bluuebunny/crossref_metadata_2025 huggingface dataset:
Using Theater Games to Enhance Language Arts Learning
Authors: Fennessey Sharon
Published: March 2006

Integrating drama and language arts lessons can provide the necessary opportunities for the development of language in an exciting and pleasurable way. Using drama as part of daily instruction gives elementary and middle‐level students an opportunity to practice oral language, improving fluency and pronunciation. Theater games also improve social skills. With regular participation, the learners develop confidence, cooperation, and concentration—attributes that provide the foundation for more elaborate drama activities. The classroom teacher does not need to be a drama specialist to lead a successful drama session. Many theater games are simple, fun, and easy to learn.

Each drama activity in this article has detailed directions. The five games described have a specific language arts focus. These games are a small sampling of drama activities, but they suggest what is possible with drama for promoting language literacy.
Think‐Tac‐Toe, a Motivating Method of Increasing Comprehension
Authors: Samblis Kelley
Published: March 2006

Many researchers agree that student choice plays a pivotal role in motivating pupils to put more into their assignments and to take responsibility. The Think‐Tac‐Toe strategy allows students to choose tasks that better align with their learning styles and interests and makes them accountable for revisiting important literacy skills. It is attractive because of its game‐like quality. To implement the Think‐Tac‐Toe strategy, the teacher decides on a specific skill or concept to review, and creates nine tasks that practice that skill or concept. The students are allowed to choose three of the tasks to complete.

This article describes the concept of Think‐Tac‐Toe, reviews the benefits of using the strategy, and explains how to create Think‐Tac‐Toe grids using comprehension examples that include story grammar, main idea, sequencing, and summarizing.
When Mama Can't Read: Counteracting Intergenerational Illiteracy
Authors: Cooter Kathleen S.
Published: March 2006

Almost 50 million American adults do not have adequate reading skills to fill out a job application, read a food label, or read a story to a child. These individuals often lack the literacy skills needed to find and keep decent jobs, support their children's education, or participate actively in civic life. In this column, the author offers some research‐proven answers to a very basic question facing many urban reading teachers: What can a mother with limited literacy skills do to support and enhance the literacy development of her children? The author reviews recent research on the causes of intergenerational illiteracy and explores several promising evidence‐based practices.
Catalase Activity Assays
Authors: Shangari Nandita , O'Brien Peter J.
Published: March 2006

Catalase (hydrogen peroxide/hydrogen peroxide oxidoreductase) is an important cellular antioxidant enzyme that defends against oxidative stress. It is found in the peroxisomes of most aerobic cells. It serves to protect the cell from toxic effects of high concentrations of hydrogen peroxide (H2O2) by catalyzing its decomposition into molecular oxygen and water, without the production of free radicals. It is important to measure catalase levels because oxidative stress is inherent in pathological conditions such as cancer, diabetes, cataracts, atherosclerosis, neurodegenerative disease, aging, and nutritional deficiencies. This unit provides methods for catalase activity measurements.
Scoring Learning and Memory in Developing Rodents
Authors: Branchi Igor , Ricceri Laura
Published: March 2006

Learning and memory abilities can be reliably measured in rodents starting from very early phases of postnatal development. In particular, in the study of learning and memory in periweanling or adolescent (from around postnatal day 20 to 50) mice or rats, two experimental protocols are appropriate for a reliable characterization of cognitive ability development: the water maze and the spatial open‐field with objects. These experimental protocols have been developed to study the behavior of adult rodents, but are easily adapted to the peculiar physiological and behavioral responses of immature animals by applying selected modifications to both test apparatuses as well as protocols. It is worth noting that these two experimental protocols have been proven to be complementary because they provide different information on possible cognitive deficits; thus, use of both is recommended for an exhaustive behavioral characterization.
Host Resistance Model to an Intracellular Pathogen
Authors: Cao Ling
Published: March 2006

This unit describes a model for the determination of host resistance in mice using a Gram‐positive intracellular bacterium, Listeria monocytogenes (LM), and discusses its broad use in immunotoxicological studies. The provides detailed procedures for LM infection and sample analysis, including preparation and infection of mice with LM, recording of sickness behaviors in infected mice, and determination of viable LM numbers in the tissues from infected animals. The protocol also describes use of serum and tissue homogenates for assessment of cytokines. Additionally, background information on LM and LM infection is provided for better understanding and utilization of this model. The LM infection model is useful for the initial screening of possible modulation of immune responses, particularly innate immunity and type‐1 cell‐mediated immunity (CMI), by environmental factors, as well as for further investigation of the underlying mechanisms of environmental factor–induced changes in immunity.
Determining the Structure of Oligosaccharides N‐ and O‐Linked to Glycoproteins
Authors: Royle Louise , Dwek Raymond A. , Rudd Pauline M.
Published: March 2006

