32 research outputs found
Is it more difficult to write or to cite a paper?
The structure of various indices that are used to evaluate the research output of a scientist is discussed on a moral base.Indices should be used with caution. Albeit scientists who work in the field of infometrics are aware on this, other scientistsof other disciplines may not be fully aware. Measuring quality in science is only the half story. Some verbal description isrequired too
Capillarity
Capillarity is an important phenomenon in nature and life. In this note the theory upon which the capillary action relies as well as the interface shapes for certain types of capillary systems under gravity is briefly outlined. Schematic presen-tations are also given
Dentifrices, mouthwashes, and remineralization/caries arrestment strategies
While our knowledge of the dental caries process and its prevention has greatly advanced over the past fifty years, it is fair to state that the management of this disease at the level of the individual patient remains largely empirical. Recommendations for fluoride use by patients at different levels of caries risk are mainly based on the adage that more is better. There is a general understanding that the fluoride compound, concentration, frequency of use, duration of exposure, and method of delivery can influence fluoride efficacy. Two important factors are (1) the initial interaction of relatively high concentrations of fluoride with the tooth surface and plaque during application and (2) the retention of fluoride in oral fluids after application
Is it more difficult to write or to cite a paper? Engineering Science and Technology Review
Abstract The structure of various indices that are used to evaluate the research output of a scientist is discussed on a moral base. Indices should be used with caution. Albeit scientists who work in the field of infometrics are aware on this, other scientists of other disciplines may not be fully aware. Measuring quality in science is only the half story. Some verbal description is required too
What is a surface excess?
J. Willard Gibbs in his pioneering work on the influence of surfaces discontinuity upon the equilibrium of heterogene-ous masses suggested for the measurement of the quantities of a system a geometrical surface dividing the interfacial layer. Surface excess is the difference between the amount of a component actually present in the system, and that which would be present in a reference system if the bulk concentration in the adjoining phases were maintained up to the arbitrary chosen but precisely determined in position dividing surface
What is spinodal decomposition?
Phase separation may occur in a way that the growth is not in extent but in amplitude. Only in the unstable region such a procedure is thermodynamically feasible. In a phase diagram the unstable region is defined by the spinodal. When a system has crossed this locus, phase separation occurs spontaneously without the presence of a nucleation step. This process is known as spinodal decomposition and commonly results to a high interconnectivity of the two phases. The Cahn-Hilliard equation describes the kinetics of the process. In this note both processes (nucleation and spinodal) are depicted schematically
The structure of adsorbed CO2 in carbon nanopores: a neutron diffraction study
The behaviour of CO2 adsorbed on a nticroporous carbon at a temperature slightly above the critical point, was studied by adsorption in conjunction with in situ neutron powder diffraction. The carbon sample was produced by carbonisation and activation of a polymer precursor and the experiment was carried out by means of a specially designed adsorption apparatus, directly mounted on the neutron diffractometer. The CO2 diffraction patterns provide evidence that the adsorbed phase is-at pressures well below the critical one-in a state comparable to high-pressure dense supercritical fluid or even bulk liquid. Furthermore, the features of the diffraction patterns are consistent with the presence of orientational correlations between adsorbed molecules. Even though, the scattering data cover a limited Q space and thus the overall resolution is rather poor, the radial distribution functions deduced at different equilibrium pressures, reveal differences, which could be attributed to changes in the arrangement of CO2 molecules along the 308 K isothermal scan. The results are discussed and compared with permeability measurements as well as Monte Carlo calculations. (C) 2004 Elsevier B.V. All rights reserved
On the Archiving and Visualisation of Scientific Data
Porous materials are important in gas separations and catalysis. Processes involving the use of porous materials have
significant potential for replacement of traditional and expensive industrial processes. This publication details the
development of a comprehensive database for organising information related to porous materials. The data includes
structural information on the material, its properties and the experimental data obtained for the material in the laboratory,
using a wide variety of characterisation techniques. The rational behind the development, the database structure, and a
technique for visualisation of the data are presented, as are examples of using the database