bluuebunny/crossref_metadata_2025_split huggingface dataset:
Knowledge management implementation frameworks: a review
Authors: Wong Kuan Yew , Aspinwall Elaine 
Published: June 2004

AbstractOne reason why many organizations are still struggling with knowledge management (KM) and failing in their endeavours to realize its full potential is that they lack the support of a strong theoretical foundation to guide them in its implementation. A sound KM implementation framework helps to fulfil this need by providing important guiding principles and directions. However, developing such a framework can be a challenging task for managers and practitioners as they may lack the knowledge of what characteristics, elements and constructs should be included in it. Implementation frameworks that do not have the necessary elements in place can paint an incomplete picture of KM and its implementation process, thus providing a suboptimal guidance for conducting KM. This paper reviews the existing KM implementation frameworks presented in the literature in order to determine and propose a set of guidelines for constructing them. By utilizing these guidelines to develop a KM implementation framework, it is hoped that a stronger theoretical foundation can be constructed, thus facilitating the accomplishment of KM. Copyright © 2004 John Wiley & Sons, Ltd.
Imidazoline binding sites and their ligands: An overview of the different chemical structures
Authors: Dardonville Christophe , Rozas Isabel 
Published: June 2004

AbstractSince Bousquet et al. discovered the imidazoline binding sites (IBS) two decades ago, when they realized that the antihypertensive drug clonidine interacts not only with the α2‐adrenenoceptors (α2‐AR) but also with a distinct imidazoline preferring binding site, these receptors have been paid a great deal of attention. At least two subtypes, I1 and I2, have been characterised based on their binding affinity for different radioligands, but their structures still remain unknown. The pharmacological profile of these IBSs has been the objective of several and very thorough reviews. However, a medicinal chemistry overview of the different IBS ligands prepared to date has never been attempted. In this study, we attempt to compile all the different chemical structures reported to date as IBS ligands and classify them in function of their chemical structure and binding affinity for the different IBS subtypes. Thus, we comment on the different endogenous IBS ligands known as well as the drugs described to interact with the I1‐IBS which have found application as antihypertensive drugs. Then, we review those compounds described in the literature to interact with the I2‐IBS, classifying them by their chemical families (imidazolines, guanidines, 2‐aminoimidazolines, β‐carbolines). Finally, some conclusions are drawn. © 2004 Wiley Periodicals, Inc. Med Res Rev, 24, No. 5, 639–661, 2004
The design and performance of a new miniature mixer for specialty polymer blends and nanocomposites
Authors: Breuer Orna , Sundararaj Uttandaraman , Toogood Roger W. 
Published: June 2004

AbstractA novel miniature mixer called the “Alberta Polymer Asymmetric Minimixer” (APAM) was designed, built and tested. In this study, polymer blends and nanofiber composites were compounded using a total of approximately 2 grams per sample. This mixer has a unique, asymmetric design consisting of a varying clearance between the rotor blade tips and the cup wall, enabling the material to be squeezed, stretched and kneaded in high shear and converging zones. Unlike the few other miniature mixing devices that are commercially available, the APAM has a combination of good mixing capability and complex flow modes required for dispersive flow, and requires minimal sample mass. In this work, the final morphology of non‐reactive blends created in the APAM was similar to that obtained in an internal mixer and in a twin‐screw extruder, and was much finer than that obtained in a MiniMAX™ mixer. The final morphology in reactive blends was comparable for all the mixers. The dispersion of nanofibers is uniform for the nanocomposites blended in the APAM and comparable to the dispersion obtained in the internal batch mixer, whereas for the MiniMAX™, the nanofibers remained in bundles and were not wetted by the matrix polymer. Polym. Eng. Sci. 44:868–879, 2004. © 2004 Society of Plastics Engineers.
Ejection force in tubular injection moldings. Part I: Effect of processing conditions
Authors: Pontes A. J. , Pouzada A. S. 
Published: June 2004

