bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of nonsteroidal antiinflammatory drugs in water samples using liquid chromatography coupled with diode‐array detector and mass spectrometry
Authors: Debska Jolanta , Kot‐Wasik Agata , Namiesnik Jacek 
Published: November 2005

AbstractAn analytical method for the determination of trace levels of six different nonsteroidal antiinflammatory drugs (NSAIDs) in water samples has been developed and validated. Environmentally relevant pharmaceuticals were chosen according to human consumption in Poland. Final analysis of the target compounds was performed by RP LC–diode‐array detection–MS, whereas sample preparation included an SPE step. For this SPE step, a number of packing materials, such as LiChrolut RP‐18, calixarene, Strata‐X, BAKERBOND Narc‐2, BAKERBOND Polar Plus, BAKERBOND styrene divinylbenzene‐1, and Discovery DSC‐18, were used, and their respective advantages and disadvantages in this study were discussed. The RP‐18 phase was found to be the most retentive for all analytes. The detection limits for compounds in surface waters were varied from 0.005 for diflunisal to 0.095 μg/L for ibuprofen. The average recoveries of NSAIDs from the surface water samples ranged from 80 up to 103%. RSD value is relatively low (from 4% for fenoprofen up to 8% for ibuprofen). The performance of the method was tested with several environmental water samples.
Surface derivatization of poly(p‐phenylene terephthalamide) fiber designed for novel separation and extraction media
Authors: Abe Akira , Saito Yoshihiro , Imaizumi Motohiro , Ogawa Mitsuhiro , Takeichi Tsutomu , Jinno Kiyokatsu 
Published: November 2005

AbstractThe surface derivatization of poly(p‐phenylene terephthalamide) fiber was studied. The obtained surface‐derivatized filaments were packed into a fused‐silica capillary to evaluate its surface characteristics by using GC. As the stationary phase for GC the surface‐derivatized fibers showed higher retention for alkanes and alkylbenzenes than that with the untreated Kevlar fiber. The improvements on the retention power and the peak shape were observed on the benzyl‐modified fibrous stationary phase. The derivatized fibrous materials were also evaluated as the extraction medium in fiber‐in‐tube SPE, and the effect of the surface modification on the extraction power was compared to the parent fiber. The results indicated that the modified fiber possessed a higher extraction power than the untreated fiber. Based on the facts, the successful modification of the fiber surface was estimated.
High extraction efficiency fiber coated with calix[4] open‐chain crown ether for solid‐phase microextraction of polar aromatic and aliphatic compounds
Authors: Liu Mingming , Zeng Zhaorui , Lei Yun , Li Haibing 
Published: November 2005

AbstractThe calix[4] open‐chain crown ether, 5,11,17,23‐tetra‐tert‐butyl‐25,27‐di(2‐allyloxyethoxyl)‐26,28‐dihydroxycalix[4]arene was synthesized and used for preparation of solid‐phase microextraction (SPME) fibers of enhanced extraction efficiency. The new SPME coating made from calix[4] open‐chain crown ether and hydroxyl‐terminated silicone oil was developed with the aid of vinyltriethoxylsilane as bridge using sol–gel method and cross‐linking technology. The efficiency of the novel fiber in the extraction of polar aromatic and aliphatic compounds, such as phenols, alcohols, and volatile fatty acids, was also investigated. Due to the introduction of the polar open‐chain crown ether in calix[4]arene molecules, the calix[4] open‐chain crown ether fiber showed much better selectivity and sensitivity to these polar compounds in comparison with calix[4]arene fiber. It also had superior extraction efficiency when compared to commercial poly(dimethylsiloxane)–divinylbenzene and polyacrylate fibers. Parts per billion to parts per trillion level detection limits were achieved for most of the analytes through SPME in conjunction with GC and flame ionization detector. The linear ranges were two to four orders of magnitude, and the RSD values were below 7% for all analytes. The novel fiber was applied to determine volatile alcohols and fatty acids in wine samples. The volatile‐free wine prepared in this work was used to assure similar chemical environment for analytes in both calibration solutions and in real wine samples, thus compensating for possible matrix interferences. The established internal standard method using 4‐methyl‐2‐pentanol as internal standard showed satisfactory accuracy and precision.
Novel RPLC stationary phases for lipophilicity measurement: Solvatochromic analysis of retention mechanisms for neutral and basic compounds
Authors: Stella Cinzia , Galland Alexandra , Liu Xiangli , Testa Bernard , Rudaz Serge , Veuthey Jean‐Luc , Carrupt Pierre‐Alain 
Published: November 2005

