bluuebunny/crossref_metadata_2025 huggingface dataset:
Refugia of marine fish in the northeast Atlantic during the last glacial maximum: concordant assessment from archaeozoology and palaeotemperature reconstructions
Authors: Kettle A. J. , Morales-Muñiz A. , Roselló-Izquierdo E. , Heinrich D. , Vøllestad L. A.
Published: March 2011

Abstract. Archaeozoological finds of the remains of marine and amphihaline fish from the Last Glacial Maximum (LGM) ca. 21 ka ago show evidence of very different species ranges compared to the present. We have shown how an ecological niche model (ENM) based on palaeoclimatic reconstructions of sea surface temperature and bathymetry can be used to effectively predict the spatial range of marine fish during the LGM. The results indicate that the ranges of marine fish species now in northwestern Europe were displaced significantly southwards from the modern distribution, challenging an existing paradigm of marine glacial refugia. The model presents strong evidence that there was an invasion of important fish through the Straits of Gibraltar in glacial times, where they were exploited by Palaeolithic human populations around the western Mediterranean Sea. The ENM results are important for ongoing studies of molecular ecology that aim to assess marine glacial refugia from the genetic structure of living populations, and they pose questions about the genetic identity of vanished marine populations during the LGM. Economically, the approach may be used to understand how the ranges of exploited fish species may be displaced with the future climate warming. The research presents a challenge for future archaeozoological work to delimit the glacial refugia and to verify palaeoclimatic reconstructions based on deep-sea core records.
Multi-rogue waves solutions to the focusing NLS equation and the KP-I equation
Authors: Dubard P. , Matveev V. B.
Published: March 2011

Abstract. We construct a multi-parametric family of quasi-rational solutions to the focusing NLS equation, presenting a profile of multiple rogue waves. These solutions have also been used by us to construct a large family of smooth, real localized rational solutions of the KP-I equation quite different from the multi-lumps solutions first constructed in Bordag et al. (1977). The physical relevance of both equations is very large. From the point of view of geosciences,the focusing NLS equation is relevant to the description of surface waves in deep water, and the KP-I equation occurs in the description of capillary gravitational waves on a liquid surface, but also when one considers magneto-acoustic waves in plasma (Zhdanov, 1984) etc. In addition, there are plenty of equations of physical importance, having their origin in fiber optics, hydrodynamics, plasma physics and many other areas, which are gauge equivalent to the NLS equation or to the KP-I equation. Therefore our results can be easily extended to a large number of systems of physical interest to be discussed in separate publications.
Painting, Nostalgia and Metaphysics: Merleau-Ponty's Line
Authors: Johnson Galen A.
Published: March 2011

none
Elizabeth Grosz, Jacques Lacan: A Feminist Introduction
Authors: Bergoffen Debra B.
Published: March 2011

none
Jean-Louis Gardies, Le raisonement par l'absurde
Authors: Morot-Sir Edouard
Published: March 2011

none
Call for Papers/Books Received
Authors: Editors The
Published: March 2011

none
Postface: l'identite d'un metier
Authors: Cornu Laurence
Published: March 2011

none
Patrick Pollard, André Gide homosexual moralist
Authors: Morot-Sir Edouard
Published: March 2011

none
Jean-Joseph Goux. Oedipus, Philosopher
Authors: Editors The
Published: March 2011

none
Jacques Poulain, et Patrice Vermeren. L'identité philosophique européenne
Authors: Editors The
Published: March 2011

none
Jeu et communication: L'intérêt, la mathesis
Authors: Meitinger Serge
Published: March 2011

none
Jusqu'au moment de la mort, tout le monde est immortel
Authors: Caws Peter
Published: March 2011

none
Body-Consciousness: Gabriel Marcel's Debt to Maine De Biran
Authors: Appelbaum David
Published: March 2011

none
Le changement, la liberté, et le socialisme chez Sartre
Authors: McBride William L.
Published: March 2011

none
Pouvoir disciplinaire et normalisation
Authors: Kemedjio Cilas
Published: March 2011

none
Beatrice Longuenesse, Kant et le pouvoir de juger
Authors: Simont Juliette
Published: March 2011

none
Annonces et nouvelles
Authors: Editors The
Published: March 2011

none
Deux tentatives de recuperation de la "pensée-Michel-Foucault"
Authors: Meitinger Serge
Published: March 2011

none
Foucault's Genealogy of Homosexuality
Authors: McWhorter Ladelle
Published: March 2011

none
Foucault's Body
Authors: Schehr Lawrence R.
Published: March 2011

none
Confession, Dissimulation, and Storytelling in the Ur-Text of Classical Eroticism
Authors: Larson Ruth
Published: March 2011

none
The Patrilineal Discourse of Enlightenment: Reading Foucault Reading Kant
Authors: Bonfiglio Thomas P.
Published: March 2011

none
The Fading of the Postmodern: Jean François Lyotard's Moralites postmoderrnes
Authors: Caws Peter
Published: March 2011

none
The dream theories of Sartre and Hobson: The case of the imprisoned consciousness
Authors: Ellis Robert Richmond
Published: March 2011

none
On François George's Sillages
Authors: Light Steve
Published: March 2011

none
Bibliographie partielle des oeuvres Philosophie en langue française pour l'année 1992
Authors: Racevskis Karlis , Ndomaina Aiah K.
Published: March 2011

none
Gabriel Marcel and the Problem of Knowledge
Authors: Sweetman Brendan
Published: March 2011

none
Nature et Culture: Paul Ricoeur
Authors: Cecilia Avelina
Published: March 2011

