, beban penyusutan, aktiva tetap, beban pokok penjualan.

Modelización global del proceso de colada continua

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Barco, J.

2005-12-01

Full Text Available In the continuous casting process the contribution of complicated physical phenomena has an important effect in the final quality of the product and productivity of the process. Moreover, the different physical phenomena do not act in isolation, they interact in a coupled way affecting the quality of the semiproduct. Therefore, a correct design and setting is a work that requires a good knowledge of the different phenomena that are present and their interactions. In this work, a simulation methodology that solves all the process as a whole is presented, where the variables of the process are the only boundary conditions. The interactions between the different phenomena are solved with the use of commercial applications (FLUENT and ABAQUS and home developed models.

En el proceso de colada continua contribuyen complicados fenómenos físicos con un marcado efecto en la calidad final del producto y en la productividad del proceso. Además, los distintos fenómenos físicos no aparecen de forma aislada, sino que interactúan unos con otros de manera acoplada, afectando a la calidad del semiproducto. El correcto diseño y ajuste es, por lo tanto, una tarea que requiere un gran conocimiento tanto de los distintos fenómenos que intervienen como de sus interacciones. En este trabajo se presenta un novedoso método de simulación que resuelve el proceso en su conjunto, siendo las variables del proceso las únicas condiciones de contorno. Mediante la utilización conjunta de herramientas comerciales (FLUENT y ABAQUS y una serie de modelos de desarrollo propio se resuelven las interacciones entre los distintos fenómenos.

Steroid-Responsive Epilepsia Partialis Continua with Anti-Thyroid Antibodies: A Spectrum of Hashimoto's Encephalopathy

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Hiroki Masuda

2014-05-01

Full Text Available Background: When a neuropsychiatric symptom due to encephalopathy develops in a patient with anti-thyroid antibodies, especially when the symptom is steroid-responsive, Hashimoto's encephalopathy (HE needs to be included in the differential diagnosis of the patient. Although HE is an elusive disease, it is thought to cause various clinical presentations including seizures, myoclonus, and epilepsia partialis continua (EPC. Case Report: We present the case of a 33-year-old Japanese woman who acutely developed EPC in the right hand as an isolated manifestation. A thyroid ultrasound showed an enlarged hypoechogenic gland, and a thyroid status assessment showed euthyroid with high titers of thyroid antibodies. A brain MRI revealed a nodular lesion in the left precentral gyrus. Corticosteroid treatment resulted in a cessation of the symptom. Conclusions: A precentral nodular lesion can be responsible for steroid-responsive EPC in a patient with anti-thyroid antibodies and may be caused by HE. The serial MRI findings of our case suggest the presence of primary demyelination, with ischemia possibly due to vasculitis around the demyelinating lesion.

Diagnóstico de necesidades de educación continua mediante un método grupal y un método individual

OpenAIRE

Maya-Ampudia, Claudia Catalina; Ángeles-Zavala, Oswaldo; Camarena-Olmedo, Javier Alejandro

2014-01-01

Introducción: La educación continua debe responder a las necesidades sociales de salud dentro del contexto histórico y social de los profesionistas, para lo cual es necesario contar con información precisa sobre las necesidades de actualización del personal en salud. El método tradicional comúnmente utiliza una encuesta individual, e identifica las necesidades individuales o sentidas del personal, sin referencia a las necesidades reales de la institución, ni del equipo de salud. Un método gru...

Presence of Streptococcus faecalis in the White Cheese Sold in Kahramanmaraş (Turkish with English Abstract)

OpenAIRE

Erdoğrul, Özlem Turgay; Dığak, Metin

2014-01-01

In this study the presence of Streptococcus faecalis in the white cheeses made from pasteurize milk sold in Kahramanmaraş were examined. For this purpose, 22 cheese samples were taken. At the end of this study, all of the samples have Streptococcus faecalis (100%). It was concluded that the examined white cheese samples were inadequate from in reads of hygienic quality by Streptococcus faecalis.

Epilepsia partialis continua present with shoulder joint-trunk-hip joint rhythmic clonic seizure: a case report

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Lv YD

2016-09-01

Full Text Available Yudan Lv, Zan Wang, Fengna Chu, Chang Liu, Hongmei Meng Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, ChangChun, People’s Republic of China Abstract: Epilepsia partialis continua (EPC is a particular type of epilepsy which is distinguished from “common epilepsy” by its characteristic semiological features. However, unusual manifestations should be described in order to give awareness at clinical diagnosis. In this case report we describe a rare EPC case not previously reported, in which left shoulder joint-trunk-hip joint jerk was present for 1 week. Abnormal electroencephalogram and cerebrospinal fluid results supported a diagnosis of viral encephalitis. Antiepileptic treatment seemed effective. Our report emphasizes that a detailed functional anatomical analysis and synchronized electroencephalogram discharge should be done to avoid misdiagnosis in patients with synchronic shoulder-trunk-hip jerk symptoms. Keywords: EPC, shoulder-trunk-hip, EEG, clonic seizure, virus encephalitis

Household expenditures on dietary supplements sold for weight loss, muscle building, and sexual function: Disproportionate burden by gender and income.

Science.gov (United States)

Austin, S Bryn; Yu, Kimberly; Liu, Selena Hua; Dong, Fan; Tefft, Nathan

2017-06-01

Dietary supplements sold for weight loss (WL), muscle building (MB), and sexual function (SF) are not medically recommended. They have been shown to be ineffective in many cases and pose serious health risks to consumers due to adulteration with banned substances, prescription pharmaceuticals, and other dangerous chemicals. Yet no prior research has investigated how these products may disproportionately burden individuals and families by gender and socioeconomic position across households. We investigated household (HH) cost burden of dietary supplements sold for WL, MB, and SF in a cross-sectional study using data from 60,538 U.S. households (HH) in 2012 Nielsen/IRi National Consumer Panel, calculating annual HH expenditures on WL, MB, and SF supplements and expenditures as proportions of total annual HH income. We examined sociodemographic patterns in HH expenditures using Wald tests of mean differences across subgroups. Among HH with any expenditures on WL, MB, or SF supplements, annual HH first and ninth expenditure deciles were, respectively: WL $5.99, $145.36; MB $6.99, $141.93; and SF $4.98, $88.52. Conditional on any purchases of the products, female-male-headed HH spent more on WL supplements and male-headed HH spend more on MB and SF supplements compared to other HH types ( p -values supplements types ( p -values supplements ( p -values supplements sold for WL, MB, and SF disproportionately burden HH by income and gender.

Nonhost resistance to rust pathogens – a continuation of continua

Directory of Open Access Journals (Sweden)

Jan eBettgenhaeuser

2014-12-01

Full Text Available The rust fungi (order: Pucciniales are a group of widely distributed fungal plant pathogens, which can infect representatives of all vascular plant groups. Rust diseases significantly impact several crop species and considerable research focuses on understanding the basis of host specificity and nonhost resistance. Like many pathogens, rust fungi vary considerably in the number of hosts they can infect, such as wheat leaf rust (Puccinia triticina, which can only infect species in the genera Triticum and Aegilops, whereas Asian soybean rust (Phakopsora pachyrhizi is known to infect over 95 species from over 42 genera. A greater understanding of the genetic basis determining host range has the potential to identify sources of durable resistance for agronomically important crops. Delimiting the boundary between host and nonhost has been complicated by the quantitative nature of phenotypes in the transition between these two states. Plant-pathogen interactions in this intermediate state are characterized either by (1 the majority of accessions of a species being resistant to the rust or (2 the rust only being able to partially complete key components of its life cycle. This leads to a continuum of disease phenotypes in the interaction with different plant species, observed as a range from compatibility (host to complete immunity within a species (nonhost. In this review we will highlight how the quantitative nature of disease resistance in these intermediate interactions is caused by a continuum of defense barriers, which a pathogen needs to overcome for successfully establishing itself in the host. To illustrate continua as this underlying principle, we will discuss the advances that have been made in studying nonhost resistance towards rust pathogens, particularly cereal rust pathogens.

Nonhost resistance to rust pathogens – a continuation of continua

Science.gov (United States)

Bettgenhaeuser, Jan; Gilbert, Brian; Ayliffe, Michael; Moscou, Matthew J.

2014-01-01

The rust fungi (order: Pucciniales) are a group of widely distributed fungal plant pathogens, which can infect representatives of all vascular plant groups. Rust diseases significantly impact several crop species and considerable research focuses on understanding the basis of host specificity and nonhost resistance. Like many pathogens, rust fungi vary considerably in the number of hosts they can infect, such as wheat leaf rust (Puccinia triticina), which can only infect species in the genera Triticum and Aegilops, whereas Asian soybean rust (Phakopsora pachyrhizi) is known to infect over 95 species from over 42 genera. A greater understanding of the genetic basis determining host range has the potential to identify sources of durable resistance for agronomically important crops. Delimiting the boundary between host and nonhost has been complicated by the quantitative nature of phenotypes in the transition between these two states. Plant–pathogen interactions in this intermediate state are characterized either by (1) the majority of accessions of a species being resistant to the rust or (2) the rust only being able to partially complete key components of its life cycle. This leads to a continuum of disease phenotypes in the interaction with different plant species, observed as a range from compatibility (host) to complete immunity within a species (nonhost). In this review we will highlight how the quantitative nature of disease resistance in these intermediate interactions is caused by a continuum of defense barriers, which a pathogen needs to overcome for successfully establishing itself in the host. To illustrate continua as this underlying principle, we will discuss the advances that have been made in studying nonhost resistance towards rust pathogens, particularly cereal rust pathogens. PMID:25566270

Wave dynamics of generalized continua

CERN Document Server

Bagdoev, Alexander G; Shekoyan, Ashot V

2016-01-01

This monograph is devoted to problems of propagation and stability of linear and nonlinear waves in continuous media with complex structure. It considers the different media, such as solid with cavities, preliminary deformed disperse medium, solid with porosity filled by the electrically conductive and non-conductive liquid, magnetoelastic, piezo-semiconductors, crystals with dislocations, composites with inclusions, an electrically conductive asymmetrical liquid, a mixture of gas with a drop liquid. The book also considers the propagation of a laser beam through a two-level medium. The presented results are based on methods of evolution and modulation equations that were developed by the authors. The book is intended for scientific and technical researchers, students and post-graduate students specializing in mechanics of continuous media, physical acoustics, and physics of the solid state.

Special Topic Interoperability and EHR: Combining openEHR, SNOMED, IHE, and Continua as approaches to interoperability on national eHealth.

Science.gov (United States)

Beštek, Mate; Stanimirović, Dalibor

2017-08-09

The main aims of the paper comprise the characterization and examination of the potential approaches regarding interoperability. This includes openEHR, SNOMED, IHE, and Continua as combined interoperability approaches, possibilities for their incorporation into the eHealth environment, and identification of the main success factors in the field, which are necessary for achieving required interoperability, and consequently, for the successful implementation of eHealth projects in general. The paper represents an in-depth analysis regarding the potential application of openEHR, SNOMED, IHE and Continua approaches in the development and implementation process of eHealth in Slovenia. The research method used is both exploratory and deductive in nature. The methodological framework is grounded on information retrieval with a special focus on research and charting of existing experience in the field, and sources, both electronic and written, which include interoperability concepts and related implementation issues. The paper will try to answer the following inquiries that are complementing each other: 1. Scrutiny of the potential approaches, which could alleviate the pertinent interoperability issues in the Slovenian eHealth context. 2. Analyzing the possibilities (requirements) for their inclusion in the construction process for individual eHealth solutions. 3. Identification and charting the main success factors in the interoperability field that critically influence development and implementation of eHealth projects in an efficient manner. Provided insights and identified success factors could serve as a constituent of the strategic starting points for continuous integration of interoperability principles into the healthcare domain. Moreover, the general implementation of the identified success factors could facilitate better penetration of ICT into the healthcare environment and enable the eHealth-based transformation of the health system especially in the countries

Caracterización de arritmias cardíacas tras el uso de infusiones analgésicas continuas de tramadol o lidocaína en perras ovariohisterectomizadas

OpenAIRE

Buriticá Gaviria, Edwin Fernando; Echeverry Bonilla, Diego Fernando; Arévalo Carbonell, Mario Fernando; Alvarado Poveda, Ana María; Ospina-Argüelles, Diego Alejandro

2017-01-01

Resumen El uso de infusiones analgésicas continuas (IACs) es una estrategia eficaz para el control del dolor posquirúrgico en caninos; sin embargo, dependiendo del fármaco empleado, la electrofisiología cardiaca puede verse alterada por la presencia de taquiarritmias, bradiarritmias, complejos ventriculares, fibrilación o bloqueos atrioventriculares. El objetivo de este estudio fue valorar la frecuencia cardiaca y caracterizar las anormalidades electrocardiográficas observadas durante el empl...

Energy-momentum conserving higher-order time integration of nonlinear dynamics of finite elastic fiber-reinforced continua

Science.gov (United States)

Erler, Norbert; Groß, Michael

2015-05-01

Since many years the relevance of fibre-reinforced polymers is steadily increasing in fields of engineering, especially in aircraft and automotive industry. Due to the high strength in fibre direction, but the possibility of lightweight construction, these composites replace more and more traditional materials as metals. Fibre-reinforced polymers are often manufactured from glass or carbon fibres as attachment parts or from steel or nylon cord as force transmission parts. Attachment parts are mostly subjected to small strains, but force transmission parts usually suffer large deformations in at least one direction. Here, a geometrically nonlinear formulation is necessary. Typical examples are helicopter rotor blades, where the fibres have the function to stabilize the structure in order to counteract large centrifugal forces. For long-run analyses of rotor blade deformations, we have to apply numerically stable time integrators for anisotropic materials. This paper presents higher-order accurate and numerically stable time stepping schemes for nonlinear elastic fibre-reinforced continua with anisotropic stress behaviour.

SHPPS 2006: School Health Policies and Programs Study--Foods and Beverages Sold Outside of the School Meals Programs

Science.gov (United States)

Centers for Disease Control and Prevention, 2007

2007-01-01

The School health Policies and Programs Study (SHPPS) is a national survey periodically conducted to assess school health policies and programs at the state, district, school, and classroom levels. This brief reports study results in the area of foods and beverages sold outside of the school meals program. (Contains 3 tables, 1 figure, and 2…

Variational formulation for dissipative continua and an incremental J-integral

Science.gov (United States)

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.

Las dosis recomendadas de β-lactámicos en el paciente séptico con técnicas continuas de reemplazo renal son insuficientes

OpenAIRE

Paz Martín, Daniel

2012-01-01

La sepsis es una causa importante de morbi-mortalidad entre los pacientes ingresados en Unidades de Cuidados Intensivos (UCI). En estos pacientes es prioritario tanto el control de la causa como el inicio temprano de la antibioterapia. De hecho, el retraso en el adecuado tratamiento antibiótico empeora el pronóstico de los pacientes sépticos. El fracaso renal agudo es una complicación frecuente de la sepsis que a menudo  precisa de técnicas continuas de reemplazo renal (TCRR). A pe...

Quality evaluation of commercially sold table water samples in Michael Okpara University of Agriculture, Umudike, Nigeria and surrounding environments

Directory of Open Access Journals (Sweden)

D.O. Okorie

2015-01-01

Full Text Available In Michael Okpara University of Agriculture, Umudike, Nigeria (MOUAU and surrounding environments, table water of different brands is commercially hawked by vendors. To the best of our knowledge, there is no scientific documentation on the quality of these water samples. Hence this study which evaluated the quality of different brands of water samples commercially sold in MOUAU and surrounding environments. The physicochemical properties (pH, total dissolved solids (TDS, biochemical oxygen demand (BOD, total hardness, dissolved oxygen, Cl, NO3, ammonium nitrogen (NH3N, turbidity, total suspended solids (TSS, Ca, Mg, Na and K of the water samples as indices of their quality were carried out using standard techniques. Results obtained from this study indicated that most of the chemical constituents of these table water samples commercially sold in Umudike environment conformed to the standards given by the Nigerian Industrial Standard (NIS, World Health Organization (WHO and American Public Health Association (APHA, respectively, while values obtained for ammonium nitrogen in these water samples calls for serious checks on methods of their production and delivery to the end users.

Special topic interoperability and EHR: Combining openEHR, SNOMED, IHE, and continua as approaches to interoperability on national ehealth

DEFF Research Database (Denmark)

Bestek, M.; Stanimirovi, D.

2017-01-01

into the eHealth environment, and identification of the main success factors in the field, which are necessary for achieving required interoperability, and consequently, for the successful implementation of eHealth projects in general. Methods: The paper represents an in-depth analysis regarding...... the potential application of openEHR, SNOMED, IHE and Continua approaches in the development and implementation process of eHealth in Slovenia. The research method used is both exploratory and deductive in nature. The methodological framework is grounded on information retrieval with a special focus on research...... could alleviate the pertinent interoperability issues in the Slovenian eHealth context. 2. Analyzing the possibilities (requirements) for their inclusion in the construction process for individual eHealth solutions. 3. Identification and charting the main success factors in the interoperability field...

Bacteriological And Nutritional Analysis Of Groundnut Cake Sold In An Open Market In Samaru Zaria-Kaduna State

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Oko

2015-05-01

Full Text Available Abstract Bacteriological and nutritional analysis of groundnut cake powder sold in open market at Samaru-Zaria was studied. The samples collected from four zones of the study area were analysed for possible microbiological contamination and its nutritional quality. The results indicated a microbial load of 1.93 x 105 cfug and 1.94 x 105 cfug for zones A and B respectively 1.01 x 105 cfug for zone C and 2.37 x 105 cfug for zone D. The bacterial isolates found to be associated with the groundnut cake powder in this study included Klebsiella oxytoca Staphylococcus aureus Bacillus cereus E. coli P. aeruginosa and Streptococcus feacalis. The nutrients content of the sample included carbohydrates 55.15 moisture 12.65 lipid 15.40 protein 12.60 ash 3.95 and crude fibre 0.25. Groundnut cake sold in the study area is highly contaminated with bacteria except for samples from zone C which is within the Food and Drugs Agency FDA recommendation of 1.0 x 105cfuml as allowable microbial contamination for food. The high level of microbial contamination is a serious cause for concern as it may trigger epidemics. However the product is highly nutritious.

A mathematical formulation for large strain analysis of geologic continua

International Nuclear Information System (INIS)

Chaudhary, A.B.; Vakili, J.E.; Hume, H.R.

1987-12-01

A solution method is presented for finite-deformation analysis of geologic materials. The principle of virtual work is used to state the equations of equilibrium in a weak form. These equations are linearized about the last-established equilibrium configuration. A material constitutive relationship between the Green-Naghdi stress rate and the rate-of-deformation tensor is used to obtain the current stresses. The finite-element governing equations are expressed in a form suitable for an iterative solution strategy. The obtained gradient matrix contains the effects of both material and geometric nonlinearities. The primary application area of this formulation is the analysis of long-term deformation response of the region adjoining the mining shafts and the waste emplacement rooms within a nuclear waste repository. In this region, the strains are expected to be large, and the infinitesimal strain analysis would introduce inaccuracies in the solution. 19 refs., 6 figs

Mislabelling of Döner kebab sold in Italy

Directory of Open Access Journals (Sweden)

Gaetano Liuzzo

2016-11-01

Full Text Available The aim of this study was to assess whether Döner kebabs sold in Italy comply with legal labelling requirements. A checklist of EU labelling requirements was drawn up and nine labels of Döner kebab marketed in the province of Modena were collected to evaluate the mandatory information laid down in article 9 of Regulation (EU No 1169/2011 together with the mandatory requirements of Regulation (EC 853/2004 for meat preparations. The study showed that different additives are commonly used in Döner kebabs, including E 621 (monosodium glutamate. This additive is not included among the ingredients authorized for the meat preparation food category. Eight frozen Döner kebab samples were taken and a visual assessment and a histologic examination were performed to verify potential changes in the meat’s inner muscle fibre structure that could allow the product to be considered among meat preparations or meat products. The Döner kebab labels showed several systematically deficient regulatory requirements in both extrinsic defects (not related to food composition and aspects concerning the protection of consumers’ health. Histological examination showed that the tissue was moderately swollen, but the muscle fibre structure was intact. Kebab can be reasonably classified as a meat preparation thereby precluding the use monosodium glutamate (E 621 as an ingredient.

Effects of narasin (Skycis) on live performance and carcass traits of finishing pigs sold in a three-phase marketing system.

Science.gov (United States)

Arkfeld, E K; Carr, S N; Rincker, P J; Gruber, S L; Allee, G L; Dilger, A C; Boler, D D

2015-10-01

The objective was to evaluate the effect of feeding narasin (Skycis; Elanco Animal Health, Greenfield, IN) on growth performance and carcass characteristics of finishing pigs sold in a 3-phase marketing system. Pigs ( = 1,232) were housed in 56 single-sex pens (22 pigs/pen) divided into 2 even blocks based on initiation of treatment. Each treatment × sex combination was replicated 14 times. Pigs were fed either 0 mg/kg narasin (control) or 15 mg/kg narasin for up to 85 d of finishing (initiated at an average of 52.95 kg BW). In each pen, 18% (4 pigs per pen) of pigs were sold in the first marketing group (Day 64 of dietary treatment), 50% (11 of the original 22) were sold in the second marketing group (Day 78), and 32% (the remaining 7 pigs) were sold in the third marketing group (Day 85). Data were analyzed as a randomized complete block design with pen as the experimental unit. The model included the fixed effects of diet, sex, and their interaction. Block and replicate nested within block were random variables. Carcass data from pigs in marketing group 3 of block 2 was not collected due to inclement weather. Narasin had no effect on growth performance traits ( ≥ 0.15) in phases 1 (Days 1-28) or 2 (Days 29-56), regardless of sex. Barrows fed narasin had a 2.0% greater overall (Day 0-85) ADG than barrows fed the control diet ( carcass composition in marketing groups 1 and 2. Narasin-fed barrows in marketing group 3 had 0.9 percentage units lower ( carcass lean compared with barrows fed control diets (51.0 vs. 52.0%); no difference existed in gilts ( = 0.21). This is likely due to narasin-fed barrows of marketing group 3 tending ( = 0.06) to have 7.7% greater fat depth than control barrows of marketing group 3. Pooled effects (across all 3 marketing groups) of feeding narasin tended ( = 0.08) to reduce loin depth by 1.1% (60.00 vs. 60.66 mm), but there were no effects on fat depth ( = 0.24) or estimated carcass lean ( = 0.11). Overall, narasin can be used during

Isolation of pathogenic Escherichia coli from buffalo meat sold in Parbhani city, Maharashtra, India

Directory of Open Access Journals (Sweden)

M. S. Vaidya

2013-10-01

Full Text Available Aim: Isolation, characterization, in-vitro pathogenicity and antibiogram study of E.coli from buffalo meat sold in Parbhani city. Materials and Methods: Meat samples were collected from buffalo immediately after slaughter. Isolation, identification and enumeration of E. coli were done by following standard methods and protocols. Hemolysin test and Congo red binding assay were used to study in-vitro pathogenicity of E. coli isolates. Disc diffusion method was used to study antibiogram of pathogenic E. coli isolates. Results: A total of 250 buffalo meat samples were collected and processed. A total of 22 (8.80 percent E. coli isolates were isolated with average differential count of 1.231 ± 0.136 log cfu/g on EMB agar. All the E. coli isolates were confirmed by 10 Grams staining, biochemical reactions and sugar fermentation and motility tests. A total of 9 (3.6 percent E. coli isolates were found to be pathogenic by in-vitro pathogenicity testing. Antibiogram studies of pathogenic E. coli isolates showed that all 9 isolates were sensitive to gentamycin (20 ± 1.49 mm while 7 isolate showed resistance to enrofloxacin (18.22 ± 3.58 mm and tetracycline (11.44 ± 2.04 mm. Conclusion: Buffalo meat sold in Parbhani city is an important source of E. coli infection to human population. A total of 9 pathogenic E. coli were isolated from buffalo meat immediately after slaughter. All isolates were characterized and confirmed pathogenic by in-vitro pathogenicity tests. Antibiogram studies of all isolates revealed sensitivity to gentamicin and resistance to tetracycline and enrofloxacin. [Vet World 2013; 6(5.000: 277-279

Transferencia de calor en la colada continua de aceros. II parte. Enfriamiento secundario

Directory of Open Access Journals (Sweden)

Cicutti, C.

1997-12-01

Full Text Available Once the strand leaves the mold, the solidification of steel progresses due to the heat extracted in the secondary cooling zone of the continuous casting machine. In this zone, heat is extracted mainly by: the incidence of water from sprays, radiation to surroundings contact with rolls and run out water accumulated between rolls and strand. In this work, all these mechanisms are evaluated and, when it is possible, they are quantified. Methods which are usually employed to measure solidification profiles in the continuous casting machine are also reviewed. Finally, the incidence of secondary cooling on the quality of cast products is discussed.

La solidificación del acero iniciada en el molde continúa en la zona de enfriamiento secundario de la máquina donde el calor es extraído, principalmente por la incidencia del agua de los rociadores, la radiación al medio ambiente, el contacto con los rodillos y el agua acumulada en ellos. En este trabajo se revisa cada uno de estos mecanismos determinando, en los casos en que es posible, valores cuantitativos de los mismos. Además, se analizan los distintos métodos empleados para medir el avance del espesor solidificado en la máquina de colada continua. Por último, se discute la incidencia del enfriamiento secundario en la calidad final de los productos colados.

Dynamics of continua and particles from general covariance of Newtonian gravitation theory

International Nuclear Information System (INIS)

Duval, C.; Kunzle, H.P.

1976-07-01

The principle of general covariance, which states that the total action functional in General Relativity is independent of coordinate transformations, is shown to be also applicable to the four-dimensional geometric theory of Newtonian gravitation. It leads to the correct conservation (or balance) equations of continuum mechanics as well as the equations of motion of test particles in a gravitational field. The degeneracy of the ''metric'' of Newtonian space-time forces to introduce a ''gauge field'' which fixes the connection and leads to a conserved current, the mass flow. The particle equations are also derived from an invariant Hamiltonian structure on the extended Galilei group and a minimal interaction principle. One not only finds the same equations of motion but even the same gauge fields

DNA barcoding unveils skate (Chondrichthyes: Rajidae) species diversity in 'ray' products sold across Ireland and the UK.

Science.gov (United States)

Griffiths, Andrew Mark; Miller, Dana D; Egan, Aaron; Fox, Jennifer; Greenfield, Adam; Mariani, Stefano

2013-01-01

Skates are widely consumed across the globe, but many large species are subject to considerable concern regarding their conservation and management. Within Europe such issues have recently driven policy changes so that, for the first time, reports of skate landings now have to be made under species-specific names. Total allowable catches have also been established for many groups, which have been set to zero for a number of the most vulnerable species (e.g., Dipturus batis, Raja undulata and Rostoraja alba). Whilst accurate species identification has become an important issue for landings, the sale of skates is still usually made under a blanket term of "skate" or "ray". The matter of identifying species of skate is further complicated by their morphologically conservative nature and the fact that they are commercially valued for their wings. Thus, before sale their bodies are usually discarded (i.e., "winged") and often skinned, making morphological identification impossible. For the first time, DNA barcoding (of the mitochondrial COI gene) was applied to samples of skate wings from retail outlets across the British Isles, providing insight into which species are sold for consumption. A total of 98 wing samples were analysed, revealing that six species were sold; blonde ray (Raja brachyura), spotted ray (Raja montagui), thornback ray (Raja clavata), cuckoo ray (Leucoraja naevus) small-eyed ray (Raja microocellata) and shagreen ray (Leucoraja fullonica). Statistical testing demonstrated that there were significant differences in the species sold in the distinct retail groups which suggests complex drivers behind the patterns of sale in skates. The results also indicate that endangered species are not commonly being passed on to consumers. In addition, the practice of selling skate wings under ambiguous labels is highlighted as it makes it extremely difficult for consumers to exercise a right to avoid species of conservation concern. Interestingly, a single retailer

[Survey of the presence of Listeria monocytogenes in meat products sold in retail].

Science.gov (United States)

Langiano, E; Lanni, L; Atrei, P; De Vito, E

2007-01-01

The present study evaluates the presence of Listeria spp and particularly of L. monocytogenes in bovine, pork and poultry meats sold by retail in supermarkets and butchers in the city of Cassino. The sensibility to the antibiotics mostly used in the veterinary practice has been tested on the isolated strains. The different species of Listeria have shown a considerable variation of isolation based on the meat's typology and on the different store's provenance. Moreover our results show greater degree of contamination than the data currently available the Italian literature. In our study poultry meat is the most contaminated one. We can assert that omissions and poor caring errors in the manipulation and conservation of meat expose the customer to an even higher risk of infection.

Potential effects of the next 100 billion hamburgers sold by McDonald's.

Science.gov (United States)

Spencer, Elsa H; Frank, Erica; McIntosh, Nichole F

2005-05-01

McDonald's has sold >100 billion beef-based hamburgers worldwide with a potentially considerable health impact. This paper explores whether there would be any advantages if the next 100 billion burgers were instead plant-based burgers. Nutrient composition of the beef hamburger patty and the McVeggie burger patty were obtained from the McDonald's website; sales data were obtained from the McDonald's customer service. Consuming 100 billion McDonald's beef burgers versus the same company's McVeggie burgers would provide, approximately, on average, an additional 550 million pounds of saturated fat and 1.2 billion total pounds of fat, as well as 1 billion fewer pounds of fiber, 660 million fewer pounds of protein, and no difference in calories. These data suggest that the McDonald's new McVeggie burger represents a less harmful fast-food choice than the beef burger.

How do different cigarette design features influence the standard tar yields of popular cigarette brands sold in different countries?

Science.gov (United States)

O'Connor, R J; Hammond, D; McNeill, A; King, B; Kozlowski, L T; Giovino, G A; Cummings, K M

2008-09-01

To examine the associations among cigarette design features and tar yields of leading cigarette brands sold in the United States, Canada, Australia and the United Kingdom. Government reports and numbers listed on packs were used to obtain data on International Organization for Standardization (ISO)/Federal Trade Commission (FTC) yields for the tar of 172 cigarette varieties sold in the United States, Canada, Australia and the United Kingdom. We used standardised methods to measure the following 11 cigarette design parameters: filter ventilation, cigarette pressure drop, filter pressure drop, tobacco rod length, filter length, cigarette diameter, tipping paper length, tobacco weight, filter weight, rod density and filter density. Filter ventilation was found to be the predominant design feature accounting for the variations between brands in ISO/FTC tar yields in each of the four countries. After accounting for filter ventilation, design parameters such as overwrap length, tobacco weight and rod density played comparatively minor roles in determining tar yields. Variation in ISO/FTC tar yields are predicted by a limited set of cigarette design features, especially filter ventilation, suggesting that governments should consider mandatory disclosure of cigarette design parameters as part of comprehensive tobacco product regulations.

7 CFR 205.308 - Agricultural products in other than packaged form at the point of retail sale that are sold...

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Agricultural products in other than packaged form at the point of retail sale that are sold, labeled, or represented as â100 percent organicâ or âorganic.â... Information § 205.308 Agricultural products in other than packaged form at the point of retail sale that are...

Differential Equations Compatible with KZ Equations

International Nuclear Information System (INIS)

Felder, G.; Markov, Y.; Tarasov, V.; Varchenko, A.

2000-01-01

We define a system of 'dynamical' differential equations compatible with the KZ differential equations. The KZ differential equations are associated to a complex simple Lie algebra g. These are equations on a function of n complex variables z i taking values in the tensor product of n finite dimensional g-modules. The KZ equations depend on the 'dual' variable in the Cartan subalgebra of g. The dynamical differential equations are differential equations with respect to the dual variable. We prove that the standard hypergeometric solutions of the KZ equations also satisfy the dynamical equations. As an application we give a new determinant formula for the coordinates of a basis of hypergeometric solutions

Estrategia integral de formación para la mejora continua de la calidad de los servicios de salud

Directory of Open Access Journals (Sweden)

Laura Magaña Valladares

2015-05-01

Full Text Available El sistema de salud mexicano ha tenido logros importantes que se reflejan en la mejora creciente del nivel de salud. Empero, la heterogeneidad en la calidad de los servicios y su repercusión en la salud de diferentes grupos poblacionales continúan siendo un reto. Los costos de fallos en la calidad representan de 20 a 40% del gasto de los sistemas de salud. Es necesario desarrollar la capacidad organizacional para implementar sistemas de gestión de calidad que permitan identificar, evaluar, superar y prevenir los retos del sistema de salud. Para ello, se propone una estrategia integral de formación de recursos humanos basada en competencias y responsabilidades, que incluye programas de pregrado, posgrado y educación continua para favorecer el ejercicio efectivo de la función de calidad en los diversos niveles de responsabilidad del sistema de salud. La estrategia responde a las necesidades del sistema mexicano, pero puede ser adaptada a diferentes sistemas y contextos.

Energy efficiency versus gains in consumer amenities—An example from new cars sold in Sweden

International Nuclear Information System (INIS)

Sprei, Frances; Karlsson, Sten

2013-01-01

Technological developments that increase energy efficiency result in net energy-saving benefits, provided the increased efficiency is not offset by enhanced consumer amenities. This paper analyzes the technology development/consumer amenities trade-off for new cars sold in Sweden between 1975 and 2010. We combine lessons learned from the policies in place and interviews with key actors in the car-purchasing process with statistical modeling of trends in vehicle attributes and technological development. Until 2007, consumer amenities were continuously enhanced, offsetting most of the efficiency gains of technological development; there was no strong policy push toward energy efficiency. In recent years, two major shifts have occurred. First, there has been a shift in the majority of new cars sold, from gasoline-powered engines to diesel engines. Flex-fuel vehicles have also contributed to a decline in the sales-share of pure gasoline engines. The observed shift of fuels, especially to flex-fuels, has been encouraged by policies. Second, after 2007 there have been major technological improvements, while attributes related to consumer amenities have remained flat, reversing the trends so that 77% of the technological development resulted in actual reduction of specific fuel consumption. EU targets, tax reforms, and consumer awareness have contributed to this trend change. - Highlights: ► Trade-offs between consumer amenities and fuel consumption of new cars in Sweden. ► Methods: Statistical modeling, policy analysis and interviews. ► Until 2007 a majority of technological development is offset by consumer amenities. ► After 2005 a shift from gasoline to diesel and flex-fuels takes place. ► Policy change and environmental awareness result in a reversion of trends.

Prevalence of Staphylococcal Enterotoxins in Ready-to-Eat Foods Sold in Istanbul.

Science.gov (United States)

Ulusoy, Beyza H; Çakmak Sancar, Burcu; Öztürk, Muhsin

2017-10-01

The aim of this study was to investigate the prevalence of staphylococcal enterotoxins (SEs) in ready-to-eat (RTE) foods sold in Istanbul, Turkey. A total of 5,241 samples were randomly collected from various caterers, hotels, and restaurants from 2014 to 2016. The samples were classified into four groups: (i) various cooked RTE meat and vegetable meals, (ii) various RTE salads, charcuterie, and cold appetizers, (iii) various cooked RTE bakery products (pasta, pastries, pizza, pita, ravioli, etc.), and (iv) any cooked RTE sweets and desserts (pudding, custard, cream, ashura, etc.). The samples were examined for the presence of SEs by 3M Tecra Staph Enterotoxin Visual Immunoassay method, which is a manual enzyme-linked immunosorbent assay method. Among all samples, only 1 (0.019%) RTE meal (vegetable meal with meat) was found to be contaminated with SEs, a good result in terms of staphylococcal food poisoning risk and public health.

Categories and continua of destructive and constructive marital conflict tactics from the perspective of U.S. and Welsh children.