AbstractAn RPLC was developed to rapidly determine lipophilicity of neutral and basic compounds using three base deactivated RPLC stationary phases particularly designed for the analysis of basic compounds, namely, Supelcosil ABZ+Plus, Discovery RP Amide C16, and Zorbax Extend C18. The work consisted of three sets of experiments. In the first log k w values of neutral compounds were extrapolated using hydroorganic mobile phases at different compositions. Good correlation between log k w and log Poct indicated that the method was appropriate for these supports, without adding a silanol masking agent. In the second set of experiments, isocratic log k values of neutral and basic compounds were measured with three different mobile phases. The best estimation of lipophilicity was obtained for neutral and basic compounds when the secondary interactions were strongly reduced (i. e., when basic compounds were under their neutral form). In the third set of experiments, isocratic retention factors of basic compounds (in their neutral form) were measured with a high‐pH mobile phase, on a chemically stable support (Zorbax Extend C18). Under these chromatographic conditions, correlation between the isocratic retention factors and log Poct (log D 10.5) for basic compounds was similar to that for neutral compounds.
Extraction and analysis of different Cannabis samples by headspace solid‐phase microextraction combined with gas chromatography‐mass spectrometry
Authors: Ilias Yara , Rudaz Serge , Mathieu Patrick , Christen Philippe , Veuthey Jean‐Luc 
Published: November 2005

AbstractA headspace solid‐phase microextraction combined with GC‐MS method was developed for the extraction and analysis of cannabinoids from Cannabis samples. Different commercially available fibres were evaluated; polydimethylsiloxane 100 μm was selected as the most efficient one. In order to enhance sensitivity and reduce analysis time, the sampling temperature was studied and it showed that extraction should be performed at a high temperature (150°C). In relation with the high lipophilicity of cannabinoids, a relatively long desorption time (3 min) was necessary to ensure a total transfer from the fibre into the injection port of the gas chromatograph. The method was finally applied to the extraction of Swiss marijuana samples from different regions. Data treatment by principal component analysis and hierarchical cluster analysis allowed a discrimination of the different batches.
Absolute enantioselective separation: Optical activity ex machina
Authors: Bielski Roman , Tencer Michal 
Published: November 2005

AbstractThe paper describes methodology of using three independent macroscopic factors affecting molecular orientation to accomplish separation of a racemic mixture without the presence of any other chiral compounds, i. e., absolute enantioselective separation (AES) which is an extension of a concept of applying these factors to absolute asymmetric synthesis. The three factors may be applied simultaneously or, if their effects can be retained, consecutively. The resulting three mutually orthogonal or near orthogonal directors constitute a true chiral influence and their scalar triple product is the measure of the chirality of the system. AES can be executed in a chromatography‐like microfluidic process in the presence of an electric field. It may be carried out on a chemically modified flat surface, a monolithic polymer column made of a mesoporous material, each having imparted directional properties. Separation parameters were estimated for these media and possible implications for the natural homochirality are discussed.
Simultaneous densitometric determination of artemisinin, artemisinic acid and arteannuin‐B in Artemisia annua using reversed‐phase thin layer chromatography
Authors: Bhandari Pamita , Gupta Ajai P. , Singh Bikram , Kaul Vijay K. 
Published: November 2005

AbstractA rapid and simple RP‐TLC method for simultaneous quantification of pharmacologically important sesquiterpene artemisinin (AM) together with its precursors arteannuin‐B (AB) and artemisinic acid (AA) in the inflorescence part of Artemisia annua plant has been developed. The RP‐TLC of sesquiterpenes was performed on RP‐18 F254 S thin‐layer chromatographic plates by developing in mobile phase, containing 0.2% TFA in water/ACN (35 : 65, v/v). The densitometric determination of AM, AB and AA was carried out after derivatization with anisaldehyde reagent at 426 nm in absorption‐reflectance mode.
Extending the array of crosslinkers suitable for the preparation of polymethacrylate‐based monoliths
Authors: Nordborg Anna , Svec Frantisek , Fréchet Jean M. J. , Irgum Knut 
Published: November 2005

