bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemistry and XPS study of an imidazoline as corrosion inhibitor of mild steel in an acidic environment
Authors: Olivares‐Xometl O. , Likhanova N. V. , Martínez‐Palou R. , Domínguez‐Aguilar M. A. 
Published: September 2008

AbstractThe effect of 2‐(2‐heptadec‐8‐enyl‐4,5‐dihydro‐imidazol‐1‐yl)‐ethylamine on the corrosion behavior of mild steel in aqueous hydrochloric acid was investigated using weight loss measurements, polarization scans, electrochemical impedance, and X‐ray photoelectron spectroscopy (XPS). The inhibition efficiencies and coverage degrees increased with the concentration of inhibitor but decreased proportionally with temperature. It appears that the steric hindrance of the aliphatic chain on the imidazoline ring adsorption may affect inhibitor efficiency. Polarization curves showed that the oleic imidazoline (OI) acted essentially as a mixed type inhibitor, in which the blocking of active sites occurred. As a result of film formation, impedance spectra revealed a considerable increase in the charge transfer resistance as indicated by the second capacitive loop. XPS depth profile analysis observed the presence of nitrogen and carbon species on the inhibitor film, which were associated to the OI.
Numerical design for cathodic protection systems for concrete
Authors: Polder R. B. , Peelen W. H. A. , Lollini F. , Redaelli E. , Bertolini L. 
Published: September 2008

AbstractCathodic protection (CP) has become a successful method for the rehabilitation of concrete structures affected by chloride‐induced corrosion of reinforcing steel. CP involves applying an electrical current from an external anode through the concrete to the reinforcement. The current causes steel polarisation, electrochemical reactions and ion transport. Normally the anode is placed over relatively large surface areas, including those where the steel is passive. Conventional views assume that protection current will not significantly flow outside the anode area. In many cases this results in a conservative design. This paper presents principles and first results of numerical calculations for design of an example CP system by finite element modelling. The final objective is to develop a tool for more economical CP system design. In particular, a CP system for the protection of local damage in bridges (e.g. at leaking joints) has been simulated. The corroding area with respect to the size of the anode is varied. Current and potential distributions and depolarisation values are predicted, both close to and more distant from the anode. It appears that current densities required to achieve sufficient polarisation are much higher than those usually found in the field. Neglecting time‐dependent repassivation processes is likely to be the main cause and further work is needed to include them. The present model can be used with reasonable confidence for preventive application to passive steel.
The attack initiation of Al‐Zn‐In‐Sn anode by the segregation concentrating Zn, Sn and In
Authors: Qi G. T. , Qiu Y. B. , Zhao Y. N. , Cai Q. Z. 
Published: September 2008

AbstractThe microstructure of Al–5%Zn–0.025%In‐0.15%Sn anode was investigated by EPMA, and EDAX. The result showed that the microstructure at the Al‐Zn‐In‐Sn anode can be categorized into two different types, namely the catenulate segregation enriched in Zn, Fe, Si, and the elliptical or rounded segregation where Zn, Sn, In concentrated. In order to explain the initial dissolution of the aluminum anode, the electrochemical behavior in 3% NaCl solution of the Al‐Zn‐In‐Sn anode and its simulated segregation concentrating Zn, Sn, In were tested using potentiodynamic polarization and electrochemical impedance spectroscopy. The result showed that the simulated segregation concentrating Zn, Sn, In would preferentially be dissolved into the solution as the anode of galvanic cell.
Growth characteristics of thermophile sulfate‐reducing bacteria and its effect on carbon steel
Authors: Liu T. , Liu H. , Hu Y. , Zhou L. , Zheng B. 
Published: September 2008

AbstractSulfate‐reducing bacteria (SRB) have been identified as the main corrosive microorganisms causing unpredictable failure of materials. In this present work, a strain of thermophile SRB isolated from Bohai oilfield of China has been characterized and preliminarily identified. Furthermore, its effects on carbon steel at 60 °C in SRB culture media were studied by electrochemical methods such as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), and weight loss measurements. The results show that the bacteria belong to Desulfotomaculum. The optimum growth temperature and pH of the bacteria were 60 °C and 7.0, respectively. Weight loss measurements suggested that the corrosion rate of carbon steel in the culture media inoculated with thermophile SRB at 60 °C was 2.2 times less than that at 37 °C. At 60 °C, SRB shifted the freely corroding potential of carbon steel toward a more positive value in the first 10 days, which later change to a negative value. Results obtained from potentiodynamic polarization and EIS were in good agreement. The changes in biofilm structure with increase in bacteria supply offers some kind of protection to the base material in the early culture days at 60 °C. Subsequently, it accelerated corrosion. Energy dispersive spectrometry (EDS) and X‐ray diffraction (XRD) methods indicate that corrosion products such as iron sulfides (FeSx) in biofilm play an important role in the biocorrosion process.
Corrosion behaviour of tool steels in tannic acids
Authors: Winkelmann H. , Badisch E. , Ilo S. , Eglsäer S. 
Published: September 2008