none
Remarques sur Fichte and Sartre
Authors: Rockmore Tom
Published: March 2011

none
Humanity and Creaturehood
Authors: Gallagher Kenneth T.
Published: March 2011

none
Notices Biographiques
Authors: Editors The
Published: March 2011

nones
François De Bernard, Le Gouvernement de la pauvreté
Authors: Editors The
Published: March 2011

none
Andre Comte-Sponville, Petit traité des grande vertus
Authors: Editors The
Published: March 2011

none
Teresa Brennan, History after Lacan
Authors: Editors The
Published: March 2011

none
Fernand Brunner, Introduction à la philosophie
Authors: Editors The
Published: March 2011

none
Vivien Burr, An Introduction to Social Constructionism
Authors: Editors The
Published: March 2011

none
Lewis E. Hahn, The Philosophy of Paul Ricoeur
Authors: Editors The
Published: March 2011

none
Annonces et Nouvelles
Authors: Editors The
Published: March 2011

none
Books Received/Livres Reçus
Authors: Editors The
Published: March 2011

none
Technics and Atheism in Gabriel Marcel
Authors: Anderson Thomas
Published: March 2011

none
Gabriel Marcel's Body-as-a-Subject: A Preeminently Postmodern Notion
Authors: De Lacoste Guillermine
Published: March 2011

none
Jean-François Lyotard: L'autre je(u)
Authors: Raynova Yvanka
Published: March 2011

none
Guerre et paix: Remarques incidentes sur le mal commun et sur le bein public
Authors: Tassin Etienne
Published: March 2011

none
L'enfer c'est las sorciers
Authors: Gbotokuma Zekeh S.
Published: March 2011

none
Camus, Science, and Metaphors
Authors: Michael Colette
Published: March 2011

none
Compte Rendus
Authors: Editors The
Published: March 2011

none
Concrete Philosophy, The Mystery of Love, and The Absurdity of Evil
Authors: Randall Bert
Published: March 2011

none
Gaston Bachelard et "le depart de l'image"
Authors: Meitinger Serge
Published: March 2011

none
Institution et Formation
Authors: Pompougnac Jean-Claude
Published: March 2011

none
Hegel et le célèbre général carnot
Authors: D'Hondt Jacques
Published: March 2011

none
Le destin de l'art grec
Authors: D'Hondt Jacques
Published: March 2011

none
Patrice Vermeren, Le gouvernement de la philosophie
Authors: Navet George
Published: March 2011

none
Pierre Manent, An Intellectual History of Liberalism
Authors: Editors The
Published: March 2011

none
Alain Renaut, The Era of the Individual: Contribution to a History of Subjectivity
Authors: Editors The
Published: March 2011

none
Comment s'en débarrasser? De "l'homme en bon" à l'"homme jetable"
Authors: Brossat Alain
Published: March 2011

none
Gérard Genette, The Work of Art: Immanence and Transcendence
Authors: Editors The
Published: March 2011

none
Alain Renaut, The Era of the Individual
Authors: Editors The
Published: March 2011

none
Anna-Teresa Tymieniecka (ed), Analecta Husserliana
Authors: Editors The
Published: March 2011

none
Anatomy of Rights-Based Violence
Authors: Herbert Gary B.
Published: March 2011

none
Rationality and its Other
Authors: Marsh James L.
Published: March 2011

none
Dufrenne and the Virtual as an Aesthetic Category in Phenomenology
Authors: Bekesi Janos
Published: March 2011

none
Dufrenne, Humanism, and Anti-humanism
Authors: Rockmore Tom
Published: March 2011

none
Subjectivity as Body and Mind
Authors: Goldsmith Marcella Terozzi
Published: March 2011

none
Le feminisme americain de Ruddick et les distinctions de Lacan
Authors: Eeuke W Ver
Published: March 2011

none
Sartre's Last Philosophy: A Feminist Interpretation
Authors: De Lacoste Guillermine
Published: March 2011

none
The Place of the Sublime: Toward a Postmodern Sublime in the Wake of Kant and in Honor of Dufrenne
Authors: Casey Ed
Published: March 2011

none
Ladelle McWhorter, Bodies & Pleasure: Foucault and the Politics of Sexual Normalization
Authors: Editors The
Published: March 2011

none
Michel VaDéE & Jean-Claude Bourdin (sous la direction de), La Philosophie saisie par l'histoire: Hommage à Jacques d'Hondt
Authors: Editors The
Published: March 2011

none
Richard H. Popkin, The Columbia History of Western Philosophy
Authors: Editors The
Published: March 2011

none
Geneviéve Rodis-Lewis, Descartes: His Life and Thoughts
Authors: Garber Daniel
Published: March 2011

none
The Aesthetic Theory of Gabriel Marcel
Authors: Vallee Rev. Dr. Robert W.
Published: March 2011

none
De la littérature à la philosophie: deleuze intercesseur
Authors: Chauderlot Fabienne-Sophie
Published: March 2011

none
Jean-Marc Gabaude, Jean Jaurès philosophe
Authors: Editors The
Published: March 2011

none
Naturality and Intentional Structures of Sexuality
Authors: Caws Peter
Published: March 2011

none
Simone de Beauvoir's Two Bodies and the Struggle for Authenticity
Authors: Mirvish Adrian
Published: March 2011

none
Traces in Time: Simone de Beavoir in China
Authors: Jinhua Dai
Published: March 2011

none
Regards D'allemagne le cinquantenaire du deuxième sexe
Authors: Hervé Florence
Published: March 2011

none
Notes on Contributors
Authors: Editors The
Published: March 2011

none
Philosophie et théologie face aux émotions
Authors: Forthomme Bernard
Published: March 2011

