bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel sugar‐based gemini surfactants: aggregation properties in aqueous solution
Authors: Johnsson Markus , Engberts Jan B. F. N. 
Published: October 2004

AbstractGemini or dimeric surfactants can in principle be viewed as two conventional surfactants connected via a spacer at the level of the polar headgroups. A novel class of sugar‐based gemini surfactants with rich and intriguing aggregation behavior in aqueous solution is the focus of this mini‐review. The headgroup of the geminis consists of reduced sugars (glucose or mannose) connected to tertiary amines or amides. The alkyl tails have been varied in terms of tail length and degree of unsaturation. The spacers used are aliphatic [(CH2)n] spacers of varying length or short ethylene oxide (EO) spacers [(CH2)2(EO)2]. By manipulating the molecular architecture and the solution conditions, a variety of supramolecular aggregates, such as vesicles and micelles, are formed from these sugar‐based surfactants. In particular, the sugar‐based gemini surfactants containing tertiary amines in the headgroup respond to the solution pH by forming vesicles in the monoprotonated state and micellar structures in the diprotonated (full protonation) state. The overall aggregation behavior is described well by conventional theories on surfactant aggregation, however, a surprising vesicle surface charge reversal as a function of pH will be described and discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Kinetics and thermodynamics of C—Cl bond activation by [Ir(CO)2Cl2]−
Authors: Vickers Paul W. , Pearson Jean M. , Ghaffar Talit , Adams Harry , Haynes Anthony 
Published: October 2004

AbstractKinetic measurements are reported for the oxidative addition reactions of methyl chloride and acetyl chloride with [Ir(CO)2Cl2]−. At 40°C the second‐order rate constant for MeCOCl addition is estimated to be nearly 40 000 times larger than that for MeCl addition. The Ir(III) products, [Ir(CO)2Cl3R]− (R = Me, COMe) have been isolated and characterised by spectroscopy and x‐ray crystallography. In the absence of excess organic chloride, both Ir(III) complexes undergo reductive elimination of RCl. Kinetic measurements show these reactions to be first order in the Ir(III) complex with elimination of MeCOCl estimated to be ca 7000 times faster than MeCl elimination at 40°C. Combination of activation parameters for the forward and reverse reactions allows calculation of thermodynamic parameters for oxidative addition. Both MeCl and MeCOCl additions are exothermic (by 44 and 68 kJ mol−1, respectively) but disfavoured entropically. The trends are predicted satisfactorily by ab initio and DFT computational methods. The results for MeCl addition to [Ir(CO)2Cl2]− are compared with data for MeI addition to [Ir(CO)2I2]−. Kinetic data are also reported for carbonylation of [Ir(CO)2Cl3Me]− into [Ir(CO)2Cl3(COMe)]− under mild conditions in PhCl–MeOH. It is concluded that the low activity of iridium–chloride carbonylation catalysts is due primarily to the relatively slow reaction of [Ir(CO)2Cl2]− with MeCl. Copyright © 2004 John Wiley & Sons, Ltd.
Addition of benzyne to thiophene—a DFT study
Authors: Smith William B. 
Published: October 2004

AbstractThe literature reports the 2 + 2‐ and 4 + 2‐cycloadditions of benzyne and thiophene and provides several reaction paths accounting for the observed products: 1‐naphthyl and 2‐naphthyl phenyl sulfides. A DFT study of these paths shows that some presumed reaction intermediates are, in fact, not stable entities. A new reaction path adapting a portion of the literature paths but with a lower activation free energy is described. Copyright © 2004 John Wiley & Sons, Ltd.
Initiation and kinetics of thiol–ene photopolymerizations without photoinitiators
Authors: Cramer Neil B. , Reddy Sirish K. , Cole Michael , Hoyle Charles , Bowman Christopher N. 
Published: October 2004