AbstractIt is well known that cutting knifes in the wood industry often suffer from corrosion. Investigations showed that the corrosiveness of different wood types is responsible for a major part of the damage, and that different woods have a different corrosive impact. It is revealed that tannin, a water‐soluble acid, which can be found in all woods in different concentrations, is the most aggressive acid contained in the wood, and so it is responsible for the main part of the corrosive attack. In view of the above, the ability of different cold‐work steels to resist corrosion caused by tannic acid has been investigated. Often corrosion is measured by the mass loss of the sample divided by the surface of the sample under certain conditions during a fixed period of time. One problem with this method is that there is also a weight gain caused by oxidation or by other side reactions at the samples surface. So in some cases the weight of the sample even increases during the testing time, which makes the quantification of the corrosion impossible with this method. Due to the reasons already mentioned, another method was used to quantify the test results. This method is based on inductive coupled plasma–optical emission spectral analyses (ICP‐OES), where the released Fe is quantified. The results of the corrosion resistant tests get correlated to the microstructure and the elemental composition of the analysed cold‐work steels. The present investigations improve the understanding of important material parameters to enhance the corrosion resistance against tannin. It is revealed that the higher the primary carbide concentration is the more Cr or other passivating elements are necessary in the matrix to show a good protection against corrosion by tannin. Three materials with different elemental compositions have been investigated, and for one of those materials the influence of different heat treatments was also analysed. The investigations could show that annealing parameters and freeze‐cycle processing (FCP) have less impact on the corrosion resistance to tannin than elemental composition and austenitising temperature.
Effect of TiO2 nanoparticles on anticorrosion property in amorphous Ni‐P‐Cr composite coating in artificial seawater and microbial environment
Authors: Ma J. , Shi Y. , Di J. , Yao Z. , Liu H. 
Published: September 2008

AbstractTo obtain the composite with a function of corrosion resistance in seawater and microbial environment, we apply low toxic electrolyte which contained Cr3+ instead of Cr6+ as a chromium source to produce Ni‐P‐Cr/TiO2, Ni‐P‐Cr/ZrO2 nanocomposite coatings, and Ni‐P‐Cr/TiO2 microcomposite coating using direct current (DC) electrodeposits technique. The surface morphology, texture, and composition of the composite coatings are characterized by SEM, XRD, and EDX measurements, respectively. The corrosion behavior of the composite coatings is evaluated by polarization curves and electrochemical impedance spectroscopy (EIS). The results with more positive‐shifting Ecorr, lowest icorr, and relatively high value of polarization resistance (Rp) proved that compared with other composite coatings, Ni‐P‐Cr/TiO2 nanocomposite coating with its better passive film and unique antibacterial activity caused by TiO2 nanoparticles incorporated, displayed excellent antibacterial and corrosion resistance property, consistent to the phenomenon that corrosion of this nanocomposite coating in SRB culture medium is not observed.
The corrosion and electrochemical behavior of pure aluminum in additive‐containing alkaline methanol–water mixed solutions
Authors: Wang J. B. , Wang J. M. , Shao H. B. , Chang X. T. , Wang L. , Zhang J. Q. , Cao C. N. 
Published: September 2008