AbstractThe development and manufacture of injection molds for high quality technical parts are complex tasks involving the knowledge of the injection molding process and the material changes induced by processing. In the case of some specific shapes (boxes, tubular fittings), the shrinkage is partially restricted by the mold. The molding shrinks against the core, inserts or pins. Thus, upon ejection, it will be necessary to overcome the frictional forces resulting from the shrinkage. The knowledge of the ejection force is a useful contribution to optimizing the design of molds with these features, and to guaranteeing the structural integrity of the moldings. A study on the effect of conditions on the ejection force required for deep tubular moldings is described for the cases of three common thermoplastic polymers. The studies were based on tubular moldings (60 mm diameter, 146 mm length, and 2 mm thickness). The injection unit cell consisted of a 1 MN clamp force injection molding machine, thermal regulator, and material dryer. During processing, pressure, temperature and ejection force evolutions were recorded. The results show that the processing conditions noticeably influence the ejection force. Polym. Eng. Sci. 44:891–897, 2004. © 2004 Society of Plastics Engineers.
Semi‐interpenetrating polymer networks based on polyurethane and poly(vinyl pyrrolidone) obtained by photopolymerization: Structure‐property relationships and bacterial adhesion
Authors: Karabanova L. V. , Mikhalovska S. V. , Sergeeva L. M. , Meikle S. T. , Helias M. , Lloyd W. 
Published: June 2004

AbstractA range of semi‐interpenetrating polymer networks (semi‐IPNs) based on polyurethane (PU) and poly(vinyl pyrrolidone) (PVP) have been synthesized and characterized with respect to their thermodynamic characteristics, morphology, mechanical properties, surface properties, water sorption and bacterial adhesion. The free energies of mixing of PU and PVP in semi‐IPNs have been determined by the vapor sorption method and were shown to be positive for all compositions. The surface properties of semi‐IPNs were investigated using the dynamic contact angle analysis. It was shown that the advancing contact angle changes from 83.1° to 65.3° with increasing PVP from 7.05% to 57.38%. Scanning electron microscopy demonstrated that the semi‐IPNs are two‐phase systems with incomplete phase separation. The mechanical properties reflect the changes in structure of semi‐IPNs with increasing of amounts of PVP in the system. Incorporation of PVP into the semi‐IPN with PU restricts the ability of PVP to sorb water. As infection is likely to be caused by bacterial adherence to biomedical implants, the bacterial adhesion data suggests that the semi‐IPNs with PVP content below 22.52% may be useful for biomedical material applications. Polym. Eng. Sci. 44:940–947, 2004. © 2004 Society of Plastics Engineers.
Effect of shrinkage and process parameters on the monitoring of bulk and surface stream temperatures in injection molding via the infrared waveguide method
Authors: Bendada A. , Simard Y. , Lamontagne M. 
Published: June 2004

AbstractThis paper analyzes for the first time the application of the infrared hollow waveguide method for the remote sensing of the temperature decay of polymer streams during injection molding. The key feature of the infrared procedure employed is its low transmission loss of the thermal energy in the mid and far infrared spectral regions. This particular advantage allows the hollow waveguide device to measure not only the bulk temperature within the polymer, as commercially available full‐core optical fiber instruments do, but also the temperature at the polymer surface. Moreover, the hollow waveguide device is able to measure quite low temperatures, which conventional thermometers cannot do either. Experimental trials have been run on a Husky injection molding press in order to investigate the effect of some process parameters and shrinkage on the bulk and surface temperature decay signals. The results showed a drastic deviation between the kinetic behaviors of the surface and bulk temperature traces throughout the injection cycle. Particularly, it was noticed that the cooling rate of the surface temperature was more affected by part shrinkage than the cooling rate of the bulk temperature. The experimental results showed also that temperatures below 60°C could be reliably measured with reasonable signal‐over‐noise ratio. Polym. Eng. Sci. 44:955–964, 2004.
The effect of long chain branching on the processability of polypropylene in thermoforming
Authors: Gotsis A. D. , Zeevenhoven B. L. F. , Hogt A. H. 
Published: June 2004

AbstractLinear polypropylene was modified by reaction with peroxydicarbonates in a twin screw extruder to obtain varied degrees of long chain branching. The melt strength and the elasticity of the modified polymers were found to increase with the modification. The processability in foaming and thermoforming processes improved with branching and showed an optimum, beyond which higher degrees of long chain branching appeared not to help any further. The branched PP samples showed distinct strain hardening in the elongational viscosity, which was absent from the original linear melts. Melt strength, elasticity and strain hardening increased with the increase of the number of long chain branches on the main chain. The effect of molecular weight and molecular weight distribution of the precursor on the improvement of the processability of the polymer was examined. Polym. Eng. Sci. 44:973–982, 2004. © 2004 Society of Plastics Engineers.
Assessing factors for reliable quantitative proteomics based on two‐dimensional gel electrophoresis
Authors: Fiévet Julie , Dillmann Christine , Lagniel Gilles , Davanture Marlène , Negroni Luc , Labarre Jean , de Vienne Dominique 
Published: June 2004

