bluuebunny/crossref_metadata_2025_split huggingface dataset:
Advanced studies on the influence of manganese on the potential increase of stainless steels
Authors: Kreikenbohm R. , Eisenbeis M. , Gümpel P. , Linhardt P. 
Published: July 2003

AbstractThe influence of manganese on the time course and on the final value of the open‐circuit potential of microbially influenced stainless steel (SS) has been examined by variation of the concentration of manganese in the aqueous phase and on the surface of the metal sample. Under the influence of bacteria stable final values of the open‐circuit potential are attained at 540 mV or 620 mV depending on the manganese concentration in the aqueous phase, the duration of the experiment, and the supply of oxygen. These potential values can also be fixed electrochemically by anodic deposition of MnO2on the metal surface.According to the results obtained with different techniques, the electron flow from the metal towards the oxygen is a combination of biotic and abiotic processes. Besides the microbial oxidation of manganese the electron flow via a Mn‐based redox enzyme system has to be discussed.
Effects of Leptothrix discophora on the potential behavior of stainless steel
Authors: Carpén L. , Raaska L. , Kujanpää K. , Hakkarainen T. 
Published: July 2003

AbstractBiofilm formation and electrochemical behavior of stainless steel have been studied in well water, in tap water and in water taken from fire extinguishing system. Some of the waters have been modified by adding manganese ions as well as in some cases acetate and yeast extract as a nutrient. Manganese oxidizing bacteria Leptothrix discophora has been used in these studies. To eliminate crevices in the specimen holder and to simulate reasonably well the conditions in fire‐extinguishing systems where the water is stagnant most of the time, a tape test arrangement with very slow flowing rate has been used in most of these studies. Also specimens with heat tint areas produced by heating inductively a small section of the specimen under flowing argon shielding gas were used in these studies. The results of these tape tests show that manganese oxidizing bacteria are able to increase the potential of both the base material (stainless steel UNS S30400) and of specimens with heat tint areas in well water, in tap water and in water taken from fire extinguishing system. Manganese oxidizing bacteria are also able to increase the cathodic reaction and thus enhance the initiation of corrosion. However, the increase of potential is not alone enough to start the corrosion. In these tests corrosion was initiated only in the specimens with heat tint areas in one of the waters taken from fire extinguishing system. No corrosion was detected in the specimens exposed to the well water or to the tap water used in these tests.
Biofouling control in industrial water systems: What we know and what we need to know
Authors: Cloete T. E. 
Published: July 2003

AbstractBiofouling contributes substantially to economic losses in industry. Although much progress has been made in understanding biofouling and its implications in industrial water systems, many questions remain unanswered.The cost of biofouling has not been enumerated. A prerequisite for this is research to elucidate the contribution that microbiologically influenced corrosion makes, to the overall corrosion process. Surface characteristics play a major role in the initial stages of microbial attachment. Ways of preventing preferential attachment to certain areas, i.e. grain boundaries and welds need further investigation. Biocides are routinely used to control biofouling. Due to the problem of resistance and potential environmental impact, alternative strategies for biofouling control need to be investigated and put to practice. These should focus on an integrated approach with the minimum impact on the environment. A number of biofouling monitoring devices have been developed. The advantages of biofouling monitoring needs to be demonstrated and monitors should become commercially available.
Electrochemical sensors for biofilm and biocorrosion
Authors: Tribollet B. 
Published: July 2003

AbstractThe presence of biofilm modifies the electrochemical properties of the interface and the mass transport near the interface. Two biofilm effects are damageable: the reduction of heat and/or mass transfer and the biocorrosion or microbiologically influenced corrosion (MIC).Two kinds of electrochemical sensors were developed: the first kind for the biofilm detection and the second one to evaluate the MIC risk. The biofilm detection is obtained by considering either the potential modification of the interface or the mass transport modification. The mass transport modification is analysed by considering the limiting diffusion current measured on a gold electrode where the biofilm development occurs.The MIC risk is evaluated with a sensor composed of two concentric electrodes in the material under investigation (e.g. carbon steel): a small disk electrode in the centre and a large ring. In a first step, a pit is artificially initiated by applying a current through these electrodes. In a second step, the risk factors of MIC are investigated by analysing the free coupling current circulating between these two short‐circuited electrodes.
Biofouling on austenitic stainless steels in spent nuclear fuel pools
Authors: Sarró M. I. , Moreno D. A. , Chicote E. , Lorenzo P. I. , García A. M. , Montero F. 
Published: July 2003