AbstractThe corrosion and electrochemical behavior of aluminum in inhibited and uninhibited 4 M KOH–methanol–water mixed solutions with a methanol/water volume ratio of 3:2 were investigated by means of hydrogen collection, polarization curve, galvanostatic discharge, and electrochemical impedance spectroscopy (EIS). The results of hydrogen collection and electrochemical experiments showed that the addition of ZnO can obviously inhibit the corrosion of aluminum in the 4 M KOH–methanol–water solutions, and its inhibition effect can be enhanced in the hydroxytryptamine (HT)‐containing KOH solution. The results of scanning electron microscopy (SEM) and energy dispersive analysis of X‐ray (EDAX) revealed that ZnO produces the inhibition effect by the formation of a zinc‐containing deposit layer on the surface of aluminum, and the cooperative effect of ZnO and HT may improve the deposit of zinc. The results of galvanostatic discharge indicated that aluminum can present good electrochemical activity in the 4 M KOH–methanol–water solution with 0.2 M ZnO and 1.0 mL/L HT.
Preparation of Poly(acrylic acid) Nano‐films by In‐situ Polymerization of Acrylic Acid Macroclusters on Silicon Oxide Surfaces
Authors: Zhang Li , Mizukami Masashi , Kurihara Kazue 
Published: September 2008

AbstractA new method for preparing poly(acrylic acid) (PAA) films on silicon oxide surfaces with smooth morphology has been developed. Acrylic acid (AA) was preferably adsorbed on silicon oxide surfaces in AA/ chloroform binary liquids and formed a hydrogen‐bonded organized structure, which was called molecular macrocluster. AA macroclusters on silicon oxide surfaces were in‐situ polymerized to obtain molecularly flat polymer films with thickness up to 10 nm. In‐situ polymerizations were conducted by photo‐irradiation in the presence of a photo initiator, 2,2‐dimethoxy‐2‐phenylacetophenone (DPA). As a reference, the adsorption of PAA polymerized in the bulk solution was examined on silicon oxide surfaces. A series of techniques such as attenuated total reflection–FTIR (ATR‐FTIR) spectroscopy, ellipsometry and atomic force microscopy (AFM) was utilized for characterizing two types of films. It was found that flat PAA films with linear hydrogen‐bonded COOH could only be obtained by in‐situ polymerization, which demonstrated this method was an effective way for preparing molecularly uniform polymer films. The surface morphology and thickness of obtained PAA films were found to be dependent on the monomer concentration, initiator amount and photoirradiation time. Molecularly uniform and flat PAA films were obtained after 5 min irradiation at 0.8 mol% AA in the presence of 5 wt% DPA.
The effect of combining two echo times in automatic brain tumor classification by MRS
Authors: García‐Gómez Juan M. , Tortajada Salvador , Vidal César , Julià‐Sapé Margarida , Luts Jan , Moreno‐Torres Àngel , Van Huffel Sabine , Arús Carles , Robles Montserrat 
Published: September 2008

Abstract1H MRS is becoming an accurate, non‐invasive technique for initial examination of brain masses. We investigated if the combination of single‐voxel 1H MRS at 1.5 T at two different (TEs), short TE (PRESS or STEAM, 20–32 ms) and long TE (PRESS, 135–136 ms), improves the classification of brain tumors over using only one echo TE. A clinically validated dataset of 50 low‐grade meningiomas, 105 aggressive tumors (glioblastoma and metastasis), and 30 low‐grade glial tumors (astrocytomas grade II, oligodendrogliomas and oligoastrocytomas) was used to fit predictive models based on the combination of features from short‐TEs and long‐TE spectra. A new approach that combines the two consecutively was used to produce a single data vector from which relevant features of the two TE spectra could be extracted by means of three algorithms: stepwise, reliefF, and principal components analysis. Least squares support vector machines and linear discriminant analysis were applied to fit the pairwise and multiclass classifiers, respectively. Significant differences in performance were found when short‐TE, long‐TE or both spectra combined were used as input. In our dataset, to discriminate meningiomas, the combination of the two TE acquisitions produced optimal performance. To discriminate aggressive tumors from low‐grade glial tumours, the use of short‐TE acquisition alone was preferable. The classifier development strategy used here lends itself to automated learning and test performance processes, which may be of use for future web‐based multicentric classifier development studies. Copyright © 2008 John Wiley & Sons, Ltd.
An assessment of the effect of thiazolidinedione exposure on the risk of myocardial infarction in type 2 diabetic patients
Authors: Koro Carol E. , Fu Qinggong , Stender Monika 
Published: September 2008

