Simple scanner-based image analysis for corrosion testing: Concrete application

A methodology for the assessment of the crown corrosion in concrete sewer pipes was developed based upon the principle that the surface roughness increases when concrete corrodes. The roughness was quantified by correlating the depths of the surface pits to the lengths of shadows produced in a single source of incident light. A computer program was used to reconstruct a pseudo three-dimensional concrete exterior and obtain the averaged corrosion rate.     

Free radical copolymerization of functional water-soluble poly(N-maleoylglycine-co-crotonic acid): polymer metal ion retention capacity, electrochemical, and thermal behavior

In this study, the water-soluble polymers of N-maleoyl glycine (MG) with crotonic acid (CA) were copolymerized by free radical polymerization to obtain hydrophilic polymers, in order to study the effect of the functional groups in the copolymers on the metal ion retention capacity, electrochemical and thermal behavior, since that important requirements for their use in technological applications are: high solubility in water, chemical stability, a high affinity for one or more metal ions, and selectivity for the metal ion of interest. The metal complexation properties of poly(MG-co-CA) for the metal ions were investigated at pH 3, 5, and 7 in aqueous solution. The metal ion investigated were: Cu(II), Co(II), Cr(III), Ni(II), Cd(II), Zn(II), and Fe(III). The polymeric systems showed high metal ion retention for Zn (II) and Fe(III) at different pH. At different pHs, the MRC of the poly(MG-co-CA) for Fe(III) ions varied from 122.1 to 146.2 mg/g and from 120.5 to 133.5 mg/g, (samples 1 and 2 at pH 3 and 7, respectively). The MRC had the highest retention values for both copolymer systems at pH 7. The copolymers presented higher thermal decomposition temperature (TDT) in comparison with copolymer–metal complexes at pH 3 and 5. The cyclic voltammetry (CV) for poly(MG-co-CA) (20 mM) was compared with the CV of the [poly(MG-co-CA)–Fe(III)] copolymer complex. Moreover, [poly(MG-co-CA)–Fe(III)] showed a redox wave difference between +0.25 and +0.50 V possibly due to the presence of metal complexed with the polymer. The electrochemical characterization of the copolymer poly(MG-co-AC) shown the reduction of carboxylic acid groups of the N-maleoylglycine and crotonic acid moiety to hydroxyl group. The results support the assumption that the copolymer presents convenient electroactivity.     

Hydroxide precursors to produce nanometric YCrO3: Characterization and conductivity analysis

A precursor to produce perovskite-type YCrO₃ was precipitated by bubbling gaseous ammonia into an yttrium/chromium salts solution. X-ray diffraction showed that the as-prepared powders were amorphous. Thermal treatment between 1273 and 1373 K, leads to formation of polycrystalline YCrO₃ with crystal sizes around 20 nm. High resolution X-ray photoelectron spectra showed uniform chemical environment for yttrium and chromium in the amorphous hydroxide and crystalline YCrO₃. Shifts between Y 3d_5/2 and Cr 2p_3/2 binding energy suggest redistribution or charge transfer between yttrium and chromium ions in the YCrO₃ structure. The electrical properties of YCrO₃, whose precursors were precipitated with gaseous ammonia are different than those prepared by combustion synthesis. Electrical conductivity presents a sudden increase at ～473 K, which is associated to the grain size and morphology of the crystallites. The redistribution of charge between Y(III) and Cr(III) is thermally activated by the hopping of small-polarons, which are characterized by the Arrhenius law as the conductive mechanism.     

Ensuring the quasi-termination of needed narrowing computations

We present a characterization of first-order functional programs which are quasi-terminating with respect to the symbolic execution mechanism of needed narrowing, i.e., computations in these programs consist of a sequence of finitely many different function calls (up to variable renaming). Quasi-terminating programs are particularly useful for program analysis and transformation, since in this context quasi-termination often amounts to full termination.     

Detection of peroxidase activity in two-dimensional gel electrophoresis

Two-dimensional gel electrophoresis is a well-known technique to detect proteins and identify them by mass spectrometry. Peroxidase activity is commonly revealed in different fields of investigation by adding a substrate to the enzyme in the sample, in the presence of hydrogen peroxide. From these two points, a useful procedure to detect this enzymatic activity on two-dimensional gels is described. The novelty and interest of this technique is that the electrophoresis developed combines a nondenaturing gel with running denaturing conditions, allowing peroxidase activity to remain after the whole process. Therefore, the isoelectric point and the molecular weight can be used to separate different isoforms of peroxidase on a two-dimensional gel.     