Many proteins involved in biological events are glycosylated. A glycoprotein consists of a mixture of glycosylation variants of a single polypeptide chain, known as glycoforms. It has become clear that a detailed understanding of the roles which glycosylation plays in the biosynthesis, transport, biological function, and degradation of a glycoprotein can only be achieved when the protein and sugar(s) are viewed as an entity. Many glycoproteins can now be modeled by combining glycan sequencing data and oligosaccharide structural information with protein structural data. Pivotal to this approach is sensitive, state‐of‐the‐art oligosaccharide sequencing technology which can give a rapid insight into the glycosylation of a glycoprotein without the need for sophisticated equipment and expertise. This unit gives a detailed introduction into the analysis of glycans, and the many figures will help the user identify which type of experiment needs to be undertaken. Methods for releasing glycans from glycoproteins are followed by protocols for labeling and purifying (by HPLC) the glycans from the rest of the components. Strategies for N‐ and O‐glycan analysis are also included.
Determining the Structure of Glycan Moieties by Mass Spectrometry
Authors: Harvey David J. , Dwek Raymond A. , Rudd Pauline M.
Published: March 2006

Acquisition of mass spectra using fast‐atom bombardment (FAB), matrix‐assisted laser desorption/ionization (MALDI), and electrospray ionization (ESI) mass spectrometry is summarized in this unit. Molecular weights of the carbohydrates provide information on their composition in terms of isobaric monosaccharide composition, and tables of residue masses are provided to assist these calculations. More detailed structural analysis can be performed by fragmentation; the main fragmentation modes of carbohydrates and their nomenclature are discussed. Fragmentation of negative ions generated by nano‐electrospray, in particular, provide very informative spectra and give details such as the position of fucose substitution, branching pattern, and the presence or absence of bisecting GlcNAc residues. Practical details are given for the purification of samples prior to mass spectrometric analysis and for recording FAB, MALDI, and ESI spectra.
Production and Use of Trimeric Isoleucine Zipper Fusion Proteins to Study Surface Receptor Ligand Interactions
Authors: Watzl Carsten
Published: March 2006

Soluble recombinant forms of surface receptors are commonly used to study the interaction between cell surface receptors and their ligands. By fusing the extracellular domain of the receptor to an isoleucine zipper (ILZ) sequence, it is possible to generate recombinant receptor fusion proteins that form trimers in solution. These ILZ fusion proteins demonstrate several advantages over the commonly used Fc fusion proteins. This unit describes the production and purification of recombinant ILZ fusion proteins. A protocol is also provided for the use of ILZ fusion proteins to study cell surface receptor‐ligand interactions on intact cells by flow cytometry.
In Vitro Systems for the Study of T Cell Development: Fetal Thymus Organ Culture and OP9‐DL1 Cell Coculture
Authors: Ramsdell Fred , Zúñiga‐Pflücker Juan Carlos , Takahama Yousuke
Published: March 2006

Most T cell development occurs within the thymus and includes a series of selection processes that are, in large part, still poorly understood. Studies of T cell development have been greatly advanced by the description of multiple phenotypic subsets of T cells and their maturational relationships. This unit describes a system for observing and modulating T cell development in vitro via the culture of entire mouse fetal thymic lobes. Methods are included for the isolation of fetal thymi and culture to allow for normal T cell development on either transwell plates or Gelfoam sponges. A method for depleting hematopoietic cells from thymic lobes using 2′‐deoxyguanosine and subsequent reconstitution with precursor cells is also described. This protocol is valuable for the study of tolerance and T cell selection. A support protocol describing methods of altering and monitoring T cell development are outlined. In addition, methods for culturing fetal thymic lobes under high oxygen submersion conditions and for the preparation of reaggregate thymus organ cultures are provided. Finally, a simple and practical method that allows for the thymus‐independent generation of T cells from defined sources of stem/progenitor cells by OP9‐DL1 coculture is described.
Web Sites of Interest to Immunologists
Authors: Lefranc Marie‐Paule
Published: March 2006

The astonishing increase in the amount of biologically relevant data on the World Wide Web enables immunologists to immediately access databases, scan literature, use tools and software, find information on collections, educational resources, and research groups, and exploit that information for scientific projects and clinical trials. This appendix presents a selection of the links available at the international ImMunoGeneTics (IMGT) database. Most of the sections such as Databases, Immunology themes, Journals, Societies, and Tools, provide direct access to Web sites. Three other sections (Molecular Biology Servers, Resources, and Universities and Institutes) offer their own lists of useful links.
Using Bioinformatics Tools for the Sequence Analysis of Immunoglobulins and T Cell Receptors
Authors: Lefranc Marie‐Paule
Published: March 2006

The huge potential repertoire of 1012 immunoglobulins and 1012 T cell receptors per individual results from complex mechanisms of combinatorial diversity between the variable (V), diversity (D), and junction (J) genes, nucleotide deletions and insertions (N‐diversity) at the junctions and, for the immunoglobulins, somatic hypermutations. The accurate analysis of rearranged immunoglobulin and T cell receptor sequences, and the annotation of the junctions, therefore represent a huge challenge. The IMGT Scientific chart rules, based on the IMGT‐ONTOLOGY concepts, were the prerequisites for the implementation of the IMGT/V‐QUEST and IMGT/JunctionAnalysis tools. IMGT/V‐QUEST analyzes germline V and rearranged V‐J or V‐D‐J nucleotide sequences. IMGT/JunctionAnalysis is the first tool that automatically analyzes the complex junctions in detail. These interactive tools are easy to use and freely available on the Web (http://imgt.cines.fr), either separately or integrated.
Viewing composite sketches: lineups and showups compared
Authors: Dekle Dawn J.
Published: March 2006