AbstractThiol–ene photopolymerizations without added photoinitiators were studied, and the kinetics accurately predicted by modeling for a wide range of different vinyl chemistries. Initiation rates in polymerizations initiated with light centered around 365 nm were found to be proportional to the concentration of ene functional groups. When 254 nm light was used as the initiating light source, initiation rates were proportional to the concentration of thiol functional groups. The mechanism of initiation at 254 nm was attributed to direct cleavage of thiol functional groups. An appropriate species or mechanism has not yet been found that is consistent with the experimental data for initiation when 365 nm light is used. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5817–5826, 2004
C. Teng, K. Yang, P. Ji, and M. Yu, "Synthesis and characterization of poly(L‐lactic acid)‐poly(ε‐caprolactone) multiblock copolymers by melt polycondensation," J. Polym. Sci. Part A: Polym. Chem. (2004) 42(20) 5045–5053
Authors: Teng Cuiqing , Yang Kai , Ji Ping , Yu Muhuo 
Published: October 2004

AbstractThe original article to which this Erratum refers was published in J. Polym. Sci. Part A: Polym. Chem. (2004) 42(20) 5045–5053No abstract.
Behavior and surface energies of polybenzoxazines formed by polymerization with argon, oxygen, and hydrogen plasmas
Authors: Chen Jem‐Kun , Lin I‐Kuan , Ko Fu‐Hsiang , Huang Chih‐Feng , Chen Kuo‐Shen , Chan Chia‐Hao , Chang Feng‐Chih 
Published: October 2004

AbstractPolybenzoxazine (PBZZ) thin films can be fabricated by the plasma‐polymerization technique with, as the energy source, plasmas of argon, oxygen, or hydrogen atoms and ions. When benzoxazine (BZZ) films are polymerized through the use of high‐energy argon atoms, electronegative oxygen atoms, or excited hydrogen atoms, the PBZZ films that form possess different properties and morphologies in their surfaces. High‐energy argon atoms provide a thermodynamic factor to initiate the ring‐opening polymerization of BZZ and result in the polymer surface having a grid‐like structure. The ring‐opening polymerization of the BZZ film that is initiated by cationic species such as oxygen atoms in plasma, is propagated around nodule structures to form the PBZZ. The excited hydrogen atom plasma initiates both polymerization and decomposition reactions simultaneously in the BZZ film and results in the formation of a porous structure on the PBZZ surface. We evaluated the surface energies of the PBZZ films polymerized by the action of these three plasmas by measuring the contact angles of diiodomethane and water droplets. The surface roughness of the films range from 0.5 to 26 nm, depending on the type of carrier gas and the plasma‐polymerization time. By estimating changes in thickness, we found that the PBZZ film synthesized by the oxygen plasma‐polymerization process undergoes the slowest rate of etching in CF4 plasma. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 4063–4074, 2004
Light Scattering by Cylindrical Fibers with High Aspect Ratio Using the Null‐Field Method with Discrete Sources
Authors: Pulbere Sorin , Wriedt Thomas 
Published: October 2004

AbstractThe problem of computing light scattering by cylindrical fibers with high aspect ratio in the framework of the Null‐Field method with discrete sources is treated. Numerical experiments for investigating the scattering properties of two fiber geometries are performed using distributed spherical vector wave functions as discrete sources.
Influence of Particle Morphology and Flow Conditions on the Dispersion Behavior of Fumed Silica in Silicone Polymers
Authors: Boyle John , Manas‐Zloczower Ica , Feke Donald L. 
Published: October 2004

AbstractThe dispersion behavior of agglomerates of several grades of fumed silica in poly(dimethyl siloxane) liquids has been studied as a function of particle morphology and applied flow conditions. The effects of primary particle size and aggregate density and structure on cohesivity were probed through tensile and shear strength tests on particle compacts. These cohesivity tests indicated that the shear strength of particle compacts was two orders of magnitude higher than the tensile strength at the same overall packing density.
Experiments carried out in both steady and time‐varying simple‐shear flows indicate that dispersion occurs through tensile failure. In the steady‐shear experiments,enhanced dispersion was obtained at higher levels of applied stress and, at comparable levels of applied stress, dispersion was found to proceed faster at higher shear rates. Experiments conducted in time‐varying flows further corroborated the results obtained in tensile cohesivity tests. Experiments in which the mean and maximum stresses in the time‐varying flows were matched to the stresses produced in steady shear flows highlight the influence of flow dynamics on dispersion behavior.
Mean Particle Diameters. Part IV: Empirical Selection of the Proper Type of Mean Particle Diameter Describing a Product or Material Property
Authors: Alderliesten Maarten 
Published: October 2004

