bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermoreversible hydrogels. XVIII. Synthesis, swelling characteristics, and diffusion behaviors of porous, ionic, thermosensitive hydrogels
Authors: Lee Wen‐Fu , Chiu Ru‐Jen 
Published: June 2004

AbstractPorous, ionic, thermosensitive hydrogels were prepared from N‐isopropylacrylamide, a cationic monomer [trimethyl (acrylamido propyl) ammonium iodide (TMAAI)], an anionic monomer [acrylic acid (AA)], a zwitterionic monomer [N′,N′‐dimethyl (acrylamido propyl) ammonium propane sulfonate], or a nonionic monomer [poly(ethylene glycol) methyl ether acrylate], and a pore‐forming agent [poly(ethylene glycol) (PEG)] of different molecular weights. Some fundamental properties and dynamic swelling kinetic parameters and solute permeation for these porous gels were investigated. The results showed that the gel containing the cationic monomer TMAAI had a higher equilibrium swelling ratio. The diffusion coefficients showed that the swelling rates for the gels with the anionic monomer AA and PEG with a higher molecular weight (20,000) were faster. The results showed that the fast swelling–deswelling behavior for the porous structure gels was due to them being more available than the gels with long hydrophilic side chains. In addition, the interactive force between the solutes and gels and the solute permeation through the porous gels were investigated. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2214–2223, 2003
Kinetic study of the curing behavior of bismaleimide modified with diallylbisphenol A
Authors: Xiong Y. , Boey F. Y. C. , Rath S. K. 
Published: June 2004

AbstractThe curing kinetics of bismaleimide modified with diallylbisphenol A were investigated for different ratios of 1,1′‐(methylene di‐4,1‐phenylene) bismaleimide and diallylbisphenol A with differential scanning calorimetry. Multiheating‐rate and isothermal methods were used to study the kinetics of the curing process. The results indicated that the activation energy changed with the extent of conversion. The activation energy obtained by the multiheating‐rate method was higher than that obtained by the isothermal method. Two kinetic models (autocatalytic and nth‐order) were successfully used to model the curing process. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2229–2240, 2003
Preparation and swelling properties of solution crosslinked poly(cis‐1,4‐butadiene) gels
Authors: Qi Zhang Gao , Hua Zhou Mei , Hong Ma Jing , Liang Bo Run 
Published: June 2004

AbstractPoly(cis‐1,4‐butadiene) (PCB) gels were prepared by the crosslinking polymerization of 4‐tert‐butylstyrene (tBS) and divinylbenzene (DVB) onto unvulcanized butadiene rubber with a solution polymerization technique with benzoyl peroxide (BPO) as an initiator. The effects of the reaction conditions, such as the amount of the solvent, the amount of DVB and tBS, and the initiator (BPO), on the equilibrium swelling ratio (Qe) were also investigated. The highest oil absorbencies of crosslinked gels in xylene and cyclohexane were 51.35 and 32.98 g/g, respectively. A swelling kinetic equation was proposed for this system: Qt = Qe − {Kt + [1/(Qe − Q0)]}−1, where Qt is the swelling ratio at time t, Q0 is the initial swelling ratio, and K is the swelling kinetic constant. This equation fit the experimental results quite well. The diffusion of organic solvents in PCB gels was Fickian. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2241–2245, 2003
Pervaporation performance of PTMSP membranes at high temperatures
Authors: González‐Velasco Juan R. , López‐Dehesa Cristina , González‐Marcos José A. 
Published: June 2004