AbstractThe in situ preparation of monolithic capillary columns comprising copolymers of butyl methacrylate with ethylene dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and pentaerythritol tetraacrylate using thermal polymerization within 250 μm ID capillaries and their application for μ‐HPLC separations of proteins has been studied. For all crosslinkers, optimization of the porogenic mixture consisting of 1‐propanol and 1,4‐butanediol yielded monoliths with pore sizes above 1 μm suitable for rapid separations at low back pressure. Very good separations were achieved for a protein mixture consisting of ribonuclease A, cytochrome c, myoglobin, and ovalbumin with all tested columns.
Towards framework for knowledge management implementation
Authors: Shankar Ravi , Gupta Amol 
Published: November 2005

AbstractThe implementation of knowledge management (KM) in an organization involves the integration of knowledge from the domains of strategy, structure, processes, and technology. These domains are generally underpinned—when assimilating roadmaps for holistic KM implementation—with standard KM models in the literature. The pioneering models manifesting the holistic ‘growth’ of knowledge in an organization are generally used to underpin the knowledge‐based segregation of organizational structure. However, some authors take a critical view of such theoretical models, and instead suggest the knowledge process‐based models manifesting the ‘circulation’ of knowledge as being a more practical approach to KM implementation. This paper takes the implementation‐oriented approach further, and modifies and integrates the fundamental aspects of KM advocated in these models resulting in the creation of an integrated KM model that renders a practical framework for the broad knowledge processes across the organization. The essence of the proposed integrated model are the knowledge activities permeating an organization, which are categorized in terms of the cyclic knowledge processes of creation, organization, dissemination, and use of knowledge. These processes traverse the segregated structure of an enterprise.It is suggested that a modified knowledge‐based segregation of enterprise into individual and group, organization, customer interface, and global enterprise be developed based on the cyclic knowledge processes. Further, based on the proposed integrated model, an implementation framework is outlined manifesting the cyclic circulation of knowledge across the organization. Such a framework can provide a link in the KM roadmaps between the abstract categorizations in KM models and the actual implementations using technologies, organizations, and people. Copyright © 2005 John Wiley & Sons, Ltd.
ICTs and knowledge codification: lessons from front office call centers
Authors: Clergeau Cécile 
Published: November 2005

AbstractThis paper investigates human resources management in call centers. Three case studies of call centers focusing on information exchange show that, even if Information and Communications Technologies (ICTs) result in the displacement of the basis of a firm's core competencies from those that may be attributed to individuals to those which may be attributed to a collective, the employees' strengths, customer pressure, environmental competitive pressure, and the specificity of the service production process all exert influences on the organizations so as to limit or even prevent such a collectivization of knowledge. In order to maintain a dynamic process of knowledge management, human resource managers have to re‐equilibrate the basis of the firm's core competencies. In the following paper, we introduce the concept of re‐equilibrating human resource management. It is through this process that management promotes a harmonious dialogue between tacit knowledge and codified knowledge and succeeds in maintaining a dynamic flexibility in skills. Copyright © 2005 John Wiley & Sons, Ltd.
Managing organisations through a process‐based perspective: its challenges and benefits
Authors: Kiraka Ruth N. , Manning Karen 
Published: November 2005

AbstractThe argument presented in this paper is that a process‐based view is useful for identifying good management practices because of its holistic multidimensional view of organisations. A process‐based view involves identifying both the external and internal factors of the organisation's environment that affect processes. With regard to the external environment two forces driving processes are discussed: (1) processes involve responding to the macro‐ and task‐environment influences; (2) processes focus on stakeholder satisfaction. With respect to the internal environment, the relationship between processes and the internal environment is twofold: (1) processes drive or are driven by the strategy of the organisation; (2) processes determine or should determine organisational structure. The theoretical model developed provides a useful tool for managers to consider in their thinking about and planning for their organisations. Copyright © 2005 John Wiley & Sons, Ltd.
Alloying with copper to reduce metal dusting of nickel
Authors: Zhang J. , Cole D.M.I. , Young D.J. 
Published: November 2005