AbstractWe statistically analysed various factors to get accurate estimates of protein quantities from two‐dimensional gels. Yeast proteins were labelled with 35S or stained with Coomassie Brilliant Blue G‐250, and spots were automatically quantified with software packages Kepler, ImageQuaNT, Melanie 3.0 and Progenesis. The different software packages proved to have very similar performances. With 35S‐labelled actin spot as a reference, we studied the staining efficiency of colloidal Coomassie blue as a function of amino acid composition of the protein, and derived an equation to estimate the number of molecules per cell from blue‐stained proteins. Absolute quantification of most glycolytic enzymes was carried out in two yeast strains.
Comparative proteome analysis of Hansenula polymorpha DL1 and A16
Authors: Kim Yang‐Hoon , Han Kyung Yeon , Lee Kibeom , Heo Joo‐Hyung , Kang Hyun Ah , Lee Jeewon 
Published: June 2004

AbstractProteomic responses of methylotrophic yeasts (Hansenula polymorpha DL1 and A16) to growth medium tuning by carbon source shift (glycerol→methanol) were monitored and analyzed by two‐dimensional gel electrophoresis. Through comparative analyses of two‐dimensional gels, intracellular yeast proteins with complex expression patterns were systematically sorted into: (1) proteins that are commonly expressed with comparable high abundance in both strains; (2) strain‐specific proteins that are expressed at high level only in a particular strain; (3) strain‐specific and methanol‐induced proteins that are expressed only in the presence of methanol; and (4) strain‐specific and constitutively‐expressed proteins that are expressed consistently irrespective of carbon source shift without extreme change in expression level. Among the DL1‐specific proteins belonging to group four, the four proteins showing the highest expression levels in the course of the fermentation process were identified as: glucose‐6‐phosphate dehydrogenase, isocitrate lyase, succinyl‐CoA synthetase, and glycerol‐3‐phosphate dehydrogenase. From these results, it is suggested that DL1 has distinct metabolic characteristics including enhanced metabolic activities both in glycerol uptake and the glyoxylate bypass cycle, as compared to A16. This is likely to explain why the DL1 strain shows a significantly higher rate of glycerol and methanol consumption during the fermentation process. Our systematic approach to the analysis of proteomic responses and the detailed analysis results reported here will be useful to better understand the global physiology of H. polymorpha, as proteome databases for various methylotrophic yeasts are established.
Focal‐point anchoring: Large proton relaxivity observed for gadolinium‐cored dendrimer complexes in water
Authors: Kawa Manabu , Takahagi Takayuki 
Published: June 2004

AbstractWater‐soluble Gd3+‐cored poly(ether amide) dendrimer complexes, bearing a diethylenetriaminepentaacetic acid Gd3+ complex (GdDTPA) core, were synthesized. The longitudinal proton relaxivity (R1), governed mainly by the rotation correlation time of the paramagnetic Gd3+ center, was measured in water (37 °C, 20 MHz). An anchor effect at the focal point of the hydrophilic dendrimer was experimentally evaluated for the first time, through a comparison of the R1 values with the ones reported for various Gd3+ complexes, including linear copolymers of GdDTPA linked by various lengths of aliphatic chains via amide bonds. Unusually large R1 values for the first‐ and second‐generation Gd3+‐cored dendrimer complexes (6.1 and 9.3 mM−1 s−1, respectively), even with relatively low molecular weights (1355 and 3877, respectively), suggested a remarkable increase in the local rigidity around the GdDTPA core. The internal rigidity of the dendrimer was supposed to take advantage of the increased nominal molecular weight in water via multihydration to the dendron to increase the rotation correlation time, and this resulted in the observed R1 gain. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2680–2689, 2004
Small molecule matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry using a polymer matrix
Authors: Soltzberg Leonard J. , Patel Pina 
Published: June 2004

