bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new concept of active temperature control for an injection molding process using infrared radiation heating
Authors: Saito Takushi , Satoh Isao , Kurosaki Yasuo 
Published: April 2004

AbstractThis paper deals with an innovative injection molding process that uses infrared radiation heating for active temperature control of the molded polymer. The feasibility of the proposed technique was investigated through numerical simulation and experimental study. By directly heating the molded polymer with radiation energy, precise and rapid temperature control and a small effect on the cooling duration were expected. Zinc‐selenide and a CO2 laser were used as a transparent mold window and radiation energy source, respectively. In the numerical simulation, temperature distribution both in the molded polymer and the mold wall was evaluated for various molding conditions. The results showed that the heating extent of the molded polymer varied with radiation intensity, radiation absorption coefficient, and melt flow rate. It was also estimated that extension of the cooling duration with the present technique was much shorter than that of a conventional conductive heating technique. In the experimental study, the present technique was applied to actively control the melt temperature and to improve the quality of molded products. As a result, apparent reduction of the residual molecular orientation and considerable improvement of the surface transcription were successfully realized.
Thermoplastic polyurethane–carbon black compounds: Structure, electrical conductivity and sensing of liquids
Authors: Segal E. , Tchoudakov R. , Narkis M. , Siegmann A. 
Published: April 2004

AbstractThermoplastic polyurethane (TPU) copolymers are interesting host matrices for the incorporation of conductive carbon black (CB) particles. The two‐phase character of the TPU systems provides an opportunity for the CB particles to distribute nonuniformly within the phases, owing to their different characteristics. Thus, in spite of its highly polar nature, the TPU/CB system percolates at a relatively low CB content. The CB presence affects the TPU two‐phase structure, resulting in a large change of its low temperature loss modulus. CB‐containing extruded filaments produced by a capillary rheometer at various shear rates were studied as sensing materials for different alcohols. All filaments displayed an increase in resistance upon exposure to various alcohols. Filaments exposed to methanol exhibited the highest sensitivity. This behavior was related to the sorption kinetics by the TPU/CB compound, which is affected by the different characteristics of the solvents. The resistance of filaments exposed to ethanol or methanol tended to reversibility during the drying cycle, returning to the initial values. The relatively rapid recovery to the filaments' initial resistance values (for methanol and ethanol) suggests that the structural changes due to solvent sorption mainly occur in the outer skin regions of the extruded filaments, whereas the core region remains essentially intact.
Copolymerization of ethylene with 1‐hexene over metallocene catalyst supported on complex of magnesium chloride with tetrahydrofuran
Authors: Czaja Krystyna , Białek Marzena , Utrata Alicja 
Published: April 2004

AbstractThe study of ethylene/1‐hexene copolymerization with the zirconocene catalyst, bis(cyclopentadienyl)zirconium dichloride (Cp2ZrCl2)/methylaluminoxane (MAO), anchored on a MgCl2(THF)2 support was carried out. The influence of 1‐hexene concentration in the feed on catalyst productivity and comonomer reactivity as well as other properties was investigated. Additionally, the effect of support modification by the organoaluminum compounds [(MAO, trimethlaluminum (AlMe3), or diethylaluminum chloride (Et2AlCl)] on the behavior of the MgCl2(THF)2/Cp2ZrCl2/MAO catalyst in the copolymerization process and on the properties of the copolymers was explored. Immobilization of the Cp2ZrCl2 compound on the complex magnesium support MgCl2(THF)2 resulted in an effective system for the copolymerization of ethylene with 1‐hexene. The modification of the support as well as the kind of organoaluminum compound used as a modifier influenced the activity of the examined catalyst system. Additionally, the profitable influence of immobilization of the homogeneous catalyst as well as modification of the support applied on the molecular weight and molecular weight distribution of the copolymers was established. Finally, with the successive self‐nucleation/annealing procedure, the copolymers obtained over both homogeneous and heterogeneous metallocene catalysts were heterogeneous with respect to their chemical composition. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2512–2519, 2004
Ethylene polymerization by bis(salicylaldiminate)nickel(II)/aluminoxane catalysts
Authors: Carlini Carlo , Macinai Alessandro , Masi Francesco , Raspolli Galletti Anna Maria , Santi Roberto , Sbrana Glauco , Sommazzi Anna 
Published: April 2004