none
François-David Sebbah, L'épreuve de la limite: Derrida, Henry, Levinas et la phénoménologie
Authors: Davidson Scott
Published: March 2011

none
Donner à voir l'idéologie: Althusser and Aesthetic Ideology
Authors: Albrecht Thomas
Published: March 2011

none
Immanence and Transcendence
Authors: Rölli Marc
Published: March 2011

none
Klossowski's Polytheism: An Introduction to Klossowski's "Nietzsche, Polytheism, and Parody"
Authors: Ford Russell
Published: March 2011

none
Palladium‐ and Copper‐Catalyzed Site Selective Monoamination of Dibromobenzoic Acid
Authors: Houpis Ioannis N. , Weerts Koen , Nettekoven Ulrike , Canters Martine , Tan Hongyu , Liu Renmao , Wang Youchu
Published: March 2011

The carboxylate anion has been used as a directing group in the aromatic amination of electronically equivalent aryl bromides to afford selective ortho‐substituted derivatives (>99:1 selectivity; 60–80% yield) in the case of copper(I) catalysis. The solvent, base and equivalents of base were important factors in the success of this reaction. Complementary selectivity was achieved with palladium catalysis where the para‐substituted derivatives were produced selectively (>99% selectivity, 70–80% yield).
Functionalization of Acetalic C(sp3)‐H Bonds by Scandium(III) Triflate‐Catalyzed Intramolecular Redox Reactions: Tandem 1,4‐Hydride Transfer/1,5‐Cyclization Processes Leading to Protected 1‐Indanones
Authors: Alajarin Mateo , Marin‐Luna Marta , Vidal Angel
Published: March 2011

A new CC bond forming reaction leading to adjacent quaternary carbons is reported. It is a one‐pot hydride shift/cyclization process facilitated by the hydricity of the acetalic CH bonds, with benzylidenemalonate fragments as electrophilic hydride acceptors, and the catalysis of scandium(III) triflate. The reaction products are 1,2‐dihydroindane derivatives. Alkoxy and alkanethiolate groups can be also intramolecularly transferred from the acetalic carbon to the electrophilic benzylidenemalonate CC bond.
Beyond thriftiness: Independent and interactive effects of genetic and dietary factors on variations in fat deposition and distribution across populations
Authors: Casazza Krista , Hanks Lynac J. , Beasley T. Mark , Fernandez Jose R.
Published: March 2011

The thrifty genotype hypothesis initiated speculation that feast and famine cycling throughout history may have led to group‐specific alterations of the human genome, thereby augmenting the capacity for excessive fat mass accrual when immersed in the modern‐day obesogenic environment. Contemporary work, however, suggests alternative mechanisms influencing fuel utilization and subsequent tissue partitioning to be more relevant in the etiology of population‐based variation in adipose storage. The objective of this study was to evaluate the independent and interactive contribution of ancestral admixture as a proxy for population‐based genetic variation and diet on adipose tissue deposition and distribution in peripubertal children and to identify differences in racial/ethnic and sex groups. Two‐hundred seventy‐eight children (53% male) aged 7–12 years, categorized by parental self‐report as African‐ (n = 91), European‐ (n = 110), or Hispanic American (n = 77), participated. Ancestral genetic admixture was estimated using 140 ancestry informative markers. Body composition was evaluated by dual‐energy X‐ray absorptiometry; energy expenditure by indirect calorimetry and accelerometry; and diet by 24‐h‐recall. Admixture independently contributed to all adiposity parameters; i.e., estimates of European and Amerindian ancestries were positively associated with all adiposity parameters, whereas African genetic admixture was inversely associated with adiposity. In boys, energy intake was associated with adiposity, irrespective of macronutrient profile, whereas in girls, the relationship was mediated by carbohydrate. We also observed moderating effects of energy balance/fuel utilization of the interaction between ancestral genetic admixture and diet. Interactive effects of genetic and non‐genetic factors alter metabolic pathways and underlie some of the present population‐based differences in fat storage. Am J Phys Anthropol, 2011. © 2011 Wiley‐Liss, Inc.
Three‐dimensional kinematics of capuchin monkey bipedalism
Authors: Demes Brigitte
Published: March 2011

Capuchin monkeys are known to use bipedalism when transporting food items and tools. The bipedal gait of two capuchin monkeys in the laboratory was studied with three‐dimensional kinematics. Capuchins progress bipedally with a bent‐hip, bent‐knee gait. The knee collapses into flexion during stance and the hip drops in height. The knee is also highly flexed during swing to allow the foot which is plantarflexed to clear the ground. The forefoot makes first contact at touchdown. Stride frequency is high, and stride length and limb excursion low. Hind limb retraction is limited, presumably to reduce the pitch moment of the forward‐leaning trunk. Unlike human bipedalism, the bipedal gait of capuchins is not a vaulting gait, and energy recovery from pendulum‐like exchanges is unlikely. It extends into speeds at which humans and other animals run, but without a human‐like gait transition. In this respect it resembles avian bipedal gaits. It remains to be tested whether energy is recovered through cyclic elastic storage and release as in bipedal birds at higher speeds. Capuchin bipedalism has many features in common with the facultative bipedalism of other primates which is further evidence for restrictions on a fully upright striding gait in primates that transition to bipedalism. It differs from the facultative bipedalism of other primates in the lack of an extended double‐support phase and short aerial phases at higher speeds that make it a run by kinematic definition. This demonstrates that facultative bipedalism of quadrupedal primates need not necessarily be a walking gait. Am J Phys Anthropol, 2011. © 2011 Wiley‐Liss, Inc.
Sexual dimorphism of the human mandible and its association with dental development
Authors: Coquerelle Michael , Bookstein Fred L. , Braga José , Halazonetis Demetrios J. , Weber Gerhard W. , Mitteroecker Philipp
Published: March 2011

