bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of the soil phosphorus–mobilization potential by microbial reduction using the Fe(III)‐reduction test
Authors: Thiele‐Bruhn Sören 
Published: December 2006

AbstractThe mobility of soil P is greatly influenced by the redox potential (Eh), which depends on the reducing activity of soil microorganisms. Standard extraction methods for the determination of the mobile soil P disregard the P mobilization caused by the influence of microorganisms on Eh, while P test methods that include soil microbial activities are lacking. Thus, the Fe(III)‐reduction test was investigated for its suitability to determine the P fraction that is mobilized in soil under reducing conditions (PRed). In this test, the soil‐microbial reducing activity is measured from the microbial Fe(III) reduction combining a bioassay with 7 d incubation and a chemical extraction using 1M KCl. After the incubation, Eh in 26 different soil samples ranged from –282 to –123 mV. The concentration of PRed in the soil samples ranged from concentrations below the limit of detection to 84.9 mg kg–1 and was on average of all soil samples by a factor of 2.4 to 18 smaller than the P fractions determined by standard soil P–extraction methods. As standard agronomic and environmental P extractants, respectively, water (PH2O), dithionite citrate bicarbonate (PDith), ammonium oxalate (POx), ammonium lactate (PAL), double lactate (PDL), and sodium bicarbonate (POlsen) were selected. The PRed fraction was not correlated with PAL, PDL, Polsen, and the degree of P saturation, but with PH2O (r = 0.43*), PDith (r = 0.60***), and POx (r = 0.61***). Furthermore, PRed depended on the concentration of amorphous Fe oxides (FeOx, r = 0.53**) and was closely correlated with the concentration of microbially reduced Fe (FeRed, r = 0.94***). This indicated the influence of the Fe(III)‐reducing activity of soil microorganisms on P mobilization. In subsoils, low in Fe(III)‐reducing activity, no P was released by the Fe(III)‐reduction test, which was in contrast to the results from the other chemical extraction methods. Additional alterations of the microbial activity by inhibiting and activating amendments, respectively, clearly affected the microbial Fe(III)‐reducing activity and the associated release of PRed. Thus, PRed, determined by the Fe(III)‐reduction test, might be termed as the fraction that is potentially released from soil by microbial reduction.
Heavy soil loading its consequence for soil structure, strength, deformation of arable soils
Authors: Peth Stephan , Horn Rainer , Fazekas Orsolya , Richards Brian G. 
Published: December 2006

AbstractThe alteration of mechanical soil properties by a single stress application exceeding all previously applied stresses is analyzed for a conventionally tilled and a conservational managed (since 1992) Stagnic Luvisol. Despite the more pronounced compactness of the plough layer under conventional management, it turned out to be less rigid compared to the “relictic” plough layer under conservation management. We assume that wheeling with a sugar beet harvester (rear wheel 140 kPa, front wheel 110 kPa, total mass 37 Mg) resulted in a break up of the plough pan. This was most obvious in the conventionally tilled soil whereas under conservation tillage, the plough pan seemed to resist the induced forces. Our results suggest that a break up of the compact plough layer and the subsequent re‐arrangement of newly formed fragments results in a smaller mechanical stability of the deformed soil. Soil structural changes within the plough pan are also indicated by the alteration of the anisotropy of cohesion and precompression stress, respectively. Altered mechanical properties induced by heavy soil loading affects the soil response to subsequent loading events, which could be shown by finite‐element simulations of stress‐strain properties. The simulations showed that a decrease in soil stiffness reduces the stress attenuation within the plough pan causing compressive and shear stresses to be transmitted into deeper soil levels, while at the same time shear strain increased.
Universality of a surface tension—contact‐angle relation for hydrophobic soils of different texture
Authors: Bachmann Jörg , Arye Gilboa , Deurer Markus , Woche Susanne K. , Horton Robert , Hartge Karl‐Heinz , Chen Yona 
Published: December 2006

