The Experts below are selected from a list of 349539 Experts worldwide ranked by ideXlab platform

Louis M. Bell - One of the best experts on this subject based on the ideXlab platform.

  • Are Organic Foods MOre Nutritious Than Conventional Foods
    NEJM Journal Watch, 2012
    Co-Authors: Louis M. Bell
    Abstract:

    Organic food sales reached US$26.7 billion in 2010. Researchers conducted a systematic analysis of peer-reviewed studies published from 1966 to 2011 to examine whether organic foods are mOre nutritious and safer than conventionally produced foods. Of 5908 potentially relevant studies identified by searching 7 databases, 237 studies met the criteria for inclusion. Most studies (223) compared organic and conventional fruits, …

Jerzy Matczuk - One of the best experts on this subject based on the ideXlab platform.

  • Double Ore Extensions Versus Iterated Ore Extensions
    Communications in Algebra, 2011
    Co-Authors: Paula A. A. B. Carvalho, Samuel A. Lopes, Jerzy Matczuk
    Abstract:

    Motivated by the construction of new examples of Artin–Schelter regular algebras of global dimension four, Zhang and Zhang [6] introduced an algebra extension A P [y 1, y 2; σ, δ, τ] of A, which they called a double Ore extension. This construction seems to be similar to that of a two-step iterated Ore extension over A. The aim of this article is to describe those double Ore extensions which can be presented as iterated Ore extensions of the form A[y 1; σ1, δ1][y 2; σ2, δ2]. We also give partial answers to some questions posed in Zhang and Zhang [6].

  • Double Ore Extensions versus Iterated Ore Extensions
    arXiv: Rings and Algebras, 2009
    Co-Authors: Paula A. A. B. Carvalho, Samuel A. Lopes, Jerzy Matczuk
    Abstract:

    Motivated by the construction of new examples of Artin-Schelter regular algebras of global dimension four, J.J. Zhang and J. Zhang (2008) introduced an algebra extension $A_P[y_1,y_2;\sigma,\delta,\tau]$ of $A$, which they called a double Ore extension. This construction seems to be similar to that of a two-step iterated Ore extension over $A$. The aim of this paper is to describe those double Ore extensions which can be presented as iterated Ore extensions of the form $A[y_1;\sigma_1, \delta_1][y_2;\sigma_2, \delta_2]$. We also give partial answers to some questions posed in Zhang and Zhang (2008).

Przemysław Korytkowski - One of the best experts on this subject based on the ideXlab platform.

  • Researchers publishing monographs are mOre productive and mOre local-oriented
    Scientometrics, 2020
    Co-Authors: Emanuel Kulczycki, Przemysław Korytkowski
    Abstract:

    In this study, we investigate what share of researchers publish monographs across fields, gender and seniority. We acquired data from the Polish current research information system (POL-on) containing metadata of about 1,031,141 peer-reviewed publications from 67,415 Polish researchers, including 30,185 monographs from 2013 to 2016. The data are aggregated at the researcher level, which allows us to shed new light on publication patterns in all fields. We show that scholars who publish monographs also publish journal articles at the same time. This pattern is observed in all dimensions, i.e. research fields, gender and seniority. However, substantial differences between the fields are observed. MOreover, we show that researchers who publish monographs are also mOre productive in terms of the number of publications than researchers who did not publish any monographs. This result is independent of the publication counting method, i.e. fractional or whole counting. At the same time, scholars who publish monographs are mOre local-oriented in terms of the publication channels they choose.

Anthony L. Komaroff - One of the best experts on this subject based on the ideXlab platform.

  • Are Organic Foods MOre Nutritious
    NEJM Journal Watch, 2009
    Co-Authors: Anthony L. Komaroff
    Abstract:

    Many of our patients (and some of our colleagues) pay premium prices for “organic” food. Two reasons for this behavior are the perceived absence of pesticides and other chemicals on organic foods and that less greenhouse gases are generated by organic farming. In …

James L. Hendrix - One of the best experts on this subject based on the ideXlab platform.

  • A mathematical model for heap leaching of one or mOre solid reactants from porous Ore pellets
    Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science, 1993
    Co-Authors: David G. Dixon, James L. Hendrix
    Abstract:

    A mathematical model is derived in dimensionless form for heap leaching of one or mOre solid reactants from nonreactive, porous, spherical Ore particles. The model is for the interpretation of column and heap leaching data and for use in the design and scaleup of heap leaching pro-cesses. Data from experimental column leaching tests are presented which validate the model. The scope of the present study is limited to the case where the rate-controlling reagent is a component of the lixiviant solution only and not of the gas phase. The effects of particle-scale kinetic factors, heap scale and operating variables, competition between multiple solid reactants, and particle size distribution are examined using the concept of the heap effectiveness factor. It is shown that heaps operate either «homogeneously,» with distribution of reagent throughout the heap at all times, or in a «zone-wise» manner, depending mostly on a single parameter. The observed value of this parameter deviates from the predicted value in inverse proportion to the degree of contact effectiveness between the lixiviant solution and the Ore particles. A rough correlation between the contact effectiveness and Reynolds number is generated from the simulation of column test results.

  • A General Model for Leaching of One or MOre Solid Reactants from Porous Ore Particles
    Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science, 1993
    Co-Authors: David G. Dixon, James L. Hendrix
    Abstract:

    A general, unsteady-state model for leaching of one or mOre solid reactant species from a nonreactive, porous, spherical pellet is derived in dimensionless form for the interpretation of leaching data and for use in the design of coarse-Ore leaching processes. Numerical solutions of the model equations are obtained with implicit finite difference approximations. The effects of diffusion rate, chemical reaction rate, and competition between multiple solid reactants are examined using the concept of the effectiveness factor. The importance of deposits of solid reactants on the pellet surface is ascertained. It is shown that the model is capable of simulating both “reaction-zone” and “homogeneous” kinetics, depending on the choice of parameters. The model is also capable of simulating leaching from a distribution of particle sizes, and techniques for the modification of model parameters for this purpose are discussed.