AbstractPurposeTo determine the likelihood of myocardial infarction (MI) in type 2 diabetic patients exposed to rosiglitazone and pioglitazone, separately, compared to other antidiabetic therapies.MethodsA case–control analysis nested within the cohort of type 2 diabetic subjects from the Integrated Healthcare Information Services (IHCIS) claims database. Incident cases of MI were matched to three controls each on age (±5 years), gender, and year of first diabetes diagnosis. Subjects were classified according to their antidiabetic drug exposure in the 3, < 6, 6–12, and > 12 months prior to the index date. The adjusted odds ratios of MI were calculated for subjects exposed to rosiglitazone and pioglitazone, separately, compared to other antidiabetic agents. Risk factors adjusted for are age, ACE inhibitors, β‐blockers, diuretics, nitrates, diagnosis of hyperlipidemia, and hypertension and coronary artery disease (CAD).ResultsA total of 891 901 diabetic subjects (9870 cases and 29 610 control) identified from 1999 to 2006 were included in the analysis. The mean age was 63 years for the cases and controls. Compared to those treated with other antidiabetic therapies, the adjusted odds ratio of MI was 1.03 [95%CI: 0.93–1.12] for rosiglitazone and 0.92 [95%CI: 0.83–1.01] for pioglitazone in the 3 months prior to the index date.ConclusionsThe results suggest that the risk of MI in subjects exposed to rosiglitazone or pioglitazone for ≤ 12 months is not different from those exposed to other antidiabetic agents but exposure for > 12 months is associated with 15 and 13% increased risk of MI, respectively. Copyright © 2008 John Wiley & Sons, Ltd.
Identification of a key element for hydrogen‐bonding patterns between protein kinases and their inhibitors
Authors: Katayama Naoko , Orita Masaya , Yamaguchi Tomohiko , Hisamichi Hiroyuki , Kuromitsu Sadao , Kurihara Hiroyuki , Sakashita Hitoshi , Matsumoto Yuzo , Fujita Shigeo , Niimi Tatsuya 
Published: September 2008

AbstractIn this article, we report crystal structures for inhibitor‐kinase complexes in which the inhibitor has different binding orientations and hydrogen‐bonding patterns with extracellular‐signal regulated kinase 2 and insulin receptor tyrosine kinase. Our crystallographic studies, and sequence and structural analyses of 532 coordinates of kinases held in the Protein Data Bank, suggest that the length of the “specificity linker” described here is a key structural element of the hydrogen‐bonding patterns between protein kinases and their inhibitors. Proteins 2008. © 2008 Wiley‐Liss, Inc.
Binding specificity of SH2 domains: Insight from free energy simulations
Authors: Gan Wenxun , Roux Benoît 
Published: September 2008

AbstractCellular signal transduction pathways are controlled by specific protein–protein interactions mediated by the binding of short peptides to small modular interaction domains. To gain insights into the specificity of these interactions, the association of phosphotyrosine‐containing peptides to Src Homology 2 (SH2) domains is characterized using computations. Molecular dynamics simulations based on high‐resolution crystal structures complemented by homology models are used to calculate the absolute binding free energies for 25 SH2‐peptides pairs. The calculations are carried out using a potential of mean force free energy simulations method with restraining potentials that was developed previously (Woo and Roux, Proc Natl Acad Sci USA 2005;102:6825–6830). The method is utilized in conjunction with an implicit solvent representation to reduce the computational cost to characterize the association of five SH2 domains and five peptides. Specificity is ascertained by directly comparing the affinities of a given SH2 domain binding for any of the different peptides. For three of the five SH2 domains, the computational results rank the native peptides, as the most preferred binding motif. For the remaining two SH2 domains, high affinity binding motifs other than the native peptides are identified. This study illustrates how free energy computations can complement experiments in trying to elucidate complex protein–protein interactions networks. Proteins 2009. © 2008 Wiley‐Liss, Inc.
Effect of nitrogen doping on Raman spectra of multi‐walled carbon nanotubes
Authors: Bulusheva L. G. , Okotrub A. V. , Kinloch I. A. , Asanov I. P. , Kurenya A. G. , Kudashov A. G. , Chen X. , Song H. 
Published: September 2008