The present study investigates whether the human mandible is sexually dimorphic during early postnatal development and whether early dimorphic features persist during subsequent ontogeny. We also examine whether mandibular dimorphism is linked to dimorphism of dental development. Dense CT‐derived mandibular meshes of 84 females and 75 males, ranging from birth to adulthood, were analyzed using geometric morphometric methods. On the basis of the specimen's chronological ages and mineralization stages of the deciduous and permanent teeth, we compute dental age as proxy for dental development by the additive conjoint measurement method. By birth, males have, on average, more advanced age‐specific shapes than females. However, sex differences decrease quickly as females catch up via a different association between shape and size. This leads to an almost complete reduction of sexual dimorphism between the ages of 4 and 14. From puberty to adulthood, males are characterized by allometric shape changes while the shape of the female mandible continues to change even after size has ceased to increase. Dimorphism of dental maturation becomes visible only at puberty. Sexual dimorphism, concentrated at the ramus and the mental region during the earliest ontogenetic stages and again at adulthood, is not associated with the development of the teeth. At puberty there is a simultaneous peak in size increase, shape development, and dental maturation likely controlled by the surge of sex hormones with a dimorphic onset age. We argue that the infant and adult dimorphism of the mental region may be associated with the development of supralaryngeal structures. Am J Phys Anthropol, 2011. © 2011 Wiley‐Liss, Inc.
Assessing endocranial variations in great apes and humans using 3D data from virtual endocasts
Authors: Bienvenu Thibaut , Guy Franck , Coudyzer Walter , Gilissen Emmanuel , Roualdès Georges , Vignaud Patrick , Brunet Michel
Published: March 2011

Modern humans are characterized by their large, complex, and specialized brain. Human brain evolution can be addressed through direct evidence provided by fossil hominid endocasts (i.e. paleoneurology), or through indirect evidence of extant species comparative neurology. Here we use the second approach, providing an extant comparative framework for hominid paleoneurological studies. We explore endocranial size and shape differences among great apes and humans, as well as between sexes. We virtually extracted 72 endocasts, sampling all extant great ape species and modern humans, and digitized 37 landmarks on each for 3D generalized Procrustes analysis. All species can be differentiated by their endocranial shape. Among great apes, endocranial shapes vary from short (orangutans) to long (gorillas), perhaps in relation to different facial orientations. Endocranial shape differences among African apes are partly allometric. Major endocranial traits distinguishing humans from great apes are endocranial globularity, reflecting neurological reorganization, and features linked to structural responses to posture and bipedal locomotion. Human endocasts are also characterized by posterior location of foramina rotunda relative to optic canals, which could be correlated to lesser subnasal prognathism compared to living great apes. Species with larger brains (gorillas and humans) display greater sexual dimorphism in endocranial size, while sexual dimorphism in endocranial shape is restricted to gorillas, differences between males and females being at least partly due to allometry. Our study of endocranial variations in extant great apes and humans provides a new comparative dataset for studies of fossil hominid endocasts. Am J Phys Anthropol, 2011. © 2011 Wiley‐Liss, Inc.
Comparison of lactase persistence polymorphism in ancient and present‐day Hungarian populations
Authors: Nagy Dóra , Tömöry Gyöngyvér , Csányi Bernadett , Bogácsi‐Szabó Erika , Czibula Ágnes , Priskin Katalin , Bede Olga , Bartosiewicz László , Downes C. Stephen , Raskó István
Published: March 2011

The prevalence of adult‐type hypolactasia varies ethnically and geographically among populations. A C/T–13910 single nucleotide polymorphism (SNP) upstream of the lactase gene is known to be associated with lactase non‐persistence in Europeans. The aim of this study was to determine the prevalence of lactase persistent and non‐persistent genotypes in current Hungarian‐speaking populations and in ancient bone samples of classical conquerors and commoners from the 10th–11th centuries from the Carpathian basin; 181 present‐day Hungarian, 65 present‐day Sekler, and 23 ancient samples were successfully genotyped for the C/T‐13910 SNP by the dCAPS PCR‐RFLP method. Additional mitochondrial DNA testing was also carried out. In ancient Hungarians, the T‐13910 allele was present only in 11% of the population, and exclusively in commoners of European mitochondrial haplogroups who may have been of pre‐Hungarian indigenous ancestry. This is despite animal domestication and dairy products having been introduced into the Carpathian basin early in the Neolithic Age. This anomaly may be explained by the Hungarian use of fermented milk products, their greater consumption of ruminant meat than milk, cultural differences, or by their having other lactase‐regulating genetic polymorphisms than C/T‐13910. The low prevalence of lactase persistence provides additional information on the Asian origin of Hungarians. Present‐day Hungarians have been assimilated with the surrounding European populations, since they do not differ significantly from the neighboring populations in their possession of mtDNA and C/T‐13910 variants. Am J Phys Anthropol, 2011. © 2011 Wiley‐Liss, Inc.
Vertebral pathologies in two early modern period (16th–19th century) populations from Croatia
Authors: Novak Mario , Šlaus Mario
Published: March 2011