AbstractThe separation of ethanol–water mixtures by pervaporation has been carried out through poly(1‐trimethylsilyl‐1‐propyne) (PTMSP) membranes. This polymer is known to be alcohol‐selective and shows high selectivity and ethanol permeation rate. The performance of this polymer was studied at high temperatures over long periods of time to examine deterioration of its transport properties. The PTMSP membrane shows an initial separation factor (α) of about 10.7 and specific permeation rate (R) of 0.054 g m m−2 h−1 for a 10 wt % ethanol solution. Although this polymer has good characteristics for the separation of gases and liquid mixtures, its selectivity decreases with operating time, reaching a value of 8 after 450 h. On the other hand, the specific permeation rate remains almost constant except during the swelling period, in which it decreases to a value of 0.035 g m m−2 h−1. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2255–2259, 2003
Synergistic effect of dual rubber system in toughening styrene maleic anhydride copolymers
Authors: Wang Rongwei , Wang Wei 
Published: June 2004

AbstractStyrene maleic anhydride (SMA) copolymers were toughened by blending with two distinctly different rubber modifiers: styrene‐butadiene‐styrene (SBS) block copolymer and methacrylated butadiene‐styrene emulsion‐made graft copolymer (MBS). The modifiers were used both individually and in combination for the examination of their roles in toughening SMA. SMA was miscible with poly(methylmethacrylate) shell of MBS, whereas it was partially miscible with the polystyrene (PS) phase of SBS. When 40–50% of SBS was used in blends, the PS phase of SBS became immiscible with SMA. SBS did not improve the Izod impact strength of SMA appreciably. A prominent synergistic toughening effect was experimentally observed when SBS and MBS were used in combination in brittle SMA. This effect may be attributed to the fact that the large SBS particles initiate crazes and small MBS particles with good adhesion to SMA matrix improve the ligament thickness, which may play a critical role in craze growth and termination. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2260–2267, 2003
Influence of elastomer distribution on the cryogenic microcracking of carbon fiber/epoxy composites
Authors: Nobelen Matthieu , Hayes Brian S. , Seferis James C. 
Published: June 2004

AbstractCarbon fiber/epoxy laminates containing three different types of rubber modifiers, separately and in combination, were developed for testing in a cryogenic environment. Preformed rubber particles, core shell rubber, and solid carboxyl‐functionalized rubber were chosen as additives to a model prepreg matrix to control the placement of the rubber within the resulting laminates. Cryogenic microcracking and mode I and II fracture toughness and interlaminar shear strength experiments were performed. Scanning electron microscopy was used to observe fracture surfaces of the rubber‐modified laminates. Fracture toughness properties were improved while the ILSS decreased because of the presence of these rubber modifiers. It was observed that the presence of these modifiers significantly reduced the microcrack density of the laminates exposed to cryogenic cycling, and in the case of one, even eliminated microcracking entirely. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2268–2275, 2003
Studies on thermal activities of fabrics treated by polyethylene glycol
Authors: Ma XiaoGuang , Guo HaoJie 
Published: June 2004

AbstractIn this study, the special adjusting‐temperature function of polyethylene glycol (PEG) with low molecular weight was introduced. PEGs and a two‐group mixing system of PEGs of different molecular weights were added to fabrics, respectively, and the thermal activities of modified fabrics were studied. In addition, the thermal stability of PEG and fabric at a higher curing temperature was also discussed in detail. The results showed that the thermal properties of PEG decreased after being crosslinked to fabrics and the thermal activity parameters of treated fabrics could be changed and adjusted by selecting an appropriate two‐group mixing system. Some thermolysis and thermooxidative degradation of PEG and fabric used in the investigations might take place at higher curing temperatures. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2288–2292, 2003
Novel positive‐working aqueous‐base developable photosensitive polyimide precursors based on diazonaphthoquinone‐capped polyamic esters
Authors: Hsu Steve Lien‐Chung , Lee Po‐I , King Jinn‐Shing , Jeng Jyh‐Long 
Published: June 2004