This study assesses the effect of high‐and low‐similarity composites on identification accuracy, using both lineups and showups. Participants witnessed a mock crime scene, viewed a composite of the perpetrator, then attempted an identification. The results indicate that witnesses are not overly influenced by low‐similarity composites on subsequent identification accuracy. There was also no evidence that showups were less accurate identification procedures than lineups, across composition conditions. In fact, in perpetrator absent situations, showups were better identification procedures than lineups in terms of accuracy. Copyright © 2006 John Wiley & Sons, Ltd.
Conidial fungi on plants in the Biebrzański National Park
Authors: Orłowska Mirosława , Lengiewicz Ilona , Ostrowska Halina
Published: March 2006

The presence of Hyphomycetes developing on Eriophorum vaginatum L. and Sphagnum apiculatum H. Lindb was monitored. Samples were collected from water bodies accumulating over excavated peat in the Biebrzan?ski National Park in autumn and winter of 2002, and in spring and summer of 2003. 67 species of Fungi imperfecti were identified. We found 54 taxa of Hyphomycetes on Sphagnum apiculatum and 41 taxa on Eriophorum. 24 species were present on both species. The highest number of species was found in spring and the fewest in summer.
Geochronology of anthropogenic contaminants in a dated sediment core of the Rhine River (Germany): emission sources and risk assessment
Authors: Heim Sabine , Hucke Achim , Schwarzbauer Jan , Littke Ralf , Mangini Augusto
Published: March 2006

A subaquatic sediment core was taken from the Rhine River to determine substance specific concentration profiles in correlation to time and depth. Based on these data emission histories were related for selected contaminants. Significant emission sources and emission pathways were compiled. In correlation to investigations of national and international monitoring programmes a significant reduction of environmental emissions up to a tenth of previous values were found since 1998. Some selected compounds, discharged by municipal and industrial activities, for example disinfectants (methyltriclosan), flame retardants (tris(chloropropyl)phosphate), chlorinated benzenes, anilines and naphthalenes, can be classified as significant synthetic substances in the scope of the Water Framework Directive. Because of their chemical characters, their persistence, bioaccumulation and ecotoxicity, as well as their occurrence within the sediment core, these compounds create a significant potential risk for water quality, but a reduction of these synthetic compounds to zero cannot be expected for the next future. In summary, this study provides a comprehensive reconstruction of the pollution history of anthropogenic contaminants, their fate and behaviour in the fluvial system. In addition, an estimation of the time period required for environmental measurements and monitoring programmes to improve, achieve and save a good status of the river systems are given.
METEOR: a step‐by‐step procedure to explore effects of indicator aggregation in multi criteria decision aiding – application to water management in Berlin, Germany
Authors: Simon Ute , Brüggemann Rainer , Behrendt Horst , Shulenberger Eric , Pudenz Stefan
Published: March 2006

METEOR (METhod of Evaluation by ORder) is introduced as a new evaluation approach, based on partial order theory. METEOR combines transparent decision support and convenient tools for data analysis with the ability to include stakeholders' preferences in the decision process. The basic idea is a systematic step‐by‐step aggregation of indicators, including their weighting. We applied METEOR to evaluate the eco‐hydrological effects of nine water management strategies upon the complex surface water system of Berlin and Potsdam, Germany. Altogether 14 river sections are defined, each of which is evaluated by a set of four hydro‐chemical indicators. Aggregation of indicators was performed on two levels: spatially with respect to the river sections, and thematically to the four indicators themselves. The METEOR result is in good agreement with that obtained by the PROMETHEE approach. However, advantages of METEOR are (1) identification of sensitive steps of indicator aggregation, and (2) extraction of explanatory background information about advantages and disadvantages of scenarios. Both topics enhance the transparency of the evaluation process and thus support public acceptance of the decision.
Vielsegmentige Nanostäbe: Templatsynthese und Eigenschaften
Authors: Hurst Sarah J. , Payne Emma Kathryn , Qin Lidong , Mirkin Chad A.
Published: March 2006

Nanomaterialien gewinnen in den Natur‐ und Ingenieurwissenschaften rasant an Stellenwert. Für viele derartige Materialien sind inzwischen zuverlässige Synthesen verfügbar, die vielfältige Anwendungen in allen Bereichen von Nanowissenschaften und Nanotechnologie ermöglicht haben. Bisweilen ist es erwünscht, dass ein einziges Nanomaterial mehrere Funktionen zugleich ausübt, sodass sich die Forschung zu Mehrkomponenten‐Nanomaterialien wie Kern‐Schale‐ oder Legierungsnanopartikeln sowie gestreiften Nanodrähten intensiviert. Solche multifunktionalen Strukturen bieten vielversprechende Perspektiven für die Entwicklung von neuartigen Anwendungen. Dieser Aufsatz präsentiert aktuelle Fortschritte bei der Synthese vielsegmentiger eindimensionaler Nanostäbe und ‐drähte mit Metallen, Halbleitern, Polymeren, Molekülen und sogar Lücken als Komponenten. Zudem werden Anwendungen dieser Mehrkomponenten‐Nanomaterialien in den Bereichen Magnetismus, Selbstorganisation, Elektronik, Biologie, Katalyse und Optik vorgestellt. Ein besonderer Schwerpunkt liegt auf neuen Materialien und Anwendungen, bei denen die Vorteile von Mehrkomponenten‐Nanodrähten gegenüber Einkomponentenstrukturen zutage treten.
Multisegmented One‐Dimensional Nanorods Prepared by Hard‐Template Synthetic Methods
Authors: Hurst Sarah J. , Payne Emma Kathryn , Qin Lidong , Mirkin Chad A.
Published: March 2006