AbstractWettability of soil affects a wide variety of processes in soils like infiltration, percolation, preferential flow, and surface runoff. Even though efforts have been made to determine contact angles and surface tension or energy of smooth surfaces, the determination on granular materials like soil particles remains unsolved. One objective of this study was to test the consistency of contact angles (CA) measured with the newly modified and easy‐to‐apply Wilhelmy plate method by using solid particles and liquids with defined variations of surface tension. A second objective was to derive basic physical surface properties for the irregularly shaped and chemically heterogeneous soil particles. Advancing contact angles were determined by using model soils varying in texture from clay to coarse sand to check the impact of grain size on the CA measurements. Varying the solid‐surface tension with dichlorodimethlylsilane treatments provided for pure‐water wetting stages ranging from wettable to extremely hydrophobic. The surface tensions of the liquids were varied from 72 mN m–1 to 25 mN m–1 by using water or water‐ethanol mixtures. The surface tensions of the model soils were determined with the zero degree–contact angle method following Zisman's critical–surface tension concept. Results show that the measured CA varied continuously with the variations of the surface tension of the liquid and the solid phase, respectively. A general interpretation of the results is possible by using the concept of the Equation of State Approach.
Fabrication and characterization of SERS‐active silver clusters on glassy carbon
Authors: Wang Yuling , Chen Hongjun , Dong Shaojun , Wang Erkang 
Published: December 2006

AbstractIn this article, a novel technique for the fabrication of surface enhanced Raman scattering (SERS) active silver clusters on glassy carbon (GC) has been proposed. It was found that silver clusters could be formed on a layer of positively charged poly(diallyldimethylammonium) (PDDA) anchored to a carbon surface by 4‐aminobenzoic acid when a drop containing silver nanoparticles was deposited on it. The characteristics of the obtained silver clusters have been investigated by atomic force microscopy (AFM), SERS and an SERS‐based Raman mapping technique in the form of line scanning. The AFM image shows that the silver clusters consist of several silver nanoparticles and the size of the clusters is in the range 80–100 nm. The SERS spectra of different concentrations of rhodamine 6G (R6G) on the silver clusters were obtained and compared with those from a silver colloid. The apparent enhancement factor (AEF) was estimated to be as large as 3.1 × 104 relative to silver colloid, which might have resulted from the presence of ‘hot‐spots’ at the silver clusters, providing a highly localized electromagnetic field for the large enhancement of the SERS spectra of R6G. The minimum electromagnetic enhancement factor (EEF) is estimated to be 5.4 × 107 by comparison with the SERS spectra of R6G on the silver clusters and on the bare GC surface. SERS‐based Raman mapping technique in the form of line scanning further illustrates the good SERS activity and reproducibility on the silver clusters. Finally, 4‐mercaptopyridine (4‐Mpy) was chosen as an analyte and the lowest detected concentration was investigated by the SERS‐active silver clusters. A concentration of 1.6 × 10−10 M 4‐Mpy could be detected with the SERS‐active silver clusters, showing the great potential of the technique in practical applications of microanalysis with high sensitivity. Copyright © 2006 John Wiley & Sons, Ltd.
Placing customer service strategy in the context of a vertical marketing system
Authors: Lee Yang‐Im , Trim Peter R.J. 
Published: December 2006

Abstract

International retailing is undergoing rapid change and because of this senior managers need to understand how to manage the change process and develop working relationships with their counterparts in partner organizations.

By embracing organizational learning it is possible for a retail organization to formulate a vertically integrated strategy that provides superior customer value and results in the formation of trust‐based relationships. These should be underpinned by mutuality and possess a strategic focus.

Copyright © 2006 John Wiley & Sons, Ltd.
Unlocking synergies between business units: internal value creation at Royal Vopak
Authors: Ansari Shahzad , Schouten Martijn , Verwaal Ernst 
Published: December 2006

Abstract

This paper examines the process of creating and exploiting synergies between business units of a multi‐unit corporation and the creation of internal value by combining and exploiting knowledge.

It offers a framework to create and manage such synergies and undertakes an empirical test through in‐depth study across three business units of Royal Vopak, a Dutch‐based global multi‐unit corporation. Finally, it offers lessons for corporate managers trying to create and manage cross‐unit synergies.

Copyright © 2006 John Wiley & Sons, Ltd.
A diagnostic framework for building HR capability in organizations
Authors: Hiltrop Jean M. 
Published: December 2006

Abstract

This paper examines some of the key factors that influence the impact of strategic HRM on organizational capability and performance. Particular attention is given to the factors that contribute towards the increasingly important capability of attracting and keeping talent in organizations and the practical implications of these factors for the way in which human talent is managed in knowledge‐intense firms.

The questions addressed here are: What are the key factors that increase organizational capability to get and keep the right types of people? How can these factors be managed in order to create and sustain competitive advantage? What are the implications for the HR strategy and effective people management?

