bluuebunny/crossref_metadata_2025 huggingface dataset:
Through a Glass, Darkly: The Dynamics of Fan‐Celebrity Encounters
Authors: Ferris Kerry O.
Published: February 2004

Mass media influence interaction in important ways: fans of serial television use mass media to incorporate the fictional and the extraordinary into their real, ordinary, everyday lives. Using ethnographic and interview data, this article examines the activities through which certain fans seek face‐to‐face encounters with the celebrities they admire and how this intersection of the ordinary with the extraordinary creates problems of interpretation that fans attempt to solve. Fans make and take advantage of opportunities for prestaged encounters at official public appearances by their favorite actors. Some fans may also encounter their favorite celebrities by chance in the course of their daily rounds in “celebrity sightings,” or unstaged encounters. Certain fans, however, actively pursue actors, deliberately seeking them out and creating fan‐staged encounters. These efforts produce a distinctive interactional tension in which pursuing fans recognize the similarities between their behavior and that of “celebrity stalkers” and attempt to differentiate themselves from the stalkers celebrities fear. This article analyzes these interactions as a step toward a theory of fan‐celebrity interaction.
The Origins of Charisma as Process: A Case Study of Hildegard of Bingen
Authors: Finlay Barbara
Published: February 2004

A case study of the twelfth‐century visionary Hildegard of Bingen is presented to examine the process through which a charismatic relationship is constructed in interaction between an individual and significant others and more distant followers. Hildegard's identity as a charismatic prophet developed over a number of years through a process of interaction with various ecclesiastical authorities; alterations occurred in both the prophet's self‐identity and the way others viewed her, leading finally to her authorization as a prophet and visionary. The cultural context provided plausibility structures, relevant symbols, and limitations that influenced the form of Hildegard's charismatic status. This status led to unprecedented achievements for a woman of her time, but her efforts mainly supported and strengthened the institutional tradition in which she served.
From River God to Research Grunt: Identity, Emotions, and the River Guide
Authors: Holyfield Lori , Jonas Lilian
Published: February 2004

Leisure identities and occupational identities are often assumed to be opposites. Drawing on two ethnographic studies, evidence is provided to illustrate how organizational contexts (or lack thereof) both interrupt and influence the social construction of identities. River running is but one activity that provides participants with opportunities to achieve a desired identity using situated emotion cues. In this study river guides are examined to highlight the negotiations they must employ as they attempt to establish a “river” identity in contexts that distinguish their work and leisure roles.
Searching for Yellowstone1
Authors: Denzin Norman K.
Published: February 2004

This experimental, layered, mixed‐genre narrative folds my biographical experiences into a critical reading of Wallace Stegner's autobiographical account of his childhood. This reading allows me to discuss three versions of the midcentury white male middle‐class American dream. I compare Stegner's father to my father and my grandfather, as I discuss a trip I almost made to Yellowstone Park with my grandfather before he died.
Rationality and Institutional Contingency: The Varying Politics of Economic Regulation in the Fire Insurance Industry
Authors: Bartley Tim , Schneiberg Marc
Published: February 2004

Are the politics of economic regulation contingent on institutions? Drawing on arguments about institutional mediation and the institutional bases of rational action, we explore how institutions shape the dynamics invoked in two theories of regulation. We argue that institutional arrangements affect both the clarity and the content of group interests in regulation. Event history analyses of U.S. states' passage of fire insurance regulation from 1906 to 1930 support these arguments in several ways. Market-heterogeneity dynamics specified by cartel-capture theory affected the passage of regulation only under some conditions—namely, relatively depoliticized settings with little overt conflict or uncertainty about policy outcomes. In addition, interest group dynamics were conditioned by the consolidation of interorganizational fields around a particular model of market order, which allowed divergent interest groups to converge in support of regulation. The research suggests ways of thinking about theoretical generality and specificity, regulatory politics, and the relationship between institutional theory and rationality.
The Social Construction of Female and Male High School Basketball Participation: Reproducing the Gender Order through a Two-Tiered Sporting Institution
Authors: Shakib Sohaila , Dunbar Michele D.
Published: February 2004

Qualitative interviews explore the meanings increased female participation in basketball have for a sample of basketball players from three high schools. To what extent are post–Title IX female inroads into sport challenging and/or reproducing the gender order? How do girls and boys give meaning to the successes and failures of girls' and boys' basketball teams and athletics? The social processes reproducing a two-tiered basketball institution at the high school level are illustrated (i.e., emphasis on playing differences, undervaluing of girls' contributions, policing of normative gender expectations). This research suggests that both girls and boys are complicit in supporting the gender order. It illustrates how challenges to the gender order signified by females' increased participation in “male-identified” sports are appropriated. Modifiable social processes for gender equity education in sport are identified as important to support Title IX legal access.
Images of Sport in Popular Nonsport Magazines: Power and Performance versus Pleasure and Participation
Authors: Curry Timothy J. , Arriagada Paula A. , Cornwell Benjamin
Published: February 2004

This research aims to analyze the relationship between sport and the gender order in society by focusing on sport-related images (N = 312) found in popular nonsport men's and women's magazines (N = 46). We find that sport images are often found in both men's and women's nonsport magazines, though these images are more common in magazines that target men. Interestingly, the types of sports portrayed differ greatly depending on the audience. Advertisers and media publishers emphasize images of power and performance sports for men, while pleasure and participation activities are more likely for women. We also note that when sport images contain representations of minorities, they do so in nonintegrated fashion. Hence we conclude that images of sport in nonsport magazines primarily serve to reinforce the existing gender and racial order.
Anabolic-Androgenic Steroid Use and other Adolescent Problem Behaviors: Rethinking the Male Athlete Assumption
Authors: Miller Kathleen E. , Barnes Grace M. , Sabo Donald F. , Melnick Merrill J. , Farrell Michael P.
Published: February 2004