AbstractThe objective of this study was to investigate the biofilm formation on three different types of austenitic stainless steel (UNS S30400, S30466 and S31600) submerged in a spent nuclear fuel pool. The presence of microorganisms in coupons was characterised using standard culture microbiological methods, microscopic techniques (epifluorescence microscopy and scanning electron microscopy), and molecular biology techniques (denaturing gradient gel electrophoresis and sequencing fragments of 16S rDNA). The microscopy techniques showed signs of colonisation of stainless steels in spite of these extreme conditions. Based on sequencing of cultured microorganisms, different bacteria belonging to α, β, γ‐Proteobacteria, Bacilli, and Actinobacteria classes have been identified. The biofilm radioactivity was measured using gamma‐ray spectrometry and, according to the data gathered, the radionuclides present in the water pool were entrapped in the biofilm increasing the amount of radiation at the surface of the different materials.
Chain Connectivity and Conformational Variability of Polymers: Clues to an Adequate Thermodynamic Description of Their Solutions, 1
Authors: Bercea Maria , Cazacu Maria , Wolf Bernhard A. 
Published: July 2003

AbstractThis is the first of two parts investigating the Flory‐Huggins interaction parameter, χ, as a function of composition and chain length. Part 1 encompasses experimental and theoretical work. The former comprises the synthesis of poly(dimethylsiloxane)s with different molar mass and the measurements of their second osmotic virial coefficients, A2, in solvents of diverse quality as a function of M via light scattering and osmotic pressures. The theoretical analysis is performed by subdividing the dilution process into two clearly separable steps. It yields the following expression for χo, the χ value in range of pair interaction: χo = α − ζ λ. The parameter α measures the effect of contact formation between solvent molecules and polymer segments at fixed chain conformation, whereas the parameter ζ quantifies the contributions of the conformational changes taking place in response to dilution; ζ becomes zero for theta conditions. The influences of M are exclusively contained in the parameter λ The new relation is capable of describing hitherto incomprehensible experimental findings, like a diminution of χo with rising M. The evaluation of experimental information for different systems according to the established equation displays the existence of a linear interrelation between ζ and α. Part 2 of this investigation presents the generalization of the present approach to solutions of arbitrary composition and discusses the physical meaning of the parameters in more detail.Conformational response, ζ, as a function of α, the interaction parameter for fixed conformation.magnified imageConformational response, ζ, as a function of α, the interaction parameter for fixed conformation.
Preparation of Inclusion Complexes between Amylose and Ester‐Containing Polymers by Means of Vine‐Twining Polymerization
Authors: Kadokawa Jun‐ichi , Nakaya Atsushi , Kaneko Yoshiro , Tagaya Hideyuki 
Published: July 2003

AbstractThis paper reports the preparation of inclusion complexes of amylose with synthetic polymers by means of enzymatic polymerization of α‐D‐glucose 1‐phosphate monomer (Glc‐1‐P). The synthetic polymers, employed as the guests, are poly(ε‐caprolactone), poly(δ‐valerolactone), and poly(ester‐ether), containing ester groups in the main chains. The formation of the inclusion complexes was carried out by the enzymatic polymerization of Glc‐1‐P catalyzed by phosphorylase in the presence of the guest polymers.
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Homologous Series of 2,5‐Diheptyloxy‐p‐Phenylene Vinylene (DHepO‐PV) Oligomers with Vinyl or 1‐Butenyl End Groups: Synthesis, Isolation, and Microstructure
Authors: Peetz Ralf , Strachota Adam , Thorn‐Csányi Emma 
Published: July 2003

AbstractIn this paper we report the synthesis, isolation, and microstructure characterization of 2,5‐diheptyloxy‐p‐phenylene vinylene (PV) oligomers. Two homologous series with their chain length dependent NMR and IR spectra are presented and discussed in detail. To obtain the products, first, oligomer mixtures were synthesized by acyclic diene metathesis (ADMET) polycondensation of 2,5‐diheptyloxy‐1,4‐divinylbenzene. The Schrock‐type alkylidene complex Mo(NPhMe2)(CHCMe2Ph) [OCMe(CF3)2]2 served as a catalyst. The polycondensation mixture was used either for the isolation of the oligomers with vinyl end groups or as a feed component for a cross metathesis reaction with 3‐hexene yielding thermally stable derivatives (investigated up to 250 °C) with 1‐butenyl end groups. From the oligomer mixtures, single oligomers up to the octamer (n = 2 … 8) were isolated by means of column chromatography. The monodispersity was determined by means of MALDI‐TOF mass spectrometry. The colors within the homologous series span widely from colorless (monomer) to yellow (trimer) to red (hexamer and upwards). The chain‐length dependence of the NMR spectra is resolved in detail. The presented data could also be used for valuable reference compounds for analogue polymer systems.Synthesis of diheptyloxy‐PV oligomers by olefin metathesis.magnified imageSynthesis of diheptyloxy‐PV oligomers by olefin metathesis.
Complexation of Bisphenol A with Calix[6]arene‐Polymer Conjugates
Authors: Kitano Hiromi , Hirabayashi Tadashi , Ide Makoto , Kyogoku Mayumi 
Published: July 2003