AbstractWe have employed a light‐absorbing electrically conductive polymer as a matrix to determine the molecular mass of small organic molecules using matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectrometry. This method, which is in contrast to the usual MALDI strategy for matrix selection in which a small molecule matrix is used with a high molecular mass analyte, addresses the problem of matrix interference which limits the usefulness of MALDI‐TOF for small molecule analysis. Use of negative ion mode offers advantages for this application. Using this approach, we have obtained clean molecular ion mass spectra of small organic molecules in the mass range 100–300 Da. Copyright © 2004 John Wiley & Sons, Ltd.
Water formation from O2 and H2 on Rh tips: studies by field ion microscopy and pulsed field desorption mass spectrometry
Authors: Visart de Bocarmé Thierry , Beketov Gennadiy , Kruse Norbert 
Published: June 2004

AbstractThe catalytic oxidation of hydrogen on Rh tips was investigated using field ion microscopy and pulsed field desorption mass spectrometry (PFDMS). The reaction was carried out in the 10−3 Pa range at 400–600 K. In a first series of experiments, emphasis was laid on revealing tip morphologies during the ongoing water formation. At a reaction temperature of 500 K, remarkable similarities with the previously studied pure oxygen case were found. Accordingly, a polyhedral tip shape with missing‐row‐type reconstruction on {011} and {113} planes was formed. In a second series of experiments, the gas mixture was varied to demonstrate the occurrence of local structural changes as well as multistability in the surface reaction at temperatures between 400 and 500 K and viewing fields of 10 V nm−1. A phase diagram was established within this temperature range. At 550 K and 9 V nm−1, self‐sustained kinetic oscillations with cycles of ∼40 s were observed in a continuous flow of O2H2 (pO2 = 1.0 × 10−3 Pa and pH2 = 1.3 × 10−3 Pa). Using PFDMS, ∼400 atomic sites close to the central (001) pole of the Rh tip were probed with varying pulse heights. During imaging in a wide range of H2O2 gas mixtures it was found that water ionization causes formation of the field ion image, leading to the conclusion that brightness analysis is suitable for measuring the local catalytic activity. On the oxygen side of the phase diagram, water molecules were formed on an oxidized surface so that RhO2+, RhO+ and Rh2O+ appeared in the mass spectra. On the other hand, by increasing the H2 pressure, the surface oxide was reacted off within ∼0.1 s, thereby leaving a relatively dark surface (H‐side of the diagram). Chemical probing in the latter case demonstrated fast water formation leaving few oxygens on the surface, i.e. negligible RhxOn+ amounts appeared in the mass spectra. Copyright © 2004 John Wiley & Sons, Ltd.
Nanostructural evolution of Al3Sc precipitates in an AlScMg alloy by three‐dimensional atom probe microscopy
Authors: Marquis Emmanuelle A. , Seidman David N. 
Published: June 2004

AbstractThe effects of Mg alloying on the precipitation of Al3Sc precipitates were investigated, focusing on nanostructural evolution during isothermal aging at 300°C. Three‐dimensional atom probe microscopy was performed on samples both in the as‐quenched state and after aging for various times. Magnesium tends to segregate at the coherent Al/Al3Sc interface, with a measured value of 1.9 ± 0.5 atom nm−2 for the relative Gibbsian excess of Mg with respect to Al and Sc. This value is constant for all heat treatments, thereby demonstrating that the system is in global thermodynamic equilibrium. This study provides direct experimental evidence for first‐principles calculations, which explain morphological changes of Al3Sc precipitates in the presence of Mg observed by high‐resolution electron microscopy. Evidence for the presence of Mg atoms in the center of the precipitates is also found, and is discussed in terms of heterogeneous nucleation of the precipitates on MgSc atomic clusters. Copyright © 2004 John Wiley & Sons, Ltd.
Numerical analysis of liquid metal flow in the presence of an electric field: application to liquid metal ion source
Authors: Suvorov Vasily G. 
Published: June 2004

AbstractTwo‐dimensional axisymmetric flow of a viscous, incompressible liquid metal with a free boundary subject to the action of an electric field is investigated in the context of liquid metal ion source operation. It is established that an almost flat surface evolves with time into a cone‐like shape, with the cone angle equal to Taylor's static value of 98.6°. The growth time of the Taylor cone and the time‐dependent behaviour of basic physical quantities (electric field strength, fluid velocity and surface curvature) near the cone apex are studied. A possible physical explanation of the effect of globule formation on the supporting needle of the liquid metal ion source has been put forward. The simulation is based on the method of adaptive numerical grid generation. Copyright © 2004 John Wiley & Sons, Ltd.
Characterization of precipitates in an aged 7xxx series Al alloy
Authors: Sha Gang , Cerezo Alfred 
Published: June 2004