Based on a national sample of over 16,000 public and private high school students (the 1997 Youth Risk Behavior Survey), we used logistic regression analysis to examine relationships among anabolicandrogenic steroid use and other problem behaviors for female and male athletes and nonathletes. After controlling for age, race/ethnicity, parental educational attainment, urbanicity, and recent exercise, users had significantly greater odds of engaging in other illicit drug, alcohol, and tobacco use, fighting, suicide attempts, sexual risk taking, vehicular risk taking, and pathogenic weight loss behavior, suggesting that steroid use is part of Jessor's problem behavior syndrome for adolescents. Despite the stereotypical images of the male athlete user, both nonathlete and female users also faced elevated risks of multiple drug use and other health-compromising behavior. Thus this study rejects the view of steroid use as merely a logical extension of the male athletic cultural imperative.
All Segregation is Not Equal: The Impact of Latino and Black School Composition
Authors: Goldsmith Pat António
Published: February 2004

Latinos are a large, highly segregated minority group achieving less than whites in school, but the extent to which segregation is responsible for their relatively low achievement is not well known. The effect of proportion Latino on educational achievement is often assumed to be identical to the effect of proportion black. I use the NELS to test this assumption. Results reveal that segregation concentrates disadvantages for Latinos and blacks, but surprisingly, proportion Latino tends to positively influence test scores over the high school years. Proportion black, in contrast, does not affect test scores except for a negative effect for blacks in science. Integration of Latinos with whites would reduce some of the inequalities between schools, it would not hurt and in some areas would help the test scores of whites, but it would hurt Latinos unless some of the helpful features of predominantly Latino schools could be copied.
Environmental Degradation, Environmental Sustainability, and Overurbanization in the Developing World: A Quantitative, Cross-National Analysis
Authors: Shandra John M. , London Bruce , Williamson John B.
Published: February 2004

This is the first quantitative, cross-national study that incorporates predictors designed to test hypotheses linking overurbanization to environmentally induced migration. The study is based on a sample of fifty-eight developing countries using lagged dependent variable panel regression. Our major findings are quite clear with respect to newer ruralpush and urban-pull arguments that developing countries suffering from various forms of environmental degradation are prone to overurbanization. Deforestation exerts a positive and significant effect on overurbanization, whereas environmental sustainability exerts a negative and significant effect on overurbanization. In addition, our results support hypotheses derived from the political modernization perspective that civil society and democratic regimes help to reduce overurbanization, as well as hypotheses suggested by neo-Malthusian theory that high levels of population growth contribute to high levels of overurbanization. We also find support for dependency theory in that transnational economic linkages based on multinational corporations and international lending institutions foster increased overurbanization in the developing world.
The Power of Apology and the Process of Historical Reconciliation
Authors: Weyeneth Robert R.
Published: February 2004

The article analyzes one of the ways that history makes the headlinestoday: in discussions of whether the present can--and should--apologize for the past. It examines this recent phenomenon by asking if historical apologies have the ability to facilitate a process of historical reconciliation. In its first three sections, the article explores the range and forms of apologies reported in the press during the last decade or so, the motives and goals of apologists, and the reasoning of those with misgivings about the utility and wisdom of apologies. A fourth section assesses the efficacy of historical apologies. Is an apology a meaningful way for the present to engage the past or to address historic human injustice? Do apologies have the power to reconcile? The conclusion offers a brief explanation for why we seem to be living in an age of apology.
Managing Historical Capital in Shandong: Museum, Monument, and Memory in Provincial China
Authors: Flath James A.
Published: February 2004

This paper traces the development and distribution of museums and public monuments in one province of China during the twentieth century, with special emphasis on the cultural policies of the post–Mao reform era. By considering the museum and monument (i.e., artifacts, historically significant geographic features, and the physical representation of historical experience) as among the most tangible aspects of historical capital, it is demonstrated how region, province, and nation are involved with public and private interests in an ongoing dialogue over what types of history are to be represented, and in what context. This evidence suggests that while the state may impose its own historical interpretation in key areas, most public history is sponsored and managed by provincial, regional, and even commercial interests which represent the immediate interest first, leaving the connection with the nation to develop on its own tenuous ground. Regional historical representation, therefore, demonstrated that "national history" is not the sum of its parts, and that the "making" of public history occurs at multiple levels of bureaucracy, and through many levels of patronage.
Commemoration, Public Art, and the Changing Meaning of the Bunker Hill Monument
Authors: Purcell Sarah J.
Published: February 2004

The controversy over a 1998 public art project by Krzysztof Wodiczko at the Bunker Hill Monument dramatizes how the meanings of monuments are subject to constant renegotiation. Reaction to Wodiczko's art, which used the monument to comment on crime in Charlestown, Massachusetts, demonstrated both changes and continuities in the understandings of monuments since the Bunker Hill Monument was first designed in the 1820s. Both Wodiczko and the monument's original planners defined it as a tool capable of providing "eternal" recognition of heroism and sacrifice. Experimental projects may have great power to teach the public about the changing meaning of the past.
Titelbild: Antifreeze Glycoproteins: Elucidation of the Structural Motifs That Are Essential for Antifreeze Activity (Angew. Chem. 7/2004)
Authors: Tachibana Yuki , Fletcher Garth L. , Fujitani Naoki , Tsuda Sakae , Monde Kenji , Nishimura Shin‐Ichiro
Published: February 2004