AbstractMean particle diameters may be used to describe and to model physical, chemical or physiological properties of products or materials containing dispersed phases. An empirical method was developed to select the proper type of mean diameter from experimental data, if this mean diameter is not known a priori from theoretical reasoning. The present method uses mean diameters, D̄p, q, defined according to the Moment‐Ratio (M‐R) definition system. They are expressed as the 1/(p‐q)‐th power of the ratio of the p‐th and the q‐th raw moment of the number density distribution of the particle sizes. After calculation of the mean diameters, D̄p, q, the relationships between the product property and these mean diameters are investigated statistically. The selection method has been illustrated by four examples, three of which stem from a high shear granulation experiment in the field of detergent processing. The fourth example is concerned with a visual ranking of bubble size distributions of chocolate mousse samples. The data set of each example consists of a set of particle size distributions and the corresponding physical product properties that are influenced by the particle sizes. Hypotheses are formulated to explain the types of selected mean diameters. Application of the selection method gives mean diameters, D̄p, q, a clear physical look and identity, replacing their anonymity. Sharing worldwide results of applications of the newly developed selection method, will lead to a build‐up of knowledge of physical meanings and application areas for the types of the mean particle diameters. This will support decision‐making in product development. The examples used to develop the selection method clearly demonstrate the physical relevance of the previously developed nomenclature system for mean particle diameters, D̄p, q.
On‐line Determination of Aggregate Size and Morphology in Suspensions
Authors: Gruy Frédéric , Cournil Michel 
Published: October 2004

AbstractInformation concerning the aggregation state of fine solid particles is an important element for process control and monitoring of product quality in many applications of industrial slurries. This work deals with the application of different in‐line methods to the characterization of silica aggregate size and morphology. All of these methods exploit turbidity signals, obtained by various means including: from analysis of turbidity fluctuations in homogeneous suspension and from overall turbidity decrease during particle settling. This work also presents the opportunity to report progress in morphological and optical models of small aggregates. As a result of these models, the morphological characteristics of the aggregates along with the number of their constituting particles are derived from experimental results. Similarities between the different methods are examined and discussed.
Identification of Regions with Inhomogeneous Particle Behavior in Dilute Gas‐solid Flows
Authors: Grüner Christof , Kanther Wolfgang , Götz Sören , Strauß Karl 
Published: October 2004

AbstractThe behavior of the particulate phase in a highly turbulent gas flow has been investigated in a vertical channel. Variations of the flow configuration (1. Flow past a cylinder, 2. flow past a wall‐mounted obstacle and 3. flow around a horizontally injected jet) have been subject to both experiments and numerical simulations.
The velocity vector field of the solid phase has been measured by digital particle image velocimetry (DPIV). The measurements have been focused on particle‐obstacle collisions and crossflow in the vicinity of the jet nozzle using the lately developed twinpeak detection method. By application of this method regions of highly inhomogeneous particle behavior could be detected mainly upstream of the flow perturbation. Numerical results have been obtained by an Eulerian‐Lagrangian method on boundary‐fitted grids. Particle‐particle interactions as well as interphase exchange of momentum have been taken into account. The simulation results showed to be well in accordance with the experimental results.
Synthesis and insecticidal activities of novel oxime ether pyrethroids
Authors: Liu Aiping , Ou Xiaoming , Huang Mingzhi , Wang Xiaoguang , Liu Xingping , Wang Yongjiang , Chen Can , Yao Jianren 
Published: October 2004

AbstractA series of novel 2‐methylthio‐3′/4′‐substituted acetophenone oxime O‐ethers were synthesized by the reaction of the corresponding acetophenone oximes with halides of pyrethroid alcohols in the presence of sodium hydroxide and phase‐transfer catalysis or with triethyl quaternary ammonium salts of halides of pyrethroid alcohols in the presence of sodium hydroxide. These compounds showed notable insecticidal activity against Homopteran and Lepidopteran pests. 2‐Methylthio‐4′‐fluoroacetophenone oxime O‐[(2‐methylbiphenyl‐3‐yl)methyl] ether was more effective than the commercial insecticides chlorfenapyr and fenvalerate. Copyright © 2004 Society of Chemical Industry
Effectiveness of allyl acetate as a fumigant against five stored grain beetle pests
Authors: Rajendran Somiahnadar , Muralidharan Narasimhan 
Published: October 2004

