bluuebunny/crossref_metadata_2025 huggingface dataset:
Contribuições para a construção de uma matriz para avaliação de projetos de educação ambiental
Authors: Guanabara Rachel , Gama Thais , Eigenheer Emílio Maciel
Published: September 2009

Hoje em dia, presenciamos uma grande proliferação de projetos de educação ambiental, mas não se observa esse mesmo desenvolvimento em relação aos métodos para avaliação destes. O presente artigo teve por objetivo colaborar com a construção de uma matriz para avaliação de tais projetos. Foram utilizados, como exemplo de avaliação, dois projetos desenvolvidos no município de Petrópolis (RJ), que apresentam os resíduos sólidos como tema central. A matriz analisou a adequação dos projetos Araras sem lixo e Petrópolis recicla com as principais políticas públicas que regem a região e o tema escolhido. Foram elaboradas 13 questões para avaliar se os projetos estavam ou não de acordo com os propostos pelas políticas públicas escolhidas. No total, cada projeto poderia pontuar um máximo de 39 e um mínimo de 13 pontos, podendo ser avaliados como: (i) não de acordo com as políticas públicas analisadas (pontuação entre 13-21); (ii) parcialmente de acordo (entre 22 e 30 pontos); e (iii) de acordo (entre 31-39 pontos). Segundo a avaliação, o projeto Araras sem lixo tem seus princípios e objetivos parcialmente de acordo com aqueles propostos pelas políticas públicas analisadas. Já o projeto Petrópolis recicla mostrou-se inadequado aos propostos por essas políticas públicas. A matriz de avaliação mostrou ser um instrumento adequado para avaliação e posterior comparação de projetos de educação ambiental, podendo ser adaptada aos mais diferentes temas e realidades.
Perfil epidemiológico de pacientes portadores de TB internados em um hospital de referência na cidade do Rio de Janeiro
Authors: Oliveira Hedi Marinho de Melo Guedes de , Brito Rossana Coimbra , Kritski Afranio Lineu , Ruffino-Netto Antonio
Published: September 2009

OBJETIVO: Analisar o perfil epidemiológico dos pacientes internados em um hospital especializado no tratamento da TB. MÉTODOS: Foi realizado estudo descritivo e retrospectivo dos prontuários dos pacientes internados com TB no Hospital Estadual Santa Maria (HESM), na cidade do Rio de Janeiro, entre janeiro de 2002 e dezembro de 2003, por meio de formulário previamente padronizado. RESULTADOS: Dos 451 pacientes incluídos, 313 (69,4%) foram referenciados para o HESM por unidades de saúde, e 302 (67,0%) eram do gênero masculino. A maioria dos pacientes tinha entre 30 e 59 anos, 443 (98,2%) residiam na região metropolitana, e 298 (66,1%) residiam no município do Rio de Janeiro. O motivo de internação mais frequente foi mau estado geral (em 237, 52,5%). A AIDS foi a comorbidade mais frequente (em 137, 30,4%). Os sinais e sintomas mais frequentes no momento da internação foram emagrecimento, febre e tosse produtiva. A baciloscopia foi positiva em 122 casos (71,0%) com tosse produtiva no momento da internação. Dos 212 pacientes que estavam em retratamento, 156 (73,6%) referiram abandono a tratamento anterior. Quanto ao desfecho, 297 (65,8%) foram encaminhados para centros municipais de saúde, 83 (18,4%) evoluíram para óbito, e 44 (9,8%) curaram. As altas indesejadas ocorreram em 27 (6,0%) dos casos. CONCLUSÕES: A provisão de hospitais especializados em TB é de relevância para o controle da TB, principalmente em regiões metropolitanas. Esses hospitais precisam estar adequados a medidas de biossegurança, assim como estar mais bem equipados e capacitados para prestar atendimento a pacientes com diversas comorbidades e problemas sociais associados à TB. A realização deste estudo resultou em melhorias para o HESM.
Dying to Know: Identity and Self-Knowledge in Baldwin's Another Country
Authors: Martínez Ernesto Javier
Published: September 2009

This article examines the prevalence of confusion and incoherence in James Baldwin's 1962 novel Another Country, arguing that the novel should be read as an extended and theoretically rich meditation on the difficulty of gaining self-knowledge in oppressive social contexts. Its central thesis is that the novel is motivated less by the tragedy of Rufus Scott's suicide early in the novel than by the ethical imperative that compels all the characters to risk their sense of self (to figuratively commit suicide) in order to better understand the circumstances they face. Through this “suicidal” sensibility, Baldwin examines how self-knowledge in oppressive contexts frequently depends on people making extreme shifts in their conception of self—of who they are in relation to their society. These shifts are often dreaded and appear self-menacing, but Baldwin ultimately implies that they hold liberatory promise.
Fresh Leaves: Practicing Environmental Criticism
Authors: Kilcup Karen L.
Published: September 2009

Ecocide is more of a threat than nuclear war.

—Lawrence Buell

It is worth noting that [environmental destruction] is not the work of ignorant people. Rather, it is largely the result of work by people with BAs, BSs, LLBs, MBAs, and PhDs.