AbstractThe homopolymerization of ethylene by using different catalytic systems based on dinitro‐substituted bis(salicylaldiminate)nickel(II) precursors such as bis[3,5‐dinitro‐N(2,6‐diisopropylphenyl)]nickel(II) and bis[3,5‐dinitro‐N(phenyl)]nickel(II) in combination with organoaluminum compounds was investigated. In particular, the catalytic performances were studied as a function of the main reaction parameters, such as temperature, pressure, Al/Ni molar ratio, and duration. Methylaluminoxane resulted in the best co‐catalyst. Activities up to 200 kg polyethylene/(mol Ni × h) to give a linear high‐molecular‐weight polymer were achieved. The influence of the bulkiness of the substituents on the N‐aryl group of the aldimine ligand was also checked; it resulted in a determinant for catalytic activity rather than for polymer characteristics. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2534–2542, 2004
Grzegorz Lapienis and Stanislaw Penczek, "Reaction of oligoalcohols with diepoxides: An easy, one‐pot way to star‐shaped, multibranched polymers. II. poly(ethylene oxide) stars—synthesis and analysis by size exclusion chromatography triple‐detection method," J Polym Sci Part A: Polym Chem (2004) 42(7) 1576–1598
Authors: Lapienis Grzegorz , Penczek Stanislaw 
Published: April 2004

AbstractThe original article to which this Erratum refers was published in
Journal of Polymer Science Part A: Polymer Chemistry (2004) 42(7) 1576–1598No abstract.
Responses of the olfactory receptor neurons of the corn stalk borer Sesamia nonagrioides to components of the pheromone blend and their inhibition by a trifluoromethyl ketone analogue of the main component
Authors: Quero Carmen , Bau Josep , Guerrero Angel , Renou Michel 
Published: April 2004

AbstractTwo types of olfactory hairs and three types of olfactory receptor neurons (ORN) have been characterized on the antennae of male Sesamia nonagrioides Lef for the first time. Type A sensilla housed a cell which fired large spikes in response to (Z)‐11‐hexadecenyl acetate (Z11‐16:Ac), the major component of the sex pheromone, and a second cell firing smaller spikes in response to (Z)‐11‐hexadecenal (Z11‐16:Ald), a minor component of the pheromone blend. Type B sensilla housed one cell firing large spikes to Z11‐16:Ac and a cell firing smaller spikes to another minor component of the pheromone blend, (Z)‐11‐hexadecenyl alcohol (Z11‐16:OH). No cell responding to dodecyl acetate, another minor component of the natural extract, was found. Fluorinated ketones were tested as inhibitors of the cell responses to pheromone compounds. The fluorinated derivatives tested, (Z)‐11‐hexadecenyl trifluoromethyl ketone (Z11‐16:TFMK), n‐hexadecyl trifluoromethyl ketone (16:TFMK), (Z,E)‐9,11‐tetradecadienyl trifluoromethyl ketone (Z9,E11‐14:TFMK), 3‐octylthio‐1,1,1‐trifluoropropan‐2‐one (OTFP), (Z)‐11‐tetradecenyl trifluoromethyl ketone (Z11‐14:TFMK) and 1,1‐difluoro‐(Z)‐11‐hexadecenyl methyl ketone (Z11‐16:DFMK), had no or only weak excitatory effects. However, the neuron responses to the pheromone compounds were significantly decreased in the presence of a constant stimulation with Z11‐16:TFMK and the effect was reversible. The latencies of the responses to the acetate and aldehyde cells were significantly increased. The effects were not specific, since Z11‐16:TFMK also inhibited the responses of the ORNs of Spodoptera littoralis Boisd. Correspondingly, Z9,E11‐14:TFMK, an analogue of the main component of the pheromone of this latter insect, inhibited responses of S nonagrioides ORNs. Implications of these results on the utilization of Z11‐16:TFMK as a communication disruptant are discussed. Copyright © 2004 Society of Chemical Industry
Decision making in controlling virus yellows of sugar beet in the UK
Authors: Qi Aiming , Dewar Alan M , Harrington Richard 
Published: April 2004