AbstractCopper is thought to be noncatalytic to carbon deposition from gas atmospheres, and owing to its extremely low solubility for carbon, inert to the metal dusting reaction. Thus, the addition of copper to nickel, which forms a near perfect solid solution, may be able to suppress or greatly retard the metal dusting of the alloy, without the need for a protective oxide scale on the surface.The dusting behaviour of Ni‐Cu alloys containing up to 50 wt% Cu, along with pure Cu, was investigated in a 68%CO‐31%H2‐1%H2O gas mixture (aC: 19) at 680°C for up to 150 h. Surface analysis showed that two types of carbon deposits, graphite particle clusters and filaments, were observed on pure Ni and Ni‐Cu alloys with Cu contents of up to 5 wt%. Alloys with more than 10 wt% Cu showed very little coking, forming filaments only. SEM and TEM analyses revealed metal particles encapsulated by graphite shells within the graphite particle clusters, and metal particles at filament tips or embedded along their lengths. A kinetic investigation showed that alloy dusting rates decreased significantly with increasing copper levels up to 10 wt%. At copper concentrations of more than 20 wt%, the rate of metal dusting was negligible. Although pure copper is not catalytic to carbon formation, scattered carbon nanotubes were observed on its surface. The effect of copper on alloy dusting rates is attributed to a dilution effect.
Performance of candidate gas turbine abradeable seal materials in high temperature combustion atmospheres
Authors: Simms N. J. , Norton J. F. , McColvin G. 
Published: November 2005

AbstractThe development of abradeable gas turbine seals for higher temperature duties has been the target of an EU‐funded R&D project, ADSEALS, with the aim of moving towards seals that can withstand surface temperatures as high as ∼ 1100°C for periods of at least 24,000 h. The ADSEALS project has investigated the manufacturing and performance of a number of alternative materials for the traditional honeycomb seal design and novel alternative designs.This paper reports results from two series of exposure tests carried out to evaluate the oxidation performance of the seal structures in combustion gases and under thermal cycling conditions. These investigations formed one part of the evaluation of seal materials that has been carried out within the ADSEALS project.The first series of three tests, carried out for screening purposes, exposed candidate abradeable seal materials to a simulated natural gas combustion environment at temperatures within the range 1050–1150°C in controlled atmosphere furnaces for periods of up to ∼ 2,500 h with fifteen thermal cycles. The samples were thermally cycled to room temperature on a weekly basis to enable the progress of the degradation to be monitored by mass change and visual observation, as well as allowing samples to be exchanged at planned intervals. The honeycombs were manufactured from PM2000 and Haynes 214. The backing plates for the seal constructions were manufactured from Haynes 214. Some seals contained fillers or had been surface treated (e.g. aluminised).The second series of three tests were carried out in a natural gas fired ribbon furnace facility that allowed up to sixty samples of candidate seal structures (including honeycombs, hollow sphere structures and porous ceramics manufactured from an extended range of materials including Aluchrom YHf, PM2Hf, Haynes 230, IN738LC and MarM247) to be exposed simultaneously to a stream of hot combustion gas. In this case the samples were cooled on their rear faces to produce a temperature gradient through the seals and the samples were thermally cycled by switching the natural gas off every three hours. The total exposure period for each test was ∼ 1,000 h, with seal face temperatures of 1000–1180°C.The performance of the materials in these tests was evaluated using visual observations and cross‐sectional examinations using optical and SEM/EDX techniques. The data gathered have included measurements of oxide thickness and metal‐loss on the exposed samples.A wide range of materials performances has been observed in these studies from minimal damage through to total destruction of samples. Overall, this study has shown that there is still a lot of development work required in order to move to higher temperature sealing systems structures in gas turbine applications.
The influence of alloying elements on the corrosion behaviour of ferritic steels in simulated combustion atmospheres
Authors: Sroda S. , Baxter D. , Arponen M. 
Published: November 2005