—David Orr

I cannot identify what sparked my environmental awareness. The romantic in me invokes childhood with an ardently outdoor maternal grandfather, who taught me to distinguish a beech tree from a birch, to plant potatoes, and to welcome the tree frogs' spring chorus with awe and delight. More likely, the recognition arrived not from childhood pleasures or reading Henry David Thoreau but from something as quotidian and cumulative as exhaustion from years of commuting from New Hampshire to Boston for work as an adjunct, sucking exhaust fumes on Route 128.
The impact of ego-involvement in the creation of false childhood memories
Authors: Zezelj Iris , Pajic Sofija , Omanovic Neda , Ninkovic Jasmina , Grcic Julija
Published: September 2009

An experiment employed a 'familiar-informant false-narrative procedure' to examine the effects of ego involvement manipulation on the creation of false memories for suggested events. Our main sample consisted of 54 Serbian adolescent students. During the pre-testing stage, students' parents (N=54) provided details from their children childhoods, which were used to create stimuli for the subsequent stages. Half of the participants were given an ego-involving suggestion- a short written statement that claimed that people with higher intelligence have a better and more detailed memory of their childhood. We hypothesized that ego-involved group would recollect more childhood events in general, create more false memories and be more confident in its' authenticity and clarity. Implanted event was recognized as autobiographic by 24% respondents in the testing stage and by 44.4% respondents in the retesting stage. There were significant qualitative differences between authentic and false memories: authentic memories were assessed as more reliable and clearer than the false ones. Ego-involvement manipulation had no impact on the frequency or quality of false memories reported by the participants. Even though the specific ego-involvement manipulation was not successful, our findings suggest that other motivating strategies we employed pushed the respondents into accepting false memory suggestion in the retesting stage. Future research could benefit from testing more elaborate ego-involving procedures.
Transgenically Induced GAD Tolerance Curtails the Development of Early β-Cell Autoreactivities but Causes the Subsequent Development of Supernormal Autoreactivities to Other β-Cell Antigens
Authors: Tian Jide , Dang Hoa , von Boehmer Harald , Jaeckel Elmar , Kaufman Daniel L.
Published: September 2009

OBJECTIVE

To study how tolerance to GAD65 affects the development of autoimmunity to other β-cell autoantigens (β-CAAs) in GAD65-transgenic (GAD-tg) NOD mice.

RESEARCH DESIGN AND METHODS

We used ELISPOT to characterize the frequency and functional phenotype of T-cell responses to GAD65 and other β-CAAs at different ages in GAD-tg mice and their NOD mouse littermates.

RESULTS

In young GAD-tg mice, Th1 responses to GAD65's dominant determinants were 13−18% of those in young NOD mice. This coincided with a great reduction in Th1 responses to other β-CAAs. Evidently, GAD65-reactive T-cells are important for activating and/or expanding early autoreactivities in NOD mice. As GAD-tg mice aged, their T-cell responses to GAD65 remained low, but they developed supernormal splenic and pancreatic lymph node T-cell autoimmunity to other β-CAAs. Apparently, the elimination/impairment of many GAD65-reactive T-cells allowed other β-CAA–reactive T-cells to eventually expand to a greater extent, perhaps by reducing competition for antigen-presenting cells, or homeostatic proliferation in the target tissue, which may explain the GAD-tg mouse's usual disease incidence.

CONCLUSIONS

Transgenically induced reduction of GAD65 autoreactivity curtailed the development of early T-cell responses to other β-CAAs. However, later in life, β-CAA–reactive T-cells expanded to supernormal levels. These data suggest that early β-cell autoreactivities are mutually dependent for support to activate and expand, while later in the disease process, autoantigen-specific T-cell pools can expand autonomously. These findings have implications for understanding type 1 diabetes immunopathogenesis and for designing antigen-based immunotherapeutics.
Does Granisetron Eliminate the Gag Reflex? A Crossover, Double-Blind, Placebo-Controlled Pilot Study
Authors: Friedlander Barenboim Silvina , Dvoyris Vladislav , Kaufman Eliezer
Published: September 2009

Although gagging is a frequent problem that, when severe, can jeopardize the dental procedure, no single protocol is used to alleviate this phenomenon. Selective 5-HT3 antagonists, such as granisetron, may attenuate gagging. In this study, granisetron and placebo were administered intravenously, in a crossover, double-blind manner, to 25 healthy volunteers in 2 different sessions. Gagging levels were recorded before and after administration, as were BP, pulse, and O2 saturation. Recorded results were analyzed with the use of tests for nonparametric values (P = .05). A significant increase in the depth of swab insertion was noted after administration of both placebo and drug. The increase in drug effectiveness correlated with decreased body weight. The true efficacy of granisetron in gagger patients with this treatment protocol has yet to be fully established, although it has been theorized that an increased dosage of granisetron may have a better effect.
Effects of lead on thyroid functions in lead-exposed workers
Authors: Pekcici Recep , Kavlakoğlu Burak , Yilmaz Sevim , Şahin Mustafa , Delibaşi Tuncay
Published: September 2009

Lead exposure is a common public health problem. Exposure to the metal can cause hematological, gastrointestinal, rheumatological, endocrine, neurological and renal problems in humans. However, effects on the thyroid gland are controversial. We retrospectively investigated thyroid function parameters in 65 adult males who had been occupationally exposed to lead. We then compared the findings with those of 60 male patients who had no history of lead exposure or thyroid abnormalities, who served as the control group. The mean ages of the lead-exposed workers and the controls were 34.3 ± 7.9 and 32.9 ± 6.6 years respectively. Blood lead levels in the lead-exposed workers were significantly higher than in the control group. The lead-exposed workers were assigned to one of three groups according to their blood lead levels, as follows: 40–59 μg/dl, 60–79 μg/dl, or 80 μg/dl and above. Thyroid Stimulating Hormone (TSH) levels in the 80 μg/dl and above group were significantly higher than in either the 40–59 μg/dl group or the 60–79 μg/dl group. However, TSH levels in the 40–59 μg/dl group did not differ significantly from those in the 60–79 μg/dl group. These results suggest that high levels of lead in the blood may affect thyroid physiology. Clinicians should be aware of the potential hazardous effects of lead on the thyroid, especially in patients who have been occupationally exposed to lead.
Magnetism and granulometry of Pleistocene sediments of Dhapasi section, Kathmandu (Nepal): implications for depositional age and paleoenvironment
Authors: Gautam Pitambar , Sakai Tetsuya , Paudayal Khum Narayan , Bhandari Sudarshan , Gyawali Babu Ram , Gautam Chinta Mani , Rijal Moti Lal
Published: September 2009