Antifrost‐Glycoproteine (AFGPs) in den Körperflüssigkeiten von Polarfischen verhindern das Einfrieren durch Unterdrückung des Eiskristallwachstums. Die relevanten Strukturmotive der AFGPs wurden durch eine Kombination aus chemischer Synthese und spektroskopischen Analysemethoden aufgedeckt. Die amphiphilen AFGPs bilden eine dreifach linksgängige Achse, die es den Zuckerdomänen ermöglicht, sich an einer Seite des Proteins zusammenzulagern. Weitere Informationen entnehmen Sie der Zuschrift von S.‐I. Nishimura et al. auf S. 874 ff.
Synthesis and characterization of poly(ethylene isophthalate‐co‐ethylene terephthalate) copolyesters
Authors: Finelli L. , Fiorini M. , Siracusa V. , Lotti N. , Munari A.
Published: February 2004

Poly(ethylene isophthalate‐co‐ethylene terephthalate) (PEIPET) copolymers of various compositions and molecular weights were synthesized by melt polycondensation and characterized in terms of chemical structure and thermal and rheological properties. At room temperature, all copolymers were amorphous and thermally stable up to about 400°C. The main effect of copolymerization was a monotonic increase of glass transition temperature (Tg) as the content of ethylene terephthalate units increased. The Fox equation accurately describes the Tg–composition data. The presence of ethylene terephthalate units was found to influence rheological behavior in the melt, with the Newtonian viscosity increasing as the content of ethylene terephthalate units increased. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 186–193, 2004
Thermotropic liquid‐crystalline polyphosphate esters containing phenolphthalein moiety
Authors: Srividhya D. , Senthil S. , Kannan P.
Published: February 2004

A new series of thermotropic liquid‐crystalline (LC) polyphosphate esters containing phenolphthalein as a part of their mesogen has been synthesized by a solution polycondensation method. The even‐numbered methylene spacers were varied from 2–10, and ethyl phosphate was used as a phosphorus heterogeneity. Thermal analysis showed that these polymers are stable up to 275–342°C with high char yield. All of the polymers exhibited liquid‐crystalline properties except for Polymers I and VI. Differential scanning calorimetry (DSC) confirmed the mesophase formation of the polymers. The glass transition temperature (Tg) and melting temperature (Tm) of the polymers were considerably low. A polymer containing phenolphthalein alone as a rigid segment with decamethylene spacers was also synthesized, but it did not show birefringent melt properties. These results reveal that phenolphthalein alone cannot act as a mesogen, whereas phenolphthalein phenylester can. Molecular modeling studies and conformational analysis confirmed that the steric hindrance of phenylester and the conjugation effect could explain the promotion of mesogenic behavior by phenolphthalein phenylester. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 194–200, 2004
Enhanced corrosion prevention effect of polysulfone–clay nanocomposite materials prepared by solution dispersion
Authors: Yeh Jui‐Ming , Chen Chi‐Lun , Chen Yen‐Chen , Ma Chin‐Yi , Huang Hsi‐Ya , Yu Yuan‐Hsiang
Published: February 2004

A series of polymer–clay nanocomposite (PCN) materials containing polysulfone (PSF) and layered MMT clay were successfully prepared by effectively dispersing inorganic nanolayers of MMT clay in an organic PSF matrix via a solution dispersion technique. The synthesized PCN materials were subsequently investigated with a series of characterization techniques, including Fourier transform infrared (FTIR) spectroscopy, wide‐angle powder X‐ray diffraction (XRD) and transmission electron microscopy (TEM). The prepared PCN coatings with low clay loading (1 wt %) on cold‐rolled steel (CRS) were found to be superior in corrosion prevention to those of bulk PSF, based on a series of electrochemical measurements of corrosion potential, polarization resistance, corrosion current and electrochemical impedance spectroscopy (EIS) in a 5 wt % aqueous NaCl electrolyte. The effects of material composition on the molecular barrier, mechanical strength and optical clarity of PSF and PCN materials, in the form of membranes, was also studied by molecular permeability analysis (GPA), dynamic mechanical analysis (DMA) and UV‐Visible transmission spectra, respectively. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 631–637, 2004
Miscibility of poly(vinylidene fluoride) and atactic poly(methyl methacrylate)
Authors: Huang Cheng , Zhang Li
Published: February 2004

Different results for the miscibility between poly(vinylidene fluoride) (PVDF) and atactic poly(methyl methacrylate) (at‐PMMA) have been reported. In this study, the interaction between PVDF and at‐PMMA was confirmed, although such a kind of force was weak. With increasing PVDF weight fraction, the blends exhibited more heterogeneous properties, and the films thus appeared more opaque. The difference spectra after subtraction of PVDF and poly(methyl methacrylate) (PMMA) showed that the interaction between the carbonyl groups of PMMA and the hydrogen atoms of PVDF increased as the stretch vibration of CO bonds band shifted to a lower frequency with higher PVDF content. From the computer analysis, the sum spectra of the blends could not be obtained by simple addition of the separate spectra of the homopolymers. The contact angle measurement demonstrated that the hydrophobicity against water increased with PVDF content and that contact angles against water were larger than 90° when the PVDF content exceeded 30%, indicating good water repellency. The contact angles against n‐hexane, however, could not be measured because of the complete wetting of the film by n‐hexane. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1–5, 2004
Steady viscosity of a polymer/liquid crystal biphasic system
Authors: Yang I‐Kuan , Lai Wei Yuan
Published: February 2004

