bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deglacial seasonal and sub‐seasonal diatom record from Palmer Deep, Antarctica
Authors: Maddison Eleanor J. , Pike Jennifer , Leventer Amy , Domack Eugene W. 
Published: July 2005

AbstractThe Antarctic Peninsula is one of the most sensitive regions of Antarctica to climate change. Here, ecological and cryospheric systems respond rapidly to climate fluctuations. A 4.4 m thick laminated diatom ooze deposited during the last deglaciation is examined from a marine sediment core (ODP Site 1098) recovered from Basin I, Palmer Deep, western Antarctic Peninsula. This deglacial laminated interval was deposited directly over a glaciomarine diamict, hence during a globally recognised period of rapid climate change. The ultra‐high‐resolution deglacial record is analysed using SEM backscattered electron imagery and secondary electron imagery. Laminated to thinly bedded orange‐brown diatom ooze (near monogeneric Hyalochaete Chaetoceros spp. resting spores) alternates with blue‐grey terrigenous sediments (open water diatom species). These discrete laminae are interpreted as austral spring and summer signals respectively, with negligible winter deposition. Sub‐seasonal sub‐laminae are observed repeatedly through the summer laminae, suggesting variations in shelf waters throughout the summer. Tidal cycles, high storm intensities and/or intrusion of Circumpolar Deep Water onto the continental shelf introduced conditions which enhanced specific species productivity through the season. Copyright © 2005 John Wiley & Sons, Ltd.
Detection system for electro‐separation analytical methods
Authors: Štohl Radek , Glovinová Eliška , Pospíchal Jan 
Published: July 2005

AbstractThe paper provides information about the on‐line monitoring of components analysed by capillary electrophoresis. For this purposes we developed a whole‐capillary transverse scanning detection system, which helps to improve and control the separation processes. A picture from a colour line scanner was used as a source of basic information for autonomous control of the separation process by regulation of the high voltage source. The application and algorithms for machine vision were designed in the progressive graphic development system LabVIEW. Real‐time control of the separation process was implemented in a compact control process logic controller. The performance of the detection system was evaluated and the function of the overall system was tested by performing isotachophoretic analysis of a model mixture.
Supercritical fluid extraction of isoflavones from biological samples with ultra‐fast high‐performance liquid chromatography/mass spectrometry
Authors: Klejdus Bořivoj , Lojková Lea , Lapčík Oldřich , Koblovská Radka , Moravcová Jitka , Kubáň Vlastimil 
Published: July 2005

AbstractAn efficient method of modifier addition for supercritical fluid extraction (SFE) of polar isoflavones was developed and yielded extraordinarily high recoveries. To find the optimal extraction conditions, a temperature and pressure optimization and modifier impact study was performed in naturally contaminated and spiked samples. Ultra‐fast high‐performance liquid chromatography/mass spectrometry (HPLC/MS) was used for the determination of isoflavones on an AtlantisTM dC18 high‐speed reversed phase chromatographic column (20×2.1 mm, 3 μm particle size). A newly elaborated supercritical fluid extraction (SFE) procedure allowed more accurate (< 5%) and precise (< 4–7%) determination of isoflavones in biological materials. The HPLC/MS method significantly reduced analysis time with simultaneous improvement of sensitivity and detection limits. The on‐column limits of detection LOD (S/N = 3) for isoflavone glycosides (daidzin, genistin, glycitin, ononin, and sissotrin) were 1.3–3.6 fmol and 0.2–1.0 fmol for aglycones (daidzein, glycitein, genistein, formononetin, and biochanin A), respectively.
Enantioselective analysis of cetirizine in pharmaceuticals by cyclodextrin‐mediated capillary electrophoresis
Authors: Mikuš Peter , Valášková Iva , Havránek Emil 
Published: July 2005