AbstractNovel positive‐working aqueous‐base developable photosensitive polyimide (PSPI) precursors based on partially diazonaphthoquinone (DNQ)‐capped polyamic esters bearing phenolic hydroxyl groups and a DNQ photosensitive compound (PIC‐3) were developed. The partially DNQ capped polyamic esters were prepared from an esterification reaction of 1,2‐naphthoquinone diazide‐5‐sulfonyl chloride with the polyamic esters. The partially DNQ capped polyamic esters decreased the dark film loss effectively in the aqueous‐base developer and were able to make thicker film resists compared to the uncapped polyamic esters. The 25 mol % DNQ‐capped BisAPAF–PMDA polyamic ester and BisAPAF–ODPA polyamic ester containing 25 wt % PIC‐3 photosensitive compound showed a sensitivity of 176 and 185 mJ/cm2, and a contrast of 1.68 and 1.02, respectively, in a 3‐μm film with 1.25 wt % tetramethylammonium hydroxide developer. A pattern with a resolution of 5 μm was obtained from both PSPI precursor compositions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2293–2300, 2003
Subject categorization of query terms for exploring Web users' search interests
Authors: Pu Hsiao‐Tieh , Chuang Shui‐Lung , Yang Chyan 
Published: June 2004

AbstractSubject content analysis of Web query terms is essential to understand Web searching interests. Such analysis includes exploring search topics and observing changes in their frequency distributions with time. To provide a basis for in‐depth analysis of users' search interests on a larger scale, this article presents a query categorization approach to automatically classifying Web query terms into broad subject categories. Because a query is short in length and simple in structure, its intended subject(s) of search is difficult to judge. Our approach, therefore, combines the search processes of real‐world search engines to obtain highly ranked Web documents based on each unknown query term. These documents are used to extract cooccurring terms and to create a feature set. An effective ranking function has also been developed to find the most appropriate categories. Three search engine logs in Taiwan were collected and tested. They contained over 5 million queries from different periods of time. The achieved performance is quite encouraging compared with that of human categorization. The experimental results demonstrate that the approach is efficient in dealing with large numbers of queries and adaptable to the dynamic Web environment. Through good integration of human and machine efforts, the frequency distributions of subject categories in response to changes in users' search interests can be systematically observed in real time. The approach has also shown potential for use in various information retrieval applications, and provides a basis for further Web searching studies.
Visualizing and tracking the growth of competing paradigms: Two case studies
Authors: Chen Chaomei , Cribbin Timothy , Macredie Robert , Morar Sonali 
Published: June 2004

AbstractIn this article we demonstrate the use of an integrative approach to visualizing and tracking the development of scientific paradigms. This approach is designed to reveal the long‐term process of competing scientific paradigms. We assume that a cluster of highly cited and cocited scientific publications in a cocitation network represents the core of a predominant scientific paradigm. The growth of a paradigm is depicted and animated through the rise of citation rates and the movement of its core cluster towards the center of the cocitation network. We study two cases of competing scientific paradigms in the real world: (1) the causes of mass extinctions, and (2) the connections between mad cow disease and a new variant of a brain disease in humans—vCJD. Various theoretical and practical issues concerning this approach are discussed.
Disciplinary differences and undergraduates' information‐seeking behavior
Authors: Whitmire Ethelene 
Published: June 2004

AbstractThis study applied the Biglan model of disciplinary differences to the information‐seeking behavior patterns of 5,175 undergraduates responding to questions on the College Student Experiences Questionnaire (CSEQ). The Biglan model categorizes academic disciplines along three dimensions: (1) hard‐soft, (2) pure‐applied, and (3) life–nonlife systems. Using t‐tests, this model proved to be valid for distinguishing differences in undergraduates' information‐seeking behavior patterns among various academic disciplines. The results indicate that the Biglan model has implications for the redesign of academic library services and use as a valid theoretical framework for future library and information science research.
Multitasking information seeking and searching processes
Authors: Spink Amanda , Ozmutlu H. Cenk , Ozmutlu Seda 
Published: June 2004