Copyright © 2006 John Wiley & Sons, Ltd.
The effect of hard coated metals on the thermo‐oxidative stability of a branched perfluoropolyalkylether lubricant
Authors: Hellman Patrick T. , Zabinski Jeffery S. , Gschwender Lois , Snyder Carl E. , Korenyi‐Both Andras L. 
Published: December 2006

AbstractM‐50 and carburized Pyrowear 675® (Carpenter Technology, Reading PA, USA) steel coupons deposited with commercially available physical vapour deposited TiN, TiCN, TiAlCN, TiCrCN/TiB4C multilayer, electroless Ni (E‐Ni) TiN and E‐Ni TiCN coatings were immersed in a branched perfluoropolyalkylether (PFPAE), Krytox AC® (E.I. du pont de Nemours and Company, Wilmington DE, USA), in an oxidative environment at temperatures ranging from 315 to 360 °C for a duration of 24 hours and compared with uncoated coupons. Coated and uncoated Pyrowear 675® coupons demonstrated superior corrosion resistance compared with coated and uncoated M‐50 respectively. The coatings most resistant to chemical attack in the PFPAE fluid were TiCN, E‐Ni TiN and E‐Ni TiCN. Copyright © 2006 John Wiley & Sons, Ltd.
Metallocene Catalysts for 1‐Butene Polymerization
Authors: Resconi Luigi , Camurati Isabella , Malizia Federica 
Published: December 2006

AbstractSummary: Isotactic polybutenes of variable isotacticity and melting points of form I in the range 100–125 °C have been prepared with both C2‐ and C1‐symmetric zirconocenes. The C1‐symmetric zirconocenes bearing the bilateral symmetric 2,5‐dimethyl‐7H‐cyclopenta[1,2‐b:4,3‐b′]dithiophene ligand connected by a dimethylsilandiyl bridge to a substituted indenyl ligand produce iPB with higher molecular mass, up to 400 000 at polymerization temperature of 70 °C in liquid butene. The degree of isotacticity depends on the substitution pattern of the indenyl ligand. The correlations between microstructure and melting points of the crystalline forms I and II of iPB have been defined. Some relevant differences in catalyst selectivity between propylene and 1‐butene polymerizations have been identified.Linear correlation of melting points of form I and form II in isotactic poly(1‐butene)s of different chain regularities.magnified imageLinear correlation of melting points of form I and form II in isotactic poly(1‐butene)s of different chain regularities.
A Highly Efficient Polyurethane‐Type Polymeric Photoinitiator Containing In‐chain Benzophenone and Coinitiator Amine for Photopolymerization of PU Prepolymers
Authors: Wei Jun , Wang Hongyu , Jiang Xuesong , Yin Jie 
Published: December 2006

AbstractSummary: A novel polyurethane‐type polymeric photoinitiator (PUIOA) was synthesized through polycondensation of a novel diamine AAPBP, TDI and MDEA. The BP and coinitiator amine structures were successfully introduced into the backbones of PUIOA. A polymeric photoinitiator without the coinitiator amine in the polymer chain (PUIO) was also synthesized for comparison. FT‐IR, 1H NMR and GPC analyses confirmed the structures of polymeric photoinitiators. The UV‐vis spectra of PUIOA and PUIO are similar to the parent AAPBP, and both exhibit high red‐shifted maximal absorption as compared with BP. ESR spectra indicate that PUIOA can generate free radicals most efficiently. Photopolymerization of the Polyurethane prepolymer, initiated by PUIOA, PUIO/MDEA, AAPBP/MDEA and BP/MDEA, was studied by photo‐DSC. The results show that PUIOA is the most efficient photoinitiator for PU prepolymer.Synthesis routes for polymeric photoinitiators.magnified imageSynthesis routes for polymeric photoinitiators.
Potentiometric Titrations of Maleic Acid Copolymers in Dilute Aqueous Solution: Experimental Results and Theoretical Interpretation
Authors: Delben Franco , Paoletti Sergio , Porasso Rodolfo D. , Benegas Julio C. 
Published: December 2006