In order to test to what degree Schmorl's nodes (SN), osteophytosis of the vertebral bodies (VO), and osteoarthritis of the articular facets (OA) are useful indicators of activity‐related stress, an analysis of their frequencies and severity of expression was conducted in two early Modern period skeletal samples from Croatia—Koprivno and Sisak. Historic and contemporary ethnographic sources suggest that living conditions were more demanding in Koprivno, and that a sexual division of labor existed in both populations. A total of 2,552 vertebral bodies (990 from Koprivno and 1,562 from Sisak) and 5,186 articular facets (2,135 from Koprivno and 3,051 from Sisak) were analyzed. Koprivno exhibits significantly higher total frequencies of SN, VO, and OA than Sisak, and the total frequencies of SN and OA in both series are significantly higher in males. When, however, the series were analyzed by age and sex categories, the same trend was noted only in SN. The frequencies and severity of VO and OA could not be interpreted in keeping with the historic and contemporary ethnographic sources and were additionally, unlike SN, found to be strongly correlated with increased age. This study, therefore, suggests that while SN are useful indicators of different lifestyles and/or different activity patterns between various archaeological populations, VO and OA are—possibly because of their more varied etiologies—less useful markers of activity‐related stress. Am J Phys Anthropol, 2011. © 2011 Wiley‐Liss, Inc.
Optimization of biomethane production by anaerobic digestion of palm oil mill effluent using response surface methodology
Authors: Saleh A. F. , Kamarudin E. , Yaacob A. B. , Yussof A. W. , Abdullah M.A.
Published: March 2011

This study investigated the effects of factors namely temperature, palm oil mill effluent (POME) volume, inoculum volume, and co‐substrate addition such as oil palm empty fruit bunch (EFB) and palm kernel on the anaerobic digestion process for biogas and methane production. Response surface methodology by the Box‐Behnken design verified that the specific biogas production rate and methane yield were mainly affected by operating temperature and co‐substrate addition. The optimal conditions for the maximum specific biogas production rate (0.0574 m3/ kg chemical oxygen demand per day) and methane yield (25.6%) have been predicted by multiple response optimization and verified experimentally at 47.8 °C operating temperature, 50.4 mL POME volume, and 5.7 g EFB addition. The error percentage between experimental and predicted values which were around 5% for methane composition and 12% for specific biogas production rate suggests the good predictability of the model. © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.
Polypropylene surface modification with stearyl alcohol ethoxylates to enhance wettability
Authors: Datla Vasantha M. , Shim Eunkyoung , Pourdeyhimi Behnam
Published: March 2011

Stearyl alcohol ethoxylated additives were melt‐blended in polypropylene (PP) films, and the characteristics of the modified films were investigated. The melt blending of stearyl alcohol ethoxylates improved the hydrophilicity of the PP films through additive surface segregation. Surface specific techniques, such as X‐ray photoelectron spectroscopy and time‐of‐flight secondary‐ion mass spectrometry, were used to study the surface compositions of the samples modified with ethoxylated additives. This revealed that the surface concentrations of the additives were significantly higher than the bulk concentrations in all samples. In addition, the surface compositions of the additive‐modified samples continuously changed, even after the films were fully solidified. We also found that the resulting surface characteristics were very dynamic, so the melt‐additive‐containing polymer surfaces responded to water exposure, and their surface properties and morphologies were altered as a result. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Polyelectrolyte complexes from polyethylene imine/acetone formaldehyde sulfite polycondensates: A novel reagent for effective fluid loss control of oil well cement slurries
Authors: Dugonjić‐Bilić Fatima , Plank Johann
Published: March 2011

When used by itself, polyethylene imine (PEI) does not perform well as cement fluid loss additive. Its combination with acetone formaldehyde sulfite (AFS) polycondensate, however, exhibits excellent filtration control. The mechanism underlying this synergistic effect was studied and the conditions producing best results were determined. For optimum performance, PEI and AFS must be reacted with each other to yield a polyelectrolyte complex (PEC) (d ∼ 5–10 μm), which effectively plugs the pores of the cement filter cake. Composition, size, and effectiveness of the PEC are strongly influenced by the anionic charge amount of the AFS dispersant. Ionic interactions between cationic imine functionalities of PEI and anionic sulfonate groups existing in AFS were confirmed by conductivity, infrared, zeta potential, and particle size measurements. For AFS samples possessing different degrees of sulfonation, the largest particle size and hence best fluid loss performance of the PEC was found to occur at a PEI:AFS molar ratio, which corresponds to neutral charge. Occurrence of large PEC particles (d ∼ 5 μm) within the cement filter cake pores was visualized by scanning electron microscopy, and their stability in highly alkaline cement pore solution was confirmed by particle size measurement. Other anionic polyelectrolytes may be used to yield such PECs with PEI to provide effective fluid loss control for cement slurries. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Combination effect of organics‐modified montmorillonite with intumescent flame retardants on thermal stability and fire behavior of polyethylene nanocomposites
Authors: Huang Guobo , Zhu Bingchun , Shi Haibo
Published: March 2011

A combination effect was observed between organics‐modified montmorillonite (OMMT) and a novel intumescent flame retardant, diphenylmethanamine spirocyclic pentaerythritol bisphosphonate (PSPD), in low‐density polyethylene (LDPE) nanocomposites. The results from X‐ray diffraction and transmission electron microscopy showed that montmorillonite can achieve better dispersion in LDPE/PSPD blend matrix, and exfoliated LDPE/PSPD/OMMT nanocomposites are formed. Thermal stability and flammability properties were investigated by thermogravimetric analysis and cone calorimeter tests. The combination effect of PSPD and montmorillonite improved thermal stability and reduced significantly the flammability (including heat release rate, total heat release, average mass loss rate, etc.). The peak heat release rate of LDPE/PSPD/OMMT is reduced by about 51% compared with pure LDPE. The morphology and composition of residues generated after cone calorimeter tests were investigated by scanning electron microscopy and X‐ray photoelectron spectroscopy. The scanning electron microscopy images showed that the compact and dense intumescent char is formed for LDPE/PSPD/OMMT nanocomposite after combustion. The results of X‐ray photoelectron spectroscopy confirmed that the carbon content of the char for LDPE/PSPD/OMMT increases obviously by the combination effect of PSPD and montmorillonite. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Fracturing fluid cleanup by controlled release of enzymes from polyelectrolyte complex nanoparticles
Authors: Barati Reza , Johnson Stephen J. , McCool Stan , Green Don W. , Willhite G. Paul , Liang Jenn‐Tai
Published: March 2011