AbstractRecent studies show that humans engage in multitasking behaviors as they seek and search information retrieval (IR) systems for information on more than one topic at the same time. For example, a Web search session by a single user may consist of searching on single topics or multitasking. Findings are presented from four separate studies of the prevalence of multitasking information seeking and searching by Web, IR system, and library users. Incidence of multitasking identified in the four different studies included: (1) users of the Excite Web search engine who completed a survey form, (2) Excite Web search engine users filtered from an Excite transaction log from 20 December 1999, (3) mediated on‐line databases searches, and (4) academic library users. Findings include: (1) multitasking information seeking and searching is a common human behavior, (2) users may conduct information seeking and searching on related or unrelated topics, (3) Web or IR multitasking search sessions are longer than single topic sessions, (4) mean number of topics per Web search ranged of 1 to more than 10 topics with a mean of 2.11 topic changes per search session, and (4) many Web search topic changes were from hobbies to shopping and vice versa. A more complex model of human seeking and searching levels that incorporates multitasking information behaviors is presented, and a theoretical framework for human information coordinating behavior (HICB) is proposed. Multitasking information seeking and searching is developing as major research area that draws together IR and information seeking studies toward a focus on IR within the context of human information behavior. Implications for models of information seeking and searching, IR/Web systems design, and further research are discussed.
Fusion of effective retrieval strategies in the same information retrieval system
Authors: Beitzel Steven M. , Jensen Eric C. , Chowdhury Abdur , Grossman David , Frieder Ophir , Goharian Nazli 
Published: June 2004

AbstractPrior efforts have shown that under certain situations retrieval effectiveness may be improved via the use of data fusion techniques. Although these improvements have been observed from the fusion of result sets from several distinct information retrieval systems, it has often been thought that fusing different document retrieval strategies in a single information retrieval system will lead to similar improvements. In this study, we show that this is not the case. We hold constant systemic differences such as parsing, stemming, phrase processing, and relevance feedback, and fuse result sets generated from highly effective retrieval strategies in the same information retrieval system. From this, we show that data fusion of highly effective retrieval strategies alone shows little or no improvement in retrieval effectiveness. Furthermore, we present a detailed analysis of the performance of modern data fusion approaches, and demonstrate the reasons why they do not perform well when applied to this problem. Detailed results and analyses are included to support our conclusions.
Popul?r oder elit?r? Anmerkungen zum Kulturbegriff in der Geschichtswissenschaft
Authors: Witte Wilfried 
Published: June 2004

AbstractWhile the Historische Kulturwissenschaft (new cultural history) is introduced as a new way of writing history the question has to be answered what Kultur (civilization) means or how it should be interpreted. The paper deals primarily with the special German notion of ‘Kultur’. The distinction between ‘intension’ and ‘extension’ is made and contrasted with both the narrow and the wide concept of ‘Kultur’. Writing history as new cultural history is shaped at least by five aspects: space, perspective, language, acting and time (particularly memory) which are discussed in this thesis. The intension of ‘Kultur’ in Historische Kulturwissenschaft leads to popularisation. The sense of the popular approach to history emphasizes modality in the conception and writing of history.
Vom Wesen der langz?ngigen Schl?rfm?use: Das Schnabeltier und die Entwicklung der Informationsgesellschaft
Authors: Herren Madeleine 
Published: June 2004

AbstractIn 1798, the skin of a platypus started to disturb the European scientific community. Even before researchers confirmed that the furry animal with a duck's bill was an egg‐laying mammal, the platypus was a challenge to contemporary taxonomies. Although a scientific interest in the platypus is self‐evident, the animal's appearance in encyclopaedias and dictionaries needs an explanation. The essay discusses the presence of the platypus in the encyclopaedias of the 19th and 20th century by asking why a rare animal without economic significance came into an encyclopaedia where knowledge had to be reduced to information of general interest. Therefore, the transformation of the platypus in a part of general knowledge describes the presence of order even outside the philosophical discourse described by Foucault. As a visual expression of order, the platypus gives an example how knowledge and society are connected, and how a social and cultural context influenced the supposed objective description of an animal.
Menschenbild und Wirtschaftsordnung: Der Menschenbegriff im Kameralismus und in der National?konomie
Authors: Bowler Richard C. 
Published: June 2004