AbstractVirus yellows is an important disease affecting yield in sugar beet in the UK. Myzus persicae (Sulzer) is the most effective and efficient aphid vector of the three viruses causing the disease: beet yellows virus, beet mild yellowing virus and beet chlorosis virus. Control of virus yellows disease is thus focused on the study and control of this aphid species. UK national surveys of virus yellows began in 1946 and these data helped to formulate disease forecasting schemes to optimise control. Over the years, in addition to improvements in farm hygiene, periodic changes and developments in control of the disease have occurred. To accommodate these important developments, virus yellows forecasting schemes have evolved accordingly. The most recent version has been adapted to take account of the current widespread use of imidacloprid seed treatment. Its application offers potential to optimise the rational use of aphicides such as imidacloprid so as to benefit beet growers and the environment by reducing prophylactic use of seed treatment. Copyright © 2004 Society of Chemical Industry
The interaction of endosulfan with the Collembolan,Proisotoma minuta(Tullberg): toxicity, the effects of sub‐lethal concentrations and metabolism
Authors: Park Eun‐Kee , Lees Edith M 
Published: April 2004

AbstractAn increased level of the Collembolan,Proisotoma minutaTullberg was found in the cotton‐growing areas of New South Wales, Australia. They were regularly exposed to endosulfan, a highly insecticidal compound. Toxicity, sub‐lethal effects and metabolism of endosulfan were studied inP minutathat had been successfully maintained in a plaster of Paris and charcoal mixture substrate with freeze‐dried yeast as a food. The 168‐h LD50values were 0.011, 0.049 and 0.055 mg liter−1for α‐ and β‐endosulfan and endosulfan sulfate, respectively. WhenP minutawere exposed to non‐lethal concentrations of the endosulfans, egg production was inhibited. On recovery from the toxic effects of the endosulfans they resumed production of viable eggs. Conversion of α‐ and β‐endosulfan to endosulfan sulfate was found and the endosulfan sulfate could be further metabolized. The rate of metabolism of α‐endosulfan was greater than that of β‐endosulfan and the product of endosulfan sulfate metabolism was not identified. Copyright © 2004 Society of Chemical Industry
Zanthoxylum piperitum (DC), a potential feeding deterrent for mammals: studies with Microtus ochrogaster (Wagner)
Authors: Epple Gisela , Bryant Bruce P. , Mezine Igor , Lewis Stanley 
Published: April 2004

AbstractTotal extract from the fruit of Szechuan pepper (Zanthoxylum piperitum DC), the volatile components of the extract and a non‐volatile fraction containing alkylamides (NVA fraction) are feeding deterrents for rats. The present study investigated the effectiveness of these natural repellents in prairie voles (Microtus ochrogaster Wagner). Two‐choice feeding trials were conducted during which food‐deprived voles were offered choices between oat‐bran wafers. In Experiment 1, 10 voles were given three sets of feeding trials, each 2 h long. Baseline consumption was established during the first set of two trials by offering a choice between two oat‐bran wafers dipped in ethanol, the control solvent. During the second set of two trials the voles were given a choice between an oat‐bran wafer dipped in ethanol and a wafer dipped in Zanthoxylum extract. During the third set the voles were given a choice between a wafer served on top of a screened dish containing a sample of ethanol and a wafer served on top of a dish containing a sample of extract. In this manner the voles were exposed to volatile compounds emanating from the extract but could not contact it. Wafers dipped in extract were almost completely avoided. The volatile components of extract also significantly reduced food intake. In Experiment 2, habituation to the volatile constituents of extract was examined in 16 Zanthoxylum‐naïve voles. Baseline consumption was established by offering two wafers served on top of screened dishes containing ethanol. This was followed by twelve tests during which a choice between a wafer served above a sample of ethanol and a wafer served above a sample of extract was given. The voles failed to habituate to the volatile components of extract, consistently consuming less of the wafers served above extract. In Experiment 3 a dose‐response curve to Zanthoxylum extract was established, using 12 stimulus‐naïve voles. After baseline consumption was established, the animals were given two tests each, presenting a choice between a control wafer and a wafer dipped in a dilution of extract (0.001–100 g liter−1). Only concentrations of 10 and 100 g liter−1 reduced food intake. In Experiment 4 the effects of the non‐volatile fraction of extract were compared to those of whole extract. Vegetable oil was used as solvent. Eight stimulus‐naïve voles were given two tests with a choice between an oil‐dipped and an extract‐dipped wafer. A second group of eight voles received two tests with a choice between an oil‐dipped and NVA‐dipped wafer. Extract‐dipped wafers were avoided, but the NVA fraction had no effect on food consumption. Copyright © 2004 Society of Chemical Industry
Effect of humanin analogues on experimentally induced impairment of spatial memory in rats
Authors: Krejcova Gabriela , Patocka Jiri , Slaninova Jirina 
Published: April 2004