In the science and engineering communities, the nanoscience revolution is intensifying. As many types of nanomaterials are becoming more reliably synthesized, they are being used for novel applications in all branches of nanoscience and nanotechnology. Since it is sometimes desirable for single nanomaterials to perform multiple functions simultaneously, multicomponent nanomaterials, such as core–shell, alloyed, and striped nanoparticles, are being more extensively researched. Nanoscientists hope to design multicomponent nanostructures and exploit their inherent multiple functionalities for use in many novel applications. This review highlights recent advances in the synthesis of multisegmented one‐dimensional nanorods and nanowires with metal, semiconductor, polymer, molecular, and even gapped components. It also discusses the applications of these multicomponent nanomaterials in magnetism, self‐assembly, electronics, biology, catalysis, and optics. Particular emphasis is placed on the new materials and devices achievable using these multicomponent, rather than single‐component, nanowire structures.
Fourier transform rheometry on carbon black filled polybutadiene compounds
Authors: Leblanc Jean L.
Published: March 2006

A series of high cis‐1,4 polybutadiene compounds with various levels of N330 carbon black were prepared and tested using a Rubber Process Analyzer RPA® (Alpha Technologies), suitably modified for so‐called Fourier transform rheometry. Strain sweep test protocols were used in order to capture strain and torque signals, that were consequently treated through Fourier transform calculations, using the appropriate proprietary software. Through strain sweep tests, the non‐linear viscoelastic behavior was investigated, with significant odd‐harmonics detected in the torque response, not only as the strain magnitude increases but also as the carbon black level increases. Differences in non‐linear behavior, due to growing filler level are easily and clearly detected and the dependence upon strain of the relative third harmonic component is adequately modelled with simple four parameter models. Two such models were compared and found to give similar results, both offering two parameters to describe the strain sensitivity. First derivatives of the models allow a single number, i.e., the slope at a given strain, to be calculated as a “quantification” of the strain sensitivity, and hence of the non‐linear character. Carbon black volume fraction appears then as the main compounding parameter influencing the non‐linear viscoelastic response. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 5102–5118, 2006
Hydrogenation of natural rubber in the presence of OsHCL(CO)(O2)(PCY3)2: Kinetics and mechanism
Authors: Hinchiranan N. , Prasassarakich P. , Rempel G. L.
Published: March 2006

The homogeneous catalyst precursor, OsHCl(CO)(O2)(PCy3)2, was utilized for the hydrogenation of natural rubber to convert the unsaturated structure to a saturated form, providing an alternating ethylene‐propylene copolymer. A detailed kinetic investigation was carried out by monitoring the amount of hydrogen consumption during the reaction using a gas‐uptake apparatus. 1H NMR spectroscopy was used to determine the final olefin conversion to the hydrogenated product. Kinetic data, collected according to a statistical design framework, defined the influence of catalyst and polymer concentration, hydrogen pressure, and reaction temperature on the catalytic activity. The kinetic results indicated that the hydrogenation rate exhibited a first‐ shifted to zero‐order dependence on hydrogen at lower hydrogen pressure, which then decreased toward an inverse behavior at pressures higher than 41.4 bar. The hydrogenation was also observed to be first‐order with respect to catalyst concentration, and an apparent inverse dependence on rubber concentration was observed due to the impurities in the rubber. The hydrogenation rate was dependent on reaction temperature, and the apparent activation energy over the temperature range of 125–145°C was found to be 122.76 kJ/mol. Mechanistic aspects of the hydrogenation of natural rubber in the presence of OsHCl(CO)(O2)(PCy3)2 were proposed on the basis of the observed kinetic results. The addition of some acids and certain nitrogen containing materials showed an effect on the hydrogenation rate. The thermal properties of hydrogenated natural rubber indicated that the thermal stability increased with increasing % hydrogenation of the rubber. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4499–4514, 2006
Graft copolymerization of 2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid onto carboxymethylcellulose (sodium salt) by H2O2/Fe+2 redox pair
Authors: Behari Kunj , Kant Pandey Peeyoosh
Published: March 2006