AbstractSummary: The paper reports a study on the flexibility of a family of 1:1 hydrolysed maleic anhydride (maleic acid, MA)–olefin copolymers in dilute aqueous solution. The copolymers were MA–ethene, MA–propene and MA–isobutene. The study was carried out in the absence and in the presence of monomonovalent salts and at different polymer concentrations. Experimental data showing the negative logarithm of the ‘apparent’ dissociation constant, pKa versus the degree of dissociation, α, experimental data were obtained from potentiometric titrations using NaOH, KOH or tetramethylammonium hydroxide as the base. The pKa data were fully described with calculated curves obtained using an extension of the counterion condensation theory of linear polyelectrolytes, in which a semiflexible model for the polymers was introduced. Under the present experimental condition, no relevant specificity of the monovalent counterions was apparently observed for the different copolymers. The calculated pKa versus α curves allowed the derivation of both the intrinsic dissociation constants of the first and the second dissociation steps for the different copolymers and the corresponding stiffness parameters built into the model. The agreement between the experimental and calculated data shows an appreciable success of the model. The results pointed to an increase of stiffness parallel to the increase of size of the olefin comonomer, in qualitative agreement with already published findings. Furthermore, for all copolymers the chain rigidity was larger in the α range of the first dissociation than in that of the second one. The former rigidity was attributed to the formation of intramolecular hydrogen bonds upon the first ionisation of the MA repeating units, followed by an increase of rotational freedom upon breaking of the H‐bond in the second dissociation step. Comparison of the rigidity parameters of the MA copolymers with the data obtained for other polyelectrolytes, both natural—poly(L‐glutamic acid) and pectic acid—and synthetic—poly(acrylic acid) and poly(methacrylic acid)—was also performed.
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The keto–enol tautomerization of ethyl butylryl acetate studied by LC‐NMR
Authors: Zhou Casey Chun , Hill David R. 
Published: December 2006

AbstractThe keto–enol tautomerism of ethyl butylryl acetate was studied in mixed solvents under a variety of experimental conditions. The direct measurement of ketonization of the enol tautomer was performed by using the hyphenated technique LC‐NMR. The keto and enol tautomers can be separated by using HPLC and their interconversion is a slow process on the NMR timescale. The ketonization reaction was found to be acid catalyzed and the solvent isotope effect, k/k, in an acetonitrile/water mixture, is 5.4. The ketonization rate constants were also measured at different compositions of binary solvents, such as CH3CN/D2O, CD3OD/D2O, and CH3CN/CD3OD. The rate constant and water percentage were found to have an exponential relationship. The reaction rate as a function of solvent polarity will be discussed in this paper. Copyright © 2006 John Wiley & Sons, Ltd.
A PGSE diffusion and electrophoretic NMR study of Cs+ and Na+ dynamics in aqueous crown ether systems
Authors: Price William S. , Hallberg Fredrik , Stilbs Peter 
Published: December 2006

AbstractMultinuclear pulsed gradient spin‐echo (PGSE) NMR diffusion and linewidth measurements were used to probe binding and transport in aqueous Na+‐15‐crown‐5, Na+‐18‐crown‐6, Cs+‐15‐crown‐5 and Cs+‐18‐crown‐6 systems. Since direct PGSE observation of many alkali cations is precluded by either low inherent sensitivity or rapid relaxation (or both), the feasibility of proton‐detected electrophoretic NMR (ENMR) measurements to complement PGSE data was investigated. ENMR measurements were performed on aqueous Cs+‐, Li+‐, Na+‐, K+‐, and Rb+‐ 18‐crown‐6 systems. The data analysis is based on a two‐site binding model and its corresponding association constants. Cs+ was found to bind considerably more tightly to 18‐crown‐6 (K = 8 M−1) than to 15‐crown‐5 (K ∼ 2 M−1), whereas Na+ had almost equal affinity (K ∼ 4.5 M−1) for 15‐crown‐5 and 18‐crown‐6. The difficulties encountered in analysing the NMR parameters, methodological limitations and the implied need for more complicated binding models are discussed. Copyright © 2006 John Wiley & Sons, Ltd.
Peripheral nerve stimulation and monitoring during operative procedures
Authors: Crum Brian A. , Strommen Jeffrey A. , Stucky S. C. 
Published: December 2006

AbstractMonitoring of peripheral nerve function is important during the surgical treatment of peripheral nerve and plexus lesions, allowing for rapid assessment of the integrity of the roots, plexus, and nerves. The results of this monitoring assist the surgeon in the overall approach to treatment of these lesions. There are, however, many technical challenges to providing this neurophysiological information in an accurate and rapid fashion. This study assesses the equipment and techniques involved in intraoperative peripheral nerve monitoring and describes its use in the more common clinical scenarios. Muscle Nerve, 2006
On determinantal representation for the generalized inverse A and its applications
Authors: Cai Jing , Chen Guoliang 
Published: December 2006