Science.gov (United States)

Goeke-Morey, Marcie C; Cummings, E Mark; Harold, Gordon T; Shelton, Katherine H

2003-09-01

Categories and continua of parents' marital conflict tactics based on multiple, conceptually grounded criteria were tested. Participants were 175 U.S. children, ages 8-16 years (88 boys, 87 girls) and 327 Welsh children, ages 11-12 years (159 boys, 168 girls). Children's responses (affective, cognitive, behavioral) to analog presentations of 10 everyday marital conflict tactics enacted by fathers or mothers showed substantial variation as a function of tactic used. Orderings of conflict tactics on the various response criteria varied as a function of moderators, particularly the gender of the parent expressing the conflict tactic. Conflict tactics were classified as either constructive or destructive according to criteria derived from the emotional security hypothesis. Except for calm discussion, classifications did not change regardless of cultural group, parent gender, or child age or gender. Recommendations for negotiating everyday marital conflict for the children's sake are discussed.

DNA barcoding unveils skate (Chondrichthyes: Rajidae) species diversity in ‘ray’ products sold across Ireland and the UK

Science.gov (United States)

Egan, Aaron; Fox, Jennifer; Greenfield, Adam; Mariani, Stefano

2013-01-01

Skates are widely consumed across the globe, but many large species are subject to considerable concern regarding their conservation and management. Within Europe such issues have recently driven policy changes so that, for the first time, reports of skate landings now have to be made under species-specific names. Total allowable catches have also been established for many groups, which have been set to zero for a number of the most vulnerable species (e.g., Dipturus batis, Raja undulata and Rostoraja alba). Whilst accurate species identification has become an important issue for landings, the sale of skates is still usually made under a blanket term of “skate” or “ray”. The matter of identifying species of skate is further complicated by their morphologically conservative nature and the fact that they are commercially valued for their wings. Thus, before sale their bodies are usually discarded (i.e., “winged”) and often skinned, making morphological identification impossible. For the first time, DNA barcoding (of the mitochondrial COI gene) was applied to samples of skate wings from retail outlets across the British Isles, providing insight into which species are sold for consumption. A total of 98 wing samples were analysed, revealing that six species were sold; blonde ray (Raja brachyura), spotted ray (Raja montagui), thornback ray (Raja clavata), cuckoo ray (Leucoraja naevus) small-eyed ray (Raja microocellata) and shagreen ray (Leucoraja fullonica). Statistical testing demonstrated that there were significant differences in the species sold in the distinct retail groups which suggests complex drivers behind the patterns of sale in skates. The results also indicate that endangered species are not commonly being passed on to consumers. In addition, the practice of selling skate wings under ambiguous labels is highlighted as it makes it extremely difficult for consumers to exercise a right to avoid species of conservation concern. Interestingly, a

DNA barcoding unveils skate (Chondrichthyes: Rajidae species diversity in ‘ray’ products sold across Ireland and the UK

Directory of Open Access Journals (Sweden)

Andrew Mark Griffiths

2013-08-01

Full Text Available Skates are widely consumed across the globe, but many large species are subject to considerable concern regarding their conservation and management. Within Europe such issues have recently driven policy changes so that, for the first time, reports of skate landings now have to be made under species-specific names. Total allowable catches have also been established for many groups, which have been set to zero for a number of the most vulnerable species (e.g., Dipturus batis, Raja undulata and Rostoraja alba. Whilst accurate species identification has become an important issue for landings, the sale of skates is still usually made under a blanket term of “skate” or “ray”. The matter of identifying species of skate is further complicated by their morphologically conservative nature and the fact that they are commercially valued for their wings. Thus, before sale their bodies are usually discarded (i.e., “winged” and often skinned, making morphological identification impossible. For the first time, DNA barcoding (of the mitochondrial COI gene was applied to samples of skate wings from retail outlets across the British Isles, providing insight into which species are sold for consumption. A total of 98 wing samples were analysed, revealing that six species were sold; blonde ray (Raja brachyura, spotted ray (Raja montagui, thornback ray (Raja clavata, cuckoo ray (Leucoraja naevus small-eyed ray (Raja microocellata and shagreen ray (Leucoraja fullonica. Statistical testing demonstrated that there were significant differences in the species sold in the distinct retail groups which suggests complex drivers behind the patterns of sale in skates. The results also indicate that endangered species are not commonly being passed on to consumers. In addition, the practice of selling skate wings under ambiguous labels is highlighted as it makes it extremely difficult for consumers to exercise a right to avoid species of conservation concern

Interpretación y medición comparada de líneas granulométricas continuas

Directory of Open Access Journals (Sweden)

Grinszpan, Pedro Enrique

1979-12-01

Full Text Available Not avaible

Se propone en este trabajo una expresión analítica que vincula al módulo de finura de Abrams con el tamaño límite superior de la serie granulométrica y con el grado de una función parabólica identificable con la analizada a efectos de poder localizar la composición con relación a los dominios de conveniencia establecidos por las normas y de este modo realizar una medición comparada de su aptitud. Se introduce el concepto de coeficiente de aptitud a efectos de medir en términos relativos la bondad de una composición granulométrica continua y se propone una escala de clasificación y calificación, cuya inclusión en los pliegos de especificaciones se recomienda para la recepción de los agregados. Por último, la función adoptada, que se considera una generalización de la distribución dé Gessner, es comparada con las de Bolomey y Ross, estableciéndose la diferencia con éstas.

Nonlinear continuum mechanics and large inelastic deformations

CERN Document Server

Dimitrienko, Yuriy I

2010-01-01

This book provides a rigorous axiomatic approach to continuum mechanics under large deformation. In addition to the classical nonlinear continuum mechanics - kinematics, fundamental laws, the theory of functions having jump discontinuities across singular surfaces, etc. - the book presents the theory of co-rotational derivatives, dynamic deformation compatibility equations, and the principles of material indifference and symmetry, all in systematized form. The focus of the book is a new approach to the formulation of the constitutive equations for elastic and inelastic continua under large deformation. This new approach is based on using energetic and quasi-energetic couples of stress and deformation tensors. This approach leads to a unified treatment of large, anisotropic elastic, viscoelastic, and plastic deformations. The author analyses classical problems, including some involving nonlinear wave propagation, using different models for continua under large deformation, and shows how different models lead t...

Tracking Foodborne Pathogenic Bacteria in Raw and Ready-to-Eat Food Illegally Sold at the Eastern EU Border.

Science.gov (United States)

Ciolacu, Luminita; Stessl, Beatrix; Bolocan, Andrei Sorin; Oniciuc, Elena Alexandra; Wagner, Martin; Rychli, Kathrin; Nicolau, Anca Ioana

2016-03-01

Food illegally brought into the European Union, mainly in the personal luggage of travelers, represents a potential threat to consumers' health. The aim of this study was to investigate the presence of five pathogens in food brought into the European Union by Moldavian citizens as personal goods and illegally sold in Romania in the vicinity of the border. The occurrence of Staphylococcus aureus and Listeria monocytogenes was 7.5% and 8%, while Campylobacter spp., Escherichia coli O157:H7, and Salmonella spp. were absent in all samples. L. monocytogenes sequence type 2, 9, 121, and 155, highly prevalent among foodstuffs worldwide, was also present among isolates from ready-to-eat food illegally sold in Romania, even at the same date of sampling, indicating cross-contamination during food handling. S. aureus spa types t449, t304, and t524 were most often isolated from raw-milk cheeses contaminated with 10(3)-10(5) colony-forming units per gram, evidencing a contamination at herd level or unhygienic conditions during processing. S. aureus t011 and t3625, both included in the livestock-associated CC398, were isolated from pork lard and poultry meat. This study shows that cross-border trade from nonmember states represents a neglected route of transmission of foodborne pathogens into the European Union that could lead to sporadic or family-associated cases of disease.

HEDONIC ANALYSIS OF CELL PHONES SOLD WITH POST-PAID SERVICE PLANS IN BRAZIL

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Cláudio R. Lucinda

2012-07-01

Full Text Available The aim of this paper is to analyze the determining factors for the pricing of handsets sold with service plans, using the hedonic price method. This was undertaken by building a database comprising 48 handset models, under nine different service plans, over a period of 53 weeks in 2008, and resulted in 27 different attributes and a total number of nearly 300,000 data registers. The results suggest that the value of monthly subscriptions and calling minutes are important to explain the prices of handsets. Furthermore, both the physical volume and number of megapixels of a camera had an effect on the prices. The bigger the handset, the cheaper it becomes, and the more megapixels a camera phone has, the more expensive it becomes. Additionally, it was found that in 2008 Brazilian phone companies were subsidizing enabled data connection handsets.

Modelo de gestión de calidad a través de la mejora continua en la manufactura de transformadores de distribución y potencia

OpenAIRE

Ramos Carrión, Jorge Carmelo

2017-01-01

Enfoca la problemática de la calidad en los procesos de manufactura de transformadores de distribución y potencia, proponiendo un modelo de gestión de calidad a través de la mejora continua. Este modelo se construye tomando como referencia el estado real de los procesos y se valida aplicándolo a un grupo de empresas constituido por una gran empresa, una mediana empresa y dos pequeñas empresas, fabricantes de máquinas eléctricas, ubicadas en la ciudad de Lima. El modelo de gestión de calidad s...

A description of interventions promoting healthier ready-to-eat meals (to eat in, to take away, or to be delivered) sold by specific food outlets in England: a systematic mapping and evidence synthesis

OpenAIRE

Hillier-Brown, Frances C.; Summerbell, Carolyn D.; Moore, Helen J.; Wrieden, Wendy L.; Adams, Jean; Abraham, Charles; Adamson, Ashley; Ara?jo-Soares, Vera; White, Martin; Lake, Amelia A.

2017-01-01

$\\textbf{Background:}$ Ready-to-eat meals (to eat in, to take away or to be delivered) sold by food outlets are often more energy dense and nutrient poor compared with meals prepared at home, making them a reasonable target for public health intervention. The aim of the research presented in this paper was to systematically identify and describe interventions to promote healthier ready-to-eat meals (to eat in, to take away, or to be delivered) sold by specific food outlets in England. $\\...

Cigarettes sold in China: design, emissions and metals.

Science.gov (United States)

O'Connor, Richard J; Li, Qiang; Stephens, W Edryd; Hammond, David; Elton-Marshall, Tara; Cummings, K Michael; Giovino, Gary A; Fong, Geoffrey T

2010-10-01

China is the home to the world's largest cigarette maker, China National Tobacco Company (CNTC), yet little is known publicly about the design and emissions of Chinese cigarettes. CNTC is currently in the process of consolidating its brands and has ambitions to export its cigarettes. Machine-measured tar yields of many of its cigarette brands have also been reduced, similar to what occurred in Western countries from the 1970s through the 1990s with so-called 'low-tar' cigarettes introduced to address consumer concerns about health risks from smoking. The current study examines the design and physical characteristics, labelled smoke emissions and tobacco metals content of leading brands of Chinese cigarettes from seven cities purchased in 2005-6 and in 2007. Findings suggest that similar to most countries, tar levels of Chinese cigarettes are predicted primarily by tobacco weight and filter ventilation. Ventilation explained approximately 50% of variation observed in tar and 60% variation in carbon monoxide yields. We found little significant change in key design features of cigarettes purchased in both rounds. We observed significant levels of various metals, averaging 0.82 μg/g arsenic (range 0.3-3.3), 3.21 μg/g cadmium (range 2.0-5.4) and 2.65 μg/g lead (range 1.2-6.5) in a subsample of 13 brands in 2005-6, substantially higher than contemporary Canadian products. Results suggest that cigarettes in China increasingly resemble those sold in Western countries, but with tobacco containing higher levels of heavy metals. As CNTC looks to export its product around the world, independent surveillance of tobacco product characteristics, including tobacco blend characteristics, will become increasingly important.

31 CFR 363.209 - How can I direct that my marketable Treasury security be sold on the open market (Sell Direct ®)?

Science.gov (United States)

2010-07-01

... account in the commercial book-entry system maintained by our agent, and will sell the security on your... will be returned to your TreasuryDirect ® account. (b) Fee. We charge a fee for each security sold on... the proceeds of the sale. If our agent is unable to complete the sale, no fee will be charged. The...

Diagnostic and therapeutic errors in trigeminal autonomic cephalalgias and hemicrania continua: a systematic review

Science.gov (United States)

2013-01-01

Trigeminal autonomic cephalalgias (TACs) and hemicrania continua (HC) are relatively rare but clinically rather well-defined primary headaches. Despite the existence of clear-cut diagnostic criteria (The International Classification of Headache Disorders, 2nd edition - ICHD-II) and several therapeutic guidelines, errors in workup and treatment of these conditions are frequent in clinical practice. We set out to review all available published data on mismanagement of TACs and HC patients in order to understand and avoid its causes. The search strategy identified 22 published studies. The most frequent errors described in the management of patients with TACs and HC are: referral to wrong type of specialist, diagnostic delay, misdiagnosis, and the use of treatments without overt indication. Migraine with and without aura, trigeminal neuralgia, sinus infection, dental pain and temporomandibular dysfunction are the disorders most frequently overdiagnosed. Even when the clinical picture is clear-cut, TACs and HC are frequently not recognized and/or mistaken for other disorders, not only by general physicians, dentists and ENT surgeons, but also by neurologists and headache specialists. This seems to be due to limited knowledge of the specific characteristics and variants of these disorders, and it results in the unnecessary prescription of ineffective and sometimes invasive treatments which may have negative consequences for patients. Greater knowledge of and education about these disorders, among both primary care physicians and headache specialists, might contribute to improving the quality of life of TACs and HC patients. PMID:23565739

Detection of food-borne bacteria in ready to eat betel leaf sold at local markets in Mymensingh.

Science.gov (United States)

Haque, Md Mazedul; Sarker, Md Atiqur Rahman; Rifa, Rafia Afroze; Islam, Md Ariful; Khatun, Mst Minara

2017-09-01

The present study was undertaken to determine bacterial load as well as characterize bacterial flora of ready to eat (RTE) betel leaf sold at local markets in Mymensingh city. A total of 25 RTE betel leaf samples were collected from five local markets such as Kamal-Ranjit (KR) market, Shesh more, Kewatkhali, Jobber more, and Ganginar par. Total viable count of bacteria in betel leaf (log 10 mean colony forming unit±standard deviation/ml) was 7.58±0.04 for KR market, 7.72±0.06 for Shesh more, 7.62±0.04 for Kewatkhali, 7.40±0.03 for Jobber more, and 7.60±0.06 for Ganginar par. A total of 98 bacterial isolates belong to five genera ( Escherichia coli , Salmonella spp., Vibrio spp., Bacillus spp., and Staphylococcus spp.) were identified. The prevalence of E. coli was 17.34%, Salmonella spp. was 25.51%, Vibrio spp. was 19.39%, Bacillus spp. was 18.37%, and Staphylococcus spp. was 19.39%. Antibiotic sensitivity test showed that all isolates were sensitive to two antibiotics such as ciprofloxacin and gentamicin. Four isolates ( E. coli , Salmonella spp., Vibrio spp., and Staphylococcus spp.) were resistant to two antibiotics (ampicillin and cephalexin). Antibiogram profile of bacterial isolates of betel leaf suggests that they were multidrug resistance. Data of this study indicate that betel leaf sold at local market harbors multidrug resistance food-borne bacteria which might cause public health hazards if these antibiotic resistant transfer to human through food chain.

Detection of food-borne bacteria in ready to eat betel leaf sold at local markets in Mymensingh

Directory of Open Access Journals (Sweden)

Md. Mazedul Haque

2017-09-01

Full Text Available Aim: The present study was undertaken to determine bacterial load as well as characterize bacterial flora of ready to eat (RTE betel leaf sold at local markets in Mymensingh city. Materials and Methods: A total of 25 RTE betel leaf samples were collected from five local markets such as Kamal-Ranjit (KR market, Shesh more, Kewatkhali, Jobber more, and Ganginar par. Results: Total viable count of bacteria in betel leaf (log10 mean colony forming unit±standard deviation/ml was 7.58±0.04 for KR market, 7.72±0.06 for Shesh more, 7.62±0.04 for Kewatkhali, 7.40±0.03 for Jobber more, and 7.60±0.06 for Ganginar par. A total of 98 bacterial isolates belong to five genera (Escherichia coli, Salmonella spp., Vibrio spp., Bacillus spp., and Staphylococcus spp. were identified. The prevalence of E. coli was 17.34%, Salmonella spp. was 25.51%, Vibrio spp. was 19.39%, Bacillus spp. was 18.37%, and Staphylococcus spp. was 19.39%. Antibiotic sensitivity test showed that all isolates were sensitive to two antibiotics such as ciprofloxacin and gentamicin. Four isolates (E. coli, Salmonella spp., Vibrio spp., and Staphylococcus spp. were resistant to two antibiotics (ampicillin and cephalexin. Antibiogram profile of bacterial isolates of betel leaf suggests that they were multidrug resistance. Conclusion: Data of this study indicate that betel leaf sold at local market harbors multidrug resistance food-borne bacteria which might cause public health hazards if these antibiotic resistant transfer to human through food chain.

Mecanismos de desgaste en refractarios de colada continua asociados al efecto Marangoni

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Brandaleze, E.

2005-12-01

Full Text Available Nozzle wear during continuous casting process is caused by physical and chemical reasons and also by refractory quality. A post mortem study on a sample of Al₂O₃ - graphite nozzle with a ZrO₂ insert allows to identify the present wear mechanisms. Different cyclic stages are carried out due to recurrent changes of interfacial tension and fluid convection. When the surface tension promote the refractory wetting by the steel, graphite of the nozzle surface is lost. Then, grains of ZrO₂ and of Al₂O₃ are dissolved by slag contact. This type of wear is associated with the Marangoni effect. Light and electronic microscopy was used to observe the refractory structure and by a cathodoluminiscence technique phases transformations under process conditions are determined.

Las buzas sumergidas se erosionan durante el proceso de la colada continua, debido a causas físicas, químicas y a la calidad del refractario. El estudio post mortem de una buza de Al₂O₃ -grafito con inserto de ZrO₂ permite identificar los mecanismos de desgaste presentes, que ocurren por etapas debido a cambios cíclicos de tensión interfacial y convección de fluidos. Cuando la tensión superficial favorece la mojabilidad del refractario por el acero, la buza pierde grafito de la superficie. Luego, los granos de ZrO₂ y de Al₂O₃ se disuelven al ser mojados por la escoria. Este desgaste está asociado al efecto Marangoni. Se observa la microestructura mediante microscopía óptica y electrónica y, por catodoluminiscencia, se determinan las transformaciones de fases ocurridas en condiciones de proceso.

Microbioligical Hazard Contamination in Fermented Vegetables Sold in Local Markets in Cambodia.

Science.gov (United States)

Chrun, Rithy; Hosotani, Yukie; Kawasaki, Susumu; Inatsu, Yasuhiro

2017-01-01

　Fermented vegetables are common part of Cambodian diet. The food safety status for these foods has not been investigated. This study was conducted to evaluate the microbiological hazards that contaminated fermented vegetables. A total of 68 samples of fermented vegetables were purchased randomly from five wet markets in Phnom Penh. The conventional culture methods for microbiological analysis were used. Coliform bacteria (Escherichia coli, Cronobactersakazakii, and Enterobacter spp.), opportunistic non-Entrobacteriaceae, Enterococcus spp., Staphylococcus spp., and Listeria spp. were found in these fermented foods. The highest contamination rate of Enterococcus spp. was 34% of total fermented vegetable samples, followed by Bacillus spp. coliform bacteria and E. coli (31%, 24% and 10%, respectively). The potential foodborne pathogen, C. sakazakii, was identified in one sample. Fermented mixed vegetables showed higher contamination rate of coliform bacteria (50%) than fermented single-type vegetables (13%). The results showed that fermented vegetables sold in wet market are poor in hygiene. The stage in the processing chain where contamination occurred should be identified and basic sanitary practice should be enforced to improve the food safety of fermented vegetables in Cambodia.

Malaysian made condoms sold locally as well as exported.

Science.gov (United States)

1979-01-01

Malaysia, famous for its natural rubber, is also producing condoms made from local rubber. About 40,000 gross of condoms a month are being produced by a factory with about 30 female workers. 30-40% of the production is exported to Europe, Middle East, Asia, Japan, Singapore and South America. The size of the condoms conform to international standards, 49 mm and 52 mm. As there is a greater demand for the 52 mm. condoms overseas, the company produces more of this than the 49 mm. condoms. In April 1975, the Standard Institution and Industrial Research of Malaysia gave its quality control approval to a condom which can hold 5 gallons of water and with thickness varying from 0.03 mm, 0.06 mm. and 0.05-0.07 mm. A 10% tax/piece and a 5% surtax are imposed on imported condoms to protect the local industry from foreign competition. Local condoms are sold tax-free. Pink and black colored condoms appear to be popular among consumers. Although complaints are few, 1 in 10,000 users may suffer from allergic problems because of the silicone oil treatment of the condoms. Another local condom factory which uses Malaysian rubber for condom manufacture is located in Klang, approximately 24 miles from Kuala Lumpur; the factory has 25 workers producing 12,000 gross of lubricated and non-lubricated condoms for local consumption only. There is increasing evidence that condoms are increasing in popularity in Malaysia and that the average consumer is now being more selective in choosing contraceptive methods.

p-Euler equations and p-Navier-Stokes equations

Science.gov (United States)

Li, Lei; Liu, Jian-Guo

2018-04-01

We propose in this work new systems of equations which we call p-Euler equations and p-Navier-Stokes equations. p-Euler equations are derived as the Euler-Lagrange equations for the action represented by the Benamou-Brenier characterization of Wasserstein-p distances, with incompressibility constraint. p-Euler equations have similar structures with the usual Euler equations but the 'momentum' is the signed (p - 1)-th power of the velocity. In the 2D case, the p-Euler equations have streamfunction-vorticity formulation, where the vorticity is given by the p-Laplacian of the streamfunction. By adding diffusion presented by γ-Laplacian of the velocity, we obtain what we call p-Navier-Stokes equations. If γ = p, the a priori energy estimates for the velocity and momentum have dual symmetries. Using these energy estimates and a time-shift estimate, we show the global existence of weak solutions for the p-Navier-Stokes equations in Rd for γ = p and p ≥ d ≥ 2 through a compactness criterion.

Equating error in observed-score equating

NARCIS (Netherlands)

van der Linden, Willem J.

2006-01-01

Traditionally, error in equating observed scores on two versions of a test is defined as the difference between the transformations that equate the quantiles of their distributions in the sample and population of test takers. But it is argued that if the goal of equating is to adjust the scores of

La modelación matemática en los procesos de formación inicial y continua de docentes

Directory of Open Access Journals (Sweden)

José David Zaldívar Rojas

2017-10-01

Full Text Available El presente estudio tiene como propósito promover la importancia de los procesos de aprendizaje e implementación del concepto modelación matemática en la formación docente inicial y/o continua. Para ello se describe una propuesta que tiene como fin el que los docentes experimenten y resuelvan una situación basada en modelación matemática tomando estos el rol de alumnos. Se discuten primeramente los aspectos teóricos que sustentan la propuesta y se presentan las dos fases que conforman el estudio. Los resultados muestran un diseño de una situación basada en un contexto biológico cuyas tareas se inscriben propiamente en las etapas del proceso de modelación matemática. En dicha situación se incorpora una herramienta tecnológica con el propósito de favorecer el tránsito entre el planteamiento del problema y la generación de modelos matemáticos.

Microbial and physicochemical assays of paracetamol in different brands of analgesic syrups sold in Sana’a City-Yemen

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Ali G. Al−Kaf

2015-02-01

Full Text Available Context: Contamination of pharmaceuticals with microorganisms irrespective whether they are harmful or nonpathogenic can bring about changes in physicochemical characteristics of the drugs. Aims: To assay the microbial and physicochemical characteristics of paracetamol of two hundreds samples of different brands of analgesic syrups sold in Sana’a City, Yemen. Methods: Total viable aerobic count, type of isolated microorganisms, physical properties, and content of active ingredients were identified and evaluated by standard methods and techniques. The SPSS program was used to statistical analysis of variance for results obtained. Results: The total bacterial count of <10 CFU/mL and <100 CFU/mL in 179 (89.5% and 21 (10.5% samples, respectively was recorded, while the total fungal count was ≤10 CFU/mL in all analyzed syrup samples. The isolated bacteria were Bacillus subtilis, Micrococcus fulvum, and Staphylococcus epidermidis while isolated fungi were Aspergillus niger, Aspergillus fumigatus, and Penicillium notatum. Bacillus subtilis and Aspergillus niger were the predominant bacteria and fungi isolated. The color results had a light red liquid with a sweet taste in the analyzed analgesic syrups. The pH values were ranged from 4.44–5.88. However, the density fluctuated from 1.149–1.184 g/mL. The paracetamol concentration as an active ingredient in the analgesic syrup was recorded from 98.19% – 106.53%. Conclusions: This finding showed that all analgesic syrups sold in Sana’a City followed Pharmacopeia specifications on microbial and physicochemical qualities.

Análisis comparativo de modelos hidrológicos de simulación continua en cuencas de alta montaña: caso del Río Chinchiná

OpenAIRE

Ocampo, Olga Lucía; Universidad Autónoma de Manizales; Vélez, Jorge Julián; Universidad Nacional de Colombia sede Manizales

2014-01-01

La modelación hidrológica es la base para la gestión integral del recurso hídrico; en cuencas de alta montaña, e involucra una compleja interacción de procesos físicoquímicos. Este estudio, realizado en la cuenca del río Chinchiná, Colombia, plantea un análisis multimodelo para capturar la incertidumbre asociada con la modelación hidrológica, mediante la aplicación de siete modelos hidrológicos, lluvia-escorrentía de simulación continua, agregados a escala mensual, con diferentes niveles de c...

Un programa de formación continua con profesores de ciencias en el contexto de la relación Museo-Escuela

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Carlos Soto Lombana

2012-04-01

Full Text Available En este artículo se presentan los resultados de un programa de formación continua con ocho profesores de ciencias naturales de educación básica y media, que integró el trabajo de dos museos de ciencia de la ciudad de Medellín, Colombia, como herramienta pedagógica y didáctica. Los resultados del programa de formación permiten apreciar el gran potencial de los museos como recurso educativo y didáctico para la enseñanza de las ciencias naturales. Como principal conclusión se plantea que el diseño de las Unidades Didácticas como parte de un ciclo de aprendizaje, es lo que establece la diferencia entre la acción pedagógica del docente en relación con la visita en el contexto formal del que realiza un colectivo escolar a un museo en el contexto informal.

equateIRT: An R Package for IRT Test Equating

Directory of Open Access Journals (Sweden)

Michela Battauz

2015-12-01

Full Text Available The R package equateIRT implements item response theory (IRT methods for equating different forms composed of dichotomous items. In particular, the IRT models included are the three-parameter logistic model, the two-parameter logistic model, the one-parameter logistic model and the Rasch model. Forms can be equated when they present common items (direct equating or when they can be linked through a chain of forms that present common items in pairs (indirect or chain equating. When two forms can be equated through different paths, a single conversion can be obtained by averaging the equating coefficients. The package calculates direct and chain equating coefficients. The averaging of direct and chain coefficients that link the same two forms is performed through the bisector method. Furthermore, the package provides analytic standard errors of direct, chain and average equating coefficients.

Optimal Overhaul-Replacement Policies for Repairable Machine Sold with Warranty

Directory of Open Access Journals (Sweden)

Kusmaningrum Soemadi

2014-12-01

Full Text Available This research deals with an overhaul-replacement policy for a repairable machine sold with Free Replacement Warranty (FRW. The machine will be used for a finite horizon, T (T <, and evaluated at a fixed interval, s (s< T. At each evaluation point, the buyer considers three alternative decisions i.e. Keep the machine, Overhaul it, or Replace it with a new identical one. An overhaul can reduce the machine age virtually, but not to a point that the machine is as good as new. If the machine fails during the warranty period, it is rectified at no cost to the buyer. Any failure occurring before and after the expiry of the warranty is restored by minimal repair. An overhaul-replacement policy is formulated for such machines by using dynamic programming approach to obtain the buyer’s optimal policy. The results show that a significant rejuvenation effect due to overhaul may extend the length of machine life cycle and delay the replacement decision. In contrast, the warranty stimulates early machine replacement and by then increases the replacement frequencies for a certain range of replacement cost. This demonstrates that to minimize the total ownership cost over T the buyer needs to consider the minimal repair cost reduction due to rejuvenation effect of overhaul as well as the warranty benefit due to replacement. Numerical examples are presented for both illustrating the optimal policy and describing the behavior of the optimal solution.

Determination of Ethyl Carbamate in Alcoholic Beverages and Fermented Foods Sold in Korea.

Science.gov (United States)

Ryu, Dayeon; Choi, Bogyoung; Kim, Eunjoo; Park, Seri; Paeng, Hwijin; Kim, Cho-Il; Lee, Jee-Yeon; Yoon, Hae Jung; Koh, Eunmi

2015-09-01

Ethyl carbamate (EC) classified as a probable human carcinogen (Group 2A) is naturally formed in alcoholic beverages and fermented foods during fermentation process and/or during storage. The objective of this study was to analyze EC in 34 food items including 14 alcoholic beverages and 20 fermented foods sold in Korea. Each food was collected from 18 supermarkets in 9 metropolitan cities in Korea, and then made into composite. According to food composition and alcohol content, samples were divided into four matrices such as apple juice, milk, Soju (liquor containing about 20% alcohol), and rice porridge. The maximum EC value of 151.06 µg/kg was found in Maesilju (liquor made from Maesil and Soju). Whisky and Bokbunjaju (Korean black raspberry wine) contained 9.90 µg/kg and 6.30 µg/kg, respectively. EC was not detected in other alcoholic beverages. Of 20 fermented foods, Japanese-style soy sauce had highest level of 15.59 µg/kg and traditional one contained 4.18 µg/kg. Soybean paste had 1.18 µg/kg, however, EC was not found in other fermented foods.

Computing generalized Langevin equations and generalized Fokker-Planck equations.

Science.gov (United States)

Darve, Eric; Solomon, Jose; Kia, Amirali

2009-07-07

The Mori-Zwanzig formalism is an effective tool to derive differential equations describing the evolution of a small number of resolved variables. In this paper we present its application to the derivation of generalized Langevin equations and generalized non-Markovian Fokker-Planck equations. We show how long time scales rates and metastable basins can be extracted from these equations. Numerical algorithms are proposed to discretize these equations. An important aspect is the numerical solution of the orthogonal dynamics equation which is a partial differential equation in a high dimensional space. We propose efficient numerical methods to solve this orthogonal dynamics equation. In addition, we present a projection formalism of the Mori-Zwanzig type that is applicable to discrete maps. Numerical applications are presented from the field of Hamiltonian systems.

Classification of frequency response areas in the inferior colliculus reveals continua not discrete classes.

Science.gov (United States)

Palmer, Alan R; Shackleton, Trevor M; Sumner, Christian J; Zobay, Oliver; Rees, Adrian

2013-08-15

A differential response to sound frequency is a fundamental property of auditory neurons. Frequency analysis in the cochlea gives rise to V-shaped tuning functions in auditory nerve fibres, but by the level of the inferior colliculus (IC), the midbrain nucleus of the auditory pathway, neuronal receptive fields display diverse shapes that reflect the interplay of excitation and inhibition. The origin and nature of these frequency receptive field types is still open to question. One proposed hypothesis is that the frequency response class of any given neuron in the IC is predominantly inherited from one of three major afferent pathways projecting to the IC, giving rise to three distinct receptive field classes. Here, we applied subjective classification, principal component analysis, cluster analysis, and other objective statistical measures, to a large population (2826) of frequency response areas from single neurons recorded in the IC of the anaesthetised guinea pig. Subjectively, we recognised seven frequency response classes (V-shaped, non-monotonic Vs, narrow, closed, tilt down, tilt up and double-peaked), that were represented at all frequencies. We could identify similar classes using our objective classification tools. Importantly, however, many neurons exhibited properties intermediate between these classes, and none of the objective methods used here showed evidence of discrete response classes. Thus receptive field shapes in the IC form continua rather than discrete classes, a finding consistent with the integration of afferent inputs in the generation of frequency response areas. The frequency disposition of inhibition in the response areas of some neurons suggests that across-frequency inputs originating at or below the level of the IC are involved in their generation.

Modelos de regresión para variables expresadas como una proporción continua Regression models for variables expressed as a continuous proportion

Directory of Open Access Journals (Sweden)

Aarón Salinas-Rodríguez

2006-10-01

Full Text Available OBJETIVO: Describir algunas de las alternativas estadísticas disponibles para el estudio de proporciones continuas y comparar los distintos modelos que existen para evidenciar sus ventajas y desventajas, mediante su aplicación a un ejemplo práctico del ámbito de la salud pública. MATERIAL Y MÉTODOS: Con base en la Encuesta Nacional de Salud Reproductiva realizada en el año 2003, se modeló la proporción de cobertura individual en el programa de planificación familiar -propuesta en un estudio previo realizado en el Instituto Nacional de Salud Pública en Cuernavaca, Morelos, México (2005- mediante el uso de los modelos de regresión normal, gama, beta y de quasi-verosimilitud. La variante del criterio de información de Akaike (AIC que propusieron McQuarrie y Tsai se utilizó para definir el mejor modelo. A continuación, y mediante simulación (enfoque Monte Carlo/cadenas de Markov, se generó una variable con distribución beta para evaluar el comportamiento de los cuatro modelos al variar el tamaño de la muestra desde 100 hasta 18 000 observaciones. RESULTADOS: Los resultados muestran que la mejor opción estadística para el análisis de proporciones continuas es el modelo de regresión beta, de acuerdo con sus supuestos y el valor de AIC. La simulación mostró que a medida que aumenta el tamaño de la muestra, el modelo gama y, en especial, el modelo de quasi-verosimilitud se aproximan en grado significativo al modelo beta. CONCLUSIONES: Para la modelación de proporciones continuas se recomienda emplear el enfoque paramétrico de la regresión beta y evitar el uso del modelo normal. Si se tiene un tamaño de muestra grande, el uso del enfoque de quasi-verosimilitud representa una buena alternativa.OBJECTIVE: To describe some of the statistical alternatives available for studying continuous proportions and to compare them in order to show their advantages and disadvantages by means of their application in a practical example of

A thermodynamically-consistent theory of the ferro/paramagnetic transition

Czech Academy of Sciences Publication Activity Database

Podio-Guidugli, P.; Roubíček, Tomáš; Tomassetti, G.

2010-01-01

Roč. 198, č. 3 (2010), s. 1057-1094 ISSN 0003-9527 Institutional research plan: CEZ:AV0Z20760514 Keywords : phase transitions * thermodynamics of continua * landau-lifshitz/gilbert equation Subject RIV: BJ - Thermodynamics Impact factor: 2.277, year: 2010 http://www.springerlink.com/content/u705l057177m6526/

Development of kinetics equations from the Boltzmann equation; Etablissement des equations de la cinetique a partir de l'equation de Boltzmann

Energy Technology Data Exchange (ETDEWEB)

Plas, R.

1962-07-01

The author reports a study on kinetics equations for a reactor. He uses the conventional form of these equations but by using a dynamic multiplication factor. Thus, constants related to delayed neutrons are not modified by efficiency factors. The author first describes the theoretic kinetic operation of a reactor and develops the associated equations. He reports the development of equations for multiplication factors.

Microbial quality of some vegetables sold in ED DueimTwon, Sudan.