Steady shear viscosities of blends of poly(butyl acrylate) and cholesteryl oleyl carbonate were studied under a cone and plate fixture. Unique shear behavior was observed for the polymer/low molar mass liquid crystal mixture. The viscosity of the liquid crystal‐rich phase increases with polymer content until a maximum is reached. The height of the viscosity maximum decreases with the magnitude of the shear stress and disappears when the stress reaches 200 Pa. Addition of liquid crystal to the polymer‐rich phase causes a viscosity reduction, and at higher stress levels, the viscosity reduction becomes more effective with the same amount of liquid crystal addition. The viscosity reduction may be related to the fibril morphology of the liquid crystal and the viscosity maximum can be interpreted by the emulsion effect being counteracted by a viscosity reduction effect. A shear‐thickening behavior was observed in the intermediate shear rates for the blends with a volume fraction of poly(butyl acrylate) between 9.4 and 49.8%. This is a novel liquid–liquid system that exhibits a shear thickening behavior. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 25–30, 2004
Studies on the fabrication of strong‐acid/weak‐base amphoteric ion exchange fibers and their adsorption property for amino acids
Authors: Fu Ruowen , Wang Fei , Tang Liyuan , Lei Yongqiang , Lui Ning , Liang Minling
Published: February 2004

The strong acid/weak base amphoteric ion exchange fibers with different ratios of acidic and basic groups and different grafting percentages were prepared by grafting styrene and 4‐vinylpyridine onto polypropylene fiber and then sulfonating with chlorosulphonic acid, under various reaction conditions, such as the feed ratio of styrene and 4‐vinylpyridine, monomers concentration, sulfonation temperature, and sulfonation time, swelling time, etc. The produced strong acidic and basic groups are the sulfonic group and the pyridyl group, respectively. Only one sulfonic group is induced into an aromatic ring in most of PP‐g‐St‐4VP and it is located in the para‐position of styrene. The contents of the strong‐acid group and the weak‐base group of the PP‐g‐SO3H‐Py fibers produced in this work are in the range of 1.98 to 4.22 and 2.33 to 4.24 mmol/g, respectively. The strong acid/weak based amphoteric fibers obtained possess good static adsorption property for basic and acidic amino acids, and they also have a good dynamic adsorption and elution property for amino acids like related strong acid ion exchange fibers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 418–425, 2004
Modification of LLDPE using esterified styrene maleic anhydride copolymer: Study of its properties and environmental degradability
Authors: Pal Jaykisor , Singh Harpal , Ghosh Anup. K.
Published: February 2004

Linear low‐density polyethylene (LLDPE) was blended with decanol‐esterified styrene maleic anhydride copolymer (MDESMA) with an aim to enhance the environmental degradability of polyethylenes. Styrene‐maleic anhydride copolymer (SMA) was synthesized by precipitation polymerization, using benzoyl peroxide (BPO) as initiator. SMA was esterified with a long‐chain monoalcohol, n‐decanol, using methyl ethyl ketone (MEK) as solvent at 80°C to obtain monoesterified styrene‐maleic anhydride (MDESMA). Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimeter (DSC), and thermogravimetric analysis (TGA) were performed to characterize SMA and MDESMA. IR spectra of MDESMA showed a decrease in intensity of peak responsible for carbonyl absorption of a five‐membered ring anhydride group along with broadening of carboxyl OH stretching peak. TGA showed two‐stage degradation for SMA and MDESMA. LLDPE was blended with MDESMA in single‐screw extruder and blends were characterized thermally by DSC and TGA. A single endothermic melting peak of LLDPE/MDESMA blend was observed. Films of the blends, formed by compression molding, showed an increase in modulus of elasticity but a decrease in elongation at break with increasing concentration of MDESMA. LLDPE/MDESMA blend compositions when kept in phosphate/citric acid buffer solution (pH ∼ 8) showed initial weight gain because of water absorption and subsequently loss in weight due to dissolution of soluble component of blends. Film samples of blends kept for soil burial also showed similar behavior. Contact‐angle measurement of film samples of the blends showed an increase in value on soil burial, indicating degradation/dissolution of MDESMA. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 102–108, 2004
Synthesis, characterization, and catalytic activity of 4 mol % N,N′‐methylene bisacrylamide crosslinked poly(acrylic acid)–metal complexes
Authors: John Magi , Jose Jincy , Mathew Beena
Published: February 2004

The metal‐ion complexation behavior and catalytic activity of 4 mol % N,N′‐methylene bisacrylamide crosslinked poly(acrylic acid) were investigated. The polymeric ligand was prepared by solution polymerization. The metal‐ion complexation was studied with Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), and Zn(II) ions. The metal uptake followed the order: Cu(II) > Cr(III) > Mn(II) > Co(II) > Fe(III) > Zn(II) > Ni(II). The polymeric ligand and the metal complexes were characterized by various spectral methods. The catalytic activity of the metal complexes were investigated toward the hydrolysis of p‐nitrophenyl acetate (NPA). The Co(II) complexes exhibited high catalytic activity. The kinetics of catalysis was first order. The hydrolysis was controlled by pH, time, amount of catalyst, and temperature. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 272–279, 2004
Crystallization of poly(tetramethylene succinate) in blends with poly(ϵ‐caprolactone) and poly(ethylene terephthalate)
Authors: Chong K. F. , Schmidt H. , Kummerlöwe C. , Kammer H. W.
Published: February 2004