A 28-m thick exposure of the younger stage deposits of Kathmandu Valley fluvio-deltaic deposits at Dhapasi has been studied for magnetic susceptibility (MS), remanent magnetization (RM), grain size characteristics of fine-grained sediments, and sedimentary fabric by anisotropy of magnetic susceptibility (AMS) . In situ volume MS (κ; in 10-3 SI) of the natural sediments ranges from 0.001 to 0.15, with lower range (<0.02) restricted to quartz-rich coarse sand, whereas the uppermost 20-cm thick section affected by anthropogenic activity exhibits enhanced range (0.15-2). RM of specimens from some 80 levels reveals predominantly normal polarity except for a part of ca. 80cm thick sandy silt, located about 6-m above the base, yielding reverse polarity attributed to the Laschamp Reversal Event/Excursion (LRE) dated in literature at ca. 41 Ka. This inference, along with majority of other 14C data, lends further support to the affinity of Dhapasi section to the Gokarna Formation (ca. >45 to 34 Ka). Laser granulometry of fine-grained sediments from 76 levels reveals polymodal (2-4 modes) nature. With two prominent modes corresponding at 7.3 and 57.5 μm, these sediments plot into sandy silt, silt, and silty sand regions. MS correlates positively among broad grain size classes (i.e., increasing trend from sand through silt to clay). Mainly oblate susceptibility ellipsoids and low anisotropy degree shown by AMS data suggest a depositional fabric contributed by mainly paramagnetic minerals (e.g., phyllosilicates) responsible to low magnitudes of mass-specific MS (5-15 × 10-8 m3kg-1). Magnetic lineations or maximum susceptibility axes (kmax) are inferred to be predominantly NNW to SSE below ca. 18-m level, but NNE to SSW above. Such difference points to shift of paleoflow during the sediment deposition, and together with slight differences in grain-size parameters, in two prominent intervals of prodelta deposits, suggests significant changes in the paleodrainage configuration and source-sink relationship.   doi: 10.3126/bdg.v12i0.2247 Bulletin of the Department of Geology, Vol. 12, 2009, pp. 17-28
Sex detectives: "Law & Order: SVU"'s fans, critics, and characters investigate lesbian desire
Authors: Russo Julie Levin
Published: September 2009

I address the contested question of whether sex crimes detective Olivia Benson (a character on TV's Law & Order: Special Victims Unit played by Mariska Hargitay) is a lesbian, and the ways in which both fans and TV scholars approach this mystery. That is, I investigate not what we "know" about lesbians on/and television, but how we frame the very processes of this knowing. In both critical and fan discourse, debates about where to locate the queerness of television oscillate irresolvably between three sites: the text itself, audience interpretations, and the surrounding metatexts and contexts. With a primary theoretical framework drawn from Eve Kosofsky Sedgwick's Epistemology of the Closet, I analyze the cultural and televisual traditions that shape SVU's portrayal of deviant sexuality, and I assess how these resonate with fan interpretations in today's context of media convergence.
magic of television: Thinking through magical realism in recent TV
Authors: Joyrich Lynne
Published: September 2009

After decades in which television has been marked as more banal than bewitching, recalling the "magic of television" is more likely to evoke a sense of wonder for the perceived innocence of an earlier televisual audience than for television itself. With TV offered on demand, captured with DVRs, downloaded or watched streaming on the Web, purchased as DVD sets, miniaturized for private screenings, jumbo-sized for public spectacles, monitored in closed circuits, and accessed for open forums, once-mysterious television flows have flowed to new media forms, giving TV an appearing/disappearing, now-you-see-it/now-you-don't magical act of its own. Has TV disappeared, or has it multiplied—redoubled each time it's sawed in half, replicating like rabbits pulled out of a hat? Is it still TV or something else when programs are screened (as if through a magic curtain) via today's delivery systems?
Interview with Mark Smith and Denise Paolucci
Authors: LikesTV Zvi
Published: September 2009

Interview with Mark Smith and Denise Paolucci, conducted by zvi LikesTV.
Extending transformation
Authors: Editor TWC
Published: September 2009

Editorial for TWC No. 3 (September 15, 2009).
Ancient Portuguese Ceramic Wall Tiles (“Azulejos”): Characterization of the Glaze and Ceramic Pigments
Authors: Pereira M. , de Lacerda-Arôso T. , Gomes M.J.M. , Mata A. , Alves L.C. , Colomban Philippe
Published: September 2009