Water‐based polymer gels are used widely in the oil and gas industry to viscosify fluids used in the hydraulic fracturing of production wells, where they serve to increase the force applied to the rock and to improve the transport of proppants used to maintain the fracture after formation. After fracturing, the gel must be degraded to a low viscosity with enzymes or gel breakers. Existing systems add the breaker either directly to the gelant or encapsulated in beads that are crushed when the applied pressure is released and the fractures close. In the former case, the gel may be broken prematurely, and this may prevent efficient fracture propagation and proppant transport, whereas in the latter case, the breaker may not be uniformly distributed throughout the gel, with the result that the gel is incompletely broken and the hydraulic conductivity of the well is reduced. To obtain delayed release, combined with the homogeneous distribution of enzyme throughout the gel, polyethylenimine–dextran sulfate polyelectrolyte complexes were used to entrap pectinase. Such particles were originally developed to entrap pharmaceuticals, and we previously demonstrated their ability to delay the release of gel crosslinking agents for oilfield applications. The degradation of both the viscosity and viscoelastic moduli of borate‐crosslinked guar gel by pectinase loaded in polyelectrolyte nanoparticles was delayed by up to 12 h, compared to about 2 h for equivalent systems where the pectinase was not entrapped. The combination of homogeneous mixing and the delayed release of enzymes packaged in polyelectrolyte complex nanoparticles showed promise for improved cleanup after hydraulic fracturing. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis, speed of ultrasound and associated acoustical parameters of epoxy acrylate of 9,9′‐bis (4‐hydroxy phenyl) anthrone‐10 solutions
Authors: Bhuva B. D. , Parsania P. H.
Published: March 2011

Density (ρ), viscosity (η), and speed of ultrasound (U) (2 MHz) of pure solvents (chloroform, THF, and 1,4‐dioxane) and solutions of epoxy acrylate of 9,9′‐bis(4‐hydroxy phenyl) anthrone‐10 (EAAN) have been investigated at 303, 308, and 313 K. Specific acoustical impedance (Z), isentropic compressibility (κs), intermolecular free path length (Lf), classical absorption coefficient (α/f2)cl, and viscous relaxation time (τ) have been determined from ρ, η, and U data and are correlated with concentration. Z, (α/f2)cl, and τ increased with C and decreased with T, while κs and Lf decreased with C and increased with T in the solvent systems studied. A fairly good to excellent correlation between a given parameter and concentration is observed in solvent systems studied. Linear increase or decrease of acoustical parameters with concentration and temperature indicated existence of strong molecular interactions. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Alginic acid‐g‐poly(N‐vinylformamide) graft copolymer: Synthesis, characerization, swelling, and flocculation property
Authors: Sand Arpit , Yadav Mithilesh , Mishra Dinesh Kumar , Behari Kunj
Published: March 2011

The graft copolymer of N‐vinylformamide with alginic acid was synthesized by free radical polymerization using potassium peroxymonosulphate and thiourea as redox pair in inert atmosphere. The optimum conditions for maximum grafting have been determined by varying the concentrations of N‐vinylformamide, potassium peroxymonosulphate, thiourea, sulfuric acid, alginic acid as well as time duration and temperature. The grafting parameters increase up to the certain concentrations of N‐vinylformamide, potassium peroxymonosulhate, thiourea, and hydrogen ion while thereafter grafting parameters decrease. The effect of alginic acid concentration on grafting parameters has been observed to decrease continuously. It has also been found that grafting parameters increase up to certain time and temperature, respectively, and thereafter decrease. The swelling properties of graft copolymer in terms of swelling ratio and percent swelling are investigated. Flocculation property of pure and grafted sample for both coking and noncoking coals is also investigated for the treatment of coal mine waste water. The graft copolymer has been characterized by Fourier transform infrared spectroscopy as well as thermogravimetic analysis. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Combining atom transfer radical polymerization and melt compounding for producing PMMA/clay nanocomposites
Authors: Lerari D. , Peeterbroeck S. , Benali S. , Benaboura A. , Dubois Ph.
Published: March 2011

Nanocomposites based on poly (methyl methacrylate) (PMMA) and 3 wt % of clay (montomorillonite) organomodified with alkylammonium cations bearing alkyl halide function (OCTANBriBBr‐CL) have been obtained by melt blending. The “nanohybrid” masterbatch approach, already used within other matrices, has also been tested to produce this type of material. Accordingly, highly filled (∼ 30 wt %) PMMA‐OCTANBriBBr‐CL nanohybrid has been synthesized by atom transfer radical polymerization (ATRP) of MMA as in situ initiated from the alkyl halide functions decorating the nanoclay surface. This nanohybrid, i.e., PMMA‐grafted organomodified clay, has been added as masterbatch and melt‐blended within commercial PMMA. A significantly better clay nanoplatelet dispersion of the samples prepared via the masterbatch process was evidenced by wide‐angle X‐ray diffraction (WAXD) and transmission electron microscopy (TEM). As a result, these exfoliated nanocomposites proved to be characterized by better thermal and mechanical properties than the more conventional physical blends, as evidenced by thermogravimetrical analysis (TGA) and dynamical mechanical analysis (DMTA), respectively. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Siderophore‐Mimetic hydrogel for iron chelation therapy
Authors: Mohammadi Zahra , Xie Sheng‐Xue , Golub Allison L. , Gehrke Stevin H. , Berkland Cory
Published: March 2011