Science.gov (United States)

Goja, Arafat Mohammed; Mahmoud, Mohamed Salih Osman

2013-06-15

This study was probably the first research carried out to investigate the microbiological quality of some vegetables sold in ED DueimTwon, Sudan. Four species of vegetables were used, Arugula (Eruca sativa), Mloukhia (Corchorus olitorius), Tomato (Lycopersicon esculentum) and Green pepper (Capsicum annuum). The samples were collected and examined according to standardized methods for total viable bacteria, coliforms and fecal coliform count. The average of total viable count ranged from 1.2 x 105-5.6 x 105 CFU mL(-1) for Arugula; 2.1 x 105-2.8 x 107 CFU mL(-1) for Mloukhia; 3.4 x 105-4.8 x 105 for Tomato and 2.3 x 105-8.0 x 106 CFU mL(-1) for Green pepper. However, the maximum level of total and fecal coliform were (93, 21); (28, 11); (75, 15) and (150, 20) MPN 100 mL(-1), respectively. Twelve bacteria belonging to five genera were isolated. Staphylococcus (33%) was the most predominant isolated followed by Enterobacteriaceae (25%), Bacillus (17%) and Streptococcus (17%). Micrococcus (8%) was the least dominant isolated. The results of microbial counts of these vegetable samples in this study indicate that, the agricultural practices, harvesting, hygiene, transporting and selling points are poor and therefore, the higher microbial load could be risked for public health.

Formación continua del profesorado, investigación educativa e innovación en la enseñanza de las ciencias

Directory of Open Access Journals (Sweden)

Jenaro Guisasola

2001-01-01

Full Text Available Este trabajo surge de las actividades en Formación Continua del profesorado que hemosdesarrollado durante un período entre los 5 y 10 últimos diez años en el País Vasco y Cantabriaa través del Departamento de Educación del País Vasco y del Centro de Profesores y Recursosde Camargo (Cantabria. Las actividades de formación realizadas han sido fundamentadas en elcuerpo teórico de la Didáctica de las Ciencias, de forma que no fueran un conjunto de cursosinconexos y sin relación con la problemática del aula. Una de las conclusiones del análisis delas experiencias realizadas es la importancia de que los profesores participen de forma conti-nuada en grupos de trabajo y reflexión sobre su práctica docente y, que este trabajo sea apoya-do por tutores y por la administración educativa.

Simple equation method for nonlinear partial differential equations and its applications

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Taher A. Nofal

2016-04-01

Full Text Available In this article, we focus on the exact solution of the some nonlinear partial differential equations (NLPDEs such as, Kodomtsev–Petviashvili (KP equation, the (2 + 1-dimensional breaking soliton equation and the modified generalized Vakhnenko equation by using the simple equation method. In the simple equation method the trial condition is the Bernoulli equation or the Riccati equation. It has been shown that the method provides a powerful mathematical tool for solving nonlinear wave equations in mathematical physics and engineering problems.

Optimización simultánea para la mejora continua y reducción de costos en procesos Optimización simultánea para la mejora continua y reducción de costos en procesos

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Jorge Domínguez Domínguez

2006-12-01

Full Text Available Muchos problemas de optimización son caracterizados por la flexibilidad para establecer la utilidad entre las funciones objetivo. La estrategia experimental desempeña un papel importante para generar estas funciones objetivo, además, ésta se ha aplicado de manera conveniente para disminuir costos de calidad y en la mejora continua de la calidad de procesos y productos. Es frecuente encontrar muchas aplicaciones industriales con varias respuestas cuya finalidad es alcanzar la calidad global de un producto, por lo que es necesario optimizar de manera simultánea las respuestas de interés. En esencia, el problema de optimización de varias respuestas involucra la selección de un conjunto de condiciones o variables independientes tales que den como resultado un producto o servicio adecuado. Es decir, se desea seleccionar los niveles de las variables independientes que optimicen todas las respuestas a la vez. En esta presentación se mostrarán dos procedimientos para construir una función que describa la combinación de los objetivos de las respuestas individuales. El primer método es un modelo de optimización multiplicativo y el segundo es aditivo, estos se aplicarán a dos casos de estudio realizados en la industria con el fin de resaltar los procesos de mejora continua y la disminución de costos. La optimización simultánea, utilizando estos dos procedimientos, se ilustrarán mediante técnicas de graficación ya que éstas permiten generar varios escenarios de posibles soluciones óptimas. En estos ejemplos se observó que ambos métodos producen resultados similares al generar el óptimo, sin embargo al compararlos de manera global mediante la función de pérdida existe una ligera diferencia entre ellos.Many problems of optimization are characterized by the flexibility to establish the utility among the functions objectives. Experimental strategy plays a very important part for generating theses functions. This specific strategy

Radionuclide Content of Pasteurized Milk Sold in Mafikeng, South Africa

International Nuclear Information System (INIS)

Olobatoke, R.; Mathuthu, M.

2015-01-01

Many food animals which are important components of human food chain are effective collectors of radionuclides from the environment particularly contaminated forages, and therefore represent a significant pathway for the transfer of radionuclides to humans. Many important radionuclides are readily transferred to milk thus the product is considered as one of the basic food items recommended for the assessment of radionuclide exposure within a population. The current study aimed at assessing the radionuclide content of commercial milk commonly sold in South Africa in other to set a baseline data for radionuclide concentration of the products. Three popular brands of commercial milk (A, B and C) were sampled, with two samples obtained for each brand. The concentration of individual radionuclide in the milk samples, particularly "1"3"1I, "1"3"7Cs and "2"3"5U was measured by gamma spectroscopy. The results showed that brand A had the highest concentrations of "2"3"5U and "1"3"7Cs (203 and 324 mBq/l respectively) but the lowest concentration of "1"3"1I (6.4 mBq/l). The highest concentration of "1"3"1I (148 mBq/l) was detected in brand B whereas both "2"3"5U and "1"3"1I were not detected in brand C. All the values however were well below the new standard limits for individual radionuclides in milk established by the Japanese Ministry of Health, Labour and Welfare. This study indicates that the commercial milk brands assessed pose no radiation health threat to the consumers. (author)

Microbiological safety and quality control of poultry products sold in retail chains of Saint Petersburg and Leningrad region.

Directory of Open Access Journals (Sweden)

A. K. Alieva

2017-01-01

Full Text Available Food safety and food raw materials is an important task which needs to be under government’s and public associations’ control, under enterprises which produce and sale them, and other economy departments. Nutrition is one of the most important factors influencing human health. To 70% alien substances of chemical and microbiological origin get into the human body with food. The heavy metals, nitrates, nitrites, pesticides, nitrosescomounds, mycotoxins, antibiotics, radionuclides and others are xenobiotics of chemical origin. The poultry products represented in commercial networks by poultry plants located in Saint-Petersburg and Leningrad region: “Roskar”, “Sinyavinskaya”, “North”, “Lebyazhye” were picked up for analysis. We used the bacteriological, virological, immunological, mycological, and statistical methods of research. Sanitary -hygienic or microbiological safety of food products was evaluated for the contenting of disease-causing (pathogenic microorganisms such as bacteria groups, coliforms, Staphylococcus, Salmonella and etc. in them. The poultry products sold in commercial networks of St. Petersburg were picked up for analysis. After processing the statistical were revealed 6 nosological forms where the leading position has finding colibacillosis – 27%. The number of positive samples for streptococcosis – 18%, staphylococcus – 8%, aspergillosis–2.6%, salmonellosis – 1.8%, pasteurellosis–1.6 %. The microbiological control of food products which can be the sources of infections should be regular for providing inhabitants with harmless poultry products. It is necessary to adopt and to use the modern microbiological criteria of food safety that will allow to realize the monitoring of their conformity with sanitary norms. The results of these analysis shows that the quality of poultry products sold in commercial networks of Saint Petersburg and the Leningrad region meet the standards.

Extended rate equations

International Nuclear Information System (INIS)

Shore, B.W.

1981-01-01

The equations of motion are discussed which describe time dependent population flows in an N-level system, reviewing the relationship between incoherent (rate) equations, coherent (Schrodinger) equations, and more general partially coherent (Bloch) equations. Approximations are discussed which replace the elaborate Bloch equations by simpler rate equations whose coefficients incorporate long-time consequences of coherence

Tobacco Surcharges on 2015 Health Insurance Plans Sold in Federally Facilitated Marketplaces: Variations by Age and Geography and Implications for Health Equity.

Science.gov (United States)

Liber, Alex C; Drope, Jeffrey M; Graetz, Ilana; Waters, Teresa M; Kaplan, Cameron M

2015-11-01

In 2014, few health insurance plans sold in the Affordable Care Act's Federally Facilitated Marketplaces had age-dependent tobacco surcharges, possibly because of a system glitch. The 2015 tobacco surcharges show wide variation, with more plans implementing tobacco surcharges that increase with age. This underscores concerns that older tobacco users will find postsubsidy health insurance premiums difficult to afford. Future monitoring of enrollment will determine whether tobacco surcharges cause adverse selection by dissuading tobacco users, particularly older users, from buying health insurance.

Are products sold in university vending machines nutritionally poor? A food environment audit.

Science.gov (United States)

Grech, Amanda; Hebden, Lana; Roy, Rajshri; Allman-Farinelli, Margaret

2017-04-01

(i) To audit the nutritional composition, promotion and cost of products available from vending machines available to young adults; and (ii) to examine the relationship between product availability and sales. A cross-sectional analysis of snacks and beverages available and purchased at a large urban university was conducted between March and September 2014. Sales were electronically tracked for nine months. A total of 61 vending machines were identified; 95% (n = 864) of the available snacks and 49% of beverages (n = 455) were less-healthy items. The mean (SD) nutrient value of snacks sold was: energy 1173 kJ (437.5), saturated fat 5.36 g (3.6), sodium 251 mg (219), fibre 1.56 g (1.29) and energy density 20.16 kJ/g (2.34) per portion vended. There was a strong correlation between the availability of food and beverages and purchases (R 2 = 0.98, P Vending machines market and sell less-healthy food and beverages to university students. Efforts to improve the nutritional quality are indicated and afford an opportunity to improve the diet quality of young adults, a group at risk of obesity. © 2016 Dietitians Association of Australia.

Numerical Solution of Heun Equation Via Linear Stochastic Differential Equation

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Hamidreza Rezazadeh

2014-05-01

Full Text Available In this paper, we intend to solve special kind of ordinary differential equations which is called Heun equations, by converting to a corresponding stochastic differential equation(S.D.E.. So, we construct a stochastic linear equation system from this equation which its solution is based on computing fundamental matrix of this system and then, this S.D.E. is solved by numerically methods. Moreover, its asymptotic stability and statistical concepts like expectation and variance of solutions are discussed. Finally, the attained solutions of these S.D.E.s compared with exact solution of corresponding differential equations.

Joint Bayesian Estimation of Quasar Continua and the Lyα Forest Flux Probability Distribution Function

Science.gov (United States)

Eilers, Anna-Christina; Hennawi, Joseph F.; Lee, Khee-Gan

2017-08-01

We present a new Bayesian algorithm making use of Markov Chain Monte Carlo sampling that allows us to simultaneously estimate the unknown continuum level of each quasar in an ensemble of high-resolution spectra, as well as their common probability distribution function (PDF) for the transmitted Lyα forest flux. This fully automated PDF regulated continuum fitting method models the unknown quasar continuum with a linear principal component analysis (PCA) basis, with the PCA coefficients treated as nuisance parameters. The method allows one to estimate parameters governing the thermal state of the intergalactic medium (IGM), such as the slope of the temperature-density relation γ -1, while marginalizing out continuum uncertainties in a fully Bayesian way. Using realistic mock quasar spectra created from a simplified semi-numerical model of the IGM, we show that this method recovers the underlying quasar continua to a precision of ≃ 7 % and ≃ 10 % at z = 3 and z = 5, respectively. Given the number of principal component spectra, this is comparable to the underlying accuracy of the PCA model itself. Most importantly, we show that we can achieve a nearly unbiased estimate of the slope γ -1 of the IGM temperature-density relation with a precision of +/- 8.6 % at z = 3 and +/- 6.1 % at z = 5, for an ensemble of ten mock high-resolution quasar spectra. Applying this method to real quasar spectra and comparing to a more realistic IGM model from hydrodynamical simulations would enable precise measurements of the thermal and cosmological parameters governing the IGM, albeit with somewhat larger uncertainties, given the increased flexibility of the model.

A generalization of the simplest equation method and its application to (3+1)-dimensional KP equation and generalized Fisher equation

International Nuclear Information System (INIS)

Zhao, Zhonglong; Zhang, Yufeng; Han, Zhong; Rui, Wenjuan

2014-01-01

In this paper, the simplest equation method is used to construct exact traveling solutions of the (3+1)-dimensional KP equation and generalized Fisher equation. We summarize the main steps of the simplest equation method. The Bernoulli and Riccati equation are used as simplest equations. This method is straightforward and concise, and it can be applied to other nonlinear partial differential equations

Modeling of thin-walled structures interacting with acoustic media as constrained two-dimensional continua

Science.gov (United States)

Rabinskiy, L. N.; Zhavoronok, S. I.

2018-04-01

The transient interaction of acoustic media and elastic shells is considered on the basis of the transition function approach. The three-dimensional hyperbolic initial boundary-value problem is reduced to a two-dimensional problem of shell theory with integral operators approximating the acoustic medium effect on the shell dynamics. The kernels of these integral operators are determined by the elementary solution of the problem of acoustic waves diffraction at a rigid obstacle with the same boundary shape as the wetted shell surface. The closed-form elementary solution for arbitrary convex obstacles can be obtained at the initial interaction stages on the background of the so-called “thin layer hypothesis”. Thus, the shell–wave interaction model defined by integro-differential dynamic equations with analytically determined kernels of integral operators becomes hence two-dimensional but nonlocal in time. On the other hand, the initial interaction stage results in localized dynamic loadings and consequently in complex strain and stress states that require higher-order shell theories. Here the modified theory of I.N.Vekua–A.A.Amosov-type is formulated in terms of analytical continuum dynamics. The shell model is constructed on a two-dimensional manifold within a set of field variables, Lagrangian density, and constraint equations following from the boundary conditions “shifted” from the shell faces to its base surface. Such an approach allows one to construct consistent low-order shell models within a unified formal hierarchy. The equations of the N th-order shell theory are singularly perturbed and contain second-order partial derivatives with respect to time and surface coordinates whereas the numerical integration of systems of first-order equations is more efficient. Such systems can be obtained as Hamilton–de Donder–Weyl-type equations for the Lagrangian dynamical system. The Hamiltonian formulation of the elementary N th-order shell theory is

Propuesta de un Modelo de Mejora Continua en los Procesos del Laboratorio Ambiental Ipsomary s.a Basado en un Sistema de Gestión de Calidad Bajo la Norma ISO 9001:2008

OpenAIRE

Zambrano Carrillo, Carolina; Rodríguez Portés, Sergio

2013-01-01

El presente estudio se realizó en la empresa privada Ipsomary S.A con el objetivo principal de elaborar un modelo de mejora continua de sus procesos que permita incrementar la eficacia del sistema de gestión de calidad empleando una gestión eficiente de sus procesos para asegurar la satisfacción de sus clientes El estudio está compuesto de una investigación del mercado de servicios ambientales, determinación de la situación actual de la organización, evaluación en relación a los requisitos de...

Análisis comparativo de dos métodos docentes en la geología aplicada a la ingeniería. Trabajos, adquisición de competencias y evaluación continua

OpenAIRE

Huerta Hurtado, Pedro; Rodríguez Bouzo, Loreto; Silva Barroso, Pablo Gabriel; Reguilón Bragado, Rosa María

2010-01-01

Memoria ID-0083. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2009-2010. La aplicación de nuevas metodologías docentes enfocadas a la adquisición de las competencias específicas y transversales supone un desarrollo pragmático de las asignaturas. Los trabajos de asignatura y la evaluación continua son dos metodologías de gran utilidad a la hora de aplicar la filosofía del Espacio Europeo de Educación Superior (EEES) a las Ingenierías. Este proyecto desarrolla dich...

Analysis of wave equation in electromagnetic field by Proca equation

International Nuclear Information System (INIS)

Pamungkas, Oky Rio; Soeparmi; Cari

2017-01-01

This research is aimed to analyze wave equation for the electric and magnetic field, vector and scalar potential, and continuity equation using Proca equation. Then, also analyze comparison of the solution on Maxwell and Proca equation for scalar potential and electric field, both as a function of distance and constant wave number. (paper)

Comparison of Kernel Equating and Item Response Theory Equating Methods

Science.gov (United States)

Meng, Yu

2012-01-01

The kernel method of test equating is a unified approach to test equating with some advantages over traditional equating methods. Therefore, it is important to evaluate in a comprehensive way the usefulness and appropriateness of the Kernel equating (KE) method, as well as its advantages and disadvantages compared with several popular item…

El numeral 8 de la norma y la mejora continua en las empresas de Ibagué

Directory of Open Access Journals (Sweden)

Mario Enrique Uribe Macías

2015-03-01

Full Text Available El proyecto de investigación se realizó a partir de la aplicación de un cuestionario estructurado, diseñado con base en la Norma ISO 9004, a siete empresas que habían sido certificadas, siendo una muestra definida por conveniencia. El artículo presenta los resultados del análisis de la aplicación del numeral 8 de la norma “Medición, análisis y mejora”, resaltándose dos grandes conclusiones: el alto grado de autoapreciación que las empresas tienen de su gestión del Sistema de calidad y la aplicación, desarrollo y demostración de las acciones que ellas adelantan se enfocan a mejorar la eficacia de sus sistemas de calidad y a fortalecer su cultura de calidad.Palabras clave: Calidad; Mejora continua; Numeral 8 Norma ISO. Standard ítem 8 and continue improvement in enterprises from IbagueAbstractThe research project was developed by a structured questionnaire application, designed ISO 9004 based-on, to seven certified enterprises that formed a sample chosen by convenience method. This paper presents the results of application of Standard numeral 8. Measuring, analysis and improve behavior analysis, emphasizing two great conclusions: the self-appreciation high level enterprises have about theirs Quality system management, and the application, development and demonstration about the actions they do are focused to improve their  quality systems efficacy and to strengthen their quality culture.Keywords: Quality; Continue improving; Standard ISO numeral 8.

Power1D: a Python toolbox for numerical power estimates in experiments involving one-dimensional continua

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Todd C. Pataky

2017-07-01

Full Text Available The unit of experimental measurement in a variety of scientific applications is the one-dimensional (1D continuum: a dependent variable whose value is measured repeatedly, often at regular intervals, in time or space. A variety of software packages exist for computing continuum-level descriptive statistics and also for conducting continuum-level hypothesis testing, but very few offer power computing capabilities, where ‘power’ is the probability that an experiment will detect a true continuum signal given experimental noise. Moreover, no software package yet exists for arbitrary continuum-level signal/noise modeling. This paper describes a package called power1d which implements (a two analytical 1D power solutions based on random field theory (RFT and (b a high-level framework for computational power analysis using arbitrary continuum-level signal/noise modeling. First power1d’s two RFT-based analytical solutions are numerically validated using its random continuum generators. Second arbitrary signal/noise modeling is demonstrated to show how power1d can be used for flexible modeling well beyond the assumptions of RFT-based analytical solutions. Its computational demands are non-excessive, requiring on the order of only 30 s to execute on standard desktop computers, but with approximate solutions available much more rapidly. Its broad signal/noise modeling capabilities along with relatively rapid computations imply that power1d may be a useful tool for guiding experimentation involving multiple measurements of similar 1D continua, and in particular to ensure that an adequate number of measurements is made to detect assumed continuum signals.

Integral equations

CERN Document Server

Moiseiwitsch, B L

2005-01-01

Two distinct but related approaches hold the solutions to many mathematical problems--the forms of expression known as differential and integral equations. The method employed by the integral equation approach specifically includes the boundary conditions, which confers a valuable advantage. In addition, the integral equation approach leads naturally to the solution of the problem--under suitable conditions--in the form of an infinite series.Geared toward upper-level undergraduate students, this text focuses chiefly upon linear integral equations. It begins with a straightforward account, acco

Partial Differential Equations

CERN Document Server

1988-01-01

The volume contains a selection of papers presented at the 7th Symposium on differential geometry and differential equations (DD7) held at the Nankai Institute of Mathematics, Tianjin, China, in 1986. Most of the contributions are original research papers on topics including elliptic equations, hyperbolic equations, evolution equations, non-linear equations from differential geometry and mechanics, micro-local analysis.

Nonlinear evolution equations

CERN Document Server

Uraltseva, N N

1995-01-01

This collection focuses on nonlinear problems in partial differential equations. Most of the papers are based on lectures presented at the seminar on partial differential equations and mathematical physics at St. Petersburg University. Among the topics explored are the existence and properties of solutions of various classes of nonlinear evolution equations, nonlinear imbedding theorems, bifurcations of solutions, and equations of mathematical physics (Navier-Stokes type equations and the nonlinear Schrödinger equation). The book will be useful to researchers and graduate students working in p

FMTLxLyLz DIMENSIONAL EQUAT DIMENSIONAL EQUATION ...

African Journals Online (AJOL)

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plant made of 12mm thick steel plate was used in de steel plate ... water treatment plant. ... ameters affecting filtration processes were used to derive an equation usin ..... system. However, in deriving the equation onl terms are incorporated.

Kinetic equations for an unstable plasma; Equations cinetiques d'un plasma instable

Energy Technology Data Exchange (ETDEWEB)

Laval, G; Pellat, R [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1968-07-01

In this work, we establish the plasma kinetic equations starting from the Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy of equations. We demonstrate that relations existing between correlation functions may help to justify the truncation of the hierarchy. Then we obtain the kinetic equations of a stable or unstable plasma. They do not reduce to an equation for the one-body distribution function, but generally involve two coupled equations for the one-body distribution function and the spectral density of the fluctuating electric field. We study limiting cases where the Balescu-Lenard equation, the quasi-linear theory, the Pines-Schrieffer equations and the equations of weak turbulence in the random phase approximation are recovered. At last we generalise the H-theorem for the system of equations and we define conditions for irreversible behaviour. (authors) [French] Dans ce travail nous etablissons les equations cinetiques d'un plasma a partir des equations de la recurrence de Bogoliubov, Born, Green, Kirkwood et Yvon. Nous demontrons qu'entre les fonctions de correlation d'un plasma existent des relations qui permettent de justifier la troncature de la recurrence. Nous obtenons alors les equations cinetiques d'un plasma stable ou instable. En general elles ne se reduisent pas a une equation d'evolution pour la densite simple, mais se composent de deux equations couplees portant sur la densite simple et la densite spectrale du champ electrique fluctuant. Nous etudions le cas limites ou l'on retrouve l'equation de Balescu-Lenard, les equations de la theorie quasi-lineaire, les equations de Pines et Schrieffer et les equations de la turbulence faible dans l'approximation des phases aleatoires. Enfin, nous generalisons le theoreme H pour ce systeme d'equations et nous precisons les conditions d'evolution irreversible. (auteurs)

Assessment of radioactivity level in granite stones sold to ornamental and building purposes in Brazilian Amazon region (Belem, PA, Brazil): a cross sectional study

International Nuclear Information System (INIS)

Queiroz, Y.M.; Santos, R.J.C.; Teixeira, C.E.C.

2015-01-01

The aim of this work was evaluate the level of radioactivity in granite sold in the region of Belem (Para, Brazil) using a Geiger-Mueller detector. The results showed that only 5 from 57 samples of 35 types of granite evaluated had count rates above that measured in the background. However, the counting statistics suggests that the measured radiation values in these 5 samples are not due random fluctuations inherent in such measures. (author)

Assessment of radioactivity level in granite stones sold to ornamental and building purposes in Brazilian Amazon region (Belem, PA, Brazil): a cross sectional study

Energy Technology Data Exchange (ETDEWEB)

Queiroz, Y.M.; Santos, R.J.C.; Teixeira, C.E.C., E-mail: cecteixeira@pq.cnpq.br [Universidade da Amazonia (UNAMA), Belem, PA (Brazil). Centro de Ciencias Biologicas e da Saude. Lab. de Radiologia

2015-07-01

The aim of this work was evaluate the level of radioactivity in granite sold in the region of Belem (Para, Brazil) using a Geiger-Mueller detector. The results showed that only 5 from 57 samples of 35 types of granite evaluated had count rates above that measured in the background. However, the counting statistics suggests that the measured radiation values in these 5 samples are not due random fluctuations inherent in such measures. (author)

equate: An R Package for Observed-Score Linking and Equating

Directory of Open Access Journals (Sweden)

Anthony D. Albano

2016-10-01

Full Text Available The R package equate contains functions for observed-score linking and equating under single-group, equivalent-groups, and nonequivalent-groups with anchor test(s designs. This paper introduces these designs and provides an overview of observed-score equating with details about each of the supported methods. Examples demonstrate the basic functionality of the equate package.

Detection of relevant amounts of cow's milk protein in non-pre-packed bakery products sold as cow's milk-free.

Science.gov (United States)

Trendelenburg, V; Enzian, N; Bellach, J; Schnadt, S; Niggemann, B; Beyer, K

2015-05-01

Currently, there is no mandatory labelling of allergens for non-pre-packed foods in the EU. Therefore, consumers with food allergy rely on voluntary information provided by the staff. The aim of this study was to characterize allergic reactions to non-pre-packed foods and to investigate whether staff in bakery shops were able to give advice regarding a safe product choice. Questionnaires were sent to 200 parents of children with a food allergy. Staff of 50 bakery shops were interviewed regarding selling non-pre-packed foods to food-allergic customers. Bakery products being recommended as 'cow's milk-free' were bought, and cow's milk protein levels were measured using ELISA. A total of 104 of 200 questionnaires were returned. 25% of the children experienced an allergic reaction due to a non-pre-packed food from bakery shops and 20% from ice cream parlours. Sixty percent of the bakery staff reported serving food-allergic customers at least once a month, 24% once a week. Eighty four percent of the staff felt able to advise food-allergic consumers regarding a safe product choice. Seventy three 'cow's milk-free' products were sold in 44 bakery shops. Cow's milk could be detected in 43% of the bakery products, 21% contained >3 mg cow's milk protein per serving. Staff in bakery shops felt confident about advising customers with food allergy. However, cow's milk was detectable in almost half of bakery products being sold as 'cow's milk-free'. Every fifth product contained quantities of cow's milk exceeding an amount where approximately 10% of cow's milk-allergic children will show clinical relevant symptoms. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

La transformación de un vehículo eléctrico, con la regulación con VTC (variador de tensión continua, en un vehículo con inversor de frecuencia y motor eléctrico asíncrono

Directory of Open Access Journals (Sweden)

Ioan Bele

2003-01-01

Full Text Available El trabajo presenta la metodología y las condiciones que deben cumplirse para transformar los vehículos de corriente continua, con regulación de la velocidad de marcha por VTC (chopper, en vehículos accionados por corriente alterna con la regulación mediante inversor y motor eléctrico de tracción asíncrono. Tanto en el primer sistema como en el segundo la regulación de la velocidad se hace mediante el autómata programable. En el primer sistema la regulación de la velocidad es posible mediante el control por impulsos del chopper, mientras que en el segundo la regulación se realiza con la modificación tanto de la tensión como de su frecuencia. Las siguientes funciones del autómata programable no se cambian: el control y el seguimiento de las instalaciones auxiliares del interruptor principal, el control y seguimiento de los contactores de línea y también el diseño de los indicadores de la velocidad, la corriente y la tensión. Otras características del autómata programable se cambian totalmente: el control de los tiristores o los transistores, las informaciones con respecto a la corriente, se elimina una serie de componentes y aparatos y además se pueden montar otros aparatos directamente en el inversor. En conclusión, el paso del sistema de accionamiento con máquina eléctrica de corriente continua, y la regulación de la velocidad de marcha con variador de tensión continua VTC (chopper, al sistema de accionamiento con máquina de corriente alterna y la regulación mediante el inversor, puede realizarse de una manera relativamente fácil después de un análisis de las funciones de las instalaciones de control y regulación.

A description of interventions promoting healthier ready-to-eat meals (to eat in, to take away, or to be delivered) sold by specific food outlets in England: a systematic mapping and evidence synthesis.

Science.gov (United States)

Hillier-Brown, Frances C; Summerbell, Carolyn D; Moore, Helen J; Wrieden, Wendy L; Adams, Jean; Abraham, Charles; Adamson, Ashley; Araújo-Soares, Vera; White, Martin; Lake, Amelia A

2017-01-19

Ready-to-eat meals (to eat in, to take away or to be delivered) sold by food outlets are often more energy dense and nutrient poor compared with meals prepared at home, making them a reasonable target for public health intervention. The aim of the research presented in this paper was to systematically identify and describe interventions to promote healthier ready-to-eat meals (to eat in, to take away, or to be delivered) sold by specific food outlets in England. A systematic search and sift of the literature, followed by evidence mapping of relevant interventions, was conducted. Food outlets were included if they were located in England, were openly accessible to the public and, as their main business, sold ready-to-eat meals. Academic databases and grey literature were searched. Also, local authorities in England, topic experts, and key health professionals and workers were contacted. Two tiers of evidence synthesis took place: type, content and delivery of each intervention were summarised (Tier 1) and for those interventions that had been evaluated, a narrative synthesis was conducted (Tier 2). A total of 75 interventions were identified, the most popular being awards. Businesses were more likely to engage with cost neutral interventions which offered imperceptible changes to price, palatability and portion size. Few interventions involved working upstream with suppliers of food, the generation of customer demand, the exploration of competition effects, and/or reducing portion sizes. Evaluations of interventions were generally limited in scope and of low methodological quality, and many were simple assessments of acceptability. Many interventions promoting healthier ready-to-eat meals (to eat in, to take away, or to be delivered) sold by specific food outlets in England are taking place; award-type interventions are the most common. Proprietors of food outlets in England that, as their main business, sell ready-to-eat meals, can be engaged in implementing

Chemical Equation Balancing.

Science.gov (United States)

Blakley, G. R.

1982-01-01

Reviews mathematical techniques for solving systems of homogeneous linear equations and demonstrates that the algebraic method of balancing chemical equations is a matter of solving a system of homogeneous linear equations. FORTRAN programs using this matrix method to chemical equation balancing are available from the author. (JN)

A new auxiliary equation and exact travelling wave solutions of nonlinear equations

International Nuclear Information System (INIS)

Sirendaoreji

2006-01-01

A new auxiliary ordinary differential equation and its solutions are used for constructing exact travelling wave solutions of nonlinear partial differential equations in a unified way. The main idea of this method is to take full advantage of the auxiliary equation which has more new exact solutions. More new exact travelling wave solutions are obtained for the quadratic nonlinear Klein-Gordon equation, the combined KdV and mKdV equation, the sine-Gordon equation and the Whitham-Broer-Kaup equations

On a functional equation related to the intermediate long wave equation

International Nuclear Information System (INIS)

Hone, A N W; Novikov, V S

2004-01-01

We resolve an open problem stated by Ablowitz et al (1982 J. Phys. A: Math. Gen. 15 781) concerning the integral operator appearing in the intermediate long wave equation. We explain how this is resolved using the perturbative symmetry approach introduced by one of us with Mikhailov. By solving a certain functional equation, we prove that the intermediate long wave equation and the Benjamin-Ono equation are the unique integrable cases within a particular class of integro-differential equations. Furthermore, we explain how the perturbative symmetry approach is naturally extended to treat equations on a periodic domain. (letter to the editor)

Concentration of ions in selected bottled water samples sold in Malaysia

Science.gov (United States)

Aris, Ahmad Zaharin; Kam, Ryan Chuan Yang; Lim, Ai Phing; Praveena, Sarva Mangala

2013-03-01

Many consumers around the world, including Malaysians, have turned to bottled water as their main source of drinking water. The aim of this study is to determine the physical and chemical properties of bottled water samples sold in Selangor, Malaysia. A total of 20 bottled water brands consisting of `natural mineral (NM)' and `packaged drinking (PD)' types were randomly collected and analyzed for their physical-chemical characteristics: hydrogen ion concentration (pH), electrical conductivity (EC) and total dissolved solids (TDS), selected major ions: calcium (Ca), potassium (K), magnesium (Mg) and sodium (Na), and minor trace constituents: copper (Cu) and zinc (Zn) to ascertain their suitability for human consumption. The results obtained were compared with guideline values recommended by World Health Organization (WHO) and Malaysian Ministry of Health (MMOH), respectively. It was found that all bottled water samples were in accordance with the guidelines set by WHO and MMOH except for one sample (D3) which was below the pH limit of 6.5. Both NM and PD bottled water were dominated by Na + K > Ca > Mg. Low values for EC and TDS in the bottled water samples showed that water was deficient in essential elements, likely an indication that these were removed by water treatment. Minerals like major ions were present in very low concentrations which could pose a risk to individuals who consume this water on a regular basis. Generally, the overall quality of the supplied bottled water was in accordance to standards and guidelines set by WHO and MMOH and safe for consumption.

Some New Integrable Equations from the Self-Dual Yang-Mills Equations

International Nuclear Information System (INIS)

Ivanova, T.A.; Popov, A.D.

1994-01-01

Using the symmetry reductions of the self-dual Yang-Mills (SDYM) equations in (2+2) dimensions, we introduce new integrable equations which are 'deformations' of the chiral model in (2+1) dimensions, generalized nonlinear Schroedinger, Korteweg-de Vries, Toda lattice, Garnier, Euler-Arnold, generalized Calogero-Moser and Euler-Calogero-Moser equations. The Lax pairs for all of these equations are derived by the symmetry reductions of the Lax pair for the SDYM equations. 34 refs

Auxiliary equation method for solving nonlinear partial differential equations

International Nuclear Information System (INIS)

Sirendaoreji,; Jiong, Sun

2003-01-01

By using the solutions of an auxiliary ordinary differential equation, a direct algebraic method is described to construct several kinds of exact travelling wave solutions for some nonlinear partial differential equations. By this method some physically important nonlinear equations are investigated and new exact travelling wave solutions are explicitly obtained with the aid of symbolic computation

The equationally-defined commutator a study in equational logic and algebra

CERN Document Server

Czelakowski, Janusz

2015-01-01

This monograph introduces and explores the notions of a commutator equation and the equationally-defined commutator from the perspective of abstract algebraic logic.  An account of the commutator operation associated with equational deductive systems is presented, with an emphasis placed on logical aspects of the commutator for equational systems determined by quasivarieties of algebras.  The author discusses the general properties of the equationally-defined commutator, various centralization relations for relative congruences, the additivity and correspondence properties of the equationally-defined commutator, and its behavior in finitely generated quasivarieties. Presenting new and original research not yet considered in the mathematical literature, The Equationally-Defined Commutator will be of interest to professional algebraists and logicians, as well as graduate students and other researchers interested in problems of modern algebraic logic.

A Comparison between Linear IRT Observed-Score Equating and Levine Observed-Score Equating under the Generalized Kernel Equating Framework

Science.gov (United States)

Chen, Haiwen

2012-01-01

In this article, linear item response theory (IRT) observed-score equating is compared under a generalized kernel equating framework with Levine observed-score equating for nonequivalent groups with anchor test design. Interestingly, these two equating methods are closely related despite being based on different methodologies. Specifically, when…

Detection of genetically modified maize in processed foods sold commercially in iran by qualitative PCR.

Science.gov (United States)

Rabiei, Maryam; Mehdizadeh, Mehrangiz; Rastegar, Hossein; Vahidi, Hossein; Alebouyeh, Mahmoud

2013-01-01

Detection of genetically modified organisms (GMOs) in food is an important issue for all the subjects involved in food control and customer's right. Due to the increasing number of GMOs imported to Iran during the past few years, it has become necessary to screen the products in order to determine the identity of the consumed daily foodstuffs. In this study, following the extraction of genomic DNA from processed foods sold commercially in Iran, qualitative PCR was performed to detect genetically modified maize. The recombinant DNA target sequences were detected with primers highly specific for each investigated transgene such as CaMV35s gene, Bt-11, MON810 and Bt-176 separately. Based on the gel electrophoresis results, Bt- 11 and MON810 events were detected in some maize samples, while, in none of them Bt- 176 modified gene was detected. For the first time, the results demonstrate the presence of genetically modified maize in Iranian food products, reinforcing the need for the development of labeling system and valid quantitative methods in routine analyses.