AbstractThis essay addresses the construction of human nature in cameralism and early German political economy. It suggests that the emergent economic sciences in Germany propounded a vision of human beings that stressed the psycho‐physiological roots of human behavior in general, and of economic activity in particular. In this vision, human beings possessed a body and soul whose constant interaction gave rise to needs and desires, and thus to the drive to behave as economic agents. Here the cameralists and early German political economists adopted conceptions of human nature current in the ‘Sciences of Man’ of the Enlightenment. This stress on the non‐rational, psycho‐physiological aspects of human nature prevented the theoretical construction of a stable human social life, and in this way justified the continued need for governmental oversight and control of economic activity.
Imagination — Einbildungskraft — Suggestion: Zur ‚Scharlatanerie’︁ in der neuzeitlichen Medizin
Authors: Schott Heinz 
Published: June 2004

AbstractIn Renaissance and early modern times, the concept of imagination (Latin imaginatio) was essential for the (natural) philosophical explanation of magic processes, especially in the anthropology of Paracelsus. He assumed that imaginatio was a natural vital power including cosmic, mental, psychical, and physical dimensions. The Paracelsians criticized traditional humor pathology ignoring their theory of ‚natural magic’︁. On the other hand, they were criticized by their adversaries as charlatans practicing ‚black magic’︁. About 1800, in between enlightenment and romanticism, the healing concept of ‚animal magnetism’︁ (Mesmerism) evoked an analogous debate, whether ‚magnetic’︁ phenomena originated from a real (physical) power (so‐called ‚fluidum’︁) or were just due to fantasy or imagination (German Einbildungskraft). At the end of the 19th century, the French internist Hippolyte Bernheim created — against the background of medical hypnosis (‚hypnotism’︁) as a consequence of Mesmerism — his theory of suggestion and autosuggestion: a new paradigm of psychological respectively psychosomatic medicine, which became the basis for the concept of ‚placebo’︁ in modern biomedicine. From now on, all the effects of ‚alternative medicine’︁ could easily be explained by the ‚placebo‐effect’︁, more or less founded — at least unconsciously — on fraud.
Paracelsus in pseudoparacelsischen Briefen
Authors: Telle Joachim 
Published: June 2004

AbstractThe article presents an investigation of pseudo‐Paracelsian letters, forgeries written by unidentified sixteenth‐century Paracelsists. It comprises information about extant texts as well as authors and addressees like Bartholomaeus Korndorfer, Salomon Trismosin and Wilhelm von Hohenheim. The separation of fact and fiction reveals Paracelsus' life and work to be misrepresented or even distorted in these letters. Paracelsus appears as a theological ‘fanaticus’, moreover as a stylised hero of the alchemia transmutatoria metallorum. A multifaceted opposition and reform movement, ‘Paracelsianism’, revolved around Paracelsus as an idolised, almost apotheosised leader and inspirational figure. Its followers are known to demand a revision of some areas of knowledge in the Aristotelian‐Galenic medical and pharmaceutical traditions; they furthermore fermented the aspirations of certain anti‐confessionalistic religious dissidents. The pseudo‐Paracelsian letters, which has hitherto been generally neglected, reinforces this.
Aufklärung durch Täuschung, Die Natürliche Magie im 18.?Jahrhundert
Authors: Hochadel Oliver 
Published: June 2004

AbstractMechanical speaking figures are very popular in the 18th century. Purportedly they are not only able to answer questions but also to divine. The enlightened philosophers are alarmed in the face of apparent fraud fostering superstition. The most successful weapon against the ‘charlatans’ seems to be the public imitation of their tricks. This leads to a ‘division of labour’ between popularisers of science, instrument‐makers and even some showmen, and natural philosophers. The former expose the imposture thanks to their special skills, the latter support these fraudbusting activities with their growing cultural authority. This paves the way for a close alliance between professional magicians and scientists in the 19th and 20th century exposing spiritistic mediums and spiritual healers.