The effect of the reaction conditions on the grafting parameters during grafting of 2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid onto sodium carboxymethylcellulose using H2O2/Fe+2 redox pair are studied at 30°C. The grafting ratio, add on, and conversion initially increase with the H2O2 concentration in the range of (10.0–15.0) × 10−2 mol dm−3. Thereafter, these parameters decrease with the H2O2 concentration. The grafting ratio, add on, and conversion increase when increasing the ferrous ion concentration from (0.5 to 4.0) × 10−2 mol dm−3 and decrease with a further increase in the concentration. It is observed that the grafting ratio and add on increase with the monomer concentration, whereas the conversion decrease. The hydrogen ions seem to be facilitating the grafting reaction up to a certain concentration and after this concentration seem to be retarding the process. The grafting ratio, add on, and conversion decrease with the sodium carboxymethylcellulose concentration. When increasing the time period from 60 to 90 min, the grafting parameters increase but decrease thereafter. Similarly, when increasing the temperature from 25 to 30°C, the grafting parameters increase and decrease thereafter. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4819–4825, 2006
Syntheses and optical properties of hybrid materials containing azobenzene groups via sol–gel process for reversible optical storage
Authors: Kim Mi‐Ra , Choi Young‐Il , Park Sang‐Wook , Lee Jae‐Wook , Lee Jin‐Kook
Published: March 2006

We focused on the synthesis and optical properties of new organic–inorganic hybrid materials containing azobenzene groups for rewritable optical recording media. Hybrid material (SGUR19‐n's) design has the structure of azobenzene group with urethane bonds in the silica network. The structures of the synthesized monomers and precursors were confirmed by FTIR and 1H NMR spectrophotometer. Also, we reported on the effects of the direction of the polarized beam, the intensity of the induced beam, and the structures of SGUR19‐n's materials on the diffraction efficiency of SGUR19‐n's films. It was revealed that SGUR19‐n's films prepared by the sol–gel process have adequate writing–erasing–rewriting properties when used as a reversible optical storage material. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4811–4818, 2006
Rheological and isothermal crystallization characteristics of neat and calcium carbonate‐filled syndiotactic polypropylene
Authors: Supaphol Pitt , Harnsiri Wipasiri
Published: March 2006

Steady‐state and oscillatory shear behavior of three neat syndiotactic polypropylene (s‐PP) resins and a s‐PP resin (s‐PP#8) filled with CaCO3 particles of varying content, size, and type of surface modification were investigated. All of the neat s‐PP resins investigated exhibited the expected shear‐thinning behavior. Both the storage and loss moduli increased with decreasing temperature. The shift factors used to construct the master curves were fitted well with both the Arrhenius and the Williams–Landel–Ferry (WLF) equations. The inclusion of CaCO3 particles of varying content, size, and type of surface modification, to a large extent, affected both the steady‐state and oscillatory shear behavior of s‐PP/CaCO3 compounds, with the property values being found to increase with increasing content, decreasing size, and surface coating of the CaCO3 particles. Lastly, the effects of melt‐annealing and crystallization temperatures on isothermal crystallization behavior of s‐PP#8 filled with CaCO3 particles of varying content, size, and type of surface modification were also investigated. The half‐time of crystallization of neat s‐PP#8 exhibited a strong correlation with the choice of the melt‐annealing temperature (Tf) when Tf was less than about 160 °C, while it became independent of Tf when Tf was greater than about 160 °C. On the other hand, the half‐time of crystallization of s‐PP#8/CaCO3 compounds did not vary much with the Tf. Generally, the observed half‐time of crystallization decreased with increasing CaCO3 content and increased with increasing CaCO3 particle size. Finally, coating the surface of CaCO3 particles with either stearic acid or paraffin reduced the ability of the particles to effectively nucleate s‐PP#8. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4515–4525, 2006
PMMA‐modified divinylester/styrene resins: Phase diagrams and morphologies
Authors: Schroeder Walter F. , Yáñez María J. , Aranguren Mirta I. , Borrajo Julio
Published: March 2006

Binary and ternary experimental cloud‐point curves (CPCs) for systems formulated with a low molar mass synthesized divinylester (DVE) resin, styrene (St), and poly(methyl methacrylate) (PMMA) were determined. The CPCs results were analyzed with the Flory–Huggins (F‐H) thermodynamic model taking into account the polydispersity of the DVE and PMMA components, to calculate the different binary interaction parameters and their temperature dependences. The St‐DVE system is miscible in all the composition range and down to the crystallization temperature of the St; therefore, the interaction parameter expression reported for a higher molar mass DVE was adapted. The interaction parameters obtained were used to calculate the phase diagrams of the St‐PMMA and the DVE‐PMMA binary systems and that of the St‐DVE‐PMMA ternary system at three different temperatures. Quasiternary phase diagrams show liquid–liquid partial miscibility of the St‐PMMA and DVE‐PMMA pairs. At room temperature, the St‐DVE‐PMMA system is miscible at all compositions. Final morphologies of PMMA‐modified cured St‐DVE materials were generated by polymerization‐induced phase separation (PIPS) mechanism from initial homogeneous mixtures. SEM and TEM micrographs were obtained to analyze the generated final morphologies, which showed a direct correlation with the initial miscibility of the system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4539–4549, 2006
A novel perfluorooctylated triazine pyridine quaternary ammonium salt: Synthesis and its application on cotton fabrics finishing
Authors: Jiang Wan‐chao , Meng Wei‐dong , Qing Feng‐Ling
Published: March 2006