AbstractThe present paper demonstrates the potential of cyclodextrin (CD)‐mediated CE for the chiral analysis of a drug of zwitterionic nature, viz. cetirizine (CET). Various separation mechanisms were applied and several parameters affecting the separation were studied, including the type and concentration of chiral selector, coselector, and carrier ion, and pH of buffer. The optimal separation conditions were based on a medium buffer pH (≈5.2) (migration velocity of CET molecule was near to zero) and a highly substituted CD derivative, sulfated‐β‐CD, serving as an analyte carrier in the anionic regime of the separation with suppressed electroosmotic flow. In this way, a baseline enantioseparation, reasonable separation efficiency, and short analysis time could be easily achieved. Acceptable validation criteria for sensitivity, linearity, precision, accuracy, and robustness were obtained using a hydrodynamically closed CE separation system. The proposed method was successfully applied to the enantioselective assay of CET in pharmaceutical formulations using fexofenadine (FEX) as an internal standard.
Simultaneous Ionic and Electronic Conductivity in Polymeric Materials
Authors: Costantini Nicola , Wegner Gerhard , Mierzwa Michal , Pakula Tadeusz 
Published: July 2005

AbstractSummary: Pyrrole and 3‐(3,6‐dioxaheptyl)pyrrole were polymerized in the presence of an oligo(oxyethylene monomethylether) sulfonate (DPPEO = 17) with ammonium peroxydisulfate as an oxidizing agent and dry chloroform as a solvent. The oligo(oxyethylene) sulfonate acted as a phase transfer agent and also became incorporated into the polymer as a counter ion. The polymers were obtained as gel‐like particles that could be easily dispersed in organic solvent and could be doped with lithium triflate to enhance the ionic conductivity of the electronically conductive materials. DSC and X‐ray measurements showed a glass transition (Tg) in all samples at around −40 °C which is related to the dynamics of the EO segments. In addition, the system composed of polypyrrole with oligo(oxyethylene) sulfonate counter ions showed partial crystallinity and a melting transition at 34 °C. Conductivity was explored by impedance spectroscopy with regard to frequency and temperature dependence. The data could be evaluated in the coordinates of an Arrhenius plot as the sum of two Arrhenius functions in all cases. Although one Arrhenius‐type function was sufficient to describe the temperature profile of the conductivity below Tg, a second term needed to be added at T > Tg. The absolute values of conductivity were also dependent on the level of doping with lithium triflate. These phenomena were interpreted as a contribution of ionic conductivity by the lithium ions to the electronic conductivity, which comes about from the oxidation state of the polypyrrole backbone.A good Li‐ion conducting polymer which also exhibits electronic conductivity.magnified imageA good Li‐ion conducting polymer which also exhibits electronic conductivity.
Polymethacrylate Copolymers Containing 4,5‐Dicyanoimidazole‐Based Chromophores and their Nonlinear Optical Behavior
Authors: Carella Antonio , Centore Roberto , Riccio Pierluigi , Sirigu Augusto , Quatela Alessia , Palazzesi Christian , Casalboni Mauro 
Published: July 2005

AbstractSummary: Two series of methacrylate copolymers were prepared, based on two new nonlinear optically (NLO) active chromophores 2‐[4‐(N‐methacryloyloxyethyl‐N‐methylamino)phenylazo]‐4,5‐dicyanoimidazole (chromophore A) and 1‐ethyl‐2‐[4‐(N‐methacryloyloxyethyl‐N‐methylamino)phenylazo]‐4,5‐dicyanoimidazole (chromophore B). Second order NLO properties of the two series of copolymers (A or B as monomer and methyl methacrylate as the comonomer) were investigated by SHG procedures at the fundamental wavelength 1368 nm; d33 values in the range 0.2–3.3 pm · V−1 were obtained, depending on the chromophore and on its molar content. The dependence of d33 on the molar content of chromophore was investigated in the two cases.
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Low‐Rate Propylene Slurry Polymerization: Morphology and Kinetics
Authors: Pimplapure Makarand S. , Zheng Xuejing , Loos Joachim , Weickert Günter 
Published: July 2005

AbstractSummary: “True” initial polymerization rates can be calculated from the adiabatic temperature rise under isoperibolic conditions. They are much higher than initial polymerization rates measured by standard mass flow meter methods under quasi‐steady‐state conditions. These high initial rates are followed by a fast apparent deactivation (“attenuation”) until a constant (“plateau”) activity is reached at low polymerization yields of 2–3 g PP · (g catalyst)−1 caused by an “increasing degree of encapsulation” of active sites. Mass transfer limitations are not observed. Cross sectional SEM images of the polymer samples support these kinetic findings.Rate of polymerization (g of PP · (g catalyst)−1 · h−1) and yield of polymerization (g of PP · (g catalyst)−1) as function of time.magnified imageRate of polymerization (g of PP · (g catalyst)−1 · h−1) and yield of polymerization (g of PP · (g catalyst)−1) as function of time.
Polymer‐Grafted Carbon Spheres by Surface‐Initiated Atom Transfer Radical Polymerization
Authors: Jin Yi Zheng , Gao Chao , Kroto Harold W. , Maekawa Toru 
Published: July 2005