Two, three dihydroxybenzoic acid (DHBA), a portion of the metal chelating domain of enterobactin, was immobilized on crosslinked organic polymer polyallylamine (PAAm) and used as a chelating agent for iron removal from aqueous solutions. The swelling behavior of PAAm and PAAm hydrogels conjugated with dihydroxybenzoic acid and the effect of contact time on the swelling and binding capacity of the hydrogel was investigated at several pH values to define the absorption mechanism. Iron uptake kinetics followed the pseudosecond order Ho model and equilibrium was described by either Temkin or Freundlich isotherms. Maximum chelating capacities of the hydrogels were found to be 500–1500 mg Fe3+ g−1 and 1500–2500 mg Fe2+ g−1 for PAAm and PAAm/DHBA hydrogels, respectively, depending on the pH of the media. The selectivity of the conjugate hydrogel toward ferric ions was studied at several different pH values. At every pH ranging from 2 to 7.5, the conjugate hydrogel showed relatively high binding affinity for ferric ions. The selective and rapid, high affinity binding of iron by this siderophore‐mimetic hydrogel offers potential application as a nonabsorbed chelator for iron in the gastrointestinal tract of patients suffering from iron overload diseases. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis and characterization of novel, highly crystalline poly(vinyl alcohol) microspheres for chemoembolization therapy
Authors: Semenzim Vinícius Ladeia , Basso Glaucia Grazielli , da Silva Danilo Antonio , de Vasconcellos Adriano , Agreli Guilherme , Lima‐Oliveira Ana Paula Marques , Kawasaki‐Oyama Rosa Sayoko , Braile Domingo Marcolino , Nery José Geraldo
Published: March 2011

Biodegradable polymeric microspheres can be used to deliver drugs through controlled rate and targeted processes. The drug is released from the particles by drug leaching or degradation of the polymeric matrix. Crystallinity can play a very important role in the degradation of polymeric matrixes; it can affect the drug‐release rate, especially in chemoembolization. Most commercial embolic agents have a low degree of crystallinity, and the correlation between the drug‐delivery rate and the degree of crystallinity is not fully understood. This study presents the appropriated synthesis conditions for the preparation of highly crystalline poly(vinyl alcohol) and poly(vinyl alcohol)/poly(vinyl acetate) microspheres and physicochemical characterizations by scanning electron microscopy, X‐ray diffraction, differential scanning calorimetry, and cross‐polarization/magic angle spinning nuclear magnetic resonance. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Crystallization behavior of biodegradable poly(L‐lactic acid) filled with a powerful nucleating agent: N,N′‐bis(benzoyl) suberic acid dihydrazide
Authors: Cai Yanhua , Yan Shifeng , Yin Jingbo , Fan Yinqing , Chen Xuesi
Published: March 2011

N,N′‐Bis(benzoyl) suberic acid dihydrazide (NA) as nucleating agent for poly(L‐lactic acid) (PLLA) was synthesized from benzoyl hydrazine and suberoyl chloride, which was deprived from suberic acid via acylation. PLLA/NA samples were prepared by melt blending and a hot‐press forming process. The nonisothermal and isothermal crystallization, spherulite morphology, and melting behavior of PLLA/NA with different contents of NA were investigated with differential scanning calorimetry, depolarized‐light intensity measurement, scanning electron microscopy, polarized optical microscopy, and wide‐angle X‐ray diffraction. With the incorporation of NA, the crystallization peak became sharper and shifted to a higher temperature as the degree of supercooling decreased at a cooling rate of 1°C/min from the melt. Nonisothermal crystallization indicated that the presence of NA accelerated the overall PLLA crystallization. In isothermal crystallization from the melt, the presence of NA affected the isothermal crystalline behaviors of PLLA remarkably. The addition of NA led to a shorter crystallization time and a faster overall crystallization rate; this meant that there was a heterogeneous nucleation effect of NA on the crystallization of PLLA. With the addition of 0.8% NA, the crystallization half‐time of PLLA/NA decreased from 26.5 to 1.4 min at 115°C. The Avrami theory was used to describe the kinetics of isothermal crystallization of the PLLA/NA samples. Also, with the presence of NA, the spherulite number of PLLA increased, and the spherulite size decreased significantly. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Facile preparation of poly(3,4‐ethylenedioxythiophene) nanoparticles via a miniemulsion polymerization process
Authors: Jin Sun‐Mi , Joo Young‐Tae , Park Ye‐Ji , Kim Yangsoo
Published: March 2011

Poly(3,4‐ethylenedioxythiophene) (PEDOT) nanoparticles were prepared via a miniemulsion polymerization process. The chemical oxidative polymerization of 3,4‐ethylenedioxythiophene (EDOT) occurred in the presence of β‐1,3‐glucan with the injection of an aqueous oxidant solution, and the nanodroplets of EDOT were transformed to PEDOT nanoparticles dispersed in the aqueous medium. The aqueous emulsion of PEDOT nanoparticles showed relatively long emulsion stability (> 8 weeks), and the recovered solid nanoparticles were also redispersible in deionized water without deposition. The size and size distribution of PEDOT nanoparticles could be controlled by adjusting the operating conditions of the ultrasonifier before the polymerization process. The building‐up of a shearing force decreases the size of the PEDOT nanoparticles and also causes the occurrence of a multimodal size distribution for the PEDOT nanoparticles. The electrical conductivity of the PEDOT nanoparticles was 0.28–1.20 S cm−1. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Fast and efficient synthesis of high molecular weight poly(epsilon‐caprolactone) diols by microwave‐assisted polymer synthesis
Authors: Gotelli Gustavo A. , Bonelli Pablo , Abraham Gustavo A. , Sosnik Alejandro
Published: March 2011