Five-dimensional Monopole Equation with Hedge-Hog Ansatz and Abel's Differential Equation

OpenAIRE

Kihara, Hironobu

2008-01-01

We review the generalized monopole in the five-dimensional Euclidean space. A numerical solution with the Hedge-Hog ansatz is studied. The Bogomol'nyi equation becomes a second order autonomous non-linear differential equation. The equation can be translated into the Abel's differential equation of the second kind and is an algebraic differential equation.

Estimates of the mean alcohol concentration of the spirits, wine, and beer sold in the United States and per capita consumption: 1950 to 2002.

Science.gov (United States)

Kerr, William C; Greenfield, Thomas K; Tujague, Jennifer

2006-09-01

Estimates of per capita consumption of alcohol in the United States require estimates of the mean alcohol content by volume (%ABV) of the beer, wine, and spirits sold to convert beverage volume to gallons of pure alcohol. The mean %ABV of spirits is estimated for each year from 1950 to 2002 and for each state using the %ABV of major brands and sales of sprits types. The mean %ABV of beer and wine is extrapolated to cover this period based on previous estimates. These mean %ABVs are then applied to alcohol sales figures to calculate new yearly estimates of per capita consumption of beer, wine, spirits, and total alcohol for the United States population aged 15 and older. The mean %ABV for spirits is found to be lower than previous estimates and to vary considerably over time and across states. Resultant per capita consumption estimates indicate that more alcohol was consumed from beer and less from wine and spirits than found in previous estimates. Empirically based calculation of mean %ABV for beer, wine, and spirits sold in the United States results in different and presumably more accurate per capita consumption estimates than heretofore available. Utilization of the new estimates in aggregate time-series and cross-sectional models of alcohol consumption and related outcomes may improve the accuracy and precision of such models.

A geometric model for magnetizable bodies with internal variables

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Restuccia, L

2005-11-01

Full Text Available In a geometrical framework for thermo-elasticity of continua with internal variables we consider a model of magnetizable media previously discussed and investigated by Maugin. We assume as state variables the magnetization together with its space gradient, subjected to evolution equations depending on both internal and external magnetic fields. We calculate the entropy function and necessary conditions for its existence.

Differential equations a dynamical systems approach ordinary differential equations

CERN Document Server

Hubbard, John H

1991-01-01

This is a corrected third printing of the first part of the text Differential Equations: A Dynamical Systems Approach written by John Hubbard and Beverly West. The authors' main emphasis in this book is on ordinary differential equations. The book is most appropriate for upper level undergraduate and graduate students in the fields of mathematics, engineering, and applied mathematics, as well as the life sciences, physics and economics. Traditional courses on differential equations focus on techniques leading to solutions. Yet most differential equations do not admit solutions which can be written in elementary terms. The authors have taken the view that a differential equations defines functions; the object of the theory is to understand the behavior of these functions. The tools the authors use include qualitative and numerical methods besides the traditional analytic methods. The companion software, MacMath, is designed to bring these notions to life.

Análisis, desarrollo e implementación del modelo de mejora continua GM-Difference para el aseguramiento de la calidad en las áreas de venta y posventa de Automotores Continental S. A.

OpenAIRE

Gálvez Gálvez, Eduardo Vinicio; Proaño Jaramillo, Pablo Miguel

2014-01-01

Este proyecto trata sobre el Análisis, Desarrollo e Implementación de un modelo de mejora continua para lograr el aseguramiento de la Calidad Total en las áreas de venta y posventa de Automotores Continental S.A., a partir de la aplicación de estándares de calidad GM Difference. Para ello, primero se hizo un diagnóstico de la Situación Actual, basados en el estudio a una muestra de 138 clientes, los cuales, a través del análisis de Diagrama de Pareto, Esquematización Causa-Efecto y Matriz de ...

Differential equations

CERN Document Server

Barbu, Viorel

2016-01-01

This textbook is a comprehensive treatment of ordinary differential equations, concisely presenting basic and essential results in a rigorous manner. Including various examples from physics, mechanics, natural sciences, engineering and automatic theory, Differential Equations is a bridge between the abstract theory of differential equations and applied systems theory. Particular attention is given to the existence and uniqueness of the Cauchy problem, linear differential systems, stability theory and applications to first-order partial differential equations. Upper undergraduate students and researchers in applied mathematics and systems theory with a background in advanced calculus will find this book particularly useful. Supplementary topics are covered in an appendix enabling the book to be completely self-contained.

New Equating Methods and Their Relationships with Levine Observed Score Linear Equating under the Kernel Equating Framework

Science.gov (United States)

Chen, Haiwen; Holland, Paul

2010-01-01

In this paper, we develop a new curvilinear equating for the nonequivalent groups with anchor test (NEAT) design under the assumption of the classical test theory model, that we name curvilinear Levine observed score equating. In fact, by applying both the kernel equating framework and the mean preserving linear transformation of…

Relations between nonlinear Riccati equations and other equations in fundamental physics

International Nuclear Information System (INIS)

Schuch, Dieter

2014-01-01

Many phenomena in the observable macroscopic world obey nonlinear evolution equations while the microscopic world is governed by quantum mechanics, a fundamental theory that is supposedly linear. In order to combine these two worlds in a common formalism, at least one of them must sacrifice one of its dogmas. Linearizing nonlinear dynamics would destroy the fundamental property of this theory, however, it can be shown that quantum mechanics can be reformulated in terms of nonlinear Riccati equations. In a first step, it will be shown that the information about the dynamics of quantum systems with analytical solutions can not only be obtainable from the time-dependent Schrödinger equation but equally-well from a complex Riccati equation. Comparison with supersymmetric quantum mechanics shows that even additional information can be obtained from the nonlinear formulation. Furthermore, the time-independent Schrödinger equation can also be rewritten as a complex Riccati equation for any potential. Extension of the Riccati formulation to include irreversible dissipative effects is straightforward. Via (real and complex) Riccati equations, other fields of physics can also be treated within the same formalism, e.g., statistical thermodynamics, nonlinear dynamical systems like those obeying a logistic equation as well as wave equations in classical optics, Bose- Einstein condensates and cosmological models. Finally, the link to abstract ''quantizations'' such as the Pythagorean triples and Riccati equations connected with trigonometric and hyperbolic functions will be shown

Bridging the Knowledge Gaps between Richards' Equation and Budyko Equation

Science.gov (United States)

Wang, D.

2017-12-01

The empirical Budyko equation represents the partitioning of mean annual precipitation into evaporation and runoff. Richards' equation, based on Darcy's law, represents the movement of water in unsaturated soils. The linkage between Richards' equation and Budyko equation is presented by invoking the empirical Soil Conservation Service curve number (SCS-CN) model for computing surface runoff at the event-scale. The basis of the SCS-CN method is the proportionality relationship, i.e., the ratio of continuing abstraction to its potential is equal to the ratio of surface runoff to its potential value. The proportionality relationship can be derived from the Richards' equation for computing infiltration excess and saturation excess models at the catchment scale. Meanwhile, the generalized proportionality relationship is demonstrated as the common basis of SCS-CN method, monthly "abcd" model, and Budyko equation. Therefore, the linkage between Darcy's law and the emergent pattern of mean annual water balance at the catchment scale is presented through the proportionality relationship.

Partial differential equations

CERN Document Server

Evans, Lawrence C

2010-01-01

This text gives a comprehensive survey of modern techniques in the theoretical study of partial differential equations (PDEs) with particular emphasis on nonlinear equations. The exposition is divided into three parts: representation formulas for solutions; theory for linear partial differential equations; and theory for nonlinear partial differential equations. Included are complete treatments of the method of characteristics; energy methods within Sobolev spaces; regularity for second-order elliptic, parabolic, and hyperbolic equations; maximum principles; the multidimensional calculus of variations; viscosity solutions of Hamilton-Jacobi equations; shock waves and entropy criteria for conservation laws; and, much more.The author summarizes the relevant mathematics required to understand current research in PDEs, especially nonlinear PDEs. While he has reworked and simplified much of the classical theory (particularly the method of characteristics), he primarily emphasizes the modern interplay between funct...

Nonlinear Dirac Equations

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Wei Khim Ng

2009-02-01

Full Text Available We construct nonlinear extensions of Dirac's relativistic electron equation that preserve its other desirable properties such as locality, separability, conservation of probability and Poincaré invariance. We determine the constraints that the nonlinear term must obey and classify the resultant non-polynomial nonlinearities in a double expansion in the degree of nonlinearity and number of derivatives. We give explicit examples of such nonlinear equations, studying their discrete symmetries and other properties. Motivated by some previously suggested applications we then consider nonlinear terms that simultaneously violate Lorentz covariance and again study various explicit examples. We contrast our equations and construction procedure with others in the literature and also show that our equations are not gauge equivalent to the linear Dirac equation. Finally we outline various physical applications for these equations.

The Correlation between Eating Utensils and Place of Sales in the Contamination of Escherichia coli in Food Sold at Campus Food Stalls

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Dewi Susanna

2015-04-01

Full Text Available Up to now, in general, the safety of food that is sold at any canteens in the campuses, the eating utensils are handled and the food stalls are managed are still uncertain. This research was aimed to understand the correlation between the eating utensils handling and the contamination of Escherichia coli (E. coli in the food sold by the food vendors in the campus. The cross-sectional design research applied on the food stalls in the university campus in Depok with a total number of 173 consumers as respondents. The variables observed as independent variables were the sanitation of the eating utensils and the sanitation of the dining place. The examination method of the Most Probable Number (MPN for E. coli was conducted to assess the food’s hygiene. The data analyzed using the chi-square test and followed by the logistic regression. The result showed that more than half of the food samples (59.54% were contaminated by E. coli. The storage place of the eating utensils was most significantly correlated with the E. coli contamination of the served food with an OR=0.45 (0.21-0.87. Therefore, it is necessary to promote the awareness of this risk and reinforce supervision by the Health Authorities and by the management of the place of sales to provide guidance to the food vendors and to the consumers as well. Further research is recommended to observe the E. coli contamination through clean water, eating utensils, the hands of the consumers and the napkins used to wipe dry the eating utensils.

Presence Of Multi Drug Resistant Coliform Bacteria Isolated From Biofilm Of Sachet And Borehole Waters Sold In Abakaliki Metropolis Ebonyi State Nigeria.

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Okafor Collins Onyebuchi Okeke

2015-06-01

Full Text Available ABSTRACT This study investigated the presence of multi drug resistant coliform bacteria from biofilm of sachet and borehole waters sold in Abakaliki metropolis in Ebonyi State Nigeria. Five hundred 500 samples of water comprising 250 each from selected brand of sachet water retailers and borehole water dispensers from seven locations were sampled for the detection of coliform bacteria from biofilm and to determine their antimicrobial susceptibility using commercially prepared antibiotic discs. Results revealed a high faecal contamination level in sachet waters as Gospel 36 72 Aqua Rapha 30 60 and Bejoy 18 36 were the highest among the sachet water brands examined with Nene and Rock Tama sachet water brands having the lowest contamination level of 612 and 1326 respectively. Borehole samples results revealed that Aboffia had 27 76.93 samples contaminated with faecal bacteria while Azugwu 11 28.5 Azuiyiokwu 18 50 Azuiyiudene 2980 Kpirikpiri 24 66.63 PrescoNtezi 1646.15 and Udensi 22 61.54. Escherichia coli Enterobacter spp and Klebsiella spp were the major contaminants of both sachet and borehole water samples. The bacteria isolates from biofilm of sachet and borehole waters were susceptible to only three of the antibiotics used namely nitrofurantoin amoxycilin and ampicillin. The bacteria were completely resistant to ciprofloxacin tetracycline norbactinnorfloxacin ofloxacin cefuroxime and gentamicin. This showed that they exhibit multi-drug resistance pattern which is a common feature of medically important biofilm bacteria. We therefore report the presence of multi-drug resistant coliform bacteria from biofilm of sachet and borehole waters sold in Abakaliki metropolis Ebonyi State Nigeria.

Modeling plant composition as community continua in a forest landscape with LiDAR and hyperspectral remote sensing.

Science.gov (United States)

Hakkenberg, C R; Peet, R K; Urban, D L; Song, C

2018-01-01

In light of the need to operationalize the mapping of forest composition at landscape scales, this study uses multi-scale nested vegetation sampling in conjunction with LiDAR-hyperspectral remotely sensed data from the G-LiHT airborne sensor to map vascular plant compositional turnover in a compositionally and structurally complex North Carolina Piedmont forest. Reflecting a shift in emphasis from remotely sensing individual crowns to detecting aggregate optical-structural properties of forest stands, predictive maps reflect the composition of entire vascular plant communities, inclusive of those species smaller than the resolution of the remotely sensed imagery, intertwined with proximate taxa, or otherwise obscured from optical sensors by dense upper canopies. Stand-scale vascular plant composition is modeled as community continua: where discrete community-unit classes at different compositional resolutions provide interpretable context for continuous gradient maps that depict n-dimensional compositional complexity as a single, consistent RGB color combination. In total, derived remotely sensed predictors explain 71%, 54%, and 48% of the variation in the first three components of vascular plant composition, respectively. Among all remotely sensed environmental gradients, topography derived from LiDAR ground returns, forest structure estimated from LiDAR all returns, and morphological-biochemical traits determined from hyperspectral imagery each significantly correspond to the three primary axes of floristic composition in the study site. Results confirm the complementarity of LiDAR and hyperspectral sensors for modeling the environmental gradients constraining landscape turnover in vascular plant composition and hold promise for predictive mapping applications spanning local land management to global ecosystem modeling. © 2017 by the Ecological Society of America.

State sales tax rates for soft drinks and snacks sold through grocery stores and vending machines, 2007.

Science.gov (United States)

Chriqui, Jamie F; Eidson, Shelby S; Bates, Hannalori; Kowalczyk, Shelly; Chaloupka, Frank J

2008-07-01

Junk food consumption is associated with rising obesity rates in the United States. While a "junk food" specific tax is a potential public health intervention, a majority of states already impose sales taxes on certain junk food and soft drinks. This study reviews the state sales tax variance for soft drinks and selected snack products sold through grocery stores and vending machines as of January 2007. Sales taxes vary by state, intended retail location (grocery store vs. vending machine), and product. Vended snacks and soft drinks are taxed at a higher rate than grocery items and other food products, generally, indicative of a "disfavored" tax status attributed to vended items. Soft drinks, candy, and gum are taxed at higher rates than are other items examined. Similar tax schemes in other countries and the potential implications of these findings relative to the relationship between price and consumption are discussed.

Functional equations with causal operators

CERN Document Server

Corduneanu, C

2003-01-01

Functional equations encompass most of the equations used in applied science and engineering: ordinary differential equations, integral equations of the Volterra type, equations with delayed argument, and integro-differential equations of the Volterra type. The basic theory of functional equations includes functional differential equations with causal operators. Functional Equations with Causal Operators explains the connection between equations with causal operators and the classical types of functional equations encountered by mathematicians and engineers. It details the fundamentals of linear equations and stability theory and provides several applications and examples.

The Quality of Selected Essential Medicines Sold in Accredited Drug Dispensing Outlets and Pharmacies in Tanzania.

Science.gov (United States)

Kaale, Eliangiringa; Manyanga, Vicky; Chambuso, Mhina; Liana, Jafary; Rutta, Edmund; Embrey, Martha; Layloff, Thomas; Johnson, Keith

2016-01-01

The purpose of this study was to investigate the quality of a select group of medicines sold in accredited drug dispensing outlets (ADDOs) and pharmacies in different regions of Tanzania as part of an in-depth cross-sectional assessment of community access to medicines and community use of medicines. We collected 242 samples of amoxicillin trihydrate, artemether-lumefantrine (ALu), co-trimoxazole, ergometrine maleate, paracetamol, and quinine from selected ADDOs and pharmacies in Mbeya, Morogoro, Singida, and Tanga regions. The analysis included physical examination and testing with validated analytical techniques. Assays for eight of nine products were conducted using high-performance thin-layer chromatography (HPTLC). For ALu tablets, we used a two-tiered approach, where tier 1 was a semi-quantitative Global Pharma Health Fund-Minilab® method and tier 2 was high-performance liquid chromatography (HPLC) as described in The International Pharmacopoeia's monograph for artemether-lumefantrine. The physical examination of samples revealed no defects in the solid and oral liquid dosage forms, but unusual discoloration in an injectable solution, ergometrine maleate. For ALu, the results showed that of 38 samples, 31 (81.6%) passed tier 1 testing and 7 (18.4%) gave inconclusive drug content results. The inconclusive ALu samples were submitted for tier 2 testing and all met the quality standards. The pass rate using the HPTLC and TLC/HPLC assays was 93.8%; the failures were the ergometrine maleate samples purchased from both ADDOs and pharmacies. The disintegration testing of the solid dosage forms was conducted in accordance with US Pharmacopeia monographs. Only two samples of paracetamol, 1.2% of the solid dosage forms, failed to comply to standards. The study revealed a high overall rate of 92.6% of samples that met the quality standards. Although the overall failure rate was 7.4%, it is important to note that this was largely limited to one product and likely due to

The Quality of Selected Essential Medicines Sold in Accredited Drug Dispensing Outlets and Pharmacies in Tanzania.

Directory of Open Access Journals (Sweden)

Eliangiringa Kaale

Full Text Available The purpose of this study was to investigate the quality of a select group of medicines sold in accredited drug dispensing outlets (ADDOs and pharmacies in different regions of Tanzania as part of an in-depth cross-sectional assessment of community access to medicines and community use of medicines.We collected 242 samples of amoxicillin trihydrate, artemether-lumefantrine (ALu, co-trimoxazole, ergometrine maleate, paracetamol, and quinine from selected ADDOs and pharmacies in Mbeya, Morogoro, Singida, and Tanga regions. The analysis included physical examination and testing with validated analytical techniques. Assays for eight of nine products were conducted using high-performance thin-layer chromatography (HPTLC. For ALu tablets, we used a two-tiered approach, where tier 1 was a semi-quantitative Global Pharma Health Fund-Minilab® method and tier 2 was high-performance liquid chromatography (HPLC as described in The International Pharmacopoeia's monograph for artemether-lumefantrine.The physical examination of samples revealed no defects in the solid and oral liquid dosage forms, but unusual discoloration in an injectable solution, ergometrine maleate. For ALu, the results showed that of 38 samples, 31 (81.6% passed tier 1 testing and 7 (18.4% gave inconclusive drug content results. The inconclusive ALu samples were submitted for tier 2 testing and all met the quality standards. The pass rate using the HPTLC and TLC/HPLC assays was 93.8%; the failures were the ergometrine maleate samples purchased from both ADDOs and pharmacies. The disintegration testing of the solid dosage forms was conducted in accordance with US Pharmacopeia monographs. Only two samples of paracetamol, 1.2% of the solid dosage forms, failed to comply to standards. The study revealed a high overall rate of 92.6% of samples that met the quality standards. Although the overall failure rate was 7.4%, it is important to note that this was largely limited to one product and

Evaluating Equating Results: Percent Relative Error for Chained Kernel Equating

Science.gov (United States)

Jiang, Yanlin; von Davier, Alina A.; Chen, Haiwen

2012-01-01

This article presents a method for evaluating equating results. Within the kernel equating framework, the percent relative error (PRE) for chained equipercentile equating was computed under the nonequivalent groups with anchor test (NEAT) design. The method was applied to two data sets to obtain the PRE, which can be used to measure equating…

Handbook of integral equations

CERN Document Server

Polyanin, Andrei D

2008-01-01

This handbook contains over 2,500 integral equations with solutions as well as analytical and numerical methods for solving linear and nonlinear equations. It explores Volterra, Fredholm, WienerHopf, Hammerstein, Uryson, and other equations that arise in mathematics, physics, engineering, the sciences, and economics. This second edition includes new chapters on mixed multidimensional equations and methods of integral equations for ODEs and PDEs, along with over 400 new equations with exact solutions. With many examples added for illustrative purposes, it presents new material on Volterra, Fredholm, singular, hypersingular, dual, and nonlinear integral equations, integral transforms, and special functions.

Full thermomechanical coupling in modelling of micropolar thermoelasticity

Science.gov (United States)

Murashkin, E. V.; Radayev, Y. N.

2018-04-01

The present paper is devoted to plane harmonic waves of displacements and microrotations propagating in fully coupled thermoelastic continua. The analysis is carried out in the framework of linear conventional thermoelastic micropolar continuum model. The reduced energy balance equation and the special form of the Helmholtz free energy are discussed. The constitutive constants providing fully coupling of equations of motion and heat conduction are considered. The dispersion equation is derived and analysed in the form bi-cubic and bi-quadratic polynoms product. The equation are analyzed by the computer algebra system Mathematica. Algebraic forms expressed by complex multivalued square and cubic radicals are obtained for wavenumbers of transverse and longitudinal waves. The exact forms of wavenumbers of a plane harmonic coupled thermoelastic waves are computed.

Ordinary differential equations

CERN Document Server

Greenberg, Michael D

2014-01-01

Features a balance between theory, proofs, and examples and provides applications across diverse fields of study Ordinary Differential Equations presents a thorough discussion of first-order differential equations and progresses to equations of higher order. The book transitions smoothly from first-order to higher-order equations, allowing readers to develop a complete understanding of the related theory. Featuring diverse and interesting applications from engineering, bioengineering, ecology, and biology, the book anticipates potential difficulties in understanding the various solution steps

A description of interventions promoting healthier ready-to-eat meals (to eat in, to take away, or to be delivered sold by specific food outlets in England: a systematic mapping and evidence synthesis

Directory of Open Access Journals (Sweden)

Frances C. Hillier-Brown

2017-01-01

Full Text Available Abstract Background Ready-to-eat meals (to eat in, to take away or to be delivered sold by food outlets are often more energy dense and nutrient poor compared with meals prepared at home, making them a reasonable target for public health intervention. The aim of the research presented in this paper was to systematically identify and describe interventions to promote healthier ready-to-eat meals (to eat in, to take away, or to be delivered sold by specific food outlets in England. Methods A systematic search and sift of the literature, followed by evidence mapping of relevant interventions, was conducted. Food outlets were included if they were located in England, were openly accessible to the public and, as their main business, sold ready-to-eat meals. Academic databases and grey literature were searched. Also, local authorities in England, topic experts, and key health professionals and workers were contacted. Two tiers of evidence synthesis took place: type, content and delivery of each intervention were summarised (Tier 1 and for those interventions that had been evaluated, a narrative synthesis was conducted (Tier 2. Results A total of 75 interventions were identified, the most popular being awards. Businesses were more likely to engage with cost neutral interventions which offered imperceptible changes to price, palatability and portion size. Few interventions involved working upstream with suppliers of food, the generation of customer demand, the exploration of competition effects, and/or reducing portion sizes. Evaluations of interventions were generally limited in scope and of low methodological quality, and many were simple assessments of acceptability. Conclusions Many interventions promoting healthier ready-to-eat meals (to eat in, to take away, or to be delivered sold by specific food outlets in England are taking place; award-type interventions are the most common. Proprietors of food outlets in England that, as their main business

Antioxidant Capacity and Metal Content of Physalis Peruviana L. Fruit Sold in Markets

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Ayse Eken

2014-12-01

Full Text Available Aim: The dietary intake of medicinal food with antioxidant activity and required amounts of trace elements is important to pursue good healthy life. In our study, we aimed to determine the antioxidant capacity and metal content of goldenberry (Physalis peruviana L. fruit sold in markets in Kayseri. Material and Method: The antioxidant capacity of P. peruviana fruit was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH free radical scavenging assay. The DPPH radical scavenger capacity of the methanol extract of fruit was compared with known antioxidants such as ascorbic acid, gallic acid, and butylated hydroxytoluene (BHT as references. The metal content of P. peruviana fruit was measured by using atomic absorption spectrometer (AAS. Results: The fruit of P. peruviana was found to possess DPPH free radical scavenging activity but the antioxidant capacity was lower than the standard substances. Inhibitory concentration 50% (IC50 values of P. peruviana, ascorbic acid, gallic acid, and BHT were determined as 32 mg/ml, 3.8 mg/ml, 3.51 mg/ml, and 1.21 mg/ml, respectively. As a result of the analysis by AAS, it was observed that P. peruviana fruit contented plentiful trace elements and the content of heavy metal was small amount or not detected. Discussion: These observations suggest that the fruit of P. peruviana has a potential source of antioxidant and trace elements of natural origin.

EL ENFOQUE CLÍNICO EN LA FORMACIÓN CONTINUA DE PROFESORES: LA TEORIZACIÓN DEL «OJO PEDAGÓGICO» COMO DESTREZA COMPLEJA

Directory of Open Access Journals (Sweden)

Paola M. Andreucci Annunziata

2012-01-01

Full Text Available El presente trabajo se ocupa del enfoque clínico en la formación continua de profesores. Esteenfoque se ha valido de diversos dispositivos para su aplicación. En este caso y, para rescatar la singularidad y agudeza del enfoque, se propone la noción de «ojo pedagógico»conceptualizadacomo destreza compleja y articuladora de aspectos emocionales y racionales de conocimiento pedagógico, que posibilita atender a la dimensión interaccional profesor - alumno y aplicarla a problemáticas de aula. En una primera parte del artículo se establece el estado actual de laformación permanente de profesores y la ineficacia de las propuestas aplicadas a la fecha, luegose presenta y actualiza el enfoque clínico para la investigación y formación docente y, en la últimaparte, se expone y discute la propuesta de teorización sobre el «ojo pedagógico»,diferenciándola de otras propuestas como la de «tacto» o sensibilidad pedagógica (Van Manen, 1998 y, se deslindan algunos desafíos para su implementación práctica.

Fractional Schroedinger equation

International Nuclear Information System (INIS)

Laskin, Nick

2002-01-01

Some properties of the fractional Schroedinger equation are studied. We prove the Hermiticity of the fractional Hamilton operator and establish the parity conservation law for fractional quantum mechanics. As physical applications of the fractional Schroedinger equation we find the energy spectra of a hydrogenlike atom (fractional 'Bohr atom') and of a fractional oscillator in the semiclassical approximation. An equation for the fractional probability current density is developed and discussed. We also discuss the relationships between the fractional and standard Schroedinger equations

Introduction to differential equations

CERN Document Server

Taylor, Michael E

2011-01-01

The mathematical formulations of problems in physics, economics, biology, and other sciences are usually embodied in differential equations. The analysis of the resulting equations then provides new insight into the original problems. This book describes the tools for performing that analysis. The first chapter treats single differential equations, emphasizing linear and nonlinear first order equations, linear second order equations, and a class of nonlinear second order equations arising from Newton's laws. The first order linear theory starts with a self-contained presentation of the exponen

Stochastic optimal control, forward-backward stochastic differential equations and the Schroedinger equation

Energy Technology Data Exchange (ETDEWEB)

Paul, Wolfgang; Koeppe, Jeanette [Institut fuer Physik, Martin Luther Universitaet, 06099 Halle (Germany); Grecksch, Wilfried [Institut fuer Mathematik, Martin Luther Universitaet, 06099 Halle (Germany)

2016-07-01

The standard approach to solve a non-relativistic quantum problem is through analytical or numerical solution of the Schroedinger equation. We show a way to go around it. This way is based on the derivation of the Schroedinger equation from conservative diffusion processes and the establishment of (several) stochastic variational principles leading to the Schroedinger equation under the assumption of a kinematics described by Nelson's diffusion processes. Mathematically, the variational principle can be considered as a stochastic optimal control problem linked to the forward-backward stochastic differential equations of Nelson's stochastic mechanics. The Hamilton-Jacobi-Bellmann equation of this control problem is the Schroedinger equation. We present the mathematical background and how to turn it into a numerical scheme for analyzing a quantum system without using the Schroedinger equation and exemplify the approach for a simple 1d problem.

Averaged RMHD equations

International Nuclear Information System (INIS)

Ichiguchi, Katsuji

1998-01-01

A new reduced set of resistive MHD equations is derived by averaging the full MHD equations on specified flux coordinates, which is consistent with 3D equilibria. It is confirmed that the total energy is conserved and the linearized equations for ideal modes are self-adjoint. (author)

Differential equations

CERN Document Server

Tricomi, FG

2013-01-01

Based on his extensive experience as an educator, F. G. Tricomi wrote this practical and concise teaching text to offer a clear idea of the problems and methods of the theory of differential equations. The treatment is geared toward advanced undergraduates and graduate students and addresses only questions that can be resolved with rigor and simplicity.Starting with a consideration of the existence and uniqueness theorem, the text advances to the behavior of the characteristics of a first-order equation, boundary problems for second-order linear equations, asymptotic methods, and diff

How to obtain the covariant form of Maxwell's equations from the continuity equation

International Nuclear Information System (INIS)

Heras, Jose A

2009-01-01

The covariant Maxwell equations are derived from the continuity equation for the electric charge. This result provides an axiomatic approach to Maxwell's equations in which charge conservation is emphasized as the fundamental axiom underlying these equations

Determination of contamination pathways of phthalates in food products sold on the Belgian market.

Science.gov (United States)

Van Holderbeke, Mirja; Geerts, Lieve; Vanermen, Guido; Servaes, Kelly; Sioen, Isabelle; De Henauw, Stefaan; Fierens, Tine

2014-10-01

As numerous studies have indicated that food ingestion is the most important exposure pathway to several phthalates, this study aimed to determine possible contamination pathways of phthalates in food products sold on the Belgian market. To do this, concentrations of eight phthalates (dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), benzylbutyl phthalate (BBP), dicyclohexyl phthalate (DCHP), di(2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DnOP)) were determined in 591 foods and 30 packaging materials. In general, the four most prominent phthalates in Belgian food products were DEHP, DiBP, DnBP and BBP. Special attention was given to the origin of these phthalates in bread, since high phthalate concentrations (especially DEHP) were determined in this frequently consumed food product. Phthalates seemed to occur in Belgian bread samples due to the use of contaminated ingredients (i.e. use of contaminated flour) as well as due to migration from phthalate containing contact materials used during production (e.g. coated baking trays). Also the results of the conducted concentration profiles of apple, bread, salami and two cheese types revealed the important role of processing - and not packaging - on phthalate contents in foods. Copyright © 2014 Elsevier Inc. All rights reserved.

Strong increase in total delta-THC in cannabis preparations sold in Dutch coffee shops.

Science.gov (United States)

Pijlman, F T A; Rigter, S M; Hoek, J; Goldschmidt, H M J; Niesink, R J M

2005-06-01

The total concentration of THC has been monitored in cannabis preparations sold in Dutch coffee shops since 1999. This annual monitoring was issued by the Ministry of Health after reports of increased potency. The level of the main psychoactive compound, Delta9-tetrahydrocannabinol (THC), is measured in marijuana and hashish. A comparison is made between imported and Dutch preparations, and between seasons. Samples of cannabis preparations from randomly selected coffee shops were analyzed using gas chromatography (GC-FID) for THC, CBD and CBN. In 2004, the average THC level of Dutch home-grown marijuana (Nederwiet) (20.4% THC) was significantly higher than that of imported marijuana (7.0% THC). Hashish derived from Dutch marijuana (Nederhasj) contained 39.3% THC in 2004, compared with 18.2% THC in imported hashish. The average THC percentage of Dutch marijuana, Dutch hashish and imported hashish was significantly higher than in previous years. It nearly doubled over 5 years. During this period, the THC percentage in imported marijuana remained unchanged. A higher price had to be paid for cannabis with higher levels of THC. Whether the increase in THC levels causes increased health risks for users can only be concluded when more data are available on adjusted patterns of use, abuse liability, bioavailability and levels of THC in the brain.

A generalized simplest equation method and its application to the Boussinesq-Burgers equation.

Science.gov (United States)

Sudao, Bilige; Wang, Xiaomin

2015-01-01

In this paper, a generalized simplest equation method is proposed to seek exact solutions of nonlinear evolution equations (NLEEs). In the method, we chose a solution expression with a variable coefficient and a variable coefficient ordinary differential auxiliary equation. This method can yield a Bäcklund transformation between NLEEs and a related constraint equation. By dealing with the constraint equation, we can derive infinite number of exact solutions for NLEEs. These solutions include the traveling wave solutions, non-traveling wave solutions, multi-soliton solutions, rational solutions, and other types of solutions. As applications, we obtained wide classes of exact solutions for the Boussinesq-Burgers equation by using the generalized simplest equation method.

On separable Pauli equations

International Nuclear Information System (INIS)

Zhalij, Alexander

2002-01-01

We classify (1+3)-dimensional Pauli equations for a spin-(1/2) particle interacting with the electro-magnetic field, that are solvable by the method of separation of variables. As a result, we obtain the 11 classes of vector-potentials of the electro-magnetic field A(t,x(vector sign))=(A 0 (t,x(vector sign)), A(vector sign)(t,x(vector sign))) providing separability of the corresponding Pauli equations. It is established, in particular, that the necessary condition for the Pauli equation to be separable into second-order matrix ordinary differential equations is its equivalence to the system of two uncoupled Schroedinger equations. In addition, the magnetic field has to be independent of spatial variables. We prove that coordinate systems and the vector-potentials of the electro-magnetic field providing the separability of the corresponding Pauli equations coincide with those for the Schroedinger equations. Furthermore, an efficient algorithm for constructing all coordinate systems providing the separability of Pauli equation with a fixed vector-potential of the electro-magnetic field is developed. Finally, we describe all vector-potentials A(t,x(vector sign)) that (a) provide the separability of Pauli equation, (b) satisfy vacuum Maxwell equations without currents, and (c) describe non-zero magnetic field

Modified Method of Simplest Equation Applied to the Nonlinear Schrödinger Equation

Science.gov (United States)

Vitanov, Nikolay K.; Dimitrova, Zlatinka I.

2018-03-01

We consider an extension of the methodology of the modified method of simplest equation to the case of use of two simplest equations. The extended methodology is applied for obtaining exact solutions of model nonlinear partial differential equations for deep water waves: the nonlinear Schrödinger equation. It is shown that the methodology works also for other equations of the nonlinear Schrödinger kind.

Elliptic and solitary wave solutions for Bogoyavlenskii equations system, couple Boiti-Leon-Pempinelli equations system and Time-fractional Cahn-Allen equation

Directory of Open Access Journals (Sweden)

Mostafa M.A. Khater

Full Text Available In this article and for the first time, we introduce and describe Khater method which is a new technique for solving nonlinear partial differential equations (PDEs.. We apply this method for each of the following models Bogoyavlenskii equation, couple Boiti-Leon-Pempinelli system and Time-fractional Cahn-Allen equation. Khater method is very powerful, Effective, felicitous and fabulous method to get exact and solitary wave solution of (PDEs.. Not only just like that but it considers too one of the general methods for solving that kind of equations since it involves some methods as we will see in our discuss of the results. We make a comparison between the results of this new method and another method. Keywords: Bogoyavlenskii equations system, Couple Boiti-Leon-Pempinelli equations system, Time-fractional Cahn-Allen equation, Khater method, Traveling wave solutions, Solitary wave solutions

Modified Method of Simplest Equation Applied to the Nonlinear Schrödinger Equation

Directory of Open Access Journals (Sweden)

Vitanov Nikolay K.

2018-03-01

Full Text Available We consider an extension of the methodology of the modified method of simplest equation to the case of use of two simplest equations. The extended methodology is applied for obtaining exact solutions of model nonlinear partial differential equations for deep water waves: the nonlinear Schrödinger equation. It is shown that the methodology works also for other equations of the nonlinear Schrödinger kind.