A novel perfluorooctyl‐containing triazine pyridine quaternary ammonium salt was designed and synthesized, which was applied to cotton fabrics by pad‐dry‐cure process. The treated fabrics showed good water and oil repellency, and washing durability. The water and oil repellent ratings were 100 and 6 respectively, and after 10 washing cycles, the water repellent rating was 90 and the oil repellent rating was 5. The modified specimen had the ultra low critical surface energy and showed excellent repellency to selected liquids (water, tea, milk, wine, machine oil, and wooster sauce). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4561–4564, 2006
Quantification of response time in poly(vinyl alcohol)–metal complex thermochromic polymeric systems
Authors: Srivastava Jyoti , Srivastava J. N. , Alam Sarfaraz , Mathur G. N.
Published: March 2006

Thermochromic poly(vinyl alcohol) (PVA)‐based material was synthesized and an extensive study of its thermochromic behavior with respect to response time was carried out. It was observed that it is possible to manipulate the response time by keeping control over chemical and physical parameters. The response time, which is the most important property of a smart material, has in this case been found to be very much influenced by rate of heat transfer into the material. Different compositions of the thermochromic material and their corresponding response time with respect to rate of heat transfer were studied and correlated. First, a theoretical equation was derived and later on it was experimentally verified to quantify the response time in PVA–metal complex‐based thermochromic systems. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4832–4834, 2006
Supercritical carbon dioxide assisted preparation of conductive polypyrrole/cellulose diacetate composites
Authors: Li Gang , Sun Xinghua , Liao Xia , Yu Jian , Zhang Jun , He Jiasong
Published: March 2006

Supercritical carbon dioxide (SC‐CO2) has been used to assist the preparation of conductive polypyrrole/cellulose diacetate (PPy/CDa) composites by in situ chemical oxidative polymerization. The morphology and conductivity of resulted composites were investigated with scanning electron microscopy and four‐probe method, respectively. With the assistance of strong swelling effect of SC‐CO2, composite films were obtained with a macroscopically homogeneous structure and conductivity up to 10−1 S cm−1 order of magnitude. Increasing the pressure of SC‐CO2 increased conductivity, while increasing the temperature decreased conductivity. For comparison, PPy/CDa composite was also prepared with conventional oxidative method in aqueous solution. From the viewpoint of conductivity and environmental protection, the SC‐CO2 method showed its superiority over the conventional one. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4575–4580, 2006
Variation of MUF and PMUF resins mass fractions during preparation
Authors: Lei Hong , Pizzi A. , Du Guanben , Despres A.
Published: March 2006

The variation of molecular mass distribution with the progress of the reaction was studied for the following: (i) sequential‐type melamine–urea–formaldehyde (MUF) resin formulations in which the sequence of addition of chemicals follows well‐defined species reactivity principles; (ii) a nonsequential MUF formulation in which simultaneous melamine and urea competition for formaldehyde yields a MF resin cocondensed with small amounts of urea. This resin became soaked with reacted and unreacted monomeric urea species. (iii) A PMUF resin, namely a MUF resin with a small proportion of phenol (7.8% by weight on melamine and urea) cocondensed with the main MUF fraction. All the formulations used were industrial resins formulations in current use. Development and variation of molecular mass fractions, from which performance and other useful resin parameters depend, have been found to depend on the type of resin formulation used for these type of aminoplastic resins. The two very different MUF resin formulations yielded different variations in molecular mass fractions during the progress of the reaction and during the so‐called ambient temperature “maturing” of the resin. The PMUF resin also showed both similar and different fractions present during manufacturing and during short term ageing at ambient temperature. While similarities in recurrent fractions and in trends are common to all the three different formulations, differences between them are also clearly observed. A major proportion of the reaction of some of the aminoplastic resins examined also occurs on ageing (i.e.“maturing” of the resin at ambient temperature), this appearing to be an essential phase of the resin preparation process. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4842–4855, 2006
Structural effects of pendant groups on thermal and electrical properties of polyimides
Authors: Wang Leeyih , Chang Poling , Cheng Chun‐Lin
Published: March 2006

Two series of aromatic polyimides containing various‐sized alkyl side groups were synthesized by thermal imidization of the poly(amic acid)s prepared from the polyaddition of benzophenonetetracarboxylic dianhydride and hexafluoro‐isopropylidene bis(phthalic anhydride) with 4,4′‐methylenedianiline, 4,4′‐methylene‐bis(2,6‐dimethylaniline), 4,4′‐methylene‐bis(2,6‐diethylaniline), and 4,4′‐methylene‐bis(2,6‐diisopropylaniline). The extent to which alkyl substitutes affect the thermal properties of polyimides was examined by differential scanning calorimetry, thermomechanical analyzer, and thermogravimetric analysis techniques. The analytical results demonstrated that the incorporation of alkyl moieties causes a moderate increase in the coefficient of thermal expansion and a slight decrease in thermal stability. Notably, all polymers had a decomposition temperature exceeding 500°C. The glass transition temperature increases markedly when hydrogen atoms at ortho positions on aniline rings are replaced with methyl groups, but decreases with growing alkyl side group size. The dielectric measurements show that the polymer possessing a large alkyl side group would have the lower dielectric value. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4672–4678, 2006
Sulfonation degree determination of polystyrene ionomers by using adiabatic bomb calorimeter
Authors: Alkan Cemil , Dumanlı Ahu Gümrah , Aras Leyla
Published: March 2006