Interchanging lexical resources on the Semantic Web

Lexica and terminology databases play a vital role in many NLP applications, but currently most such resources are published in application-specific formats, or with custom access interfaces, leading to the problem that much of this data is in “data silos” and hence difficult to access. The Semantic Web and in particular the Linked Data initiative provide effective solutions to this problem, as well as possibilities for data reuse by inter-lexicon linking, and incorporation of data categories by dereferencable URIs. The Semantic Web focuses on the use of ontologies to describe semantics on the Web, but currently there is no standard for providing complex lexical information for such ontologies and for describing the relationship between the lexicon and the ontology. We present our model, lemon, which aims to address these gaps while building on existing work, in particular the Lexical Markup Framework, the ISOcat Data Category Registry, SKOS (Simple Knowledge Organization System) and the LexInfo and LIR ontology-lexicon models.     

Development of an optimized multi-biomarker panel for the detection of lung cancer based on principal component analysis and artificial neural network modeling

Lung cancer is a public health priority worldwide due to the high mortality rate and the costs involved. Early detection of lung cancer is important for increasing the survival rate, however, frequently its diagnosis is not made opportunely, since detection methods are not sufficiently sensitive and specific. In recent years serum biomarkers have been proposed as a method that might enhance diagnostic capabilities and complement imaging studies. However, when used alone they show low sensitivity and specificity because lung cancer is a heterogeneous disease. Recent reports have shown that simultaneous analysis of biomarkers has the potential to separate lung cancer patients from control subjects. However, it has become clear that a universal biomarker panel does not exist, and optimized panels need to be developed and validated in each population before their application in a clinical setting. In this study, we selected 14 biomarkers from literature, whose diagnostic or prognostic value had been previously demonstrated for lung cancer, and evaluated them in sera from 63 patients with lung cancer and 87 non-cancer controls (58 Chronic Obstructive Pulmonary Disease (COPD) patients and 29 current smokers). Principal component analysis and artificial neural network modeling allowed us to find a reduced biomarker panel composed of Cyfra 21.1, CEA, CA125 and CRP. This panel was able to correctly classify 135 out of 150 subjects, showing a correct classification rate for lung cancer patients of 88.9%, 93.3% and 90% in training, validation and testing phases, respectively. Thus, sensitivity was increased 18.31% (sensitivity 94.5% at specificity 80%) with respect to the best single marker Cyfra 21.1. This optimized panel represents a potential tool for assisting lung cancer diagnosis, therefore it merits further consideration.     

Preparation,characterization, and metal ion retention capacity of Co(II) and Ni(II) from poly(p‐HO‐ and p‐Cl‐phenylmaleimide‐co‐2‐hydroxypropylmethacrylate) using the ultra filtration technique

p‐Chlorophenylmaleimide and p‐hydroxyphenylmaleimide with 2‐hydroxypropyl methacrylate were synthesized by radical polymerization, and the metal ion retention capacity and thermal behavior of the copolymers were evaluated. The copolymers were obtained by solution radical polymerization with a 0.50 : 0.50 feed monomer ratio. The maximum retention capacity (MRC) for the removal of two metal ions, Co(II) and Ni(II) in aqueous phase were determined using the liquid‐phase polymer based retention technique. Inorganic ion interactions with the hydrophilic polymer were determined as a function of pH. The metal ion retention capacity does not depend strongly on the pH. Metal ion retention increased with an increase of pH for a copolymer composition 0.50 : 0.50. At different pH, the MRC of the poly(p‐chlorophenylmaleimide‐co‐2‐hydroxypropylmethacrylate) for Co(II) and Ni(II) ions varied from 44.1 to 48.6 mg/g and from 41.5 mg/g to 46.0 mg/g, respectively; while the MRC of poly(p‐hydroxyphenylmaleimide‐co‐2‐hydroxypropyl methacrylate) for Co(II) and Ni(II) ions varied from 28.4 to 35.6 mg/g and from 27.2 to 30.8 mg/g, respectively. The copolymers and copolymer–metal complexes were characterized by elemental analysis, FT‐IR, ¹H NMR spectroscopy, and thermal behavior. The thermal behavior of the copolymer and polymer–metal complexes were studied using differential scanning calorimetry and thermogravimetry techniques under nitrogen atmosphere. The thermal decomposition temperature and T_g were influenced by the binding‐metal ion on the copolymer. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Mesoporous carbon supported nanoparticulated PdNi2: A methanol tolerant oxygen reduction electrocatalyst

The kinetics of the oxygen reduction reaction (ORR) of PdNi₂ nanoparticles supported on a high specific area mesoporous carbon (MC) and Vulcan carbon was studied in the presence and absence of methanol in acid media. The electrocatalysts, synthesized by chemical reduction of the metal chlorides with NaBH₄ in aqueous media were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The catalyst supported on MC has a higher degree of Ni alloying and a smaller particle size than that supported on Vulcan. The electrochemical characterizations by RDE and DEMS indicate that PdNi₂ supported on the high surface area MC exhibits higher catalytic activity for the ORR, very similar to that of Pd- and Pt-based alloys with the advantage of a very low noble metal loading. Moreover, the PdNi₂ supported on MC shows an excellent methanol tolerance in acid media. Thus, this novel combination catalyst/support would be a suitable cathodic catalyst for direct methanol fuel cells.