Efficiency and fairness of the terms and conditions under which electricity is sold to British manufacturing establishments. [Optimality of Bulk Supply Tariff questioned

Energy Technology Data Exchange (ETDEWEB)

Cannon, C M

1977-06-01

This paper reports on an inquiry into three aspects of the terms and conditions under which electricity is sold to manufacturing establishments. These aspects are the adequacy of information services; the fairness of the pricing behavior of electricity boards; and the efficiency of one schedule of charges agreed with a large industrial consumer. Except the charge for night-time units, the schedule of charges agreed with the large consumer appears to be efficient. However, regional statistics on the percentage of high-voltage customers that pay agreed terms rather than published tariffs suggest that the pricing behavior by boards is often unfair.

Integrable dissipative nonlinear second order differential equations via factorizations and Abel equations

Energy Technology Data Exchange (ETDEWEB)

Mancas, Stefan C. [Department of Mathematics, Embry–Riddle Aeronautical University, Daytona Beach, FL 32114-3900 (United States); Rosu, Haret C., E-mail: hcr@ipicyt.edu.mx [IPICYT, Instituto Potosino de Investigacion Cientifica y Tecnologica, Apdo Postal 3-74 Tangamanga, 78231 San Luis Potosí, SLP (Mexico)

2013-09-02

We emphasize two connections, one well known and another less known, between the dissipative nonlinear second order differential equations and the Abel equations which in their first-kind form have only cubic and quadratic terms. Then, employing an old integrability criterion due to Chiellini, we introduce the corresponding integrable dissipative equations. For illustration, we present the cases of some integrable dissipative Fisher, nonlinear pendulum, and Burgers–Huxley type equations which are obtained in this way and can be of interest in applications. We also show how to obtain Abel solutions directly from the factorization of second order nonlinear equations.

Morphological and chemical analyses of Eriocauli Flos sold in Taiwan markets

Directory of Open Access Journals (Sweden)

I-Jung Lee

2017-10-01

Full Text Available Eriocauli Flos (Gujingcao; EF, the dried capitulum with the peduncle of Eriocaulon buergerianum Koern. (Eriocaulaceae, is a Chinese herbal medicine for treating eye diseases and inflammation. However, several species of the Eriocaulon genus are used as substitutes in different areas. To examine the species of EF used in Taiwan and to establish the quality control platform, morphological and chemical analyses have been performed. Ten major compounds, including apigenin (7 and its 7-O-β-D-glucopyranoside (1 and 7-O-(6-O-E-coumaroyl-β-D-glucopyranoside (6, hispidulin (8 and its 7-O-β-D-glucopyranoside (2 and 7-O-(6-O-E-coumaroyl-β-D-glucopyranoside (5, jaceosidin (9 and its 7-O-β-D-glucopyranoside (3, and toralactone (10 and its 9-O-β-D-glucopyranosyl(1→6-β-D-glucopyranoside (4, were isolated and identified from commercially available EF. Morphological investigation showed that two kinds of EFs and most of the EFs sold in Taiwan herbal markets are capitulum without the peduncle. A simultaneous high performance liquid chromatography and ultra performance liquid chromatography analyses of multiple components (1–10 in commercially available EFs, collected from different areas of Taiwan, was conducted. Results showed wide variations in morphology and chemical profiles between capitulum with and without the peduncle. In comparison with an authentic E. buergerianum, we found not only the morphology but also the chemical profile was different from both collected samples. In terms of the morphological examination, the samples without peduncle are closer to the authentic one. To ensure the correct EF materia medica is used in Taiwan so as to guarantee their therapeutic efficacy in clinical practice, further monitoring is necessary.

On the Existence and the Applications of Modified Equations for Stochastic Differential Equations

KAUST Repository

Zygalakis, K. C.

2011-01-01

In this paper we describe a general framework for deriving modified equations for stochastic differential equations (SDEs) with respect to weak convergence. Modified equations are derived for a variety of numerical methods, such as the Euler or the Milstein method. Existence of higher order modified equations is also discussed. In the case of linear SDEs, using the Gaussianity of the underlying solutions, we derive an SDE which the numerical method solves exactly in the weak sense. Applications of modified equations in the numerical study of Langevin equations is also discussed. © 2011 Society for Industrial and Applied Mathematics.

An Auxiliary Equation for the Bellman Equation in a One-Dimensional Ergodic Control

International Nuclear Information System (INIS)

Fujita, Y.

2001-01-01

In this paper we consider the Bellman equation in a one-dimensional ergodic control. Our aim is to show the existence and the uniqueness of its solution under general assumptions. For this purpose we introduce an auxiliary equation whose solution gives the invariant measure of the diffusion corresponding to an optimal control. Using this solution, we construct a solution to the Bellman equation. Our method of using this auxiliary equation has two advantages in the one-dimensional case. First, we can solve the Bellman equation under general assumptions. Second, this auxiliary equation gives an optimal Markov control explicitly in many examples

Covariant field equations in supergravity

Energy Technology Data Exchange (ETDEWEB)

Vanhecke, Bram [KU Leuven, Institute for Theoretical Physics, Leuven (Belgium); Ghent University, Faculty of Physics, Gent (Belgium); Proeyen, Antoine van [KU Leuven, Institute for Theoretical Physics, Leuven (Belgium)

2017-12-15

Covariance is a useful property for handling supergravity theories. In this paper, we prove a covariance property of supergravity field equations: under reasonable conditions, field equations of supergravity are covariant modulo other field equations. We prove that for any supergravity there exist such covariant equations of motion, other than the regular equations of motion, that are equivalent to the latter. The relations that we find between field equations and their covariant form can be used to obtain multiplets of field equations. In practice, the covariant field equations are easily found by simply covariantizing the ordinary field equations. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Covariant field equations in supergravity

International Nuclear Information System (INIS)

Vanhecke, Bram; Proeyen, Antoine van

2017-01-01

Covariance is a useful property for handling supergravity theories. In this paper, we prove a covariance property of supergravity field equations: under reasonable conditions, field equations of supergravity are covariant modulo other field equations. We prove that for any supergravity there exist such covariant equations of motion, other than the regular equations of motion, that are equivalent to the latter. The relations that we find between field equations and their covariant form can be used to obtain multiplets of field equations. In practice, the covariant field equations are easily found by simply covariantizing the ordinary field equations. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Reduction of lattice equations to the Painlevé equations: PIV and PV

Science.gov (United States)

Nakazono, Nobutaka

2018-02-01

In this paper, we construct a new relation between Adler-Bobenko-Suris equations and Painlevé equations. Moreover, using this connection we construct the difference-differential Lax representations of the fourth and fifth Painlevé equations.

Test equating methods and practices

CERN Document Server

Kolen, Michael J

1995-01-01

In recent years, many researchers in the psychology and statistical communities have paid increasing attention to test equating as issues of using multiple test forms have arisen and in response to criticisms of traditional testing techniques This book provides a practically oriented introduction to test equating which both discusses the most frequently used equating methodologies and covers many of the practical issues involved The main themes are - the purpose of equating - distinguishing between equating and related methodologies - the importance of test equating to test development and quality control - the differences between equating properties, equating designs, and equating methods - equating error, and the underlying statistical assumptions for equating The authors are acknowledged experts in the field, and the book is based on numerous courses and seminars they have presented As a result, educators, psychometricians, professionals in measurement, statisticians, and students coming to the subject for...

On generalized fractional vibration equation

International Nuclear Information System (INIS)

Dai, Hongzhe; Zheng, Zhibao; Wang, Wei

2017-01-01

Highlights: • The paper presents a generalized fractional vibration equation for arbitrary viscoelastically damped system. • Some classical vibration equations can be derived from the developed equation. • The analytic solution of developed equation is derived under some special cases. • The generalized equation is particularly useful for developing new fractional equivalent linearization method. - Abstract: In this paper, a generalized fractional vibration equation with multi-terms of fractional dissipation is developed to describe the dynamical response of an arbitrary viscoelastically damped system. It is shown that many classical equations of motion, e.g., the Bagley–Torvik equation, can be derived from the developed equation. The Laplace transform is utilized to solve the generalized equation and the analytic solution under some special cases is derived. Example demonstrates the generalized transfer function of an arbitrary viscoelastic system.

Differential equations for dummies

CERN Document Server

Holzner, Steven

2008-01-01

The fun and easy way to understand and solve complex equations Many of the fundamental laws of physics, chemistry, biology, and economics can be formulated as differential equations. This plain-English guide explores the many applications of this mathematical tool and shows how differential equations can help us understand the world around us. Differential Equations For Dummies is the perfect companion for a college differential equations course and is an ideal supplemental resource for other calculus classes as well as science and engineering courses. It offers step-by-step techniques, practical tips, numerous exercises, and clear, concise examples to help readers improve their differential equation-solving skills and boost their test scores.

Every Equation Tells a Story: Using Equation Dictionaries in Introductory Geophysics

Science.gov (United States)

Caplan-Auerbach, Jacqueline

2009-01-01

Many students view equations as a series of variables and operators into which numbers should be plugged rather than as representative of a physical process. To solve a problem they may simply look for an equation with the correct variables and assume it meets their needs, rather than selecting an equation that represents the appropriate physical…

Fundamental equations for two-phase flow. Part 1: general conservation equations. Part 2: complement and remarks; Equations fondamentales des ecoulements diphasiques. Premiere partie: equations generales de conservation. Deuxieme partie: complements et remarques

Energy Technology Data Exchange (ETDEWEB)

Delhaye, J M [Commissariat a l' Energie Atomique, 38 - Grenoble (France). Centre d' Etudes Nucleaires

1968-12-01

This report deals with the general equations of mass conservation, of momentum conservation, and energy conservation in the case of a two-phase flow. These equations are presented in several forms starting from integral equations which are assumed initially a priori. 1. Equations with local instantaneous variables, and interfacial conditions; 2. Equations with mean instantaneous variables in a cross-section, and practical applications: these equations include an important experimental value which is the ratio of the cross-section of passage of one phase to the total cross-section of a flow-tube. 3. Equations with a local statistical mean, and equations averaged over a period of time: A more advanced attempt to relate theory and experiment consists in taking the statistical averages of local equations. Equations are then obtained involving variables which are averaged over a period of time with the help of an ergodic assumption. 4. Combination of statistical averages and averages over a cross-section: in this study are considered the local variables averaged statistically, then averaged over the cross-section, and also the variables averaged over the section and then averaged statistically. 5. General equations concerning emulsions: In this case a phase exists in a locally very finely divided form. This peculiarity makes it possible to define a volume concentration, and to draw up equations which have numerous applications. - Certain points arising in the first part of this report concerning general mass conservation equations for two-phase flow have been completed and clarified. The terms corresponding to the interfacial tension have been introduced into the general equations. The interfacial conditions have thus been generalized. A supplementary step has still to be carried out: it has, in effect, been impossible to take the interfacial tension into account in the case of emulsions. It was then appeared interesting to compare this large group of fundamental

Fundamental equations for two-phase flow. Part 1: general conservation equations. Part 2: complement and remarks; Equations fondamentales des ecoulements diphasiques. Premiere partie: equations generales de conservation. Deuxieme partie: complements et remarques

Energy Technology Data Exchange (ETDEWEB)

Delhaye, J.M. [Commissariat a l' Energie Atomique, 38 - Grenoble (France). Centre d' Etudes Nucleaires

1968-12-01

This report deals with the general equations of mass conservation, of momentum conservation, and energy conservation in the case of a two-phase flow. These equations are presented in several forms starting from integral equations which are assumed initially a priori. 1. Equations with local instantaneous variables, and interfacial conditions; 2. Equations with mean instantaneous variables in a cross-section, and practical applications: these equations include an important experimental value which is the ratio of the cross-section of passage of one phase to the total cross-section of a flow-tube. 3. Equations with a local statistical mean, and equations averaged over a period of time: A more advanced attempt to relate theory and experiment consists in taking the statistical averages of local equations. Equations are then obtained involving variables which are averaged over a period of time with the help of an ergodic assumption. 4. Combination of statistical averages and averages over a cross-section: in this study are considered the local variables averaged statistically, then averaged over the cross-section, and also the variables averaged over the section and then averaged statistically. 5. General equations concerning emulsions: In this case a phase exists in a locally very finely divided form. This peculiarity makes it possible to define a volume concentration, and to draw up equations which have numerous applications. - Certain points arising in the first part of this report concerning general mass conservation equations for two-phase flow have been completed and clarified. The terms corresponding to the interfacial tension have been introduced into the general equations. The interfacial conditions have thus been generalized. A supplementary step has still to be carried out: it has, in effect, been impossible to take the interfacial tension into account in the case of emulsions. It was then appeared interesting to compare this large group of fundamental

Equating TIMSS Mathematics Subtests with Nonlinear Equating Methods Using NEAT Design: Circle-Arc Equating Approaches

Science.gov (United States)

Ozdemir, Burhanettin

2017-01-01

The purpose of this study is to equate Trends in International Mathematics and Science Study (TIMSS) mathematics subtest scores obtained from TIMSS 2011 to scores obtained from TIMSS 2007 form with different nonlinear observed score equating methods under Non-Equivalent Anchor Test (NEAT) design where common items are used to link two or more test…

La parábola como lugar geométrico : una formación continua de profesores de matemáticas basada en la Teoría de Registros de Representación Semiótica

OpenAIRE

Lara Torres, Isabel Mercedes

2016-01-01

La presente investigación aborda la parábola como lugar geométrico en una formación continua de profesores de matemáticas por medio de una secuencia de actividades con el uso del Geogebra y que toma la Teoría de Registros de Representación Semiótica como base teórica. Por ello, nos planteamos la siguiente pregunta de investigación: ¿Cómo profesores de matemática movilizan la noción de parábola como lugar geométrico cuando coordinan diferentes registros de representación semióti...

Solving polynomial differential equations by transforming them to linear functional-differential equations

OpenAIRE

Nahay, John Michael

2008-01-01

We present a new approach to solving polynomial ordinary differential equations by transforming them to linear functional equations and then solving the linear functional equations. We will focus most of our attention upon the first-order Abel differential equation with two nonlinear terms in order to demonstrate in as much detail as possible the computations necessary for a complete solution. We mention in our section on further developments that the basic transformation idea can be generali...

Lorentz-force equations as Heisenberg equations for a quantum system in the euclidean space

International Nuclear Information System (INIS)

Rodriguez D, R.

2007-01-01

In an earlier work, the dynamic equations for a relativistic charged particle under the action of electromagnetic fields were formulated by R. Yamaleev in terms of external, as well as internal momenta. Evolution equations for external momenta, the Lorentz-force equations, were derived from the evolution equations for internal momenta. The mapping between the observables of external and internal momenta are related by Viete formulae for a quadratic polynomial, the characteristic polynomial of the relativistic dynamics. In this paper we show that the system of dynamic equations, can be cast into the Heisenberg scheme for a four-dimensional quantum system. Within this scheme the equations in terms of internal momenta play the role of evolution equations for a state vector, whereas the external momenta obey the Heisenberg equation for an operator evolution. The solutions of the Lorentz-force equation for the motion inside constant electromagnetic fields are presented via pentagonometric functions. (Author)

Differential Equation over Banach Algebra

OpenAIRE

Kleyn, Aleks

2018-01-01

In the book, I considered differential equations of order $1$ over Banach $D$-algebra: differential equation solved with respect to the derivative; exact differential equation; linear homogeneous equation. In noncommutative Banach algebra, initial value problem for linear homogeneous equation has infinitely many solutions.

Elements of partial differential equations

CERN Document Server

Sneddon, Ian Naismith

1957-01-01

Geared toward students of applied rather than pure mathematics, this volume introduces elements of partial differential equations. Its focus is primarily upon finding solutions to particular equations rather than general theory.Topics include ordinary differential equations in more than two variables, partial differential equations of the first and second orders, Laplace's equation, the wave equation, and the diffusion equation. A helpful Appendix offers information on systems of surfaces, and solutions to the odd-numbered problems appear at the end of the book. Readers pursuing independent st

New exact solutions to MKDV-Burgers equation and (2 + 1)-dimensional dispersive long wave equation via extended Riccati equation method

International Nuclear Information System (INIS)

Kong Cuicui; Wang Dan; Song Lina; Zhang Hongqing

2009-01-01

In this paper, with the aid of symbolic computation and a general ansaetz, we presented a new extended rational expansion method to construct new rational formal exact solutions to nonlinear partial differential equations. In order to illustrate the effectiveness of this method, we apply it to the MKDV-Burgers equation and the (2 + 1)-dimensional dispersive long wave equation, then several new kinds of exact solutions are successfully obtained by using the new ansaetz. The method can also be applied to other nonlinear partial differential equations.

Introduction to partial differential equations

CERN Document Server

Greenspan, Donald

2000-01-01

Designed for use in a one-semester course by seniors and beginning graduate students, this rigorous presentation explores practical methods of solving differential equations, plus the unifying theory underlying the mathematical superstructure. Topics include basic concepts, Fourier series, second-order partial differential equations, wave equation, potential equation, heat equation, approximate solution of partial differential equations, and more. Exercises appear at the ends of most chapters. 1961 edition.

A New Fractional Projective Riccati Equation Method for Solving Fractional Partial Differential Equations

International Nuclear Information System (INIS)

Feng Qing-Hua

2014-01-01

In this paper, a new fractional projective Riccati equation method is proposed to establish exact solutions for fractional partial differential equations in the sense of modified Riemann—Liouville derivative. This method can be seen as the fractional version of the known projective Riccati equation method. For illustrating the validity of this method, we apply this method to solve the space-time fractional Whitham—Broer—Kaup (WBK) equations and the nonlinear fractional Sharma—Tasso—Olever (STO) equation, and as a result, some new exact solutions for them are obtained. (general)

A new sine-Gordon equation expansion algorithm to investigate some special nonlinear differential equations

International Nuclear Information System (INIS)

Yan Zhenya

2005-01-01

A new transformation method is developed using the general sine-Gordon travelling wave reduction equation and a generalized transformation. With the aid of symbolic computation, this method can be used to seek more types of solutions of nonlinear differential equations, which include not only the known solutions derived by some known methods but new solutions. Here we choose the double sine-Gordon equation, the Magma equation and the generalized Pochhammer-Chree (PC) equation to illustrate the method. As a result, many types of new doubly periodic solutions are obtained. Moreover when using the method to these special nonlinear differential equations, some transformations are firstly needed. The method can be also extended to other nonlinear differential equations

Singular stochastic differential equations

CERN Document Server

Cherny, Alexander S

2005-01-01

The authors introduce, in this research monograph on stochastic differential equations, a class of points termed isolated singular points. Stochastic differential equations possessing such points (called singular stochastic differential equations here) arise often in theory and in applications. However, known conditions for the existence and uniqueness of a solution typically fail for such equations. The book concentrates on the study of the existence, the uniqueness, and, what is most important, on the qualitative behaviour of solutions of singular stochastic differential equations. This is done by providing a qualitative classification of isolated singular points, into 48 possible types.

Consumer use and understanding of labelling information on edible marijuana products sold for recreational use in the states of Colorado and Washington.

Science.gov (United States)

Kosa, Katherine M; Giombi, Kristen C; Rains, Caroline B; Cates, Sheryl C

2017-05-01

In 2014, the states of Colorado and Washington began allowing retail sales of marijuana for recreational use. The regulatory agencies in these states have implemented specific labelling requirements for edible marijuana products sold for recreational use to help address concerns such as delayed activation time, accidental ingestion, and proper dosing. We conducted 12 focus groups with 94 adult consumers and nonconsumers of edibles in Denver and Seattle to collect information on their use and understanding of labelling information on edible marijuana products sold for recreational use. Specifically, we asked participants about the usefulness, attractiveness, ease of comprehension, relevancy, and acceptability of the label information. Some focus group participants look for and read specific information, such as the potency profile and serving size statement, but do not read or were unfamiliar with other labelling features. The focus groups revealed that participants have some concerns about the current labelling of edibles. In particular, participants were concerned that there is too much information on the labels so consumers may not read the label, there is no obvious indication that the product contains marijuana (e.g., a Universal Symbol), and the information on consumption advice is not clear. Participants in both locations suggested that education in a variety of formats, such as web- and video-based education, would be useful in informing consumers about the possible risks of edibles. The focus group findings suggest that improvements are needed in the labelling of edibles to prevent unintentional ingestion among adult nonusers and help ensure proper dosing and safe consumption among adult users. These findings, along with lessons learned from Colorado and Washington, can help inform the labelling of edibles as additional states allow the sale of edibles for recreational use. Copyright © 2017 Elsevier B.V. All rights reserved.

Reactimeter dispersion equation

OpenAIRE

A.G. Yuferov

2016-01-01

The aim of this work is to derive and analyze a reactimeter metrological model in the form of the dispersion equation which connects reactimeter input/output signal dispersions with superimposed random noise at the inlet. It is proposed to standardize the reactimeter equation form, presenting the main reactimeter computing unit by a convolution equation. Hence, the reactimeter metrological characteristics are completely determined by this unit hardware function which represents a transient re...

La utilidad del uso de datos administrativos en la investigación de salud pública: la Muestra continua de vidas laborales

Directory of Open Access Journals (Sweden)

María Andrée López

2014-07-01

Full Text Available La utilización de datos administrativos es práctica habitual en la investigación en salud pública. El objetivo de este trabajo es describir la Muestra continua de vidas laborales (MCVL y su utilidad en la investigación en salud. La MCVL está construida sobre registros que generan todos los contactos con la Seguridad Social (laborales, incapacidades, etc., más datos fiscales (percepciones dinerarias, ingresos, etc. y del padrón (nivel educativo, país de nacimiento, etc., sin que sea posible la identificación individual. La MCVL se inició en 2004 con el 4% (1,1 millón de personas del total de población cotizante o perceptora de la Seguridad Social. Los datos de las personas que forman parte de la MCVL son actualizados anualmente, y se sustituyen las bajas producidas. Este diseño continuo permite generar una cohorte con información de la vida laboral y económica, y valorar su asociación con la incapacidad laboral. El supuesto de conexión con la historia clínica posibilitaría el análisis de otros resultados de salud.

Symmetries and Invariants of the Time-dependent Oscillator Equation and the Envelope Equation

CERN Document Server

Qin, Hong

2005-01-01

Single-particle dynamics in a time-dependent focusing field is examined. The existence of the Courant-Snyder invariant* is fundamentally the result of the corresponding symmetry admitted by the oscillator equation with time-dependent frequency.** A careful analysis of the admitted symmetries reveals a deeper connection between the nonlinear envelope equation and the oscillator equation. A general theorem regarding the symmetries and invariants of the envelope equation, which includes the existence of the Courant-Snyder invariant as a special case, is demonstrated. The symmetries of the envelope equation enable a fast algorithm for finding matched solutions without using the conventional iterative shooting method.

A generalized fractional sub-equation method for fractional differential equations with variable coefficients

International Nuclear Information System (INIS)

Tang, Bo; He, Yinnian; Wei, Leilei; Zhang, Xindong

2012-01-01

In this Letter, a generalized fractional sub-equation method is proposed for solving fractional differential equations with variable coefficients. Being concise and straightforward, this method is applied to the space–time fractional Gardner equation with variable coefficients. As a result, many exact solutions are obtained including hyperbolic function solutions, trigonometric function solutions and rational solutions. It is shown that the considered method provides a very effective, convenient and powerful mathematical tool for solving many other fractional differential equations in mathematical physics. -- Highlights: ► Study of fractional differential equations with variable coefficients plays a role in applied physical sciences. ► It is shown that the proposed algorithm is effective for solving fractional differential equations with variable coefficients. ► The obtained solutions may give insight into many considerable physical processes.

True amplitude wave equation migration arising from true amplitude one-way wave equations

Science.gov (United States)

Zhang, Yu; Zhang, Guanquan; Bleistein, Norman

2003-10-01

One-way wave operators are powerful tools for use in forward modelling and inversion. Their implementation, however, involves introduction of the square root of an operator as a pseudo-differential operator. Furthermore, a simple factoring of the wave operator produces one-way wave equations that yield the same travel times as the full wave equation, but do not yield accurate amplitudes except for homogeneous media and for almost all points in heterogeneous media. Here, we present augmented one-way wave equations. We show that these equations yield solutions for which the leading order asymptotic amplitude as well as the travel time satisfy the same differential equations as the corresponding functions for the full wave equation. Exact representations of the square-root operator appearing in these differential equations are elusive, except in cases in which the heterogeneity of the medium is independent of the transverse spatial variables. Here, we address the fully heterogeneous case. Singling out depth as the preferred direction of propagation, we introduce a representation of the square-root operator as an integral in which a rational function of the transverse Laplacian appears in the integrand. This allows us to carry out explicit asymptotic analysis of the resulting one-way wave equations. To do this, we introduce an auxiliary function that satisfies a lower dimensional wave equation in transverse spatial variables only. We prove that ray theory for these one-way wave equations leads to one-way eikonal equations and the correct leading order transport equation for the full wave equation. We then introduce appropriate boundary conditions at z = 0 to generate waves at depth whose quotient leads to a reflector map and an estimate of the ray theoretical reflection coefficient on the reflector. Thus, these true amplitude one-way wave equations lead to a 'true amplitude wave equation migration' (WEM) method. In fact, we prove that applying the WEM imaging condition

First-order partial differential equations

CERN Document Server

Rhee, Hyun-Ku; Amundson, Neal R

2001-01-01

This first volume of a highly regarded two-volume text is fully usable on its own. After going over some of the preliminaries, the authors discuss mathematical models that yield first-order partial differential equations; motivations, classifications, and some methods of solution; linear and semilinear equations; chromatographic equations with finite rate expressions; homogeneous and nonhomogeneous quasilinear equations; formation and propagation of shocks; conservation equations, weak solutions, and shock layers; nonlinear equations; and variational problems. Exercises appear at the end of mo

Equating Multidimensional Tests under a Random Groups Design: A Comparison of Various Equating Procedures

Science.gov (United States)

Lee, Eunjung

2013-01-01

The purpose of this research was to compare the equating performance of various equating procedures for the multidimensional tests. To examine the various equating procedures, simulated data sets were used that were generated based on a multidimensional item response theory (MIRT) framework. Various equating procedures were examined, including…

Comparing the IRT Pre-equating and Section Pre-equating: A Simulation Study.

Science.gov (United States)

Hwang, Chi-en; Cleary, T. Anne

The results obtained from two basic types of pre-equatings of tests were compared: the item response theory (IRT) pre-equating and section pre-equating (SPE). The simulated data were generated from a modified three-parameter logistic model with a constant guessing parameter. Responses of two replication samples of 3000 examinees on two 72-item…

Beginning partial differential equations

CERN Document Server

O'Neil, Peter V

2014-01-01

A broad introduction to PDEs with an emphasis on specialized topics and applications occurring in a variety of fields Featuring a thoroughly revised presentation of topics, Beginning Partial Differential Equations, Third Edition provides a challenging, yet accessible,combination of techniques, applications, and introductory theory on the subjectof partial differential equations. The new edition offers nonstandard coverageon material including Burger's equation, the telegraph equation, damped wavemotion, and the use of characteristics to solve nonhomogeneous problems. The Third Edition is or

A new formulation of equations of compressible fluids by analogy with Maxwell's equations

International Nuclear Information System (INIS)

Kambe, Tsutomu

2010-01-01

A compressible ideal fluid is governed by Euler's equation of motion and equations of continuity, entropy and vorticity. This system can be reformulated in a form analogous to that of electromagnetism governed by Maxwell's equations with source terms. The vorticity plays the role of magnetic field, while the velocity field plays the part of a vector potential and the enthalpy (of isentropic flows) plays the part of a scalar potential in electromagnetism. The evolution of source terms of fluid Maxwell equations is determined by solving the equations of motion and continuity. The equation of sound waves can be derived from this formulation, where time evolution of the sound source is determined by the equation of motion. The theory of vortex sound of aeroacoustics is included in this formulation. It is remarkable that the forces acting on a point mass moving in a velocity field of an inviscid fluid are analogous in their form to the electric force and Lorentz force in electromagnetism. The significance of the reformulation is interpreted by examples taken from fluid mechanics. This formulation can be extended to viscous fluids without difficulty. The Maxwell-type equations are unchanged by the viscosity effect, although the source terms have additional terms due to viscosities.

Degenerate nonlinear diffusion equations

CERN Document Server

Favini, Angelo

2012-01-01

The aim of these notes is to include in a uniform presentation style several topics related to the theory of degenerate nonlinear diffusion equations, treated in the mathematical framework of evolution equations with multivalued m-accretive operators in Hilbert spaces. The problems concern nonlinear parabolic equations involving two cases of degeneracy. More precisely, one case is due to the vanishing of the time derivative coefficient and the other is provided by the vanishing of the diffusion coefficient on subsets of positive measure of the domain. From the mathematical point of view the results presented in these notes can be considered as general results in the theory of degenerate nonlinear diffusion equations. However, this work does not seek to present an exhaustive study of degenerate diffusion equations, but rather to emphasize some rigorous and efficient techniques for approaching various problems involving degenerate nonlinear diffusion equations, such as well-posedness, periodic solutions, asympt...

Computational partial differential equations using Matlab

CERN Document Server

Li, Jichun

2008-01-01

Brief Overview of Partial Differential Equations The parabolic equations The wave equations The elliptic equations Differential equations in broader areasA quick review of numerical methods for PDEsFinite Difference Methods for Parabolic Equations Introduction Theoretical issues: stability, consistence, and convergence 1-D parabolic equations2-D and 3-D parabolic equationsNumerical examples with MATLAB codesFinite Difference Methods for Hyperbolic Equations IntroductionSome basic difference schemes Dissipation and dispersion errors Extensions to conservation lawsThe second-order hyperbolic PDE

Integrable systems of partial differential equations determined by structure equations and Lax pair

International Nuclear Information System (INIS)

Bracken, Paul

2010-01-01

It is shown how a system of evolution equations can be developed both from the structure equations of a submanifold embedded in three-space as well as from a matrix SO(6) Lax pair. The two systems obtained this way correspond exactly when a constraint equation is selected and imposed on the system of equations. This allows for the possibility of selecting the coefficients in the second fundamental form in a general way.

Drift-Diffusion Equation

Directory of Open Access Journals (Sweden)

K. Banoo

1998-01-01

equation in the discrete momentum space. This is shown to be similar to the conventional drift-diffusion equation except that it is a more rigorous solution to the Boltzmann equation because the current and carrier densities are resolved into M×1 vectors, where M is the number of modes in the discrete momentum space. The mobility and diffusion coefficient become M×M matrices which connect the M momentum space modes. This approach is demonstrated by simulating electron transport in bulk silicon.

Symmetries of the Euler compressible flow equations for general equation of state

Energy Technology Data Exchange (ETDEWEB)

Boyd, Zachary M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ramsey, Scott D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Baty, Roy S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2015-10-15

The Euler compressible flow equations exhibit different Lie symmetries depending on the equation of state (EOS) of the medium in which the flow occurs. This means that, in general, different types of similarity solution will be available in different flow media. We present a comprehensive classification of all EOS’s to which the Euler equations apply, based on the Lie symmetries admitted by the corresponding flow equations, restricting to the case of 1-D planar, cylindrical, or spherical geometry. The results are conveniently summarized in tables. This analysis also clarifies past work by Axford and Ovsiannikov on symmetry classification.

Alternatives to the Dirac equation

International Nuclear Information System (INIS)

Girvin, S.M.; Brownstein, K.R.

1975-01-01

Recent work by Biedenharn, Han, and van Dam (BHvD) has questioned the uniqueness of the Dirac equation. BHvD have obtained a two-component equation as an alternate to the Dirac equation. Although they later show their alternative to be unitarily equivalent to the Dirac equation, certain physical differences were claimed. BHvD attribute the existence of this alternate equation to the fact that their factorizing matrices were position-dependent. To investigate this, we factor the Klein-Gordon equation in spherical coordinates allowing the factorizing matrices to depend arbitrarily upon theta and phi. It is shown that despite this additional freedom, and without involving any relativistic covariance, the conventional four-component Dirac equation is the only possibility

Nonlinear differential equations

Energy Technology Data Exchange (ETDEWEB)

Dresner, L.

1988-01-01

This report is the text of a graduate course on nonlinear differential equations given by the author at the University of Wisconsin-Madison during the summer of 1987. The topics covered are: direction fields of first-order differential equations; the Lie (group) theory of ordinary differential equations; similarity solutions of second-order partial differential equations; maximum principles and differential inequalities; monotone operators and iteration; complementary variational principles; and stability of numerical methods. The report should be of interest to graduate students, faculty, and practicing scientists and engineers. No prior knowledge is required beyond a good working knowledge of the calculus. The emphasis is on practical results. Most of the illustrative examples are taken from the fields of nonlinear diffusion, heat and mass transfer, applied superconductivity, and helium cryogenics.

Nonlinear differential equations

International Nuclear Information System (INIS)

Dresner, L.

1988-01-01

This report is the text of a graduate course on nonlinear differential equations given by the author at the University of Wisconsin-Madison during the summer of 1987. The topics covered are: direction fields of first-order differential equations; the Lie (group) theory of ordinary differential equations; similarity solutions of second-order partial differential equations; maximum principles and differential inequalities; monotone operators and iteration; complementary variational principles; and stability of numerical methods. The report should be of interest to graduate students, faculty, and practicing scientists and engineers. No prior knowledge is required beyond a good working knowledge of the calculus. The emphasis is on practical results. Most of the illustrative examples are taken from the fields of nonlinear diffusion, heat and mass transfer, applied superconductivity, and helium cryogenics

Semilinear Schrödinger equations

CERN Document Server

Cazenave, Thierry

2003-01-01

The nonlinear Schrödinger equation has received a great deal of attention from mathematicians, in particular because of its applications to nonlinear optics. It is also a good model dispersive equation, since it is often technically simpler than other dispersive equations, such as the wave or Korteweg-de Vries equation. Particularly useful tools in studying the nonlinear Schrödinger equation are energy and Strichartz's estimates. This book presents various mathematical aspects of the nonlinear Schrödinger equation. It examines both problems of local nature (local existence of solutions, unique

Effect of management, marketing, and certified health programs on the sale price of beef calves sold through a livestock video auction service from 1995 through 2009.

Science.gov (United States)

Seeger, Jon T; King, Michael E; Grotelueschen, Dale M; Rogers, Glenn M; Stokka, Gerald S

2011-08-15

To evaluate and update the previously quantified effects of management, marketing, and certified health programs on the sale price of beef calves sold through a livestock video auction service. Longitudinal study. 41,657 lots representing 5,042,272 beef calves sold from 1995 through 2009. Data describing each lot of beef calves marketed from 1995 through 2009 by a livestock video auction service were obtained from sale catalogues. For each year of the study, multiple regression analysis was used to quantify the effect of management, marketing, and certified health programs on sale price. Sale date, base sale weight, quadratic effect of base weight, sex of calf, region of origin, breed description, inclusion in a certified health program, and number of calves in the lot significantly affected sale price for every year of the study. Variation in body weight, flesh score, and number of days between sale and delivery date had significant effects on price in most of the years; frame score and calves with horns affected price in 7 of 15 years; age and source verification influenced sale price in every year since source verification was introduced in 2005; and the auction service's progressive genetics program increased price during the 1 year that program was available. Some management, marketing, and certified health initiatives have consistently increased the sale price of beef calves, and producers can increase the price of their calves by implementing these practices.

Quantum linear Boltzmann equation

International Nuclear Information System (INIS)

Vacchini, Bassano; Hornberger, Klaus

2009-01-01

We review the quantum version of the linear Boltzmann equation, which describes in a non-perturbative fashion, by means of scattering theory, how the quantum motion of a single test particle is affected by collisions with an ideal background gas. A heuristic derivation of this Lindblad master equation is presented, based on the requirement of translation-covariance and on the relation to the classical linear Boltzmann equation. After analyzing its general symmetry properties and the associated relaxation dynamics, we discuss a quantum Monte Carlo method for its numerical solution. We then review important limiting forms of the quantum linear Boltzmann equation, such as the case of quantum Brownian motion and pure collisional decoherence, as well as the application to matter wave optics. Finally, we point to the incorporation of quantum degeneracies and self-interactions in the gas by relating the equation to the dynamic structure factor of the ambient medium, and we provide an extension of the equation to include internal degrees of freedom.