Ancient ceramic wall tiles, called “azulejo”, firstly used on Portuguese churches, monasteries and palaces (15-18th century) have progressively been used in particular houses till the last century. These tiles and its use in huge decorative panels can be considered as a precious but fragile cultural heritage from Brazil to India, in several countries influenced by Portuguese culture. Morphologically, these tiles are composed by a porous clay-based ceramic body, the terracotta, covered by a protective glassy phase, the glaze. As artistic paintings, these murals incorporated various kinds of pigments in the glaze layer to create a pictorial impact on the walls of rich palaces or churches, real and durable monumental works-of-art. In the 21st century, degradation marks are visible on these ceramic tiles because of their use under corrosive conditions (moisture, atmospheric cycles…) along centuries. In order to promote their conservation and enhance their restoration, the physical-chemical characterization of the azulejos is performed in the present work, using mainly non-destructive processes like micro-Raman spectroscopy or X-Ray diffraction. In particular, Raman spectroscopy allows the detection of some nano/microcrystals present in the amorphous glaze due to pigments or opacifying agents or related to the elaboration process of the azulejo. Based on the observation of various selected fragments, one states that very few pigments have been used as colouring agents in this ceramic art during 17-18th centuries. Thus, the relationship between the different colours, the introduced pigments and the structural aspects of the glass will be focused. Some features related with the ancient ceramic technology will also be discussed.
Recent Advances in the Chemical Synthesis of RNA
Authors: Beaucage Serge L. , Reese Colin B.
Published: September 2009

As a consequence largely of recent developments in RNA interference (RNAi) research, the availability of rapid and efficient methods for the chemical synthesis of RNA sequences has become a matter of considerable urgency. This unit is concerned mainly with work that has been carried out, especially in the past decade, on the design of new and improved methods of RNA synthesis. The main criteria for the choice of protecting groups for the 2′‐hydroxy functions of the ribonucleoside building blocks, which is arguably the most crucial strategic decision to be made, are discussed. A number of new ether‐, acetal‐, orthoester‐, and ester‐based 2′‐protecting groups are described and their application, mainly in phosphoramidite‐based solid‐phase synthesis, is discussed in some detail. Brief consideration is also given to solution‐phase RNA synthesis, which may well prove to be of great importance if a systemic drug is developed and multikilogram quantities of synthetic RNA sequences are required. Curr. Protoc. Nucleic Acid Chem. 38:2.16.1‐2.16.31. © 2009 by John Wiley & Sons, Inc.
A Metabolomic Perspective of Small Molecule Toxicity
Authors: Patterson Andrew D. , Idle Jeffrey R.
Published: September 2009

Recent advances in small molecule profiling, including ultraperformance liquid chromatography and time‐of‐flight mass spectrometry, have given unprecedented views of the metabolic response to toxic stimuli. Metabolomics, the process of measuring the concentration changes in metabolites of biofluids such as urine, serum, sweat or saliva or that of intact cells, tissues or single‐celled organisms, is the missing piece of the omics puzzle (genomics, transcriptomics, proteomics) necessary for providing a holistic view (DNA, RNA, protein and metabolites) of the biological response to a toxicant. Furthermore, metabolomics is an essential addition to any toxicity biomarker‐screening programme, as evidenced by its strong foothold in both pharmaceutical and academic settings. Here we discuss metabolomic science with respect to its past and future contributions to the field of toxicology and describe blueprints necessary for conducting a well‐designed and robust metabolomics experiment from sample collection to data acquisition and analysis. Metabolomics holds great promise as a tool for advancing the field of toxicology by uncovering novel biomarkers of toxic responses and by significantly improving xenobiotic metabolite identification.
New Iron(II) Complexes for Atom‐Transfer Radical Polymerization: The Ligand Design for Triazacyclononane Results in High Reactivity and Catalyst Performance
Authors: Kawamura Mitsunobu , Sunada Yusuke , Kai Hidetomo , Koike Nobuyuki , Hamada Akane , Hayakawa Hitoshi , Jin Ren‐Hua , Nagashima Hideo
Published: September 2009

Mononuclear cordinatively unsaturated iron(II) complexes having a triazacyclononane ligand were developed as highly efficient and environmentally friendly catalysts for the atom‐transfer radical polymerization (ATRP). These iron catalysts showed high performance in the well‐controlled ATRP of styrene, methacrylates, and acrylates. The high reactivity of these catalysts led to well‐controlled polymerization and block copolymerization even with lower catalyst concentrations.
Manganese‐Promoted Regioselective Ring‐Opening of 2,3‐Epoxy Acid Derivatives: A New Route to α‐Hydroxy Acid Derivatives
Authors: Concellón José M. , Bernad Pablo L. , Rodríguez‐Solla Humberto , Díaz Pamela
Published: September 2009

A simple and general methodology directed towards the synthesis 3‐aryl‐2‐hydroxy amides, or esters with total regioselectivity from the easily available 2,3‐epoxy amides or esters, promoted by active manganese is described. Utilizing enantiopure epoxy amides as starting materials, the corresponding 3‐aryl‐2‐hydroxy amides in enantiopure form are also available. Some synthetic applications of selected examples of 3‐aryl‐2‐hydroxy carboxylic acid derivatives are shown. A mechanism has been proposed to explain this novel reaction.
The Synthesis of Polysubstituted Pyrroles via the Coupling of Phenyliodonium Ylides and Enamine Esters
Authors: Wang Jun‐Yan , Wang Xian‐Pei , Yu Zheng‐Sen , Yu Wei
Published: September 2009

The boron trifluoride etherate (BF3⋅Et2O)‐catalyzed reactions between phenyliodonium ylides and enamine esters provide an efficient method for the synthesis of polysubstituted pyrroles.
Are recently identified genetic variants regulating BMI in the general population associated with anorexia nervosa?
Authors: Brandys Marek K. , van Elburg Annemarie A. , Loos Ruth J.F. , Bauer Florianne , Hendriks Judith , van der Schouw Yvonne T. , Adan Roger A.H.
Published: September 2009