The crystallization behavior of polymer blends of poly(tetramethylene succinate) (PTMS) with poly(ϵ‐caprolactone) (PCL) or poly(ethylene terephthalate) (PET) was investigated with differential scanning calorimetry under isothermal and nonisothermal conditions. The blends were prepared by solution casting and precipitation, respectively. The constituent polymers were semicrystalline materials and crystallized nearly independently in the blends. The addition of the second component to PTMS showed that PCL did not significantly influence the crystallinity of the constituents in the blends under isothermal conditions, whereas the crystallization of PTMS was slightly suppressed by crystalline PET. Nonisothermal crystallization under constant cooling rates was examined in terms of a quasi‐isothermal Avrami approach. In blends, the rates of crystallization were differently influenced by the second component. The rate of the constituent that crystallized at the higher temperature was barely influenced by the second component being in the molten state, whereas the rate of the second component, crystallizing when the first component was already crystalline, was altered differently under isothermal and nonisothermal conditions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 149–160, 2004
A novel chemically and mechanically stable glycerol‐based crosslinked polystyrene support for polypeptide synthesis: A comparative study with Merrifield resin
Authors: Sasikumar P. G. , Kumar K. S. , Pillai V. N. Rajasekharan
Published: February 2004

A novel chemically and mechanically stable polymer support for solid‐phase peptide synthesis with excellent swelling performance in various organic solvents is described. The crosslinked polymer in its bead form was prepared by the aqueous suspension polymerization of the styrene and tri(propylene glycol) glycerolate diacrylate. The support is unique because the hydroxyl group is introduced into the polymer support in the polymerization step itself, which makes it highly cost effective. The hydroxyl functionality of the crosslinker in the polymer was used as a growth site for peptide synthesis, thus minimizing the incompatibility arising because of the styrene core as compared to styrene‐based polymer supports currently used in polypeptide synthesis. The utility of the resin for solid‐phase peptide synthesis was tested by the synthesis of a 19‐residue peptide amide of the envelope region of hepatitis C viral polyprotein and was compared with Merrifield resin by the 2‐(1H‐benzotriazol‐1‐yl)‐1,1,3,3‐tetramethyl uronium hexafluoro phosphate/1‐hydroxy benzatriazole method with a Rink amide linker. The molecular character of the polymer and the extent of crosslinking density on the dependence of the reactivity of the attached amino groups were investigated by a reactivity study of the amide bond formation of a model Val‐Ala dipeptide. Enhanced swelling, the increased rate of aminoacylation, and the high purity of the peptides synthesized on the novel support highlighted the influence of the polarity of the solid support in the solid‐phase synthesis. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 288–294, 2004
Synthesis and characterization of biodegradable block copolymers of poly(propylene fumarate‐co‐sebacate)‐co‐poly(ethylene glycol) and poly(ethylene fumarate‐co‐sebacate)‐co‐poly(ethylene glycol)
Authors: Najafi Farhood , Sarbolouki Mohammad N.
Published: February 2004

The synthesis of two low molecular weight linear unsaturated oligoester precursors, poly(propylene fumarate‐co‐sebacate) (PPFS) and poly(ethylene fumarate‐co‐sebacate) (PEFS), are described. PPFS, PEFS, and poly(ethylene glycol) are then used to prepare poly(propylene fumarate‐co‐sebacate)‐co‐poly(ethylene glycol) (PPFS‐co‐PEG) and poly(ethylene fumarate‐co‐sebacate)‐co‐poly(ethylene glycol) (PEFS‐co‐PEG) block copolymers. The products thus obtained are investigated in terms of the molecular weight, composition, structure, thermal properties, and solubility behavior. A number of design parameters including the molecular weights of PPFS, PEFS, and PEG, the reaction time in the polymer synthesis, and the weight ratio of PEG to PPFS or to PEFS are varied to assess their effects on the product yield and properties. The hydrolytic degradation of PPFS‐co‐PEG and PEFS‐co‐PEG in an isotonic buffer (pH 7.4, 37°C) is investigated, and it is found that the fumarate ester bond cleaves faster than does the sebacate ester bond. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 295–300, 2004
Study of the effect of poly(acrylonitrile‐co‐butadiene‐co‐styrene) on the mechanical properties of an epoxy system
Authors: Torres A. , López‐de‐Ullibarri I. , Abad M. J. , Barral L. , Cano J. , García‐Garabal S. , Díez F. J. , López J. , Ramírez C.
Published: February 2004

The mechanical properties of an epoxy system containing a diglycidyl ether of bisphenol A and 1,3‐bis(aminomethylcyclohexane) modified with different amounts of poly(acrylonitrile‐co‐butadiene‐co‐styrene) (ABS) were studied. Properties examined include tensile stress, percentage strain, tensile modulus, and tensile toughness determined in tensile tests, Rockwell hardness, and energy and maximum force to break a specimen in Charpy impact tests. The effect of the modification produced with the ABS was also studied using statistical methods including analysis of variance and multiple comparisons. The obtained data showed a significant effect of the modification produced with the ABS on the mechanical properties of this epoxy system, especially with the amount of 5 ABS per hundred parts of resin on the tensile properties and on the hardness. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 461–467, 2004
Fluorescence property of polycarbonate related to radial‐pattern formation
Authors: Tanimura M. , Tachibana M. , Kojima K.
Published: February 2004