Exact Solutions to Nonlinear Schroedinger Equation and Higher-Order Nonlinear Schroedinger Equation

International Nuclear Information System (INIS)

Ren Ji; Ruan Hangyu

2008-01-01

We study solutions of the nonlinear Schroedinger equation (NLSE) and higher-order nonlinear Schroedinger equation (HONLSE) with variable coefficients. By considering all the higher-order effect of HONLSE as a new dependent variable, the NLSE and HONLSE can be changed into one equation. Using the generalized Lie group reduction method (GLGRM), the abundant solutions of NLSE and HONLSE are obtained

Nonlinear diffusion equations

CERN Document Server

Wu Zhuo Qun; Li Hui Lai; Zhao Jun Ning

2001-01-01

Nonlinear diffusion equations, an important class of parabolic equations, come from a variety of diffusion phenomena which appear widely in nature. They are suggested as mathematical models of physical problems in many fields, such as filtration, phase transition, biochemistry and dynamics of biological groups. In many cases, the equations possess degeneracy or singularity. The appearance of degeneracy or singularity makes the study more involved and challenging. Many new ideas and methods have been developed to overcome the special difficulties caused by the degeneracy and singularity, which

On the F-equation

International Nuclear Information System (INIS)

Kalinowski, M.W.; Szymanowski, L.

1982-03-01

A generalization of the Truesdell F-equations is proposed and some solutions to them - generalized Fox F-functions - are found. It is also shown that a non-linear difference-differential equation, which does not belong to the Truesdell class, nevertheless may be transformed into the standard F-equation. (author)

How to obtain the covariant form of Maxwell's equations from the continuity equation

Energy Technology Data Exchange (ETDEWEB)

Heras, Jose A [Departamento de Ciencias Basicas, Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Av. San Pablo No. 180, Col. Reynosa, 02200, Mexico D. F. (Mexico); Departamento de Fisica y Matematicas, Universidad Iberoamericana, Prolongacion Paseo de la Reforma 880, Mexico D. F. 01210 (Mexico)

2009-07-15

The covariant Maxwell equations are derived from the continuity equation for the electric charge. This result provides an axiomatic approach to Maxwell's equations in which charge conservation is emphasized as the fundamental axiom underlying these equations.

Linear integral equations and soliton systems

International Nuclear Information System (INIS)

Quispel, G.R.W.

1983-01-01

A study is presented of classical integrable dynamical systems in one temporal and one spatial dimension. The direct linearizations are given of several nonlinear partial differential equations, for example the Korteweg-de Vries equation, the modified Korteweg-de Vries equation, the sine-Gordon equation, the nonlinear Schroedinger equation, and the equation of motion for the isotropic Heisenberg spin chain; the author also discusses several relations between these equations. The Baecklund transformations of these partial differential equations are treated on the basis of a singular transformation of the measure (or equivalently of the plane-wave factor) occurring in the corresponding linear integral equations, and the Baecklund transformations are used to derive the direct linearization of a chain of so-called modified partial differential equations. Finally it is shown that the singular linear integral equations lead in a natural way to the direct linearizations of various nonlinear difference-difference equations. (Auth.)

Supplementary dataset for child and adult exposure and health risk evaluation following the use of metal- and metalloid-containing costume cosmetics sold in the United States

Directory of Open Access Journals (Sweden)

Angela L. Perez

2017-08-01

Full Text Available The data presented in this article are related to the research article entitled "Child and adult exposure and health risk evaluation following the use of metal- and metalloid-containing costume cosmetics sold in the United States" [1]. This article describes the concentration of metals and metalloids contained in various cosmetic products such as body paint, lipstick and eye shadow, the relative percent deviation of two analyses performed on the products and the physico-chemico properties of the metals and metalloids used in the SkinPerm model presented in the aforementioned article.

Lectures on partial differential equations

CERN Document Server

Petrovsky, I G

1992-01-01

Graduate-level exposition by noted Russian mathematician offers rigorous, transparent, highly readable coverage of classification of equations, hyperbolic equations, elliptic equations and parabolic equations. Wealth of commentary and insight invaluable for deepening understanding of problems considered in text. Translated from the Russian by A. Shenitzer.

Reduction operators of Burgers equation.

Science.gov (United States)

Pocheketa, Oleksandr A; Popovych, Roman O

2013-02-01

The solution of the problem on reduction operators and nonclassical reductions of the Burgers equation is systematically treated and completed. A new proof of the theorem on the special "no-go" case of regular reduction operators is presented, and the representation of the coefficients of operators in terms of solutions of the initial equation is constructed for this case. All possible nonclassical reductions of the Burgers equation to single ordinary differential equations are exhaustively described. Any Lie reduction of the Burgers equation proves to be equivalent via the Hopf-Cole transformation to a parameterized family of Lie reductions of the linear heat equation.

The magnetic field experiment onboard Equator-S and its scientific possibilities

Directory of Open Access Journals (Sweden)

K.-H. Fornacon

1999-12-01

Full Text Available The special feature of the ringcore fluxgate magnetometer on Equator-S is the high time and field resolution. The scientific aim of the experiment is the investigation of waves in the 10–100 picotesla range with a time resolution up to 64 Hz. The instrument characteristics and the influence of the spacecraft on the magnetic field measurement will be discussed. The work shows that the applied pre- and inflight calibration techniques are sufficient to suppress spacecraft interferences. The offset in spin axis direction was determined for the first time with an independent field measurement by the Equator-S Electron Drift Instrument. The data presented gives an impression of the accuracy of the measurement.Key words. Magnetospheric physics (instruments and techniques · Space plasma physics (instruments and techniques

The magnetic field experiment onboard Equator-S and its scientific possibilities

Directory of Open Access Journals (Sweden)

K.-H. Fornacon

Full Text Available The special feature of the ringcore fluxgate magnetometer on Equator-S is the high time and field resolution. The scientific aim of the experiment is the investigation of waves in the 10–100 picotesla range with a time resolution up to 64 Hz. The instrument characteristics and the influence of the spacecraft on the magnetic field measurement will be discussed. The work shows that the applied pre- and inflight calibration techniques are sufficient to suppress spacecraft interferences. The offset in spin axis direction was determined for the first time with an independent field measurement by the Equator-S Electron Drift Instrument. The data presented gives an impression of the accuracy of the measurement.

Key words. Magnetospheric physics (instruments and techniques · Space plasma physics (instruments and techniques

Formación profesional y continua de los técnicos de nivel medio. Experiencia cubana

Directory of Open Access Journals (Sweden)

Luis Téllez Lazo

2015-05-01

Full Text Available El resultado que se presenta tuvo como finalidad perfeccionar el proceso de formación profesional y continua de los técnicos medios, enmarcado en los estudios de profundización del proyecto de investigación: la formación técnico-profesional en las empresas de la provincia Las Tunas. Se partió de un diagnóstico del contexto donde se forman los estudiantes y graduados de nivel medio en varias especialidades técnicas, el cual incluyó, profesores, tutores, trabajadores y adiestrados. El objetivo de este estudio fue ofrecer una concepción pedagógica para el perfeccionamiento de la Educación Técnica y Profesional, en las condiciones de integración escuela-empresa, sobre la base de criterios científicos, que le permitan a las autoridades locales y directivos de los Institutos Politécnicos de la provincia, tomar decisiones en beneficio de la calidad de la formación en este tipo de instituciones educativas. La investigación se sustentó en la teoría de la educación avanzada (Añorga, 1999 y la teoría de la Pedagogía Profesional (Abreu, 2004 y enriquecidas por sus seguidores hasta la actualidad. Se utilizó la metodología de la investigación acción participativa, mediante el desarrollo del método talleres de opinión crítica y construcción colectiva, así como se determinaron los indicadores, instrumentos y técnicas que permitieron indagar en los cambios cualitativos que experimentaron los sujetos y procesos objeto de estudio. Los resultados impactan en directivos, estudiantes, profesores y tutores, con la novedad del acompañamiento pedagógico como forma de superación del tutor y la concepción de dirección de las prácticas preprofesionales.

Methods for Equating Mental Tests.

Science.gov (United States)

1984-11-01

1983) compared conventional and IRT methods for equating the Test of English as a Foreign Language ( TOEFL ) after chaining. Three conventional and...three IRT equating methods were examined in this study; two sections of TOEFL were each (separately) equated. The IRT methods included the following: (a...group. A separate base form was established for each of the six equating methods. Instead of equating the base-form TOEFL to itself, the last (eighth

Supersymmetric quasipotential equations

International Nuclear Information System (INIS)

Zaikov, R.P.

1981-01-01

A supersymmetric extension of the Logunov-Tavkhelidze quasipotential approach is suggested. The supersymmetric Bethe- Salpeter equation is an initial equation. The transition from the four-time to the two-time Green function is made in the super- center-of-mass system. The two-time Green function has no inverse function in the whole spinor space. The resolvent operator if found using the Majorana character of the spinor wave function. The supersymmetric quasipotential equation is written. The consideration is carried out in the framework of the theory of chiral scalar superfields [ru

Ordinary differential equations

CERN Document Server

Miller, Richard K

1982-01-01

Ordinary Differential Equations is an outgrowth of courses taught for a number of years at Iowa State University in the mathematics and the electrical engineering departments. It is intended as a text for a first graduate course in differential equations for students in mathematics, engineering, and the sciences. Although differential equations is an old, traditional, and well-established subject, the diverse backgrounds and interests of the students in a typical modern-day course cause problems in the selection and method of presentation of material. In order to compensate for this diversity,

Uncertain differential equations

CERN Document Server

Yao, Kai

2016-01-01

This book introduces readers to the basic concepts of and latest findings in the area of differential equations with uncertain factors. It covers the analytic method and numerical method for solving uncertain differential equations, as well as their applications in the field of finance. Furthermore, the book provides a number of new potential research directions for uncertain differential equation. It will be of interest to researchers, engineers and students in the fields of mathematics, information science, operations research, industrial engineering, computer science, artificial intelligence, automation, economics, and management science.

Introduction to nonlinear dispersive equations

CERN Document Server

Linares, Felipe

2015-01-01

This textbook introduces the well-posedness theory for initial-value problems of nonlinear, dispersive partial differential equations, with special focus on two key models, the Korteweg–de Vries equation and the nonlinear Schrödinger equation. A concise and self-contained treatment of background material (the Fourier transform, interpolation theory, Sobolev spaces, and the linear Schrödinger equation) prepares the reader to understand the main topics covered: the initial-value problem for the nonlinear Schrödinger equation and the generalized Korteweg–de Vries equation, properties of their solutions, and a survey of general classes of nonlinear dispersive equations of physical and mathematical significance. Each chapter ends with an expert account of recent developments and open problems, as well as exercises. The final chapter gives a detailed exposition of local well-posedness for the nonlinear Schrödinger equation, taking the reader to the forefront of recent research. The second edition of Introdu...

Generalized Lorentz-Force equations

International Nuclear Information System (INIS)

Yamaleev, R.M.

2001-01-01

Guided by Nambu (n+1)-dimensional phase space formalism we build a new system of dynamic equations. These equations describe a dynamic state of the corporeal system composed of n subsystems. The dynamic equations are formulated in terms of dynamic variables of the subsystems as well as in terms of dynamic variables of the corporeal system. These two sets of variables are related respectively as roots and coefficients of the n-degree polynomial equation. In the special n=2 case, this formalism reproduces relativistic dynamics for the charged spinning particles

A new evolution equation

International Nuclear Information System (INIS)

Laenen, E.

1995-01-01

We propose a new evolution equation for the gluon density relevant for the region of small x B . It generalizes the GLR equation and allows deeper penetration in dense parton systems than the GLR equation does. This generalization consists of taking shadowing effects more comprehensively into account by including multigluon correlations, and allowing for an arbitrary initial gluon distribution in a hadron. We solve the new equation for fixed α s . We find that the effects of multigluon correlations on the deep-inelastic structure function are small. (orig.)

Determination of selected elements in canned food sold in Jordan markets.

Science.gov (United States)

Massadeh, Adnan M; Al-Massaedh, Ayat Allah T; Kharibeh, Sameh

2018-02-01

In this study, the concentrations of seven heavy metals including As, Cd, Cr, Cu, Ni, Pb, and Zn in imported canned food samples of different brands including tuna, beef, sardines, and mushroom were determined. Samples were collected from popular Jordanian market, Irbid city, Northern Jordan (44 samples of each type). The metal concentrations in canned food samples were found to be in the range of 1.85-4.50 μg/g for As, 0.42-0.58 μg/g for Cd, 0.47-1.67 μg/g for Cr, 0.73-0.90 μg/g for Cu, 1.08-2.77 μg/g for Ni, 2.5-3.0 μg/g for Pb, and 0.43-2.25 μg/g for Zn. Results revealed that As and Pb have the highest concentrations in all samples analyzed, whereas, the lowest concentrations obtained were in Cd. For example, in canned sardine, the mean concentrations of heavy metals are 0.43 μg/g for Zn, 2.50 μg/g for Pb, 1.74 μg/g for Ni, 0.80 μg/g for Cu, 0.47 μg/g for Cr, 0.42 μg/g for Cd, and 1.85 μg/g for As. Whereas, the mean concentrations in canned tuna were 3.48 μg/g for As, 0.47 μg/g for Cd, 0.53 μg/g for Cr, 0.73 μg/g for Cu, 2.77 μg/g for Ni, 2.80 μg/g for Pb, and 1.63 μg/g for Zn. The results of this study indicated that the concentration of the tested elements including As, Cd, Cr, Ni, and Pb in canned food samples sold in Jordanian markets exceeded the permissible limits set by health organizations such as FAO/WHO. The results were compared with the literature values.

The microbiological quality of pasteurized milk sold by automatic vending machines.

Science.gov (United States)

Angelidis, A S; Tsiota, S; Pexara, A; Govaris, A

2016-06-01

The microbiological quality of pasteurized milk samples (n = 39) collected during 13 weekly intervals from three automatic vending machines (AVM) in Greece was investigated. Microbiological counts (total aerobic (TAC), total psychrotrophic (TPC), Enterobacteriaceae (EC), and psychrotrophic aerobic bacterial spore counts (PABSC)) were obtained at the time of sampling and at the end of shelf-life (3 days) after storage of the samples at 4 or 8°C. TAC were found to be below the 10(7 ) CFU ml(-1) limit of pasteurized milk spoilage both during sampling as well as when milk samples were stored at either storage temperature for 3 days. Enterobacteriaceae populations were below 1 CFU ml(-1) in 69·2% of the samples tested at the time of sampling, whereas the remaining samples contained low numbers, typically less than 10 CFU ml(-1) . All samples tested negative for the presence of Listeria monocytogenes. Analogous microbiological data were also obtained by sampling and testing prepackaged, retail samples of pasteurized milk from two dairy companies in Greece (n = 26). From a microbiological standpoint, the data indicate that the AVM milk samples meet the quality standards of pasteurized milk. However, the prepackaged, retail milk samples yielded better results in terms of TAC, TPC and EC, compared to the AVM samples at the end of shelf-life. Recently, Greek dairy farmers organized in cooperatives launched the sale of pasteurized milk via AVM and this study reports on the microbiological quality of this product. The data show that AVM milk is sold at proper refrigeration temperatures and meets the quality standards of pasteurized milk throughout the manufacturer's specified shelf-life. However, based on the microbiological indicators tested, the keeping quality of the tested prepackaged, retail samples of pasteurized milk at the end of shelf-life upon storage under suboptimal refrigeration temperature (8°C) was better. © 2016 The Society for Applied

PHYSICAL AND CHEMICAL QUALITY OF MARKET MILK SOLD AT TANDOJAM, PAKISTAN

Directory of Open Access Journals (Sweden)

S. B. JAVAID, J. A. GADAHI, M. KHASKELI, M. B. BHUTTO, S. KUMBHER AND A. H. PANHWAR

2009-02-01

Full Text Available The present study was conducted to evaluate the quality of milk sold at Tandojam, Pakistan. A total of 125 milk samples (25 samples from each source collected from five milk marketing agencies viz direct seller (DS, milk collection center(MCC, milk vendor shop (MVS, hotel (HT and buffalo dairy farm (DF, which served as control. Acidity of milk obtained from DS, MCC, MVS and HT averaged 0.13, 0.15, 0.12 and 0.13, respectively compared to 0.14 for DF milk. The pH values of milk from MVS (6.54 and HT (6.53 were significantly different (P0.05 to that of DF milk i.e. 6.65. Viscosity, specific gravity and freezing point of milk procured from DS (1.48, 1.026 and –0.460, respectively, MCC (1.58, 1.026 and –0.470, respectively, MVS (1.34, 1.026 and –0.440, respectively and HT (1.46, 1.027 and –0.480, respectively were significantly (P<0.001 lower than DF milk (1.86, 1.031 and -0.551, respectively. Chemical quality of milk procured from DS, MCC, MVS and HT compared to DF milk (control averaged 13.45, 14.18, 13.19 and 14.06% vs. 16.30% for TS content, 8.25, 8.81, 8.06 and 8.51% vs. 9.79% for SNF content, 5.20, 5.41, 5.13 and 5.54% vs. 6.51% for fat content, 3.85, 3.96, 3.91 and 4.23% vs. 4.35% for protein content, 2.70, 2.77, 2.56 and 3.20% vs. 3.56% for casein content, 3.65, 4.03, 3.34 and 3.52% vs. 4.53% for lactose content and 0.75, 0.78, 0.74 and 0.76% vs. 0.91% for ash content, respectively. All the attributes of chemical quality of milk supplied through four agencies were significantly lower (P<0.05 than DF milk.

Thermoviscous Model Equations in Nonlinear Acoustics

DEFF Research Database (Denmark)

Rasmussen, Anders Rønne

Four nonlinear acoustical wave equations that apply to both perfect gasses and arbitrary fluids with a quadratic equation of state are studied. Shock and rarefaction wave solutions to the equations are studied. In order to assess the accuracy of the wave equations, their solutions are compared...... to solutions of the basic equations from which the wave equations are derived. A straightforward weakly nonlinear equation is the most accurate for shock modeling. A higher order wave equation is the most accurate for modeling of smooth disturbances. Investigations of the linear stability properties...... of solutions to the wave equations, reveal that the solutions may become unstable. Such instabilities are not found in the basic equations. Interacting shocks and standing shocks are investigated....

Invalidity of the spectral Fokker-Planck equation forCauchy noise driven Langevin equation

DEFF Research Database (Denmark)

Ditlevsen, Ove Dalager

2004-01-01

-called alpha-stable noise (or Levy noise) the Fokker-Planck equation no longer exists as a partial differential equation for the probability density because the property of finite variance is lost. In stead it has been attempted to formulate an equation for the characteristic function (the Fourier transform...

Difference equations theory, applications and advanced topics

CERN Document Server

Mickens, Ronald E

2015-01-01

THE DIFFERENCE CALCULUS GENESIS OF DIFFERENCE EQUATIONS DEFINITIONS DERIVATION OF DIFFERENCE EQUATIONS EXISTENCE AND UNIQUENESS THEOREM OPERATORS ∆ AND E ELEMENTARY DIFFERENCE OPERATORS FACTORIAL POLYNOMIALS OPERATOR ∆−1 AND THE SUM CALCULUS FIRST-ORDER DIFFERENCE EQUATIONS INTRODUCTION GENERAL LINEAR EQUATION CONTINUED FRACTIONS A GENERAL FIRST-ORDER EQUATION: GEOMETRICAL METHODS A GENERAL FIRST-ORDER EQUATION: EXPANSION TECHNIQUES LINEAR DIFFERENCE EQUATIONSINTRODUCTION LINEARLY INDEPENDENT FUNCTIONS FUNDAMENTAL THEOREMS FOR HOMOGENEOUS EQUATIONSINHOMOGENEOUS EQUATIONS SECOND-ORDER EQUATIONS STURM-LIOUVILLE DIFFERENCE EQUATIONS LINEAR DIFFERENCE EQUATIONS INTRODUCTION HOMOGENEOUS EQUATIONS CONSTRUCTION OF A DIFFERENCE EQUATION HAVING SPECIFIED SOLUTIONS RELATIONSHIP BETWEEN LINEAR DIFFERENCE AND DIFFERENTIAL EQUATIONS INHOMOGENEOUS EQUATIONS: METHOD OF UNDETERMINED COEFFICIENTS INHOMOGENEOUS EQUATIONS: OPERATOR METHODS z-TRANSFORM METHOD SYSTEMS OF DIFFERENCE EQUATIONS LINEAR PARTIAL DIFFERENCE EQUATI...

Weak self-adjoint differential equations

International Nuclear Information System (INIS)

Gandarias, M L

2011-01-01

The concepts of self-adjoint and quasi self-adjoint equations were introduced by Ibragimov (2006 J. Math. Anal. Appl. 318 742-57; 2007 Arch. ALGA 4 55-60). In Ibragimov (2007 J. Math. Anal. Appl. 333 311-28), a general theorem on conservation laws was proved. In this paper, we generalize the concept of self-adjoint and quasi self-adjoint equations by introducing the definition of weak self-adjoint equations. We find a class of weak self-adjoint quasi-linear parabolic equations. The property of a differential equation to be weak self-adjoint is important for constructing conservation laws associated with symmetries of the differential equation. (fast track communication)

Solutions of system of P1 equations without use of auxiliary differential equations coupled

International Nuclear Information System (INIS)

Martinez, Aquilino Senra; Silva, Fernando Carvalho da; Cardoso, Carlos Eduardo Santos

2000-01-01

The system of P1 equations is composed by two equations coupled itself one for the neutron flux and other for the current. Usually this system is solved by definitions of two integrals parameters, which are named slowing down densities of the flux and the current. Hence, the system P1 can be change from integral to only two differential equations. However, there are two new differentials equations that may be solved with the initial system. The present work analyzes this procedure and studies a method, which solve the P1 equations directly, without definitions of slowing down densities. (author)

Equations of radiation hydrodynamics

International Nuclear Information System (INIS)

Mihalas, D.

1982-01-01

The purpose of this paper is to give an overview of the role of radiation in the transport of energy and momentum in a combined matter-radiation fluid. The transport equation for a moving radiating fluid is presented in both a fully Eulerian and a fully Lagrangian formulation, along with conservation equations describing the dynamics of the fluid. Special attention is paid to the problem of deriving equations that are mutually consistent in each frame, and between frames, to 0(v/c). A detailed analysis is made to show that in situations of broad interest, terms that are formally of 0(v/c) actually dominate the solution, demonstrating that it is esential (1) to pay scrupulous attention to the question of the frame dependence in formulating the equations; and (2) to solve the equations to 0(v/c) in quite general circumstances. These points are illustrated in the context of the nonequilibrium radiation diffusion limit, and a sketch of how the Lagrangian equations are to be solved will be presented

The numerical solution of linear multi-term fractional differential equations: systems of equations

Science.gov (United States)

Edwards, John T.; Ford, Neville J.; Simpson, A. Charles

2002-11-01

In this paper, we show how the numerical approximation of the solution of a linear multi-term fractional differential equation can be calculated by reduction of the problem to a system of ordinary and fractional differential equations each of order at most unity. We begin by showing how our method applies to a simple class of problems and we give a convergence result. We solve the Bagley Torvik equation as an example. We show how the method can be applied to a general linear multi-term equation and give two further examples.

A Comparison of Kernel Equating and Traditional Equipercentile Equating Methods and the Parametric Bootstrap Methods for Estimating Standard Errors in Equipercentile Equating

Science.gov (United States)

Choi, Sae Il

2009-01-01

This study used simulation (a) to compare the kernel equating method to traditional equipercentile equating methods under the equivalent-groups (EG) design and the nonequivalent-groups with anchor test (NEAT) design and (b) to apply the parametric bootstrap method for estimating standard errors of equating. A two-parameter logistic item response…

Monge-Ampere equations and tensorial functors

International Nuclear Information System (INIS)

Tunitsky, Dmitry V

2009-01-01

We consider differential-geometric structures associated with Monge-Ampere equations on manifolds and use them to study the contact linearization of such equations. We also consider the category of Monge-Ampere equations (the morphisms are contact diffeomorphisms) and a number of subcategories. We are chiefly interested in subcategories of Monge-Ampere equations whose objects are locally contact equivalent to equations linear in the second derivatives (semilinear equations), linear in derivatives, almost linear, linear in the second derivatives and independent of the first derivatives, linear, linear and independent of the first derivatives, equations with constant coefficients or evolution equations. We construct a number of functors from the category of Monge-Ampere equations and from some of its subcategories to the category of tensorial objects (that is, multi-valued sections of tensor bundles). In particular, we construct a pseudo-Riemannian metric for every generic Monge-Ampere equation. These functors enable us to establish effectively verifiable criteria for a Monge-Ampere equation to belong to the subcategories listed above.

Nonlinear integrodifferential equations as discrete systems

Science.gov (United States)

Tamizhmani, K. M.; Satsuma, J.; Grammaticos, B.; Ramani, A.

1999-06-01

We analyse a class of integrodifferential equations of the `intermediate long wave' (ILW) type. We show that these equations can be formally interpreted as discrete, differential-difference systems. This allows us to link equations of this type with previous results of ours involving differential-delay equations and, on the basis of this, propose new integrable equations of ILW type. Finally, we extend this approach to pure difference equations and propose ILW forms for the discrete lattice KdV equation.

Analytic solutions of hydrodynamics equations

International Nuclear Information System (INIS)

Coggeshall, S.V.

1991-01-01

Many similarity solutions have been found for the equations of one-dimensional (1-D) hydrodynamics. These special combinations of variables allow the partial differential equations to be reduced to ordinary differential equations, which must then be solved to determine the physical solutions. Usually, these reduced ordinary differential equations are solved numerically. In some cases it is possible to solve these reduced equations analytically to obtain explicit solutions. In this work a collection of analytic solutions of the 1-D hydrodynamics equations is presented. These can be used for a variety of purposes, including (i) numerical benchmark problems, (ii) as a basis for analytic models, and (iii) to provide insight into more complicated solutions

The modified simplest equation method to look for exact solutions of nonlinear partial differential equations

OpenAIRE

Efimova, Olga Yu.

2010-01-01

The modification of simplest equation method to look for exact solutions of nonlinear partial differential equations is presented. Using this method we obtain exact solutions of generalized Korteweg-de Vries equation with cubic source and exact solutions of third-order Kudryashov-Sinelshchikov equation describing nonlinear waves in liquids with gas bubbles.

Equationally Noetherian property of Ershov algebras

OpenAIRE

Dvorzhetskiy, Yuriy

2014-01-01

This article is about equationally Noetherian and weak equationally Noetherian property of Ershov algebras. Here we show two canonical forms of the system of equations over Ershov algebras and two criteria of equationally Noetherian and weak equationally Noetherian properties.

Differential equations extended to superspace

International Nuclear Information System (INIS)

Torres, J.; Rosu, H.C.

2003-01-01

We present a simple SUSY Ns = 2 superspace extension of the differential equations in which the sought solutions are considered to be real superfields but maintaining the common derivative operators and the coefficients of the differential equations unaltered. In this way, we get self consistent systems of coupled differential equations for the components of the superfield. This procedure is applied to the Riccati equation, for which we obtain in addition the system of coupled equations corresponding to the components of the general superfield solution. (Author)

Differential equations extended to superspace

Energy Technology Data Exchange (ETDEWEB)

Torres, J. [Instituto de Fisica, Universidad de Guanajuato, A.P. E-143, Leon, Guanajuato (Mexico); Rosu, H.C. [Instituto Potosino de Investigacion Cientifica y Tecnologica, A.P. 3-74, Tangamanga, San Luis Potosi (Mexico)

2003-07-01

We present a simple SUSY Ns = 2 superspace extension of the differential equations in which the sought solutions are considered to be real superfields but maintaining the common derivative operators and the coefficients of the differential equations unaltered. In this way, we get self consistent systems of coupled differential equations for the components of the superfield. This procedure is applied to the Riccati equation, for which we obtain in addition the system of coupled equations corresponding to the components of the general superfield solution. (Author)

Integral equation for inhomogeneous condensed bosons generalizing the Gross-Pitaevskii differential equation

International Nuclear Information System (INIS)

Angilella, G.G.N.; Pucci, R.; March, N.H.

2004-01-01

We give here the derivation of a Gross-Pitaevskii-type equation for inhomogeneous condensed bosons. Instead of the original Gross-Pitaevskii differential equation, we obtain an integral equation that implies less restrictive assumptions than are made in the very recent study of Pieri and Strinati [Phys. Rev. Lett. 91, 030401 (2003)]. In particular, the Thomas-Fermi approximation and the restriction to small spatial variations of the order parameter invoked in their study are avoided

Iterative Splitting Methods for Differential Equations

CERN Document Server

Geiser, Juergen

2011-01-01

Iterative Splitting Methods for Differential Equations explains how to solve evolution equations via novel iterative-based splitting methods that efficiently use computational and memory resources. It focuses on systems of parabolic and hyperbolic equations, including convection-diffusion-reaction equations, heat equations, and wave equations. In the theoretical part of the book, the author discusses the main theorems and results of the stability and consistency analysis for ordinary differential equations. He then presents extensions of the iterative splitting methods to partial differential

Algorithm for research of mathematical physics equations symmetries. Symmetries of the free Schroedinger equation

International Nuclear Information System (INIS)

Kotel'nikov, G.A.

1994-01-01

An algorithm id proposed for research the symmetries of mathematical physics equation. The application of this algorithm to the Schroedinger equation permitted to establish, that in addition to the known symmetry the Schroedinger equation possesses also the relativistic symmetry

Generalized quantal equation of motion

International Nuclear Information System (INIS)

Morsy, M.W.; Embaby, M.

1986-07-01

In the present paper, an attempt is made for establishing a generalized equation of motion for quantal objects, in which intrinsic self adjointness is naturally built in, independently of any prescribed representation. This is accomplished by adopting Hamilton's principle of least action, after incorporating, properly, the quantal features and employing the generalized calculus of variations, without being restricted to fixed end points representation. It turns out that our proposed equation of motion is an intrinsically self-adjoint Euler-Lagrange's differential equation that ensures extremization of the quantal action as required by Hamilton's principle. Time dependence is introduced and the corresponding equation of motion is derived, in which intrinsic self adjointness is also achieved. Reducibility of the proposed equation of motion to the conventional Schroedinger equation is examined. The corresponding continuity equation is established, and both of the probability density and the probability current density are identified. (author)

Higher order field equations. II

International Nuclear Information System (INIS)

Tolhoek, H.A.

1977-01-01

In a previous paper wave propagation was studied according to a sixth-order partial differential equation involving a complex mass M. The corresponding Yang-Feldman integral equations (indicated as SM-YF-equations), were formulated using modified Green's functions Gsub(R)sup(M)(x) and Gsub(A)sup(M)(x), which then incorporate the partial differential equation together with certain boundary conditions. In this paper certain limit properties of these modified Green's functions are derived: (a) It is shown that for mod(M)→infinity the Green's functions Gsub(R)sup(M)(x) and Gsub(A)sup(M)(x) approach the Green's functions Δsub(R)(x) and Δsub(A)(x) of the corresponding KG-equation (Klein-Gordon equation). (b) It is further shown that the asymptotic behaviour of Gsub(R)sup(M)(x) and Gsub(A)sup(M)(x) is the same as of Δsub(R)(x) and Δsub(A)(x)-and also the same as for Dsub(R)(x) and Dsub(A)(x) for t→+-infinity;, where Dsub(R) and Dsub(A) are the Green's functions for the KG-equation with mass zero. It is essential to take limits in the sense of distribution theory in both cases (a) and (b). The property (b) indicates that the wave propagation properties of the SM-YF-equations, the KG-equation with finite mass and the KG-equation with mass zero are closely related in an asymptotic sense. (Auth.)

Bäcklund transformation of fractional Riccati equation and its applications to nonlinear fractional partial differential equations

International Nuclear Information System (INIS)

Lu, Bin

2012-01-01

In this Letter, the fractional derivatives in the sense of modified Riemann–Liouville derivative and the Bäcklund transformation of fractional Riccati equation are employed for constructing the exact solutions of nonlinear fractional partial differential equations. The power of this manageable method is presented by applying it to several examples. This approach can also be applied to other nonlinear fractional differential equations. -- Highlights: ► Backlund transformation of fractional Riccati equation is presented. ► A new method for solving nonlinear fractional differential equations is proposed. ► Three important fractional differential equations are solved successfully. ► Some new exact solutions of the fractional differential equations are obtained.

Equational type logic

NARCIS (Netherlands)

Manca, V.; Salibra, A.; Scollo, Giuseppe

1990-01-01

Equational type logic is an extension of (conditional) equational logic, that enables one to deal in a single, unified framework with diverse phenomena such as partiality, type polymorphism and dependent types. In this logic, terms may denote types as well as elements, and atomic formulae are either

Reduced Braginskii equations

International Nuclear Information System (INIS)

Yagi, M.; Horton, W.

1994-01-01

A set of reduced Braginskii equations is derived without assuming flute ordering and the Boussinesq approximation. These model equations conserve the physical energy. It is crucial at finite β that the perpendicular component of Ohm's law be solved to ensure ∇·j=0 for energy conservation

Model Compaction Equation

African Journals Online (AJOL)

The currently proposed model compaction equation was derived from data sourced from the. Niger Delta and it relates porosity to depth for sandstones under hydrostatic pressure condition. The equation is useful in predicting porosity and compaction trend in hydrostatic sands of the. Niger Delta. GEOLOGICAL SETTING OF ...

Reduction of infinite dimensional equations

Directory of Open Access Journals (Sweden)

Zhongding Li

2006-02-01

Full Text Available In this paper, we use the general Legendre transformation to show the infinite dimensional integrable equations can be reduced to a finite dimensional integrable Hamiltonian system on an invariant set under the flow of the integrable equations. Then we obtain the periodic or quasi-periodic solution of the equation. This generalizes the results of Lax and Novikov regarding the periodic or quasi-periodic solution of the KdV equation to the general case of isospectral Hamiltonian integrable equation. And finally, we discuss the AKNS hierarchy as a special example.

Construction of Chained True Score Equipercentile Equatings under the Kernel Equating (KE) Framework and Their Relationship to Levine True Score Equating. Research Report. ETS RR-09-24

Science.gov (United States)

Chen, Haiwen; Holland, Paul

2009-01-01

In this paper, we develop a new chained equipercentile equating procedure for the nonequivalent groups with anchor test (NEAT) design under the assumptions of the classical test theory model. This new equating is named chained true score equipercentile equating. We also apply the kernel equating framework to this equating design, resulting in a…

Applied partial differential equations

CERN Document Server

Logan, J David

2004-01-01

This primer on elementary partial differential equations presents the standard material usually covered in a one-semester, undergraduate course on boundary value problems and PDEs. What makes this book unique is that it is a brief treatment, yet it covers all the major ideas: the wave equation, the diffusion equation, the Laplace equation, and the advection equation on bounded and unbounded domains. Methods include eigenfunction expansions, integral transforms, and characteristics. Mathematical ideas are motivated from physical problems, and the exposition is presented in a concise style accessible to science and engineering students; emphasis is on motivation, concepts, methods, and interpretation, rather than formal theory. This second edition contains new and additional exercises, and it includes a new chapter on the applications of PDEs to biology: age structured models, pattern formation; epidemic wave fronts, and advection-diffusion processes. The student who reads through this book and solves many of t...