AbstractSodium calix[6]arenehexasulfonic acid (SCX6) was introduced into polymer molecules by the cross‐linking of SCX6 with epichlorohydrin (PolySCX6) or by the covalent binding of carboxymethylated SCX6 to an amino group‐carrying vinyl polymer (Poly(SCX6HMA‐co‐AAm)). The complexation of bisphenol A (BPA) with the SCX6 group in the polymers was examined fluorimetrically using acridine red (AR) as a probe. From the inhibitory effect of BPA on the complexation of AR with the SCX6 group in the polymers, the association constant (Kassoc) of BPA with the SCX6 group was evaluated and the value for BPA with the SCX6 group in Poly(SCX6HMA‐co‐AAm) was much larger than that with the non‐conjugated SCX6, probably because of the support of hydrophobic interactions between the guest and the hydrocarbon moieties in the polymer (polymer main chain and hexamethylene groups introduced for the conjugation of SCX6). The Kassoc value for bisphenol B (BPB) with a non‐conjugated SCX6 was larger than those for bisphenol A and bisphenol F, because of the higher hydrophobicity of BPB among the bisphenols examined. Thermodynamic parameters indicated that the inclusion of BPA into the cavity of sodium propyloxycalix[6]arenehexasulfonic acid (SPCX6) was enthalpy driven, and the entropy change was largely negative (−92 J · mol−1 · K−1). This is probably because of a tight fit of guest molecules in the SPCX6 cavity, resulting in the loss of freedom of both the SPCX6 and the guest molecules. The entropy change for the complexation of BPA with the SCX6 group in the polymer was less negative, probably because of a partial release of water molecules around the SCX6 group upon the complexation. The effect of the structure of guest and host molecules on the complexation was also examined.Chemical structure of various calix[6]arenes: R = H, sodium calix[6]arenehexasulfonic acid; R = C3H7, sodium propyloxycalix[6]arenehexasulfonic acid; R = C4H9, sodium butyloxycalix[6]arenehexasulfonic acid; R = C6H13, sodium hexyloxycalix[6]arenehexasulfonic acid.magnified imageChemical structure of various calix[6]arenes: R = H, sodium calix[6]arenehexasulfonic acid; R = C3H7, sodium propyloxycalix[6]arenehexasulfonic acid; R = C4H9, sodium butyloxycalix[6]arenehexasulfonic acid; R = C6H13, sodium hexyloxycalix[6]arenehexasulfonic acid.
Exponential stability for a mirror–symmetric three phase boundary motion by surface diffusion
Authors: Escher Joachim , Garcke Harald , Ito Kazuo 
Published: July 2003

AbstractWe apply the principle of linearized stability to prove that a stationary state is exponentially stable under a mirror–symmetric three phase boundary motion by surface diffusion. A main difficulty in the application of the linearized stability principle arises from the inhomogeneous nonlinear boundary conditions.
An elliptic boundary problem in a half–space
Authors: Faierman Melvin , Möller Manfred 
Published: July 2003

AbstractThe spectral theory for general non–selfadjoint elliptic boundary problems involving a discontinuous weight function has been well developed under certain restrictions concerning the weight function. In the course of extending the results so far established to a more general weight function, there arises the problem of establishing, in an Lp Sobolev space setting, the existence of and a priori estimates for solutions for a boundary problem for the half–space ℝn+ involving a weight function which vanishes at the boundary xn = 0. In this paper we resolve this problem.
The theory of trying and goal‐directed behavior: The effect of moving up the hierarchy of goals
Authors: Bay Darlene , Daniel Harold 
Published: July 2003