AbstractIn this paper, first we establish a determinantal representation for the group inverse Ag of a square matrix A. Based on this, a determinantal representation for the generalized inverse A is presented. As an application, we give a determinantal formula for the unique solution of the general restricted linear system: Ax=b(x ∈ T, b ∈ AT and dim(AT)=dim(T)), which reduces to the common Cramer rule if A is non‐singular. These results extend our earlier work. Copyright © 2006 John Wiley & Sons, Ltd.
Dynamic mechanical properties of filled styrene butadiene rubber compounds: comparison of tensile and shear data
Authors: Konečný P. , Černý M. , Voldánová J. , Maláč J. , Šimoník J. 
Published: December 2006

AbstractMost rubber articles are prepared from filler‐elastomer compounds and dynamic mechanical data can give valuable insight into behavior of such systems. The aim of this study was to compare complex tensile modulus E* and complex shear modulus G* using seven types of vulcanized filled rubbers and two testing devices.Carbon black and clay filled styrene butadiene rubber (SBR) compounds were tested. The E* value was measured using a dynamic mechanical analyzer (DMA DX04T from R.M.I.) and the G* value using a rubber process analyzer (RPA 2000 from Alpha Technologies) at 1 Hz, 30°C and at small deformation amplitudes common to both devices. For characterization of tested materials absolute values of complex modulus |E*| and |G*| were used together with values of loss factor tan δ.The highest values of |E*|, |G*| and tan δ in tested carbon blacks were obtained for type N330. The highest values of |E*|, |G*| and tan δ in tested clay fillers were found for organoclay Cloisite 93A.Maximum at the dependence tan δ/amplitude, obtained in a broader shear amplitude range, was found to be smaller for carbon black filled compounds than expected and maximum at this dependence for clay filled compounds was not observed.The amplitude dependences of analogous dynamic mechanical characteristics from dynamic mechanical analysis (DMA) and rubber process analysis (RPA) measurements seem to be similar. Between the analogous dynamic mechanical characteristics from DMA and from RPA usually a linear relationship exists with high correlation coefficient.Conclusions derived from DMA and RPA testing on the same series of rubber compounds seem to be the same. Copyright © 2006 John Wiley & Sons, Ltd.
Study of adhesion and surface properties of low‐density poly(ethylene) pre‐treated by cold discharge plasma
Authors: Novák Igor , Števiar Marián , Chodák Ivan , Krupa Igor , Nedelčev Tomáš , Špírková Milena , Chehimi Mohamed M. , Mosnáček Jaroslav , Kleinová Angela 
Published: December 2006

AbstractThe low‐density poly(ethylene), which is prone to hydrophilicity, dyeability, and bondability, was modified by surface barrier discharge and radio‐frequency discharge plasma. A process of plasma modification was investigated to improve adhesion between poly(ethylene) and more polar polymers, to improve surface properties, and to form a new surface containing polar functional groups incoming to reactions with diazo‐compounds, and/or vinyl silanes. The measurements of contact angles and peel strengths of adhesive joints were carried out for characterization of the surface and adhesive properties of the polymer modified by plasma. The topography of modified poly(ethylene) was studied using atomic force microscopy, and changes in chemical structure were analyzed with X‐ray photoelectron spectroscopy. Copyright © 2006 John Wiley & Sons, Ltd.
A new polymeric silicone hydrogel for medical applications: synthesis and properties
Authors: Chekina N. A. , Pavlyuchenko V. N. , Danilichev V. F. , Ushakov N. A. , Novikov S. A. , Ivanchev S. S. 
Published: December 2006

AbstractA novel silicone hydrogel polymeric material is developed. The preparation method is based on sequential interpenetrating network synthesis. A silicone network is obtained by the interaction between two siloxane oligomers comprising hydride and vinyl functional groups. A hydrophilic network is prepared by radical copolymerization of hydrophilic monomers (N‐vinyl pyrrolidone, N,N‐dimethylacrylamide) and crosslinking agent (ethylene glycol dimethacrylate). In the hydrated state the developed material has high mechanical properties, transparency, hydrophilicity, oxygen and water permeability. The developed new technology affords obtaining a silicone hydrogel material with a good wettability without additional chemical or plasma surface treatment. Copyright © 2006 John Wiley & Sons, Ltd.