Sulfonation degree determination of sulfonated polystyrene and the corresponding ionomers are performed by adiabatic bomb calorimeter. The theoretical calculations from the band energies for the combustion enthalpy values (calorific values) and the experimental values are compared, and a linear relation between the values is found. Sulfonation and neutralization processes are examined by elemental sulfur analysis and atomic absorption spectroscopy (AAS). It was obvious that increasing sulfonation degree yields a decrease in the combustion enthalpy values, as it is expected from the theoretical calculations. In addition, metal ion incorporation to the structure deviates the experimental combustion enthalpy values especially for the ionomers which have higher sulfonation degrees. This is due to the formation of a higher degree aggregation. © Wiley Periodicals, Inc. J Appl Polym Sci 100: 4684–4688, 2006
Shear strength of calabrian pine (Pinus brutia Ten.) bonded with polyurethane and polyvinyl acetate adhesives
Authors: Burdurlu Erol , Kiliç Yilmaz , Eli'Bol Gülcin Cankiz , Kiliç Murat
Published: March 2006

In this study, the change in shear strength on radial and tangential surfaces of Calabrian pine (Pinus brutia Ten.) wood having different roughness values as the result of sawing with a circular ripsaw, planning, and sanding, and bonded with polyurethane (PU) and polyvinyl acetate (PVAc) adhesives at the pressure levels of 3, 6, and 9 kg f/cm2 were studied. A total of 360 specimens of each, prepared with the objective of being able to determine the effect of the variables on bond performance, were subjected to the shear test in the universal test machine in accordance with the ASTM D 905–98 standard. The values obtained were analyzed statistically and the results were interpreted. The highest shear strength (11.83 N/mm2) for plane of cut was obtained on the tangential surface after sanding and applying PVAc adhesive with a pressing pressure of 9 kg f/cm2. The lowest shear strength (6.01 N/mm2) was obtained in the joinings made on the planed surfaces by using PU adhesive and a pressing pressure of 3 kg f/cm2. The highest shear strength (9.10 N/mm2) on the radial surface was obtained after sanding and applying PVAc adhesive and pressing with a pressure of 6 kg f/cm2. The lowest shear strength (3.76 N/mm2) was obtained in the specimens whose surfaces were sanded and by using PU adhesive and with a pressing pressure of 3 kg f/cm2. In general, in the radial surfaces, just like in the tangential surfaces, the specimens bonded with PVAc produced a higher shear strength compared to those glued with PU. According to these results, it is definitely necessary to sand the surfaces prior to the bonding process to have a higher shear strength. The bonding process should be made on the tangential surfaces with higher pressures. The PVAc adhesive should be preferred instead of the PU adhesive. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4856–4867, 2006
Influence of ionic groups on the crystallization and melting behavior of segmented polyurethane ionomers
Authors: Zhu Y. , Hu J. L. , Yeung K. W. , Liu Y. Q. , Liem H. M.
Published: March 2006

The isothermal crystallization kinetics and melting behavior of the soft segment in polyurethane (PU) ionomer/nonionomer based on PCL‐4000 (poly(ε‐caprolactone)) were investigated using polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). In general, the presence of ionic groups in PU ionomers can promote the formation of a more stable crystalline structure and lower the equilibrium melting temperature of the crystallizable phase. Comparison between the crystallization characteristics of PU nonionomers and ionomers suggests that the Coulombic Forces between ionic groups within hard segment can increase the crystallization rate and decrease the crystal size of soft segment when the total molecular weight (Mw) of PU ionomer is higher than ∼71,000. On the other hand, the opposite effect of ionic groups on the crystallization rate is observed in PU ionomers with Mw below ∼20,000. The DSC thermograms illustrate that the ionic groups can significantly enhance the microphase separation in PU ionomers with higher Mw values. By the control and manipulation of crystallization and microstructure formation in PU ionomer, it is possible to achieve shape memory PUs with superior physical property. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4603–4613, 2006
Effect of degree of substitution and molecular weight of carboxymethyl chitosan nanoparticles on doxorubicin delivery
Authors: Shi Xiaowen , Du Yumin , Yang Jianhong , Zhang Baozhong , Sun Liping
Published: March 2006

The aim of this study was to evaluate the potential of carboxymethyl chitosan (CM‐chitosan) nanoparticles as carriers for the anticancer drug, doxorubicin (DOX). Different kinds of CM‐chitosan with various molecular weight (MW) and degree of substitution (DS) were employed to prepare nanoparticles through ionical gelification with calcium ions. Factors affecting nanoparticles formation in relation to MW and DS of CM‐chitosan were discussed. By the way of dynamic light scattering (DLS), TEM, and atomic force microscopy (AFM), nanoparticles were shown to be around 200–300 nm and in a narrow distribution. FTIR revealed strong electrostatic interactions between carboxyl groups of CM‐chitosan and calcium ions. DOX delivery was affected by the molecular structure of CM‐chitosan. Increasing MWs of CM‐chitosan from 4.50 to 38.9 kDa, DOX entrapment efficiency was enhanced from 10 to 40% and higher DS slightly improved the load of DOX. In vitro release studies showed an initial burst followed by an extended slow release. The DOX release rate was hindered by CM‐chitosan with high MW and DS. These preliminary studies showed the feasibility of CM‐chitosan nanoparticles to entrap DOX and the potential to deliver it as controlled release nanoparticles. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4689–4696, 2006
Swelling behavior of hydroxyapatite‐filled chitosan–poly(acrylic acid) polyelectrolyte complexes
Authors: Sailaja G. S. , Ramesh P. , Varma H. K.
Published: March 2006