The pattern change in a laminar flow of molten polycarbonate in a disk mold was experimentally investigated by altering the flow velocity. By use of a light‐scattering method, a radial pattern characterized by a periodic array of needlelike regions and the matrix was found to form as the flow velocity was increased. The density distribution of the polycarbonate molecules was an essential factor for pattern formation. As a result of the formation of this pattern, it was found that the boundaries between the needlelike regions and the matrix emitted weak fluorescence in the wavelength range of 600–700 nm under laser irradiation. An analysis indicated that transitions between excited π electron states in the phenylene groups were the sources of this fluorescence and that a key factor behind its occurrence was a decrease in the molecule density at the boundaries. These results reveal that the radial‐pattern formation changes the fluorescence property of polycarbonate in the visible and near‐infrared regions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 468–473, 2004
Biocidal polystyrene beads. III. Comparison of N‐halamine and quat functional groups
Authors: Chen Y. , Worley S. D. , Huang T. S. , Weese J. , Kim J. , Wei C.‐I. , Williams J. F.
Published: February 2004

A comparison has been made between the biocidal efficacies of N‐chlorinated polymeric beads and two derivatives of polyquat beads. Biocidal effects were measured after brief contact exposures of aqueous suspensions of either Staphylococcus aureus or Escherichia coli to the water‐insoluble beads. The polymeric backbone was held the same in all three types of beads, so they differed only in their biocidal derivative moieties. In all cases, functionalization of crosslinked chloromethylated polystyrene beads was performed to introduce the biocidal properties. Synthetic methods and test data will be presented. The most effective biocide, as measured by degree of inactivation in the shortest contact time of the two species of bacteria, was the N‐chlorinated hydantoinyl derivative of methylated polystyrene. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 363–367, 2004
Influences of co‐monomers and electrolyte acidity on morphological structure of copper‐in‐copolymer gradient film
Authors: Tang Jianguo , Chen Qiang , Liu Haiyan , Wang Yao
Published: February 2004

In this paper, the influences of composition of copolymers and acidity of electrolyte in an electrochemical reactor on morphological structure of copper‐in‐polymer gradient composite film were investigated. For binary copolymers, poly(acrylonitrile‐co‐methyl acrylate) [P(AN‐co‐MA)] and poly(acrylonitrile‐co‐sodium allyl sulfonate) [P(AN‐co‐SAS)], the charged group SO in P(AN‐co‐SAS) improves the swelling of the copolymer phase and copper reduction to form gradient morphology; the carboxylic ester group in P(AN‐co‐MA) is not effective because of its poor hydrophilicity, but it is a cooperating component with P(AN‐co‐SAS) to avoid excess of counterion (i.e., Na+) in SCF, which might severely interrupt Cu2+ coexistence. The swelling of the polymer phase is helpful to decrease the energy of the transfer ions in SCF and to enhance copper deposition and gradient formation. The increase of surface energy because of cluster growth raises the surface energy level of deposited Cu0 clusters. The conteraction between these two energy factors allows the size of clusters to be 50–100 nm. The appropriate H+ concentration improves active Cu2+ reduction and thus deposited gradient copper phase in the copolymer matrix. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 373–380, 2004
Proliferation rate of fibroblast cells on polyethylene surfaces with wettability gradient
Authors: Choee Jong‐Hwa , Lee Sang Jin , Lee Young Moo , Rhee John Moon , Lee Hai Bang , Khang Gilson
Published: February 2004

Surface wettability on anchorage‐dependent cells has an important role in cell growth rate. In our previous studies, we prepared a wettability gradient on polyethylene (PE) surfaces using corona discharge treatment from a knife‐type electrode whose power increased gradually along the sample length. The PE surfaces were oxidized gradually with increasing power and characterized by Fourier transform infrared spectroscopy, contact angle goniometry, and electron spectroscopy for chemical analysis. The purpose of this study is to determine the rate of proliferation on polymer surfaces with different wettability. The behavior of cell growth for NIH/3T3 fibroblast cells attached on the polymer surfaces with different hydrophilicity was investigated using wettability gradient PE surfaces prepared by corona discharge treatment. They were investigated for the number of grown cells from 24 to 60 h in terms of surface wettability. From the slope of cell number on PE gradient surface versus culture time, the proliferation rates (number of cell/cm2 · h) were calculated. It was observed that the proliferation rate was increased more on positions with moderate hydrophilicity of the wettability gradient surface than on the more hydrophobic or hydrophilic positions, i.e., 1111 (number of cell/cm2 · h) of 57° of water contact angle at the 2.5‐cm position (P < 0.05). This result seems closely related to the serum protein adsorption on the surface: the serum proteins were also adsorbed more on the moderately hydrophilic surface. In conclusion, surface wettability plays an important role in cell adhesion, spreading, and proliferation on the polymer surfaces. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 599–606, 2004
Effect of the Secondary Structure of Carbohydrate Residues of α1‐Acid Glycoprotein (Orosomucoid) on the Local Dynamics of Trp Residues
Authors: Albani Jihad René
Published: February 2004