The influence of body mass index (BMI) on susceptibility to anorexia nervosa (AN) is not clear. Recently published genome‐wide association (GWA) studies of the general population identified several variants influencing BMI. We genotyped these variants in an AN sample to test for association and to investigate a combined effect of BMI‐increasing alleles (as determined in the original GWA studies) on the risk of developing the disease. Individual single nucleotide polymorphisms (SNPs) were tested for association with AN in a sample of 267 AN patients and 1,636 population controls. A logistic regression for the combined effect of BMI‐increasing alleles included 225 cases and 1,351 controls. We found no significant association between individual SNPs and AN. The analysis of a combined effect of BMI‐increasing alleles showed absence of association with the investigated condition. The percentages of BMI‐increasing alleles were equal between cases and controls. This study found no evidence that genetic variants regulating BMI in the general population are significantly associated with susceptibility to AN. © 2009 Wiley‐Liss, Inc.
Assessment of organochlorine pesticides and metals in ring‐tailed lemurs (Lemur catta) at Beza Mahafaly Special Reserve, Madagascar
Authors: Rainwater Thomas R. , Sauther Michelle L. , Rainwater Katherine A.E. , Mills Rachel E. , Cuozzo Frank P. , Zhang Baohong , McDaniel Les N. , Abel Michael T. , Marsland Eric J. , Weber Martha A. , Youssouf Jacky Ibrahim Antho , Platt Steven G. , Cobb George P. , Anderson Todd A.
Published: September 2009

Like most of Madagascar's endemic primates, ring‐tailed lemurs (Lemur catta) face a number of threats to their survival. Although habitat loss is of greatest concern, other anthropogenic factors including environmental contamination may also affect lemur health and survival. In this study, we examined ring‐tailed lemurs from the Beza Mahafaly Special Reserve (BMSR), southern Madagascar for exposure to organochlorine (OC) pesticides and metals and examined differences in contaminant concentrations between sexes and among age groups, troops, and habitats. A total of 14 pesticides and 13 metals was detected in lemur blood (24 individuals) and hair (65 individuals) samples, respectively. p,p′‐DDT, heptachlor, aldrin, heptachlor epoxide, endrin aldehyde, and endrin were among the most prevalent pesticides detected. Surprisingly, the persistent metabolite of p,p′‐DDT, p,p′‐DDE, was not detected. The most commonly detected metals were aluminum, zinc, boron, phosphorus, silicon, and copper, whereas metals considered more hazardous to wildlife (e.g. arsenic, cadmium, lead, selenium, vanadium) were not found above detection limits. Overall, concentrations of OC pesticides and metals were low and similar to those considered to be background concentrations in other studies examining the ecotoxicology of wild mammals. Few inter‐sex, ‐age, ‐troop, and ‐habitat differences in contaminant concentrations were observed, suggesting a uniform distribution of contaminants within the reserve. Several statistically significant relationships between lemur body size and contaminant concentrations were observed, but owing to the lack of supportive data regarding contaminant exposure in wild primates, the biological significance of these findings remains uncertain. Results of this study document exposure of ring‐tailed lemurs at BMSR to multiple OC pesticides and metals and provide essential baseline data for future health and toxicological evaluations of lemurs and other wild primates, especially those in regions with expanding agricultural and mining operations. Am. J. Primatol. 71:998–1010, 2009. © 2009 Wiley‐Liss, Inc.
Pd–Ag membranes for auto‐thermal ethanol reforming
Authors: Tosti Silvano , Borelli Rodolfo , Santucci Alessia , Scuppa Leonardo
Published: September 2009

The auto‐thermal ethanol reforming was carried out at 200 kPa by a two‐step process consisting of a traditional reformer operating at high temperature (700–740 °C) and a Pd–Ag multitube membrane module where the separation of hydrogen took place at 350–380 °C.

The membrane module was a bundle of 11 thin‐wall Pd–Ag tubes of wall thickness 50–60 µm, diameter 10 mm, and length 270 mm: permeation tests were performed at 300–395 °C with lumen pressure of 150–200 kPa, and nitrogen sweep flow rates in the shell side ranged from 10 to 30 l min−1 at atmospheric pressure. A hydrogen permeance Pe = 1.317 × 10−2 exp (−3.622 × 103/T(K)) mol m−2 s−1 Pa−0.5 was measured and complete hydrogen selectivity was verified.

A water/ethanol mixture of molar ratio 2.50/1.00 was used as feed stream for carrying out ethanol reforming in the traditional fixed‐bed reactor filled with a Ni on alumina catalyst. As a second step, the water gas shift (WGS) membrane reaction was carried out in the multitube membrane reactor: the Pd–Ag alloy of the membrane tubes worked for both catalyzing the reaction and for separating all the hydrogen produced in the reformer and in the membrane reactor itself. The hydrogen separated through the membrane was collected in the shell side of the membrane module: by operating with a water/ethanol feed flow rate of 200 g h−1, up to 1.2 l min−1 of pure hydrogen was produced. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Multiple percolation in a carbon‐filled polymer composites via foaming
Authors: Thompson M. R. , Motlagh G. H. , Oxby K. J. , Hrymak A. N.
Published: September 2009

This article describes an investigation into the effects of foaming on the electrical conductivity for a carbon‐filled cyclic olefin copolymer (COC) composite incorporating both chopped carbon fibers (cCF) and carbon black (CB). Foamed and solid samples were injection molded and then analyzed for cell size, fiber length, fiber orientation, and electrical conductivity. Foamed samples exhibited higher electrical conductivity in the through‐plane direction for materials containing only CB or composites containing both filler types, and reduced electrical conductivity in the cCF‐filled composites. The increased electrical property gained by foaming was attributed to multiple percolation with CB aggregates forming more effective conductive clusters and networks in the continuous polymer phase during growth of the gas domains. A mechanism for the phenomenon was proposed based on these experimental observations. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation and characterization of polypropylene homocomposites: Exploiting polymorphism of PP homopolymer
Authors: Karger‐Kocsis J. , Wanjale S. D. , Abraham T. , Bárány T. , Apostolov A. A.
Published: September 2009