AbstractPrecipitates in a 7050 Al alloy under two‐step ageing treatments were characterized using an energy‐compensated optical position‐sensitive atom probe and transmission electron microscopy. Selected‐area diffraction analyses indicated that the early‐stage precipitates present after a stabilization ageing treatment at 121°C for 4 h have a crystallographic structure similar to η′, but probably rich with defects. After T6 treatment ageing at 121°C for 24 h followed by 12 h at 154°C, η′ and η coexist within the Al matrix. Energy‐compensated optical position‐sensitive atom probe analysis was used to measure the partitioning of Zn, Mg and Cu to the precipitates. Early‐stage precipitates in the alloy after stabilization treatment have a Zn/Mg ratio of ∼1.3 and a (Zn + Cu)/Mg ratio of 1.4. The T6‐aged alloy contained η precipitates with an Zn/Mg ratio of ∼1.2 and a (Zn + Cu)/Mg ratio of 1.3 coexisting with η′ precipitates with a Zn/Mg ratio of ∼0.7 and a (Zn + Cu)/Mg ratio of ∼1. Copyright © 2004 John Wiley & Sons, Ltd.
Nanoscale studies of segregation at coherent heterophase interfaces in α‐Fe based systems
Authors: Isheim Dieter , Seidman David N. 
Published: June 2004

AbstractHeterophase interfaces are characterized with respect to atomic‐scale local compositions in two α‐Fe‐based alloy systems by three‐dimensional atom probe microscopy. The proximity histogram method is utilized for determining the compositions of the precipitates, the matrix phase and the Gibbsian interfacial excess of solute. Suitable methods to measure segregation in multicomponent systems at heterophase interfaces independent of the position of the dividing interface are discussed. Very little Sb segregates to the heterophase interface between coherent plate‐shaped moybdenum nitride precipitates, which are <1 nm thick, and the α‐Fe matrix: the relative interfacial excess of Sb is only 0.12 ± 0.1 nm−2. This is in sharp contrast to the interfacial excess of 7 ± 3 nm−2 for molybdenum nitride plates that have grown to 2–10 nm thick (or 20–30 nm in diameter for spheroidal precipitates) with a semicoherent interface with misfit dislocations, as reported earlier. Small coherent Cu‐rich precipitates with a metastable bcc structure in an α‐Fe matrix exhibit interfacial segregation of Ni and Mn at their interfaces with excesses of 1.47 ± 0.43 and 0.95 ± 0.31 nm−2, respectively. Copyright © 2004 John Wiley & Sons, Ltd.
Precipitation of niobium carbides in Fe–C–Nb steel
Authors: Bémont E. , Cadel E. , Maugis P. , Blavette D. 
Published: June 2004

AbstractThe precipitation of carbides in Fe–C–Nb alloy has been investigated using field ion microscopy and atom probe tomography. Analyses show that niobium carbide precipitates already exist in the state quenched from 1240°C. Detailed structural analysis of the states aged at 750°C reveals the existence of two types of niobium carbide precipitates with different concentrations of carbon. In addition, the direction of the habit plane for the matrix/niobium carbide interface has been determined. Copyright © 2004 John Wiley & Sons, Ltd.
Dependence of interfacial excess on the threshold value of the isoconcentration surface
Authors: Yoon Kevin E. , Noebe Ronald D. , Hellman Olof C. , Seidman David N. 
Published: June 2004

AbstractThe proximity histogram (or proxigram for short) is used for analyzing data collected by a three‐dimensional atom probe microscope. The interfacial excess of Re (2.41 ± 0.68 atoms nm−2) is calculated by employing a proxigram in a completely geometrically independent way for γ/γ′ interfaces in René N6, a third‐generation single‐crystal Ni‐based superalloy. A possible dependence of interfacial excess on the variation of the threshold value of an isoconcentration surface is investigated using the data collected for René N6 alloy. It is demonstrated that the dependence of the interfacial excess value on the threshold value of the isoconcentration surface is weak. Copyright © 2004 John Wiley & Sons, Ltd.