Evaluation of toxic heavy metals in ayurvedic syrups sold in local markets of hazara, pakistan

International Nuclear Information System (INIS)

Hajra, B.; Orakzai, S.; Hussain, F.; Farya, U.

2015-01-01

Herbal and Ayurvedic preparations, widely used in Pakistan and the developing world, present serious risk of heavy metal toxicity related to their medicinal content and prolonged use by patients. The objective of this study was to find out the concentration of heavy metals in Herbal and Ayurvedic liquid preparations commonly used for treatment of different diseases, from local markets of Hazara. Methods: The cross sectional survey of traditional herbal and Ayurvedic medicine shops included ten liquid preparations selected from local shops of Mansehra and Abbottabad after interviewing the shopkeepers; so as to select the most commonly sold preparations along with their indications. All samples were analysed on standard Atomic Absorption Spectroscopy for qualitative and quantitative study of toxic heavy metals (Mercury, Iron, Zinc, Lead, Manganese and Arsenic). Results: Toxic levels of Mercury were present in seven syrups, i.e., (Kashneeze, Akseer e Pachas, Tankar, Sharbat e folad, Urosinal, Akseer e Jigar and Amrat dhara) while Arsenic was present only in Urosinal. Iron, Zinc, Manganese and Lead were present in permissible limits in all syrups. Conclusion: Mercury and Arsenic are present in local Herbal and Ayurvedic liquid preparations far beyond the permissible limits as proposed by the International Regulatory Authorities for health drugs while the rest of metals, i.e., Zinc, Manganese, and Iron are within the therapeutic limits. (author)

Equations of motion derived from a generalization of Einstein's equation for the gravitational field

International Nuclear Information System (INIS)

Mociutchi, C.

1980-01-01

The extended Einstein's equation, combined with a vectorial theory of maxwellian type of the gravitational field, leads to: a) the equation of motion; b) the equation of the trajectory for the static case of spherical symmetry, the test particle having a rest mass other than zero, and c) the propagation of light on null geodesics. All the basic tests of the theory given by Einstein's extended equation. Thus, the new theory of gravitation suggested by us is competitive. (author)

The Wouthuysen equation

NARCIS (Netherlands)

M. Hazewinkel (Michiel)

1995-01-01

textabstractDedication: I dedicate this paper to Prof. P.C. Baayen, at the occasion of his retirement on 20 December 1994. The beautiful equation which forms the subject matter of this paper was invented by Wouthuysen after he retired. The four complex variable Wouthuysen equation arises from an

Approach in Theory of Nonlinear Evolution Equations: The Vakhnenko-Parkes Equation

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V. O. Vakhnenko

2016-01-01

Full Text Available A variety of methods for examining the properties and solutions of nonlinear evolution equations are explored by using the Vakhnenko equation (VE as an example. The VE, which arises in modelling the propagation of high-frequency waves in a relaxing medium, has periodic and solitary traveling wave solutions some of which are loop-like in nature. The VE can be written in an alternative form, known as the Vakhnenko-Parkes equation (VPE, by a change of independent variables. The VPE has an N-soliton solution which is discussed in detail. Individual solitons are hump-like in nature whereas the corresponding solution to the VE comprises N-loop-like solitons. Aspects of the inverse scattering transform (IST method, as applied originally to the KdV equation, are used to find one- and two-soliton solutions to the VPE even though the VPE’s spectral equation is third-order and not second-order. A Bäcklund transformation for the VPE is used to construct conservation laws. The standard IST method for third-order spectral problems is used to investigate solutions corresponding to bound states of the spectrum and to a continuous spectrum. This leads to N-soliton solutions and M-mode periodic solutions, respectively. Interactions between these types of solutions are investigated.

Mejora continua de la calidad en una unidad médica de valoración de incapacidad temporal

Directory of Open Access Journals (Sweden)

Esther Álvarez Theurer

2007-06-01

Full Text Available Objetivo: Nuestro objetivo es el diseño de un plan de mejora continua de la calidad en una Unidad Medica de Valoración de Incapacidades (UMVI. Métodos: La metodología utilizada sigue las directrices marcadas por la Consejería de Salud, en cuanto a procesos e indicadores, que se recogen en el Plan Anual de Inspección. En nuestra Unidad estamos implantando el modelo EFQM de Excelencia. Resultados: Se expone nuestra propuesta de Plan de Calidad para la UMVI. Conclusiones: Destacamos la falta de formación de los profesionales sanitarios responsables de la prescripción de la prestación de IT. Existe unanimidad respecto a la necesidad de unificar criterios de gestión de la Incapacidad Temporal, por lo que seria interesante consensuar este documento con el resto de Unidades Medicas de Valoración de Incapacidades que realizan su trabajo en la Comunidad Autónoma Andaluza, pudiéndose extender a otras Autonomías.Objective: Our objective is design a continuous improvement quality plan in the Medical Unit for Disabilities Valuation (MUDV. Methods: The used methodology follows the guidelines marked by the Health Council, as for processes and indicators that are picked up in the Annual Plan of Inspection. In our Unit we are implanting the EFQM pattern of Excellency. Results: Our proposal of Quality Plan is exposed for the MUDV. Conclusions: We highlight the lack of the sanitary professionals' responsible for the benefit prescription of the of Temporary Disability (DT formation. Unanimity exists regarding the necessity of unifying approaches to administrate the DT. It would be interesting staying according to this document with other Medical Units for Disabilities Valuation that carries out its work in the Andalusia Autonomous Community, being able to extend to other Autonomies.

Parallels between control PDE's (Partial Differential Equations) and systems of ODE's (Ordinary Differential Equations)

Science.gov (United States)

Hunt, L. R.; Villarreal, Ramiro

1987-01-01

System theorists understand that the same mathematical objects which determine controllability for nonlinear control systems of ordinary differential equations (ODEs) also determine hypoellipticity for linear partial differentail equations (PDEs). Moreover, almost any study of ODE systems begins with linear systems. It is remarkable that Hormander's paper on hypoellipticity of second order linear p.d.e.'s starts with equations due to Kolmogorov, which are shown to be analogous to the linear PDEs. Eigenvalue placement by state feedback for a controllable linear system can be paralleled for a Kolmogorov equation if an appropriate type of feedback is introduced. Results concerning transformations of nonlinear systems to linear systems are similar to results for transforming a linear PDE to a Kolmogorov equation.

Exact results for the Boltzmann equation and Smoluchowski's coagulation equation

International Nuclear Information System (INIS)

Hendriks, E.M.

1983-01-01

Almost no analytical solutions have been found for realistic intermolecular forces, largely due to the complicated structure of the collision term which calls for the construction of simplified models, in which as many physical properties are maintained as possible. In the first three chapters of this thesis such model Boltzmann equations are studied. Only spatially homogeneous gases with isotropic distribution functions are considered. Chapter I considers transition kernels, chapter II persistent scattering models and chapter III very hard particles. The second part of this dissertation deals with Smoluchowski's coagulation equation for the size distribution function in a coagulating system, with chapters devoted to the following topics: kinetics of gelation and universality, coagulation equations with gelation and exactly soluble models of nucleation. (Auth./C.F.)

Hybrid quantum-classical master equations

International Nuclear Information System (INIS)

Diósi, Lajos

2014-01-01

We discuss hybrid master equations of composite systems, which are hybrids of classical and quantum subsystems. A fairly general form of hybrid master equations is suggested. Its consistency is derived from the consistency of Lindblad quantum master equations. We emphasize that quantum measurement is a natural example of exact hybrid systems. We derive a heuristic hybrid master equation of time-continuous position measurement (monitoring). (paper)

Quantum equations from Brownian motions

International Nuclear Information System (INIS)

Rajput, B.S.

2011-01-01

Classical Schrodinger and Dirac equations have been derived from Brownian motions of a particle, it has been shown that the classical Schrodinger equation can be transformed to usual Schrodinger Quantum equation on applying Heisenberg uncertainty principle between position and momentum while Dirac Quantum equation follows it's classical counter part on applying Heisenberg uncertainly principle between energy and time without applying any analytical continuation. (author)

B-splines and Faddeev equations

International Nuclear Information System (INIS)

Huizing, A.J.

1990-01-01

Two numerical methods for solving the three-body equations describing relativistic pion deuteron scattering have been investigated. For separable two body interactions these equations form a set of coupled one-dimensional integral equations. They are plagued by singularities which occur in the kernel of the integral equations as well as in the solution. The methods to solve these equations differ in the way they treat the singularities. First the Fuda-Stuivenberg method is discussed. The basic idea of this method is an one time iteration of the set of integral equations to treat the logarithmic singularities. In the second method, the spline method, the unknown solution is approximated by splines. Cubic splines have been used with cubic B-splines as basis. If the solution is approximated by a linear combination of basis functions, an integral equation can be transformed into a set of linear equations for the expansion coefficients. This set of linear equations is solved by standard means. Splines are determined by points called knots. A proper choice of splines to approach the solution stands for a proper choice of the knots. The solution of the three-body scattering equations has a square root behaviour at a certain point. Hence it was investigated how the knots should be chosen to approximate the square root function by cubic B-splines in an optimal way. Before applying this method to solve numerically the three-body equations describing pion-deuteron scattering, an analytically solvable example has been constructed with a singularity structure of both kernel and solution comparable to those of the three-body equations. The accuracy of the numerical solution was determined to a large extent by the accuracy of the approximation of the square root part. The results for a pion laboratory energy of 47.4 MeV agree very well with those from literature. In a complete calculation for 47.7 MeV the spline method turned out to be a factor thousand faster than the Fuda

Reduced Braginskii equations

International Nuclear Information System (INIS)

Yagi, M.; Horton, W.

1993-11-01

A set of reduced Braginskii equations is derived without assuming flute ordering and the Boussinesq approximation. These model equations conserve the physical energy. It is crucial at finite β that we solve the perpendicular component of Ohm's law to conserve the physical energy while ensuring the relation ∇ · j = 0

New multiple soliton solutions to the general Burgers-Fisher equation and the Kuramoto-Sivashinsky equation

International Nuclear Information System (INIS)

Chen Huaitang; Zhang Hongqing

2004-01-01

A generalized tanh function method is used for constructing exact travelling wave solutions of nonlinear partial differential equations in a unified way. The main idea of this method is to take full advantage of the Riccati equation which has more new solutions. More new multiple soliton solutions are obtained for the general Burgers-Fisher equation and the Kuramoto-Sivashinsky equation

An interpolation between the wave and diffusion equations through the fractional evolution equations Dirac like

International Nuclear Information System (INIS)

Pierantozzi, T.; Vazquez, L.

2005-01-01

Through fractional calculus and following the method used by Dirac to obtain his well-known equation from the Klein-Gordon equation, we analyze a possible interpolation between the Dirac and the diffusion equations in one space dimension. We study the transition between the hyperbolic and parabolic behaviors by means of the generalization of the D'Alembert formula for the classical wave equation and the invariance under space and time inversions of the interpolating fractional evolution equations Dirac like. Such invariance depends on the values of the fractional index and is related to the nonlocal property of the time fractional differential operator. For this system of fractional evolution equations, we also find an associated conserved quantity analogous to the Hamiltonian for the classical Dirac case

Seasonal variability of thermophilic Campylobacter spp. in raw milk sold by automatic vending machines in Lombardy Region

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Barbara Bertasi

2016-06-01

Full Text Available In temperate climates, a seasonal trend was observed in the incidence of human campylobacteriosis cases, with peaks reported in spring and autumn in some countries, or in summer in others; a similar trend was observed in Campylobacter spp. dairy cattle faecal shedding, suggesting that cattle may play a role in the seasonal peak of human infection. The objectives of this study were to assess if a seasonal trend in thermophilic Campylobacter spp. contamination of raw milk exists and to evaluate a possible relation between this and the increase of human campylobacteriosis incidence in summer months. The results showed a mean prevalence of 1.6% of milk samples positive for thermophilic Campylobacter spp. with a wide range (0.0-3.1% in different months during the three years considered. The statistical analysis showed a significant difference (PCampylobacter spp. between warmer and cooler months (2.3 vs 0.6%. The evidence of a seasonal trend in thermophilic Campylobacter spp. contamination of raw milk sold for direct consumption, with an increase of the prevalence in warmer months, may represent one of the possible links between seasonal trend in cattle faecal shedding and seasonal trend in human campylobacteriosis.

Equationally Compact Acts : Coproducts / Peeter Normak

Index Scriptorium Estoniae

Normak, Peeter

1998-01-01

In this article equational compactness of acts and its generalizations are discussed. As equational compactness does not carry over to coproducts a slight generalization of c-equational campactness is introduced. It is proved that a coproduct of acts is c-equationally compact if and only if all components are c-equationally campact

Supersymmetric two-particle equations

International Nuclear Information System (INIS)

Sissakyan, A.N.; Skachkov, N.B.; Shevchenko, O.Yu.

1986-01-01

In the framework of the scalar superfield model, a particular case of which is the well-known Wess-Zumino model, the supersymmetric Schwinger equations are found. On their basis with the use of the second Legendre transformation the two-particle supersymmetric Edwards and Bethe-Salpeter equations are derived. A connection of the kernels and inhomogeneous terms of these equations with generating functional of the second Legendre transformation is found

Solving Ordinary Differential Equations

Science.gov (United States)

Krogh, F. T.

1987-01-01

Initial-value ordinary differential equation solution via variable order Adams method (SIVA/DIVA) package is collection of subroutines for solution of nonstiff ordinary differential equations. There are versions for single-precision and double-precision arithmetic. Requires fewer evaluations of derivatives than other variable-order Adams predictor/ corrector methods. Option for direct integration of second-order equations makes integration of trajectory problems significantly more efficient. Written in FORTRAN 77.

Numerical resolution of Navier-Stokes equations coupled to the heat equation

International Nuclear Information System (INIS)

Zenouda, Jean-Claude

1970-08-01

The author proves a uniqueness theorem for the time dependent Navier-Stokes equations coupled with heat flow in the two-dimensional case. He studies stability and convergence of several finite - difference schemes to solve these equations. Numerical experiments are done in the case of a square domain. (author) [fr

Reduced Braginskii equations

Energy Technology Data Exchange (ETDEWEB)

Yagi, M. [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Horton, W. [Texas Univ., Austin, TX (United States). Inst. for Fusion Studies

1993-11-01

A set of reduced Braginskii equations is derived without assuming flute ordering and the Boussinesq approximation. These model equations conserve the physical energy. It is crucial at finite {beta} that we solve the perpendicular component of Ohm`s law to conserve the physical energy while ensuring the relation {del} {center_dot} j = 0.

Improving multilevel Monte Carlo for stochastic differential equations with application to the Langevin equation.

Science.gov (United States)

Müller, Eike H; Scheichl, Rob; Shardlow, Tony

2015-04-08

This paper applies several well-known tricks from the numerical treatment of deterministic differential equations to improve the efficiency of the multilevel Monte Carlo (MLMC) method for stochastic differential equations (SDEs) and especially the Langevin equation. We use modified equations analysis as an alternative to strong-approximation theory for the integrator, and we apply this to introduce MLMC for Langevin-type equations with integrators based on operator splitting. We combine this with extrapolation and investigate the use of discrete random variables in place of the Gaussian increments, which is a well-known technique for the weak approximation of SDEs. We show that, for small-noise problems, discrete random variables can lead to an increase in efficiency of almost two orders of magnitude for practical levels of accuracy.

A new sub-equation method applied to obtain exact travelling wave solutions of some complex nonlinear equations

International Nuclear Information System (INIS)

Zhang Huiqun

2009-01-01

By using a new coupled Riccati equations, a direct algebraic method, which was applied to obtain exact travelling wave solutions of some complex nonlinear equations, is improved. And the exact travelling wave solutions of the complex KdV equation, Boussinesq equation and Klein-Gordon equation are investigated using the improved method. The method presented in this paper can also be applied to construct exact travelling wave solutions for other nonlinear complex equations.

Construction and accuracy of partial differential equation approximations to the chemical master equation.

Science.gov (United States)

Grima, Ramon

2011-11-01

The mesoscopic description of chemical kinetics, the chemical master equation, can be exactly solved in only a few simple cases. The analytical intractability stems from the discrete character of the equation, and hence considerable effort has been invested in the development of Fokker-Planck equations, second-order partial differential equation approximations to the master equation. We here consider two different types of higher-order partial differential approximations, one derived from the system-size expansion and the other from the Kramers-Moyal expansion, and derive the accuracy of their predictions for chemical reactive networks composed of arbitrary numbers of unimolecular and bimolecular reactions. In particular, we show that the partial differential equation approximation of order Q from the Kramers-Moyal expansion leads to estimates of the mean number of molecules accurate to order Ω(-(2Q-3)/2), of the variance of the fluctuations in the number of molecules accurate to order Ω(-(2Q-5)/2), and of skewness accurate to order Ω(-(Q-2)). We also show that for large Q, the accuracy in the estimates can be matched only by a partial differential equation approximation from the system-size expansion of approximate order 2Q. Hence, we conclude that partial differential approximations based on the Kramers-Moyal expansion generally lead to considerably more accurate estimates in the mean, variance, and skewness than approximations of the same order derived from the system-size expansion.

Linear determining equations for differential constraints

International Nuclear Information System (INIS)

Kaptsov, O V

1998-01-01

A construction of differential constraints compatible with partial differential equations is considered. Certain linear determining equations with parameters are used to find such differential constraints. They generalize the classical determining equations used in the search for admissible Lie operators. As applications of this approach equations of an ideal incompressible fluid and non-linear heat equations are discussed

Transmission problem for the Laplace equation and the integral equation method

Czech Academy of Sciences Publication Activity Database

Medková, Dagmar

2012-01-01

Roč. 387, č. 2 (2012), s. 837-843 ISSN 0022-247X Institutional research plan: CEZ:AV0Z10190503 Keywords : transmission problem * Laplace equation * boundary integral equation Subject RIV: BA - General Mathematics Impact factor: 1.050, year: 2012 http://www.sciencedirect.com/science/article/pii/S0022247X11008985

Introduction to partial differential equations

CERN Document Server

Borthwick, David

2016-01-01

This modern take on partial differential equations does not require knowledge beyond vector calculus and linear algebra. The author focuses on the most important classical partial differential equations, including conservation equations and their characteristics, the wave equation, the heat equation, function spaces, and Fourier series, drawing on tools from analysis only as they arise.Within each section the author creates a narrative that answers the five questions: (1) What is the scientific problem we are trying to understand? (2) How do we model that with PDE? (3) What techniques can we use to analyze the PDE? (4) How do those techniques apply to this equation? (5) What information or insight did we obtain by developing and analyzing the PDE? The text stresses the interplay between modeling and mathematical analysis, providing a thorough source of problems and an inspiration for the development of methods.

Differential equations methods and applications

CERN Document Server

Said-Houari, Belkacem

2015-01-01

This book presents a variety of techniques for solving ordinary differential equations analytically and features a wealth of examples. Focusing on the modeling of real-world phenomena, it begins with a basic introduction to differential equations, followed by linear and nonlinear first order equations and a detailed treatment of the second order linear equations. After presenting solution methods for the Laplace transform and power series, it lastly presents systems of equations and offers an introduction to the stability theory. To help readers practice the theory covered, two types of exercises are provided: those that illustrate the general theory, and others designed to expand on the text material. Detailed solutions to all the exercises are included. The book is excellently suited for use as a textbook for an undergraduate class (of all disciplines) in ordinary differential equations. .

Gauge-invariant flow equation

Science.gov (United States)

Wetterich, C.

2018-06-01

We propose a closed gauge-invariant functional flow equation for Yang-Mills theories and quantum gravity that only involves one macroscopic gauge field or metric. It is based on a projection on physical and gauge fluctuations. Deriving this equation from a functional integral we employ the freedom in the precise choice of the macroscopic field and the effective average action in order to realize a closed and simple form of the flow equation.

Fundamental equations for two-phase flow. Part 1: general conservation equations. Part 2: complement and remarks

International Nuclear Information System (INIS)

Delhaye, J.M.

1968-12-01

This report deals with the general equations of mass conservation, of momentum conservation, and energy conservation in the case of a two-phase flow. These equations are presented in several forms starting from integral equations which are assumed initially a priori. 1. Equations with local instantaneous variables, and interfacial conditions; 2. Equations with mean instantaneous variables in a cross-section, and practical applications: these equations include an important experimental value which is the ratio of the cross-section of passage of one phase to the total cross-section of a flow-tube. 3. Equations with a local statistical mean, and equations averaged over a period of time: A more advanced attempt to relate theory and experiment consists in taking the statistical averages of local equations. Equations are then obtained involving variables which are averaged over a period of time with the help of an ergodic assumption. 4. Combination of statistical averages and averages over a cross-section: in this study are considered the local variables averaged statistically, then averaged over the cross-section, and also the variables averaged over the section and then averaged statistically. 5. General equations concerning emulsions: In this case a phase exists in a locally very finely divided form. This peculiarity makes it possible to define a volume concentration, and to draw up equations which have numerous applications. - Certain points arising in the first part of this report concerning general mass conservation equations for two-phase flow have been completed and clarified. The terms corresponding to the interfacial tension have been introduced into the general equations. The interfacial conditions have thus been generalized. A supplementary step has still to be carried out: it has, in effect, been impossible to take the interfacial tension into account in the case of emulsions. It was then appeared interesting to compare this large group of fundamental

Partial differential equations II elements of the modern theory equations with constant coefficients

CERN Document Server

Shubin, M

1994-01-01

This book, the first printing of which was published as Volume 31 of the Encyclopaedia of Mathematical Sciences, contains a survey of the modern theory of general linear partial differential equations and a detailed review of equations with constant coefficients. Readers will be interested in an introduction to microlocal analysis and its applications including singular integral operators, pseudodifferential operators, Fourier integral operators and wavefronts, a survey of the most important results about the mixed problem for hyperbolic equations, a review of asymptotic methods including short wave asymptotics, the Maslov canonical operator and spectral asymptotics, a detailed description of the applications of distribution theory to partial differential equations with constant coefficients including numerous interesting special topics.

Comparison between results of solution of Burgers' equation and Laplace's equation by Galerkin and least-square finite element methods

Science.gov (United States)

Adib, Arash; Poorveis, Davood; Mehraban, Farid

2018-03-01

In this research, two equations are considered as examples of hyperbolic and elliptic equations. In addition, two finite element methods are applied for solving of these equations. The purpose of this research is the selection of suitable method for solving each of two equations. Burgers' equation is a hyperbolic equation. This equation is a pure advection (without diffusion) equation. This equation is one-dimensional and unsteady. A sudden shock wave is introduced to the model. This wave moves without deformation. In addition, Laplace's equation is an elliptical equation. This equation is steady and two-dimensional. The solution of Laplace's equation in an earth dam is considered. By solution of Laplace's equation, head pressure and the value of seepage in the directions X and Y are calculated in different points of earth dam. At the end, water table is shown in the earth dam. For Burgers' equation, least-square method can show movement of wave with oscillation but Galerkin method can not show it correctly (the best method for solving of the Burgers' equation is discrete space by least-square finite element method and discrete time by forward difference.). For Laplace's equation, Galerkin and least square methods can show water table correctly in earth dam.

INVARIANTS OF GENERALIZED RAPOPORT-LEAS EQUATIONS

Directory of Open Access Journals (Sweden)

Elena N. Kushner

2018-01-01

Full Text Available For the generalized Rapoport-Leas equations, algebra of differential invariants is constructed with respect to point transformations, that is, transformations of independent and dependent variables. The finding of a general transformation of this type reduces to solving an extremely complicated functional equation. Therefore, following the approach of Sophus Lie, we restrict ourselves to the search for infinitesimal transformations which are generated by translations along the trajectories of vector fields. The problem of finding these vector fields reduces to the redefined system decision of linear differential equations with respect to their coefficients. The Rapoport-Leas equations arise in the study of nonlinear filtration processes in porous media, as well as in other areas of natural science: for example, these equations describe various physical phenomena: two-phase filtration in a porous medium, filtration of a polytropic gas, and propagation of heat at nuclear explosion. They are vital topic for research: in recent works of Bibikov, Lychagin, and others, the analysis of the symmetries of the generalized Rapoport-Leas equations has been carried out; finite-dimensional dynamics and conditions of attractors existence have been found. Since the generalized RapoportLeas equations are nonlinear partial differential equations of the second order with two independent variables; the methods of the geometric theory of differential equations are used to study them in this paper. According to this theory differential equations generate subvarieties in the space of jets. This makes it possible to use the apparatus of modern differential geometry to study differential equations. We introduce the concept of admissible transformations, that is, replacements of variables that do not derive equations outside the class of the Rapoport-Leas equations. Such transformations form a Lie group. For this Lie group there are differential invariants that separate

Carotene and provitamin A content of vegetables sold in Viçosa, MG, Brazil, during spring and winter

Directory of Open Access Journals (Sweden)

Pollyanna Costa Cardoso

2009-09-01

Full Text Available This study investigated the α- and β-carotene content and provitamin A value of four leafy vegetables sold at local and street markets in Viçosa, MG, Brazil, in the spring and winter of 2002. Carotenoids were analyzed by high-performance liquid chromatography. α-Carotene was detected in all samples sold during spring, but was only present in a few samples of smooth and curly lettuce and kale in winter. β-Carotene was found in marked quantities in all leafy vegetables analyzed. Duncan's test (α = 5% showed significantly higher α-carotene content in curly lettuce and vitamin A value in large-leaved watercress in the spring. Mean β-carotene content and vitamin A value were 7544, 8751, 2584, 2792, 8193, and 5338 μg/100 g and 666, 760, 227, 238, 698, and 460 μg RAE/100 g in large-leaved and hydroponic watercress, smooth and curly lettuce, kale and spinach, respectively. All leafy vegetables analyzed represent important sources of provitamin A and supply an important part of the daily requirements of children and adults.Investigou-se o conteúdo de α e β-caroteno e avaliou-se o valor pro-vitamínico A de quatro hortaliças folhosas comercializadas em mercados locais e feira- livre de Viçosa, MG durante a primavera e o inverno de 2002. Os carotenóides foram analisados por Cromatografia Líquida de Alta Eficiência (CLAE. O α-caroteno foi detectado em todas as amostras analisadas na primavera, porém no inverno, somente algumas amostras de alface crespa e lisa, e couve apresentaram tal carotenóide. O β-caroteno foi encontrado, em quantidades apreciáveis, em todas as hortaliças folhosas analisadas. O teste de Duncan (α=5% detectou que o conteúdo de α-caroteno em alface crespa e o valor de vitamina A em agrião de folha larga foram estatisticamente superiores na primavera. Os teores médios de β-caroteno e de valor de vitamina A para agrião de folha larga e hidropônico, alface crespa e lisa, couve e espinafre foram: 7544; 8751

On matrix fractional differential equations

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Adem Kılıçman

2017-01-01

Full Text Available The aim of this article is to study the matrix fractional differential equations and to find the exact solution for system of matrix fractional differential equations in terms of Riemann–Liouville using Laplace transform method and convolution product to the Riemann–Liouville fractional of matrices. Also, we show the theorem of non-homogeneous matrix fractional partial differential equation with some illustrative examples to demonstrate the effectiveness of the new methodology. The main objective of this article is to discuss the Laplace transform method based on operational matrices of fractional derivatives for solving several kinds of linear fractional differential equations. Moreover, we present the operational matrices of fractional derivatives with Laplace transform in many applications of various engineering systems as control system. We present the analytical technique for solving fractional-order, multi-term fractional differential equation. In other words, we propose an efficient algorithm for solving fractional matrix equation.

Integral equations and their applications

CERN Document Server

Rahman, M

2007-01-01

For many years, the subject of functional equations has held a prominent place in the attention of mathematicians. In more recent years this attention has been directed to a particular kind of functional equation, an integral equation, wherein the unknown function occurs under the integral sign. The study of this kind of equation is sometimes referred to as the inversion of a definite integral. While scientists and engineers can already choose from a number of books on integral equations, this new book encompasses recent developments including some preliminary backgrounds of formulations of integral equations governing the physical situation of the problems. It also contains elegant analytical and numerical methods, and an important topic of the variational principles. Primarily intended for senior undergraduate students and first year postgraduate students of engineering and science courses, students of mathematical and physical sciences will also find many sections of direct relevance. The book contains eig...

Equations of motion for a (non-linear) scalar field model as derived from the field equations

International Nuclear Information System (INIS)

Kaniel, S.; Itin, Y.

2006-01-01

The problem of derivation of the equations of motion from the field equations is considered. Einstein's field equations have a specific analytical form: They are linear in the second order derivatives and quadratic in the first order derivatives of the field variables. We utilize this particular form and propose a novel algorithm for the derivation of the equations of motion from the field equations. It is based on the condition of the balance between the singular terms of the field equation. We apply the algorithm to a non-linear Lorentz invariant scalar field model. We show that it results in the Newton law of attraction between the singularities of the field moved on approximately geodesic curves. The algorithm is applicable to the N-body problem of the Lorentz invariant field equations. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

The relativistic electron wave equation

International Nuclear Information System (INIS)

Dirac, P.A.M.

1977-08-01

The paper was presented at the European Conference on Particle Physics held in Budapest between the 4th and 9th July of 1977. A short review is given on the birth of the relativistic electron wave equation. After Schroedinger has shown the equivalence of his wave mechanics and the matrix mechanics of Heisenberg, a general transformation theory was developed by the author. This theory required a relativistic wave equation linear in delta/delta t. As the Klein--Gordon equation available at this time did not satisfy this condition the development of a new equation became necessary. The equation which was found gave the value of the electron spin and magnetic moment automatically. (D.P.)

Equation with the many fathers

DEFF Research Database (Denmark)

Kragh, Helge

1984-01-01

In this essay I discuss the origin and early development of the first relativistic wave equation, known as the Klein-Gordon equation. In 1926 several physicists, among them Klein, Fock, Schrödinger, and de Broglie, announced this equation as a candidate for a relativistic generalization of the us...... as electrodynamics. Although this ambitious attempt attracted some interest in 1926, its impact on the mainstream of development in quantum mechanics was virtually nil....... of the usual Schrödinger equation. In most of the early versions the Klein-Gordon equation was connected with the general theory of relativity. Klein and some other physicists attempted to express quantum mechanics within a five-dimensional unified theory, embracing general relativity as well...

Solving (2 + 1)-dimensional sine-Poisson equation by a modified variable separated ordinary differential equation method

International Nuclear Information System (INIS)

Ka-Lin, Su; Yuan-Xi, Xie

2010-01-01

By introducing a more general auxiliary ordinary differential equation (ODE), a modified variable separated ordinary differential equation method is presented for solving the (2 + 1)-dimensional sine-Poisson equation. As a result, many explicit and exact solutions of the (2 + 1)-dimensional sine-Poisson equation are derived in a simple manner by this technique. (general)

On the Saha Ionization Equation

Indian Academy of Sciences (India)

Abstract. We revisit the Saha Ionization Equation in order to highlightthe rich interdisciplinary content of the equation thatstraddles distinct areas of spectroscopy, thermodynamics andchemical reactions. In a self-contained discussion, relegatedto an appendix, we delve further into the hidden message ofthe equation in terms ...

Application of a Lie group admitted by a homogeneous equation for group classification of a corresponding inhomogeneous equation

Science.gov (United States)

Long, Feng-Shan; Karnbanjong, Adisak; Suriyawichitseranee, Amornrat; Grigoriev, Yurii N.; Meleshko, Sergey V.

2017-07-01

This paper proposes an algorithm for group classification of a nonhomogeneous equation using the group analysis provided for the corresponding homogeneous equation. The approach is illustrated by a partial differential equation, an integro-differential equation, and a delay partial differential equation.

Neoclassical MHD equations for tokamaks

International Nuclear Information System (INIS)

Callen, J.D.; Shaing, K.C.

1986-03-01

The moment equation approach to neoclassical-type processes is used to derive the flows, currents and resistive MHD-like equations for studying equilibria and instabilities in axisymmetric tokamak plasmas operating in the banana-plateau collisionality regime (ν* approx. 1). The resultant ''neoclassical MHD'' equations differ from the usual reduced equations of resistive MHD primarily by the addition of the important viscous relaxation effects within a magnetic flux surface. The primary effects of the parallel (poloidal) viscous relaxation are: (1) Rapid (approx. ν/sub i/) damping of the poloidal ion flow so the residual flow is only toroidal; (2) addition of the bootstrap current contribution to Ohm's laws; and (3) an enhanced (by B 2 /B/sub theta/ 2 ) polarization drift type term and consequent enhancement of the perpendicular dielectric constant due to parallel flow inertia, which causes the equations to depend only on the poloidal magnetic field B/sub theta/. Gyroviscosity (or diamagnetic vfiscosity) effects are included to properly treat the diamagnetic flow effects. The nonlinear form of the neoclassical MHD equations is derived and shown to satisfy an energy conservation equation with dissipation arising from Joule and poloidal viscous heating, and transport due to classical and neoclassical diffusion

The extended Fan's sub-equation method and its application to KdV-MKdV, BKK and variant Boussinesq equations

International Nuclear Information System (INIS)

Yomba, Emmanuel

2005-01-01

An extended Fan's sub-equation method is used for constructing exact travelling wave solutions of nonlinear partial differential equations (NLPDEs). The key idea of this method is to take full advantage of the general elliptic equation involving five parameters which has more new solutions and whose degeneracies can lead to special sub-equations involving three parameters. More new solutions are obtained for KdV-MKdV, Broer-Kaup-Kupershmidt (BKK) and variant Boussinesq equations. Then we present a technique which not only gives us a clear relation among this general elliptic equation and other sub-equations involving three parameters (Riccati equation, first kind elliptic equation, auxiliary ordinary equation, generalized Riccati equation and so on), but also provides an approach to construct new exact solutions to NLPDEs

On the relation between elementary partial difference equations and partial differential equations

NARCIS (Netherlands)

van den Berg, I.P.

1998-01-01

The nonstandard stroboscopy method links discrete-time ordinary difference equations of first-order and continuous-time, ordinary differential equations of first order. We extend this method to the second order, and also to an elementary, yet general class of partial difference/differential

A novel numerical flux for the 3D Euler equations with general equation of state

KAUST Repository

Toro, Eleuterio F.; Castro, Cristó bal E.; Bok Jik, Lee

2015-01-01

Euler equations for ideal gases and its extension presented in this paper is threefold: (i) we solve the three-dimensional Euler equations on general meshes; (ii) we use a general equation of state; and (iii) we achieve high order of accuracy in both

From ordinary to partial differential equations

CERN Document Server

Esposito, Giampiero

2017-01-01

This book is addressed to mathematics and physics students who want to develop an interdisciplinary view of mathematics, from the age of Riemann, Poincaré and Darboux to basic tools of modern mathematics. It enables them to acquire the sensibility necessary for the formulation and solution of difficult problems, with an emphasis on concepts, rigour and creativity. It consists of eight self-contained parts: ordinary differential equations; linear elliptic equations; calculus of variations; linear and non-linear hyperbolic equations; parabolic equations; Fuchsian functions and non-linear equations; the functional equations of number theory; pseudo-differential operators and pseudo-differential equations. The author leads readers through the original papers and introduces new concepts, with a selection of topics and examples that are of high pedagogical value.

Completely integrable operator evolutionary equations

International Nuclear Information System (INIS)

Chudnovsky, D.V.

1979-01-01

The authors present natural generalizations of classical completely integrable equations where the functions are replaced by arbitrary operators. Among these equations are the non-linear Schroedinger, the Korteweg-de Vries, and the modified KdV equations. The Lax representation and the Baecklund transformations are presented. (Auth.)

On the fluid-dynamical approximation to the Boltzmann equation at the level of the Navier-Stokes equation

International Nuclear Information System (INIS)

Kawashima, S.; Matsumara, A.; Nishida, T.