AbstractSummary: In situ atom transfer radical polymerization techniques have been used to produce polymer‐grafted carbon spheres (CSs). The surfaces of as‐prepared CSs were functionalized in the presence of CS‐supported macroinitiators. The resulting materials were characterized by FTIR and NMR spectroscopy, TGA, SEM, TEM, and HRTEM. The amount of polymer grafted onto the surfaces of the spheres can be controlled by varying the monomer/initiator feed ratio. The wetting ability and dispersibility of the polymer‐grafted CSs were improved significantly, compared with crude CSs, enabling stable dispersions in organic solvents to be produced. SEM and TEM studies indicate that a uniform distribution of the carbon spheres in the continuous polymer phase can be produced.SEM image (left) of poly(glycerol monomethacrylate) grafted carbon spheres, inset shows the structure. HRTEM image (right) of a polystyrene grafted carbon sphere, inset is the SAED pattern.magnified imageSEM image (left) of poly(glycerol monomethacrylate) grafted carbon spheres, inset shows the structure. HRTEM image (right) of a polystyrene grafted carbon sphere, inset is the SAED pattern.
Shape of Micelles Formed From Strongly Adsorbed Grafted Polymers in Poor Solvents
Authors: Pattanayek Sudip K. , Pereira Gerald G. 
Published: July 2005

AbstractSummary: We consider the shape of strongly adsorbed polymer chains in poor solvents. Using both SCF theory and Monte Carlo simulations, we find these chains undergo an instability which is driven, surprisingly, by polymer entropy. This instability occurs above some critical grafting separation and the intermediate segregation regime. An analytical calculation also suggests that this instability occurs for strongly adsorbed polymer chains. We proceed to study multi‐chain systems and observe a number of novel morphological structures including circular polymer droplets, lamellae and a polymer layer with a solvent‐filled hole.Shape of strongly adsorbed multi‐chain polymer globules.magnified imageShape of strongly adsorbed multi‐chain polymer globules.
Proxy reports in Parkinson's disease: Caregiver and patient self‐reports of quality of life and physical activity
Authors: Fleming Allison , Cook Karon F. , Nelson Naomi D. , Lai Eugene C. 
Published: July 2005

AbstractWe evaluated patient–proxy agreement in a population of veterans with Parkinson's disease and compared levels of agreement by patient subgroups. Patient and caregiver pairs completed questionnaires composed of standard measures and additional demographic and activity questions. Participants completed the Center for Epidemiologic Studies Depression Scale (CES‐D), the PD Questionnaire 39 (PDQ‐39), and three questions regarding physical activity. Caregivers completed proxy forms of the PDQ‐39 and the physical activity questionnaire. The proxy forms asked caregivers to choose the answers that best described their “friend's/patient's situation.” The results of our comparison of patient and proxy reports of quality of life were consistent with findings in other diseases. On average, proxies rated patient disability higher and quality of life lower than did patients. However, our comparison of patient and proxy reports of frequency of exercise diverged from previously published work. Less agreement was observed between patient and proxy reports of physical activity, even though this is a more objective variable than are the domains measured by the PDQ‐39. Proxy reports may diverge appreciably from patient self‐reports. These differences should be considered in research design and clinical decision making. Alternative approaches to the measurement of patient relevant outcomes could supplement traditional, retrospective self‐reports. © 2005 Movement Disorder Society
Numerical analysis of a model for an axisymmetric guide for electromagnetic waves Part I: the continuous problem and its Fourier expansion
Authors: Belgacem Faker Ben , Bernardi Christine , Rapetti Francesca 
Published: July 2005

AbstractSUMMARYAs a first model for an electromagnetic wave guide, we consider Maxwell's system in a three‐ dimensional axisymmetric domain provided with appropriate boundary conditions on different parts of the boundary. We check the well‐posedness of the corresponding variational problem. We write the Fourier expansion of the solution as a function of the angular variable and derive the well‐posedness of the two‐dimensional problems satisfied by each Fourier coefficient. The first step for approximating the three‐dimensional solution relies on Fourier truncation, and we prove optimal estimates for the error issued from this truncation. Copyright © 2005 John Wiley & Sons, Ltd.
Cobalt(II) octanoate and cobalt(II) perfluorooctanoate catalyzed atom transfer radical polymerization of styrene in toluene and fluorous media—A versatile route to catalyst recycling and oligomer formation
Authors: Weiser Marc‐Stephan , Mülhaupt Rolf 
Published: July 2005