In this study, the properties of polypropylene (PP) homocomposites, prepared by film‐stacking followed by hot pressing, were investigated. Alpha‐ and beta‐PP served as matrices, whereas highly oriented PP tapes of the alpha form acted as reinforcement in the homocomposites. Tapes with different draw ratios (DR = 6–12) have been produced and characterized by mechanical and wide‐angle X‐ray scattering measurements. Tapes with a DR = 8 were incorporated in a cross‐ply (CP) manner in the corresponding homocomposite laminates. Specimens were subjected to static (tensile, flexural) and dynamic (instrumented falling weight impact, IFWI) tests. The thermal and thermomechanical properties of the PP tapes and homocomposites were studied by differential scanning calorimetry and dynamic mechanical thermal analysis. The homocomposite morphology was probed by polarized light microscopy, which gave evidence of transcrystalline layer at the interface between tape and matrix. The storage modulus of the CP homocomposites was improved prominently by the tape reinforcement. In static tensile tests, the homocomposites exhibited much higher stiffness and strength when compared with the neat PP specimens. However, this was accompanied with a marked reduction in the ultimate elongation. The IFWI tests showed that both alpha‐ and the beta‐PP failed in macroscopically brittle manner, whereas the corresponding homocomposites failed in semiductile way. The homocomposite laminates prepared with beta‐PP matrix exhibited higher resistance to penetration than those with alpha‐PP. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Room temperature‐curable VARTM epoxy resins: Promising alternative to vinyl ester resins
Authors: Chatterjee Amit , Gillespie John W.
Published: September 2009

The objective of this investigation is to characterize various room temperature (RT)‐curable epoxies for vacuum‐assisted resin transfer molding (VARTM) of large structure manufacturing. Six epoxy candidate resins: X‐40, 780‐33, 780‐35, 8601/8602, 8602, 8603, and two vinyl ester resins (VE), 411‐350 and 411‐510A, are physically and thermochemically characterized. All the resins are cured at RT with extended period of time. The degree of cure for 24‐h RT‐cured samples ranges from 70 to 85% for epoxies and is comparable with the baseline VE systems (75%). After 1 year at RT, the degree of cure increases from 90 to 98%. Most of the epoxies show a single transition in dynamic mechanical analysis and differential scanning calorimetry. However, two heterogeneous transitions are observed for the VE systems. The glass transition temperature increases monotonically with exposure time, except X‐40, that rapidly achieves a plateau and remains constant. The degree of cure for the majority of the systems increases logarithmically with RT curing time with excellent fitting (R2 varies from 0.92 to 1). Consistent with the increase in degree of cure, the storage modulus increases and (tan δ)max decreases with time of exposure. A negative correlation between the curing temperature range and the total heat of reaction is observed among the epoxy systems. However, the VE systems show the reverse trend. RT curing epoxy resin (X‐40) shows promising overall result to VE system and can be a viable alternative to VE for VARTM processing. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effect of the temperature on the kinetic of natural rubber vulcanization with the sulfur donor agent dipentamethylene thiuram tetrasulphide
Authors: Posadas P. , Fernández‐Torres A. , Valentín J. L. , Rodríguez A. , González L.
Published: September 2009

The effect of the temperature on the kinetics of vulcanization of natural rubber with the sulfur donor agent dipentamethylene thiuram tetrasulphide (DPTT) was investigated. The oscillatory disk rheometer and differential scanning calorimetry under dynamic and isothermal conditions were used. The Coran's model was applied to set the kinetic constants within each distinct step of the vulcanization process using the obtained values of the rheometer curves. During the curing period it was observed that there were two stages. Either the torque increment (ΔS) or the crosslink density arise a maximum value at 130°C. The dynamic and isothermal thermograms showed two overlapped peaks during the curing reaction. These results were in concordance with those obtained by curemeter testing. In addition, the activation energy of the vulcanization process was also calculated by means of both techniques. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Nucleation mechanism of polyhydroxybutyrate and poly(hydroxybutyrate‐co‐hydroxyhexanoate) crystallized by orotic acid as a nucleating agent
Authors: Jacquel Nicolas , Tajima Koichirou , Nakamura Nobuo , Kawachi Hideo , Pan Pengju , Inoue Yoshio
Published: September 2009

The mechanism involved in the crystallization of bacterial polyhydroxybutyrate (PHB) and poly(hydroxybutyrate‐co‐hydroxyhexanoate) P(HB‐co‐HH) induced by orotic acid as a nucleant was investigated by using differential scanning calorimetry (DSC), gel permeation chromatography (GPC) and proton nuclear magnetic resonance spectroscopy (1H‐NMR). GPC measurements both carried on solvent cast and hot pressed samples did not show any significant drop of the molecular weight caused by the addition of the nucleant, indicating that no chemical reaction happened during the nucleation process. This result was confirmed by 1H‐NMR analysis of oligohydroxybutyrate (OHB) treated with an excess amount of orotic acid. The possibility of epitaxial growth of the polymer crystal on the surface of the nucleant crystal was then investigated. It was found that there is an outstanding crystalline lattice matching between the plane (100) of the PHB crystal and the plane (001) of the orotic acid crystal. In comparison, the matching obtained with conventional nucleating agents, such as boron nitride and talc, was worse. Moreover, some regular hydrogen bonds between the polyester and orotic acid could stabilize the physical process. According to these results, the physical mechanism involving the epitaxial matching between orotic acid and PHB appears to be the most probable nucleation mechanism. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Isothermal cold crystallization and melting behaviors of poly(L‐lactic acid)s prepared by melt polycondensation
Authors: Wu Linbo , Hou Hongbin
Published: September 2009