AbstractMulti‐walled carbon nanotubes (CNTs) and nitrogen‐doped carbon (CNx) nanotubes have been synthesized by the aerosol‐assisted chemical vapour deposition (CVD) method. The samples were prepared from toluene and acetonitrile taken in different proportion. The structure of CNTs and CNx nanotubes was compared using first‐ and second‐order Raman spectra. The disorder‐induced D band was found to up‐shift with increase of the acetonitrile fraction. The ID/IG and IG′/IG ratios showed the opposite dependence on the doping level of CNTs. Both kinds of the substitute nitrogen: graphitic‐like and pyridinic‐like contribute to the disorder in CNx nanotube layers. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ageing effects in nanographite monitored by Raman spectroscopy
Authors: Makarova Tatiana , Riccò Mauro , Pontiroli Daniele , Mazzani Marcello , Belli Matteo , Goffredi Angelo 
Published: September 2008

AbstractThe structural relaxation of nanographite ball‐milled in argon atmosphere and stored in evacuated ampoules, has been studied by monitoring the evolution of the Raman spectra. Reduction of some Raman bands associated with “in‐plane” structural defects, such as vacancies, dislocations or grain boundaries, and those associated with “out‐of‐plane” defects, such as stacking faults, is accompanied by the rise of new bands around 1180 and 2000 cm–1. The development of these bands is suppressed in nanographite samples exposed to a flux of pure anhydrous hydrogen. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Loss‐spectroscopy on sparse arrays of aligned single‐wall carbon nanotubes
Authors: Kramberger Christian , Rümmeli Mark , Knupfer Martin , Fink Jörg , Büchner Bernd , Einarsson Erik , Maruyama Shigeo , Pichler Thomas 
Published: September 2008

AbstractWe performed angle resolved electron energy‐loss spectroscopy on vertically aligned single wall carbon nanotubes. We observe two distinct loss‐peaks in the energy range from 4:6 eV to 5:1 eV. This doublet of loss‐peaks is attributed to the on‐axis and crossed plasma oscillations of the π electrons in sp2 carbon.The unique identification and assignment of these two oriented excitations is derived from their dispersion relations. The available momenta are aligned on the nanotube axis and reflect the confinement of a particle on a wire. The observed angle resolved loss‐peaks are a gapless extension of polarized optical spectroscopy into finite momenta. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Double layer supercapacitor properties of onion‐like carbon materials
Authors: Bushueva E. G. , Galkin P. S. , Okotrub A. V. , Bulusheva L. G. , Gavrilov N. N. , Kuznetsov V. L. , Moiseekov S. I. 
Published: September 2008

AbstractThis paper describes the electrochemical performance of carbon onions as electrode materials in electrical double layer capacitors with water electrolytes. Onion‐like carbon (OLC) species were produced by vacuum annealing of detonation nanodiamonds (NDs) powder at 1170–2170 K. The material capability of the charge accumulation in the electric double layer was estimated using the voltammetric technique. The correlations between specific capacitance, surface area and conductivity were found. Charge‐discharge measurements revealed a dependence of the specific capacitance of OLC on the degree of diamond particle graphitization and defectness of particle surfaces. Promising capacitance values, ranging within 20−40 F g–1 and within 70−100 F g–1 were found for the OLC materials operating respectively in acid electrolytic solution (1 M H2SO4) and alkaline electrolytic solution (6 M KOH). (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Field emission from single‐wall nanotubes obtained from carbon and boron nitride mixtures
Authors: Kleshch V. I. , Obraztsova E. D. , Arutyunyan N. R. , Grebenyukov V. V. , Pozharov A. S. , Obraztsov A. N. 
Published: September 2008

AbstractHeterophase BN:C single‐wall nanotubes are prospective as a material with a predicted possibility to vary the bandgap via changing a relative content of BN and C fractions in the nanotube walls. The challenge is both to find the ways of synthesis of such nanotubes and, in case of success, to confirm BN embedding. In this work field emission studies have been performed for revealing the difference between arc‐produced pure carbon nanotubes and nanotubes grown from BN:C mixtures. The relative BN content in the mixtures was varied from 0% up to 50% (by mass). The materials have been characterized by a high resolution transmission electron microscopy, Raman scattering and UV‐VIS‐NIR optical absorption techniques. The single‐wall nanotubes have been revealed in all samples synthesized, but their composition remained questionable. The field emission properties of the samples have been examined in a vacuum diode configuration. It has been found that the threshold fields and slopes of the Fowler–Nordheim plot, evaluated from the measured current–voltage dependences, increased with an enrichment of the starting mixtures with h‐BN. This increase could be attributed to the work function rise due to h‐BN embedding into the carbon nanotube walls. This result opens a way to use the field‐emission characterization for an indirect confirmation of the heterophase BN:C nanotube formation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)