We studied in this work the relation between the secondary structure of the carbohydrate residues of α1‐acid glycoprotein and the local motions of Trp residues of the protein. We measured for this purpose the fluorescence emission intensity and anisotropy of the Trp residues between −46 and +30° of the sialylated and asialylated protein. Our results indicate that, in both forms, the global profile of the emission intensity with temperature shows that Trp residues display static and collisional interaction with the neighboring amino acids. However, the profile of the asialylated form is more structured than that observed for the sialylated protein. The Y‐plot analysis of the emission‐anisotropy results indicated that the frictional resistance to rotation of the surface Trp residue is less important in the sialylated protein than in the asialylated form. This result is in good agreement with the fact that, in the asialylated conformation, the carbohydrate residues are closer to the protein surface than in the sialylated form, thereby increasing the contact of the surface Trp residue with the neighboring amino acids. Also, the interaction between the carbohydrate residues and the surface Trp residue contributes to the modification of the frictional resistance to rotation of the fluorophore.
Polarized Vesicles in Molecular Recognition and Catalysis
Authors: Sakai Naomi , Matile Stefan
Published: February 2004

This account summarizes studies on chemistry in polarized vesicles with rigid‐rod molecules. Examples for the recognition of and self‐assembly, molecular recognition, and catalysis in polarized vesicles are discussed with emphasis on ‘remote control’ by dipolepotential interactions and electrostatic steering.
Cyclopropane‐Annelated Azaoligoheterocycles by Ti‐Mediated Intramolecular Reductive Cyclopropanation of Cyclic Amino Acid Amides
Authors: Gensini Martina , de Meijere Armin
Published: February 2004

Starting from pyrrole‐ and indole‐2‐carboxylic acids 5 a and 5 b, the tri‐ and tetracyclic N,N‐dibenzylcyclopropylamines 7 a and 7 b have been synthesized in 52 and 33 % overall yield, respectively. The synthesis of the enantiopure tetracyclic diamine 10 has been achieved applying the established set of reactions to N‐tert‐butoxycarbonylindoline‐2‐carboxylic acid (8) in 46 % overall yield. The amide 15 could not be prepared in the same way starting from the N‐tert‐butoxycarbonylproline 11. In fact, in the allylation step the stereogenic center was deprotonated and the doubly alkylated amide 13 was formed. However, the desired intermediate 15 could be obtained from L‐proline in 49 % yield performing first the N‐allylation step, then the introduction of the amide function. From 15, the cyclopropane‐annelated pyrrolizidine 16 was obtained in 70 % yield as a mixture of (1aS,6aS,6bR)‐16 and (1aR,6aS,6bS)‐16 diastereoisomers in a ratio of 1:2.9.
Heteronuclear Rhodium, Palladium, Platinum, and Gold Organoimido Complexes from Dinuclear Organoamido Rhodium Precursors
Authors: Oro Luis A. , Ciriano Miguel A. , Tejel Cristina , Bordonaba Marta , Graiff Claudia , Tiripicchio Antonio
Published: February 2004

Treatment of the organoamido complexes [Rh2(μ‐4‐HNC6H4Me)2(L2)2] (L2 = 1,5‐cyclooctadiene (cod), L = CO) with nBuLi gave solutions of the organoimido species [Li2Rh2(μ‐4‐NC6H4Me)2(L2)2]. Further reaction of [Li2Rh2(μ‐4‐NC6H4Me)2(cod)2] with [Rh2(μ‐Cl)2(cod)2] afforded the neutral tetranuclear complex [Rh4(μ‐4‐NC6H4Me)2(cod)4] (2), which rationalizes the direct syntheses of 2 from [Rh2(μ‐Cl)2(cod)2] and Li2NC6H4Me. Reactions of [Li2Rh2(μ‐4‐NC6H4Me)2(CO)4] with chloro complexes such as [Rh2(μ‐Cl)2(CO)4], [MCl2(cod)] (M = Pd, Pt), and [Ru2(μ‐Cl)2Cl2(p‐cymene)2] afforded the homo‐ and heterotrinuclear complexes PPN[Rh3(μ‐4‐NC6H4Me)2(CO)6] (5; PPN=bis(triphenylphosphine)iminium), [(CO)4Rh2(μ‐4‐NC6H4Me)2M(cod)] (M = Pd (6), Pt(7)) and [(CO)4Rh2(μ‐4‐NC6H4Me)2Ru(p‐cymene)] (8), while the reaction with [AuCl(PPh3)] gave the tetranuclear compound [(CO)4Rh2(μ‐4‐NC6H4Me)2{Au(PPh3)}2] (9). The structures of complexes 6, 8, and 9 were determined by X‐ray diffraction studies. The anion of 5 reacts with [AuCl(PPh3)] to give the butterfly cluster [{Rh3(μ‐4‐NC6H4Me)2(CO)6}Au(PPh3)] (10), in which the Au atom is bonded to two rhodium atoms. Reaction of the anion of 5 with [Rh(cod)(NCMe)2](BF4) gave the tetranuclear complex [Rh4(μ‐4‐NC6H4Me)2(CO)6(cod)] (11) in which the Rh(cod) fragment is π‐bonded to one of the arene rings, while the reaction of the anion of 5 with [PdCl2(cod)] afforded the heterotrinuclear complex 6 through a metal exchange process.
α,α‐Disubstituted Glycines Bearing a Large Hydrocarbon Ring: Peptide Self‐Assembly through Hydrophobic Recognition
Authors: Ohwada Tomohiko , Kojima Daisuke , Kiwada Tatsuto , Futaki Shiroh , Sugiura Yukio , Yamaguchi Kentaro , Nishi Yoshinori , Kobayashi Yuji
Published: February 2004

