The evaluation of scientific production: Towards a neutral impact factor

Measurement of research activity still remains a controversial question. The use of the impact factor from the Institute for Scientific Information (ISI) is quite widespread nowadays to carry out evaluations of all kinds; however, the calculation formula employed by ISI in order to construct its impact factors biases the results in favour of knowledge fields which are better represented in the sample, cite more in average and whose citations are concentrated in the early years of the articles. In the present work, we put forward a theoretical proposal regarding how aggregated normalization should be carried out with these biases, which allows comparing scientific production between fields, institutions and/or authors in a neutral manner. The technical complexity of such work, together with data limitations, lead us to propose some adjustments on the impact factor proposed by ISI which — although they do not completely solve the problem — reduce it and allow glimpsing the path towards more neutral evaluations. The proposal is empirically applied to three analysis levels: single journals, knowledge fields and the set of journals from the Journal Citation Report.     

Physical examination of arteriovenous fistula: The influence of professional experience in the detection of complications

Vascular access is one of the leading causes of mobilization of financial resources in health systems for people with chronic kidney disease on hemodialysis. Physical examination of the arteriovenous fistula (AVF) has demonstrated its effectiveness in identifying complications. We decided to evaluate the influence of nurses' professional experience in the detection of complications of the AVF (venous stenosis and steal syndrome). The study took place in eight hemodialysis centers between May and September of 2011 in the north of Portugal. Sample was constituted by registered nurses. The nurses involved in the experiment were divided in two groups: those who had more than 5 years of experience and those who had less than 5 years of experience. Ninety‐two nurses participated in the study: 34 nurses had less than 5 years of professional experience and 58 had more than 5 years of professional experience. In the practices considered by nurses in the detection of venous stenosis, there were no differences observed between the groups (P > 0.05). In steal syndrome, there were no differences observed between the groups in the practices of the nurses in the detection of this complication of the AVF (P > 0.05). We concluded that professional experience does not influence the detection of venous stenosis and steal syndrome.     

Monitoring of zincate pre-treatment of aluminium prior to electroless nickel plating

Zincating is used as a pre-treatment for aluminium prior to electroless nickel deposition during preparation of magnetic computer memory discs. Four immersion zincating solutions were evaluated at 22°C using single step or double zincating followed by electroless nickel deposition from a high phosphorus hypophosphite bath at 90°C. The coating process was monitored by potential vs. time curves obtained under open-circuit conditions during zincating then electroless nickel plating. The surface morphology of the aluminium, at various stages, was imaged by scanning electron microscopy and atomic force microscopy. Zero resistance ammetry was used to record galvanic currents between the aluminium and an inert platinum counter electrode during zincating. This, together with potential-time measurements, provided simple and valuable methods for following the zincating process and subsequent electroless Ni plating. Double zincating enabled a shorter induction time for electroless Ni deposition and resulted in a more complete coverage of the surface by Zn.     

Comparison between Ozonation and Photo-Fenton Processes for Pesticide Methomyl Removal in Advanced Greenhouses

So-called “Advanced Greenhouses” are a new approach to the concept of protected agriculture. Among other technological and structural improvements, these facilities give the possibility of recycling the irrigation surplus water, rich in lixiviates, salts, pesticides and its metabolites. After many cycles, the current is so concentrated on those substances that it becomes necessary for the presence of a membrane separation stage which brine, highly concentrated on those named pollutants, has to be treated before being sent to the public sewage system. Advanced Oxidation Processes, among other chemical treatments, can be considered an alternative to process this current effluent. In this work, concentrated aqueous solutions of methomyl as model pesticide (200 mg·L^?1) have been subjected to two of those processes: ozonation and photo-Fenton reaction. Analysis of the elimination of the pesticide itself and the grade of mineralization achieved have shown how, while the ozonation is the most effective process decomposing the pesticide (eliminating the total concentration in 60 minutes), the photo-Fenton reaction mineralizes successfully the 40% of the total organic load (the ozonation only can cope with 20%) but only decompose a 40% of the pesticide. Evolution of biodegradability and toxicity of the effluent along both processes was also analyzed. Intermediates generated both by ozonation and photo-Fenton did not increase the biodegradability of the treated effluents. Nevertheless, while acute toxicity just after 15 minutes of treatment with ozone is notably higher than for raw solution, and it is maintained till the end of the experiment (120 min), though, toxicity along photo-Fenton reaction has two growing and decreasing regions, always shows lower values than the provoked during ozonation. None of the two assayed processes has been proved to increase biocompatibility of highly concentrated methomyl solutions.     

Thermal wave oscillations and thermal relaxation time determination in a hyperbolic heat transport model

One of the major challenges in the study of thermal transport and its analysis, based on the hyperbolic model associated with Cattaneo equation, is the fact that it is necessary to determine the thermal relaxation time for the analyzed materials. This parameter has been an elusive physical quantity to be determined experimentally even though it is of crucial importance in heat transport. In this paper a system formed by a semi-infinite layer in contact with a finite one, that is excited by a modulated heat source is studied. It is shown that a frequency range can be found in which the amplitude and phase of the spatial component of the oscillatory surface temperature show strong oscillations when the thermal relaxation time of the finite layer is close to its thermalization time. When the thermal effusivities of the layers are quite different or their thermal relaxation times are similar, it is shown that simple analytical expressions for the values of the maxima and minima of the oscillations as well as for the frequencies, at which they occur, are obtained. These results were used to establish a methodology to determine the thermal relaxation time as well as additional thermal properties of the finite layer.     

Asymmetric bihomologous crosslinkers for bicomponent gels—The way to strongly increased elastic moduli

2‐Hydroxyethylmethacrylate (HEMA) and acrylamide (AA) have been copolymerized via free radical mechanism, in the presence of 5 mol % of four different crosslinker systems, the symmetric ethylenglycoldimethacrylate (EGDMA), bisacrylamide (BIS), a mixture of EGDMA and BIS, and the asymmetric acrylamideethylenmethacrylate (METAA). The polymerizations have been monitored with a rheometer, exhibiting the gel obtained with the asymmetric METAA, an elastic modulus that is dramatically increased compared with those of the gels prepared with the other three crosslinker systems. A kinetic analysis using the terminal model has been used to build probabilistic surfaces that give information about how the crosslinker is incorporated into the network. This analysis shows a high dissimilarity between the reactions using the asymmetric and the mixture of symmetric crosslinkers, what has been correlated to the difference in modulus. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010