AbstractFive esters, butyl acetate, allyl acetate, ethyl acetoacetate, isopropyl acetate and propyl acetate, were screened as fumigants in the laboratory for 24 h at 27 (±2) °C against the adults of Rhyzopertha dominica (F), Sitophilus oryzae (L) and Tribolium castaneum (Herbst). Of the compounds tested, allyl acetate was the most toxic, with LD99 values of 7.56, 12.81 and 11.42 mg litre−1 against R dominica, S oryzae and T castaneum, respectively. Tests with allyl acetate against mixed‐age cultures of Cryptolestes ferrugineus (Stephens), Oryzaephilus surinamensis (L), R dominica, S oryzae and T castaneum revealed that doses of 50–150 mg litre−1 with 24–120‐h exposures were necessary to achieve 100% mortality of all life stages. Cryptolestes ferrugineus was the most tolerant insect tested, whilst R dominica was highly susceptible. The insect toxicity data indicates that allyl acetate has potential as a fumigant of stored food grains. Copyright © 2004 Society of Chemical Industry
Measured and computed volatilisation of the fungicide fenpropimorph from a sugar beet crop
Authors: Leistra Minze , Smelt Johan H , van den Berg Frederik 
Published: October 2004

AbstractDepending on their vapour pressure, volatilisation can be one of the main pathways of emission of pesticides into the environment. The volatilisation of fenpropimorph was studied in a field experiment in which the fungicide was sprayed onto a sugar beet crop. Volatilisation rates were calculated by measuring the concentration gradient in air, using the Aerodynamic and Bowen Ratio methods. A simplified computation model was used to simulate pesticide volatilisation, together with the concurrent processes of penetration into the plant leaves and phototransformation. Input data for the model had already been obtained by carrying out a wind‐tunnel study with fenpropimorph, whereby field conditions were imitated. The computations yielded a reasonable description of the level and rate of decline of fenpropimorph volatilisation in the first 4 h after spraying. The continued volatilisation 2 and 3 days after spraying could be described by assuming that a fraction of the deposit was poorly exposed with comparatively low rates of the decline processes. In the first 3 days, penetration of fenpropimorph into the plant leaves was computed to be the main route for the pesticide (52% of the dosage), with substantial contributions from volatilisation (12%) and phototransformation (11%). The computation model can be developed further as a tool for extrapolating results on volatilisation from small‐scale experiments to field conditions, but this requires more information on the effect of environmental conditions on the model parameters. Copyright © 2004 Society of Chemical Industry
A task‐independent control method for spoken dialogs
Authors: Oku Tomoki , Nishimoto Takuya , Araki Masahiro , Niimi Yasuhisa 
Published: October 2004

AbstractIn this paper the authors propose a task‐independent control method for spoken dialogs. This is an expansion of the frame‐driven dialog control method used in text‐based dialog systems, which employs knowledge specific for a task using a database and frames. The frame consists of a set of related topics that can be treated in specific tasks, the priority ranking, and the behavior of the system when each topic is completed. When there is a hierarchical relationship among topics, this is described as a hierarchical relationship among frames. The dialog history is represented by the topic frame using a tree structure that can provide dynamic links (this is called a dynamic topic tree). System‐initiative and user‐initiative dialog can be accomplished by searching the dynamic topic tree using two types of approaches. The authors created a spoken dialog system for four typical tasks and performed spoken dialog experiments in order to evaluate the system. The results showed that all subjects were able to complete the tasks. This demonstrates that the authors' method is valid as a way to create a practical task‐independent spoken dialog system. © 2004 Wiley Periodicals, Inc. Syst Comp Jpn, 35(14): 87–95, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10589
SVM that maximizes the margin in the input space
Authors: Akaho Shotaro 
Published: October 2004