AbstractCobalt(II) perfluorooctanoate‐catalyzed atom transfer radical polymerization (ATRP) and reverse ATRP were developed to prepare oligostyrenes (Mn < 2500) with low polydispersities Mw/Mn < 1.5. Fluorous biphase catalysis was applied for effective recycling of catalyst and fluorous solvent. The homogeneous polymerization reaction was performed at 90 °C in toluene/cyclohexane/perfluorodecalin mixture (1:1:1) and fluorine‐free solvents. Temperature‐induced phase separation of this fluorous solvent mixture occurred at room temperature and proved to be the key for the very effective separation of the cobalt(II) perfluorooctanoate from the oligostyrene and fluorine‐free solvents. Both the fluorine‐tagged cobalt catalysts and the fluorous media were recycled and reused up to three times without encountering catalyst activity losses. The roles of cobalt catalysts, fluorous media, and monomer/initiator ratio were examined with respect to the polymerization kinetics. Fluorine‐containing and fluorine‐free cobalt(II) octanoate catalyzed controlled styrene oligomerization according to the ATRP mechanism. The molar mass control range was limited in fluorous biphase catalysis most likely because of precipitation of high molar mass polystyrenes in the fluorous reaction medium. To the best of our knowledge, this is the first time temperature‐induced phase separation of fluorous and fluorine‐free solvents has been successfully applied to polymerization processing. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3804–3813, 2005
Hydrogen‐bond‐assisted stereocontrol in the radical polymerization of N‐isopropylacrylamide with secondary alkyl phosphate: The effect of the bulkiness of the ester group
Authors: Hirano Tomohiro , Kitajima Hiroko , Ishii Satoshi , Seno Makiko , Sato Tsuneyuki 
Published: July 2005

AbstractThe radical polymerization of N‐isopropylacrylamide (NIPAAm) in toluene at low temperatures was investigated in the presence of triisopropyl phosphate (TiPP). The addition of TiPP induced a syndiotactic specificity that was enhanced by the polymerization temperature being lowered, whereas atactic polymers were obtained in the absence of TiPP, regardless of the temperature. Syndiotactic‐rich poly(NIPAAm) with a racemo dyad content of 65% was obtained at −60 °C with a fourfold amount of TiPP, but almost atactic poly(NIPAAm)s were obtained by the temperature being lowered to −80 °C. This result contrasted with the result in the presence of primary alkyl phosphates, such as tri‐n‐propyl phosphate: the stereospecificity varied from syndiotactic to isotactic as the polymerization temperature was lowered. NMR analysis at −80 °C revealed that TiPP predominantly formed a 1:1 complex with NIPAAm, although primary alkyl phosphates preferentially formed a 1:2 complex with NIPAAm. Thus, it was concluded that a slight increase in the bulkiness of the added phosphates influenced the stoichiometry of the NIPAAm–phosphate complex at lower temperatures, and consequently a drastic change in the effect on the stereospecificity of NIPAAm polymerization was observed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3899–3908, 2005
Large LNG fire thermal radiation—modeling issues and hazard criteria revisited
Authors: Raj Phani K. 
Published: July 2005

AbstractCurrent models for evaluating the exclusion (hazard) zones around liquefied natural gas (LNG) fires in both U.S. Regulations and NFPA‐59A standard are prescriptive and require the consideration of large LNG releases. These models do not consider the effects of the combustion dynamics associated with large‐size pool burning. Oxygen starvation in the core of LNG fires of diameters ≳ 35 m leads to the formation of nonluminous, cold soot (smoke) resulting in a reduction of thermal energy radiated by the fire to the surroundings. The net effect is smaller (calculated) thermal hazard distances for exposure to people (by factors of 2 or 3 compared to results ignoring this phenomenon). Available large‐scale LNG fire test information is reviewed to quantify the effect of this phenomenon. This paper also discusses the common mistakes made in calculating the thermal radiation hazard distances around large fires by using, for the energy radiated from the fire, a constant percentage of energy generated by combustion. The criteria for setting thermal radiation hazard zones around large hydrocarbon fires are also reviewed. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2005
Monitoring Infrequent Failures of High‐volume Production Processes
Authors: Di Bucchianico A. , Mooiweer G. D. , Moonen E. J. G. 
Published: July 2005