The isothermal cold crystallization and melting behaviors of poly(L‐lactic acid)s (PLLAs, weight average molecular weight, Mw, 6000–80,000) prepared via melt polycondensation were studied with differential scanning calorimeter in this work. It is found that the crystallization rate increased with decreasing Mw, reached a maximum at Mw of ca. 21,000 and then decreased again. The crystallinity of PLLA can be controlled in the range 30–50% by crystallization temperature (Tc) and time to fulfill the requirement of subsequent solid state polycondensation. The melting behavior strongly depends on Tc. The samples crystallized at high Tc melted with a single peak but those crystallized at low Tc melted with double peaks. The higher melting point (TmH) kept almost constant and the lower melting point (TmL) increased clearly with Tc. But the TmL changed in jumps and a triple melting peak appeared at the vicinity of a characteristic crystallization temperature Tb, possibly because of a change of crystal structure. The equilibrium melting temperature of PLLA with Mw of 21,300 was extrapolated to be 222°C with nonlinear Hoffman‐Weeks method. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis, electroluminescence, and photovoltaic cells of new vinylene‐copolymers with 4‐(anthracene‐10‐yl)‐2,6‐diphenylpyridine segments
Authors: Mikroyannidis John A. , Vellis Panagiotis D. , Yang Sheng‐Hsiung , Hsu Chain‐Shu
Published: September 2009

Three new soluble vinylene‐copolymers F, C, and P that contain 4‐(anthracene‐10‐yl)‐2,6‐diphenylpyridine as common segment and fluorene, carbazole, or phenylene, respectively, as alternating segment were prepared by Heck coupling. The glass transition temperature was high for F and C (110 and 117°C), whereas was lower than 25°C for P. The polymers were stable up to ∼ 300°C. They emitted blue–green light with maximum located at wavelength of 456–550 nm, which was of the order F < C < P. The photoluminescence quantum efficiency in THF solution was ∼ 30% for F and P and only 5% for C. All three copolymers were used as active layers for polymer light emitting diodes (PLEDs) and organic photovoltaic cells. The double PLEDs with configuration of indium‐tin oxide (ITO)/poly(ethylenedioxythiophene (PEDOT) : poly(styrenesulfonate)(PSS)/Copolymer F, C, or P/TPBI(1,3,5‐tris(2‐N‐phenylbenzimidazolyl)benzene)/Ca/Al were fabricated. Copolymer P emitted green light with maximum brightness of 28 cd/m2 and a current yield of 0.85 cd/A. Organic photovoltaics with the configuration of ITO/PEDOT : PSS/Copolymer and [6,6]‐phenyl‐C61‐butyric acid methyl ester blend (1 : 1) /Ca/Al were also fabricated. Copolymer P showed the highest power conversion efficiency of 0.034%. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Hydrophilic polystyrene/maleic anhydride ultrafine fibrous membranes
Authors: Cécile Corine , Hsieh You‐Lo
Published: September 2009

Polystyrene/maleic anhydride (PSMA) was synthesized to reach a viscosity‐average molecular weight of 700 kDa and fabricated into ultrafine fibrous membranes consisting of fibers with an average diameter of 300 nm. These ultrafine PSMA fibers were rendered insoluble in organic solvents by reactions with hydrazine and ethylenediamine (ED). The highly efficient incorporation of diamines into the fibrous membranes was easily achieved by brief immersions in either dilute (0.5 wt %) hydrazine for 1 min or ED ether solution for 2 min. Heating at 150°C for 5 min produced crosslinked PSMA with very little or no solubility in acetone with the retention of the fibrous membrane structure. The ED‐crosslinked membranes were particularly stable to both bases and acids as well as hydrophilic solvents, had a 46° water contact angle, and absorbed 22 times the amount of water as the as‐spun fibrous membrane. This post‐fiber‐formation crosslinking approach was robust, highly efficient, and fast and required very little crosslinking reagent. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effect of clay dispersion on the synergism between clay and intumescent flame retardants in polystyrene
Authors: Chen Yajun , Fang Zhengping , Yang Chunzhuang , Wang Yu , Guo Zhenghong , Zhang Yan
Published: September 2009

Different formulations were designed to evaluate the effect of organically modified clay (DK4) on the combustion behavior of polystyrene (PS) containing an intumescent flame retardant, poly(4,4‐diaminodiphenyl methane spirocyclic pentaerythritol bisphosphonate) (PDSPB). The results of transmission electron microscopy reveal that DK4 selectively dispersed in the PDSPB phase. An investigation of thermogravimetric analysis revealed that the thermal stability of PS resin showed no obvious change with the addition of PDSPB and DK4, but the residue increased. From the results of cone calorimetry, we observed that there were two steps during combustion. The dispersion of DK4 played an important role in improving the thermal stability and the flammability of the PS/PDSPB/DK4 nanocomposites. In the first step, DK4 was restricted in the PDSPB phase; there was no synergistic effect. A synergistic effect occurred in the second step when clay had a homogeneous distribution, in which the peak heat release rates were reduced by about 40 and 61% compared to the pure PS. A model of combustion behavior was developed according to these results. The synergistic mechanism was caused by the formation of the silicoaluminophosphate (SAPO) structure formed by reactions between PDSPB and DK4. Field emission scanning electron microscopy characterization showed that such an SAPO structure led to a ceramic‐like residue after burning. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
A study of antimicrobial property of textile fabric treated with modified dendrimers
Authors: Ghosh Subhas , Yadav Sangeeta , Vasanthan Nadarajah , Sekosan Gabriela
Published: September 2009