AbstractWhile the original SVM seeks the discriminative plane that maximizes the margin in the feature space (the Hilbert space), this paper investigates the framework that maximizes the margin in the input space. This framework is considered to be effective for cases in which a priori knowledge is embedded as input space estimates. In the approach taken in this paper, approximating the margin in the input space by Taylor expansion is essential. The algorithm obtained is a kind of alternating optimization comprising the step of obtaining projections onto the discriminative plane from sample points by Newton's method and the step of determining parameters of the discriminative plane by convex quadratic programming. The algorithm converges to a stably local optimal solution under comparatively lenient conditions. In addition, the optimization problem to be solved includes the original SVM as a special case. However, since the amount of computation increases as the dimensions of the input space increase in the proposed algorithm, this paper proposes a simplified algorithm obtained by combining the original SVM and the abridged proposed algorithm. © 2004 Wiley Periodicals, Inc. Syst Comp Jpn, 35(14): 78–86, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10631
Mutual region growing for adaptive segmentation of geographical images
Authors: Mikami Naoto , Kosugi Yukio 
Published: October 2004

AbstractIn this paper we propose a new technique of mutual region growing for solving land‐cover sorting problems. Land‐cover classification subdivides regions of aerial photographs and satellite photographic images into distinct regions, and automation is required for large‐scale investigations. In the conventional division method and region growing scheme used for classification without tutorial data, the processing algorithm is simple. However, much labor is required to find the appropriate processing rules, depending on the type of images. In this study, we propose a method of region growing using the structural features of adjacent pixels in the tutorial image, while also utilizing the features of region growing which organize regions with identical properties.In our new method, we aim at flexibly acquiring classification rules by referring to the classification results for the tutorial data. We propose a region growing method in which region growing is performed in the tutorial image by using characteristics based on the neighboring structures of the pixel under consideration. In this technique, the features of the region to be classified in the tutorial image are expressed in the output image by using an agreement index. This index can be obtained by comparing the image structures of the input image and the tutorial image. We also attempt to speed up processing by rearranging the image structure in the teacher image, using a statistical technique. © 2004 Wiley Periodicals, Inc. Syst Comp Jpn, 35(14): 64–77, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10688
Musex: A system for supporting children's collaborative learning in a museum with PDAs
Authors: Yatani Koji , Onuma Mayumi , Sugimoto Masanori , Kusunoki Fusako 
Published: October 2004

AbstractIn recent years, handheld devices have been playing an important role in children's learning. How to utilize mobile devices such as handheld devices to support collaborative learning has been an important research topic of Computer‐Supported Collaborative Learning (CSCL). Educators in Japan are seeking an educational system structure that supports “integrated courses,” which have been introduced due to the revision of National Curriculum Standards. We focused on a museum as one of the appropriate locations where “integrated courses” are held and constructed a system named Musex for supporting children's learning with two personal digital assistants (PDAs). Musex provides children with opportunities to answer questions related to exhibitions collaboratively. We performed an experiment on Musex in a science museum and discuss the results in this paper. © 2004 Wiley Periodicals, Inc. Syst Comp Jpn, 35(14): 54–63, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10696
Model analysis of coronary hemodynamics incorporating autoregulation
Authors: Kagiyama Mitsuyasu , Michinishi Hiroyuki , Kagotani Hiroto , Okamoto Takuji , Ogasawara Yasuo , Kajiya Fumihiko 
Published: October 2004

AbstractThis paper models the autoregulation function for the coronary circulation and analyzes the pulsatile coronary hemodynamics. The autoregulation function acts to maintain a constant average blood flow in the arterioles, as determined by the oxygen consumption in the heart muscle, even if the average coronary arterial pressure changes. The regulation is realized by partially controlling the vessel characteristics which correspond to the vessel tonus. In this study, the function is incorporated into the existing three‐layered coronary hemodynamics model. Then, the arteriole hemodynamics is analyzed by simulation for the case of the normal coronary arterial pressure waveform and for the case of systolic hypertension. © 2004 Wiley Periodicals, Inc. Syst Comp Jpn, 35(14): 21–31, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10709