AbstractWe present a case study in monitoring a high‐volume production process with a high yield. Testing the products is difficult and is only possible in a destructive way with a defect/no‐defect result. We review several attribute charting procedures for high‐yield processes. It turns out that monitoring the number of conforming items between the occurrence of non‐conforming items is appropriate. We discuss several implementation aspects of CCCr charts in our case study. The implementation is based on a new formula for the standard deviation of the number of inspected items before a signal. Copyright © 2005 John Wiley & Sons, Ltd.
The Circular Safety Region: a Useful Graphical Tool in Capability Analysis
Authors: Vännman Kerstin 
Published: July 2005

AbstractWhen measuring the capability of a manufacturing process some form of process capability index is often used. To assess the capability, using a random sample, confidence intervals or hypothesis tests on the index are frequently used. Here, an alternative approach is presented. A process is usually defined to be capable if the capability index exceeds a stated threshold value, e.g. Cpm > $4\over 3$. This inequality can be expressed graphically as a region in the plane defined by the process parameters (μ, σ). This graphical region, or safety region, similar to a confidence region for (μ, σ), can be plotted to test for capability. Under the assumption of normality a circular safety region for the capability index Cpm is constructed that can be used to draw conclusions about the capability at a given significance level. This simple graphical approach is helpful when trying to understand if it is the variability, the deviation from target or both that need to be reduced to improve the capability. Using circular regions several characteristics can be monitored in the same plot. Copyright © 2005 John Wiley & Sons, Ltd.
Electronic Fock spaces: Phase prefactors and new algebraic structure
Authors: Panin A. I. 
Published: July 2005

AbstractAn efficient technique of manipulation with phase prefactors in electronic Fock spaces is developed. Its power is demonstrated in an example of both relatively simple classic configuration interaction matrix element evaluation and an essentially more complicated coupled cluster case. Interpretation of coupled cluster theory in terms of a certain commutative algebra is given. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Modelling the spread of penicillin‐resistant Streptococcus pneumoniae in day‐care and evaluation of intervention
Authors: Andersson Mikael , Ekdahl Karl , Mölstad Sigvard , Persson Kristina , Hansson Hans Bertil , Giesecke Johan 
Published: July 2005

AbstractIn 1995, a disease control and intervention project was initiated in Malmöhus county in southern Sweden to limit the spread of penicillin‐resistant pneumococci. Since most of the carriers of pneumococci are preschool children, and since most of the spread is believed to take place in day‐care, a mathematical model, in the form of a stochastic process, for the spread in a day‐care group was constructed. Effects of seasonal variation and size of the day‐care group were particularly considered. The model was then used for comparing results from computer simulations without and with intervention. Results indicate that intervention is highly effective in day‐care groups with more than ten children during the second half of the year. Copyright © 2005 John Wiley & Sons, Ltd.
Continuous Bayesian adaptive randomization based on event times with covariates
Authors: Cheung Ying Kuen , Inoue Lurdes Y. T. , Wathen J. Kyle , Thall Peter F. 
Published: July 2005

AbstractIn comparative clinical trials, the randomization probabilities may be unbalanced adaptively by utilizing the interim data available at each patient's entry time to favour the treatment or treatments having comparatively superior outcomes. This is ethically appealing because, on average, more patients are assigned to the more successful treatments. Consequently, physicians are more likely to enrol patients onto trials where the randomization is outcome‐adaptive rather than balanced in the conventional manner. Outcome‐adaptive methods based on a binary variable may be applied by reducing an event time to the indicator of the event's occurrence within a predetermined time interval. This results in a loss of information, however, since it ignores the censoring times of patients who have not experienced the event but whose evaluation interval is not complete. This paper proposes and compares exact and approximate Bayesian outcome‐adaptive randomization procedures based on time‐to‐event outcomes. The procedures account for baseline prognostic covariates, and they may be applied continuously over the course of the trial. We illustrate these methods by application to a phase II selection trial in acute leukaemia. A simulation study in the context of this trial is presented. Copyright © 2005 John Wiley & Sons, Ltd.