AbstractHumanin and its analogues have been shown to protect cells against death induced by various Alzheimer's disease genes and amyloid‐β‐peptides in vitro; the analogue [Gly14]‐humanin has also been shown to be potent in reversing learning and memory impairment induced by scopolamine in mice in vivo. It is important to validate these results by using other behavioral methods. In this study, the effect of [Gly14]‐humanin and des‐Leu‐PAGA, another analogue (0.2 µmol kg−1, i.p.) on the 3‐quinuclidinyl benzilate‐induced (2 mg kg−1, i.p.) impairment of spatial memory in the multiple T‐maze in rats has been evaluated. Both peptides reversed the impairment of spatial memory. These results indicate the potential of humanin analogues in modulation of the cholinergic system. Copyright © 2004 European Peptide Society and John Wiley & Sons, Ltd.
High‐yield, solid‐phase synthesis of humanin, an Alzheimer's disease associated, novel 24‐mer peptide which contains a difficult sequence
Authors: Evangelou Alexandra , Zikos Christos , Livaniou Evangelia , Evangelatos Gregory P. 
Published: April 2004

AbstractHumanin is a novel, 24‐mer residue bioactive peptide, which antagonizes Alzheimer's disease (AD) related neurotoxicity and offers a hope for developing new therapeutics against AD. Access to adequate amounts of pure humanin is a prerequisite for further, thorough, investigation of the pharmacological properties and therapeutic potency of the peptide. Until now, humanin has been obtained mainly by molecular biology techniques. In this work the Fmoc solid‐phase synthesis of humanin on an in‐house prepared 2‐Cl‐tritylamidomethyl polystyrene resin is described fully. Special precautions, i.e. prolonged deprotection steps, should be taken to achieve a high overall yield, since humanin seems to contain a ‘difficult sequence’ (R4G5F6S7C8L9) near its highly lipophilic, biologically important region L9L10L11L12. Copyright © 2004 European Peptide Society and John Wiley & Sons, Ltd.
Are language‐based activities in science effective for all students, including low achievers?
Authors: Rivard Léonard P. 
Published: April 2004

AbstractThe study investigated achievement status as a factor determining the use of language‐based activities for learning science. A total of 154 eighth‐grade students were randomly assigned to four groups, all stratified for gender and achievement level. The treatments involved various combinations of talk and writing, and descriptive and explanatory tasks. The dependent measures included scores on multiple choice tests obtained at three times during the study. Records of student talk and writing were also analyzed to identify patterns of differences between groups of achievers. The findings suggested that low achievers complete more problems, and develop better understanding and comprehension of ecology concepts when they have engaged in peer discussions of explanatory tasks. In comparison, high achievers benefit more from writing than talking, and writing explanations enhances comprehension more than restricted writing activities. © 2004 Wiley Periodicals, Inc. Sci Ed 88:420–442, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/.sce10114
Difficulties in learning the introductory magnetic field theory in the first years of university
Authors: Guisasola Jenaro , Almudí José M. , Zubimendi José L. 
Published: April 2004