AbstractThe low‐chromium steels (Cr content 0.7–1.4 wt.%) are usually being used in low temperature boiler applications where the environments are not so aggressive as in waste‐fire boilers. To improve their mechanical properties and corrosion resistance several alloying elements have been used. In the present study the new low‐chromium steels modified with Si, Ni and Ce have been investigated. These steels were compared with the common boiler steel – 2.25Cr1M.The multi‐sample exposure tests were made in moist air (8% O2 + 15% H2O) with and without 200 ppm SO2 or 2000 ppm HCl addition at the isothermal temperature of 500°C. Corrosion products were analysed by Scanning Electron Microscope with Energy Dispersive Spectrometer (SEM/EDS) and XRD techniques. The results of the study show that addition of Ni and Si to the steels studied could improve their corrosion resistance, but only in moist air atmospheres. In SO2‐containing atmospheres the corrosion resistance seems to remain the same, when in HCl‐containing atmospheres Ni and Si additions seem to have a negative effect on the corrosion behaviour. As could by seen from SEM analysis, the scales formed, on the steels with above elements, are more adherent to the metallic core.The cerium was added to the studied materials mainly to improve their mechanical properties. This alloying element seems to increase the corrosion rate of materials, especially in atmospheres containing Cl.
Molten glass corrosion resistance of new. Mo‐Ru‐Si compounds
Authors: Littner A. , François M. , Tobola J. , Elkaim E. , Malaman B. , Vilasi M. 
Published: November 2005

AbstractIn spite of a very promising potential for a large field of high temperature applications, MoSi2 shows only a limited resistance against molten glass corrosion. Efforts to improve the performance of MoSi2‐based materials led to the investigation of the Mo‐Ru‐Si phase diagram. The isothermal section at 1673 K revealed five new intermetallics with original structures. The crystallographic study of two of them was made using standard and synchrotron X‐ray measurements combined with KKR (Korringa‐Kohn‐Rostoker) calculations. The use of such total energy electronic structure calculations was helpful in order to localize accurately Mo and Ru in the new compound β‐Mo26Ru47Si27. This compound crystallizes in P4/mmm space group with a = 9.2164(1) Å, c = 2.88721(1) Å, Dx = 9.69(1) g/cm3. The structure has been refined by the Rietveld method down to Rp = 1.1%, RB = 12.0 %, RF = 8.7% for 6814 observed data and 271 independent reflections. Moreover, electrochemical techniques enabled the determination of the redox properties of the new intermetallic compounds. It has been shown that, in contact with molten glass at 1623 K, Mo‐Ru‐Si compounds were subjected to electrochemical reactions leading to the simultaneous oxidation of silicon and molybdenum. The progressive superficial depletion of Si and Mo resulted in the more or less rapid formation of a thick, porous and low adherent Ru‐layer. Consequently, the results showed that Ru‐additions had no positive effect on the molten glass corrosion resistance of MoSi2‐based materials. The formation of a porous Ru‐layer should even accelerate the degradation kinetics through galvanic coupling occurring between the superficial layer and the bulk material.
Improving metal dusting resistance of. transition‐metals and Ni‐Cu alloys
Authors: Nishiyama Y. , Moriguchi K. , Otsuka N. , Kudo T. 
Published: November 2005

AbstractThe present study focuses on a new technique for the prevention of metal dusting in carbonaceous gas environments at intermediate temperature. Preliminary laboratory metal dusting test was conducted for transition‐metals and Ni‐x%Cu binary alloys in a simulated 60%CO‐26%H2‐11.5%CO2‐2.5%H2O (in vol.%) gas mixture at 650°C for 100 h. The metal dusting caused no coke deposition on transition‐metals of Cu, Ag, and Pt, while those of Fe, Co, and Ni have a large amount of coke and lost mass. Whether or not coking behavior of Ni‐Cu binary alloys formed any oxide scales in the simulated gas environment depended on the Cu content. Specimens containing low Cu were entirely covered with coke and showed rough metal surfaces due to the degradation of metal. Alloys of 20% and more Cu, on the contrary, had no coke deposition and smooth metal surfaces, suggesting alloys with an adequate Cu do not react with CO in the gas mixture without an oxide scale barrier. Based on these results, we conclude that Cu does not protect by formation of the oxide scale but has a “Surfactant‐Mediated Suppression” against metal dusting. This effect can be explained in terms of atomistic interaction of CO with transition‐metal surfaces by electronic structure analyses. The concept can be also useful for the practical material design of Ni‐Cr base alloy with excellent metal dusting resistance.