AbstractThis article extends the literature regarding goal‐directed behavior as modeled by the theory of trying by incorporating the concept of the hierarchy of goals. Individuals develop “programs” intended to implement their principles and life goals. Within these programs, goals are arranged in a hierarchical order depending on how close they are to the overall goal of the program. Lower‐level goals are intended to set the stage for the achievement of higher‐level goals. Although most tests of the theory of trying have been implemented with the use of fairly low‐level goals (losing weight or learning a new piece of software), in this article, the model is applied in the context of a higher‐level goal: achieving a college education. There are important differences in the results compared to those in prior tests of the theory of trying. Most importantly, attitude toward failure is highly significant and attitude toward process is not. © 2003 Wiley Periodicals, Inc.
Musical tempo and waiting perceptions
Authors: Oakes Steve 
Published: July 2003

AbstractDigital technology was used to isolate musical tempo from other musical variables, and experimental results in an undergraduate registration queue context confirmed the existence of a significant, positive relationship between background musical tempo variation and temporal perception (perceived minus actual wait duration). Findings also revealed how slow‐tempo music produced significantly enhanced affective response (satisfaction, positive disconfirmation of expectations, and relaxation) compared to fast‐tempo music. © 2003 Wiley Periodicals, Inc.
Face consciousness and risk aversion: Do they affect consumer decision‐making?
Authors: Bao Yeqing , Zhou Kevin Zheng , Su Chenting 
Published: July 2003

AbstractThis article explores the effects of two cultural dimensions, face consciousness and risk aversion, on consumers' decision‐making styles. Data from China and the United States show that consumers in the United States differ from their counterparts in China in decision‐making styles. Face consciousness and risk aversion appear to contribute to such divergence. Implications for future research are discussed. © 2003 Wiley Periodicals, Inc.
New Millable Polyurethane/Organoclay Nanocomposite: Preparation, Characterization and Properties
Authors: Mishra Joy K. , Kim Il , Ha Chang‐Sik 
Published: July 2003

AbstractThe preparation, characterization and properties of novel millable polyurethane/organoclay nanocomposites are reported. Clay treated with methyl tallow bis(2‐hydroxyethyl) quaternary ammonium chloride was used as an organoclay for nanocomposite preparation. X‐ray diffraction indicated the intercalation of polymer chains inside the interlayer spacings of the clay. Dynamic mechanical analysis showed a significant increase in storage modulus, and tensile strength increases with increased organoclay loading.X‐ray diffraction patterns of millable polyurethane/organoclay nanocomposites.magnified imageX‐ray diffraction patterns of millable polyurethane/organoclay nanocomposites.
η3‐Benzyl‐Nickel‐Diimine Complex: Synthesis and Catalytic Properties in Ethylene Polymerization
Authors: Fassina Viviane , Ramminger Carolina , Seferin Marcus , Mauler Raquel S. , de Souza Roberto F. , Monteiro Adriano L. 
Published: July 2003

AbstractThe oxidative addition of benzyl chloride to Ni(cod)2 in the presence of 1,4‐bis(2,6‐diisopropylphenyl)acenaphthenediimine followed by chloride abstraction affords [(η3‐CH2C6H5)Ni(α‐diimine)][PF6] (α‐diimine = 1,4‐bis(2,6‐diisopropylphenyl)acenaphthenediimine) in 70% yield. The complex is active in ethylene polymerization in the presence of methylaluminoxane and under mild reaction conditions. The polyethylenes obtained are highly branched, have very low densities, do not show Tm or measurable crystallinity and have molecular weights ranging from 80 × 103 to 290 × 103 g · mol−1.magnified image
Inkjet Printing of Polymer Micro‐Arrays and Libraries: Instrumentation, Requirements, and Perspectives
Authors: de Gans Berend‐Jan , Schubert Ulrich S. 
Published: July 2003

AbstractThis article reviews commercially available instrumentation for inkjet printing of polymer micro‐arrays for combinatorial materials research, and requirements thereof. These include a print head positioning accuracy better than 10 μm and a minimum drop volume of 100 pL. Commercially available instruments that fulfill these requirements can be divided into two categories, depending on whether they receive ink from a reservoir (dispense mode) or through fluid aspiration (pipette mode). Instruments belonging to the first category are restricted to the preparation of polymer blend micro‐arrays. These consist of a few substances mixed in various ratios. The other instruments can be used for the preparation of both micro‐arrays of large numbers of different pure polymer compounds and polymer blend micro‐arrays. Moreover, ways to mix compounds are discussed.magnified image
Polysilsesquioxane Nanosheets Synthesized in Confined Environment
Authors: Ma Jun , Su Wei , Zhang Yong‐Jun , Hu Teng‐Jiao , Liu Hai‐Yun , Li Bai‐Yu , Shi Liang‐He , Xu Jian , Mai Yiu‐Wing 
Published: July 2003