AbstractThis study examined university engineering and physical science students' misconceptions of the nature of magnetic field. It is assumed that a significant knowledge of the sources of magnetic field is a basic prerequisite when students have to think about electromagnetic phenomena. To analyze students' conceptions, we have taken into account the fact that individuals build mental representations to help them understand the functioning of a physical system. These mental representations include different explanatory categories of reality in one same individual, depending on the context and the contents concerned. Therefore, we have designed an interview and an open‐question questionnaire with an emphasis on explanations, so as to analyze the students' reasoning. We found that most of the students failed to identify the source of the magnetic field and they confuse magnetic force and magnetic field. It is concluded that although the questionnaire and interviews involved a wide range of phenomena, the misconceptions identified fall into four main categories of explanations which can inform curriculum development by identifying the strengths and weaknesses of the students' conceptions. © 2004 Wiley Periodicals, Inc. Sci Ed 88:443–464, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/.sce10119
Using concept mapping for assessing and promoting relational conceptual change in science
Authors: Liu Xiufeng 
Published: April 2004

AbstractIn this article, we adopted the relational conceptual change as our theoretical framework to accommodate current views of conceptual change such as ontological beliefs, epistemological commitment, and social/affective contexts commonly mentioned in the literature. We used a specific concept mapping format and process—digraphs and digraphing—as an operational framework for assessing and promoting relational conceptual change. We wanted to find out how concept mapping can be used to account for relational conceptual change. We collected data from a Grade 12 chemistry class using collaborative computerized concept mapping on an ongoing basis during a unit of instruction. Analysis of progressive concept maps and interview transcripts of representative students and the teacher showed that ongoing and collaborative computerized concept mapping is able to account for student conceptual change in ontological, epistemological, and social/affective domains. © 2004 Wiley Periodicals, Inc. Sci Ed 88:373–396, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/.sce10127
PEXIS: Probabilistic experience representation based adaptive interaction system for personal robots
Authors: Inamura Tetsunari , Inaba Masayuki , Inoue Hirochika 
Published: April 2004

AbstractIn this paper the authors focus on the interaction between users and personal robots that can move in a real environment. When the creation of robots that can perform in an ordinary home or office is considered, it is difficult to imagine beforehand what kind of environment will be used, and so the approach in which developers embed environmental knowledge and strategies for autonomous movement fails. Thus, the authors propose an approach in which knowledge of the environment and the knowledge needed to move are acquired after development by allowing the robot and the user who is using the robot to engage in dialogue, and representing experience statistically. The authors introduce PEXIS, an interaction system developed using this approach, and then describe the characteristics and utility of their system via examples such as learning to avoid objects in an office environment and adapting to the vocabulary expressions of a particular user. © 2004 Wiley Periodicals, Inc. Syst Comp Jpn, 35(6): 98–109, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10034
Transformation from population codes to firing rate codes by learning: Neural representation of smooth pursuit eye movements
Authors: Taguchi Shinya , Tabata Hiromitsu , Shibata Tomohiro , Kawato Mitsuo 
Published: April 2004

AbstractIt has been reported that not only the information related to retinal slip but also the non‐visual information were population‐coded in the middle temporal (MT) area and the medial superior temporal (MST) area during smooth pursuit eye movements. On the other hand, it has been also reported that the information related to motor signals to generate eye movements were firing rate‐coded in the Purkinje cells in the cerebellum. Here, we propose a computational model of smooth pursuit that includes various temporal patterns of neural firing in the MT/MST areas and synaptic plasticity in the cerebellar cortex. We show that the signals to generate smooth pursuit eye movements could be extracted from the signals population‐coded in the cerebral cortex by means of the synaptic plasticity in the cerebellar cortex. Our results indicate that the transformation from population codes to firing rate‐codes occurs in the cerebellum during smooth pursuit eye movements © 2004 Wiley Periodicals, Inc. Syst Comp Jpn, 35(6): 79–88, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10322