A method was developed for synthesizing α,α‐disubstituted glycine residues bearing a large (more than 15‐membered) hydrophobic ring. The ring‐closing metathesis reactions of the dialkenylated malonate precursors proceed efficiently, particularly when long methylene chains tether both terminal olefin groups. Surprisingly, the amino groups of these α,α‐disubstituted glycines are inert to conventional protective reactions (e.g., N‐tert‐butoxycarbonyl (Boc) protection: Boc2O/4‐dimethylaminopyridine (DMAP)/CH2Cl2; N‐benzyloxycarbonyl (Z) protection: Z‐Cl/DMAP/CH2Cl2). Curtius rearrangement of the carboxylic acid functionality of the malonate derivative after ring‐closing metathesis leads to formation of an amine functionality and can be catalyzed by diphenylphosphoryl azide. However, only the intermediate isocyanates can be isolated, even in the presence of alcohols such as benzyl alcohol. The isocyanates obtained by Curtius rearrangement in an aprotic solvent (benzene) were isolated in high yields and treated with 9‐fluorenylmethanol in a high‐boiling‐point solvent (toluene) under reflux to give the N‐9‐fluorenylmethoxycarbonyl (Fmoc)‐protected aminomalonate derivatives in high yield. These hydrophobic amino acids can be incorporated into a peptide by Fmoc solid‐phase peptide synthesis and the acid fluoride activation method. The stability of the monomeric α‐helical structure of a 17‐amino‐acid peptide was enhanced by replacement of two alanine residues with two hydrophobic amino acid residues bearing a cyclic 18‐membered ring. The results of sedimentation equilibrium studies suggested that the peptide assembles into hexamers in the presence of 100 mM NaCl.
Wärmeübergang bei instationären Prallstrahlen
Authors: Herwig H. , Göppert S. , Gürtler T. , Mocikat H.
Published: February 2004

No abstracts.
Untersuchungen zur Adsorptionstrocknung bei tiefen Temperaturen
Authors: Haida H. , Tomova P. , Behns W. , Ihlow M. , Mörl L.
Published: February 2004

No abstracts.
Experimentelle Untersuchung und Modellierung der Löslichkeit von Kalkstein und Gips bei höheren Ionenstärken – Teil 2: Einfluss von Carbonsäuren
Authors: Loos D. , Pasel C. , Luckas M. , Schmidt K.G. , Herbell J.‐D.
Published: February 2004

No abstracts.
Untersuchungen an BINSERT‐ Mischern – Vergleich zwischen Experiment und Simulation
Authors: Dürr V. , Dau G. , Ebert F.
Published: February 2004

No abstracts.
Protonenaustauschmembranen durch strahlungsinduzierte Pfropfpolymerisation von Polyhydroxyethylmethacrylat auf ETFE‐ und PP‐Folien für den Einsatz in Brennstoffzellen
Authors: Schmidt‐Naake G. , Pacheco M.
Published: February 2004

No abstracts.
Untersuchung des Trocknungsverhaltens von Feststoffen mit kernmagnetischer Resonanz
Authors: Dicoi O. , Walzel P. , Blümich B. , Rähse W.
Published: February 2004

No abstracts.
Optimierung biologischer Reinigungsstufen mit dem Phänomen der „Biologischen Resonanz”︁
Authors: Schmid A.
Published: February 2004

No abstracts.
Measurement of online visibility and its impact on Internet traffic
Authors: Drèze Xavier , Zufryden Fred
Published: February 2004

The Internet landscape is an increasingly crowded space where hundreds of thousands of companies are fighting for attention. Some of these companies are universally known (Yahoo!, Amazon) while others are more obscure (Literary Guild, Just Say Wow). Regardless of their level of Internet presence, all these companies are interested in improving their position, particularly now that managers are asked to justify their online activities. To help managers assess their online presence, and give them a way to compare their position relative to their competitors, this article aims to develop a measure of a company's online visibility. Moreover, this study seeks to understand what factors drive online visibility, and how.

The visibility measure we develop captures the extent to which a user is likely to come across an online reference to a company's Web site. It is based on data collected from multiple sources that include search engine results, Web-site contents, and online directory listings. It is calibrated using a large-scale telephone survey, and is validated using data obtained from Web crawlers and Internet consumer-panel sources.

In the latter part of the article, we show how managers can use the visibility measure to compare the online presence of their company to their competitors’. We also show how they can use this information to perform scenario analysis aimed at finding the best way to improve their online position.
Capturing evolving visit behavior in clickstream data
Authors: Moe Wendy W. , Fader Peter S.
Published: February 2004

Many online sites, both retailers and content providers, routinely monitor visitor traffic as a useful measure of their overall success. However, simple summaries such as the total number of visits per month provide little insight about individual-level site-visit patterns, especially in a changing environment such as the Internet. This article develops an individual-level model for evolving visiting behavior based on Internet clickstream data. We capture cross-sectional variation in site-visit behavior as well as changes over time as visitors gain experience with the site. In addition, we examine the relationship between visiting frequency and purchasing propensity at an e-commerce site. We find evidence supporting the notion that people who visit a retail site more frequently have a greater propensity to buy. We also show that changes (i.e., evolution) in an individual's visit frequency over time provides further information regarding which customer segments are likely to have higher purchasing conversion rates.