Because of advantageous features such as shorter reaction times, greater yields, limited generation of by‐products and relatively easy and straightforward scale‐up, microwave‐assisted synthesis has become a very appealing tool in organic synthesis. Conversely, its implementation in the context of the synthesis of biomaterials for biopharmaceutical applications has been more limited. The present work reports on the fast and efficient microwave‐assisted synthesis of poly(ethylene glycol) (PEG)‐initiated poly(ε‐caprolactone) diols (PCL) by the ring‐opening polymerization (ROP) of ε‐caprolactone using stannous octanoate as catalyst. Since the PEG content in the synthesized copolymers was extremely low (0.2–1.9%), products were highly hydrophobic and displayed the intrinsic thermal properties of pure PCL. As opposed to the more time‐consuming conventional thermally‐driven synthesis that usually demands 2–3 h, the microwave technique resulted in intermediate to high molecular weight PEG‐PCL derivatives within 10–15 min. The influence of different parameters affecting the synthetic process, namely monomer‐to‐initiator ratio, reaction time, catalyst concentration and the presence, type, and concentration of solvent were thoroughly investigated. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Soft PVC foams: Study of the gelation, fusion, and foaming processes. I. Phthalate ester plasticizers
Authors: Zoller Agnes , Marcilla Antonio
Published: March 2011

The use of foamed plastics gains more and more interest every day. Flexible poly(vinyl chloride) (PVC) foams have excellent mechanical properties and low price, thus their application is extensive. Foams are produced from plastisols, which are based on the suspension of the PVC resin in a plasticizer. Phthalates are the most used plasticizers in flexible PVC foam formation. In this study, we have studied the influence of the phthalate ester‐type plasticizers on the foaming process and the quality of the foams obtained from the corresponding plastisols. For the plastisols prepared with the nine phthalate plasticizers considered, we have studied and discussed the complex and extensional viscosities; the thermal behavior (DSC) including the decomposition of the chemical blowing agent, and the foam production by rotational molding. In addition, we have characterized the foams obtained by thermomechanical analysis, density, and bubble size distribution. As expected, clear correlations have been obtained between the molecular weight and structure of the plasticizer with the rheological behavior of the plastisols. The knowledge of the gelation and fusion processes and evolution of the extensional viscosity of the plastisols combined with the study of the thermal decomposition of the blowing agent in each plastisol allows for better understanding of the complex dynamic behavior of these foaming systems. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
The graft copolymerization of corn starch by microwave irradiation with rheological phase reaction
Authors: Da‐Wei Han , Jian‐Kun Wang , Hai‐Rong Lv , Ming‐Ming Xu
Published: March 2011

The corn starch was grafted by microwave irradiation with rheological phase reaction, to meet the sizing requirements of polyester/cotton blended yarn and avoid the disadvantages of corn starch size including brittle, hard, and size shedding. On the basis of the damping characteristics of corn starch film and the polarity of grafting monomer, the grafting effect of grafted corn starch was researched by using infrared spectroscopy, SEM, rotary viscometer, and thermomechanical analyzer. The results showed that both hydrophilic groups and hydrophobic groups were introduced in the molecular chains of grafted corn starch. The storage modulus of grafted corn starch film reached 285–315 MPa, being four times higher than that of nongrafted corn starch film. Compared with corn starch sizing, the viscosity of grafted corn starch sizing decreased 62.5%. Furthermore, through analyzing grafting law and establishing regression equation, it was indicated that the irradiation time and initiator content influenced the grafting ratio of grafted starch significantly. The grafting ratio could reach 19.57%, when the irradiation time and initiator content were selected with 3.5 min and 4.55%, respectively. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Preparation of raspberry‐shaped styrene‐butadiene‐methyl acrylate‐acrylic acid latex particles by emulsion polymerization followed by alkali/heating method
Authors: Wan Qichun , Li Yongfu , Todd Clifford , Harris Joe , Nicholson Dwayne , Chaput Bruce
Published: March 2011

Monodispersed raspberry‐shaped polystyrene‐butadiene‐methyl acrylate‐acrylic acid particles were made by semi‐batch emulsion polymerization followed by alkali and heat treatment. The particle sizes and size distributions were studied by hydrodynamic chromatography and transmission electronic microscopy. The morphology of the particles was observed by SEM, cryo‐SEM, and TEM. Treatment temperature was found to have a significant impact on the particle size and morphology of the treated latexes. Higher temperatures lead to larger particle sizes and more discernible raspberry domains with sizes around 50 nm on the particle surfaces. Higher levels of alkali did not significantly change the particle size but did increase the total titratable acid amount, presumably due to the hydrolysis of methyl acrylate during the treatment. GPC results showed that higher amount of oligomers or polymers are produced in the serum for the heat‐treated latexes. Divinylbenzene crosslinking agent at the levels of 0.05–3% limited the particle expansion and decreased the serum acid. A possible mechanism of raspberry particle formations was proposed, which involves migration of hydrophilic and hydrophobic species during the heat treatment. Lastly, potential applications for raspberry particles in paper coating were explored. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011