AbstractPolysilsesquioxane nanosheets with a thickness of four nanometers and lateral dimensions of several hundreds of nanometers were synthesized by polymerization of a trifunctional monomer in the layer space of montmorillonite as the confined environment.AFM image of a polymethylsilsesquioxane nanosheet.magnified imageAFM image of a polymethylsilsesquioxane nanosheet.
Mild Synthesis of Amino‐Poly(ethylene glycol)s. Application to Steric Stabilization of Clays
Authors: Mongondry Philippe , Bonnans‐Plaisance Chantal , Jean Martine , Tassin Jean François 
Published: July 2003

AbstractThe hydroxyl end groups of poly(ethylene glycol) (PEG) have been transformed easily and quantitatively into amino groups via the Mitsunobu reaction. Phthalimide was alkylated with PEGs and the hydrazinolysis of the resulting phthalimido‐PEGs gave the amino compounds in high yields. Quaternization of the amino groups leads to hydrophilic polymer chains bearing a positive charge on one or two ends, depending on the chosen PEG. Such products can be used to protect sterically, negatively charged particles such as clays.magnified image
Thermal Breakdown by the Retro Diels–Alder Reaction of Crosslinking in Poly[styrene‐co‐(furfuryl methacrylate)]
Authors: Goiti Eunate , Huglin Malcolm B. , Rego José M. 
Published: July 2003

AbstractCrosslinked poly[styrene‐co‐(furfuryl methacrylate)] has been produced by the Diels–Alder (D‐A) reaction between the furan ring (within the copolymer) and the maleimide (MI) group (within the other reactant, bismaleimide). The retro D‐A reaction was followed by the analysis of MI groups produced at different times at five constant temperatures. The process was shown to follow first‐order kinetics, and the rate constants were determined. The findings are believed to be the first to provide quantitative information on the breakdown by a retro D‐A reaction of crosslinking in a polymer system. The D‐A and retro D‐A processes constitute a thermoreversible gelling system with respect to the formation and breakdown of crosslinks.First‐order rate plot for the retro D‐A breakdown of crosslinked poly(ST‐co‐FM).magnified imageFirst‐order rate plot for the retro D‐A breakdown of crosslinked poly(ST‐co‐FM).
Soluble Polyimides from a New Dianhydride: 5′‐tert‐Butyl‐m‐terphenyl‐3,4,3″,4″‐tetracarboxylic Acid Dianhydride
Authors: García Carolina , Lozano Angel E. , de la Campa José G. , de Abajo Javier 
Published: July 2003

AbstractA novel tert‐butyl‐containing dianhydride was prepared from readily available reagents. It was reacted with various aromatic diamines to prepare a set of polyimides containing tert‐butyl pendent groups. The resulting polyimides exhibit high molecular weights (high inherent viscosity), and a combination of desirable properties, such as good solubility in aprotic amide solvents and cresols, high glass transition temperatures (up to 320 °C), high thermal resistance, film‐forming capability and good mechanical properties.magnified image
Well‐posedness and asymptotic behaviour of a non‐dissipative beam equation with a quotient space method
Authors: O'Dowd G. 
Published: July 2003

AbstractA beam equation model is studied, for which no suitable dissipative norm can be associated but only a semi‐norm, vanishing on some subspace. Considering a quotient by that subspace creates dissipativity which guarantees well posedness of this problem. Asymptotic behaviour is also obtained by using the quotient. The linear problem, involving high‐order multiplier is studied and then the non‐linear problem, thanks to the artificial problem method. Copyright © 2003 John Wiley & Sons, Ltd.
Blow‐up estimates for a quasi‐linear reaction–diffusion system
Authors: Zuodong Yang , Qishao Lu 
Published: July 2003

AbstractIn this paper, some sufficient conditions under which the quasilinear elliptic system ‐div(∣∇u∣p‐2∇u) = uv, ‐div(∣∇u∣q‐2∇u) = uv in ℝN(N≥3) has no radially symmetric positive solution is derived. Then by using this non‐existence result, blow‐up estimates for a class of quasilinear reaction–diffusion systems ut = div (∣∇u∣p‐2∇u)+uv,vt = div(∣∇v∣q‐2∇v) +uv with the homogeneous Dirichlet boundary value conditions are obtained. Copyright © 2003 John Wiley & Sons, Ltd.