Dendrimers have been used as a vehicle to develop the antimicrobial properties of textile fabrics. We have taken advantage of the large number of functional groups present in the regular and highly branched three‐dimensional architecture of dendrimers. In this study, the poly(amidoamine) (PAMAM) G‐3 dendrimer was modified to provide antimicrobial properties. Following a procedure similar to what is suggested in the literature, PAMAM (G3) with primary amine end groups was converted into ammonium functionalities. The modification was then confirmed by FTIR and 13C‐NMR analysis. Dendrimers have unique properties owing to their globular shape and tunable cavities, this allows them to form complexes with a variety of ions and compounds; and also act as a template to fabricate metal nanoparticles. AgNO3–PAMAM (G3) complex as well as a MesoSilver–PAMAM (G3) complex were formed and these modified dendrimers were characterized by a UV–Visible spectrophotometer to study the complex formation. Modified dendrimers were applied to the Cotton/Nylon blend fabric. SEM and EDX analysis were performed to study the dispersion of silver nanoparticles onto the fabric. An antimicrobial test of the treated‐fabric against Staphylococcus aureus exhibited significant biocidal activities for each type of modified‐dendrimer. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
The Cage and Metal Effect: Spectroscopy and Electrochemical Survey of a Series of Sm‐Containing High Metallofullerenes
Authors: Liu Jia , Shi Zujin , Gu Zhennan
Published: September 2009

A series of Sm‐containing high metallofullerenes, namely, Sm@C82 (I, II, III, IV), Sm@C84 (I, II, III), Sm@C86, Sm@C88 (I, II, III), Sm@C90 (I, II, III), Sm@C92 (I, II), Sm@C94 (I, II, III), and Sm@C96, is successfully synthesized and characterized by UV/Vis/NIR absorption spectroscopy, and cyclic and differential pulse voltammetry. Sm‐containing high metallofullerenes have a relatively larger number of isomers compared with other divalent ones. The highest boiling point of Sm among Group II metals may be responsible for this phenomenon. Comparing the spectroscopic and electrochemical behaviors of Sm‐containing metallofullerenes with those of other divalent ones, it is seen that when the size of the carbon cage enlarges, different structures form stable molecules with different metals. Furthermore, there are also some important differences in the electrochemistry properties. The cage effect on the electronic structures of high metallofullerenes is also estimated from the differences in reduction potentials between metallofullerenes and their corresponding fullerenes. It is believed that the influence of transferred electrons from the metal to the carbon cage becomes much weaker for high fullerenes. The redox property of high metallofullerene is more dependent on the carbon‐cage structure than the effect of electron transfer.
Synthesis and luminescence properties of lanthanide complexes with a new tripodal ligands featuring salicylamide arms
Authors: Song Xue‐Qin , Dong Wen‐Kui , Zhang Yu‐Jie , Liu Wei‐Sheng
Published: September 2009

A series of luminescent lanthanide complexes with a new tripodal ligand featuring salicylamide arms, 2,2′,2″‐nitrilotris(2‐furfurylaminoformylphenoxy)triethylamine (L), were synthesized and characterized by elemental analysis, IR and molar conductivity measurements. Photophysical properties of the complexes were studied by means of UV–vis absorption and steady‐state luminescence spectroscopy. Excited‐state luminescence lifetimes and quantum yield of the complexes were determined. Luminescence studies demonstrated that the tripodal ligand featuring salicylamide arms exhibits a good antennae effect with respect to the Tb(III) and Dy(III) ion due to efficient intersystem crossing and ligand to metal energy transfer. From a more general perspective, this work offers interesting perspectives for the development of efficient luminescent stains and enlarges the arsenal for developing novel luminescent lanthanide complexes of salicylamide derivatives. Copyright © 2009 John Wiley & Sons, Ltd.
G‐rich sequence‐functionalized polystyrene microsphere‐based instantaneous derivatization for the chemiluminescent amplified detection of DNA
Authors: Xin Liang , Cao Zhijuan , Lau Choiwan , Kai Masaaki , Lu Jianzhong
Published: September 2009

Herein, we develop a novel chemiluminescence (CL) approach with high sensitivity and excellent selectivity, by taking advantage of magnetic beads as preconcentration carriers and polystyrene microspheres as an amplification platform. Briefly, a ‘sandwich‐type’ detection strategy is employed in our design, which involves capture probe DNA immobilized on the surface of carboxyl‐terminated magnetic beads and multiple biotinylated reporter DNA self‐assembled on the surface of streptavidin‐modified polystyrene microspheres. The reporter DNA includes a guanine nucleobase‐rich (G‐rich) sequence domain for the generation of light and an additional tethered nucleic acid domain complementary with the target DNA. The CL signal is obtained via a novel instantaneous derivatization reaction between a specific CL reagent and the guanine nucleo­bases rich in the target and reporter DNA. As a result, we demonstrate that this DNA assay is reproducible, stable, easy to use, and can sensitively detect femtomolar target DNA related to anthrax lethal factors with excellent differentiation ability for single‐base mismatched sequences. Overall, this new CL protocol couples the high sensitivity of CL analysis with effective magnetic separation for discriminating against unwanted constituents such as mismatched sequences, and hence, offers great promise for DNA hybridization analysis. Copyright © 2009 John Wiley & Sons, Ltd.