1979-01-01

The compressible and heat-conductive Navier-Stokes equation obtained as the second approximation of the formal Chapman-Enskog expansion is investigated on its relations to the original nonlinear Boltzmann equation and also to the incompressible Navier-Stokes equation. The solutions of the Boltzmann equation and the incompressible Navier-Stokes equation for small initial data are proved to be asymptotically equivalent (mod decay rate tsup(-5/4)) as t → + infinitely to that of the compressible Navier-Stokes equation for the corresponding initial data. (orig.) 891 HJ/orig. 892 MKO

Solution of radial spin-1 field equation in Robertson-Walker space-time via Heun's equation

International Nuclear Information System (INIS)

Zecca, A.

2010-01-01

The spin-1 field equation is considered in Robertson-Walker spacetime. The problem of the solution of the separated radial equations, previously discussed in the flat space-time case, is solved also for both the closed and open curvature case. The radial equation is reduced to Heun's differential equation that recently has been widely reconsidered. It is shown that the solution of the present Heun equation does not fall into the class of polynomial-like or hypergeometric functions. Heun's operator results also non-factorisable. The properties follow from application of general theorems and power series expansion. In the positive curvature case of the universe a discrete energy spectrum of the system is found. The result follows by requiring a polynomial-like behaviour of at least one component of the spinor field. Developments and applications of the theory suggest further study of the solution of Heun's equation.

Differential equations I essentials

CERN Document Server

REA, Editors of

2012-01-01

REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Differential Equations I covers first- and second-order equations, series solutions, higher-order linear equations, and the Laplace transform.

Beginning partial differential equations

CERN Document Server

O'Neil, Peter V

2011-01-01

A rigorous, yet accessible, introduction to partial differential equations-updated in a valuable new edition Beginning Partial Differential Equations, Second Edition provides a comprehensive introduction to partial differential equations (PDEs) with a special focus on the significance of characteristics, solutions by Fourier series, integrals and transforms, properties and physical interpretations of solutions, and a transition to the modern function space approach to PDEs. With its breadth of coverage, this new edition continues to present a broad introduction to the field, while also addres

Banking on the equator. Are banks that adopted the equator principles different from non-adopters?

NARCIS (Netherlands)

Scholtens, B.; Dam, L.

We analyze the performance of banks that adopted the Equator Principles. The Equator Principles are designed to assure sustainable development in project finance. The social, ethical, and environmental policies of the adopters differ significantly from those of banks that did not adopt the Equator

Hartree--Fock density matrix equation

International Nuclear Information System (INIS)

Cohen, L.; Frishberg, C.

1976-01-01

An equation for the Hartree--Fock density matrix is discussed and the possibility of solving this equation directly for the density matrix instead of solving the Hartree--Fock equation for orbitals is considered. Toward that end the density matrix is expanded in a finite basis to obtain the matrix representative equation. The closed shell case is considered. Two numerical schemes are developed and applied to a number of examples. One example is given where the standard orbital method does not converge while the method presented here does

Exact solutions to sine-Gordon-type equations

International Nuclear Information System (INIS)

Liu Shikuo; Fu Zuntao; Liu Shida

2006-01-01

In this Letter, sine-Gordon-type equations, including single sine-Gordon equation, double sine-Gordon equation and triple sine-Gordon equation, are systematically solved by Jacobi elliptic function expansion method. It is shown that different transformations for these three sine-Gordon-type equations play different roles in obtaining exact solutions, some transformations may not work for a specific sine-Gordon equation, while work for other sine-Gordon equations

dimensional Jaulent–Miodek equations

Indian Academy of Sciences (India)

(2+1)-dimensional Jaulent–Miodek equation; the first integral method; kinks; ... and effective method for solving nonlinear partial differential equations which can ... of the method employed and exact kink and soliton solutions are constructed ...

Random walk and the heat equation

CERN Document Server

Lawler, Gregory F

2010-01-01

The heat equation can be derived by averaging over a very large number of particles. Traditionally, the resulting PDE is studied as a deterministic equation, an approach that has brought many significant results and a deep understanding of the equation and its solutions. By studying the heat equation by considering the individual random particles, however, one gains further intuition into the problem. While this is now standard for many researchers, this approach is generally not presented at the undergraduate level. In this book, Lawler introduces the heat equation and the closely related notion of harmonic functions from a probabilistic perspective. The theme of the first two chapters of the book is the relationship between random walks and the heat equation. The first chapter discusses the discrete case, random walk and the heat equation on the integer lattice; and the second chapter discusses the continuous case, Brownian motion and the usual heat equation. Relationships are shown between the two. For exa...

On integrability of the Killing equation

Science.gov (United States)

Houri, Tsuyoshi; Tomoda, Kentaro; Yasui, Yukinori

2018-04-01

Killing tensor fields have been thought of as describing the hidden symmetry of space(-time) since they are in one-to-one correspondence with polynomial first integrals of geodesic equations. Since many problems in classical mechanics can be formulated as geodesic problems in curved space and spacetime, solving the defining equation for Killing tensor fields (the Killing equation) is a powerful way to integrate equations of motion. Thus it has been desirable to formulate the integrability conditions of the Killing equation, which serve to determine the number of linearly independent solutions and also to restrict the possible forms of solutions tightly. In this paper, we show the prolongation for the Killing equation in a manner that uses Young symmetrizers. Using the prolonged equations, we provide the integrability conditions explicitly.

Algebraic entropy for differential-delay equations

OpenAIRE

Viallet, Claude M.

2014-01-01

We extend the definition of algebraic entropy to a class of differential-delay equations. The vanishing of the entropy, as a structural property of an equation, signals its integrability. We suggest a simple way to produce differential-delay equations with vanishing entropy from known integrable differential-difference equations.

Hyperbolic partial differential equations

CERN Document Server

Witten, Matthew

1986-01-01

Hyperbolic Partial Differential Equations III is a refereed journal issue that explores the applications, theory, and/or applied methods related to hyperbolic partial differential equations, or problems arising out of hyperbolic partial differential equations, in any area of research. This journal issue is interested in all types of articles in terms of review, mini-monograph, standard study, or short communication. Some studies presented in this journal include discretization of ideal fluid dynamics in the Eulerian representation; a Riemann problem in gas dynamics with bifurcation; periodic M

Children sold for transplants: medical and legal aspects. Amnesty International--Danish Working Group for Children.

Science.gov (United States)

Fasting, U; Christensen, J; Glending, S

1998-11-01

Over the last few decades there has been a substantially higher percentage of successful organ transplants but also a significant imbalance between the demand for and the supply of organs, creating the basis for a highly profitable black market trade in human organs. Sometimes there are reports that children have been kidnapped, only to reappear later lacking one kidney, or that they simply disappear and are subsequently killed to have all their transplantable organs removed for profit. The European Union feels that there is a need for action and that it has a duty to act in this field, especially for ethical reasons. There is now established close co-operation between the various European transplant organizations. The legal protection of children with regard to organ transplantation is not specifically mentioned in the existing conventions because this issue was not foreseen at the time of their preparation. However, the issue is covered in a broader sense by more general provisions. There are endless rumours surrounding this area. Members of various organizations who travel in the suspected countries say that the trafficking in children who are sold for transplantation is well known, but it is too difficult and very dangerous to catch the people involved. We have to conclude that it has been impossible to prove or disprove the rumours, but they are consistent and we all, especially in the health care professions, have an obligation to be keenly aware of how and where organs are obtained.

Dynamical equations for the optical potential

International Nuclear Information System (INIS)

Kowalski, K.L.

1981-01-01

Dynamical equations for the optical potential are obtained starting from a wide class of N-particle equations. This is done with arbitrary multiparticle interactions to allow adaptation to few-body models of nuclear reactions and including all effects of nucleon identity. Earlier forms of the optical potential equations are obtained as special cases. Particular emphasis is placed upon obtaining dynamical equations for the optical potential from the equations of Kouri, Levin, and Tobocman including all effects of particle identity

Group foliation of finite difference equations

Science.gov (United States)

Thompson, Robert; Valiquette, Francis

2018-06-01

Using the theory of equivariant moving frames, a group foliation method for invariant finite difference equations is developed. This method is analogous to the group foliation of differential equations and uses the symmetry group of the equation to decompose the solution process into two steps, called resolving and reconstruction. Our constructions are performed algorithmically and symbolically by making use of discrete recurrence relations among joint invariants. Applications to invariant finite difference equations that approximate differential equations are given.

Manhattan equation for the operational amplifier

OpenAIRE

Mishonov, Todor M.; Danchev, Victor I.; Petkov, Emil G.; Gourev, Vassil N.; Dimitrova, Iglika M.; Varonov, Albert M.

2018-01-01

A differential equation relating the voltage at the output of an operational amplifier $U_0$ and the difference between the input voltages ($U_{+}$ and $U_{-}$) has been derived. The crossover frequency $f_0$ is a parameter in this operational amplifier master equation. The formulas derived as a consequence of this equation find applications in thousands of specifications for electronic devices but as far as we know, the equation has never been published. Actually, the master equation of oper...

Benney's long wave equations

International Nuclear Information System (INIS)

Lebedev, D.R.

1979-01-01

Benney's equations of motion of incompressible nonviscous fluid with free surface in the approximation of long waves are analyzed. The connection between the Lie algebra of Hamilton plane vector fields and the Benney's momentum equations is shown

The forced nonlinear Schroedinger equation

International Nuclear Information System (INIS)

Kaup, D.J.; Hansen, P.J.

1985-01-01

The nonlinear Schroedinger equation describes the behaviour of a radio frequency wave in the ionosphere near the reflexion point where nonlinear processes are important. A simple model of this phenomenon leads to the forced nonlinear Schroedinger equation in terms of a nonlinear boundary value problem. A WKB analysis of the time evolution equations for the nonlinear Schroedinger equation in the inverse scattering transform formalism gives a crude order of magnitude estimation of the qualitative behaviour of the solutions. This estimation is compared with the numerical solutions. (D.Gy.)

Solving Nonlinear Coupled Differential Equations

Science.gov (United States)

Mitchell, L.; David, J.

1986-01-01

Harmonic balance method developed to obtain approximate steady-state solutions for nonlinear coupled ordinary differential equations. Method usable with transfer matrices commonly used to analyze shaft systems. Solution to nonlinear equation, with periodic forcing function represented as sum of series similar to Fourier series but with form of terms suggested by equation itself.

Structural Equation and Mei Conserved Quantity of Mei Symmetry for Appell Equations in Holonomic Systems with Unilateral Constraints

International Nuclear Information System (INIS)

Jia Liqun; Cui Jinchao; Zhang Yaoyu; Luo Shaokai

2009-01-01

Structural equation and Mei conserved quantity of Mei symmetry for Appell equations in holonomic systems with unilateral constraints are investigated. Appell equations and differential equations of motion for holonomic mechanic systems with unilateral constraints are established. The definition and the criterion of Mei symmetry for Appell equations in holonomic systems with unilateral constraints under the infinitesimal transformations of groups are also given. The expressions of the structural equation and Mei conserved quantity of Mei symmetry for Appell equations in holonomic systems with unilateral constraints expressed by Appell functions are obtained. An example is given to illustrate the application of the results. (general)

Direct 'delay' reductions of the Toda equation

International Nuclear Information System (INIS)

Joshi, Nalini

2009-01-01

A new direct method of obtaining reductions of the Toda equation is described. We find a canonical and complete class of all possible reductions under certain assumptions. The resulting equations are ordinary differential-difference equations, sometimes referred to as delay-differential equations. The representative equation of this class is hypothesized to be a new version of one of the classical Painleve equations. The Lax pair associated with this equation is obtained, also by reduction. (fast track communication)

Reduction of the equation for lower hybrid waves in a plasma to a nonlinear Schroedinger equation

Science.gov (United States)

Karney, C. F. F.

1977-01-01

Equations describing the nonlinear propagation of waves in an anisotropic plasma are rarely exactly soluble. However it is often possible to make approximations that reduce the exact equations into a simpler equation. The use of MACSYMA to make such approximations, and so reduce the equation describing lower hybrid waves into the nonlinear Schrodinger equation which is soluble by the inverse scattering method is demonstrated. MACSYMA is used at several stages in the calculation only because there is a natural division between calculations that are easiest done by hand, and those that are easiest done by machine.

Quadratic Diophantine equations

CERN Document Server

Andreescu, Titu

2015-01-01

This monograph treats the classical theory of quadratic Diophantine equations and guides the reader through the last two decades of computational techniques and progress in the area. These new techniques combined with the latest increases in computational power shed new light on important open problems. The authors motivate the study of quadratic Diophantine equations with excellent examples, open problems, and applications. Moreover, the exposition aptly demonstrates many applications of results and techniques from the study of Pell-type equations to other problems in number theory. The book is intended for advanced undergraduate and graduate students as well as researchers. It challenges the reader to apply not only specific techniques and strategies, but also to employ methods and tools from other areas of mathematics, such as algebra and analysis.

Quantum-statistical kinetic equations

International Nuclear Information System (INIS)

Loss, D.; Schoeller, H.

1989-01-01

Considering a homogeneous normal quantum fluid consisting of identical interacting fermions or bosons, the authors derive an exact quantum-statistical generalized kinetic equation with a collision operator given as explicit cluster series where exchange effects are included through renormalized Liouville operators. This new result is obtained by applying a recently developed superoperator formalism (Liouville operators, cluster expansions, symmetrized projectors, P q -rule, etc.) to nonequilibrium systems described by a density operator ρ(t) which obeys the von Neumann equation. By means of this formalism a factorization theorem is proven (being essential for obtaining closed equations), and partial resummations (leading to renormalized quantities) are performed. As an illustrative application, the quantum-statistical versions (including exchange effects due to Fermi-Dirac or Bose-Einstein statistics) of the homogeneous Boltzmann (binary collisions) and Choh-Uhlenbeck (triple collisions) equations are derived

The self- and foreign-absorption continua of water vapor by cavity ring-down spectroscopy near 2.35 μm.

Science.gov (United States)

Mondelain, D; Vasilchenko, S; Čermák, P; Kassi, S; Campargue, A

2015-07-21

The room temperature self- and foreign-continua of water vapor have been measured near 4250 cm(-1) with a newly developed high sensitivity cavity ring down spectrometer (CRDS). The typical sensitivity of the recordings is αmin≈ 6 × 10(-10) cm(-1) which is two orders of magnitude better than previous Fourier transform spectroscopy (FTS) measurements in the spectral region. The investigated spectral interval is located in the low energy range of the important 2.1 μm atmospheric transparency window. Self-continuum cross-sections, CS, were retrieved from the quadratic dependence of the spectrum base line level measured for different water vapor pressures between 0 and 15 Torr, after subtraction of the local water monomer lines contribution calculated using HITRAN2012 line parameters. The CS values were determined with 5% accuracy for four spectral points between 4249.2 and 4257.3 cm(-1). Their values of about 3.2 × 10(-23) cm(2) molecule(-1) atm(-1) are found 20% higher than predicted by the MT_CKD V2.5 model but two times weaker than reported in the literature using FTS. The foreign-continuum was evaluated by injecting various amounts of synthetic air in the CRDS cell while keeping the initial water vapor partial pressure constant. The foreign-continuum cross-section, CF, was retrieved from a linear fit of the spectrum base line level versus the air pressure. The obtained CF values are larger by a factor of 4.5 compared to the MT_CKD values and smaller by a factor of 1.7 compared to previous FTS values. As a result, for an atmosphere at room temperature with 60% relative humidity, the foreign-continuum contribution to the water continuum near 4250 cm(-1) is found to be on the same order as the self-continuum contribution.

A linearizing transformation for the Korteweg-de Vries equation; generalizations to higher-dimensional nonlinear partial differential equations

NARCIS (Netherlands)

Dorren, H.J.S.

1998-01-01

It is shown that the Korteweg–de Vries (KdV) equation can be transformed into an ordinary linear partial differential equation in the wave number domain. Explicit solutions of the KdV equation can be obtained by subsequently solving this linear differential equation and by applying a cascade of

PREFACE: Symmetries and integrability of difference equations Symmetries and integrability of difference equations

Science.gov (United States)

Levi, Decio; Olver, Peter; Thomova, Zora; Winternitz, Pavel

2009-11-01

The concept of integrability was introduced in classical mechanics in the 19th century for finite dimensional continuous Hamiltonian systems. It was extended to certain classes of nonlinear differential equations in the second half of the 20th century with the discovery of the inverse scattering transform and the birth of soliton theory. Also at the end of the 19th century Lie group theory was invented as a powerful tool for obtaining exact analytical solutions of large classes of differential equations. Together, Lie group theory and integrability theory in its most general sense provide the main tools for solving nonlinear differential equations. Like differential equations, difference equations play an important role in physics and other sciences. They occur very naturally in the description of phenomena that are genuinely discrete. Indeed, they may actually be more fundamental than differential equations if space-time is actually discrete at very short distances. On the other hand, even when treating continuous phenomena described by differential equations it is very often necessary to resort to numerical methods. This involves a discretization of the differential equation, i.e. a replacement of the differential equation by a difference one. Given the well developed and understood techniques of symmetry and integrability for differential equations a natural question to ask is whether it is possible to develop similar techniques for difference equations. The aim is, on one hand, to obtain powerful methods for solving `integrable' difference equations and to establish practical integrability criteria, telling us when the methods are applicable. On the other hand, Lie group methods can be adapted to solve difference equations analytically. Finally, integrability and symmetry methods can be combined with numerical methods to obtain improved numerical solutions of differential equations. The origin of the SIDE meetings goes back to the early 1990s and the first

Local instant conservation equations

International Nuclear Information System (INIS)

Delaje, Dzh.

1984-01-01

Local instant conservation equations for two-phase flow are derived. Derivation of the equation starts from the recording of integral laws of conservation for a fixed reference volume, containing both phases. Transformation of the laws, using the Leibniz rule and Gauss theory permits to obtain the sum of two integrals as to the volume and integral as to the surface. Integrals as to the volume result in local instant differential equations, in particular derivatives for each phase, and integrals as to the surface reflect local instant conditions of a jump on interface surface

Differential equations problem solver

CERN Document Server

Arterburn, David R

2012-01-01

REA's Problem Solvers is a series of useful, practical, and informative study guides. Each title in the series is complete step-by-step solution guide. The Differential Equations Problem Solver enables students to solve difficult problems by showing them step-by-step solutions to Differential Equations problems. The Problem Solvers cover material ranging from the elementary to the advanced and make excellent review books and textbook companions. They're perfect for undergraduate and graduate studies.The Differential Equations Problem Solver is the perfect resource for any class, any exam, and

Local Observed-Score Kernel Equating

Science.gov (United States)

Wiberg, Marie; van der Linden, Wim J.; von Davier, Alina A.

2014-01-01

Three local observed-score kernel equating methods that integrate methods from the local equating and kernel equating frameworks are proposed. The new methods were compared with their earlier counterparts with respect to such measures as bias--as defined by Lord's criterion of equity--and percent relative error. The local kernel item response…

Numerical solution of Boltzmann's equation

International Nuclear Information System (INIS)

Sod, G.A.

1976-04-01

The numerical solution of Boltzmann's equation is considered for a gas model consisting of rigid spheres by means of Hilbert's expansion. If only the first two terms of the expansion are retained, Boltzmann's equation reduces to the Boltzmann-Hilbert integral equation. Successive terms in the Hilbert expansion are obtained by solving the same integral equation with a different source term. The Boltzmann-Hilbert integral equation is solved by a new very fast numerical method. The success of the method rests upon the simultaneous use of four judiciously chosen expansions; Hilbert's expansion for the distribution function, another expansion of the distribution function in terms of Hermite polynomials, the expansion of the kernel in terms of the eigenvalues and eigenfunctions of the Hilbert operator, and an expansion involved in solving a system of linear equations through a singular value decomposition. The numerical method is applied to the study of the shock structure in one space dimension. Numerical results are presented for Mach numbers of 1.1 and 1.6. 94 refs, 7 tables, 1 fig

The Dirac equation and its solutions

CERN Document Server

Bagrov, Vladislav G

2014-01-01

Dirac equations are of fundamental importance for relativistic quantum mechanics and quantum electrodynamics. In relativistic quantum mechanics, the Dirac equation is referred to as one-particle wave equation of motion for electron in an external electromagnetic field. In quantum electrodynamics, exact solutions of this equation are needed to treat the interaction between the electron and the external field exactly.In particular, all propagators of a particle, i.e., the various Green's functions, are constructed in a certain way by using exact solutions of the Dirac equation.

The Dirac equation and its solutions

International Nuclear Information System (INIS)

Bagrov, Vladislav G.; Gitman, Dmitry; P.N. Lebedev Physical Institute, Moscow; Tomsk State Univ., Tomsk

2013-01-01

The Dirac equation is of fundamental importance for relativistic quantum mechanics and quantum electrodynamics. In relativistic quantum mechanics, the Dirac equation is referred to as one-particle wave equation of motion for electron in an external electromagnetic field. In quantum electrodynamics, exact solutions of this equation are needed to treat the interaction between the electron and the external field exactly. In particular, all propagators of a particle, i.e., the various Green's functions, are constructed in a certain way by using exact solutions of the Dirac equation.

The modified extended Fan's sub-equation method and its application to (2 + 1)-dimensional dispersive long wave equation

International Nuclear Information System (INIS)

Yomba, Emmanuel

2005-01-01

By using a modified extended Fan's sub-equation method, we have obtained new and more general solutions including a series of non-travelling wave and coefficient function solutions namely: soliton-like solutions, triangular-like solutions, single and combined non-degenerative Jacobi elliptic wave function-like solutions for the (2 + 1)-dimensional dispersive long wave equation. The most important achievement of this method lies on the fact that, we have succeeded in one move to give all the solutions which can be previously obtained by application of at least four methods (method using Riccati equation, or first kind elliptic equation, or auxiliary ordinary equation, or generalized Riccati equation as mapping equation)

A probabilistic risk assessment approach used to prioritize chemical constituents in mainstream smoke of cigarettes sold in China.

Science.gov (United States)

Xie, Jianping; Marano, Kristin M; Wilson, Cody L; Liu, Huimin; Gan, Huamin; Xie, Fuwei; Naufal, Ziad S

2012-03-01

The chemical and physical complexity of cigarette mainstream smoke (MSS) presents a challenge in the understanding of risk for smoking-related diseases. Quantitative risk assessment is a useful tool for assessing the toxicological risks that may be presented by smoking currently available commercial cigarettes. In this study, yields of a selected group of chemical constituents were quantified in machine-generated MSS from 30 brands of cigarettes sold in China. Using constituent yields, exposure estimates specific to and representative of the Chinese population, and available dose-response data, a Monte Carlo method was applied to simulate probability distributions for incremental lifetime cancer risk (ILCR), hazard quotient (HQ), and margin of exposure (MOE) values for each constituent as appropriate. Measures of central tendency were extracted from the outcome distributions and constituents were ranked according to these three risk assessment indices. The constituents for which ILCR >10(-4), HQ >1, and MOE risk contributed by each MSS constituent, this approach provides a plausible and objective framework for the prioritization of toxicants in cigarette smoke and is valuable in guiding tobacco risk management. Copyright © 2011 Elsevier Inc. All rights reserved.

Painleve test and discrete Boltzmann equations

International Nuclear Information System (INIS)

Euler, N.; Steeb, W.H.

1989-01-01

The Painleve test for various discrete Boltzmann equations is performed. The connection with integrability is discussed. Furthermore the Lie symmetry vector fields are derived and group-theoretical reduction of the discrete Boltzmann equations to ordinary differentiable equations is performed. Lie Backlund transformations are gained by performing the Painleve analysis for the ordinary differential equations. 16 refs

Chew-Low equations as Cremoma transformations

International Nuclear Information System (INIS)

Rerikh, K.V.

1982-01-01

The Chew-Low equations for the p-wave pion-nucleon scattering with the crossing-symmetry matrix (3x3) are investigated in their well-known formulation as a system of nonlinear difference equations. These equations interpreted as geometrical transformations are shown to be a special case of the Cremona transformaions. Using the properties of the Cremona transformations we obtain the general 3-parametric functional equation on invariant algebraic and nonalgebraic curves in the space solutions of the Chew- Low equations. It is proved that there exists only one invariant algebraic curve, the parabola corresponding to the well-known solution. Analysis of the general functional equation on invariant nonalgebraic curves makes it possible to select in addition to this parabola 3 invariant forms defining implicitly 3 nonalgebraic curves and to concretize for them the general equation by means of fixing the parameters. From the transformational properties of the invariant forms with respect to the Cremona transformations, there follows an important result that the ration of these forms in proper powers is the general integral of the nonlinear system of the Chew-Low equations, which is an even antiperiodic function. The structure of the second general integral is given and the functional equations which determinne this integral are presented [ru

General particle transport equation. Final report

International Nuclear Information System (INIS)

Lafi, A.Y.; Reyes, J.N. Jr.

1994-12-01

The general objectives of this research are as follows: (1) To develop fundamental models for fluid particle coalescence and breakage rates for incorporation into statistically based (Population Balance Approach or Monte Carlo Approach) two-phase thermal hydraulics codes. (2) To develop fundamental models for flow structure transitions based on stability theory and fluid particle interaction rates. This report details the derivation of the mass, momentum and energy conservation equations for a distribution of spherical, chemically non-reacting fluid particles of variable size and velocity. To study the effects of fluid particle interactions on interfacial transfer and flow structure requires detailed particulate flow conservation equations. The equations are derived using a particle continuity equation analogous to Boltzmann's transport equation. When coupled with the appropriate closure equations, the conservation equations can be used to model nonequilibrium, two-phase, dispersed, fluid flow behavior. Unlike the Eulerian volume and time averaged conservation equations, the statistically averaged conservation equations contain additional terms that take into account the change due to fluid particle interfacial acceleration and fluid particle dynamics. Two types of particle dynamics are considered; coalescence and breakage. Therefore, the rate of change due to particle dynamics will consider the gain and loss involved in these processes and implement phenomenological models for fluid particle breakage and coalescence

Microbial community assessment of mealworm larvae (Tenebrio molitor) and grasshoppers (Locusta migratoria migratorioides) sold for human consumption.

Science.gov (United States)

Stoops, J; Crauwels, S; Waud, M; Claes, J; Lievens, B; Van Campenhout, L

2016-02-01

In Western countries, the popularity of edible insects as an alternative animal protein source is increasing. Nevertheless, there is a lack of profound insight into the microbial safety and shelf life of living insects sold for human consumption. The purpose of this study was to characterise the microflora of fresh edible mealworm larvae and grasshoppers in a quantitative and qualitative way. Therefore, culture-dependent analyses (the total viable aerobic count, Enterobacteriaceae, lactic acid bacteria, yeasts and moulds, and bacterial endospores) and next-generation sequencing (454amplicon pyrosequencing) were performed. High microbial counts were obtained for both insect species. Different insect batches resulted in quite similar microbial numbers, except for bacterial endospores. However, the bacterial community composition differed between both insect species. The most abundant operational taxonomic unit in mealworm larvae was Propionibacterium. Also members of the genera Haemophilus, Staphylococcus and Clostridium were found. Grasshoppers were mainly dominated by Weissella, Lactococcus and Yersinia/Rahnella. Overall, a variety of potential spoilage bacteria and food pathogens were characterised. The results of this study suggest that a processing step with a microbiocidal effect is required to avoid or minimize risks involved with the consumption of edible insects. Copyright © 2015 Elsevier Ltd. All rights reserved.

Seasonal Variability of Thermophilic Campylobacter Spp. in Raw Milk Sold by Automatic Vending Machines in Lombardy Region.

Science.gov (United States)

Bertasi, Barbara; Losio, Marina Nadia; Daminelli, Paolo; Finazzi, Guido; Serraino, Andrea; Piva, Silvia; Giacometti, Federica; Massella, Elisa; Ostanello, Fabio

2016-06-03

In temperate climates, a seasonal trend was observed in the incidence of human campylobacteriosis cases, with peaks reported in spring and autumn in some countries, or in summer in others; a similar trend was observed in Campylobacter spp. dairy cattle faecal shedding, suggesting that cattle may play a role in the seasonal peak of human infection. The objectives of this study were to assess if a seasonal trend in thermophilic Campylobacter spp. contamination of raw milk exists and to evaluate a possible relation between this and the increase of human campylobacteriosis incidence in summer months. The results showed a mean prevalence of 1.6% of milk samples positive for thermophilic Campylobacter spp. with a wide range (0.0-3.1%) in different months during the three years considered. The statistical analysis showed a significant difference (P<0.01) of the prevalence of positive samples for thermophilic Campylobacter spp. between warmer and cooler months (2.3 vs 0.6%). The evidence of a seasonal trend in thermophilic Campylobacter spp. contamination of raw milk sold for direct consumption, with an increase of the prevalence in warmer months, may represent one of the possible links between seasonal trend in cattle faecal shedding and seasonal trend in human campylobacteriosis.

Analytical solutions of time-fractional models for homogeneous Gardner equation and non-homogeneous differential equations

Directory of Open Access Journals (Sweden)

Olaniyi Samuel Iyiola

2014-09-01

Full Text Available In this paper, we obtain analytical solutions of homogeneous time-fractional Gardner equation and non-homogeneous time-fractional models (including Buck-master equation using q-Homotopy Analysis Method (q-HAM. Our work displays the elegant nature of the application of q-HAM not only to solve homogeneous non-linear fractional differential equations but also to solve the non-homogeneous fractional differential equations. The presence of the auxiliary parameter h helps in an effective way to obtain better approximation comparable to exact solutions. The fraction-factor in this method gives it an edge over other existing analytical methods for non-linear differential equations. Comparisons are made upon the existence of exact solutions to these models. The analysis shows that our analytical solutions converge very rapidly to the exact solutions.

Electronic representation of wave equation

Energy Technology Data Exchange (ETDEWEB)

Veigend, Petr; Kunovský, Jiří, E-mail: kunovsky@fit.vutbr.cz; Kocina, Filip; Nečasová, Gabriela; Valenta, Václav [University of Technology, Faculty of Information Technology, Božetěchova 2, 612 66 Brno (Czech Republic); Šátek, Václav [IT4Innovations, VŠB Technical University of Ostrava, 17. listopadu 15/2172, 708 33 Ostrava-Poruba (Czech Republic); University of Technology, Faculty of Information Technology, Božetěchova 2, 612 66 Brno (Czech Republic)

2016-06-08

The Taylor series method for solving differential equations represents a non-traditional way of a numerical solution. Even though this method is not much preferred in the literature, experimental calculations done at the Department of Intelligent Systems of the Faculty of Information Technology of TU Brno have verified that the accuracy and stability of the Taylor series method exceeds the currently used algorithms for numerically solving differential equations. This paper deals with solution of Telegraph equation using modelling of a series small pieces of the wire. Corresponding differential equations are solved by the Modern Taylor Series Method.

The Dirac equation for accountants

International Nuclear Information System (INIS)

Ord, G.N.

2006-01-01

In the context of relativistic quantum mechanics, derivations of the Dirac equation usually take the form of plausibility arguments based on experience with the Schroedinger equation. The primary reason for this is that we do not know what wavefunctions physically represent, so derivations have to rely on formal arguments. There is however a context in which the Dirac equation in one dimension is directly related to a classical generating function. In that context, the derivation of the Dirac equation is an exercise in counting. We provide this derivation here and discuss its relationship to quantum mechanics

Polygons of differential equations for finding exact solutions

International Nuclear Information System (INIS)

Kudryashov, Nikolai A.; Demina, Maria V.

2007-01-01

A method for finding exact solutions of nonlinear differential equations is presented. Our method is based on the application of polygons corresponding to nonlinear differential equations. It allows one to express exact solutions of the equation studied through solutions of another equation using properties of the basic equation itself. The ideas of power geometry are used and developed. Our approach has a pictorial interpretation, which is illustrative and effective. The method can be also applied for finding transformations between solutions of differential equations. To demonstrate the method application exact solutions of several equations are found. These equations are: the Korteveg-de Vries-Burgers equation, the generalized Kuramoto-Sivashinsky equation, the fourth-order nonlinear evolution equation, the fifth-order Korteveg-de Vries equation, the fifth-order modified Korteveg-de Vries equation and the sixth-order nonlinear evolution equation describing turbulent processes. Some new exact solutions of nonlinear evolution equations are given

Unsplit complex frequency shifted perfectly matched layer for second-order wave equation using auxiliary differential equations.

Science.gov (United States)

Gao, Yingjie; Zhang, Jinhai; Yao, Zhenxing

2015-12-01

The complex frequency shifted perfectly matched layer (CFS-PML) can improve the absorbing performance of PML for nearly grazing incident waves. However, traditional PML and CFS-PML are based on first-order wave equations; thus, they are not suitable for second-order wave equation. In this paper, an implementation of CFS-PML for second-order wave equation is presented using auxiliary differential equations. This method is free of both convolution calculations and third-order temporal derivatives. As an unsplit CFS-PML, it can reduce the nearly grazing incidence. Numerical experiments show that it has better absorption than typical PML implementations based on second-order wave equation.

The Dirac equation and its solutions

Energy Technology Data Exchange (ETDEWEB)

Bagrov, Vladislav G. [Tomsk State Univ., Tomsk (Russian Federation). Dept. of Quantum Field Theroy; Gitman, Dmitry [Sao Paulo Univ. (Brazil). Inst. de Fisica; P.N. Lebedev Physical Institute, Moscow (Russian Federation); Tomsk State Univ., Tomsk (Russian Federation). Faculty of Physics

2013-07-01

The Dirac equation is of fundamental importance for relativistic quantum mechanics and quantum electrodynamics. In relativistic quantum mechanics, the Dirac equation is referred to as one-particle wave equation of motion for electron in an external electromagnetic field. In quantum electrodynamics, exact solutions of this equation are needed to treat the interaction between the electron and the external field exactly. In particular, all propagators of a particle, i.e., the various Green's functions, are constructed in a certain way by using exact solutions of the Dirac equation.

On the Inclusion of Difference Equation Problems and Z Transform Methods in Sophomore Differential Equation Classes

Science.gov (United States)

Savoye, Philippe

2009-01-01

In recent years, I started covering difference equations and z transform methods in my introductory differential equations course. This allowed my students to extend the "classical" methods for (ordinary differential equation) ODE's to discrete time problems arising in many applications.

Boussinesq evolution equations

DEFF Research Database (Denmark)

Bredmose, Henrik; Schaffer, H.; Madsen, Per A.

2004-01-01

This paper deals with the possibility of using methods and ideas from time domain Boussinesq formulations in the corresponding frequency domain formulations. We term such frequency domain models "evolution equations". First, we demonstrate that the numerical efficiency of the deterministic...... Boussinesq evolution equations of Madsen and Sorensen [Madsen, P.A., Sorensen, O.R., 1993. Bound waves and triad interactions in shallow water. Ocean Eng. 20 359-388] can be improved by using Fast Fourier Transforms to evaluate the nonlinear terms. For a practical example of irregular waves propagating over...... a submerged bar, it is demonstrated that evolution equations utilising FFT can be solved around 100 times faster than the corresponding time domain model. Use of FFT provides an efficient bridge between the frequency domain and the time domain. We utilise this by adapting the surface roller model for wave...

Fractional Diffusion Equations and Anomalous Diffusion

Science.gov (United States)

Evangelista, Luiz Roberto; Kaminski Lenzi, Ervin

2018-01-01

Preface; 1. Mathematical preliminaries; 2. A survey of the fractional calculus; 3. From normal to anomalous diffusion; 4. Fractional diffusion equations: elementary applications; 5. Fractional diffusion equations: surface effects; 6. Fractional nonlinear diffusion equation; 7. Anomalous diffusion: anisotropic case; 8. Fractional Schrödinger equations; 9. Anomalous diffusion and impedance spectroscopy; 10. The Poisson–Nernst–Planck anomalous (PNPA) models; References; Index.