A family of hydroxyapatite (HAP)‐filled chitosan (CHI)–poly(acrylic acid) (PAA) polyelectrolyte complexes was prepared for the development of a degradable biocompatible organic matrix with nascent HAP that will degrade in vivo over a period of time. The effects of complexation on the degradation profile of the composites as well as the interaction between the CHI–PAA matrix and HAP in the composite system were evaluated by studying the swelling behavior of these composites in phosphate‐buffered saline (PBS) by varying their CHI–PAA ratio and HAP content. All composite systems showed a general trend of three stages of swelling with the variation in the degree of equilibrium swelling. The percentage weight gain initially decreased in a linear way with increases in the HAP weight percentages, leading to a first equilibrium swelling, represented by the plateau; further increased to a greater extent; and finally stabilized. The CHI/PAA/HAP composites were stable in PBS up to a period of more than 45 days whereas the 50/50 CHI/PAA control sample showed a single equilibrium attained after a period of 288 h. Further exposure of the specimen to the medium led to its disintegration. It was also observed that, even though CHI and PAA were capable of binding HAP, because of the lack of efficient binding, the integrity of the CHI–HAP and PAA–HAP composites were lost within 48 h. The 50/50/80 CHI/PAA/HAP composition showed the minimum amount of swelling in the series. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4716–4722, 2006
High performance polymer composites on PEEK reinforced with aluminum oxide
Authors: Goyal R. K. , Negi Y. S. , Tiwari A. N.
Published: March 2006

A study on high performance poly(ether‐ether‐ketone) (PEEK) composites prepared by incorporating aluminum oxide (Al2O3), 0 to 50 wt % by hot compaction at 15 MPa and 350°C was described. Density, thermogravimetric analysis/differential scanning calorimetry, and scanning electron microscopy (SEM) were employed to evaluate their density, thermal stability, crystallinity, and morphology. Experimental density was found higher than theoretical density, which indicates that composite samples are sound. It was found that the addition of micron sized (< 15 μm) Al2O3 increased the peak crystallization temperature by 12°C when compared with neat PEEK with insignificant increase in melting temperature. Half‐time of crystallization is reduced from 2.05 min for the neat PEEK to 1.08 min for PEEK incorporated with 30 wt % Al2O3 because of the strong nucleation effect of Al2O3. The thermal stability of composites in air atmosphere was increased by 26°C. However, thermal stability in nitrogen atmosphere decreases at lower concentration of Al2O3 but increases above 20 wt % of Al2O3. Uniform dispersion of Al2O3 particles was observed in PEEK polymer matrix by SEM. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4623–4631, 2006
Monomer reactivity ratios for acrylonitrile/ammonium itaconate during aqueous‐deposited copolymerization initiated by ammonium persulfate
Authors: Chuansheng Cui , Chengguo Wang , Yaqi Zhao
Published: March 2006

Monomer reactivity ratios of acrylonitrile/ammonium itaconate during aqueous‐deposited copolymerization initiated by ammonium persulfate were investigated. Kelen–Tudos method was used to examine the reactivity ratios. It was shown that the reactivity ratios were influenced by the conversions and temperatures of copolymerization. The reactivity ratios in aqueous‐deposited copolymerization system were similar to those in the solution polymerization system at polymerization conversions of less than 5% [reactivity ratio of acrylonitrile (r1) 0.842 ± 0.02, reactivity ratio of ammonium itaconate (r2) = 3.624 ± 0.02]. The reactivity ratio of AN rises and that of (NH4)2IA decreases, when the polymerization conversion increases till 13%. Aqueous‐deposited copolymerization initiated by AIBN was also studied. It was found that some polymers were formed in water phase and the monomers had different reactivity ratios by comparison with those initiated by ammonium persulfate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4645–4648, 2006
Degradation kinetics of acrylonitrile/ammonium acrylate copolymers
Authors: Ying Liang , Hou Chen , Fei Wang
Published: March 2006

acrylonitrile (AN)/ammonium acrylate (AAT) copolymers were prepared by H2O/dimethyl formamide suspension polymerization technique. Differential scanning calorimetry results of the degradation of AN/AAT copolymers in air are presented. The apparent activation energy of degradation of the copolymer was calculated by using Kissinger method. Effects of copolymerization conditions on the apparent activation energy of copolymer were studied. It has been found that increasing dimethyl formamide concentration in the solvent mixture leads to a rapid increase in the degradation apparent activation energy of AN/AAT copolymer. The value of the degradation apparent activation energy of the copolymer synthesized in dimethyl formamide solvent increases up to 141.7 kJ mol−1. The apparent activation energy decreases quickly, along with increase in AAT concentration, and this change becomes less prominent as the weight ratio of AAT/AN goes beyond 6/94. The apparent activation energy shows a trend of increase with increasing copolymerization temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4649–4653, 2006